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By the use of high-throughput molecular technologies, the number of genes and proteins potentially relevant to testicular germ cell tumor (TGCT) and other diseases will increase rapidly. In a recent transcriptional profiling, we demonstrated the overexpression of GRB7 and JUP in TGCTs, and confirmed the reported overexpression of CCND2. We also have recent evidences for frequent genetic alterations of FHIT and epigenetic alterations of MGMT. To evaluate whether the expression of these genes is related to any clinicopathological variables, we constructed a tissue microarray with 510 testicular tissue cores from 279 patients diagnosed with TGCT, covering various histological subgroups and clinical stages. By immunohistochemistry, we found that JUP, GRB7, and CCND2 proteins were rarely present in normal testis, but frequently expressed at high levels in TGCT. Additionally, all premalignant intratubular germ cell neoplasias were JUP-immunopositive. MGMT and FHIT were expressed by normal testicular tissues, but at significantly lower frequencies in TGCT. Except for CCND2, the expressions of all markers were significantly associated with various TGCT subtypes. In summary, we have developed a high-throughput tool for the evaluation of TGCT markers, and utilized this to validate five candidate genes whose protein expressions were indeed deregulated in TGCT.

Background: The first phase of the MetAction trial established the required diagnostic infrastructure, implemented security-approved systems for handling of sensitive information, educated the Trial Team within the context of tumor boards, and estimated costs of the initiative within public health services. The endeavor enabled expedited and safe mutation profiling of metastatic tumors in order to offer molecularly matched medication for end-stage cancer (Ree et al., ESMO Open 2017;2:e000158). The aim of the second trial phase was to investigate the utility of the MetAction pipeline in clinical practice. Procedures: An eligible patient with end-stage metastatic disease from any origin had been on the previous line of systemic therapy for 6 or more weeks with radiologic evaluation intervals of 6-12 weeks and disease progression according to the Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1. Biopsy-sampled metastatic tissue was analyzed by DNA sequencing (Ion Oncomine™ Comprehensive Panel), where called variants were filtered prior to assessment and prioritization, supplemented with fluorescence in situ hybridization to cover relevant biomarkers. The Molecular Tumor Board interpreted the findings within the likelihood of signaling pathway activity, for the sequential Clinical Tumor Board to conclude on potential systemic tumor-directed medication. On study therapy, radiologic work-up was performed every 8 weeks. The primary objective was to compare progression-free survival (PFS) on study treatment, termed Period-B, with PFS for the most recent therapy, termed Period-A. If Period-B/Period-A was ≥1.3, the study therapy was deemed to be of benefit. The incidence of diagnostic adverse events and treatment-related grade 3-5 Common Terminology Criteria for Adverse Events (CTCAE) toxicities was secondary end points. Results: 26 patients were enrolled. Biopsy procedures were undertaken at lung or pleural sites (6 cases), liver or peritoneal sites (19 cases), and an inguinal lymph node (1 case), and did not cause adverse events. Histologic entities were 18 adenocarcinomas (AC), 2 undifferentiated carcinomas, 1 case each of cholangiocarcinoma and squamous cell carcinoma, and 4 different sarcoma entities. 13 patients were found eligible for off-label use of molecularly matched therapy (inhibitor of ALK-, BRAF-, EGFR-, FGFR-, mTOR-, PARP-, ROS1-, or PD-1-mediated signaling). Among the 10 individuals who received study treatment until radiologic evaluation, 5 met the primary end point. The patient with cholangiocarcinoma and a patient with rectal AC primaries, both given crizotinib, obtained Period-B/Period-A outcome slightly better than 1.3. Notably, 3 patients with colon AC primaries, receiving either a combination of panitumumab with vemurafenib or chemotherapy or single-agent pembrolizumab, obtained long-lasting responses. In addition, 1 colon AC patient receiving pembrolizumab with RECIST progression (i.e., primary end point failure) before a long-lasting response to off-protocol continuation, reported CTCAE grade 3 toxicity (a colitis event that immediately resolved on high-dose prednisolone). Conclusion: MetAction procedures and treatments were safe. 15% (4/26) of patients with progressing end-stage cancer had the disease course substantially reversed by this biomarker-directed therapy approach. Citation Format: Anne Hansen Ree, Kjersti Flatmark, Vigdis Nygaard, Daniel Heinrich, Kjetil Boye, Svein Dueland, Vegard Nygaard, Eivind Hovig, Klaus Beiske, Marius Lund-Iversen, Vivi A. Flørenes, Christin Johansen, Inger Riise Bergheim, Menaka Sathermugathevan, Sigve Nakken, Gry A. Geitvik, Ole C. Lingjærde, Anne-Lise Børresen-Dale, Hege G. Russnes, Gunhild M. Mælandsmo. The MetAction trial: long-lasting responses to molecularly matched therapy in end-stage cancer [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2017 Oct 26-30; Philadelphia, PA. Philadelphia (PA): AACR; Mol Cancer Ther 2018;17(1 Suppl):Abstract nr A101.

e14033 Background: The MetAction project consists of two clinical trial phases. The completed first phase established the required diagnostic infrastructure, implemented security-approved systems for handling of sensitive information, educated the entire project staff within the context of tumor boards, and estimated costs of the initiative within public health services. The endeavor enabled expedite and safe mutation profiling of metastatic tumors in order to offer biomarker-based treatment with molecularly matched medication to patients with end-stage cancer, as reported in Ree et al., ESMO Open 2017. The ongoing second trial phase investigates the feasibility of the established MetAction pipeline in clinical practice. Methods: An eligible patient has end-stage metastatic disease from a solid cancer. Metastatic tissue is analyzed by DNA sequencing (Ion Oncomine™ Comprehensive Panel), where called variants are filtered prior to assessment and prioritization, supplemented with fluorescence in situ hybridization to cover relevant biomarkers. The Molecular Tumor Board interprets the findings within the likelihood of signaling pathway activity, and the sequential Clinical Tumor Board (CTB) may conclude on treatment with any systemic tumor-directed medication. Results: At the time of writing, 19 patients enrolled onto the second trial phase have accomplished the diagnostic procedures from sampling of metastatic tissue to CTB conclusion. Biopsy procedures were undertaken at lung or pleural sites (five cases), liver or superficial or deep peritoneal sites (13 cases), and an inguinal lymph node (one case) and did not cause adverse events. Histologic entities were 12 adenocarcinomas and one case each of squamous cell and undifferentiated carcinoma, cholangiocarcinoma, and four different sarcoma entities. Twelve patients have been found eligible for off-label use of molecularly matched therapy (inhibitor of ALK-, BRAF-, EGFR-, FGFR-, mTOR-, PARP-, or PD-1-mediated signaling). Conclusions: We will report on patient outcome (progression-free survival, overall response rate, and tolerance) to this biomarker-directed treatment in end-stage cancer. Clinical trial information: NCT02142036.

Cancerous inhibitor of protein phosphatase 2A (CIP2A) is an important oncogene contributing to cancer progression partially by regulating cMYC and AKT. We examined CIP2A expression in cutaneous melanomas, its association with clinicopathological parameters and mapped molecular mechanisms regulated by CIP2A in vitro. CIP2A expression was analyzed by immunohistochemistry in 17 nevi, 132 primary melanomas and 49 metastases. Effects of siRNA-mediated down-regulation on proliferation, apoptosis and signaling pathways were assessed in melanoma cell lines. In superficial spreading melanomas (SSM), high nuclear CIP2A expression was associated with poor overall survival (OS) (P = 0.0018). Surprisingly, high cytoplasmic expression was related to improved relapse-free (P = 0.031) and OS (P = 0.014) in nodular melanomas (NM). In vitro experiments revealed that CIP2A can regulate proliferation and/or apoptosis partially through the PI3K/AKT pathway but also independently. In summary, CIP2A could represent a potential therapeutic target in SSM. However, in NM cytoplasmic CIP2A is associated with improved prognosis indicating that CIP2A has distinct, complex functions dependent on the molecular context and histological subtype. As seen in other cancer types, CIP2A can influence cMYC and AKT, but our data also suggest that in melanoma it has additional targets which need to be identified.

Objective Wee1-like kinase (Wee1) is a tyrosine kinase which negatively regulates entry into mitosis at the G2 to M-phase transition and has a role in inhibition of unscheduled DNA replication in S-phase. The present study investigated the clinical role of Wee1 in advanced-stage (FIGO III–IV) ovarian serous carcinoma. Methods Wee1 protein expression was analyzed in 287 effusions using immunohistochemistry. Expression was analyzed for association with clinicopathologic parameters, including survival. Forty-five effusions were additionally studied using Western blotting. Wee1 was further silenced in SKOV3 and OVCAR8 cells by siRNA knockdown and proliferation was assessed. Results Nuclear expression of Wee1 in tumor cells was observed in 265/287 (92%) and 45/45 (100%) effusions by immunohistochemistry and Western blotting, respectively. Wee1 expression by immunohistochemistry was significantly higher in post-chemotherapy disease recurrence compared to pre-chemotherapy effusions obtained at diagnosis (p=0.002). Wee1 silencing in SKOV3 and OVCAR8 cells reduced proliferation. In univariate survival analysis of the entire cohort, a trend was observed between high (>25% of cells) Wee1 expression and poor overall survival (p=0.083). Survival analysis for 109 patients with post-chemotherapy effusions showed significant association between Wee1 expression and poor overall survival (p=0.004), a finding which retained its independent prognostic role in Cox multivariate analysis (p=0.003). Conclusions Wee1 is frequently expressed in ovarian serous carcinoma effusions, and its expression is significantly higher following exposure to chemotherapy. The present study is the first to report that Wee1 is an independent prognostic marker in serous ovarian carcinoma.

Objective. The aim of this study was to investigate the expression of cell cycle proteins in ovarian carcinoma cells in serous effusions and respective solid tumors. Methods. Fifty-five malignant effusions and 38 tumors (20 primary, 18 metastatic) were immunohistochemically stained for cyclin A, p27 kip1 , and Ki-67. Staining extent (0–100% cells) and intensity (0–3 scale) were scored. Cyclin A and p27 kip1 expression was additionally studied in 29 malignant effusions using immunoblotting. Immunohistochemistry results in effusions were evaluated for possible association with clinicopathologic parameters. Results. Nuclear immunoreactivity for all markers was detected on carcinoma cells in the majority of effusions using immunohistochemistry. Similarly, immunoblotting showed the presence of cyclin A and p27 kip1 in 29/29 and 25/29 specimens, respectively. Intense (3) immunoreactivity for Ki-67 was detected more often in peritoneal effusions, compared with those of pleural location ( P = 0.036). Staining in primary and metastatic lesions was generally comparable to that of tumor cells in effusions. Staining for p27 kip1 was more diffuse in effusion specimens obtained prior to the institution of chemotherapy ( P = 0.042). In an analysis of all effusions, an association was observed between the number of cells that were immunoreactive for Ki-67, cyclin A, and p27 kip1 (cyclin A–Ki-67: P = 0.008; p27 kip1 –Ki-67: P = 0.019; cyclin A–p27 kip1 : P = 0.032). In survival analysis, the presence of more diffuse ( P = 0.042) and intense ( P = 0.019) staining for cyclin A correlated with prolonged overall survival. Conclusions. The expression of the studied cell cycle markers does not differ markedly between ovarian carcinoma cells in the pleural and peritoneal cavity, supporting our previous studies of several metastasis-associated molecules. The presence of cyclin-A-positive cell populations is associated with a more favorable disease outcome, possibly due to the targeting of proliferating cells by chemotherapeutic agents. However, the decline in the fraction of p27 kip1 -positive cells in posttreatment specimens may point to additional mechanisms involved in this selection.

The present study analysed by immunohistochemistry the protein level of cyclin A and Ki-67 in a panel of paraffin-embedded tissue obtained from 172 primary (110 superficial and 62 nodular) and 73 metastatic melanomas, and ten benign naevi. Since cyclin A exists in the same quaternary complex in the S-phase of the cell cycle as the cdk inhibitor p21WAF1/CIP1, the levels of the two proteins were compared. Cyclin A and Ki-67 were heterogeneously expressed in the malignant tumours, whereas in benign naevi, only rare positive cells were detected. In superficial spreading melanomas, the cyclin A level was related to tumour thickness, with less expression in thinner lesions (p

The aims of this study were firstly, to investigate the expression of E-cadherin complex proteins in ovarian carcinoma cells in serous effusions and in primary and metastatic lesions; and secondly to study the value of these four proteins and calretinin, a mesothelial marker, in the differential diagnosis of ovarian carcinoma cells from reactive mesothelial cells in effusions. Sixty-seven malignant effusions and 97 corresponding primary (n=36) and metastatic (n=61) lesions were immunohistochemically stained for E-cadherin and alpha-, beta-, and gamma-catenin. Staining extent and intensity were scored. Effusion specimens were additionally analysed for calretinin immunoreactivity. Membrane immunoreactivity for E-cadherin and alpha-, beta-, and gamma-catenin was detected on carcinoma cells in the majority of the effusions, but rarely on reactive mesothelial cells (p

Ephrin-A1, formerly called B61, is a new melanoma growth factor; it is angiogenic and chemoattractant for endothelial cells. EPH-A2, or ECK (a receptor for ephrin-A1), is ectopically expressed in most melanoma cell lines; the pathology where this expression is first manifested and the possible role of the receptor in tumor progression are unknown. To determine these, we studied the expression of this ligand and receptor in biopsies of benign and malignant melanocytic lesions. EPH-A2 was not detected in normal melanocytes, benign compound nevi or advanced melanomas, though it was found in 2 of 9 biopsies of malignant melanoma in situ. Ephrin-A1 was present in occasional early lesions and in advanced primary melanomas (43%) and metastatic melanomas (67%). Expression of ephrin-A1 was induced in melanoma cells by pro-inflammatory cytokines. Our findings are consistent with 2 possible roles for ephrin-A1 in melanoma development: it may promote melanocytic cell growth or survival and induce vascularization in advanced melanomas. Both effects may be potentiated by inflammatory responses. Our data are consistent with earlier observations that an inflammatory infiltrate is associated with poor prognosis in thin primary melanomas.

Human melanoma cell lines derived from early stage primary tumors are particularly sensitive to growth arrest induced by interleukin-6 (IL-6). This response is lost in cell lines derived from advanced lesions, a phenomenon which may contribute to tumor aggressiveness. We sought to determine whether resistance to growth inhibition by IL-6 can be explained by oncogenic alterations in cell cycle regulators or relevant components of intracellular signaling. Our results show that IL-6 treatment of early stage melanoma cell lines caused G1 arrest, which could not be explained by changes in levels of G1 cyclins (D1, E), cdks (cdk4, cdk2) or by loss of cyclin/cdk complex formation. Instead, IL-6 caused a marked induction of the cdk inhibitor p21WAF1/CIP1 in three different IL-6 sensitive cell lines, two of which also showed a marked accumulation of the cdk inhibitor p27Kip1. In contrast, IL-6 failed to induce p21WAF1/CIP1 transcript and did not increase p21WAF1/CIP1 or p27kip1 proteins in any of the resistant lines. In fact, of five IL-6 resistant cell lines, only two expressed detectable levels of p21WAF1/CIP1 mRNA and protein, while in three other lines, p21WAF1/CIP1 was undetectable. IL-6 dependent upregulation of p21WAF1/CIP1 was associated with binding of both STAT3 and STAT1 to the p21WAF1/CIP1 promoter. Surprisingly, however, IL-6 stimulated STAT binding to this promoter in both sensitive and resistant cell lines (with one exception), suggesting that gross deregulation of this event is not the unifying cause of the defect in p21WAF1/CIP1 induction in IL-6 resistant cells. In somatic cell hybrids of IL-6 sensitive and resistant cell lines, the resistant phenotype was dominant and IL-6 failed to induce p21WAF1/CIP1. Thus, our results suggest that in early stage human melanoma cells, IL-6 induced growth inhibition involves induction of p21WAF1/CIP1 which is lost in the course of tumor progression presumably as a result of a dominant oncogenic event.

In the present study we analyzed, by immunohistochemistry, a panel of human melanomas for protein expression of the cyclin-dependent kinase (cdk) inhibitor p27Kip1 and evaluated whether deregulated expression correlates with clinical outcome for this type of cancer. We found that p27Kip1 was strongly expressed by normal melanocytes and benign nevi, whereas in malignant melanoma, a heterogeneous expression pattern was observed. In the case of nodular melanomas, the level of p27Kip1 was found to correlate significantly with the thickness of the tumor, with less protein expressed in thicker lesions. We also found that patients having tumors with fewer than 5% p27Kip1-staining cells had a significantly higher risk of early relapse of their disease compared with those expressing moderate or high levels. In contrast, the level of p27Kip1 did not correlate with tumor thickness or disease-free survival in patients with superficial spreading melanomas, suggesting that p27Kip1 may play different roles in these two major pathological subgroups of malignant melanoma. Furthermore, p27Kip1 did not appear to have an influence on overall survival for either subgroup. When we examined the combined effect of p21WAF1/CIP1 (another cdk inhibitor) and p27Kip1 on clinical outcome, we found that analysis of these two cdk inhibitors together may have greater prognostic potential than either alone. In conclusion, our results suggest that virtually complete loss of p27Kip1 protein expression has potential importance as a prognostic indicator of early relapse in patients with nodular melanoma. The results, furthermore, underscore the value of analyzing multiple cell cycle regulatory proteins to obtain the most reliable indication of prognosis.

Three members of the S100 gene family, S100A2, S100A4 and S100A6, have been suggested to be associated with cancer development and metastasis. To study their involvement in the tumorigenesis of human melanoma, we examined the mRNA expression levels of the 3 genes in 45 melanoma metastases and in 20 benign nevi. Interestingly, whereas none of the metastases expressed S100A2 mRNA, and the expression level was low in 6 cell lines established from primary melanomas, all nevi showed moderate to high expression levels. Our results suggest that loss of S100A2 gene expression may be an early event in melanoma development. A significant correlation was found between the expression of S100A6 in melanoma metastases and both the survival time of the patients and the thickness of the corresponding primary tumors. For the S100A4 gene, however, no relationship was found between gene expression and clinical parameters of melanoma malignancy. The observed differences in expression patterns of the 3 S100 genes suggest distinct roles of their products in melanoma tumorigenesis and/or metastasis, and the results encourage studies to evaluate the potential value of using S100A2 and S100A6 expression levels as markers in the clinical management of melanoma.

Protein tyrosine kinases (PTKs) have been implicated in the development of many common human tumours including melanoma. Previously we isolated PTK gene sequences expressed in normal melanocytes. Here we examined expression of 9 of these genes in cell lines derived from defined stages of melanoma progression, by Northern blotting and in some cases immunoblotting. We also tested cells from 2 animal models of particular stages in progression, as well as uncultured biopsies of metastatic melanoma. The expression of 2 receptor kinase family members found in melanocytes, PTK7/CCK-4 and SEK/TYRO1, was decreased or lost in advanced melanomas. PTK7 mRNA was found in only 54% of melanoma cell lines and 20% of melanoma biopsies. Similarly, expression was lost in 2 advanced cell lines selected from an early melanoma line that did express PTK7 mRNA. SEK/TYRO1 expression was observed in 75% and 17% of cell lines from primary and metastastic melanomas, respectively. Conversely, mRNA for the non-receptor kinase PTK6/BRK was not detected in normal melanocytes or primary melanoma lines, but was found in 9% of metastatic melanoma cell lines.

Objective Through the conduct of an individual-based intervention study, the main purpose of this project was to build and evaluate the required infrastructure that may enable routine practice of precision cancer medicine in the public health services of Norway, including modelling of costs. Methods An eligible patient had end-stage metastatic disease from a solid tumour. Metastatic tissue was analysed by DNA sequencing, using a 50-gene panel and a study-generated pipeline for analysis of sequence data, supplemented with fluorescence in situ hybridisation to cover relevant biomarkers. Cost estimations compared best supportive care, biomarker-agnostic treatment with a molecularly targeted agent and biomarker-based treatment with such a drug. These included costs for medication, outpatient clinic visits, admission from adverse events and the biomarker-based procedures. Results The diagnostic procedures, which comprised sampling of metastatic tissue, mutation analysis and data interpretation at the Molecular Tumor Board before integration with clinical data at the Clinical Tumor Board, were completed in median 18 (8-39) days for the 22 study patients. The 23 invasive procedures (12 from liver, 6 from lung, 5 from other sites) caused a single adverse event (pneumothorax). Per patient, 0–5 mutations were detected in metastatic tumours; however, no actionable target case was identified for the current single-agent therapy approach. Based on the cost modelling, the biomarker-based approach was 2.5-fold more costly than best supportive care and 2.5-fold less costly than the biomarker-agnostic option. Conclusions The first project phase established a comprehensive diagnostic infrastructure for precision cancer medicine, which enabled expedite and safe mutation profiling of metastatic tumours and data interpretation at multidisciplinary tumour boards for patients with end-stage cancer. Furthermore, it prepared for protocol amendments, recently approved by the designated authorities for the second study phase, allowing more comprehensive mutation analysis and opportunities to define therapy targets.

Malignant serous effusions are a common manifestation of advanced cancer, associated with significant morbidity and mortality. The aim of this study was to identify the metabolic differences between ovarian serous carcinoma effusions obtained pre- and post-chemotherapy, as well as to compare ovarian carcinoma (OC) effusions with breast carcinoma and malignant mesothelioma specimens. The supernatants of 115 effusion samples were analyzed by high-resolution magnetic resonance spectroscopy in vitro and multivariate analysis. The samples comprised pleural and peritoneal effusions from 95 OC, 10 breast carcinomas, and 10 malignant mesotheliomas. Among the OC, 8 were paired peritoneal specimens obtained pre- and post-chemotherapy from the same patient. OC had elevated levels of ketones (aceto-acetate and β-hydroxybutyrate) and lactate compared to malignant mesotheliomas and breast carcinomas, whereas the latter had more glucose, alanine, and pyruvate. Multivariate analysis of paired effusions in OC showed a significant increase in glucose and lipid levels in the post-treatment spectra (P = .039). Magnetic resonance spectroscopy is a promising technique for comprehensive and comparative studies of metabolites in malignant serous effusions, and our study shows that small metabolites associated with effusions might improve our understanding of tumor biology and disease progression and has diagnostic potential in this differential diagnosis. Copyright © 2013 Elsevier Inc. All rights reserved. This is the authors' accepted and refereed manuscript to the article.

Cytoreductive surgery and intraperitoneal (i.p.) chemotherapy constitute a curative treatment option in mucinous peritoneal surface malignancies of intestinal origin, but treatment outcome is highly variable and the search for novel therapies is warranted. Immunotoxins are attractive candidates for targeted therapy in the peritoneal cavity because of direct cytotoxicity, distinct mechanisms of action and tumor cell selectivity. The MOC31PE immunotoxin targets the tumor-associated adhesion protein EpCAM (Epithelial Cell Adhesion Molecule), and has been administered safely in early clinical trials. In our work, the efficacy of i.p. administration of MOC31PE alone and together with mitomycin C (MMC) was investigated in unique animal models of human mucinous peritoneal surface malignancies. In initial model validation experiments, clear differences in efficacy were demonstrated between MMC and oxaliplatin, favoring MMC in five investigated tumor models. Subsequently, MOC31PE and MMC were given as single i.p. injections alone and in combination. In the PMCA-2 model, moderate growth inhibition was obtained with both drugs, while the combination resulted in at least additive effects; whereas the PMP-2 model was highly sensitive to both drugs separately and in combination and intermediate sensitivity was found for the PMCA-3 model. Furthermore, results from ex vivo experiments on freshly obtained mucinous tumor tissue from animals and patients suggested that classic mechanisms of immunotoxin activity were involved, i.e., inhibition of protein synthesis and induction of apoptosis. The present results suggest that adding MOC31PE to MMC-based i.p. chemotherapy should be further explored for EpCAM-expressing peritoneal surface malignancies, and a phase I trial is in preparation.

The novel synthetic retinoid, CD437, shows potent anti-tumor activity in a range of different cancer cell lines and now serves as a prototype for development of new retinoid related molecules (RRMs). The purpose of this study was to examine the effect and cellular targets of CD437 in the human metastatic melanoma cell lines FEMX-1 and WM239. We showed that treatment with CD437 led to cell cycle arrest and induced apoptosis through both the extrinsic- and intrinsic pathways (caspase 8, -9 and PARP cleavage) in both cell lines. Interestingly, apoptosis was induced independently of DNA-fragmentation in FEMX-1 cells, and appeared partially caspase-independent in the WM239 cells. Additionally, up-regulation of CHOP mRNA and cathepsin D protein expression, following retinoid treatment, suggests involvement of the endoplasmatic reticulum (ER) and lysosomes, respectively. Combination of suboptimal concentrations of CD437 and lexatumumab, a TRAIL death receptor-2 agonist, resulted in synergistic reduction of viable cells, along with increased PARP cleavage. These results indicate that CD437 has a strong anti-neoplastic effect alone and in combination with lexatumumab in melanoma cell lines.

Background/aims Breast cancer metastasis suppressor 1 (BRMS1) blocks metastasis in melanoma xenografts; however, its usefulness as a biomarker in human melanomas has not been widely studied. The goal was to measure BRMS1 expression in benign nevi, primary and metastatic melanomas and evaluate its impact on disease progression and prognosis. Methods Paraffin-embedded tissue from 155 primary melanomas, 69 metastases and 15 nevi was examined for BRMS1 expression using immunohistochemistry. siRNA mediated BRMS1 down-regulation was used to study impact on invasion and migration in melanoma cell lines. Results A significantly higher percentage of nevi (87%), compared to primary melanomas (20%) and metastases (48%), expressed BRMS1 in the nucelus (p < 0.0001). Strong nuclear staining intensity was observed in 67% of nevi, and in 9% and 24% of the primary and metastatic melanomas, respectively (p < 0.0001). Comparable cytoplasmic expression was observed (nevi; 87%, primaries; 86%, metastases; 72%). However, a decline in cytoplasmic staining intensity was observed in metastases compared to nevi and primary tumors (26%, 47%, and 58%, respectively, p < 0.0001). Score index (percentage immunopositive celles multiplied with staining intensity) revealed that high cytoplasmic score index (≥ 4) was associated with thinner tumors (p = 0.04), lack of ulceration (p = 0.02) and increased disease-free survival (p = 0.036). When intensity and percentage BRMS1 positive cells were analyzed separately, intensity remained associated with tumor thickness (p = 0.024) and ulceration (p = 0.004) but was inversely associated with expression of proliferation markers (cyclin D3 (p = 0.008), cyclin A (p = 0.007), and p21Waf1/Cip1 (p = 0.009)). Cytoplasmic score index was inversely associated with nuclear p-Akt (p = 0.013) and positively associated with cytoplasmic p-ERK1/2 expression (p = 0.033). Nuclear BRMS1 expression in ≥ 10% of primary melanoma cells was associated with thicker tumors (p = 0.016) and decreased relapse-free period (p = 0.043). Nuclear BRMS1 was associated with expression of fatty acid binding protein 7 (FABP7; p = 0.011), a marker of invasion in melanomas. In line with this, repression of BRMS1 expression reduced the ability of melanoma cells to migrate and invade in vitro. Conclusion Our data suggest that BRMS1 is localized in cytoplasm and nucleus of melanocytic cells and that cellular localization determines its in vivo effect. We hypothesize that cytoplasmic BRMS1 restricts melanoma progression while nuclear BRMS1 possibly promotes melanoma cell invasion. Please see related article: http://www.biomedcentral.com/1741-7015/10/19

The C/EBP-homologous transcription factor CHOP ( GADD153 ) is inducible by growth inhibition or DNA damage, and has been shown to be oncogenically activated by the specific (12;16) translocation in human myxoid liposarcoma. We have now found CHOP amplification in two sarcoma cell lines with previously reported amplification of the nearby GLI gene. Among 98 other human sarcomas of various types, CHOP was amplified in a hemangiopericytoma, a liposarcoma, and two osteosarcomas. High constitutive expression levels of CHOP were observed in tumors with gene amplification, but also in some other samples. The nearby MDM2 gene, which codes for a protein that may inactivate wild-type p53 , has previously been reported to be frequently amplified in sarcoma. In our sarcoma panel, MDM2 was amplified in 9 cases. MDM2 and CHOP were co-amplified in two of these, whereas the two osteosarcomas had amplified CHOP but not MDM2 . CHOP was amplified in both cell lines with GLI amplification, and MDM2 only in one. No mutations in the TP53 gene have been found in samples with amplification of MDM2 . In contrast, the cell line in which CHOP but not MDM2 was amplified had mutated TP53 , suggesting that selection of this amplicon was not mediated through p53 inactivation.

Background CDC25 phosphatases are important regulators of the cell cycle. Their abnormal expression detected in a number of tumors implies that their dysregulation is involved in malignant transformation. However, the role of CDC25s in vulvar cancer is still unknown. To shed light on their roles in the pathogenesis and to clarify their prognostic values, expression of CDC25A, CDC25B and CDC25C in a large series of vulvar squamous cell carcinomas were examined. Methods Expression of CDC25A, CDC25B, CDC25C and phosphorylated (phospho)-CDC25C (Ser216) were examined in 300 vulvar carcinomas using immunohistochemistry. Western blot analysis was utilized to demonstrate CDC25s expression in vulvar cancer cell lines. Kinase and phosphatase assays were performed to exclude cross reactivity among CDC25s isoform antibodies. Results High nuclear CDC25A and CDC25B expression were observed in 51% and 16% of the vulvar carcinomas, respectively, whereas high cytoplasmic CDC25C expression was seen in 63% of the cases. In cytoplasm, nucleus and cytoplasm/nucleus high phospho-CDC25C (Ser216) expression was identified in 50%, 70% and 77% of the carcinomas, respectively. High expression of CDC25s correlated significantly with malignant features, including poor differentiation and infiltration of vessel for CDC25B, high FIGO stage, presence of lymph node metastases, large tumor diameter, poor differentiation for CDC25C and high FIGO stage, large tumor diameter, deep invasion and poor differentiation for phospho-CDC25C (Ser216). In univariate analysis, high expression of phospho-CDC25C (Ser216) was correlated with poor disease-specific survival (p = 0.04). However, such an association was annulled in multivariate analysis. Conclusions Our results suggest that CDC25C and phospho-CDC25C (Ser216) play a crucial role and CDC25B a minor role in the pathogenesis and/or progression of vulvar carcinomas. CDC25B, CDC25C and phospho-CDC25C (Ser216) were associated with malignant features and aggressive cancer phenotypes. However, the CDC25s isoforms were not independently correlated to prognosis.

The present study analyzed the site-specific expression and clinical role of S100A4 in advanced-stage ovarian carcinoma (OC). S100A4 expression was analyzed in 161 effusions, 67 primary carcinomas and 127 solid metastases using immunohistochemistry. S100A4 levels were additionally measured in 20 effusion supernatants using the immunofluorometric assay IFMA. Cytoplasmic and nuclear S100A4 was detected in cancer cells at all anatomic sites, while myofibroblasts in solid tumors expressed only cytoplasmic S100A4. Nuclear expression was higher in solid tumors than in effusions (p0.001), while stromal cell expression was higher in metastases than primary tumors (p = 0.001). IFMA analysis detected S100A4 in all 20 supernatants. Nuclear S100A4 expression in primary carcinomas (p = 0.049), FIGO stage IV (p = 0.019) and poor response to chemotherapy at diagnosis (p0.001) were associated with worse overall survival. All three parameters were independent prognosticators in Cox analysis (S100A4: p = 0.048, FIGO stage: p = 0.015, response to chemotherapy: p0.001). S100A4 is frequently expressed in tumor and host cells in OC, with upregulated stromal expression in solid metastases. Tumor cell nuclear S100A4 expression is higher in solid tumors than in effusions, and is associated with more aggressive clinical disease in primary carcinoma, suggesting that the tumor-promoting role of this molecule is predominantly exerted at this anatomic site.

We recently reported on higher expression of the insulin-like growth factor pathway genes IGF-II and IGFBP3 in serous ovarian/peritoneal carcinoma compared to malignant peritoneal mesothelioma. The present study analyzed the diagnostic and clinical role of these proteins in serous effusions. Effusions (n = 327), including 294 carcinomas (205 ovarian, 48 breast, 17 cervical/endometrial, 12 lung, 12 gastrointestinal/genitourinary) and 33 malignant mesotheliomas, were immunostained for insulin-like growth factor-II and insulin-like growth factor binding protein-3. Surgical ovarian carcinoma (n = 124) and peritoneal mesothelioma (n = 18) specimens were additionally studied. Insulin-like growth factor binding protein-3 levels were measured in 148 effusion supernatants (114 ovarian carcinomas, 18 breast carcinomas, 16 mesotheliomas) using enzyme-linked immunosorbent assay. Insulin-like growth factor binding protein-3 promoter methylation was analyzed in 11 ovarian carcinoma effusions. Insulin-like growth factor binding protein-3 (P = .002) and insulin-like growth factor-II (P < .001) expression by immunohistochemistry was significantly higher in carcinomas compared to mesotheliomas, with diagnostic sensitivity of 77% and 70% and specificity of 55% and 70%, respectively. In surgical specimens, insulin-like growth factor binding protein-3 expression was higher in ovarian carcinomas compared to peritoneal mesotheliomas (P = .007), whereas insulin-like growth factor-II expression was comparable (P = .505). Insulin-like growth factor binding protein-3 levels by enzyme-linked immunosorbent assay were comparable in the 3 analyzed cancer types. Insulin-like growth factor binding protein-3 promoter methylation was found in 6 of 11 effusions. High insulin-like growth factor binding protein-3 expression in prechemotherapy and high insulin-like growth factor-II expression in postchemotherapy ovarian carcinoma effusions correlated with poor overall survival (P = .031 and P = .024, respectively). Insulin-like growth factor-II expression in postchemotherapy effusions was an independent prognostic factor in Cox multivariate analysis (P = .04). In conclusion, insulin-like growth factor-II and insulin-like growth factor binding protein-3 are more frequently expressed in metastatic carcinomas compared to mesothelioma in effusions but are less specific than currently used markers. Insulin-like growth factor-II and insulin-like growth factor binding protein-3 may be novel prognostic markers in metastatic ovarian carcinoma.

Tumor progression and treatment failure in ovarian carcinoma are frequently associated with metastasis to effusions. The present study analyzed the expression and clinical role of nuclear factor-kappaB p65, nuclear factor-kappaB inhibitor alpha, and parameters of apoptosis in serous carcinoma. Cleaved caspase-3 and caspase-8 levels and deoxyuridine triphosphate incorporation were measured in 65 effusions using flow cytometry. Effusions (n = 209) and corresponding primary carcinomas and solid metastases (n = 114) were immunohistochemically analyzed for nuclear factor-kappaB p65 and nuclear factor-kappaB inhibitor alpha expression. Effusions (n = 75) were further analyzed for nuclear factor-kappaB phospho-p65 (Ser536) levels using immunoblotting. Results were analyzed for association with anatomic site, clinicopathologic parameters, and survival. Caspase cleavage and deoxyuridine triphosphate incorporation were limited to less than 10% of cells in most effusions. Nuclear factor-kappaB p65 expression was frequently detected at all anatomic sites, with less frequent cytoplasmic nuclear factor-kappaB p65 and nuclear factor-kappaB inhibitor alpha expressions. Immunoblotting showed nuclear factor-kappaB p65 phosphorylation in 72 (96%) of 75 effusions. Higher than median cleaved caspase-3 levels correlated with improved overall and progression-free survival in univariate analysis of all patients (P = .024 and P = .046, respectively) and of those with postchemotherapy effusions (P = .042 and P = .036, respectively). Cleaved caspase-3 expression was an independent predictor of longer progression-free survival for patients with postchemotherapy effusions (P = .029). Nuclear factor-kappaB p65 expression correlated with poor progression-free survival for all patients (P = .048) and for those with postchemotherapy effusions (P = .025). Ovarian carcinoma cells in effusions undergo little apoptosis, but high levels of cleaved caspase-3 are associated with improved survival. Nuclear factor-kappaB p65 is frequently expressed in advanced-stage serous ovarian carcinoma, and its nuclear localization is associated with poor progression-free survival.

Fibroblast activation protein-alpha (FAP-alpha) and urokinase-type plasminogen activator (uPA) are serine proteases involved in cancer invasion and metastasis. The authors examined FAP-alpha and uPA expression in premalignant and malignant stages of esophageal adenocarcinoma by immunohistochemistry. Additionally, Western blotting was performed on fresh-frozen tissue samples. FAP-alpha and uPA were detected in metaplastic, dysplastic, and carcinoma cells, as well as in adjacent stroma. Stromal FAP-alpha expression was associated with depth of tumor invasion, while stromal uPA expression correlated with lymph node metastases in adenocarcinomas. Stromal uPA expression in cells with premalignant changes correlated with histological grading. Immunoblotting showed higher protease expression in carcinoma tissues than in normal esophageal epithelium. These results suggest that FAP-alpha and uPA expression in metaplastic, dysplastic, and esophageal cancer tissue is associated with neoplastic progression of esophageal lesions.

Background The molecular mechanisms underlying melanoma tumor development and progression are still not completely understood. One of the new candidates that emerged from a recent gene expression profiling study is fatty acid-binding protein 7 (FABP7), involved in lipid metabolism, gene regulation, cell growth and differentiation. Methods We studied the functional role of FABP7 in human melanoma cell lines and using immunohistochemistry analyzed its expression pattern and clinical role in 11 nevi, 149 primary melanomas and 68 metastases. Results FABP7 mRNA and protein level is down-regulated following treatment of melanoma cell lines with a PKC activator (PMA) or MEK1 inhibitor (PD98059). Down-regulation of FABP7 using siRNA decreased cell proliferation and invasion but did not affect apoptosis. In clinical specimens, FABP7 was expressed in 91% of nevi, 71% of primary melanomas and 70% of metastases, with a cytoplasmic and/or nuclear localization. FABP7 expression was associated with tumor thickness in superficial spreading melanoma (P = 0.021). In addition, we observed a trend for an association between FABP7 expression and Ki-67 score (P = 0.070) and shorter relapse-free survival (P = 0.069) in this group of patients. Conclusion Our data suggest that FABP7 can be regulated by PKC and the MAPK/ERK1/2 pathway through independent mechanisms in melanoma cell lines. Furthermore, FABP7 is involved in cell proliferation and invasion in vitro, and may be associated with tumor progression in melanoma.

Seprase, dipeptidyl peptidase IV (DPPIV) and urokinase-type plasminogen activator (uPA) play a crucial role in the degradation of the extracellular matrix and in the progression of various human tumors. However, their pathophysiologic significance in esophageal carcinoma has not yet been fully elucidated.The expression of seprase, DPPIV and uPA in esophageal dysplasia, squamous cell carcinoma (SCC) and normal epithelium was examined by immunohistochemistry.Seprase, DPPIV and uPA immunoreactivity was found in dysplastic and cancer cells as well as in stromal cells adjacent to dysplasia and cancer sites, but not in normal epithelium. We found a significant association between uPA expression and sex, tumor size and histological classification in carcinomas. High expression of DPPIV in cancer cells correlated with longer survival of the patients. No significant associations between seprase and clinicopathological features either in dysplasia or in carcinomas were found. Finally, we demonstrated higher levels of seprase, DPPIV and uPA in SCC cell lines than in normal esophageal epithelial cell lines.Our results showed that seprase, DPPIV and uPA are expressed in both premalignant and malignant forms of SCC, but are lacking in normal esophageal epithelia, suggesting that they are involved in SCC neoplastic progression.

A series of cis-restricted 1,5-disubstituted 1,2,3-triazole analogues of combretastatin A-4 (1) have been prepared. The triazole 12f, 2-methoxy-5-(1-(3,4,5-trimethoxyphenyl)-1H-1,2,3-triazol-5-yl)aniline, displayed potent cytotoxic activity against several cancer cell lines with IC(50) values in the nanomolar range. The ability of triazoles to inhibit tubulin polymerization has been evaluated, and 12f inhibited tubulin polymerization with IC(50)=4.8microM. Molecular modeling experiments involving 12f and the colchicine binding site of alpha,beta-tubulin showed that the triazole moiety interacts with beta-tubulin via hydrogen bonding with several amino acids.

BACKGROUND. Death receptors mediate both apoptosis and survival in cancer cells. The authors analyzed death receptor expression in metastatic ovarian carcinoma. METHODS. Viable tumor cells in ovarian carcinoma effusions (n = 95) were analyzed for DR4, DR5, Fas, TNFR1, and TNFR2 expression using flow cytometry. Results were analyzed for association with clinicopathologic parameters, chemotherapy response, and survival. RESULTS. DR4, DR5, and Fas were expressed by the majority of specimens, with less frequent expression of TNFR1 and TNFR2. DR4 (P = .005) and TNFR2 (P = .041) expression was higher in FIGO stage IV compared with stage III tumors. Effusions from patients who responded poorly to chemotherapy administered at disease recurrence had significantly higher DR4 (P = .006), DR5 (P = .01), and Fas (P = .001) expression. In univariate survival analysis, higher DR4 expression in viable cells correlated with poor overall (P = .0352) and progression-free (P = .0411) survival. DR4 expression was found to be an independent predictor of overall (P = .008) and progression-free (P = .003) survival. CONCLUSIONS. The authors have presented the first evidence of death receptor coexpression in ovarian carcinoma effusions. The association of death receptor expression in effusions with advanced stage, poor response to chemotherapy, and shorter survival suggests that these molecules are linked to an aggressive clinical course in metastatic ovarian carcinoma. Cancer 2008. © 2007 American Cancer Society.

We analyzed the expression and prognostic role of inhibitors of apoptosis in breast carcinoma effusions. We used immunoblotting to analyze 22 effusions for XIAP, survivin, and livin expression. Based on immunoblotting results, 49 effusions and 46 corresponding solid tumors were immunostained for XIAP and survivin. Results were analyzed for association with anatomic site, clinicopathologic parameters, and survival. Immunoblotting showed frequent expression of XIAP and survivin and no expression of livin. Carcinoma cells in effusions showed lower survivin immunostaining compared with lymph node metastases (P = .008) and primary carcinomas (P = .041). Higher cytoplasmic survivin expression correlated with poor disease-free survival for patients with postchemotherapy effusions (P = .035). XIAP and survivin, but not livin, are frequently expressed in advanced breast carcinoma. Survivin is down-regulated in effusions compared with solid tumors, possibly in relation to the different cellular economy at this anatomic site. Survivin expression may predict disease-free survival for patients with postchemotherapy effusions.

BACKGROUND. The authors recently reported on the role of cyclin E in differentiating ovarian/primary peritoneal carcinoma from malignant peritoneal mesothelioma using gene expression arrays. In the current study, they analyzed the expression of low-molecular weight (LMW) forms of cyclin E in ovarian carcinoma, malignant mesothelioma, and benign reactive effusions. METHODS. Cyclin E protein expression was analyzed in 98 effusions (72 ovarian carcinomas, 14 malignant mesotheliomas, and 12 reactive specimens) using immunoblotting. Sixty-two ovarian carcinoma effusions were studied further for cyclin E expression using immunohistochemistry. The correlations between cyclin E expression in ovarian carcinoma and clinical parameters, including chemotherapy response, were analyzed. RESULTS. LMW forms of cyclin E were identified in 54 of 72 ovarian carcinoma effusions (75%) compared with 1 of 14 malignant mesothelioma effusions (7%) and 1 of 12 reactive effusions (8%) (P < .001). Their presence in ovarian carcinoma was associated with a higher percentage of cyclin E-positive cells (P = .001) and increased staining intensity (P < .001) using immunohistochemistry. The presence of LMW forms of cyclin E was correlated with shorter overall survival (P = .021) and progression-free survival (P = .020). The presence of a higher percentage of cyclin E-positive cells using immunohistochemistry was correlated with shorter progression-free survival (P = .026). No association with chemotherapy response was observed. CONCLUSIONS. LMW forms of cyclin E differentiated ovarian carcinoma from benign and malignant mesothelial cells and were associated with increased protein expression using immunohistochemistry. The expression of LMW cyclin E forms was not associated with chemotherapy response, although it may be a marker of aggressive disease in patients with metastatic ovarian carcinoma. Cancer 2007. © 2007 American Cancer Society.

The aim of this study was to analyze the expression and clinical role of DJ-1, a negative regulator of PTEN (phosphatase and tensin homolog deleted on chromosome 10), in ovarian carcinoma, and investigate the putative association between DJ-1 levels and expression of its transcriptional regulators specificity protein 1 (Sp1) and specificity protein 3 (Sp3). Effusions (n = 72) and solid tumors (n = 57, 42 primary and 15 metastases) were analyzed for DJ-1 messenger RNA (mRNA) expression using reverse transcriptase-polymerase chain reaction. Most specimens (48 effusions, 50 solid tumors) were additionally analyzed for Sp1 and Sp3 mRNA expression. PTEN protein expression was analyzed in 201 effusions and 92 solid tumors using immunohistochemistry. DJ-1 mRNA was expressed in more than 80% of specimens, with no preferential anatomical site. DJ-1 expression was positively associated with Sp1 expression in effusions (P = .03) and with Sp1 (P = .02) and Sp3 (P = .002) expression in solid tumors. In effusions, DJ-1 expression was higher in postchemotherapy compared with prechemotherapy specimens (P = .012). Higher DJ-1 levels (P = .027) and more advanced FIGO stage (IV versus III; P = .003) correlated with shorter progression-free survival in univariate analysis for patients with postchemotherapy effusions. PTEN expression was low in effusions and solid tumors (23% and 13%, respectively), and its expression showed no association with DJ-1 levels or survival. Our data show that DJ-1 is frequently expressed in advanced-stage ovarian carcinoma at all anatomical sites and is coexpressed with its transcriptional regulators Sp1 and Sp3. In contrast, PTEN expression is infrequent in this disease. These findings may provide one of the molecular mechanisms that mediate cancer cell survival and aggressiveness in this tumor.

Inhibitor of apoptosis proteins (IAPs) mediate cancer cell survival and chemoresistance. The expression of XIAP, Survivin, and Livin in ovarian carcinoma was analyzed.Effusions (106) were analyzed for XIAP, Survivin, and Livin expression using immunoblotting. Effusions (220), corresponding primary tumors (60), and solid metastases (103) were further immunohistochemically analyzed for XIAP and Survivin expression. The results were analyzed for association with anatomic site, clinicopathologic parameters, and survival.Immunoblotting showed frequent expression of XIAP and Survivin, and no expression of Livin. Immunohistochemistry showed cytoplasmic XIAP expression in 208 of 220 (94%) effusions, 50 of 60 (83%) primary tumors, and 87 of 103 (84%) solid metastases, with a significantly higher staining extent in effusions (P.001). Cytoplasmic Survivin was found in 194 of 220 (88%) effusions, 55 of 60 (92%) primary tumors, and 102 of 103 (99%) solid metastases, with a significantly higher cytoplasmic staining extent in solid metastases (P = .018 and P = .006 compared with primary tumors and effusions, respectively). Nuclear Survivin was expressed in 159 of 220 (72%) effusions, 54 of 60 (90%) primary carcinomas, and 96 of 103 (93%) solid metastases (P.05). For patients with prechemotherapy effusions, higher nuclear Survivin expression correlated with better progression-free (P = .0003) and overall (P = .002) survival in univariate survival analysis. Nuclear Survivin expression was found to be an independent predictor of progression-free survival (P = .004).XIAP and Survivin, but not Livin, are frequently expressed in ovarian carcinoma. XIAP and cytoplasmic Survivin are up-regulated in effusions and solid metastases, respectively, possibly mediating survival at these sites. Nuclear Survivin expression predicts better outcome in prechemotherapy patients.

Purpose: Ovarian/primary peritoneal serous carcinoma (OC/PPC) and diffuse peritoneal malignant mesothelioma (DMPM) are highly aggressive tumors that are closely related morphologically and histogenetically. It remains unclear whether both tumors are molecularly distinct neoplasms. The current study compared global gene expression patterns in OC/PPC and DMPM. Experimental Design: Ten OC/PPC and five DMPM effusions were analyzed for gene expression profiles using the Affymetrix U133 Plus 2 arrays and the dCHIP analysis program. Differentially expressed candidate genes were validated using quantitative real-time PCR and immunohistochemistry. Results: Unsupervised hierarchical clustering using all 54,675 genes in the array classified the samples into two groups: DMPM specimens versus OC/PPC specimens. A total of 189 genes that were differentially expressed in these two groups were selected based on statistical significance. Genes overexpressed in DMPM (n = 68) included calretinin, vitronectin, claudin 15, α4 laminin, hyaluronan synthase 1, cadherin 11, RAB7, v-maf, and the epidermal growth factor–containing fibulin-like extracellular matrix protein 1. Genes overexpressed in OC/PPC (n = 121) included insulin-like growth factor II (IGF-II); IGF-II binding protein 3; cyclin E1; folate receptors 1 and 3; RAB25; MUC4; endothelin-1; CD24; kallikreins 6, 7, and 8; claudins 3, 4, and 6; Notch3; and MMP-7. Quantitative real-time PCR validated the differential expression of 13 genes, and immunohistochemistry confirmed the differences for four gene products. Conclusions: Expression profiling separates OC/PPC from DMPM and identifies a number of genes that are differentially expressed in these tumors. The molecular signatures unique to OC/PPC and DMPM should provide a molecular basis to study both tumors and new potential markers for facilitating their differential diagnosis.

Signaling pathways regulating cell proliferation and survival have become attractive targets for anticancer strategies. In the present study, we analyzed by immunohistochemistry, a panel of benign nevi, superficial spreading and nodular primary melanomas and metastases for expression of activated p38/mitogen-activated protein kinase (p-p38) and c-jun N-terminal kinase (JNK) (p-JNK) and correlated the findings with known prognostic variables. Twenty-five and 35% of the primaries and 9 and 25% of the metastases expressed variable levels of p-p38 and p-JNK, respectively. In benign nevi, 73.5% expressed p-JNK and 7% expressed p-p38. For patients with superficial spreading melanomas, high level of cytoplasmic p-JNK was associated with thicker tumors (P=0.017) and shorter disease-free survival (P=0.003) as well as with markers of cell proliferation (cyclin A (P=0.017) and p21 (P=0.021)). In nodular melanomas, nuclear p-p38 was associated with Ki-67 (P=0.012), but neither cytoplasmic nor nuclear localized p-p38 was associated with disease outcome. Of note, in superficial spreading melanomas, a positive correlation between cytoplasmic p-JNK and cytoplasmic p-extracellular signal-regulated kinase ERK(1/2) (P=0.005) and p-p38 (P=0.003) was observed. Likewise, p-p38 in cytoplasm was positively associated with cytoplasmic p-ERK1/2 (P

Background While numerous studies have characterized primary ovarian tumors, little information is available regarding expression patterns of metastatic sites of this cancer. To define sets of genes that distinguish primary and metastatic ovarian tumors, we used cDNA microarrays to characterize global gene expression patterns in 38 effusions (28 peritoneal, 10 pleural) and 8 corresponding primary ovarian tumors, and searched for associations between expression patterns and clinical parameters. Results We observed multidimensional variation in expression patterns among the cancers. Coordinate variation in expression of genes from two chromosomal regions, 8q and 19q, was seen in subsets of the cancers indicating possible amplifications in these regions. A set of 112 unique genes of known function was differentially expressed between primary tumors and effusions using supervised analysis. Relatively few differences were seen between effusions isolated from the pleural and peritoneal cavities or between effusions from patients diagnosed with stage III and stage IV cancers. A set of 84 unique genes was identified that distinguished high from lower grade ovarian cancers. The results were corroborated using immunocytochemistry, mRNA in situ hybridization, and immunoblotting. Conclusion The extensive variation in expression patterns observed underscores the molecular heterogeneity of ovarian cancer, but suggests a similar molecular profile for ovarian carcinoma cells in serosal cavities.

The phorbol ester, phorbol-12-myristate-13-acetate (PMA), an activator of PKCs, is known to stimulate the in vitro growth of monolayer cultures of normal human melanocytes whereas it inhibits the growth of most malignant melanoma cell lines. We examined the effect of PMA on proliferation and survival of melanoma cells grown as multicellular aggregates in suspension (spheroids), and aimed to elucidate downstream targets of PKC signaling. In contrast to monolayer cultures, PMA increased cell proliferation as well as protected melanoma cells from suspension-mediated apoptosis (anoikis). Supporting the importance of PKC in anchorage-independent growth, treatment of anoikis-resistant melanoma cell lines with antisense oligonucleotides against PKC-alpha, or the PKC inhibitor Go6976, strongly induced anoikis. PMA induced activation of ERK1/2, but this effect was not prevented by the MEK inhibitors PD98059 or by U0126. Whereas PD98059 treatment alone led to marked activation of the pro-apoptotic Bim and Bad proteins and significantly increased anoikis, these effects were clearly reversed by PMA. In conclusion, our results indicate that the protective effect of PMA on anchorage-independent survival of melanoma cells at least partly is mediated by MEK-independent activation of ERK1/2 and inactivation of downstream pro-apoptotic effector proteins.

The granulin-epithelin precursor (GEP) was preferentially expressed in invasive ovarian tumor epithelium specimens compared with specimens of borderline ovarian tumors. The objective of the current study was to evaluate the anatomic site-related and cellular expression of GEP and its association with clinicopathologic parameters and survival in patients with advanced-stage ovarian carcinoma.Effusions (n = 190), corresponding primary tumor specimens (n = 64), and specimens of metastatic lesions (n = 125) were analyzed using immunohistochemistry with a specific polyclonal antipeptide antibody. In addition, 36 effusions were analyzed using immunoblotting.GEP was detected in tumor cells in 171 of 190 (90%) effusions and demonstrated both focal membrane and cytoplasmic localization. Mesothelial cells were often GEP positive (81%). GEP was found in carcinoma cells in 180 of 189 (95%) tumor biopsy specimens, with stromal and endothelial cell expression in 93 of 180 (52%) and 124 of 185 (67%) specimens, respectively. Lower GEP expression in stromal cells was observed in metastases sampled during or after chemotherapy (P = 0.034). The presence of GEP-positive stromal cells in untreated primary tumor specimens correlated with worse overall survival (P = 0.014). Significantly more frequent GEP expression was observed in tumor cells of both primary (P = 0.002) and metastatic (P0.001) tissue specimens compared with malignant effusions.GEP expression was observed in primary and metastatic epithelial ovarian carcinoma specimens, with down-regulated expression in tumor cells of malignant effusions. The poor outcome associated with stromal GEP expression suggests a prognostic role for this growth factor in ovarian carcinoma.

The aim of this study was to characterize phenotypic alterations along the progression of breast carcinoma from primary tumor to pleural effusion through analysis of the expression of nerve growth factor (NGF) and its receptors phospho-TrkA (p-TrkA activated receptor) and p75. Sections from 42 malignant pleural effusions from breast cancer patients and 65 corresponding solid tumors (34 primary, 31 metastatic) were evaluated for protein expression of the activated p-TrkA receptor. The majority of lesions were additionally studied for NGF and p75 expression. Six effusions and four breast carcinoma cell lines were studied for expression of p-TrkA using immunoblotting (IB). Membrane expression of p-TrkA was high in carcinoma cells in effusions (39/42, 93%) and locoregional recurrences (12/13, 92%), with significantly lower expression in both primary tumors (14/34, 41%) and lymph node metastases (8/18, 44%), respectively (p < 0.001 for effusions vs. primary tumors; p = 0.001 for effusions vs. lymph nodes). In contrast, p75 expression was less frequent in effusions compared to both primary tumors and lymph node metastases, significantly so for the latter (p = 0.019). NGF expression was comparable at all sites, but its expression in tumor cells in effusions (7/21 cases) was limited to cases in which time to progression (TTP) to effusion occurred within 5 years or less from primary operation. In univariate analysis of survival, mean and median TTP were 6.3 and 6 years for NGF-negative effusions, compared to 3 and 4 years for NGF-positive cases (p = 0.013). IB confirmed expression of p-TrkA in five of six effusions, while all four breast cancer cell lines were p-TrkA-negative. Our data provide the first documented evidence of molecular events that occur along tumor progression of breast carcinoma from primary tumors to effusion. The almost universal expression of p-TrkA in cancer cells in effusions and late recurrences is in full agreement with our recent report linking this factor with poor prognosis in ovarian cancer. Furthermore, the rapid progression to effusion in cases showing NGF expression in tumor cells underscores the aggressive clinical behavior of tumors that are able to utilize this pathway in an autocrine manner.

The purpose of the present work was to analyze the protein expression of activated extracellular signal-regulated kinases 1 and 2 (ERK1/2) in a panel of superficial spreading (SSM) and nodular (NM) primary and metastatic melanomas, and to correlate the expression level with clinicopathological parameters.Expression of activated ERK1/2 was examined by immunohistochemistry in 172 primary melanomas (108 SSM and 64 NMs), 67 metastatic lesions, and in 41 benign nevi.Fifty four percent of primary and 33% of metastatic melanomas expressed variable levels of activated ERK1/2. No immunoreactivity was detected in benign nevi. In 21% of the primaries only cytoplasmic expression was detected, whereas 3% and 30% showed positive immunoreactivity in either nucleus or cytoplasm and nucleus, respectively. Activated ERK1/2 expression varied significantly with the thickness of superficial spreading melanomas, with lower expression in thinner lesions (P = 0.016). A significant correlation between activated ERK1/2 and cyclin D1 (P = 0.031) in nodular, as well as between activated ERK1/2 and cyclin D3 (P = 0.030) in SSMs were observed. The protein level of p27(Kip1) correlated with activated ERK1/2 (P = 0.048) in the nucleus. Furthermore, a strong inverse correlation between activated ERK1/2 and membrane-bound beta-catenin (P = 0.004) in nodular melanomas was revealed. Activation of ERK1/2 did not have any impact on relapse-free or overall survival.Our results suggest that activation of ERK1/2 may be involved in cell cycle regulation in SSMs. Moreover, the inverse association between membrane-bound beta-catenin and ERK1/2 in NMs suggest that ERK1/2 activation may play a role in decreasing homotypic interactions through destabilization of beta-catenin.

The purpose of the present work was to analyze the expression of beta-catenin in a panel of superficial and nodular spreading primary and metastatic melanomas, and to correlate the level of immunohistochemical staining to clinicopathological parameters.Expression of beta-catenin was examined by immunohistochemistry in 106 superficial and 58 nodular spreading primary melanomas, as well as in 66 metastatic lesions.Membrane-associated staining was detected in nearly all of the cases, and no association to clinical parameters could be revealed. When cytoplasmic localization of the protein was recorded, a significant higher fraction of the superficial than the nodular spreading primary lesions expressed the protein in the majority of the cells (P0.0001). Interestingly, metastatic lesions from superficial melanomas demonstrated down-regulated expression of the protein, and in agreement with this a significant inverse correlation between protein expression and the vertical thickness of the primary lesion was detected (P = 0.012). Furthermore, a significant correlation between cytoplasmic localization and disease-free survival (P = 0.0006) was revealed, but beta-catenin did not have any significant impact on overall survival for this group of patients (P = 0.0824). No association was detected between beta-catenin expression and clinicopathological parameters in the nodular subgroup of melanomas, indicating that the protein may play different roles in the malignant progression of the two main types of melanomas.In summary, we hypothesize that cytoplasmic beta-catenin has a protective role in early melanoma development.

The objective of the present report was to study the expression of the low affinity nerve growth factor (NGF) receptor p75 and of the activated high-affinity NGF receptor TrkA in malignant mesothelioma (MM). In addition, to analyze whether expression of these receptors is site-related (pleural versus peritoneal MM, solid lesions versus effusions). Sections from 81 MM (57 biopsies, 24 effusions) were analyzed. Sixty-one mesotheliomas were of pleural origin, while the remaining 20 were peritoneal. Effusion specimens consisted of 6 peritoneal and 18 pleural effusions, while biopsies consisted of 14 peritoneal and 43 pleural lesions. Specimens were immunohistochemically stained using antibodies against p75 and phospho-TrkA (p-TrkA). Six effusions were additionally analyzed for p-TrkA expression using immunoblotting (IB). p-TrkA membrane expression (66/81 specimens; 81%) was by far more frequent than that of p75 (26/81 specimens; 32%). In addition, p-TrkA expression was significantly higher in peritoneal MM compared to their pleural counterparts (20/20 versus 46/61 positive tumors; P = 0.014). p-TrkA membrane expression was marginally higher in effusions (P = 0.058), while the opposite was true for p75 membrane expression (P = 0.008) and p-TrkA cytoplasmic expression (P = 0.003). In conclusion, our results document for the first time frequent expression of p-TrkA and lower expression of p75 in MM, in agreement with the biological aggressiveness of this tumor. The enhanced expression of p-TrkA in peritoneal MM, tumors that appear in younger patients, and in effusions as compared to solid tumors, suggest that p-TrkA plays a significant role in the biology of this disease and may aid in defining tumor progression in this setting.

The purpose is to analyze the possible correlation between expression and activation of the high-affinity nerve growth factor (NGF) receptor TrkA, cell cycle protein expression, and disease outcome in serous ovarian carcinoma. In addition, we wished to study the possible link between expression of NGF, a novel angiogenic factor and its receptor TrkA, and the expression of factors involved in angiogenesis in effusions and solid tumors.Sections from 80 malignant effusions and 65 corresponding solid tumors were evaluated for protein expression of NGF, TrkA, and phospho-TrkA (p-TrkA). Effusions were additionally studied for expression of p53, p21(WAF1/CIP1), Ki-67, and the M(r) 85,000-cleaved fragment of poly(ADP-ribose) polymerase (p85-PARP) using immunohistochemistry (IHC). Thirty-two effusions were studied for TrkA, p-TrkA, p53, and p21(WAF1/CIP1) expression using immunoblotting. mRNA expression of basic fibroblast growth factor (bFGF), interleukin 8, and vascular endothelial growth factor (VEGF) was studied in 63 effusions and all solid tumors using in situ hybridization. Protein expression of bFGF, interleukin 8, and VEGF was additionally studied in 30 effusions using IHC.NGF, TrkA, and p-TrkA were expressed in carcinoma cells in effusions in 60 of 80 (75%), 64 of 80 (80%), and 15 of 80 (19%) specimens, respectively. In solid tumors, p-TrkA expression was more frequent (52 of 65 tumors; 80%) and was accompanied by p-TrkA expression in endothelial cells. NGF colocalized with bFGF protein (P = 0.016) and mRNA (P = 0.032) in effusions, and with VEGF (P0.001) and bFGF (P = 0.008) in solid tumors. In survival analysis, expression of p85-PARP (P = 0.017) and cytoplasmic TrkA (P0.001) in effusions predicted better outcome, whereas membrane expression of p-TrkA in solid tumors correlated with poor survival (P = 0.004). Diffuse expression of p53 and Ki-67 was often seen using IHC, whereas p21(WAF1/CIP1) and p85-PARP expression was infrequent and focal. None of these correlated with NGF or TrkA expression or activity.Coexpression of NGF with molecules involved in angiogenesis and p-TrkA expression in endothelial cells suggest that the proangiogenic role attributed to NGF in vitro and in vivo may be relevant in clinical cancer. Expression of p85-PARP as a marker of apoptosis and cytoplasmic expression of TrkA (probably representing nonglycosylated receptor) predict better outcome, whereas p-TrkA activation correlates with poor outcome in advanced stage serous ovarian carcinoma.

Gains of 1q21-q23 have been associated with metastasis and chemotherapy response, particularly in bladder cancer, hepatocellular carcinomas and sarcomas. By positional cloning of amplified genes by yeast artificial chromosome-mediated cDNA capture using magnetic beads, we have identified three candidate genes (COAS1, -2 and -3) in the amplified region in sarcomas. COAS1 and -2 showed higher amplification levels than COAS3. Most notably, amplification was very common in osteosarcomas, where in particular COAS2 was highly expressed. COAS1 has multiple repeats and shows no homology to previously described genes, whereas COAS2 is a novel member of the cyclosporin-binding peptidyl-prolyl isomerase family, very similar to cyclophilin A. COAS2 was overexpressed almost exclusively in aggressive metastatic or chemotherapy resistant tumours. Although COAS2 was generally more amplified than COAS1, it was not expressed in well-differentiated liposarcomas, where amplification of this region is very common. All three genes were found to be amplified and over-expressed also in breast carcinomas. The complex nature of the 1q21-23 amplicons and close proximity of the genes make unequivocal determination of the gene responsible difficult. Quite likely, the different genes may give selective advantages to different subsets of tumours.

PRUNE, the human homologue of the Drosophila gene, is located in 1q21.3, a region highly amplified in human sarcomas, malignant tumours of mesenchymal origin. Prune protein interacts with the metastasis suppressor nm23-H1, but shows impaired affinity towards the nm23-H1 S120G mutant associated with advanced neuroblastoma. Based on these observations, we previously suggested that prune may act as a negative regulator of nm23-H1 activity. We found amplification of PRUNE in aggressive sarcoma subtypes, such as leiomyosarcomas and malignant fibrous histiocytomas (MFH) as well as in the less malignant liposarcomas. PRUNE amplification was generally accompanied by high mRNA and moderate to high protein levels. The sarcoma samples expressed nm23-H1 mostly at low or moderate levels, whereas mRNA and protein levels were moderate to high in breast carcinomas. For the more aggressive sarcoma subtypes, 9/13 patients with PRUNE amplification developed metastases. A similar situation was observed in all breast carcinomas with amplification of PRUNE. Infection of NIH3T3 cells with a PRUNE recombinant retrovirus increased cell proliferation. Possibly, amplification and overexpression of PRUNE has the same effect in the tumours. We suggest that amplification and overexpression of PRUNE could be a mechanism for inhibition of nm23-H1 activity that affect the development or progression of these tumours.

The search for better prognostic indicators and new treatment modalities in node-negative breast carcinoma patients is important. The aim of this study was to determine the immunohistochemical expression of central cell regulator proteins in relation to hormone receptor status, tumour-cell differentiation and prognosis. We investigated the immunoreactivity of p27, p21, cdk4, cyclin D1 and p53 in 77 node-negative breast carcinomas, with long-term follow-up (mean 163 months; range 20−227). Nuclear staining for p27 was seen in 87% of the carcinomas, for cdk4 in 92%, for p21 in 68%, for cyclin D1 in 58% and for p53 in 18%. Oestrogen receptor (ER) and progesterone receptor (PgR) nuclear staining was seen in 69% and 65% of the tumours, respectively. No correlation between the levels of p21 and p53 was observed. P21 overexpression was, however, associated with positive ER status. Elevated levels of p27 and cyclin D1 correlated with positive hormone status (both ER and PgR). We did find a significant correlation between p27 and cyclin D1 and histological grade of the tumours, with extensive positive immunostaining of p27 and cyclin D1 in well-differentiated carcinomas. The only significant prognostic factor in our series was histological grading. Ten-year relapse-free survival was significantly prolonged in patients with histological grade I tumours versus histological grade II and III tumours. Our results suggest that the expression of p27 and cyclin D1 is closely linked to hormone receptor status in breast carcinomas and to tumour differentiation, a finding that may be of importance in the treatment of hormone-dependent tumours.

Recent studies have demonstrated the importance of E-cadherin, a homophilic cell–cell adhesion molecule, in contact inhibition of growth of normal epithelial cells. Many tumor cells also maintain strong intercellular adhesion, and are growth-inhibited by cell– cell contact, especially when grown in three-dimensional culture. To determine if E-cadherin could mediate contact-dependent growth inhibition of nonadherent EMT/6 mouse mammary carcinoma cells that lack E-cadherin, we transfected these cells with an exogenous E-cadherin expression vector. E-cadherin expression in EMT/6 cells resulted in tighter adhesion of multicellular spheroids and a reduced proliferative fraction in three-dimensional culture. In addition to increased cell–cell adhesion, E-cadherin expression also resulted in dephosphorylation of the retinoblastoma protein, an increase in the level of the cyclin-dependent kinase inhibitor p27 kip1 and a late reduction in cyclin D1 protein. Tightly adherent spheroids also showed increased levels of p27 bound to the cyclin E-cdk2 complex, and a reduction in cyclin E-cdk2 activity. Exposure to E-cadherin–neutralizing antibodies in three-dimensional culture simultaneously prevented adhesion and stimulated proliferation of E-cadherin transfectants as well as a panel of human colon, breast, and lung carcinoma cell lines that express functional E-cadherin. To test the importance of p27 in E-cadherin–dependent growth inhibition, we engineered E-cadherin–positive cells to express inducible p27. By forcing expression of p27 levels similar to those observed in aggregated cells, the stimulatory effect of E-cadherin–neutralizing antibodies on proliferation could be inhibited. This study demonstrates that E-cadherin, classically described as an invasion suppressor, is also a major growth suppressor, and its ability to inhibit proliferation involves upregulation of the cyclin-dependent kinase inhibitor p27.

Malignant melanoma is one of the most increasing forms of cancer worldwide, in addition to being notoriously resistant to therapy. Despite recent advances, there are no curative treatments once the cancer has spread (stage IV); there is thus a precarious need to find new and better treatment alternatives. Unlike normal cells, the majority of cancer cells have a defective G1/S DNA-damage checkpoint and are therefore more dependent on the G2/M checkpoint when DNA damages arise. Central in regulating the latter checkpoint is Wee1, a kinase which may stop the cell cycle by adding a negative phosphorylation on CDK1. Wee1 is regulated by Chk1 which upon DNA damage can also inhibit the complimentary counterpart of Wee1; CDC25. In recent studies, Wee1 and Chk1 have additionally been indicated as key players in regulating DNA replication in S-phase. We have previously reported that increased Wee1 protein expression was associated with malignancy in melanoma tumour samples, and that siWee1 transfection led to reduced viability in melanoma cell lines. In the present study we have combined inhibitors of Wee1 (MK1775) and Chk1 (AZD7762) in a panel consisting of both metastatic melanoma- and normal cells, including a Plexxikon resistant melanoma cell line (MelJR post3.3). We found that the combination synergistically reduced the amount of viable cells in the melanoma cell lines (∼50-80% reduction), whilst only having very moderate effect (∼10% reduction) in the normal cells. Interestingly, the reduction in number of viable cells was found in both p53WT and p53Mut cell lines, indicating that the p53 status do not predict the response to such treatment. Furthermore, combinational treatment with the inhibitors caused increased cleavage of PARP and caspases, indicative of apoptosis, as compared to MK1775 or AZD7762 treatment alone. The combination also caused a marked increase in DNA double-strand breaks, as demonstrated by augmented levels of γ-H2AX (predominantly found in S-phase cells). In line with this, preliminary results from melanoma cells grown as spheroids, revealed the same tendency, with approximately 50% reduction in spheroid volume when combining the inhibitors. In vivo experiments using melanoma cells grown in SCID mice are currently ongoing. In conclusion, our results indicate a potential new role for inhibitors of Wee1 and Chk1 in treatment of malignant melanoma. Citation Format: Gry I. Magnussen, Vivi A. Florenes, Birgit Engesæter, Elisabeth Emilsen. Increased anticancer effect of combining Wee1 (MK1775) and Chk1 (AZD7762) inhibitors in malignant melanoma cell lines. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3417. doi:10.1158/1538-7445.AM2013-3417

A low proliferating fraction in solid tumors limits the effectiveness of cell cycle-dependent chemotherapeutic agents. To understand the molecular basis of such "kinetic" resistance we cultured tumor cells as multicellular spheroids and examined levels of p27Kip1, a cyclin-dependent kinase inhibitor known to be upregulated by intercellular contact in normal cells. When transferred from monolayer to three-dimensional culture, a consistent upregulation (up to 15-fold) of p27 protein was observed in a panel of mouse and human carcinoma cell lines. Antisense-oligonucleotide-mediated downregulation of p27 in EMT-6 mammary tumor cell spheroids reduced intercellular adhesion, increased cell proliferation, sensitized tumor cells to 4-hydroperoxycyclophosphamide, and restored drug- or radiation-induced cell-cycle perturbations repressed in spheroid culture. Our results implicate p27 as a regulator of drug resistance in solid tumors and suggest that tumor-targeted p27 antagonists may be useful chemosensitizers in conjunction with conventional anticancer therapy.

Homozygous deletions of the putative tumour-suppressor gene CDKN2, which encodes an inhibitor of cdk4, have been detected in a high percentage of cancer cell lines of various histological types. In the present study, 109 human sarcomas were examined for homozygous deletions and for mRNA expression levels of the CDKN2 gene. Altogether, deletions were found in only eight (7%) of the cases, but, interestingly, in two (of eight) malignant Schwannomas and in two (of five) rhabdomyosarcomas. In comparison, such deletions were seen in only one (of 21) osteosarcomas and in none of 20 MFHs and 21 liposarcomas. Notably, highly elevated CDKN2 mRNA levels were found in 33% of the sarcomas, whereas no detectable transcript was present in 12 normal tissues. Amplifications of CDK4 and CCND1 (cyclin D1) were observed in 11% and 4% of the sarcomas respectively, but never in tumours with CDKN2 deletions. The level of CDK4 mRNA expression was increased in nine tumours in addition to the 12 samples with CDK4 amplification. Increased levels of the cyclin D1 transcript was found in 37 cases, four with and 33 without amplification. The data indicate that aberrations of these functionally related genes, or in regulation of the expression of the kinase, the activator or the inhibitor, may participate in sarcoma development. Furthermore, the data suggest that homozygous CDKN2 deletions may be of dissimilar significance in different sarcoma subtypes. Images Figure 1 Figure 2

Malignant melanoma is the most increasing form of cancer worldwide, in addition to being the second most common cancer in young adults. Whereas the prognosis is good when detected early, there are no curative treatments once the cancer has spread (stage IV). Thus, there is a precarious need for new and more effective treatment options. Since the G1/S checkpoint of the cell cycle is dysfunctional in the majority of human cancers, the G2/M transition has been a focus of attention for targeted therapy the recent years. The Wee1 kinase is a major regulator of the G2/M checkpoint, and may halt the cell cycle by adding a negative phosphorylation on CDK1 (Tyr15). Additionally, Wee1 has a function in safeguarding the genome integrity during DNA synthesis. To assess the role of Wee1 in the progression of malignant melanoma we examined its expression in a panel of paraffin-imbedded patient derived tissues of benign nevi, primary- and metastatic melanoma. We found that Wee1 expression increased in the direction of malignancy, and had a strong, positive correlation with known markers of proliferation: Cyclin A (p Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3056. doi:1538-7445.AM2012-3056