Search

BackgroundRight- (R) and left-sided (L) metastatic colorectal cancer (mCRC) exhibit different clinical and molecular features. Several retrospective analyses showed that survival benefit of anti-EGFR-based therapy is limited to RAS/BRAF wt L-sided mCRC patients. Few data are available about third-line anti-EGFR efficacy according to primary tumor site.MethodsRAS/BRAF wt patients mCRC treated with third-line anti-EGFR-based therapy versus regorafenib or trifluridine/tipiracil (R/T) were retrospectively collected. The objective of the analysis was to compare treatment efficacy according to tumor site. The primary endpoint was progression-free survival (PFS); secondary endpoints were overall survival (OS), response rate (RR) and toxicity.ResultsA total of 76 RAS/BRAF wt mCRC patients, treated with third-line anti-EGFR-based therapy or R/T, were enrolled. Of those, 19 (25%) patients had a R-sided tumor (9 patients received anti-EGFR treatment and 10 patients R/T) and 57 (75%) patients had a L-sided tumor (30 patients received anti-EGFR treatment and 27 patients R/T). A significant PFS [7.2 vs 3.6 months, HR 0.43 (95% CI 0.2-0.76), p= 0.004] and OS benefit [14.9 vs 10.9 months, HR 0.52 (95% CI 0.28-0.98), p= 0.045] in favor of anti-EGFR therapy vs R/T was observed in the L-sided tumor group. No difference in PFS and OS was observed in the R-sided tumor group. A significant interaction according to primary tumor site and third-line regimen was observed for PFS (p= 0.05). RR was significantly higher in L-sided patients treated with anti-EGFR vs R/T (43% vs. 0%; p ConclusionsOur results demonstrated a different benefit from third-line anti-EGFR-based therapy according to primary tumor site, confirming the role of L-sided tumor in predicting benefit from third-line anti-EGFR vs R/T. At the same time, no difference was observed in R-sided tumor.

The Meet-URO score allowed a more accurate prognostication than the International Metastatic RCC Database Consortium (IMDC) for patients with pre-treated metastatic renal cell carcinoma (mRCC) by adding the pre-treatment neutrophil-to-lymphocyte ratio and presence of bone metastases.A post hoc analysis was carried out to validate the Meet-URO score on the overall survival (OS) of patients with IMDC intermediate-poor-risk mRCC treated with first-line nivolumab plus ipilimumab within the prospective Italian Expanded Access Programme (EAP). We additionally considered progression-free survival (PFS) and disease response rates. Harrell's c-index was calculated to compare the accuracy of survival prediction.Overall the EAP included 306 patients, with a median follow-up of 12.2 months, median OS was not reached, 1-year OS was 66.8% and median PFS was 7.9 months. By univariable analysis, both the IMDC score and the two additional variables of the Meet-URO score were associated with either OS or PFS (P0.001 for all comparisons). The four Meet-URO risk groups (G) had 1-year OS of 92%, 72%, 50% and 21% for G2 (29.1% of patients), G3 (28.8%), G4 (33.0%) and G5 (9.1%), respectively. OS was significantly shorter in each consecutive G (P = 0.001 for G3, P0.001 for both G4 and G5 compared to G2). Similarly, Meet-URO Gs 2-5 showed decreasing median PFS and response rates. The Meet-URO score showed the highest c-index for both OS (0.73) and PFS (0.67). Limitations include the post hoc nature of this analysis and the lack of a comparative arm to assess predictive value.The Meet-URO score appeared to show better prognostic classification than the IMDC alone in patients with mRCC at IMDC intermediate-poor risk treated with first-line nivolumab and ipilimumab.

10587 Background: GMs in DDR genes, in particular BRCA1/2, are associated with increased risk of cancer, including PDAC. Their identification is crucial for the clinical relevance, the best treatment choice, and the family implications in cancer prevention. However, there are few data regarding the epidemiology and the prognostic role of DDR GMs in PDAC patients (pts). The aim of our study is to determine the prevalence of DDR GMs, their correlation with clinicopathological features and their prognostic role. Methods: Unselected PDCA pts, assessed by BRCA1/2 GM analysis or multigenic panel at our Institution, were retrospectively analyzed. We divided the overall population into three groups based on GMs: pts with pathogenic variants (PVs), pts with variants of uncertain significance (VUS) and pts with no alterations. Clinicopathologic characteristics and treatment data were collected. The incidence of DDR GMs variants and their association with overall survival (OS) were evaluated. Univariate and multivariate analyses for OS were performed. Results: From September 2019 to August 2021, 200 PDAC pts were tested for DDR GMs: all pts were evaluated for BRCA 1/2; 140 pts were tested for further DDR GMs by a multigenic panel. Twenty-five pts (12.5%) had PVs, 45 (22.5%) pts had VUS and 130 (65%) pts had no GMs. BRCA 1-2 PVs were found in 10 pts (5%). Out of 91 pts with metastatic disease, the rate of PVs BRCA1/2 was 8.8%. Among 140 pts tested with multigenic panel, further PVs included: 7 (5%) ATM, 5 (3.6%) MUTYH, 1 (0.7%) TP53, 1 (0.7%) BARD1, and 1 (0.7%) MSH6. The most frequent VUS were: CHECK2 (5%), APC (3.6%), ATM (3.6%) and BRCA2 (3.6%). Regarding cancer family history, a statistically significant difference was reported between the 3 group (76% in PV pts, 82% in VUS pts and 60% in pts with no GMs; p 0.01). No difference was found concerning age (p 0.69), stage at diagnosis (p 0.31) and platinum-exposure (p 0.27). Out of 189 evaluable pts, median OS was 23 months. A significant difference in OS was observed in the 3 groups (30 months in PVs pts, 14 months in VUS pts and 24 months in pts with no GMs, p 0.0006). No factor, including the presence or the type of GMs, age, stage and family history, was significantly associated with OS at the multivariate analysis. Conclusions: In our study, we observed a high incidence of DDR GMs PV (12.5%), beyond BRCA 1/2, regardless of age, stage and family history. Despite retrospective nature of our analysis, small population, and single-institution evaluation, our findings confirm the importance of genetic testing for BRCA1/2 and, where available, of a multigenic test in all PDAC pts, due to the therapeutic implications and cancer risk prevention in patients relatives. The prognostic role of DDR GMs and the impact of VUS remain unclear.

e13641 Background: The management of CRC is complex, particularly in metastatic disease, where it is crucial the definition of disease burden, the assessment of radiological response and the identification of the right timing for potential radical surgery or loco-regional treatments. A correct CRC evaluation and the subsequent choice of the most appropriate treatment strategy, need, therefore, a MDT involving surgeons, oncologists, radiologists, radiation oncologists, endoscopists, gastroenterologists and pathologists. Based on such considerations, we investigated the impact of the MDT meeting in the management of CRC at our Institution. Methods: We retrospectively evaluated all the cases discussed at our MDT meeting between September 2019 and September 2021. We collected data, both pre- and post-MDT meeting, regarding radiology evaluation (disease control vs progression), surgical assessment (yes vs no) and radiotherapy evaluation (yes vs no). Primary endpoint was the overall rate of discrepancy in evaluation between pre- and post-MDT meeting. Results: Between September 2019 and September 2021, 696 cases were presented at our MDT meeting. The median age was 65 years (24-86), 391 (56%) patients were male and 553 (79%) patients had metastatic disease at diagnosis. After MDT meeting, a total of 214 decisions were modified, for an overall discrepancy rate of 31%. In particular, among 377 cases discussed for radiology evaluation, 110 decisions (29%) were modified after a central imaging review: 80 cases initially evaluated as progressed disease before MDT meeting were defined stable after MDT meeting, for a discrepancy rate of 73%. Regarding the 246 cases discussed for surgical assessment on primary tumor and/or metastatic sites, treatment strategy changed in 86 cases (35%). More specifically, 16 cases (19%), evaluated unresectable before MDT meeting, were then considered resectable after MDT meeting. Finally, among the 71 cases discussed for radiotherapy evaluation, treatment strategy changed in 18 cases (25%). Conclusions: Our analysis demonstrates a significant rate of discrepancy in radiology and/or surgical evaluation between pre- and post-MDT meeting. Our results show that a MDT allows a considerable modification in CRC management, maximizing the treatment strategy, in particular avoiding unnecessary changes in therapy and allowing surgery where possible.

Manuale di Oncologia Clinica rivolto agli studenti delle Facoltà di Medicina e Chirurgia e agli specializzandi in Oncologia Medica

e16180 Background: The prognosis of advanced biliary tract cancers (ABTCs) is poor with a 5 year overall survival (OS) lower than 20%. The standard of care first-line chemotherapy is the combination of cisplatin plus gemcitabine. The efficacy of second-line treatment is supported by few evidence and only one randomized phase III clinical trial is reported. The ABC-06 trial showed a minimal improvement in overall survival with FOLFOX compared to active symptoms control (ASC). Herein, we provide a retrospective analysis of patients treated with second-line treatment at our Institution investigating the impact of treatment regimen and possible prognostic or predictive factors. Methods: ABTCs patients receiving second-line treatment following a first-line chemotherapy with cisplatin plus gemcitabine were included in the analysis. The following variables were collected: gender; age (< 65 years vs ≥ 65 years); baseline ECOG PS (0-1 vs ≥2); second-line regimen (FOLFIRI vs FOLFOX); comorbidities (yes vs no); number of comorbidities (0-1 vs ≥ 2); number of metastatic sites (1 vs ≥2). Univariate and multivariate analysis for progression free survival (PFS) and OS were performed. Results: Fifty-one patients affected with ABTCs receiving second-line treatment between January 2016 and May 2021 were included in the analysis. The median age was 70 years (38-82), 39% (20) were males, 70% (36) were aged ≥ 65 years, ECOG PS was 0-1 in 86% (44) of patients; 39% (20) had ≥2 comorbidities; 60% (31) had ≥ 2 metastatic sites. Second-line regimen included FOLFIRI (28; 55%), FOLFOX (15; 29%), capecitabine (2; 4%) and experimental drugs (6; 12%). The overall population median PFS and OS at second-line were 3.5 months (median follow-up 11.4 months) and 8.8 months (median follow-up 22.6 months), respectively. Two patients (4%) achieved a partial response and the disease control rate was 39%. At the univariate and multivariate analysis, no variable was associated with PFS. At the univariate analysis, second-line regimen FOLFIRI (p = 0.03) and single metastatic site (p = 0.06) were associated with improved OS; at the multivariate analysis only the second-line regimen was confirmed associated with OS (p = 0.02). In particular, out of 43 evaluable patients, the median OS according to treatment (FOLFIRI vs FOLFOX) was 11.3 months versus 5.4 months (p = 0.019, HR 0.46, 95% CI: 0.18-0.88). Conclusions: Despite the retrospective analysis and the limited sample size, we confirm the importance of second-line chemotherapy in ABTCs patients, when feasible. Our results show that the second-line FOLFIRI regimen after a platinum-containing fist-line, was independently associated with improved OS. Given that the ABC-06 trial compared FOLFOX to ASC, a randomized trial of FOLFOX vs FOLFIRI as second-line would provide further information in this setting.

Introduction The clinico-pathological and molecular factors that drive the prognosis of invasive lobular breast carcinoma (ILC) are not entirely explored. In this regard, the development and validation of a prognostic model for ILC and the investigation of the distribution of molecular abnormalities (focusing on CDK4/6 alterations) according to prognosis were the aims of this study. Patients and methods Two clinico-pathological multi-center data-sets of early-stage ILC patients (Training/Validation Set, TS/VS) were gathered. A 3-class model was developed according to the multivariate analysis for disease-free-survival (DFS) and externally validated. Mutational, copy number variation and transcriptomic analyses by targeted next generation sequencing (NGS) were performed (and validated with quantitative PCR) in an explorative cohort of patients with poor and good prognosis. Results Data from overall 773 patients (TS/VS: 491/282) were gathered. The developed model significantly discriminated low/intermediate/high risk in the TS (10-years DFS: 76.3%/67.6%/39.8%, respectively, p, Highlights • The current multicenter analysis developed and validated a prognostic nomogram for early stage ILC. • A next-generation sequencing analysis was performed in prognostic ‘outlier’ patients. • CDK4 gain emerges as a potential negative prognostic factor in ILC patients. .

The epidermal growth factor receptor (EGFR) is frequently overexpressed in a wide range of human tumors; such overexpression often correlates with poor prognosis and worse clinical outcome. It has been demonstrated that the EGFR autocrine pathway plays a crucial role in human cancer since it contributes to a number of highly relevant processes in tumor development and progression, including cell proliferation, regulation of apoptotic cell death, angiogenesis and metastatic spread. For these reasons EGFR is one of the most studied and exploited targets for molecular cancer therapy. Two classes of anti-EGFR agents have entered clinical practice: monoclonal antibodies and small molecules targeting receptor tyrosine kinases. The possibility of combining conventional cytotoxic drugs with agents that specifically interfere with key pathways controlling cancer cell survival, proliferation, invasion and/or metastatic spread has generated wide interest. This could be a promising therapeutic approach for several reasons. First, the occurrence of cross-resistance is infrequent since the cellular targets and mechanisms of action of cytotoxic drugs and EGFR antagonists are different. Second, alterations in the expression and/or activity of genes that regulate mitogenic signals may either cause perturbation of cell growth or affect the sensitivity of cancer cells to conventional chemotherapy and radiotherapy. In fact, EGFR inhibitors have shown activity alone and/or in combination with conventional antitumor treatments.

Objectives To investigate the different outcomes in patients with metastatic renal cell carcinoma (mRCC) who receive a reduced first-line dose of sunitinib or pazopanib compared to those who continue at the standard dose. Patients and methods All the patients treated in 11 oncological centers in Italy for mRCC who started first-line treatment with sunitinib or pazopanib at the standard dose. Descriptive statistical tests were used to highlight differences among groups. Survival was estimated by the Kaplan-Meier method and compared across the groups using log-rank tests, the Cox proportional hazards model adjusted for statistically significant variables was also done. Results A total of 591 patients were included in the study. Of these, 45.7% received a reduced dose of sunitinib or pazopanib after a median treatment time of 3.6 months at the standard dose. The median overall survival in the patients who continued to receive the standard dose was 24.0 months compared to 49.4 months for those who received a reduced dose (hazard ratio = 1.80; 95% CI: 1.42–2.29; P Only 45% of the patients received second-line therapy: 42.5% had an mTOR and 54.1% a tyrosine kinase inhibitor. Second-line overall survival was 19.8 and 11.8 months, respectively, in the patients who received, or did not, a reduced dose during first-line therapy (P = 0.007). Conclusions Toxicity-related dose reduction is a common event in mRCC patients who have started first-line therapy with either sunitinib or pazopanib. This is positively related to the outcomes of both first- and second-line therapy.

Prostate cancer (PCa) shows a broad spectrum of biological and clinical behavior, which represents the epiphenomenon of an extreme genetic heterogeneity. Recent genomic profiling studies have deeply improved the knowledge of the genomic landscape of localized and metastatic PCa. The AR and PI3K/Akt/mTOR signaling pathways are the two most frequently altered, representing therefore interestingly targets for therapy. Moreover, somatic or germline aberrations of DNA repair genes (DRGs) have been observed at high frequency, supporting the potential role of platinum derivatives and PARP inhibitors as effective therapeutic strategies. In the future, the identification of driver mutations present at a specific stage of the disease, the classification PCa based on specific molecular alterations, and the selection of the most appropriate therapy based on biomarkers predictors of response represent the foundations for an increasingly more accurate personalized medicine.

Prostate cancer is a common malignancy with highly molecular heterogeneity responsible for a wide spectrum of clinical behavior. To date, several treatment options are available, whose selection is currently based mainly on clinical criteria. Given the weakness of conventional imaging and PSA assay, the identification of a prognostic and predictive biomarker for choosing the appropriate treatment and monitoring its efficacy is a very topical issue in prostate cancer management. Circulating tumor cells (CTCs) have substantial promise for early tumor diagnosis, disease recurrence and metastatic spread monitoring as well as for biological tumor characterization, thus representing a reliable translational real-time biomarkers of prostate cancer. This paper summarized the main data available about CTCs detection, their prognostic value, and their potential predictive role for metastatic prostate cancer patients management.

The new WHO 2016 classification of renal neoplasia encounters the new entity called “clear cell papillary renal cell carcinoma” (ccpRCC). The ccpRCC has been long included as a subtype of clear cell RCC histotype and it actually ranges from 2 to 9% in different routinely available cohort of renal carcinomas. Of important note, ccpRCC does not show any recurrences or metastases or lymph-node invasion and the outcome is always good. We reviewed twenty-four publications with available follow-up for patients (no. 362) affected by clear cell papillary RCCs/renal adenomatoid tumours and notably ccpRCC harbors an indolent clinical behavior after a mean of 38 months (3,5 years) of follow-up. This paper reviews the histological, molecular and clinical features characterizing ccpRCC, with the goal of focusing the knowledge of the benign fashion of this new tumour entity, supporting the idea of a new renal cell adenoma recruited morphologically from ex conventional clear cell RCC tumours.

Purpose: Resistance to anti-HER2 monoclonal antibody trastuzumab is a relevant issue in breast cancer patients. Among the mechanisms implicated in trastuzumab resistance, increasing evidence supports a role of tumor microenvironment. We previously found that a novel toll-like receptor 9 agonist, referred to as immune modulatory oligonucleotide (IMO) and currently under clinical investigation, acts through epidermal growth factor receptor (EGFR) and shows direct antiangiogenic effects by cooperating with anti-EGFR or anti-VEGF drugs, thus interfering with cancer cells and microenvironment.Experimental Design: In this study, we used KPL-4 and JIMT-1 trastuzumab-resistant breast cancer cells to evaluate the combination IMO plus trastuzumab as a therapeutic option for trastuzumab-resistant breast cancers.Results: IMO inhibits KPL-4 and JIMT-1 xenografts growth and potentiates trastuzumab antitumor effect, with complete suppression of tumor growth, potent enhancement of trastuzumab-mediated antibody-dependent cell-mediated cytotoxicity, and strong inhibition of EGFR/HER2-related signaling. In KPL-4 xenografts, IMO alone interferes with HER signal transduction, whereas trastuzumab is ineffective. IMO induces an HER-dependent signal inhibition also in vitro by modulating a functional interaction between toll-like receptor 9 and HER receptors occurring at membrane level. Finally, IMO plus trastuzumab produces a cooperative antiangiogenic effect related to suppression of endothelial HER-related signaling.Conclusions: We showed a cooperative effect of IMO plus trastuzumab in trastuzumab-resistant breast cancers due to IMO direct antitumor and antiangiogenic activity and antibody-dependent cell-mediated cytotoxicity enhancement. Moreover, we provided first evidence of a toll-like receptor 9/HER interaction at membrane level as novel mechanism of action. Altogether, we propose IMO plus trastuzumab as an effective strategy in trastuzumab-resistant breast cancers. (Clin Cancer Res 2009;15(22):692130)

Mouse models of cancer have consistently been used to qualify new anti-cancer drugs for development of human clinical trials. The most used models are xenografts of human tumors grown subcutaneously in immunodeficient mice such as athymic (nude) or severe combined immune deficient (SCID) mice. However, the number of anti-cancer agents that fail in the clinic far outweighs those considered effective, suggesting that the selection procedure for progression of molecules into the clinic requires improvement. This has provoked considerable skepticism about the value of using such preclinical models. As a result, a shift has occurred towards developing and using spontaneous mouse tumor arising in transgenic and/or knockout mice engineered to recapitulate various genetic alterations thought to be causative of specific types of human cancers. Alternatively, the option has been to improve human tumor xenograft models by using orthotopic transplantation and, therefore, promotion of metastatic spread of the resultant ‘primary’ tumors. Here we review the value and the limitations of xenograft models and their role in developing new anti-cancer treatments.

Purpose This phase II study investigated the efficacy and safety of cetuximab combined with standard oxaliplatin-based chemotherapy (infusional fluorouracil, leucovorin, and oxaliplatin [FOLFOX-4]) in the first-line treatment of epidermal growth factor receptor–expressing metastatic colorectal cancer (mCRC). Patients and Methods The activity of cetuximab plus oxaliplatin was investigated in colon cancer cell lines and xenograft models. In the clinical study, patients with mCRC received on day 1 of a 14 day cycle, cetuximab (initial dose 400 mg/m2 during week 1, then 250 mg/m2 weekly) followed by FOLFOX-4 (oxaliplatin 85 mg/m2 on day 1; leucovorin 200 mg/m2 on days 1 and 2, followed by fluorouracil 400 mg/m2 bolus then 600 mg/m2 intravenous infusion during 22 hours on days 1 and 2). Results The preclinical studies confirmed the supra-additive activity of cetuximab to oxaliplatin. In the clinical study, 43 patients were included, with a median age of 65 years (range, 43 to 78 years). Response rates (RRs) were 79% (unconfirmed) and 72% (confirmed), with 95% disease control. Median progression-free survival (mPFS) and median duration of response were 12.3 and 10.8 months, respectively. Ten patients (23%) underwent resection with curative intent of previously unresectable metastases. After a median follow-up of 30.5 months, median overall survival (mOS) was 30.0 months. Cetuximab did not increase the characteristic toxicity of FOLFOX-4 and was generally well tolerated. Conclusion Cetuximab in combination with FOLFOX-4 is a highly active first-line treatment for mCRC, showing encouraging RR, mPFS, and mOS values. The treatment resulted in a high resectability rate, which could potentially result in an improved cure rate. This combination is under phase III development.

ABSTRACT The standard of care for patients with local advanced or metastatic urothelial carcinoma is chemotherapy. However, results with this are rather disappointing, and validated prognostic factors and biomarkers of tumor response, which are useful in the decision-making process, are still lacking. PubMed databases were searched for articles published until November 2013. Several promising clinical and biological candidate prognostic factors or markers of tumor response to first- or second-line therapy, such as hemoglobin, performance status, visceral metastasis and ERCC1, hENT1 and EMT markers, have been identified and described in this article. In summary, clinical parameters and molecular profiling could revolutionize the management of local advanced or metastatic urothelial cancer, but an improvement in individualized therapeutic approaches still seems distant.

Purpose: Standard treatments have modest effect against pancreatic cancer, and current research focuses on agents targeting molecular pathways involved in tumor growth and angiogenesis. This study investigated the interactions between ZD6474, an inhibitor of tyrosine kinase activities of vascular endothelial growth factor receptor-2 and epidermal growth factor receptor (EGFR), gemcitabine, and ionizing radiation in human pancreatic cancer cells and analyzed the molecular mechanisms underlying this combination.Experimental Design: ZD6474, ionizing radiation, and gemcitabine, alone or in combination, were given in vitro to MIA PaCa-2, PANC-1, and Capan-1 cells and in vivo to MIA PaCa-2 tumor xenografts. The effects of treatments were studied by the evaluation of cytotoxicity, apoptosis, cell cycle, EGFR and Akt phosphorylation, modulation of gene expression of enzymes related to gemcitabine activity (deoxycytidine kinase and ribonucleotide reductase), as well as vascular endothelial growth factor immunohistochemistry and microvessel count.Results: In vitro, ZD6474 dose dependently inhibited cell growth, induced apoptosis, and synergistically enhanced the cytotoxic activity of gemcitabine and ionizing radiation. Moreover, ZD6474 inhibited phosphorylation of EGFR and Akt and triggered cell apoptosis. PCR analysis showed that ZD6474 increased the ratio between gene expression of deoxycytidine kinase and ribonucleotide reductase. In vivo, ZD6474 showed significant antitumor activity alone and in combination with radiotherapy and gemcitabine, and the combination of all three modalities enhanced MIA PaCA-2 tumor growth inhibition compared with gemcitabine alone.Conclusions: ZD6474 decreases EGFR and Akt phosphorylation, enhances apoptosis, favorably modulates gene expression in cancer cells, and acts synergistically with gemcitabine and radiotherapy to inhibit tumor growth. These findings support the investigation of this combination in the clinical setting.

Purpose: Glioblastoma multiforme is an aggressive disease in which vascular endothelial growth factor (VEGF) and the EGF receptor (EGFR) are implicated in tumor growth, relapse, and resistance to radiotherapy and chemotherapy. The VEGF receptors VEGFR-1 (flt-1) and VEGFR-2 (KDR), typically present on endothelial cells, have also been identified in human glioblastoma tissues and cell lines. In addition, EGFR is dysregulated in the majority of human glioblastomas and EGFR overexpression correlates with shorter survival. We have investigated the antitumor and antiangiogenic effect of ZD6474, an inhibitor of both VEGFR and EGFR signaling as a single agent and in combination with ionizing radiation. Experimental Design: We have used ZD6474 and/or ionizing radiation in human glioblastoma cell lines D54 and U251 in vitro and in nude mice bearing established xenografts. The effects of treatment on tumor blood vessels and protein expression were evaluated by Western blot and immunohistochemistry. Results: As single agents, ionizing radiation and ZD6474 caused a dose-dependent inhibition of soft agar growth in D54 and U251 cell lines, whereas a cooperative effect was obtained in combination. Treatment of mice bearing D54 xenografts with either ZD6474 or radiotherapy alone caused tumor growth inhibition that was reversible upon treatment cessation. A cooperative and long-lasting inhibition of tumor growth was obtained with ZD6474 in combination with concomitant radiotherapy. The antiproliferative effect was accompanied by inhibition of VEGF protein expression and inhibition of angiogenesis as measured by vessel counting. Conclusion: This study shows the antitumor activity of ZD6474 in combination with ionizing radiation in glioblastoma both in vitro and in vivo, and provides a scientific rationale to evaluate ZD6474 alone or in combination with radiotherapy in patients affected by this disease.

The MDM2 oncogene is overexpressed in many human cancers, including sarcomas, certain hematologic malignancies, and breast, colon and prostate cancers. The p53-MDM2 interaction pathway has been suggested as a novel target for cancer therapy. To that end, several strategies have been explored, including the use of small polypeptides targeted to the MDM2-p53 binding domain, anti-MDM2 antisense oligonucleotides, and natural agents. Different generations of anti-human-MDM2 oligonucleotides have been tested in in vitro and in vivo human cancer models, revealing specific inhibition of MDM2 expression and significant antitumor activity. Use of antisense oligos potentiated the effects of growth inhibition, p53 activation and p21 induction by several chemotherapeutic agents. Increased therapeutic effectiveness of chemotherapeutic drugs in human cancer cell lines carrying p53 mutations or deletions have shown the ability of MDM2 inhibitors to act as chemosensitizers in various types of tumors through both p53-dependent and p53-independent mechanisms. Inhibiting MDM2 appears to also have a role in radiation therapy for human cancer, regardless of p53 status, providing a rationale for the development of a new class of radiosensitizers. Moreover, MDM2 antisense oligonucleotides potentiate the effect of epidermal growth factor receptor (EGFR) inhibitors by affecting in vitro and in vivo proliferation, apoptosis and protein expression in hormonerefractory and hormone-dependent human prostate cancer cells. These data support the development, among other MDM2 inhibitors, of anti-MDM2 antisense oligonucleotides as a novel class of anticancer agents, and suggest a potentially relevant role for the oligonucleotides when integrated with conventional treatments and / or other signaling inhibitors in novel therapeutic strategies.

Background: The current study investigated the clinical benefit, the impact on biochemical and objective response and tolerability of weekly docetaxel with vinorelbine (VIN-DOX) in symptomatic patients with hormone refractory prostate cancer (HRPC). Methods: Patients were treated with docetaxel 25mg/m 2 and vinorelbine 20mg/m 2 , intravenously for 6 consecutive weeks followed by a 2 week rest repeatedly until disease progression. Clinical benefit evaluations, based on Karnofsky performance status (KPS) and pain measure, were assessed weekly during therapy. A clinical benefit response was defined as a sustained (≥4 weeks) improvements in one of these parameters. Changes in prostate-specific antigen (PSA) levels, tumoral response and toxicity also were evaluated. Results: 19 men (median age 68 years), were treated. Overall, 42% of patients achieved a KPS significant change and positive pain response; 47% achieved a 50% or greater reduction in PSA. The objective response rate was observed in 2 of 9 patients with measurable disease (22%). The most important toxicity was neutropenia (Grade 3=32%). Conclusions: The combination of weekly VIN-DOX appears to be feasible. VIN-DOX was found to be associated with improvement in clinical benefit response and biochemical response and well tolerated as first line treatment in HRPC.

Objectives Pemetrexed has been approved for the treatment of advanced non-small cell lung cancer (NSCLC) non-squamous histology, both as first- and second-line therapy. Pemetrexed is an antimetabolite drug, that inhibits enzymes involved in nucleotides bio-synthesis arresting cancer cells cycle. The aim of this study was the evaluation of the impact of pemetrexed on erythrocyte mean corpuscular volume (MCV) change and its possible correlation with disease control rate (DCR), progression free (PFS) and overall survival (OS) in NSCLC patients. Materials and methods A retrospective collection of clinical and laboratory data (including basal MCV and maximum MCV occurred during therapy) in advanced NSCLC patients treated with pemetrexed at seven Italian centers was performed. Nonparametric tests, univariate and multivariate analysis were used to assess correlation between variables and to identify predictors of outcomes. Results 191 patients were enrolled: median age 62, 60% male, 61% performance status (PS) 0, 91% stage IV, 88% adenocarcinoma histotype, 25% never smoker, 62% received pemetrexed as first-line. Mean MCV significantly increased from basal (89 fL) to during treatment (94 fL), with mean ΔMCV = 4 fL. The median time from therapy start to maximum MCV was 2.2 months. Median PFS was 7 [CI95% 6–8] and 3 [CI95% 2–4] months [ P = 0.0016], and median survival was 17 [CI95% 12–23] and 10 [CI95% 8–12] months [ P = 0.02], in patients with ΔMCV > 5 fL ( n = 80) and ΔMCV ≤ 5 fL ( n = 111), respectively. Multivariate analysis identified age ≥62, PS 0, adenocarcinoma histology and ΔMCV > 5 fL as independent predictors of longer PFS. A ΔMCV > 5 fL significantly correlates with DCR. Conclusion Pemetrexed induces macrocytosis. ΔMCV > 5 fL on pemetrexed therapy correlated with better DCR, PFS and OS. These results deserve further validation in prospective studies.

Metastatic disease occurs in a significant percentage of patients with renal cell carcinoma (RCC) and is usually associated with an overall poor prognosis. However, not all of the sites of metastases seem to have the same prognostic significance in patients receiving targeted agents. Indeed, patients with lung-only metastases seem to present a better survival than patients with other sites, whereas liver and bone metastases are associated with a worst prognosis. Some clinical studies suggest that metastatic sites are more responsive than primary tumors. This event may be due to intratumor heterogeneity in terms of somatic mutations, chromosome aberrations, and tumor gene expression, primarily centered around Von Hippel–Lindau (VHL) pathway, such as VHL mutations, HIF levels, vascular endothelial growth factor (VEGF) isoforms, and VEGF receptor levels. Nevertheless, these data do not completely explain the discordant biological behavior between primary tumor and metastatic sites. Understanding the causes of this discordance will have profound consequences on translational research and clinical trials in RCC. In this review, we overview current data on the differences between primary RCC and metastases in terms of drug target expression and clinical/radiological response to targeted agents, thus describing the prognostic role of different metastatic sites in RCC patients.

MDA-468 human breast cancer cells overexpress the EGFR and exhibit a functional TGFalpha-EGFR autocrine pathway. Loss of EGFR expression following stable transfection with an antisense EGFR cDNA containing plasmid down-regulates type I cAMP-dependent protein kinase (PKAI) expression with acquisition of cell growth resistance to the PKAI inhibitor 8-Cl-cAMP. These results suggest that PKAI expression and function are controlled by a TGFalpha-EGFR autocrine pathway in human breast cancer cells overexpressing the EGFR.

The prognosis of patients affected by metastatic renal cell carcinoma (mRCC) has improved markedly with targeted therapies. Unfortunately, 20-25% of the patients are refractory to treatment at the first response assessment and most patients will acquire drug resistance during the treatment. Moreover, current data on the clinical activity of targeted agents in poor risk or non-clear-cell mRCC patients are inconclusive because of the absence of prospective trials. Therefore, there are still several patients in need of new therapeutic approaches to improve clinical outcomes. Kidney cancer is historically considered resistant to chemotherapy on the basis that the results of phase II trials have not always been promising. We carried out a systematic review of both monochemotherapy and polychemotherapy alone or combined with immunotherapy or targeted agents in mRCC to define the state of the art and to evaluate further clinical research fields. All retrospectives, phase I/dose finding, phase II and phase III studies on chemotherapy in mRCC, published in the literature from January 2003 to November 2012, with at least 20 patients enrolled, were evaluated. Although the results of clinical trials have often been disappointing, in selected cases of mRCC, chemotherapy may have a promising antitumor activity, particularly when there are sarcomatoid differentiation features, or in highly progressive disease where the combination of doxorubicine plus gemcitabine or capecitabine has yielded interesting results. Chemotherapy may play a role in mRCC, whereas targeted agents and immunotherapy have not yielded durable and satisfactory results; further studies are needed. © 2013 Wolters Kluwer Health | Lippincott Williams & Wilkins.

8-Cl-cAMP is a novel agent able to inhibit the growth of a wide variety of cancer cell types in vitro and in vivo by interfering with the protein kinase A type I (PKAI), a protein directly involved in mitogenic signalling and neoplastic transformation. In a recent phase I study conducted in cancer patients we have demonstrated that 8-Cl-cAMP, at doses devoid of toxicity, may achieve plasma concentrations in a range previously shown effective for cancer cell growth inhibition. In the present study we have investigated the effect of 8-Cl-cAMP in association with cytotoxic drugs acting by different mechanisms of action on the growth of LS174T and GEO human colon cancer cells. We here demonstrate that 8-Cl-cAMP administered after the cytotoxic drugs does not interfere with their growth inhibitory effect but rather is additive with most of them. Moreover, a synergistic effect was observed when 8-Cl-cAMP was administered after cisplatin or paclitaxel. The sequence of treatment seems to be important since pretreatment with 8-Cl-cAMP interferes with the effect of the cytoxic drugs. These results demonstrate that 8-Cl-cAMP is not only able to induce cell growth inhibition when used alone but also exhibit the capacity to enhance the efficacy of different cytotoxic drugs.

Background: The ‘targeted therapy’ has been defined as an innovative therapy designed to interfere with molecular targets playing a critical role in tumour growth or progression. The epidermal growth factor receptor (EGFR) is a tyrosine kinase receptor mediating the effect of growth factors both in physiological and pathological conditions; aberrations in the EGFR may result in the development of a tumour phenotype. Objective: To summarise the current state of the development of anti-EGFR drugs. Methods: Patent literature and preclinical/clinical studies about EGFR inhibitors are analysed. Conclusion: Some monoclonal antibodies and small-molecule tyrosine kinase inhibitors have been approved in several countries for the treatment of various human cancer types; moreover, more than ten EGFR-targeting agents are actually in advanced clinical development.

Ovarian carcinomas overexpress endothelin A receptors (ETAR) and epidermal growth factor (EGF) receptor (EGFR). In these cells, endothelin-1 (ET-1) triggers mitogenic and invasive signaling pathways that are in part mediated by EGFR transactivation. Combined targeting of ETAR, by the specific ETAR antagonist ZD4054, and of EGFR by the EGFR inhibitor gefitinib (IRESSA), may offer improvements in ovarian carcinoma treatment. In HEY and OVCA 433 ovarian carcinoma cells, ET-1 or EGF induced rapid activation of EGFR, p42/44 mitogen-activated protein kinase (MAPK), and AKT. ZD4054 was able to reduce the ET-1–induced EGFR transactivation. Gefitinib significantly inhibited EGF- and ET-1–induced EGFR phosphorylation, but incompletely reduced the ET-1–induced activation of downstream targets. ZD4054 plus gefitinib resulted in a greater inhibition of EGFR, MAPK, and AKT phosphorylation, indicating the critical role of these interconnected signaling proteins. ZD4054 effectively inhibited cell proliferation, invasiveness, and vascular endothelial growth factor (VEGF) secretion. Concomitantly, ZD4054 enhanced apoptosis and E-cadherin promoter activity and expression. In both cell lines, the drug combination resulted in a significant decrease in cell proliferation (65%), invasion (52%), and VEGF production (50%), accompanied by a 2-fold increase in apoptosis. The coadministration of ZD4054 enhanced the efficacy of gefitinib leading to partial (82%) or complete tumor regression on HEY ovarian carcinoma xenografts. Antitumor effects were paralleled by biochemical and immunohistologic evidence of decreased vascularization, Ki-67, matrix metalloproteinase-2 (MMP-2), VEGF, MAPK and EGFR, and enhanced E-cadherin expression. The cross-signaling between the EGFR/ETAR pathways provides a rationale to combine EGFR inhibitors with ETAR antagonists, identifying new effective therapeutic opportunities for ovarian cancer. [Cancer Res 2007;67(13):6351–9]

Accumulating evidence suggests that cancer can be envisioned as a "signaling disease", in which alterations in the cellular genome affect the expression and/or function of oncogenes and tumour suppressor genes. This ultimately disrupts the physiologic transmission of biochemical signals that normally regulate cell growth, differentiation and programmed cell death (apoptosis). From a clinical standpoint, signal transduction inhibition as a therapeutic strategy for human malignancies has recently achieved remarkable success. However, as additional drugs move forward into the clinical arena, intrinsic and acquired resistance to "targeted" agents becomes an issue for their clinical utility. One way to overcome resistance to targeted agents is to identify genetic and epigenetic aberrations underlying sensitivity/resistance, thus enabling the selection of patients that will most likely benefit from a specific therapy. Since resistance often ensues as a result of the concomitant activation of multiple, often overlapping, signaling pathways, another possibility is to interfere with multiple, cross-talking pathways involved in growth and survival control in a rational, mechanism-based, fashion. These concepts may be usefully applied, among others, to agents that target two major signal transduction pathways: the one initiated by epidermal growth factor receptor (EGFR) signaling and the one converging on mitogen-activated protein kinase (MAPK) activation. Here, we review the molecular mechanisms of sensitivity/resistance to EGFR inhibitors, as well as the rationale for combining them with other targeted agents, in an attempt to overcome resistance. In the second part of the paper, we review MAPK-targeted agents, focusing on their therapeutic potential in haematologic malignancies, and examine the prospects for combinations of MAPK inhibitors with cytotoxic agents or other signal transduction-targeted agents to obtain synergistic anti-tumour effects.

Molecularly targeted, customized therapies are designed based on the molecular portraits of cancer tissue. The efficacy of targeted therapy in individual patients depends on the contribution of single individual cancer cells within the context of their microenvironment. We have developed an in vitro model of human mammary epithelial-stromal cocultures to answer specific clinical questions related to breast cancer, to provide a tool with which to identify a signature in each breast tumor, and to identify the metabolic molecular targets of therapy in an attempt to optimize the efficacy of targeted therapy in each patient. Fifty-five human breast cancer samples were obtained through surgery. Epithelial and stromal cells were isolated from tissue specimens by differential centrifugation, and cryopreserved. Western blot analysis and RT-PCR were used to identify the tissue-specific expression patterns of cancer cells. Dose-response curves were constructed for the aromatase inhibitor formestane and for herceptin, and a 3-(4,5-dimethylthiazol)-2,5-diphenyltetrazolium bromide assay was done for combined treatment. We collected and cryopreserved, for future use, viable living cells from 55 breast tumor specimens from which we derived short-term cocultures. The presence of cytokeratins and vimentin was evaluated in 20 samples, and pHER2/neu and aromatase were evaluated in 4 cocultures. Formestane and herceptin had a cumulative growth-inhibitory effect on cocultures expressing epidermal growth factor receptors and aromatase. The in vitro model of human mammary epithelial-stromal cocultures reported herein can be used to examine, and to store, a patient's tumor-derived, living cells that retain the characteristics of the mother-tissue and respond, in vitro, to therapy. [Mol Cancer Ther 2007;6(12):3091–100]

Growth factor signals are propagated from the cell surface, through the action of transmembrane receptors, to intracellular effectors that control critical functions in human cancer cells, such as differentiation, growth, angiogenesis, and inhibition of cell death and apoptosis. Several kinases are involved in transduction pathways via sequential signalling activation. These kinases include transmembrane receptor kinases (e.g., epidermal growth factor receptor EGFR); or cytoplasmic kinases (e.g., PI3 kinase). In cancer cells, these signalling pathways are often altered and results in a phenotype characterized by uncontrolled growth and increased capability to invade surrounding tissue. Therefore, these crucial transduction molecules represent attractive targets for cancer therapy. This review will summarize current knowledge of key signal transduction pathways, that are altered in cancer cells, as therapeutic targets for novel selective inhibitors. The most advanced targeted agents currently under development interfere with function and expression of several signalling molecules, including the EGFR family; the vascular endothelial growth factor and its receptors; and cytoplasmic kinases such as Ras, PI3K and mTOR.

Biphosphonates (BPs) are widely used to inhibit osteoclastic activity in malignant diseases such as bone metastatic breast and prostate carcinoma. Recent studies reported that BPs could also cause a direct antitumor effect, probably due to their ability to interfere with several intracellular signalling molecules. The enzyme cyclooxygenase-2 (COX-2) and the epidermal growth factor receptor (EGFR) play an important role in the control of cancer cell growth and inhibitors of COX-2 and EGFR have shown antitumor activity in vitro and in vivo in several tumor types. We, and others, have previously shown that EGFR and COX-2 may be directly related to each other and that their selective inhibitors may have a cooperative effect. In the present study we have evaluated the combined effect of zoledronic acid, the most potent nitrogen-containing BP, with the COX-2 inhibitor SC-236 and the selective EGFR-tyrosine kinase inhibitor gefitinib, on breast and prostate cancer models in vitro and in xenografted nude mice. We show that combination of zoledronic acid with SC-236 and gefitinib causes a cooperative antitumor effect accompanied by induction of apoptosis and regulation of the expression of mitogenic factors, proangiogenic factors and cell cycle controllers both in vitro and in xenografted nude mice. The modulatory effect on protein expression and the inhibitory effect on tumor growth is much more potent when the three agents are used together. Since studies are ongoing to explore the antitumor effect of zoledronic acid, our results provide new insights into the mechanism of action of these agents and a novel rationale to translate this feasible combination treatment strategy into a clinical setting.

BACKGROUND: Epidermal growth factor receptor (EGFR) inhibitors are in clinical development in cancer treatment. Preclinical studies have shown potential antitumor efficacy of these agents in combination with chemotherapy or with radiotherapy. However, controversial results have been obtained in different clinical trials. MATERIALS AND METHODS: The effects on proliferation, cell cycle distribution and induction of apoptosis of three different anti-EGFR agents (gefitinib, ZD6474, cetuximab) were evaluated in different sequences of combination with either a platinum derivative (cisplatin, carboplatin, oxaliplatin) or a taxane (docetaxel, paclitaxel) in KYSE30 cells, a model of a human cancer cell line with a functional EGFR autocrine pathway. RESULTS: The combination of a cytotoxic drug with an EGFR inhibitor caused different antiproliferative effects on KYSE30 cancer cells depending on the treatment schedule. An antagonistic effect was observed when treatment with each EGFR inhibitor was done before chemotherapy. In contrast, a synergistic antiproliferative activity was obtained when chemotherapy was followed by treatment with EGFR antagonists. This effect was accompanied by potentiation of apoptosis and arrest of the surviving cancer cells in the G(2)/M phases of the cell cycle. CONCLUSIONS: This study provides a rationale for the evaluation of a potentially synergistic sequence of cytotoxic drugs and EGFR inhibitors in a clinical setting.

The epidermal growth factor receptor (EGFR) autocrine pathway plays a crucial role in human cancer since it contributes to a number of highly relevant processes in tumor development and progression, including cell proliferation, regulation of apoptotic cell death, angiogenesis and metastatic spread. Among a variety of approaches used to target EGFR signaling, EGFR blocking monoclonal antibodies and small molecular weight EGFR tyrosine kinase compounds have been successfully developed. The results of a large body of preclinical studies and clinical trials suggest that targeting the EGFR could represent a significant contribution to cancer therapy. Both types of agent exert a significant antiproliferative activity when used alone or in combination with conventional antitumor treatments, such as chemotherapy or radiation therapy. Although the advanced clinical development of EGFR blocking drugs demonstrates their efficacy in some human metastatic diseases, such as lung, head and neck and colorectal cancers, the issue of constitutive resistance in a large number of patients and the development of acquired resistance in the responders remains an unexplored subject of investigation. Recent evidence suggests the role of specific activating mutations within the tyrosine kinase domain of EGFR to explain the dramatic responses to small molecule tyrosine kinase inhibitors in a subgroup of lung cancer patients. However, the intrinsic molecular mechanisms of resistance to these drugs are still unclear. This review will focus on the preclinical findings on therapeutic resistance to EGFR targeting agents.

The currently available treatment of cancer patients is based on the use of cytotoxic drugs and/or of ionizing radiations, which have potent antitumor activity, but also cause clinically relevant side effects, since they affect cellular targets that are common to both cancer cells and normal proliferating cells. In the past 20 years, the discoveries on the molecular mechanisms of cancer development and progression have prompted the search for agents which are more selective for cancer cell molecular targets. The possibility of combining conventional cytotoxic drugs with novel agents that specifically interfere with key pathways controlling cancer cell survival, proliferation, invasion and/or metastatic spreading has generated a wide interest. This could be a promising therapeutic approach for several reasons. First, since the cellular targets for these agents and their mechanism(s) of action are different from those of cytotoxic drugs, it is possible for their combination with chemotherapy without cross-resistance. Second, alterations in the expression and/or the activity of genes that regulate mitogenic signals not only can directly cause perturbation of cell growth, but also may affect the sensitivity of cancer cells to conventional chemotherapy and radiotherapy. In this review, we will discuss the biologic bases of the combination of molecular targeted drugs with conventional medical cancer treatments and the available results of the first series of clinical trials in cancer patients.

The epidermal growth factor receptor (EGFR) is a rational target for cancer therapy because it is commonly expressed at a high level in a variety of solid tumours and it has been implicated in the control of cell survival, proliferation, metastasis and angiogenesis. However, despite evidence to suggest that EGFR expression is associated with a poor prognosis in some tumours (e.g. breast, head and neck carcinomas), the situation is by no means clear-cut. A number of issues are worthy of particular consideration, including how EGFR is measured and whether these assays are sensitive and reproducible, which mechanisms other than increased EGFR expression might cause the EGFR signalling drive to be increased, and the relationship, if any, between EGFR expression and the response to EGFR-targeted agents.

The development of prostate cancer and the progression from a normal prostate epithelium to androgen-dependent cancer and eventually to hormone-refractory prostate cancer is a multistep process involving several changes in the function of different growth-regulatory signals. In the past 10 years, conflicting results on epidermal growth factor receptor (EGFR) family expression in prostate cancer have been reported. These differences may result from technical differences, lack of standardization of immunohistochemical assays, or different scoring methodologies. Recently, 4 studies have shown experimental evidence of a role of the EGFR family, particularly ErbB-2, in the development of prostate cancer and, more specifically, in the progression to hormone-refractory clinical behavior. These 4 studies were similar in some relevant aspects, such as the patient population. In fact, the patients in each study were divided into 3 groups that represent the progression of prostate cancer. In 3 of 4 studies, a statistically significant increase in ErbB-2 expression was detected by immunohistochemistry in the progression from hormonedependent to hormone-independent disease. The expression of EGFR was also evaluated in 1 of the 4 studies. In a recent report from our group, a significant increase in EGFR expression was observed in patients treated with radical surgery, in patients who received hormonal therapy as primary therapy before radical prostatectomy, and, finally, in patients with metastatic and hormone-refractory disease. It has been proposed that EGFR family receptors and androgen receptors function synergistically in the absence of androgen suggesting cross-talk between the ErbB-2 and androgen receptor pathways, and that mitogen-activated protein kinase and phosphatidylinositol 3- kinase can be considered the transduction pathways. Finally, clinical trials are currently in progress in patients with prostate cancer testing novel agents that selectively interfere with these receptors, such as trastuzumab, an anti–ErbB-2 monoclonal antibody, and gefitinib (ZD1839, Iressa™), a small-molecule selective EGFR tyrosine kinase inhibitor.

Background: DNA damage caused by platinum agents is frequently followed by induction of topoisomerase I, providing a rationale for use of platinum-based compounds with topoisomerase I inhibitors. Materials and methods: We studied the effect of a sequential schedule of oxaliplatin on day 1 and topotecan on days 2–5, in human colon and ovarian cancer cells in vitro, in nude mice bearing human cancer xenografts and finally in cancer patients in a phase I trial. Results: We demonstrated a supra-additive effect of this combination on inhibition of colony formation and induction of apoptosis in vitro. We then demonstrated that the two agents in combination markedly inhibit tumor growth in nude mice. We translated these results into a clinical setting, conducting a phase I study in cancer patients with oxaliplatin 85 mg/m 2 on day 1 and topotecan at doses escalating from 0.5 to 1.5 mg/m 2 on days 2–5. Sixty cycles of treatment were administered to 18 patients affected prevalently by ovarian and colorectal cancer. Combination with topotecan 1.5 mg/m 2 caused a doselimiting toxicity. Therefore the maximum tolerated dose of topotecan was 1.25 mg/m 2 , at which six patients experienced a mild hematological and gastrointestinal toxicity. We also obtained evidence of clinical activity, particularly in ovarian cancer. Conclusions: Our results provide a solid biological and clinical rationale for a phase II trial at the recommended doses of oxaliplatin 85 mg/m 2 and topotecan 1.25 mg/m 2 , possibly in ovarian cancer

We have constructed a series of 22 phosphorothioate 20-mer antisense oligonucleotides directed against different regions of the human (EGFR) mRNA. Treatment with EGFR antisense oligonucleotides showed a dose-dependent inhibition of human GEO colon cancer cell growth in soft agar. Western blot analysis demonstrated a significant reduction in EGFR expression after treatment with each EGFR antisense oligonucleotide. The ability to inhibit GEO anchorage-independent growth, however, varied among the EGFR antisense sequences with an IC(50) ranging between 0.5 and 3.5 microM. Two of these antisense oligonucleotides targeting the regions between 2457-2476 and 614-4633 bases of the human EGFR mRNA have been modified as hybrid DNA/RNA mixed backbone oligonucleotides (MBO) to examine their anticancer properties in vivo. The 2 EGFR antisense MBOs retained the same biological properties of the fully phosphorothioate EGFR antisense oligonucleotides targeting the same EGFR mRNA sequences, such as blocking EGFR synthesis, inhibiting cell growth and enhancing programmed cell death in human cancer cell lines that express functional EGFRs. Furthermore, a potentiation in the growth inhibitory effect on GEO cancer cells was observed after treatment with these EGFR antisense MBOs in combination with cytotoxic drugs, including cisplatin, doxorubicin, paclitaxel, or topotecan. These results show the antiproliferative activity of specific EGFR antisense oligonucleotides and allow to identify novel EGFR antisense MBOs that deserve further evaluation as potential selective anticancer agents alone or in combination with cytotoxic drugs in human carcinomas that express functional EGFRs.