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Low-grade serous carcinoma of the ovary/peritoneum (LGSC) is relatively chemoresistant in the adjuvant, neoadjuvant, and recurrent settings. We sought to expand our prior work and evaluate response rates of women with LGSC to neoadjuvant chemotherapy (NACT) compared to women with high-grade serous carcinoma of the ovary/peritoneum (HGSC).Thirty-six patients with LGSC who received NACT were matched to patients with HGSC. A single radiologist re-reviewed pre- and post-NACT imaging for response using RECIST 1.1. Pre- and post-NACT CA-125 values were compared using paired t-tests. Kaplan-Meier estimates of progression free survival (PFS) and overall survival (OS) were performed.All patients received neoadjuvant platinum-based regimens. LGSC patients received a median of 5 cycles (range 3-9), HGSC patients received a median of 4 cycles (range 3-9). Interval cytoreductive surgery was performed in 29/36 (81%) of LGSC and 32/36 (89%) HGSC patients. Complete cytoreduction was reported and achieved in 11/29 (38%) of LGSC patients and 24/32 (75%) of HGSC patients (p = 0.002). Median pre- and post-treatment CA-125 levels for LGSC patients were 295.5 U/mL and 144 U/mL (52% decrease) (p 0.001). The median pre- and post-treatment CA-125 levels for HGSC patients were 767.5 and 35.6 (96% decrease) (p 0.001). For LGSC patients, 4/36 (11%) had partial response (PR), 30/36 (83%) had stable disease (SD), and 2/36 (6%) had progressive disease (PD). In HGSC patients, 27/36 (75%) had PR, and 9/36 (25%) SD. Median PFS for LGSC patients was 18.5 months and median OS was 47.4 months.This study provides further evidence of relative chemoresistance of LGSC in patients treated with NACT.

Molecular studies in ovarian serous borderline tumors (OSBTs) have been used to understand different aspects of this neoplasm. (i) Pathogenesis, Kras and Braf mutations represent very early events in the tumorigenesis of OSBT as both are detected in serous cystadenomas associated with OSBTs. In contrast, serous cystadenomas without OSBTs do not show Kras or Braf mutations. In OSBTs, Kras mutations range from 17% to 39.5%, while Braf mutations range from 23% to 48%. The former is comparable with the range of Kras mutations in ovarian low-grade serous carcinomas (OLGSCa), 19%-54.5%. In contrast, Braf mutations in OLGSCa range from 0% to 33%. Serous cystadenomas appear to progress to OSBT due to a Braf mutation, but this mutation is rarely involved in the progression to OLGSCa. OSBTs with Braf mutation are associated with cellular senescence and up-regulation of tumor suppressor genes. In contrast, OSBTs without a Braf mutation may progress to OLGSCa due to Kras mutation or some other genetic alterations. (ii) The relationship between OSBTs and the extraovarian disease, a monoclonal versus mutifocal origin? This is still matter of debate as studies using different techniques have failed to settle this controversy. (iii) Biological behavior, Braf mutations appear to have a protective role against the progression of OSBT to OLGSCa, while Kras mutations are commonly seen in cases of OSBT that recurred as LGSCa. Nevertheless, LGSCa as a recurrence of an OSBT can originate from OSBTs with or without detectable Kras mutations. Also, it appears to be an association between Kras G12v mutation and a more aggressive phenotype of OSBT that recurred as LGSCa. (iv) Actionable targets, currently there are limited data. It has been reported that cancer cell lines with Kras G12v mutation are more sensitive to selumetinib than cell lines with wild-type Kras.

Granulocyte macrophage-colony stimulating factor (GM-CSF) is a potent immunomodulatory cytokine that is known to facilitate vaccine efficacy by promoting the development and prolongation of both humoral and cellular immunity. Here, we investigated a novel vaccine approach using a human papillomavirus (HPV)-16 E6/E7-transformed cell line, TC-1, that ectopically expresses a codon-optimized 26-11-2015 murine GM-CSF (cGM-CSF). Ectopically expressing cGM-CSF in TC-1 (TC-1/cGM) cells significantly increased expression of a GM-CSF that was functionally identical to wt GM-CSF by 9-fold compared with ectopically expressed wild type GM-CSF in TC-1 cells (TC-1/wt). Mice vaccinated with irradiated TC-1/cGM cells exhibited enhanced survival compared with mice vaccinated with TC-1/wt cells when both groups were subsequently injected with live TC-1. Consistently, mice vaccinated with irradiated TC-1/cGM cells exhibited stronger IFN-γ production in HPV E7-specific CD8(+) T cells. More dendritic cells were recruited to the draining lymph nodes (dLNs) of mice vaccinated with TC-1/cGM cells than C-1/wt cells. Regarding dLN cell recall responses, both proliferation and IFN-γ production in the HPV E7-specific CD8(+) T cells were enhanced in mice that were vaccinated with TC-1/cGM cells. Our results demonstrate that a novel practical molecular strategy utilizing a codon-optimized GM-CSF gene overcomes the limitation and improves the efficacy of tumor cell-based vaccines.

To validate the overexpression of insulin-like growth factor 1 (IGF-1) and its receptor (IGF-1R) in low-grade serous ovarian carcinoma (SOC), and to investigate whether the IGF-1 pathway is a potential therapeutic target for low-grade SOC.Gene expression profiling was performed on serous borderline ovarian tumors (SBOTs) and low-grade SOC, and overexpression of IGF-1 in low-grade SOC was validated by RT-PCR and immunohistochemistry. The effect of exogenous IGF-1 on cell proliferation was determined in cell lines by cell proliferation assays, cell migration assays, and Western blot. Signaling pathways downstream of IGF-1 and the effects of the AKT inhibitor MK-2206 were investigated by Western blot analysis and by generating IGF-1R short hairpin RNA stable knockdown cell lines. Low- and high-grade cell lines were treated with the dual IGF-1R- and insulin receptor-directed tyrosine kinase inhibitor OSI-906, and cellular proliferation was measured.mRNA analysis and immunostaining revealed significantly higher IGF-1 expression in low-grade SOCs than in SBOTs or high-grade SOCs. In response to exogenous treatment with IGF-1, low-grade cell lines exhibited more intense upregulation of phosphorylated AKT than did high-grade cell lines, an effect that was diminished with IGF-1R knockdown and MK-2206 treatment. Low-grade SOC cell lines were more sensitive to growth inhibition with OSI-906 than were high-grade cell lines.IGF-1 is overexpressed in low-grade SOCs compared with SBOTs and high-grade SOCs. Additionally, low-grade SOC cell lines were more responsive to IGF-1 stimulation and IGF-1R inhibition than were high-grade lines. The IGF-1 pathway is therefore a potential therapeutic target in low-grade SOC.

Low-grade ovarian serous carcinomas are believed to arise via an adenoma-serous borderline tumor-serous carcinoma sequence. In this study, we found that advanced-stage, low-grade ovarian serous carcinomas both with and without adjacent serous borderline tumor shared similar regions of loss of heterozygosity. We then analyzed 91 ovarian tumor samples for mutations in TP53, BRAF, and KRAS. TP53 mutations were not detected in any serous borderline tumors (n = 30) or low-grade serous carcinomas (n = 43) but were found in 73% of high-grade serous carcinomas (n = 18). BRAF (n = 9) or KRAS (n = 5) mutation was detected in 47% of serous borderline tumors, but among the low-grade serous carcinomas (39 stage III, 2 stage II, and 2 stage I), only one (2%) had a BRAF mutation and eight (19%) had a KRAS mutation. The low frequency of BRAF mutations in advanced-stage, low-grade serous carcinomas, which contrasts with previous findings, suggests that aggressive, low-grade serous carcinomas are more likely derived from serous borderline tumors without BRAF mutation. In addition, advanced-stage, low-grade carcinoma patients with BRAF or KRAS mutation have a better apparent clinical outcome. However, further investigation is needed.

Ovarian cancer is the most lethal gynecologic cancer, and this is largely related to its late diagnosis. High grade serous cancers often initially respond to chemotherapy, resulting in a better survival rate, compared to other ovarian carcinoma subtypes. We review recent work identifying a survival-associated gene expression profile for advanced serous ovarian cancer. Within this signature, the authors identified MAGP2, also known as microfibrillar associated protein 5 (MFAP5), as a highly significant indicator of survival and chemosensitivity. MAGP2 is a multifunctional secreted protein—important for elastic microfibril assembly and modulating endothelial cell behavior—with a newly identified role in cell survival. Through αVβ3 integrin-mediated signaling, MAGP2 promotes tumor and endothelial cell survival and endothelial cell motility, providing a potential mechanistic link between MAGP2 and angiogenesis as well as patient survival.

Hepatoblastoma is the most common malignant tumor of the liver of children worldwide. Histologically, hepatoblastomas show marked variation in the type and proportion of epithelial (fetal, embryonal, or small cell) and mesenchymal components with differing prognosis and response to therapy. The pure fetal-type hepatoblastoma, presenting as stage 1 and resectable, has the best prognosis, whereas the small cell histology has been associated with unfavorable outcome. Using gene expression profiling, we demonstrate that in addition to Wnt pathway deregulation, cell growth and survival pathways are also globally deregulated in hepatoblastomas. Furthermore, the different histologic subtypes are characterized by specific gene expression and pathway signatures that give insight into the degree of molecular heterogeneity that is present among these tumors. Although Wnt signaling pathway upregulation is common to all histologic types of hepatoblastoma, this pathway is even more significantly deregulated in aggressive hepatoblastomas. In addition, deregulation of MAPK signaling pathway and antiapoptotic signaling is preferentially upregulated in aggressive epithelial hepatoblastomas with a small cell component. The gene expression signatures reported here provide possible prognostic and diagnostic markers as well as therapeutic targets for this disease.

Suppression of ovarian tumor growth by chromosome 3p was demonstrated in a previous study. Deleted in Lung and Esophageal Cancer 1 (DLEC1) on 3p22.3 is a candidate tumor suppressor in lung, esophageal, and renal cancers. The potential involvement of DLEC1 in epithelial ovarian cancer remains unknown. In the present study, DLEC1 downregulation was found in ovarian cancer cell lines and primary ovarian tumors. Focus-expressed DLEC1 in two ovarian cancer cell lines resulted in 41% to 52% inhibition of colony formation. No chromosomal loss of chromosome 3p22.3 in any ovarian cancer cell line or tissue was found. Promoter hypermethylation of DLEC1 was detected in ovarian cancer cell lines with reduced DLEC1 transcripts, whereas methylation was not detected in normal ovarian epithelium and DLEC1-expressing ovarian cancer cell lines. Treatment with demethylating agent enhanced DLEC1 expression in 90% (9 of 10) of ovarian cancer cell lines. DLEC1 promoter methylation was examined in 13 high-grade ovarian tumor tissues with DLEC1 downregulation, in which 54% of the tumors showed DLEC1 methylation. In addition, 80% of ovarian cancer cell lines significantly upregulated DLEC1 transcripts after histone deacetylase inhibitor treatment. Therefore, our results suggested that DLEC1 suppressed the growth of ovarian cancer cells and that its downregulation was closely associated with promoter hypermethylation and histone hypoacetylation.

We have established a method for using a cDNA array platform in combination with degenerate oligonucleotide primer polymerase chain reaction (DOP-PCR) and taramide signal amplification (TSA) to identify DNA copy number abnormalities (CNA) in cancer cell lines and cancer cells procured with laser-based microdissection. To determine the sensitivity and specificity for detecting single-copy gain and loss, receiver-operator curve analysis was performed on hybridization signal ratios generated from non-DOP and DOP amplified female and male DNA using a 10,816-element cDNA microarray. A cutoff value of 1.12 and 1.07 average signal ratio for X-chromosomal genes versus autosomal genes provided a sensitivity and specificity of 50 and 79%, respectively, for non-DOP amplified DNA and a sensitivity and specificity of 50 and 72%, respectively, for DOP amplified DNA. We used this approach to identify DNA copy number abnormalities in the ovarian cancer cell line OVCA633, which has previously been shown to have 12p amplification. Transcription profiling of OVCA633 was also performed. Two amplified and overexpressed genes located on 12p11, KRAS2 and LRMP, were identified; these were validated with quantitative real-time PCR. Subsequently, the same approach was used to identify CNAs and gene expression alterations in 11 microdissected serous ovarian adenocarcinoma cases. Validated data revealed amplification and overexpression of ERBB3 and FOS and deletion and underexpression of KRT6 and APXL in more than 50% of the tissue samples. These results show the feasibility of using the cDNA array platform to identify changes in DNA and mRNA copy number simultaneously in microdissected tumor tissues.

Gene amplifications have been observed in many different tumor cells, and many of these changes are related to tumor pathogenesis. Comparative genomic hybridization (CGH) using metaphase chromosomes can detect changes in chromosome copy number with a resolution of 10–20 Mb. Current advances in CGH analysis in a microarray format allow us to refine such changes down to the gene level. We applied microarray technology to detect novel gene amplification in a malignant mixed tumor of salivary gland. Besides detecting previously known gene amplifications ( MDM2 and MYC ), we identified four other highly amplified genes located at 8q11.2∼q13: MGC2177 , PLAG1 , PSMC6P , and LYN . The amplification was further validated with real-time quantitative polymerase chain reaction.

A DNA-fingerprinting approach has been adapted to detect differentially expressed genes in human ovarian carcinoma. This method is based on the use of arbitrary primers to generate fingerprints from total RNA isolated from normal ovarian epithelial cells and ovarian carcinoma cells by polymerase chain reaction (PCR). Using this method, we cloned two cDNA fragments (DOC-1 and DOC-2) which were present in normal ovarian surface epithelial cells but consistently absent in all of the ovarian cancer cell lines from the differential display. In addition, we also identified a cDNA fragment (LF4.0) which is overexpressed in most of the tumor cell lines and tumor tissues in comparison to the normal ovarian surface epithelial cells. The differential expression of the genes in the tumor cell lines as well as in the tumor tissues was also confirmed by Northern analysis. The clone DOC-2, which is a 800-bp cDNA fragment, has one open reading frame suggesting that the gene may be translated. Assuming that this frame is the sense strand, we generated both sense and antisense riboprobe for in situ mRNA hybridization. Only the antisense DOC-2 riboprobe revealed a hybridization signal which was restricted to the human surface ovarian epithelium. The potential functional roles of these genes is now under investigation.