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Abstract: Objective: 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. Methods: 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. Results: 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. Conclusions: 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. [Copyright &y& Elsevier]

Abstract: Objective: Identifying markers specific for mucinous ovarian neoplasms (MON) is important for cancer diagnosis and surveillance, and will help improve our general understanding of the pathobiology of these tumors. CEACAM6 overexpression appears to be an early molecular event with prognostic significance in gastrointestinal carcinomas. Microarray analysis previously demonstrated high CEACAM6 overexpression in MON''s and this study sought to validate this finding. Methods: Western blot compared CEACAM6 expression in normal human ovarian surface epithelium (HOSE) and ovarian cancer cell lines. Quantitative RT-PCR (qRT-PCR) was performed on 75 laser-microdissected HOSE and ovarian cancer tissue samples. Immunohistochemistry (IHC) was performed and slides were analyzed in a semi-quantitative manner. Results: CEACAM6 was expressed in 2 of 3 mucinous cancer cell lines. Expression was absent in all 2 HOSE, 7 serous cancer, and 2 clear cell cancer cell lines. 100-fold CEACAM6 overexpression (qRT-PCR) was demonstrated in 13/16 (81%) borderline, low-grade, and high-grade invasive MON''s, compared to 5/50 (10%) serous and 1/5 (20%) benign mucinous samples. CEACAM6 expression was not different between borderline and invasive MON''s (p =0.55) or across tumor stage (p =0.76). CEACAM6 staining was present in 24/28 (86%) borderline, low-grade, and high-grade invasive MON''s; 13/28 (46%) exhibited moderate-strong staining. Neither CEACAM6 expression (p =0.36) nor staining intensity (p =0.51) was different between borderline and invasive MON''s. None of the serous or benign mucinous tumors exhibited CEACAM6 staining. Conclusions: CEACAM6 is overexpressed in borderline and invasive MON''s. [Copyright &y& Elsevier]

Abstract: Objectives. : In this study, we analyzed the PTEN expression in a large collection of clear cell adenocarcinomas of the ovary. Furthermore, we analyzed the expression of cyclin D1 and p27, and investigated the correlation among all these variables. Methods. : Totally, 40 clear cell adenocarcinomas were included in this study. The protein expression of PTEN, cyclin D1 and p27 was investigated by immunohistochemistry. Results. : Of 40 clear cell adenocarcinomas, 15 (37.5%) lost all PTEN immunoreactivity. There was no significant correlation between PTEN expression and clinical stage. Cyclin D1 expression and loss of p27 expression were detected in 16/40 (40.0%) and 14/40 (35.0%) clear cell adenocarcinoma cases. There was no significant correlation between PTEN expression and cyclin D1 or p27 protein expression. Conclusions. : Loss of PTEN expression is relatively common and both cyclin D1 and p27 expressions are not related with PTEN inactivation in clear cell adenocarcinoma of the ovary. [Copyright &y& Elsevier]

Abstract: Objective.: (1) To identify and (2) validate genes that are up-regulated in ovarian cancer, and (3) to investigate whether the activity of a candidate gene, creatine kinase B (CKB) is elevated in pre-operative sera from ovarian cancer patients compared to patients with benign pelvic masses and normal controls. Methods.: MICROMAX cDNA microarray system and RNA derived from pooled ovarian cancer cell lines and normal ovary surface epithelial cells (HOSE) were used to identify differentially expressed genes. Using RNA from both cell lines and from tissue obtained through laser capture microdissection (LCM), we performed quantitative PCR in order to validate up-regulation of one of these genes, creatine kinase B (CKB). Using a commercially available enzyme assay, CKB activity was measured in pre-operative serum samples obtained from 45 ovarian cancer patients, 49 patients with a benign pelvic mass, as well as 37 normal controls. Statistical analysis was preformed using an unpaired Student''s t test. Results.: Microarray technology revealed that CKB gene expression had a cancer to HOSE ratio of 18. RNA levels of CKB, measured by real-time PCR, were elevated a mean (and standard error) of 36-fold (8.4) in cancer cell lines compared with HOSE cells and 22.75-fold (10.45) in microdissected ovarian cancer epithelial cells compared with normal ovarian epithelial cells. In serum, the mean (±standard error) of CKB enzyme activity in cancer cases was 24.7 U/L units (±5.1) compared to 9.6 U/L (±1.6) for benign mass cases (P = 0.0088) and to 8.5 U/L (1.7) for normal controls (P = 0.0096). Conclusions.: Microarray technology offers a method to identify tumor biomarkers with potential clinical usefulness. Our data indicated that CKB gene expression is up-regulated in ovarian cancer cells in vitro and in vivo and that CKB enzyme activity is significantly elevated in sera from ovarian cancer patients, including those with stage I disease. These findings suggest a potential role for CKB as a marker for early diagnosis. [Copyright &y& Elsevier]