Abstract 3037: Integrated Genomic, MicroRNA (miRNA) and Proteomic Profiling of Ovarian Carcinoma for Biomarker Discovery

Ovarian cancer (OCa) is the fifth leading cause of cancer-related deaths in North American women and the first due to a gynecologic malignancy. The long-term effectiveness of standard therapy is generally poor and is accompanied by serious side effects. Thus there is a need for developing markers not only for diagnosis and prognosis, but also for predicting therapeutic response. Tumour progression and resistance to therapy is a consequence of the complexity of DNA, RNA and proteins. The search for effective and specific biomarkers should integrate aspects of all these factors. We have previously demonstrated that KLK6 is a promising biomarker for OCa and its observed over-expression is linked to copy-number gains of the 19q13.3/4 locus. Here, we demonstrate by multi-colour FISH analyses that the KLK locus in 81 OCas is subject to high-level of genomic instability (p<0.001); and such instability is significantly co-related to grade (p<0.001). KLK6-specific immunohistochemistry (IHC) showed no strong corelation with KLK6 copy-number, suggesting that other mechanisms, together with copy-number, drive its over-expression. Because 19q contains the highest number of annotated microRNAs (miRNAs) and copy-number instability may affect expression of these miRNAs, we investigated the role of miRNAs in OCa, not only for regulating KLK6, but as biomarkers for OCa. miRNA profiling of OCa cell lines and primary tumours by RT2-PCR showed the differential expression of miRNAs, consistent with other published studies in OCa. Since miRNAs can potentially affect the protein expression of hundreds of genes, the identification of such differentially expressed proteins not only provides putative biomarkers, but may also elucidate pathways for therapeutic intervention. Using Stable Isotope Labelling with Amino Acids in Cell Culture (SILAC) coupled to mass spectrometry for the OVCAR-3 cell line, cultures were labeled separately in light-Arg/Lys and heavy-Arg/Lys. In this control experiment, over 2,800 proteins were identified with 2,465 quantified. Over 94% of these quantified proteins showed a heavy:light ratio between 0.8 and 1.2, making this a robust system for quantitatively distinguishing differentially expressed proteins in the presence of miRNA precursors or inhibitors. Our profiling, as well as others, has shown the loss of expression of let-7 family members and hsa-125a-5p in OCas, and both miRNAs show decreased expression in OVCAR-3. Interestingly, these miRNAs are also predicted to target KLK6. Thus, we hypothesize that these miRNAs will not only affect the expression of KLK6, but also the expression of other target genes. In the future, using SILAC, we will identify the differentially expressed proteins affected upon re-introduction of these miRNAs through the differential labeling of miRNA-transfected OVCAR-3 vs. non-transfected OVCAR-3; thus revealing novel biomarkers for OCa.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 3037.

Abstract 834: IGF-II promoter specific methylation patterns are associated with its expression and disease progression in epithelial ovarian cancer

Purpose: High insulin-like growth factor-II (IGF-II) expression in epithelial ovarian cancer is associated with aggressive disease and poor prognosis. IGF-II expression is regulated by promoter methylation; aberrant methylation is common in cancer. The effect of promoter methylation on IGF-II expression and the role of methylation in ovarian cancer are investigated in a clinical study.

Patients and Methods: The study enrolled 211 epithelial ovarian cancer patients who were followed after surgery for disease outcomes. Fresh tumor samples were collected from the patients and were analyzed for IGF-II promoter methylation using methylation-specific PCR, as well as for IGF-II mRNA expression with qRT-PCR. IGF-II peptide concentrations were measured with an ELISA kit in tumor tissues.

Results: The study found different levels of methylation in 3 IGF-II promoters (P2-P4) which are located in a large CpG island, high methylation in P2 (64.2%) and P3 (52.1%) and low in P4 (9.8%). Promoter-specific mRNA expression was lower in methylated than in unmethylated tumors. P3 methylation and expression appeared to play a major role for IGF-II in ovarian cancer. While methylation in individual promoter was not related to the disease, a methylation pattern between P2 and P3 was significantly associated with clinical and pathological features of ovarian cancer, including tumor grade, debulking results, residual tumor size and treatment response. The methylation pattern was also linked to disease progression, but not overall survival.

Conclusions: Our findings suggest that IGF-II expression affects tumor progression and the expression is regulated by methylation which may have clinical implications in disease management.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 834.

Phase III Trial of Observation Versus Six Courses of Paclitaxel in Patients With Advanced Epithelial Ovarian Cancer in Complete Response After Six Courses of Paclitaxel/Platinum-Based Chemotherapy: Final Results of the After-6 Protocol 1

Purpose

To assess whether six courses of paclitaxel are effective as consolidation treatment in patients with advanced epithelial ovarian cancer who are in complete response after first-line paclitaxel/platinum–based chemotherapy.

Patients and Methods

Patients with stages IIb to IV disease in clinical or pathologic complete response after six courses of paclitaxel/platinum–based chemotherapy were randomly allocated to either observation (ie, control) or six courses of paclitaxel 175 mg/m2 every 3 weeks (ie, maintenance).

Results

Two hundred patients were randomly assigned from March 1999 to July 2006. Because of the low accrual rate, an unplanned interim analysis of futility according to the Bayesian approach was performed. Grade 2 or greater motor neurotoxicity and sensory neurotoxicity were reported in 11.3% and 28.0% of the paclitaxel-arm patients, respectively. After a median follow-up of 43.5 months, 107 patients (53%) had experienced relapse, and 48 patients (24%) had died. Two-year progression-free survival rates were 54% (95% CI, 43% to 64%) and 59% (95% CI, 49% to 69%; P = not significant) in the control and maintenance arms, respectively. Corresponding 2-year overall survival rates were 90% (95% CI, 84% to 97%) and 87% (95% CI, 80% to 94%; P = not significant), respectively. The Cox model showed that residual disease after initial surgery (macroscopic v no macroscopic residuum; hazard ratio [HR], 1.91; 95%CI, 1.21 to 3.03) and stage (IIIc to IV v others; HR, 3.10; 95% CI, 1.13 to 8.48) were independent prognostic factors for progression-free survival, whereas the treatment arm (maintenance v control) had no prognostic relevance.

Conclusion

A consolidation treatment with six cycles of paclitaxel does not prolong progression-free survival or overall survival in patients in complete response after first-line paclitaxel/platinum–based regimens.

Down-regulation of dicer expression in ovarian cancer tissues

OBJECTIVES

Although numerous recent studies have focused on analyses of microRNA expression profiles in cancer cells, the expression patterns of the enzymes responsible for the generation of miRNAs remains largely unexplored. The purpose of this study was to investigate whether Dicer mRNA expression is altered during progression of ovarian cancer.

DESIGN AND METHODS

Total RNA was extracted from ovarian tissue specimens (normal, benign and malignant tumors). The expression of Dicer was analyzed by semi-quantitative RT-PCR.

RESULTS

We analyzed a total of 34 ovarian tissue samples and found that Dicer mRNA expression is down-regulated in the majority of ovarian tumors when compared to normal tissues.

CONCLUSIONS

Our results suggest that the levels of Dicer mRNA should be evaluated as a potential new candidate biomarker for ovarian cancer.

Weekly low-dose paclitaxel as maintenance treatment in patients with advanced ovarian cancer who had microscopic residual disease at second-look surgery after 6 cycles of paclitaxel/platinum-based chemotherapy: results of an open noncomparative phase 2 multicenter Italian study (After-6 Protocol 2)

The aim of this paper was to assess whether weekly intravenous 60-mg/m2 paclitaxel for 21 weeks is feasible and effective as maintenance treatment in 64 patients with advanced ovarian cancer who had microscopic residual disease after 6 cycles of paclitaxel/platinum-based chemotherapy. Forty-eight patients completed the planned cycles of weekly paclitaxel. The worst toxicities were grade 2 leukopenia in 22.4% of the patients, grade 2 neutropenia in 25.9%, grade 2 sensorial neurotoxicity in 20.7%, and grade 2 motor neurotoxicity in 6.9%. Seventeen patients underwent a third-look surgery that showed a pathological complete response in 6 (35.3%, 95% confidence interval [CI], 17.3%-59.0%) cases. The 3-year progression-free survival rate was 18% (95% CI, 9.6%-33.8%), and the 3-year overall survival rate was 64% (95% CI, 52.0%-78.0%). Weekly low-dose paclitaxel is a feasible and well-tolerated maintenance treatment.

Stathmin and tubulin expression and survival of ovarian cancer patients receiving platinum treatment with and without paclitaxel

BACKGROUND

Paclitaxel interacts with microtubules to exert therapeutic effects. Molecules that affect microtubule activity, such as betaIII-tubulin and stathmin, may interfere with the treatment. In this study, the authors analyzed betaIII-tubulin and stathmin expression in ovarian tumors and examined their associations with treatment response and patient survival.

METHODS

The study included 178 patients with epithelial ovarian cancer who underwent cytoreductive surgery followed by platinum-based chemotherapy; of these patients, 75 also received paclitaxel. Fresh tumor samples that were collected at surgery were analyzed for messenger RNA expression of betaIII-tubulin and stathmin using real-time polymerase chain reaction analysis. Associations of these molecules with treatment response, disease progression, and overall survival were evaluated.

RESULTS

High stathmin expression was associated with worse disease progression-free and overall survival compared with low stathmin expression. This association was independent of patient age, disease stage, tumor grade, histology, and residual tumor size and was observed in patients who received platinum plus paclitaxel, but not in patients who received platinum without paclitaxel, suggesting that stathmin expression in tumor tissue may interfere with paclitaxel treatment. Similar effects were not observed for betaIII-tubulin, although high betaIII-tubulin expression was associated with disease progression among patients who received platinum without paclitaxel. No associations were observed between treatment response and tubulin or stathmin expression. Expression levels of betaIII-tubulin and stathmin were correlated significantly.

CONCLUSIONS

High stathmin expression predicted an unfavorable prognosis in patients with ovarian cancer who received paclitaxel and platinum chemotherapy. This finding supports the possibility that stathmin may interfere with paclitaxel treatment, leading to a poor prognosis for patients with ovarian cancer.

Epithelial-mesenchymal transition of ovarian tumor cells induces an angiogenic monocyte cell population

Vasculogenesis, or recruitment of progenitors able to differentiate into endothelial-like cells, may provide an important contribution to neovessel formation in tumors. However, the factors involved in the vasculogenic process and in particular the role of the epithelial-mesenchymal transition of tumor cells have not yet been investigated. We found a CD14(+)/KDR(+) angiogenic monocyte population in undifferentiated ovarian tumors, significantly increased in the corresponding tumor metastasis. In vitro, monocyte differentiation into CD14(+)/KDR(+) cells was induced by conditioned media from the primary ovarian tumor cells expressing a mesenchymal phenotype. In contrast, the ovarian tumor cell line SKOV3 expressing an epithelial phenotype was unable to stimulate the differentiation of monocytes into CD14(+)/KDR(+) cells. When an epithelial-mesenchymal transition was induced in SKOV3, they acquired this differentiative ability. Moreover, after mesenchymal transition pleiotrophin expression by SKOV3 was increased and conversely its blockade significantly reduced monocyte differentiation. The obtained CD14(+)/KDR(+) cell population showed the expression of endothelial markers, increased the formation of capillary-like structures by endothelial cells and promoted the migration of ovarian tumor cells in vitro. In conclusion, we showed that the epithelial-mesenchymal transition of ovarian tumor cells induced differentiation of monocytes into the pro-angiogenic CD14(+)/KDR(+) population and thus it may provide a tumor microenvironment that favours vasculogenesis and metastatization of the ovarian cancer.

Pluripotent factor lin-28 and its homologue lin-28b in epithelial ovarian cancer and their associations with disease outcomes and expression of let-7a and IGF-II

Lin-28 and lin-28B are RNA-binding proteins which can block microRNA let-7 maturation and affect the differentiation and proliferation of embryonic stem cells. Lin-28 may also regulate the expression of insulin-like growth factor II (IGF-II). As one of the pluripotent factors involved in making induced pluripotent stem cells (iPS), lin-28 is considered a potential therapeutic target for cancer treatment. To further understand the role of lin-28 in cancer, we analysed the expression of lin-28 and its homologue lin-28B in tumour samples, and evaluated their associations with let-7a maturation, IGF-II expression, disease features and outcomes in 211 patients with primary epithelial ovarian cancer. The analysis showed that both lin-28 and lin-28B were positively correlated with primary and pre-let-7a-3; lin-28B, not lin-28, was inversely correlated with mature let-7a. A positive correlation was also observed between lin-28B and IGF-II expression, while no association was found between lin-28B and IGF-I or IGFBP-3. The study further demonstrated that lin-28B expression was associated with the risk of disease progression and death; patients with high lin-28B had shorter progression-free and overall survival than those with low lin-28B. These results seem to support the findings of recent in vitro experiments, showing that lin-28 blocks the process of let-7a maturation. Our study also suggests that lin-28B may promote ovarian cancer progression and serve as an unfavourable prognostic marker for the disease. The correlation between lin-28B and IGF-II indicates that the growth factor may mediate the effect of lin-28B on tumour growth.

A phase II, randomized trial of neo-adjuvant chemotherapy comparing a three-drug combination of paclitaxel, ifosfamide, and cisplatin (TIP) versus paclitaxel and cisplatin (TP) followed by radical surgery in patients with locally advanced squamous cell cervical carcinoma: the Snap-02 Italian Collaborative Study

BACKGROUND

The efficacy and tolerability of the regimen containing paclitaxel and cisplatin (TP) in the neo-adjuvant treatment of locally advanced squamous cell cervical cancer are unknown. The TIP regimen (TP plus ifosfamide) showed high efficacy but high toxicity and it is used as an internal control.

PATIENTS AND METHODS

In all, 154 patients were randomized to TP (paclitaxel 175 mg/m(2) + cisplatin 75 mg/m(2); n = 80) or TIP (TP + ifosfamide 5 g/m(2); n = 74), three cycles, followed by radical surgery. Pathological response to chemotherapy was classified as optimal [no residual tumor (complete response) or residual disease with < or = 3 mm stromal invasion (PR1)] or suboptimal response.

RESULTS

Patient characteristics (TP/TIP): stage IB2 (56%/64%), IIA (18%/14%), IIB (20%/19%), III-IVA (5%/4%) and median age (42 years/45 years). The optimal response rate in the TP group was 25%, 95% confidence interval (CI) = 16% to 37% and 43%, 95% CI = 31% to 55% in the TIP group. Grades 3-4 leukopenia (6%/53%) and neutropenia (26%/76%) were significantly more frequent on TIP.

CONCLUSION

TP performance was below expectation since the lower 95% confidence limit of the optimal response rate failed to reach the prespecified minimum requirement of efficacy, i.e. 22%. The TIP regimen confirmed its activity but was associated with higher haematological toxicity than TP.

Expression of activated PIK3CA in ovarian surface epithelium results in hyperplasia but not tumor formation

Background

The Phosphatidylinositol 3′-kinase is a key regulator in various cancer-associated signal transduction pathways. Genetic alterations of its catalytic subunit alpha, PIK3CA, have been identified in ovarian cancer. Our in vivo data suggests that PIK3CA activation is one of the early genetic events in ovarian cancer. However, its role in malignant transformation of ovarian surface epithelium (OSE) is largely unclear.

Methodology/Principal Findings

Using the Müllerian inhibiting substance type II receptor (MISIIR) promoter, we generated transgenic mice that expressed activated PIK3CA in the Müllerian epithelium. Overexpression of PIK3CA in OSE induced remarkable hyperplasia, but was not able to malignantly transform OSE in vivo. The consistent result was also observed in primary cultured OSEs. Although enforced expression of PIK3CA could not induce OSE anchorage-independent growth, it significantly increased anchorage-independent growth of OSE transformed by mutant K-ras.

Conclusions/Significance

While PIK3CA activation may not be able to initiate OSE transformation, we conclude that activation of PIK3CA may be an important molecular event contributing to the maintenance of OSE transformation initiated by oncogenes such as K-ras.

MicroRNA microarray identifies Let-7i as a novel biomarker and therapeutic target in human epithelial ovarian cancer

MicroRNAs (miRNA) are approximately 22-nucleotide noncoding RNAs that negatively regulate protein-coding gene expression in a sequence-specific manner via translational inhibition or mRNA degradation. Our recent studies showed that miRNAs exhibit genomic alterations at a high frequency and their expression is remarkably deregulated in ovarian cancer, strongly suggesting that miRNAs are involved in the initiation and progression of this disease. In the present study, we performed miRNA microarray to identify the miRNAs associated with chemotherapy response in ovarian cancer and found that let-7i expression was significantly reduced in chemotherapy-resistant patients (n = 69, P = 0.003). This result was further validated by stem-loop real-time reverse transcription-PCR (n = 62, P = 0.015). Both loss-of-function (by synthetic let-7i inhibitor) and gain-of-function (by retroviral overexpression of let-7i) studies showed that reduced let-7i expression significantly increased the resistance of ovarian and breast cancer cells to the chemotherapy drug, cis-platinum. Finally, using miRNA microarray, we found that decreased let-7i expression was significantly associated with the shorter progression-free survival of patients with late-stage ovarian cancer (n = 72, P = 0.042). This finding was further validated in the same sample set by stem-loop real-time reverse transcription-PCR (n = 62, P = 0.001) and in an independent sample set by in situ hybridization (n = 53, P = 0.049). Taken together, our results strongly suggest that let-7i might be used as a therapeutic target to modulate platinum-based chemotherapy and as a biomarker to predict chemotherapy response and survival in patients with ovarian cancer.

Systematic pelvic lymphadenectomy vs. no lymphadenectomy in early-stage endometrial carcinoma: randomized clinical trial

BACKGROUND

Pelvic lymph nodes are the most common site of extrauterine tumor spread in early-stage endometrial cancer, but the clinical impact of lymphadenectomy has not been addressed in randomized studies. We conducted a randomized clinical trial to determine whether the addition of pelvic systematic lymphadenectomy to standard hysterectomy with bilateral salpingo-oophorectomy improves overall and disease-free survival.

METHODS

From October 1, 1996, through March 31, 2006, 514 eligible patients with preoperative International Federation of Gynecology and Obstetrics stage I endometrial carcinoma were randomly assigned to undergo pelvic systematic lymphadenectomy (n = 264) or no lymphadenectomy (n = 250). Patients' clinical data, pathological tumor characteristics, and operative and early postoperative data were recorded at discharge from hospital. Late postoperative complications, adjuvant therapy, and follow-up data were collected 6 months after surgery. Survival was analyzed by use of the log-rank test and a Cox multivariable regression analysis. All statistical tests were two-sided.

RESULTS

The median number of lymph nodes removed was 30 (interquartile range = 22-42) in the pelvic systematic lymphadenectomy arm and 0 (interquartile range = 0-0) in the no-lymphadenectomy arm (P < .001). Both early and late postoperative complications occurred statistically significantly more frequently in patients who had received pelvic systematic lymphadenectomy (81 patients in the lymphadenectomy arm and 34 patients in the no-lymphadenectomy arm, P = .001). Pelvic systematic lymphadenectomy improved surgical staging as statistically significantly more patients with lymph node metastases were found in the lymphadenectomy arm than in the no-lymphadenectomy arm (13.3% vs 3.2%, difference = 10.1%, 95% confidence interval [CI] = 5.3% to 14.9%, P < .001). At a median follow-up of 49 months, 78 events (ie, recurrence or death) had been observed and 53 patients had died. The unadjusted risks for first event and death were similar between the two arms (hazard ratio [HR] for first event = 1.10, 95% CI = 0.70 to 1.71, P = .68, and HR for death = 1.20, 95% CI = 0.70 to 2.07, P = .50). The 5-year disease-free and overall survival rates in an intention-to-treat analysis were similar between arms (81.0% and 85.9% in the lymphadenectomy arm and 81.7% and 90.0% in the no-lymphadenectomy arm, respectively).

CONCLUSION

Although systematic pelvic lymphadenectomy statistically significantly improved surgical staging, it did not improve disease-free or overall survival.

Activity of chemotherapy in mucinous ovarian cancer with a recurrence free interval of more than 6 months: results from the SOCRATES retrospective study

BACKGROUND

Mucinous ovarian carcinoma have a poorer prognosis compared with other histological subtypes. The aim of this study was to evaluate, retrospectively, the activity of chemotherapy in patients with platinum sensitive recurrent mucinous ovarian cancer.

METHODS

The SOCRATES study retrospectively assessed the pattern of care of a cohort of patients with recurrent platinum-sensitive ovarian cancer observed in the years 2000-2002 in 37 Italian centres. Data were collected between April and September 2005. Patients with recurrent ovarian cancer with > 6 months of platinum free interval were considered eligible.

RESULTS

Twenty patients with mucinous histotype and 388 patients with other histotypes were analyzed. At baseline, mucinous tumours differed from the others for an higher number of patients with lower tumor grading (p = 0.0056) and less advanced FIGO stage (p = 0.025). At time of recurrence, a statistically significant difference was found in performance status (worse in mucinous, p = 0.024). About 20% of patients underwent secondary cytoreduction in both groups, but a lower number of patients were optimally debulked in the mucinous group (p = 0.03). Patients with mucinous cancer received more frequently single agent platinum than platinum based-combination therapy or other non-platinum schedules as second line therapy (p = 0.026), with a response rate lower than in non-mucinous group (36.4% vs 62.6%, respectively, p = 0.04). Median time to progression and overall survival were worse for mucinous ovarian cancer. Finally, mucinous cancer received a lower number of chemotherapy lines (p = 0.0023).

CONCLUSION

This analysis shows that platinum sensitive mucinous ovarian cancer has a poor response to chemotherapy. Studies dedicated to this histological subgroup are needed.

A gene expression signature that can predict the recurrence of tamoxifen-treated primary breast cancer

PURPOSE

The identification of a molecular signature predicting the relapse of tamoxifen-treated primary breast cancers should help the therapeutic management of estrogen receptor-positive cancers.

EXPERIMENTAL DESIGN

A series of 132 primary tumors from patients who received adjuvant tamoxifen were analyzed for expression profiles at the whole-genome level by 70-mer oligonucleotide microarrays. A supervised analysis was done to identify an expression signature.

RESULTS

We defined a 36-gene signature that correctly classified 78% of patients with relapse and 80% of relapse-free patients (79% accuracy). Using 23 independent tumors, we confirmed the accuracy of the signature (78%) whose relevance was further shown by using published microarray data from 60 tamoxifen-treated patients (63% accuracy). Univariate analysis using the validation set of 83 tumors showed that the 36-gene classifier is more efficient in predicting disease-free survival than the traditional histopathologic prognostic factors and is as effective as the Nottingham Prognostic Index or the "Adjuvant!" software. Multivariate analysis showed that the molecular signature is the only independent prognostic factor. A comparison with several already published signatures demonstrated that the 36-gene signature is among the best to classify tumors from both training and validation sets. Kaplan-Meier analyses emphasized its prognostic power both on the whole cohort of patients and on a subgroup with an intermediate risk of recurrence as defined by the St. Gallen criteria.

CONCLUSION

This study identifies a molecular signature specifying a subgroup of patients who do not gain benefits from tamoxifen treatment. These patients may therefore be eligible for alternative endocrine therapies and/or chemotherapy.

A multiparametric panel for ovarian cancer diagnosis, prognosis, and response to chemotherapy

PURPOSE

Our goal was to examine a panel of 11 biochemical variables, measured in cytosolic extracts of ovarian tissues (normal, benign, and malignant) by quantitative ELISAs for their ability to diagnose, prognose, and predict response to chemotherapy of ovarian cancer patients.

EXPERIMENTAL DESIGN

Eleven proteins were measured (9 kallikreins, B7-H4, and CA125) in cytosolic extracts of 259 ovarian tumor tissues, 50 tissues from benign conditions, 35 normal tissues, and 44 tissues from nonovarian tumors that metastasized to the ovary. Odds ratios and hazard ratios and their 95% confidence interval were calculated. Time-dependent receiver operating characteristic curves for censored survival data were used to evaluate the performance of the biomarkers. Resampling was used to validate the performance.

RESULTS

Most biomarkers effectively separated cancer from noncancer groups. A composite marker provided an area under the curve of 0.97 (95% confidence interval, 0.95-0.99) for discriminating normal and cancer groups. Univariately, hK5 and hK6 were positively associated with progression. After adjusting for clinical variables in multivariate analysis, both hK10 and hK11 significantly predicted time to progression. Increasing levels of hK13 were associated with chemotherapy response, and the predictive power of hK13 to chemotherapy response was improved by a panel of five biomarkers.

CONCLUSIONS

The evidence shows that a group of kallikreins and multiparametric combinations with other biomarkers and clinical variables can significantly assist with ovarian cancer classification, prognosis, and response to platinum-based chemotherapy. In particular, we developed a multiparametric strategy for predicting ovarian cancer response to chemotherapy, comprising several biomarkers and clinical features.

Klotho expression in epithelial ovarian cancer and its association with insulin-like growth factors and disease progression

Klotho is an anti-aging hormone and is able to suppress the action of IGFs. High IGF activities are associated with cancer risk and tumor progression. Klotho's role in cancer is unknown. To evaluate Klotho expression in ovarian cancer and its association with IGFs and ovarian cancer progression, a clinical follow-up study of 189 ovarian cancer patients was conducted. Patients were recruited from a teaching hospital at University of Turin in Italy. All patients were diagnosed with epithelial ovarian cancer and underwent surgery for the disease. Fresh tumor tissue was collected from each patient during surgery. Patient clinical and pathological information was collected, including patient age at surgery, disease stage, tumor grade, tumor histology, residual tumor size, debulking result, post-operative chemotherapeutic agent, treatment response, follow-up time and survival outcome. Expressions of total and secreted Klotho as well as IGFs in tumor tissue were analyzed using quantitative real-time PCR. Survival analysis was performed to evaluate the association of Klotho expression with the risk of disease progression and death using Cox proportional hazards regression model. High expression of secreted Klotho was associated with increased risk of disease progression and death. These associations were independent of patient clinical and pathological characteristics. Expression of secreted Klotho was positively correlated with the expression of IGF-I and IGFBP-3 but not with IGF-II. In conclusion, Klotho expression is associated with epithelial ovarian cancer progression, and the protein may serve as an independent marker for ovarian cancer prognosis. Klotho's role in cancer warrants further elucidation.

Transcriptional regulation of PIK3CA oncogene by NF-kappaB in ovarian cancer microenvironment

PIK3CA upregulation, amplification and mutation have been widely reported in ovarian cancers and other tumors, which strongly suggests that PIK3CA is a promising therapeutic target. However, to date the mechanisms underlying PIK3CA regulation and activation in vivo is still unclear. During tumorigenesis, host-tumor interactions may play a critical role in editing the tumor. Here, we report a novel mechanism through which the tumor microenvironment activates the PIK3CA oncogene. We show that PIK3CA upregulation occurs in non-proliferating tumor regions in vivo. We identified and characterized the PIK3CA 5' upstream transcriptional regulatory region and confirmed that PIK3CA is transcriptionally regulated through NF-kappaB pathway. These results offer a new mechanism through which the tumor microenvironment directly activates oncogenic pathways in tumor cells.

Phase III Trial of Gemcitabine Compared With Pegylated Liposomal Doxorubicin in Progressive or Recurrent Ovarian Cancer

Purpose

We aimed at investigating the efficacy, tolerability, and quality of life (QOL) of gemcitabine (GEM) compared with pegylated liposomal doxorubicin (PLD) in the salvage treatment of recurrent ovarian cancer.

Patients and Methods

A phase III randomized multicenter trial was planned to compare GEM (1,000 mg/m2 on days 1, 8, and 15 every 28 days) with PLD (40 mg/m2 every 28 days) in ovarian cancer patients who experienced treatment failure with only one platinum/paclitaxel regimen and who experienced recurrence or progression within 12 months after completion of primary treatment.

Results

One hundred fifty-three patients were randomly assigned to PLD (n = 76) or GEM (n = 77). Treatment arms were well balanced for clinicopathologic characteristics. Grade 3 or 4 neutropenia was more frequent in GEM-treated patients versus PLD-treated patients (P = .007). Grade 3 or 4 palmar-plantar erythrodysesthesia was documented in a higher proportion of PLD patients (6%) versus GEM patients (0%; P = .061). The overall response rate was 16% in the PLD arm compared with 29% in the GEM arm (P = .056). No statistically significant difference in time to progression (TTP) curves according to treatment allocation was documented (P = .411). However, a trend for more favorable overall survival was documented in the PLD arm compared with the GEM arm, although the P value was of borderline statistical significance (P = .048). Statistically significantly higher global QOL scores were found in PLD-treated patients at the first and second postbaseline QOL assessments.

Conclusion

GEM does not provide an advantage compared with PLD in terms of TTP in ovarian cancer patients who experience recurrence within 12 months after primary treatment but should be considered in the spectrum of drugs to be possibly used in the salvage setting.

Hypermethylation of let-7a-3 in epithelial ovarian cancer is associated with low insulin-like growth factor-II expression and favorable prognosis

MicroRNAs (miRNA) are endogenous noncoding small RNAs that regulate the activity of mRNAs. Many miRNA genes, including let-7a-3, are located in CpG islands, suggesting possible epigenetic regulation of their expression. Promoter CpG island methylation of tumor suppressor genes is involved in cancer development and progression. Using real-time methylation-specific PCR and real-time reverse transcription-PCR, we analyzed DNA methylation in the let-7a-3 gene and miRNA expression of let-7a in 214 patients with epithelial ovarian cancer to assess the effect of let-7a-3 methylation on the expressions of let-7a as well as a possible target of let-7 regulation, insulin-like growth factor-II (IGF-II). The association of let-7a-3 methylation with patient survival outcomes was also evaluated. let-7a-3 methylation was detected in epithelial ovarian cancer, and the expression of let-7a was slightly affected by the methylation, but the effect was not substantial. The methylation of let-7a-3, however, was inversely correlated with IGF-II expression and positively with insulin-like growth factor binding protein-3 (IGFBP-3) expression. Patients with methylated let-7a-3 seemed to have reduced risk for death compared with those without, and the association was independent of patient age at surgery, tumor grade, disease stage, and IGF-II or IGFBP-3 expression. No association was found for let-7a-3 methylation and disease progression. These results suggest that the let-7a-3 gene is methylated and the methylation may affect IGF-II expression and the survival of ovarian cancer patients. Further investigation of the role of miRNAs and their regulation in cancer is warranted.

ERCC1 Genotype and Phenotype in Epithelial Ovarian Cancer Identify Patients Likely to Benefit From Paclitaxel Treatment in Addition to Platinum-Based Therapy

Purpose

To investigate the effect of excision repair cross-complementation group 1 (ERCC1) on treatment response and survival of patients treated with platinum chemotherapy with or without paclitaxel.

Patients and Methods

Tumor samples from epithelial ovarian cancer patients were evaluated for ERCC1 mRNA expression and a single nucleotide polymorphism at codon 118 (C>T). Of 178 patients treated with postoperative platinum-based chemotherapy, 75 were also given paclitaxel. For all of these patients, ERCC1 expression and genotype were analyzed for associations with treatment response and survival.

Results

Among the 103 patients treated with platinum without paclitaxel, the C/C genotype, compared with C/T and T/T, was associated with greater risk of disease progression and death (hazard ratio [HR], 1.95, P = .051; HR, 2.01, P = .033, respectively); high levels of ERCC1 mRNA, compared with low levels, were associated with greater risk of disease progression (HR, 2.41; P = .014). Similarly, when the ERCC1 data were combined, patients with the C/C genotype and high ERCC1 expression had greater risk for disease progression (HR, 3.73; P = .003) compared with those with low expression and non-C/C genotype. However, for the 75 patients treated with platinum plus paclitaxel, the C/C genotype and high ERCC1 expression were not associated with poor prognosis, suggesting that paclitaxel may help to alleviate ERCC1-related platinum resistance.

Conclusion

Ovarian cancer patients with high ERCC1 expression or the C/C genotype at codon 118 may benefit from the combination of platinum and paclitaxel, while those with low ERCC1 expression or the C/T or T/T genotype may respond well to platinum without paclitaxel.