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The expression "lost at sea" means to be confused or perplexed. By extension, lost at SCLC references the current confusion about how to circumvent the chemoresistance, particularly platinum resistance, which so plagues the treatment of extensive-stage small cell lung cancer (ES-SCLC) that in 2012 the US National Cancer Institute (NCI) designated it a "recalcitrant cancer." Over a decade later, despite the approval of immune checkpoint inhibitors and the conditional approval of lurbinectedin, the prognosis for ES-SCLC, and especially platinum-resistant ES-SCLC, has scarcely improved. The focus of this review, which briefly summarizes current treatment options for ES-SCLC, is on five clinical-stage therapies with the potential to successfully reverse the platinum resistance that is perhaps the biggest obstacle to better clinical outcomes. [ABSTRACT FROM AUTHOR]

ImmunoGen developed mirvetuximab soravtansine as an antibody–drug conjugate comprising of a humanized anti-folate receptor—α (FRα) monoclonal antibody of IgG1k subtype, a cleavable linker, and a cytotoxic payload, DM4. Mirvetuximab soravtansine was granted accelerated approval by the US FDA on November 14, 2022, for the treatment of adult patients with FRα positive, platinum-resistant epithelial ovarian, fallopian tube or primary peritoneal cancer who have received 1—3 prior systemic treatment regimens. The approval of mirvetuximab soravtansine represents a breakthrough for addressing the unmet medical needs of ovarian cancer, especially for up to 80% of patients who relapse and become resistant to platinum-based chemotherapy, resulting in poor prognosis and limited treatment options. However, it is my impression that addressing several pharmacological factors could improve the safety and efficacy of mirvetuximab soravtansine. This article summarizes the current pharmacological profile of mirvetuximab soravtansine and provides an expert opinion on pharmacological strategies for optimizing its safety and efficacy profile for the treatment of platinum-resistant ovarian cancer. [ABSTRACT FROM AUTHOR]

Background: Increasing evidences has indicated that primary and acquired resistance of ovarian cancer (OC) to platinum is mediated by multiple molecular and cellular factors. Understanding these mechanisms could promote the therapeutic efficiency for patients with OC. Methods: Here, we screened the expression pattern of circRNAs in samples derived from platinum-resistant and platinum-sensitive OC patients using RNA-sequencing (RNA-seq). The expression of hsa_circ_0010467 was validated by Sanger sequencing, RT-qPCR, and fluorescence in situ hybridization (FISH) assays. Overexpression and knockdown experiments were performed to explore the function of hsa_circ_0010467. The effects of hsa_circ_0010467 on enhancing platinum treatment were validated in OC cells, mouse model and patient-derived organoid (PDO). RNA pull-down, RNA immunoprecipitation (RIP), and dual-luciferase reporter assays were performed to investigate the interaction between hsa_circ_0010467 and proteins. Results: Increased expression of hsa_circ_0010467 is observed in platinum-resistant OC cells, tissues and serum exosomes, which is positively correlated with advanced tumor stage and poor prognosis of OC patients. Hsa_circ_0010467 is found to maintain the platinum resistance via inducing tumor cell stemness, and silencing hsa_circ_0010467 substantially increases the efficacy of platinum treatment on inhibiting OC cell proliferation. Further investigation reveals that hsa_circ_0010467 acts as a miR-637 sponge to mediate the repressive effect of miR-637 on leukemia inhibitory factor (LIF) and activates the LIF/STAT3 signaling pathway. We further discover that AUF1 could promote the biogenesis of hsa_circ_0010467 in OC. Conclusion: Our study uncovers the mechanism that hsa_circ_0010467 mediates the platinum resistance of OC through AUF1/hsa_circ_0010467/miR-637/LIF/STAT3 axis, and provides potential targets for the treatment of platinum-resistant OC patients. [ABSTRACT FROM AUTHOR]

Platinum drugs, as a class of widely used chemotherapy agents, frequently appear in the treatment of cancer at different phrases. However, platinum resistance is the major bottleneck of platinum drugs for exerting anti-tumor effect. At present, the mechanism of platinum resistance has been thoroughly explored in terms of drug delivery methods, DNA damage repair function, etc., but it has not yet been translated into an effective weapon for reversing platinum resistance. Recently, autophagy has been proved to be closely related to platinum resistance, and the involved molecular mechanism may provide a new perspective on platinum resistance. The aim of this review is to sort out the studies related to autophagy and platinum resistance, and to focus on summarizing the relevant molecular mechanisms, so as to provide clues for future studies related to autophagy and platinum resistance. [ABSTRACT FROM AUTHOR]

Patients with platinum-resistant ovarian cancer (PROC) have limited therapeutic options and poor survival. There is a need for the development of newer therapies. Sodium valproic acid (VPA) is a short-chain fatty acid histone deacetylase (HDAC) inhibitor with antitumor activity in preclinical models of PROC. Synergism with conventional cytotoxic agents like etoposide has been demonstrated. In this prospective, single-arm, open-label, phase 2 study, we included patients ≥ 18 years with histologically or cytologically confirmed PROC and Eastern Cooperative Oncology Group performance status (ECOG-PS) 0–3. Patients received oral VPA 60 mg/kg/day in three divided doses for 3 days (D1–D3), followed by oral etoposide 50 mg once daily for two consecutive weeks (D4–D17). Serum samples were collected to assess peak VPA drug levels. The primary endpoint was the overall response rate (ORR). The secondary endpoints were progression-free survival (PFS), overall survival (OS), and toxicity. We sought to show an improvement in response rate from 25% (historically with oral etoposide) to 40% with the addition of VPA. 27 patients were enrolled in the study, and 18 [median age: 52 (45–59) years; serous histology:17 (94%); ECOG-PS 2 or 3: 14 (78%)] were evaluable for the response after 4 months. Nine patients were lost from follow-up before achieving the primary endpoint (mainly due to Covid-related lockdown issues). The median number of prior lines of treatment was 2 (1–3). ORR was 0% according to GCIG criteria. The disease was stable in two patients [clinical benefit rate (CBR) of 11%]. The median OS and PFS were 7 months and 2 months, respectively. Grade ≥ 3 adverse events were reported in 6 (33%) patients. The addition of valproic acid to oral etoposide in patients with PROC and poor general condition was not helpful and failed to improve responses compared to those historically achieved with single-agent etoposide. However, further phase 2 randomized controlled trials with larger sample size can be done to confirm the findings. [ABSTRACT FROM AUTHOR]

Chemoresistance is the inevitable outcome of chemotherapy for epithelial ovarian carcinoma (EOC), and its mechanism is still not fully understood. This study explored the role of ribosomal protein L23 (RPL23) in cisplatin resistance of EOC. WGCNA based on TCGA and GEO was used to screen and analyze target genes related to EOC chemotherapy sensitivity. Clinical samples of cisplatin resistance were collected to detect the expression of target genes. Cisplatin resistance was induced in EOC cell lines A2780 and SKOV3. The cell abilities of invasion, migration and adhesion were observed. Western blotting was used to detect protein expressions. Bioinformatics analysis showed that RPL23 may be related to EOC chemotherapy sensitivity, and was highly expressed in clinical samples and cell lines of cisplatin-resistant. After A2780 and SKOV3 were resistant to cisplatin, the inhibitory abilities of therapeutic dose of cisplatin on their invasion, migration and adhesion were significantly attenuated, and N-cadherin and vimentin were significantly up-regulated while E-cadherin was significantly down-regulated. However, above phenomena were significantly reversed after RPL23 knockdown. Taken together, the overexpressed RPL23 may lead to platinum resistance by inducing epithelial-mesenchymal transition (EMT) in EOC. Targeting knockdown RPL23 would restore the sensitivity of EOC cells to cisplatin by inhibiting EMT, suggesting that RPL23 is a potential therapeutic target for EOC after platinum resistance. [ABSTRACT FROM AUTHOR]

Background: Ovarian cancer is the deadliest of gynecologic malignancies with the 5-year overall survival rate remaining at approximately 30%, a rate that has not improved over the last three decades. Standard of care for epithelial ovarian cancer patients consists of a platinum compound with a taxane given intravenously following debulking surgery; however, 80% of cases relapse within 2 years of diagnosis. This review sought to identify key underlying biomarkers related to platinum resistance in ovarian cancer to establish possible prognostic biomarkers of chemoresponse. Methods: A systematic literature review was conducted across three databases PubMed, EMBASE and SCOPUS to summarise the evidence for prognostic biomarkers in platinum-resistant ovarian cancer patients. Results: Forty-eight human studies were used in the review encompassing 6719 participants in retrospective and prospective study designs. A total of 68 biomarkers were reported that were significantly correlated with chemoresponse and/or survival reporting a p value less than or equal to 0.05. Conclusion: This review accentuates the pleiotropic phenotypic complexities related to the response to platinum therapy in ovarian cancer. A one-size-fits-all approach may be ineffective in a large portion of patients, emphasising the need for a whole system-based approach and personalised treatment strategies. Identifying key biomarkers to aid clinical decision-making is the first essential step in developing and appropriating therapies for at-risk patients, reducing toxicity and improving quality of life. [ABSTRACT FROM AUTHOR]

Background: Angiogenesis is a driver of platinum resistance in ovarian cancer. We assessed the effect of combination pazopanib and paclitaxel followed by maintenance pazopanib in patients with platinum-resistant/refractory ovarian cancer. Integrins αvβ3 and αvβ5 are both upregulated in tumor-associated vasculature. [18F]Fluciclatide is a novel PET tracer that has high affinity for integrins αvβ3/5, and was used to assess the anti-angiogenic effect of pazopanib. Patients and methods: We conducted an open-label, phase Ib study in patients with platinum-resistant/refractory ovarian cancer. Patients received 1 week of single-agent pazopanib (800 mg daily) followed by combination therapy with weekly paclitaxel (80 mg/m2). Following completion of 18 weeks of combination therapy, patients continued with single-agent pazopanib until disease progression. Dynamic [18F]fluciclatide-PET imaging was conducted at baseline and after 1 week of pazopanib. Response (RECIST 1.1), toxicities, and survival outcomes were recorded. Circulating markers of angiogenesis were assessed with therapy. Results: Fourteen patients were included in the intention-to-treat analysis. Complete and partial responses were seen in seven patients (54%). Median progression-free survival (PFS) was 10.63 months, and overall survival (OS) was 18.5 months. Baseline [18F]fluciclatide uptake was predictive of long PFS. Elevated baseline circulating angiopoietin and fibroblast growth factor (FGF) were predictive of greater reduction in SUV60,mean following pazopanib. Kinetic modeling of PET data indicated a reduction in K1 and Ki following pazopanib indicating reduced radioligand delivery and retention. Conclusions: Combination therapy followed by maintenance pazopanib is effective and tolerable in platinum-resistant/refractory ovarian cancer. [18F]Fluciclatide-PET uptake parameters predict clinical outcome with pazopanib therapy indicating an anti-angiogenic response. [ABSTRACT FROM AUTHOR]

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Summary: Ovarian cancer (OC) is the foremost lethal gynaecologic malignancy and among the top five deadliest cancers in women. Current treatment comprises a combination therapy of surgery, platinum-based chemotherapy and anti-vascular endothelial growth factor (VEGF) antibodies. However, patients typically experience a disease relapse within two years. Recurrent OC is incurable and resistance to platins and anti-VEGF treatment is a major determinant of prognosis. Understanding the molecular mechanisms that contribute to tumour metastasis and chemoresistance are essential to improve patient outcome and especially survival. In a current OC model, tumour metastasis and chemoresistance critically depend on the biology of cancer stem cells (CSCs). Recent studies also suggest that intratumour heterogeneity is the main cause of treatment failure due to chemoresistance. Furthermore, the proinflammatory tumour microenvironment seems to contribute to metastasis and chemoresistance. Despite an improved understanding of the complex interplay between classical mechanisms of drug inactivation or efflux, clonal selection and the tumour microenvironment, mechanisms of resistance in human OC are poorly understood. This review summarises current concepts in the treatment of OC, mechanisms of resistance to chemotherapy and angiogenic inhibitors and approaches to overcome drug resistance. [ABSTRACT FROM AUTHOR]

Testicular tumors are the most common tumors in adolescent and young men and germ cell tumors (TGCTs) account for most of all testicular cancers. Increasing incidence of TGCTs among males provides strong motivation to understand its biological and genetic basis. Gains of chromosome arm 12p and aneuploidy are nearly universal in TGCTs, but TGCTs have low point mutation rate. It is thought that TGCTs develop from premalignant intratubular germ cell neoplasia that is believed to arise from the failure of normal maturation of gonocytes during fetal or postnatal development. Progression toward invasive TGCTs (seminoma and nonseminoma) then occurs after puberty. Both inherited genetic factors and environmental risk factors emerge as important contributors to TGCT susceptibility. Genome-wide association studies have so far identified more than 30 risk loci for TGCTs, suggesting that a polygenic model fits better with the genetic landscape of the disease. Despite high cure rates because of its particular sensitivity to platinum-based chemotherapy, exploration of mechanisms underlying the occurrence, progression, metastasis, recurrence, chemotherapeutic resistance, early diagnosis and optional clinical therapeutics without long-term side effects are urgently needed to reduce the cancer burden in this underserved age group. Herein, we present an up-to-date review on clinical challenges, origin and progression, risk factors, TGCT mouse models, serum diagnostic markers, resistance mechanisms, miRNA regulation, and database resources of TGCTs. We appeal that more attention should be paid to the basic research and clinical diagnosis and treatment of TGCTs. [ABSTRACT FROM AUTHOR]

Ovarian cancer is a leading cause of death among gynecologic malignancies. This disappointing prognosis is closely related to intrinsic or acquired resistance to conventional platinum-based chemotherapy, which can affect a third of patients. As such, investigating relevant molecular targets is crucial in the fight against this disease. So far, many mutations involved in ovarian cancer pathogenesis have been identified. Among them, a few pathways were implicated. One such pathway is the P13K/AKT/mTOR with abnormalities found in many cases. This pathway is considered to have an instrumental role in proliferation, migration, invasion and, more recently, in chemotherapy resistance. Many miRNAs have been found to influence P13K/AKT/mTOR pathway with different potential role in tumor genesis and ovarian cancer behaviour. In particular, their biological function was recently investigated as regards chemoresistance, therefore, leading to the identification of potential specific indirect biomarker of platinum sensitivity in ovarian cancer. [ABSTRACT FROM AUTHOR]

Purpose: To compare a cohort of patients with platinum-resistant recurrent ovarian cancer (PROC) treated with bevacizumab and gemcitabine (Bev-Gem) to that of patients treated only with gemcitabine (Gem).Methods: Between 2011 and 2017, we identified the Bev-Gem and Gem PROC groups. The regimen included 1000 mg/m2 of Gem on days 1, 8, and 15, and 15 mg/m2 of Bev on day 1, every 4 weeks. Progression-free survival (PFS) and overall survival (OS) were calculated from the date of the administration of Bev-Gem or Gem until disease progression or death.Results: The Bev-Gem and Gem groups included 18 and 29 patients, respectively. More patients had advanced stage disease in the Bev-Gem group (p = 0.048); no other characteristics differed between the groups. The response rates [ratio of complete remission (CR) to partial remission (PR)] of Bev-Gem and Gem were 38.9 and 3.4%, respectively (p < 0.01). The clinical benefit rates [combined percentages of CR, PR, and stable disease] of the Bev-Gem and Gem groups were 88.9 and 41.4%, respectively (p = 0.04). PFS and OS of the Bev-Gem group were superior (p < 0.01, p = 0.03, respectively). Bev-Gem was the better prognostic factor of both PFS [hazard ratio (HR) 0.17, p < 0.01] and OS (HR 0.31, p = 0.01). The frequency of hematologic and non-hematologic adverse effects was similar in each group.Conclusion: Bev-Gem regimens improved PFS and OS for PROC. Furthermore, the adverse effects of Bev-Gem were tolerable. Thus, Bev-Gem could be a candidate treatment strategy for PROC. [ABSTRACT FROM AUTHOR]

Background: Accumulating literature proved that miRNAs can regulate the sensitivity of platinum and act as a promising candidate to predict the response of patients with lung adenocarcinoma to chemotherapy. However, most studies on miRNAs were restricted to in vitro experiments. This study aimed to evaluate whether miRNAs alone or in combination (miRNA signature) can act as predictive biomarkers of platinum-based chemotherapy in patients with lung adenocarcinoma.Methods: Eight miRNAs that most probably predict the efficacy of platinum were screened in 111 tumor tissues of lung adenocarcinoma. Univariate and multivariate Cox analyses, Kaplan–Meier survival curve analysis, Chi-square test, and univariate and multivariate logistic regression analyses were employed to determine whether miRNA expression is associated with the response of patients to platinum-based chemotherapy. The maximum significant odds ratio value was acquired by multiple cycles of multivariate logistic regression analysis. The cut-off points of miRNAs were obtained. A miRNA chemo-sensibility index (CI) formula was established, and its prediction performance was confirmed in another independent set (n = 31).Results: Underexpression of three miRNAs (miRNA-21, miRNA-125b, and miRNA-224) was independently associated with the chemotherapy sensitivity of patients with lung adenocarcinoma. The miRNA CI formula containing these three miRNAs was calculated as (1.364 × miR-21) + (1.323 × miR-125b) + (1.131 × miR-224). A high CI was related to platinum-based chemotherapy resistance, and its prediction performance was confirmed in the testing set. The MAPK, PI3K-Akt, Ras, and cGMP-PKG signaling pathways were considered to be most probably correlated with platinum resistance.Conclusion: Our miRNA CI formula can act as an independent predictor to predict the response of patients with lung adenocarcinoma to platinum-based chemotherapy. [ABSTRACT FROM AUTHOR]

High grade serous ovarian cancer (HGSOC) patients have a high recurrence rate after surgery and adjuvant chemotherapy due to inherent or acquired drug resistance. Cell lines derived from HGSOC tumors that are resistant to chemotherapeutic agents represent useful pre-clinical models for drug discovery. Here, we describe establishment of a human ovarian carcinoma cell line, which we term WHIRC01, from a patient-derived mouse xenograft established from a chemorefractory HGSOC patient who did not respond to carboplatin and paclitaxel therapy. This newly derived cell line is platinum- and paclitaxel-resistant with cisplatin, carboplatin, and paclitaxel half-maximal lethal doses of 15, 130, and 20 µM, respectively. Molecular characterization of this cell line was performed using targeted DNA exome sequencing, transcriptomics (RNA-seq), and mass spectrometry-based proteomic analyses. Results from exomic sequencing revealed mutations in TP53 consistent with HGSOC. Transcriptomic and proteomic analyses of WHIRC01 showed high level of alpha-enolase and vimentin, which are associated with cell migration and epithelial-mesenchymal transition. WHIRC01 represents a chemorefractory human HGSOC cell line model with a comprehensive molecular profile to aid future investigations of drug resistance mechanisms and screening of chemotherapeutic agents. [ABSTRACT FROM AUTHOR]

Introduction: In developed countries, ovarian cancer is the fourth most common cancer in women. Due to the non-specific symptomatology associated with the disease many patients with ovarian cancer are diagnosed late, which leads to significantly poorer prognosis. Apart from surgery and radiotherapy, a substantial number of ovarian cancer patients will undergo chemotherapy and platinum based agents are the mainstream first-line therapy for this disease. Despite the initial efficacy of these therapies, many women relapse; therefore, strategies for second-line therapies are required. Regulation of DNA transcription is crucial for tumour progression, metastasis and chemoresistance which offers potential for novel drug targets. Methods: We have reviewed the existing literature on the role of histone deacetylases, nuclear enzymes regulating gene transcription. Results and conclusion: Analysis of available data suggests that a signifant proportion of drug resistance stems from abberant gene expression, therefore HDAC inhibitors are amongst the most promising therapeutic targets for cancer treatment. Together with genetic testing, they may have a potential to serve as base for patient-adapted therapies. [ABSTRACT FROM AUTHOR]

Purpose: Cluster of differentiation (CD) 44 is a cell surface receptor that correlates with the development of drug resistance in epithelial ovarian cancer (EOC). Here, we prospectively investigated the clinical impact of CD44 expression on the development of chemoresistance, and on disease-free and overall survival in EOC. Methods: This study included patients with primary serous EOC that was at International Federation of Gynecology and Obstetrics stages IIIB-IVA and tumors that were CD44 positive and negative in a 1:1 ratio. All patients underwent primary surgical cytoreduction, followed by six cycles of combined paclitaxel and carboplatin chemotherapy every 3 weeks. The treatment was considered complete after the chemotherapy had finished. All patients were followed up for 24 months after completing their chemotherapy. Results: Of the 96 patients with serous EOC at stages IIIB-IVA, 51 % of the tumors were negative for the expression of CD44 and 49 % showed variable CD44 expression. Patients who had CD44-positive tumors had statistically significant shorter disease-free ( p ≤ 0.001) and overall survival ( p ≤ 0.001) intervals compared with patients with CD44-negative tumors. The hazard ratio for death was 6.8 (95 % confidence interval 2.4-19.2, p ≤ 0.001) among the patients with CD44-positive tumors. A multivariate analysis showed that carboplatin-resistant or carboplatin-refractory EOC was the only independent predictive factor for death. Conclusions: CD44 expression contributes to the development of carboplatin resistance in advanced serous EOC, and it may contribute to worse prognoses for patients, but it is neither an independent predictor of survival nor of recurrence. [ABSTRACT FROM AUTHOR]

The microenvironment plays an important role in tumorigenesis. Fibroblast activation protein alpha (FAP) is overexpressed by fibroblasts present in the microenvironment of many tumors. High FAP expression is a negative prognostic factor in several malignancies, but this has not been investigated in epithelial ovarian cancer (EOC). The aim of this study is to define the value of FAP in EOC. Immunohistochemical staining using an anti-FAP antibody was performed on 338 EOC tissues. mRNA levels in cancer cell lines and FAP silencing using siRNA was also done. FAP immunoexpression by tumor stroma was a significant predictive factor for platinum resistance ( p = 0.0154). In survival analysis of days to recurrence, FAP stoma was associated with shorter recurrence than those with FAP stroma ( p = 0.0247). In 21.8 % of tumors, FAP protein was expressed by the tumor epithelium, and FAP mRNA was more highly expressed in tumors ( n = 489) than in normal tissues ( n = 8) ( p = 3.88 × 10). In vitro, addition of FAP to EOC cells induced a 10-12 % increase in cell viability both in the presence and absence of cisplatin. Conversely, siRNA silencing of FAP resulted in ~10 % reduction in EOC cell proliferation. We have shown that FAP expression in EOC is associated with poorer clinical outcomes. FAP may have novel cell-autonomous effects suggesting that targeting FAP could have pleiotropic anti-tumor effects, and anti-FAP therapy could be a highly effective novel treatment for EOC, especially in cisplatinum-resistant cases. [ABSTRACT FROM AUTHOR]

Purpose Preclinical data showed that trientine, a copper-lowering agent, re-sensitized cancer cells to carboplatin through enhanced human copper transporter 1 (hCtr1) -mediated platinum uptake. Experimental Design We studied carboplatin and trientine in patients ( n = 55; 45 who had failed platinum) with advanced malignancies (Phase I, modified 3 + 3 design). Results The most common cancers were head and neck ( n = 13), non-small cell lung ( n = 10) and epithelial ovarian ( n = 8). The median number of prior regimens was four. No dose-limiting toxicity or treatment-related deaths were observed at doses up to carboplatin AUC 6 given with trientine. Eight patients achieved stable disease (SD) ≥ 6 months (six platinum failures) and one patient with platinum-resistant ovarian cancer, partial response (PR) (total SD ≥ 6 months/PR = 9, 16.4 %). The mean nadir serum copper level in the nine patients with SD ≥ 6 months/PR was 0.55 μg/mL (95 % CI, 0.34-0.75) versus 1.22 μg/mL (95 % CI, 1.02-1.42) ( p < 0.001) in 38 tested patients with progression. In patients who maintained their ceruloplasmin (major copper-carrying protein) levels at 5-15 mg/dL ( n = 9), the median progression-free and overall survivals were 9.2 and 15.2 months versus 1.9 ( p = 0.001) and 5.7 months ( p = 0.033) in patients who did not ( n = 38), respectively. Conclusions The combination of a copper-lowering agent with carboplatin was well tolerated and associated with antitumor activity, especially in patients in whom copper and/or ceruloplasmin levels were lowered. Further investigation of this strategy for reversing platinum resistance is warranted. [ABSTRACT FROM AUTHOR]

Purpose: Stage, tumor grade and histological subtype determine the clinical behavior in ovarian tumors. Some additional factors are related to tumor cell biology and are the useful predictors for identifying the patients with poor prognosis. The aim of this study is to evaluate the prognostic significance of survivin, Ki-67 and Topoisomerase IIα (TOPO IIα) in epithelial ovarian cancer (EOC). Materials and methods: Seventy-three patients with EOC were included in this study. Survivin, Ki-67 and TOPO IIα expressions were studied by immunohistochemistry on formalin-fixed, paraffin-embedded tissue sections. Nuclear staining for all antibodies was scored on a three-tiered system and more than 10 % staining was accepted as expression. The relationship between the expressions of survivin, Ki-67, TOPO IIα and clinicopathological parameters including age, stage, grade, platinum resistance and survival was evaluated. Results: Survivin, Ki-67 and TOPO IIα expressions were found in 20, 82 and 86 % of the tumors, respectively. Ki-67 and TOPO IIα expressions were found to be related to poor overall survival ( p = 0.005, 0.004, respectively), while survivin expression was not associated with overall survival. There was no association between TOPO IIα and Ki-67 expressions and histological subtype, stage or grade. However, we found an important relationship between TOPO IIα expression and platinum resistance ( p = 0.044). Platinum resistance was found to be an independent prognostic factor in EOC. Conclusion: Ki-67 and TOPO IIα expressions were found to be related to poor overall survival, and TOPO IIα expression was found to be associated with platinum resistance. [ABSTRACT FROM AUTHOR]

Ovarian carcinoma patients are initially responsive to platinum-based therapy, but eventually become refractory to treatment due to the development of platinum chemoresistance. Elevated levels of interleukin-6 (IL-6) in the sera and ascites of these patients predict poor clinical outcome. Our goal was to analyze the interaction between cisplatin and cisplatin-resistant ovarian cancer cells, and to identify means of circumventing platinum resistance. We studied ovarian carcinoma cell lines and cells drawn from ovarian carcinoma patients. Gene array analyses were performed on ovarian carcinoma cells upon treatment with cisplatin, and the results were validated by ELISA and Western blotting (WB). Cytotoxicity assays were performed on anti-IL-6 Ab-, IL-6-, and cellular inhibitor of apoptosis 2 (cIAP-2) siRNA-treated cells, following cisplatin addition. Our results revealed a highly significant increase in IL-6 and cIAP-2 mRNA and protein levels upon treatment with cisplatin. WB analysis of cisplatin-treated cells exhibited decreased cIAP-2 expression level following anti-IL-6 Ab addition. Furthermore, IL-6 by itself, significantly increased cIAP-2 levels in ovarian carcinoma cells. Finally, cytotoxicity assays showed sensitization to cisplatin following the addition of IL-6 and cIAP-2 inhibitors. In conclusion, cisplatin treatment of ovarian carcinoma cells upregulates IL-6 and cIAP-2 levels while their inhibition significantly sensitizes them to cisplatin. Here, we present cIAP-2 as a novel inducer of platinum resistance in ovarian carcinoma cells, and suggest an axis beginning with an encounter between cisplatin and these cells, mediated sequentially by IL-6 and cIAP-2, resulting in cisplatin resistance. Consequently, we propose that combining IL-6/cIAP-2 inhibitors with cisplatin will provide new hope for ovarian carcinoma patients by improving the current treatment. [ABSTRACT FROM AUTHOR]

Background: The aim of this phase II study was to evaluate the efficacy and toxicity of docetaxel and irinotecan combination chemotherapy in patients with ovarian cancer refractory and resistant to both platinum and taxan treatment. Patients and methods: Patients who had been treated with platinum and paclitaxel but whose ovarian cancer progressed or recurred within 6 months of treatment ( n = 41) received docetaxel 60 mg/m (day 1) and irinotecan 60 mg/m (days 1, 8), repeated every 21 days [Japan Gynecologic Oncology Group (JGOG) study 3015] or every 28 days [West Japan Gynecologic Oncology Group (WJGOG) study 002] until disease progression was observed or unacceptable toxicity. Sixteen patients had platinum/paclitaxel-refractory disease, and 25 patients had platinum/paclitaxel-resistant disease. Results: Thirty-two patients were available for determination of the clinical response. The overall response rate [complete response (CR) + partial response (PR)] was 6.3%, and the disease control rate (CR + PR + stable disease) was 34.4%. Among the 23 patients with resistant tumor, the disease control rate was 47.8%. Ten patients with refractory tumor showed a 10% disease control rate. The median progression-free interval was 12.1 weeks and the median overall survival time was 45.3 weeks. The major toxic adverse effect was neutropenia (grade 4, 56.1%), but the incidence of neutropenic fever was less frequent (4.9%). Neurotoxicity and gastro-intestinal toxicity were mild. Conclusion: Among our patients, a combination of docetaxel and irinotecan was well tolerated. However, this combination may not be a beneficial option for patients with platinum-refractory and -resistant ovarian cancer in terms of response rate and survival. [ABSTRACT FROM AUTHOR]

Purpose: We aimed to identify primary platinum resistance in epithelial ovarian cancer (OC) patients with FIGO stage III-IV disease by an in vitro drug-response assay and to correlate the findings with clinical response. We considered whether neoadjuvant chemotherapy or anatomic sample site and tumor heterogeneity would influence the results. Methods: We combined the ATP-based tumor-chemosensitivity and the extreme drug resistance assays for testing of 85 biopsies from 58 patients. Tumors were classified as sensitive or resistant by a resistance index (RI). We did separate analyses of primary tumors and metastases and compared chemo-naïve samples with samples obtained after neoadjuvant chemotherapy. Results were analyzed for association with clinical platinum resistance, progression-free survival (PFS), and overall survival (OS). Results: RI ≤ 250 predicted primary platinum resistance, without misclassification of sensitive patients. The test sensitivity for primary tumors was 15/15, specificity 3/10, negative predictive value 3/3, and positive predictive value 15/22. Patients with in vitro platinum-resistant samples had shorter PFS compared with patients with sensitive samples (3.4 vs. 10.0 months, p = 0.02). Comparing patient-matched primary and metastatic samples, there was about 1/3 mismatch in resistance. RI for platinum was lower in primary tumors exposed to neoadjuvant chemotherapy than in chemo-naïve tumors ( p < 0.01). Conclusions: This in vitro assay predicted primary platinum resistance, without misclassification of sensitive OC patients, and the results were significantly associated with PFS. We suggest that samples from primary tumor and metastatic samples have different responses to chemotherapy and that exposure to chemotherapy might induce in vitro platinum resistance. [ABSTRACT FROM AUTHOR]

Today most of the available platinum thin-film (TF) resistance thermometers tend to exceed the IEC 60751 Class A tolerances for temperatures above about 400 °C and below about −50 °C. The main reason for this behavior is their specific R( T) characteristic which systematically and reproducibly differs from the standard characteristic to IEC 60751. This could be proven in the context of an extensive comparison test. However, just recently the first types of a new generation of Pt TF sensors that no longer show this typical characteristic deviation but which adhere to the tolerance class A according to the IEC 60751 standard in the temperature range of ≤−50 °C to 660 °C have become available. [ABSTRACT FROM AUTHOR]

MUC1 (CA15-3) and MUC16 (CA125) tumor-associated antigens are upregulated in ovarian cancer and can be detected in patients' sera by standardized tests. We postulated that increased MUC1 and MUC16 antigens augment antibody responses in platinum-resistant ovarian cancer patients and that the frequency and intensity of these responses can be used as immune biomarkers of treatment response and disease outcome. We measured MUC1 and MUC16 tumor expression by immunohistochemistry (IHC), assessed serum antigenic levels and quantitated circulating antibodies by ELISA in a cohort of 28 ovarian cancer patients with platinum-resistant or platinum-refractory ovarian cancer, and treated with intraperitoneal (IP) interleukin-2 (IL-2). MUC1 and MUC16 were overexpressed in tumor samples and showed differential distribution profiles. Serum MUC1 (CA15-3) measurements were elevated in all patients and significantly correlated with increased risk of death ( P = 0.003). MUC1-specific IgM and IgG anitbodies were found in 92 and 50% of cases, respectively. Patients with progressive disease had higher mean anti-MUC1 IgG than responders at both early ( P = 0.025) and late ( P = 0.022) time points during IP IL-2 treatment. Anti-MUC1 IgM antibodies inversely correlated with overall survival at both early ( P = 0.052) and late ( P = 0.009) time points. In contrast to MUC1, neither soluble MUC16 nor MUC16-specific antibodies were significantly associated with clinical response or overall survival in this study. Increased serum MUC1 and high anti-MUC1 antibody levels are prognostic for poor clinical response and reduced overall survival in platinum-resistant or platinum-refractory ovarian cancer. [ABSTRACT FROM AUTHOR]

Purpose: We analyzed the anti-tumor effect and the mechanism of action of perifosine, an orally active alkylphospholipid AKT inhibitor using in vitro models of human ovarian cancer. Methods: Ovarian cancer cells OAW42, PA-1, SKOV3, and A2780 as well as platinum resistant A2780cis cells were incubated with increasing concentrations of perifosine, with and without multi-caspase inhibitor zVAD-FMK. The effect of a combined treatment with cisplatin and perifosine was investigated in OAW42, SKOV3, A2780 and A2780cis cells. Cytotoxic effects of perifosine were analyzed using crystal violet staining, FACS analysis of DNA content as well as Annexin V/propidium iodide-double staining. The effect of perifosine on AKT phosphorylation was determined by Western blotting. Results: Perifosine displayed anti-tumor activity in all five cell lines, which increased time-dependently. While IC values at 24 h were >40 μM, IC values after 72 h decreased to 10 μM in OAW42 and 25 μM in PA-1 and 30 μm in SKOV3 cells. In platinum resistant A2780cis cells perifosine showed good antiproliferative activity (IC = 3 μm). At adequate doses, perifosine increased cytotoxic effects of cisplatin in OAW42, A2780 and A2780cis cell. Anti-tumor activity of perifosine was not confined to a specific phase of the cell cycle and could not be decreased by the pan-caspase inhibitor zVAD-FMK. AnnexinV/propidium iodide-double staining after treatment with perifosine was not indicative of classical apoptosis. AKT phosphorylation was dose-dependently inhibited by perifosine. Conclusions: Perifosine showed substantial cytotoxic effects in various in vitro models of ovarian cancer. Since anti-tumor effects were not confined to platinum-sensitive cells perifosine seems to be a good candidate for clinical studies in patients especially with platinum resistant ovarian cancer. [ABSTRACT FROM AUTHOR]

Purpose: To understand the mechanisms behind platinum drug/DENSPM-induced inhibition of cancer cell growth, we compared the effects of oxaliplatin and cisplatin when combined with DENSPM on the induction of SSAT mRNA, activity, polyamines and cell growth in A2780 human ovarian carcinoma cells and their oxaliplatin- and cisplatin-resistant variants A2780/C10B and A2780/CP, respectively. Methods: Parental and Pt-resistant cells were treated with platinum agent alone, DENSPM alone or combination (10 μM each, 20 h). QRT-PCR, radioactive product measurement and HPLC were used for mRNA, activity and polyamine pools, respectively; drug interaction on cell growth was by SRB and isobologram analysis. Results: Both platinum agents induced SSAT mRNA in parental A2780 cells, but not in resistant cells. Platinum drug/DENSPM combinations produced high levels of SSAT activity in parental cells with significant depletion of spermine and spermidine, but not in resistant cells. Co-treatment with platinum agents increased the levels of DENSPM in all cell lines. Oxaliplatin/DENSPM combination was superior to cisplatin/DENSPM in the inhibition of cell growth in parental cells. No synergy was observed in the resistant cells. Conclusions: Increased DENSPM levels following co-treatment with Pt agents enhances the translation and stability of SSAT protein leading to polyamine pool depletion, facilitating more Pt-DNA adduct formation in parental cells. Oxaliplatin/DENSPM combination is superior to cisplatin/DENSPM in cell growth inhibition as DACH-Pt DNA adducts are cytotoxic even at relatively fewer numbers. Reduced platinum uptake in Pt-resistant cells contributes to reduced SSAT mRNA induction and absence of synergy when combined with DENSPM. [ABSTRACT FROM AUTHOR]

To evaluate drug resistance after exposure to neoadjuvant chemotherapy and to postoperative chemotherapy in epithelial ovarian, fallopian, and primary peritoneal carcinomas. In vitro drug resistance assay results (EDR Assay, Oncotech, Inc.) for platinum and taxane were evaluated for the following three groups: (1) primary cytoreductive surgery without prior chemotherapy; (2) primary cytoreductive surgery after neoadjuvant chemotherapy with platinum and taxane; and (3) recurrent cases after postoperative chemotherapy with platinum and taxane. Proportions of extreme drug resistance (EDR) were analyzed with Fisher’s exact test. There were 277 cases that underwent primary cytoreductive surgery without prior chemotherapy: 14 cases of primary cytoreductive surgery after neoadjuvant chemotherapy with platinum and taxane, and 65 recurrent cases. Primary cytoreductive cases following neoadjuvant chemotherapy displayed an increased proportion of EDR to platinum agents compared to primary cytoreductive surgery without prior chemotherapy: neoadjuvant versus non-neoadjuvant, cisplatin 30 versus 7.3%, OR 5.4, 95%CI 1.3–23.2, P = 0.027; carboplatin 33.3 versus 9.2%, OR 4.9, 95%CI 1.4–17.6, P = 0.038. There were no differences in the proportion of EDR to taxanes between the two groups. On the contrary, recurrent cases showed an increased proportion of EDR to paclitaxel compared to primary cytoreductive surgery without prior chemotherapy: recurrent versus primary, paclitaxel 33.3 versus 21.1%, OR 1.9, 95%CI 1.0–3.5, P = 0.031. There were no differences in the proportion of EDR for platinum and docetaxel between the two groups. Among recurrent cases, there was statistical significance between proportion of paclitaxel EDR and time interval of initial and recurrent surgeries ( R2 0.143, P = 0.011). Recurrent surgery after 5 years from initial cytoreduction was significantly associated with increased proportion of EDR to paclitaxel: 61.5 versus 22.6%, OR 5.5, 95%CI 1.35–22.2, P = 0.011. Platinum resistance was common after neoadjuvant chemotherapy, while paclitaxel resistance was common after postoperative chemotherapy. [ABSTRACT FROM AUTHOR]

Background: Loss of HLA class I is important in ovarian cancer prognosis but its role as a prognostic indicator in relation to therapy remains unproven. We studied the prognostic potential of this antigen and its significance in relation to platinum therapy.Methods: A total of 157 primary ovarian cancers were assessed for HLA class I immunohistochemically and linked to a comprehensive database of clinicopathological variables, treatment details, and platinum sensitivity.Results: Tumours expressing high levels of HLA class I had significantly improved survival (P=0.044). There was a 19-month difference in the median overall survival between tumours with high and low antigen expression. HLA class I antigen expression, stage, and platinum sensitivity were independently predictive of prognosis on multivariate analysis. HLA class I antigen was shown to be expressed at higher levels in patients with good overall survival in platinum-resistant patients (P=0.042). HLA class I significantly correlated with overall survival on multivariate analyses (P=0.034).Conclusion: Low-level HLA class I expression is an independent prognostic indicator of poor clinical outcome in ovarian cancer. The survival advantage of patients with platinum-resistant tumours expressing high levels of HLA class I suggests that immunotherapy may be of use in these ovarian cancers resistant to standard chemotherapy. [ABSTRACT FROM AUTHOR]

Previous studies have described one nuclear localization signal (NLSI) in p53 and speculated on two additional sites termed NLSII and NLSIII. Drug-resistant KB cells selected with cisplatin or oxaliplatin were found to have increased p53 levels and in oxaliplatin-selected cells, a larger p53 predominantly in the cytoplasm. In oxaliplatin-selected cells a single nucleotide deletion in the sequence-encoding amino acid 382, part of NLSIII, resulted in a frame shift and a 420 amino acid protein (p53420). We investigated explanations for the cytoplasmic sequestration of p53420 while assessing the role, if any, of NLSII and NLSIII in p53 nuclear import. We found that neither NLSII nor NLSIII are essential for p53 nuclear localization. Furthermore, we confirmed p53420 is able to tetramerize, transactivate a p21 promoter, bind dynein and that the reduced nuclear accumulation is not a consequence of increased p53 nuclear export. However, the association of p53420 with importin-β, essential for nuclear import, was significantly impaired. We conclude that despite sequence similarity to consensus NLSs neither NLSII nor NLSIII have roles in p53 nuclear transport. We also identified impaired association with importin as a novel mechanism of p53 cytoplasmic sequestration that impairs nuclear transport rendering cells functionally deficient in p53. [ABSTRACT FROM AUTHOR]

Gemcitabine has been recommended as an active agent for salvage chemotherapy in patients with recurrent epithelial ovarian cancer, but no clinical study of this agent has been conducted for Japanese women with ovarian cancer. To evaluate the efficacy and feasibility of gemcitabine for heavily pretreated Japanese patients with recurrent epithelial ovarian cancer, we conducted a single-institute phase II clinical trial. All patients had received a minimum of two previous chemotherapy regimens, In this study, gemcitabine was administered at 1000 mg/m2 on days 1, 8, and 15 of a 28-day cycle. A total of 28 patients participated in this study. Although 5 patients (17.9%) needed dose reduction to 800 mg/m2 because of thrombocytopenia and granulocytopenia, all patients completed an average of 6.7 courses (range, 2–24 courses). The overall response rate, including five partial responses, was 17.9% (95% confidence interval [C I], 6.0–36.9). The median time to progression was 8.8 months and the median survival period was 11.2 months. Grade 3/4 hematological toxicities included leucopenia, 35.7%; granulocytopenia, 39.3%; anemia, 46.4%; and thrombocytopenia, 10.7%. However, no grade 3/4 nonhematological toxicity was observed. The mean delay in treatment was 5.0 ± 7.7 days (range, 0–15 days) in a total of 562 cycles. Single-agent gemcitabine is an effective salvage chemotherapy regimen in heavily pretreated Japanese patients with recurrent epithelial ovarian cancer. [ABSTRACT FROM AUTHOR]

The Fanconi gene family has a role in DNA repair and inactivation of FANCF has been proposed as a mechanism of sensitisation to platinum chemotherapy. This study sought to confirm this hypothesis in cell lines and a large series of ovarian cancer samples. Promoter methylation was assessed by methylation-sensitive polymerase chain reaction of FANCF in nine ovarian cancer cell lines and 74 ovarian cancer samples taken from patients entered on a trial of cisplatin-based chemotherapy. This study confirmed methylation-dependent silencing of FANCF in one out of nine ovarian cancer cell lines. Methylation of FANCF was demonstrated in 13.2% of 53 evaluable ovarian tumour samples. Progression-free survival gave an HR of 3.63 (95% CI: 1.54-8.54, P=0.0016) in favour of the unmethylated cases. There was no association with overall survival. This study does not support methylation-dependent silencing of FANCF as a mechanism of sensitisation to platinum-based chemotherapy in ovarian cancer. [ABSTRACT FROM AUTHOR]

Oxaliplatin (Eloxatine) is a third-generation platinum compound which has shown a wide antitumour effect both in vitro and in vivo, a better safety profile than cisplatin and a lack of cross-resistance with cisplatin and carboplatin. In this scenario, oxaliplatin may represent an innovative and challenging drug extending the antitumour activity in diseases such as gastrointestinal cancer that are not usually sensitive to these coordination complexes. Oxaliplatin has a non-hydrolysable diaminocyclohexane (DACH) carrier ligand which is maintained in the final cytotoxic metabolites of the drug. Like cisplatin, oxaliplatin targets DNA producing mainly 1,2-GG intrastrand cross-links. The cellular and molecular aspects of the mechanism of action of oxaliplatin have not yet been fully elucidated. However, the intrinsic chemical and steric characteristics of the DACH-platinum adducts appear to contribute to the lack of cross-resistance with cisplatin. To date, mismatch repair and replicative bypass appear to be the processes most likely involved in differentiating the molecular responses to these agents. [ABSTRACT FROM AUTHOR]

The standard definition of platinum-resistant ovarian cancer or primary peritoneal carcinoma commonly includes patients whose disease initially responded to a platinum-based combination regimen, but recurred less than 6 months after the completion of primary therapy. Recent experience with several patients with these malignancies treated in the Gynecologic Cancer Program of the Cleveland Clinic Foundation, whose disease recurred within this period but who subsequently responded to platinum therapy, calls into question the validity and clinical relevance of this commonly employed definition, both for the conduct of phase 2 trials of new agents in ovarian cancer and primary peritoneal carcinoma, and for the standard management of women in this clinical setting. [ABSTRACT FROM AUTHOR]