Antiandrogen Flutamide-Induced Restoration of miR-449 Expression Mitigates Functional Biomarkers Associated with Ovarian Cancer Risk.

Background: The involvement of the androgen and androgen receptor (AR) pathway in the development of epithelial ovarian cancer is increasingly recognized. However, the specific mechanisms by which anti-androgen agents, such as flutamide, may prevent ovarian cancer and their efficacy remain unknown. We examined the effects of flutamide on the miRNA expression profile found in women at high risk (HR) for ovarian cancer. Methods: Ovarian and tubal tissues, free from ovarian, tubal, peritoneal cancers, and serous tubal intraepithelial carcinoma (STIC), were collected from untreated and flutamide-treated HR women. Low-risk (LR) women served as controls. Transcriptomic miRNA sequencing was performed on these 3 sample cohorts. The miRNAs that showed the most notable differential expression were subjected to functional assays in primary ovarian epithelial cells and ovarian cancer cells. Results: Flutamide treatment demonstrated a normalization effect on diminished miRNA levels in HR tissues compared to LR tissues. Particularly, the miR-449 family was significantly upregulated in HR ovarian tissues following flutamide treatment, reaching levels comparable to those in LR tissues. MiR-449a and miR-449b-5p, members of the miR-449 family, were computationally predicted to target the mRNAs of AR and colony-stimulating factor 1 receptor (CSF1R, also known as c-fms), both of which are known contributors to ovarian cancer progression, with emerging evidence also supporting their roles in ovarian cancer initiation. These findings were experimentally validated in primary ovarian epithelial cells and ovarian cancer cell lines (SKOV3 and Hey): flutamide treatment resulted in elevated levels of miR-449a and miR-449b-5p, and introducing mimics of these miRNAs reduced the mRNA and protein levels of CSF1R and AR. Furthermore, introducing miR-449a and miR-449b-5p mimics showed inhibitory effects on the migration and proliferation of ovarian cancer cells. Conclusion: Flutamide treatment restored the reduced expression of miR-449a and miR-449b-5p in HR tissues, thereby decreasing the expression of CSF1R and AR, functional biomarkers associated with an increased risk of ovarian cancer. In addition to the known direct binding of flutamide to the AR, we found that flutamide also suppresses AR expression via miR-449a and miR-449b-5p upregulation, revealing a novel dual-inhibitory mechanism on the AR pathway. Taken together, our study highlights mechanisms supporting the chemopreventive potential of flutamide in ovarian cancer, particularly in HR patients with reduced miR-449 expression.

A phase III, multicenter, randomized study of olvimulogene nanivacirepvec followed by platinum-doublet chemotherapy and bevacizumab compared with platinum-doublet chemotherapy and bevacizumab in women with platinum-resistant/refractory ovarian cancer.

BACKGROUND: Treatment options for patients with platinum-resistant/refractory ovarian cancers are limited and only marginally effective. The development of novel, more effective therapies addresses a critical unmet medical need. Olvimulogene nanivacirepvec (Olvi-Vec), with its strong immune modulating effect on the tumor microenvironment, may provide re-sensitization to platinum and clinically reverse platinum resistance or refractoriness in platinum-resistant/refractory ovarian cancer. PRIMARY OBJECTIVE: The primary objective is to evaluate the efficacy of intra-peritoneal Olvi-Vec followed by platinum-based chemotherapy and bevacizumab in patients with platinum-resistant/refractory ovarian cancer. STUDY HYPOTHESIS: This phase III study investigates Olvi-Vec oncolytic immunotherapy followed by platinum-based chemotherapy and bevacizumab as an immunochemotherapy evaluating the hypothesis that such sequential combination therapy will prolong progression-free survival (PFS) and bring other clinical benefits compared with treatment with platinum-based chemotherapy and bevacizumab. TRIAL DESIGN: This is a multicenter, prospective, randomized, and active-controlled phase III trial. Patients will be randomized 2:1 into the experimental arm treated with Olvi-Vec followed by platinum-doublet chemotherapy and bevacizumab or the control arm treated with platinum-doublet chemotherapy and bevacizumab. MAJOR INCLUSION/EXCLUSION CRITERIA: Eligible patients must have recurrent, platinum-resistant/refractory, non-resectable high-grade serous, endometrioid, or clear-cell ovarian, fallopian tube, or primary peritoneal cancer. Patients must have had ≥3 lines of prior chemotherapy. PRIMARY ENDPOINT: The primary endpoint is PFS in the intention-to-treat population. SAMPLE SIZE: Approximately 186 patients (approximately 124 patients randomized to the experimental arm and 62 to the control arm) will be enrolled to capture 127 PFS events. ESTIMATED DATES FOR COMPLETING ACCRUAL AND PRESENTING RESULTS: Expected complete accrual in 2024 with presentation of primary endpoint results in 2025. TRIAL REGISTRATION: NCT05281471.

NRF2 controls iron homeostasis and ferroptosis through HERC2 and VAMP8.

Enhancing the intracellular labile iron pool (LIP) represents a powerful, yet untapped strategy for driving ferroptotic death of cancer cells. Here, we show that NRF2 maintains iron homeostasis by controlling HERC2 (E3 ubiquitin ligase for NCOA4 and FBXL5) and VAMP8 (mediates autophagosome-lysosome fusion). NFE2L2/NRF2 knockout cells have low HERC2 expression, leading to a simultaneous increase in ferritin and NCOA4 and recruitment of apoferritin into the autophagosome. NFE2L2/NRF2 knockout cells also have low VAMP8 expression, which leads to ferritinophagy blockage. Therefore, deletion of NFE2L2/NRF2 results in apoferritin accumulation in the autophagosome, an elevated LIP, and enhanced sensitivity to ferroptosis. Concordantly, NRF2 levels correlate with HERC2 and VAMP8 in human ovarian cancer tissues, as well as ferroptosis resistance in a panel of ovarian cancer cell lines. Last, the feasibility of inhibiting NRF2 to increase the LIP and kill cancer cells via ferroptosis was demonstrated in preclinical models, signifying the impact of NRF2 inhibition in cancer treatment.

A Phase III Study of Pafolacianine Injection (OTL38) for Intraoperative Imaging of Folate Receptor-Positive Ovarian Cancer (Study 006).

PURPOSE: The adjunctive use of intraoperative molecular imaging (IMI) is gaining acceptance as a potential means to improve outcomes for surgical resection of targetable tumors. This confirmatory study examined the use of pafolacianine for real-time detection of folate receptor-positive ovarian cancer. METHODS: This phase III, open-label, 11-center study included subjects with known or suspected ovarian cancer, scheduled to undergo cytoreductive surgery. The objectives were to confirm safety and efficacy of pafolacianine (0.025 mg/kg IV), given ≥ 1 hour before intraoperative near-infrared imaging to detect macroscopic lesions not detected by palpation and normal white light. RESULTS: From March 2018 through April 2020, 150 patients received a single infusion of pafolacianine (safety analysis set); 109 patients with folate receptor-positive ovarian cancer comprised the full analysis set for efficacy. In 33.0% of patients (95% CI, 24.3 to 42.7; P < .001), pafolacianine with near-infrared imaging identified additional cancer on tissue not planned for resection and not detected by white light assessment and palpation, exceeding the prespecified threshold of 10%. Among patients who underwent interval debulking surgery, the rate was 39.7% (95% CI, 27.0 to 53.4; P < .001). The sensitivity to detect ovarian cancer was 83%, and the patient false-positive rate was 24.8%. Investigators reported achieving complete R0 resection in 62.4% (68 of 109) of patients. Drug-related adverse events were reported by 30% of patients (45 of 150) and most commonly included nausea, vomiting, and abdominal pain. No drug-related serious adverse events or deaths were reported. CONCLUSION: This phase III study of pafolacianine met its primary efficacy end point, identifying additional cancers not otherwise identified or planned for resection. Pafolacianine may offer an important real-time adjunct to current surgical approaches for ovarian cancer.

Advances in Chemotherapy and Targeted Therapies in Endometrial Cancer.

Endometrial cancer is now recognized to be several diseases with differing biology and responses to treatment. Improved molecular characterization has furthered the development and testing of targeted therapies in the different cohorts of endometrial cancer. Lessons are being learned from other cancers that share similar molecular typing, and hence, potentially similar tumor behavior. This commentary serves as a broad overview of the types of advances to which our patients now have access.

Dissection of transcriptome dysregulation and immune characterization in women with germline BRCA1 mutation at single-cell resolution.

BACKGROUND: High-grade serous carcinoma (HGSC) is the most frequent and lethal type of ovarian cancer. It has been proposed that tubal secretory cells are the origin of ovarian HGSC in women with familial BRCA1/2 mutations. However, the molecular changes underlying malignant transformation remain unknown. METHOD: We performed single-cell RNA and T cell receptor sequencing of tubal fimbriated ends from 3 BRCA1 germline mutation carriers (BRCA1 carriers) and 3 normal controls with no high-risk history (non-BRCA1 carriers). RESULTS: Exploring the transcriptomes of 19,008 cells, predominantly from BRCA1+ samples, we identified 5 major cell populations in the fallopian tubal mucosae. The secretory cells of BRCA1+ samples had differentially expressed genes involved in tumor growth and regulation, chemokine signaling, and antigen presentation compared to the wild-type BRCA1 controls. There are several novel findings in this study. First, a subset of the fallopian tubal secretory cells from one BRCA1 carrier exhibited an epithelial-to-mesenchymal transition (EMT) phenotype, which was also present in the mucosal fibroblasts. Second, we identified a previously unreported phenotypic split of the EMT secretory cells with distinct evolutionary endpoints. Third, we observed increased clonal expansion among the CD8+ T cell population from BRCA1+ carriers. Among those clonally expanded CD8+ T cells, PD-1 was significantly increased in tubal mucosae of BRCA1+ patients compared with that of normal controls, indicating that T cell exhaustion may occur before the development of any premalignant or malignant lesions. CONCLUSION: These results indicate that EMT and immune evasion in normal-looking tubal mucosae may represent early events leading to the development of HGSC in women with BRCA1 germline mutation. Our findings provide a probable molecular mechanism explaining why some, but not all, women with BRCA1 germline mutation present with early development and rapid dissemination of HGSC.

Adavosertib with Chemotherapy in Patients with Primary Platinum-Resistant Ovarian, Fallopian Tube, or Peritoneal Cancer: An Open-Label, Four-Arm, Phase II Study.

PURPOSE: This study assessed the efficacy, safety, and pharmacokinetics of adavosertib in combination with four chemotherapy agents commonly used in patients with primary platinum-resistant ovarian cancer. PATIENTS AND METHODS: Women with histologically or cytologically confirmed epithelial ovarian, fallopian tube, or peritoneal cancer with measurable disease were enrolled between January 2015 and January 2018 in this open-label, four-arm, multicenter, phase II study. Patients received adavosertib (oral capsules, 2 days on/5 days off or 3 days on/4 days off) in six cohorts from 175 mg once daily to 225 mg twice daily combined with gemcitabine, paclitaxel, carboplatin, or pegylated liposomal doxorubicin. The primary outcome measurement was overall response rate. RESULTS: Three percent of patients (3/94) had confirmed complete response and 29% (27/94) had confirmed partial response. The response rate was highest with carboplatin plus weekly adavosertib, at 66.7%, with 100% disease control rate, and median progression-free survival of 12.0 months. The longest median duration of response was in the paclitaxel cohort (12.0 months). The most common grade ≥3 adverse events across all cohorts were neutropenia [45/94 (47.9%) patients], anemia [31/94 (33.0%)], thrombocytopenia [30/94 (31.9%)], and diarrhea and vomiting [10/94 (10.6%) each]. CONCLUSIONS: Adavosertib showed preliminary efficacy when combined with chemotherapy. The most promising treatment combination was adavosertib 225 mg twice daily on days 1-3, 8-10, and 15-17 plus carboplatin every 21 days. However, hematologic toxicity was more frequent than would be expected for carboplatin monotherapy, and the combination requires further study to optimize the dose, schedule, and supportive medications.

Regulation of closely juxtaposed proto-oncogene c-fms and HMGXB3 gene expression by mRNA 3' end polymorphism in breast cancer cells.

Sense-antisense mRNA pairs generated by convergent transcription is a way of gene regulation. c-fms gene is closely juxtaposed to the HMGXB3 gene in the opposite orientation, in chromosome 5. The intergenic region (IR) between c-fms and HMGXB3 genes is 162 bp. We found that a small portion (∼4.18%) of HMGXB3 mRNA is transcribed further downstream, including the end of the c-fms gene generating antisense mRNA against c-fms mRNA. Similarly, a small portion (∼1.1%) of c-fms mRNA is transcribed further downstream, including the end of the HMGXB3 gene generating antisense mRNA against the HMGXB3 mRNA. Insertion of the strong poly(A) signal sequence in the IR results in decreased c-fms and HMGXB3 antisense mRNAs, resulting in up-regulation of both c-fms and HMGXB3 mRNA expression. miR-324-5p targets HMGXB3 mRNA 3' UTR, and as a result, regulates c-fms mRNA expression. HuR stabilizes c-fms mRNA, and as a result, down-regulates HMGXB3 mRNA expression. UALCAN analysis indicates that the expression pattern between c-fms and HMGXB3 proteins are opposite in vivo in breast cancer tissues. Together, our results indicate that the mRNA encoded by the HMGXB3 gene can influence the expression of adjacent c-fms mRNA, or vice versa.

Molecular and clinical determinants of response and resistance to rucaparib for recurrent ovarian cancer treatment in ARIEL2 (Parts 1 and 2).

ARIEL2 (NCT01891344) is a single-arm, open-label phase 2 study of the PARP inhibitor (PARPi) rucaparib in relapsed high-grade ovarian carcinoma. In this post hoc exploratory biomarker analysis of pre- and post-platinum ARIEL2 samples, RAD51C and RAD51D mutations and high-level BRCA1 promoter methylation predict response to rucaparib, similar to BRCA1/BRCA2 mutations. BRCA1 methylation loss may be a major cross-resistance mechanism to platinum and PARPi. Genomic scars associated with homologous recombination deficiency are irreversible, persisting even as platinum resistance develops, and therefore are predictive of rucaparib response only in platinum-sensitive disease. The RAS, AKT, and cell cycle pathways may be additional modulators of PARPi sensitivity.

Loss of tubal ciliated cells as a risk for "ovarian" or pelvic serous carcinoma.

Recent advances suggest the fallopian tube as the main anatomic site for high-grade ovarian or pelvic serous carcinoma (O/PSC). Many studies on the biologic role of tubal secretory cells in O/PSC development has been performed in the last decade. However, the role of tubal ciliated cells in this regard has rarely been explored. The purpose of this study was to determine if the change of the tubal ciliated cells is associated with serous neoplasia within the female pelvis. This study included 3 groups (low-risk or benign control, high-risk, and O/PSC) of patients and they were age-matched. Age of patients ranged from 20 to 85 and the age-associated data was stratified by 10-year intervals. The number of tubal ciliated cells was determined by microscopy and by tubulin immunohistochemical staining. The data was then professionally analyzed. The results showed that the absolute number of tubal ciliated cells decreased significantly with age within each age group. A reduction in ciliated cell counts within the tubal segments remained a significant risk factor for the development of serous cancers within the female pelvis after age adjustment. A dramatic decrease of tubal ciliated cells was identified in patients with high-risk and with O/PSC compared to those in the benign control or low-risk group (P < 0.001). Further, within the tubal fimbria, the number of ciliated cells reduction was more prominent in the high-risk group when compared to those of O/PSC patients. Our findings suggest that a decreased number of ciliated cells within women's fallopian tubes represents another histologic hallmark for early serous carcinogenesis. There is a relationship between loss of tubal ciliated cells and aging, the presence of high-risk factors for tubal-ovarian cancer, and co-existing O/PSCs. This represents an initial study identifying the role of tubal ciliated cells in the development of high-grade serous carcinoma in women's pelvis.

Fluorescence and Multiphoton Imaging for Tissue Characterization of a Model of Postmenopausal Ovarian Cancer.

BACKGROUND AND OBJECTIVES: To determine the efficacy of targeted fluorescent biomarkers and multiphoton imaging to characterize early changes in ovarian tissue with the onset of cancer. STUDY DESIGN/MATERIALS AND METHODS: A transgenic TgMISIIR-TAg mouse was used as an animal model for ovarian cancer. Mice were injected with fluorescent dyes to bind to the folate receptor α, matrix metalloproteinases, and integrins. Half of the mice were treated with 4-vinylcyclohexene diepoxide (VCD) to simulate menopause. Widefield fluorescence imaging (WFI) and multiphoton imaging of the ovaries and oviducts were conducted at 4 and 8 weeks of age. The fluorescence signal magnitude was quantified, and texture features were derived from multiphoton imaging. Linear discriminant analysis was then used to classify mouse groups. RESULTS: Imaging features from both fluorescence imaging and multiphoton imaging show significant changes (P < 0.01) with age, VCD treatment, and genotype. The classification model is able to classify different groups to accuracies of 75.53%, 69.53%, and 86.76%, for age, VCD treatment, and genotype, respectively. Building a classification model using features from multiple modalities shows marked improvement over individual modalities. CONCLUSIONS: This study demonstrates that using WFI with targeted biomarkers, and multiphoton imaging with endogenous contrast shows promise for detecting early changes in ovarian tissue with the onset of cancer. The results indicate that multimodal imaging can provide higher sensitivity for classifying tissue types than using single modalities alone. Lasers Surg. Med. © 2020 Wiley Periodicals, Inc.

The alternative spliced 3'-UTR mediated differential secretion of macrophage colony stimulating factor in breast cancer cells.

CSF-1 mRNA 3'UTR variants (var) are generated from alternative splicing. CSF-1 protein encoded by var-1 mRNA with long 3'UTR derived from exon-10 is rapidly secreted compared to the CSF-1 protein encoded by var-4 mRNA with short 3'UTR derived from exon-9. Secretion kinetics indicates that HuR, which binds the CSF-1 var-1 mRNA, but not var-4 mRNA, accelerates the secretion of CSF-1 protein. HuR overexpression increases the secretion rate of CSF-1 protein. In contrast, silencing of HuR does not have such an effect, suggesting other compensatory mechanisms. Effect of the CSF-1 mRNA variant 3'UTRs on cellular phenotype shows both CSF-1 var-1 or -4 mRNA is involved in the enhanced rates of migration and invasion observed by both in vitro in breast cancer cells. Our study indicates that the alternative splicing of CSF-1 mRNA 3'UTR can regulate differential secretion of CSF-1 protein.

Circulating miRNA Profiling of Women at High Risk for Ovarian Cancer.

Survival of epithelial ovarian cancer patients remains poor without significant change over many decades. There is a need to better identify women at high risk (HR) for ovarian cancer. We propose that miRNA dysregulation may play critical roles in the early stages of ovarian cancer development. Circulating miRNAs may represent an important biomarker in this context, and miRNA profiling of serum in women at HR compared to those at low risk (LR) may give insights in tumor initiation pathways. There is also rationale for a specific focus on regulation of the androgen and its related hypoxia pathways in tumor initiation. We hypothesized that subsets of these pathway related miRNAs may be downregulated in the HR state. Serum from four HR and five LR women were sequenced and analyzed for 2083 miRNAs. We found 137 miRNAs dysregulated between the HR and LR groups, of which 36 miRNAs were overexpressed in HR and the vast majority (101 miRNAs or 74%) downregulated in the HR, when compared to LR serum. mRNA targets for the differentially expressed miRNAs were analyzed from three different miRNA-mRNA interaction resources. Functional association analysis of hypoxia and androgen pathway mRNA targets of dysregulated miRNAs in HR serum revealed that all but one of the miRNAs that target 52 hypoxia genes were downregulated in HR compared to LR serum. Androgen pathway analysis also had a similar expression pattern where all but one of the miRNAs that target these 135 identified genes were downregulated in HR serum. Overall, there were 91 differentially expressed miRNA-mRNA pairings in the hypoxia analysis. In the androgen-related analysis, overall, there were 429 differentially expressed miRNA-mRNA pairs. Our pilot study suggests that almost all miRNAs that are conserved and/or validated are downregulated in the HR compared to LR serum. This study, which requires validation, suggests that, via miRNA dysregulation, involvement of both hypoxia and its related androgen pathways may contribute to the HR state. This pilot study is the first report to our knowledge that studies circulating miRNA profiling of HR and LR women.

Incidence of Hypersensitivity Reactions to Carboplatin or Paclitaxel in Patients With Ovarian, Fallopian Tube, or Primary Peritoneal Cancer With or Without BRCA1 or BRCA2 Mutations.

The association of BRCA mutation status with hypersensitivity reactions (HSRs) to carboplatin has gained interest in recent years, particularly in patients with ovarian, fallopian tube, and primary peritoneal cancer. The primary objective of this study is to determine whether the presence of BRCA mutations increased the likelihood of HSRs to carboplatin. The incidence of HSRs to paclitaxel and symptom grade based on the Common Terminology Criteria for Adverse Events, version 4.0, were explored as secondary endpoints. A retrospective chart review of patients with ovarian, fallopian tube, or primary peritoneal cancer at the University of Arizona Cancer Center who underwent treatment with carboplatin-containing regimens and received genetic testing was performed. Institutional review board approval was obtained for this study. Fisher's exact test was used to analyze the primary outcome. Out of 167 initial patients, 62 with germline test results constituted the evaluable sample. 15 of 62 (24.2%) BRCA-tested patients were treated with carboplatin monotherapy, while 44 of 62 (71.0%) patients were treated with paclitaxel-containing regimens. Hypersensitivity reactions occurred in 4 of 13 (30.8%) BRCA-mutated patients and 22 of 49 (44.9%) BRCA wild-type patients (p = .5291). Hypersensitivity reactions to paclitaxel occurred in 1 of 13 (7.7%) BRCA-mutated patients and 26 of 49 (53.1%) BRCA wild-type patients (p = .0039). Overall, there were 11 grade 1 reactions, 14 grade 2 reactions, and 16 grade 3 reactions to carboplatin. All reactions to carboplatin in BRCA-mutated patients were grade 1. All paclitaxel reactions manifested as grade 2. The sample size was the main study limitation. The presence of BRCA mutations was not statistically significantly associated with a higher incidence of HSRs to carboplatin, but was statistically significant with regards to paclitaxel.

Phenotype of vigilin expressing breast cancer cells binding to the 69 nt 3'UTR element in CSF-1R mRNA.

Vigilin, a nucleocytoplasmic shuttling protein, post-transcriptionally suppresses proto-oncogene c-fms expression (encoding CSF-1R) in breast cancer by binding to a 69 nt cis-acting 3-UTR element in CSF-1R mRNA. CSF-1R is an important mediator of breast cancer development, metastasis, and survival. We confirm that vigilin decreases in vitro reporter luciferase activity as well as the translation rate of target mRNAs. We further explore the mechanism of suppression of CSF-1R. We show that the 69 nt binding element has profound effects on translation efficiency of CSF-1R mRNA, not seen in the presence of mutation of the element. Also, mutation of the 69 nt element in the CSF-1R mRNA 3'UTR both interferes with direct vigilin binding and obviates effect of vigilin overexpression on translational repression of CSF-1R. We show that stable vigilin binding requires the full length 69 nt CSF-1R element, including the 26 nt pyrimidine-rich core. Furthermore, titration of endogenous vigilin and other proteins which bind the 69 nt element, by exogenously introduced CSF-1R mRNA 3'UTR containing the pyrimidine-rich sequence, increases the adhesion, motility, and invasion of breast cancer cells. This phenotypic effect is not seen when the 69 nt element is deleted. Lastly, we are the first to show that human breast tissues exhibit strong vigilin expression in normal breast epithelium. Our pilot data suggest decreased vigilin protein expression, along with shift from the nucleus to the cytoplasmic location, in the transition to ductal carcinoma in situ.

Human ALKBH3-induced m1A demethylation increases the CSF-1 mRNA stability in breast and ovarian cancer cells.

In ovarian and breast cancers, the actions of the cytokine CSF-1 lead to poor prognosis. CSF-1 expression can be regulated post-transcriptionally. RNA methylation is another layer of posttranscriptional regulation. The methylation of N1 atom of adenine (m1A) results in a conformational change of RNA which regulates translational efficiency. Our study indicates that the m1A is also involved in the CSF-1 mRNA decay. The alteration of ALKBH3 expression, an m1A demethylase, regulates the CSF-1 mRNA stability. Demethylation of m1A by ALKBH3 increases the half-life of CSF-1 mRNA without affecting the translation efficiency. The m1A in CSF-1 mRNA is mapped in the 5'UTR near the translation initiation site. YTHDF2, a known m6A reader which interacts with the CCR4-NOT deadenylation complex, is not the reader of m1A-containing CSF-1 mRNA. Overexpression of ALKBH3 increases CSF-1 expression and the degree of cancer cell invasiveness without affecting cell proliferation or migration. Collectively, we showed that CSF-1 mRNA decay can be regulated at an epigenetic level, and that alteration of the N1­methylation status leads to phenotypic changes in cancer cell behavior.

BRCA Reversion Mutations in Circulating Tumor DNA Predict Primary and Acquired Resistance to the PARP Inhibitor Rucaparib in High-Grade Ovarian Carcinoma.

A key resistance mechanism to platinum-based chemotherapies and PARP inhibitors in BRCA-mutant cancers is the acquisition of BRCA reversion mutations that restore protein function. To estimate the prevalence of BRCA reversion mutations in high-grade ovarian carcinoma (HGOC), we performed targeted next-generation sequencing of circulating cell-free DNA (cfDNA) extracted from pretreatment and postprogression plasma in patients with deleterious germline or somatic BRCA mutations treated with the PARP inhibitor rucaparib. BRCA reversion mutations were identified in pretreatment cfDNA from 18% (2/11) of platinum-refractory and 13% (5/38) of platinum-resistant cancers, compared with 2% (1/48) of platinum-sensitive cancers (P = 0.049). Patients without BRCA reversion mutations detected in pretreatment cfDNA had significantly longer rucaparib progression-free survival than those with reversion mutations (median, 9.0 vs. 1.8 months; HR, 0.12; P < 0.0001). To study acquired resistance, we sequenced 78 postprogression cfDNA, identifying eight additional patients with BRCA reversion mutations not found in pretreatment cfDNA. SIGNIFICANCE: BRCA reversion mutations are detected in cfDNA from platinum-resistant or platinum-refractory HGOC and are associated with decreased clinical benefit from rucaparib treatment. Sequencing of cfDNA can detect multiple BRCA reversion mutations, highlighting the ability to capture multiclonal heterogeneity.This article is highlighted in the In This Issue feature, p. 151.

Comparison of Reproductive Function in Female TgMISIIR-TAg Transgenic and Wildtype C57BL/6 Mice.

Transgenic TgMISIIR-TAg (TAg) mice express the oncogenic virus SV40 in Mullerian epithelial cells. Female TAg mice spontaneously develop epithelial ovarian carcinoma, the most common type of ovarian cancer in women. Female TAg mice are infertile, but the reason has not been determined. We therefore investigated whether female TAg mice undergo puberty, demonstrate follicular development, maintain regular cycles, and ovulate. Ovarian cancers in women commonly develop after menopause. The occupational chemical 4-vinylcyclohexene diepoxide (VCD) accelerates follicle degeneration in the ovaries of rats and mice, causing early ovarian failure. We therefore used VCD dosing of mice to develop an animal model for menopause. The purpose of this study was to characterize reproductive parameters in female TAg mice and to investigate whether the onset of ovarian failure due VCD dosing differed between female TAg and WT C57BL/6 mice. As in WT female mice, TAg female mice underwent puberty (vaginal opening) and developed cyclicity in patterns that were similar between the groups. Vehicle-only TAg mice had fewer ovulations (numbers of corpora lutea) than WT animals. VCD exposure delayed the onset of puberty (day of first estrus) in TAg as compared with WT mice. Morphologic evaluation of ovaries revealed many more degenerating follicles in TAg mice than WT mice, and more VCD-dosed TAg mice were in ovarian failure than VCD-dosed WT mice. These results suggest that despite showing similar onset of sexual maturation, TAg mice have increased follicular degeneration and fewer ovulations than WT. These features may contribute to the inability of female TAg mice to reproduce.

Randomized Phase II Trial of Carboplatin-Paclitaxel Versus Carboplatin-Paclitaxel-Trastuzumab in Uterine Serous Carcinomas That Overexpress Human Epidermal Growth Factor Receptor 2/neu.

Purpose Uterine serous carcinoma is a rare, aggressive variant of endometrial cancer. Trastuzumab is a humanized monoclonal antibody that targets human epidermal growth factor receptor 2 (HER2)/neu, a receptor overexpressed in 30% of uterine serous carcinoma. This multicenter, randomized phase II trial compared carboplatin-paclitaxel with and without trastuzumab in patients with advanced or recurrent uterine serous carcinoma who overexpress HER2/neu. Methods Eligible patients had primary stage III or IV or recurrent HER2/neu-positive disease. Participants were randomly assigned to receive carboplatin-paclitaxel (control arm) for six cycles with or without intravenous trastuzumab (experimental arm) until progression or unacceptable toxicity. The primary end point was progression-free survival, which was assessed for differences between treatment arms via one-sided log-rank tests. Results From August 2011 to March 2017, 61 patients were randomly assigned. Forty progression-free survival-related events occurred among 58 evaluable participants. Among all patients, median progression-free survival was 8.0 months (control) versus 12.6 months (experimental; P = .005; hazard ratio [HR], 0.44; 90% CI, 0.26 to 0.76). Similarly, median progression-free survival was 9.3 (control) versus 17.9 (experimental) months among 41 patients with stage III or IV disease undergoing primary treatment ( P = .013; HR, 0.40; 90% CI, 0.20 to 0.80) and 6.0 (control) versus 9.2 months (experimental), respectively, among 17 patients with recurrent disease ( P = .003; HR, 0.14; 90% CI, 0.04 to 0.53). Toxicity was not different between treatment arms, and no unexpected safety signals emerged. Conclusion Addition of trastuzumab to carboplatin-paclitaxel was well tolerated and increased progression-free survival. These encouraging results deserve further investigation to determine their impact on overall survival in patients with advanced or recurrent uterine serous carcinoma who overexpress HER2/neu.

Expression of the cytoplasmic nucleolin for post-transcriptional regulation of macrophage colony-stimulating factor mRNA in ovarian and breast cancer cells.

The formation of the mRNP complex is a critical component of translational regulation and mRNA decay. Both the 5' and 3'UTRs of CSF-1 mRNA are involved in post-transcriptional regulation. In CSF-1 mRNA, a small hairpin loop structure is predicted to form at the extreme 5' end (2-21nt) of the 5'UTR. Nucleolin binds the hairpin loop structure in the 5'UTR of CSF-1 mRNA and enhances translation, while removal of this hairpin loop nucleolin binding element dramatically represses translation. Thus in CSF-1 mRNA, the hairpin loop nucleolin binding element is critical for translational regulation. In addition, nucleolin interacts with the 3'UTR of CSF-1 mRNA and facilitates the miRISC formation which results in poly (A) tail shortening. The overexpression of nucleolin increases the association of CSF-1 mRNA containing short poly (A)n≤26, with polyribosomes. Nucleolin both forms an mRNP complex with the eIF4G and CSF-1 mRNA, and is co-localized with the eIF4G in the cytoplasm further supporting nucleolin's role in translational regulation. The distinct foci formation of nucleolin in the cytoplasm of ovarian and breast cancer cells implicates the translational promoting role of nucleolin in these cancers.