N6-methyladenosine-modified circPLPP4 sustains cisplatin resistance in ovarian cancer cells via PIK3R1 upregulation.

BACKGROUND: Cisplatin (CDDP) is the first-line chemotherapeutic strategy to treat patients with ovarian cancer (OC). The development of CDDP resistance remains an unsurmountable obstacle in OC treatment and frequently induces tumor recurrence. Circular RNAs (circRNAs) are noncoding RNAs with important functions in cancer progression. Whether circRNAs function in CDDP resistance of OC is unclear. METHODS: Platinum-resistant circRNAs were screened via circRNA deep sequencing and examined using in situ hybridization (ISH) in OC. The role of circPLPP4 in CDDP resistance was assessed by clone formation and Annexin V assays in vitro, and by OC patient-derived xenografts and intraperitoneal tumor models in vivo. The mechanism underlying circPLPP4-mediated activation of miR-136/PIK3R1 signaling was examined by luciferase reporter assay, RNA pull-down, RIP, MeRIP and ISH. RESULTS: circPLPP4 was remarkably upregulated in platinum resistant OC. circPLPP4 overexpression significantly enhanced, whereas circPLPP4 silencing reduced, OC cell chemoresistance. Mechanistically, circPLPP4 acts as a microRNA sponge to sequester miR-136, thus competitively upregulating PIK3R1 expression and conferring CDDP resistance. The increased circPLPP4 level in CDDP-resistant cells was caused by increased RNA stability, mediated by increased N6-methyladenosine (m6A) modification of circPLPP4. In vivo delivery of an antisense oligonucleotide targeting circPLPP4 significantly enhanced CDDP efficacy in a tumor model. CONCLUSIONS: Our study reveals a plausible mechanism by which the m6A -induced circPLPP4/ miR-136/ PIK3R1 axis mediated CDDP resistance in OC, suggesting that circPLPP4 may serve as a promising therapeutic target against CDDP resistant OC. A circPLPP4-targeted drug in combination with CDDP might represent a rational regimen in OC.

A Novel Platinum Resistance-Related Immune Gene Signature for Overall Survival Prediction in Patients with Ovarian Cancer.

Ovarian cancer (OV) is a highly heterogeneous gynecological tumor that makes the prognostic prediction challenging. Resistance to platinum-based chemotherapy is associated with a poor prognosis in OV. There seems to be an overlap between molecular mechanisms responsible for platinum resistance and immunogenicity in OV. However, the predictive role of platinum resistance-related immune genes for OV prognosis needs to be further explored. In our study, the mRNA expression data of OV patients with corresponding clinical information were collected from The Cancer Genome Atlas (TCGA) cohort and International Cancer Genome Consortium (ICGC) cohort. A multigene signature was constructed for OV patients in the TCGA cohort using the least absolute shrinkage and selection operator (LASSO) Cox regression model according to the optimal value of λ and was validated in the ICGC cohort. Furthermore, we performed functional analysis to explore the immune status between low- and high-risk groups based on the median value of the risk score for the multigene signature. Our data showed that there were 41.1% of the platinum resistance-related genes which differentially expressed between immune score low- and high-OV patients in the TCGA cohort. Univariate Cox regression analysis identified 30 differentially expressed genes (DEGs) associated with overall survival (OS) (P < 0.05). 14 genes were identified to construct a novel platinum resistance-related immune model for classifying OV patients into the low- and high- risk groups. Patients in the low-risk group showed significantly higher OS than those in the high-risk group (P < 0.0001 in the both TCGA and ICGC cohort), which was associated with different immune status for the two risk groups. A novel platinum resistance-related immune model can be used for prognostic prediction in OV. Targeting tumor immunity may be a therapeutic alternative for OV with platinum resistance.

Single-Cell Atlas of Human Ovaries Reveals The Role Of The Pyroptotic Macrophage in Ovarian Aging.

Female fecundity declines in a nonlinear manner with age during the reproductive years, even as ovulatory cycles continue, which reduces female fertility, disrupts metabolic homeostasis, and eventually induces various chronic diseases. Despite this, the aging-related cellular and molecular changes in human ovaries that occur during these reproductive years have not been elucidated. Here, single-cell RNA sequencing (scRNA-seq) of human ovaries is performed from different childbearing ages and reveals that the activation of the pyroptosis pathway increased with age, mainly in macrophages. The enrichment of pyroptotic macrophages leads to a switch from a tissue-resident macrophage (TRM)-involve immunoregulatory microenvironment in young ovaries to a pyroptotic monocyte-derived macrophage (MDM)-involved proinflammatory microenvironment in middle-aged ovaries. This remolded ovarian immuno-microenvironment further promotes stromal cell senescence and accelerated reproductive decline. This hypothesis is validated in a series of cell and animal experiments using GSDMD-KO mice. In conclusion, the work expands the current understanding of the ovarian aging process by illustrating a pyroptotic macrophage-involved immune mechanism, which has important implications for the development of novel strategies to delay senescence and promote reproductive health.

Resveratrol reduces lactate production and modifies the ovarian cancer immune microenvironment.

Tumor cells show deregulated metabolism leading to an enrichment of lactate in the tumor microenvironment (TME). This lactate-rich environment has been reported to impair effector T cells. However, T-regulatory cells (Tregs) show metabolic advantages in lactate-rich TME that maintain a strong suppression of effector T cells, which leads to tumor immune evasion. Therefore, the glycolytic process of tumors could represent a therapeutic target, and agents that modify the energy metabolism of tumor cells have therapeutic potential. Resveratrol is a naturally occurring polyphenol that has been confirmed to suppress tumor cells' glycolytic metabolism. In this study, we show that resveratrol induces metabolic reprogramming in ovarian cancer cells. Resveratrol increases oxidative and decreases glycolysis, in association with decreased lactate production both in vitro and in vivo. Lactate reduction in TME weakens the suppressive function of Tregs, and subsequently restores anti-tumor immunity. Significantly, combined resveratrol and PD-1 blockade promote anti-tumor efficacy. These data suggest that resveratrol's anti-tumor actions in ovarian cancer could be explained, in part, through modification of the anti-tumor immunity, and indicate a novel treatment strategy for improving immune checkpoint blockade therapy using resveratrol.

[Retracted] MicroRNA­1297 inhibits metastasis and epithelial­mesenchymal transition by targeting AEG­1 in cervical cancer.

Following the publication of this paper, it was drawn to the Editors' attention by a concerned reader that certain of the immunohistochemical data shown in Fig. 4C and the cell migration assay data shown in Fig. 3B and D and Fig. 7B and D were strikingly similar to data that had appeared in different form in other articles by different authors. Owing to the fact that the contentious data in the above article had already been published elsewhere, or were already under consideration for publication, prior to its submission to Oncology Reports, the Editor has decided that this paper should be retracted from the Journal. After having been in contact with the authors, they agreed with the decision to retract the paper. The Editor apologizes to the readership for any inconvenience caused. [Oncology Reports 38: 3121­3129, 2017; DOI: 10.3892/or.2017.5979].

Family with sequence similarity 46 member a confers chemo-resistance to ovarian carcinoma via TGF-ß/Smad2 signaling.

Ovarian cancer is the most lethal malignancy with depressive 5-year survival rate, mainly due to patients with advanced stages experience tumor recurrence and resistance to the current chemotherapeutic agents. Thus, exploring the underlying molecular mechanisms involved in chemo-resistance is crucial for management of treatment to improve therapeutic outcomes. In the current study, we found overexpression of FAM46A in ovarian cancer patients demonstrated an aggressive phenotype and poor outcome. Furthermore, FAM46A overexpression in ovarian cancer cells induces higher CDDP resistance. However, inhibition of FAM46A sensitized ovarian cancer cell lines to CDDP cytotoxicity both in vitro and in vivo. Mechanically, upregulation of FAM46A activated transforming growth factor-ß (TGF-ß)/Smad signaling and upregulated the levels of nuclear Smad2. Taken together, our results highlight the important oncogenic role of FAM46A in ovarian cancer progression and might provide a potential clinical target for patients with chemo resistant ovarian cancer.

The value of first-trimester platelet parameters in predicting gestational diabetes mellitus.

OBJECTIVE: To explore the potential clinical value of platelet parameters in early pregnancy in predicting gestational diabetes mellitus (GDM). METHODS: A total of 1188 singleton pregnant women were included in the regular antenatal examination and delivered in the First Affiliated Hospital of Sun Yat-Sen University from January 2016 to December 2018, who had no pre-pregnancy diabetes, no factors leading to elevated blood glucose level, no medical complications and no other obstetrical complications. Blood routine examination was performed at the 11-13+6 gestational weeks. All pregnant women underwent 75 g OGTT directly at the 24-28th gestational weeks. And they were divided into GDM group (n = 192) and non-GDM group (n = 996). Binomial Logistic regression analysis and receiver operating characteristic (ROC) curve were used to evaluate the ability of first-trimester platelet parameters to predict GDM, that is the sensitivity and specificity of platelet parameters at the optimal critical value. RESULTS: There were significant differences in platelet count (PLT), platelet distribution width (PDW), mean platelet volume (MPV), and plateletcrit (PCT) between the GDM group and the normal group (p＜.05). After adjusting for the related factors such as maternal age, parity and pregestational body mass index (BMI), the MPV and PCT were correlated with the incidence of GDM (p＜.05). The area under the curve (AUC) of MPV was 0.577; 95% confidence interval (CI) 0.533-0.621 and that of PCT was 0.628. 95%CI 0.582-0.674. PLT and PDW were not correlated with GDM. CONCLUSION: MPV and PCT in early pregnancy are potential indicators in predicting gestational diabetes mellitus.

Overexpression of glycosyltransferase 8 domain containing 2 confers ovarian cancer to CDDP resistance by activating FGFR/PI3K signalling axis.

It has been reported that chemotherapy resistance mainly contributed to treatment failure and poor survival in patients with ovarian cancer. Therefore, clarifying the molecular mechanism and identifying effective strategies to overcome drug resistance may play an important clinical impact on this malignant tumor. In our study, we found that the expression of Glycosyltransferase 8 domain containing 2 (GLT8D2) was significantly upregulated in ovarian cancer samples with CDDP (Cis-dichlorodiammine-platinum) resistance. Biological experiment demonstrate that GLT8D2 overexpression confers CDDP resistance on ovarian cancer cells; however, inhibition of GLT8D2 sensitized ovarian cancer cell lines to CDDP cytotoxicity both in vitro and in vivo. By using affinity purification/mass spectrometry (IP/MS) and reciprocal co-immunoprecipitation (co-IP) analyses, we found that GLT8D2 interacts with fibroblast growth factor receptor 1(FGFR1) in ovarian cancer cells. Furthermore, overexpression of GLT8D2 activated FGFR/PI3K signaling axis and upregulated the phosphorylation levels of FRS2a and AKT (AKT serine/threonine kinase). Importantly, pharmacological inhibition of FGFR and PI3K (phosphatidylinositol 3-kinase) signaling pathway significantly counteracted GLT8D2-induced chemoresistance and enhanced platinum's therapeutic efficacy in ovarian cancer. Therefore, our findings suggest that GLT8D2 is a potential therapeutic target for the treatment of ovarian cancer; targeting GLT8D2/FGFR/PI3K/AKT signaling axis may represent a promising strategy to enhance platinum response in patients with chemoresistant ovarian cancer.

PARP inhibitors in breast and ovarian cancer with BRCA mutations: a meta-analysis of survival.

OBJECTIVE: To evaluate the efficacy of poly ADP ribose polymerase (PARP) inhibitors (PARPis) in breast and ovarian cancer with BRCA (BReast CAncer susceptibility gene) mutation (BRCAm). METHODS: We conducted a meta-analysis of randomized controlled, phase II or III trials by searching of electronic databases from inception to September 1, 2020. The efficacy of PARPis measured by hazard ratios (HRs) and 95% confidence intervals (95% CIs) for progression free survival (PFS) and overall survival (OS) of patients. RESULTS: By addition of PARPis to conventional therapy, breast or ovarian cancer patients carrying BRCAm significantly benefited PFS (breast cancer: HR 0.64, 95% CI=0.55-0.75, P<0.001; ovarian cancer: HR 0.33, 95% CI=0.27-0.42, P<0.001), but OS of patients did not increase significantly in these two cancer types (breast cancer: HR 0.87, 95% CI=0.76-1.01, P=0.065; ovarian cancer: HR 0.78, 95% CI=0.61-1.01, P=0.058). For ovarian cancer patients carrying BRCAm, the use of therapy with PARPis yielded longer PFS at the stage of newly diagnosed than the stage of recurrence (22.5 months vs 9.6 months). CONCLUSION: PARPis were beneficial to all with BRCAm, but they were "most" beneficial to the ovarian cancer subset when administered early after diagnosis, rather than after recurrence.

PTOV1 promotes cisplatin-induced chemotherapy resistance by activating the nuclear factor kappa B pathway in ovarian cancer.

Chemotherapy resistance is a bottleneck for ovarian cancer treatment; therefore, revealing its regulatory mechanism is critical. In the present study, we found that prostate tumor overexpressed-1 (PTOV1) was upregulated significantly in ovarian cancer cells and tissues. Patients with high PTOV1 levels had a poor outcome. In addition, PTOV1 overexpression increased CDDP (cisplatin) resistance, while PTOV1 knockdown inhibited CDDP resistance, as determined using cell viability assays, apoptosis assays, and an animal model. Mechanistic analysis showed that PTOV1 increased nuclear factor kappa B (NF-κB) pathway activity, reflected by increased nuclear translocation of its p65 subunit and the phosphorylation of inhibitor of nuclear factor kappa-B kinase subunits alpha and beta, which are markers of NF-κB pathway activation. Inhibition of the NF-κB pathway in PTOV1-overexpressing ovarian cancer cells increased CDDP-induced apoptosis, suggesting that PTOV1 promoted chemotherapy resistance by activating the NF-κB pathway. In summary, we identified PTOV1 as a prognostic factor for patients with ovarian cancer. PTOV1 might be a target for inhibition of chemotherapy resistance.

FAM83B inhibits ovarian cancer cisplatin resistance through inhibiting Wnt pathway.

Cisplatin resistance is frequently occurred in ovarian cancer therapy, understanding its regulatory mechanisms is critical for developing novel treatment methods and drugs. Here, we found ovarian cancer patients with low FAM83B levels had shorter survival time, tissues with cisplatin resistance also had low FAM83B levels, suggesting FAM83B might inhibit cisplatin resistance. FAM83B overexpression inhibits cisplatin resistance showed in increased ovarian cancer cell proliferation and growth rate, and reduced apoptosis rate, while FAM83B knockdown promotes cisplatin resistance. Mechanism analysis showed FAM83B interacted with APC to inhibit Wnt pathway activity, causing ovarian cancer cisplatin resistance. We also found FAM83B levels were negative with Wnt pathway activity in clinic samples, confirming FAM83B inhibited Wnt pathway activity. In summary, we found FAM83B inhibits ovarian cancer cisplatin resistance through inhibiting Wnt pathway, providing a new target for ovarian cancer therapy.

FABP5 promotes lymph node metastasis in cervical cancer by reprogramming fatty acid metabolism.

Patients with cervical cancer (CCa) with lymph node metastasis (LNM) have an extremely poor prognosis. Elucidation of the molecular mechanisms underlying LNM may provide clinical therapeutic strategies for CCa. Upregulation of fatty acid-binding protein 5 (FABP5) expression in CCa tumours was demonstrated to positively correlate with LNM. However, the precise role and mechanisms of FABP5 in the LNM of CCa remain unknown. Methods: The diagnostic value of FABP5 as a predictor of LNM in CCa was evaluated in CCa tumour samples. The functional role of FABP5 and its upstream and downstream regulatory factors were investigated by gain-of-function and loss-of-function assays in vitro and in vivo. A mouse model of LNM was used to determine the effect of FABP5 on LNM and the therapeutic value of FABP5 targeting. Results: We demonstrated that FABP5 was markedly upregulated in CCa with LNM and correlated with poor prognosis. FABP5 protein was an independent predictor of LNM in a multivariate logistic analysis. Furthermore, FABP5 promoted epithelial-mesenchymal transition, lymphangiogenesis, and LNM by reprogramming fatty acid (FA) metabolism. Mechanistically, FABP5 promoted lipolysis and FA synthesis, which led to an increase in intracellular fatty acids (FAs) that activated NF-κB signalling, thus inducing LNM. Importantly, administration of orlistat, which attenuates FA metabolism reprogramming, inhibited FABP5-induced LNM in CCa. The pro-metastatic effect of FABP5 was reduced by miR-144-3p. Moreover, miR-144-3p was significantly downregulated and FABP5 was upregulated in CCa in a hypoxic microenvironment. Conclusion: Our findings highlight a FA metabolism-dependent mechanism of FABP5-induced LNM. Moreover, the expression and biological function of FABP5 can be regulated by miR-144-3p in hypoxia. Our study identifies FABP5 as a potential diagnostic biomarker and therapeutic target for LNM in CCa.

Correction: High expression of CTHRC1 promotes EMT of epithelial ovarian cancer (EOC) and is associated with poor prognosis.

[This corrects the article DOI: 10.18632/oncotarget.5358.].

Efficacy and safety of PARP inhibitors as the maintenance therapy in ovarian cancer: a meta-analysis of nine randomized controlled trials.

PURPOSE: Poly ADP ribose polymerase (PARP) inhibitors can effectively kill cancer cells by restraining the activity of DNA repair enzymes and utilizing the characteristics of BRCA mutations. This article evaluates the efficacy and safety of PARP inhibitors (PARPis) in the maintenance treatment of ovarian cancer. METHOD: We searched for clinical trials in electronic databases. PARPis efficacy were evaluated by the hazard ratios (HR) and its 95% confidence intervals (95% CI) of overall survival (OS) and progression-free survival (PFS) between the PARPis groups and placebo groups, while the PARPis' safety was assessed by relative risk (RR) values of adverse events (AEs) between the two arms. RESULTS: The immature OS data manifested that patients with BRCA mutation receiving PARPis therapy versus placebo therapy appeared to have longer OS (HR = 0.78, 95%CI = 0.61-1.01; P = 0.06). Compared with placebo group, PARP group had a significant advantage in PFS in ovarian cancer patients with BRCA wild-type (BRCAwt), BRCA mutation (BRCAm), BRCA status unclassified, BRCA1 mutation subgroup and the BRCA2 mutation subgroup (BRCAwt: HR = 0.53, 95%CI = 0.42-0.68, P < 0.00001; BRCAm: HR = 0.30, 95%CI = 0.26-0.34, P < 0.00001; BRCA status unclassified: HR = 0.52, 95%CI = 0.41-0.66, P < 0.00001; BRCA1m: HR = 0.38, 95%CI = 0.29-0.48, P < 0.00001; BRCA2m: HR = 0.23, 95%CI = 0.10-0.57, P = 0.001). Our analysis revealed the incidence rates for AEs of grade ≥3 (grades 3 to 4) and serious AEs in PARPis group were 55.19% and 26.29%, respectively. CONCLUSION: Our meta-analysis demonstrates that PARPis therapy can significantly improve PFS in ovarian cancer patients, but it has no benefit in OS. However, the therapy is associated with a significant increase in the risk of AEs of grade ≥ 3 and serious AEs.

The role of a semi-automated NanoVelcro system in capturing circulating tumor cells and evaluating their prognostic value for gestational choriocarcinoma.

To investigate whether circulating tumor cells (CTCs) are detectable in patients with gestational choriocarcinoma (GC) and evaluate the prognostic value of CTC enumeration. In this multicenter study, the presence of CTCs was examined in 180 GC patients using a semi-automated NanoVelcro system, among whom 106 patients underwent CTC re-evaluation after one cycle of chemotherapy. Approximately 96% of the GC patients contained ≥2 CTCs in 7.5 mL of blood. The number of CTCs per 7.5 mL of blood was much higher in patients with distant metastases (n = 95; range, 0 to 104) than in patients without distant metastases (n = 85; range, 0 to 6). Applying a 90-patient training and 90-patient validation cohort, a cutoff value of ≥6 CTCs was defined as the prognostic threshold for progression-free survival (PFS) and overall survival (OS). The presence of ≥6 CTCs was significantly associated with worse PFS and OS (both P < 0.001). A multivariate analysis showed that the CTC number (≥6 CTCs) was the strongest predictor of OS (hazard ratio [HR], 15.8; 95% confidence interval [CI], 4.3-57.9; P < 0.001). The number of CTCs decreased after one cycle of chemotherapy; univariate analyses demonstrated that the CTC count after the first chemotherapy cycle was a strong predictor of OS (HR, 36.1; 95% CI, 4.8-271.5; P < 0.001). CTCs are a promising prognostic factor for GC. The absolute CTC count after one cycle of chemotherapy in the context of this disease is a strong predictor of chemotherapy response.

Clinical significance of circulating tumor cells in predicting disease progression and chemotherapy resistance in patients with gestational choriocarcinoma.

Gestational choriocarcinoma (GC) is a highly aggressive tumor. In our study, we systematically investigated EpCAM/CD147 expression characteristics in patients with GC and assessed the role of circulating tumor cells (CTCs) in predicting chemotherapy response and disease progression. GC tissues were positive for either epithelial cellular adhesion molecule (EpCAM) or CD147, and all samples exhibited strong human chorionic gonadotropin (HCG) expression. Among all the recruited patients (n = 115), 103 had at least 1 CTC in a 7.5-mL peripheral blood sample, and the percentage of patients with ≥4 CTCs in a particular FIGO stage group increased with a higher FIGO stage (p < 0.001). Furthermore, the pretreatment CTC count was related to tumor size (r = 0.225, p = 0.015) and the number of metastases (r = 0.603, p < 0.001). A progression analysis showed that among the 115 included patients who qualified for further examination, 52 of the 64 patients defined as progressive had ≥4 pretreatment CTCs, while only 7 of the 51 non-progressive patients had ≥4 pretreatment CTCs (p < 0.001). In multivariate analysis, CTCs (≥4) remained the strongest predictor of PFS when other prognostic markers, FIGO score and FIGO stage were included. Moreover, based on the chemotherapy response, patients with ≥4 CTCs were more likely to be resistant to chemotherapy than those with <4 CTCs (P < 0.001). These findings demonstrates the feasibility of CTC detection in cases of GC by adopting EpCAM/CD147 antibodies together as capturing antibodies. The CTC count is a promising indicator in the evaluation of biological activities and the chemotherapy response in GC patients.

Overexpression of long non-coding RNA RP11-396F22.1 correlates poor prognosis of patients with early-stage cervical cancer.

OBJECTIVE: The expression level and clinical significances of long non-coding RNAs (LncRNAs) are presently unknown in the early-stage cervical cancer (CC). This study was aimed to explore the expression signatures of lncRNAs between normal and cervix carcinoma tissues and the prognostic value of LncRNAs in early-stage CC patients. MATERIALS AND METHODS: The patients diagnosed with FIGO stage I-IIb CC of the First Affiliated Hospital of Sun Yat-sen University between January 1st 2006 and December 31st 2009 were retrospectively reviewed. Molecular microarray was conducted to identify differentially expression profiles of LncRNAs. In situ hybridization was applied for detection of candidate lncRNAs in cervical tissues. RESULTS: A total of 2574 upregulated lncRNAs and 3270 downregulated lncRNAs with significantly differential expression (≥2.0-fold) were identified. Among the differentially expressed lncRNAs, RP11-396F22.1 expression was one of the most significantly overexpressed in the CC tissues compared to nomal cervical tissues (P<0.001). In situ hybridization confirmed RP11-396F22.1 expression was highly expressed in cancerous tissues. The results of Scratch and Transwell test showed that the migration ability decreased remarkably in transfected group (P<0.001). Moreover, the coding gene cpne8 was significantly upregulated by RP11-396F22.1 knockdown (P=0.035). CONCLUSIONS: These findings demonstrate that LncRNA RP11-396F22.1 might be a potent biomarker for CC progression.

Up-regulation of long non-coding RNA SNHG20 promotes ovarian cancer progression via Wnt/ß-catenin signaling.

Long non-coding RNA small nucleolar RNA host gene 20 (SNHG20) has been demonstrated to play crucial regulatory roles in many types of cancer. However, the biological function of long ncRNA (lncRNA) SNHG20 in ovarian cancer is still unclear. In the present study, we found that lncRNA SNHG20 was significantly increased in ovarian cancer. In addition, lncRNA SNHG20 knockdown suppressed the ovarian cancer progression, whereas overexpression of SNHG20 showed the opposite effects. Moreover, our results also revealed that lncRNA SNHG20 knockdown inhibited Wnt/ß-catenin signaling activity by suppressing ß-catenin expression and reversing the downstream target gene expression. Taken together, lncRNA SNHG20 plays an pivotal role in ovarian cancer progression by regulating Wnt/ß-catenin signaling.