Exosomal miR-4516 derived from ovarian cancer stem cells enhanced cisplatin tolerance in ovarian cancer by inhibiting GAS7.

Ovarian cancer (OC) is a devastating disease for women, with chemotherapy resistance taking the lead. Cisplatin has been the first-line therapy for OC for a long time. However, the resistance of OC to cisplatin is an important impediment to its efficacy. Mounting studies showed that ovarian cancer stem cells (OCSCs) affected chemotherapy resistance by secreting exosomes. MicroRNAs (miRNAs) play important roles in exosomes secreted by OCSCs. Here, through the analysis of GEO database (GSE107155) combined with RT-qPCR of OC-related cells/clinical tissues, it was found that hsa-miR-4516 (miR-4516) was significantly up-regulated in OCSCs. Then, OCSCs-derived exosomes were isolated and identified, and it was observed the influence of exosomes on the chemoresistance in SKOV3/cisplatin (SKOV3/DDP) cells. These results manifested that OCSCs-mediated exosomes facilitated the chemoresistance of SKOV3/DDP cells by delivering miR-4516 into them. Growth arrest-specific 7 (GAS7), a downstream target of miR-4516, was determined by bioinformatics prediction combined with molecular biological detection. Next, we up-regulated GAS7 expression and discovered that the promotion of chemoresistance in SKOV3/DDP cells by OCSCs-derived exosomes was significantly impaired. Finally, the mice tumor model of SKOV3/DDP cells was built to estimate the effect of GAS7 over-expression on OC growth. The results showed that GAS7 inhibited the chemoresistance of OC in vivo. In conclusion, our experiments suggested that OCSCs-derived exosomes enhanced OC cisplatin resistance by suppressing GAS7 through the delivery of miR-4516. This study provides a possible target for the treatment of OC DDP resistance.

A meta-analysis of efficacy on dexamethasone and clomiphene in the treatment of polycystic ovary syndrome patients.

OBJECTIVE: Polycystic ovary syndrome (PCOS) is an endocrine gynecological disease affecting many women of reproductive age. Clomiphene is the first-line treatment for PCOS patients, but most individuals may be resistant to it. This study aims to assess the efficacy of dexamethasone and clomiphene in the treatment of PCOS patients, and to provide a theoretical basis for clinicians to study and treat PCOS. METHODS: Chinese and English databases including PubMed, Embase, Cochrane Library, China National Knowledge Infrastructure (CNKI), WanFang Medical Network, and VIP Information Chinese Journal Service Platform (VIP) were searched from the inception to January 2023. Review Manager and Stata software were used for meta- analysis. The risk of bias of eligible studies were assessed using Cochrane's risk of bias tool. Publication bias was assessed by funnel plots, Begg's and Egger's tests. RESULTS: A total of 12 literatures were finally included, with a total of 1270 PCOS patients. Compared with the control group, dexamethasone combined with clomiphene could significantly improve pregnancy (RR = 1.71, P < 0.00001), ovulation (RR = 1.30, P < 0.00001), luteinizing hormone level (SMD = -0.94, P < 0.00001), estradiol level (SMD = 0.99, P = 0.05), progesterone level (SMD = 5.08, P = 0.002) and testosterone level (SMD = -1.59, P < 0.00001). However, there were no significant effects on ovulation-stimulating hormone level (SMD = 0.15, P = 0.37), adverse reactions (RR = 1.30, P = 0.30), dizziness (RR = 1.50, P = 0.45), and vomiting (RR = 1.67, P = 0.48). CONCLUSION: The treatment of dexamethasone combined with clomiphene is helpful to improve the ovulation and pregnancy rate in patients with PCOS, and improve the hormone levels of patients.

Research Advances in the Roles of N6-Methyladenosine Modification in Ovarian Cancer.

Ovarian cancer (OC) is the most lethal gynecological tumor, characterized by its insidious and frequently recurring metastatic progression. Owing to limited early screening methods, over 70% of OC cases are diagnosed at advanced stages, typically stage III or IV. Recently, N6-methyladenosine (m6A) modification has emerged as a hotspot of epigenetic research, representing a significant endogenous RNA modification in higher eukaryotes. Numerous studies have reported that m6A-related regulatory factors play pivotal roles in tumor development through diverse mechanisms. Moreover, recent studies have indicated the aberrant expression of multiple regulatory factors in OC. Therefore, this paper comprehensively reviews research advancements concerning m6A in OC, aiming to elucidate the regulatory mechanism of m6A-associated regulators on pivotal aspects, such as proliferation, invasion, metastasis, and drug resistance, in OC. Furthermore, it discusses the potential of m6A-associated regulators as early diagnostic markers and therapeutic targets, thus contributing to the diagnosis and treatment of OC.

Ovarian cancer (OC) presents a formidable challenge in the medical field, often detected at advanced stages, necessitating urgent exploration of diagnostic and therapeutic avenues. This review delves into the intricate role of N6-methyladenosine (m6A) RNA modification in OC, a dynamic epigenetic process increasingly recognized for its regulatory role in cancer biology. Highlighting recent advancements, the review sheds light on how m6A-related factors influence crucial aspects of OC progression, including tumor growth, metastasis, and resistance to treatment. Specifically, m6A methyltransferases, binding proteins, and demethylases exert multifaceted effects on OC progression, influencing the expression of pivotal oncogenes and tumor suppressors. While promising, translating these insights into effective therapies requires further investigation. By comprehensively understanding the influence of m6A on OC, there lies hope for developing improved diagnostic techniques and novel treatment strategies to combat this complex disease.

M6A-mediated hsa_circ_0061179 inhibits DNA damage in ovarian cancer cells via miR-143-3p/TIMELESS.

Ovarian cancer (OC) is among the most common and deadly solid malignancies in women. Despite many advances in OC research, the incidence of OC continues to rise, and its pathogenesis remains largely unknown. Herein, we elucidated the function of hsa_circ_0061179 in OC. The levels of hsa_circ_0061179, miR-143-3p, TIMELESS, and DNA damage repair-related proteins in OC or normal ovarian tissues and cells were measured using real-time quantitative polymerase chain reaction and immunoblotting. The biological effects of hsa_circ_0061179 and miR-143-3p on proliferation, clone formation, DNA damage, and apoptosis of OC cells were detected by the cell counting kit-8 assay, 5-methylethyl-2'-deoxyuridine, flow cytometry, the comet assay, and immunofluorescence staining combined with the confocal microscopy. The interaction among hsa_circ_0061179, miR-143-3p, and TIMELESS was validated by the luciferase reporter assay. Mice tumor xenograft models were used to evaluate the influence of hsa_circ_0061179 on OC growth in vivo. We found that human OC biospecimens expressed higher levels of hsa_circ_0061179 and lower levels of miR-143-3p. Hsa_circ_0061179 was found to bind with miR-143-3p, which directly targets TIMELESS. Hsa_circ_0061179 knockdown or miR-143-3p overexpression suppressed the proliferation and clone formation of OC cells and increased DNA damage and apoptosis of OC cells via the miR-143-3p/TIMELESS axis. Furthermore, we demonstrated that METTL3 could direct the formation of has_circ_0061179 through a specific m6A modification site. YTHDC1 facilitated the cytoplasmic transfer of has_circ_0061179 by directly binding to the modified m6A site. Our findings suggest that hsa_circ_0061179 acts as the sponge of miR-143-3p to activate TIMELESS signaling and inhibits DNA damage and apoptosis in OC cells.

Current understanding of circular RNAs in preeclampsia.

Preeclampsia (PE) is a multiple organ and system disease that seriously threatens the safety of the mother and infant during pregnancy, and has a profound impact on the morbidity and mortality of the mother and new babies. Presently, there are no remedies for cure of PE as to the mechanisms of PE are still unclear, and the only way to eliminate the symptoms is to deliver the placenta. Thus, new therapeutic targets for PE are urgently needed. Approximately 95% of human transcripts are thought to be non-coding RNAs, and the roles of them are to be increasingly recognized of great importance in various biological processes. Circular RNAs (circRNAs) are a class of non-coding RNAs, with no 5' caps and 3' polyadenylated tails, commonly produced by back-splicing of exons. The structure of circRNAs makes them more stable than their counterparts. Increasing evidence shows that circRNAs are involved in the pathogenesis of PE, but the biogenesis, functions, and mechanisms of circRNAs in PE are poorly understood. In the present review, we mainly summarize the biogenesis, functions, and possible mechanisms of circRNAs in the development and progression of PE, as well as opportunities and challenges in the treatment and prevention of PE.

The mir-199b-5p encapsulated in adipocyte-derived exosomes mediates radioresistance of colorectal cancer cells by targeting JAG1.

Radiotherapy is a key treatment option for colorectal cancer, but its efficacy varies among patients. Our previous studies suggested that adipose tissue may confer the radioresistance of several abdominal tumors, such as pancreatic cancer, biliary cancer, and others. In the present work, the effects of adipocytes in regulating the radiosensitivity of colorectal cancer are explored for the first time. It was found that colony formation was increased and radiation-induced apoptosis decreased in colorectal cancer cells HCT8 and HCT116 co-cultured with adipocytes, which verified the mediation of adipocyte-driven radioresistance in colorectal cancer in vitro. Next, the colorectal cancer cells were incubated with adipocyte-derived exosomes, and a perceptible reduction in radiosensitivity was detected. Furthermore, to investigate the possible mechanisms involved, the exosomes were isolated, the encapsulated microRNAs were extracted and analyzed by small RNA sequencing. Based on bioinformatics analysis and qRT-PCR verification, miR-199b-5p was chosen for functional annotation. It was shown that miR-199b-5p expression was significantly upregulated after 6 Gy irradiation, and overexpressed miR-199b-5p significantly suppressed the radiosensitivity of HCT8 and HCT116 cells. In addition, jagged canonical Notch ligand 1(JAG1) was identified as the target gene of miR-199b-5p by using bioinformatics prediction and dual luciferase reporter gene assay. It was demonstrated that JAG1 conferred the radioresistance of colorectal cancer cells both in vivo and in vitro. Taken together, the present study demonstrates that adipocytes trigger the radioresistance of colorectal cancer cells, probably by targeting JAG1 through an adipocyte-derived exosomal miR-199b-5p.