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Background and Aims: CircRNAs and autophagy are closely involved in the physiological and pathological processes of ovarian cancer; however, their exact mechanisms are still undetermined. This investigation aimed to elucidate the function and associated pathways of circFAM188A, which modulates proliferation, autophagy, and invasion in ovarian cancer (EOC)., Methods: The expression of circFAM188A in the tissues of EOC patients was assessed via RT-PCR. To elucidate proliferation, invasion, and autophagy in the tumor cells, Transwell, 5-ethynyl-2'-deoxyuridine (EdU), and mRFP-GFP-LC3 reporter assays were conducted. The binding sites between circ-FAM188A and the miR-670-3p, miR-670-3p and YY1 were predicted using bioinformatics and verified by dual-luciferase reporter assays. Pulldown assays demonstrated binding between ULK1 and circ-FAM188A. ULK1 was found to be crucial in the initial stage of autophagy. Moreover, an in vivo xenograft model was established by subcutaneous injection of nude mice with EOC cells., Result: Expression of circ-FAM188A was increased in EOC tissues relative to normal ovarian tissues and circ-FAM188A overexpression promoted proliferation, invasion, and autophagy; these effects were reversed by circ-FAM188A silencing. miR-670-3p and circ-FAM188A co-localized in the cytoplasm. circ-FAM188A enhanced YY1 expression by sponging miR-670-3p and was also shown to interact with ULK1., Conclusion: It is thus suggested that circ-FAM188A modulates autophagy by sponging miR-670-3p as well as interacting with ULK1., (© 2024 The Author(s). Cancer Reports published by Wiley Periodicals LLC.)

Fetal growth restriction (FGR) severely affects the health outcome of newborns and represents a major cause of perinatal morbidity. The precise involvement of circCULT1 in the progression of FGR remains unclear. We performed next-generation sequencing and RT-qPCR to identify differentially expressed circRNAs in placental tissues affected by FGR by comparing them with unaffected counterparts. Edu, flow cytometry, and transwell assay were conducted to detect HTR8/SVneo cell's function in regard to cell proliferation, migration, and invasion. The interaction between circCUL1 and hsa-miR-30e-3p was assessed through dual-luciferase reporter assays, validation of the interaction between circCUL1 and ANXA1 was performed using RNA pulldown and immunoprecipitation assays. Western blot analysis was performed to evaluate protein levels of autophagy markers and components of the PI3K/AKT signaling pathway. A knockout (KO) mouse model was established for homologous mmu-circ-0001469 to assess fetal mouse growth and development indicators. Our findings revealed an upregulation of circCUL1 expression in placental tissues from patients with FGR. We found that suppression of circCUL1 increased the trophoblast cell proliferation, migration, and invasion, circCUL1 could interact with hsa-miR-30e-3p. Further, circCUL1 stimulated autophagy, modulating trophoblast cell autophagy via the ANXA1/PI3K/AKT pathway, and a notable disparity was observed, with KO mice displaying accelerated embryo development and exhibiting heavier placentas in comparison to wild-type C57BL/6 mice. By modulating the ANXA1/PI3K/AKT signaling pathway through the interaction with hsa-miR-30e-3p, circCUL1 promotes autophagy while concurrently suppressing trophoblast cell proliferation, migration, and invasion. These findings offer novel insights into potential diagnostic markers and therapeutic targets for FGR research., (© 2024 Wiley Periodicals LLC.)

Gouty arthritis (GA) is mainly caused by the precipitation of monosodium urate (MSU) crystals in the joint. Recently, different regulatory roles of microRNAs (miRNAs) in arthritis have been widely verified. Nevertheless, the specific function of microRNA-486-5p (miR-486-5p) in GA is still unclear. GA cell models in vitro were established by the treatment of 250 μg/mL MSU crystals into THP-1 cells or J774A.1 cells. Then, the accumulation of tumor necrosis factor (TNF)-α, interleukin (IL)-8, and IL-β was estimated by ELISA. The mRNA levels of TNF-α, IL-8, and IL-β were measured through RT-qPCR. The protein level of forkhead box protein O1 (FOXO1) was tested via western blot. Furthermore, the interplay of miR-486-5p and FOXO1 was evaluated via the luciferase reporter assay. In this study, MSU treatment successfully stimulated the inflammatory response in macrophage cells. MiR-486-5p downregulation was observed in THP-1 and J774A.1 cells treated with MSU, and its upregulation markedly decreased the concentration and mRNA levels of TNF-α, IL-8, and IL-β. Furthermore, FOXO1 was demonstrated to be negatively modulated by miR-486-5p. The rescue assay indicated that overexpressing FOXO1 reversed the effects of overexpressing miR-486-5p on inflammatory cytokines. Overall, this study proves that miR-486-5p inhibits GA inflammatory response via modulating FOXO1.

At present, no systematic and in-depth study is available on the function and potential mechanisms of circular RNA in autophagy. This study aimed to screen the expression profiles of circRNA, miRNA, and mRNA of ovarian cancer cells induced by Torin 1 (10 µM). The expression profiles of circRNA, miRNA, and mRNA were analyzed with next-generation sequencing technology. CircRAB11FIP1 expression was elevated in epithelial ovarian cancer (EOC) tissues than in normal ovarian tissues. Silencing circRAB11FIP1 inhibited the autophagic flux of ovarian cancer SKOV3 cells. However, circRAB11FIP1 overexpression activated the autophagic flux of ovarian cancer A2780 cells. CircRAB11FIP1-induced autophagy accelerated EOC proliferation and invasion. Also, circRAB11FIP1 directly bound to miR-129 and regulated its targets ATG7 and ATG14. CircRAB11FIP1 bound to desmocollin 1to facilitate its interaction with ATG101. Also, circRAB11FIP1 directly bound to the mRNA of fat mass and obesity-associated protein and promoted its expression. Then, circRAB11FIP1 mediated mRNA expression levels of ATG5 and ATG7 depending on m6A. In general, this study demonstrated that circRAB11FIP1 regulated ATG7 and ATG14 by sponging miR-129. The data suggested that circRAB11FIP1 might serve as a candidate biomarker for EOC diagnosis and treatment.

Background: Circular RNA (circRNA) has been proven to play a significant role in multiple types of cancer. However, the expression and role of circRNAs in epithelial ovarian cancer (EOC) remains elusive., Methods: CircRNA and mRNA expression profiles of EOC were screened with sequencing analysis. Gene silencing and over-expression were used to study circRNA function. Cell proliferation and Matrigel invasion assays were used to detect cell proliferation and invasion, respectively. The expression of circRNAs, mRNAs and miRNAs was detected using qPCR. The location of circRNAs was detected using FISH. The expression of proteins was detected using western blot and immunohistochemistry., Results: CircMUC16 had increased expression in EOC tissues as compared to healthy ovarian tissues. The expression of circMUC16 was linked to the progression in stage and grade of EOC. Hence, silencing circMUC16 suppressed autophagy flux of SKOV3 cells. In contrast, ectopic expression of circMUC16 promoted autophagy flux of A2780 cells. CircMUC16-mediated autophagy exacerbated EOC invasion and metastasis. Mechanistically, circMUC16 could directly bind to miR-199a-5p and relieve suppression of target Beclin1 and RUNX1. In turn, RUNX1 elevated the expression of circMUC16 via promotion of its transcription. CircMUC16 could directly bind to ATG13 and promote its expression., Conclusion: This study demonstrated that circMUC16 regulated Beclin1 and RUNX1 by sponging miR-199a-5p. The data suggested that circMUC16 could be a potential target for EOC diagnosis and therapy.

Trastuzumab is commonly used in the treatment of human epidermal growth factor receptor-2 positive (HER-2+) breast cancer, but its efficacy is often limited by the emergence of chemoresistance. Recent studies indicate that exosomes act as vehicles for exchange of genetic cargo between heterogeneous populations of tumor cells, engendering a transmitted drug resistance for cancer development and progression. However, the specific contribution of breast cancer-derived exosomes is poorly understood. In this study, publicly available expression profiling data from breast cancer and bioinformatics analyses were used to screen potential miRNAs in trastuzumab resistance. A series of gain- or loss-functional assays were performed to define the function of miR-567 and ATG5 in trastuzumab resistance and autophagy, both in vitro and in vivo. Our results showed that miR-567 was significantly decreased in trastuzumab-resistant patients compared with responding patients. Moreover, miR-567 was also downregulated in trastuzumab-resistant cells compared with parental cells. Overexpression of miR-567 reversed chemoresistance, whereas silence of miR-567 induced trastuzumab resistance, both in vitro and in vivo. In addition, enhanced miR-567 could be packaged into exosomes, incorporated into receipt cells, suppressing autophagy and reversed chemoresistance by targeting ATG5. To conclude, exosomal miR-567 plays a key role in reversing trastuzumab resistance via regulating autophagy, indicating it may be a promising therapeutic target and prognostic indicator for breast cancer patients.

Ubiquitin E3 ligase membrane-associated RING-CH-type finger 7 (MARCH7), also known as axotrophin, was originally identified in mouse embryonic stem cells. MARCH7 is involved in T-cell proliferation, neuronal development, and the immune system. However, its role in endometrial cancer (EC) remains unclear. This study aimed to investigate the role of MARCH7 in EC. Quantitative polymerase chain reaction, immunohistochemistry, and western blot analysis were used to examine the expression of MARCH7, E-cadherin, Snail, and Vimentin in EC cell lines or clinical specimens. The role of MARCH7 in maintaining EC cell malignant phenotype was determined by transwell assay and using xenograft tumor model. Dual-luciferase reporter gene assay was performed to determine whether MARCH7 is an authentic target of miR-27b-3p. Our data showed that the expression level of MARCH7 in EC tissues was higher than that in normal endometrium tissues. The level of MARCH7 was positively associated with that of Snail and Vimentin, clinical stage, and histological grade, while negatively associated with that of E-cadherin. Knockdown of MARCH7 inhibited the invasion and metastasis of EC cells in vitro and in vivo. The opposite effect was observed after overexpressing MARCH7. MARCH7 promoted invasion and metastasis of EC cells via the Snail-mediated pathway. Furthermore, MARCH7 was demonstrated to be an authentic target of miR-27b-3p, and miR-27b-3p decreased the stimulus effect induced by MARCH7. These data indicate that MARCH7 may be an oncogenic factor and a therapeutic target for EC. miR-27b-3p/MARCH7 may also regulate EC cell invasion and metastasis via the Snail-mediated pathway., (© The Author(s) 2019. Published by Oxford University Press on behalf of the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background: ALKBH5 regulated the malignant behavior of breast cancer and glioblastoma. However, the expression and function of ALKBH5 in epithelial ovarian cancer have not yet been determined. In the present study, we investigated the expression and function of ALKBH5 in epithelial ovarian cancer with respect to its potential role in the tumorigenesis of the disease as well as an early diagnostic marker., Methods: Immunohistochemistry and western blot were used to detect protein expression. Gene silencing and over-expression experiment were used to study gene function. Cell proliferation assay and Matrigel invasion assays were used to detect cell proliferation and invasion, respectively. The nude mouse tumor formation experiment was used to evaluate the growth of cells in vivo., Results: The expression of ALKBH5 was found to be increased in epithelial ovarian cancer tissue as compared to the normal ovarian tissues. The silencing of ALKBH5 in SKOV3 cells enhanced the autophagy and inhibited the proliferation and invasion in vitro and in vivo, whereas the ectopic expression of ALKBH5 in A2780 cells exerted an opposite effect. Mechanical study revealed that ALKBH5 physically interacted with HuR. ALKBH5 activated EGFR-PIK3CA-AKT-mTOR signaling pathway. Also, ALKBH5 enhanced the stability of BCL-2 mRNA and promoted the interaction between Bcl-2 and Beclin1., Conclusion: Overall, the present study identified ALKBH5 as a candidate oncogene in epithelial ovarian cancer and a potential target for ovarian cancer therapy.

Background: Trastuzumab resistance followed by metastasis is a major obstacle for improving the clinical outcome of patients with advanced human epidermal growth factor receptor 2-positive (HER-2+) breast cancer. While long non-coding RNAs (lncRNAs) can modulate cell behavior, the contribution of these RNAs in trastuzumab resistance and metastasis of HER-2+ breast cancer is not well known. In this study, we sought to identify the regulatory role of lncRNA in trastuzumab resistance and accompanied Epithelial-mesenchymal Transition (EMT) process in advanced HER-2+ breast cancer., Methods: Trastuzumab-resistant SKBR-3-TR and BT474-TR cell lines were established by grafting SKBR-3 and BT474 cells into mouse models and subjected to trastuzumab treatment. LncRNA microarray followed by quantitative reverse transcription PCR (qRT-PCR) was carried out to verify the differentially expressed lncRNAs. Western blotting, bioinformatics analysis, immunofluorescence assay and immunoprecipitation assays (ChIP and RIP) were performed to identify the involvement and functional interactions between H3K27 acetylation and terminal differentiation-induced non-coding RNA (TINCR) or between TINCR and its downstream genes including miR-125b, HER-2 and Snail-1. In addition, a series of in vitro and in vivo assays were performed to assess the functions of TINCR., Results: An increase in both, IC 50 value of trastuzumab and EMT was observed in the established trastuzumab-resistant cell lines. The expression level of TINCR was significantly increased in trastuzumab-resistant cells when compared with sensitive cells. Knockdown of TINCR reversed the trastuzumab resistance and the acquired EMT in these cells. TINCR was detected in the cytoplasm of breast cancer cells and could sponge miR-125b, thereby releasing HER-2 and inducing trastuzumab resistance. In addition, Snail-1 was found to be the target gene of miR-125b and overexpression of Snail-1 could reverse the suppressed migration, invasion, and EMT caused by TINCR silencing. The upregulation of TINCR in breast cancer was attributed to the CREB-binding protein (CBP)-mediated H3K27 acetylation at the promoter region of TINCR. Clinically, HER-2+ breast cancer patients with high TINCR expression levels were associated with poor response to trastuzumab therapy and shorter survival time., Conclusion: TINCR could promote trastuzumab resistance and the accompanied EMT process in breast cancer. Therefore, TINCR might be a potential indicator for prognosis and a therapeutic target to enhance the clinical efficacy of trastuzumab treatment.

Endothelial-mesenchymal transition (EndMT) is closely associated with embryogenesis, injury restitution, tissue neogenesis, tumor progressions and viscera fibrosis. EndMT may occur in the proximal tubular endothelial cells, inducing fibroblasts to produce matrix and then accelerating the process of cardiac fibrosis. Transforming growth factor-β1 (TGF-β1), a profibrotic cytokine, was recently shown to be a crucial trigger of EndMT in tubular endothelial cells. Increasing evidence suggests that growth factor receptor-bound 2 (GRB2) dysfunction affects fibrocytes; thus, GRB2 may be a novel target for treating fibrosis. The miR-200 miRNA cluster (miR-429, miR-141, miR-200c, miR-200b and miR-200a) was reported to inhibit EndMT. However, the underlying mechanisms, specifically that of miR-200a, are unclear. To elucidate the vital role of miR-200a in EndMT, we established a cardiac interstitial fibrosis model with a widely used EndMT assay, TGF-β1-induced EndMT in human aortic endothelial cells (HAECs). We found that overexpression of miR-200a blocked EndMT in HAECs by inhibiting fibroblast-specific protein-1 (FSP-1) and α-smooth muscle actin (α-SMA) expression and increasing platelet endothelial cell adhesion molecule-1 (CD31) and vascular endothelial cadherin (VE-cadherin) expression, regardless of the presence of TGF-β1. MiR-200a expression was suppressed during the EndMT process, in both time- and dose-dependent manners, following GRB2 upregulation. EndMT was promoted by ectopic expression of GRB2 via decreased CD31 and VE-cadherin. Furthermore, EndMT was partially inhibited by co-transfection of miR-200a with GRB2 ORF, likely by restoring CD31 and VE-cadherin expression. MiR-200a negatively regulated GRB2 protein levels via direct binding to the GRB2 3'UTR. Finally, these discoveries may provide novel insights into the functional mechanism of miR-200a in regulating fibrosis via the TGFβ1/miR-200a/GRB2/EndMT pathway, and miR-200a may serve as a new target for treating fibrosis in the future., (Copyright © 2017. Published by Elsevier Masson SAS.)

Background: Atrial fibrillation (AF) is a highly prevalent condition associated with high morbidity and mortality that can cause or exacerbate heart failure and is an important risk factor for stroke. AF is the disorganized propagation of electrical activity in the atrium, which prevents organized contractions. However, the effect of microRNAs and the patterns of the regulatory network of AF remain vague., Material and Methods: The mRNA expression data of atrial tissue splices from 3 conditions - permanent atrial fibrillation (AF), sinus rhythm (SR), and human left ventricular non-failing myocardium (LV) - were downloaded from GSE2240 and the differentially expressed genes (DEGs) between the 3 kinds of samples were calculated. Then we constructed 3 miRNA-DEGs networks and these networks were integrated to construct the final merged AF-related microRNA regulatory network. Finally, we constructed the miRNA-inflammation networks to detect the roles of miRNAs in inflammation development of AF., Results: This network included 108 DEGs, and 27 microRNAs and DEGs are regulated by both microRNAs. We found that a sub-network composed by miR-124, miR-183, miR-215, miR-192, and a DEG of EGR1 were all represents in these 3 networks. Based on functional enrichment analysis, some biological process, such as energy and glucan metabolic process and heart and blood vessel development, were found to be regulated by miRNAs in AF. Some miRNAs, such as miR-26b and miR-355p, were involved in inflammation in AF., Conclusions: In conclusion, the microRNA regulatory network sheds new light on the molecular mechanism of AF with this non-coding regulated model.

Esophageal cancer is the eighth most common cancer and causes the sixth highest cancer-related mortality worldwide. The 5-year survival of patients suffering from esophageal cancer in either advanced stage or metastasis is less than 20%. MicroRNAs are small, well conserved, non-coding RNA molecules that either repress translation or promote mRNA degradation based on the degree of complementary between miRNAs and mRNAs. Based on biogenesis and function of microRNAs, specific microRNA profiles, either from cancerous tissues or serum, were able to serve as diagnostic and prognostic biomarkers of esophageal cancer and predicted the effectiveness of surgery and chemoradiotherapy. MicroRNAs could also influence the biological behaviors of esophageal cancer cells, such as cellular proliferation, apoptosis, invasion and metastasis. MicroRNAs were also associated with multi-drug resistance of esophageal cancer. Further studies on the roles of microRNAs in esophageal cancer would provide a strategy to prevent and treat esophageal cancer, and reverse multi-drug resistance of esophageal cancer.

Aims: Here we aimed to firstly investigate the role of miR-27a in proliferation and multidrug resistance of gastric cancer cells., Methods: The role of miR-27a in gastric cancer cells was detected using MTT assay, soft agar assay, flow cytometry assay, nude mice assay, real-time PCR, western blot and reporter gene assay, etc., Results: Down-regulation of miR-27a could inhibit porliferation of gastric cancer cells in vitro and in vivo. Down-regulation of miR-27a could also confer sensitivity of drugs on gastric cancer cells, and might increase accumulation and decrease releasing amount of adriamycin in gastric cancer cells. Down-regulation of miR-27a could significantly decrease the expression of P-glycoprotein and the transcriptional activity of cyclin D1, and up-regulate the expression of p21., Conclusions: MiR-27a might play important roles in porliferation and drug resistance of gastric cancer. MiR-27a might be considered as a useful target for cancer therapy.

Here we firstly investigated the role of miR-138 in multidrug resistance of leukemia cells. miR-138 was found up-regulated in the vincristine-induced multidrug resistance (MDR) leukemia cell line HL-60/VCR as compared with HL-60 cells. Up-regulation of miR-138 could reverse resistance of both P-glycoprotein-related and P-glycoprotein-non-related drugs on HL-60/VCR cells, and promote adriamycin-induced apoptosis, accompanied by increased accumulation and decreased releasing amount of adriamycin. miR-138 could significantly down-regulate the expression of P-glycoprotein, Bcl-2, and the transcription of the multidrug resistance gene 1. Further study of the biological functions of miR-138 might be helpful for developing possible strategies to treat leukemia., (Copyright (c) 2010 Elsevier Ltd. All rights reserved.)