CircWHSC1 regulates malignancy and glycolysis by the miR-212-5p/AKT3 pathway in triple-negative breast cancer.

Triple-negative breast cancer (TNBC) is the most aggressive malignant tumor in breast cancer (BC). Circular RNA circWHSC1 (circWHSC1) is connected with the progression of tumors. However, the role and regulatory mechanism of circWHSC1 in TNBC are unclear. The expression of circWHSC1, microRNA (miR)-212-5p, and protein kinase B-3 (AKT3) mRNA in BC tissues and/or cells was examined by quantitative real-time polymerase chain reaction (qRT-PCR). The viability, colony formation, migration, invasion, and apoptosis of TNBC cells were determined by cell counting kit-8 (CCK-8), colony formation, transwell, or flow cytometry assays. The levels of glucose consumption and lactate production were assessed with commercial kits. The levels of hexokinase II (HK2) and AKT3 protein were detected by western blotting. The role of circWHSC1 in vivo was verified by tumor xenograft assay. The relationship between miR-212-5p and circWHSC1 or AKT3 was verified via dual-luciferase reporter and RNA pull-down assays. CircWHSC1 was upregulated in BC tissues and cells. Also, circWHSC1 could discriminate BC tissues and paracancerous normal tissues. TNBC patients with high circWHSC1 possessed a poor prognosis. CircWHSC1 silencing reduced TNBC cell growth in vivo and repressed proliferation, migration, invasion, glycolysis, and induced apoptosis of TNBC cells in vitro. CircWHSC1 regulated AKT3 expression by sponging miR-212-5p. Silencing of miR-212-5p overturned circWHSC1 knockdown-mediated impacts on malignancy and glycolysis of TNBC cells. AKT3 overexpression reversed the inhibitory effect of miR-212-5p mimic on malignancy and glycolysis of TNBC cells. CircWHSC1 accelerated malignancy and glycolysis of TNBC cells by the miR-212-5p/AKT3 axis. The research provided a potential prognostic biomarker and therapeutic target for TNBC.

Ding L ，Xie Z 《-》

Circ_0000520 contributes to triple-negative breast cancer progression through mediating the miR-1296/ZFX axis.

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer with a high incidence of local recurrence and metastasis. Circular RNAs (circRNAs) are implicated in the pathomechanism of TNBC. Here, we investigated the function of circ_0000520 in TNBC and its associated mechanism. Reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western blot assay were used to measure RNA and protein expression. Cell proliferation was analyzed by cell counting kit-8 (CCK8) assay, flow cytometry and colony formation assay. Cell apoptosis was assessed by flow cytometry. Cell migration ability was analyzed by transwell migration and wound healing assays. Transwell invasion assay was conducted to analyze the invasion ability. Dual-luciferase reporter assay, RNA immunoprecipitation (RIP) assay, and RNA-pulldown assay were performed to verify the interaction between microRNA-1296 (miR-1296) and circ_0000520 or zinc finger protein X-linked (ZFX). Xenograft mice model was established to analyze the role of circ_0000520 in xenograft tumor growth in vivo. Circ_0000520 expression was upregulated in TNBC tissues and cell lines. Circ_0000520 knockdown suppressed the proliferation, migration, and invasion whereas induced the apoptosis of TNBC cells. miR-1296 was verified as a target of circ_0000520, and circ_0000520 silencing-mediated suppressive effects on the malignant potential of TNBC cells were partly overturned by miR-1296 knockdown. miR-1296 interacted with the 3' untranslated region (3'UTR) of ZFX, and ZFX overexpression partly reversed miR-1296 overexpression-mediated effects in TNBC cells. Circ_0000520 absence reduced ZFX expression by upregulating miR-1296 in TNBC cells. Circ_0000520 silencing suppressed xenograft tumor growth in vivo. Circ_0000520 contributed to TNBC development by binding to miR-1296 to induce ZFX expression.

Zhou Y ，Ma G ，Peng S ，Tuo M ，Li Y ，Qin X ，Yu Q ，Kuang S ，Cheng H ，Li J ... -  《-》

CircRNA WHSC1 promotes non-small cell lung cancer progression via sponging microRNA-296-3p and up-regulating expression of AKT serine/threonine kinase 3.

Lung cancer is the most commonly diagnosed cancer and leading cause of cancer death, with 80%-85% of non-small cell lung cancer (NSCLC). Circular RNAs (circRNAs) have been shown to be promising early diagnostic and therapeutic molecular biomarkers for NSCLC. However, biological role and regulatory mechanism of circRNA WHSC1 (circWHSC1) in NSCLC are unknown. Therefore, we aim to explore the function and mechanism of circWHSC1 in NSCLC oncogenesis and progression. qRT-PCR was used for circWHSC1 level evaluation; Kaplan-Meier was used for survival analysis; bioinformatics, dual-luciferase activity, and RNA pull-down were used for evaluating competing endogenous RNA (ceRNA) network; cell viability, colony formation, apoptosis, migration, and invasion were used for cell function analysis; function gain and loss with rescue experiments were used for exploring mechanism of circWHSC1 in NSCLC development. Significantly up-regulated circWHSC1 and down-regulated microRNA-296-3p (miR-296-3p) were identified in NSCLC tissues and cells. Up-regulated circWHSC1 was associated with poor prognosis in NSCLC patients. MiR-296-3p was sponged by circWHSC1, and AKT serine/threonine kinase 3 (AKT3) was target of miR-296-3p; meanwhile, miR-296-3p over-expression significantly down-regulated AKT3 expression, and co-transfecting anti-miR-296-3p rescued circWHSC1 silence caused AKT3 down-regulation. CircWHSC1 silence significantly inhibited colony formation, viability, invasion, and migration, while increased NSCLC cell apoptosis, which were partially rescued by anti-miR-296-3p. CircWHSC1 is an independent indicator of poor prognosis in NSCLC patients, and functions as a ceRNA of miR-296-3p to up-regulate AKT3, consequently promotes NSCLC cell growth and metastasis. Targeting circWHSC1 might be a prospective strategy for diagnosis, therapeutics, and prognosis of NSCLC.

Shi F ，Yang Q ，Shen D ，Chen J ... -  《-》

CircWHSC1 serves as an oncogene to promote hepatocellular carcinoma progression.

Circular RNAs (circRNAs) function as vital regulators in multifarious cancers, including hepatocellular carcinoma (HCC). However, the roles of circRNA Wolf-Hirschhorn syndrome candidate gene-1 (circWHSC1) in HCC are barely known. Quantitative real-time polymerase chain reaction (qRT-PCR) was conducted for the levels of circWHSC1, miR-142-3p, miR-421, miR-665 and homeobox A1 (HOXA1) mRNA. Cell Counting Kit-8 (CCK-8) assay, colony formation assay and 5'-ethynyl-2'-deoxyuridine (EdU) assay were used to evaluate cell proliferation ability. Transwell assay was adopted for cell migration and invasion. Western blot assay was employed for protein levels. RNA pull-down assay, dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were executed to verify the interaction between miR-142-3p and circWHSC1 or HOXA1. Murine xenograft model assay was conducted for the role of circWHSC1 in vivo. The morphology of exosomes was observed by transmission electron microscopy (TEM). CircWHSC1 was elevated in HCC tissues and cells, and high level of circWHSC1 was associated with worse overall survival of HCC patients. Knockdown of circWHSC1 suppressed HCC cell proliferation and metastasis in vitro and restrained tumorigenesis in vivo. CircWHSC1 functioned as the sponge for miR-142-3p, which directly targeted HOXA1. Inhibition of miR-142-3p ameliorated the effects of circWHSC1 knockdown on HCC cell proliferation and metastasis. Moreover, miR-142-3p overexpression restrained the growth and motility of HCC cells, with HOXA1 elevation reversing the impacts. Additionally, circWHSC1 was increased in HCC patients' serum and might be a diagnostic indicator for HCC. CircWHSC1 played a tumour-promoting role in HCC by elevating HOXA1 through sponging miR-142-3p.

Lyu P ，Zhai Z ，Hao Z ，Zhang H ，He J ... -  《-》

Circ-PVT1/miR-106a-5p/HK2 axis regulates cell growth, metastasis and glycolytic metabolism of oral squamous cell carcinoma.

Zhu X ，Du J ，Gu Z 《-》