Circular RNA (circ)_0053277 Contributes to Colorectal Cancer Cell Growth, Angiogenesis, Metastasis and Glycolysis.

Circular RNAs (circRNAs) have been found to be abnormally expressed in many cancers, including colorectal cancer (CRC). Circ_0053277 has been found to mediate CRC malignant processes and may be a key regulator for CRC progression. Therefore, its role and potential molecular mechanism in CRC process deserve further investigation. Quantitative real-time PCR was used to detect the expression levels of circ_0053277, microRNA-520 h (miR-520 h) and hexokinase 1 (HK1). Cell Counting Kit-8, 5-ethynyl-2'-deoxyuridine assay, flow cytometry, wound healing assay, transwell assay, and tube formation assay were used to detect CRC cell proliferation, apoptosis, migration, invasion, and angiogenesis. The protein levels of apoptosis-related markers and HK1 were detected by western blot. The relationship between circ_0053277 and miR-520 h or miR-520 h and HK1 in CRC cells was verified by dual-luciferase reporter assay, RNA immunoprecipitation assay and RNA pull-down assay. Cell glycolysis was assessed by detecting glucose uptake and lactate production. The effect of silenced circ_0053277 on CRC tumor growth was evaluated by xenograft model in vivo. Our study found that circ_0053277 expression was elevated in CRC tissues and cells. Moreover, circ_0053277 knockdown suppressed CRC cell proliferation, angiogenesis, migration and invasion, while promoting apoptosis. In terms of mechanism, circ_0053277 sponged miR-520 h, and HK1 was the target of miR-520 h. Meanwhile, miR-520 h inhibitor reversed the inhibitory effect of circ_0053277 silencing on CRC cell progression, and HK1 overexpression also overturned the suppressive effect of miR-520 h on CRC cell growth, angiogenesis and metastasis. Moreover, circ_0053277 knockdown inhibited the glycolysis of CRC cells by regulating miR-520 h/HK1 pathway. In addition, knockdown of circ_0053277 reduced CRC tumor growth in vivo. Circ_0053277 promoted CRC cell growth, angiogenesis, metastasis and glycolysis by miR-520 h/HK1 pathway, confirming that circ_0053277 might be a potential clinical target for CRC treatment.

Zhuang J ，Song W ，Li M ，Kang D ，Cheng K ... -  《-》

Circular RNA circ_0004630 promotes malignancy and glycolysis of nonsmall cell lung cancer by sponging microRNA-1208 and regulating leucine-rich repeat kinase 2 expression.

Emerging evidence has discovered that circular RNAs play important regulators of nonsmall cell lung cancer (NSCLC), but the role and potential molecular mechanism of hsa_circ_100549 (circ_0004630) involved in NSCLC is poorly defined. In this study, circ_0004630, microRNA-1208 (miR-1208), and leucine-rich repeat kinase 2 (LRRK2) expression were detected using real-time quantitative polymerase chain reaction. Cell proliferation, colony formation, apoptosis, and invasion were assessed using 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine, colony formation, flow cytometry, and transwell assays. Protein levels of glucose transporter 1, Hexokinase 2, and LRRK2 were detected using western blot assay. Glucose consumption, lactate production, and adenosine triphosphate content were assessed using the corresponding kits. After predicting via bioinformatics software Circinteractome and Targetscan, the binding between miR-1208 and circ_0004630 or LRRK2 was verified by a dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assay. The xenograft tumor model analyzed the biological role circ_000460 on tumor growth in vivo. It was found that circ_0004630 and LRRK2 were increased, and miR-1208 was low expression in NSCLC tissues and cells. Functionally, the downregulation of circ_0004630 inhibited NSCLC cell proliferation, invasion, glycolysis, and accelerated apoptosis in vitro. In mechanism, circ_0004630 might work as a sponge of miR-1208 to modulate LRRK2 expression. In addition, DUXAP8 deficiency cured neuroblastoma tumor growth in vivo. In conclusion, circ_0004630 knockdown might suppress NSCLC cell proliferation, metastasis, and glycolysis partly by the miR-1208/LRRK2 axis. Our findings hinted at an important theoretical basis for further elucidating the pathogenesis of NSCLC and targeted therapy.

Zhang X ，Wu J ，Miao Y ，Wang J ，Wang E ... -  《-》

Downregulation of hsa_circ_0006620 inhibits the malignant progression of prostate cancer by regulation of the miR-502-3p/HK2 axis mediated by aerobic glycolysis.

Circular RNAs (circRNA) are a class of covalently-closed, single-stranded RNAs that have been implicated in cancer progression due to their regulation of metabolism. However, the roles of circRNA in prostate cancer remain largely unknown. In this study, fluorescence in situ hybridization and RT-qPCR were used to investigate hsa_circ_0006620 expressions in both prostate cancer cells and tissues, after high-throughput sequencing. The luciferase reporter assay was used to identify hsa_circ_0006620 downstream targets. Transwell migration assays, 5-ethynyl-20-deoxyuridine assays, and Cell Counting Kit-8assays were used to investigate both proliferation and migration. In vivo tumorigenesis and metastasis assays were performed to investigate the role of hsa_circ_0006620 in prostate cancer. The results showed that hsa_circ_0006620 expression increased in prostate cancer cells and tissues. Hsa_circ_0006620 downregulation inhibited prostate cancer cell proliferation as well as in vivo and in vitro migrations. The luciferase results validated that miR-502-3p and hexokinase 2 (HK2) were hsa_circ_0006620 downstream targets. HK2 overexpression or miR-502-3p inhibition reversed prostate cancer cell migration after hsa_circ_0006620 silencing. The study also found that overexpression of HK2 or inhibition of prostate cancer reversed aerobic glycolysis after hsa_circ_0006620 silencing. In summary, the results showed thathsa_circ_0006620 downregulation inhibited prostate cancerby regulation of the miR-502-3p/HK2 axis mediated by aerobic glycolysis.

Jin M ，Wang M ，Luo Y ，Yuan T ，Li X ，Huang G ，Huang Q ，Sun H ... -  《-》

Circ_0004674 regulation of glycolysis and proliferation mechanism of osteosarcoma through miR-140-3p/TCF4 pathway.

As a subclass of noncoding RNAs, circular RNA play an important role in tumour development. The aim of this study was to investigate the role of circ_0004674 in osteosarcoma glycolysis and the molecular mechanism of its regulation. We examined the expression of circ_0004674, miR-140-3p, TCF4 and glycolysis-related proteins (including HK2, PKM2, GLUT1 and LDHA) in osteosarcoma cells and tissues by quantitative reverse transcription-polymerase chain reaction and immunoblotting (Western blot analysis). The role of circ_0004674, miR-140-3p and TCF4 in the proliferation, apoptosis, migration and invasion of OS cells was examined using CCK8 assay, Apoptosis assay, Wound healing assay, Transwell migration and Matrigel invasion assay. The interaction of circ_0004674/miR-140-3p and miR-1543/TCF4 was also analysed using a dual luciferase reporter assay. Finally, the glycolytic process was assessed by glucose uptake assays and lactate production measurements. The results showed that the expression of circ_0004674 and TCF4 was significantly higher in MG63 and U2OS cells compared to hFOB1.19 cells, while the expression of miR-140-3p was downregulated. Silencing of circ_0004674 gene significantly inhibited the proliferation, migration and invasion of cancer cells and promoted apoptosis of cancer cells. Experiments such as dual luciferase reporter analysis showed that circ_0004674 regulates the expression of glycolysis-related proteins through the miR-140-3p/TCF4 pathway, and inhibition of this gene attenuated the depletion of glucose content and the production of lactate in cancer cells. Furthermore, inhibition of miR-140-3p or overexpression of TCF could reverse the phenotypic changes in cancer cells induced by circ_0004674 silencing. In summary, this study elucidated the specific function and potential mechanisms of circ_0004674 in osteosarcoma glycolysis. The findings demonstrate that miR-140-3p and TCF4 function respectively as a tumor suppressor gene and an oncogene in osteosarcoma. Notably, they influence glycolysis and associated pathways, regulating osteosarcoma proliferation. Therefore, circ_0004674 promotes osteosarcoma glycolysis and proliferation through the miR-140-3p/TCF4 pathway, enhancing the malignant behaviour of tumours, and it is expected to be a potential molecular target for osteosarcoma treatment.

Ma Y ，Du S ，Wang S ，Liu X ，Cong L ，Shen W ，Ye K ... -  《-》

The miR-1269a/PCDHGA9/CXCR4/β-catenin pathway promotes colorectal cancer invasion and metastasis.

Colorectal cancer (CRC) is the third most common cancer worldwide and the second leading cause of cancer-related death. This research focuses on investigating the impact and underlying molecular mechanisms of protocadherin gamma subfamily A, 9 (PCDHGA9) on the invasion and metastasis of CRC, aiming to identify more precise molecular markers for the diagnosis and prognosis of CRC. PCDHGA9 expression was detected using quantitative real-time quantitative polymerase chain reaction (RT-qPCR) in 63 pairs of colorectal cancer tissues. Differential gene expression from high-throughput sequencing was analyzed using ingenuity pathway analysis (IPA) to explore the biological functions of PCDHGA9 and its potential regulated genes. Bioinformatics tools were employed to explore potential upstream regulatory microRNAs of PCDHGA9. Dual-luciferase assays were performed to demonstrate the regulation between PCDHGA9 and miR-1269a. Protein mass spectrometry suggested an interaction between PCDHGA9 and HOXA1. JASPAR predicted that HOXA1 may act as a transcription factor of CXCR4. Coimmunoprecipitation, dual-luciferase assays, and nuclear-cytoplasmic fractionation experiments confirmed the molecular mechanism involving PCDHGA9, CXCR4, HOXA1, and β-catenin. Transwell, wound healing, and western blot assays were conducted to confirm the impact of PCDHGA9, miR-1269a, and CXCR4 on the invasion, metastasis, and epithelial-mesenchymal transition (EMT) functions of CRC cells in in vitro experiments. A whole-body fluorescence imaging system was used to evaluate the combined impact of miR-1269a and PCDHGA9 on the invasion and metastasis of CRC in in vivo experiments. The expression of PCDHGA9 was found to be lower in CRC tissues compared with their corresponding adjacent tissues. Low expression of PCDHGA9 potentially correlated with worse prognosis and increased chances of invasion and metastasis in CRC. miR-1269a was highly expressed in CRC tissues and acted as a negative regulator for PCDHGA9, promoting invasion, migration, and EMT of CRC cells. PCDHGA9's interaction with HOXA1 downregulated CXCR4, a transcription factor, leading to accumulation of β-catenin and further promoting invasion, migration, and EMT of CRC cells. PCDHGA9, acting as a tumor suppressor, is downregulated by miR-1269a. The low level of PCDHGA9 activates the Wnt/β-catenin pathway by releasing its interaction with HOXA1, promoting the expression of CXCR4, and causing invasion, migration, and EMT in CRC.

Mei H ，Luo Q ，Weng J ，Hao J ，Cai J ，Zhou R ，Bian C ，Ye Y ，Luo S ，Wen Y ... -  《-》