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A previous study has elucidated that circular RNA circCLK3 acts as an oncogenic gene in cervical cancer. However, the role and regulatory mechanism of circCLK3 in tongue squamous cell carcinoma (TSCC) remain unknown. Quantitative real‐time PCR was used to examine targeted gene expression in different groups. Cell viability and proliferation were investigated by MTT and 5‐ethynyl‐2′‐deoxyuridine assays. Cell migration and invasion were detected by Transwell assays, and cell apoptosis was measured by flow cytometry analysis. The interaction among genes was investigated using luciferase reporter assay, RNA pull‐down assay, and RNA immunoprecipitation assay. In the present study, our findings revealed the upregulated expression of circCLK3 in TSCC tissues and cell lines. CircCLK3 knockdown suppressed cell proliferation, migration invasion, and induced cell cycle arrest at G0/G1 phase in TSCC. Moreover, circCLK3 acted as a molecular sponge for miR‐455‐5p. PARVA was the target gene of miR‐455‐5p. Furthermore, the negative correlation between expression of miR‐455‐5p and circCLK3 or PARVA in TSCC tissues was discovered. Rescue assays indicated that PARVA overexpression reversed the circCLK3 knockdown‐mediated inhibitory effects on the progression of TSCC. In summary, circCLK3 exerts its carcinogenic effects on TSCC progression via absorbing miR‐455‐5p to upregulate PARVA, which expands our knowledge on the underlying mechanism of TSCC. [ABSTRACT FROM AUTHOR]

The study aimed to explore the specific function and mechanism of miR-144-3p in glioblastoma ( GBM) cells with different phosphatase and tensin homolog (PTEN) phenotypes. We demonstrated that the miR-144-3p level was significantly down-regulated in glioma compared with the non-neoplastic brain tissues, and decreased with ascending grades. The loss of miR-144-3p effectively predicted the decreased overall survival in glioma patients. Interestingly, the expression of MET was up-regulated and inversely associated with miR-144-3p level in glioma tissues. Next, we certified that miR-144-3p specifically bound to MET 3′-untranslated region (3′ UTR) and inhibited its expression. miR-144-3p potently repressed GBM cell proliferation and invasion via suppressing MET in vitro and in vivo. In addition, our results showed no difference in malignancy inhibition induced by miR-144-3p in GBM cells with different PTEN phenotypes. miR-144-3p inhibited several survival signaling pathways by targeting MET independent of PTEN status in GBM cells. Over-expression of miR-144-3p inhibited survival capability and increased apoptosis, resulting in enhancement of radiation and temozolomide sensitivity. Our data provide new insights into the potential application of miR-144-3p in GBM therapy by targeting MET and then inhibiting the downstream signaling. [ABSTRACT FROM AUTHOR]

Objective: We aimed to explore the role of long intergenic non‐protein coding RNA 460 (LINC00460) in tongue squamous cell carcinoma (TSCC). Methods: We enrolled 27 TSCC patients to explore LINC00460 expression in clinical TSCC samples. RT‐qPCR measured expression of molecules in this research. Loss‐of‐function assays explored biological function of LINC00460 in TSCC cells. RNA pull‐down assay, luciferase reporter assay, and RIP assay investigated mechanism of LINC00460 underlying TSCC cells. Results: TSCC tissues and cell lines both showed high expression of LINC00460. Functionally, LINC00460 downregulation inhibited TSCC cell growth and promoted TSCC cell apoptosis. Additionally, LINC00460 silencing suppressed tumor growth in vivo. Mechanistically, LINC00460 bound with microRNA 320b (miR‐320b) in TSCC cells. MiR‐320b overexpression suppressed TSCC cell growth and promoted TSCC cell apoptosis. Moreover miR‐320b targeted insulin‐like growth factor 2 mRNA‐binding protein 3 (IGF2BP3) 3′untranslated region in TSCC cells. Furthermore, IGF2BP3 silencing suppressed TSCC cell growth and promoted TSCC cell apoptosis. IGF2BP3 upregulation countervailed effects of silenced LINC00460 on TSCC cells. The LINC00460/miR‐320b/IGF2BP3 axis was associated with lymph node metastasis of TSCC patients. Conclusion: Our research illustrated that LINC00460 facilitated TSCC progression via the miR‐320b/IGF2BP3 axis, highlighting a potential insight for the treatment of TSCC. [ABSTRACT FROM AUTHOR]

Accumulating evidence has suggested that long noncoding RNAs (lncRNAs) are involved in the progression of types of human cancers. It has been known that exosomes can mediate cell-cell crosstalk by transferring lncRNAs in tumor progression. This study aimed to investigate the role of exosomal lncRNA HEIH on cisplatin (DDP) resistance in tongue squamous cell carcinoma (TSCC). The expression of HEIH in human oral keratinocytes cell line (HOK), DDP-sensitive TSCC cell line (SCC4/S) and DDP-resistant TSCC cell line (SCC4/DDP) was measured. SCC4/S and SCC4/DDP cells were transfected with sh-HEIH to examine TSCC cell proliferation and apoptosis. The DDP-resistant exosomes were extracted and identified. The expression of miR‑3619-5p and TDGF in DDP-sensitive recipient cells was determined. The binding capacity between HEIH and miR‑3619-5p, along with miR‑3619-5p and TDGF was verified. HEIH expression was significantly upregulated in SCC4/DDP cells. Downregulation of HEIH inhibited DDP resistance and cell proliferation and promoted cell apoptosis. HEIH acted as a competing endogenous RNA (ceRNA) for miR‑3619-5p to upregulate HDGF expression. Exosomal HEIH promoted cell proliferation and drug resistance and inhibited cell apoptosis by sponging miR‑3169-5p and upregulating HDGF. Exosomal HEIH acted as a ceRNA for miR‑3619-5p to upregulate HDGF, thereby promoting DDP resistance in TSCC cells. [ABSTRACT FROM AUTHOR]

Background and Aim: MicroRNAs are short noncoding RNA molecules that are responsible for the posttranscriptional regulation of target genes. The aim of this study was to determine whether microRNA-199b-5p (miR-199b) plays a role in the progression and prognosis of hepatocellular carcinoma (HCC), and to elucidate whether hypoxia-inducible factor-1α (Hif1α) is regulated by miR-199b. Methods: In this study, 35 matched HCCs and cirrhosis tissues were assayed for miR-199b and Hif1α expression. To evaluate the role of miR-199b, we assessed cell proliferation rate and clonogenic survival of miR-199b- or negative control-transfected cells by MTT and clone formation assay, respectively. In addition, the regulation of Hif1α by miR-199b was evaluated by Western blotting and luciferase assay. MiR-199b was downregulated in 77% of HCCs, whereas Hif1α protein was upregulated in 69% of cases. A significant inverse correlation between miR-199b and Hif1α was observed in HCCs. Results: Patients with lower levels of miR-199b expression had poorer overall survival and progression-free survival rates, whereas patients with higher levels of miR-199b expression had better survival. Moreover, miR-199b could restrain cell growth and obviously enhance the radiosensitizing effect of HepG2 cells. MiR-199b and pGL3-Hif1α vector-transfected cells showed suppressed Hif1α protein expression and significant reduced luciferase activity. Conclusions: Underexpressed miR-199b, which may be via the upregulation of Hif1α in HCCs, is inversely correlated with survival and directly correlated with the malignant status of HCC patients. [ABSTRACT FROM AUTHOR]