ABSTRACT
To study the effect of miR-340-5p on the proliferation of laryngeal cancer Hep2 cells and explore its intrinsic molecular mechanism, so as to screen potential biomarkers and targets for the diagnosis and treatment of laryngeal cancer. The expression of miR-340-5p in laryngeal cancer tissues, paracancerous tissues, laryngeal cancer cell lines Hep2 and normal bronchial HBE cell lines was quantitatively analyzed by qRT-PCR; The double luciferase reporter vector was constructed to verify whether STAT3 was a potential target gene of microRNA-340-5p; The miR-340-5p mimics/inhibitor was transfected into Hep2 cells by liposome and verified by qRT-PCR; The CCK-8 method and Annexin V/PI method were used to analyze the proliferation and apoptosis of transfected cells; and Western Blot was used to detect the expression of STAT3 and Wnt/β-catenin pathway-related proteins after transfection. The results of qRT-PCR showed that the level of miR-340-5p in laryngeal cancer tissues and Hep2 cells was significantly lower than that in adjacent tissues and HBE cells, and the expression of miR-340-5p was significantly increased or decreased after overexpression or inhibition; Luciferase activity showed that miR-340-5p directly interacted with target gene STAT3 3'-UTR and negatively regulated its expression; Cell proliferation and apoptosis analysis showed that up-regulation of microRNA-340-5p could significantly inhibit the proliferation and induce apoptosis of Hep2 cells in vitro, and vice versa; Western Blot results showed that the levels of STAT3 and β-catenin, c-Myc, TCF-4, CyclinD1 and ROCK1 in Hep2 cells were significantly lower than those in the control group after over-expression of miR-340-5p, and vice versa. The expression of miR-340-5p is abnormally low in laryngeal cancer tissues and Hep2 cells. It can be used as a potential biological target for diagnosis and treatment of laryngeal cancer by targeting STAT3 gene to negatively regulate Wnt/β-catenin signaling pathway.
ABSTRACT
Objective@#To study the effect of miR-340-5p on the proliferation of laryngeal cancer Hep2 cells and explore its intrinsic molecular mechanism, so as to screen potential biomarkers and targets for the diagnosis and treatment of laryngeal cancer. @*Method@#The expression of miR-340-5p in laryngeal cancer tissues, paracancerous tissues, laryngeal cancer cell lines Hep2 and normal bronchial HBE cell lines was quantitatively analyzed by qRT-PCR; The double luciferase reporter vector was constructed to verify whether STAT3 was a potential target gene of microRNA-340-5p; The miR-340-5p mimics/inhibitor was transfected into Hep2 cells by liposome and verified by qRT-PCR; The CCK-8 method and Annexin V/PI method were used to analyze the proliferation and apoptosis of transfected cells; and Western Blot was used to detect the expression of STAT3 and Wnt/β-catenin pathway-related proteins after transfection. @*Result@#The results of qRT-PCR showed that the level of miR-340-5p in laryngeal cancer tissues and Hep2 cells was significantly lower than that in adjacent tissues and HBE cells, and the expression of miR-340-5p was significantly increased or decreased after overexpression or inhibition; Luciferase activity showed that miR-340-5p directly interacted with target gene STAT3 3'-UTR and negatively regulated its expression; Cell proliferation and apoptosis analysis showed that up-regulation of microRNA-340-5p could significantly inhibit the proliferation and induce apoptosis of Hep2 cells in vitro, and vice versa; Western Blot results showed that the levels of STAT3 and β-catenin, c-Myc, TCF-4, CyclinD1 and ROCK1 in Hep2 cells were significantly lower than those in the control group after over-expression of miR-340-5p, and vice versa. @*Conclusion@#The expression of miR-340-5p is abnormally low in laryngeal cancer tissues and Hep2 cells. It can be used as a potential biological target for diagnosis and treatment of laryngeal cancer by targeting STAT3 gene to negatively regulate Wnt/β-catenin signaling pathway.
ABSTRACT
ObjectiveTo explore regulation effect of miR-340-5p on regulating bone morphogenetic protein 4(BMP4) expression and the differentiation of rat's NSCs.MethodsNSCs of rats were divided randomly into three groups: normal group (Mock),group with nonsense oligonucleotide (Anti-Con) and group with antisense oligonucleotide of miR-340-5p (Anti-miR-340-5p).The qRT-PCR was used to detect the relative expression of miR-340-5p.The expression of NF200 and MAP-2 was detected by immunocytochemical staining and immunofluorescence,respectively.Western blot was used to detect the expression of BMP4 protein.ResultsThe relative levels of miR-340-5p expression were significantly decreased in Anti-miR-340-5p group (0.14±0.01) compared with that of Mock group(1.01±0.17) and Anti-Con group(1.07±0.13) (P<0.01).Immunocytochemical staining indicated that NF200 was positive in cells of Anti-miR-340-5p group.The proportion of MAP2 positive cells was increased in Anti-miR-340-5p group compared with other groups (P<0.05).Western blot showed the increased expression of BMP4 protein in Anti-miR-340-5p group (0.84±0.09) compared with Mock group(0.53±0.04) and Anti-Con group (0.63±0.09) (P<0.05).ConclusionThe miR-340-5p may exert a potential function in regulating differentiation of NSCs into neurons through a negative regulation of BMP4.
ABSTRACT
MicroRNAs (miRNAs) play an important role in drug resistance and modulate the efficiency of chemotherapy. A recent study indicated that miR-340 functions as a tumor suppressor in various types of cancer. However, the role of miR-340 in chemotherapy has not been reported yet. In this study, we found that miR-340 enhanced cisplatin (CDDP)-induced cell death. Induction of miR-340-5p expression decreased the IC50 of CDDP and increased the apoptosis of CDDP-resistant MG-63 and Saos-2 cells. Moreover, miR-340-5p decreased the accumulation of MRP1 and MDR1. We further explored the mechanism underlying the promoting effects of miR-340-5p on CDDP-induced cell death. We identified a potential target of miR-340 in the 3′ untranslated region of lysophosphatidic acid acyltransferase (LPAATβ) using the online program Targetscan (http://www.microrna.org). Luciferase reporter assays showed that miR-340 binds to the 3′UTR of LPAATβ. Enforced expression of miR-340-5p decreased the accumulation of LPAATβ in both MG-63 and Saos-2 cells. Silencing LPAATβ decreased the IC50 of CDDP and increased the apoptosis of CDDP-resistant MG-63 and Saos-2 cells, which is consistent with the effect of miR-340-5p on CDDP-induced cell death. Moreover, induced expression of LPAATβ compromised the effects of miR-340-5p on CDDP-induced cell death and accumulation of MRP1 and MDR1. Taken together, our data indicated that miR-340-5p enhanced the sensitivity to CDDP by targeting LPAATβ.