MiR-145 Regulates the Chemoresistance of Hepatic Carcinoma Cells Against 5-Fluorouracil by Targeting Toll-Like Receptor 4

• Published in: Cancer management and research 2020-01, Vol.12, p.6165-6175
• Main Authors: Zheng, Rui-Peng, Ma, Dong-Kai, Li, Zhuo, Zhang, Hai-Feng
• Format: Article
• Language: English
• Subjects: 5- fluorouracil; Apoptosis; Cancer staging; Carcinoma; Chemotherapy; Development and progression; Drug resistance; Fluorouracil; hepatic carcinoma; mir-145; Original Research; Prognosis; Proteins; Scientific equipment industry; toll-like receptor 4 (tlr4)
• ISSN: 1179-1322; 1179-1322
• DOI: 10.2147/CMAR.S257598

5-fluorouracil (5-FU) is a common drug for hepatic carcinoma (HCC), but the drug resistance of clinical chemotherapy restricts its use. Studies have demonstrated that miRNA molecules can act as a chemoresistance regulator in drug resistance of tumors, whereas the role of miR-145 in the 5-FU-resistant HCC remains unclear. To explore the prognostic value of miR-145 in HCC and its molecular mechanism in 5-FU-resistant HCC cells. A qRT-PCR assay was conducted to quantify miR-145 in HCC tissues and 5-FU-resistant HCC cells. The Cell Counting Kit-8 (CCK-8) and flow cytometry were adopted to analyze the proliferation and apoptosis of 5-FU-resistant HCC cells. The Western blot was adopted to quantify toll-like receptor 4 (TLR4), myeloid differentiation factor 88 (MyD88), and apoptosis-related proteins. Moreover, an in vivo tumor xenotransplantation of nude mice was conducted to determine the effect of miR-145 on 5-FU-resistant HCC cells. MiR-145 was expressed lowly in HCC tissues and cells, and linked to high TNM staging and lymph node metastasis of HCC patients. Down-regulation of miR-145 indicated a poorer prognosis and it promoted drug resistance of HCC cells and inhibited cell apoptosis. In contrast, miR-145 overexpression improved the sensitivity of HCC cells to 5-FU and enhanced the inhibition of 5-FU on tumor growth. The luciferase reporter gene assay showed that TLR4 was the direct target of miR-145, and the Western blot assay revealed that overexpression of TLR4 reversed the inhibitory effect of miR-145 overexpression on TLR4 and MyD88 protein and the effects of it on apoptosis-related proteins. MiR-145 is an inhibiting factor in HCC and can target TLR4 to mediate the chemoresistance of HCC, which may provide novel ideas for treating HCC.