Long noncoding RNA LINC01189 is associated with HCV-hepatocellular carcinoma and regulates cancer cell proliferation and chemoresistance through hsa-miR-155-5p.

INTRODUCTION AND OBJECTIVES: Emerging evidence has demonstrated that long noncoding RNAs (lncRNAs) may be closely associated with Hepatitis C virus (HCV) infection and the development of hepatocellular carcinoma (HCC). In this study, we investigated the expression and functions of a lncRNA, LINC01189, in HCV-associated HCC. PATIENTS OR MATERIALS AND METHODS: LINC01189 expression was measured in HCC tumors, HCV-infected HCC tumors and HCV-infected HCC cells. LINC01189 was overexpressed in HCV-infected HepG2 cells to measure its function on HCV-correlated cancer proliferation. In HCC cell lines of Huh7 and Hep3B, LINC01189 was upregulated to investigate its effects on cancer cell proliferation and 5-FU chemoresistance. The competing endogenous RNA (ceRNA) target of LINC01189, human microRNA-155-5p (hsa-miR-155-5p) was probed by dual-luciferase assay and qRT-PCR. Hsa-miR-155-5p was upregulated in LINC01189-overexpessed Huh7 and Hep3B cells to investigate their epigenetic correlation on HCC development regulation. RESULTS: LINC01189 is downregulated in HCV-infected HCC tumors and cell lines. LINC01189 overexpression inhibited HCC cancer cell proliferation and 5-FU chemoresistance. Hsa-miR-155-5p was confirmed to be a ceRNA target of LINC01189 in HCC. Upregulating hsa-miR-155-5p reversed the LINC01189-mediated inhibition on HCC proliferation and 5-FU chemoresistance. CONCLUSIONS: LINC01189 downregulation is associated with HCV infection in HCC, and it has tumor-suppressing effects on HCC development through hsa-miR-155-5p.

HMGB1-TLR4 signaling participates in renal ischemia reperfusion injury and could be attenuated by dexamethasone-mediated inhibition of the ERK/NF-κB pathway.

Studies have shown that the HMGB1-TLR4 (High-mobility group protein B1, toll-like receptor 4) pathway participates in renal ischemic reperfusion injury (IRI) and that dexamethasone (DEX) could protect the kidney against IRI. This study aims to examine the protective effects of DEX on renal IRI and further explore the possible mechanism of action. During mouse renal IRI, HMGB1-TLR4 signals changed markedly including HMGB1 translocation and TLR4 up-regulation, resulting in histological damage and an increase in MPO expression. Treatment with DEX markedly decreased the damage to renal function (serum Cr and BUN; kidney KIM-1 expression) and the histological pathology of the kidney after renal IRI. The activation of GR by DEX did not suppress p38 and JNK activity but inhibited ERK phosphorylation. Treatment with DEX also attenuated IκB-α phosphorylation and further reduced NF-κB expression in the nucleus by decreasing acetylation of the p65 subunit. Furthermore, the HMGB1-TLR4 inflammatory pathway was inhibited via the attenuated translocation of HMGB1 from the nucleus to the cytoplasm and the down-regulation of TLR4 expression through DEX treatment. The inhibition of HMGB1 translocation may interact with acetyltransferase and attenuate HMGB1 acetylation. As a result, the levels of cytokines (TNF-α, IL-6, and IL-1ß) were down-regulated and inflammatory cell infiltration after renal IRI was attenuated by treatment with DEX. This study demonstrated that the HMGB1-TLR4 pathway may play a critical role in renal IRI. DEX may attenuate renal IRI by suppressing ERK and NF-κB activation, followed by attenuating the HMGB1-TLR4 pathway through inhibiting acetyltransferases.