Abstract. Excision repair cross-complementary gene 1 (ERCC1) is a downstream regulatory target of fibroblast growth factor receptor 2 (FGFR2); however, the mechanism of its action has not been elucidated. The cascades downstream of FGFR2 include the PKC, Ras̸Raf̸MEK̸ERK, JAK̸STAT and PI3K pathways. ERCC1 is considered to be a closely related downstream target gene of extracellular signal-regulated kinase (ERK)1/2, since ERCC1 mRNA and protein levels may be inhibited by the ERK inhibitor U0126. It was hypothesized that FGFR2, which specifically binds with fibroblast growth factor 7 (FGF7), may regulate ERCC1 gene expression through the ERK signaling pathway. The aim of the present study was to explore the association between the regulatory effect of FGFR2 on ERCC1 gene expression and the p-ERK1/2 signaling pathway in a drug-resistant hepatocellular carcinoma (HCC) cell line. The drug-resistant cell line HepG2/OXA and its parental cell line HepG2 were transfected with Bek shRNA in the logarithmic growth phase. Transfected and untransfected HepG2 and HepG2/OXA cells were then stimulated with FGF7 and changes in the protein expression of FGFR2, p-ERK1/2 and ERCC1 was detected with western blot analysis. Following transfection, HepG2̸T and HepG2̸OXA̸T cells were observed to grow stably in a screening medium containing puromycin. The western blot analysis demonstrated a significant decrease in the protein expressions of FGFR2, p-ERK1/2 and ERCC1 in HepG2̸T

Background: This study aimed to investigate the regulatory role of long non-coding RNA associated with microvascular invasion in hepatocellular carcinoma (lnc-MVIH) in the progression of acute myeloid leukemia (AML) and the underlying mechanism. Methods: Lnc-MVIH expression was detected in AML cell lines AML-193, KG-1, HL-60, OCI-AML2 and primary normal bone marrow mononuclear cells (BMMC). The effect of lnc-MVIH knockdown on cell proliferation, apoptosis and miR-505 expression were detected by transfection of lnc-MVIH shRNA and control shRNA into KG-1 cells. And the effect of miR-505 knockdown on lnc-MVIH, cell proliferation, cell apoptosis as well as potential miR-505 target genes [high mobility group box 1 (HMGB1) and cyclin E2 (CCNE2)] in lnc-MVIH knockdown treated KG-1 cells was assessed by transfection of lnc-MVIH shRNA and lnc-MVIH shRNA & miR-505 shRNA into KG-1 cells. Results: Lnc-MVIH expression was elevated in AML-193, KG-1, OCI-AML2 cell lines, but similar in HL-60 cell line compared with primary normal BMMC. Lnc-MVIH knockdown inhibited cell proliferation but promoted cell apoptosis in KG-1 cells, meanwhile miR-505 expression was increased by lnc-MVIH knockdown in KG-1 cells. And in rescue experiments, miR-505 knockdown had no effect on expression of lnc-MVIH, while it increased the expressions of HMGB1 and CCNE2, promoted cell proliferation, inhibited cell apoptosis in lnc-MVIH knockdown treated KG-1 cells.Conclusions: Lnc-MVIH knockdown inhibits cell proliferation but promotes cell apoptosis via regulating miR-505 mediated HMGB1 and CCNE2 in AML.

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