MiRNA-335 Modulates Hepatoma Cell Lines Apoptosis and Proliferation by Targeting Forkhead Box O3a (FOXO3a)

This study intends to elucidate MiRNA-335’s role in hepatoma cell lines (HCC). Real-time PCR was used to detect MiRNA-335 expression in HCC, flow cytometry and MTT were used to detect apoptosis and proliferation. Luciferase reporting system analyzed the targeting relationship between Foxo3a and MiRNA-335. HCC (SMMC7721 cell) exhibited significantly reduced MiRNA-335 compared to normal hepatocyte cell (HL7702). MiRNA-335 mimic inhibited HCC proliferation and enhanced apoptosis, which were reversed by MiRNA-335 inhibitor. Luciferase reporter gene system showed that MiRNA-335 significantly inhibited the fluorescent activity of Foxo3a 3′-UTR, indicating that MiRNA-335 could target Foxo3a RNA. In conclusion, the decrease of MiRNA-335 can promote the proliferation of hepatoma cells and inhibit apoptosis possibly through regulating Foxo3a, which provides a new direction for the treatment of liver cancer.

Caveolin-1 Knockdown Decreases SMMC7721 Human Hepatocellular Carcinoma Cell Invasiveness by Inhibiting Vascular Endothelial Growth Factor-Induced Angiogenesis

Background. Recently, several studies have demonstrated that caveolin-1 overexpression is involved in apoptosis resistance, angiogenesis, and invasiveness in hepatocellular carcinoma (HCC). However, the mechanisms underlying caveolin-1-mediated tumor progression remain unclear. Methodogy. Lentiviral vectors were used to construct caveolin-1 small interfering RNA- (siRNA-) expressing cells. Secreted VEGF levels in SMMC7721 cells were evaluated by enzyme-linked immunosorbent assay (ELISA). SMMC7721 cell proliferation, cycle, apoptosis, and invasiveness were detected by MTT, flow cytometry, Annexin V-FITC/PI, and invasion assay, respectively. Phospho-eNOS levels in human umbilical vein endothelial cells (HUVECs) cocultured with SMMC7721 cell supernatants were analyzed by Western blot. Capillary-like tubule formation assay was performed to analyze endothelial tubular structure formation in HUVECs treated with supernatants from caveolin-1 siRNA-expressing SMMC7721 cells. SMMC7721 implantation and growth in nude mice were observed. Angiogenesis in vivo was analyzed by immunohistochemical angiogenesis assay. Results. Caveolin-1 siRNA-expressing SMMC7721 cells secreted reduced levels of VEGF. Caveolin-1 RNAi also caused an inhibition of SMMC7721 cell proliferation and cell cycle progression that was accompanied by increased apoptosis. Supernatants from caveolin-1 siRNA-expressing SMMC7721 cells inhibited cell cycle progression and decreased phospho-eNOS levels in HUVECs. Endothelial tubular structure formation in HUVECs treated with supernatants from caveolin-1 siRNA-expressing SMMC7721 cells was considerably reduced. Caveolin-1 siRNA-expressing SMMC7721 cells also showed reduced tumorigenicity and angiogenesis induction in vivo. Conclusion. Our results reveal a novel mechanism, whereby caveolin-1 positively regulates human HCC cell invasiveness by coordinating VEGF-induced angiogenesis.

Synthesis, DNA-binding and antiproliferative activity of N-(Nitrogen heterocyclic) norcantharidin acylamide acid

Two novel norcantharidin acylamide acids (HL1=N-pyrimidine norcantharidin acylamide acid, C12H13N3O4; HL2=N-pyridine norcantharidin acylamide acid, C13H14N2O4) were synthesized by a reaction of norcantharidin(NCTD) with 2-aminopyrimidine and 2-aminopyridine, respectively. Their structures were characterized by elemental analysis, IR, UV and 1 H NMR. Fluorescence titration and viscosity measurements indicated that HL1, HL2 and HL3 (HL3=N-phenyl norcantharidin acylamide acid, C14H15NO4) can bind calf thymus DNA via partial intercalation. The liner Stern-Volmer quenching constant Ksv values for HL1, HL2 and HL3 were 2.05 × 104 L mol−1, 1.15 × 104 L mol−1 and 8.30×103 L mol−1, respectively. Two compounds containing heterocycle of HL1 and HL2 have been found to cleave pBR322 plasmid DNA at physiological pH and temperature. The test of antiproliferation activity showed that the compounds had moderate to strong antiproliferative ability against the tested cell lines except of HL3 against the SMMC7721 cell line. The results indicated that the heterocycle attached to the norcantharidin was favorable to antiproliferative activity. This result was consistent with the DNA binding experiment.