miR-338-3p Targets and Regulates RNF121 to Promote the Proliferation and Invasion of Human Lung Cancer A549 Cells / 中国生物化学与分子生物学报

Recent studies have shown that miR-338-3p plays an important role in the proliferation and invasion of lung cancer, but whether miR-338-3p regulates lung cancer proliferation and invasion through targeting ring finger protein 121 (RNF121) is still unclear. In order to explore its mechanism, the normal lung cell line MRC-5 and the non-small cell lung cancer line A549 were cultured in vitro. Using qRTPCR and Western blotting detection, we found that the expression of miR-338-3p in A549 lung cancer cells was lower than that in MRC-5 cells, while RNF121 expression increased (P0. 05). In summary, miR-338-3p can target the expression of RNF121 to inhibit the proliferation and invasion of A549 cells and inhibit the growth of subcutaneous transplanted tumors in nude mice. RNF121 is expected to become a new target for the treatment of non-small cell lung cancer.

The anti-apoptotic effect of cytoplasmic alpha-fetoprotein in hepatoma cells induced by all-trans retinoic acid involves activation of the PI3K/AKT signaling pathway / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the effect of alpha-fetoprotein (AFP) on transduction of the PI3K/ AKT signal in hepatocellular carcinoma cells and the role played by AFP in resistance to cytotoxicity of all-trans retinoic acid (ATRA).</p><p><b>METHODS</b>The effects of ATRA of human liver cancer cells was assessed using the BEL-7402 cell line with the MTT assay (to evaluate proliferation), microscopy (to evaluate morphology), flow cytometry (to evaluate apoptosis), laser confocal microscopy and coimmunoprecipitation (co-IP; to evaluate co-localization and interaction of AFP with PTEN), Western blotting (to evaluate expression of phosphorylated-protein kinase B (pAKT) and Src, and RNA interference (RNAi)-mediated knockdown of AFP. Finally, application of the PI3K-specific inhibitor Ly294002 was used to monitor the influence of AFP in transduction of the PI3K signal pathway.</p><p><b>RESULTS</b>The human hepatoma cell line BEL-7402 were resistant to ATRA cytotoxicity. PTEN and AFP co-localized in the cytoplasm, and co-IP indicated that AFP interacts with PTEN in BEL-7402 cells.RNAi knockdown of AFP expression led to reduced growth of BEL-7402 cells.BEL-7402 cells transfected with AFP-short interfering (si)RNA vectors showed enhanced sensitivity to ATRA and reduced expression of pAKT(Ser473) and Src; Ly294002 reduced the role of AFP in stimulating expression of pAKT(Ser473) and Src.</p><p><b>CONCLUSION</b>AFP can activate transduction of the PI3K/AKT signal, and expression of AFP in hepatoma cells is a pivotal event for resisting ATRA-induced apoptosis.</p>

Effects of alpha-fetoprotein on the expression of TRAIL death receptor-2 and its role on resisting the cytotoxicity of TRAIL in hepatoma cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To explore the mechanism of Alpha-fetoprotein (AFP) effects on hepatocellular carcinoma cells (HCC) resistances apoptosis induced by tumor necrosis factor-related apoptosis inducing-ligand (TRAIL).</p><p><b>METHODS</b>The expressed alteration of TRAIL receptor-2 (DR5) after the human hepatoma cells line Bel 7402 (AFP-producing) and HLE cells (non-AFP producing) were treated with all trans retinoic acid (ATRA) were determined by Western blot; Interaction of AFP with RAR-beta was analyzed by co-immunoprecipitation (Co-IP); Laser confocal microscopy was used to observe co-localization of AFP and RAR-beta; Short small RNA interfering (RNAi) was applied to knock down the expression of AFP in Bel 7402 cells; The full AFP gene cDNA was inserted into pcDNA3.1 vector and constructed the expressed vector of AFP (named pcDNA3.1-afp); The growth of hepatoma cells was analyzed by MTT.</p><p><b>RESULTS</b>Bel 7402 and HLE cells expressed DR5, lowed dosage of ATRA (40mumol/L) had no influence on the expression of DR5 in Bel 7402 cells, but ATRA (160mumol/L) could inhibit the expression of AFP and promote the expression of DR5 significantly; Co-IP indicated that AFP had a property for interacting with RAR-beta; The results also demonstrated AFP co-localization with RAR-beta in cytoplasm of Bel 7202 cells; The expression of DR5 was enhanced while the expression of AFP was knocked down by RNAi. pcDNA3.1-afp vector was transfected into HLE cells, the growth of HLE cells were stimulated and TRAIL cytotoxicity of HLE cells were reduced. But when the expression of AFP was knocked down the sensitivity of Bel 7402 cells to TRAIL was enhanced.</p><p><b>CONCLUSIONS</b>These data provided that AFP had a capability to interact with RAR-beta and suppressed the expression of DR5. AFP could play pivotal role on hepatoma cells resistance-induced apoptosis by TRAIL.</p>

Influence of nitric oxide on the angiotensin II-activated protein kinase C activity in cultured neonatal rat cardiomycytes / 生理学报

We examined the effect of endogenous and exogenous nitric oxide (NO) on protein kinase C (PKC) activity induced by angiotensin II (Ang II) in cultured neonatal rat cardiomyocytes. The results are as follows. The activity of PKC was increased by Ang II (0.01-10 micromol/L) in a dose-dependent manner, but decreased by NO precursor L-arginine (L-Arg) (10 micromol/L-10 mmol/L) in a dose-dependent manner in cultured neonatal rat cardiomyocytes. Pretreatment with L-Arg (100 micromol/L) decreased significantly Ang II -activated PKC activity and PKC activity induced by phorbol 12-myristate 13-acetate (PMA) ( 10 micromol/L), a PKC activator. Pretreatment with N(G)-nitro-L-argingie methyl ester (L-NAME), a nitric oxide synthase (NOS) blocker, may inhibit significantly the role of L-Arg on Ang II - and PMA-activated PKC activity. The activity of PKC was also decreased by NO donor sodium nitroprusside (SNP) (10 micromol/L-1 mmol/L) in a dose-dependent manner in cultured neonatal rat cardiomyocytes. Pretreatment with SNP (10 micromol/L) decreased significantly Ang II - and PMA-activated PKC activity. These results indicate that PKC was controlled by both NO and Ang II. PKC may be a cross talk between Ang II and NO in cardiomyocytes. NO abolished the activity of PKC and impaired PKC downstream signaling transduction pathway cascades.