TGF-ß1 signaling pathway serves a role in HepG2 cell regulation by affecting the protein expression of PCNA, gankyrin, p115, XIAP and survivin.

The transforming growth factor-ß (TGF-ß) signaling pathway serves a key role in the pathogenesis of liver cancer. To investigate the association between TGF-ß1 and the following proteins: Proliferating cell nuclear antigen (PCNA), gankyrin, general vesicular transport factor p115 (p115), X-linked inhibitor of apoptosis protein (XIAP) and survivin, HepG2 liver cancer cells were transfected with small interfering RNA (siRNA) directed against TGF-ß1, or were treated with exogenous TGF-ß1. TGF-ß1 protein expression levels were assessed at 72 and 96 h using western blotting, cell growth was evaluated using a Cell Counting kit-8 assay, and flow cytometry was used to examine cell cycle distribution and apoptosis. In addition, PCNA, gankyrin, p115, XIAP and survivin protein levels were evaluated using western blotting. TGF-ß1 protein expression levels were decreased at 72 and 96 h following siRNA transfection, indicating that the siRNA against TGF-ß1 was effective. In the TGF-ß1-knockdown group, the HepG2 cells exhibited G1 or S-phase cell cycle arrest; therefore, the number of G2-phase cells was decreased, cell growth was inhibited and apoptotic peaks were observed. By contrast, no significant alteration in cell cycle distribution or apoptosis was observed in the cells treated with exogenous TGF-ß1. In the exogenous TGF-ß1 group, PCNA and XIAP protein expression levels were increased, whereas gankyrin, p115 and survivin protein expression was observed to be dependent on the duration of treatment. By contrast, PCNA, gankyrin, XIAP and survivin protein expression decreased following TGF-ß1 knockdown; however, p115 protein expression increased. In conclusion, the TGF-ß1 signaling pathway may affect cell growth, cell cycle distribution and apoptosis through the regulation of PCNA, gankyrin, p115, XIAP and survivin protein expression in liver cancer. The results of the present study may improve the current understanding of the role of the TGF-ß signaling pathway during the pathogenesis of liver cancer.

Simultaneous silencing of ß-catenin and signal transducer and activator of transcription 3 synergistically induces apoptosis and inhibits cell proliferation in HepG2 liver cancer cells.

The tumorigenesis and maintenance of a cancer cells is dependent upon the collaboration of multiple signaling pathways. Signal transducer and activator of transcription 3 (STAT3) and ß-catenin are at the center of multiple cancer-associated signaling pathways; therefore, simultaneously targeting STAT3 and ß-catenin may be a potential cancer treatment, leading to induced lethality of cancer cells. In the present study, HepG2 liver cancer cells were transfected with small interfering RNA (siRNA) against ß-catenin and STAT3 alone or in combination. The cell growth was assessed using an MTT assay and the levels of cell apoptosis were detected using flow cytometry. Protein levels of caspase-3, cleaved caspase-3, poly(ADP-ribose) polymerase (PARP) and cleaved PARP were determined using western blot analysis. Following siRNA transfection, ß-catenin and STAT3 protein levels decreased at 72 h. HepG2 cell growth inhibition and early apoptosis in the ß-catenin and STAT3 siRNA co-transfection group were significantly greater than those in the groups transfected with ß-catenin or STAT3 siRNA alone. Decreased caspase-3 and PARP levels, as well as enhanced cleavage of caspase-3 and PARP were observed in the ß-catenin and STAT3 co-transfection group. Simultaneous silencing of ß-catenin and STAT3 using siRNAs resulted in an enhanced loss of cell viability and induction of apoptosis in HepG2 liver cancer cells, suggesting that these genes are promising targets for the further preclinical and clinical development of anti-cancer therapeutic strategies, which target several cancer signaling pathways simultaneously.

An improved method of nasojejunal feeding tube placement for patients requiring endoscopic nasobiliary drainage.

OBJECTIVE: To avoid a second endoscopy for nasojejunal feeding tube placement (NFTP) in patients undergoing endoscopic nasobiliary drainage (ENBD), we studied improved NFTP method and compared it to endoscopic method. METHODS: Patients with ENBD were divided into two groups. One group (18 patients) received endoscopic NFTP and the other group (26 patients) received improved NFTP. Placement time, physical condition of the patients and complications were recorded. RESULTS: In 18 patients who underwent endoscopic NFTP, NFT was successfully placed on the first attempt in 14 patients with a first placement success rate of 77.8%. NFT was wrongly intubated into the trachea in one patient inducing coughing, and after it was removed, the second placement was successful. The total success rate of endoscopic NFTP was 83.3% with an average placement time of 17.0 minutes. In 26 patients undergoing improved NFTP, all were successfully placed on the first attempt with a success rate of 100%, and an average placement time of 2.55 minutes. In patients with ENBD, the success rate of improved NFTP was significantly higher than endoscopic NFTP (χ²=36.4, p<0.05) with a significantly shorter placement time (t=18.5, p<0.05). CONCLUSION: For patients with ENBD, improved NFTP method is superior to the endoscopic method as it is more effective, convenient, faster, and cheaper. Additionally it avoids a second endoscopy and has fewer complications, better security and a higher success rate. The improved method is a safer, easier, more effective and practical method of EN and deserves general adoption in clinical work.