[Wnt/b-catenin signaling pathway affects the protein expressions of caspase-3, XIAP and Grp-78 in hepatocellular carcinoma]

To investigate the relationship and significance of Wnt/b-catenin signaling pathway with caspase-3, XIAP, HSP27and Grp-78. The HCC cell line HepG2 was transfected with small interfering RNA (siRNA) directed against b-catenin. After 72 and 96 h, protein was extracted and the protein expressions of b-catenin, caspase-3, XIAP, Grp-78 and HSP27 were detected by Western blot. b-catenin protein expression was inhibited at both time points and the expression at 96 h was higher than that at 72 h (F = 160.72, P is less than to 0.01). Interestingly, Caspase-3 protein expression was decreased at 72 h and increased to normal at 96 h (F = 136.10, P is less than to 0.01), while p-caspase-3 protein expression increased at 72 h and decreased to normal at 96 h (F = 98.65, P is less than to 0.01). XIAP protein expression decreased at 72 h (F = 37.29, P is less than to 0.01) and increased at 96 h. Grp-78 protein expression increased at 72 h and decreased to normal at 96 h ( F = 58.72, P is less than to 0.01). HSP27 protein expression showed no change following transfection ( F = 1.91, P is more than to 0.05). Wnt/b-catenin signaling pathway is related to the protein expressions of caspase-3, XIAP and Grp-78, but not related to HSP27 protein expression in HCC. Wnt/b-catenin signaling pathway may participate in the regulation of HCC apoptosis, proliferation and differentiation through affecting these factors.

Functional mechanism of the enhancement of 5-fluorouracil sensitivity by TUSC4 in colon cancer cells

5-Fluorouracil (5-FU) is the chemotherapeutic drug of choice for the treatment of metastatic colorectal cancer (CRC). Tumor suppressor candidate 4 (TUSC4), also referred to as nitrogen permease regulator-like 2 (NPRL2), is located at chromosome 3p21.3 and expressed in numerous normal tissues, including the heart, liver, skeletal muscle, kidney, and pancreas. The aim of the present study was to investigate the functional mechanism by which TUSC4 affects sensitivity to 5-FU and to determine its clinical significance in CRC. The results of the present study demonstrated that TUSC4 overexpression increases the sensitivity of HCT116 cells to 5-FU. The IC₅₀ of 5-FU was reduced in cells transduced with TUSC4 compared with negative control (NC) cells, and the effect of TUSC4 on 5-FU sensitivity was time dependent. Following TUSC4 transduction in HCT116 cells, a proportion of the cells were arrested in the G1 phase of the cell cycle, and a reduction in the S phase population was observed. Flow cytometry analysis revealed that TUSC4 transduction and 5-FU treatment increased apoptosis compared with NC cells. The mechanism through which TUSC4 overexpression enhances 5-FU sensitivity involves the downregulation of the function of the PI3K/Akt/mTOR network. Furthermore, 5-FU upregulated caspase-3 and caspase-9, promoting apoptosis in TUSC4-overexpressing cells compared with cells that were transduced with TUSC4 or treated with 5-FU and NC cells. The findings of the present study indicate that TUSC4 has potential as a biomarker for the prediction of the response to 5-FU and prognosis in patients with colorectal cancer and other types of human cancer. TUSC4 may also act as a molecular therapeutic agent for enhancing the patient's response to 5-FU treatment.

Wnt/β-catenin signaling pathway may regulate the expression of angiogenic growth factors in hepatocellular carcinoma

The Wnt/β-catenin signaling pathway plays a key role during hepatocellular carcinoma (HCC) genesis and development. The present study aimed to investigate the effects of the Wnt/β-catenin signaling pathway on the expression of angiogenic growth factors involved in HCC. The HCC HepG2 cell line was transfected with small interfering RNA (siRNA) against β-catenin. After 72 and 96 h, protein was extracted and the expression levels of β-catenin, matrix metalloproteinase (MMP)-2, MMP-9, vascular endothelial growth factor (VEGF)-A, VEGF-C and basic fibroblast growth factor (bFGF) were detected by western blot analysis. β-catenin protein expression was inhibited at both time points. Notably, MMP-2, MMP-9, VEGF-A, VEGF-C and bFGF protein expression levels decreased at 72 h and then increased at 96 h after transfection. Our results demonstrated that in HCC cells, the Wnt/β-catenin signaling pathway may regulate the protein expression of the angiogenic factors, MMP-2, MMP-9, VEGF-A, VEGF-C and bFGF. These proteins were downstream of β-catenin signaling and were also regulated by other factors. In conclusion, the Wnt/β-catenin signaling pathway may contribute to the regulation of HCC angiogenesis, infiltration and metastasis through regulating the expression of these angiogenic factors.

Prevalence of Helicobacter pylori vacA, cagA and iceA genotypes and correlation with clinical outcome

The aim of this study was to assess the genetic status of cagA, vacA subtype and iceA genotypes of Helicobacter pylori and the relationship with upper gastrointestinal diseases in Northeast China. Gastric biopsies were obtained from 378 patients with upper gastrointestinal diseases and 197 samples were used. The cagA, vacA alleles and iceA genotypes were determined by polymerase chain reaction. CagA was present in 176 (89.3%) of 197 patients. Of the 197 cases, 186 (94.4%) had vacA signal sequence s1c allele, 6 (3%) had s1a and 5 (2.5%) had s1b. The vacA s2 genotype was not detected in our study. VacA middle region sequences, m1 and m2, were found in 20 (10.2%) and 150 (76.1%), respectively. The allelic variant iceA1 (70.1%) was more prevalent than iceA2 (23.4%). The vacA allele s1am2 had a significant relationship with the presence of gastric cancer (p<0.05) and the iceA1 genotype was also associated with gastric cancer (p<0.05). These may be useful risk factors for upper gastrointestinal diseases.