Inhibition of PRRX2 suppressed colon cancer liver metastasis via inactivation of Wnt/ß-catenin signaling pathway.

The aim of this study was to investigate whether PRRX2 may regulate the liver metastasis of colon cancer via the Wnt/ß-catenin signaling pathway. PRRX2 and ß-catenin in patients with the liver metastases of colon cancer was detected by immunochemistry. Colon cancer cells (CT-26 and CMT93) were divided into Normal, si-Ctrl, si-PRRX2 and si-PRRX2 +LiCl groups. Cell invasive and migrating abilities and the related proteins were detected. Liver-metastatic mice model was constructed consisting of Normal, NC shRNA and PRRX2 shRNA groups to examine the function of PRRX2 shRNA on liver metastasis. We found that PRRX2 and ß-catenin positive rate was elevated in colon cancer tissues, especially in those tissues with liver metastasis, and there was a close relation between PRRX2 and the clinical staging, lymph node metastasis and numbers of liver metastases of colon cancer patients with liver metastasis. In vitro, the invasive and migrating abilities of CT-26 and CMT93 cells decreased apparently in the si-PRRX2 group, with down-regulation of PRRX2, p-GSK3ßSer9/GSK3ß, nucleus and cytoplasm ß-catenin, TCF4 and Vimentin but up-regulation of E-cadherin. However, LiCl, the Wnt/ß-catenin pathway activator, can reverse the inhibitory effect of si-PRRX2 on invasive and migrating ability of colon cancer cells. In vivo, the volume and weight of transplanted tumor and the number of liver metastases in the PRRX2 shRNA group were significantly reduced, with the similar protein expression patterns as in vitro. In a word, PRRX2 inhibition may reduce invasive and migrating abilities to hinder epithelial-mesenchymal transition (EMT), and suppress colon cancer liver metastasis through inactivation of Wnt/ß-catenin pathway.

[Assessment of the factors associated with insulin resistance in patients with chronic hepatitis B infection].

OBJECTIVE: To investigate the factors associated with insulin resistance (IR) in patients with chronic hepatitis B virus (HBV) infection. METHODS: Sixty-eight patients with mild chronic hepatitis B (MCHB) caused by HBV were recruited for study. Sixty-seven healthy individuals with no hepatitis virus infections and normal liver function were enrolled as controls. Demographic, anthropometric, clinical, and blood biochemical parameters were compared between the two groups. IR was determined by the homeostasis model assessment (HOMA-IR). The MCHB group was further divided into patients with IR (HOMA-IR: > 2.7) and patients without IR (HOMA-IR: less than 2.7). Demographic, anthropometric, clinical, and blood biochemical parameters were compared between the two sub-groups. Finally, the potential factors associated with IR were evaluated. RESULTS: Compared to the healthy controls, the MCHB patients had significantly higher serum insulin (Z = -5.451, P less than 0.01), alanine aminotransferase (ALT) (Z = -8.211, P less than 0.01) and HOMA-IR (Z = -5.631, P less than 0.01). IR was detected in 44.12% (30/68) of the MCHB patients. The levels of ALT and body mass index (BMI) were significantly different between the MCHB patients with IR and without IR (t = -2.358, and t = -3.566, P less than 0.05). There was a significant correlation between BMI, ALT, and HOMA-IR in the MCHB patients (r = 0.374, r = 0.282, P less than 0.05), but not with the HBV DNA loads (r = 0.015, P = 0.904). Binary logistic regression analysis indicated that BMI [Exp(B): 1.859, P less than 0.01] and ALT [Exp(B): 1.022, P less than 0.05] were independent risk factors of IR in MCHB. CONCLUSION: There is a high prevalence of insulin resistance in patients with mild hepatitis caused by chronic HBV infection. In these patients, IR is correlated with abnormal liver function and BMI, and not HBV load.

[Effect of HBV on the expression of SREBP in the hepatocyte of chronic hepatitis B patients combined with hepatic fatty change].

To investigate the effect of HBV on the expression of Sterol regulatory element binding proteins( SREBP ) in the hepatocyte of patients with chronic hepatitis B (CHB) combined with hepatic fatty change. 55 cases diagnosed as CHB combined with hepatic fatty change in our department were selected and liver biopsies were carried out. The patients were dividied into 3 groups, group A: HBV DNA is less than or equal to 1000 copies/ml(15 cases), group B: 1000 copies/ml less than HBV DNA less than 100000 copies/ml (18 cases) and group C: HBV DNA is more than or equal to 100000 copies/ml (22 cases). 10 patients with HBV DNA in less than or equal to 1000 copies/ml after antiviral therapy with Nucleoside analogues were seen as group C1 (before treatment) and group C2 (after treatment) respectively; 12 patients with HBV DNA is more than or equal to 100000 copies/ml after antiviral therapy were classified as group C3 (before treatment) and group C4 (after treatment). Lipid droplets in the hepatic tissue were observed with oil red staining. Real time PCR were performed to detect the expressions of SREBP-1c and SREBP-2 mRNA in the liver. The protein expressions of SREBP-1c and SREBP-2 were detected with immunohistochemistry staining. Statistic data were analysed with SPSS11.5 software. (1) Red integrated optical densities (IOD) reflected by lipid drops in group A, B and C are 1004.27+/-218.63, 1937.01+/-401.47 and 4133.79+/-389.28 respectively, the degree of oil red O in each group was different (F = 385.69, P is less than to 0.01), which is increased as HBV DNA load increasing; Red IOD in group C1, C2 and C3, C4 are 4020.84+/-326.64, 1012.02+/-244.89, 4189.18+/-329.21 and 4121.76+/-304.09 respectively. Compared with group C1, the degree of oil red O in group C2 is decreased and the difference is statistically significant (t = 22.55, P is less than to 0.01); However, the difference of the degree of oil red O between group C4 and C3 is not statistically significant. (2) Compared with group A, the expressions of SREBP-1c mRNA in group B and C are raised by 1.218+/-0.130 and 1.798+/-0.118 times respectively, among group A, B, C, the expressions of SREBP-1c mRNA are statistically significant different ( F = 297.47, P is less than to 0.01). The expressions of SREBP-2 mRNA in group B and C are decreased by 0.956+/-0.118 and 0.972+/-0.153 times as compared to group A. However, the difference of SREBP-2 mRNA expression among the 3 groups is not statistically significant ( F = 0.568, P is more than to 0.05). Compared with group C1, SREBP-1c mRNA in group C2 is decreased by 0.714+/-0.081 folds (t=11.224, P is less than to 0.01), while SREBP-2 mRNA in group C2 is raised by1.034+/-0.155 times(t=0.692, P is more than to 0.05). SREBP-1c mRNA and SREBP-2 mRNA in group C4 are raised by 1.012+/-0.206 times and decreased by 0.998+/-0.183 times as compared to group C3 without difference found (t=0.196 or 0.031, P is more than to 0.05). (3) the expressions of SREBP-1c protein in group A, B and C are 36257.21+/-5709.79, 50413.47+/-4989.28 and 71025.83+/-6047.13 respectively, and the difference is statistically significant among the 3 groups (F = 178.26, P is less than to 0.01); the expressions of SREBP-2 protein in group A, B and C are 32913.52+/-3951.21, 32625.91+/-4025.06 and 34173.44+/-5316.25 respectively, but the difference is not statistically significant among the 3 groups ( F = 0.562, P is more than to 0.05), SREBP-1c protein levels in group C1, C2, C3, C4 are 69832.16+/-4941.36, 48735.47+/-5471.41, 70871.69+/-5083.14 and 68913.32+/-5343.22 respectively, the difference of SREBP-1c protein levels between group C1 and C2 is statistically significant (t=10.260, P is less than to 0.01); while the difference between group C3 and group C4 is not statistically significant(t=1.558, P is more than to 0.05). The expressions of SREBP-2 protein in group C1, C2, C3 and C4 are 33 980.21+/-4081.80, 34011.50+/-3859.27, 33610.12+/-4761.10 and 32915.66+/-5023.61 respectively, the difference of SREBP-2 protein levels in group C1 and group C2 is not statistically significant (t=0.038, P is more than to 0.05) and same result exists between group C3 and group C4 (t=0.459, P is more than to 0.05). HBV DNA may participate in the hepatic steatosis formation through interfering with the SREBP-1c expression.