👤 Sopit Wongkham

Periostin (PN) (also known as osteoblast‑specific factor OSF‑2) is a protein that in humans is encoded by the POSTN gene and has been correlated with a reduced survival of cholangiocarcinoma (CCA) patients, with the well‑known effect of inducing epithelial‑to‑mesenchymal transition (EMT). The present study investigated the effect of PN, through integrin (ITG)α5β1, in EMT‑mediated CCA aggressiveness. The alterations in EMT‑related gene and protein expression were investigated by real‑time PCR, western blot analysis and zymogram. The effects of PN on migration and the level of TWIST‑2 were assessed in CCA cells with and without siITGα5 transfection. PN was found to induce CCA cell migration and EMT features, including increments in Twist‑related protein 2 (TWIST‑2), zinc finger protein SNAI1 (SNAIL‑1), α-smooth muscle actin (ASMA), vimentin (VIM) and matrix metallopeptidase 9 (MMP‑9), and a reduction in cytokeratin 19 (CK‑19) together with cytoplasmic translocation of E-cadherin (CDH‑1). Additionally, PN markedly induced MMP‑9 activity. TWIST‑2 was significantly induced in PN‑treated CCA cells; this effect was attenuated in the ITGα5β1‑knockdown cells and corresponded to reduced migration of the cancer cells. These results indicated that PN induced CCA migration through ITGα5β1/TWIST-2‑mediated EMT. Moreover, clinical samples from CCA patients showed that higher levels of TWIST‑2 were significantly correlated with shorter survival time. In conclusion, the ITGα5β1‑mediated TWIST‑2 signaling pathway regulates PN‑induced EMT in CCA progression, and TWIST‑2 is a prognostic marker of poor survival in CCA patients. Show less

A proteomic-based approach was used to search for potential markers in the plasma of hamsters in which cholangiocarcinoma (CCA) was induced by Opisthorchis viverrini infection and N-nitrosodimethylamine treatment. The plasma proteins of CCA-induced hamsters were resolved by 1-D PAGE, digested by trypsin, and analyzed by LC-MS/MS. From the criteria of protein ID scores >15 and an overexpression of at least three times across all time points, 37 proteins were selected. These overexpressed proteins largely consisted of signal transduction, structural, transport, and transcriptional proteins in the order. Among the most frequently upregulated proteins, exostosin 1 (EXT1) was selected for further validation. By western blot analysis, the EXT1 expression level in the plasma of hamster CCA was significantly higher than that of controls at 1 month and thereafter. Immunohistochemistry revealed that EXT1 was expressed at vascular walls and fibroblasts at 21 days (before tumor onset) and at 2 months (early CCA) posttreatment. Its expression was also observed in bile duct cancer cells during tumor progression at 6 months posttreatment. In the human CCA tissue microarray, EXT1 immunoreactivity was found not only in vascular walls and fibroblasts but also in bile duct cancer cells and was positive in 89.7 % (61/68) of the cases. By ELISA and immunoblotting, plasma EXT1 level was significantly higher in human CCA compared to healthy controls. In conclusion, these results suggest that increased expression of EXT1 level in the plasma might be involved in CCA genesis and might be a potential biomarker of CCA. Show less

Intrahepatic cholangiocarcinoma (ICC) is ranked as one of the top five causes of cancer-related deaths. ICC in Thai patients is associated with infection with the liver fluke, Opisthorchis viverrini, but the molecular basis for development remains unclear. The present study employed a microarray approach to compare gene expression profiles of ICCs and normal liver tissues from the same patients residing in Northeast Thailand, a region with a high prevalence of liver fluke infection. In ICC samples, 2,821 and 1,361 genes were found to be significantly up- and down-regulated respectively (unpaired t-test, p<0.05; fold-change>2.0). For validation of the microarray results, 7 up-regulated genes (FXYD3, GPRC5A, CEACAM5, MUC13, EPCAM, TMC5, and EHF) and 3 down- regulated genes (CPS1, TAT, and ITIH1) were selected for confirmation using quantitative RT-PCR, resulting in 100% agreement. The metallothionine heavy metal pathway contains the highest percentage of genes with statistically significant changes in expression. This study provides exon-level expression profiles in ICC that should be fruitful in identifying novel genetic markers for classifying and possibly early diagnosis of this highly fatal type of cholangiocarcinoma. Show less