CD44 is a transmembrane glycoprotein, the phosphorylation of which can directly trigger intracellular signaling, particularly Akt protein, for supporting cell growth, motility and invasion. This study examined the role of CD44 on the progression of Cholangiocarcinoma (CCA) using metabolic profiling to investigate the molecular mechanisms involved in the Akt signaling pathway. Our results show that the silencing of CD44 decreases Akt and mTOR phosphorylation resulting in p21 and Bax accumulation and Bcl-2 suppression that reduces cell proliferation. Moreover, an inhibition of cell migration and invasion regulated by CD44. Similarly, the silencing of CD44 showed an alteration in the epithelial-mesenchymal transition (EMT), e.g. an upregulation of E-cadherin and a downregulation of vimentin, and the reduction of the matrix metalloproteinase (MMP)-9 signal. Interestingly, a depletion of CD44 leads to metabolic pathway changes resulting in redox status modification and Trolox (anti-oxidant) led to the recovery of the cancer cell functions. Based on our findings, the regulation of CCA progression and metastasis via the redox status-related Akt signaling pathway depends on the alteration of metabolic profiling synchronized by CD44.

Infection by Opisthorchis viverrini causes significant health problems, including cholangiocarcinoma (CCA); thus control and elimination of this trematode is an important strategy for the reduction of CCA. Currently, urine and copro antigen detection is more sensitive than parasitological examination of the feces for the diagnosis of opisthorchiasis. Given limitations in human studies, we used an animal model to quantify the parasite antigen profiles in urine and feces in O. viverrine–infected hamsters, and postdrug treatment. The positive detections of O. viverrini antigen began from week 1 in urine and week 2 in feces after infection until week 28 of the study. The recoveries of O. viverrini worms were detected starting from week 1 and eggs of O. viverrini were detected in feces from week 3 after infection and remained detectable throughout the study period. There was a significant positive correlation of urine and copro antigen levels with the number of fecal egg counts (P < 0.01) and worm recovery (P < 0.01). In the drug-treatment experiment, treatment of infected hamsters with praziquantel significantly reduced worm burden, fecal egg output, and antigen in urine and feces compared with the untreated controls (P < 0.001). At 4 weeks posttreatment, the egg and worm reduction rates were 100% and 95.5%, respectively. The positive antigen detections in urine and feces corresponded with partial worm clearance from praziquantel treatment. This study demonstrated a direct link of urine and copro antigen tests with worms infecting the liver thereby reaffirming the reliability of urine and copro antigen assay in opisthorchiasis diagnosis.

Background: Opisthorchis viverrini (Ov) infectioninduced cholangiocarcinoma (CCA) is a major public health problem in northeastern Thailand. Praziquantel was shown to prevent CCA development in an Ov-infected hamster model; however, the molecular mechanism remains unknown. Materials and Methods: In this study, we used a hamster model with Ov and N-nitrosodimethylamine-induced CCA to study the mechanisms of praziquantel action. The liver tissues from the hamsters with and without praziquantel treatment were analyzed using 1 H nuclear magnetic resonance spectroscopy. Results: A total of 14 metabolites were found to be significantly different between the two groups. Furthermore, the combination of acetate, inosine and sarcosine was shown to exert an anti-inflammatory effect through interleukin-6 inhibition in a macrophage cell line, suggesting a mechanism by which praziquantel may prevent inflammation caused by Ov, cholangiocyte transformation and further CCA develpoment. Conclusion: These findings might avail the development of a preventive strategy for CCA in high-risk populations.Cholangiocarcinoma (CCA), a malignancy of bile duct epithelial cells, is a major public health problem in Northeast Thailand, which has the highest incidence in the world of this disease (1). A parasitic infection caused by Opisthorchis viverrini (Ov), a liver fluke, was identified as a cause of CCA in 1994 and is associated with CCA development (1). Upon liver fluke infection, CCA genesis is hypothesized to be initially induced via multiple mechanistic pathways, including mechanical damage caused by the fluke suckers, fluke toxic secretory products, and the host immunopathological response, leading to chronic inflammation (2). Moreover, the overproduction of reactive oxygen species and reactive nitrogen species from chronic inflammation results in tissue injury associated with CCA initiation and progression (3). In accordance with the hepatic changes first reported in 1978 in an Ov-infected hamster model, hyperplasia, adenomatous formations and periductal and portal scarring of the bile duct epithelium were also observed at 22 weeks post infection, although bile duct carcinoma was not seen at that time (4). In addition, a previous study showed that alone, Nnitrosodimethylamine (NDMA), a potential carcinogen, did not induce tumor formation in hamsters, but together with Ov infection, CCA was observed in a number of animals (5). Furthermore, histological changes, such as inflammatory reactions, bile duct proliferation, periductal fibrosis and cholangiocarcinoma lesions, were all observed in this cotreatment group (5). At the gene-expression level, we have shown a single down-regulated and 23 up-regulated give transcripts that were involved in Ov-induced CCA development (6). The up-regulated genes include signal 29 This article is freely accessible online.

The protein 14-3-3ζ contributes important regulatory functions in several cellular processes via binding to phosphorylated serine/threonine residues, which promotes cell cycle progression, cell proliferation and anti-apoptosis in multiple types of cancer. The aim of the present study was to investigate the functions of 14-3-3ζ in cholangiocarcinoma (CCA) progression and elucidate the molecular mechanism of 14-3-3ζ expression-mediated protein kinase B (Akt) phosphorylation and chemosensitivity in CCA cells. In the present study, 14-3-3ζ expression was investigated in clinical specimens using immunohistochemistry and compared with the clinicopathological features of patients with CCA. The association between 14-3-3ζ and phosphorylated Akt (pAkt) was determined among the tissues of the same patients using bivariate correlation analysis. The effects of 14-3-3ζ suppression on CCA cell function and gemcitabine sensitivity were investigated using small interfering RNA (siRNA). It was identified that 14-3-3ζ expression was positively correlated with pAkt (P=0.013) and that increased expression of 14-3-3ζ and pAkt were significantly associated with poor overall survival rate and metastasis (P=0.025 and 0.006, respectively). Downregulation of 14-3-3ζ using siRNA in CCA cell lines decreased cell proliferation, resulting in the inhibition of pAkt activity and increasing the protein level of the cell cycle inhibitor p27. The suppression of 14-3-3ζ enhanced the inhibitory effect of gemcitabine on CCA cell proliferation by inducing apoptotic cell death. Taken together, the results of the present study indicated that 14-3-3ζ is a potential target for CCA and may serve as a novel therapeutic approach to enhance chemosensitivity in the treatment of CCA.

Background/Aim: This study examined the in vitro effects of the bile duct cancer drug PRIMA-1 MET on cholangiocarcinoma (CCA) cell growth to determine its potential usefulness in CCA therapy. Materials and Methods: The effect of this drug on the expression of senescent markers (p16 INK4A and p21) and the phosphorylation of p53 was investigated, as was the association between senescent markers and the patients' clinicopathological data. Results: PRIMA-1 MET inhibited CCA cell growth with the half maximalinhibitory concentration (IC 50) values of 21.9-40.8 μM. PRIMA-1 MET induced phospho-p53, p16 INK4A and p21 triggering cellular senescence and apoptosis. High expressions of p16 INK4A and p21 were associated with a high survival rate of patients with CCA. Conclusion: PRIMA-1 MET may potentially be an alternative anticancer agent that might lead to a better prognosis in patients with CCA. Cholangiocarcinoma (CCA) is described as a malignant tumor arising from the bile duct epithelia (1). Although rare in Western countries, it has high incidences in Asia, with the highest rate occurring in the Northeast Thailand (2). In these countries, CCA develops along the biliary trees after repeated infection with liver fluke (Opisthorchis viverrini) followed by chronic inflammation. This is defined as a major risk factor of CCA (3-5). This cancer is resistant to common chemotherapy, leading to a poor prognosis, with low 5-year survival and high mortality rates. Most patients receive treatment when the disease is already advanced, when surgical resection, which is prospectively curative for earlystage disease, is usually ineffective (6, 7). Therefore, the development of targeted cancer therapies leading to the replacement of conventional cancer chemotherapy could be a better strategy for CCA treatment. Recently, targeting the cellular senescence pathway became a new strategy for cancer therapy (8). Cellular senescence is an irreversible growth arrest in response to various stresses by activating p53-dependent and-independent pathways (9). Currently, increased levels of lysosomal β-galactosidase activity and tumor-suppressor proteins such as p16 INK4A and p21 are commonly used as biomarkers of senescence (10, 11). Moreover, cellular senescence also acts as a barrier to tumorigenesis. Environmental stresses can force cancer cells to become responsive to cellular senescence via the activation of the p53dependent and-independent pathways. The accumulation of p16 INK4A and p21 represents a good prognostic factor for cancer treatment (12). This leads us to focus more on using prosenescent agents for CCA treatment. PRIMA-1 MET is a methylated derivative and structural analog of PRIMA-1 (p53 re-activation and induction of massive apoptosis). PRIMA-1 MET has been reported to restore p53 activity leading to the induction of cellular senescence and apoptosis (13). PRIMA-1 MET has been approved for treatment of acute myeloid leukemia and other hematological malignancies, and cancer of the lung, prostate, colorectum, ovary, esophagus, and br...