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As an essential post-translational modification, O-GlcNAcylation has been thought to be able to modulate various nuclear and cytoplasmic proteins and is emerging as a key regulator of multiple biological processes, such as transcription, cell growth, signal transduction, and cell motility. Recently, authoritative glycomics analyses have reported extensive crosstalk between O-GlcNAcylation and phosphorylation, which always dynamically interplay with each other and regulate signaling, transcription, and other cellular processes. Also, plentiful studies have shown close correlation between YB-1 phosphorylation and tumorigenesis. Therefore, our study aimed to determine whether YB-1 was O-GlcNAc modified and whether such modification could interact with its phosphorylation during the process of HCC development. Western blot and immunohistochemistry were firstly conducted to reveal obvious up-regulation of YB-1, OGT and O-GlcNAc modification in HCC tissues. What is more, not only YB-1 was identified to be O-GlcNAcylated but hyper-O-GlcNAcylation was demonstrated to facilitate HCC cell proliferation in a YB-1 dependent manner. Moreover, we detected four specific O-GlcNAc sites and confirmed T126A to be the most effective mutant in HCC cell proliferation via close O-GlcNAcylation-phosphorylation interaction. Even more interestingly, we discovered that T126A-induced HCC cell retardation and subdued transcriptional activity of YB-1 could be partially reversed by T126A/S102E mutant. From all above, it is not difficult to find that glycosylated-YB-1 mainly enhanced cell proliferation through congenerous actions with YB-1 phosphorylation and thus played indispensable roles in fine-tuning cell proliferation and procession of HCC.

The mechanism underlying poor prognosis and sorafenib resistance in patients with hepatocellular carcinoma (HCC) is unknown and, to date, no useful predictive biomarkers of sorafenib resistance have been identified. Distal-less homeobox 2 (DLX2) is a transcription factor involved in cell cycle regulation that is closely correlated with cancer prognosis. In this study, we showed that DLX2 is overexpressed in HCC tissues and cell lines and that the level of DLX2 overexpression is positively correlated with histological grade, metastasis and Ki67 expression, which are indicators of poor prognosis. We also found that DLX2 accumulates in proliferating HCC cells, where it is associated with the expression of proliferating cell nuclear antigen (PCNA), Cyclin D1 and Cyclin A. Flow cytometry and cell counting kit-8 (CCK-8) assays indicated that DLX2 depletion causes cell cycle arrest at the G1 phase and hinders cell proliferation. Moreover, the sensitivity of HCC cells to sorafenib is restored when the DLX2 gene is knocked down using a short interfering RNA. We demonstrated that DLX2 facilitates sorafenib resistance by promoting the expression of markers of epithelial–mesenchymal transition and by activating the extracellular signal-regulated protein kinase pathway. Our findings reveal that DLX2 plays a regulatory role in HCC cell proliferation and suggests that targeting DLX2 represents a novel strategy to increase sorafenib efficacy in the management of HCC. In conclusion, DLX2 is a novel marker of poor prognosis and sorafenib resistance in patients with HCC.

BCCIP was originally identified as a BRCA2- and CDKN1A- (Cip1/waf1/p21) interacting protein, also known as BCCIP. It has been reported to express in various types of cancers, including colorectal cancer (CRC), astrocytic brain tumors, and glioblastomas. However, the relationship between BCCIP expression and clinicopathological features of hepatocellular carcinoma (HCC) remains to be determined. Herein, we demonstrated that BCCIP was downregulated in clinical HCC tissues; its level was inversely correlated with multiple clinicopathological factors, such as tumor grade, tumor size, and Ki67 expression. Cox regression analysis of tumor samples revealed that BCCIP expression status was an independent prognostic factor for HCC patients' poor survival. Our study also indicated that BCCIP shutdown reduces p21 expression and accelerates G1 to S progression of LO2 hepatocytes significantly. Moreover, there is an interaction between BCCIP and p53 in hepatic L02 cells, and the downregulation of p21 expression by BCCIP is in a p53-dependent way. These findings revealed that BCCIP may play a significant role for the determination of HCC progression through its role in regulating cell growth. Thus, our results suggest that BCCIP is of potential interest for prognostic marker and therapeutic target of HCC.

Metastasis remains the most common cause of lethal outcomes in hepatocellular carcinoma (HCC) after curative resection. Understanding molecular mechanisms that regulate metastasis process is crucial for improving treatment of hepatocellular carcinoma. In this article, we examined whether Eps15 homology domain-containing 2 (EHD2) played a critical role in hepatocellular carcinoma metastasis and explored the possible mechanism. EHD2 and E-cadherin expression levels in hepatocellular carcinoma patients were examined using Western blotting and immunohistochemistry. The cell migration and invasion were evaluated by wound-healing assay and trans-well assay. Epithelial-mesenchymal transition was analyzed by immunofluorescence, and the vital markers were detected by Western blotting. The correlation of EHD2 and E-cadherin was confirmed by co-immunoprecipitation. EHD2 expression, along with the epithelial marker E-cadherin, was markedly reduced in tumor tissues than in adjacent noncancerous tissues. Moreover, EHD2 was positively correlated with E-cadherin, histological grade, tumor metastasis, and microvascular invasion. Kaplan–Meier survival analysis showed that hepatocellular carcinoma patients with decreased EHD2 expression had shorter overall survival times than those with higher EHD2 expression. Knockdown of EHD2 induced an increase in cell invasion and changes characteristic of epithelial-mesenchymal transition, while overexpression of EHD2 inhibited these processes. Molecular data indicated that EHD2 inhibited migration and invasion of hepatocellular carcinoma probably by interacting with E-cadherin and it might be an independent, significant risk factor for survival after curative resection.

γ-glutamyl transferase isoenzyme II (GGT-II) is a sensitive biomarker of hepatocellular carcinoma (HCC). However, numerous disadvantages of the traditional manual method affected its application. The commercial kit provided a convenient and fast method for the determination of GGT-II levels. The purposes of the present study were to compare the reproducibility and sensitivity between the manual and commercial kit methods and to evaluate the diagnostic efficiency for HCC with the combined analysis of GGT-II, α-L-fucosidase (AFU) and α-fetoprotein (AFP). In patients with various liver diseases (HCC, liver cirrhosis and chronic hepatitis) and normal subjects, GGT-II was detected by manual and commercial polyacrylamide gel electrophoresis (PAGE). The levels of AFU and AFP were assayed by colorimetry and a chemiluminescence immunoassay, respectively. The commercial PAGE had equal diagnostic efficiency with traditional manual PAGE and no significant differences were observed in intra- and average-gel reproducibility and GGT-II sensitivities between the manual and commercial PAGE (P>0.05). The incidence of GGT-II detected by commercial PAGE in HCC patients was 84.1% and 636.5 μmol/l h and AFP >44.0 μg/l, respectively. There were no significant correlations between GGT-II and AFU or AFP. Combined detection of GGT-II with AFU or AFP increased the diagnostic sensitivity to 92.9 and 93.8%, respectively. These results suggest that commercial PAGE provides a simple and reproducible method for GGT-II detection. Combined determination of GGT-II with AFU or AFP exhibited superior sensitivity and specificity for the diagnosis of HCC.

Aim: The impact of hepatitis B e-antigen (HBeAg) on recurrence of hepatocellular carcinoma (HCC) after curative resection remains controversial. This meta-analysis aimed to determine whether the presence of HBeAg influenced the recurrence of HCC after curative resection. Methods: We performed a meta-analysis including six studies (a total of 865 patients) to assess the effect of HBeAg on recurrence of HCC after curative resection. The pooled odds ratios (OR) were calculated using a random or fixed effects model. PUBMED, MEDLINE, EMBASE and the Cochrane Database were searched for articles published from 1990 to March 2012. Sensitivity analysis and publication bias estimate were also performed to evaluate the potential risk bias in the overall results of pooled analysis. Results: Our results showed that the presence of HBeAg significantly increased the overall HCC recurrence risk after curative resection (OR = 1.63, 95% confidence interval (CI) = 1.11–2.40; P = 0.01). Pooled data from three studies on the risk of early recurrence among HBeAg positive patients compared with HBeAg negative patients showed an increased risk of early recurrence (OR = 1.50, 95% CI = 1.02–2.19; P = 0.04). However, there was no significant difference in late HCC recurrence between HBeAg positive and negative patients (OR = 1.17, 95% CI = 0.62–2.19; P = 0.62). Conclusion: The present study suggested that HBeAg positive patients had a significantly higher risk of early recurrence after curative resection of HCC.

A subset of patients with a pre-operative diagnosis of ulcerative colitis can develop Crohn’s disease (CD) of the pouch after restorative proctocolectomy. While appendectomy has been implicated to be associated with an increased risk for CD, its impact on the development of de novo CD of the pouch in patients’ ileal pouch-anal anastomosis (IPAA) has not been studied. The aims of the study were to assess the prevalence of CD of the pouch in patients with pre-colectomy appendectomy and to investigate the impact of appendectomy on the development of de novo CD of the pouch. All eligible patients with restorative proctocolectomy and IPAA for IBD who had available information on pre-colectomy appendectomy were studied. Demographic and clinical characteristics were evaluated. Cox regression analysis was performed. The study included 434 patients (44.9 % male) with a mean age of 45.2 ± 14.4 years and follow-up of 4.6 ± 2.3 years. Forty patients (9.2 %) had had appendectomy prior to colectomy. Appendectomy was not shown to be associated with CD of the pouch or its phenotypes in both univariable and multivariable analyses. In the Cox model, independent risk factors associated with CD of the pouch were active smoking (hazard ratio [HR] = 1.58; 95 % confidence interval [CI], 1.03–2.43) and family history of CD (HR = 1.82; 95 % CI, 0.99–3.32). While this study has shown no association between previous appendectomy and the development of CD of pouch, active smoking was an independent risk factor for development of CD of the pouch.

FOXJ1 is a member of the forkhead box (FOX) family of transcription factors. Recent studies suggested that FOXJ1 may function as a tumor suppressor gene in breast cancer. To investigate the potential roles of FOXJ1 in hepatocellular carcinoma (HCC), expression of FOXJ1 was first examined in eight paired frozen HCC and adjacent noncancerous liver tissues by Western blot, and we found that FOXJ1 was upregulated in HCC specimens. In addition, immunohistochemistry was performed to confirm our results in 108 HCC samples. Moreover, we also evaluated its relation with clinicopathological variables and the prognostic significance. The data showed that high expression of FOXJ1 was associated with histological grade (P

The molecular mechanisms leading to gastric carcinogenesis still remain unclear. Recently, several studies demonstrated that over-expression of guanylyl cyclase C (GCC) has been detected in intestinal-type gastric cancer (GC) and precursor lesions. Our objective was to explore the expression levels of GCC and endogenous ligands guanylin (GN) and uroguanylin (UGN) and the correlation between Helicobacter pylori (H. pylori) and GCC, GN, and UGN expressions in patients at different stages from normal mucosa to superficial gastritis, atrophic gastritis, intestinal metaplasia (IM), dysplasia, and finally adenocarcinoma. The expression of GCC and GN was absent in the distal normal gastric tissues and superficial gastritis in all cases, whereas they were measured in IM, dysplasia, and GC. The expression of GCC and GN was closely related to intestinal-type GC. From superficial gastritis to gastric carcinomas, the H. pylori positive rate was 19.7, 33.3, 69.6, 80.0, and 82.1%, respectively. The positive correlation was found between GCC and GN in IM, dysplasia, and GC. Also, the positive correlation was found between GCC, GN, and H. pylori infection in them. These results demonstrate that the detection of GCC and GN will be beneficial to diagnosis human gastric carcinoma and precancerous lesions. Ectopic expression of GCC and GN in human gastric mucosa and H. pylori infection may play an important role in the carcinogenesis of the intestinal-type GC.

S100A11 is a member of S100 protein family, and our previous study showed that S100A11 is one of the up-regulated proteins that have not been reported to be associated with pancreatic carcinoma. The purpose of this study was to investigate the relation between S100A11 expression and the clinicopathological variables and clinical outcome in patients with pancreatic adenocarcinoma. Immunohistochemistry analysis was performed for S100A11 in 78 pairs of specimens of human pancreatic adenocarcinoma tissues and adjacent nontumorous tissues. The univariate and multivariate survival analyses were also performed to determine its prognostic significance. S100A11 expression in pancreatic adenocarcinoma (62/78) was significantly higher than that in the adjacent nontumorous tissues (19/78) (P = 0.000). High expression of S100A11 was associated with the lymph node metastasis and histological differentiation (P = 0.003 and 0.004, respectively). Univariate analysis showed that S100A11 expression was associated with poor prognosis (P = 0.0000). Multivariate analysis using the Cox regression model indicated that age ≥ 65 years, CA19-9 ≥ 1,000 U/ml and positive S100A11 were independent prognostic indicators of pancreatic adenocarcinoma (P = 0.002, 0.004 and 0.001, respectively). These results suggested that S100A11 might be a significant tumor marker for pancreatic adenocarcinoma and an unfavorable predictor for prognosis of patients who have undergone surgical resection.

Nek6 is a cell cycle regulatory gene, which can control cell proliferation and survival. Recent studies suggested that desregulation of Nek6 expression plays a key role in oncogenesis. This study was aimed to investigate the potential roles of Nek6 in hepatocellular carcinoma (HCC) development. Immunohistochemistry and Western blot analysis was performed for Nek6 in 80 hepatocellular carcinoma samples. The data were correlated with clinicopathological features. The univariate and multivariate survival analyses were performed to determine the prognostic significance of Nek6 in HCC. In addition, Nek6 expression vector was used to detect its role in cell cycle control. Nek6 was overexpressed in hepatocellular carcinoma as compared with the adjacent normal tissue. High expression of Nek6 was associated with histological grade and the level of alpha fetal protein, and Nek6 was positively correlated with proliferation marker Ki-67. Univariate analysis showed that Nek6 expression was associated with poor prognosis. Multivariate analysis indicated that Nek6 and Ki-67 protein expression was an independent prognostic marker for HCC. While in vitro, following release from serum starvation of HuH7 HCC cell, the expression of Nek6 was upregulated. Overexpression Nek6 in Huh7 cell could promote the cell cycle. In conclusion, Nek6 is involved in the pathogenesis of hepatocellular carcinoma. It may be a favorable independent poor prognostic parameter for hepatocellular carcinoma.

p53-Induced ring-H2 protein (Pirh2), a recently identified ubiquitin-protein ligase, interacts with p27(Kip1) to promote ubiquitination of p27(Kip1) independently of p53. High Pirh2 and low p27(Kip1) immunoreactivity are associated with a poor prognosis in several cancers, including resistant phenotypes. In the present study, we investigated the role of Pirh2 and p27(Kip1) in human hepatocellular carcinoma (HCC) progression. Immunohistochemical analysis was performed on formalin-fixed paraffin sections of 87 specimens. Statistical analysis showed that expression of Pirh2 was negatively related to p27(Kip1) expression (r = 0.787; P < .05), and Pirh2 expression correlated significantly with histologic grade (P < .001), venous invasion (P = .004), tumor size (P = .024), and the presence of multiple tumor-bearing lymph nodes (P = .017), whereas p27(Kip1) expression correlated significantly with histologic grade (P < .001), venous invasion (P = .048), and cirrhosis (P = .028). By Kaplan-Meier analysis, the survival curves of low versus high expressers of Pirh2 and p27(Kip1) showed significant separation (P < .01). Molecular interaction could be demonstrated between Pirh2 and p27(Kip1) in three HCC cell lines. In vitro, following release of two HCC cell lines from serum starvation, the expression of Pirh2 was upregulated, whereas p27(Kip1) was downregulated. Our results suggest that Pirh2 mediates the degradation of p27(Kip1) and participates in cell proliferation in human HCC. These findings provide a rational framework for further development of Pirh2 inhibitors as a novel class of anti-tumor agents.

Objective To investigate the correlation between polymorphism of the 5′-untranslated region (5′-UTR) of thymidylate synthase genes, as well as the lifestyle, and the susceptibility of gastric carcinoma.

Elevated apoptosis of intestinal epithelial cells (IECs) greatly impairs the epithelial barrier integrity and contributes to the pathogenesis of Crohn's Disease (CD). Overproduction of pro-inflammatory cytokine Interferon-γ (IFN-γ) induces the excessive apoptosis of IECs and is involved in CD development. PRDM5 (PR domain containing 5 PFM2) a member of PRDM family, reportedly acts as a transcriptional regulator involved in tissue specific differentiation and tumor development. In this study, we investigated PRDM5 expression and its potential functions in both human CD (Crohn's disease) and TNBS (2,4,6-trinitrobenzenesulfonic acid sol)-induced mice experimental colitis. As shown by western blot and immunohistochemistry, significant up-regulation of PRDM5 was found in the inflamed intestinal tissues of CD patients and TNBS-treated mice, and the molecule was mainly located in IECs. To explore the biological functions of PRDM5 in IEC apoptosis, we established the interferon-γ (IFN-γ) induced cellular apoptosis model on human IEC line HT29 in vitro. IFN-γ significantly increased the expression of PRDM5 in a both time-dependent and concentration-dependent manner in HT29 cells, which was accompanied with an up-regulated expression of apoptotic markers (active caspase-3 and cleaved PARP(poly (ADP-ribpse) polymerase)). Inhibiting PRDM5 expression by siRNA attenuated the IFN-γ-triggered accumulation of active caspase-3 and cleaved PARP in IECs. Moreover, flow cytometry assay and CCK-8 analysis revealed that PRDM5 knockdown significantly alleviated the IFN-γ-induced cellular apoptosis in HT29 cells. Taken together, these data suggest that highly expressed PRDM5 may promote the IFN-γ-induced IEC apoptosis in the progression of CD.

The tumor suppressor p27, which is a member of the Cip/Kip family of Cyclin-dependent kinase inhibitory proteins (CKIs), controls anti-proliferative events. The post-translational addition of O-GlcNAc to p27 occurs in HEK293T and HCC (hepatocellular carcinoma) cell lines, and we identified Ser2, Ser106, Ser110, Thr157, and Thr198 as the glycosylation sites of p27 based on the Q-TOF spectrum. Here, immunoprecipitation analysis showed that Ser2 was O-GlcNAcylated and that this modification was associated with the increased phosphorylation of p27 at Ser10, ultimately resulting in p27 accumulation in the cytoplasm and increased p27 ubiquitination. In addition, O-GlcNAcylation at Ser2 suppressed Cyclin/CDK complex-p27 interactions by promoting the nuclear export of p27, thus facilitating cell cycle progression. Cell proliferation was negatively regulated when Ser2 of p27 was replaced with Ala. Furthermore, western blot and immunohistochemical analyses of HCC tissues and their corresponding nontumorous tissues were performed, and we found that O-GlcNAcylated p27 correlated with cell proliferation in HCC. Together, our results indicate that the dynamic interplay between O-GlcNAcylation and p27 phosphorylation coordinates and regulates cell proliferation in hepatocellular carcinoma. © 2016 Wiley Periodicals, Inc.

Epithelial-specific ETS-1 (ESE1), also named as ELF3, ERT and ESX, belonging to the ETS family of transcription factors, exerts multiple activities in inflammation, epithelial differentiation and cancer development. Previous data demonstrated that ESE1 synergizes with NF-κB to induce inflammation and drive tumor progress, and the nuclear translocation of ESE1 promotes colon cells apoptosis. However, the expression and biological functions of ESE1 in ulcerative colitis (UC) remain unclear. In this study, we reported for the first time that ESE1/ELF3 was over-expressed in intestinal epithelial cells (IECs) of patients with UC. In DSS-induced colitis mouse models, we observed the up-regulation of ESE1/ELF3 accompanied with the elevated levels of IEC apoptotic markers (active caspase-3 and cleaved PARP) and NF-κB activation indicators [phosphorylated NF-κB p65 subunit (p-p65) and p-IκB] in colitis IECs. Increased co-localization of ESE1/ELF3 with active caspase-3 (and p-p65) in IECs of the DSS-induced colitis group further indicated the possible involvement of ESE1/ELF3 in NF-κB-mediated IEC apoptosis in UC. Employing the TNF-α-treated HT-29 cells as an IEC apoptosis model, we confirmed the positive correlation of ESE1/ELF3 with NF-κB activation and caspase-dependent IEC apoptosis in vitro. Immunoprecipitation and immunofluorescence assay revealed the physical interaction and increased nuclear translocation of ESE1/ELF3 and the NF-κB p65 subunit in TNF-α-treated HT-29 cells. Knocking ESE1/ELF3 down by siRNA significantly alleviated TNF-α-induced NF-κB activation and cellular apoptosis in HT-29 cells. Taken together, our data suggested that ESE1/ELF3 may promote the UC progression via accelerating NF-κB activation and thus facilitating IEC apoptosis.

Sam68 (Src-associated in mitosis of 68 kD) is a KH domain RNA-binding protein. The expression of Sam68 was correlated with kinds of tumors. Yet, the expression mechanisms and physiological significance of Sam68 in ESCC remains unclear. In this study, we clarified a potential role of Sam68 in the treatment of ESCC. Western blot and immunohistochemistry (IHC) analysis revealed that the protein level of Sam68 was higher in ESCC tumor tissues and cell lines. In addition, IHC stain revealed that Sam68 was positively correlated with clinical pathologic variables such as tumor grade and tumor invasion. In addition, Sam68 could be an independent prognostic indicator for patients’ overall survival. In vitro studies such as starvation and refeeding assay along with Sam68-shRNA transfection assay demonstrated that Sam68 expression promoted proliferation of ESCC cells. And Sam68 downregulation caused decreased rate of cell growth and colony formation. Reasons are associated with growth arrest of cell cycle at G1/S phase. Moreover, our results clarified that Sam68 could promote ESCC cell proliferation via the activation of Akt/GSK-3β pathway. This research indicated that Sam68 might accelerate the cell cycle progression and be considered as a new therapy target in ESCC.

Hepatocellular carcinoma (HCC) is the third leading cause of cancer-related deaths worldwide. It is indispensable to understanding molecular mechanisms of HCC progression and to developing clinically useful biomarkers for this disease. In this article, we examined whether HOXC8 was associated with the poor prognosis of hepatocellular carcinoma and explored the possible underlying mechanism. The HOXC8 and Ki67 expression levels in 86 patients with hepatocellular carcinoma were examined using immunohistochemistry. HOXC8 levels in HCC cells were downregulated by siRNA transfection. The cycle progression and cell proliferation status of HCC cells and the oxaliplatin effectiveness were evaluated by flow cytometry and CCK-8 assay. HOXC8, CyclinD1, PCNA, Nkd2, and cleaved caspase-3 levels were detected by western blot. HOXC8 was upregulated in HCC tissues, compared with adjacent non-tumor ones. HOXC8 expression levels in 86 patients with hepatocellular carcinoma were positively correlated with histological grade. Univariate and multivariate survival analysis revealed that HOXC8 was a significant predictor for overall survival of HCC patients. HOXC8 siRNA knockdown delayed the G1–S phase transition, inhibited cell proliferation, and attenuated resistance to oxaliplatin. HOXC8 promoted HCC proliferation and predicted poor prognosis. Furthermore, upregulated HOXC8 expression was associated with oxaliplatin resistance in hepatocellular carcinoma.

CtBP2, as a transcriptional corepressor of epithelial-specific genes, has been reported to promote tumor due to upregulating epithelial-mesenchymal transition (EMT) in cancer cells. CtBP2 was also demonstrated to contribute to the proliferation of esophageal squamous cell carcinoma (ESCC) cells through a negative transcriptional regulation of p16(INK4A). In this study, for the first time, we reported that CtBP2 expression, along with CCNH/CDK7, was higher in ESCC tissues with lymph node metastases than in those without lymph node metastases. Moreover, both CtBP2 and CCNH/CDK7 were positively correlated with E-cadherin, tumor grade, and tumor metastasis. However, the concrete mechanism of CtBP2's role in enhancing ESCC migration remains incompletely understood. We confirmed that CCNH/CDK7 could directly interact with CtBP2 in ESCC cells in vivo and in vitro. Furthermore, our data demonstrate for the first time that CtBP2 enhanced the migration of ESCC cells in a CCNH/CDK7-dependent manner. Our results indicated that CCNH/CDK7-CtBP2 axis may augment ESCC cell migration, and targeting the interaction of both may provide a novel therapeutic target of ESCC.

OBJECTIVE To investigate the clinical value of hepatoma-specific alpha-fetoprotein (HS-AFP) and gamma-glutamyltransferase II (GGT II) for judgment of postoperative prognosis of patients with hepatocellular carcinoma (HCC).

OBJECTIVE To study the clinical value of hepatoma-specific alpha-fetoprotein (HS-AFP) in the diagnosis and differential diagnosis of hepatocellular carcinoma (HCC).

Vacuolar protein sorting 4B (VPS4B), a member of ATPase family proteins, reportedly possesses multiple biological functions, such as regulating the development of breast cancer and non-small-cell lung cancer, participating in Parkinson's disease, and modulating neuronal apoptosis after cerebral ischemia. However, its expression and potential functions in Crohn's disease (CD) has not been understood. In this study, we reported for the first time that VPS4B was over-expressed in intestinal epithelial cell (IECs) of patients with CD. In TNBS-induced mouse colitis models, we observed the up-regulation of VPS4B was accompanied with the elevated levels of IEC apoptotic markers (active caspase-3 and cleaved PARP) and phosphorylated p38 in colitis IECs. Co-localization of VPS4B and active caspase-3 in IECs of the TNBS group further indicated the possible involvement of VPS4B in IEC apoptosis. Employing the TNF-α-treated HT29 cells as an in vitro IEC apoptosis model, we confirmed the positive correlation of VPS4B with caspase-dependent cellular apoptosis. Knocking VPS4B down by siRNA significantly alleviated TNF-α-induced p38 phosphorylation and cellular apoptosis in HT29 cells. Taken together, our findings suggested that VPS4B may facilitate the IEC apoptosis in CD via p38 MAPK signaling pathway.

Charged multivesicular body protein 4B (CHMP4B), a subunit of the endosomal sorting complex required for transport (ESCRT)-III complex, plays an important part in cytokinetic membrane abscission and the late stage of mitotic cell division. In this study, we explored the prognostic significance of CHMP4B in human hepatocellular carcinoma (HCC) and its impact on the physiology of HCC cells. Western blot and immunohistochemistrical analyses showed that CHMP4B was significantly upregulated in HCC tissues, compared with adjacent non-tumorous tissues. Meanwhile, clinicopathological analysis revealed that high CHMP4B expression was correlated with multiple clinicopathological variables, including AFP, cirrhosis, AJCC stage, Ki-67 expression, and poor prognosis. More importantly, univariate and multivariate survival analyses demonstrated that CHMP4B served as an independent prognostic factor for survival of HCC patients. Using HCC cell cultures, we found that the expression of CHMP4B was progressively upregulated after the release from serum starvation. To verify whether CHMP4B could regulate the proliferation of HCC cells, CHMP4B was knocked down through the transfection of CHMP4B-siRNA oligos. Flow cytometry and CCK-8 assays indicated that interference of CHMP4B led to cell cycle arrest and proliferative impairment of HCC cells. Additionally, depletion of CHMP4B expression could increase the sensitivity to doxorubicin in HepG2 and Huh7 cells. Taken together, our results implied that CHMP4B could be a promising prognostic biomarker as well as a potential therapeutic target of HCC.

Vacuolar protein sorting 4B (VPS4B) is a member of ATPase family proteins that have been shown to play important roles in the formation of MVBs, virus budding and abscission of cytokinesis. In this study, we investigated the prognostic role of VPS4B in human hepatocellular carcinoma (HCC) and its effect on the growth of HCC cells. Western blot and immunohistochemistrical analyses revealed that VPS4B was significantly upregulated in 98 HCC tissues, compared with adjacent nontumorous samples. Meanwhile, clinicopathological variables and univariate and multivariate survival analyses showed that high VPS4B expression was correlated with multiple clinicopathological factors, including AJCC stage, microvascular invasion, Ki-67 and a poor prognosis. More importantly, univariate and multivariate survival analyses demonstrated that VPS4B served as an independent prognostic factor for survival in HCC patients. Furthermore, we found that VPS4B was lowly expressed in serum-starved Huh7 and HepG2 HCC cells, and was progressively increased after serum-refeeding. To study whether VPS4B could regulate the proliferation of HCC cells, VPS4B was knocked down in both Huh7 and HepG2 cells through the transfection of VPS4B-siRNA oligos. Flow cytometry and CCK-8 assay results indicated that interference of VPS4B led to cell cycle arrest and reduced cell proliferation of HCC cells. Taken together, our results implied that VPS4B could be a candidate prognostic biomarker as well as a potential therapeutical target of HCC.

SYF2, also known as CCNDBP1-interactor or p29, is reported in pre-mRNA splicing and cell cycle progression. However, the role of SYF2 in esophageal squamous cell carcinoma (ESCC) development remains elusive. In the present study, Western blot and immunohistochemistry assays demonstrated that SYF2 was overexpressed in ESCC tumor tissues and cell lines. In addition, immunohistochemistry analysis revealed that SYF2 expression was positively correlated with tumor grade and predicted poor prognosis of ESCC. In vitro studies using serum starvation-refeeding experiment and SYF2-siRNA transfection assay demonstrated that SYF2 expression promoted proliferation of ESCC cells, while SYF2 knockdown led to decreased cell growth rate and colony formation resulted from growth arrest of cell cycle at G0/G1 phase. Furthermore, our results indicated that SYF2 can down-regulate the sensitivity of ESCC cells for cisplatin. Our findings for the first time supported that SYF2 might play an important role in the regulation of ESCC proliferation and would provide a novel therapeutic strategy against human ESCC.

ErbB3 binding protein 1 (EBP1) has been recently reported to function as a tumor suppressor in the progression of multiple cancers, including breast cancer, prostate cancer, salivary adenoid cystic carcinoma (ACC), and oral squamous cell carcinoma (OSCC). However, the expression and physiological significance of EBP1 in hepatocellular carcinoma (HCC) remain unclear. In the study, we showed that EBP1 was significantly downregulated in clinical HCC specimens, and that decreased expression of EBP1 was associated with enhanced proliferation in HCC cells. Western blot and immunohistochemical analyses revealed that EBP1 was remarkably downregulated in HCC tissues compared with the adjacent normal ones. The levels of EBP1 were significantly associated with histological grade (P = 0.034), tumor size (P = 0.001), and Ki67 expression (P < 0.001) in HCC specimens. Univariate and multivariate analyses showed that EBP1 could serve as an independent prognostic indicator of patients' survival. Serum starvation and refeeding assay indicated that EBP1 was accumulated in growth-arrested HCC cells, and was progressively decreased when cells entered into S phase. Moreover, the depletion of EBP1 induced growth acceleration and cell cycle progression in L02 hepatocytes. On the basis of these findings, we conclude that EBP1 may be a valuable prognostic marker and promising therapeutic target of HCC.

Aim: Intestinal epithelial barrier is essential for maintaining normal intestinal homeostasis; its breakdown leads to chronic inflammatory pathologies, such as inflammatory bowel diseases. Far upstream element binding protein 1 (FBP1) has been reported to play an important role in cell apoptosis and proliferation. We aimed to investigate the expression and the role of FBP1 in dextran sodium sulphate (DSS)-induced experimental colitis. Methods: Mice experimental colitis model was established by administration of DSS, and the expression and localization of FBP1 was examined using Western blot and immunohistochemistry. Colon epithelial cell line HT-29 was used to determinethe role of FBP1. In vitro study, the expression of FBP1 was determined in HT-29 cells stimulated with tumor necrosis factor α (TNF-α). HT-29 cells were transfected with FBP1 siRNA and then measured for viability. Results: Significant decreasing of FBP1 expression was found in mice colitis. In addition, FBP1 was cleaved and translocated from nucleus to cytoplasm during apoptosis. Downregulated expression of FBP1 induced cell cycle arrest. Conclusions: We demonstrate that apoptosis-mediated cleavage of FBP1 and its decreased expression in epithelial cells induces cell cycle arrest, which may play an important role in colonic epithelial disruption

GTP binding protein overexpressed in skeletal muscle (Gem) is a Ras-related protein whose expression is induced in several cell types upon activation by extracellular stimuli. To investigate the potential roles of Gem in hepatocellular carcinoma (HCC), expression of Gem was examined in human HCC samples. Western blot analysis showed that compared with primary human hepatocytes and adjacent noncancerous tissue, significant down-regulation of Gem was found in HCC cells and tumor tissues. In addition, immunohistochemical analysis of Gem expression was investigated in 108 specimens of HCC tissues. Clinicopathological data were collected to analyze the association with Gem expression. Expression of Gem was significantly negatively correlated with histological grade (P=0.001), tumor size (P=0.020), and vascular invasion (P=0.005), and Gem was also negatively correlated with proliferation marker Ki-67 (P0.01). More importantly, the Kaplan-Meier survival curves analysis revealed that low expression of Gem was associated with poor prognosis in HCC patients. Univariate analysis showed that Gem expression was associated with poor prognosis (P=0.006). Multivariate analysis indicated that Gem expression was an independent prognostic marker for HCC (P=0.007). Finally, serum starvation and release experiments showed that Gem expression was negatively related with cell proliferation. In the conclusion, our results suggested that down regulation of Gem expression was involved in the pathogenesis of hepatocellular carcinoma, and it might be a favorable independent prognostic parameter for HCC.

Ring finger protein 1 (RING1) have recently been reported to be related to aggressive tumor features in Prostate Cancer and urothelial carcinoma of the bladder. However, the role of RING1 in non-small-cell lung cancer (NSCLC) tumorigenesis has never been elucidated. So we aimed at investigating the potential role of RING1 in NSCLC. RING1 expression was evaluated by Immunoblot in 8 paired fresh lung cancer tissues and immunohistochemistry on 69 paraffin-embedded sections from 2006 to 2009. Furthermore, flow-cytometry and RNA interference were performed to analyse the role of RING1 in A549 cells. We showed that the expression level of RING1 was significant increased in lung cancer as compared with the adjacent normal tissue. High expression level of RING1 was associated with TNM stage (P = 0.013), and RING1 was positively related with proliferation marker Ki67 (P

A small glutamine-rich tetratricopeptide repeat-containing protein alpha (SGTA) is a 35 kDa protein involved in a number of biological processes. However, the role of SGTA in non-small-cell lung cancer (NSCLC) tumorigenesis has never been elucidated. The purpose of this study was to determine whether SGTA could serve as a biomarker for stratification and prediction of prognosis in NSCLC.Small glutamine-rich tetratricopeptide repeat-containing protein alpha expression was evaluated by Western blot in 8 paired fresh lung cancer tissues and immunohistochemistry on 83 paraffin-embedded sections. The effect of SGTA was assessed by RNA interference in A549 cells. Serum starvation and refeeding, flow cytometry, CCK-8, and tunnel assays were performed.Small glutamine-rich tetratricopeptide repeat-containing protein alpha was highly expressed in NSCLC and significantly correlated with NSCLC histological differentiation, clinical stage, and Ki-67. Multivariate analysis indicated that SGTA was an independent prognostic factor for NSCLC patients' survival. The present investigation demonstrated that suppression of SGTA expression resulted in a significant decline of proliferation in A549 cells. Besides, SGTA could abolish the toxicity of cisplatin in A549 cells.These findings suggested that SGTA might play an important role in promoting the tumorigenesis of NSCLC, and thus be a promising therapeutic target to prevent NSCLC progression.

Ski-interacting protein (SKIP) is a transcriptional cofactor distinct from other cofactors and involved in the regulation of many cancer-related proteins. This study investigated the expression of SKIP and its potential clinical and biological significances in hepatocellular carcinoma (HCC). Immunohistochemistry and Western blot were performed to detect the expression of SKIP in clinical HCC samples and adjacent noncancerous tissues. In addition, expression of SKIP was correlated with clinicopathological variables, and univariate and multivariate survival analyses were performed to determine the prognostic significance. Moreover, the biological significance of the aberrant expression of SKIP was investigated in vitro. High SKIP expression was detected in clinical HCC samples compared with adjacent noncancerous tissues. Expression of SKIP correlated directly with the histological grades of HCC and high expression of SKIP was associated with a poor prognosis. SKIP depletion by small interfering RNA inhibited cell proliferation and blocked S phase entry in HepG2 cells. Owing to overexpression of SKIP in HCC tissues and its important role in predicting poor prognosis and the development of HCC, SKIP could be a potential prognostic marker and therapeutic target of HCC.

Epithelial membrane protein 3 (EMP3) is a typical member of the epithelial membrane protein (EMP) family which has been reported to be a tumor suppressor gene in neuroblastomas and gliomas and recently reported to be commonly repressed in esophageal squamous cell carcinoma (ESCC) cell lines. However, the expression and clinical significance of EMP3 protein in lung cancer have not yet been elucidated. In this article, we detected that the expression of EMP3 in non-small cell lung cancer was significantly lower than the expression of normal lung tissues (P < 0.01) by western blot. EMP3 expression in Lung cancer was significantly related to p-TNM stage (P < 0.05) and EMP3 was negatively correlated with proliferation marker Ki67(r = -0.775; P < 0.01), However, no significant correlations were found between EMP3 and other clinical parameters. The post-recurrent survival after radical surgery was poorer in lung cancer patients with lower EMP3 expression (P < 0.01). While in vitro, following release from serum starvation of A549 NSCLC cell, the expression of EMP3 was deregulated. Thus, our finding suggests that EMP3 may be a tumor suppressor gene at the late step of lung cancer, and EMP3 may be a potential prognostic marker and therapeutic target of NSCLC.

Bcl-2-associated athanogene-1 (BAG-1) is a multifunctional anti-apoptotic protein which regulates an array of cellular processes, including apoptosis, signaling, proliferation, transcription, and cell motility and has been reported to be over-expressed in a number of human malignancies. To investigate the possible involvement of BAG-1 in tumorigenesis of hepatocellular carcinoma (HCC), we performed Western blot analysis in eight paired samples of HCC and adjacent peritumoral tissues and immunohistochemistry in 65 paraffin sections of HCC, which both showed an enhanced expression of nuclear BAG-1 isoform in HCC tissues. Statistical analysis confirmed that overexpression of nuclear BAG-1 in HCC tissues was significantly associated with histological grading (P 0.001), poor prognosis (P = 0.004), and was found to be an independent prognostic indicator for HCC (P = 0.023). We also noted that BAG-1 was overexpressed in four HCC cell lines compared with a normal hepatocyte cell line, and BAG-1 overexpression increased resistance of HCC cells to doxorubicin, a common chemotherapeutic agent for HCC. Furthermore, we observed that knock down of BAG-1 with siRNA in HepG2 cells increased the chemosensitivity of cells, a process mediated through inhibition of doxorubicin-triggered NF-κB activation; and knock down of BAG-1 suppressed proliferation and cell cycle transition of HepG2 cells. In consequence, our results for the first time indicated that BAG-1 was dysregulated in HCC and suppression of BAG-1 expression which resulted in inhibiting of NF-κB signaling might be developed into a new strategy in HCC therapy.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer deaths worldwide. It is important to understand molecular mechanisms of HCC progression and to develop clinically useful biomarkers for the disease.We aimed to investigate the possible involvement of α-tubulin1b (TUBA1B) in HCC pathology.Tissue specimens were obtained from 114 HCC patients during hepatectomy. Immunohistochemistry and western blot analysis were used to detect TUBA1B expression in HCC tissues and cell lines. TUBA1B was knocked down in HCC cells by siRNA transfection. CCK-8 assay and flow cytometry were applied to determine cell proliferation and cell cycle progression, respectively. The efficacy of paclitaxel chemotherapy was evaluated by plate colony formation assay.TUBA1B was higher expressed in HCC tumor tissues than in adjacent nontumor tissues. TUBA1B and Ki-67 expressions were positively related to each other, and both their expressions were significantly associated with histological grade of HCC patients. Univariate and multivariate survival analyses revealed that TUBA1B was a significant predictor for overall survival of HCC patients. TUBA1B expression was increased in HCC cells during the G1- to S-phase transition. TUBA1B knockout in HCC cells inhibited cell proliferation, and attenuated resistance to paclitaxel.Our results indicated that TUBA1B expression was upregulated in HCC tumor tissues and proliferating HCC cells, and an increased TUBA1B expression was associated with poor overall survival and resistance to paclitaxel of HCC patients.

To investigate the potential role of small glutamine-rich TPR-containing protein A (SGTA) in hepatocarcinogenesis, immunohistochemistry and Western blot were performed to detect the expression of SGTA in clinical Hepatocellular carcinoma (HCC) samples, adjacent nontumorous liver tissues and HCC cell lines. In addition, expression of SGTA was correlated with clinicopathological variables and univariate and multivariate survival analyses were performed to determine the prognostic significance. Moreover, the biological significance of the aberrant expression of SGTA was investigated in vitro. Both immunohistochemistry evaluation and Western blot analyses demonstrated that SGTA was overexpressed in HCC tissues compared with adjacent nontumorous liver tissues. Expression of SGTA directly correlated with the histological grades of HCC and high expression of SGTA was associated with a poor prognosis. SGTA depletion by siRNA inhibited cell proliferation, blocked S-phase and mitotic entry in Huh7 cells. Western blot analyses showed that SGTA depletion decreased cyclin A and cyclin B levels. Taken together, owing to overexpression of SGTA in HCC and its important role in predicting poor prognosis and the development of HCC, SGTA could be a potential prognostic marker and therapeutic target of HCC.

Objective: Glyoxylate reductase/hydroxypyruvate reductase (GRHPR) is a key enzyme in the glyoxylate cycle. Its deficiency causes primary hyperoxaluria type 2. We first noticed that GRHPR was also lost in human hepatocellular carcinoma (HCC) and proliferative HCC cells. The aim of the present study was to investigate the potential clinical utility of GRHPR in HCC. Methods: The expression of GRHPR in tissues and cells was detected by Western blotting. Immunohistochemistry was utilized to examine the expression patterns of GRHPR and Ki-67 in a surgical cohort of HCC and adjacent liver tissues. Results: We demonstrated that GRHPR showed a lower expression in tumor tissues than in nontumoral tissues. GRHPR was negatively correlated with Ki-67 (R2 = 0.771, p < 0.05) and GRHPR was reduced in proliferative Huh7 cells (p < 0.05). Patients with negative GRHPR both in tumor tissues and nontumoral tissues had a significantly shorter survival time than those with positive GRHPR (p < 0.001). Multivariate analysis established that GRHPR was detected in nontumoral tissues as an independent prognostic factor for patients with HCC. Conclusions: Our findings suggest that the GRHPR defect in noncancerous tissues may represent an independent predictor of poor survival for HCC patients after curative resection and that there may be a link between GRHPR and prognosis of HCC patients.

Cyclin G1 is a cell-cycle-regulatory protein that is frequently seen in elevated amounts in malignant tissue, including astrocytomas; melanoma; carcinoma of the esophagus, lung, and breast; as well as cancer of the cervix, uterus, and ovary. By contrast, it has demonstrated inhibitory activity in human hepatocellular carcinoma (HCC).We investigated the role of cyclin G1 in HCC tissue obtained from 76 donors using immunohistochemistry and Western blot analysis to explore its relationship with HCC pathology and univariate and multivariate analyses to explore its relationship with surgical prognosis and patient survival.We found that cyclin G1 levels were increased in normal tissue compared with HCC tissue and vary over the course of the cell cycle, with equal distribution between the nucleus and cytoplasm observed during normal serum support and accelerated release from the nucleus into the cytoplasm observed during serum starvation.Our findings suggest a role for cyclin G1 in anti-HCC gene therapy.

C-terminal binding protein-2 (CtBP2), as a transcriptional co-repressor, has been shown to mediate the repression of p16(INK4A) , a tumor suppressor gene product, in primary human cells. Here we aimed to investigate how the correlation between CtBP2 and p16(INK4A) influenced the development of esophageal squamous cell carcinoma (ESCC). Immunohistochemistry of ESCC tissue sections indicated that the CtBP2 and p16(INK4A) expressions were inversely correlated to each other with a linear regression coefficient of -0.747 (P < 0.05), and Western blot analysis revealed that CtBP2 was higher expressed in tumorous tissues than in adjacent non-tumorous tissues. Either CtBP2 or p16(INK4A) expression was significantly related to histological differentiation (P = 0.016 or 0.001) and to the expression of Ki-67, a proliferating marker (P = 0.006 or 0.02), and patients with higher CtBP2 and lower p16(INK4A) expressions had shorter overall survival. We also observed that CtBP2 modulated the cell proliferation and cell cycle in ECA109 cells, an ESCC cell line, by inhibiting p16(INK4A) . Overexpression or knockdown of CtBP2 in ECA109 cells was found to inhibit or activate the mRNA or protein expression of p16(INK4A) , which in turn altered the cell proliferation and cell cycle in ECA109 cells, as measured by flow cytometry and cell count assay. Additionally, after ECA109 cells silenced for CtBP2 were treated with cisplatin (an anti-ESCC agent), the p16(INK4A) expression was up-regulated, and the cell apoptosis was promoted, thus confirming the repression of p16(INK4A) by CtBP2. Collectively, all results suggested that CtBP2 might contribute to the progression of ESCC through a negative transcriptional regulation of p16(INK4A).

Galectin-3, a member of the beta-galactoside-binding protein family, is involved in many biological processes, including cell proliferation, regulating cell cycle, angiogenesis, tumorigenesis, metastasis, etc. The aim of this study is to elucidate the relationship between galectin-3 and clinicopathological variables and to evaluate the clinical significance of serum galectin-3 in the diagnosis of pancreas carcinoma.Galectin-3 expression in 78 pairs of pancreatic carcinoma tissues and the adjacent nontumorous tissues was tested by immunohistochemistry. The relationship between galectin-3 expression and clinical variables was analyzed. A sensitive method of time-resolved fluorescence immunological assay (TRFIA) for the detection of galectin-3 was established, and serum galectin-3 in cases with different pancreatic diseases was measured by TRFIA and ELISA. Further we compared the sensitivity and specificity of determining galectin-3, carcinoembryonic antigen (CEA) and carbohydrate antigen199 (CA199) for diagnosis of pancreatic carcinoma and assessed the complementary diagnostic value of galectin-3, CEA and CA199 for pancreatic carcinoma.Immunohistochemistry showed that galectin-3 expression was significantly higher in the human pancreatic carcinoma tissues than in the adjacent nontumorous tissues. The expression levels were correlated with the differentiation degree with the higher expression in poor differentiation tissues. Serum galectin-3 detected by both TRFIA and ELISA was much higher in patients with pancreatic carcinoma than in other groups. Serum galectin-3 was not correlated with CEA and CA199. Combined determination of these three markers has the complementary diagnostic value for human pancreatic carcinoma and may increase the diagnostic sensitivity to 97.5%.Galectin-3 is overexpressed in pancreatic carcinoma tissues, and it is correlated with the tumor differentiation. Serum galectin-3 is higher in cases with pancreatic carcinoma than in benign pancreatic diseases and healthy persons. Combined determination of serum galectin-3, CEA and CA199 may improve the diagnostic power for pancreatic carcinoma.

Early mitotic inhibitor-1 (Emi1) is a key cell-cycle regulator that promotes S-phase and M-phase entry by inhibiting anaphase-promoting complex/cyclosome (APC/C) activity. Immunohistochemical analysis was performed in 114 human hepatocellular carcinoma (HCC) samples, and the data were correlated with clinicopathologic features. Univariate and multivariate survival analyses were performed to determine the prognostic significance of the proteins. Expression of Emi1 correlated directly with the stage of HCC. More importantly, high expression of Emi1 was associated with a poor outcome. Western blot analysis showed that Emi1 was highly expressed in HCC compared with the adjacent noncancerous tissue. In vitro, after the release of HCC cell lines from serum starvation, the expression of Emi1 APC/C substrates (cyclins A, B) and Skp2 was up-regulated, whereas p27(Kip1) was down-regulated. In addition, we used small interfering RNA to knock out Emi1 expression and observed its effects on HCC growth in vitro to determine whether loss of Emi1 could inhibit cell proliferation by blocking S-phase and mitotic entry. Western blot analyses indicated that deletion of Emi1 was positively correlated with APC/C substrates (cyclins A, B) and Skp2 but was negatively correlated with p27(Kip1). Emi1 inhibits APC/C activity, whereas Skp2 degradation is mediated by APC/C, and degradation of Skp2 can stabilize p27(kip1). These results suggested that Emi1 participates in HCC cell proliferation and that progression is controlled by APC/C inhibition, which stabilized Skp2 and enabled p27(kip1) degradation. These findings provide a potential therapeutic strategy for HCC.

We have shown that a synthetic vitamin K analog, 2-(2-mercaptoethanol)-3-methyl-1,4-naphthoquinone or compound 5 (Cpd 5), potently inhibits cell growth and suggested that the analog exerts its effects mainly via sulfhydryl arylation rather than redox cycling. Since protein-tyrosine phosphatases (PTPases), which have pivotal roles in many cellular functions, have a critical cysteine in their active site, we have proposed PTPases as likely targets for Cpd 5. To test this hypothesis, we examined the effects of Cpd 5 on protein tyrosine phosphorylation of cellular proteins and on the activity of PTPases. We found that Cpd 5 rapidly induced protein tyrosine phosphorylation in a human hepatocellular carcinoma cell line (Hep3B) at growth inhibitory doses, and the effect was blocked by thiols but not by non-thiol antioxidants or tyrosine kinase inhibitors. Cpd 5 inhibited PTPase activity, which was also significantly antagonized by reduced glutathione. Furthermore, the well studied PTPase inhibitor orthovanadate also induced protein tyrosine phosphorylation and growth inhibition in Hep3B cells. These results suggest that inhibition of cellular PTPases by sulfhydryl arylation and subsequent perturbation of protein tyrosine phosphorylation may be involved in the mechanisms of Cpd 5-induced cell growth inhibition.

A new subunit, named RC6-I, of the rat 20 S proteasome was purified and the partial amino acid sequences of several peptide fragments obtained by digestion with lysyl-endopeptidase were determined by Edman degradation. Amplification of cDNAs encoding RC6-I by the polymerase chain reaction (PCR) technique revealed two types of cDNA, tentatively designated as RC6-IL and RC6-IS in order of size. The nucleotide sequences of the two cDNAs are identical except that RC6-IL contains an insertion of 18 nucleotides in the coding region compared with RC6-IS. The polypeptide predicted from the open reading frame of RC6-IS cDNA consists of 248 amino acid residues with a calculated molecular weight of 27,783. These values are consistent with those obtained by protein chemical analyses. Computer-assisted homology analysis showed that RC6-I belongs to the alpha-type subfamily of the proteasome gene family, which shows similarity to the alpha-subunit of the archaebacterium Thermoplasma acidophilum proteasome, and that the 18 nucleotide insert, encoding six amino acid residues, VVASVS, appears to be unique to RC6-IL, because this motif has not been conserved in any other alpha-type subunit. By reverse transcription (RT)-PCR analysis, the mRNAs for both RC6-IL and RC6-IS were found in all the rat tissues examined. These results suggest that proteasomes are present as a heterogeneous population, possibly for acquisition of diversity of functions.

Mature adult rat hepatocytes were cultured as monolayers in serum-free Williams medium E containing 10(-7) M each of insulin (Ins), dexamethasone (Dex) and triiodothyronine (T3) and 30 mM pyruvate. The hepatocytes remained morphologically intact for at least 14 days, during which period they maintained normal liver functions such as the expressions of cytochrome P-450 mRNA and glucokinase and secretion of albumin. They also retained the ability to resume proliferation. Cells cultured with pyruvate had a much higher ATP level than those without pyruvate, suggesting that pyruvate can sustain functional hepatocytes for a long period in culture in the presence of Ins, Dex and T3, probably by producing enough energy for their maintenance.

To study the anti-hepatoma efficiency of arsenic trioxide (As(2)O(3)) in the treatment of experimental rat hepatocellular carcinoma (HCC) induced by 2-acetamidofluorene (2-FAA) and to elucidate the possible mechanisms.SD rats (2 mo old) had been fed with 2-FAA for 8 wk to induce HCC, and then they were treated with As(2)O(3) or matrine. On d 29, the rats were killed and the liver was weighed and liver tumors were counted. The histological changes of liver tissue were observed under microscope, and the cellular dynamic parameters were studied by flow cytometry. Immunohistochemistry (two-step method) was used to observe the expression of vascular endothelial growth factor (VEGF) and micro-vessel density (MVD) on consecutive sections. The pathological parameters were also analyzed, the levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), total bilirubin (TBi), and direct bilirubin (DBi).The number of liver tumors decreased significantly in groups treated with As(2)O(3), especially in medium-dose (1 mg/kg) group (t = 2.80, P0.01). As(2)O(3) caused HCC cell death via apoptosis; necrosis was seen and apoptosis was common when the dose was 1 mg/kg. Proliferation index decreased sharply in medium-dose (1 mg/kg) group (7.87+/-4.11 vs 24.46+/-6.49, t = 2087, P0.01), but not in 0.2 mg/kg group. However, S-phase fraction decreased dramatically in both groups, it reached the bottom level only when the dose was 1 mg/kg compared with control (0.40+/-0.13 vs 3.01+/-0.51, t = 2.97, P0.01), and it was obviously accompanied with accumulation of cells in G(0)/G(1) (G(0)/G(1) restriction). The expressions of VEGF and MVD in medium-dose (1 mg/kg) group were significantly lower than normal saline group (0.63+/-0.74 vs 2.44+/-0.88, P0.05; 15.75+/-3.99 vs 47.44+/-13.41, t = 2.80, P0.01). Compared with normal saline group, medium- and low-dose groups As(2)O(3) and matrine lowered the levels of ALT in serum (61.46+/-9.46, 63.75+/-20.40, 61.18+/-13.00 vs 108.98+/-29.86, t = 2.14, P0.05), but had no effect on the level of serum AST, TBi, and DBi.As(2)O(3) had inhibitory effect on growth of experimental HCC in rats induced by 2-FAA, but had no obvious effect on normal hepatic cells. The mechanisms may involve decrease of cell division, accumulation of cells in G(0)/G(1) phase, apoptosis of tumor cells, and inhibitory effect on angiogenesis through blocking VEGF.