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Objective: To explore the effect of heat shock protein 90 (HSP90) inhibitor (17-DMAG) and oxaliplatin on the proliferation and invasion of colorectal cancer., Methods: After 17-DMAG, oxaliplatin and half-dose combination of 2 drugs processing colorectal cancer SW480 and HCT116 cell lines, CCK8 assay was applied to detect cell viability. RT-PCR and Western blot were used to detect the expression level of the apoptosis-related molecules. Transwell chemokine axis experiment and Western blot were employed to detect cell invasion ability and the expression level of tumor metastasis-associated protein., Results: The growth of SW480 and HCT116 cells was inhibited after the administration of 17-DMAG and oxaliplatin(P<0.05) in dose- and time-dependent manner. Processed by 17-DMAG 100 nmol/L, oxaliplatin 50 mg/L and half-dose combination of 2 drugs, transcription level of the apoptosis inhibitory gene (Bcl-2) in SW480 and HCT116 cells was decreased, the level of apoptosis promoting gene (Bax) transcription and protein PARP-1 spliceosome expression was increased, and the above trend was more obvious when using half-dose combination of 2 drugs. Transwell chemokine axis experiments showed the penetrating relative percentage and expression level of MMP9 and integrin β3 decreased, especially for half-dose combination of 2 drugs., Conclusion: 17-DMAG and oxaliplatin can co-inhibit the proliferation and invasion of colorectal cancer.

MicroRNAs are endogenously expressed, small non-coding RNAs that regulate gene expression by targeting mRNAs for translational repression or degradation. Our previous studies indicated that miR-874 played a suppressive role in gastric cancer (GC) development and progression. However, the role of miR-874 in tumor angiogenesis and the mechanisms underlying its function in GC remained to be clarified. Here, gain- and loss-of-function assays demonstrated that miR-874 inhibited the tumor angiogenesis of GC cells in vitro and in vivo. Through reporter gene and western blot assays, STAT3 was shown to be a direct target of miR-874. Overexpression of STAT3 rescued the loss of tumor angiogenesis caused by miR-874. Conversely, the STAT3-shRNA attenuated the increased tumor angiogenesis caused by the miR-874-inhibitor. Furthermore, the levels of miR-874 were inversely correlated with those of STAT3 protein in GC tissues. Taken together, these findings indicate that down-regulation of miR-874 contributes to tumor angiogenesis through STAT3 in GC, highlighting the potential of miR-874 as a target for human GC therapy.

More and more evidence reveals that noncoding RNA miR-34b/c and tumor suppressor gene TP-53 independently, and/or jointly, play crucial roles in carcinogenesis. The purpose of the present hospital-based case-control study was to investigate the association between the miR-34b/c rs4938723 and TP53 Arg72Pro polymorphisms and the risk of gastric cancer. Two polymorphisms were genotyped in 419 gastric cancer patients and 402 age- and sex-matched cancer-free controls using polymerase chain reaction-restriction fragment length polymorphism analysis. The CC genotype and C allele of the miR-34b/c rs4938723 were associated with a significantly decreased risk of gastric cancer compared with the TT genotype and T allele (CC vs. TT: P = 0.006, adjusted odds ratio (OR) = 0.53, 95 % confidence interval (95 % CI) = 0.34-0.83; C vs. T: P = 0.005, adjusted OR = 0.75, 95 % CI = 0.61-0.92). Compared with individuals with the wild-type TT genotype, subjects with the variant genotypes (CT + CC) had a significantly decreased risk of gastric cancer (P = 0.047, adjusted OR = 0.75, 95 % CI = 0.57-0.99). Stratified analysis showed that the association between the risk of gastric cancer and the variant genotypes of miR-34b/c was more profound among men. However, no overall association was found between the TP53 Arg72Pro polymorphism and gastric cancer risk. In the combined analysis, no effects of the interaction of miR-34b/c rs4938723 and TP53Arg72Pro on gastric cancer risk were observed. Our findings indicate that the miR-34b/c rs4938723 CT/CC genotypes may be associated with a decreased risk of gastric cancer and the C allele may be a protective factor in gastric cancer.

Pancreatic cancer is an aggressive malignancy with an extremely poor prognosis. The human ether-a-go-go-related potassium channel (HERG1) is a human rapid delayed rectifier, which is involved in many crucial cellular events. In this article, we find that HERG1 expression is dramatically increased both in pancreatic cancer tissues and cell lines, and that increased HERG1 expression is significantly related to the development of pancreatic cancer. HERG1 silencing in pancreatic cancer-derived cell lines PANC-1 and CFPAC-1 strongly inhibits their malignant capacity in vitro as well as tumorigenicity and metastasis in nude mice. In addition, HERG1 is identified as a direct target of miR-96, which is downregulated in pancreatic cancer tissues and cell lines. Ectopic expression of miR-96 represses the HERG1 expression in pancreatic cancer and significantly inhibits malignant behavior of pancreatic cancer cells in vitro and in vivo. Collectively, our findings suggest that miR-96 acts as a tumor suppressor in pancreatic cancer and may therefore serve as a useful therapeutic target for the development of new anticancer therapy.

Background: Aquaporin-3 (AQP3) is a water transporting protein which plays an oncogenic role in several malignant tumors. However, its regulatory mechanism remains elusive to date. In this study, we investigated the microRNA-mediated gene repression mechanism involved in AQP3's role., Methods: The potential microRNAs targeting AQP3 were searched via bioinformatic methods and identified by luciferase reporter assays, microRNA RT-PCR and western blotting. The expression patterns of miR-874 and AQP3 in human gastric cancer (GC) specimens and cell lines were determined by microRNA RT-PCR and western blotting. 5-ethynyl-2'-deoxyuridine, cell migration and invasion assays and tumorigenicity in vivo were adopted to observe the effects of miR-874 depletion or ectopic miR-874 expression on GC cell phenotypes. Cell apoptosis was evaluated by FACS and TUNEL in vitro and in vivo respectively., Results: miR-874 suppressed AQP3 expression by binding to the 3'UTR of AQP3 mRNA in GC cells. miR-874 was significantly down-regulated and reversely correlated with AQP3 protein levels in clinical samples. Analysis of the clinicopathological significance showed that miR-874 and AQP3 were closely correlated with GC characteristics. Functional analyses indicated that ectopic miR-874 expression suppressed the growth, migration, invasion and tumorigenicity of GC cells, whereas miR-874 knockdown promoted these phenotypes. Down-regulation of Bcl-2, MT1-MMP, MMP-2 and MMP-9 and upregulation of caspase-3 activity and Bax were involved in miR-874 inducing cell apoptosis, and inhibiting migration and invasion., Conclusions: These results provide a mechanism by which AQP3 is upregulated, as well as highlight the importance of miR-874 in gastric cancer development and progression.

The human murine double minute 2 (MDM2) is known as an oncoprotein through inhibiting P53 transcriptional activity and mediating P53 ubiquitination. Therefore, the amplification of MDM2 may attenuate the P53 pathway and promote tumorigenesis. The SNP309 T>G polymorphism (rs2279744), which is located in the intronic promoter of MDM2 gene, was reported to contribute to the increased level of MDM2 protein. In this hospital-based case-control study, which consisted of 573 cases and 588 controls, we evaluated the association between MDM2 SNP309 and the risk of colorectal cancer (CRC) in a Chinese population by using the TaqMan method to genotype the polymorphism. We found that the MDM2 SNP309 polymorphism was significantly associated with CRC risk. In addition, in our meta-analysis, we found a significant association between MDM2 SNP309 and CRC risk among Asians, which was consistent with our results. In conclusion, we demonstrated that the MDM2 SNP309 polymorphism increased the susceptibility of CRC in Asian populations.

MUC4/Y, the transcript variant 4 of MUC4, lacks exon 2 as compared with the transcript variant 1 of MUC4. To date, direct evidence for the function of MU4/Y remains to be reported. Previous studies based their hypotheses regarding the function of MUC4/Y on the characteristic structure domains of this variant. The aim of the present study was to investigate the specific function of MUC4/Y. The pancreatic cancer cell line MIA PaCa-2 with low MUC4/Y expression was used to establish a stable cell model of MUC4/Y upregulation using a lentivirus vector system. Results showed that MUC4/Y anchored on the cytomembrane and affected cell morphology and cell cycle. Functional analyses indicated that MUC4/Y upregulation slightly potentiated cell proliferation and significantly suppressed apoptosis both in vivo and in vitro. Further studies revealed that the JNK and AKT signalling pathways were activated. Meanwhile, MUC4/Y upregulation elicited minimal effect on the phosphorylation level of HER2, a membrane partner of MUC4. These results suggest that MUC4/Y promotes tumour progression through its anti-apoptotic and weak mitogenic effect on MIA PaCa-2 cells.

Centrosomal protein 55 (CEP55) is the latest found member in the centrosomal relative protein family, which participates in cell-cycle regulation. CEP55 exists in many kinds of normal tissues and tumour cells such as hepatocellular carcinoma, and is important in carcinogenesis. However, the role of CEP55 in the pathogenesis of gastric cancer (GC) remains unclear. The mRNA levels of CEP55 in GC tissues and GC cell lines were examined by quantitative real-time PCR, and the protein expression of CEP55 in GC tissues was detected by Western blot and immunohistochemistry. The role of CEP55 in regulating the proliferation of GC cell lines was investigated both in vitro and in vivo. CEP55 was strongly upregulated in human GC, indicating that CEP55 contributed to carcinogenesis and progression of GC. Ectopic overexpression of CEP55 enhanced the cell proliferation, colony formation, and tumourigenicity of GC cells, whereas CEP55 knockdown inhibited these effects. We discovered that cell transformation induced by CEP55 was mediated by the AKT signalling pathway. Overexpression of CEP55 enhanced the phosphorylation of AKT and inhibited the activity of p21 WAF1/Cip1. In addition, cellular proliferation was suppressed as a result of cell cycle arrest at the G2/M phase in CEP55-knockdown cells. CEP55 expression was elevated in GC compared with normal control tissues. Credible evidence showed that CEP55 can be a potential therapeutic target in GC.

The membrane mucin MUC4 is aberrantly expressed in multiple cancers and is of clinical significance to diagnosis and prognosis in pancreatic cancer. However, the role of MUC4 in angiogenesis and the potential association among these malignant capabilities have not been explored. In this study, we investigated the collective signaling mechanisms associated with MUC4-induced growth, metastasis and angiogenesis in pancreatic cancer. Knockdown of MUC4 in two pancreatic cancer cell lines led to downregulation of lysosomal degradation of E-cadherin by Src kinase through downregulation of pFAK and pSrc pathway. The downregulation of lysosomal degradation of E-cadherin in turn induced the formation of E-cadherin/β-catenin complex and membrane translocation of β-catenin, resulting in the downregulation of Wnt/β-catenin signaling pathway. Thus, the Wnt/β-catenin target genes c-Myc, Cyclin D1, CD44 and VEGF were down-regulated and their malignant functions proliferation, metastasis and angiogenesis were reduced. Taken together, MUC4-induced nuclear translocation of β-catenin is a novel mechanism for growth, metastasis and angiogenesis of pancreatic cancer., (Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.)

Intestinal ischemic injury is a significant clinical problem arising from diseases or as a complication of abdominal surgery. Our previous study showed aquaporin 3 is involved in intestinal barrier impairment. Here, we revealed that intestinal ischemia induced a time-dependent increase of miR-874 expression and a time-dependent decrease of AQP3 expression, and the level of miR-874 expression was inversely related to AQP3 protein expression. In addition, miR-874 promoted the paracellular permeability in vitro through targeting 3'UTR of AQP3. Two of the tight junction proteins, Occludin and Claudin-1, were found to be involved in miR-874-induced intestinal barrier dysfunction., (Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Objective: To expand the current knowledge on the feasibility and safety of laparoscopic total gastrectomy (LTG) for gastric cancer in comparison with open total gastrectomy (OTG)., Background: Additional studies comparing laparoscopic versus open total gastric resection have been published, and it is necessary to update the meta-analysis of this subject., Methods: Original articles compared LTG and OTG for gastric cancer, which published in English from January 1990 to July 2013 were searched in PubMed, Embase, and Web of Knowledge by two reviewers independently. Operative time, blood loss, harvested lymph nodes, proximal resection margin, analgesic medication, first flatus day, first oral intake, postoperative hospital stay, postoperative complications, hospital mortality, 5-year overall survival (OS) and disease-free survival (DFS) were compared using STATA version 10.1., Results: 17 studies were selected in this analysis, which included a total of 2313 patients (955 in LTG and 1358 in OTG). LTG showed longer operative time, less blood loss, fewer analgesic uses, earlier passage of flatus, quicker resumption of oral intake, earlier hospital discharge, and reduced postoperative morbidity. The number of harvested lymph nodes, proximal resection margin, hospital mortality, 5-year OS and DFS were similar., Conclusion: LTG had the benefits of less blood loss, less postoperative pain, quicker bowel function recovery, shorter hospital stay and lower postoperative morbidity, at the price of longer operative time. There were no statistical differences in lymph node dissection, resection margin, hospital mortality, and long-term outcomes, which indicated the similar oncological safety with OTG. A positive trend was indicated towards LTG. So LTG can be performed as an alternative to OTG by the experienced surgeons in high-volume centers. Whereas, due to the relative small sample size of long-term outcomes and lack of randomized control trials, more studies are required.

Objective: To investigate the expression of protein phosphatase 2A catalytic subunit (PP2Ac) in pancreatic cancer and the regulation of this gene on JNK/c-Jun/AP-1 pathway and cell growth., Methods: Expression of PP2Ac was determined by real-time PCR. Cell viability was tested by MTT.Expression and phosphorylation levels of proteins were detected by Western blotting. Cell cycle was assayed by flow cytometry. Transcription activity was measured by luciferase reporter gene assay., Results: Suppressed PP2Ac expression was detected in pancreatic cancer tissues. PP2Ac expression in the pancreatic cancer cell lines was also at a low level.Overexpression of the two isoforms of PP2Ac, PP2Acα and PP2Acβ, in pancreatic cancer cells repressed cell growth. Cell viability decreased (33.89 ± 2.05)% (t = 28.607, P < 0.001) and (16.66 ± 2.81)% (t = 10.257, P = 0.001) respectively 72 hours after transfection.Overexpression of PP2Acα and PP2Acβ down-regulated the phosphorylation levels of JNK and c-Jun, and made the transcriptional activity of AP-1 decrease (47.18 ± 2.28)% (t = 11.230, P < 0.001) and (30.89 ± 8.09)% (t = 6.612, P = 0.003) respectively, indicating the down-regulation of PP2Ac up-regulated the activity of JNK/c-Jun/AP-1 pathway. Blocking the JNK pathway using a selective inhibitor, SP600125, induced G2/M cell cycle arrest and repressed cell proliferation. Cell viability decreased (31.38 ± 1.33)% (t = 40.930, P < 0.001) after treatment with JNK inhibitor for 72 hours., Conclusion: Suppressed expression of PP2Ac in pancreatic cancer facilitated cell growth through up-regulating the activity of JNK/c-Jun/AP-1 pathway.

Background: Imatinib has become the standard first line treatment of gastrointestinal stromal tumors (GIST) in the advanced phase and adjuvant setting. We carried out an up-to-date meta-analysis to determine the practical role of mutation analysis for imatinib treatment in patients with advanced GIST., Methods: Eligible studies were limited to imatinib treatment for patients with advanced GIST and reported on mutation analysis. Statistical analyses were conducted to calculate the odds ratio (OR), hazard ratio (HR) and 95% confidence interval (CI) using fixed-effects and random-effects models., Results: A total of 2834 patients from 3 randomized controlled trials and 12 cohort studies were included. The ORs of response rates in KIT exon 11-mutant GISTs were 3.504 (95% CI 2.549-4.816, p<0.001) and 3.521 (95% CI 1.731-7.165, p=0.001) compared with KIT exon 9-mutant and wild type GISTs, respectively. The HRs of progression-free survival in KIT exon 11-mutant GISTs were 0.365 (95% CI 0.301-0.444, p<0.001) and 0.375 (95% CI 0.270-0.519, p<0.001) compared with KIT exon 9-mutant and wild type GISTs. The HRs of overall survival in KIT exon 11-mutant GISTs were 0.388 (95% CI 0.293-0.515, p<0.001) and 0.400 (95% CI 0.297-0.538, p<0.001) compared with KIT exon 9-mutant and wild type GISTs. No statistical significant differences were found between KIT exon 9-mutant and wild type. The overall response rate in KIT-exon 11-mutant GISTs were 70.5% (65%-75.9%) compared with 57.1% (51%-63.2%) in KIT-positive GISTs. No evidence of publication bias was observed., Conclusion: Patients with advanced GIST harboring a KIT exon 11 mutation have the best response rate and long-term survival with imatinib treatment. Mutation analysis would be more helpful than KIT expression analysis to decide appropriate therapy for a specific patient.

Objective: To elucidate the feasibility and safety of laparoscopic total gastrectomy with D2 dissection (LTGD2) for gastric cancer in comparison with open total gastrectomy with D2 dissection (OTGD2)., Background: More surgeons have chosen laparoscopic total gastrectomy as an alternative to open total gastrectomy. But no meta-analysis has been performed to evaluate the value of LTGD2., Methods: Original articles compared LTGD2 and OTGD2 for gastric cancer, which published in English from January 1990 to March 2013 were searched in PubMed, Embase, and Web of Knowledge by two reviewers independently. Operative time, blood loss, harvested lymph nodes, analgesic medication, first flatus day, postoperative hospital stay, postoperative complications, and hospital mortality were compared using STATA version 10.1., Results: 8 studies were selected in this analysis. A total of 1,498 patients were included (559 in LTG and 939 in OTG). LTGD2 showed longer operative time (WMD 39.29; 95 % CI 20.52, 58.06; P < 0.001), less blood loss (WMD -157.94; 95 % CI -245.25 -70.62; P < 0.001), fewer analgesic requirements (WMD -2.01; 95 % CI -3.10, -0.93; P < 0.001), earlier passage of flatus (WMD -0.73; 95 % CI -1.19, -0.27; P = 0.002), earlier hospital discharge (WMD -2.69; 95 % CI -3.42, -1.97; P < 0.001), and reduced postoperative morbidity (RR 0.70; 95 % CI 0.50, 0.98; P = 0.035). The number of harvested lymph nodes (WMD 0.27; 95 % CI -1.43, 1.98; P = 0.752) and hospital mortality rate (RR 0.57; 95 % CI 0.11, 3.09; P = 0.513) were similar., Conclusion: LTGD2 was associated with less blood loss, less postoperative pain, quicker bowel function recovery, shorter hospital stay, and reduced postoperative morbidity, at the expense of longer operative time. No statistical differences were observed in lymph node dissection, and hospital mortality, which indicated the similar ability of lymph nodes clearance and short-term outcomes with OTGD2. A positive trend was indicated toward LTGD2. So we encourage the experienced surgeons to achieve LTGD2 instead of OTGD2. Whereas, due to non-randomized control trails and lack of long-term outcomes, more studies are required.

Pancreatic cancer is a disease with an extremely poor prognosis. The acquisition of invasion properties in pancreatic cancer is accompanied by the process of epithelial-mesenchymal transition (EMT). Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) is emerging as an important determinant of the malignant phenotype in a range of cancers, including pancreatic cancer. Therefore, the aim of this study was to evaluate the potential involvement of CEACAM6 in the invasion and metastasis of pancreatic cancer cells via EMT regulation. The results of our study showed a positive association between CEACAM6 expression and poor prognosis of pancreatic cancer, differentiation and lymph node metastasis. Elevated levels of CEACAM6 in pancreatic cancer cells promoted EMT, migration and invasion in vitro and metastasis in animal models, whereas shRNA-mediated CEACAM6 knockdown had the opposite effect. Furthermore, we demonstrated that miR-29a/b/c specific for CEACAM6 could regulate its expression at the post-transcriptional level. Collectively, our findings identified CEACAM6, which is regulated by miR-29a/b/c, as an important positive regulator of EMT in pancreatic cancer offering an explanation for how elevated levels of CEACAM6 are likely to contribute to the highly metastatic phenotype of pancreatic cancer.

The increase of eukaryotic translation initiation factor 4E (eIF4E) expression is frequently observed in several types of cancer, making eIF4E an attractive anticancer drug target. However, the role of eIF4E in gastric cancer pathogenesis remains unclear. Perifosine is a bioavailable alkylphospholipid exhibiting antitumor activity in a series of cancer types. In this study, gastric cancer cell lines were selected to explore the role of eIF4E as a potential target for treating human gastric cancer. The expression of total eIF4E (T-eIF4E)and phosphorylated eIF4E (p-eIF4E) in gastric cancer samples was detected by immunohistochemical assay. RNA interference was used to silence eIF4E expression. Sulforhodamine B assay was performed to evaluate tumor cell viability. Colony formation assay was used to examine the effects of eIF4E small interfering RNA (siRNA) or perifosine on colony formation. The mRNA levels of eIF4E were analyzed by qRT-PCR and western blot analysis was carried out to evaluate the expression of Akt and eIF4E. The results showed that increased expression levels of T-eIF4E and p-eIF4E were found in gastric cancer tissues and cells. Reduced eIF4E expression blocked the proliferation of gastric cancer cells. Perifosine downregulated the T-eIF4E and p-eIF4E levels in a dose- and time-dependent manner; it also inhibited the growth of gastric cancer cells. Moreover, this inhibitory effect was significantly enhanced by the combination of eIF4E siRNA and perifosine treatments. Our results indicate that eIF4E gene silencing can inhibit tumor cell growth, and eIF4E can be developed as a promising therapeutic target for gastric cancer.

Background: MicroRNAs (miRNAs) play critical roles in tumor development and progression. The finding that a single miRNA can regulate hundreds of genes places miRNAs at critical hubs of signaling pathways. For the current study, the authors investigated the miRNA expression profile of gastric adenocarcinomas and compared it with esophageal adenocarcinomas to better identify a unique miRNA signature of gastric adenocarcinoma., Methods: miRNA expression profiles were obtained using 2 different proprietary microarray platforms on primary gastric adenocarcinoma tissue samples. The cross comparison of results identified 17 up-regulated miRNAs and 12 down-regulated miRNAs that overlapped in both platforms. Quantitative real-time polymerase chain reaction was performed for independent validation of a representative set of 8 miRNAs in gastric and esophageal adenocarcinomas compared with normal gastric mucosa or esophageal mucosa, respectively., Results: The deregulation of miR-146b-5p, miR-375, miR-148a, miR-31, and miR-451 was associated significantly with gastric adenocarcinomas. Conversely, deregulation of miR-21 (up-regulation) and miR-133b (down-regulation) was detectable in both gastric and esophageal adenocarcinomas. It was noteworthy that miR-200a was significantly down-regulated in gastric adenocarcinoma samples (P = .04) but was up-regulated in esophageal adenocarcinoma samples (P = .001). In addition, the expression level of miR-146b-5p displayed a strong correlation with the tumor stage of gastric cancer., Conclusions: Gastric adenocarcinoma displayed a unique miRNA signature that distinguished it from esophageal adenocarcinoma. This specific signature may reflect differences in the etiology and/or molecular signaling in these 2 closely related cancers. The current findings suggest important miRNA candidates that can be investigated for their biological functions and for their possible diagnostic, prognostic, and therapeutic role in gastric adenocarcinoma., (Copyright © 2013 American Cancer Society.)

Background/aims: The aim of this study was to compare the oncological outcome of ultralow anterior resection (ULAR) and abdominoperineal resection (APR) for lower rectal cancer., Methodology: Medical records of 276 patients with lower rectal cancer of whom 140 underwent ULAR and 136 underwent APR were included in a retrospective comparative study. Clinicopathological parameters, overall survival and tumor relapse and prognostic factors were analyzed retrospectively., Results: There was no postoperative mortality in either group. Medical and surgical morbidity, especially pelvic abscess formation were similar in the two groups. The operation time was longer in the APR group (p<0.001). The hospital stay was shorter in the ULAR group (p=0.003). The 5 year overall and disease-free survival rates were 60.5% and 51.1%. There was no difference of overall and disease-free survival (p>0.05), between ULAR and APR surgery at 5 years. Patients who underwent ULAR showed more total recurrence (34.3% vs. 22.1%, p=0.031) and more local recurrence (20.7% vs. 8.8%, p=0.01) but showed no difference in distant recurrence (13.6% vs. 13.2%, p=0.92)., Conclusions: Ultralow anterior resection and abdominoperineal resection have similar long-term outcome in lower rectal cancer. In tumor local relapse, APR is more effective than ULAR, but in distant metastasis, it not better than ULAR.

The aim of this study was to determine the expression of growth hormone receptor (GHR) in patients with primary gastric adenocarcinoma. We investigated 48 specimens of primary gastric adenocarcinoma and their corresponding normal gastric mucosa. Immunohistochemistry and reverse transcription-polymerase chain reaction (RT-PCR) were used to detect the expression of GHR. Immunohistochemical analyses revealed that GHR was expressed in human primary gastric adenocarcinoma (36/48, 75.0%) and appeared to be upregulated, compared to the normal mucosa (28/48, 58.3%, P < 0.001). A significant correlation was found between GHR expression and tumor stage (P < 0.001) and tumor differentiation (P < 0.001). The average positive rate of ki-67 in GHR-positive tumors was 16.06%, while the positive rate in GHR-negative tumors was 6.17% (P < 0.01). The average apoptosis index (AI) of GHR-positive tumors was 3.36%, which was significantly lower than that (7.33%) of GHR-negative tumors. In addition, 27 of 48 cases of tumors had GHR mRNA expression, while only 17 of all 48 cases of normal mucosa did so. Our results indicate that the frequency of GHR was significantly higher in primary gastric adenocarcinoma than that in normal gastric mucosa. GHR expression was significantly correlated with tumor differentiation and tumor grade. This finding supported a possible role of growth hormone in primary gastric adenocarcinoma pathophysiology.

Background: Cytochrome P450 2E1 (CYP2E1), an ethanol-inducible enzyme, has been shown to metabolically activate various carcinogens, which is critical for the development and progression of cancers. It has demonstrated that CYP2E1 polymorphisms alter the transcriptional activity of the gene. However, studies on the association between CYP2E1 polymorphisms (PstI/RsaI or DraI) and gastric cancer have reported conflicting results. Thus, the aim of the present study was to investigate whether CYP2E1 polymorphisms is associated with the development and progression of gastric cancer and its prognosis in Chinese patients., Methods: A case-control study was conducted in which CYP2E1 PstI/RsaI and DraI polymorphisms were analyzed in 510 Chinese patients with gastric cancer and 510 age- and sex- matched healthy controls by PCR-RFLP. Odds ratios were estimated by multivariate logistic regression, and the lifetime was calculated by Kaplan-Meier survival curves. In addition, a meta-analysis was also conducted to verify the findings., Results: For CYP2E1 PstI/RsaI polymorphism, C2C2 homozygotes (OR = 2.15; CI: 1.18-3.94) and C2 carriers (OR = 1.48; CI: 1.13-1.96) were associated with an increased risk of gastric cancer when compared with C1C1 homozygotes. Both C1C2 and C2C2 genotypes were associated with advanced stage, but not the grade of gastric cancer. Moreover, C2C2 genotype was identified as an independent marker of poor overall survival for gastric cancer. However, there was not any significant association between CYP2E1 DraI polymorphism and the risk of gastric cancer. In the meta-analysis, pooled data from 13 studies confirmed that the CYP2E1 PstI/RsaI polymorphism was associated with a significantly increased risk of gastric cancer., Conclusion: CYP2E1 PstI/RsaI polymorphism is associated with increased risk of development, progression and poor prognosis of gastric cancer in Chinese patients. Pooled data from 13 studies, mainly in Asian countries, are in agreement with our findings.

Hepatocellular carcinoma (HCC) is one of the most frequent malignant tumors in the world. The only serological marker widely used for the diagnosis of HCC is alpha-fetoprotein (AFP). Despite that AFP is widely used for the diagnosis of HCC, it has a limit as a serological marker due to its low sensitivity and specificity. The human cervical cancer proto-oncogene 1 (HCCR-1) was previously reported as a new biomarker for HCC. To further evaluate the HCCR-1 as a biomarker for HCC, we conducted the prospective cohort study. We evaluated the significance of simultaneous measurement of 2 tumor markers in the diagnosis of HCC in China, Japan and Korea. Two markers for HCC, AFP and HCCR-1, were measured in the sera obtained from 1,338 patients at the time of initial diagnosis of HCC. Of the 1338 HCC patients, 616 (46%) and 686 (51.3%) were sero-positive for AFP and HCCR-1, respectively. The positive rate for HCC was increased up to 74.1% in combined use of AFP and HCCR-1. Many cases (54%) for AFP-negative HCC were positive for HCCR-1 and vice versa. More importantly, the diagnostic rate for small HCC (< 2 cm) was significantly improved in the combined analysis of AFP and HCCR-1 to 56.9% although it was only 40.1% and 23.4% in the single analysis of HCCR-1 and AFP, respectively. Our result suggests that the HCCR-1 could be an useful biomarker for HCC while the diagnostic rate could be significantly improved in the combined use of HCCR-1 and AFP.

AQP3 is a water/glycerol transporter expressed at the basolateral membrane of colonic epithelial cells. Although AQPs are expressed in the gastrointestinal tract, their effect on intestinal barrier has not been clear. Here, we showed that knockdown of AQP3 caused a dramatic, dose-dependent increase in E. coli C25 translocation, with the reduction of TEER and increasing LY permeability. Western blots revealed that expression of Claudin-1 and Occludin were significantly decreased in the AQP3 knockdown group, demonstrating that this treatment enhances paracellular permeability via an opening of the tight junction complex. These data not only describe the correlation between transcellular and paracellular pathways in human intestines, but also show that targeted knockdown of AQP3 might impair the intestinal barrier integrity., (Copyright © 2011 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.)

Background: matrix metalloproteinases (MMPs) are produced by tumor cells, so they may be associated with tumor progression including invasion, migration, angiogenesis and metastasis. Aquaporin-3 (AQP3) also plays a critical role in gastric cancer cell migration and proliferation., Methods: In this study, AQP3 was silenced or over-expressed in SGC7901 cells., Results: We found a significant decrease in MT1-MMP, MMP-2, and MMP-9 expression after AQP3 knockdown, and a significant increase in MT1-MMP, MMP-2, and MMP-9 expression after AQP3 over-expression in SGC7901 cells. We also found that AQP3 silence led to a significant decrease of phosphorylation of ser473 in AKT in SGC7901 cells., Conclusion: Our findings showed that AQP3 might positively regulate MMPs proteins expression through PI3K/AKT signal pathway in human gastric carcinoma SGC7901 cells.

Objectives: This study aimed to clarify that the activated pancreatic stellate cells (PaSCs) are the origin of the highly expressed galectin-1 in the stroma of pancreatic ductal adenocarcinoma (PDAC) tissue and to evaluate the effect of the secreted galectin-1 on proliferation and invasion ability of pancreatic cancer cell line CFPAC-1 in vitro., Methods: Different kinds of PaSCs were isolated from the normal or cancerous pancreatic tissues and cultured. Immunohistochemistry study, quantitative polymerase chain reaction, and Western blot were carried out to check the cellular origin of galectin-1 in PDAC tissue. By using modified Boyden chambers, in vitro coculture system of PaSCs was established with the pancreatic cancer cell line CFPAC-1 and based on which we assessed the proliferation and invasion ability of CFPAC-1 with or without galectin-1 antagonists., Results: We identified PaSCs as the primary source of the highly expressed galectin-1 in PDAC stroma. Galectin-1 secreted by PaSCs increased CFPAC-1 proliferative rate in the proliferation assay and facilitated CFPAC-1 infiltration in the invasion assay., Conclusions: Under malignant circumstances, PaSCs express and secret galectin-1, which could further promote the proliferation and invasion of cancer cells.

Regular use of aspirin (ASA) could reduce the risk of gastric cancer although the precise mechanism remains unclear. Down-regulation of survivin may be one of the cyclooxygenase-independent mechanisms whereby ASA induces apoptosis of gastric cancer cell. In this study, we investigated the effect of ASA on the growth, apoptosis and survivin expression of gastric cancer cell line SGC7901. The survival of cells treated with 3.0 and 10.0 mmol/L ASA for 24 h was decreased by 44.6% and 88.5%, respectively. ASA at 3.0 mmol/L inhibited the viability of SGC7901 cells in a time-dependent manner. Apoptosis analysis showed similar results with MTT assay. ASA at 3.0 and 10.0 mmol/L decreased the mRNA transcript levels of survivin and reduced survivin protein levels in SGC7901 cells also in a time-dependent manner. Our findings indicated that ASA inhibited the proliferation of SGC7901 by suppressing survivin at both the transcriptional and translational level.

Serine/threonine protein phosphatase 2A (PP2A), is thought to be a cancer suppresser, as inhibition of PP2A can induce phosphorylation and activation of substrate kinases, most of which can accelerate growth. Interestingly, cantharidin potently inhibits PP2A but efficiently represses various cancer cells. In the present study, we found that PP2A inhibitors, cantharidin or Okadaic acid, inhibited cell viability and triggered apoptosis in PANC-1 pancreatic cancer cell line dependent on PP2A/IKKα/IκBα/p65 NF-κB pathway. The activation of NF-κB pathway up-regulated downstream pro-apoptotic genes, TNF-α, TRAILR1 and TRAILR2, and triggered apoptosis through the extrinsic pathway, indicating that PP2A is a potential target for pancreatic cancer treatment., (Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.)

Serum alpha fetoprotein (AFP) is the most widely used tumor marker in detecting patients with hepatocellular carcinoma (HCC). However, it has been indicated that HCCR-1 (human cervical cancer oncogene 1) might be supplementary to AFP in the detection. We conducted a prospective study in 120 normal and 524 liver disease patients to evaluate the significance of simultaneous measurement of 2 tumor markers (AFP and HCCR-1) in the diagnosis of HCC through the cohort study in Korea and China. We also performed immunohistochemical studies using 25 normal subjects (N), 32 liver cirrhosis (LC) and 116 HCC tissues. The sensitivities of AFP (20 ng/mL) and HCCR-1 (10 ng/mL) in HCC were 55.8% (164/294) and 44.2% (130/294), respectively. When AFP was combined with HCCR-1, sensitivities increased to 4.2% (N), 12.7% (chronic hepatitis; CH), 50.0% (LC), and 77.2% (HCC), respectively. Although there was no significant difference in the diagnostic rate for HCC between AFP and HCCR-1, many cases for AFP-negative HCC were positive for HCCR-1 and vice versa. Moreover, the combined use of AFP and HCCR-1 improved the diagnostic rate to 70.8% in small HCC (< 2 cm) and 81.6% in large HCC (⩾ 2 cm), respectively. AFP and HCCR-1 are independent markers. Our result suggests that the HCCR-1 could be an useful biomarker for HCC while the diagnostic rate could be significantly improved in the combined use of HCCR-1 and AFP.

The intraorgan renin-angiotensin system (RAS) plays an important role in the pathophysiology of a variety of diseases and has been implicated in fibrogenesis. The role of RAS in the development of chronic pancreatitis is not well established. The blockade of RAS in rat models with angiotensin-converting enzyme inhibitors (ACEi) or angiotensin receptor 1 (AT1) blockers (ARBs) mostly have reduced pancreatic inflammation and fibrosis with a few exceptions. At the same time, the use of ACEi and ARBs in humans is associated with a modest risk of acute pancreatitis. The aim of this study was to elucidate the effect of the AT1 signaling pathway in the development of pancreatitis using AT1a- and AT1b-deficient mice as well as the ARB losartan. Chronic pancreatitis was induced by repetitive cerulein administration in C57BL/6J wild-type (WT) and AT1a- and AT1b-deficient mice (AT1a-/- and AT1b-/-), and pancreatic injury was assessed at day 10. Pancreatic weight of cerulein treated groups was significantly reduced. There was severe parenchymal atrophy and fibrosis assessed by histological examination. Fibrosis was accompanied by activation of pancreatic stellate cells (PSC) evaluated by Western blot analysis for alpha-smooth muscle actin. No differences were seen between cerulein-treated WT, AT1a-/- , AT1b-/- mice, or losartan treated-WT mice with regards to morphological or molecular alterations induced by cerulein. Our results demonstrate that AT1a and AT1b receptor pathways do not seem to be essential for the development of pancreatitis in the mouse model of pancreatitis induced by repetitive cerulein injury.

The human mucin gene MUC4 is overexpressed in pancreatic cancer and cancer cell lines, while remaining undetectable in the normal pancreas, indicating its important role in pancreatic cancer pathogenesis. The molecular mechanisms involved in the regulation of MUC4 gene expression are not fully understood. In this report, we used pancreatic cancer cell line (Bxpc-3) to explore the potential transcription factors regulating MUC4 transcriptional activity. Through promoter screening, overexpressing methods and luciferase reporter studies, we found that transcription factors CREB, Ets-1, Elk-1 and STAT1 can positively regulate MUC4 expression at the promoter and mRNA level. Our findings will be helpful for better understanding the transcriptional regulation of MUC4 in pancreatic cancer cells and identifying key biologically relevant factors that may account for its aberrant expression in pancreatic cancer.

Cantharidin is an active constituent of mylabris, a traditional Chinese medicine. It is a potent and selective inhibitor of protein phosphatase 2A (PP2A) that plays an important role in control of cell cycle, apoptosis, and cell-fate determination. Owing to its antitumor activity, cantharidin has been frequently used in clinical practice. In the present study, we investigated the therapeutic potential of cantharidin in pancreatic cancer. Cantharidin efficiently inhibited the growth of pancreatic cancer cells, but presented a much lighter toxicity effect against normal pancreatic duct cells. It caused G2/M cell-cycle arrest that was accompanied by the down-regulation of cyclin-dependent kinase 1 (CDK1) and up-regulation of p21 expression. It induced apoptosis and elevated the expressions of pro-apoptotic factors tumor necrosis factor-alpha (TNF-alpha), TNF-related apoptosis inducing receptor 1 (TRAILR1), TRAILR2, Bad, Bak, and Bid, and decreased the expression of anti-apoptotic Bcl-2. Activation of caspase-8 and caspase-9 suggested that both extrinsic and intrinsic pathways are involved in the induction of apoptosis. Interestingly, unlike previous studies on other cancer cells, we found that the inhibitory role of cantharidin is independent of oxidative stress in pancreatic cancer cells. Mitogen-activated protein kinases (MAPKs), including ERK, JNK, and p38, were activated after treatment with cantharidin. Inhibition of JNK, but not ERK or p38, alleviated the cytotoxity effect of cantharidin, suggesting cantharidin exerted its anticancer effect through the JNK-dependent way. Hence, in addition to being an attractive candidate compound with therapeutic potential, cantharidin also highlighted the possibility of using PP2A as a therapeutic target for pancreatic cancer treatment.

Background: Human cervical cancer oncoprotein 1 (HCCR-1), reported as a negative regulator of p53, is over-expressed in a variety of human cancers. However, it is yet unknown whether HCCR-1 plays any role in pancreatic cancer development. The aim of this study was to investigate the effect of epidermal growth factor on the expression of HCCR in pancreatic cancer cells, and to explore if PI3K/Akt/mTOR signaling pathway mediated this expression., Methods: A polyclonal antibody against HCCR protein was raised by immunizing Balb/c mice with the purified recombinant protein pMBPc-HCCR. Tissue samples were constructed on a tissue chip, and the expression of HCCR was investigated by immunohistochemistry assay and Western blotting. Pancreatic cell line, PANC-1 cells were stably transfected with plasmids containing sense-HCCR-1 fragment and HCCR siRNA fragment. MTT and transwell assay were used to investigate the proliferation and invasion of stable tansfectants. The specific inhibitor of PI3K and mTOR was used to see if PI3K/mTOR signal transduction was involved in the induction of HCCR gene expression. A Luciferase assay was used to see if Akt can enhance the HCCR promoter activity., Results: HCCR was up-regulated in pancreatic tumor tissues (mean Allred score 4.51+/-1.549 vs. 2.87+/-2.193, P<0.01), especially with high expression in poorly differentiated pancreatic cancer. The growth of cells decreased in HCCR-1 siRNA transfected cells compared with vector transfectants. The number of invasion cells was significantly lower in HCCR-1 siRNA transfected cells (24.4+/-9.9) than that in vector transfectants (49.1+/-15.4). Treatment of PANC-1 cells with epidermal growth factor increased HCCR protein level in a dose- and time-dependent manner. However, application of LY294002 and rapamycin caused a dramatic reduction of epidermal growth factor-induced HCCR expression. Over-expression of exogenous constitutively active Akt increased the HCCR promoter activity; in contrast, dominant negative Akt decreased the promoter activity., Conclusions: EGF-induced HCCR-1 over-expression is mediated by PI3K/AKT/mTOR signaling which plays a pivotal role in pancreatic tumor progression, suggesting that HCCR-1 could be a potential target for cancer therapeutics.

The renin-angiotensin system contributes to pathological processes in a variety of organs. In the pancreas, blocking the angiotensin II (AII) type 1 receptor (AT1) attenuates pancreatic fibrogenesis in animal models of pancreatitis. Because the role of the AII type 2 receptor (AT2) in modulating pancreatic injury is unknown we investigated the role of AT2 in pancreatic injury and fibrosis. Pancreatic fibrosis was induced by repetitive cerulein administration in C57BL/6 wild-type (WT) or AT2-deficient (AT2-/-) mice and assessed by morphology and gene expression at 10 days. There was no difference between WT and AT2-/- mice in the degree of acute pancreatic injury as assessed by amylase release at 9 and 12 h and by histological examination of the pancreas at 12 h. In contrast, parenchymal atrophy and fibrosis were more pronounced in AT2-/- mice compared with WT mice at 10 days. Fibrosis was accompanied by activation of pancreatic stellate cells (PSC) evaluated by Western blot analysis for alpha-smooth muscle actin and by immunocytochemistry; PSC activation was further increased in AT2-/- mice compared with WT mice. The level of pancreatic transforming growth factor-beta1 mRNA and protein after repetitive cerulein treatment was higher in AT2-/- mice than in WT mice. Our results demonstrate that, in contrast to AT1 receptor signaling, AT2 receptor signaling modulates protective antifibrogenic effects in a mouse model of cerulein-induced pancreatic fibrogenesis. We propose that the effects of AII on injury-induced pancreatic fibrosis may be determined by the balance between AT1 and AT2 receptor signaling.

Recent research has indicated that MUC4 plays an important role in the development of many tumors and may prove useful as a novel cancer immunotherapy target. We aimed to identify HLA-A*0201-restrictive cytotoxic T lymphocyte (CTL) epitopes of the cancer-associated antigen MUC4. The MUC4 sequence was scanned for immunogenic peptides using HLA-binding prediction software. Dendritic cells (DCs) from peripheral blood mononuclear cells (PBMCs) were induced by cytokines. Five possible CTL epitopes were selected by software analysis, synthesized, and used to pulse mature DCs. The CD8(+) T cells from PBMCs from an HLA-A*0201 healthy donor were stimulated with autologous MUC4-peptide-loaded DCs and expanded in vitro. T cell activation was assessed by ELISPOT, and cytotoxicity was determined by (51)chromium ((51)Cr)-release assays. Our results show that CTLs induced by peptide P01204 could lyse T2 cells pulsed with peptide P01204 and HCT-116 cells (MUC4(+), HLA-A2(+)). Compared with a control peptide, P01204 increased the number of IFN-gamma producing T cells. Overall, these results suggest that P01204 is a novel HLA-A*0201-restrictive CTL epitope of the cancer-associated antigen MUC4. This will provide a foundation for the development of tumor-specific peptide vaccines.

Objective: CYP2C19 polymorphisms have been inconsistently reported to associate with the efficacy of proton pump inhibitor (PPI)-based triple therapies for eradicating Helicobacter pylori infection. The aim of this meta-analysis was to determine whether CYP2C19 polymorphism affect H. pylori eradication rates obtained with first-line PPI-based triple therapies., Methods: A systematic literature search was conducted up to July 2007 using Medline, PubMed, EMBase, Cochrane Central Register of Controlled Trials (CENTRAL), ISI Web of Science, CNKI (Chinese), and Wanfang (Chinese) digital database. MeSH terms and keywords included proton pump inhibitor, omeprazole, lansoprazole, rabeprazole, pantoprazole, or esomeprazole, cytochrome P4502C19 or CYP2C19, and Helicobacter pylori or H. pylori. Twenty articles met the inclusion criteria, and were included in the meta-analysis by using Review Manager 4.2.8., Results: Eradication rates were significantly different between poor metabolizers (PM) and heterozygous extensive metabolizers (HetEM) (odds ratio (OR) = 1.73, p = .002) and between PM and homozygous extensive metabolizers (HomEM) (OR = 2.79, p < .0001). Moreover, eradication rates were also significant difference between HetEM and HomEM (OR = 2.00, p < .0001). Triple omeprazole and lansoprazole therapies achieved higher H. pylori eradication rates in PM than in HomEM (OR = 4.28, p = .0005 for omeprazole and OR = 3.06, p = .001 for lansoprazole), and higher in HetEM than those in HomEM (OR = 3.22, p < .0001 for omeprazole and OR = 1.95, p = .040 for lansoprazole). Rabeprazole therapies had no significant effect on H. pylori eradication rates (between PM and HomEM, OR = 1.35, p = .610 and between HetEM and HomEM, OR = 1.57, p = .190). No significant difference in H. pylori eradication rates between PM and HetEM was observed in the three individual PPI therapies., Conclusion: The efficacy of omeprazole- and lansoprazole-based first-line triple therapies at the standard doses is dependent on CYP2C19 genotype status, which appears not to affect the efficacy of the regimens including rabeprazole.

Viral breakthrough is a recognized response pattern to interferon-based antiviral therapy in patients with chronic hepatitis C virus (HCV) infection. The emergence of drug-resistant HCV quasispecies variants is assumed to be a major mechanism responsible for viral breakthrough. By using a long reverse transcription-PCR protocol recently developed in our lab, multiple nearly full-length HCV quasispecies variants were generated from 9.1-kb amplicons at both the baseline and breakthrough points in two patients experiencing viral breakthrough. Comparative analyses of consensus dominant quasispecies variants revealed that most mutations, occurring at the time of breakthrough, involved three functional viral genes, E2, NS2, and NS5a. Interestingly, similar mutation patterns were also observed in minor quasispecies variants at baseline. These three genes had the highest values of average amino acid complexity at the HCV 1a population level. No single amino acids were identified to be associated with viral breakthrough. Taken together, at the near-full-length HCV genome level, our data suggested that viral breakthrough might be attributed to the selection of minor quasispecies variants at the baseline with or without additional mutations during antiviral therapy. Furthermore, the pattern for mutation clustering indicated potential mutation linkage among E2, NS2, and NS5a due to structural or functional relatedness in HCV replication.