Inhibitory effects of rapamycin on the different stages of hepatic fibrosis.

AIM: To investigate and compare the inhibitory effects of rapamycin in the different stages of liver fibrosis. METHODS: We performed bile duct ligation (BDL) in male Wistar rats (n = 24). The experimental rats were classified into four groups: the BDL(+)/Rapa(-) group (un-treated control, n = 4), the BDL(+)/Rapa(+) group (treated 14 d after BDL, n = 8), the BDL(+)/Rapa(++) group (treated on the day after BDL, n = 8), and the BDL(-)/Rapa(-) group (un-treated, sham -operated control, n = 4). The BDL(+)/Rapa(+) and BDL(+)/Rapa(++) groups were administered rapamycin (2 mg/kg) for 28 d. The liver tissues were tested by immunohistochemical staining for α-smooth muscle actin (α-SMA) and cytokeratin. RESULTS: The liver mRNA levels of transforming growth factor (TGF)-ß1 and platelet-derived growth factor (PDGF) were measured using the polymerase chain reaction. The protein levels of liver p70s6K and p-p70s6k were determined using Western blotting. α-SMA expression was lowest in the BDL(+)/Rapa(++)group. TGF-ß1 and PDGF expression levels in the rapamycin-treated group were lower than those in the un-treated group and higher than those in the control groups (TGF-ß1: 0.23 ± 0.00 vs 0.34 ± 0.01, 0.23 ± 0.0 vs 0.09 ± 0.00, P < 0.0001; PDGF: 0.21 ± 0.00 vs 0.34 ± 0.01, 0.21 ± 0.0 vs 0.09 ± 0.00, P < 0.0001). The p70s6k and p-p70s6k levels decreased in the treated groups and were lowest in the BDL(+)/Rapa(++)group (p70s6k: 1.05 ± 0.17 vs 1.30 ± 0.56, 0.40 ± 0.01 vs 1.30 ± 0.56, P < 0.0001; p-p70s6k: 1.40 ± 0.5 vs 1.67 ± 0.12, 0.70 ± 0.01 vs 1.67 ± 0.12, P < 0.0001). CONCLUSION: The results of our study indicate that rapamycin has inhibitory effects on liver fibrosis, and the treatment is most effective in the early stages of fibrosis.

Epigenetic silencing of BTB and CNC homology 2 and concerted promoter CpG methylation in gastric cancer.

BTB and CNC homology 2 (BACH2) is a lymphoid-specific transcription factor with a prominent role in B-cell development. Genetic polymorphisms within a single locus encoding BACH2 are associated with various autoimmune diseases and allergies. In this study, restriction landmark genomic scanning revealed methylation at a NotI site in a CpG island covering the BACH2 promoter in gastric cancer cell lines and primary gastric tumors. Increased methylation of the BACH2 promoter was observed in 52% (43/83) of primary gastric tumors, and BACH2 hypermethylation was significantly associated with decreased gene expression. Treatment with 5-aza-2'-deoxycytidine and/or trichostatin. A restored BACH2 expression in BACH2-silenced gastric cancer cell lines, and knockdown of BACH2 using short hairpin RNA (i.e. RNA interference) increased cell proliferation in gastric cancer cells. Clinicopathologic data showed that decreased BACH2 expression occurred significantly more frequently in intestinal-type (27/44, 61%) compared with diffuse-type (13/50, 26%) gastric cancers (P<0.001). Furthermore, BACH2 promoter methylation paralleled that of previously identified targets, such as LRRC3B, LIMS2, PRKD1 and POPDC3, in a given set of gastric tumors. We propose that concerted methylation in many promoters plays a role in accelerating gastric tumor formation and that methylated promoter loci may be targets for therapeutic treatment, such as the recently introduced technique of epigenetic editing.

Integrative genomics analysis reveals the multilevel dysregulation and oncogenic characteristics of TEAD4 in gastric cancer.

Tumorigenesis is a consequence of failures of multistep defense mechanisms against deleterious perturbations that occur at the genomic, epigenomic, transcriptomic and proteomic levels. To uncover previously unrecognized genes that undergo multilevel perturbations in gastric cancer (GC), we integrated epigenomic and transcriptomic approaches using two recently developed tools: MENT and GENT. This integrative analysis revealed that nine Hippo pathway-related genes, including components [FAT, JUB, LATS2, TEA domain family member 4 (TEAD4) and Yes-associated protein 1 (YAP1)] and targets (CRIM1, CYR61, CTGF and ITGB2), are concurrently hypomethylated at promoter CpG sites and overexpressed in GC tissues. In particular, TEAD4, a link between Hippo pathway components and targets, was significantly hypomethylated at CpG site cg21637033 (P = 3.8 × 10(-) (20)) and overexpressed (P = 5.2 × 10(-) (10)) in 108 Korean GC tissues compared with the normal counterparts. A reduced level of methylation at the TEAD4 promoter was significantly associated with poor outcomes, including large tumor size, high-grade tumors and low survival rates. Compared with normal tissues, the TEAD4 protein was more frequently found in the nuclei of tumor cells along with YAP1 in 53 GC patients, demonstrating the posttranslational activation of this protein. Moreover, the knockdown of TEAD4 resulted in the reduced growth of GC cells both in vitro and in vivo. Finally, chromatin immunoprecipitation-sequencing and microarray analysis revealed the oncogenic properties of TEAD4 and its novel targets (ADM, ANG, ARID5B, CALD1, EDN2, FSCN1 and OSR2), which are involved in cell proliferation and migration. In conclusion, the multilevel perturbations of TEAD4 at epigenetic, transcriptional and posttranslational levels may contribute to GC development.

Aberrant upregulation of ASCL2 by promoter demethylation promotes the growth and resistance to 5-fluorouracil of gastric cancer cells.

Achaete scute-like 2 (ASCL2), a basic helix-loop-helix transcription factor, plays an essential role in the maintenance of adult intestinal stem cells. However, the function of ASCL2 in gastric cancer (GC) is poorly understood. Therefore, we investigated the roles and regulatory transcription mechanisms of ASCL2 in GC. Gene expression and methylation data analysis showed that ASCL2 was upregulated and hypomethylated in GC tissues. Using real-time RT-PCR and pyrosequencing analysis, we confirmed that ASCL2 was overexpressed and hypomethylated in GC tissues compared to adjacent normal tissues. We then investigated the mechanisms underlying the aberrant expression of ASCL2 in GC and found that treatment with a methylation inhibitor induced ASCL2 expression in GC cell lines. MBD-sequencing assay also revealed hypermethylation of the promoter region of ASCL2 in GC cell lines, which barely expressed the ASCL2 gene. Furthermore, ASCL2 expression levels were inversely correlated with GC patient survival. Ectopic overexpression of ASCL2 showed that ASCL2 increased cell growth and promoted resistance to 5-fluorouracil in GC cells. These results suggest that ASCL2 might play an important role in gastric tumor growth and chemoresistance, and could be a useful prognostic marker for GC patients.

Quantitative analysis of cell-free DNA in the plasma of gastric cancer patients.

In the present study, an accurate and reproducible method for quantifying cell-free DNA (cfDNA) in human blood was established and tested for its ability to predict gastric cancer in patients. Using 'Alu81-qPCR' to amplify 81-bp Alu DNA sequences, we first estimated the amount of cfDNA in the serum or plasma of 130 patients with gastric cancer to identify which source of cfDNA is more suitable for the biomarker screening of these patients. The results of Alu81-qPCR revealed that the amount of cfDNA in the plasma was low compared with that in the serum, but was found at similar levels among the samples, indicating that the plasma may be a more suitable source of cfDNA for biomarker screening. For the 54 patients with gastric cancer and the 59 age-matched healthy controls, the mean levels of plasma cfDNA were 2.4-fold higher in the patient group compared with the control group, indicating that plasma cfDNA levels may be useful for predicting patients with gastric cancer. The results of our study suggest that Alu81-qPCR is a more reliable method than other techniques, such as the PicoGreen assay, for quantifying cfDNA in human blood, demonstrating the potential to complement current diagnostic procedures for the management of gastric cancer patients.

Epigenetic alteration of CCDC67 and its tumor suppressor function in gastric cancer.

In this study, the promoter of the gene coiled-coil domain-containing 67 (CCDC67) was found to be frequently methylated in gastric cancer cell lines and in primary gastric tumors, as examined by restriction landmark genomic scanning. In addition, CCDC67 expression was down-regulated in 72.7% of gastric cancer cell lines tested. In most cases, gene down-regulation was associated with CpG hypermethylation in the CCDC67 promoter. Treatment with 5-aza-2'-deoxycytidine and/or trichostatin A restored CCDC67 expression in down-regulated cell lines. Pyrosequencing analysis of 150 paired primary gastric cancer samples revealed that promoter CpG methylation was increased in 74% of tested tumors compared with paired adjacent normal tissues, and this hypermethylation correlated significantly with down-regulation of CCDC67. CCDC67 protein was localized to the cell membrane by immunocytochemistry. Stable transfection of a CCDC67 gene in one gastric cancer cell line inhibited adhesion-dependent and -independent colony formation, and CCDC67 expression suppressed tumorigenesis in nude mice. We suggest that CCDC67 is a putative tumor suppressor gene that is silenced in gastric cancers by promoter CpG methylation and that it may play an important role in cell signaling and migration related to tumorigenesis.

Pyruvate kinase M2 promotes the growth of gastric cancer cells via regulation of Bcl-xL expression at transcriptional level.

PKM2 is an isoenzyme of the glycolytic enzyme pyruvate kinase that promotes aerobic glycolysis. Here, we describe an important role for PKM2 in regulating the survival of gastric cancer (GC) cells. We showed that PKM2 was overexpressed in gastric tumor tissues compared to normal tissues and its expression level was associated with poor survival of gastric cancer patients. We also showed that PKM2 affected cell survival by regulating Bcl-xL at the transcriptional level. PKM2 knockdown partially affected the stability of NF-kB subunit p65, suggesting that post-translational regulation of p65 by PKM2 is one of plausible mechanisms for the increased cell growth. Therefore, PKM2 may function as an upstream molecule that regulates p65 function and thus enhances the growth of tumor cells.

Elevated fibroblast growth factor-inducible 14 expression promotes gastric cancer growth via nuclear factor-κB and is associated with poor patient outcome.

The fibroblast growth factor-inducible 14 (Fn14) gene encodes a type I transmembrane protein that belongs to the tumor necrosis factor receptor superfamily and regulates multiple cellular processes in diverse physiological and pathological conditions, including cancer. Here, we describe an important role for Fn14 in regulating the growth of gastric cancer cells. Previous gene expression data analysis demonstrated that Fn14 was up-regulated in various tumor tissues, including gastric cancer. Using qRT-PCR, we showed that Fn14 was overexpressed in gastric tumor tissues compared to normal tissues. Furthermore, Fn14 expression levels were inversely correlated with gastric cancer patient survival. Using ectopic overexpression and shRNA-mediated knockdown of Fn14, we demonstrated that the expression level of Fn14 affected cell growth in gastric cancer. The effect of Fn14 on cell growth was mediated by the NF-κB activity and eventually by the transcriptional regulation of the anti-apoptotic Bcl-2 family gene (Bcl-xL). These results suggest that Fn14 may play an important role in gastric tumor growth by regulating NF-κB-mediated anti-apoptosis and that Fn14 may be a useful prognostic marker for gastric cancer.

Identification of potential serum biomarkers for gastric cancer by a novel computational method, multiple normal tissues corrected differential analysis.

BACKGROUND: Genes specifically expressed in one or a few tissues and upregulated in tumors are potentially good serum biomarkers. METHODS: By applying a recently developed computational method, called multiple normal tissues corrected differential analysis (MNTDA), we identified genes that are likely to be upregulated in the blood of gastric cancer patients as compared to normal controls. RESULTS: We identified four genes (MMP-1, MMP-3, MMP-12, and CXCL5) as potential serum biomarkers for gastric cancer. Of these four genes, only MMP-1 was significantly upregulated in the sera of 40 gastric cancer patients, as compared to 40 control sera. The same pattern was observed in the second cohort of 80 gastric cancer patients and 80 controls. In a combined analysis, the level of serum MMP-1 in gastric cancer patients was significantly higher than the level in control samples (P<0.0001). The use of MMP-1 was 62.5% sensitive and 62.5% specific in detecting gastric cancer patients. Patients with high serum levels of MMP-1 had a significantly worse outcome than patients with low serum MMP-1 levels. Finally, we determined that preoperative serum MMP-1 levels were prognostic, independent of tumor stage. CONCLUSIONS: MMP-1 is a potential prognostic marker for gastric cancer patients after gastrectomy.

Epigenetic regulation of microRNA-10b and targeting of oncogenic MAPRE1 in gastric cancer.

MicroRNAs act as negative regulators of gene expression, and the altered expression of microRNAs by epigenetic mechanisms is strongly implicated in carcinogenesis. Here we report that the microRNA-10b gene (miR-10b) was silenced in gastric cancer cells by promoter methylation. In this study, using a methylation array and bisulfate pyrosequencing analysis, we found that miR-10b promoter CpGs were heavily methylated in gastric cancers. Clinicopathologic data showed that miR-10b methylation increased with patient age and occurred significantly more frequently in intestinal-type (28/44, 64%) than in diffuse-type (22/56, 39%) gastric cancers (P = 0.016). In addition, miR-10b methylation was also associated with an increase in expression of the oncogene that encodes microtubule-associated protein, RP/EB family, member 1 (MAPRE1; P = 0.004), which was identified as a potential miR-10b target. After 5-aza-2'-deoxycytidine treatment of gastric cancer cells, miR-10b methylation was significantly decreased, and expression of miR-10b and HOXD4, which is 1 kb downstream of miR-10b, was greatly restored. Moreover, decreased MAPRE1 expression coincided with increased miR-10b expression, suggesting that miR-10b targets MAPRE1 transcription. We also found that transfection with precursor miR-10b into gastric cancer cells dramatically decreased MAPRE1 mRNA and protein, resulting in a significant decrease in colony formation and cell growth rates. Thus, we show a tumor-suppressive role for miR-10b in gastric carcinogenesis. miR-10b methylation may be a useful molecular biomarker for assessing the risk of gastric cancer development, and modulation of miR-10b may represent a therapeutic approach for treating gastric cancer.

Aberrant up-regulation of LAMB3 and LAMC2 by promoter demethylation in gastric cancer.

The LAMB3 and LAMC2 genes encode the laminin-5 ß3 and γ2 chains, respectively, which are parts of laminin-5, one of the major components of the basement membrane zone. Here, we report the frequent up-regulation of LAMB3 and LAMC2 by promoter demethylation in gastric cancer. Gene expression data analysis showed that LAMB3 and LAMC2 were up-regulated in various tumor tissues. Combined analyses of DNA methylation and gene expression of both genes in gastric cancer cell lines and tissues showed that DNA hypomethylation was associated with the up-regulation of both genes. Treatment with a methylation inhibitor induced LAMB3 and LAMC2 expression in gastric cancer cell lines in which both genes were silenced. By chromatin immunoprecipitation assay, we showed the activation histone mark H3K4me3 was associated with the expression of both genes. The expression level of LAMB3 affected multiple malignant phenotypes in gastric cancer cell lines. These results suggest that epigenetic activation of LAMB3 and LAMC2 may play an important role in gastric carcinogenesis.

Retrospective analysis of treatment outcomes after postoperative chemoradiotherapy in advanced gastric cancer.

PURPOSE: To evaluate retrospectively the survival outcome, patterns of failure, and complications in patients treated with postoperative chemoradiotherapy (CRT) in advanced gastric cancer. MATERIALS AND METHODS: Between January 2000 and December 2006, 80 patients with advanced gastric cancer who received postoperative concurrent CRT were included. Pathological staging was IB-II in 9%, IIIA in 38%, IIIB in 33%, and IV in 21%. Radiotherapy consisted of 45 Gy of radiation. Concurrent chemotherapy consisted of a continuous intravenous infusion of 5-fluorouracil and leucovorin on the first 4 days and last 3 days of radiotherapy. RESULTS: The median follow-up period was 48 months (range, 3 to 83 months). The 5-year overall survival, disease-free survival, and locoregional recurrence-free survivals were 62%, 59%, and 80%, respectively. In the multivariate analysis, significant factors for disease-free survival were T stage (hazard ratio [HR], 0.278; p = 0.038), lymph node dissection extent (HR, 0.201; p = 0.002), and maintenance oral chemotherapy (HR, 2.964; p = 0.004). Locoregional recurrence and distant metastasis occurred in 5 (6%) and 18 (23%) patients, respectively. Mixed failure occurred in 10 (16%) patients. Grade 3 leukopenia and thrombocytopenia were observed in 4 (5%) and one (1%) patient, respectively. Grade 3 nausea and vomiting developed in 8 (10%) patients. Intestinal obstruction developed in one (1%). CONCLUSION: The survival outcome of the postoperative CRT in advanced gastric cancer was similar to those reported previously. Our postoperative CRT regimen seems to be a safe and effective method, reducing locoregional failure without severe treatment toxicity in advanced gastric cancer patients.

The single incision laparoscopic intragastric wedge resection of gastric submucosal tumor.

PURPOSE: Laparoscopic wedge resection of gastric submucosal tumor may be difficult in case of the endophytic mass or the mass located unreachable area such as cardia, and intragastric approach can be useful. We would present the experiences of the intragastric wedge resection. MATERIALS AND METHODS: There were 7 patients diagnosed as gastric submucosal tumor and underwent the intragastric wedge resection at Surgery, Chungnam National University Hospital. We reviewed medical record. RESULTS: There were 3 male and 4 female. Mean age was 65 years-old (57~73). Mean body mass index was 26.28 kg/m(2) (21.28~35.30). Location of lesions was 4 cardia, 2 fundus and 1 midbody, respectively. Mean operation time was 83.6 minutes (70~105). All patients were healed without any complication. Mean postoperative hospital stay was 5.4 days (4~6). Mean size was 2.7 cm (2.3~3.8). Pathologic finding was 5 gastrointestinal stromal tumor and 2 leiomyoma. CONCLUSIONS: The single incision intragastric wedge resection of gastric submucosal tumor is feasible and acceptable, especially in mass of gastric upper part.

Enigma negatively regulates p53 through MDM2 and promotes tumor cell survival in mice.

The human E3 ubiquitin ligase murine double minute 2 (MDM2) targets the tumor suppressor p53 for ubiquitination and degradation but also promotes its own ubiquitination and subsequent degradation. As the balance between MDM2 and p53 levels plays a crucial role in regulating cell proliferation and apoptosis, we sought to identify factors selectively inhibiting MDM2 self-ubiquitination. Here we have shown that the LIM domain protein Enigma directly interacts with MDM2 to form a ternary complex with p53 in vitro and in human hepatoma and colon carcinoma cell lines and mouse embryonic fibroblasts. We found that Enigma elicited p53 degradation by inhibiting MDM2 self-ubiquitination and increasing its ubiquitin ligase activity toward p53 in cells. Moreover, mitogenic stimuli such as serum, FGF, and HGF increased Enigma transcription via induction of serum response factor (SRF), leading to MDM2 stabilization and subsequent p53 degradation. We observed similar results in the livers of mice treated with HGF. In humans, we found SRF and Enigma coexpressed with MDM2 but not p53 in several liver and stomach tumors. Finally, we showed that Enigma promoted cell survival and chemoresistance by suppressing p53-mediated apoptosis in both cell lines and a mouse xenograft model. Our findings suggest a role for Enigma in tumorigenesis and uncover a mechanism whereby mitogens attenuate p53 antiproliferative activity through an SRF/Enigma/MDM2 pathway.

Frequent silencing of popeye domain-containing genes, BVES and POPDC3, is associated with promoter hypermethylation in gastric cancer.

The Popeye domain-containing (POPDC) genes BVES, POPDC2 and POPDC3 encode proteins that regulate cell-cell adhesion and cell migration during development. Herein, we report the frequent downregulation of BVES and POPDC3 by promoter hypermethylation in gastric cancer. POPDC expression in 11 gastric cancer cell lines and 96 paired gastric tumor and normal adjacent tissues was analyzed with quantitative reverse transcription-polymerase chain reaction. The methylation status of BVES and POPDC3 was analyzed with methylated DNA immunoprecipitation sequencing, bisulfite sequencing and pyrosequencing. Expression of BVES and POPDC3 was downregulated in 73% of the gastric cancer cell lines and in 69% (BVES) and 87% (POPDC3) of the gastric cancer tissues. The BVES and POPDC3 promoter regions were hypermethylated in the gastric cancer cell lines in which they were silenced. Combined treatment with a DNA methylation inhibitor and a histone deacetylase inhibitor strongly induced BVES and POPDC3 expression. BVES and POPDC3 were hypermethylated in 69% (BVES) and 64% (POPDC3) of the gastric cancer tissues. We knocked down POPDC3 expression with short hairpin RNAs and examined the consequences on cell migration and invasion. Knockdown of POPDC3 in SNU-216 cells caused increased cell migration and invasion. Thus, epigenetic inactivation of BVES and POPDC3 occurs frequently in gastric tumors and may promote gastric cancer cell migration and invasion.

Activation of AMP-activated protein kinase on human gastric cancer cells by apoptosis induced by corosolic acid isolated from Weigela subsessilis.

Corosolic acid is one of the triterpenoids present in the leaves of Weigela subsessilis. The antidiabetic activity of corosolic acid has been reported previously, but to date, the anticancer effects on gastric cancer have been poorly studied. In this study, corosolic acid showed growth inhibition on SNU-601 human gastric cancer cells, with an IC50 value of 16.9 ± 2.9 µM. Corosolic acid also triggered the activation of caspase-3 and poly (ADP-ribose) polymerase, while it was recovered by Z-VAD-FMK. Moreover, the cell growth/apoptosis activities of corosolic acid were regulated by the AMP-activated protein kinase-mammalian target of rapamycin (AMPK-mTOR) signals. These results showed that corosolic acid-mediated AMPK activation leads to inhibition of mTOR, thus providing a possible mechanism of action of corosolic acid in the inhibition of cancer cell growth and the induction of apoptosis.

SERPINE1 intron polymorphisms affecting gene expression are associated with diffuse-type gastric cancer susceptibility.

BACKGROUND: A primary inhibitor of plasminogen activators, SERPINE1 (serpin peptidase inhibitor 1, clade E, member 1, also known as plasminogen activator inhibitor type 1), is an important regulator in tumorigenesis and is highly expressed in many cancers. METHODS: Five tag single nucleotide polymorphisms (SNPs) and 1 insertion polymorphism within SERPINE1 were genotyped in 1101 unrelated Korean individuals (a case group of 612 patients with gastric cancer and a control group of 489 healthy individuals). Associations with susceptibility to diffuse-type gastric cancer (DGC) and intestinal-type gastric cancer were assessed using multivariate logistic regression analyses adjusted for age and sex. Allelic differences in the contribution to gene expression were measured using luciferase assays. RESULTS: SNP c.1162+162C>T (rs2227692) in intron 7 was associated with susceptibility to DGC but not with susceptibility to intestinal-type gastric cancer. The minor allele-carrying genotypes C/T and T/T had 1.6-fold greater odds of DGC than the C/C genotype (P = .00084). This SNP was linked to a repeat-number variation c.1162+604AAAG(11_17), a deletion (del) variation c.1162+664_1162+673del, and another SNP c.1162+859T>A (rs2070683) in intron 7 based on the sequencing of 5 patients and 5 controls. The risk haplotype of the 4 variations exhibited a 30% greater gene expression level than the nonrisk haplotype in luciferase reporter assays (P = .025). In contrast, DGC susceptibility was not associated with the c.-1969_-1968insG polymorphism (rs1799768) in the promoter, commonly known as 4G/5G, in which the minor 5G allele is less active in transcription than the major 4G allele. CONCLUSIONS: An association between SERPINE1 and DGC susceptibility was observed with 4 correlated polymorphisms in intron 7 rather than the 4G/5G polymorphism in the promoter, although all polymorphisms affected gene expression.

Prognostic significance of preoperative blood transfusion in stomach cancer.

PURPOSE: We did a retrospective study to understand the prognostic effects of preoperative blood transfusions in stomach cancer surgery. MATERIALS AND METHODS: Data for 1,360 patients who underwent gastrectomy for stomach cancer between 2001 and 2009 were retrospectively reviewed. We analyzed factors that affect preoperative transfusion and clinicopathologic features. We also analyzed 5-year and overall survival rates of the transfusion and non transfusion subgroups. RESULTS: Sixty patients (4.4%) required blood transfusion within the preoperative period. The transfused group included patients who took aspirin or clopidogrel (P<0.001), with more advanced T stages (P<0.001), with more advanced nodal metastasis (P=0.00), and with more advanced stages (P=0.00) than the non transfusion group. On multivariate analysis, preoperative transfusion was a statistically significant negative influence on 5-year survival and overall survival rates (58.2% vs 79.9% (P=0.00), 58.2% vs 76.8% (P=0.00)). Applying Cox-regression analyses, blood transfusion did appear to have an effect on prognosis and on 5-year and overall survival rates. CONCLUSIONS: We found a direct negative relation between preoperative transfusion and long term prognosis in patients receiving gastric cancer surgery.

Genetic variants A1826H and D2937Y in GAG-beta domain of versican influence susceptibility to intestinal-type gastric cancer.

PURPOSE: Versican regulates adhesion, migration, proliferation, and survival of cells, and plays an important role in cancer development. A case-control association study was performed to test genetic association of versican polymorphisms with susceptibility to gastric cancer. METHODS: In this study, 1,101 unrelated Korean subjects including 612 gastric cancer patients and 489 healthy controls were genotyped for all 21 exonic polymorphisms in the versican gene (VCAN) encoding amino acid changes in versican. Cancer susceptibility associations with the polymorphisms were assessed using multivariate logistic regression analysis with adjustment for age and gender and with control for multiple testing. RESULTS: Two amino acid changes in GAG-beta domain of versican encoded by two almost fully correlated (r (2) = 0.97) nonsynonymous single-nucleotide polymorphisms in VCAN were associated with gastric cancer. The association was evident in intestinal-type but not in diffuse-type gastric cancer. The minor-allele homozygote of rs188703 (G > A, R1826H) or rs160277 (G > T, D2937Y) was significantly associated with a twofold decreased susceptibility to intestinal-type gastric cancer when compared with the other genotypes (adjusted odds ratio = 0.52 or 0.51, P = 0.0098 or 0.0087, respectively). CONCLUSIONS: The intestinal-type gastric cancer susceptibility is associated with two amino acid changes of versican in the GAG-beta domain, which is critical for enhancement of cell proliferation and activation of EGFR signal pathway by versican, and changes from the major to minor alleles may impair the function to decrease susceptibility to cancer.

A regulatory polymorphism at position -309 in PTPRCAP is associated with susceptibility to diffuse-type gastric cancer and gene expression.

PTPRCAP (CD45-AP) is a positive regulator of protein tyrosine phosphatase PTPRC (CD45), which activates Src family kinases implicated in tumorigenesis. Single-nucleotide polymorphism (SNP) rs869736 located at position -309 of the PTPRCAP promoter was associated with susceptibility to diffuse-type gastric cancer in the current case-control study. The minor-allele homozygote was significantly associated with a 2.5-fold increased susceptibility to diffuse-type gastric cancer (P = .0021, n = 252), but not to intestinal-type (P = .30, n = 178), versus the major-allele homozygote, when comparing unrelated Korean patients with healthy controls (n = 406). Nine other SNPs were in nearly perfect linkage disequilibrium (r(2) >or= 0.97) with this SNP, exhibiting the same association, and spread out for 26 kb on chromosome 11q13.1 covering RPS6KB2, PTPRCAP, CORO1B, and GPR152. Among the four genes, however, only PTPRCAP expression was affected by haplotypes of the 10 SNPs. Endogenous transcript levels of PTPRCAP were linearly correlated with copy numbers (0, 1, and 2) of the risk-haplotype (P = .0060) in 12 lymphoblastoid cells derived from blood samples, but those of the other three genes were not. Furthermore, the cancer-risk, minor-allele T of rs869736 increased both promoter activity and specific nuclear protein-binding affinity than the nonrisk, major-allele G in luciferase reporter and electrophoretic mobility shift assays, respectively. Accordingly, the minor allele of rs869736 in the PTPRCAP promoter is associated with increased susceptibility to diffuse-type gastric cancer by increasing PTPRCAP expression, possibly leading to activation of the oncogenic Src family kinases.