Ming-Chu Chang

Tumor Necrosis Factor–α and Interleukin-10 Promoter Polymorphisms in Epstein-Barr Virus–Associated Gastric Carcinoma

To investigate whether genetic differences in cytokine promoter polymorphisms effect various outcomes after exposure to Epstein-Barr virus (EBV) infection, 30 patients with EBV-positive gastric carcinoma (GC), 120 patients with EBV-negative GC, and 220 control subjects were enrolled. Promoter polymorphisms of tumor necrosis factor (TNF)-alpha at positions -238 and -308 and of interleukin (IL)-10 at position -1082 were determined. The frequency of the high-producer allele (-308A) in the TNF-alpha gene was significantly higher among EBV-positive GC patients compared with control subjects (23.3% vs. 12.0%, P<.05), whereas the frequency of the high-producer allele (-1082G) in the IL-10 gene was significantly higher among EBV-negative GC patients compared with control subjects (6.3% vs. 3.0%, P<.05). These data support the notion that genetic factors may modify the outcomes of infectious diseases through different TNF-alpha- or IL-10-producing capabilities.

Distinct clinicopathologic and genetic profiles in sporadic gastric cancer with different mutator phenotypes.

A subset of sporadic gastric cancers (GC) exhibits microsatellite instability (MSI). To define the precise role of MSI in GC, a total of 100 patients with sporadic GC were classified into three groups, i.e., high‐frequency MSI (MSI‐H), low‐frequency MSI (MSI‐L), and microsatellite stable (MSS), based on 10 microsatellite markers. Mutational analyses of TGFβRII, IGFIIR, BAX, MSH3, MSH6, E2F4, MSH2, MLH1, and TP53 genes, and methylation and protein expression of MLH1 and MSH2 were performed and correlated. Twenty‐seven percent of GC showed MSI at least in one locus and could be further graded as MSI‐H (14%) and MSI‐L (13%). No clinicopathologic difference was noted between GC with MSI‐L and MSS. Compared with GC with MSI‐L or MSS, GC with MSI‐H had a significantly higher frequency of antral location, intestinal subtype, H. pylori seropositivity, but a lower incidence of lymph node metastasis, and displayed a higher frequency of frameshift mutations of TGFβRII, IGFIIR, BAX, MSH3, and E2F4 genes but a lower incidence of TP53 mutations. Furthermore, hypermethylation of the MLH1 promoter was responsible for the loss of protein function in 13 of 14 MSI‐H tumors. It was concluded that a specific phenotype and a distinct profile of genetic alterations exist in MSI‐H GC. We speculate that epigenetic inactivation of MLH1 by methylation plays a crucial role in initiating such a pathway of carcinogenesis. In contrast, GCs with MSS and MSI‐L exhibit clinicopathologic features that are distinct from MSI‐H tumors and have a higher frequency of TP53 mutations, suggesting that they may evolve through an entirely different pathway. Genes Chromosomes Cancer 27:403–411, 2000.

High mesothelin correlates with chemoresistance and poor survival in epithelial ovarian carcinoma

The objective of this paper is to investigate the mesothelin expression level to the clinicopathological features, chemoresponse, and to the outcome of patients with epithelial ovarian carcinoma (EOC). Mesothelin mRNA was detected by real-time quantitative reverse-transcription PCR in 139 EOC patients. Clinical characteristics, histopathological items, responses to chemotherapy, progression-free survival (PFS), and overall survival (OS) were recorded. Tumours with advanced stages had higher mesothelin than those with early stages. The chemoresistant patients showed significantly higher mesothelin than did chemosensitive patients (2.81 vs 0.43, P<0.001), irrespective of optimal or suboptimal surgery in those with advanced stages. Highly expressed levels of mesothelin were an independent but poor prognostic factor in the PFS (2.03 (1.23–3.37) P=0.006) and OS (3.72 (1.64–8.45), P=0.002) of the 139 EOC patients in multivariate analysis. In addition, patients in advanced stages with highly expressed mesothelin also had significantly worse OS, regardless of whether they had undergone optimal (13.85 (1.76–125.60), P=0.013) or suboptimal (4.47 (1.83–10.88), P=0.001) debulking surgery in multivariate analysis. Out results provide new evidence that mesothelin expression is associated with chemoresistance and with shorter disease-free survival and worse OS of patients with EOC.

Correlation of histologic subtypes and replication error phenotype with comparative genomic hybridization in gastric cancer

To characterize phenotypic and genotypic changes in gastric cancer (GC), DNA copy number aberrations (CNAs) were assessed in 53 tumors using comparative genomic hybridization (CGH) and correlated with clinicopathologic characteristics and status of TP53 and replication error (RER). The number of CNAs per tumor was 6.8 (gain 5.3, loss 1.5), and the number of changes was significantly higher in tumors with advanced stage, TP53 mutation, and without RER than in those with early stage (7.7 vs. 3.0), no TP53 mutations (12.4 vs. 4.8) or RER phenotype (8.2 vs. 2.6). Frequent abnormalities included gains on chromosomal arms 8q (43%), 6q (26%), 11q (26%), 13q (24%), 7p (23%), 17q (23%), and 20q (23%), and losses on chromosomal arms 16q (26%), 19p (23%), 5q (19%), 3p (15%), 4q(15%), and 1p (15%). Advanced GC demonstrated a higher prevalence of gains of 8q (51% vs. 10%, P < 0.05) and loss of 16q (33% vs. 0%, P < 0.05) than early GC. Gains on 8q (64% vs. 20%, P < 0.05), 17q (39% vs. 4%, P < 0.05) and losses on 3p (25% vs. 4%, P = 0.05) and 5q (32% vs. 4%, P < 0.05) were higher in intestinal GC than in diffuse GC. On the other hand, gains on 13q were more common in the diffuse type (40% vs. 11%, P < 0.05). As compared with noncardia cancer, cardia cancer showed more gains on 7p (58% vs. 12%, P < 0.05) and 20q (58% vs. 12%, P < 0.05) and more losses on 4q (50% vs. 5%, P < 0.05). The finding of histology‐related aberrations and the combination of CGH and molecular data thus provide additional evidence suggesting genetic heterogeneity of GC.

Adiponectin as a potential differential marker to distinguish pancreatic cancer and chronic pancreatitis.

Serum adiponectin (ADP) levels are reported inversely related to the risk in breast, endometrial cancer, and gastric cancer. Serum ADP as a potential marker compared with CA-19-9 in pancreatic carcinoma (PC) and chronic pancreatitis (CP) was studied. Adiponectin and CA-19-9 levels were examined at the time of diagnosis in patients with CP and PC. Methods: Serum ADP and CA-19-9 levels were measured by immunoassays in 72 patients with PC and 39 with CP and 290 control subjects. Results: The median levels of ADP for PC were significantly higher than those for CP and control subjects (P = 0.0035). Increasing the upper reference value of ADP allowed for better discrimination between CP and PC. The introduction of 28 ng/mL as a cutoff for ADP significantly improved its specificity. At an elevated cutoff level for ADP (28 ng/mL), a better discrimination between PC and CP was obtained. Conclusions: Adiponectin might be useful in the differential diagnosis of PC and CP with elevated CA-19-9. This gives rise to the possibility that ADP has a potential role in differentiating CP and PC.

Mesothelin enhances invasion of ovarian cancer by inducing MMP-7 through MAPK/ERK and JNK pathways.

Ovarian cancer has one of the highest mortalities in malignancies in women, but little is known of its tumour progression properties and there is still no effective molecule that can monitor its growth or therapeutic responses. MSLN (mesothelin), a secreted protein that is overexpressed in ovarian cancer tissues with a poor clinical outcome, has been previously identified to activate PI3K (phosphoinositide 3-kinase)/Akt signalling and inhibit paclitaxel-induced apoptosis. The present study investigates the correlation between MSLN and MMP (matrix metalloproteinase)-7 in the progression of ovarian cancer, and the mechanism of MSLN in enhancing ovarian cancer invasion. The expression of MSLN correlated well with MMP-7 expression in human ovarian cancer tissues. Overexpressing MSLN or ovarian cancer cells treated with MSLN showed enhanced migration and invasion of cancer cells through the induction of MMP-7. MSLN regulated the expression of MMP-7 through the ERK (extracellular-signal-regulated kinase) 1/2, Akt and JNK (c-Jun N-terminal kinase) pathways. The expression of MMP-7 and the migrating ability of MSLN-treated ovarian cancer cells were suppressed by ERK1/2- or JNK-specific inhibitors, or a decoy AP-1 (activator protein 1) oligonucleotide in in vitro experiments, whereas in vivo animal experiments also demonstrated that mice treated with MAPK (mitogen-activated protein kinase)/ERK- or JNK-specific inhibitors could decrease intratumour MMP-7 expression, delay tumour growth and extend the survival of the mice. In conclusion, MSLN enhances ovarian cancer invasion by MMP-7 expression through the MAPK/ERK and JNK signal transduction pathways. Blocking the MSLN-related pathway could be a potential strategy for inhibiting the growth of ovarian cancer.

Serum vascular endothelial growth factor/soluble vascular endothelial growth factor receptor 1 ratio is an independent prognostic marker in pancreatic cancer.

Objectives: Tumor angiogenesis is the consequence of an imbalance between positive and negative angiogenic regulatory factors. We sought to determine the role of pretreated serum angiogenic factors, including vascular endothelial growth factor (VEGF), placental growth factor (PlGF), and soluble vascular endothelial growth factor receptor 1 (sVEGFR-1), in predicting clinical outcome in patients with pancreatic cancer. Methods: We assessed pretreated serum VEGF, PlGF, and sVEGFR-1 levels in 92 patients with pancreatic adenocarcinoma and 60 healthy control subjects using an enzyme-linked immunosorbent assay. The correlation between these angiogenesis-related factors and clinicopathologic factors, including staging and overall survival, was analyzed. Results: Serum levels of VEGF, PlGF, and sVEGFR-1 were significantly higher in patients with pancreatic cancer compared with those in controls (583.8 ± 559.5 vs 187.63 ± 393.32, 17.65 ± 7.34 vs 10.93 ± 1.21, and 50.94 ± 51.17 vs 15.55 ± 1.98 pg/mL, respectively; P < 0.0001). A reverse correlation was observed between sVEGFR-1 level and the advance of tumor stage. Cox regression analysis showed that the VEGF/sVEGFR-1 ratio was an independent predictor for pancreatic cancer survival. Higher VEGF/sVEGFR-1 ratio was significantly correlated with poor outcome in patents with pancreatic cancer. Conclusions: Vascular endothelial growth factor/sVEGF-1 ratio is an independent prognostic factor for survival in pancreatic cancer. Its significance should be assessed when considering antiangiogenic therapy in treating pancreatic cancer patients.

Hypoxia-induced apoptosis in endothelial cells and embryonic stem cells

Background: To evaluate the influence of hypoxia and molecular events in endothelial and embryonic stem cells.Materials and Methods: Human umbilical vein endothelial cells (HUVECs) and mouse embryoid body (EB) cells were subjected to hypoxic conditions for different time courses. DNA fragmentation assay, quantification of apoptotic cells by TUNEL assay measured by flowcytometry, and Western blot analysis for the molecular events of apoptosis were performed.Results: DNA fragmentation could be identified under hypoxic conditions in HUVECs and mouse EBs. The DNA fragmentation increased when the hypoxic interval was extended.In situ internucleosomal DNA fragmentation-TUNEL assay also found that the percentages of apoptotic cells increased gradually in HUVECs and mouse EBs when the hypoxic interval was extended. Furthermore, the levels of expression of p53 and Bax both increased in hypoxic conditions.Conclusions: Hypoxia increases both HUVEC and mouse EB apoptosis, which is associated with increase in p53/Bax expression.

Sindbis virus replicon particles encoding calreticulin linked to a tumor antigen generate long-term tumor-specific immunity

Alphavirus vectors have emerged as a promising strategy for the development of cancer vaccines and gene therapy applications. In this study, we used the replication-defective vaccine vector SIN replicon particles from a new packaging cell line (PCL) to develop SIN replicon particles encoding calreticulin (CRT) linked to a model tumor antigen, human papillomavirus type 16 (HPV16) E7 protein. The linkage of CRT to E7 in SIN replicon particles resulted in a significant increase in E7-specific CD8+ T-cell precursors and a strong antitumor effect against E7-expressing tumors in vaccinated mice. SINrep5-CRT/E7 replicon particles enhanced presentation of E7 through the major histocompatibility complex (MHC) class I pathway by infecting dendritic cells (DCs) directly and pulsing DCs with lysates of cells infected by SINrep5-CRT/E7 replicons. Vaccination of immunocompromised (BALB/c nu/nu) mice with SINrep5-CRT/E7 replicon particles also generated significant reduction of lung tumor nodules, suggesting that antiangiogenesis may contribute to the antitumor effect of SINrep5-CRT/E7 replicon particles. Furthermore, SINrep5-CRT/E7 replicon particles generated long-term in vivo tumor protection effects and antigen-specific memory immunities. We concluded that the CRT strategy used in the context of SIN replicon particles facilitated the generation of a highly effective vaccine for cancer prophylaxis and immunotherapy.

Association of HLA-DQB1*0301 and HLA-DQB1*0602 with different subtypes of gastric cancer in Taiwan.

Gastric cancer (GC) is a heterogeneous disorder with multifactorial etiologies. Genetic predisposition, environmental factors, and Helicobacter pylori infection are thought to interact in the manifestation of GC. Particular human leukocyte antigen (HLA) alleles play a pivotal role in cellular immunity and may be an important genetically determined host trait. To elucidate the association between the genotype of HLA class II genes and the clinical phenotype of GC, polymorphisms of HLA‐DRB1 and HLA‐DQB1 were determined by polymerase chain reaction with sequence‐specific primers in 106 Taiwanese patients with GC and in 208 healthy controls. Comparison of allele frequencies between GC patients and healthy controls showed no significant difference at the HLA‐DRB1 locus. Patients with GC had a higher frequency of DQB1★0602 (9.4% vs. 3.6%, P<0.05, odds ratio 2.79, 95% confidence interval 1.41–5.47) and a lower frequency of DQB1★0301 (14.6% vs. 23.8%, P<0.05, odds ratio 0.55, 95% confidence interval 0.35–0.85) compared to healthy controls. Correlation of HLA‐DQB1 status with clinicopathologic features revealed predominance of male gender (16/3 vs. 50/37, P<0.05) and proximal location (12/7 vs. 28/59, P<0.05) in patients with positive HLA‐DBQ1★0602 compared to those with negative HLA‐DBQ1★0602. In contrast, a higher ratio of diffuse/intestinal subtype (20/10 vs. 30/46, P<0.05) and a lower seropositivity of Helicobacter pylori (14/30 vs. 58/76, P<0.005) were noted in patients with positive HLA‐DQB1★0301 compared to those with negative HLA‐DQB1★0301. In conclusion, HLA‐DQB1★0602 confers susceptibility to gastric cancer, especially for male Taiwanese and proximal tumor location, while HLA‐DQB1★0301 may have a protective effect on GC, probably through resistance to Helicobacter pyloriinfection. HLA‐DQB1 alleles are associated with susceptibility or resistance to GC and also influence its clinical features.