PTEN hypermethylation profiles of Chinese Kazakh patients with esophageal squamous cell carcinoma.

Aberrant DNA methylation of promoter region CpG islands may serve as an alternative mechanism to genetic defects in the inactivation of tumor suppressor genes (TSGs) in human malignancies. The aim of this study was to examine the promoter methylation status of the PTEN TSG and its association with esophageal squamous cell carcinoma (ESCC) carcinogenesis in a Chinese Kazakh population, which is known to have a relatively high ESCC incidence and mortality. The methylation status of the PTEN promoter region was determined in patients with ESCC (n = 95) and healthy individuals (n = 65) using highly sensitive Sequenom Epityper assays. The methylation level of the PTEN gene was significantly higher in patients with ESCC than in healthy controls. The median methylation level was 10.0% (interquartile range [IQR]: 7.0-11.0%) in patients with ESCC and 6.0% in controls (IQR: 4.0-9.0%; P = 0.001). PTEN methylation levels were higher in male patients with ESCC than in male controls, whereas a trend toward significance was observed between female patients with ESCC and female controls (P = 0.005 and P = 0.086, respectively). The PTEN methylation level was associated with histopathological grade and lymph node metastasis in patients with ESCC (P = 0.002 and P = 0.009, respectively). To our knowledge, this is the first report to show the presence of PTEN promoter CpG hypermethylation in ESCC and its association with tumor metastasis.

Prognostic value of the stem cell markers CD133 and ABCG2 expression in esophageal squamous cell carcinoma.

In the light of increasing evidence supporting cancer stem cells (CSCs) theory, the expression of two stem cell markers, CD133 and adenosine triphosphate-binding cassette superfamily G member 2 (ABCG2), in esophageal squamous cell carcinoma (ESCC) was investigated, and their prognostic values were evaluated. Paraffin-embedded tissue sections of 110 ESCC patients were investigated using Immunohistochemistry. The association of CD133 and ABCG2 expression with clinicopathologic characteristics was analyzed by χ(2) test. Survival analysis was carried out using Kaplan-Meier method and Cox proportional hazards model. CD133 and ABCG2 expression were detected in 27.3% and 15.5% of ESCC patients, respectively. The presence of CD133-positive cancer cells was associated with tumor cell differentiation (P= 0.008) but not significantly related to the survival of ESCC patients (P= 0.085). ABCG2 expression was not associated with clinicopathologic characteristics but was a significant prognostic factor for adverse overall survival of ESCC patients (P= 0.005). The median overall survival time for ESCC patients with and without ABCG2 expression were 21.8 and >49.3 months, respectively. A combined analysis of CD133 and ABCG2 expression did not show that ESCC patients with coexpression of these two markers had a worse prognosis than those with only ABCG2 expression (P= 0.934). Moreover, ABCG2 expression was revealed to be an independent prognostic factor along with tumor node metastasis stage in multivariate analysis (hazard ratio of ABCG2, 3.38; 95% confidence interval, 1.61∼7.09; P= 0.001). By survival analysis based on tumor node metastasis stage of ESCC, the association between ABCG2 expression and the patients' prognosis was found significant in the group of relatively early stage (P= 0.005) and marginally significant in the group of relatively late stage (P= 0.058). This is the first time to report the presence of CD133-positive cancer cells in ESCC but not supporting its prognostic value and validity as a CSC marker for ESCC. ABCG2 expression was found to correlate with the survival of ESCC patients, especially those at relatively early stage, suggesting that ABCG2-positive cancer cells may represent a pool of CSCs in ESCC, and relatively early-stage patients with ABCG2 expression may deserve more intensive or targeted therapy.

Gross anatomy of the pancreatic lobes and ducts in six breeds of domestic ducks and six species of wild ducks in China.

A previously unreported pancreatic duct was found by Liu (1989) in Pekin ducks. This duct has now been consistently found in six breeds of domestic ducks and six species of wild ducks in China. For purposes of Nomina Anatomica Avium it is hereby called the 'first pancreatic duct' (Ductus pancreaticus primus) since it enters the duodenum at or near the flexure where the descending duodenum becomes the ascending duodenum. All other pancreatic ducts enter the duodenum later, closer to where it joins the jejunum. This first pancreatic duct drains the caudal extremity of the dorsal lobe of the pancreas and can be easily exteriorized for experimental purposes. Within the parenchyma of the dorsal lobe of the pancreas this duct communicates with the dorsal pancreatic duct. In the present study of the gross anatomy of the pancreatic lobes of domestic and wild Chinese ducks we describe and illustrate variations in position and number of all biliary and pancreatic ducts.

[Controversy between endoscopic and surgical treatment against early gastric and colorectal cancer].

Although endoscopic treatment against the patients with early cancer in gastrointestinal tract is an excellent method especially in high aged or poor risk patients, there still exists controversy about the indication for endoscopic treatment because of deeper invasion of the cancer or lymph node metastases. In order to clarify whether the patient has a possibility of nodal involvement or not, we made the clinicopathological analysis concerning 220 cases with early gastric cancers and 118 cases with colorectal cancers. Our retrospective analysis shows that endoscopic resection can be indicated for small polypoid cancer less than 10 mm in size, excluding IIa + IIc type. As to small depressed type, this procedure should be applied for IIc type which is well differentiated adenocarcinoma without ulcer formation (U1 (-)). Regarding early colorectal cancer there has been many discussion how to treat the patients with sm-cancer. Based on our analysis of 39 cases with sm-cancer, we led to the conclusion that the characteristics of sm-cancer with lymph node metastases are i) massive invasion into submucosal layer, ii) positive lymphatic permeation, or iii) "de novo" cancer. As a result, a decision of further surgery should be made even in small lesions less than 10 mm, taking the fact into consideration of the possibility of nodal involvement of sm-cancer.