ORIGINAL ARTICLES Transcriptional down regulation of hTERT and senescence

induction in HepG2 cells by chelidonin

Telomerase Activity In Iranian Patients With Esophageal Squamous Cell Carcinoma

Telomerase activation is one of the main pathways to immortalize cancer cells. In many kinds of cancer cells, this special reverse transcriptase stabilizes and elongates telomeres and prevents telomere erosion that naturally occurs in every cell division. Esophageal cancer is the fifth most frequent cause of cancer death worldwide, and is highly associated with alcohol, smoking, cultural habits, and environmental factors. Telomerase has been suggested as a tumor marker and a molecular target for drug design in several kinds of cancers. In this work telomerase activation was inspected among Iranian patients with Esophageal Squamous Cell Carcinoma (ESCC), and detected in 90% of samples of different stages. This may be an indication that telomerase activation happens in an initial step in the development of ESCC. Although there is no correlation between telomerase activity and the progress of ESCC, it could be considered as a good tumor marker in ESCC. Telomerase activity te! sts are suggested for screening purposes in high risk areas for ESCC, which can be easily done on a small amount of scrapped samples of esophageal mucosa. It is also possible that ESCC results from incomplete differentiation or a failure in telomerase gene switching off that normally occurs during the differentiation of esophageal epithelial cells

Differential gene expression between squamous cell carcinoma of esophageus and its normal epithelium; altered pattern of mal, akr1c2, and rab11a expression

AIM: To identify the altered gene expression patterns in squamous cell carcinoma of esophagus (ESCC) in relation to adjacent normal esophageal epithelium. METHODS: Total RNA was extracted using SV total RNA isolation kit from snap frozen tissues of ESCC samples and normal esophageal epithelium far from the tumor. Radio-labeled cDNA were synthesized from equal quantities of total RNAs of tumor and normal tissues using combinations of 24 arbitrary 13-mer primers and three different anchoring oligo-dT primers and separated on sequencing gels. cDNA with considerable different amounts of signals in tumor and normal tissue were reamplified and cloned. Using southern blot, the clones of each band were controlled for false positive results caused by probable heterogeneity of cDNA population with the same size. Clones that confirmed differential expression by slot blot selected for sequencing and northern analysis. Corresponding full-length gene sequences was predicted using human genome project data, related transcripts were translated and used for various protein/motif searches to speculate their probable functions. RESULTS: The 97 genes showed different levels of cDNA in tumor and normal tissues of esophagus. The expression of mal gene was remarkably down regulated in all 10 surveyed tumor tissues. Akr1c2, a member of the aldo-keto reductase 1C family, which is involved in metabolism of sex hormones and xenobiotics, was up-regulated in 8 out of 10 inspected ESCC samples. Rab11a, RPL7, and RPL28 showed moderate levels of differential expression. Many other cDNAs remained to further studies. CONCLUSION: The mal gene which is switched-off in all ESCC samples can be considered as a tumor suppressor gene that more studies in its regulation may lead to valuable explanations in ESCC development. Akr1c2 which is up-regulated in ESCC probably plays an important role in tumor development of esophagus and may be proposed as a potential molecular target in ESCC treatments. Differential display technique in spite of many disadvantages is still a valuable technique in gene function exploration studies to find new candidates for improved ones like gene chips

Combination of meta-analysis and graph clustering to identify prognostic markers of ESCC

Esophageal squamous cell carcinoma (ESCC) is one of the most malignant gastrointestinal cancers and occurs at a high frequency rate in China and other Asian countries. Recently, several molecular markers were identified for predicting ESCC. Notwithstanding, additional prognostic markers, with a clear understanding of their underlying roles, are still required. Through bioinformatics, a graph-clustering method by DPClus was used to detect co-expressed modules. The aim was to identify a set of discriminating genes that could be used for predicting ESCC through graph-clustering and GO-term analysis. The results showed that CXCL12, CYP2C9, TGM3, MAL, S100A9, EMP-1 and SPRR3 were highly associated with ESCC development. In our study, all their predicted roles were in line with previous reports, whereby the assumption that a combination of meta-analysis, graph-clustering and GO-term analysis is effective for both identifying differentially expressed genes, and reflecting on their functions in ESCC

Erratum to: Guidelines for the use and interpretation of assays for monitoring autophagy (3rd edition) (Autophagy, 12, 1, 1-222, 10.1080/15548627.2015.1100356

non present