effect of exogenous expression of TP53 gene carried by dendrosme, an lranian vector, on human T-lymphomd and leukemia cells

The tumor suppressor p53 protein can induce apoptosis in some cellular contexts. Among the apoptosis-inducing genes, p53 has received the most attention for cancer gene therapy. In this study, the role of Dendrosome and Lipofectin mediated normal cDNA of TP53 into MOLT-4, CCRF-CEM[T-lymphoma] and K562 cell lines was assessed. At first, CCRF-CEM, MOLT-4 and K562 [erythroleukemic] cell lines were transfected by Dendrosome and Lipofectin separately. Then, viability study was carried out by Trypan blue exclusion. The rate of apoptosis and necrosis in transfected cell lines was evaluated by Flow Cytometry. Trypan blue exclusion assay in K562 and CCRF-CEM revealed 55.8% and 17.97% viability reduction in the Dend+p53 in comparison to Dend+pcDNA3 [control], respectively. Flow Cytometry studies confirmed a significant enhancement of apoptosis and necrosis in TP53 transrected K562 and CCRF-CEM cells. Flow Cytometry and viability studies on transfected MOLT-4 cells showed no significant changes. The results showed that expression of normal cDNA of TP53 in K562 and CCRF-CEM cell lines could induce apoptosis in these cell lines with different levels. Transfection of MOLT-4 cell Line by Dend+p53 and Lipo+53 could not result in apoptosis

Expression of hepatitis B surface antigen in saccharomyces cerevisiae

The genome of HBV virus of serotype ayw cloned in pBR322 and expression shuttle vector pYES2 were used for construction of the HBsAg chimeric genes and their expression in Saccharomyces cerevisiae. Two recombinant plasmids were constructed. One of them contained the coding sequences for the major polypeptide of surface antigen. Another construct carried the major polypeptide with the pre-S2 antigenic determinant. These vectors were transferred into the yeast. Only pDF1 which contained the HBsAg gene was expressed. Some peculiar features of recombinant plasmid construction and expression of the HBsAg gene are discussed

Drinking water and esophageal cancer in northern Iran

Fifty-one out of one-thousand stations were selected in Northern Iran for evaluating the genotoxicity of daily consumed drinking water. This part of Iran has one of the highest prevalences of esophageal cancer in the world. Water sampling was carried out from river, stored rain water, spring, canal, deep and shallow wells. Extracts prepared from river and stored-rain waters induced high mutagenicity in Salmonella typhimurium TA98 strain, while the TA100 strain did not show any response. Spring and canal water extracts caused a significant increase in the TA98 his+ revertants which was not observed in TA100. Among the 40 sampled deep and shallow well water concentrates, only 1/3 of the latter induced significant mutagenicity in the TA98 strain, 2/3 of extracts of both sources showed no sign of mutagenicity in TA100, while the remaining 1/3 caused various levels of lethalities in this strain. No lethalities were detected in this strain when river and stored rain water extracts were tested. Among all of the prepared extracts, only those belonging to river and stored rain water caused remarkable induction of DNA breaks in V79 fibroblasts