aim : the aim of this study is to evaluate the polymorphism in bax gene and its association with some clinical pathology traits in gastric cancer.   background : gastric cancer is considered as the fourth most common cancer in the north and northwest of iran. bcl2 family has a key role in regulation of apoptosis, and any changes in the expression of bcl2 lead to cancer. patients and methods : b...

To identify the essential motifs of the promoter of the human gene for thymidylate synthase (TS), we constructed a set of deletion mutants from the 5'-terminal region of the human TS gene. From the results of assays of the expression of chloramphenicol acetyltransferase (CAT), we identified two functional elements with positive effects on the promoter activity: a CACCC box (CCACACCC) and an Sp1...

SP1 is a ubiquitous transcription factor that is involved in the regulation of various house-keeping genes. It is known that it acts by binding to a double-stranded consensus motif. Here, we have discovered that SP1 binds also to a non-canonical DNA structure, a G-quadruplex, with high affinity. In particular, we have studied the SP1 binding site within the promoter region of the c-KIT oncogene...

Promyelocytic leukemia nuclear bodies (PML NBs) are comprised of PML and a striking variety of its associated proteins. Various cellular functions have been attributed to PML NBs, including the regulation of gene expression. We report here that induced expression of PML recruits Sp1 into PML NBs, leading to the reduction of Sp1 transactivation function. Specifically, Chromatin immunoprecipitati...

Previously, the existence of dual promoters was reported in mouse mu-opioid receptor (mor) gene, with mor transcription in the mouse brain predominantly initiated by the proximal promoter. In this study, we further analyzed the proximal promoter region, base pairs -450 to -249, to identify cis-DNA regulatory elements and trans-acting protein factors that are important for mor promoter activity....

Coxsackie and adenovirus receptor (CAR) was first known as a virus receptor. Recently, it is also known to have tumor suppressive activity such as inhibition of cell proliferation, migration, and invasion. It is important to understand how CAR expression can be regulated in cancers. Based on an existence of putative Sp1 binding site within CAR promoter, we investigated whether indeed Sp1 is inv...

Rabbit corneal epithelial cells cultured in the presence of 3T3 feeder cells undergo biochemical differentiation, as evidenced by their initial expression of K5 and K14 keratins characteristic of basal keratinocytes, followed by the subsequent expression of K3 and K12 keratin markers of corneal epithelial differentiation. Previous data established that mutations of an Sp1 site in a DNA element,...

17beta-Estradiol (E2) induces cathepsin D gene expression in MCF-7 human breast cancer cells and previous analyses of the proximal promoter region of this gene identified two functional enhancer sequences; namely an Sp1(N)23estrogen-responsive element (ERE) half-site (-199 to -165) and an imperfect palindromic ERE (-119 to -107). A third region of the cathepsin D gene promoter (CD/L, -145 to -1...

Functional modification of regulatory proteins can affect hundreds of genes throughout the genome, and is therefore thought to be almost universally deleterious. This belief, however, has recently been challenged. A potential example comes from transcription factor SP1, for which statistical evidence indicates that motif preferences were altered in eutherian mammals. Here, we set out to discove...