Project description:CpG hypermethylation in gene promoters is a frequent mechanism of tumor suppressor gene silencing in various types of cancers. 5-aza-2'-deoxycytidine (AZA) is a DNA demethylating and anti-cancer agent resulting in induction of genes suppressed via DNA hypermethylation. Using microarray expression profiling of AZA or DMSO treated and untreated breast cancer (MCF7 and MDA-MB-231) and non-tumorigenic breast (NTB) cells, we aim to identify candidate genes that are downregulated via promoter hypermethylation in breast cancer.
Project description:Increased proliferation and elevated levels of protein synthesis are characteristic of transformed and tumor cells. Though components of the translation machinery are often misregulated in cancers, how tRNA plays a role in cancer cells has not been explored. We compare genome-wide tRNA expression in tumorigenic versus non-tumorigenic breast cell lines, as well as tRNA expression in breast tumors versus normal breast tissues. In tumorigenic versus non-tumorigenic cell lines, nuclear-encoded tRNAs increase by up to 3-fold and mitochondrial-encoded tRNAs increase by up to 5-fold. In tumors versus normal breast tissues, both nuclear and mitochondrial-encoded tRNAs increase by up to 10-fold. This tRNA over-expression is selective and coordinates with the properties of cognate amino acids. Nuclear- and mitochondrial-encoded tRNAs exhibit distinct expression patterns, indicating that tRNAs can be used as biomarkers for breast cancer. We analyzed tRNA expression levels in 2 non-tumorigenic breast cell lines, 6 tumorigenic breast cancer cell lines, 3 normal breast tissue samples, and 9 breast tumor samples. We used a non-tumorigenic breast cell line (MCF10A) as a reference sample in all hybridizations. All data is dye-swapped.
Project description:Gene expression profiling of immortalized human mesenchymal stem cells with hTERT/E6/E7 transfected MSCs. hTERT may change gene expression in MSCs. Goal was to determine the gene expressions of immortalized MSCs.
Project description:Initial screening for potential metastases suppressors down regulated by methylation was performed using breast cancer cell line models specific for site-specific metastasation. Gene expression profiling and qRT-PCR validations were conducted on tumor tissues from primary breast cancer (BC) and BCBM. CADM1 and RECK were further characterized for their methylation patterns and finally the protein expression of CADM1 was validated in a large number of BC and BCBM samples and correlated with clinico-pathologic parameters. A subclone of MDA-MB-231, which has a high metastatic potential for the brain (MDA-MB-231 BR), was compared to the parental MDA-MB-231 WT and to a bone-seeking subclone (MDA-MB-231 SA) in order to find genes, which might be specifically involved in brain metastasis formation. The cell lines were treated with 5-Aza-2'-deoxycytidine in order to find genes potentially down regulated by methylation. The non-tumorigenic epithelial cell line MCF 10A was used to control for stress response after the treatment with 5-Aza-2'-deoxycytidine.