Project description:In recent years, a greater appreciation for the microbes inhabiting human body sites has emerged. In the female mammary gland, milk has been shown to contain bacterial species, ostensibly reaching the ducts from the skin. We decided to investigate whether there is a microbiome within the mammary tissue. Using 16S rRNA sequencing and culture, we analyzed breast tissue from 81 women with and without cancer in Canada and Ireland. A diverse population of bacteria was detected within tissue collected from sites all around the breast in women aged 18 to 90, not all of whom had a history of lactation. The principal phylum was Proteobacteria. The most abundant taxa in the Canadian samples were Bacillus (11.4%), Acinetobacter (10.0%), Enterobacteriaceae (8.3%), Pseudomonas (6.5%), Staphylococcus (6.5%), Propionibacterium (5.8%), Comamonadaceae (5.7%), Gammaproteobacteria (5.0%), and Prevotella (5.0%). In the Irish samples the most abundant taxa were Enterobacteriaceae (30.8%), Staphylococcus (12.7%), Listeria welshimeri (12.1%), Propionibacterium (10.1%), and Pseudomonas (5.3%). None of the subjects had signs or symptoms of infection, but the presence of viable bacteria was confirmed in some samples by culture. The extent to which these organisms play a role in health or disease remains to be determined.
Project description:Recently, the H3K4 demethylase, KDM5B, was shown to be amplified and overexpressed in luminal breast cancer, suggesting it might constitute a potential cancer therapy target. Here, we characterize, in breast cancer cells, the molecular effects of a recently developed small-molecule inhibitor of the KDM5 family of proteins, either alone, or in combination with the DNA demethylating agent 5-aza-2’ deoxycytidine (DAC). Alone, the KDM5 inhibitor (KDM5i) increased expression of a small number of genes, but when combined with DAC, the drug enhanced the effects of the latter for increasing expression of hundreds of DAC responsive genes. ChIP-seq studies revealed that KDM5i resulted in the broadening of existing, and creation of thousands of new H3K4me3 domains. When compared to DAC alone, increased promoter and gene body H3K4me3 occupancy at DAC responsive genes was observed in cells treated with the drug combination. Importantly, treatment with either DAC or DAC+KDM5i induced a dramatic increase in H3K27ac at enhancers with an associated significant increase in target gene expression, suggesting a previously unappreciated effect of DAC on transcriptional regulation. Finally, we found that KDM5i could synergize with DAC to reduce the viability of luminal breast cancer cells in in-vitro assays. Our study provides the first look into the molecular effects of novel KDM5i compounds and suggests that combining these with DAC may represent an exciting new approach to epigenetic therapy.
Project description:JIMT-1 and T-47D cell lines, were transfected with a DCK expression vector and exposed to low-dose decitabine (DAC). DAC, a DNA methyltransferase (DNMT) inhibitor, is tested in combination with conventional anticancer drugs as a treatment option for various solid tumors.