Project description:Type I, II, III and V collagens were commonly identified in human, pig, and mouse breast ECM. Mammary epithelial cells were able to form acini on certain types or combinations of the four collagens at normal breast tissue stiffness levels. Comparison of the collagen species in mouse normal breast and breast tumor ECM revealed common and distinct sets of collagens within the two types of tissues. Elevated collagen type I alpha 1 chain expression was found in human breast cancers. Collagen type XXV alpha 1 chain was identified in mouse breast tumors but not in normal breast tissues. Our data provide insights into modeling human breast pathophysiological structures and functions using native tissue-derived hydrogels and potential contributions of different collagen types or their monomers in breast cancer development.
Project description:Type I, II, III and V collagens were commonly identified in human, pig, and mouse breast ECM. Mammary epithelial cells were able to form acini on certain types or combinations of the four collagens at normal breast tissue stiffness levels. Comparison of the collagen species in mouse normal breast and breast tumor ECM revealed common and distinct sets of collagens within the two types of tissues. Elevated collagen type I alpha 1 chain expression was found in human breast cancers. Collagen type XXV alpha 1 chain was identified in mouse breast tumors but not in normal breast tissues. Our data provide insights into modeling human breast pathophysiological structures and functions using native tissue-derived hydrogels and potential contributions of different collagen types or their monomers in breast cancer development.
Project description:We are investigating the transcriptional response of yeast to modulation of the expression of base excision repair players, these generate different dna lesions of abasic sites of strand breaks; We used microarrays to detail the global programme of gene expression underlying the DNA damage response in yeast Experiment Overall Design: Yeaststrains with different expression levels of players in base excision repair (in biological triplicate) were grown to mid log phase. The expression responses were compared to each other and we have deciphered a gene expression profile that is specific for DNA damage in yeast.
Project description:We are investigating the transcriptional response of yeast to treatment with enediynes or gamma radiation, which generate different extents of double or single strand breaks in DNA. We used microarrays to detail the global programme of gene expression underlying the DNA damage response in yeast Keywords: dose
Project description:Genomic instability is one of the hallmarks of cancer. Several chemotherapeutic drugs and radiotherapy induce DNA damage to prevent cancer cell replication. Cells in turn activate different DNA damage response (DDR) pathways to either repair the damage or induce cell death. These DDR pathways also elicit metabolic alterations which can play a significant role in the proper functioning of the cells. The understanding of these metabolic effects resulting from different types of DNA damage and repair mechanisms is currently lacking. In this study, we used NMR metabolomics to identify metabolic pathways which are altered in response to different DNA damaging agents. By comparing the metabolic responses in MCF-7 cells, we identified the activation of poly (ADP-ribose) polymerase (PARP) in methyl methanesulfonate (MMS)-induced DNA damage. PARP activation led to a significant depletion of NAD+. PARP inhibition using veliparib (ABT-888) was able to successfully restore the NAD+ levels in MMS-treated cells. In addition, double strand break induction by MMS and veliparib exhibited similar metabolic responses as zeocin, suggesting an application of metabolomics to classify the types of DNA damage responses. This prediction was validated by studying the metabolic responses elicited by radiation. Our findings indicate that cancer cell metabolic responses depend on the type of DNA damage responses and can also be used to classify the type of DNA damage.
Project description:We are investigating the transcriptional response of yeast to modulation of the expression of base excision repair players, these generate different dna lesions of abasic sites of strand breaks We used microarrays to detail the global programme of gene expression underlying the DNA damage response in yeast Keywords: dose
Project description:An in silico model to examine damage-induced circadian phase shifts by investigating a possible mechanism linking circadian rhythms to metabolism. The proposed model involves two DNA damage response proteins, SIRT1 and PARP1, that are each consumers of nicotinamide adenine dinucleotide (NAD), a metabolite involved in oxidation-reduction reactions and in ATP synthesis.
Project description:Recent studies have highlighted the critical role of metabolism in the response to DNA damage. However, the precise metabolic interactions that are set in motion to tune this fundamental process remain largely unknown. In this study, we investigated the role of nuclear metabolism in the DNA damage response using triple-negative breast cancer as a model. By comparing the chromatin-associated proteome of different breast cancer subtypes, we observed that the purine synthesis enzyme Inosine monophosphate dehydrogenase 2 (IMPDH2) is enriched in the chromatin of triple-negative breast cancer cells, which are often prone to DNA damage accumulation. Downregulation, depletion, or inhibition of IMPDH2 leads to accumulation of DNA damage. IMPDH2 chromatin localization is DNA damage dose dependent and happens at a late stage of the DNA damage repair. On chromatin, IMPDH2 interacts with PARP1. The enzymatic function of IMPDH2, which consumes NAD+, modulates PARP1 activity, thus mediating a pondered DNA damage response. However, forcing the nuclear localization of exogenous IMPDH2 provokes a dramatic NAD+ depletion that results in PARP1 cleavage and consequent cytoplasmic translocation, which mediates apoptosis. Our study identifies a moonlighting role for IMPDH2 in the control of nuclear ATP and NAD+ level, which fine-tune the activation of PARP1 and regulates the DNA damage response.