Project description:Today, Radiation therapy (RT) regimens are often used for many types of cancer including breast cancer (BC) disease. BC is an heterogeneous disease, at both clinical and molecular levels, presenting distinct subtypes associated with different clinical outcomes. This variability response may be caused by some factors linked to radiation or dependent to BC specific features such as tumor stage and hormone receptor (HR) status. We analyze and compare molecular responses, in term of gene expression profile (GEP) changes, induced by 9 and 23Gy of ionizing radiation (IR) in immortalized and primary cell cultures grouped according their Estrogen (ER) and Progesteron (PR) receptors positive or negative expression. Our explorative study gives some comprehensive hallmarks of the effects of the irradiation in BC cells. We trust that this study could have a role in driving RT towards personalised treatments, based also on the molecular characterization in BC.
Project description:Purpose:The identification of biomarkers predictive of neoadjuvant chemotherapy response in breast cancer patients would be an important advancement in personalized cancer therapy. We hypothesized that due to similarities between radiation and chemotherapy induced cellular response mechanisms, radiation responsive genes may be useful in predicting response to neoadjuvant chemotherapy. Materials and Methods: Murine p53 null breast cancer cell lines representative of the luminal, basal-like and claudin-low human breast cancer subtypes were irradiated to identify radiation responsive genes. These murine radiation induced genes were then converted to their human orthologs. These genes were then used to develop a predictor of pathologic complete response (pCR) that was validated on two independent published neoadjuvant chemotherapy data sets of genomic data with response. Results: A radiation induced gene signature consisting of 30 genes was identified on a training set of 337 human primary breast cancer tumor samples that was prognostic for survival. Mean expression of this signature was calculated for individual samples in two independent published datasets and was found to be significantly predictive of pathologic complete response. Multivariate logistic regression analysis in both independent datasets showed that this 30 gene signature added significant predictive information independent of that provided by standard clinical predictors and other gene expression based predictors of pathologic complete response. Conclusion: This study provides new biologic information regarding response to neoadjuvant chemotherapy and a means of possibly improving the prediction of pathologic complete response. reference x sample
Project description:Purpose:The identification of biomarkers predictive of neoadjuvant chemotherapy response in breast cancer patients would be an important advancement in personalized cancer therapy. We hypothesized that due to similarities between radiation and chemotherapy induced cellular response mechanisms, radiation responsive genes may be useful in predicting response to neoadjuvant chemotherapy. Materials and Methods: Murine p53 null breast cancer cell lines representative of the luminal, basal-like and claudin-low human breast cancer subtypes were irradiated to identify radiation responsive genes. These murine radiation induced genes were then converted to their human orthologs. These genes were then used to develop a predictor of pathologic complete response (pCR) that was validated on two independent published neoadjuvant chemotherapy data sets of genomic data with response. Results: A radiation induced gene signature consisting of 30 genes was identified on a training set of 337 human primary breast cancer tumor samples that was prognostic for survival. Mean expression of this signature was calculated for individual samples in two independent published datasets and was found to be significantly predictive of pathologic complete response. Multivariate logistic regression analysis in both independent datasets showed that this 30 gene signature added significant predictive information independent of that provided by standard clinical predictors and other gene expression based predictors of pathologic complete response. Conclusion: This study provides new biologic information regarding response to neoadjuvant chemotherapy and a means of possibly improving the prediction of pathologic complete response.
Project description:Exposure to genotoxic stresses such as cosmic radiation and second-hand tobacco smoke may increase the risk of breast cancer formation. Towards an understanding of how exposure to these genotoxic agents affect breast cancer biogenesis, we have shown that treating non-tumorigenic immortalized breast MCF 10A cells with low doses (0.1 Gray) of radiation as well as cigarette smoke condensate can generate a neoplastic breast cancer phenotype. The transformed phenotype promoted increased mammosphere numbers, altered cell cycle phases, and increased invasion and motility. In addition, exclusion of Hoechst 33342 dye, a surrogate marker for increased ABC transporters, was observed, which indicates a possible increase in drug resistance. Furthermore, differential gene expression profiles were generated from the individual and combination treatment. Overall, the results indicate that when normal breast cells are exposed to low dose radiation in combination with cigarette smoke condensate a phenotype is generated that exhibits traits indicative of neoplastic transformation. Taken together, these results provide a new insight into a possible etiology for breast cancer formation in individuals exposed to cosmic radiation and second-hand smoke.
Project description:Genome-wide analysis of dihydrotestosterone (DHT) induced changes in gene expression in primary and immortalized human corneal epithelial cells. Analysis of regulation of primary and immortalized human corneal epithelial cells by dihydrotestosterone at gene expression level. The hypothesis tested in the present study was that the androgen-eye interaction in ocular surface epithelial cells like corneal cells is influenced by androgens through regulation of the expression of multiple genes. Results provide important information of the differential regulation and comparitive analysis of numerous genes in response to dihydrotestosterone incubation in primary and immortalized human corneal epithelial cells.
Project description:Exposure to genotoxic stresses such as cosmic radiation and second-hand tobacco smoke may increase the risk of breast cancer formation. Towards an understanding of how exposure to these genotoxic agents affect breast cancer biogenesis, we have shown that treating non-tumorigenic immortalized breast MCF 10A cells with low doses (0.1 Gray) of radiation as well as cigarette smoke condensate can generate a neoplastic breast cancer phenotype. The transformed phenotype promoted increased mammosphere numbers, altered cell cycle phases, and increased invasion and motility. In addition, exclusion of Hoechst 33342 dye, a surrogate marker for increased ABC transporters, was observed, which indicates a possible increase in drug resistance. Furthermore, differential gene expression profiles were generated from the individual and combination treatment. Overall, the results indicate that when normal breast cells are exposed to low dose radiation in combination with cigarette smoke condensate a phenotype is generated that exhibits traits indicative of neoplastic transformation. Taken together, these results provide a new insight into a possible etiology for breast cancer formation in individuals exposed to cosmic radiation and second-hand smoke. To study the effects of low dose ionizing radiation and tobacco smoke on breast cells, MCF 10A cells were treated either with radiation (Rad - 0.1 Gray) or cigarette smoke condensate (Csc - 10 microgram/ml of medium) or a combination of Rad + Csc). Following treatments, the cells were incubated for 72 hr, RNA extracted and analyzed for differential gene expression pattern.
Project description:Breast cancer (BC) recovery has considerably increased thanks to the advances achieved from research in this field. However, despite the important results obtained, BC remains a complex multifactorial disease with distinct subtypes associated with different outcomes.So, many efforts from radiobiological research are needed to help clinicians in understanding molecular features of a specific tumor subtype, in order to better define the most successful treatment plan, including the choice of the best Radiation Teraphy (RT) modality and schedule in clinical practice. The aim of the present study was to analyze the GEPs in primary breast cancer cells following irradiation with doses of 9 Gy and 23 Gy electron beam delivered by IOERT treatment, in order to define gene signatures of response to high doses of IR.
Project description:Genome-wide analysis of dihydrotestosterone (DHT) induced changes in gene expression in primary and immortalized human corneal epithelial cells. Analysis of regulation of primary and immortalized human corneal epithelial cells by dihydrotestosterone at gene expression level. The hypothesis tested in the present study was that the androgen-eye interaction in ocular surface epithelial cells like corneal cells is influenced by androgens through regulation of the expression of multiple genes. Results provide important information of the differential regulation and comparitive analysis of numerous genes in response to dihydrotestosterone incubation in primary and immortalized human corneal epithelial cells. Total RNA was obtained from primary and immortalized human corneal epithelial cells treated for 5 days with 10 nM dihydrotestosterone (n=3) or vehicle (n=3). The RNA was then used with Illumina HumanHT-12 v3 Expression BeadChips to determine the effect of DHT on gene expression in the primary human corneal cells grown in our laboratory and the immortalized human corneal epithelial cell line developed in Dr. Rheinwald's laboratory [Rheinwald et al. MCB, 22 (14): 5157. (2002)] and charecterized in Dr. Ilene Gibson's laboratory [Gipson et al. IOVS, 44 (6): 2496. (2003)].