Radiation-induced GEPs in immortalized and primary breast cells

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. Radiation-induced gene expression changes in non- tumorigenic (MCF10A) and in tumorigenic breast (MCF7 and MDA-MB-231) immortalized cell lines; and in healthy (HMEC) and BC (BCpc7 and BCpcEMT) primary cultures obtained from surgical biopsies, were analyzed as two-color hybridizations using Agilent Technologies whole human genome 4x44K microarrays. New Samples were named as follow: MCF10A_9Gy; MCF7_9Gy; MDA-MB-231_9Gy; HMEC_9Gy; BCpc7_9Gy; BCpcEMT_9Gy; MDA-MB-231_23Gy. In addition, we have used the our existing samples following listed: GSM1611676-81;GSM1554983-88; GSM3019056-61;GSM3019068-73;GSM3019080-85.