Differential expression of genes and protein networks in the primary breast tumor that proceed to distant metastasis

The presence or absence of lymph node metastasis plays a major role in the prediction of prognosis and subsequent patient management. However, good proportion of patients who display lymph node positivity remain disease free for 3 years or more, after the initial treatment, while a third of those who were lymph node negative at presentation, develop distant metastasis within the same period. We performed gene expression profiling on a cohort Indian breast cancer patients followed up for a period of 3-5 years and in comparison with a previously published Caucasian cohort data, we identified gene signatures that are associated with distant metastasis. This association was irrespective of the hormone receptor status. Our results show that the genes that signify immune system development and response are repressed, while factors for DNA replication are up regulated in patients who develop distant metastasis. A large number of genes encoding proteins involved in the mitotic spindle formation that belong to the TRIM28 protein network, are differentially regulated in the metastatic tumors. Also, there was a significant overlap of genes reported in a mouse model of bone metastasis, with patients who developed bone metastasis in our cohort. In conclusion, we present for the first time probable gene signatures that correlate with distant metastasis in breast cancer patients irrespective of nodal or hormone receptor status 80 indian breast cancer patients(samples),comprising of 22ER+(estrogen receptor),and 55 ER-.PR(progesterone receptor) ,HER and NOD status are also given in corresponding sample title and array files