Abstract

Many genes and signalling pathways controlling cell proliferation, death and differentiation, as well as genomic integrity, are involved in cancer development. Techniques, such as cDNA microarrays, have enabled measurement of the expression of thousands of genes in a single experiment, revealing many new, potentially important cancer genes. Human breast cancer is usually caused by genetic alterations of somatic cells of the breast, but occasionally, susceptibility to the disease is inherited. As a step towards understanding the differences between familial and sporadic breast cancer in humans, gene expression patterns were examined in breast tumours. Sporadic (n=7) and familial (n=6) tissue samples, and normal breast tissue (n=3) samples, were collected from women who underwent breast surgery at Karnataka Cancer Therapy and Research Institute (KCTRI), Hubli. Total RNA was isolated and subjected to cDNA microarray for 14,992 genes on Agilent’s Human 8x15K Array. Gene expression profiles were analysed using Genespring software. F-Test was carried out to find the variance in terms of gene expression patterns between familial and sporadic breast cancer tissue samples. Our study revealed, that, there is no significant variation between sporadic and familial breast cancer in terms of gene expression profiles. With this, it can be concluded that both familial and sporadic breast cancers are similar in terms of the gene expression profiles. This will guide in development of common biomarkers for both familial and sporadic breast cancer and will also help in diagnosis, prognosis and treatment.

Key words: cDNA microarray, gene expression profiling, familial breast cancer, sporadic breast cancer, F-test, variance, India.