Study on Breast Cancer Stem Cells and their Role in Anti Cancer Drug Response

Abstract

Breast cancer constitutes the most common malignancy and the most common cause of cancer related deaths in Indian women. Incidence of breast cancer in India is rising steadily. In India, the average incidence rate for breast cancer is 16.5 per 100,000, varying from 22-28 per 100,000 in urban areas to 8 per 100,000 in rural areas. Also a significant proportion of Indian breast cancer patients are younger than 35 years of age. In India, the etiology of breast cancer appears to be different from that in the west, with early onset, short disease-free interval and high mortality. But there is no breast cancer cell line available from Indian population in the international or national cell culture repository. Despite recent therapeutic advances, locoregional and systemic disease recurrence remain an ever-present threat to the health and well being of breast cancer survivors. Disease recurrence originates from residual treatment resistant cells called the Cancer Stem Cells (CSCs). CSCs are defined as being able to self-renew and are the origin of other cancer cells that contribute to the mass of the tumor. They are responsible for maintaining the tumor and have been hypothesized to lead the invasive front of the tumor and contribute to metastatic seeding. CSCs were first discovered in acute myeloid leukemia and subsequently in solid tumors, including breast, pancreas, colon, glioblastoma, and others. Previous studies demonstrated that their quantification in tumor tissues would have significant prognostic value. Breast cancer stem cells (BCSCs) from tumor tissues/ cell lines can be identified and sorted out based on the presence of markers like CD44+/CD24- or aldehyde dehydrogenase enzyme (ALDH1A1+ cells) and can be further enriched and propagated in suspension cultures as mammospheres . The mammosphere system offers an in vitro model to study mammary stem cell biology and pathogenesis. However, little is known about the behavior of these cells in long-term cultures. The inability to maintain cancer stem cells.