Thesis (M.Sc.) - Cairo University - Faculty of Science - Department of Zoology

Introduction: The most known cause of death due to cancer in women is breast cancer.The breast carcinoma incidence is increasing in the developing countries and most of breast carcinoma patients in middle and low income countries aren{u2019}t diagnosed early. Increased risk factors like smoking, obesity, changing reproduction patterns, growth and aging of the population were considered as causes of the increase in the incidence of cancer in general including breast cancer. Over the years the burden caused by cancer became more common in women in countries with low- and middle-income (LMICs) than in countries with high-income (HICs). This was attributed to worsening economic, social, scientific challenges and lack of equipment for early diagnosis and treatment leading to poor prognosis. Breast Cancer Stem Cells (BCSCs) play important role(s) in the development and progression of invasive duct carcinoma (IDC).We assessed the role of BCSC markers expression and the number of mammospheres in cultures of BC tissues and correlated these data to relevant clinico-pathological features of the patients and overall survival (OS). Methods: Fresh tumor tissue samples were collected from 45 Egyptian female patients with IDC of the breast and 25 normal females undergoing reduction mammoplasty as a control. The mammosphere number and the RNA expression levels of some CSCs-related genes (PTEN, PI3K, AKT, Wnt and Ý-catenin) was assessed by RTPCR in the separated BCSCs at different stages of differentiation compared to normal control samples.Results: The number of CD44+CD24-/low was high in 43/45(97.8%) cases. This number associated significantly at the end of culture with the expression level of Wnt, Ý-catenin and distant metastasis (P<0.001, P=0.015& P=0.003; respectively).There was significant association between the mammospheres number and CD44+CD24-/low cells as well as AKT expression (P =0.040 and 0.021; respectively)

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