Dr. Hajra sadia
Biography
Mouse mammary tumor virus (MMTV), an established cause of mammary tumors in mice, is still controversial for its role in human breast cancer. MMTV has been detected in human breast cancer samples from several parts of the world, but the establishment of a causal role is under debate. With reported presence of MMTV-like sequences in human breast cancer samples from Pakistan, 26% of breast cancer tissues, we also present a supposition that integration of MMTV might be in part responsible for breast cancer development. Employing LM-PCR we have identified multiple (16) distinct integration sites of MMTV in human breast cancer tissues. This study is first of its kind in MMTV research in human subjects. The data lends support to the idea of a viral etiology of breast cancer. Furthermore, our data also indicates anomalous behavior of MMTV-like sequences. Previous data suggests a totally random integration of MMTV in both mouse and human genome in cell lines. However, some sites were found to be repeating in different samples, thus, also supporting sequence specific bias in integration. Our data suggests that integration in the genome might give cells a distinct advantage for survival of transformed cells. Although, the link is still not clear, but further studies on these integration sites might reveal a link between MMTV-like sequences and human breast cancer.