Detection of Mouse Mammary Tumor Virus MMTV Antigens in Different Pathological Tissue forms of Iraqi Women- Breast Samples using Immunohistochemistry Staining

Abstract

Mouse mammary tumor virus (MMTV) is a β-retrovirus that cosider as the most common cause of breast cancer in mice. However  its role in human breast cancer is very controversial yet. Iraq having increasing rate of breast cancer and high prevalence in comparison to other cancer types among Iraqi people, Iraqi women suffering from a very aggressive fast-growing breast cancer, revealing causes and predisposing factors for such cases may help in saving lives of such women. Accordingly, the current study worked on detection of MMTV antigens (envelope glycoprotein 52(gp52) and capsid protein 27 (p27)) within Iraqi women breast cancer tissue samples and other comparative groups, cases were chosen from area highly endemic with house mouse. Immunohistochemical staining was performed using 97 samples of Formalin-Fixed Paraffin –Embedded (FFPE) Breast Tissues using specific antibodies targeting gp52 & p27 antigens. Although, results showed non significant differences for percentage of MMTV antigens positive results within Breast Cancer samples  7.31% (3 of 41), Fibroadenoma samples 5.26% (1 of 19), Mastitis samples 5.55% (1 of 18) and Ductectesia samples 5.26% (1 of 5.26). Despite of this low positive percentage, the presence of MMTV in human breast tissues is significant because MMTV is an animal virus so, the results may support the possibility of viral transmission from mice to human by direct or indirect contact and act as a co-factor with other oncogenes to induce breast cancer.

Keywords: MMTV, Iraqi, Breast cancer.