Koosha Rokhzadi,1Kaveh Haji-Allahverdipoor,2,*
1. Department of Molecular Medicine and Medical biotechnology, Faculty of Medicine, Kurdistan University of Medical sciences
Introduction: Antigens are the targets for the immune system which are present in cancer cells. However, many are not cancer-specific and may also be found on normal tissues. These antigens are often products of mutated cellular genes, aberrantly expressed normal genes, and genes encoding viral proteins. Furthermore, tumor antigens are responsible for initiating an immune respond in cancer patients and their recognition may provide new biomarkers for cancer diagnosis and targets for immunotherapy. In addition, Antigens that are found and studied in breast cancer include CEA, HER2, MUC-1 which is hyperglycosylated in adenocarcinomas, carbohydrate antigens (Tn, TF, STn), p53 – a tumor suppressor gene mutated in cancers, TERT, WT1 and so more
Methods: Further, the human epidermal growth factor receptor 2 (HER2) is a 185-kDa protein receptor with tyrosine kinase activity and extensive homology to the epidermal growth factor receptor. HER2 is expressed in many epithelial tumors and overexpressed in approximately twenty five percent of all primary breast carcinomas.
Results: Overexpression of HER2 is associated with poor prognosis. HER2 is a suitable target because it involves an extracellular domain (ECD) that can be targeted by antibodies produced by B cells. Moreover, Mucin 1 (MUC-1) is a membrane-associated glycoprotein expressed by many types of ductal epithelia, including the pancreas, breast, lung, and gastrointestinal tract. It is overexpressed and aberrantly glycosylated in malignant cells. It is a multifunctional protein involved in the protection of mucous membranes, signal transduction, and modulation of the immune system. More than seventy percent of cancers overexpress MUC-1, making this antigen a potential target for immunotherapy.
Conclusion: Also, carcinoembryonic antigen (CEA) is a 180-kDa glycoprotein that is overexpressed in a wide range of carcinomas, including colorectal, gastric, pancreatic, non-small cell lung, and breast carcinomas. The Tn, TF, and sialyl-Tn (STn) antigens represent the immature glycosylation products of serine and threonine of the protein core and are naturally masked by the complete glycosylate chain. All 3 epitopes are strongly expressed on cancer cells and may be associated with disease progression and metastasis. Additionally, the Wilms’ tumor gene (WT1) was initially identified in sporadic and hereditary cases of Wilms’ tumor as being either mutated or overexpressed, and WT1 is involved in cell growth regulation or differentiation.