Restoration of the Lost Human Beta Defensin (hBD-1) in Cancer as a Strategy to Improve the Efficacy of Chemotherapy

Abstract

Both innate and adaptive immunity are the important components of the human defense system against various diseases including cancer. Human Beta Defensin (hBD-1) is one such immunomodulatory peptide which is lost at high frequencies in malignant cancers, while high levels of expression are maintained in benign regions making it a potential biomarker for the onset and metastasis of the disease. Loss of putative function of hBD-1 as a tumor suppressor gene combined with the defects in apoptosis pathways (CD95, ASK1) make tumor cells insensitive to chemotherapy and render it ineffective. Triple negative breast cancer (TNBC) is an aggressive form of breast cancer for which no targeted therapy works due to lack of biomarkers (ER, PR and HER2 negative). That makes chemotherapy as a first line of treatment despite high side effects. TNBC is known for avoiding immunosurveillance and desensitizing themselves to intervention by dysregulating cell death pathways (CD95 & ASK1) and developing resistance to chemotherapy A priori Activation of Apoptosis Pathways of Tumor often referred to as AAAPT is a novel targeted tumor sensitizing technology which sensitizes low responsive and resistant tumor cells to evoke a better response from the current treatments for TNBC. Here, we show that hBD-1 is shown to target tumor specific biomarker Trx, activates dual cell death pathways CD95 and ASK1 (apoptosis stimulating kinase) to sensitize TNBC cells to chemotherapy drug Doxorubicin. As far as we know, this is the first-time injection of hBD-1 in TNBC mouse model to prove the restoration of hBD-1 back to the basal level can sensitize cancer cells which resulted in significant reduction of tumor volume in TNBC mouse model in vivo. Sensitizing the low or non-responsive tumor cells by AAAPT and making chemotherapy work at lower doses may lead to the significant reduction of dose related side effects and may expand the therapeutic index of the current treatments.