Dissected the Role of Defensin 6 (Def 6),The Clinically Therapeutic Implication and Drug Development in Colon Cancer

Cancer has been the leading cause of death all over the world. And colorectal cancer is the 3rd most common cancer and 2nd leading cause of cancer death in western countries. In Taiwan, colorectal cancer has become the most commonly diagnosed malignancy in Taiwan and is also the 3rd leading cause of cancer death. In clinical, the local recurrence and distant metastasis, to locations such as liver and lung, are the major causes of colorectal cancer-related death. Tumor over-growth or radiation resistance is the reason for local recurrence, and chemo-resistance is the cause of distant metastasis. Thus, understanding the mechanism for tumor growth, metastasis and treatment resistance is an important issue. Defensin 6 (DEF6) is a small antimicrobial peptide. Previous study indicated DEF6 is overexpression in colorectal adenocarcinoma. However, up till now the role and its related mechanism in the progression and therapeutic response in colorectal cancer are still unclear. Surprisingly, according to our preliminary data, we found DEF6 expression is lower in colon cancer tissue. Moreover, when overexpressed DEF6 decreased the cellular proliferation, migration, invasion in DLD-1 cells. Those preliminary results show that DEF6 may play an important role in colon cancer. In the study, we plan to further dissect the role and its mechanism of DEF6 in colon cancer including cellular proliferation migration, invasion and therapeutic response. Moreover, we also want develop drugs that target to DEF6 for colorectal cancer. We believe this research can provide useful information not only to identify how dose DEF6 involved in the cancer progression, therapeutic efficacy, but a new targeted therapy for colon cancer.