Antheraea proylei J. Sericin Induces Apoptosis in a Caspase-Dependent Manner in A549 and HeLa Cells

aims: To investigate anticancer activity of sericin preparation from cocoons of A. proylei. background: In spite of much progress in understanding the biology of cancer disease, advancement in technology for early diagnosis, the expanding array of anticancer drugs and treatment modalities, the global cancer burden is still significant and increasing. It is estimated that the new cases of cancer in the year 2040 will be 29.4 million per year globally. Sericin, an adhesive protein of silk cocoons has been shown to be a potential protein in various biomedical applications including cancer therapeutics. The present study evaluates the anticancer property of sericin from cocoons of Antheraea proylei J (SAP) against human lung cancer (A549) and cervical cancer (HeLa) cell lines. This is the first report of anti-cancer activity of the non-mulberry silkworm A. proylei J. objective: 1. Establish antiproliferative potential of SAP. 2. Identify the molecular mechanism of cell death induced by SAP on two different cell lines. method: SAP was prepared from cocoons of A. proylei J. by the process of degumming method. The amino acid composition of SAP was determined by HPLC. Cytotoxicity activity was assessed by MTT assay and genotoxicity activity was assessed by comet assay. Cleavage of caspase and PARP proteins and phosphorylation of MAPK pathway members were analysed by Western blotting. Cell cycle analysis was done by flow cytometer. result: SAP causes cytotoxicity to A549 and HeLa cell lines with the IC50 values 3.8 and 3.9 µg/µl respectively. SAP induces apoptosis in a dose dependent manner through caspase-3 and p38, MAPK pathways in A549 and HeLa cells. Moreover, in A549 and HeLa cells SAP induces cell cycle arrest at S phase in a dose dependent manner. conclusion: The difference in the molecular mechanisms of apoptosis induced by SAP in A549 and HeLa cell lines may be due to the difference in the genotypes of the cancer cell lines. However, further investigation is warranted. The overall results of the present study envisage the possibility of using SAP as anti-tumorigenic agent. other: This is the first report of sericin preparation from A. proylei to show anticancer activity. Other reports were from domesticated silkworms.