Molecular Mechanism Of Apoptosis Induction By Cucurmosin And Its Synergy With STI571 Against K562 Cells

Chemotherapy is one of the three major therapeutic modalities for the treatment of malignancies. In recent years, apoptosis-inducing therapy and induction of differentiation have opened new avenues to cancer chemotherapy and have achieved some success. However, ideal drugs for induction of apoptosis and differentiation have yet remained to be developed. Further investigation of biologically active substances from natural sources on their anti-tumor activities especially to induce apoptosis and differentiation will acid in the discovery of ideal anticancer drugs.The ribosome-inactivating proteins (RIPs) from plant sources have been shown to possess a variety of biological properties including anti-fertile and anti-viral activities, etc. Their anti-tumor activities have attracted considerable attention. A new RIP, Cucurmosin, was isolated from pumpkin, the sarcocarp of Cucurbita moschata, by this laboratory. The goal of this study was to examine its anti-tumor effects both in vitro and in vivo and explore the underlying mechanisms with the aim of providing theoretical rationale and experimental evidence for its potential clinical application.â… . In vitro and in vivo anti-tumor activities of Cucurmosin and its effect on induction of apoptosis in K562 cellsThe results from in vitro studies showed that Cucurmosin exhibited relatively potent killing effect on the human chronic myeloid leukemia (CML) K562 cell line and the murine B16 melanoma cell line in a concentration- and time- dependent manner. The result by MTT assay revealed that the IC50 on K562 cells for the positive control trichosanthin (TCS) was more than 4-fold greater than...