The Mechanisms Of A New Protein From Malva Seed Exhibit Anticancer Activities Via Induced Apoptosis

The malva seed is dry mature fruits of malvaceae malva plants, which are abundant resources of medicinal plants and primarily grow in Inner Mongolia, Sichuan, Shanxi and Yunnan provinces of China. They circulate through the large intestine and urinary bladder meridian, therefore, they have anti-inflammation, anti-bacterial effects on the digestive and urinary system in according to "Compendium of Materia Medica". Moreover, malva seed, is used to as an anticancer ingredient from traditional Chinese medicine, but little is known about its inhibitory mechanism on the growth of cancer cells. The study shows that MSP, a new protein from malva seed, exhibits anti-cancer potential. The research includes the following three parts:1. The protein with anti-tumor activity was isolated by a few steps of purification, and named as MSP. Results of mass spectrometry analysis showed that MSP shared high homology with the pre-mRNA cleavage complex 2 protein Pcfll of Homo sapiens. The results from MTT showed that MSP had obvious effects on the apoptosis of colon cancer as well as bladder cancer cells.2. Cell cycle analysis was performed to evaluate MSP influenced cancer cell growth by flow cytometry. Western blotting assay was used to detect the alteration of cell cycle-related proteins. The levels of c-Myc, Cyclin D1 and p-Rb proteins were progressively reduced in a time-dependent manner. Furthermore, MSP treatment induced G1 phase arrest in DLD1 and T24 cells, and had no remarkable effect on FHC cells.3. FHC, DLD1 and T24 cell death by MSP treatment were analyzed by flow cytometry and DAPI staining; the mitochondrial membrane potential was estimated using JC-1 fluorescent staining; Western blotting assay was used to detect the alteration of extrinsic and intrinsic apoptosis pathways related proteins. The results indicated that MSP could trigger the extrinsic pathways by up-regulation of Fas/FasL, caspase-8 and caspase-3 protein levels. Meanwhile, MSP could result in the loss of mitochondrial transmembrane potential, which up-regulated the expressions of cyt-c, Bax as well as p53 and down-regulated Bcl-2 proteins, and led to cell apoptosis.In summary, MSP displays anti-tumor effects on DLD1 and T24 cells via the cell cycle arrest and induction of apoptosis, and has promising potential to be exploited as a therapeutic drug.