Studies On The Mechanism Of Apoptosis Of MD Cancer Cell Induced By Arsenic Trioxide

Marek's disease(MD) is a chicken's cancer disease induced by Marek's disease virus(MDV), which is characteristic with lymphocyte proliferation. Traditional vaccine can't get effective protection because of emergence of super velogenic strain. Immunity failure is a common thing in the course of using HVT vaccine. On the other hand, MD may be take as a modle of cancer disease research by virtue of resemblance with mammal cancer. The proven efficacy of arsenic trioxide(ATO)in the treatment of APL and the emerging importance of ATO in other diseases prompted extensive studies of the mechanisms of action of ATO in APL and in other types of cancers. Nowadays, studies on the mechanisms of MDCC-MSB1 are still few. In the study we will focus on inhibitory action and ATO-induced apoptotic pathways with an emphasis on mechanisms in ATO-induced apoptosis through the detection of relative apoptosis index in MDCC-MSB1. The mechanism will provide evidence in the treatment of MD and other cancer diseases. The results showed as follows:1. Inhibition of cell growth was detected by MTT assay. The result showed that cell proliferation may be inhibited by ATO and inhibition ratio exhibite dose dependent.2. Cell growth condition was detected by inverted microscope. Morphology changes were detected by AO/EB double fluorescence coloration, which revealed that MDCC-MSB1 apoptosis was induced by ATO. Apoptosis ratio exhibite dose dependent.3. The change of△Ψm was detected by flow cytometry. It showed that ATO induced MDCC-MSB1 apoptosis by decrease of△Ψm.4. The change of Caspase3 mRNA expression and Caspase3 activity were detected by RT-PCR and Caspase3 Colorimetric Assay Kit. It revealed that the increase of Caspase3 mRNA expression and Caspase3 activity were a key to MDCC-MSB1 apoptosis induced by ATO.5. The changes of [Ca²⁺]i and CaM mRNA expression were detected by fluorometric method and RT-PCR. The result showed that ATO induced MDCC-MSB1 apoptosis by the increase of [Ca²⁺]i and disequilibrium of calcium homeostasis.6. The effect of ATO on expression of Fas mRNA was detected by RT-PCR. It revealed that ATO can induce MDCC-MSB1 apoptosis by increase of FasmRNA expression. It may be one of the mechanisms of apoptosis induced by ATO.ATO may inhibit MDCC-MSB1 growth and induce apoptosis. The mechanisms in ATO-induced apoptosis were related to the increase of△Ψm, [Ca²⁺]i, Caspase3 mRNA expression level, Caspase3 activity and Fas mRNA expression level.