Studies On Telomere And Telomerase Activity In Apoptotic Mechanism Of MDCC-MSB1 Induced By LaCl₃ In Vitro

Some early studies imply that high level of rare earth has some hereditary toxieity, while low level rare earth may be very effective in cancer therapy. As the research of rare earth goes further every day in the regions of medicine and biochemistry, it will play a more important role in the life science. Telomerase is a reverse transcription enzyme which relied on RNA and prolonged the telomere length. Telomerase activation is the key step of cell immortalization and tumor formation. Telomerase activity increased in malignant tumors. Telomerase reverse transcriptase (TERT) is the catalytic subunit in telomerase, which increased the transcriptional level is the key step in telomerase activated. MD may taken as a model of cancer desease research by virtue of resemblance with mammal cancer. In the study, discuss the role of telomere and telomerase activity of MDCC-MSB1 induced by LaCl₃ in vitro. We cultivated the MDCC-MSB1 cell regularly, add 3 mmol·L^-1 LaCl₃. After 12h, 24h, 36h, 48h cuture, utilizing flow cytometry, TUNEL, electrophoretic analysis of DNA, fluorescence in situ hybridization (FISH) analysis, TRAP assay, real-time quantitative to detect the changes of apoptotic morphology and DNA fragmentation, cell cycle, telomere length, telomerase activity and the expression of chTERT mRNA. The mechanism will provide evidence in the treatment of MD and other cancer diseases. The results showed as follows:1. Cell growth condition was detected by inverted microscope. Morphology changes were detected by AO/EB double fluorescence coloration, HE staining, transmission electron microscope, which revealed that MDCC-MSB1 apoptosis was induced by LaCl₃ accompanied with time-effect relation.2. Applying agarose gel electrophoresis, alkality SCGE, TUNEL to detect MDCC-MSB1 DNA damage. The results showed that LaCl₃ could damage the DNA of MDCC-MSB1 accompanied with time-effect relation. It hinted that causing cell DNA damage may be one mechanism of cell apoptosis induced by LaCl₃.3. Utilizing PI dyeing flow cytometry to detect the change of cell cycle. The result showed that LaCl₃ could induce cell G1 period blocking while inhibited cell generation accompanied with time-effect relation. 4. Utilizing Flow-FISH analysis, TRAP assay, real-time quantitative to detect the telomere length, telomerase activity and the expression of chTERT mRNA. LaCl₃ was able to shorten telomere length of MDCC-MSB1 and reduced its expression of chTERT mRNA and inhibited telomerase activity which could induce cell apoptotic through telomerase activity pathway.In conclusion, LaCl₃ could induce MDCC-MSB1 cell apoptosis accompanied with time-effect relation in experiment concentration. It indicated that LaCl₃ could damage DNA and shorten the telomere length through down-regulating of the expression of telomerase chTERT mRNA, and decrease the activation of telomerase in tumor cells which may be one mechanism of cell apoptotic induced by LaCl₃.