[Dynamic change of intracellular-free calcium levels and its mechanism in the process of gastric carcinoma cellular apoptosis].
OBJECTIVE
To study the dynamic change of intracellular-free calcium levels ([Ca2+]i) and its mechanism in the process of gastric carcinoma cellular apoptosis.


METHODS
Apoptosis induced by cisplatin in gastric carcinoma cell was investigated by applying light microscopy, electron microscopy, agarose gel electrophoresis, and flow cytometry. [Ca2+]i was determined by applying Fura-2 fluorescein load technic, inositol 1,4,5-trisphosphate (IP3) levels were determined by applying competitive protein binding method.


RESULTS
Gastric carcinoma cell treated with cisplatin (2 micrograms/ml) for 24 hours expressed typical change of apoptosis, such as apoptosis body, cell shrinkage, condensation and fragmentation of chromosomes, DNA ladder bands, apoptosis beak in flow cytometry. [Ca2+]i in the process of gastric carcinoma cellular apoptosis was significantly higher than that in control groups, especially at the beginning stage of apoptosis. In the other experiment, we compared the common effect of cisplatin and verapanil (a kind blocking agent of calcium channel) on [Ca2+]i. Verapanil limited the increase of [Ca2+]i resulting from cisplatin. At the early stage of gastric carcinoma cellular apoptosis, IP3-levels were significantly higher.


CONCLUSIONS
Intracellular-free calcium is an important signal molecule in the process of signal transduction of gastric carcinoma cellar apoptosis, and [Ca2+]i is significantly higher, the increase of [Ca2+]i is resulted from the entry of extra cellular calcium and the release of intracellular calcium pools.
Xing
C
C
Department of Oncology, First Hospital of China Medical University, Shenyang 110001.
Chen
J
J
D000970:Antineoplastic Agents / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects*; D001693:Biological Transport, Active; D002118:Calcium / Q000378:metabolism*; D000252:Calcium-Transporting ATPases; D002945:Cisplatin / Q000494:pharmacology; D006801:Humans; D015398:Signal Transduction; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology*; D014407:Tumor Cells, Cultured
D000970:Antineoplastic Agents; D000252:Calcium-Transporting ATPases; D002945:Cisplatin; D002118:Calcium