Antiproliferative effect of octreotide on gastric cancer cells mediated by inhibition of Akt/PKB and telomerase.
OBJECTIVE
To investigate the antiproliferative effect of octreotide, a long-acting analogue of somatostatin, on gastric cancer cell line SGC7901 and its possible molecular mechanisms.


METHODS
Gastric cancer cell line SGC7901 employed in the study was treated with 0.008, 0.04, 0.2, 1, 5 and 25 microg.ml(-1) of octreotide respectively for 24 h to evaluate the antiproliferative effect of somatostatin analog on the tumor cells by MTT assay method. To elucidate the underlying mechanism, the cells were exposed to 1 microg.ml(-1) of octreotide for 0, 12, 24 and 48 h, when their Akt/PKB and telomerase activities were respectively determined using PCR-ELSIA and nonradioactive protein kinase assay protocols. The same experimental procedures were also performed in the control cells that were treated with corresponding vehicles instead of somatostatin analog.


RESULTS
After exposed to octreotide for 24 h at the concentrations of more than 1 microg.ml(-1), SGC7901 cells exhibited a dose-dependent inhibition of growth with the inhibiting rate to be as high as 34.66% when 25 microg.ml(-1) of octreotide was applied. The Akt/PKB and telomerase activity of SGC7901 cells was significantly inhibited when the cells were exposed to 1 microg.ml(-1) of octreotide for 12, 24 and 48 h compared with that of their control counterparts (P<0.01), both of which exhibited in a time-dependent manner.


CONCLUSIONS
The antiproliferative effect of octreotide on SGC7901 cells might be mediated by the inhibition of Akt/PKB and telomerase.
Gao
Shan
S
Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, Hubei Province, China.
Yu
Bao-Ping
BP
Li
Yan
Y
Dong
Wei-Guo
WG
Luo
He-Sheng
HS
D018931:Antineoplastic Agents, Hormonal / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects; D045744:Cell Line, Tumor / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D015282:Octreotide / Q000494:pharmacology*; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D013274:Stomach Neoplasms; D019098:Telomerase / Q000037:antagonists & inhibitors* / Q000378:metabolism
D018931:Antineoplastic Agents, Hormonal; D011518:Proto-Oncogene Proteins; C494918:AKT1 protein, human; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D019098:Telomerase; D015282:Octreotide