[Effect of a selective inducible nitric oxide synthase inhibitor on cell growth in human colorectal cancer Lovo cell line].
OBJECTIVE
To investigate the effect of a selective inducible nitric oxide synthase(iNOS) inhibitor, aminoguanidine (AG), on the proliferation and apoptosis of human colorectal cancer (CRC) Lovo cell line, and explore its possible mechanism.


METHODS
MTT assay was used to detect the inhibition of Lovo cell growth by aminoguanidine. Apoptosis and cell cycle of Lovo cells were examined by flow cytometry (FCM). Morphologic change of Lovo cell treated by AG was observed with AO/EB staining.


RESULTS
There were significant differences in 0.5 mmol/L and 1.0 mmol/L AG groups as compared to the control group (P<0.05). The absorbance (A) values of Lovo cells in each time point were significantly different (P<0.05). Growth of Lovo cells was inhibited by aminoguanidine in a dose- and time-dependent manner. FCM analysis showed that the cell ratio of G(0)/G(1) phase increased with the increasing of the concentration of aminoguanidine, but the cell ratio of S-and G(2)/M phase decreased correspondingly (P<0.05). S phase fraction and proliferation index (PI) decreased remarkably, and the apoptotic rate of Lovo cells increased. After AG treatment, AO/EB staining revealed some apoptotic morphological features such as cell shrinkage, nuclear condensation, DNA fragmentation, and formation of apoptosis bodies.


CONCLUSIONS
Aminoguanidine inhibits the proliferation and facilitates the apoptosis of human CRC Lovo cells. One of the mechanisms may be explained as blocking the progress of cell cycle of CRC Lovo cells by aminoguanidine.
Wei
Bo
B
Department of Gastrointestinal Surgery, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou 510630, China.
Wei
Hong-Bo
HB
Qi
Cui-Ling
CL
Han
Xiao-Yan
XY
Wang
Tian-Bao
TB
D017209:Apoptosis / Q000187:drug effects; D002453:Cell Cycle / Q000187:drug effects; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects*; D015179:Colorectal Neoplasms / Q000378:metabolism; D019008:Drug Resistance, Neoplasm / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006146:Guanidines / Q000494:pharmacology*; D006801:Humans; D052247:Nitric Oxide Synthase Type II / Q000037:antagonists & inhibitors*
D004791:Enzyme Inhibitors; D006146:Guanidines; D052247:Nitric Oxide Synthase Type II; C004479:pimagedine