Influence of paeonol on expression of COX-2 and p27 in HT-29 cells.
OBJECTIVE
To investigate the effect of paeonol on controlling the proliferation of colorectal cancer cell line HT-29 and to discuss its possible mechanism.


METHODS
The inhibitory effect of paeonol on proliferation of HT-29 cells was detected by MTT assay. The results of apoptosis were measured by flow cytometry. Immunocytochemical staining was performed to detect the expression of cyclooxygenase-2 (COX-2) and protein p27 in HT-29 cells treated with paeonol at different concentrations. Reverse transcription-polymerase chain reaction (RT-PCR) was used for mRNA analysis.


RESULTS
From the data of both MTT and flow cytometry, we observed that cell proliferation was inhibited by different concentrations of paeonol. By immunocytochemical staining, we found that HT-29 cells treated with paeonol (0.024-1.504 mmol/L) reflected reduced expression of COX-2 and increased expression of p27 in a dose-dependent manner. RT-PCR showed that paeonol down-regulated COX-2 and up-regulated p27 in a dose- and time-dependent manner in HT-29 cells.


CONCLUSIONS
One of the apoptotic mechanisms of paeonol is down-regulation of COX-2. p27 is up-regulated simultaneously and plays an important part in controlling cell proliferation and is a crucial factor in the Fas/FasL apoptosis pathway.
Ye
Jun-Mei
JM
Gastroenterology Department, Renmin Hospital, Wuhan University, Wuhan 430060, Hubei Province, China.
Deng
Tao
T
Zhang
Jian-Bao
JB
D000098:Acetophenones / Q000494:pharmacology*; D017209:Apoptosis / Q000187:drug effects*; D049109:Cell Proliferation / Q000187:drug effects; D050760:Cyclin-Dependent Kinase Inhibitor p27 / Q000187:drug effects / Q000378:metabolism*; D051546:Cyclooxygenase 2 / Q000187:drug effects / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D005434:Flow Cytometry; D019073:HT29 Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D015854:Up-Regulation
D000098:Acetophenones; D018809:Proliferating Cell Nuclear Antigen; D012333:RNA, Messenger; D050760:Cyclin-Dependent Kinase Inhibitor p27; C013638:paeonol; D051546:Cyclooxygenase 2