Effect of NF-kappaB constitutive activation on proliferation and apoptosis of gastric cancer cell lines.
OBJECTIVE
To observe whether there is constitutive activation of nuclear transcription factor kappaB (NF-kappaB) and its effect on proliferation and apoptosis of human gastric cancer cell lines.


METHODS
Nuclear/cytoplasmic protein expression of NF-kappaB was analyzed by Western blot in four different gastric cancer cell lines. Trans AM(TM) NF-kappaB p65 Kit was used for detecting the difference of p65 activity. The effect of PDTC (pyrrolidine dithiocarbamate), a specific inhibitor of NF-kappaB on the proliferation of gastric cancer cells, was measured by MTT (3-[4,5-dimethythiazol-2-yl]-2,5-diphenyltetrazolium bromide) method. The apoptotic rates of AGS and SGC-7901 gastric cancer cell lines were measured with flow cytometer (FCM) after treatment by PDTC.


RESULTS
The constitutive activations of NF-kappaB were identified in four gastric cancer cell lines. The expression of activated subunit of p50 was lower in AGS cell line, and higher in MKN28, MKN45 and SGC-7901 cell lines. The expression of activated subunit of p65 was lower in MKN28 and MKN45 cell lines, and higher in AGS and SGC-7901 cell lines. Both the activity of NF-kappaB and the cell proliferation were significantly inhibited in experimental group treated by PDTC, compared with control groups (p<0.01). An increased apoptotic rate and a decreased proliferating activity were observed after the gastric cancer cells were exposed to PDTC for 24 h.


CONCLUSIONS
These results suggested that the constitutive activation and the protein expression of NF-kappaB are different in gastric cancer cell lines. PDTC can inhibit NF-kappaB activity and cell proliferation, which related to an increased cell apoptosis. The results disclosed that NF-kappaB could be a potential therapeutic target for solid tumor therapy.
Li
Q
Q
Shanghai Institute of Digestive Surgery, Ruijin Hospital, Shanghai Second Medical University, Shanghai, China.
Yu
Y-Y
YY
Zhu
Z-G
ZG
Ji
Y-B
YB
Zhang
Y
Y
Liu
B-Y
BY
Chen
X-H
XH
Lin
Y-Z
YZ
D000230:Adenocarcinoma / Q000378:metabolism* / Q000473:pathology; D017209:Apoptosis; D002455:Cell Division; D045744:Cell Line, Tumor; D002467:Cell Nucleus / Q000378:metabolism; D005260:Female; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D052002:NF-kappa B p50 Subunit; D011498:Protein Precursors / Q000378:metabolism; D013274:Stomach Neoplasms / Q000378:metabolism* / Q000473:pathology; D051996:Transcription Factor RelA
D016328:NF-kappa B; D052002:NF-kappa B p50 Subunit; D011498:Protein Precursors; D051996:Transcription Factor RelA