Anticancer activity of resveratrol on implanted human primary gastric carcinoma cells in nude mice.
OBJECTIVE
To investigate the apoptosis of implanted primary gastric cancer cells in nude mice induced by resveratrol and the relation between this apoptosis and expression of bcl-2 and bax.


METHODS
A transplanted tumor model was established by injecting human primary gastric cancer cells into subcutaneous tissue of nude mice. Resveratrol (500 mg/kg, 1,000 mg/kg and 1,500 mg/kg) was directly injected beside tumor body 6 times at an interval of 2 d. Then changes of tumor volume were measured continuously and tumor inhibition rate of each group was calculated. We observed the morphologic alterations by electron microscope, measured the apoptotic rate by TUNEL staining method, detected the expression of apoptosis-regulated genes bcl-2 and bax by immunohistochemical staining and PT-PCR.


RESULTS
Resveratrol could significantly inhibit carcinoma growth when it was injected near the carcinoma. An inhibitory effect was observed in all therapeutic groups and the inhibition rate of resveratrol at the dose of 500 mg/kg, 1,000 mg/kg and 1,500 mg/kg was 10.58%, 29.68% and 39.14%, respectively. Resveratrol induced implanted tumor cells to undergo apoptosis with apoptotic characteristics, including morphological changes of chromatin condensation, chromatin crescent formation, nucleus fragmentation. The inhibition rate of 0.2 mL of normal saline solution, 1,500 mg/kg DMSO, 500 mg/kg resveratrol, 1 000 mg/kg resveratrol, and 1 500 mg/kg resveratrol was 13.68+/-0.37%, 13.8+/-0.43%, 48.7+/-1.07%, 56.44+/-1.39% and 67+/-0.96%, respectively. The positive rate of bcl-2 protein of each group was 29.48+/-0.51%, 27.56+/-1.40%, 11.86+/-0.97%, 5.7+/-0.84% and 3.92+/-0.85%, respectively by immunohistochemical staining. The positive rate of bax protein of each group was 19.34+/-0.35%, 20.88+/-0.91%, 40.02+/-1.20%, 45.72+/-0.88% and 52.3+/-1.54%, respectively by immunohistochemical staining. The density of bcl-2 mRNA in 0.2 mL normal saline solution, 1,500 mg/kg DMSO, 500 mg/kg resveratrol, 1,000 mg/kg resveratrol, and 1,500 mg/kg resveratrol decreased progressively and the density of bax mRNA in 0.2 mL normal saline solution, 1,500 mg/kg DMSO, 500 mg/kg resveratrol, 1,000 mg/kg resveratrol, and 1,500 mg/kg increased progressively with elongation of time by RT-PCR.


CONCLUSIONS
Resveratrol is able to induce apoptosis of transplanted tumor cells. This apoptosis may be mediated by down-regulating apoptosis-regulated gene bcl-2 and up-regulating the expression of apoptosis-regulated gene bax.
Zhou
Hai-Bo
HB
Department of Gastroenterology, Second Hospital of Zhejiang University, Hangzhou 310009, Zhejiang Province, China. zhouhaibohz@163.com
Chen
Juan-Juan
JJ
Wang
Wen-Xia
WX
Cai
Jian-Ting
JT
Du
Qin
Q
D020533:Angiogenesis Inhibitors / Q000627:therapeutic use*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D002455:Cell Division / Q000187:drug effects; D017931:DNA Primers; D006801:Humans; D051379:Mice; D008819:Mice, Nude; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000235:genetics; D000077185:Resveratrol; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013267:Stilbenes / Q000627:therapeutic use*; D013274:Stomach Neoplasms / Q000188:drug therapy / Q000235:genetics / Q000473:pathology*; D014183:Transplantation, Heterologous; D051028:bcl-2-Associated X Protein
D020533:Angiogenesis Inhibitors; C494826:BAX protein, human; C494827:Bax protein, mouse; D017931:DNA Primers; D019253:Proto-Oncogene Proteins c-bcl-2; D013267:Stilbenes; D051028:bcl-2-Associated X Protein; D000077185:Resveratrol