BACKGROUND. Gastric cancer is one of the most common cancers in Asia.
Chemotherapy and radiation therapy have had limited success. Recently,
paclitaxel has been found to be effective against a variety of cancer
s, including lung, breast, ovary, melanoma, and prostate. Whether pacl
itaxel is effective in the treatment of gastric cancer is not known an
d is worthy of investigation. METHODS. Human gastric carcinoma cell li
nes NUGC-3 and SC-M1 were examined for response to paclitaxel treatmen
t. Cancer cells were treated with paclitaxel (0.001, 0.01, 0.1, and 1
mu M) for 1-3 days. Cell number was counted by hemocytometer and cell
viability was determined by the trypan blue exclusion method. Cell cyc
le progression and expression of proliferating cell nuclear antigen (P
CNA) were examined by flow cytometry. The percentage of apoptotic cell
s was determined after staining with hematoxylin and eosin. RESULTS. P
aclitaxel was cytotoxic to the two human gastric carcinoma cell lines
examined. The growth-inhibiting dose was 0.01 mu M. Paclitaxel-treatcd
gastric carcinoma cells were arrested mainly in G(2)/M phases before
apoptosis. However, treatment with 0.01 mu M of paclitaxel resulted in
a decrease of cells at G(0)/C-1 phases without an increase of cells a
t G(2)/M phase indicating that paclitaxel was also cytotoxic to gastri
c carcinoma cells at G(0)/G(1) phases. In addition, the expression of
PCNA was significantly increased in 0.1 and 1 mu M paclitaxel-treated
cells, suggesting that DNA repair was increased in these cells. CONCLU
SIONS. Paclitaxel is effective in growth inhibition of gastric carcino
ma cell lines in clinically attainable concentrations. Our results sug
gest that paclitaxel is a potential chemotherapeutic drug for gastric
carcinoma. (C) 1996 American Cancer Society.