Background. The aim of this study was to clarify the
effect of bevacizumab on gastric cancer with peritoneal
metastasis in nude mice.
Materials and Methods. The expression of vascular
endothelial growth factor mRNA (VEGF mRNA) in
four gastric cancer cell lines, NCI-N87, MKN-45, MKN-
45P, and Kato-III, was examined by polymerase chain
reaction. We created a model of peritoneal metastasis
by injecting mice with the human gastric cancer cell
line MKN-45P. Mice were injected intraperitoneally
with bevacizumab (0.1mg/100mL) on days 5–14, after inoculation
(n[10) or with phosphate-buffered saline
(PBS) over the same time period (n[10). The maximum
abdominal circumference, ascites volume, and
the total number and weight of peritoneal tumors
were measured. To assess the effect of bevacizumab
on angiogenesis, immunohistochemical analysis was
performed.
Results. VEGF mRNA was expressed at a high level
in MKN-45P cells as well as MKN-45 and Kato-III. The
mean maximum abdominal circumference and ascites
volume in the bevacizumab group were significantly
less than those in the control group (P<0.001, respectively).
The total weight of disseminated tumors in the
bevacizumab group was also significantly less than
that in the control group (P<0.01). In addition, immunohistochemical
analysis of CD31-stained peritoneally
disseminated nodules showed that the vessel area in
the bevacizumab group was significantly less than
that in the control group (P<0.001).
Conclusions. These results show that intraperitoneal
administration of bevacizumab inhibits peritoneal metastasis and reduces malignant ascites in tumorbearing
mice.