Suppression of in vivo tumor growth by the transfection of the interleukin-5 gene into colon tumor cells.
To investigate the influence of tumor producing interleukin-5 (IL-5) on growth kinetics of tumors, we transduced the murine IL-5 gene into murine colon C26 tumor cells. Two IL-5-secreting clones, low-level IL-5 producer C26-8B and high-level IL-5 producer C26-6F, were established. Both tumors, C26-6F and C26-8B, grew more slowly than the mock C26 tumor, although the in vitro growth rate of these IL-5 transfectants was much the same as that of the mock C26 cells. There was a significantly decreased number of colonies in the lung of mice given C26-6F or C26-8B tumors i.v. than in mice given mock C26 tumors i.v. Moreover, in mice given C26-6F cells i.v., a smaller number of tumor colonies in the lung was observed, as compared to the case with C26-6B cells. While the growth rate of C26-8B tumors in mice treated with anti-IL-5 mAb was more rapid than that seen in control mAb-treated mice, growth of C26-6F tumors in anti-IL-5-mAb-treated mice was slightly more rapid compared to findings in control mAb-treated mice. The isotype-matched mAb did not alter the in vitro growth of mock-C26 cells or of the IL-5-gene-modified C26 cells. Growth of IL-5-secreting C26 tumors transplanted in nude mice was also inhibited. These results suggest that tumor-producing IL-5 inhibits growth of colon tumors mediated through T-cell-independent protective mechanisms of the host.
Masuda
Y
Y
Department of Surgery II, Kumamoto University Medical School, Japan.
Mita
S
S
Sakamoto
K
K
Ishiko
T
T
Ogawa
M
M
D000818:Animals; D000911:Antibodies, Monoclonal / Q000276:immunology / Q000494:pharmacology; D002277:Carcinoma / Q000473:pathology / Q000517:prevention & control / Q000556:secondary / Q000628:therapy*; D002455:Cell Division; D003110:Colonic Neoplasms / Q000473:pathology / Q000628:therapy*; D015316:Genetic Therapy; D007155:Immunologic Factors / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D015848:Interleukin-5 / Q000235:genetics / Q000276:immunology / Q000378:metabolism / Q000502:physiology*; D008175:Lung Neoplasms / Q000517:prevention & control / Q000556:secondary; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D009368:Neoplasm Transplantation; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014162:Transfection; D014407:Tumor Cells, Cultured
D000911:Antibodies, Monoclonal; D007155:Immunologic Factors; D015848:Interleukin-5; D011993:Recombinant Fusion Proteins