Inhibition of CT-26 murine adenocarcinoma growth in the rectum of mice treated with recombinant human interleukin-6.
In the present study we evaluated the antitumor effects of recombinant human interleukin-6 (rhIL-6), expressed in Chinese hamster ovary cells, in a murine primary tumor model. We showed that treatment with rhIL-6 substantially inhibited the implantation and growth rates of CT-26 adenocarcinoma tumor cells in the rectal submucosa of syngeneic mice. This effect was achieved by injecting rhIL-6 for 7 consecutive days starting 1 day prior to tumor inoculation. No obvious antitumor effect was noted when rhIL-6 injections started 5 days after tumor inoculation. Analysis of the mechanisms by which rhIL-6 exerts its antitumor effects did not reveal a direct antitumor effect on CT-26 tumor cells or the up-regulation of major histocompatibility complex antigens on these cells. However, infiltration of lymphocytes at the tumor site was observed. Increase of carcinoembryonic antigen by IL-6 was clearly seen in human HT-29 colon carcinoma cells. The possible application of these results for adjuvant immunotherapy of selected colorectal patients and prevention of reimplantation of tumor cells disseminated during surgery is discussed.
Rabau
M
M
Department of Oncology, Sourasky Medical Center, Ichilov Hospital, Tel Aviv, Israel.
Kashtan
H
H
Baron
S
S
Yossiphov
J
J
Skornik
Y
Y
Revel
M
M
Eisenthal
A
A
D000230:Adenocarcinoma / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D000818:Animals; D000951:Antigens, Neoplasm / Q000096:biosynthesis; D002455:Cell Division / Q000187:drug effects; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C; D011994:Recombinant Proteins / Q000627:therapeutic use; D012004:Rectal Neoplasms / Q000276:immunology / Q000473:pathology / Q000628:therapy*; D014407:Tumor Cells, Cultured
D000951:Antigens, Neoplasm; D015850:Interleukin-6; D011994:Recombinant Proteins