Role of concomitant resistance in the development of murine lung metastases.
An attempt was made to explain the distinct lung metastatic patterns of 2 mammary adenocarcinomas with a common BALB/c origin: M3, which does not induce spontaneous metastases, and MM3 with an almost 100% incidence. No difference between the 2 tumors was detected with respect to host mononuclear cell content, degree of immunogenicity or lung-colony-forming ability. Conversely, there was a marked difference in the capacity to induce concomitant resistance: M3-bearing mice induced stronger and earlier resistance against i.v. challenge of both M3 and MM3 tumor cells than MM3-bearing mice; this resistance was expressed as lower number of lung metastases and lower tumor-cell proliferation in metastatic nodules. M3 was also able to control the development of spontaneous metastases: metastases developed in all M3-excised mice, compared with none in M3-bearing mice, while MM3-bearing mice also bearing a secondary M3 tumor developed fewer metastases than mice bearing MM3 only. This anti-metastatic effect does not appear to depend on classical immunological mechanisms since no difference could be detected between the 2 tumors in response to T cells, NK, macrophages or antibodies.
Bonfil
R D
RD
Seccion Leucemia Experimental, Academia Nacional De Medicina, Buenos Aires, Argentina.
Ruggiero
R A
RA
Bustuoabad
O D
OD
Meiss
R P
RP
Pasqualini
C D
CD
D000230:Adenocarcinoma / Q000276:immunology / Q000556:secondary*; D000818:Animals; D005260:Female; D008175:Lung Neoplasms / Q000276:immunology / Q000556:secondary*; D008325:Mammary Neoplasms, Experimental / Q000276:immunology*; D051379:Mice; D009368:Neoplasm Transplantation