PT  - JOURNAL ARTICLE
AU  - Fisher, Bernard
AU  - Soliman, Osama
AU  - Fisher, Edwin R.
TI  - Further Observations Concerning Effects of Antilymphocyte Serum on Tumor Growth: With Special Reference to Allogeneic Inhibition
DP  - 1970 Jul 01
TA  - Cancer Research
PG  - 2035--2042
VI  - 30
IP  - 7
4099  - http://cancerres.aacrjournals.org/content/30/7/2035.short
4100  - http://cancerres.aacrjournals.org/content/30/7/2035.full
SO  - Cancer Res1970 Jul 01; 30
AB  - Antilymphocyte serum (ALS) administration was observed to abrogate preexisting immunity to C3H tumors, permitting them to grow equally as well as, or slightly better than, in nonimmunized animals. Metastases from spontaneous C3H tumors were observed in ALS-treated mice but not in controls, indicating the possible importance of concomitant immunity in the phenomenon of metastases. This was not related to effects of ALS on the tumor cells per se as revealed by the behavior of transplants from treated animals in syngeneic hosts as well as their unaltered subcellular appearance. ALS failed to influence the latent period of 3-methylcholanthrene-induced tumors. These findings are considered in relation to the observations of others on the mechanism of 3-methylcholanthrene tumor induction. Incubation in vitro of tumor cells in ALS was without effect on their subsequent growth in syngeneic hosts. However, such incubation resulted in complete abrogation of the tumor growth-inhibitory effect observed in F1 hybrids (C3H × DBA). The amount of ALS used in the incubation was insufficient to influence tumor growth when administered at a site remote from that utilized for tumor incubation. Prior incubation in ALS allowed C3H tumor cells to grow in allogeneic DBA mice. When F1 hybrid spleen cells or sensitized lymphocytes were incubated with tumor cells before their inoculation into syngeneic hosts, a retardation of tumor growth occurred. Addition of ALS to the incubate eliminated this inhibitory effect. Inoculation of tumor cells alone resulted in a depression of circulating lymphocytes. When cells were injected in ALS or the latter was inoculated at a separate site, depression of lymphocytes was greater and more sustained than after the administration of either alone. Such findings minimize the importance of lymphopenia in accounting for these results, particularly in the F1 hybrid. Considerations pertinent to these observations strongly indicate the nonimmunological nature of allogeneic inhibition but, also as discussed, tend to minimize the role of the latter as a surveillance mechanism for autochthonous tumors. ©1970 American Association for Cancer Research.