Synergistic inhibition of mammary carcinoma transplants in A-strain mice by antitumour globulin and C. parvum.

M F A Woodruff,M P Inchley

doi:10.1038/bjc.1971.74

Abstract

It has been confirmed that the growth of intrastrain transplants of a mammary carcinoma in A/HeJ mice is inhibited to a moderate extent by giving the prospective recipient an intravenous injection of killed C. parvum 2 days before tumour inoculation. Intraperitoneal injection of C. parvum gave similar results but subcutaneous injection was less effective. Incubation of tumour cells with heterospecific antitumour globulin (ATG) in the absence of complement before inoculation sometimes but not always resulted in moderate inhibition of tumour growth. When pre-incubation of tumour cells with ATG and treatment of the host with C. parvum were combined the inhibitory effect was much greater than that produced by either procedure alone, and was roughly equivalent to reducing the dose of viable cells in control animals by a factor of 100. Since A/HeJ mice lack the fifth component of complement (C'5) it was expected that this serum would be ineffective as a source of C' in in vitro cytotoxic tests but effective in opsonisation tests. This has been confirmed. The possible significance of this finding in relation to the synergistic effect of ATG and C. parvum is discussed.

Highlights

SUMMARY.-It has been confirmed that the growth of intrastrain transplants of a mammary carcinoma in A/HeJ mice is inhibited to a moderate extent by giving the prospective recipient an intravenous injection of killed C. parvum 2 days before tumour inoculation
As already reported (Woodruff and Smith, 1970), the growth of isogeneic mammary carcinoma transplants in A-strain mice may be inhibited by treating the recipient with heterospecific antitumour globulin (ATG), but the degree of inhibition is variable and never very marked
We have found that, while tumour growth may be inhibited to a modest extent following this procedure, it may, on the other hand, be unaffected or even facilitated

Summary

Introduction

SUMMARY.-It has been confirmed that the growth of intrastrain transplants of a mammary carcinoma in A/HeJ mice is inhibited to a moderate extent by giving the prospective recipient an intravenous injection of killed C. parvum 2 days before tumour inoculation. It has already been reported from this laboratory that intravenous injection of this material, either 2 days before or 8-12 days after subcutaneous inoculation of viable mammary carcinoma cells in A-strain mice, significantly delays growth of the tumour (Woodruff and Boak, 1966; Smith and Woodruff, 1968).

Results

Conclusion