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Abstract

Using the method of flow cytofluorometry we found that proteinase activity eliminating antigenic determinants from the surface of tumor cells disappeared from the serum of mice with Ehrlich carcinoma. This activity towards Ehrlich carcinoma cells is present in the sera of mice without tumors and in mice with other transplanted tumors. The serum from mice of one strain with Ehrlich carcinoma showed no protease activity against Ehrlich carcinoma cells in mice of other strain. Hence, Ehrlich carcinoma growth is associated with tumor-specific changes in the serum resulting in disappearance of specific protease activity of the serum against tumor cells.

Specificity of relapses and metastases of experimental transplanted Ehrlich carcinoma and B16 melanoma

“…Metastatic growth of only resected tumor was observed in animals with two transplanted tumors (Ehrlich carcinoma and B16 melanoma); the life span was determined by the growth rate of the more rapidly growing tumor (B16 melanoma), this indicating some specific effect. This specific effect cannot be mediated by the known angiogenic factors [2,3,6], because they should be common for all tumors and stimulate metastatic growth of both Ehrlich carcinoma and B16 melanoma after resection of one of the tumors. We think that the specific inhibitory effect of the primary tumor can be due to peculiar glycosylation and subsequent formation of complexes of serum proteins with the tumor [3][4][5].…”

“…This specific effect cannot be mediated by the known angiogenic factors [2,3,6], because they should be common for all tumors and stimulate metastatic growth of both Ehrlich carcinoma and B16 melanoma after resection of one of the tumors. We think that the specific inhibitory effect of the primary tumor can be due to peculiar glycosylation and subsequent formation of complexes of serum proteins with the tumor [3][4][5]. The formation of complexes with serum proteins (the complex consists of 4 proteins, one of which is haptoglobin with 20% carbohydrates) was detected in mice with Ehrlich carcinoma.…”

“…Attempts at isolation of the primary tumor inhibitory factor failed and its existence was not confirmed [7]. Moreover, the problem of specificity of angiogenic factors for each tumor remains unsolved [3].We studied the specificity of metastases of tumors of different origin after removal of the primary node. …”

Lectin Binding to Mouse Blood Lymphocytes during Tumor Growth

“…Ehrlich carcinoma and CaO-1 ovarian carcinoma cells were transplanted intramuscularly (10 6 cells in 0.2 ml RPMI-1640) [1]. Lymphocytes were isolated from the peripheral blood of mice on day 15 after tumor transplantation by the standard method in 1.093 density gradient [3]. Each experiment was repeated at least 3 times.…”

“…On the other hand, there are virtually no data on tumor-specific changes in the body during tumor growth. The presence of these changes is demonstrated in reports indicating that serum and leukocytes of animals with transplanted tumors are characterized by a specific biological effect protecting tumor cells in the host [4,5,7]. We showed that Ehrlich carcinoma causes changes in mouse serum, specific of this tumor [2].…”