Preferential splenic metastases in parabiotic animals

Abstract

A reticulum cell sarconia which metastasizes preferentially to the spleens of inbred C, H mice has been studied. Placement of tumor-bearing animals in parabiosis with normal animals was followed by the development of gross metastases limited to the spleen in 100% of the normal animals. The pattern of metastases observed when a tumor-bearing animal was placed in parabiosis with a splenectomized animal is described. The splenotrophic tendencies of this tumor and its ability to metastasize selectively across a parabiotic union provide a model for investigation of the role of immunity and humoral factors in tumor metastases.

The role of the spleen and immunity in the metastatic pattern of a murine reticulum cell sarcoma

“…The role of the spleen in this RCS tumor system is of considerable interest. It has previously been shown that in the absence of the spleen there is an increased incidence of metastases developing in the liver and kidneys, whereas in animals with a spleen, visceral metastases develop primarily in that organ (Pilgrim, 1971 ;Schour and Faraci, 1974). Findings in the present study suggest that this is a quantitative phenomenon since, in the experimental model containing two spleens, there is a further decrease in the incidence of nonsplenic visceral metastases.…”

“…Previous studies (Pilgrim, 1969;Schour and Faraci, 1974) have described a reticulum cell sarcoma (RCS) which metastasizes selectively to the spleen. Since removal of the spleen has been reported to alter the distribution of metastases in this tumor system (Pilgrim, 1971), experiments were devised to determine the effect of the addition of splenic tissue on the behavior of this tumor.…”