Invasivol fails to stop growth of tumor cells in areas with many Ehrlich’s mouse cancer cells. Spread of cancer cells from these locations, however, is stopped by Invasivol. Treatment with Invasivol can even lead to the formation of a local tumor at the subcutaneous transplantation sites in mice, while untreated mice do not get any local tumor at the injection site, only ascites with cancer cells in peritoneum. The export of metastatic cells from the transplantation sites in untreated mice probably reduces the local cell number below the limit that is necessary for the tumor cells to catch on there.
If identical cells are collocated, such as in a tumor or in many normal organs, Invasivol will not inhibit growth. But as soon as the cells leave a tumor and invade surrounding tissues, enter the circulation as possible metastases, or settle in peripheral tissues, these scattered cells will be significantly inhibited, inactivated or possibly killed by Invasivol.
The number of subcutaneous transplanted Ehrlich’s mouse tumor cells is probably quickly reduced since the untreated mice develop ascites containing huge amounts of cancer cells often instead of local growth.
In Invasivol treated mice, however, tumor cells transplanted subcutaneously do not reach the abdominal cavity or their growth there is stopped or both. The transplanted and collocated cells in subcutaneous tissue, however, are not killed since they are able to develop tumors at least in sites having got enough cancer cells.
This indicates that a new biological and medical principle is discovered, namely that the substance Invasivol specifically inhibits the growth of single scattered cells in culture or if they are spread sufficiently far from collocated identical cells in the body. However, collocated identical cells are not inhibited locally by this compound. In the body other cell types seem not to affect the effect of Invasivol on such tumor cells.
In a growing cell clone consisting of identical cells, such as tumor cells or immune cells, Invasivol may lose its inhibitory effect on growth when the local collocation exceeds a certain critical value. It is believed that this happens before the size of the tumor is as large as the follicles in the lymph nodes which seem not to be affected by Invasivol.