Collagen and stromal proliferation as preventive mechanisms against cancer invasion by purified polysaccharides from human tubercle bacillus (SSM).

The antitumor activity of SSM consists in the activation and intensification of collagen proliferation against carcinoma. The experiment in vitro and in vivo (xenografts) indicates that SSM did no direct damage to the cancer cells, but that it accelerated the proliferation of collagen fibers of the stroma. These collagen fibers enclosed the cancer cells and prevented cancer cell proliferation. It was also made clear that the proliferation of collagen fibers was accelerated remarkably by SSM under a certain condition of immunity. Therefore, one of the basic activities of SSM is to stimulate the proliferation of collagen fibers in the stroma invaded by cancer cells. Collagen serves in the composition of small blood vessels, blood capillaries, muscle fibers, and nerve fibers. Besides, the biosynthesis of collagen seems to be accelerated by carcinomatous infiltration, and it may also take place with fibroblasts, endothelial cells, and the amorphous matrix in the normal tissue or cancer cells themselves.