If the inert material is perforated, the incidence of tumors is reduced. If it is inserted in the form of a finely divided powder or a textile mesh, no tumors occur. C. Angiogenesis in Tumorigenesis Angiogenesis might be a prerequisite for tumor development. Solid tumors are angiogenesis-dependent. Certain animal tumors will undergo complete regression when treated by anti-angiogenesis alone.
Apoptosis is the terminal event in the natural history of cell differentiation.
It is a response to environmental growth factors and antibodies. C. Apoptosis in Tumorigenesis Failure of apoptotic removal of abnormal cells is one pathogenetic mechanism closely associated with neoplastic cell transformation and clonal expansion. Overexpression of proliferation promoting genes, BCL-2. CAM expression during embryonic development is dynamic and occurs in definite spatiotemporal patterns, resulting in steady-state expression in adult tissues. B. Cell Adhesion Molecules in Tumorigenesis Loss of CAM expression can be correlated with decreased aggregation, increased motility, and increased invasiveness.