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What is Which of the following factor is essential for tumor metastasis? and explain in detail?
A critical element in the growth of primary tumors and formation of metastatic sites is the angiogenic switch: the ability of the tumor to promote the formation of new capillaries from preexisting host vessels. Stimuli for tumor angiogenesis include hypoxemia, inflammation, and genetic lesions in oncogenes or tumor suppressors that alter tumor cell gene expression. Angiogenesis consists of several steps, including the stimulation of endothelial cells (ECs) by growth factors, the degradation of the ECM by proteases, proliferation of ECs and migration into the tumor, and the eventual formation of new capillary tubes. Ref: Longo D.L. (2012). Chapter 84. Cancer Cell Biology and Angiogenesis. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds), Harrison's Principles of Internal Medicine, 18e.