Question

1) a) For each of the eight Hallmarks of Cancer described by Hanahan and Weinberg, compare and contrast all of the characteristics of in vitro cell transformation to what is observed in vivo (in cancer growing in an organism). What Hallmarks of Cancer are NOT observed in transformed cells and why are they not seen in vitro?

Answer 1

The hallmarks of cancer comprise six biological capabilities acquired during the multistep development of human tumors. The hallmarks constitute an organizing principle for rationalizing the complexities of neoplastic disease. They include sustaining proliferative signaling, evading growth suppressors, resisting cell death, enabling replicative immortality, inducing angiogenesis, and activating invasion and metastasis. Underlying these hallmarks are genome instability, which generates the genetic diversity that expedites their acquisition, and inflammation, which fosters multiple hallmark functions. Conceptual progress in the last decade has added two emerging hallmarks of potential generality to this list—reprogramming of energy metabolism and evading immune destruction. In addition to cancer cells, tumors exhibit another dimension of complexity: they contain a repertoire of recruited, ostensibly normal cells that contribute to the acquisition of hallmark traits by creating the “tumor microenvironment.” Recognition of the widespread applicability of these concepts will increasingly affect the development of new means to treat human cancer.

In comparision to the In vivo cancer cells the in vitro transformed cells, doesnot possess Metastasis and angiogenesis