AP BIOLOGY

Detailed explanation-1: -The alteration of cell death mechanisms is a common feature in cancer, and can lead to drug resistance and, consequently, treatment failure. Cell death is a tightly controlled mechanism based on molecular programs in which several genes and related proteins are regulated.

Detailed explanation-2: -Unlike healthy cells, cancer cells don’t carry on maturing or become so specialised. Cells mature so that they are able to carry out their function in the body. This process of maturing is called differentiation. In cancer, the cells often reproduce very quickly and don’t have a chance to mature.

Detailed explanation-3: -Evasion of cell death is one of the hallmarks of cancer [33]. Cancer cells employ various means of preventing cell death including deregulation of the intrinsic apoptosis pathway. Upregulation of the anti-apoptotic BCL-2 proteins and loss of pro-apoptotic BH3 proteins has been observed in many cancers [34, 35].

Detailed explanation-4: -Tumors form because cells ignore the normal signals that tell them it’s time to stop growing, or that it’s time to die. Therefore, these aberrations in cell signaling pathways are integral to the formation and growth of cancer.