Question

(A) How do cancer cells get the hallmarks/skills of cancer?

(B) Do different cancers get the hallmarks/skills of cancer in the same way? Why or why not?

(C) Do different cancers get the hallmarks/skills of cancer in the same order? Why or why not?

Answer 1

ans to Q (A)

to understand the concept of cancer hallmarks there is need to understand the definition of cancer

CANCER is defined as Excessive abnormal uncontrolled unchecked spontaneous proliferation of cells

* Normal cells need external growth signals in form of hormones or chemical messengers to carry out normal division process but cancer cells are self-sufficient when it comes to needing of growth signals. they grow spontaneously by permanently activating the signalling pathways that respond to these signals

*normal cells to ensure normal division only if there is nothing wrong with DNA and damaged or inappropriate proteins are not present. to find out situations like these there is the provision of tumour suppresser gene like p53 p17 pRB if these genes are mutated cell cycle is not properly regulated cell proceeds into a division with faulty DNA and inappropriate proteins resulting into excessive cell division.

* above-stated tumour suppressor genes initiate apoptosis in case of any damage to DNA but cancer cells get those mechanism altered which detect damage and abnormalities and in that case, excessive division takes place rather than cell death.

*cancer cells represent abnormally high no of cell divisions. no of cell division is kept under control with help of telomere length decreasing with each cell division but cancer cells have increase activity of telomerase which maintains telomere length for a longer duration resulting into indefinite division without initiating senescence.

*to get enough oxygen and nutrients for new tissue mass cancer cells need increased blood supply for this need they increase the production of those factors which increase the growth of blood vessels and suppressing those factors which inhibitb angiogenesis

*along with these hallmarks cancer cells also have ability to bypass contact inhibition and causing local tissue invasion and later on with the help of newly formed blood vessels or lymphatics or body cavities they tend to metastasize.