Question

Explain the steps of cancer progression in detail. Describe at least two ways the first step of cancer progression could occur.

Answer 1

The multi- hit model can explain the progress of cancer: Mutation cause cancer. However, luckily for us, multiple mutation are usually required to convert a normal body cell into malignant one. According to this model, cancers arise by a process of evolutionary(or "survival of the fittest") clonal selection not unlike the selection of individual animals in a large population. A mutation in one cell gives it a slight growth advantage. One of its progeny cells then undergoes a second mutation that allows its descendants to grow more uncontrollably and form a small benign tumor. A third mutation in a cell within this tumor allows it to outgrow the others and overcome constraints imposed by the tumor microenvironment, and it's progeny form a mass of cells, each of which has these three genetic changes. An additional mutation in one of these cells allows its progeny to escape into the bloodstream and establish daughter colonies at other sites, the hallmark of metastatic cancer.

Describes two ways the first step of cancer progression could occur: (a) The genetic makeup of most cancer cells is dramatically altered:- Tumor harbor all types of genetic alternation like point mutation, small and large amplifications, deletions, translocations, aneuploidy, chromosome arms gains or losses, DNA replication and chromosome segregation errors. Decrease replication fidelity and mutagens also profoundly affect the cancer genome. (b) Cellular housekeeping functions are fundamentally altered:- Genomic changes have a profound effect on the protein composition of the cell . This in turn, causes a stress response that is amied at offspring the protein imbalances . Unusual energy generating mechanism observed, glycolysis for energy production irrespective of whether oxygen are high or low. Affected cells rewire their metabolic pathways, some produce novel metabolites that play a critical role in the disease.