Question

How does apoptosis relate to cancer cells?

Answer 1

Hint: The deficiency of apoptotic control permits disease cells to endure longer and gives more opportunity for the collection of transformations which can increment intrusiveness during tumor movement, invigorate angiogenesis, liberate cell multiplication and meddle with separation.

Complete answer:
Cancers have long been found to contain apoptotic cells. For example, the high rate of apoptosis seen in basal cell carcinomas of the skin explains why, despite their high mitotic rate, these tumors grow slowly. Increased apoptosis was observed in irradiated tumors and those treated with cytotoxins, implying that apoptosis-inducing treatments could be used to treat cancer.

However, the role of apoptosis failure in cancer development was discovered much later. This came after it was discovered that the bcl-2 gene, which is frequently translocated in follicular lymphoma, encoded a cell death inhibitory protein . As the first component of the apoptotic mechanism to be identified, bcl-2 aided in the understanding of other components of the apoptotic mechanism.

While it is simple to determine whether or not a cell is dead, it is much more difficult to determine whether or not it is still alive. Although it is not applicable to all cell types, the loss of the ability to reproduce and generate a clone is the gold standard for determining if a cell has died. Of course, this is especially important in cancer cells.

The loss of apoptotic control allows cancer cells to survive longer and gives more time for the accumulation of mutations which can increase invasiveness during tumor progression, stimulate angiogenesis, deregulate cell proliferation and interfere with differentiation.

Note: The evidence that inhibiting cell death can lead to cancer comes primarily from natural occurrences, such as translocations in lymphomas and leukemias. For some cell death genes, knockout and transgenic mice have provided evidence that cell death failure can cause cancer.