Question

Describe two abnormalities of chromosomes in cancer.

Short answer

Two chromosomal abnormalities that can lead to cancer are Chromosome Translocation, seen in chronic myeloid leukemia, and Chromosome Amplification, evident in cancers such as breast and ovarian cancer. These abnormalities disrupt normal gene functioning, triggering abnormal cell growth and division.

Step-by-step solution

Identifying the 1st Abnormality - Chromosome Translocation

The 1st abnormality is 'Chromosome Translocation'. Translocation indicates a situation where segments from two different chromosomes have swapped places with each other. This can disrupt the normal functioning of genes and sometimes lead to a gene being turned on all the time. This 'always-on' gene can drive the abnormal growth of cells, leading to cancer. This translocation is common in chronic myeloid leukemia, where parts of chromosome 9 and 22 swap places, leading to the creation of an 'always-on' gene called BCR-ABL.

Identifying the 2nd Abnormality - Chromosome amplification

The 2nd abnormality could be 'Chromosome amplification' or chromosomal instability. This refers to a situation where there are changes in the number of copies of chromosomes in cells. Certain cancers, such as breast cancer and ovarian cancer demonstrate this abnormality. One specific example is gene amplification of `HER2/neu` in breast cancer. This gene is responsible for regulating cell growth and survival, but when amplified, leads to increased growth and division, leading to cancer.