Microbial Pathogenesis & Infectious Diseases

Cancer Pathogenesis

Cancer is a disease of tissue growth regulation. For a normal cell to transform into a cancer cell, the genes that regulate cell growth and differentiation must be altered.

The affected genes are classified   into two broad categories:

1) Oncogenes - Genes that promote cell growth and reproduction.

2) Tumor suppressor genes - Genes that inhibit cell division and survival.

The gain or loss of an entire chromosome can occur through errors in mitosis. The most common are mutations, which changes in the nucleotide sequence of genomic DNA. Cancer epigenetics is the study of epigenetic modifications to the DNA of cancer cells that do not involve a change in the nucleotide sequence. Metastasis is the spread of cancer to other locations in the body by which  dispersed tumors are called metastatic tumors. It is common in the late stages of cancer and it can occur through the blood or the lymphatic system or both of it . Different types of cancers tend to metastasize to particular organs like the lungs, liver, brain and bones.