Final answer:
Viruses can contribute to cancer by interfering with the normal regulation of the host cell cycle. Some examples include Hepatitis B virus and liver cancer, Influenza virus and lung cancer, Herpes simplex virus and skin cancer, and Adenovirus and brain cancer.
Step-by-step explanation:
Viruses can contribute to cancer by interfering with the normal regulation of the host cell cycle, either by introducing genes that stimulate unregulated cell growth (oncogenes) or by interfering with the expression of genes that inhibit cell growth. Some examples include:
- Hepatitis B virus and liver cancer: Hepatitis B virus can cause chronic liver infection, leading to inflammation and damage to liver cells. Over time, this chronic inflammation can increase the risk of developing liver cancer.
- Influenza virus and lung cancer: Influenza virus can induce apoptosis, a process of programmed cell death. If the virus infects lung cells and causes excessive apoptosis, it may contribute to the development of lung cancer.
- Herpes simplex virus and skin cancer: Herpes simplex virus can promote cell differentiation, which is the process of specialized cells forming. If this process becomes dysregulated, it can contribute to the development of skin cancer.
- Adenovirus and brain cancer: Adenovirus has been found in some cases of brain cancer. It is believed that the virus may inhibit DNA replication, leading to mutations in brain cells that can contribute to the development of cancer.