Question

7-what mechanism enable chronic viral infections to exert a carcinogenic influence on a tissue

Answer 1

Ans: Some viruses are able to integrate their genome into the host genome stably examples are retroviruses, Retroviruses have ss RNA genome and when they infect the host cell first they reverse transcribed themselves into ds DNA through viral reverse transcriptase which is encoded by the viral genome. After that they also encode an enzyme called integrase which enables them to integrate their genome into the host cell. Now when they integrate their genome into the host genome there will be a chance that this will lead to cancer because their genome integration may disrupt some genes which are tumor suppressor genes or majorly involved in cell cycle checkpoints but because of their disruption the cell's machinery faulted and it results in uncontrolled growth which eventually leads to cancer. Example: Human T-cell lymphotrophic virus type 1 (HTLV-1), it is a type of retrovirus and it basically weakned the immume system and stably integrate its genome into the host genome and it will exert a carcinogenic influence on a tissue