RNAi is currently being tested as a therapeutic tool for genetic diseases and other conditions. Consider the following: cystic fibrosis caused by loss of function of the CFTR gene, HIV infection, and cancer caused by hyperactivity of a growth factor receptor. Which of these may be treatable by RNAi, and which not? Explain your reasoning.

Key Concepts

RNA Interference (RNAi)

RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression or translation, effectively silencing specific genes. This mechanism can be harnessed therapeutically to target and degrade mRNA from genes that are overactive or mutated, making it a promising approach for treating genetic diseases and conditions like cancer and viral infections.

Gene Function and Loss of Function Mutations

Gene function refers to the specific role a gene plays in the body, including the production of proteins necessary for normal cellular processes. Loss of function mutations, such as those in the CFTR gene causing cystic fibrosis, result in the absence or malfunction of these proteins, which can be challenging to treat with RNAi since the underlying issue is not merely the presence of faulty mRNA but the lack of functional protein.

Targeting Oncogenes and Viral Genes

Oncogenes are genes that, when mutated or overexpressed, can lead to cancer by promoting uncontrolled cell growth. RNAi can effectively target these oncogenes or viral genes, such as those involved in HIV infection, by degrading their mRNA, thereby reducing the expression of harmful proteins and potentially reversing disease progression.