Cdkn2a, also known as cyclin-dependent kinase inhibitor 2A, is a crucial tumor suppressor gene. It encodes p16 and p14, which are involved in regulating the cell cycle. p16 inhibits cyclin-dependent kinases CDK4/6, preventing cell-cycle progression from G1 to S phase, thus playing a vital role in tumor suppression. This gene is associated with pathways controlling cell growth and proliferation, and its function is of great biological importance in maintaining normal cellular homeostasis [1,2].

Loss of Cdkn2a is a frequent event driving melanoma progression. Pharmacological inhibition of the p16 targets CDK4/6 is a potential therapeutic strategy for melanoma patients with Cdkn2a loss [1]. Additionally, Cdkn2a is the most common homozygously deleted gene in all human cancers. Tumors often codelete the nearby gene MTAP, creating a dependency on PRMT5, and an MTA-cooperative PRMT5 methyltransferase inhibitor MRTX1719 selectively kills Cdkn2a/MTAP-codeleted cancers [2]. In familial melanoma, germline mutations in Cdkn2a are common, and carriers may have a worse overall and melanoma-specific survival, with a higher incidence of melanoma and a higher risk of a second melanoma [3].

In conclusion, Cdkn2a is an essential tumor suppressor gene regulating the cell cycle. Model-based research, especially studies related to its loss-of-function, has revealed its significant role in melanoma and other cancers. Understanding Cdkn2a function through these models provides potential therapeutic directions for treating cancers where Cdkn2a is mutated or deleted.

References:

1. Kreuger, Inger Z M, Slieker, Roderick C, van Groningen, Tim, van Doorn, Remco. 2022. Therapeutic Strategies for Targeting CDKN2A Loss in Melanoma. In The Journal of investigative dermatology, 143, 18-25.e1. doi:10.1016/j.jid.2022.07.016. https://pubmed.ncbi.nlm.nih.gov/36123181/

2. Mulvaney, Kathleen M. . Early Clinical Success of MTA-Cooperative PRMT5 Inhibitors for the Treatment of CDKN2A/MTAP-Deleted Cancers. In Cancer discovery, 13, 2310-2312. doi:10.1158/2159-8290.CD-23-0951. https://pubmed.ncbi.nlm.nih.gov/37909092/

3. Taibo, Ana, Paradela, Sabela, Suanzes-Hernández, Jorge, Amado-Bouza, Javier, Fonseca, Eduardo. 2023. Prognosis of CDKN2A germline mutation in patients with familial melanoma: a systematic review and meta-analysis. In Melanoma research, 34, 9-15. doi:10.1097/CMR.0000000000000920. https://pubmed.ncbi.nlm.nih.gov/37924530/