Loss of methylthioadenosine phosphorylase (MTAP) by immunohistochemistry is an established marker of malignancy in mesothelial proliferations, but to the authors' knowledge largely has been applied only to biopsies.
Recently, loss of methylthioadenosine phosphorylase (MTAP), a deletion frequently occurring in cancer, has been shown to create vulnerability to the inhibition of the protein arginine methyltransferase 5 (PRMT5).
SIGNIFICANCE: This study links the frequently mutated metabolic enzyme MTAP to dysregulated epigenetics and cancer cell stemness and establishes MTAP status as a factor for consideration in characterizing GBM and developing therapeutic strategies.
The 5'-methylthioadenosine phosphorylase (MTAP), an enzyme involved in purine and polyamine metabolism and in the methionine salvage pathway, is considered as a potential drug target against cancer and trypanosomiasis.
We evaluated the genetic variants at 9p21.3 reported in cancer genome-wide association studies with a case-control study including 2139 ESCC cases and 2273 controls in a Chinese population, and measured the mRNA expression levels of MTAP, CDKN2A, CDKN2B, and CDKN2B-AS1 in paired ESCC tumor and adjacent normal tissues.
Integrating data from comprehensive genomic profiling of cancer cell lines and from functional characterization of cancer cell dependencies, we discovered that loss of the enzyme methylthioadenosine phosphorylase (MTAP) confers a selective dependence on protein arginine methyltransferase 5 (PRMT5) and its binding partner WDR77.
In addition, we describe novel SNPs and INDELs in cancer relevant genes with no prior reported association of point mutations with cancer, such as MTAP and MAGED1.
The S-adenosylmethionine (AdoMet) salvage enzyme 5'-methylthioadenosine phosphorylase (MTAP) has been implicated as both a cancer target and a tumor suppressor.
Thus, pancreatic cancer is a promising cancer type in which to explore novel chemotherapeutic strategies to exploit the selective loss of MTAP function.
Thus, our results support the use of L-alanosine alone or in combination with a salvage agent as a MTAP-selective therapy and therefore lay the foundation for the initiation of clinical trials for the treatment of T-ALL and other MTAP-deficient malignancies with L-alanosine.
However, the order of the MTAP, p16, p15, and IFNA genes on chromosome 9p is uncertain, and the molecular basis for MTAP deficiency in cancer is unknown.