[3] All of these proteins as well as the genes responsible for their production (i.e. CKLF and CMTM1 to CMTM8, respectively) have similar structures[3] but vary in their apparent physiological and pathological functions.
The methylation of certain CpG clusters (i.e. DNA areas high in cytosine and guanine) regulate the transcriptional activity of nearby genes.
On the other hand, the CpG cluster(s) controlling the CMTM5 gene in the blood of individuals with the autoimmune disease of rheumatoid arthritis are hypo-methylated and therefore highly active.
[12] Finally, various cancer human cell lines including those of the liver, breast, prostate, colon, stomach, nasopharynx, laryngopharynx, esophagus, lung, and cervix express low levels of, or no, CMTM5-v1 and concurrently have highly methylated CpG sites near to the CMTM5 gene.
The findings also support further studies to confirm and expand these relationships and determine if the expression of CMTM5 isoforms can be used as tumor markers for these cancers severities/prognoses and/or targets as for treating them.