Ovarian cancer G protein-coupled receptor 1 inhibits A549 cells migration through casein kinase 2[alpha] intronless gene and neutral endopeptidase

Background We have previously reported that a new intronless gene for casein kinase 2[alpha] (CK2[alpha]), CSNK2A3, is expressed in human cells. The promoter of the well-known CK2[alpha], CSNK2A1, displays characteristics of a housekeeping gene, whereas CSNK2A3 has a characteristic of a regulated promoter with two TATA boxes and a CAAT box. GPR68, a family of the G protein-coupled receptors, is also known as ovarian cancer G protein-coupled receptor 1 (OGR1). In the current study, we analyzed the roles of CK2[alpha] genes and neutral endopeptidase (NEP), a key enzyme that influences a variety of malignancies, in the OGR1-induced inhibition of A549 cell migration. Methods We analyzed the transcript expressions of both the CK2[alpha] genes (CSNK2A1 and CSNK2A3) and NEP upon OGR1 overexpression. Protein expression of CK2[alpha] and NEP were also analyzed. We further elucidated the functional roles of both CK2[alpha] and NEP in the OGR1-induced inhibition of A549 cell migration in vitro using a wound-healing assay. We also analyzed the molecular mechanisms involved in the OGR1-induced inhibition of lung cancer cell migration. Results The findings of this study showed that OGR1 upregulated the expression of CSNK2A3 but not CSNK2A1 in the A549 cells. The findings further suggested OGR1 also upregulates the expression of NEP. The OGR1-induced inhibition of A549 cell migration was abrogated completely by inhibition of CK2[alpha] activity, whereas partial abrogation (~ 30%) was observed in the presence of NEP inhibition. The results also revealed that OGR1 regulates CSNK2A3 via activation of Rac1/cdc42 and MAPKs pathways. CK2 is ubiquitously expressed, and in contrast, is believed to be a constitutively active enzyme, and its regulation appears to be independent of known second messengers. Conclusion In the current study, we report for the first time the OGR1-induced regulation of CSNK2A3, CK2[alpha]P, and NEP in A549 cancer cells. Our study also decoded the downstream cellular proteins of OGR1 as well as the molecular mechanism involved in OGR1-induced inhibition of A549 cell migration. The findings of this research suggest the potential therapeutic targets to inhibit lung cancer progression. Keywords: GPR68, Ovarian cancer G protein-coupled receptor 1, Casein kinase 2[alpha], Intronless, Neutral endopeptidase