Fig. 10: NHE7 activates the cAMP-CREB pathway to upregulate GRIN2B, influencing calcium signaling.

A Flow cytometry was used to detect the effect of NHE7 overexpression combined with BLU0588 treatment (5 nmol/L) on Ca²⁺ levels in Ishikawa cells. A value of p below 0.05 is considered significant, *p < 0.05. B The JASPAR database (http://jaspar.genereg.net/) predicted potential binding sites between the GRIN2B promoter region and CREB. C WB assay detected the expressions of PKACA, CREB, and pCREB in Ishikawa cells with NHE7 overexpression and BLU0588 treatment (5 nmol/L). *p < 0.05, **p < 0.01. D The Dual-luciferase reporter assay detected the luciferase intensity of the pGLO or GRIN2B WT in Ishikawa cells with NHE7 overexpression and BLU0588 treatment (5 nmol/L). *p < 0.05, **p < 0.01. E In Ishikawa cells with overexpressed NHE7, the potential binding site of CREB to the GRIN2B promoter underwent mutation. A dual-luciferase reporter assay was conducted to measure the luciferase activity of each group. **p < 0.01. F The binding interaction between NHE7 and CREB was confirmed through a ChIP assay. **p < 0.01. G IHC assay was used to detect the expression levels of PKACA and GRIN2B in tumor tissues with different NHE7 expressions (Scale bar: 50 μm). The main image is magnified 400×, with an inset showing a 40× magnified view. All data came from three repeated experiments (n = 3). *p < 0.05, **p < 0.01.