Figure 3. CACNA2D2 expression in CRC and prognostic value in a CRC validation cohort.

(A) CACNA2D2 gene expression was analyzed by qPCR in seven CRC cell lines and compared to the primary colon fibroblast cell line CCD-18Co, the data was normalized with 18S and relative to CCD-18Co (Log₁₀RQ). #ND: not detected, CACNA2D2 mRNA was not detected in this sample by qPCR. (B) CACNA2D2 mRNA expression (y-axis at the LHS) and CDC42 protein levels (y-axis at the RHS) in 54 CRC tumor samples are represented. CACNA2D2 and CDC42 expression levels are presented as the quantity of CACNA2D2 gene in each tumor sample, normalized to an endogenous reference, 18S for CACNA2D2 and the housekeeping protein GAPDH in the case of CDC42 and relative to its corresponding matched normal tissue for each patient. (C) Mean expression of CACNA2D2 gene in normal and tumor tissues (***p-value < 0.0001). Data are presented as mean × 10⁷ ± SEM. (D) Mean expression of CACNA2D2 gene in tumor tissues according to presence of lymphovascular invasion. *, significantly different from no presence of invasion (p-value = 0.03). (E) Disease-specific survival of the patients according the new proposed classifier based on CACNA2D2 and CDC42 levels. Low risk group includes patients with Dukes´ C and D with low levels of CDC42 and moderate to high levels of CACNA2D2 and the high risk group corresponds to Dukes´ C and D patients with high levels of CDC42 and low levels of CACNA2D2.