Downregulated CMTM8 Correlates with Poor Prognosis in Gastric Cancer Patients

This study aimed to examine the expression and clinical significance of chemokine-like factor-like MARVEL transmembrane domain-containing family member 8 (CMTM8) in gastric cancer (GC). The mRNA and protein expression of CMTM8 were detected by bioinformatics analysis and immunohistochemistry (IHC), respectively. Bioinformatics analysis found that there was a high mRNA expression of CMTM8 in GC tissues, but failed to identify a significant relationship with the clinicopathological features or prognosis of GC patients. However, IHC results showed that the positive expression of CMTM8 protein in GC tissues was significantly lower than that of adjacent nontumor tissues and correlated with differentiation, tumor node metastasis stage, and distal metastasis of GC patients (p < 0.05). Moreover, the survival time of GC patients with negative CMTM8 protein expression group was shorter than that of positive CMTM8 protein expression group by Kaplan-Meier survival analysis (p < 0.05). Cox proportional hazards model (COX) regression analysis indicated that CMTM8 protein was an independent protective factor for the overall survival of GC patients. Further Gene Set Enrichment Analysis suggested that CMTM8 may be involved in regulating the calcium signaling pathway, cell adhesion molecules, and cytokine-cytokine receptor interaction in GC. Our study shows that CMTM8 protein is downregulated in GC tissues, and CMTM8 protein expression is related to GC metastasis and the prognosis of GC patients.