Protocadherin Beta 2 as a Promising Prognostic and Immunotherapeutic Predictive Indicator in Gastric Cancer

Protocadherin beta 2 belongs to the procalcitonin family and is implicated in the progression of various tumors. It is linked to unfavorable prognosis in patients suffering from different types of cancers, whereas limited investigation was conducted on protocadherin beta 2 in gastric cancer. This study identified the key genes involved in tumor microenvironment of gastric cancer, ultimately pinpointing protocadherin beta 2 as the main focus of investigation. Analysis of survival data in the Cancer Genome Atlas and Gene Expression Omnibus databases indicated that patients with gastric cancer who exhibited elevated levels of protocadherin beta 2 had higher likelihood of experiencing unfavorable survival outcomes. Furthermore, the expression of protocadherin beta 2 demonstrated a strong association with tumor staging and grading. Gene set enrichment analysis indicated that protocadherin beta 2 was primarily linked to cell adhesion molecules, transforming growth factor-beta signaling pathway, phosphoinositide-3-kinase-protein kinase B signaling pathway and antigen-antibody presentation. Analysis of immune infiltration revealed a robust association between the expression of protocadherin beta 2 and infiltration of immune cells into tumors, which was found to be significant in relation to immune checkpoint inhibitors, leukocyte antigens; negatively correlated with microsatellite instability index, tumor mutation burden index and tumor immune dysfunction and exclusion scores. The analysis of drug prediction indicated that increased expression of protocadherin beta 2 exhibited greater responsiveness to anticancer medications like gemcitabine, 5-fluorouracil and adriamycin. Examining the prognostic and immunotherapeutic significance of protocadherin beta 2 in gastric cancer, this investigation reveals that protocadherin beta 2 influences the tumor microenvironment and prognosis of gastric cancer.