Abstract: Objective The objective of this study was to investigate the correlation between the expression of proteasome activating factor PA28γ and microRNA-7-5p(miR-7-5p)and postoperative survival in cancer tissues of patients with non-small cell lung cancer(NSCLC). Methods The clinical data of 82 NSCLC patients who underwent surgical treatment from March 2018 to May 2020 were retrospectively analyzed, and immunohistochemistry and qPCR were used to detect the expression of PA28γ and miR-7-5p in cancer tissue and adjacent tissue samples. Their correlation between PA28γ and miR-7-5P and pathological characteristics of NSCLC patients was analyzed. Postoperative follow-up was conducted for 14 to 42 months to observe the patient′s survival and draw a ROC curve to analyze the predictive effect of PA28γ and miR-7-5p expression in cancer tissues on the prognosis of patients with NSCLC. Results The expression of PA28γ in NSCLC cancer tissues was significantly higher than that in adjacent tissues as determined by immunohistochemistry. The expression of miR-7-5p was significantly lower than that in adjacent tissues as determined by qPCR(P＜0.05). PA28γ expression in NSCLC cancer tissues was significantly different from that in adjacent tissues, and negatively correlated with miR-7-5p(r=-0.557, P＜0.001). The expression of PA28γ was correlated with tumor differentiation, TNM stage, depth of invasion and distant metastasis(P＜0.05);the expression of miR-7-5p was correlated with tumor pathological type, degree of differentiation, TNM staging, depth of invasion and distant metastasis(P＜0.05). The ROC curve analysis showed that the AUC of PA28γ expression in predicting survival was 0.696(95% CI:0.555-0.837), and the AUC of miR-7-5p expression was 0.853(95% CI:0.735-0.971). Conclusion Both PA28γ and miR-7-5p are abnormally expressed in NSCLC tissues, and are closely related to the pathological characteristics such as cancer cell differentiation degree, TNM stage, depth of invasion, and distant metastasis. It is speculated that they are both involved in the occurrence and development of NSCLC, which can be used as a tumor marker for early diagnosis and targeted therapy of NSCLC.

Key words: Non-small cell lung cancer, Proteasome activator PA28γ, miR-7-5p, Clinical significance, Prognosis