NUSAP1 is a Prognostic Biomarker and Correlated to Immune Infiltration in Lung Adenocarcinoma

Lung adenocarcinoma (LUAD) is the most frequent subtype of lung cancer, the leading cancer-related death worldwide. Nucleolar spindle-associated protein 1 (NUSAP1) is a microtubule-associated protein firstly been found in proliferating cells, and recently known to be involved in carcinogenesis. However, the role of NUSAP1 in LUAD has yet to be explored. In current study, we used GEO datasets to identified a group of hub genes in LUAD, used Kaplan-Meier analysis to explore their impact on prognosis. NUSAP1 was chosen based on clinical relevance and literature searching results. The expression level of NUSAP1 was explored using TIMER, TCGA-LUAD database, human protein atlas (HPA), and verified by immunohistochemistry. Genes co-expressed with NUSAP1 were identified and GO/KEGG were performed to identify its biological functions. The impact of NUSAP1 on immune infiltration was investigated in TIMER. The correlation between NUSAP1 expression and clinical relevance were identified using diagnostic receiver operating characteristic (ROC) curves, nomogram model, and cox regression analysis. Immunohistochemistry was used to confirm the over-expression of NUSAP1 in LUAD and its correlation with MDSC. In short, we found a group of 20 hub genes in LUAD, all of which were differentially expressed in LUAD and most of them predicted a poor prognosis. NUSAP1 was upregulated in LUAD and most of the malignancies and correlated to multiple clinical parameters like pathological stage, N stage, M stage. Co-expressed genes and GO/KEGG showed that NUSAP1 mainly participates in cell cycle. Immune infiltration study demonstrated that NUSAP1 correlated to multiple immune cells, particularly myeloid-derived suppressor cell (MDSC). PrognoScan database verified the prognostic value of NUSAP1. Lastly, high expression of NUSAP1 and its correlation with MDSC was testified by immunohistochemistry. In summary, we found NUSAP1 were upregulated in LUAD and can serve as potential biomarker to indicate prognosis of LUAD.