AUNIP Expression Is Correlated With Immune Infiltration and Is a Candidate Diagnostic and Prognostic Biomarker for Hepatocellular Carcinoma and Lung Adenocarcinoma

Abstract

AUNIP, a novel prognostic biomarker, has been shown to be associated with stromal and immune scores in oral squamous cell carcinoma (OSCC). Nonetheless, its role in other cancer types was unclear. In this study, AUNIP expression was increased in hepatocellular carcinoma (HCC) and lung adenocarcinoma (LUAD) according to data from The Cancer Genome Atlas (TCGA) database, Integrative Molecular Database of Hepatocellular Carcinoma (HCCDB), and Gene Expression Omnibus (GEO) database (GSE45436, GSE102079, GSE10072, GSE31210, and GSE43458). Further, according to copy number variation analysis, AUNIP up-regulation may be associated with copy number variation. Immunohistochemistry showed AUNIP expression was higher in HCC and LUAD compared with the normal tissues. Receiver operating characteristic (ROC) curve analysis demonstrated that AUNIP is a candidate diagnostic biomarker for HCC and LUAD. Next, TCGA, International Cancer Genome Consortium (ICGC), and GEO (GSE31210 and GSE50081) data showed that increased AUNIP expression clearly predicted poor overall survival (OS), disease-specific survival (DSS), and progression-free interval (PFI) in HCC and LUAD. Additionally, multivariate Cox regression analysis involving various clinical factors showed that AUNIP is an independent prognostic biomarker for HCC and LUAD. Next, the role of AUNIP in HCC and LUAD was explored via a co-expression analysis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses, and a gene set variation analysis (GSVA). HCC and LUAD exhibited almost identical enrichment results. More specifically, high AUNIP expression was associated with DNA replication, cell cycle, oocyte meiosis, homologous recombination, mismatch repair, the p53 signal transduction pathway, and progesterone-mediated oocyte maturation. Lastly, the Tumor Immune Estimation Resource (TIMER) tool was used to determine the correlations of AUNIP expression with tumor immune infiltration. AUNIP expression was positively correlated with the infiltration degree of B cells, CD4+ T cells, CD8+ T cells, neutrophils, macrophages, and dendritic cells in HCC. However, AUNIP expression was negatively correlated with the infiltration degree of B cells, CD4+ T cells, and macrophages in LUAD. In addition, AUNIP expression was correlated with immune infiltration in various other tumors. In conclusion, AUNIP, which is associated with tumor immune infiltration, is a candidate diagnostic and prognostic biomarker for HCC and LUAD.

Keywords: AUNIP; hepatocellular carcinoma; lung adenocarcinoma; prognosis; tumor-infiltrating.

Figure 1

AUNIP expression in 33 cancer types based on TCGA data. *P < 0.05, **P < 0.01, ***P < 0.001.

Figure 2

Survival analysis of 33 cancer types based on TCGA data. P < 0.05 indicates statistical significance and the significant values are marked in yellow.

Figure 3

AUNIP expression in HCC and LUAD. (A) Chart and plot of AUNIP expression in HCC and matched non-carcinoma tissues based on HCCDB data. Box plots of AUNIP expression in HCC and adjacent normal tissues in the (B) GSE45436 and (C) GSE102079 cohorts. Box plots of AUNIP expression in LUAD and adjacent normal tissues in the (D) GSE10072, (E) GSE31210, and (F) GSE43458 cohorts. Dot plot and correlation graph showing the positive correlation between AUNIP expression (z-scores) and AUNIP copy number values in (G, H) HCC and (I, J) LUAD. (K) Representative IHC staining for AUNIP in HCC and normal tissues. Scale bars: 100 μm (insets 50 μm). (L) Representative IHC staining for AUNIP in LUAD and normal tissues. Scale bars: 100 μm (insets 50 μm).

Figure 4

Multifaceted prognostic value of AUNIP in HCC/LIHC and LUAD. (A) Overall survival (OS) of ICGC liver cancer, RIKEN, Japan (LIRI-JP) cases. (B) Disease-specific survival (DSS) of TCGA LIHC cases. (C) Progression-free interval (PFI) of TCGA LIHC cases. (D) Univariate and (E) multivariate Cox regression analyses of OS-related factors among TCGA LIHC cases. (F) OS of GSE31210 LUAD cases. (G) OS of GSE50081 LUAD cases. (H) DSS of TCGA LUAD cases. (I) PFI of TCGA LUAD cases. (J) Univariate and (K) multivariate Cox regression analyses of OS-related factors among TCGA LUAD cases.

Figure 5

Diagnostic performance of AUNIP in HCC and LUAD. ROC curves evaluating the diagnostic performance of AUNIP for HCC patients in the (A) TCGA LIHC, (B) GSE45436, and (C) GSE102079 cohorts. ROC curves evaluating the diagnostic performance of AUNIP for LUAD patients in the (D) TCGA LUAD, (E) GSE10072, (F) GSE31210, and (G) GSE43458 cohorts.

Figure 6

Functional enrichment analyses of AUNIP in HCC and LUAD. (A) Heatmap of 20 genes with the most significant correlations with AUNIP in HCC. (B) GO and (C) KEGG analysis of the co-expressed genes in HCC. (D) Heatmap and (E) violin plot of the normalized enrichment scores (NESs) for seven pathways between high and low AUNIP expression groups for HCC. (F) Heatmap of 20 genes with the most significant correlations with AUNIP in LUAD. (G) GO and (H) KEGG analysis of the co-expressed genes in LUAD. (I) Heatmap and (J) violin plot of the NESs for seven pathways between high and low AUNIP expression groups for LUAD. *P < 0.05, **P < 0.01, ***P < 0.001.

Figure 7

AUNIP expression is related to the immune infiltration degrees in HCC and LUAD. (A) Heatmap of the abundances of six infiltrating immune cell types in HCC and LUAD. Spearman correlations between immune cell abundances in (B) HCC and (C) LUAD. Blue and red represent negative and positive correlation, respectively, and the thicker the line, the larger the correlation coefficient. Spearman correlations between AUNIP expression and the immune cell abundances in (D) HCC and (E) LUAD. Comparisons of immune cell abundances between the high and low AUNIP expression groups in (F) HCC and (G) LUAD. Spearman correlations between AUNIP expression and markers of B cells, monocytes, neutrophils, CD8+ T cells, natural killer cells, macrophages, Treg cells, Th1 cells, and DCs in HCC and LUAD (H) before and (I) after adjusting for tumor purity. *P < 0.05, **P < 0.01, ***P < 0.001.

Figure 8

AUNIP expression is associated with immune infiltration degrees in additional cancer types. Spearman correlations between AUNIP expression and six infiltrating immunocyte abundances in (A) 30 cancer types, (B) KIRC, (C) PRAD, (D) STAD, and (E) THYM. *P < 0.05, **P < 0.01, ***P < 0.001.