Retinol-binding protein type 1 expression predicts poor prognosis in head and neck squamous cell carcinoma

Abstract

Background: Head and neck squamous cell carcinoma (HNSCC) is the sixth most prevalent malignancy worldwide, with high incidence and poor survival rates. RBP1 is highly expressed in several kinds of cancer and plays a potential prognostic factor. However, the relationship between RBP1 and HNSCC were analyzed based on The Cancer Genome Atlas (TCGA) database.

Materials and methods: RBP1 expression and clinical information were obtained from the Cancer Genome Atlas (TCGA) database. Tumor tissue and adjacent normal tissue of 6 HNSCC patients were collected to analyze the RBP1 mRNA expression level by quantitative PCR. Cox regression analysis was used to evaluate the prognostic values of RBP1 and clinical data in HNSCC. A nomogram was also established to predict the impact of RBP1 on prognosis based on Cox multivariate results. The methylation level of RBP1 in HNSC and its prognosis were analyzed in UALACN and MethSurv. Finally, the potential biological functions of RBP1 were investigated using gene set enrichment analysis (GSEA) and single sample GSEA (ssGSEA).

Results: The mRNA expression levels of RBP1 were highly expressed in HNSCC tissue. The Cox analyses demonstrate that highly-expressed RBP1 is an independent prognosis marker(P < 0.05). ROC curve analysis showed that performances of RBP1 (area under the ROC curve: 0.887, sensitivity: 84.1%, specificity: 79.9%). The methylation was increased in HNSCC patients compared with normal subjects(P < 0.05) and was associated with better prognosis at sites cg06208339, cg12298268, cg12497564, cg15288618, cg20532370, cg23448348. Additionally, RBP1 expression is mildly associated with immune cell infiltration and immunological checkpoints.

Conclusion: RBP1 is overexpressed and associated with poor patient prognosis in head and neck squamous cell carcinoma.

Keywords: Bioinformatic analysis; Head and neck squamous cell carcinoma; Prognosis biomarker; RBP1.

Fig. 1

(A) RBP1 expression significantly up-regulated in multiple cancers including HNSCC. ACC, Adrenocortical carcinoma; BLCA, Bladder Urothelial Carcinoma; BRCA, Breast invasive carcinoma; CESC, Cervical squamous cell carcinoma and endocervical adeno carcinoma; CHOL, Cholangio carcinoma; COAD, Colon adenocarcinoma; DLBC, Lymphoid Neoplasm Diffuse Large B-cell Lymphoma; ESCA, Esophageal carcinoma; GBM, Glioblastoma multiforme; HNSC, Head and Neck squamous cell carcinoma; KICH, Kidney Chromophobe; KIRC, Kidney renal clear cell carcinoma; KIRP, Kidney renal papillary cell carcinoma; LAML, Acute Myeloid Leukemia; LGG, Brain Lower Grade Glioma; LIHC, Liver hepatocellular carcinoma; LUAD, Lung adenocarcinoma; LUSC, Lung squamous cell carcinoma; MESO, Mesothelioma; OV, Ovarian serous cystadenocarcinoma; PAAD, Pancreatic adenocarcinoma; PCPG, Pheochromocytoma and Paraganglioma; PRAD, Prostate adenocarcinoma; READ, Rectum adenocarcinoma; SARC, Sarcoma; SKCM, Skin Cutaneous Melanoma; STAD, Stomach adenocarcinoma; TGCT, Testicular Germ Cell Tumors; THCA, Thyroid carcinoma; THYM, Thymoma; UCEC, Uterine Corpus Endometrial Carcinoma; UCS, Uterine Carcinosarcoma; UVM, Uveal Melanoma. (B) RBP1 expression levels in HNSCC and matched normal tissues. (C) RBP1 expression levels in HNSCC and normal tissues. (D) RBP1 expression levels were significantly higher in the HNSCC tissues compared to the adjacent peritumoral tissues in GSE83519. (E)ROC analysis of RBP1 shows promising discrimination power between tumor and normal tissues based on TCGA. (F)ROC analysis of RBP1 shows promising discrimination power between tumor and normal tissues based on GSE83519. (G) the level of RBP1 mRNA expression in 6 different head and neck squamous cell carcinoma and normal normal tissues

Fig. 2

Association of RBP1 expression and clinical characteristics of HNSCC. (A) Expression of RBP1 in HNSCC based on individual cancer stages. (B) Expression of RBP1 in HNSCC based on nodal metastasis status. (C)Expression of RBP1 in HNSC based on TP53 mutation status. (D) Expression of RBP1 in HNSCC based on tumor grade. (E) Expression of RBP1 in HNSC based on HPV infection status

Fig. 3

The association of RBP1 expression and prognosis in HNSCC. Kaplan-Meier plotter database analysis shows the differences in (A) Progress free interval; (B) Disease specific survival; (C) Overall survival; (D) nomogram integrates RBP1 and other prognostic factors in HNSCC from TCGA data; (E) The calibration plot of the nomogram

Fig. 4

Ecrichment plots of RBP1 in HNSCC from GSEA. (A) Mitochondrial translation; (B) Peptide hormone biosynthesis; (C)Translation; (D) CD22 mediated BCR regulation; (E) Creation of C4 and C2 activator; (F) FCGR activation

Fig. 5

Correlations between the relative abundance of 24 immune cells and RBP1 expression levels. The size of the dots represents the absolute Spearman’s correlation coefficient values

Fig. 6

Associations between RBP1 expression and tumor immune infiltration. (A) Associations between RBP1 expression and immune checkpoint molecules in HNSCC from TCGA dataset; (B) Associations between RBP1 expression and mismatch repair genes in HNSCC from TCGA dataset; (C) Associations between RBP1 expression and tumor microenvironment in HNSCC from TCGA dataset; *P < 0.05; **P < 0.05; ***P < 0.001

Fig. 7

Protein–protein interaction network and GO enrichment in HNSCC. (A) RBP1 interaction protein plot and description. (B) The top 5 GO enrichment terms in MF. (C) The top 5 GO enrichment terms in BP.(D) The top 5 GO enrichment terms in CC

Fig. 8

Mutation feature of RBP1 in HNSCC from TCGA cohort using the cBioPortal tool; (A) The alteration frequency with mutation type of RBP1 in different tumor samples from TCGA cohorts; (B) K-M survival analysis of OS with or without RBP1 alteration; (C) The methylation level of RBP1 in HNSCC; (D) The Kaplan-Meier survival of the promoter methylation of RBP1S