PES1 is a biomarker of head and neck squamous cell carcinoma and is associated with the tumor microenvironment

Abstract

Background: As a nucleolar protein associated with ribosome biogenesis in multiple cancer types, PES1 has been reported to be overexpressed, promoting cancer cell proliferation and invasion. However, in head and neck squamous cell carcinoma (HNSCC), the role of PES1 on the prognosis and immune infiltration remains unknown.

Methods: Multiple databases and qRT-PCR evaluated the expression of PES1 in HNSCC. The prognostic potential of PES1 in HNSCC patients was analyzed by Cox regression and Kaplan-Meier curves. Then, we used LASSO regression and stepwise multivariate Cox regression to construct the PES1-related risk assessment model. In addition, the association between PES1 and tumor immune microenvironment and drug sensitivity was explored by R packages. Finally, we used cell function assays to explore in HNSCC if PES1 influences tumor growth and metastasis.

Results: PES1 was significantly up-regulated in HNSCC and closely correlated with HPV status, tumor stage, clinical grade, and TP53 mutation status. Survival analysis suggested that PES1 is associated with worse survival outcomes, acting as an independent prognostic indicator for HNSCC. Our model also performed well in terms of prognosis prediction. Furthermore, tumor-infiltrating immune cells and antitumor drug susceptibility were negatively related to PES1 expression. Functionally, as for HNSCC cell lines in vitro, the knockdown of PES1 could inhibit proliferation, migration, and invasion.

Conclusion: We have demonstrated that PES1 may be a promoter of tumor growth. PES1 holds excellent promise as a novel biomarker to assess the prognosis of patients with HNSCC and may guide immunotherapy.

Keywords: PES1; TCGA; head and neck squamous cell carcinoma; immune infiltration; prognosis.

FIGURE 1

The expression profile of PES1 in HNSCC. (A) High or low expression of PES1 in various cancer tissues compared with normal tissues from the TCGA database. (B) The expression level of PES1 was higher in HNSCC tissue than in the adjacent normal tissue in the TCGA database. (C) The relative expression of PES1 in HNSCC tissues and adjacent normal tissues was detected by qRT‐PCR (n = 27). (D–F) The expression level of PES1 was more elevated in tumor tissues in GSE13601, GSE25099, and GSE30784 datasets.

FIGURE 2

(A) Immunohistochemical staining of PES1 in normal oral tissues and HNSCC tissues from HPA. Comparison of PES1 expression in different subgroups of TP53 status (B), HPV status (C), tumor stage (D), and tumor grade (E) (*p < 0.05, **p < 0.01, ***p < 0.001).

FIGURE 3

High‐PES1 expression was associated with a favorable prognosis in HNSCC samples. (A–C) Overall survival curves of TCGA and GEO patients by Kaplan–Meier plotter. (D, E) Univariate and multivariate analyses of overall survival and clinicopathologic characteristics in TCGA patients.

FIGURE 4

Functional enrichment analysis in HNSCC. (A, B) GSEA shows the top five GO terms and KEGG items enriched in the high and low PES1 expression groups.

FIGURE 5

Risk Assessment Model for Prognosis Prediction (A) The risk model's 1‐, 3‐, and 5‐year ROC curves with AUC values. (B) Youden Index identifies the cut‐off risk score. (C) The risk score curve and the distribution of survival status of HNSCC patients. (D) Patients in the low‐risk group experienced a longer survival time tested by the Kaplan–Meier test.

FIGURE 6

Estimation of immune‐infiltrating cells. (A) The PES1 expression was significantly negatively correlated with most immune cells. (B–E) The low‐PES1 group has higher TME scores and more active immune function (*p < 0.05, **p < 0.01, ***p < 0.001).

FIGURE 7

Immune responses of PES1 gene to immunotherapies. (A) Different distributions of TIDE scores between high and low PES1 expression. (B) The prediction of response rates of immunotherapies in patients with high and low PES1 expression. (C) Prediction of immune response by IMvigor210 cohort. (D) TIDE biomarker evaluation of PES1 in response to immunotherapy in HNSCC.

FIGURE 8

PES1 promotes the proliferation, migration, and invasion of HNSCC cells in vitro. (A) The relative expression of PES1 in the cells was detected by qRT‐PCR. (B) PES1 protein expression was detected by western blot in the cells. (C) qRT‐PCR analysis of PES1 expression in SCC9 and CAL27 cells treated with siRNAs. (D, E) The proliferation ability of SCC9 and CAL27 cells transfected with NC or si‐PES1 was examined by CCK‐8 and colony formation assay. (F, G) The migration and invasion ability of the cells was detected by wound healing and transwell assays. Data were showed as mean ± SD, *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001.