TGFA expression is associated with poor prognosis and promotes the development of cervical cancer

Abstract

Cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) are the second most common cancers in women aged 20-39. While HPV screening can help with early detection of cervical cancer, many patients are already in the medium to late stages when they are identified. As a result, searching for novel biomarkers to predict CESC prognosis and propose molecular treatment targets is critical. TGFA is a polypeptide growth factor with a high affinity for the epidermal growth factor receptor. Several studies have shown that TGFA can improve cancer growth and progression, but data on its impact on the occurrence and advancement of CESC is limited. In this study, we used clinical data analysis and bioinformatics techniques to explore the relationship between TGFA and CESC. The results showed that TGFA was highly expressed in cervical cancer tissues and cells. TGFA knockdown can inhibit the proliferation, migration and invasion of cervical cancer cells. In addition, after TGFA knockout, the expression of IL family and MMP family proteins in CESC cell lines was significantly reduced. In conclusion, TGFA plays an important role in the occurrence and development of cervical cancer. Therefore, TGFA may become a new target for cervical cancer treatment.

Keywords: TGFA; bioinformatics; biomarker; cervical cancer; prognosis.

FIGURE 1

The expression of transforming growth factor α (TGFA) in different patients was analysed by bioinformatics and immunohistochemistry. (A) TGFA expression difference analysis results of 33 tumours based on TCGA database data. (B) Pan‐cancer analysis of paired samples based on TCGA database data. (C) Differential analysis of TGFA expression in unpaired cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) samples. (D) Differential analysis of TGFA expression in paired CESC samples. (E) TGFA expression differential analysis based on GSE6791 data. (F) TGFA expression differential analysis based on GSE7410 data. (G) Immunohistochemical results of TGFA in normal cervical tissues and cervical squamous cell carcinoma with different degrees of differentiation. (H) Immunohistochemical results of TGFA in normal and adenocarcinoma tissues of the cervix. (I) Group comparison of TGFA immunohistochemical results in 16 normal cervical tissues, 6 precancerous lesions (CIN‐III), and 42 CESC tissues. Significance identifier: ns (no significance), p ≥ 0.05; *, p < 0.05; **p < 0.01; ***p < 0.001.

FIGURE 2

Influence of transforming growth factor α (TGFA) expression in cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) on diagnosis and prognosis of patients. (A) TGFA diagnostic ROC curve; the area under the ROC curve is between 0.5 and 1. The closer the AUC is to 1, the better the diagnostic effect. When the AUC is between 0.5 and 0.7, the accuracy is low, when the AUC is between 0.7 and 0.9, the accuracy is moderate, and when the AUC is above 0.9, the accuracy is high. (B, C) Clinical significance of TGFA expression with age and menopausal status. (D–F) Stratified KM survival curves for overall survival (OS), disease‐specific survival (DSS), and progression‐free period (PFI) based on TGFA expression. (G) Binary logistic regression analysis results of correlation between TGFA expression level and clinical features in 58 patients. The data is incomplete because some records are missing. Significance identifier: ns (no significance), p ≥ 0.05; *p < 0.05; **p < 0.01; ***p < 0.001.

FIGURE 3

Analysis of transforming growth factor α (TGFA)‐related differentially expressed genes. (A) Volcano map by TGFA single gene difference analysis. (B) Protein interaction network diagram of HUB gene. (C) Heat maps of co‐expression of the top 35 genes most associated with TGFA in single gene correlation analysis. (D) Gene Ontology (GO) analysis results. (E) Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis results. (F, G) GO and KEGG analysis class names correspond to GO and KEGG identifiers. (H, I) Gene set enrichment analysis (GSEA) results. When the horizontal coordinate is positive, TGFA expression is positively correlated with this pathway, and when the horizontal coordinate is negative, transforming growth factor α (TGFA) expression is opposite to this pathway.

FIGURE 4

Transforming growth factor α (TGFA) levels are associated with tumour immune cell infiltration. (A) Infiltration levels of 24 types of immune cells in samples with different TGFA expression levels. (B) Analysis of the correlation between TGFA and 24 kinds of immune cell infiltration levels. (C) Thermogram of correlation between TGFA expression and surface labelled proteins of various immune cells:CR2 (B cells), CD8A(cytotoxic cells), SIGLEC8(eosinophils), CD1A (iDCs), TPSAB1(mast cells), B3GAT1 (NK cells), and IL3RA (pDCs), CD3G (T cells), CD3D (T cells), CD3E (T cells), CD4 (T helper cells), PTPRC (Tcm), CXCR5 (Tfh), IL17A (Th17), GATA3 (Th2) and FOXP3 (Treg). (D–F) Correlation analysis of TGFA with DSG2, RAB31 and CLCA2 expression levels. Significance identifier: ns (no significance), p ≥ 0.05; *p < 0.05; **p < 0.01; ***p < 0.001.

FIGURE 5

Functional validation of TGFA in CESC cell lines. (A) Fluorescence maps of lentivirus transfected HeLa and SiHa cells. (B) HeLa and SiHa cells were transfected with shTGFA, and the expression level of TGFA was detected by qRT‐PCR. (C, D) The proliferation of HeLa and SiHa cells was detected by CCK‐8. (E–G) The ability of HeLa and SiHa cells to metastasize was examined by wound healing assay. Significance identifier: ns (no significance), p ≥ 0.05; *p < 0.05; **p < 0.01; ***p < 0.001.

FIGURE 6

Functional validation of TGFA in CESC cell lines. (A, C) The proliferation of HeLa and SiHa cells was detected by colony formation assay. (B, D) The invasion ability of HeLa and SiHa cells was detected by Transwell assay. (E–G) The expression of IL‐1A, IL‐17, MMP1, MMP10 and MMP13 after TGFA expression reduction was detected by western blot. Significance identifier: ns (no significance), p ≥ 0.05; *, p < 0.05; **p < 0.01; ***p < 0.001.