ZNF692 Promotes the Progression of Colon Adenocarcinoma by Regulating HSF4 Expression

Abstract

Background: Colon adenocarcinoma (COAD) is one of the most common cancer happened in gastrointestinal tract, with the overall incidence rate of 4%-5% among human beings. Like most malignancies, we uncovered the exact mechanisms of the pathogenesis of colorectal cancer yet. Therefore, there is an urgent need to explore the molecules that can be used as diagnostic maker at early stage. In addition, we also need to define the essential factors that related to the prognosis and treatment of the colon carcinoma.

Methods: The study was conducted at the Third Affiliated Hospital of Qiqihar Medical University, Qiqihar, China in September 2020. The R language was used to identify the differentially expressed genes. We performed receiver operating characteristic curve analysis to determine the diagnostic markers for COAD. The machine learning strategy was used to assess the effectiveness of genes in the diagnosis of COAD. The molecular mechanism and prognostic value of genes were explored by bioinformatics analysis and molecular experiments.

Results: The expression level of heat shock factor 4 (HSF4) was significantly elevated in COAD patients (P=1.89×10^-29), according to The Cancer Genome Atlas (TCGA) database. Additionally, survival analysis showed the higher expression level of the HSF4 was correlated with the poor prognosis in COAD.

Conclusion: The HSF4 was the target gene of zinc finger protein 692(ZNF692). HSF4 might promote the progression of COAD through the apoptosis pathway. It was diagnostic and prognosis maker of COAD. Furthermore, the upstream gene of HSF4, ZNF692, promotes the progression of colorectal cancer by regulating HSF4 expression.

Keywords: Biomarker; Colon adenocarcinoma; Heat shock factor 4; Zinc finger protein 692.

Fig. 1:

HSF4 is elevated in COAD patients and COAD cells. (A)TCGA database showed that HSF4 expression was considerably elevated in COAD patients. (B) ROC curve analysis showed that HSF4 had high diagnostic significance for COAD. (C). Evaluation metrics of each fold. (D). Western blot was used to detect the protein levels of HSF4. (E). RT-qPCR was used to detect the mRNA levels of HSF4. ****P < 0.0001

Fig. 2:

Survival analysis of HSF4 in COAD. (A) HSF4 expression and the survival time scatter gram of COAD patients; (B) The survival curves for groups with different expression levels of HSF4; (C) Time-dependent receiver operating characteristic (ROC) curve of HSF4 expression in predicting OS of COAD

Fig. 3:

Knockdown of HSF4 promoted apoptosis and inhibited cell proliferation in vitro. (A). The cell proliferation was measured by CCK-8 assay after HSF4 knockdown. (B). GSEA analysis showed that apoptosis were significantly enriched. **P< 0.01

Fig. 4:

HSF4 was the target gene of ZNF692. (A) TCGA database showed that ZNF692 expression was elevated considerably in COAD patients. (B) RT-qPCR indicated that the mRNA level of ZNF692 was raised in the COAD cell lines compared to those in normal human colon tissue cells (CCD-18CO cells). (C) Western blot revealed that the protein level of ZNF692 was raised compared to those in normal human colon tissue cells (CCD-18CO cells). (D) We found that overexpression of ZNF692 did induce the expression of HSF4. (E) shRNA-mediated knockdown of ZNF692 did reduce the expression of HSF4. **P < 0.01, ****P < 0.0001

Fig. 5:

ZNF692 stimulates COAD cell proliferation in a HSF4 dependent manner. CCK-8 was utilized to assess the proliferation of LS513 cells that were stable in their expression of ZNF692 + sh-HSF4. **P < 0.01, ***P < .001,****P< 0.0001