Dataset Information

High ATF4 Expression Is Associated With Poor Prognosis, Amino Acid Metabolism, and Autophagy in Gastric Cancer.

ABSTRACT:

Background

The role of activating transcription factor 4 (ATF4) underlying gastric cancer (GC) remains unclear. The purpose of this study was to investigate the expression levels and biological functions of ATF4 in GC.

Methods

Expression of ATF4 was detected by quantitative PCR (qPCR), Western blotting, and immunohistochemistry. Cox regression was used for survival analysis and the construction of the nomogram. Immunofluorescence was used to identify the intracellular localization of ATF4. Knockdown and overexpression of ATF4 in GC cells followed by wound healing and Transwell assays, EdU and Calcein-AM/propidium iodide (PI) staining, and cell cycle detection were performed to examine its function in vitro. Transmission electron microscopy was performed to assess the autophagy levels upon ATF4 silencing. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis and gene set enrichment analysis (GSEA) were used to determine gene enrichment. SPSS 22.0 software, GraphPad Prism 7.0, and R version 3.6.1 were used for statistical analysis.

Results

ATF4 expression was upregulated in GC cells and tissues compared with corresponding normal tissues. Survival analysis suggested that a high ATF4 expression was strongly associated with worse overall survival (OS) of GC patients (p < 0.001). The nomogram and the receiver operating characteristic (ROC) curves demonstrated that ATF4 was a highly sensitive and specific prognostic marker of GC [C-index = 0.797, area under the ROC curve (AUC) of 3-year OS = 0.855, and AUC of 5-year OS = 0.863]. In addition, ATF4 knockdown inhibited the cell proliferation, migration, invasion, and cell cycle progression of GC cells in vitro, while overexpression of ATF4 exerted the opposite effects. Bioinformatics analysis showed that ATF4 could promote GC progression possibly by regulating asparagine (Asn) metabolism and autophagy pathways. Further experiments indicated that ATF4 expression was significantly positively correlated with ASNS expression. The inhibition of cell clone formation in Asn-deprived conditions was more significant in the shATF4 group. Finally, we found that ATF4 promoted autophagy through regulating the mTORC1 pathway in GC cells.

Conclusion

These findings suggested that ATF4 can significantly promote GC development and serve as an independent prognostic factor for GC.

SUBMITTER: Wang M

PROVIDER: S-EPMC8718699 | biostudies-literature |

REPOSITORIES: biostudies-literature

ACCESS DATA

Similar Datasets

Project description:The switching/sucrose non-fermenting (SWI/SNF) chromatin remodeling complexes use the energy of ATP hydrolysis to remodel nucleosomes and modulate transcription, which plays an important role in tumors by regulating epigenetics. SWI/SNF Related, Matrix Associated, Actin Dependent Regulator of Chromatin, Subfamily C, Member 1 (SMARCC1) has dual roles in tumors but its role in gastric cancer remains unclear. This study was aimed to find the role of SMARCC1 in gastric cancer. SMARCC1 expression across various tumors from The Cancer Genome Atlas was analyzed using TIMER 2.0 (http://timer.comp-genomics.org/). SMARCC1 mRNA expression profiles in gastric cell lines and gastric tissues were compared with normal tissues and analyzed in the Cancer Cell Line Encyclopedia, Oncomine, and Gene Expression Omnibus databases. SMARCC1 mRNA and protein were then examined in fresh gastric cancer tissues and compared with adjacent normal tissues using quantitative real-time PCR, western blotting, and immunohistochemistry. Associations between SMARCC1 expression and clinicopathological factors, overall survival, and disease-free survival were further evaluated using 130 gastric cancer samples harvested from patients after radical total gastrectomy or subtotal gastrectomy at the Xiangya Hospital of Central South University (Changsha, China). SMARCC1 was frequently upregulated in gastric cancer cells and tissues. SMARCC1 overexpression was significantly associated with tumor size (P=0.002), differentiation (P=0.006), depth of invasion (P=0.001), lymph node involvement (P=0.016), and TNM stage (P=0.007). Furthermore, univariate and multivariate Cox analysis revealed that high SMARCC1 expression, depth invasion, lymph node involvement, and TNM stage were independent risk factors for both overall and disease-free survival in gastric cancer patients (all P<0.05). Kaplan-Meier survival analysis revealed that high SMARCC1 expression predicted poor prognosis in gastric cancer patients (P<0.01). High SMARCC1 expression contributes to poor prognosis in gastric cancer patients. SMARCC1 may be a prognostic biomarker and therapeutic target in gastric cancer.

Project description:P53-induced gene 11 (PIG11) is an early transcription-related target of p53 that is involved in cell apoptosis and tumor development. However, its biological function in gastric cancer (GC) tissues and relationship with the prognosis of patients with GC have remained elusive. In the present retrospective study, 60 fresh and 790 paraffin-embedded samples of GC were obtained from the Affiliated Hospital of Nantong University (Nantong, China) with complete clinical data from all patients. Reverse transcription-quantitative PCR and tissue microarray-immunohistochemical analysis were used to determine the expression of PIG11 in the respective GC tissues. A receiver operating characteristic (ROC) curve was plotted to determine the diagnostic utility of PIG11 expression in GC. Furthermore, three online databases, including Gene Expression Profiling Interactive Analysis (GEPIA), Oncomine and Kaplan-Meier plotter, were used for bioinformatics analysis of PIG11. PIG11 expression in GC tissues was high, which was positively correlated with invasive depth (P<0.001), lymph node metastasis (P<0.001), distant metastasis (P=0.019), TNM staging (P<0.001) and carcinoembryonic antigen in serum (P<0.001), and negatively associated with the overall survival of patients with GC. The ROC curve analysis suggested that based on PIG11 expression, it was possible to distinguish GC tissues from adjacent normal tissues (P<0.0001) with a sensitivity and specificity of 81.67 and 76.67%, respectively. In addition, Cox logistic regression analysis demonstrated that high PIG11 expression is a novel biomarker for unfavorable prognosis of patients with GC. Furthermore, the results obtained from the GEPIA database indicated that PIG11 expression is correlated with TNF, carcinoembryonic antigen related cell adhesion molecule 5, phosphatidylinositol-4, 5-bisphosphate 3-kinase catalytic subunit alpha, VEGFA and kinase insert domain receptor. Therefore, PIG11 expression may be associated with the malignancy of GC and may serve as a potential diagnostic and prognostic biomarker for GC.

Project description:Background: Lysyl oxidase (LOX) is a key enzyme for the cross-linking of collagen and elastin in the extracellular matrix. This study evaluated the prognostic role of LOX in gastric cancer (GC) by analyzing the data of The Cancer Genome Atlas (TCGA) and the Gene Expression Omnibus (GEO) dataset. Methods: The Wilcoxon rank-sum test was used to calculate the expression difference of LOX gene in gastric cancer and normal tissues. Western blot and immunohistochemical staining were used to evaluate the expression level of LOX protein in gastric cancer. Kaplan-Meier analysis was used to calculate the survival difference between the high expression group and the low expression group in gastric cancer. The relationship between statistical clinicopathological characteristics and LOX gene expression was analyzed by Wilcoxon or Kruskal-Wallis test and logistic regression. Univariate and multivariate Cox regression analysis was used to find independent risk factors affecting the prognosis of GC patients. Gene set enrichment analysis (GSEA) was used to screen the possible mechanisms of LOX and GC. The CIBERSORT calculation method was used to evaluate the distribution of tumor-infiltrating immune cell (TIC) abundance. Results: LOX is highly expressed in gastric cancer tissues and is significantly related to poor overall survival. Wilcoxon or Kruskal-Wallis test and Logistic regression analysis showed, LOX overexpression is significantly correlated with T-stage progression in gastric cancer. Multivariate Cox regression analysis on TCGA and GEO data found that LOX (all p < 0.05) is an independent factor for poor GC prognosis. GSEA showed that high LOX expression is related to ECM receptor interaction, cancer, Hedgehog, TGF-beta, JAK-STAT, MAPK, Wnt, and mTOR signaling pathways. The expression level of LOX affects the immune activity of the tumor microenvironment in gastric cancer. Conclusion: High expression of LOX is a potential molecular indicator for poor prognosis of gastric cancer.