FJX1 overexpression is associated with poor prognosis and promotes gastric cancer proliferation via the PI3K/AKT signaling pathway / 南方医科大学学报

OBJECTIVE@#To investigate the expression of four-jointed box kinase 1 (FJX1) in gastric cancer (GC), its correlation with survival outcomes of the patients, and its role in GC progression.@*METHODS@#The expression level of FJX1 in GC tissues and normal gastric mucosal tissues and its correlation with the survival outcomes of GC patients were analyzed using TCGA and GEO database GC cohort. Immunohistochemistry was used to detect FJX1 expression level in clinical specimens of GC tissue, and its correlations with the patients' clinicopathological parameters and prognosis were analyzed. Bioinformatic analysis was performed to identify the potential pathways of FJX1 in GC. The effects of FJX1 overexpression or FJX1 silencing on GC cell proliferation and expressions of proliferation-related proteins, PI3K, AKT, p-PI3K, and p-AKT were evaluated using CCK-8 assay and Western blotting. The effect of FJX1 overexpression on GC cell tumorigenicity was evaluated in nude mice.@*RESULTS@#GC tissues showed significantly higher expressions of FJX1 mRNA and protein compared with normal gastric mucosa tissues (P < 0.05). The high expression of FJX1 was associated with poor prognosis of GC patients (P < 0.05) and served as an independent risk factor for poor survival outcomes in GC (P < 0.05). FJX1 was expressed mainly in the cytoplasm of GC cells in positive correlation with Ki67 expression (R=0.34, P < 0.05), and was correlated with CA199 levels, depth of tumor infiltration and lymph node metastasis of GC (P < 0.05). In the cell experiment, FJX1 level was shown to regulate the expressions of Ki67 and PCNA and GC cell proliferation (P < 0.05). Gene set enrichment analysis indicated that the PI3K/AKT pathway potentially mediated the effect of FJX1, which regulated the expressions of PI3K and AKT and their phosphorylated proteins. In nude mice, FJX1 overexpression in GC cells significantly promoted the growth of the transplanted tumors (P < 0.05).@*CONCLUSION@#FJX1 is highly expressed in GC tissues and is correlated with poor prognosis of GC patients. FJX1 overexpression promotes GC cell proliferation through the PI3K/AKT signaling pathway, and may serve as a potential prognostic biomarker and therapeutic target for GC.

Expression of four-jointed box kinase 1 gene in colorectal cancer and its clinical significance / 肿瘤研究与临床

Objective:To investigate the differential expression of four-jointed box kinase 1 (FJX1) gene in colorectal cancer and its relationship with prognosis and the related mechanisms.Methods:On July 16, 2021, the transcriptome data and clinical data of colorectal cancer were downloaded from The Cancer Genome Atlas (TCGA) database to analyze the expressions of FJX1 mRNA in colorectal cancer tissues and paracancerous tissues, and the relationship between FJX1 mRNA and clinicopathological characteristics and prognosis of patients. Receiver operating characteristic (ROC) curve was drawn to evaluate the value of FJX1 mRNA in predicting the survival of patients with colorectal cancer. Cox proportional hazards model was used to evaluate whether FJX1 mRNA was an independent influencing factor for prognosis of colorectal cancer. The overall survival (OS) time and survival status of colorectal cancer patients were downloaded from the Gene Expression Omnibus (GEO) database, and the relationship between FJX1 mRNA and prognosis of patients was analyzed. The methylation data of colorectal cancer was downloaded from the University of California, Santa Cruz (UCSC xena) database to determine the degree of methylation at each site of FJX1 mRNA and the correlation between the expression of FJX1 mRNA and the degree of methylation at each site. Signaling pathways associated with FJX1 mRNA in colorectal cancer were analyzed by using the Gene Set Enrichment Analysis (GSEA) (4.1.0). The correlation between FJX1 mRNA and tumor-infiltrating immune cells was investigated by using the Tumor Immunity Evaluation Resource (TIMER) database. Spearman analysis and small molecule/drug sensitivity analysis were used to explore the correlation between FJX1 mRNA expression and drug sensitivity.Results:In the transcriptome data of 612 colorectal cancer cases in TCGA database, the expression of FJX1 mRNA in colorectal cancer tissues was higher than that in the paracancerous tissues ( P < 0.001). In 549 colorectal cancer patients with complete data, FJX1 mRNA expression was correlated with M stage ( P = 0.007), pathological stage (stage Ⅳ vs. stage Ⅰ, P = 0.016; stage Ⅳ vs. stage Ⅱ, P = 0.03; stage Ⅳ vs. stage Ⅲ, P = 0.012), but it was not correlated with age, gender, T stage and N stage (all P > 0.05). In TCGA database and GEO database, the patients were divided into high expression group and low expression group according to the median expression of FJX1 mRNA. The OS in FJX1 mRNA high expression group was worse than that in low expression group (all P<0.05). The ROC curve of FJX1 mRNA expression on the 1-, 3-, and 5-year OS rates of colorectal cancer patients was drawn by using the data in TCGA database, and the areas under the curve (AUC) were 0.595, 0.625 and 0.764, respectively. Multivariate Cox regression analysis showed that age ( HR = 1.050, 95% CI 1.028-1.073, P < 0.001), T stage ( HR = 1.787, 95% CI 1.090-2.927, P = 0.021) and high FJX1 mRNA expression ( HR = 1.160, 95% CI 1.049-1.282, P = 0.004) were independent influencing factors for poor OS in colorectal cancer. The gene set enrichment analysis found that FJX1 mRNA was related to colorectal cancer, TGF-β signaling pathway, VEGF signaling pathway, Wnt signaling pathway, etc. The expression of FJX1 mRNA in colon cancer was negatively correlated with the degree of methylation of FJX1 mRNA ( r = -0.16, P < 0.001), and the expression of FJX1 mRNA in rectal cancer was positively correlated with the degree of methylation of FJX1 mRNA ( r = 0.33, P < 0.001). The expression of FJX1 mRNA was related to the infiltration of resting memory CD4 + T cells, M0 macrophages and resting dendritic cells. FJX1 mRNA was significantly associated with the resistance of various chemotherapeutic drugs and tumor-targeted drugs such as methotrexate, 5-fluorouracil, gefitinib, etc. Conclusions:FJX1 mRNA may be a potential biomarker of colorectal cancer and is associated with the infiltration of immune cells.