Objective:To investigate the effect of ribonucleotide reductase regulatory subunit M2 (RRM2) on the malignant biological behavior and aerobic glycolysis of gastric cancer cells by regulating cyclin-dependent kinase (CDK) 1.Methods:Human gastric cancer MKN-45 cells were divided into si-NC group (transfected with blank fragment) , CoCl 2+si-NC group (hypoxia control transfected with blank fragment) , CoCl 2+si-RRM2 group (hypoxia with RRM2 silencing) , CoCl 2+si-RRM2+pcDNA3.1 NC group (hypoxia with RRM2 silencing and blank vector) and CoCl 2+si-RRM2+pcDNA3.1 CDK1 group (hypoxia with RRM2 silencing and CDK1 overexpression) . The mRNA relative expression levels of RRM2 and CDK1 were analyzed by real time fluorescent quantitative reverse transcription PCR. Co-immunoprecipitation (CoIP) was used to analyze the interaction between RRM2 and CDK1 protein. MTT assay was used to analyze the proliferation activity of cells. The cell migration distance was detected by cell scratch assay. Cell apoptosis was detected by flow cytometry. Adenosine triphosphate (ATP) and glucose kit were used to detect ATP production and glucose consumption. The protein expressions of ENO1, RRM2, HK2, PKM2, GLUT1 and p-CDK1/CDK1 were detected by Western blotting. Results:Real time fluorescent quantitative reverse transcription PCR results showed that the relative expression levels of CDK1 mRNA in si-NC group, CoCl 2+si-NC group and CoCl 2+si-RRM2 group were 1.01±0.15, 1.30±0.06 and 0.51±0.18, and the relative expression levels of RRM2 mRNA were 1.03±0.32, 1.59±0.28 and 0.44±0.17, respectively, and there were statistically significant differences ( F=25.52, P=0.001; F=14.47, P=0.005) . The mRNA expressions of RRM2 and CDK1 in CoCl 2+si-NC group were higher than those in si-NC group. Compared with the si-NC group and the CoCl 2+si-NC group, the mRNA expressions of RRM2 and CDK1 were lower in the CoCl 2+si-RRM2 group (all P<0.05) . CoIP results showed that there was interaction between RRM2 and CDK1. MTT assay, cell scratch assay and flow cytometry showed that the cell proliferation activity of si-NC group, CoCl 2+si-NC group, CoCl 2+si-RRM2 group, CoCl 2+si-RRM2+pcDNA3.1 NC group and CoCl 2+si-RRM2+pcDNA3.1 CDK1 group were 1.04±0.01, 1.18±0.04, 0.84±0.03, 0.81±0.03 and 0.93±0.05, respectively. The cell migration distances were (301.83±2.75) , (369.67±0.76) , (176.50±6.38) , (175.83±3.69) , (254.17±1.61) μm, respectively. The apoptosis rates were 8.05%±0.21%, 5.75%± 0.20%, 28.28%±0.04%, 30.18%±1.51% and 17.79%±0.22%, respectively, all with statistically significant differences ( F=73.82, P<0.001; F=1 600.01, P<0.001; F=787.15, P<0.001) . Compared with the si-NC group and CoCl 2+si-NC group, the proliferation and migration ability of cells in the CoCl 2+si-RRM2 group, CoCl 2+si-RRM2+pcDNA3.1 NC group and CoCl 2+si-RRM2+pcDNA3.1 CDK1 group were weaker, and the apoptosis rates were higher (all P<0.05) . Compared with the CoCl 2+si-RRM2+pcDNA3.1 NC group, the proliferation and migration ability of cells in the CoCl 2+si-RRM2+pcDNA3.1 CDK1 group were stronger, and the apoptosis rate was lower (all P<0.05) . The results of ATP and glucose detection showed that there were statistically significant differences in the amount of ATP production and glucose consumption among the above five groups ( F=12.53, P<0.001; F=19.21, P<0.001) . Compared with the si-NC group, the glucose consumption of cells was lower in the CoCl 2+si-RRM2+pcDNA3.1 CDK1 group ( P<0.05) . Compared with the CoCl 2+si-NC group, the ATP production and glucose consumption of cells in the CoCl 2+si-RRM2+pcDNA3.1 CDK1 group were lower (both P<0.05) . Compared with the CoCl 2+si-RRM2+pcDNA3.1 NC group, the ATP production and glucose consumption of the CoCl 2+si-RRM2+pcDNA3.1 CDK1 group were higher (both P<0.05) . Western blotting showed that there were statistically significant differences in the protein expressions of ENO1, RRM2, HK2, PKM2, GLUT1, and p-CDK1/CDK1 among the above five groups (all P<0.001) . Compared with the si-NC group and the CoCl 2+si-NC group, the protein expressions of ENO1, RRM2, HK2, PKM2, GLUT1 and p-CDK1/CDK1 in the CoCl 2+si-RRM2+pcDNA3.1 CDK1 group were lower (all P<0.05) . Compared with the CoCl 2+si-RRM2+pcDNA3.1 NC group, the protein expressions of ENO1, RRM2, PKM2, GLUT1 and p-CDK1/CDK1 in the CoCl 2+si-RRM2+pcDNA3.1 CDK1 group were higher (all P<0.05) . Conclusions:Silencing RRM2 can inhibit the malignant biological behavior of gastric cancer cells and the occurrence of aerobic glycolysis by regulating CDK1.

Objective:To construct a predictive model of ≥ grade 2 radiation esophagitis (RE) in patients with esophageal cancer during concurrent radiochemotherapy (CRT) based on machine learning (ML) algorithm.Methods:A retrospective analysis was conducted on the clinical data of 276 patients with esophageal cancer who had received CRT at Lu'an Hospital of Anhui Medical University from January 2018 to January 2023. The occurrence of RE was evaluated according to grading criteria of RE developed by American Radiation Therapy Oncology Group, with ≥ grade 2 RE as the outcome event. After screening variables through the least absolute shrinkage and selection operator (LASSO) regression, the dataset was re-established. The dataset was then divided into training set ( n=193) and testing set ( n=83) in a 7∶3 ratio and included in four ML models: random forest (RF) , decision tree (DT) , extreme gradient boosting (XGBoost) , and support vector machine (SVM) . In the models, data training and model optimization were conducted in the training set, and model performance was evaluated in the testing set using the receiver operator characteristic (ROC) curve. The area under the curve (AUC) , accuracy, precision, sensitivity, and F1 score were calculated to assess the model. SHAP analysis was used to explain the optimal model. Results:By the end of follow-up, 91 cases (32.97%) of esophageal cancer patients had experienced ≥ grade 2 RE during CRT. There were statistically significant differences in tumor lesion length ( Z=-5.53, P<0.001) , Karnofsky performance status (KPS) score ( χ2=5.92, P=0.015) , the Eastern Cooperative Oncology Group (ECOG) score ( χ2=4.01, P=0.045) , hypertension ( χ2=15.35, P<0.001) , diabetes ( χ2=13.06, P<0.001) , white blood cell count ( Z=-6.59, P<0.001) , neutrophil count ( Z=-6.72, P<0.001) , and radiotherapy dose ( χ2=9.81, P=0.002) between ≥ grade 2 RE occurrence group ( n=91) and no occurrence group ( n=185) . After LASSO regression screening, 7 characteristic variables were ultimately selected, which were tumor lesion length, ECOG score, KPS score, neutrophil count, hypertension, diabetes, and radiotherapy dose. ROC curve analysis showed that the XGBoost model had better predictive performance, with an AUC of 0.90, accuracy of 0.82, precision of 0.80, sensitivity of 0.73, and F1 score of 0.76. The AUC, accuracy, precision, sensitivity, and F1 score of RF model were 0.89, 0.78, 0.76, 0.48, and 0.59, respectively. The AUC, accuracy, precision, sensitivity, and F1 score of DT model were 0.72, 0.72, 0.44, 0.60, and 0.52, respectively. The AUC of SVM model was 0.74, with an accuracy of 0.82, precision of 0.52, sensitivity of 0.88, and F1 score of 0.65. The XGBoost model was explained using SHAP analysis, which indicated that the tumor lesion length, neutrophil count, hypertension, diabetes, and radiotherapy dose had a strong predictive ability for the occurrence of ≥ grade 2 RE during CRT in esophageal cancer patients. Conclusions:The model established based on the XGBoost method has good predictive performance for the occurrence of ≥ grade 2 RE in esophageal cancer patients during CRT. Meanwhile, combined with SHAP analysis, it can provide an intuitive understanding of the impact of important features in the model on the outcome.

Objective:To investigate the predictive value of maximum tumor diameter and the peripheral blood neutrophil to lymphocyte ratio (NLR) before radiotherapy for the occurrence of esophageal fistula after radiotherapy in patients with esophageal squamous cell carcinoma (ESCC) .Methods:A total of 98 patients with ESCC who underwent radiotherapy in Hefei Cancer Hospital, Chinese Academy of Sciences from February 2017 to February 2021 were selected, and the patients were divided into esophageal fistula group (13 cases) and no esophageal fistula group (85 cases) according to whether esophageal fistula occurred during the follow-up process. The prognostic nutritional index (PNI) , NLR, and systemic inflammatory response index (SIRI) were calculated. Univariate and multivariate logistic regression were used to analyze the influencing factors of esophageal fistula, and the predictive value of each indicator was evaluated by using the receiver operator characteristic (ROC) curve.Results:There were no statistically significant differences in age, smoking history, diabetes mellitus history, gender, concurrent chemotherapy and alcohol history between the esophageal fistula group and the no esophageal fistula group (all P>0.05) , while there were statistically significant differences in PNI ( t=2.24, P=0.041) , NLR ( t=3.75, P=0.001) , SIRI ( t=2.68, P=0.015) . Univariate analysis showed that tumor length ( OR=1.16, 95% CI: 1.01-1.35, P=0.043) , maximum tumor diameter ( OR=1.63, 95% CI: 1.11-2.39, P=0.012) , PNI ( OR=0.83, 95% CI: 0.71-0.98, P=0.023) , NLR ( OR=1.94, 95% CI: 1.20-3.12, P=0.007) and SIRI ( OR=1.82, 95% CI: 1.03-3.24, P=0.041) were related to esophageal fistula. Multivariate analysis showed that maximum tumor diameter ( OR=2.17, 95% CI: 1.02-4.94, P=0.033) and NLR ( OR=2.40, 95% CI: 1.89-6.59, P=0.018) were independent influencing factors for the development of esophageal fistula in patients with ESCC after radiotherapy. ROC curve analysis showed that the area under the curve of maximum tumor diameter before radiotherapy combined with NLR for predicting esophageal fistula in patients with esophageal squamous cell carcinoma after radiotherapy was 0.83 (95% CI: 0.74-0.90) , which was greater than that of maximum tumor diameter before radiotherapy (0.71, 95% CI: 0.63-0.81, Z=1.80, P=0.039) and NLR (0.74, 95% CI: 0.67-0.85, Z=1.64, P=0.046) alone. Conclusions:The maximum tumor diameter before radiotherapy and NLR are closely related to the occurrence of esophageal fistula in ESCC after radiotherapy, and these factors are expected to serve as key predictors of the occurrence of esophageal fistula.

Although patients with stage pT 2-3N 0M 0 thoracic esophageal squamous cell carcinoma are staged earlier, their postoperative local recurrence and distant metastasis rates are higher, resulting in a low five-year survival rate of such patients. The current neoadjuvant treatment for such patients is still in the research stage, and whether to give adjuvant radiotherapy and chemotherapy after surgery is still controversial. In addition, the prognostic factors of patients with pT 2-3N 0M 0 thoracic esophageal squamous cell carcinoma have not yet been clarified, and the causes of recurrence and metastasis are not yet clear. Therefore, it is of great significance to clarify treatment strategies and explore the impact of prognostic factors on improving the survival rate of such patients, which is expected to provide new directions for improving the prognosis and survival rate of patients with pT 2-3N 0M 0 thoracic esophageal squamous cell carcinoma.

Esophageal cancer is one of the leading causes of death from cancer worldwide. Radiotherapy plays an important role in the treatment of esophageal cancer. Compared with photon radiotherapy, proton radiotherapy significantly reduces normal organ dose due to its unique biophysical properties, which makes this modality potential ideal for esophageal cancer treatment. Proton radiotherapy plays an important role in radical radiotherapy, neoadjuvant radiotherapy and re-radiotherapy for esophageal cancer. The efficacy is equivalent to or better than that of photon radiotherapy, and proton radiotherapy is superior than photon radiotherapy in security. The combination of proton radiotherapy and immunotherapy, the increase of radiotherapy dose, and large-scale randomized controlled studies based on intensity-modulated proton radiotherapy technology will be hot topics for further research.

The early diagnosis rate of esophageal cancer is low, and most of the patients are already in the middle or late stage when diagnosed, making treatment difficult, shortening the survival period and resulting in an extremely poor prognosis. In recent years, the continuous development of targeted therapy and immunotherapy has significantly improved the survival rate and therapeutic effect of esophageal cancer patients. Analyzing the research progress of targeted therapy and immunotherapy for esophageal cancer is of great significance and can provide reference for guiding the treatment of esophageal cancer.

In recent years, studies have found that the abnormal expression of rhythm genes is closely related to the risk of occurrence and the progression of the disease course of colorectal cancer. In addition, chronotherapy based on the circadian rhythm theory has shown certain effects in the clinical treatment of colorectal cancer, but there are still great limitations. Therefore, it is very important to clarify the mechanism of action of rhythm genes in the occurrence and development of colorectal cancer, which may provide a theoretical basis for the clinical application of chronotherapy.

Objective:To investigate the role and potential mechanism of m 6A demethylase ALKBH5 in esophageal squamous cell carcinoma (ESCC) . Methods:Real time fluorogenic quantitative PCR and Western blotting were used to detect ALKBH5 expression in normal esophageal epithelial cells (Het-1A) and ESCC cell lines (Eca109, KYSE30, KYSE150, KYSE410). Transient cell lines with overexpression/knockdown of ALKBH5 (siRNA transfection was divided into si-ALKBH5-1 group and si-ALKBH5-2 group) and control cell lines were constructed. The effects of ALKBH5 on ESCC cell proliferation, migration and apoptosis were studied by MTT assay, cell scratch assay and cell apoptosis assay respectively. The differentially expressed gene was screened by the intersection of RNA sequencing (RNA-seq) and methylated RNA immunoprecipitation sequencing (MeRIP-seq) techniques, and the effect of ALKBH5 on the gene expression was detected by RT-qPCR.Results:Real time fluorogenic quantitative PCR results showed that, the relative expression levels of ALKBH5 RNA in Het-1A, Eca109, KYSE30, KYSE150 and KYSE410 were 1.03±0.28, 0.46±0.02, 0.23±0.10, 0.04±0.02, 0.05±0.00, respectively, with a statistically significant difference ( F=444.60, P<0.001). Western blotting showed that, the relative expression levels of ALKBH5 protein in Het-1A, Eca109, KYSE30, KYSE150 and KYSE410 were 1.14±0.03, 0.88±0.04, 0.66±0.01, 0.69±0.01, 0.95±0.01, respectively, with a statistically significant difference ( F=139.90, P<0.001). MTT test showed that the absorbance ( A) values of KYSE30 control group and ALKBH5 overexpression group were 0.86±0.01 and 1.25±0.01 after 72 hours, respectively, with a statistically significant difference ( t=46.93, P<0.001). The A values of KYSE150 control group and ALKBH5 overexpression group were 1.00±0.03 and 1.43±0.02 after 72 hours, respectively, with a statistically significant difference ( t=16.80, P<0.001). The A values of KYSE30 control group, si-ALKBH5-1 group and si-ALKBH5-2 group were 0.98±0.01, 0.85±0.02 and 0.80±0.09 after 96 hours, respectively, with a statistically significant difference ( F=72.97, P<0.001). The A values of KYSE30 control group were higher than those of si-ALKBH5-1 and si-ALKBH5-2 groups (both P<0.001). The A values of KYSE410 control group, si-ALKBH5-1 group and si-ALKBH5-2 group were 1.28±0.02, 1.15±0.02 and 1.08±0.05 after 72 hours, respectively, with a statistically significant difference ( F=16.97, P=0.003). The A values in KYSE410 control group were higher than those in si-ALKBH5-1 group and si-ALKBH5-2 group ( P=0.020; P=0.003). The cell scratch test showed that 48 hours after scratch, the migration rates of KYSE30 cells in control group and ALKBH5 overexpression group were (27.39±0.54) % and (48.89±5.12) %, respectively, with a statistically significant difference ( t=5.90, P=0.004). The migration rates of KYSE150 cells in control group and ALKBH5 overexpression group were (39.67±0.43) % and (62.20±0.60) %, respectively, with a statistically significant difference ( t=43.15, P<0.001). The migration rates of KYSE30 cells in control group, si-ALKBH5-1 group and si-ALKBH5-2 group were (25.08±1.86) %, (18.75±1.59) % and (7.67±0.52) %, respectively, with a statistically significant difference ( F=74.28, P<0.001). The migration rates of KYSE30 cells in control group were higher than those of si-ALKBH5-1 group and si-ALKBH5-2 group ( P=0.010; P<0.001). The migration rates of KYSE410 cells in control group and si-ALKBH5-1 group, si-ALKBH5-2 group were (38.70±0.41) %, (28.27±1.01) % and (19.40±0.47) %, respectively, with a statistically significant difference ( F=400.20, P<0.001). The migration rates of KYSE410 cells in control group were higher than those of si-ALKBH5-1 group and si-ALKBH5-2 group (both P<0.001). Apoptosis test showed that the apoptosis rates of KYSE30 cells in control group and ALKBH5 overexpression group were (9.59±0.88) % and (4.81±0.89) %, respectively, with a statistically significant difference ( t=6.23, P=0.006). The apoptosis rates of KYSE150 cells in control group and ALKBH5 overexpression group were (8.36±0.09) % and (6.42±0.19) %, respectively, with a statistically significant difference ( t=12.90, P<0.001). The apoptosis rates of KYSE30 cells in control group, si-ALKBH5-1 group and si-ALKBH5-2 group were (4.31±0.19) %, (5.72±0.30) % and (8.94±0.71) %, respectively, with a statistically significant difference ( F=53.46, P<0.001). The apoptosis rates in KYSE30 cells in control group were lower than those in si-ALKBH5-1 group and si-ALKBH5-2 group ( P=0.049; P<0.001). The apoptosis rates of KYSE410 control group, si-ALKBH5-1 group and si-ALKBH5-2 group were (4.45±0.36) %, (5.40±0.11) % and (6.64±0.15) %, respectively, with a statistically significant difference ( F=43.36, P<0.001). The apoptosis rates in KYSE410 cells in control group were lower than those in si-ALKBH5-1 group and si-ALKBH5-2 group ( P=0.016; P<0.001). The differentially expressed gene IGF2BP3 was screened by the intersection of RNA-seq and MeRIP-seq techniques, and the RT-qPCR results showed that, the relative expression levels of IGF2BP3 in KYSE30 were 1.01±0.10 and 1.41±0.10 in control group and ALKBH5 overexpression group, respectively, with a statistically significant difference ( t=4.06, P=0.015). The relative expression levels of IGF2BP3 in KYSE150 were 1.00±0.10 and 1.94±0.24 in control group and ALKBH5 overexpression group, respectively, with a statistically significant difference ( t=5.08, P=0.007). The relative expression levels of IGF2BP3 in KYSE410 were 1.01±0.14, 0.67±0.04 and 0.41±0.04 in control group, si-ALKBH5-1 group and si-ALKBH5-2 group, respectively, with a statistically significant difference ( F=24.36, P=0.001). The relative expression levels of IGF2BP3 in KYSE410 control group were higher than those in si-ALKBH5-1 group and si-ALKBH5-2 group ( P=0.017; P=0.001) . Conclusions:ALKBH5 is underexpressed in ESCC cell lines, but the overexpression of ALKBH5 can promote the proliferation and migration of ESCC cells and inhibit cell apoptosis, which may be related to some negative feedback regulation mechanism. IGF2BP3 may be the downstream target of ALKBH5.

Objective:To investigate the value of MRI combined with serum long non-coding RNA (lncRNA) KCNQ1OT1 and microRNA-204-5p (miR-204-5p) in predicting axillary lymph node metastasis in breast cancer patients.Methods:A total of 70 patients with breast cancer who were surgically diagnosed in the No.2 Hospital of Baoding, Hebei Province from January 2020 to December 2022 were selected as the study objects. Patients were divided into metastatic group ( n=31) and non-metastatic group ( n=39) according to the status of lymph node metastasis. The MRI features and the levels of serum lncRNA KCNQ1OT1 and miR-204-5p were compared between the two groups. Receiver operator characteristic (ROC) curve was used to evaluate the predictive efficacy of the three detections alone and in combination for axillary lymph node metastasis in breast cancer. Results:There were statistically significant differences in tumor maximum diameter ( χ2=4.28, P=0.039) and Ki-67 expression ( χ2=10.88, P=0.001) between the metastatic and non-metastatic groups. There were statistically significant differences between the breast cancer axillary lymph node metastatic group and the non-metastatic group in the mode of internal reinforcement type ( χ2=6.60, P=0.037), peripheral vessel diameter ( t=4.33, P<0.001), number of peripheral vessel roots ( t=4.38, P<0.001), apparent diffusion coefficient ( t=3.59, P=0.001), and MRI lymph node status ( χ2=29.70, P<0.001). The level of serum lncRNA KCNQ1OT1 in metastatic group was higher than that in non-metastatic group (1.41±0.32 vs. 0.99±0.18, t=6.94, P<0.001), and the level of miR-204-5p was lower than that in non-metastatic group (0.72±0.17 vs. 1.03±0.21, t=6.66, P<0.001). Bioinformatics analysis showed that miR-204-5p may have a targeting relationship with lncRNA KCNQ1OT1. ROC curve analysis showed the area under the curve of MRI features, serum levels of lncRNA KCNQ1OT1, miR-204-5p and their combined detection to predict lymph node metastasis of breast cancer patients were 0.823, 0.858, 0.843, 0.946, respectively. The predictive efficacy of the combined detection was better than that of MRI features and serum lncRNA KCNQ1OT1 and miR-204-5p levels alone ( Z=3.29, P=0.001; Z=2.07, P=0.038; Z=2.23, P=0.026) . Conclusions:Serum lncRNA KCNQ1OT1 level is up-regulated and the level of miR-204-5p is down-regulated in patients with axillary lymph node metastasis of breast cancer. And the combination of MRI features with serum lncRNA KCNQ1OT1 and miR-204-5p has high predictive efficacy in predicting lymph node metastasis in breast cancer patients.

Objective:To explore the expression of 7-dehydrocholesterol reductase (DHCR7) in gastric cancer using bioinformatics methods and its relationship with clinical pathological characteristics and prognosis of gastric cancer patients.Methods:DHCR7 expression in gastric cancer was analyzed using the UALCAN database; DHCR7 mRNA expression and its relationship with the prognosis of gastric cancer patients were analyzed using the Kaplan-Meier plotter database; The expression of DHCR7 and its correlation with tumor immune infiltration level were analyzed using Sangerbox 3.0 and TIMER database; Real-time fluorescence quantitative PCR was used to detect the expression of DHCR7 mRNA in gastric cancer tissues and adjacent tissues; immunohistochemical staining was conducted to detect the DHCR7 expression in gastric cancer tissues and adjacent tissues and its correlation with clinical pathological parameters; Receiver operator characteristic (ROC) curve was used to evaluate the efficacy of DHCR7 expression in the diagnosis of gastric cancer.Results:The analysis results of the UALCAN database showed that there were statistically significant differences in DHCR7 mRNA expression among gastric cancer patients of different genders ( χ2=18.15, P<0.001), grades ( χ2=16.32, P<0.001), and TP53 mutation status ( χ2=20.12, P<0.001). Survival analysis showed that the 10-year overall survival (OS) rate ( HR=1.55, 95% CI: 1.31-1.84, P<0.001), 10-year progression free survival (PFS) rate ( HR=1.67, 95% CI: 1.36-2.05, P<0.001), and 10-year post progression survival (PPS) rate ( HR=1.81, 95% CI: 1.43-2.28, P<0.001) of gastric cancer patients with high DHCR7 expression were significantly lower than those with low DHCR7 expression. Immune infiltration analysis showed the expression of DHCR7 was negatively correlated with the comprehensive score ( r=-0.51, P<0.001), stromal cell score ( r=-0.48, P<0.001), immune cell score ( r=-0.45, P<0.001), CD4 + T cells ( r=-3.01, P<0.001), macrophages ( r=-0.40, P<0.001), neutrophils ( r=-0.32, P<0.001), and dendritic cells ( r=-0.37, P<0.001) infiltration levels in gastric cancer, and positively correlated with the purity of gastric cancer cells ( r=0.15, P<0.001). The qRT-PCR results showed that compared with adjacent tissues (1.86±0.51), the expression of DHCR7 in gastric cancer tissues (3.43±0.13) was significantly upregulated, with a statistically significant difference ( t=42.89, P<0.001). The relative expression level of DHCR7 in normal gastric mucosal cells GES-1 was 1.06±0.19, and the relative expression levels in four types of gastric cancer cells (HGC-27, AGS, SNU-1, and SGC-7901) were 2.40±0.26, 1.88±0.11, 1.51±0.04, and 2.63±0.20, respectively, there were statistically significant differences in the expression of DHCR7 among the five types of cells ( F=38.34, P<0.001), and the relative expression level of DHCR7 in normal gastric mucosal cells was statistically significant different compared to the four types of gastric cancer cells mentioned above ( P=0.002; P=0.003; P=0.017; P<0.001) ; The immunohistochemical results showed that the high expression rate of DHCR7 in gastric cancer tissues was 80.0% (96/120), which was significantly higher than that in adjacent tissues (68.3%) (82/120) ( χ2=56.84, P<0.001). There were statistically significant differences in tumor maximum diameter ( χ2=40.17, P<0.001), histological grade ( χ2=16.20, P<0.001) and pTNM stage ( χ2=16.99, P<0.001) between patients with high and low DHCR7 expression. The ROC curve results showed that the area under the curve (AUC) of DHCR7 expression level for diagnosing gastric cancer were 0.76 (based on TCGA database, 95% CI: 0.68-0.83, P<0.001) and 0.97 (120 clinical samples of gastric cancer, 95% CI: 0.95-0.99, P<0.001), respectively. Conclusions:DHCR7 is highly expressed in gastric cancer and closely associated with poor prognosis in patients, which may be a novel biomarker for the diagnosis and prognosis of gastric cancer.