Objective:To investigate the role of cholinergic anti-inflammatory pathway in the regulation of peptide transporter 1 (PepT1) expression in small intestinal epithelium of septic rats by Ghrelin.Methods:One hundred adult male Sprague-Dawley (SD) rats were randomly divided into sham operation group, sepsis group, sepsis+vagotomy group, sepsis+Ghrelin group, and sepsis+vagotomy+Ghrelin group, with 20 rats in each group. In the sham operation group, the cecum was separated after laparotomy, without ligation and perforation. In the sepsis group, the rats received cecal ligation puncture (CLP). In the sepsis+vagotomy group, the rats received CLP and vagotomy after laparotomy. In the sepsis+Ghrelin group, 100 μmol/L Ghrelin was intravenously injected after CLP immediately. The rats in the sepsis+vagotomy+Ghrelin group received CLP and vagotomy at the same time, then the Ghrelin was intravenously injected immediately with the same dose as the sepsis+Ghrelin group. Ten rats in each group were taken to observe their survival within 7 days. The remaining 10 rats were sacrificed 20 hours after the operation to obtain venous blood and small intestinal tissue. The condition of the abdominal intestine was observed. The injury of intestinal epithelial cells was observed with transmission electron microscopy. The contents of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) in serum and small intestinal tissue were detected by enzyme-linked immunosorbent assay (ELISA). The brush border membrane vesicle (BBMV) was prepared, the levels of mRNA and protein expression of PepT1 in the small intestinal epithelium were detected by real-time fluorescence quantitative polymerase chain reaction (RT-qPCR) and Western blotting.Results:All rats in the sham operation group survived at 7 days after operation. The 7-day cumulative survival rate of rats in the sepsis group was significantly lower than that in the sham operation group (20% vs. 100%, P < 0.05). The cumulative survival rate of rats after Ghrelin intervention was improved (compared with sepsis group: 40% vs. 20%, P < 0.05), but the protective effect of Ghrelin was weakened after vagotomy (compared with sepsis+Ghrelin group: 10% vs. 40%, P < 0.05). Compared with the sham operation group, in the sepsis group, the small intestine and cecum were dull red, the intestinal tubules were swollen and filled with gas, the intestinal epithelial cells were seriously injured under transmission electron microscopy, the levels of TNF-α and IL-1β in serum and small intestinal were significantly increased, and the expression levels of PepT1 mRNA and protein in the small intestinal epithelium were significantly decreased. It indicated that the sepsis rat model was successfully prepared. After vagotomy, the intestinal swelling and gas accumulation became worse in septic rats, leading to the death of all rats. Compared with the sepsis group, the abdominal situation in the sepsis+Ghrelin group was improved, the injury of intestinal epithelial cells was alleviated, the serum and small intestinal TNF-α and IL-1β were significantly decreased [serum TNF-α (ng/L): 253.27±23.32 vs. 287.90±19.48, small intestinal TNF-α (ng/L): 95.27±11.47 vs. 153.89±18.15, serum IL-1β (ng/L): 39.16±4.47 vs. 54.26±7.27, small intestinal IL-1β (ng/L): 28.47±4.13 vs. 42.26±2.59, all P < 0.05], and the expressions of PepT1 mRNA and protein in the small intestinal epithelium were significantly increased [PepT1 mRNA (2 -ΔΔCt): 0.66±0.05 vs. 0.53±0.06, PepT1 protein (PepT1/GAPDH): 0.80±0.04 vs. 0.60±0.05, both P < 0.05]. Compared with the sepsis+Ghrelin group, after vagotomy in the sepsis+vagotomy+Ghrelin group, the effect of Ghrelin on reducing the release of inflammatory factors in sepsis rats was significantly reduced [serum TNF-α (ng/L): 276.58±19.88 vs. 253.27±23.32, small intestinal TNF-α (ng/L): 144.28±12.99 vs. 95.27±11.47, serum IL-1β (ng/L): 48.15±3.21 vs. 39.16±4.47, small intestinal IL-1β (ng/L): 38.75±4.49 vs. 28.47±4.13, all P < 0.05], the up-regulated effect on the expression of PepT1 in small intestinal epithelium was lost [PepT1 mRNA (2 -ΔΔCt): 0.58±0.03 vs. 0.66±0.05, PepT1 protein (PepT1/GAPDH): 0.70±0.02 vs. 0.80±0.04, both P < 0.05], and the injury of small intestinal epithelial cells was worse. Conclusion:Ghrelin plays a protective role in sepsis by promoting cholinergic neurons to inhibit the release of inflammatory factors, thereby promoting the transcription and translation of PepT1.

Objective:To investigate the role of LncRNA-TUG1 in the injury of intestinal epithelial cells induced by lipopolysaccharide (LPS).Methods:LPS was used to treat HIEC-6 human intestinal epithelial cells for 24 h to construct a sepsis injury model. Whole transcriptome RNA sequencing was used to analyze the expression changes of mRNA, microRNA and lncRNA in HIEC-6 cells after LPS treatment. Real-time fluorescence quantitative (qRT-PCR) and Western blot was performed to detect the expression changes of lncRNA-TUG1, microRNA-132-3p (miR-132-3p), SIRT1 mRNA and SIRT1 protein in HIEC-6 cells after LPS treatment. The expression levels of LncRNA-TUG1, miR-132-3p and SIRT1 were artificially changed by in vitro transfection. qRT-PCR and Western blot were used to confirm the regulatory effect of lncRNA-TUG1 on microRNA-132-3p and SIRT1. CCK-8 and flow cytometry were used to analyze the effects of LncRNA-TUG1, miR-132-3p and SIRT1 on the proliferation and apoptosis of HIEC-6 cells. The dual luciferase report analysis was used to verify the targeting relationship between LncRNA-TUG1, miR-132-3p and SIRT1. Statistical analysis was performed using SPSS 17.0, and differences between the two groups were compared using independent sample t test. Results:RNA sequencing results showed that the expressions of lncRNA-TUG1 and SIRT1 were decreased in HIEC-6 cells after LPS treatment ( t=3.26, P<0.05 and t=2.55, P<0.05), but the expression of miR-132-3p was increased ( t=4.12, P<0.05). In vitro cell experiments, the expression of lncRNA-TUG1 and SIRT1 were decreased in HIEC-6 cells treated with LPS ( t=5.69, P<0.05 and t=5.712, P<0.05), while the expression of miR-132-3p was increased ( t=3.88, P<0.05). Overexpression of lncRNA-TUG1 increased the proliferation rate ( t=6.55, P<0.05) and decreased the apoptosis rate ( t=3.94, P<0.05) of LPS-treated cells. Upregulation of lncRNA-TUG1 decreased the expression of miR-132-3p ( t=4.66, P<0.05), and increased the mRNA and protein levels of SIRT1 ( t=3.91, P<0.05). Transfection of miR-132-3P mimic could inhibit the mRNA ( t=4.08, P<0.05) and protein levels of SIRT1. In LPS-treated cells, the cells co-transfected with miR-132-3pmimic and siRNA-SIRT1 had a lower proliferation rate ( t=4.55, P<0.05 and t=5.67, P<0.05) and a higher apoptosis rate ( t=3.90, P<0.05 and t=4.22, P<0.05) than those transfected with only pcDNA3.1-lncRNA-TUG. Conclusions:lncRNA-TUG1 may act as a ceRNA to regulate miR-132-3p/SIRT1, therefore alleviating HIEC-6 cell injury caused by LPS. Intervention of lncRNA-TUG1/miR-132-3p/SIRT1 regulatory pathway may become a potential strategy to prevent sepsis-induced intestinal mucosal damage.

Objective:To explore and establish an artificial neural network (ANN) model for predicting the efficacy of first-line FOLFOX chemotherapy for metastatic colorectal cancer.Methods:A set of FOLFOX chemotherapy data from a group of patients with metastatic colorectal cancer (mCRC) (GSE104645) was downloaded from the GEO database as a training set. According to the FOLFOX protocol, the efficacy was divided into two groups: the chemo-sensitive group (including complete response and partial response) and the chemo-resistant group (including stable disease and progressive disease), including 31 cases in the sensitive group and 23 in the resistant group. Then, chip data (accessible number: GSE69657) from Fujian Medical University Union Hospital were chosen as a test set. A total of 30 patients were enrolled in the study, including 13 in the sensitive group and 17 in the resistant group. The batch effect correction was performed on the expression values of the two sets of matrices using the R 3.5.1 software Combat package. The gene expression difference of sensitive and resistant group in GSE104645 was analyzed by the GEO2R platform. P<0.05 and the absolute value of log 2FC>0.33 (FC abbreviation of fold change) were used as the threshold value to screen the drug resistance and sensitive genes of the FOLFOX regimen. An ANN was constructed using the multi-layer perceptron (MLP) to perform the FOLFOX regimen on the GSE104645 dataset. The GSE69657 expression matrix and clinical efficacy parameters were then used for retrospective verification. Receiver operating characteristic(ROC) curves were used to evaluate the test results and predictive power. Results:A total of 2, 076 differentially expressed genes in GSE104645 were selected, of which 822 genes were up-regulated and 1, 254 genes were down-regulated in the chemo-resistance group. The down-regulated genes were sensitive genes. GO analysis of the biological processes in which the differentially expressed genes were involved, revealed that they were mainly involved in the regulation of substance metabolism. A total of 39 genes were included in the final model construction. This was a neural network model with two hidden layers. The accuracy of predicting training samples and test samples was 75.7% and 76.5%, respectively, and the area under the ROC curve was 0.875. The chip data set of our department (GSE69657) was set as the test set, and the area under the ROC curve was 0.778.Conclusions:In this study, an artificial neural network model is successfully constructed to predict the efficacy of first-line FOLFOX regimen for metastatic colorectal cancer based on the microarray, and an independent external verification is also conducted. The model has good stability and well prediction efficiency. Besides, the results of this study suggest that the gene functions related to oxaliplatin resistance are mainly enriched in the regulation process of substance metabolism.

Objective:To explore and establish an artificial neural network (ANN) model for predicting the efficacy of first-line FOLFOX chemotherapy for metastatic colorectal cancer.Methods:A set of FOLFOX chemotherapy data from a group of patients with metastatic colorectal cancer (mCRC) (GSE104645) was downloaded from the GEO database as a training set. According to the FOLFOX protocol, the efficacy was divided into two groups: the chemo-sensitive group (including complete response and partial response) and the chemo-resistant group (including stable disease and progressive disease), including 31 cases in the sensitive group and 23 in the resistant group. Then, chip data (accessible number: GSE69657) from Fujian Medical University Union Hospital were chosen as a test set. A total of 30 patients were enrolled in the study, including 13 in the sensitive group and 17 in the resistant group. The batch effect correction was performed on the expression values of the two sets of matrices using the R 3.5.1 software Combat package. The gene expression difference of sensitive and resistant group in GSE104645 was analyzed by the GEO2R platform. P<0.05 and the absolute value of log 2FC>0.33 (FC abbreviation of fold change) were used as the threshold value to screen the drug resistance and sensitive genes of the FOLFOX regimen. An ANN was constructed using the multi-layer perceptron (MLP) to perform the FOLFOX regimen on the GSE104645 dataset. The GSE69657 expression matrix and clinical efficacy parameters were then used for retrospective verification. Receiver operating characteristic(ROC) curves were used to evaluate the test results and predictive power. Results:A total of 2, 076 differentially expressed genes in GSE104645 were selected, of which 822 genes were up-regulated and 1, 254 genes were down-regulated in the chemo-resistance group. The down-regulated genes were sensitive genes. GO analysis of the biological processes in which the differentially expressed genes were involved, revealed that they were mainly involved in the regulation of substance metabolism. A total of 39 genes were included in the final model construction. This was a neural network model with two hidden layers. The accuracy of predicting training samples and test samples was 75.7% and 76.5%, respectively, and the area under the ROC curve was 0.875. The chip data set of our department (GSE69657) was set as the test set, and the area under the ROC curve was 0.778.Conclusions:In this study, an artificial neural network model is successfully constructed to predict the efficacy of first-line FOLFOX regimen for metastatic colorectal cancer based on the microarray, and an independent external verification is also conducted. The model has good stability and well prediction efficiency. Besides, the results of this study suggest that the gene functions related to oxaliplatin resistance are mainly enriched in the regulation process of substance metabolism.

Objective To investigate the effects of the number of harvested lymph nodes in neoadjuvant chemoradiotherapy (nCRT) combined with surgery on prognosis of middle-low rectal cancer.Methods The retrospective case-control study was conducted.The clinicopathological data of 373 patients with middle-low rectal cancer who underwent nCRT combined with surgery in the Fujian Medical University Union Hospital from January 2009 to December 2013 were collected.There were 241 males and 132 females,aged from 26 to 81 years,with the age of (55 ± 11) years.Observation indicators:(1) treatment situations;(2) follow-up and survival;(3)influencing factors for the number of harvested lymph nodes;(4) prognostic analysis of the different number of harvested lymph nodes as cut-off for grouping;(5) stratified analysis.Follow-up using telephone interview and outpatient examination was performed to detect postoperative survival of patients once every three months within postoperative 2 years and once every 6 months during the postoperative third year up to March 2016.The endpoint of follow-up was tumor recurrence,retastasis or death.Measurement data with normal distribution were represented as Mean±SD,and comparison between groups was done using the independent sample t test.Measurement data with skewed distribution were represented as M (range),and comparison between groups was done using the Kruska1-Wallis H test.Count data was described as absolute numbers.Univariate and multivariate analyses were done by the multiple linear regression model.Survival rate was calculated by the Kaplan-Meier method,and Logrank test was used for survival analysis.Results (l) Treatment situations:373 patients underwent nCRT combined with surgery,including 329 combined with sphincter-sparing rectal resection and 44 combined with abdominoperineal rectal resection.The number of harvested lymph nodes was 12 ± 6 in 373 patients.There were 185 patients with the number of harvested lymph nodes ＜ 12 and 188 with the number of harvested lymph nodes ≥ 12.(2) Follow-up and survival:373 patients were followed up for 5-77 months,with a median follow-up time of 43 months.During the follow-up,the 1-,3-,5-year disease-free survival rates were respectively 90.4％,76.3％,and 67.5％ in the 373 patients.(3) Influencing factors for the number of harvested lymph nodes:univariate analysis showed that distance between the tumor and anal verge,tumor diameter,tumor pathological N staging,and regression grade of rectal cancer were associated factors for the number of harvested lymph nodes (t =3.156,2.992,x2=8.183,10.839,P＜0.05).Multivariate analysis showed that distance between the tumor and anal verge,regression grade of rectal cancer,and tumor pathological N staging were independent factors for the number of harvested lymph nodes (t=3.308,2.690,2.584,95％ confidence interval:0.808-3.180,0.446-2.873,0.332-2.448,P＜0.05).(4) Prognostic analysis of the different number of harvested lymph nodes as cut-off for grouping:with the number of harvested lymph nodes of 6,7,8,9,10,11,12,13,14,15,and 16 as cut-off for grouping,there was no significant difference in the 3-year disease-free survival rate,cumulative local recurrence rate,and cumulative distant metastasis rate between ＜6 group and ≥6 group,between ＜7 group and ≥7 group,between＜8 group and ≥8 group,between ＜9 group and ≥9 group,between ＜10 group and ≥ 10 group,between ＜11 group and ≥ll group,between ＜12 group and ≥12 group,between ＜13 group and ≥13 group,between ＜ 14 group and ≥ 14 group,between ＜ 15 group and ≥ 15 group,between ＜ 16 group and ≥ 16 group,respectively (P＞0.05).(5) Stratified analysis:with the number of harvested lymph nodes of 7,8,9,and 10 as cut-off for grouping in 45 of 373 patients with Ⅱ-Ⅲ regression grade of rectal cancer and negative lymph nodes (NO staging),there was no significant difference in the 3-year disease-free survival rate between ＜7 group and ≥ 7group,between ＜8 group and ≥8 group,between ＜9 group and ≥9 group,between＜10 group and ≥ 10 group,respetively (x2 =3.946,5.346,6.375,4.297,P＜0.05).Conclusions The number of lymph nodes as 12 is not the independent factor for prognosis of patients with middle-low rectal cancer after nCRT combined with surgery.The number of harvested lymph nodes as 7 to 10 is the important factor for evaluating the prognosis of middle-low rectal cancer patients with Ⅱ-Ⅲ regression grade of rectal cancer and negative lymph nodes after nCRT combined with surgery.

OBJECTIVE: To explore the efficacy of radiotherapy combined with surgery for locally advanced rectal mucinous adenocarcinoma. METHODS: Clinical data of patients with locally advanced rectal mucinous adenocarcinoma (T3-4 and/or N+) diagnosed by postoperative pathology from 1992 to 2013 were retrieved from the US Surveillance, Epidemiology, and End Results (SEER) database. Patients with local excision only, tumor biopsy or combined organ excision and incomplete follow-up information were excluded. All the enrolled patients were divided into three groups according to different treatments, including surgery alone (SA) group, preoperative radiotherapy combined with surgery (RT+S) group and surgery combined with postoperative radiotherapy (S+RT) group. The extracted data included basic data of patients and tumor, treatment status, and follow-up results. The χ² test was used to compare the count data. Kaplan-Meier method was used to draw the survival curve and calculate the survival rate. The survival was analyzed and compared by Log-rank test. The R language 2.8.1 was used to match the patients as 1:1 pairing through the propensity score matching (PSM). The matching variables included gender, age at diagnosis, year at diagnosis, ethnicity, degree of tissue differentiation, TNM stage, depth of invasion, making the baseline data of subgroups comparable. The Cox proportional hazard model was used for multivariate analysis of prognostic factors. RESULTS: A total of 2 149 patients with locally advanced rectal mucinous adenocarcinoma were enrolled in the study, including 1 255 males (58.4%) and 894 females (41.6%). There were 706 patients (32.9%) in the SA group, 772 patients (35.9%) in the RT+S group and 671 patients (31.2%) in the S+RT group. In SA, RT+S and S+RT groups, the median overall survival time was 39, 85, and 74 months respectively; the 5-year overall survival (OS) rate was 38.7%, 56.5%, and 55.2% respectively; the median cancer-specific survival (CSS) time was 86, 127, and 111 months respectively, and the 5-year CSS rate was 53.7%, 62.2% and 60.7% respectively. In comparison among the 3 groups, the 5-year OS rate and CSS rate in the SA group were significantly lower than those in the RT+S group and S+RT group (all P<0.001); the 5-year OS rate and CSS rate between RT+S group and S+RT group were not significantly different (P=0.166 and 0.392,respectively). After the baseline data of subgroups were corrected through PSM, the 5-year OS rate and CSS rate in the SA group (n=375) were significantly lower than those in the RT+S group (n=375)(OS:40.1% vs. 54.5%, P<0.001; CSS:54.3% vs. 63.3%, P=0.023). The 5-year OS rate and CSS rate in the SA group (n=403) were also lower than those in the S+RT group (n=403) (OS:37.4% vs. 54.7%,P<0.001;CSS:51.6% vs. 61.0%,P=0.031). The 5-year OS rate and CSS rate between RT+S group (n=363) and S+RT group (n=363) were not significantly different (OS:51.7% vs. 55.5%, P=0.789; CSS:57.7% vs. 60.5%, P=0.484). Cox multivariate analysis showed that radiotherapy (HR=0.845, 95%CI: 0.790 to 0.903, P=0.001) was an independent prognostic factor for OS of locally advanced rectal mucinous adenocarcinoma; radiotherapy (HR=0.907, 95% CI: 0.835 to 0.985, P=0.021) was also an independent prognostic factor affecting CSS in patients with locally advanced rectal mucinous adenocarcinoma. CONCLUSION As compared with surgery alone, surgery combined with preoperative or postoperative radiotherapy is beneficial to the long-term survival of patients with locally advanced rectal mucinous adenocarcinoma.
Adenocarcinoma, Mucinous ; pathology ; radiotherapy ; surgery ; therapy ; Female ; Humans ; Male ; Neoplasm Staging ; Proctectomy ; Prognosis ; Radiotherapy, Adjuvant ; Rectal Neoplasms ; pathology ; radiotherapy ; surgery ; therapy ; Retrospective Studies ; SEER Program ; Survival Analysis ; Treatment Outcome

Objective: To screen out the potential gene biomarkers to predict responses to neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer and to explore the main downstream pathways of resistance. Methods: The gene expression profiles (GSE35452) of locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy from 46 specimens (24 responders, TRG 0/1, and 22 non-responders, TRG 2/3) were downloaded from the GEO database. The differentially expressed genes were identified to screen out the potential biomarkers by use of the GCBI platform. GO and KEGG pathways enrichment analysis were performed to integrate enrichment results of differentially expressed genes. Signal-signal interaction network was constructed and analyzed to screen out potential main downstream pathways. Results: A total of 1079 differentially expressed genes were screened, including 657 up-regulated and 422 down-regulated ones. Among these genes, REG4 had the maximum fold change value of -6.029 491. In GO term, these differentially expressed genes were mainly enriched in molecule metabolic process, cell cycle, DNA-dependent transcription, signal transduction and apoptotic process. The KEGG pathways enrichment analysis showed that the differentially expressed genes were enriched in 65 KEGG pathways, including metabolic pathways, cell cycle and metabolism pathways. Signal-signal interaction network analysis showed that MAPK signaling pathway and cell cycle pathway might play a determinant role in the development of neoadjuvant chemoradiotherapy resistance. Further analysis showed that CDKN1B, CDKN2A, RBL1, TFDP1, CCND2, CCNE2, CDC6 and CDK6 in cell cycle might induce chemoradiotherapy resistance by blocking G1/S phase cell cycle arrest, decreasing the apoptosis of tumor cells and increasing S phase ratio of chemoradiotherapy resistance. Conclusion G1/S phase cell cycle arrest blocking plays an important role in the development of chemoradiotherapy resistance in patients with rectal cancer. Moreover, the key genes, such as REG4, may be useful in predicting responses to neoadjuvant chemoradiotherapy.

Objective To screen out the potential gene biomarkers to predict responses to neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer and to explore the main downstream pathways of resistance. Methods The gene expression profiles (GSE35452) of locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy from 46 specimens (24 responders, TRG 0/1, and 22 non?responders, TRG 2/3) were downloaded from the GEO database. The differentially expressed genes were identified to screen out the potential biomarkers by use of the GCBI platform. GO and KEGG pathways enrichment analysis were performed to integrate enrichment results of differentially expressed genes. Signal?signal interaction network was constructed and analyzed to screen out potential main downstream pathways. Results A total of 1079 differentially expressed genes were screened, including 657 up?regulated and 422 down?regulated ones. Among these genes, REG4 had the maximum fold change value of –6.029 491. In GO term, these differentially expressed genes were mainly enriched in molecule metabolic process, cell cycle, DNA?dependent transcription, signal transduction and apoptotic process. The KEGG pathways enrichment analysis showed that the differentially expressed genes were enriched in 65 KEGG pathways, including metabolic pathways, cell cycle and metabolism pathways. Signal?signal interaction network analysis showed that MAPK signaling pathway and cell cycle pathway might play a determinant role in the development of neoadjuvant chemoradiotherapy resistance. Further analysis showed that CDKN1B, CDKN2A, RBL1, TFDP1, CCND2, CCNE2, CDC6 and CDK6 in cell cycle might induce chemoradiotherapy resistance by blocking G1/S phase cell cycle arrest, decreasing the apoptosis of tumor cells and increasing S phase ratio of chemoradiotherapy resistance. Conclusion G1/S phase cell cycle arrest blocking plays an important role in the development of chemoradiotherapy resistance in patients with rectal cancer. Moreover, the key genes, such as REG4, may be useful in predicting responses to neoadjuvant chemoradiotherapy.

Objective To screen out the potential gene biomarkers to predict responses to neoadjuvant chemoradiotherapy (CRT) in patients with rectal cancer and to explore the main downstream pathways of resistance. Methods The gene expression profiles (GSE35452) of locally advanced rectal cancer undergoing neoadjuvant chemoradiotherapy from 46 specimens (24 responders, TRG 0/1, and 22 non?responders, TRG 2/3) were downloaded from the GEO database. The differentially expressed genes were identified to screen out the potential biomarkers by use of the GCBI platform. GO and KEGG pathways enrichment analysis were performed to integrate enrichment results of differentially expressed genes. Signal?signal interaction network was constructed and analyzed to screen out potential main downstream pathways. Results A total of 1079 differentially expressed genes were screened, including 657 up?regulated and 422 down?regulated ones. Among these genes, REG4 had the maximum fold change value of –6.029 491. In GO term, these differentially expressed genes were mainly enriched in molecule metabolic process, cell cycle, DNA?dependent transcription, signal transduction and apoptotic process. The KEGG pathways enrichment analysis showed that the differentially expressed genes were enriched in 65 KEGG pathways, including metabolic pathways, cell cycle and metabolism pathways. Signal?signal interaction network analysis showed that MAPK signaling pathway and cell cycle pathway might play a determinant role in the development of neoadjuvant chemoradiotherapy resistance. Further analysis showed that CDKN1B, CDKN2A, RBL1, TFDP1, CCND2, CCNE2, CDC6 and CDK6 in cell cycle might induce chemoradiotherapy resistance by blocking G1/S phase cell cycle arrest, decreasing the apoptosis of tumor cells and increasing S phase ratio of chemoradiotherapy resistance. Conclusion G1/S phase cell cycle arrest blocking plays an important role in the development of chemoradiotherapy resistance in patients with rectal cancer. Moreover, the key genes, such as REG4, may be useful in predicting responses to neoadjuvant chemoradiotherapy.

Objective To screen out the potential gene to predict regional lymph node metastasis after neoadjuvant chemoradiotherapy (CRT) for locally advanced rectal cancer (LARC) and develop a 6-gene model using an artificial neural network (ANN).Methods The gene expression profiles (GSE46862) of locally advanced rectal cancer undergoing preoperative chemoradiotherapy from 64 specimens (21 with ypN-and 43 with ypN+) were downloaded from the gene expression omnibus (GEO) database.The differentially expressed genes were identified to screen out the potential biomarkers through the Gene-Cloud of Biotechnology Information (GCBI) platform.The top 6 genes were screened out for building model.An ANN model was trained and validated using the SPSS Modeler software.The study samples were allocated randomly into the training sample group and testing sample group with a 7∶3 ratio.The training samples and testing samples were respectively used for building an ANN model and independent back-substitution test.Observation indicators:(1) screening results of differentially expressed genes;(2) analysis results of ANN model.The receiver operating characteristic (ROC) curve was drawn and the area under the curve (AUC) was calculated to evaluate the predictive abilities of ANN and each biomarker.Results (1) Screening results of differentially expressed genes:A total of 50 genes were screened.Six top genes included IL6,AKR1B1,AREG,SELE,ROBO1 and CD274.(2) Analysis results of ANN model:Six top genes were selected to construct a three-layer ANN model with a 7-5-2 structure.The IL6 made the greatest effect on the ANN model,followed by ROBO1,AKR1B1,AREG,CD274 and SELE.The AUC was 0.929.The sensitivity and specificity of ANN model were 96.7％ and 85.7％,and accuracy of training samples was 93.2％.In the independent back-substitution test,sensitivity and specificity were 92.3％ and 85.7％,and accuracy of testing samples was 90.0％.Conclusion The prediction ANN model based on multiple molecular markers (IL6,ROBO1,AKR1B1,AREG,CD274 and SELE) for regional lymph node metastases in LARC patients after CRT would be beneficial in selecting potential candidates for rectum-preserving surgery following CRT for LARC.