FOXA1/MND1/TKT axis regulates gastric cancer progression and oxaliplatin sensitivity via PI3K/AKT signaling pathway.

BACKGROUND: Drug resistance is a main factor affecting the chemotherapy efficacy of gastric cancer (GC), in which meiosis plays an important role. Therefore, it is urgent to explore the effect of meiosis related genes on chemotherapy resistance. METHODS: The expression of meiotic nuclear divisions 1 (MND1) in GC was detected by using TCGA and clinical specimens. In vitro and in vivo assays were used to investigate the effects of MND1. The molecular mechanism was determined using luciferase reporter assay, CO-IP and mass spectrometry (MS). RESULTS: Through bioinformatics, we found that MND1 was highly expressed in platinum-resistant samples. In vitro experiments showed that interference of MND1 significantly inhibited the progression of GC and increased the sensitivity to oxaliplatin. MND1 was significantly higher in 159 GC tissues in comparison with the matched adjacent normal tissues. In addition, overexpression of MND1 was associated with worse survival, advanced TNM stage, and lower pathological grade in patients with GC. Further investigation revealed that forkhead box protein A1 (FOXA1) directly binds to the promoter of MND1 to inhibit its transcription. CO-IP and MS assays showed that MND1 was coexpressed with transketolase (TKT). In addition,TKT activated the PI3K/AKT signaling axis and enhanced the glucose uptake and lactate production in GC cells. CONCLUSIONS: Our results confirm that FOXA1 inhibits the expression of MND1, which can directly bind to TKT to promote GC progression and reduce oxaliplatin sensitivity through the PI3K/AKT signaling pathway.

Cellular senescence-related genes: predicting prognosis in hepatocellular carcinoma.

Recent studies have shown that the high incidence and low cure rate of hepatocellular carcinoma (HCC) have not improved significantly. Surgery and liver transplantation are the mainstays of prolonging the survival of HCC patients. However, the surgical resection rate of HCC patients is very low, and even after radical surgical resection, the recurrence rate at 5 years postoperatively remains high and the prognosis is very poor, so more treatment options are urgently needed. Increasing evidence suggests that cellular senescence is not only related to cancer development but may also be one of its primary driving factors. We aimed to establish a prognostic signature of senescence-associated genes to predict the prognosis and therapeutic response of HCC patients. The aim of this study was to develop a risk model associated with cellular senescence and to search for potential strategies to treat HCC. We divided HCC patients into two clusters and identified differentially expressed genes (DEGs) between clusters. In this study, low-risk patients had a better prognosis, higher levels of immune cell infiltration, and better efficacy to fluorouracil, Paclitaxel and Cytarabine chemotherapy compared to high-risk patients. To further identify potential biomarkers for HCC, we further validated the expression levels of the four signature genes in HCC and neighbouring normal tissues by in vitro experiments. In conclusion, we identified and constructed a relevant prognostic signature, which performed well in predicting the survival and treatment response of HCC patients. This helps to differentiate between low-score and high-risk HCC, and the results may contribute to precise treatment protocols in clinical practice.

Determination of the cutoff point for Smartphone Application-Based Addiction Scale for adolescents: a latent profile analysis.

BACKGROUNDS: The Smartphone Application-Based Addiction Scale (SABAS) is a validated 6-item measurement tool for assessing problematic smartphone use (PSU). However, the absence of established cutoff points for SABAS hinders its utilities. This study aimed to determine the optimal cutoff point for SABAS through latent profile analysis (LPA) and receiver operating characteristic curve (ROC) analyses among 63, 205. Chinese adolescents. Additionally, the study explored whether PSU screening with SABAS could effectively capture problematic social media use (PSMU) and internet gaming disorder (IGD). METHOD: We recruited 63,205. adolescents using cluster sampling. Validated questionnaires were used to assess PSMU, IGD, and mental health (depression, anxiety, sleep disturbances, well-being, resilience, and externalizing and internalizing problems). RESULTS: LPA identified a 3-class model for PSU, including low-risk users (38.6%, n = 24,388.), middle-risk users (42.5%, n = 26,885.), and high-risk users (18.9%, n = 11,932.). High-risk users were regarded as "PSU cases" in ROC analysis, which demonstrated an optimal cut-off point of 23 (sensitivity: 98.1%, specificity: 96.8%). According to the cutoff point, 21.1% (n = 13,317.) were identified as PSU. PSU adolescents displayed higher PSMU, IGD, and worse mental health. PSU screening effectively captured IGD (sensitivity: 86.8%, specificity: 84.5%) and PSMU (sensitivity: 84.5%, specificity: 80.2%). CONCLUSION: A potential ideal threshold for utilizing SABAS to identify PSU could be 23 (out of 36). Employing SABAS as a screening tool for PSU holds the potential to reliably pinpoint both IGD and PSMU.

Prevalence and associated factors of depressive and anxiety symptoms among Chinese secondary school students.

BACKGROUND: Depressive and anxiety symptoms affect about one-fourth of Chinese secondary school students. However, the prevalence and correlates of mental distress among secondary school students from Western China remain largely unexplored. This study aimed to examine the prevalence and associations of depressive and anxiety symptoms with demographic, family, school, life, and behavior factors in a large, representative sample of secondary school students in Zigong, a city in Western China. METHODS: Secondary school students were recruited using cluster sampling. The 9-item Patient Health Questionnaire, the 7-item Generalized Anxiety Disorder Questionnaire, Multidimensional Peer-Victimization Scale, the Pittsburgh Sleep Quality Index, and Nine-Item Internet Gaming Disorder Scale-Short Form were used. Descriptive statistic was used to describe the sociodemographic characteristics of participants. The clustering effect was adjusted by the "survey" package of R to calculate weighted prevalence. Univariate and multivariate logistic regression were used to explore associated factors of depression and anxiety, respectively. RESULTS: A total of 63,205 participants were involved, in which the weighted prevalence of depression in all subjects was 23.0% (95% CI: 19.6- 27.0%), and the weighted prevalence of anxiety was 13.9% (95% CI: 11.2- 17.0%). Logistic regression results showed girls, being single-child, non-nuclear family, peer bullying, sleep disturbance, and internet gaming disorder symptoms were positively associated with depressive and anxiety symptoms. CONCLUSION: Depressive and anxiety symptoms were prevalent among secondary school students in Western China. Our results can guide policy strategies for the assessment, prevention, and intervention of psychological status among Chinese secondary school students.

CircTMC5 promotes gastric cancer progression and metastasis by targeting miR-361-3p/RABL6.

BACKGROUND: Gastric cancer (GC) is common in East Asia, yet its molecular and pathogenic mechanisms remain unclear. Circular RNAs (circRNAs) are differentially expressed in GC and may be promising biomarkers. Here, we investigated the role and regulatory mechanism of circTMC5 in GC. METHODS: CircTMC5 expression was detected in human GC and adjacent tissues using microarray assays and qRT-PCR, while the clinicopathological characteristics of patients with GC were used to assess its diagnostic and prognostic value. The circTMC5/miR-361-3p/RABL6 axis was examined in vitro and vivo, and the immune roles of RABL6 were evaluated using bioinformatics analyses and immunohistochemistry (IHC). RESULTS: CircTMC5 was highly expressed in GC tissues, plasma, and cell lines, and was closely related to histological grade, pathological stage, and T classification in patients with GC. CircTMC5 expression was also an independent prognostic factor for GC and its combined detection with carcinoembryonic antigen may improve GC diagnosis. Low circTMC5 expression correlated with good prognosis, inhibited GC cell proliferation, and promoted apoptosis. Mechanistically, circTMC5 overexpression promoted GC cell proliferation, invasion, and metastasis but inhibited apoptosis by sponging miR-361-3p and up-regulating RABL6 in vitro and vivo, whereas miR-361-3p up-regulation had the opposite effects. RABL6 was highly expressed in GC and was involved in immune regulation and infiltration in GC. CONCLUSIONS: CircTMC5 promotes GC and sponges miR-361-3p to up-regulate RABL6 expression, thus may have diagnostic and prognostic value in GC. RABL6 also displays therapeutic promise due to its role in the immune regulation of GC.

Effects of oral contraceptives plus orlistat in patients with polycystic ovary syndrome and overweight/obesity: A meta-analysis.

AIM: This meta-analysis was conducted to compare the effect and safety of oral contraceptive pills (OCP) plus orlistat with OCP alone in clinical, hormonal, and lipid metabolism outcomes in patients with polycystic ovary syndrome (PCOS) and overweight/obesity. METHODS: Pubmed, Embase, Web of Science, Chinese National Knowledge Infrastructure (CNKI), and SinoMed were systematically reviewed. A random-effects or fixed-effects model was used to pool the estimate. RESULTS: Eight studies were included in this meta-analysis. Significant reductions in BMI, WHR, and waist circumference were observed in combination group as compared with OCP alone group. Regarding the hormonal outcome, T, SHBG, FAI, LH, DHEAS, FSH, and E2 levels were significantly improved in combination group compared with OCP alone group. However, the TT and FT did not change significantly between the two groups. Regarding the lipid metabolism outcomes, TC, LDL-C, and TG levels were reduced and HDL-C level was increased in the combination group. Regarding the insulin metabolism outcomes, FINS and HOMA-IR levels were reduced in combination group than in OCP group. The ovulation rate, pregnancy rate, and overall effective rate were significantly higher in combination group than in OCP alone group. Fewer complications were observed in the combination group than in OCP group, and the difference between them was significant. CONCLUSION: This combination treatment of OCP and orlistat was more effective than OCP alone in reducing the weight, hormonal, lipid, and insulin metabolism profiles, as well as improving the ovulation rate, pregnancy rate, and overall effective rate, as compared with OCP alone.

Identification of a ferroptosis-related gene signature predictive model in colon cancer.

BACKGROUND: The prognosis of colon cancer (CC) is challenging to predict due to its highly heterogeneous nature. Ferroptosis, an iron-dependent form of cell death, has roles in various cancers; however, the correlation between ferroptosis-related genes (FRGs) and prognosis in CC remains unclear. METHODS: The expression profiles of FRGs and relevant clinical information were retrieved from the Cancer Genome Atlas (TCGA) database. Cox regression analysis and the least absolute shrinkage and selection operator (LASSO) regression model were performed to build a prognostic model in TCGA cohort. RESULTS: Ten FRGs, five of which had mutation rates ≥ 3%, were found to be related to the overall survival (OS) of patients with CC. Patients were divided into high- and low-risk groups based on the results of Cox regression and LASSO analysis. Patients in the low-risk group had a significantly longer survival time than patients in the high-risk group (P < 0.001). Enrichment analyses in different risk groups showed that the altered genes were associated with the extracellular matrix, fatty acid metabolism, and peroxisome. Age, risk score, T stage, N stage, and M stage were independent predictors of patient OS based on the results of Cox analysis. Finally, a nomogram was constructed to predict 1-, 3-, and 5-year OS of patients with CC based on the above five independent factors. CONCLUSION: A novel FRG model can be used for prognostic prediction in CC and may be helpful for individualized treatment.

MiR-122-5p suppresses the proliferation, migration, and invasion of gastric cancer cells by targeting LYN.

Gastric cancer (GC) is one of malignant tumors with high mortality and morbidity in the world. MicroRNA-122 (miR-122) acts as a tumor suppressor in a variety of cancers and has been found to be dominant in gastric adenocarcinoma. However, the specific biological function of miR-122-5p in GC is not completely clear. In this study, we found that miR-122-5p was low-expressed in GC tissues and cell lines by using qRT-PCR. Overexpression of miR-122-5p inhibited the proliferation, migration, and invasion of GC cells by using CCK-8 and transwell assays. On the contrary, downregulation of miR-122-5p promoted the proliferation, migration, and invasion of GC cells. In addition, we found that the expression of LYN, an Src family tyrosine kinase, was inversely correlated with miR-122-5p expression in GC tissues by using western blot analysis, immunohistochemistry, and qRT-PCR assays. Meanwhile, luciferase assay results indicated that LYN is a direct target of miR-122-5p in GC cells. Moreover, silencing LYN expression by its siRNA inhibited the proliferation, migration, and invasion of GC cells. Importantly, overexpression of LYN restored miR-122-5p-mediated inhibition of the proliferation, migration, and invasion of GC cells. Taken together, our results indicated miR-122-5p inhibited the proliferation, migration, and invasion by targeting LYN in GC.

MicroRNA-31 Negatively Regulates Interleukin-34 Expression In Vitro.

Interleukin-34 (IL-34) is a recently discovered cytokine that promotes tissue macrophage maturation and differentiation. We previously found that 1α,25-Dihydroxyvitamin D3 up-regulated IL-34 expression in SH-SY5Y neural cells. However, whether microRNA regulates IL-34 expression is not completely clear. By using on-line TargetScan and MiRanda software, we found that there was only one conserved microRNA-31 (miR-31) binding site in the 3' untranslated region (3'UTR) of IL-34 mRNA. Intriguingly, using qPCR we demonstrated that miR-31 levels were negatively correlated to IL-34 mRNA levels in different cell lines. By examining the effect of miR-31 on IL-34 3' UTR reporter luciferase activity and on IL-34 mRNA and argonaute RISC catalytic component 2 (AGO2) binding, it was found that miR-31 bound directly to IL-34 3'UTR and regulated the post-transcriptional expression of IL-34 in MGC-803 cells. Moreover, a miR-31 mimic significantly reduced IL-34 expression levels while a miR-31 inhibitor up-regulated IL-34 expression in KYSE-45 and HT-29 cells. Taken together, these results show that miR-31 negatively regulates IL-34 expression by directly binding to the IL-34 3' UTR in vitro.

Voltage-gated sodium channel Nav1.5 promotes proliferation, migration and invasion of oral squamous cell carcinoma.

The protein voltage-gated sodium channel Nav1.5 is highly upregulated in various types of cancer and, in general, promotes cancer cell invasiveness and metastatic progression. A previous study found that Nav1.5 was highly expressed in poorly differentiated oral squamous cell carcinoma (OSCC). However, whether Nav1.5 enhances invasiveness and metastasis of OSCC are still unknown. In this study, we found that Nav1.5 was highly expressed in OSCC cell lines compared with normal oral keratinocyte HOK cell line by using western blot analysis. CCK-8 assay results revealed that downregulation of Nav1.5 expression by its specific siRNA reduced proliferation of OSCC HSC-3 cells. Moreover, transwell assay results showed Nav1.5 knockdown significantly inhibited migration and invasion of HSC-3 cells. Meanwhile, qRT-PCR and western blot analysis results showed that epidermal growth factor (EGF) induced Nav1.5 expression in a time- and dose-dependent manner. In addition, EGF promoted proliferation, migration and invasion of HSC-3 cells. Importantly, the Nav1.5 inhibitor tetrodotoxin significantly inhibited the proliferation of HSC-3 cells and impeded the migration and invasion of HSC-3 cells. Furthermore, it was found that siRNA-mediated knockdown of Nav1.5 also lessened the proliferation of HSC-3 cells and blocked the migration and invasion of HSC-3 cells. Taken together, these results indicate that Nav1.5 is involved in the progression of OSCC and Nav1.5 promotes the proliferation, migration and invasion of OSCC cells.

Preoperative pre-albumin predicts prognosis of patients after gastrectomy for adenocarcinoma of esophagogastric junction.

BACKGROUND: Adenocarcinoma of esophagogastric junction (AEG) was initially proposed in 1999 by Siewert. During recent decades, the incidence and prevalence of AEG were arising globally whereas the incidence of gastric cancer is gradually declining. Complete blood counting and liver function tests, as the routine examination of immune and nutritional status, were reported to be the predictors of overall survival (OS) in some tumors. However, little is known about the prognostic significance of these indexes in AEG patients. The purpose of this study was to assess the prediction of preoperative pre-albumin, hemoglobin, and prognostic nutritional index (PNI) for survival outcomes in AEG patients. METHODS: A retrospective cohort of 101 AEG patients followed by radical surgery was recruited between January and July 2010. Clinical and laboratory data were obtained and used to evaluate the predictive value through survival analysis. Receiver operating characteristic (ROC) curve analysis determined 200 mg/L, 120 g/L, 5 cm, and 51 as the cutoff values of pre-albumin, hemoglobin, tumor size, and PNI, respectively. RESULTS: Univariate analysis revealed that AEG patients with hemoglobin ≥120 g/L, albumin ≥40 g/L, pre-albumin ≥200 g/L, PNI ≥51, and tumor size <5 cm had longer OS (P < 0.05). Additionally, pre-albumin, tumor size, and TNM stage were demonstrated to be independent prognostic indicators by multivariate analysis with Cox regression, and the performance of pre-albumin for predicting OS in AEG patients was further identified by ROC curves (P = 0.006). CONCLUSIONS: Preoperative pre-albumin was an independent prognostic factor, and a high level of pre-albumin predicted longer OS in AEG patients.

Inhibition of Hepatitis B virus replication by SAMHD1.

Sterile alpha motif and HD-domain containing protein 1 (SAMHD1) is a newly identified intracellular antiviral factor. By depleting the dNTPs pool of host cells to a low level that cannot support the efficient synthesis of viral cDNA, it restricts replication of some retroviruses. As a DNA virus, Hepatitis B virus (HBV) experiences a process of reverse transcription in its life cycle akin to that of retroviruses. However, whether SAMHD1 can restrict HBV replication in liver cells is unknown. Here, we reported that SAMHD1 expression was detectable in four liver cell lines. Exogenous expression of SAMHD1 in SMMC-7721 cells restrained HBV replication. Similarly, SAMHD1 impeded HBV replication in another liver cell line, BEL-7402. Remarkably, the catalytically inactive mutant, SAMHD1 HD/AA also hampered HBV replication. Additionally, HBV replication reduced SAMHD1 expression in HepG2 cells. Moreover, it was found that IFN-α induced expression of SAMHD1 in liver cells. Together, these findings suggested that IFN-α-inducible SAMHD1 inhibited HBV replication in liver cells.

Gender differences in alcohol drinking among adolescents: a school-based survey in China.

BACKGROUND: Alcohol drinking among adolescents is associated with their health development. However, the prevalence of alcohol drinking among adolescents in Southwestern China remains largely unexplored. This study aimed to investigate the prevalence of alcohol drinking, with a particular focus on gender differences, among primary and middle school students in Zigong, a city in Southwestern China. Additionally, we examined the association between alcohol consumption and demographic and family factors. METHODS: A school-based cross-sectional survey was conducted in a city in Southwestern China, encompassing a total of 89 360 students from 132 different ordinary schools, including both primary and middle schools. Participants were recruited through cluster sampling. The Alcohol Use Disorders Identification Test Consumption was employed to assess alcohol consumption. Gender differences in the prevalence of alcohol drinkers across various schools and grades were analysed. Multivariable logistic regression analysis was used to investigate factors associated with hazardous drinking. RESULTS: Out of the 89 360 participants, 19.0% reported alcohol drinking, with 2.1% classified as hazardous drinkers. There was a higher prevalence of alcohol drinking among boys compared with girls, as well as hazardous drinking. There were significant gender disparities in alcohol drinking observed across various schools and grade levels. A notable divergence between boys and girls was observed starting from grade 10, with a rising prevalence of hazardous drinking among boys and a decline among girls. Additionally, older age, male gender and being left-behind children were identified as risk factors for hazardous drinking, while belonging to a nuclear family and having parents who do not drink were protective factors against hazardous drinking. CONCLUSIONS: Alcohol consumption is prevalent among Chinese adolescents, with some even classified as hazardous drinkers. These findings may offer valuable insights for policymakers and caregivers, guiding them in formulating appropriate interventions and support strategies.

A prognostic gene signature for gastric cancer and the immune infiltration-associated mechanism underlying the signature gene, PLG.

BACKGROUND: Globally, gastric cancer (GC) is a common and lethal solid malignant tumor. Identifying the molecular signature and its functions can provide mechanistic insights into GC development and new methods for targeted therapy. METHODS: Differentially expressed genes (DEGs) and prognostic genes (from univariate Cox regression analysis) were overlapped to obtain prognostic DEGs. Subsequently, molecular modules and the functions of these prognostic DEGs were identified by Metascape and Gene Ontology (GO)/Kyoto Encyclopedia of Genes and Genomes (KEGG)/Gene Set Enrichment Analysis (GSEA) enrichment analyses, respectively. Protein-protein interaction (PPI) networks of up- and down-regulated prognostic DEGs in GC were analyzed using the MCC algorithm of the Cytohubba plug-in in Cytoscape. The prognostic gene signature was defined on hub genes of the PPI networks by least absolute shrinkage and selection operator (LASSO)-Cox regression analysis. Furthermore, the expressional level of PLG in our clinical GC samples was validated by quantitative PCR (qPCR), western blotting, and immunohistochemistry (IHC). Subsequently, the PLG expression-correlation analysis was performed to assess the role of PLG in GC progression. Immune infiltration analysis was performed by single-sample gene set enrichment analysis (ssGSEA) to assess the inhibitory effect of PLG on immune infiltration. RESULTS: Firstly, Up- and down-regulated prognostic DEGs and hub genes in protein-protein interaction (PPI) networks in GC were identified. A prognostic five-gene signature (i.e., PLG, SPARC, FGB, SERPINE1, and KLHL41) was identified. Among the five genes, the relationship between plasminogen (PLG) and GC remains largely unclear. Moreover, the functions of PLG-correlated genes in GC, like 'fibrinolysis', 'hemostasis', 'ion channel complex', and 'transporter complex' were identified. In addition, PLG expression correlated negatively with the infiltration of almost all immune cell types. Interestingly, the expression of PLG was significantly and highly correlated with that of CD160, an immune checkpoint inhibitor. CONCLUSION: Our findings defined a new five-gene signature for predicting GC prognosis, but more validation is required to assess the effects and mechanism of the five genes, especially PLG, for the development of new GC therapies.

Effects and mechanisms of trifluridine alone or in combination with cryptotanshinone in inhibiting malignant biological behavior of gastric cancer.

BACKGROUND: The incidence of gastric cancer (GC) ranks fourth among all malignant tumors worldwide, and the fatality rate ranks second among all malignant tumors. Several Chinese traditional medicines have been used in the treatment of advanced gastric cancer. This study aims to investigate the effect of combinational use of natural product cryptotanshinone (CTS) with anti-cancer drug trifluorothymidine (FTD) in GC. METHODS: Cell Counting Kit-8 assay was used to detect the inhibitory effect of the combinational or separate use of FTD and CTS on the growth of HGC-27 and AGS GC cells. The combined index of FTD and CTS was calculated using CompuSyn software. To understand the mechanism, we applied flow cytometry to study the cell cycle and cell apoptosis after treatment. We also investigated the amount of FTD incorporated into the DNA by immunofluorescence assay. The expression of relevant proteins was monitored using western blot. Furthermore, the effect of using TAS-102 in combination with CTS was studied in xenograft tumor nude mice model. RESULTS: FTD and CTS inhibited the growth of GC cells in a dose-dependent manner, respectively. They both exhibited low to sub-micromolar potency in HGC-27 and AGS cells. The combination of FTD and CTS showed synergistic anticancer effect in HGC-27 cells and AGS cells. Our mechanism studies indicate that FTD could block HGC-27 cells at G2/M phase, while CTS could block HGC-27 cells at G1/G0 phase, while FTD combined with CTS could mainly block HGC-27 cells at G2 phase. FTD in combination with CTS significantly increased the apoptosis of HGC-27 cells. We observed that CTS treatment increased the incorporation of FTD into the DNA HGC-27 cell. FTD treatment activated STAT3 phosphorylation in HGC-27 cells, while CTS treatment down-regulated the concentration of p-STAT3. Interestingly, the combination of CTS and FTD reduced STAT3 phosphorylation induced by FTD. In the in vivo experiments, we observed that the combination of TAS-102 with CTS was significantly more potent than TAS-102 on tumor growth inhibition. CONCLUSIONS: FTD combined with CTS has a synergistic anti-gastric cancer effect as shown by in vitro and in vivo experiments, and the combined treatment of FTD and CTS will be a promising treatment option for advanced gastric cancer.

Correction to "Interleukin-34 promotes the proliferation and epithelial-mesenchymal transition of gastric cancer cells".

[This corrects the article on p. 1968 in vol. 14, PMID: 36310707.].

SAMHD1, positively regulated by KLF4, suppresses the proliferation of gastric cancer cells through MAPK p38 signaling pathway.

SAMHD1 was reported to be related with the development of tumors, while its function in gastric cancer (GC) has not been elucidated yet. Here, we investigated the role and mechanism of SAMHD1 in regulating the proliferation of GC, as well as the mechanism of its expression regulation. Our results revealed that SAMHD1 was downregulated in GC tissues and cell lines, which was correlated with tumor size, depth of invasion and TNM stage. Overexpression of SAMHD1 inhibited the proliferation, clone formation, DNA synthesis and cell cycle progression, while knockdown of SAMHD1 promoted the proliferation of GC cells in vitro and vivo. Meanwhile, SAMHD1 inhibited the activation of MAPK p38 signaling pathway. Moreover, SB203580, as a MAPK p38 inhibitor, could reverse the proliferation and activation of MAPK p38 signaling pathway caused by knockdown of SAMHD1 in GC cells. Additionally, transcription factor Krüppel-like factor 4 (KLF4) bound to the core promoter of SAMHD1, increasing its transcriptional expression in GC cells. In conclusion, SAMHD1 suppressed the proliferation of GC through negatively regulating the activation of MAPK p38 signaling pathway and was upregulated by KLF4 in GC cells.

Identification of necroptosis-related genes for predicting prognosis and exploring immune infiltration landscape in colon adenocarcinoma.

Background: Necroptosis is a recently discovered form of cell death that plays an important role in the occurrence and development of colon adenocarcinoma (COAD). Our study aimed to construct a risk score model to predict the prognosis of patients with COAD based on necroptosis-related genes. Methods: The gene expression data of COAD and normal colon samples were obtained from the Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx). The least absolute shrinkage and selection operator (LASSO) Cox regression analysis was used to calculate the risk score based on prognostic necroptosis-related differentially expressed genes (DEGs). Based on the risk score, patients were classified into high- and low-risk groups. Then, nomogram models were built based on the risk score and clinicopathological features. Otherwise, the model was verified in the Gene Expression Omnibus (GEO) database. Additionally, the tumor microenvironment (TME) and the level of immune infiltration were evaluated by "ESTIMATE" and single-sample gene set enrichment analysis (ssGSEA). Functional enrichment analysis was carried out to explore the potential mechanism of necroptosis in COAD. Finally, the effect of necroptosis on colon cancer cells was explored through CCK8 and transwell assays. The expression of necroptosis-related genes in colon tissues and cells treated with necroptotic inducers (TNFα) and inhibitors (NEC-1) was evaluated by quantitative real-time polymerase chain reaction (qRT-PCR). Results: The risk score was an independent prognostic risk factor in COAD. The predictive value of the nomogram based on the risk score and clinicopathological features was superior to TNM staging. The effectiveness of the model was well validated in GSE152430. Immune and stromal scores were significantly elevated in the high-risk group. Moreover, necroptosis may influence the prognosis of COAD via influencing the cancer immune response. In in-vitro experiments, the inhibition of necroptosis can promote proliferation and invasion ability. Finally, the differential expression of necroptosis-related genes in 16 paired colon tissues and colon cancer cells was found. Conclusion: A novel necroptosis-related gene signature for forecasting the prognosis of COAD has been constructed, which possesses favorable predictive ability and offers ideas for the necroptosis-associated development of COAD.

Interleukin-34 promotes the proliferation and epithelial-mesenchymal transition of gastric cancer cells.

BACKGROUND: Interleukin (IL)-34 is a pro-inflammatory cytokine involved in tumor development. The role of IL-34 in the proliferation and epithelial-mesenchymal transition (EMT) of gastric cancer (GC) remains to be investigated. AIM: To investigate whether and how IL-34 affects the proliferation of GC cells and EMT. METHODS: Using immunohistochemical staining, the expression of IL-34 protein was detected in 60 paired GC and normal paracancerous tissues and the relationship between IL-34 and clinicopathological factors was analyzed. The expression of IL-34 mRNA and protein in normal gastric epithelial cell lines and GC was detected using quantitative real-time polymerase chain reaction (qRT-PCR) and western blotting, respectively. Stable IL-34 knockdown and overexpression in AGS cell lines were established by lentiviral infection and validated by qRT-PCR and western blotting. The cholecystokinin-8 assay, clone formation assay, cell scratch assay, and transwell system were used to detect GC cell proliferation, clone formation, migration, and invasion capacity, respectively. The effects of IL-34 on the growth of GC transplant tumors were assessed using a subcutaneous transplant tumor assay in nude mice. The effects of IL-34 on the expression level of EMT-associated proteins in AGS cells were examined by western blotting. RESULTS: Expression of IL-34 protein and mRNA was higher in GC cell lines than in GES-1 cells. Compared to matched normal paraneoplastic tissues, the expression of IL-34 protein was higher in 60 GC tissues, which was correlated with tumor size, T-stage, N-stage, tumor, node and metastasis stage, and degree of differentiation. Knockdown of IL-34 expression inhibited the proliferation, clone formation, migration, and invasion of AGS cells, while overexpression of IL-34 promoted cell proliferation, clone formation, migration, and invasion. Furthermore, the reduction of IL-34 promoted the expression of E-cadherin in AGS cells but inhibited the expression of vimentin and N-cadherin. Overexpression of IL-34 inhibited E-cadherin expression but promoted expression of vimentin and N-cadherin in AGS cells. Overexpression of IL-34 promoted the growth of subcutaneous transplanted tumors in nude mice. CONCLUSION: IL-34 expression is increased in GC tissues and cell lines compared to normal gastric tissues or cell lines. In GC cells, IL-34 promoted proliferation, clone formation, migration, and invasion by regulating EMT-related protein expression cells. Interference with IL-34 may represent a novel strategy for diagnosis and targeted therapy of GC.

Dual roles of SAMHD1 in tumor development and chemoresistance to anticancer drugs.

Human sterile alpha motif and HD-domain-containing protein 1 (SAMHD1) has been identified as a GTP or dGTP-dependent deoxynucleotide triphosphohydrolase (dNTPase) and acts as an antiviral factor against certain retroviruses and DNA viruses. Genetic mutation in SAMHD1 causes the inflammatory Aicardi-Goutières Syndrome and abnormal intracellular deoxyribonucleoside triphosphates (dNTPs) pool. At present, the role of SAMHD1 in numerous types of cancer, such as chronic lymphocytic leukemia, lung cancer and colorectal cancer, is highly studied. Furthermore, it has been found that methylation, acetylation and phosphorylation are involved in the regulation of SAMHD1 expression, and that genetic mutations can cause changes in its activities, including dNTPase activity, long interspersed element type 1 (LINE-1) suppression and DNA damage repair, which could lead to uncontrolled cell cycle progression and cancer development. In addition, SAMHD1 has been reported to have a negative regulatory role in the chemosensitivity to anticancer drugs through its dNTPase activity. The present review aimed to summarize the regulation of SAMHD1 expression in cancer and its function in tumor growth and chemotherapy sensitivity, and discussed controversial points and future directions.