ObjectiveTo investigate the relationship between solute carrier family 7 member 11 （SLC7A11） expression in esophageal squamous cell carcinoma （ESCC） and clinical prognosis， and to determine its effects on ESCC cell growth， migration， and other biological activities. MethodsSLC7A11 protein expression was measured in 310 ESCC tissues and 259 adjacent normal tissues using immunohistochemistry to statistically assess the association of SLC7A11 with clinicopathologic characteristics and prognosis in ESCC patients. The expression of SLC7A11 in ESCC cell lines was suppressed through siRNA-mediated knockdown. The specific effects of SLC7A11 knockdown on proliferation and migration were evaluated using CCK-8， clonogenic assay， and Transwell assays. Adenosine triphosphate （ATP）， lactic acid and pyruvate assays were used to measure ESCC metabolism. ResultsSLC7A11 protein expression was localized predominantly in the cytoplasm of ESCC tissues. Significantly higher SLC7A11 expression levels were observed in ESCC tissues compared to adjacent normal tissues （P<0.001）. High SLC7A11 expression was associated with poorer differentiation in patients （P<0.01）. Kaplan-Meier survival analysis demonstrated significantly shorter overall survival in patients with high SLC7A11 expression compared to those with low expression （P<0.05）. CCK-8 and colony formation assays demonstrated that the knockdown of SLC7A11 expression significantly suppressed the proliferative capacity of tumor cells （P<0.001）. Furthermore， Transwell assays revealed a marked decline in tumor cell migration capacity following SLC7A11 suppression （P<0.001）. Critically， SLC7A11 knockdown also reduced intracellular levels of ATP， lactate， and pyruvate， demonstrating that SLC7A11 modulated metabolic activity in ESCC cells（P<0.001）. ConclusionThe expression level of SLC7A11 is relatively high in ESCC and is strongly associated with poor prognosis. Silencing SLC7A11 significantly inhibits esophageal cancer cell growth and migration. SLC7A11 has the ability to regulate glucose， lactic acid and ATP metabolism levels in ESCC， thereby affecting the metabolic microenvironment of ESCC.

BackgroundPatients with depressive episode and schizophrenia have a high risk of suicide. The sleep electroencephalogram power spectral density characteristics of patients with depressive episode accompanied by suicidal behavior and those with schizophrenia may be different， but there is currently a lack of direct comparative studies on these two groups of patients. ObjectiveTo compare the sleep electroencephalogram power spectral density between depressive episode and schizophrenic patients with suicidal behavior， in order to provide references for exploring predictive indicators of suicidal behavior. MethodsFrom June 2018 to December 2020， 20 patients with depressive episode and 20 patients with schizophrenia who had committed suicide within the past month and were treated at the outpatient department of Shenzhen Kangning Hospital were selected. All of them met the diagnostic criteria for depressive episode or schizophrenia as defined in the International Classification of Diseases， tenth edition （ICD-10）. Using a random sampling method， 20 volunteers with matching gender and age to the patient groups were selected from the Cuiping community in Shenzhen as the control group. The subjective sleep of the patients was evaluated using the Insomnia Severity Index （ISI）， the Dysfunctional Belief and Attitude about Sleep （DBAS）， the Disturbing Dreams and Nightmare Severity Index （DDNSI）， and the Epworth Somnolence Scale （ESS）. The objective sleep of the patients was assessed using polysomnography. The sleep electroencephalogram was filtered and the power spectral density of the brain wave was analyzed and processed for all the subjects. The subjective and objective sleep conditions of the two patient groups were compared， and the sleep electroencephalogram power spectral density of the patient groups and the control group were also compared. ResultsA comparison of subjective and objective sleep conditions between patients with depressive episode accompanied by suicidal behavior and patients with schizophrenia accompanied by suicidal behavior showed no statistically significant differences （P>0.05）. Comparisons of sleep electroencephalogram power spectral density in the W stage （average power of α wave， total power of δ wave， average power of δ wave， average power of θ wave）， N1 stage （average power of β wave， total power of α wave， total power of δ wave）， N2 stage （total power of α wave， average power of α wave， total power of δ wave， average power of δ wave）， N3 stage （average power of α wave， average power of δ wave）， and R stage （total power of α wave， average power of α wave， total power of δ wave， average power of δ wave） between patients with depressive episode accompanied by suicidal behavior， patients with schizophrenia accompanied by suicidal behavior， and the control group showed statistically significant differences （P<0.05 or 0.01）. The total power of δ wave in the W stage and the average power of β wave and δ wave in the N1 stage were higher in two patient groups were higher than those of the control group. The total power of α wave and the average power of α wave in the N2 stage were lower than those of the control group， while the average power of δ wave was higher than that of the control group. The average power of α wave in the N3 stage of both patient groups were lower than that of the control group， while the average power of δ wave was higher than that of the control group. The total power and average power of α wave in the R stage were lower than those of the control group， while the total power and average power of δ wave were higher than those of the control group. All the differences were statistically significant. Patients with depressive episode accompanied by suicidal behavior had higher average powers of α wave， δ wave， and θ wave in the W stage compared with the control group， while the total power of α wave in the N1 stage was lower in the former group. All these differences were statistically significant （P<0.05）. ConclusionThe depressive episode patients accompanied by suicidal behavior have highly overlapping sleep electroencephalogram abnormal patterns with those of schizophrenia patients， mainly manifested as a general decrease in α wave power （N2， N3， R stage） and a general increase in δ wave power （W， N1， N2， N3， R stage） as well as β wave power in N1 stage. At the same time， patients with depressive episode accompanied by suicidal behavior also show specific changes， including an increase in the average power of α and θ waves during the wakefulness period （W stage）， and a decrease in the total power of α wave in N1 stage. ［Funded by Guangdong Province High-level Clinical Key Specialty （with supporting funds from Shenzhen City） （number， SZGSP013）； Shenzhen Key Medical Discipline （number， SZXK041）； Shenzhen Clinical Medicine Research Center Project （number， 20210617155253001）］

Machado-Joseph disease, or spinocerebellar ataxia type 3 (SCA3), represents the most common autosomal dominant cerebellar ataxia worldwide. Despite its progressive and debilitating nature, disease-modifying therapies remain elusive. Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising non-invasive intervention; however, its clinical application has been hindered by inconsistent protocols and a lack of mechanistic understanding. A recent landmark study published in Brain Stimulation by Chen et al. addressed these challenges by combining a high-dose intermittent theta-burst stimulation (iTBS) protocol with concurrent transcranial magnetic stimulation-electroencephalography (TMS-EEG). This commentary provides an in-depth analysis of their findings, highlighting the restoration of cerebello-cortical inhibition (CBI) as a key therapeutic mechanism. Furthermore, we discuss the broader implications of this work, proposing that future translational research should integrate accelerated iTBS (aiTBS) paradigms, cortical response measurements (CRM), and individualized neuro-navigation to establish a new era of precision neuromodulation for ataxia.

Machado-Joseph disease, or spinocerebellar ataxia type 3 (SCA3), represents the most common autosomal dominant cerebellar ataxia worldwide. Despite its progressive and debilitating nature, disease-modifying therapies remain elusive. Repetitive transcranial magnetic stimulation (rTMS) has emerged as a promising non-invasive intervention; however, its clinical application has been hindered by inconsistent protocols and a lack of mechanistic understanding. A recent landmark study published in Brain Stimulation by Chen et al. addressed these challenges by combining a high-dose intermittent theta-burst stimulation (iTBS) protocol with concurrent transcranial magnetic stimulation-electroencephalography (TMS-EEG). This commentary provides an in-depth analysis of their findings, highlighting the restoration of cerebello-cortical inhibition (CBI) as a key therapeutic mechanism. Furthermore, we discuss the broader implications of this work, proposing that future translational research should integrate accelerated iTBS (aiTBS) paradigms, cortical response measurements (CRM), and individualized neuro-navigation to establish a new era of precision neuromodulation for ataxia.

Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.

Cyclic GMP-AMP synthase (cGAS), a pivotal molecule in innate immunity, has emerged as a keypoint in interdisciplinary research at the intersection of basic immunology and tumor biology. As a cytosolic nucleic acid sensor, cGAS is primarily characterized by its capacity to recognize double-stranded DNA (dsDNA) in the cytosol. Upon binding to dsDNA, cGAS undergoes a conformational change that promotes its dimerization and subsequent enzymatic activation. Once activated, it catalyzes the synthesis of the second messenger 2',3'-cGAMP from ATP and GTP. cGAMP then binds to the adaptor protein STING, which resides on the endoplasmic reticulum (ER) membrane. The binding process triggers STING to traffic from the ER to the Golgi apparatus, where it is phosphorylated by the kinase TBK1. Phosphorylated STING serves as a docking site for the transcription factor IRF3, facilitating its phosphorylation by TBK1. Once phosphorylated, IRF3 forms dimers and translocates to the nucleus, where it drives the expression of type I interferons and pro-inflammatory cytokines, initiating a potent antimicrobial state. The DNA-sensing mechanism of cGAS is inherently non-selective regarding the origin of its ligand. It readily detects exogenous DNA from invading pathogens, thereby playing an indispensable role in host defense against microbial infections. However, this same mechanism also enables cGAS to recognize self-DNA that leaks from the nucleus or mitochondria into the cytosol under various cellular stress conditions. While critical for immunity, the recognition of self-dsDNA by cGAS can disrupt cellular homeostasis and trigger aberrant inflammatory responses. The loss of self-tolerance can precipitate or exacerbate the pathogenesis of autoimmune disorders such as systemic lupus erythematosus (SLE) and Aicardi-Goutières syndrome (AGS), highlighting the dual role of cGAS as both a sentinel for infection and a potential driver of autoimmune pathology. Notably, the subcellular localization of cGAS is not still. Increasing recent researches have revealed that cGAS is also abundant within the nucleus, challenging the traditional view of it solely as a cytosolic nucleic acid sensor. Within the nucleus, cGAS exhibits non-canonical functions that are distinct from its canonical immunological role. First, cGAS exists in a state of stringent immunological silence in the nucleus, with mechanisms involving its competitive binding to histones and its post-translational modifications which block the activation of cGAS enzymatic activity, thus, effectively preventing it from mounting an autoimmune attack on genomic DNA. Second, cGAS plays a critical role in maintaining genomic stability. Upon DNA damage, cGAS is rapidly recruited to the lesion site and participates in the DNA damage repair process. Moreover, under conditions of DNA replication stress, cGAS contributes to the stabilization of replication forks, preventing the cell from entering a state of uncontrolled hyper-replication. Consequently, in light of the dual role of cGAS in both immune regulation and tumor development, the development of small-molecule drugs targeting cGAS holds significant therapeutic promise. This review summarizes the structural characteristics of cGAS and its canonical function as a pattern recognition receptor in the cytosol, including the types of pathogens it recognizes and the autoimmune responses resulting from erroneous recognition of self-DNA. It then focuses on its emerging non-canonical functions within the nucleus, detailing its nucleocytoplasmic shuttling, the mechanisms underlying its nuclear immune quiescence, and its role in mediating DNA damage repair and replication fork stabilization. Finally, the review discusses the progress and application prospects of small-molecule drugs targeting cGAS for the treatment of autoimmune diseases and cancer.

Objective : To explore the mechanism of isorhamnetin (Iso) in the treatment of oral squamous cell carcinoma (OSCC) using network pharmacology and molecular docking methods and to verify it in vitro. Methods : The key targets were obtained by constructing the PPI protein interaction network based on the common intersection targets of Iso-OSCC. At the same time, gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) were used to analyze the related signaling pathways of the intersection targets. Iso and core targets were also analyzed through molecular docking and visualization. Colony formation assay and Transwell assay were used to identify the effect of Iso on the proliferation and invasion of Cal-27 cells. Western blot was used to analyze the regulatory effects of different concentrations of Iso on estrogen receptor-1 (ESR1), phosphoinositide-3-kinase regulatory subunit-1 (PIK3R1), Src tyrosine kinase (SRC), and phosphatidylinositol 3-kinase (PI3K)/protein kinase B (AKT) signaling pathway proteins. Results: A total of 269 potential intersection targets of Iso-regulated OSCC were obtained. According to the degree obtained by topological analysis, PIK3R1, AKT1, SRC, ESR1, and other core targets were screened out. KEGG analysis showed that 165 signaling pathways were enriched in the intersection targets of Iso-OSCC, among which the PI3K/AKT signaling pathway played an important role in the treatment of OSCC with Iso. Molecular docking results showed that the absolute value of binding energy between target proteins PIK3R1, AKT1, SRC, ESR1, and Iso was high. After Cal-27 cells were treated with Iso, the number of cell colony formations, the number of transmembrane cells, and the expression of PIK3R1, ESR1, SRC, p-PI3K, and p-AKT were negatively correlated with the increase in Iso concentration (P < 0.05). Conclusion Iso can inhibit PI3K/AKT signal transduction and influence the expression of PIK3R1, AKT1, SRC, and ESR1 proteins, thereby inhibiting the occurrence and development of OSCC.

Objective:To investigate the effect of type 2 taste receptor(T2R)38 activation on ferroptosis of human airway epithelium NuLi-1 cells induced by cigarette smoke exposure,and to clarify its possible mechanism.Methods:The human airway epithelial NuLi-1 cells were divided into control group(without any treatment),cigarette smoke extract(CSE)group(treated with 5％CSE for 24 h)and CSE+T2R38 specific agonist phenylthiocarbamide(PTC)group(CSE+PTC group)(treated with 5％CSE and 1 mmol·L-1 PTC for 24 h).The expression levels of T2R38 mRNA and protein in NuLi-1 cells in various groups were determined by real-time fluorescence quantitative PCR(RT-qPCR)and Western blotting methods.The cell viabilities in various groups were determined by cell counting kit-8(CCK-8)assay.The activities of inducible nitric oxide synthase(iNOS),endothelial nitric oxide synthase(eNOS),and superoxide dismutase(SOD)in the cells in various groups were measured by kits.DAX-J2 red fluorescence probe was used to determine the levels of nitric oxide(NO)in the cells in various groups.The reactive oxygen species(ROS)levels in the cells in various groups were detected by fluorescent probe kit.The levels of malondialdehyde(MDA),Fe2+,and reduced glutathione(GSH)in the cells in various groups were determined by enzyme-linked immunosorbent assay(ELISA)method.Western blotting method was used to determine the expression levels of nuclear factor erythroid 2-related factor 2(Nrf2)and glutathione peroxidases 4(GPx4)proteins in the cells in various groups.Results:Compared with control group,the expression levels of T2R38 mRNA and protein in NuLi-1 cells in CSE group were increased(P＜0.05).Compared with control group,the viability of NuLi-1 cells in CSE group was decreased(P＜0.05),the activities of iNOS and SOD in cells in CSE group were increased(P＜0.05),the levels of NO and ROS were increased(P＜0.05),the levels of MDA and Fe2+were increased(P＜0.05),and the GSH level and the expression levels of Nrf2 and GPx4 proteins were decreased.Compared with CSE group,the viability of NuLi-1 cells in CSE+PTC group was increased(P＜0.05),the activity of SOD and the GSH level in the cells were increased(P＜0.05),the activity of iNOS in cells was decreased(P＜0.05),the levels of NO and ROS in cells were decreased(P＜0.05),the levels of MDA and Fe2+were decreased(P＜0.05),and the expression levels of Nrf2 and GPx4 proteins were increased(P＜0.05).There was no significant difference in eNOS activity among control group,CSE group,and CSE+PTC group(P＞0.05).Conclusion:Activation of bitter taste receptor T2R38 can inhibit ferroptosis in human airway epithelium NuLi-1 cells induced by cigarette smoke exposure,and its mechanism may be related to the reduction of iNOS activity in the cells.

Objective:To discuss the inhibitory effects of combined application of chlorogenic acid(CA),procyanidin(PC),and paeoniflorin(PF),the active components of Paeoniae Radix Rubra,on Enterococcus faecalis(E.faecalis)and its biofilm,and to clarify the mechanism.Methods:The minimal inhibitory concentration(MIC)and minimal bactericidal concentration(MBC)of CA,PC,and PF against E.faecalis were detected by microdilution method;the fractional inhibitory concentration index(FICI)and fractional bactericidal concentration index(FBCI)of the three active components of Paeoniae Radix Rubra in combination were detected by checkerboard dilution method.The experiment was divided into control group,high concentration of single-drug groups(PF-10 group,PC-6 group,and CA-10 group),and drug combination groups(CA-2+PC-1 group,CA-2+PC-2 group,PF-4+PC-2 group,PF-6+PC-2 group,PF-4+CA-4 group,and PF-6+CA-4 group).Crystal violet staining was used to detect the biofilm formation of E.faecalis in various groups after treated with three active components in combination;scanning electron microscope(SEM)was used to observe the morphology of E.faecalis biofilm in various groups after treated with three active components in combination;spot assay was used to detect the inhibitory effects of three active components in combination on E.faecalis planktonic bacteria and biofilm in various groups;SEM was used to observe the damage to E.faecalis cell membrane in various groups after treated with three active components in combination;kit was used to detect the adenosine triphosphate(ATP)levels in E.faecalis planktonic bacteria and biofilm in various groups after treated with three active components in combination.Results:Among the three active components of Paeoniae Radix Rubra,the MIC of PC was 4 g·L?1 and the MBC was 6 g·L?1;the MIC of CA was 8 g·L?1 and the MBC was 10 g·L?1;the MIC and MBC of PF were both>10 g·L?1,and the concentration of PF was selected as 10 g·L?1.The combination of PC and CA showed synergistic effects,the combination of PC and PF showed additive effects,and the combination of CA and PF showed additive effects.The crystal violet staining results showed that compared with control group,the biofilm formations of E.faecalis in PF-10 group,PC-6 group,CA-10 group,and drug combination groups were significantly decreased(P<0.05);compared with PF-10 group,the biofilm formations of E.faecalis in PC-6 group,CA-10 group,CA-2+PC-1 group,CA-2+PC-2 group,PF-4+PC-2 group,PF-6+PC-2 group,and PF-6+CA-4 group were significantly decreased(P<0.05 or P<0.01).The SEM results showed that in control group,the E.faecalis biofilm was thick,with tightly connected bacteria,regular morphology,and intact cell membranes;in PF-10 group,PC-6 group,and CA-10 group,the thickness of E.faecalis biofilm was significantly reduced,and the arrangement of bacteria became relatively loose;in all drug combination groups,the E.faecalis biofilm was significantly reduced or even completely disappeared,and under high magnification,the biofilm structure was completely absent,with bacterial fragments adhering and aggregating,losing their original bacterial morphology.The spot assay results showed that compared with control group,the colonies of E.faecalis planktonic bacteria in PF-10 group,PC-6 group,and CA-10 group were significantly reduced after treated for 5,10,and 30 min,indicating gradually enhanced bactericidal effects;among drug combination groups,the combination of CA and PC significantly reduced the colonies of E.faecalis planktonic bacteria within 5 min,showing strong bactericidal effects.Compared with CA group and PC group,the colonies of E.faecalis planktonic bacteria in all drug combination groups showed no significant reduction after treated for 5,10,and 30 min;compared with control group,the colonies of E.faecalis biofilm in PF-10 group,PC-6 group,and CA-10 group were gradually decreased after the treated for 30 and 60 min,suggesting that the high concentration of single-drug groups exhibited gradually enhanced bactericidal effects on E.faecalis in biofilm.Among them,the biofilm-killing effect of PC-6 group was the most significant,with no colony formation observed after treated for 30 min;in drug combination groups,only a few colonies of E.faecalis biofilm were observed in CA-2+PC-2 group after treated for 30 min,indicating effective killing of bacteria in biofilm;compared with PC-6 group and CA-10 group,all drug combination groups achieved the bactericidal effects of high concentration of single-drug groups at low concentrations.The SEM results showed that in control group,E.faecalis exhibited an oval shape with intact cell membranes;in PF group,bacterial morphology was altered,and cell membrane integrity was damaged;in CA group,most bacterial cell membranes remained relatively intact,but the bacterial surface showed shrinkage and depression,with a few bacteria exhibiting disrupted cell membrane integrity;in PC group,the integrity of bacterial cell membranes was most severely damaged,leading to leakage of cellular contents and aggregation of cell fragments into flocculent structures;in all drug combination groups,E.faecalis exhibited ruptured cell membranes,leakage of contents,and aggregation of bacterial debris,especially in the combination of CA and PC,where the most severe disruption of bacterial cell membrane integrity and complete leakage of contents were observed;in the combination of PF and CA,bacterial surface pits and shrinkage were observed,with occasional cell membrane rupture.The kit results showed that compared with control group,the ATP levels in E.faecalis planktonic bacteria and biofilm in various groups were significantly decreased(P<0.01);compared with PF-10 group,the ATP levels in E.faecalis planktonic bacteria in CA-10 group,CA-2+PC-2 group,PF-4+CA-4 group,and PF-6+CA-4 group were significantly decreased(P<0.05 or P<0.01),and the ATP levels in E.faecalis biofilm in CA-10 group and CA-2+PC-2 group were significantly decreased(P<0.05 or P<0.01).Conclusion:The combined application of PF,PC,and CA,the active components of Paeoniae Radix Rubra,exhibits significant inhibitory effects on E.faecalis and its biofilm formation.The pairwise combinations of three active components show synergistic or additive effects,with the combination of CA and PC demonstrating the most significant synergistic effect.The underlying mechanism may be related to the disruption of E.faecalis cell membrane integrity and inhibition of bacterial ATP levels.

Objective:To discuss the expression of Rh family C glycoprotein(RHCG)in the esophageal squamous cell carcinoma(ESCC)tissue and its effect on the malignant biological behavior of ESCC cells,and to clarify the value of RHCG as a diagnostic and prognostic marker for the ESCC patients.Methods:A total of 143 ESCC tissue samples and 105 adjacent normal tissue samples were collected.Using immunohistochemical staining method,141 ESCC samples were divided into two groups:RHCG low expression group(immunohistochemistry score≤6)and RHCG high expression group(immunohistochemistry score>6).Immunohistochemical method was used to detect the RHCG protein expression in 143 ESCC tissues and 105 normal tissues,and the relationship between the clinicopathological characteristics of the ESCC patients was analyzed.Receiver operating characteristic(ROC)curve and Kaplan-Meier survival analysis were used to evaluate the value of RHCG in diagnosis and prognosis of the ESCC patients;univariate and multivariate COX regression analysis were used to determine the independent risk factors affecting the prognosis of the ESCC patients.Gene Expression Profiling Interactive Analysis(GEPIA2)database was used to analyze the expression of RHCG mRNA in various tumor tissues.The ESCC TE-1 cells were cultured and transfected in to 6-well cell culture plates with different Lipofectamine2000∶RHCG ratios;the cells in RHCG transfection group were transfected with weights of 2.0,2.5,and 3.0 μg for 24 and 48 h,respectively,and the cells in NC group transfected with empty vector as control.Western blotting method was used to detect the RHCG protein expression level in the TE-1 cells in various groups after transfection at different concentrations and verify the optimal transfection conditions;cell counting kit-8(CCK-8)assay was used to detect the proliferation activities of the TE-1 cells;plate clone formation assay was used to detect the colony formation numbers of the TE-1 cells;Transwell chamber assay was used to detect the numbers of migrating TE-1 cells.Results:Compared with adjacent normal tissue,the RHCG gene expression level in various cancer tissues including ESCC,glioblastoma multiforme,and head and neck squamous cell carcinoma was significantly decreased(P<0.05).RHCG protein was mainly located on the cell membrane of normal esophageal squamous epithelial cells;the RHCG protein expression intensity in ESCC tissues was lower than that in adjacent normal esophageal tissue(χ2=109.373,P<0.001),and the patients in RHCG low expression group had poorer differentiation than those in RHCG high expression group(P=0.041).The area under the curve(AUC)value of RHCG for diagnosing ESCC was 0.86,with sensitivity and specificity of 95.1%and 75.0%,respectively;the Kaplan-Meier survival analysis results showed that compared with high RHCG expression group,the patients in low RHCG expression group had shorter survival time and poorer prognosis[harard ratio(HR)=0.269,95%confidence interval(CI):0.113-0.639,P=0.020];the COX regression analysis results showed that low RHCG expression could serve as an independent risk factor affecting the prognosis of ESCC[HR=4.569,95%CI=1.315-15.877,P=0.017)].The Western blotting results verified that the optimal transfection condition was 3.0 μg RHCG plasmid for 48 h,at which time RHCG overexpression was optimal and RHCG protein expression level was highest.The CCK-8 assay results showed that compared with control group,the proliferation activity in RHCG overexpression group was decreased on the 4th day after cell seeding(P<0.001).In the TE-1 cells,the colony formation number of the TE-1 cells in RHCG over-expression group was lower than that in control group(t=17.70,P<0.001).The Transwell chamber assay results showed that compared with control group,the number of migrating cells in RHCG over-expression group was decreased(t=23.74,P<0.001).Conclusion:RHCG expression is decreased in ESCC tissues and associated with poor prognosis in ESCC patients;overexpression of RHCG can inhibit the proliferation and migration of the TE-1 cells,providing a theoretical basis for RHCG as a novel diagnostic and prognostic marker and therapeutic target for ESCC.