BACKGROUND Through experimental research on the biological function of GATA6-AS1,it was confirmed that GATA6-AS1 can inhibit the proliferation,invasion,and migration of gastric cancer cells,suggesting that GATA6-AS1 p...BACKGROUND Through experimental research on the biological function of GATA6-AS1,it was confirmed that GATA6-AS1 can inhibit the proliferation,invasion,and migration of gastric cancer cells,suggesting that GATA6-AS1 plays a role as an anti-oncogene in the occurrence and development of gastric cancer.Further experi-ments confirmed that the overexpression of fat mass and obesity-associated protein(FTO)inhibited the expression of GATA6-AS1,thereby promoting the occurrence and development of gastric cancer.AIM To investigate the effects of GATA6-AS1 on the proliferation,invasion and migration of gastric cancer cells and its mechanism of action.METHODS We used bioinformatics methods to analyze the Cancer Genome Atlas(https://portal.gdc.cancer.gov/.The Cancer Genome Atlas)and download expression data for GATA6-AS1 in gastric cancer tissue and normal tissue.We also constructed a GATA6-AS1 lentivirus overexpression vector which was transfected into gastric cancer cells to investigate its effects on proliferation,migration and invasion,and thereby clarify the expression of GATA6-AS1 in gastric cancer and its biological role in the genesis and development of gastric cancer.Next,we used a database(http://starbase.sysu.edu.cn/starbase2/)to analysis GATA6-AS1 whether by m6A methylation modify regulation and predict the methyltransferases that may methylate GATA6-AS1.Furthermore,RNA immunoprecipitation experiments confirmed that GATA6-AS1 was able to bind to the m6A methylation modification enzyme.These data allowed us to clarify the ability of m6A methylase to influence the action of GATA6-AS1 and its role in the occurrence and development of gastric cancer.RESULTS Low expression levels of GATA6-AS1 were detected in gastric cancer.We also determined the effects of GATA6-AS1 overexpression on the biological function of gastric cancer cells.GATA6-AS1 had strong binding ability with the m6A demethylase FTO,which was expressed at high levels in gastric cancer and negatively correlated with the expression of GATA6-AS1.Following transfection with siRNA to knock down the expression of FTO,the expression levels of GATA6-AS1 were up-regulated.Finally,the proliferation,migration and invasion of gastric cancer cells were all inhibited following the knockdown of FTO expression.CONCLUSION During the occurrence and development of gastric cancer,the overexpression of FTO may inhibit the expression of GATA6-AS1,thus promoting the proliferation and metastasis of gastric cancer.展开更多
Background:Drug resistance is the main factor contributing to cancer recurrence and poor prognosis.Exploration of drug resistance-related mechanisms and effective therapeutic targets are the aim of molecular targeted ...Background:Drug resistance is the main factor contributing to cancer recurrence and poor prognosis.Exploration of drug resistance-related mechanisms and effective therapeutic targets are the aim of molecular targeted therapy.In our study,the role of long non-coding RNA(lncRNA)AFAP1-AS1 in gemcitabine resistance and related mechanisms were explored in cervical cancer cells.Methods:Gemcitabine-resistant cervical cancer cell lines HT-3-Gem and SW756-Gem were constructed using the gemcitabine concentration gradient method.The overall survival rates and recurrence-free survival rates were evaluated by Kaplan-Meier analysis.The interaction was verified through a Dual-luciferase reporter gene assay and a Biotinylated RNA pull-down assay.Cell proliferation ability was assessed through methyl-thiazolyl-tetrazolium(MTT),soft agar,and colony formation experiments.Cell cycle and apoptosis were detected byflow cytometry.Results:Up-regulation of AFAP1-AS1 in cervical cancer predicted a poor prognosis.Besides,patients in the gemcitabine-resistance group had higher levels of AFAP1-AS1 than the gemcitabine-sensitive group.AFAP1-AS1 promoted tumor growth and induced gemcitabine tolerance of cervical cancer cells.In addition,AFAP1-AS1 mediated epidermal growth factor receptor(EGFR)expression by serving as a molecular sponge for microRNA-7a-5p(miR-7-5p).This present study also proved that the knockdown of EGFR or overexpression of miR-7a-5p abolished the accelerative role of AFAP1-AS1 overexpression in cancer progression and gemcitabine tolerance.Conclusions:In general,the AFAP1-AS1/miR-7-5p/EGFR axis was tightly related to the progression and gemcitabine tolerance of cervical cancer,providing potential targets for the management of cervical cancer.展开更多
BACKGROUND Gastric cancer (GC) is the fourth most frequent malignancy all over the world. The diagnosis of GC is challenging and the prognosis of GC is very unfavorable. Accumulating evidence reveals that serum long n...BACKGROUND Gastric cancer (GC) is the fourth most frequent malignancy all over the world. The diagnosis of GC is challenging and the prognosis of GC is very unfavorable. Accumulating evidence reveals that serum long noncoding RNAs (lncRNAs) can function as biomarkers in various types of cancers, including GC. AIM To explore the level and molecular mechanism of the lncRNA HOXA11-AS in GC and the diagnostic and prognostic significance of serum HOXA11-AS in GC. METHODS HOXA11-AS levels in GC tissue, cell lines, and serum samples were measured. The correlation between HOXA11-AS expression and clinicopathological characteristics was analyzed. The role of HOXA11-AS in the diagnosis and prognosis of GC was evaluated. Cell function assays were performed for exploration of the roles of HOXA11-AS in GC cells. Moreover, Western blot was performed to explore the target regulated by HOXA11-AS in GC cells. RESULTS Up-regulation of HOXA11-AS was found in GC tissues, cell lines, and serum samples. In GC patients, decreased serum HOXA11-AS levels were negatively related with tumor size, TNM stage, and lymph node metastasis. The area under the receiver operating characteristic curve of serum HOXA11-AS in the diagnosis of GC was 0.924 (95%CI: 0.881-0.967;sensitivity, 0.787;specificity 0.978). Results of the Kaplan-Meier survival curves suggested the GC patients with a lower HOXA11-AS level having a better overall survival rate. HOXA11-AS promoted GC cell proliferation and invasion. SRSF1 may be the target regulated by HOXA11-AS in GC cells. CONCLUSION HOXA11-AS promotes GC cell proliferation and invasion via SRSF1 and may function as a promising marker in GC.展开更多
BACKGROUND Previous studies have suggested that long non-coding RNAs(lncRNA)TP73-AS1 is significantly upregulated in several cancers.However,the biological role and clinical significance of TP73-AS1 in pancreatic canc...BACKGROUND Previous studies have suggested that long non-coding RNAs(lncRNA)TP73-AS1 is significantly upregulated in several cancers.However,the biological role and clinical significance of TP73-AS1 in pancreatic cancer(PC)remain unclear.AIM To investigate the role of TP73-AS1 in the growth and metastasis of PC.METHODS The expression of lncRNA TP73-AS1,miR-128-3p,and GOLM1 in PC tissues and cells was detected by quantitative real-time polymerase chain reaction.The bioinformatics prediction software ENCORI was used to predict the putative binding sites of miR-128-3p.The regulatory roles of TP73-AS1 and miR-128-3p in cell proliferation,migration,and invasion abilities were verified by Cell Counting Kit-8,wound-healing,and transwell assays,as well as flow cytometry and Western blot analysis.The interactions among TP73-AS1,miR-128-3p,and GOLM1 were explored by bioinformatics prediction,luciferase assay,and Western blot.RESULTS The expression of TP73-AS1 and miRNA-128-3p was dysregulated in PC tissues and cells.High TP73-AS1 expression was correlated with a poor prognosis.TP73-AS1 silencing inhibited PC cell proliferation,migration,and invasion in vitro as well as suppressed tumor growth in vivo.Mechanistically,TP73-AS1 was validated to promote PC progression through GOLM1 upregulation by competitively binding to miR-128-3p.CONCLUSION Our results demonstrated that TP73-AS1 promotes PC progression by regulating the miR-128-3p/GOLM1 axis,which might provide a potential treatment strategy for patients with PC.展开更多
BACKGROUND Highly upregulated in liver cancer (HULC) is a long non-coding RNA (lncRNA) which has recently been identified as a key regulator in hepatocellular carcinoma (HCC) progression. However, its role in the secr...BACKGROUND Highly upregulated in liver cancer (HULC) is a long non-coding RNA (lncRNA) which has recently been identified as a key regulator in hepatocellular carcinoma (HCC) progression. However, its role in the secretion of exosomes from HCC cells remains unknown. AIM To explore the mechanism by which HULC promotes the secretion of exosomes from HCC cells. METHODS Serum and liver tissue samples were collected from 30 patients with HCC who had not received chemotherapy, radiotherapy, or immunotherapy before surgery. HULC expression in serum exosomes and liver cancer tissues of patients was measured, and compared with the data obtained from healthy controls and tumor adjacent tissues. The effect of HULC upregulation in HCC cell lines and the relationship between HULC and other RNAs were studied using qPCR and dualluciferase reporter assays. Nanoparticle tracking analysis was performed to detect the quantity of exosomes.RESULTS HULC expression in serum exosomes of patients with HCC was higher than that in serum exosomes of healthy controls, and HULC levels were higher in liver cancer tissues than in tumor adjacent tissues. The expression of HULC in serum exosomes and liver cancer tissues correlated with the tumor-node-metastasis (TNM) classification, and HULC expression in tissues correlated with that in serum exosomes. Upregulation of HULC promoted HCC cell growth and invasion and repressed apoptosis. Notably, it also facilitated the secretion of exosomes from HCC cells. Moreover, qPCR assays showed that HULC repressed microRNA-372-3p (miR-372-3p) expression. We also identified Rab11a as a downstream target of miR-372-3p. Dual-luciferase reporter assays suggested that miR-372-3p could directly bind both HULC and Rab11a. CONCLUSION Our findings illustrate the importance of the HULC/miR-372-3p/Rab11a axis in HCC and provide new insights into the molecular mechanism regulating the secretion of exosomes from HCC cells.展开更多
Long noncoding RNAs(lnc RNAs)participate in many pathophysiological processes after traumatic brain injury by mediating neuroinflammation and apoptosis.Homeobox A11 antisense RNA(HOXA11-AS)is a member of the lnc RNA f...Long noncoding RNAs(lnc RNAs)participate in many pathophysiological processes after traumatic brain injury by mediating neuroinflammation and apoptosis.Homeobox A11 antisense RNA(HOXA11-AS)is a member of the lnc RNA family that has been reported to participate in many inflammatory reactions;however,its role in traumatic brain injury remains unclear.In this study,we established rat models of traumatic brain injury using a weight-drop hitting device and injected LV-HOXA11-AS into the right lateral ventricle 2 weeks before modeling.The results revealed that overexpression of HOXA11-AS aggravated neurological deficits in traumatic brain injury rats,increased brain edema and apoptosis,promoted the secretion of proinflammatory factors interleukin-1β,interleukin-6,and tumor necrosis factorα,and promoted the activation of astrocytes and microglia.Microglia were treated with 100 ng/m L lipopolysaccharide for 24 hours to establish in vitro cell models,and then transfected with pc DNA-HOXA11-AS,mi R-124-3 p mimic,or sh-MDK.The results revealed that HOXA11-AS inhibited mi R-124-3 p expression and boosted MDK expression and TLR4-nuclear factor-κB pathway activation.Furthermore,lipopolysaccharide enhanced potent microglia-induced inflammatory responses in astrocytes.Forced overexpression of mi R-124-3 p or downregulating MDK repressed microglial activation and the inflammatory response of astrocytes.However,the mi R-124-3 p-mediated anti-inflammatory effects were reversed by HOXA11-AS.These findings suggest that HOXA11-AS can aggravate neuroinflammation after traumatic brain injury by modulating the mi R-124-3 p-MDK axis.This study was approved by the Animal Protection and Use Committee of Southwest Medical University(approval No.SMU-2019-042)on February 4,2019.展开更多
Background:Long non-coding RNAs(lncRNAs)plays an important role in the progression of gastric cancer(GC).Their involvement ranges from genetic regulation to cancer progression.However,the mechanistic roles of RP11-789...Background:Long non-coding RNAs(lncRNAs)plays an important role in the progression of gastric cancer(GC).Their involvement ranges from genetic regulation to cancer progression.However,the mechanistic roles of RP11-789C1.1 in GC are not fully understood.Methods:We identified the expression of lncRNA RP11-789C1.1 in GC tissues and cell lines by real-time fluorescent quantitative polymerase chain reaction.A series of functional experiments revealed the effect of RP11-789C1.1 on the proliferation of GC cells.In vivo experiments verified the effect of RP11-789C1.1 on the biological behavior of a GC cell line.RNA pull-down unveiled RP11-789C1.1 interacting proteins.Western blot analysis indicated the downstream pathway changes of RP11-789C1.1,and an oxaliplatin dosing experiment disclosed the influence of RP11-789C1.1 on the drug sensitivity of oxaliplatin.Results:Our results demonstrated that RP11-789C1.1 inhibited the proliferation of GC cells and promoted the apoptosis of GC cells.Mechanistically,RP11-789C1.1 inhibited checkpoint kinase 1(CHK1)phosphorylation by binding ataxiatelangiectasia mutated and Rad3 related(ATR),a serine/threonine-specific protein kinase,promoted GC apoptosis,and mediated oxaliplatin sensitivity.Conclusion:In general,we discovered a tumor suppressor molecule RP11-789C1.1 and confirmed its mechanism of action,providing a theoretical basis for targeted GC therapy.展开更多
基金Natural Science Foundation of Shandong Province,No.ZR2020MH207 and No.ZR2020MH251.
文摘BACKGROUND Through experimental research on the biological function of GATA6-AS1,it was confirmed that GATA6-AS1 can inhibit the proliferation,invasion,and migration of gastric cancer cells,suggesting that GATA6-AS1 plays a role as an anti-oncogene in the occurrence and development of gastric cancer.Further experi-ments confirmed that the overexpression of fat mass and obesity-associated protein(FTO)inhibited the expression of GATA6-AS1,thereby promoting the occurrence and development of gastric cancer.AIM To investigate the effects of GATA6-AS1 on the proliferation,invasion and migration of gastric cancer cells and its mechanism of action.METHODS We used bioinformatics methods to analyze the Cancer Genome Atlas(https://portal.gdc.cancer.gov/.The Cancer Genome Atlas)and download expression data for GATA6-AS1 in gastric cancer tissue and normal tissue.We also constructed a GATA6-AS1 lentivirus overexpression vector which was transfected into gastric cancer cells to investigate its effects on proliferation,migration and invasion,and thereby clarify the expression of GATA6-AS1 in gastric cancer and its biological role in the genesis and development of gastric cancer.Next,we used a database(http://starbase.sysu.edu.cn/starbase2/)to analysis GATA6-AS1 whether by m6A methylation modify regulation and predict the methyltransferases that may methylate GATA6-AS1.Furthermore,RNA immunoprecipitation experiments confirmed that GATA6-AS1 was able to bind to the m6A methylation modification enzyme.These data allowed us to clarify the ability of m6A methylase to influence the action of GATA6-AS1 and its role in the occurrence and development of gastric cancer.RESULTS Low expression levels of GATA6-AS1 were detected in gastric cancer.We also determined the effects of GATA6-AS1 overexpression on the biological function of gastric cancer cells.GATA6-AS1 had strong binding ability with the m6A demethylase FTO,which was expressed at high levels in gastric cancer and negatively correlated with the expression of GATA6-AS1.Following transfection with siRNA to knock down the expression of FTO,the expression levels of GATA6-AS1 were up-regulated.Finally,the proliferation,migration and invasion of gastric cancer cells were all inhibited following the knockdown of FTO expression.CONCLUSION During the occurrence and development of gastric cancer,the overexpression of FTO may inhibit the expression of GATA6-AS1,thus promoting the proliferation and metastasis of gastric cancer.
文摘Background:Drug resistance is the main factor contributing to cancer recurrence and poor prognosis.Exploration of drug resistance-related mechanisms and effective therapeutic targets are the aim of molecular targeted therapy.In our study,the role of long non-coding RNA(lncRNA)AFAP1-AS1 in gemcitabine resistance and related mechanisms were explored in cervical cancer cells.Methods:Gemcitabine-resistant cervical cancer cell lines HT-3-Gem and SW756-Gem were constructed using the gemcitabine concentration gradient method.The overall survival rates and recurrence-free survival rates were evaluated by Kaplan-Meier analysis.The interaction was verified through a Dual-luciferase reporter gene assay and a Biotinylated RNA pull-down assay.Cell proliferation ability was assessed through methyl-thiazolyl-tetrazolium(MTT),soft agar,and colony formation experiments.Cell cycle and apoptosis were detected byflow cytometry.Results:Up-regulation of AFAP1-AS1 in cervical cancer predicted a poor prognosis.Besides,patients in the gemcitabine-resistance group had higher levels of AFAP1-AS1 than the gemcitabine-sensitive group.AFAP1-AS1 promoted tumor growth and induced gemcitabine tolerance of cervical cancer cells.In addition,AFAP1-AS1 mediated epidermal growth factor receptor(EGFR)expression by serving as a molecular sponge for microRNA-7a-5p(miR-7-5p).This present study also proved that the knockdown of EGFR or overexpression of miR-7a-5p abolished the accelerative role of AFAP1-AS1 overexpression in cancer progression and gemcitabine tolerance.Conclusions:In general,the AFAP1-AS1/miR-7-5p/EGFR axis was tightly related to the progression and gemcitabine tolerance of cervical cancer,providing potential targets for the management of cervical cancer.
文摘BACKGROUND Gastric cancer (GC) is the fourth most frequent malignancy all over the world. The diagnosis of GC is challenging and the prognosis of GC is very unfavorable. Accumulating evidence reveals that serum long noncoding RNAs (lncRNAs) can function as biomarkers in various types of cancers, including GC. AIM To explore the level and molecular mechanism of the lncRNA HOXA11-AS in GC and the diagnostic and prognostic significance of serum HOXA11-AS in GC. METHODS HOXA11-AS levels in GC tissue, cell lines, and serum samples were measured. The correlation between HOXA11-AS expression and clinicopathological characteristics was analyzed. The role of HOXA11-AS in the diagnosis and prognosis of GC was evaluated. Cell function assays were performed for exploration of the roles of HOXA11-AS in GC cells. Moreover, Western blot was performed to explore the target regulated by HOXA11-AS in GC cells. RESULTS Up-regulation of HOXA11-AS was found in GC tissues, cell lines, and serum samples. In GC patients, decreased serum HOXA11-AS levels were negatively related with tumor size, TNM stage, and lymph node metastasis. The area under the receiver operating characteristic curve of serum HOXA11-AS in the diagnosis of GC was 0.924 (95%CI: 0.881-0.967;sensitivity, 0.787;specificity 0.978). Results of the Kaplan-Meier survival curves suggested the GC patients with a lower HOXA11-AS level having a better overall survival rate. HOXA11-AS promoted GC cell proliferation and invasion. SRSF1 may be the target regulated by HOXA11-AS in GC cells. CONCLUSION HOXA11-AS promotes GC cell proliferation and invasion via SRSF1 and may function as a promising marker in GC.
基金National Natural Science Foundation of China,No.81974372.
文摘BACKGROUND Previous studies have suggested that long non-coding RNAs(lncRNA)TP73-AS1 is significantly upregulated in several cancers.However,the biological role and clinical significance of TP73-AS1 in pancreatic cancer(PC)remain unclear.AIM To investigate the role of TP73-AS1 in the growth and metastasis of PC.METHODS The expression of lncRNA TP73-AS1,miR-128-3p,and GOLM1 in PC tissues and cells was detected by quantitative real-time polymerase chain reaction.The bioinformatics prediction software ENCORI was used to predict the putative binding sites of miR-128-3p.The regulatory roles of TP73-AS1 and miR-128-3p in cell proliferation,migration,and invasion abilities were verified by Cell Counting Kit-8,wound-healing,and transwell assays,as well as flow cytometry and Western blot analysis.The interactions among TP73-AS1,miR-128-3p,and GOLM1 were explored by bioinformatics prediction,luciferase assay,and Western blot.RESULTS The expression of TP73-AS1 and miRNA-128-3p was dysregulated in PC tissues and cells.High TP73-AS1 expression was correlated with a poor prognosis.TP73-AS1 silencing inhibited PC cell proliferation,migration,and invasion in vitro as well as suppressed tumor growth in vivo.Mechanistically,TP73-AS1 was validated to promote PC progression through GOLM1 upregulation by competitively binding to miR-128-3p.CONCLUSION Our results demonstrated that TP73-AS1 promotes PC progression by regulating the miR-128-3p/GOLM1 axis,which might provide a potential treatment strategy for patients with PC.
基金Supported by Tianjin Clinical Research Center for Organ Transplantation Project,No.15ZXLCSY00070The Nonprofit Central Research Institute Fund of Chinese Academy of Medical Sciences,No.2018PT32021
文摘BACKGROUND Highly upregulated in liver cancer (HULC) is a long non-coding RNA (lncRNA) which has recently been identified as a key regulator in hepatocellular carcinoma (HCC) progression. However, its role in the secretion of exosomes from HCC cells remains unknown. AIM To explore the mechanism by which HULC promotes the secretion of exosomes from HCC cells. METHODS Serum and liver tissue samples were collected from 30 patients with HCC who had not received chemotherapy, radiotherapy, or immunotherapy before surgery. HULC expression in serum exosomes and liver cancer tissues of patients was measured, and compared with the data obtained from healthy controls and tumor adjacent tissues. The effect of HULC upregulation in HCC cell lines and the relationship between HULC and other RNAs were studied using qPCR and dualluciferase reporter assays. Nanoparticle tracking analysis was performed to detect the quantity of exosomes.RESULTS HULC expression in serum exosomes of patients with HCC was higher than that in serum exosomes of healthy controls, and HULC levels were higher in liver cancer tissues than in tumor adjacent tissues. The expression of HULC in serum exosomes and liver cancer tissues correlated with the tumor-node-metastasis (TNM) classification, and HULC expression in tissues correlated with that in serum exosomes. Upregulation of HULC promoted HCC cell growth and invasion and repressed apoptosis. Notably, it also facilitated the secretion of exosomes from HCC cells. Moreover, qPCR assays showed that HULC repressed microRNA-372-3p (miR-372-3p) expression. We also identified Rab11a as a downstream target of miR-372-3p. Dual-luciferase reporter assays suggested that miR-372-3p could directly bind both HULC and Rab11a. CONCLUSION Our findings illustrate the importance of the HULC/miR-372-3p/Rab11a axis in HCC and provide new insights into the molecular mechanism regulating the secretion of exosomes from HCC cells.
基金supported by the Science and Technology Project of Sichuan Province of China,No.2020YJ0188the Science and Technology Foundation of Luzhou of China,No.2017LZXNYD-J10(both to XLL)。
文摘Long noncoding RNAs(lnc RNAs)participate in many pathophysiological processes after traumatic brain injury by mediating neuroinflammation and apoptosis.Homeobox A11 antisense RNA(HOXA11-AS)is a member of the lnc RNA family that has been reported to participate in many inflammatory reactions;however,its role in traumatic brain injury remains unclear.In this study,we established rat models of traumatic brain injury using a weight-drop hitting device and injected LV-HOXA11-AS into the right lateral ventricle 2 weeks before modeling.The results revealed that overexpression of HOXA11-AS aggravated neurological deficits in traumatic brain injury rats,increased brain edema and apoptosis,promoted the secretion of proinflammatory factors interleukin-1β,interleukin-6,and tumor necrosis factorα,and promoted the activation of astrocytes and microglia.Microglia were treated with 100 ng/m L lipopolysaccharide for 24 hours to establish in vitro cell models,and then transfected with pc DNA-HOXA11-AS,mi R-124-3 p mimic,or sh-MDK.The results revealed that HOXA11-AS inhibited mi R-124-3 p expression and boosted MDK expression and TLR4-nuclear factor-κB pathway activation.Furthermore,lipopolysaccharide enhanced potent microglia-induced inflammatory responses in astrocytes.Forced overexpression of mi R-124-3 p or downregulating MDK repressed microglial activation and the inflammatory response of astrocytes.However,the mi R-124-3 p-mediated anti-inflammatory effects were reversed by HOXA11-AS.These findings suggest that HOXA11-AS can aggravate neuroinflammation after traumatic brain injury by modulating the mi R-124-3 p-MDK axis.This study was approved by the Animal Protection and Use Committee of Southwest Medical University(approval No.SMU-2019-042)on February 4,2019.
基金supported by the National Natural Science Foundation of China(No.81871908)Guangdong Provincial Natural Science Foundation(Nos.2018A030313715,2022A1515012202)+3 种基金Guangzhou Science and Technology plan-General Project(No.201904010036)Research Project Fund of Sun Yat-sen University(No.2015013)National Natural Science Foundation of China(No.82070529)General projects of Guangdong Provincial Natural Science Foundation(No.2021A1515010791).
文摘Background:Long non-coding RNAs(lncRNAs)plays an important role in the progression of gastric cancer(GC).Their involvement ranges from genetic regulation to cancer progression.However,the mechanistic roles of RP11-789C1.1 in GC are not fully understood.Methods:We identified the expression of lncRNA RP11-789C1.1 in GC tissues and cell lines by real-time fluorescent quantitative polymerase chain reaction.A series of functional experiments revealed the effect of RP11-789C1.1 on the proliferation of GC cells.In vivo experiments verified the effect of RP11-789C1.1 on the biological behavior of a GC cell line.RNA pull-down unveiled RP11-789C1.1 interacting proteins.Western blot analysis indicated the downstream pathway changes of RP11-789C1.1,and an oxaliplatin dosing experiment disclosed the influence of RP11-789C1.1 on the drug sensitivity of oxaliplatin.Results:Our results demonstrated that RP11-789C1.1 inhibited the proliferation of GC cells and promoted the apoptosis of GC cells.Mechanistically,RP11-789C1.1 inhibited checkpoint kinase 1(CHK1)phosphorylation by binding ataxiatelangiectasia mutated and Rad3 related(ATR),a serine/threonine-specific protein kinase,promoted GC apoptosis,and mediated oxaliplatin sensitivity.Conclusion:In general,we discovered a tumor suppressor molecule RP11-789C1.1 and confirmed its mechanism of action,providing a theoretical basis for targeted GC therapy.