Circular RNAs(circRNAs)have been recognized as pivotal regulators in tumorigenesis,yet the biological functions as well as molecular mechanisms of the majority of circRNAs in hepatocellular carcinoma(HCC)remain elusiv...Circular RNAs(circRNAs)have been recognized as pivotal regulators in tumorigenesis,yet the biological functions as well as molecular mechanisms of the majority of circRNAs in hepatocellular carcinoma(HCC)remain elusive.We sought to unveil the expression profile and biological role of circMYBL2 in HCC.Initial microarray analyses were conducted to probe the expression profile of circMYBL2 in HCC cells,and qRT‒PCR analysis was then performed in HCC cell lines and tissues,revealing significant upregulation of circMYBL2.Subsequent experiments were conducted to evaluate the biological function of circMYBL2 in HCC progression.Furthermore,bioinformatics analysis,qRT‒PCR analysis,luciferase reporter assays,and western blot analysis were employed to investigate the interplay among circMYBL2,miR-1205,and E2F1.CircMYBL2 was found to exhibit marked upregulation in tumor tissues as well as HCC cell lines.Elevated expression of circMYBL2 increased the proliferation and migration of HCC cells,whereas circMYBL2 knockdown elicited contrasting effects.Mechanistically,our results indicated that circMYBL2 promoted E2F1 expression and facilitated HCC progression by sponging miR-1205.Our findings revealed that circMYBL2 contributed to HCC progression through the circMYBL2/miR-1205/E2F1 axis,suggesting the potential of circMYBL2 as a novel target for HCC treatment or a prognostic biomarker for HCC.展开更多
Background: Apolipoprotein E2(ApoE2) is a pleiotropic protein that influences several aspects of cancer metabolism and development. Evading apoptosis is a vital factor for facilitating cancer cell growth. However, the...Background: Apolipoprotein E2(ApoE2) is a pleiotropic protein that influences several aspects of cancer metabolism and development. Evading apoptosis is a vital factor for facilitating cancer cell growth. However, the role and mechanism of ApoE2 in regulating cell apoptosis of pancreatic cancer remain unclear. Methods: In this study, we firstly detected the m RNA and protein expressions of ApoE2 in PANC-1 and Capan-2 cells by real-time polymerase chain reaction and Western blotting. We then performed TUNEL and flow cytometric analyses to explore the role of recombinant human ApoE2, p CMV6-ApoE2 and si ApoE2 in the apoptosis of PANC-1 and Capan-2 cells. Furthermore, we investigated the molecular mechanism through which ApoE2 affected apoptosis in PANC-1 cells using immunofluorescence, immunoprecipitation, Western blotting and co-immunoprecipitation analysis. Results: ApoE2 phosphorylated ERK1/2 and inhibited pancreatic cancer cell apoptosis. In addition, our data showed that ApoE2/ERK1/2 altered the expression and mitochondrial localization of BCL-2 via activating CREB. ApoE2/ERK1/2/CREB also increased the total BCL-2/BAX ratio, inhibited the opening of the mitochondrial permeability transition pore and the depolarization of mitochondrial transmembrane potential, blocked the leakage of cytochrome-c and the formation of the apoptosome, and consequently, suppressed mitochondrial apoptosis. Conclusions: ApoE2 regulates the mitochondrial localization and expression of BCL-2 through the activation of the ERK1/2/CREB signaling cascade to evade the mitochondrial apoptosis of pancreatic cancer cells. ApoE2 may be a distinct prognostic marker and a potential therapeutic target for pancreatic cancer.展开更多
Objective:Epidermal growth factor receptor variant III(EGFRvIII)is a constitutively-activated mutation of EGFR that contributes to the malignant progression of glioblastoma multiforme(GBM).Temozolomide(TMZ)is a standa...Objective:Epidermal growth factor receptor variant III(EGFRvIII)is a constitutively-activated mutation of EGFR that contributes to the malignant progression of glioblastoma multiforme(GBM).Temozolomide(TMZ)is a standard chemotherapeutic for GBM,but TMZ treatment benefits are compromised by chemoresistance.This study aimed to elucidate the crucial mechanisms leading to EGFRvIII and TMZ resistance.Methods:CRISPR-Cas13a single-cell RNA-seq was performed to thoroughly mine EGFRvIII function in GBM.Western blot,realtime PCR,flow cytometry,and immunofluorescence were used to determine the chemoresistance role of E2F1 and RAD51-associated protein 1(RAD51AP1).Results:Bioinformatic analysis identified E2F1 as the key transcription factor in EGFRvIII-positive living cells.Bulk RNA-seq analysis revealed that E2F1 is a crucial transcription factor under TMZ treatment.Western blot suggested enhanced expression of E2F1 in EGFRvIII-positive and TMZ-treated glioma cells.Knockdown of E2F1 increased sensitivity to TMZ.Venn diagram profiling showed that RAD51AP1 is positively correlated with E2F1,mediates TMZ resistance,and has a potential E2F1 binding site on the promoter.Knockdown of RAD51AP1 enhanced the sensitivity of TMZ;however,overexpression of RAD51AP1 was not sufficient to cause chemotherapy resistance in glioma cells.Furthermore,RAD51AP1 did not impact TMZ sensitivity in GBM cells with high O6-methylguanine-DNA methyltransferase(MGMT)expression.The level of RAD51AP1 expression correlated with the survival rate in MGMT-methylated,but not MGMT-unmethylated TMZ-treated GBM patients.Conclusions:Our results suggest that E2F1 is a key transcription factor in EGFRvIII-positive glioma cells and quickly responds to TMZ treatment.RAD51AP1 was shown to be upregulated by E2F1 for DNA double strand break repair.Targeting RAD51AP1 could facilitate achieving an ideal therapeutic effect in MGMT-methylated GBM cells.展开更多
BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its ro...BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its role in hepatocellular carcinoma(HCC)has not been fully deciphered.AIM To decipher the role of CDKN2B-AS1 in the progression of HCC.METHODS CDKN2B-AS1 expression in HCC was detected by quantitative real-time polymerase chain reaction.The malignant phenotypes of Li-7 and SNU-182 cells were detected by the CCK-8 method,EdU method,and flow cytometry,respectively.RNA immunoprecipitation was executed to confirm the interaction between CDKN2B-AS1 and E2F transcription factor 1(E2F1).Luciferase reporter assay and chromatin immunoprecipitation were performed to verify the binding of E2F1 to the promoter of G protein subunit alpha Z(GNAZ).E2F1 and GNAZ were detected by western blot in HCC cells.RESULTS In HCC tissues,CDKN2B-AS1 was upregulated.Depletion of CDKN2B-AS1 inhibited the proliferation of HCC cells,and the depletion of CDKN2B-AS1 also induced cell cycle arrest and apoptosis.CDKN2B-AS1 could interact with E2F1.Depletion of CDKN2B-AS1 inhibited the binding of E2F1 to the GNAZ promoter region.Overexpression of E2F1 reversed the biological effects of depletion of CDKN2B-AS1 on the malignant behaviors of HCC cells.CONCLUSION CDKN2B-AS1 recruits E2F1 to facilitate GNAZ transcription to promote HCC progression.展开更多
Objective: Growing evidence indicates that FAT atypical cadherin 1(FAT1) has aberrant genetic alterations and exhibits potential tumor suppressive function in esophageal squamous cell carcinoma(ESCC). However, the rol...Objective: Growing evidence indicates that FAT atypical cadherin 1(FAT1) has aberrant genetic alterations and exhibits potential tumor suppressive function in esophageal squamous cell carcinoma(ESCC). However, the role of FAT1 in ESCC tumorigenesis remains not well elucidated. The aim of this study was to further investigate genetic alterations and biological functions of FAT1, as well as to explore its transcriptional regulation and downstream targets in ESCC.Methods: The mutations of FAT1 in ESCC were achieved by analyzing a combined study from seven published genomic data, while the copy number variants of FAT1 were obtained from an analysis of our previous data as well as of The Cancer Genome Atlas(TCGA) and Cancer Cell Line Encyclopedia(CCLE) databases using the cBioPortal. The transcriptional regulation of FAT1 expression was investigated by chromatin immunoprecipitation(ChIP) and the luciferase reporter assays. In-cell western, Western blot and reverse transcription-quantitative polymerase chain reaction(RT-qPCR) were used to assess the indicated gene expression. In addition, colony formation and Transwell migration/invasion assays were employed to test cell proliferation, migration and invasion.Finally, RNA sequencing was used to study the transcriptomes.Results: FAT1 was frequently mutated in ESCC and was deleted in multiple cancers. Furthermore, the transcription factor E2 F1 occupied the promoter region of FAT1, and depletion of E2 F1 led to a decrease in transcription activity and mRNA levels of FAT1. Moreover, we found that knockdown of FAT1 promoted KYSE30 and KYSE150 cell proliferation, migration and invasion;while overexpression of FAT1 inhibited KYSE30 and KYSE410 cell proliferation, migration and invasion. In addition, knockdown of FAT1 led to enrichment of the mitogen-activated protein kinase(MAPK) signaling pathway and cell adhesion process.Conclusions: Our data provided evidence for the tumor suppressive function of FAT1 in ESCC cells and elucidated the transcriptional regulation of FAT1 by E2 F1, which may facilitate the understanding of molecular mechanisms of the progression of ESCC.展开更多
Objective:Mitochondria play multifunctional roles in carcinogenesis.Deciphering uncertainties of molecular interactions within mitochondria will promote further understanding of cancer.Interleukin enhancer binding fac...Objective:Mitochondria play multifunctional roles in carcinogenesis.Deciphering uncertainties of molecular interactions within mitochondria will promote further understanding of cancer.Interleukin enhancer binding factor 2(ILF2)is upregulated in several malignancies,however,much remains unknown regarding ILF2 in small cell lung cancer(SCLC).In the current study,we explored ILF2's role in SCLC and demonstrated its importance in mitochondria quality control.Methods:Colony formation,cell proliferation,cell viability and xenograft studies were performed to examine ILF2's role on SCLC progression.Glucose uptake,lactate production,cellular oxygen consumption rate and extracellular acidification rate were measured to examine the effect of ILF2 on glucose metabolism.RNA-sequencing was utilized to explore genes regulated by ILF2.E2 F1 transcriptional activity was determined by dual luciferase reporter assay.Mitochondria quantification and mitochondrial membrane potential assays were performed to examine mitochondrial quality.Gene expression was determined by RT-qPCR,Western blot and IHC assay.Results:ILF2 promotes SCLC tumor growth in vitro and in vivo.ILF2 elevates oxidative phosphorylation expression and declines glucose intake and lactate production.Genome-wide analysis of ILF2 targets identified a cohort of genes regulated by E2 F1.In consistent with this,we found ILF2 interacts with E2 F1 in SCLC cells.Further studies demonstrated that suppression of E2 F1 expression could reverse ILF2-induced tumor growth and enhanced mitochondria function.Significantly,expression of ILF2 is progressively increased during SCLC progression and high ILF2 expression is correlated with higher histologic grades,which indicates ILF2's oncogenic role in SCLC.Conclusions:Our results demonstrate that ILF2 interacts with E2 F1 to maintain mitochondria quality and confers SCLC cells growth advantage in tumorigenesis.展开更多
BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the ...BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the effect of miR-34c and its upstream transcription factor E2F1 on paclitaxel combined with cisplatin resistance in GC cells.METHODS Paired GC tissues and adjacent normal tissues were randomly sampled from 74 GC patients.miR-34c and E2F1 were detected by real-time quantitative PCR(qPCR)and Western blot.In addition,the drug resistance of GC cells to paclitaxel and cisplatin was induced by concentration gradient increasing methods,and changes in miR-34c and E2F1 during this process were measured.Furthermore,E2F1 and miR-34c overexpression or underexpression vectors were constructed and transfected into drug-resistant GC cells.MTT was employed to test the sensitivity of cells to paclitaxel combined with cisplatin,qPCR was adopted to detect the expression of miR-34c,Western blot was applied to detect the expression levels of E2F1,drug resistance-related proteins and apoptosis-related proteins,and flow cytometry was used for the determination of cell apoptosis and cell cycle status.RESULTS E2F1 was overexpressed while miR-34c was underexpressed in GC.After inducing GC cells to be resistant to paclitaxel and cisplatin,E2F1 expression increased while miR-34c expression decreased.Both silencing E2F1 and overexpressing miR-34c could increase the sensitivity of drug-resistant GC cells to paclitaxel combined with cisplatin,promote cell apoptosis and inhibit cell proliferation.Among which,silencing E2F1 could reduce the expression of drug resistance-related proteins and apoptosis-related proteins,while over-expression of miR-34c could upregulate the expression of apoptosis-related proteins without affecting the expression of MDR-1,MRP and other drug resistance-related proteins.Rescue experiments demonstrated that inhibiting miR-34c could significantly weaken the sensitization of drug resistant cells,and Si E2F1 to paclitaxel combined with cisplatin.CONCLUSION E2F1 inhibits miR-34c to promote the proliferation of GC cells and enhance the resistance to paclitaxel combined with cisplatin,and silencing E2F1 is conducive to improving the efficacy of paclitaxel combined with cisplatin in GC cells.展开更多
Certain pseudogenes may regulate their protein-coding cousins by competing for miRNAs and play an active biological role in cancer. However, few studies have focused on the association of genetic variations in pseudog...Certain pseudogenes may regulate their protein-coding cousins by competing for miRNAs and play an active biological role in cancer. However, few studies have focused on the association of genetic variations in pseudogenes with cancer prognosis. We selected six potentially functional single nucleotide polymorphisms (SNPs) in cancerrelated pseudogenes, and performed a case-only study to assess the association between those SNPs and the prognosis of hepatocellular carcinoma (HCC) in 331 HBV-positive HCC patients without surgical treatment. Log-rank test and Cox proportional hazard models were used for survival analysis. We found that the A allele of rs9909601 in E2F3P1 was significantly associated with a better prognosis compared with the G allele [adjusted hazard ratio (HR) = 0.69, 95% confidence interval (CI) = 0.56-0.86, P = 0.001]. Additionally, this protective effect was more predominant for patients without chemotherapy and transcatheter hepatic arterial chemoembolization (TACE) treatment. Interestingly, we also detected a statistically significant multiplicative interaction between genotypes of rs9909601 and chemotherapy or TACE status on HCC survival (P for multiplicative interaction 〈 0.001). These findings indicate that rs9909601 in the pseudogene E2F3P1 may be a genetic marker for HCC prognosis in Chinese.展开更多
Objective: To investigate the expression of E2F and Bc1-2 and the clinicopathological significance in hepatocellular carcinoma. Methods: The expressions of E2F-3 and Bc1-2 in 74 patients with hepatic carcinoma, paraca...Objective: To investigate the expression of E2F and Bc1-2 and the clinicopathological significance in hepatocellular carcinoma. Methods: The expressions of E2F-3 and Bc1-2 in 74 patients with hepatic carcinoma, paracarcinoma and 15 patients with liver cirrhosis were detected by S-P immunohistochemical staining. Results: The expression of E2F in hepatic carcinoma was significantly higher than that in paracarcinoma or liver cirrhosis (P<0.005), the expression of Bc1-2 in hepatic carcinoma was significantly higher than that in paracarcinoma (P<0.005), in which Bc1-2 expression was lower than in liver cirrhosis(P<0.05). The expression of E2F-3 was related with histological grade, tumor size, and the expression of Bc1-2 was related with histological grade, tumor size and tumor number. There was correlation between the expression of E2F-3 and Bc1-2 in hepatic carcinoma. Conclusion: E2F-3 and Bc1-2 expression may play an important role in development, progression and cell apoptosis of tumor.展开更多
In this study,we sought to investigate the expression of the transcription factor E2F1 in chicken pulmonary arterial smooth muscle cells upon hypoxia exposure,as well as the role that E2F1 played in the regulation of ...In this study,we sought to investigate the expression of the transcription factor E2F1 in chicken pulmonary arterial smooth muscle cells upon hypoxia exposure,as well as the role that E2F1 played in the regulation of cell proliferation.Isolated chicken pulmonary arterial smooth muscle cells were subjected to hypoxia or normoxia for indicated time points.Cell viability,DNA synthesis,cell cycle profile,and expression of E2F1 were analyzed.The results showed that hypoxia promoted cell proliferation and DNA synthesis which was accompanied by an increased S phase entry and upregulation of E2F1 at mRNA and protein levels.Using siRNA technology,we demonstrated that gene inactivation of endogenous E2F1 abolished hypoxia-induced cell proliferation,DNA synthesis,and S phase entry compared with negative siRNA transfected cells.These results suggest that hypoxia-induced proliferation is mediated by inducing E2F1 in chicken pulmonary arterial smooth muscle cells.展开更多
OBJECTIVE To investigate the correlation of E2F-1, Rb and ER expression with peripheral papilloma (Peri-PM) and ductal carcinoma in situ of the breast (DCIS), and further explore some molecular mechanisms of the c...OBJECTIVE To investigate the correlation of E2F-1, Rb and ER expression with peripheral papilloma (Peri-PM) and ductal carcinoma in situ of the breast (DCIS), and further explore some molecular mechanisms of the canceratin of Peri-PM.METHODS Imunohistochemistry was used to examine the expression of E2F-1, Rb and ER in 60 Peri-PM, 60 Peri-PM with atypical ductal hyperplasia (Peri-PM with ADH) and 60 DCIS. Normal breast tissues were selected as a control group.RESULTS Based on immunohistochemical staining, the positive rate of E2F-1 expression in Peri-PM, Peri-PM with ADH and DCIS was 21.7%, 46.7% and 78.3% respectively. The positive rate of Rb expression was 83.3 %, 53.9% and 21.7% and the ER expression was 86.7%,61.7% and 55.0%. Significant differences were found among the 3 groups (Peri-PM, Peri-PM with ADH and DCIS) (P〈0.05). Significant differences existed between any 2 groups (P〈0.05) except for the rate of ER positive expression comparing Peri-PM with ADH verus DCIS (P〉0.05). The expression of E2F-1 was nega- tively correlated with ER and Rb, and at the same time the expression of ER was positively correlated with Rb. Following the degree of breast epithelial hyperplasia involved and its development into carcinoma, the positive rate of E2F-1 expression displayed an elevating tendency, but that of Rb and ER expression showed a tendency to decline.CONCLUSION The interaction of the 3 indexes studied may play an important role in the conversion of precancerous lesions to early in situ breast carcinoma, and the evaluation of these indexes might provide a valuable basis for screening high-risk cases of Peri-PM.展开更多
基金supported by the Guangdong Basic and Applied Basic Research Foundation(No.2021A1515010403,Ning Lyu)Natural Science Foundation of Guangdong Province,China(No.1914050001553,Dong Chen).
文摘Circular RNAs(circRNAs)have been recognized as pivotal regulators in tumorigenesis,yet the biological functions as well as molecular mechanisms of the majority of circRNAs in hepatocellular carcinoma(HCC)remain elusive.We sought to unveil the expression profile and biological role of circMYBL2 in HCC.Initial microarray analyses were conducted to probe the expression profile of circMYBL2 in HCC cells,and qRT‒PCR analysis was then performed in HCC cell lines and tissues,revealing significant upregulation of circMYBL2.Subsequent experiments were conducted to evaluate the biological function of circMYBL2 in HCC progression.Furthermore,bioinformatics analysis,qRT‒PCR analysis,luciferase reporter assays,and western blot analysis were employed to investigate the interplay among circMYBL2,miR-1205,and E2F1.CircMYBL2 was found to exhibit marked upregulation in tumor tissues as well as HCC cell lines.Elevated expression of circMYBL2 increased the proliferation and migration of HCC cells,whereas circMYBL2 knockdown elicited contrasting effects.Mechanistically,our results indicated that circMYBL2 promoted E2F1 expression and facilitated HCC progression by sponging miR-1205.Our findings revealed that circMYBL2 contributed to HCC progression through the circMYBL2/miR-1205/E2F1 axis,suggesting the potential of circMYBL2 as a novel target for HCC treatment or a prognostic biomarker for HCC.
基金supported by grants from the National Natural Science Foundation of China (31370861)the Tianjin Basic Re-search Plan Project (13JCZDJC31300)。
文摘Background: Apolipoprotein E2(ApoE2) is a pleiotropic protein that influences several aspects of cancer metabolism and development. Evading apoptosis is a vital factor for facilitating cancer cell growth. However, the role and mechanism of ApoE2 in regulating cell apoptosis of pancreatic cancer remain unclear. Methods: In this study, we firstly detected the m RNA and protein expressions of ApoE2 in PANC-1 and Capan-2 cells by real-time polymerase chain reaction and Western blotting. We then performed TUNEL and flow cytometric analyses to explore the role of recombinant human ApoE2, p CMV6-ApoE2 and si ApoE2 in the apoptosis of PANC-1 and Capan-2 cells. Furthermore, we investigated the molecular mechanism through which ApoE2 affected apoptosis in PANC-1 cells using immunofluorescence, immunoprecipitation, Western blotting and co-immunoprecipitation analysis. Results: ApoE2 phosphorylated ERK1/2 and inhibited pancreatic cancer cell apoptosis. In addition, our data showed that ApoE2/ERK1/2 altered the expression and mitochondrial localization of BCL-2 via activating CREB. ApoE2/ERK1/2/CREB also increased the total BCL-2/BAX ratio, inhibited the opening of the mitochondrial permeability transition pore and the depolarization of mitochondrial transmembrane potential, blocked the leakage of cytochrome-c and the formation of the apoptosome, and consequently, suppressed mitochondrial apoptosis. Conclusions: ApoE2 regulates the mitochondrial localization and expression of BCL-2 through the activation of the ERK1/2/CREB signaling cascade to evade the mitochondrial apoptosis of pancreatic cancer cells. ApoE2 may be a distinct prognostic marker and a potential therapeutic target for pancreatic cancer.
基金supported by the Science and Technology Project of Tianjin Municipal Health Commission(Grant Nos.TJWJ2022MS003 and TJWJ2021ZD008)the Tianjin Science and Technology Plan Project(Grant Nos.21JCYBJC01520 and 20JCYBJC01070)。
文摘Objective:Epidermal growth factor receptor variant III(EGFRvIII)is a constitutively-activated mutation of EGFR that contributes to the malignant progression of glioblastoma multiforme(GBM).Temozolomide(TMZ)is a standard chemotherapeutic for GBM,but TMZ treatment benefits are compromised by chemoresistance.This study aimed to elucidate the crucial mechanisms leading to EGFRvIII and TMZ resistance.Methods:CRISPR-Cas13a single-cell RNA-seq was performed to thoroughly mine EGFRvIII function in GBM.Western blot,realtime PCR,flow cytometry,and immunofluorescence were used to determine the chemoresistance role of E2F1 and RAD51-associated protein 1(RAD51AP1).Results:Bioinformatic analysis identified E2F1 as the key transcription factor in EGFRvIII-positive living cells.Bulk RNA-seq analysis revealed that E2F1 is a crucial transcription factor under TMZ treatment.Western blot suggested enhanced expression of E2F1 in EGFRvIII-positive and TMZ-treated glioma cells.Knockdown of E2F1 increased sensitivity to TMZ.Venn diagram profiling showed that RAD51AP1 is positively correlated with E2F1,mediates TMZ resistance,and has a potential E2F1 binding site on the promoter.Knockdown of RAD51AP1 enhanced the sensitivity of TMZ;however,overexpression of RAD51AP1 was not sufficient to cause chemotherapy resistance in glioma cells.Furthermore,RAD51AP1 did not impact TMZ sensitivity in GBM cells with high O6-methylguanine-DNA methyltransferase(MGMT)expression.The level of RAD51AP1 expression correlated with the survival rate in MGMT-methylated,but not MGMT-unmethylated TMZ-treated GBM patients.Conclusions:Our results suggest that E2F1 is a key transcription factor in EGFRvIII-positive glioma cells and quickly responds to TMZ treatment.RAD51AP1 was shown to be upregulated by E2F1 for DNA double strand break repair.Targeting RAD51AP1 could facilitate achieving an ideal therapeutic effect in MGMT-methylated GBM cells.
文摘BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its role in hepatocellular carcinoma(HCC)has not been fully deciphered.AIM To decipher the role of CDKN2B-AS1 in the progression of HCC.METHODS CDKN2B-AS1 expression in HCC was detected by quantitative real-time polymerase chain reaction.The malignant phenotypes of Li-7 and SNU-182 cells were detected by the CCK-8 method,EdU method,and flow cytometry,respectively.RNA immunoprecipitation was executed to confirm the interaction between CDKN2B-AS1 and E2F transcription factor 1(E2F1).Luciferase reporter assay and chromatin immunoprecipitation were performed to verify the binding of E2F1 to the promoter of G protein subunit alpha Z(GNAZ).E2F1 and GNAZ were detected by western blot in HCC cells.RESULTS In HCC tissues,CDKN2B-AS1 was upregulated.Depletion of CDKN2B-AS1 inhibited the proliferation of HCC cells,and the depletion of CDKN2B-AS1 also induced cell cycle arrest and apoptosis.CDKN2B-AS1 could interact with E2F1.Depletion of CDKN2B-AS1 inhibited the binding of E2F1 to the GNAZ promoter region.Overexpression of E2F1 reversed the biological effects of depletion of CDKN2B-AS1 on the malignant behaviors of HCC cells.CONCLUSION CDKN2B-AS1 recruits E2F1 to facilitate GNAZ transcription to promote HCC progression.
基金supported by the National Basic Research Program of China (973 Program) (No. 2015CB553906 and 2015CB553904)the National Natural Science Foundation of China (No. 81490753 and 81830086)the Education Department of Liaoning Province in China (Scientific Research Projects, No. L2016038)
文摘Objective: Growing evidence indicates that FAT atypical cadherin 1(FAT1) has aberrant genetic alterations and exhibits potential tumor suppressive function in esophageal squamous cell carcinoma(ESCC). However, the role of FAT1 in ESCC tumorigenesis remains not well elucidated. The aim of this study was to further investigate genetic alterations and biological functions of FAT1, as well as to explore its transcriptional regulation and downstream targets in ESCC.Methods: The mutations of FAT1 in ESCC were achieved by analyzing a combined study from seven published genomic data, while the copy number variants of FAT1 were obtained from an analysis of our previous data as well as of The Cancer Genome Atlas(TCGA) and Cancer Cell Line Encyclopedia(CCLE) databases using the cBioPortal. The transcriptional regulation of FAT1 expression was investigated by chromatin immunoprecipitation(ChIP) and the luciferase reporter assays. In-cell western, Western blot and reverse transcription-quantitative polymerase chain reaction(RT-qPCR) were used to assess the indicated gene expression. In addition, colony formation and Transwell migration/invasion assays were employed to test cell proliferation, migration and invasion.Finally, RNA sequencing was used to study the transcriptomes.Results: FAT1 was frequently mutated in ESCC and was deleted in multiple cancers. Furthermore, the transcription factor E2 F1 occupied the promoter region of FAT1, and depletion of E2 F1 led to a decrease in transcription activity and mRNA levels of FAT1. Moreover, we found that knockdown of FAT1 promoted KYSE30 and KYSE150 cell proliferation, migration and invasion;while overexpression of FAT1 inhibited KYSE30 and KYSE410 cell proliferation, migration and invasion. In addition, knockdown of FAT1 led to enrichment of the mitogen-activated protein kinase(MAPK) signaling pathway and cell adhesion process.Conclusions: Our data provided evidence for the tumor suppressive function of FAT1 in ESCC cells and elucidated the transcriptional regulation of FAT1 by E2 F1, which may facilitate the understanding of molecular mechanisms of the progression of ESCC.
基金supported by the National Natural Science Foundation of China (Grant No. 81602026)the Natural Science Foundation of Tianjin (Grant No. 18JCQNJC81600 and 18JCZDJC32600)
文摘Objective:Mitochondria play multifunctional roles in carcinogenesis.Deciphering uncertainties of molecular interactions within mitochondria will promote further understanding of cancer.Interleukin enhancer binding factor 2(ILF2)is upregulated in several malignancies,however,much remains unknown regarding ILF2 in small cell lung cancer(SCLC).In the current study,we explored ILF2's role in SCLC and demonstrated its importance in mitochondria quality control.Methods:Colony formation,cell proliferation,cell viability and xenograft studies were performed to examine ILF2's role on SCLC progression.Glucose uptake,lactate production,cellular oxygen consumption rate and extracellular acidification rate were measured to examine the effect of ILF2 on glucose metabolism.RNA-sequencing was utilized to explore genes regulated by ILF2.E2 F1 transcriptional activity was determined by dual luciferase reporter assay.Mitochondria quantification and mitochondrial membrane potential assays were performed to examine mitochondrial quality.Gene expression was determined by RT-qPCR,Western blot and IHC assay.Results:ILF2 promotes SCLC tumor growth in vitro and in vivo.ILF2 elevates oxidative phosphorylation expression and declines glucose intake and lactate production.Genome-wide analysis of ILF2 targets identified a cohort of genes regulated by E2 F1.In consistent with this,we found ILF2 interacts with E2 F1 in SCLC cells.Further studies demonstrated that suppression of E2 F1 expression could reverse ILF2-induced tumor growth and enhanced mitochondria function.Significantly,expression of ILF2 is progressively increased during SCLC progression and high ILF2 expression is correlated with higher histologic grades,which indicates ILF2's oncogenic role in SCLC.Conclusions:Our results demonstrate that ILF2 interacts with E2 F1 to maintain mitochondria quality and confers SCLC cells growth advantage in tumorigenesis.
文摘BACKGROUND MicroRNA 34c(miR-34c)has been reported to be associated with malignant types of cancer,however,it remains unknown whether miR-34c is involved in chemoresistance in gastric cancer(GC).AIM To investigate the effect of miR-34c and its upstream transcription factor E2F1 on paclitaxel combined with cisplatin resistance in GC cells.METHODS Paired GC tissues and adjacent normal tissues were randomly sampled from 74 GC patients.miR-34c and E2F1 were detected by real-time quantitative PCR(qPCR)and Western blot.In addition,the drug resistance of GC cells to paclitaxel and cisplatin was induced by concentration gradient increasing methods,and changes in miR-34c and E2F1 during this process were measured.Furthermore,E2F1 and miR-34c overexpression or underexpression vectors were constructed and transfected into drug-resistant GC cells.MTT was employed to test the sensitivity of cells to paclitaxel combined with cisplatin,qPCR was adopted to detect the expression of miR-34c,Western blot was applied to detect the expression levels of E2F1,drug resistance-related proteins and apoptosis-related proteins,and flow cytometry was used for the determination of cell apoptosis and cell cycle status.RESULTS E2F1 was overexpressed while miR-34c was underexpressed in GC.After inducing GC cells to be resistant to paclitaxel and cisplatin,E2F1 expression increased while miR-34c expression decreased.Both silencing E2F1 and overexpressing miR-34c could increase the sensitivity of drug-resistant GC cells to paclitaxel combined with cisplatin,promote cell apoptosis and inhibit cell proliferation.Among which,silencing E2F1 could reduce the expression of drug resistance-related proteins and apoptosis-related proteins,while over-expression of miR-34c could upregulate the expression of apoptosis-related proteins without affecting the expression of MDR-1,MRP and other drug resistance-related proteins.Rescue experiments demonstrated that inhibiting miR-34c could significantly weaken the sensitization of drug resistant cells,and Si E2F1 to paclitaxel combined with cisplatin.CONCLUSION E2F1 inhibits miR-34c to promote the proliferation of GC cells and enhance the resistance to paclitaxel combined with cisplatin,and silencing E2F1 is conducive to improving the efficacy of paclitaxel combined with cisplatin in GC cells.
基金funded by the National Natural Science Foundation of China(81372606 and 81072344)supported by the National Key Basic Research Program Grant(2013CB911400)+6 种基金the project supportedby the National Science Foundation for Distinguished Young Scholarsof China(81225020)Foundation of Jiangsu Province for Distinguished Young Scholars(BK2012042)Foundation for the Program for NewCentury Excellent Talents in University(NCET-10-0178)the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions(122031)Young Tip-top Talents Support Program by the Organization Department of the CPC Central Committee,the Author of National Excellent Doctoral Dissertation(201081)Jiangsu Province Clinical Science and Technology Projects(BL2012008)the Priority Academic Program for the Development of Jiangsu Higher Education Institutions(Public Health and PreventiveMedicine)
文摘Certain pseudogenes may regulate their protein-coding cousins by competing for miRNAs and play an active biological role in cancer. However, few studies have focused on the association of genetic variations in pseudogenes with cancer prognosis. We selected six potentially functional single nucleotide polymorphisms (SNPs) in cancerrelated pseudogenes, and performed a case-only study to assess the association between those SNPs and the prognosis of hepatocellular carcinoma (HCC) in 331 HBV-positive HCC patients without surgical treatment. Log-rank test and Cox proportional hazard models were used for survival analysis. We found that the A allele of rs9909601 in E2F3P1 was significantly associated with a better prognosis compared with the G allele [adjusted hazard ratio (HR) = 0.69, 95% confidence interval (CI) = 0.56-0.86, P = 0.001]. Additionally, this protective effect was more predominant for patients without chemotherapy and transcatheter hepatic arterial chemoembolization (TACE) treatment. Interestingly, we also detected a statistically significant multiplicative interaction between genotypes of rs9909601 and chemotherapy or TACE status on HCC survival (P for multiplicative interaction 〈 0.001). These findings indicate that rs9909601 in the pseudogene E2F3P1 may be a genetic marker for HCC prognosis in Chinese.
文摘Objective: To investigate the expression of E2F and Bc1-2 and the clinicopathological significance in hepatocellular carcinoma. Methods: The expressions of E2F-3 and Bc1-2 in 74 patients with hepatic carcinoma, paracarcinoma and 15 patients with liver cirrhosis were detected by S-P immunohistochemical staining. Results: The expression of E2F in hepatic carcinoma was significantly higher than that in paracarcinoma or liver cirrhosis (P<0.005), the expression of Bc1-2 in hepatic carcinoma was significantly higher than that in paracarcinoma (P<0.005), in which Bc1-2 expression was lower than in liver cirrhosis(P<0.05). The expression of E2F-3 was related with histological grade, tumor size, and the expression of Bc1-2 was related with histological grade, tumor size and tumor number. There was correlation between the expression of E2F-3 and Bc1-2 in hepatic carcinoma. Conclusion: E2F-3 and Bc1-2 expression may play an important role in development, progression and cell apoptosis of tumor.
基金supported by the Yangtze River Scholar and Innovation Research Team Development Program(Project No.IRT0945)grants from the National Natural Science Foundation of China(NO.30700576,31172225,31272451)State Key Laboratory of Animal Nutrition(Project No.2004DA125184-0807)
文摘In this study,we sought to investigate the expression of the transcription factor E2F1 in chicken pulmonary arterial smooth muscle cells upon hypoxia exposure,as well as the role that E2F1 played in the regulation of cell proliferation.Isolated chicken pulmonary arterial smooth muscle cells were subjected to hypoxia or normoxia for indicated time points.Cell viability,DNA synthesis,cell cycle profile,and expression of E2F1 were analyzed.The results showed that hypoxia promoted cell proliferation and DNA synthesis which was accompanied by an increased S phase entry and upregulation of E2F1 at mRNA and protein levels.Using siRNA technology,we demonstrated that gene inactivation of endogenous E2F1 abolished hypoxia-induced cell proliferation,DNA synthesis,and S phase entry compared with negative siRNA transfected cells.These results suggest that hypoxia-induced proliferation is mediated by inducing E2F1 in chicken pulmonary arterial smooth muscle cells.
基金the Research Program of Tianjin City Government in China (No.993607811)
文摘OBJECTIVE To investigate the correlation of E2F-1, Rb and ER expression with peripheral papilloma (Peri-PM) and ductal carcinoma in situ of the breast (DCIS), and further explore some molecular mechanisms of the canceratin of Peri-PM.METHODS Imunohistochemistry was used to examine the expression of E2F-1, Rb and ER in 60 Peri-PM, 60 Peri-PM with atypical ductal hyperplasia (Peri-PM with ADH) and 60 DCIS. Normal breast tissues were selected as a control group.RESULTS Based on immunohistochemical staining, the positive rate of E2F-1 expression in Peri-PM, Peri-PM with ADH and DCIS was 21.7%, 46.7% and 78.3% respectively. The positive rate of Rb expression was 83.3 %, 53.9% and 21.7% and the ER expression was 86.7%,61.7% and 55.0%. Significant differences were found among the 3 groups (Peri-PM, Peri-PM with ADH and DCIS) (P〈0.05). Significant differences existed between any 2 groups (P〈0.05) except for the rate of ER positive expression comparing Peri-PM with ADH verus DCIS (P〉0.05). The expression of E2F-1 was nega- tively correlated with ER and Rb, and at the same time the expression of ER was positively correlated with Rb. Following the degree of breast epithelial hyperplasia involved and its development into carcinoma, the positive rate of E2F-1 expression displayed an elevating tendency, but that of Rb and ER expression showed a tendency to decline.CONCLUSION The interaction of the 3 indexes studied may play an important role in the conversion of precancerous lesions to early in situ breast carcinoma, and the evaluation of these indexes might provide a valuable basis for screening high-risk cases of Peri-PM.