Objective:Pancreatic ductal adenocarcinoma(PDAC)is a highly malignant gastrointestinal cancer with a 5-year survival rate of only 9%.Of PDAC patients,15%-20%are eligible for radical surgery.Gemcitabine is an important...Objective:Pancreatic ductal adenocarcinoma(PDAC)is a highly malignant gastrointestinal cancer with a 5-year survival rate of only 9%.Of PDAC patients,15%-20%are eligible for radical surgery.Gemcitabine is an important chemotherapeutic agent for patients with PDAC;however,the efficacy of gemcitabine is limited due to resistance.Therefore,reducing gemcitabine resistance is essential for improving survival of patients with PDAC.Identifying the key target that determines gemcitabine resistance in PDAC and reversing gemcitabine resistance using target inhibitors in combination with gemcitabine are crucial steps in the quest to improve survival prognosis in patients with PDAC.Methods:We constructed a human genome-wide CRISPRa/dCas 9 overexpression library in PDAC cell lines to screen key targets of drug resistance based on sgRNA abundance and enrichment.Then,co-IP,ChIP,ChIP-seq,transcriptome sequencing,and qPCR were used to determine the specific mechanism by which phospholipase D1(PLD1)confers resistance to gemcitabine.Results:PLD1 combines with nucleophosmin 1(NPM1)and triggers NPM1 nuclear translocation,where NPM1 acts as a transcription factor to upregulate interleukin 7 receptor(IL7R)expression.Upon interleukin 7(IL-7)binding,IL7R activates the JAK1/STAT5 signaling pathway to increase the expression of the anti-apoptotic protein,BCL-2,and induce gemcitabine resistance.The PLD1 inhibitor,Vu0155069,targets PLD1 to induce apoptosis in gemcitabine-resistant PDAC cells.Conclusions:PLD1 is an enzyme that has a critical role in PDAC-associated gemcitabine resistance through a non-enzymatic interaction with NPM1,further promoting the downstream JAK1/STAT5/Bcl-2 pathway.Inhibiting any of the participants of this pathway can increase gemcitabine sensitivity.展开更多
VEGF inhibitors are one of the most successful antiangiogenic drugs in the treatment of many solid tumors.Nevertheless,pancreatic adenocarcinoma(PAAD)cells can reinstate tumor angiogenesis via activation of VEGF-indep...VEGF inhibitors are one of the most successful antiangiogenic drugs in the treatment of many solid tumors.Nevertheless,pancreatic adenocarcinoma(PAAD)cells can reinstate tumor angiogenesis via activation of VEGF-independent pathways,thereby conferring resistance to VEGF inhibitors.Bioinformatic analysis showed that BICC1 was one of the top genes involved in the specific angiogenesis process of PAAD.The analysis of our own cohort confirmed that BICC1 was overexpressed in human PAAD tissues and was correlated to increased microvessel density and tumor growth,and worse prognosis.In cells and mice with xenograft tumors,BICC1 facilitated angiogenesis in pancreatic cancer in a VEGF-independent manner.Mechanistically,as an RNA binding protein,BICC1 bounds to the 3’UTR of Lipocalin-2(LCN2)mRNA and post-transcriptionally up-regulated LCN2 expression in PAAD cells.When its level is elevated,LCN2 binds to its receptor 24p3R,which directly phosphorylates JAK2 and activates JAK2/STAT3 signal,leading to increased production of an angiogenic factor CXCL1.Blocking of the BICC1/LCN2 signalling reduced the microvessel density and tumor volume of PAAD cell grafts in mice,and increased the tumor suppressive effect of gemcitabine.In conclusion,BICC1 plays a pivotal role in the process of VEGF-independent angiogenesis in pancreatic cancer,leading to resistance to VEGF inhibitors.BICC1/LCN2 signaling may serve as a promising anti-angiogenic therapeutic target for pancreatic cancer patients.展开更多
Toll-like receptors （TLRs） are sentinels of the host defense system, which recognize a large number of microbial pathogens. The host defense system may be inefficient or inflammatory diseases may develop if microbia...Toll-like receptors （TLRs） are sentinels of the host defense system, which recognize a large number of microbial pathogens. The host defense system may be inefficient or inflammatory diseases may develop if microbial recognition by TLRs and subsequent TLR-triggered cytokine production are deregulated. Activating transcription factor 4 （ATF4）, a member of the ATF/CREB transcription factor family, is an important factor that participates in several pathophysiological processes. In this report, we found that ATF4 is also involved in the TLR-mediated innate immune response, which participates in TLR4 signal transduction and mediates the secretion of a variety of cytokines. We observed that ATF4 is activated and translocates to the nucleus following l ipopolysaccharide （LPS） stimulation via the TLR4-MyD88-dependent pathway. Additionally, a cytokine array assay showed that some key inflammatory cytokines, such as I L-6, I L-8 and RANTES, are positively regulated by ATF4. We also demonstrate that c-Jun directly binds to ATF4, thereby promoting the secretion of inflammatory cytokines. Taken together, these results indicate that ATF4 acts as a positive regulator in TLR4-triggered cytokine production.展开更多
Metastases are the main cause of cancer-related mortality in breast cancer.Although significant progress has been made in the field of tumor metastasis,the exact molecular mechanisms involved in tumor metastasis are s...Metastases are the main cause of cancer-related mortality in breast cancer.Although significant progress has been made in the field of tumor metastasis,the exact molecular mechanisms involved in tumor metastasis are still unclear.Here,we report that ATOH8-V1,a novel isoform of ATOH8,is highly expressed in breast cancer and is a negative prognostic indicator of survival for patients.Forced expression of ATOH8-V1 dramatically enhances,while silencing of ATOH8-V1 decreases the metastasis of breast cancer cell lines.Moreover,ATOH8-V1 directly binds to the RhoC promoter and stimulates the expression of RhoC,which in turn enhances the metastasis of breast cancer.Altogether,our data demonstrate that ATOH8-V1 is a novel pro-metastatic factor that enhances cancer metastasis,suggesting that AT0H8-V1 is a potential therapeutic target for treatment of metastatic cancers.展开更多
TIFA,also called T2BP,was first identified using yeast two-hybrid screening.Our previous work showed that TIFA suppresses hepatocellular carcinoma(HCC)progression via apoptosis and cell cycle arrest.However,the mechan...TIFA,also called T2BP,was first identified using yeast two-hybrid screening.Our previous work showed that TIFA suppresses hepatocellular carcinoma(HCC)progression via apoptosis and cell cycle arrest.However,the mechanism by which this TIFA suppression occurs remains unclear.Here we demonstrated that TIFA-induced apoptosis demonstrates two distinct time patterns(i.e.,at 48 h and 47 days)when TIFA reconstitution occurs.Moreover,we found that MALT1(a competitor of TIFA)plays a crucial role in short-duration TIFA reconstitution.In this regard,MALT1 silencing with shRNA markedly enhances TIFA-induced apoptosis in vitro and in vivo.In addition,TIFA overexpression triggers JNK and p38 activation in long-duration TIFA reconstitution through TRAF6 binding.In particular,JNK activation leads to TIFA-induced apoptosis while p38 activation governs TIFA-induced cell cycle arrest by p53-p21 signaling in vitro and in vivo.Our data suggest a novel mechanism by which TIFA suppresses HCC progression via both MALT1-dependent and MALT1-independent signaling pathways.This may provide insights into a novel targets where HCC progression may be vulnerable to clinical treatment.展开更多
基金supported by the National Key Research and Development Program of China(Grant No.2021YFA1201100)the National Natural Science Foundation of China(Grant Nos.82103006,82030092,81720108028,82072657,82072716,82103003,82173295,81871968,81871978,82072691,and 82103222)+1 种基金the Tianjin Hygiene Healthy Science and Technology Project(Grant No.TJWJ2022MS007)the Science&Technology Development Fund of Tianjin Education Commission for Higher Education(Grant No.2020KJ141).
文摘Objective:Pancreatic ductal adenocarcinoma(PDAC)is a highly malignant gastrointestinal cancer with a 5-year survival rate of only 9%.Of PDAC patients,15%-20%are eligible for radical surgery.Gemcitabine is an important chemotherapeutic agent for patients with PDAC;however,the efficacy of gemcitabine is limited due to resistance.Therefore,reducing gemcitabine resistance is essential for improving survival of patients with PDAC.Identifying the key target that determines gemcitabine resistance in PDAC and reversing gemcitabine resistance using target inhibitors in combination with gemcitabine are crucial steps in the quest to improve survival prognosis in patients with PDAC.Methods:We constructed a human genome-wide CRISPRa/dCas 9 overexpression library in PDAC cell lines to screen key targets of drug resistance based on sgRNA abundance and enrichment.Then,co-IP,ChIP,ChIP-seq,transcriptome sequencing,and qPCR were used to determine the specific mechanism by which phospholipase D1(PLD1)confers resistance to gemcitabine.Results:PLD1 combines with nucleophosmin 1(NPM1)and triggers NPM1 nuclear translocation,where NPM1 acts as a transcription factor to upregulate interleukin 7 receptor(IL7R)expression.Upon interleukin 7(IL-7)binding,IL7R activates the JAK1/STAT5 signaling pathway to increase the expression of the anti-apoptotic protein,BCL-2,and induce gemcitabine resistance.The PLD1 inhibitor,Vu0155069,targets PLD1 to induce apoptosis in gemcitabine-resistant PDAC cells.Conclusions:PLD1 is an enzyme that has a critical role in PDAC-associated gemcitabine resistance through a non-enzymatic interaction with NPM1,further promoting the downstream JAK1/STAT5/Bcl-2 pathway.Inhibiting any of the participants of this pathway can increase gemcitabine sensitivity.
基金National Natural Science Foundation of China(grants 82272680,82072659,81871978,81772633,82272799,81720108028,81525021,81502067,81302082,81272685,31301151,81172355,31471340,31470957,81472264,and 81401957)National Key R&D Program of China(grants 2020YFA0803704)+1 种基金Tianjin Science Foundation for Distinguished Young Scholars(grants 19JCJQJC63100)NIH grant R01CA233844,R01CA256911(to S.Y.).
文摘VEGF inhibitors are one of the most successful antiangiogenic drugs in the treatment of many solid tumors.Nevertheless,pancreatic adenocarcinoma(PAAD)cells can reinstate tumor angiogenesis via activation of VEGF-independent pathways,thereby conferring resistance to VEGF inhibitors.Bioinformatic analysis showed that BICC1 was one of the top genes involved in the specific angiogenesis process of PAAD.The analysis of our own cohort confirmed that BICC1 was overexpressed in human PAAD tissues and was correlated to increased microvessel density and tumor growth,and worse prognosis.In cells and mice with xenograft tumors,BICC1 facilitated angiogenesis in pancreatic cancer in a VEGF-independent manner.Mechanistically,as an RNA binding protein,BICC1 bounds to the 3’UTR of Lipocalin-2(LCN2)mRNA and post-transcriptionally up-regulated LCN2 expression in PAAD cells.When its level is elevated,LCN2 binds to its receptor 24p3R,which directly phosphorylates JAK2 and activates JAK2/STAT3 signal,leading to increased production of an angiogenic factor CXCL1.Blocking of the BICC1/LCN2 signalling reduced the microvessel density and tumor volume of PAAD cell grafts in mice,and increased the tumor suppressive effect of gemcitabine.In conclusion,BICC1 plays a pivotal role in the process of VEGF-independent angiogenesis in pancreatic cancer,leading to resistance to VEGF inhibitors.BICC1/LCN2 signaling may serve as a promising anti-angiogenic therapeutic target for pancreatic cancer patients.
文摘Toll-like receptors （TLRs） are sentinels of the host defense system, which recognize a large number of microbial pathogens. The host defense system may be inefficient or inflammatory diseases may develop if microbial recognition by TLRs and subsequent TLR-triggered cytokine production are deregulated. Activating transcription factor 4 （ATF4）, a member of the ATF/CREB transcription factor family, is an important factor that participates in several pathophysiological processes. In this report, we found that ATF4 is also involved in the TLR-mediated innate immune response, which participates in TLR4 signal transduction and mediates the secretion of a variety of cytokines. We observed that ATF4 is activated and translocates to the nucleus following l ipopolysaccharide （LPS） stimulation via the TLR4-MyD88-dependent pathway. Additionally, a cytokine array assay showed that some key inflammatory cytokines, such as I L-6, I L-8 and RANTES, are positively regulated by ATF4. We also demonstrate that c-Jun directly binds to ATF4, thereby promoting the secretion of inflammatory cytokines. Taken together, these results indicate that ATF4 acts as a positive regulator in TLR4-triggered cytokine production.
基金This work was supported by the National Science Foundation for Young Scientists of China(81702994)International S&T Cooperation Program of China(2015DFA30420)We thank Dr Ralph A.Reisfeld from the Scripps Research In stitute for his valuable suggestions and for proof-readi ng this manuscript.
文摘Metastases are the main cause of cancer-related mortality in breast cancer.Although significant progress has been made in the field of tumor metastasis,the exact molecular mechanisms involved in tumor metastasis are still unclear.Here,we report that ATOH8-V1,a novel isoform of ATOH8,is highly expressed in breast cancer and is a negative prognostic indicator of survival for patients.Forced expression of ATOH8-V1 dramatically enhances,while silencing of ATOH8-V1 decreases the metastasis of breast cancer cell lines.Moreover,ATOH8-V1 directly binds to the RhoC promoter and stimulates the expression of RhoC,which in turn enhances the metastasis of breast cancer.Altogether,our data demonstrate that ATOH8-V1 is a novel pro-metastatic factor that enhances cancer metastasis,suggesting that AT0H8-V1 is a potential therapeutic target for treatment of metastatic cancers.
基金This project is supported by the National Basic Research Program(973)of China(No.2013CB967202)the National Natural Science Foundation of China(No.81273331)+2 种基金the National Natural Science Foundation of China(No.81470354)National Natural Science Foundation of China(81301856NL).
文摘TIFA,also called T2BP,was first identified using yeast two-hybrid screening.Our previous work showed that TIFA suppresses hepatocellular carcinoma(HCC)progression via apoptosis and cell cycle arrest.However,the mechanism by which this TIFA suppression occurs remains unclear.Here we demonstrated that TIFA-induced apoptosis demonstrates two distinct time patterns(i.e.,at 48 h and 47 days)when TIFA reconstitution occurs.Moreover,we found that MALT1(a competitor of TIFA)plays a crucial role in short-duration TIFA reconstitution.In this regard,MALT1 silencing with shRNA markedly enhances TIFA-induced apoptosis in vitro and in vivo.In addition,TIFA overexpression triggers JNK and p38 activation in long-duration TIFA reconstitution through TRAF6 binding.In particular,JNK activation leads to TIFA-induced apoptosis while p38 activation governs TIFA-induced cell cycle arrest by p53-p21 signaling in vitro and in vivo.Our data suggest a novel mechanism by which TIFA suppresses HCC progression via both MALT1-dependent and MALT1-independent signaling pathways.This may provide insights into a novel targets where HCC progression may be vulnerable to clinical treatment.
