Changes in gene expression by SNAI2 knockdown in the human pancreatic cancer cell line KLM1.
Ontology highlight
ABSTRACT: The prognosis of pancreatic cancer is still poor due to resistance to conventional therapies, and cancer stem cells (CSCs) targeted therapy is expected to be a promising therapy. Although epithelial mesenchymal transition-inducing transcription factors (EMT-TF) are known to impart the CSCs properties to some of solid tumors, it has not been clearly reported in pancreatic cancer yet. Zinc finger protein SNAI2, a member of the Snail superfamily of EMT-TF, is frequently overexpressed in pancreatic cancer cells and the poor prognosis has been reported in cases with high SNAI2 expression. we found the suppression of SNAI2 expression using RNA interference decreased the tumorigenicity in vitro (sphere formation assay) as well as in vivo (xenograft assay) in the pancreatic cancer cell line KLM1. Furthermore, microarray analysis suggests that the mechanism is mediated by insulin-like growth factor binding protein 2 (IGFBP2). These results indicate that SNAI2 may be a critical factor for the CSCs properties and indispensable for the homeostasis of pancreatic CSCs.
Project description:The prognosis of pancreatic cancer is still poor due to resistance to conventional therapies, and cancer stem cells (CSCs) targeted therapy is expected to be a promising therapy. Although epithelial mesenchymal transition-inducing transcription factors (EMT-TF) are known to impart the CSCs properties to some of solid tumors, it has not been clearly reported in pancreatic cancer yet. Zinc finger protein SNAI2, a member of the Snail superfamily of EMT-TF, is frequently overexpressed in pancreatic cancer cells and the poor prognosis has been reported in cases with high SNAI2 expression. we found the suppression of SNAI2 expression using RNA interference decreased the tumorigenicity in the tumor spheroid (Sph) derived from surgically resected pancreatic cancer tissues. Also, it increased the sensitivities to Gemcitabine treatment and reduced the expression of CD44, one of the pancreatic CSCs markers. Furthemore, microarray analysis suggests that the mechanism is mediated by insulin-like growth factor binding protein 2 (IGFBP2). These results indicate that SNAI2 may be a critical factor for the CSCs properties and indispensable for the homeostasis of pancreatic CSCs.
Project description:The synthetic lethal association between BRCA deficiency and poly (ADP-ribose) polymerase (PARP) inhibition supports PARP inhibitor (PARPi) clinical efficacy in BRCA-mutated tumors. PARPis also demonstrate activity in non-BRCA mutated tumors presumably through induction of PARP1-DNA trapping. Despite pronounced clinical response, therapeutic resistance to PARPis inevitably develops. An abundance of knowledge has been built around resistance mechanisms in BRCA-mutated tumors, however, parallel understanding in non-BRCA mutated settings remains insufficient. In this study, we find a strong correlation between the epithelial-mesenchymal transition (EMT) signature and resistance to a clinical PARPi, Talazoparib, in non-BRCA mutated tumor cells. Genetic profiling demonstrates that SNAI2, a master EMT transcription factor, is transcriptionally induced by Talazoparib treatment or PARP1 depletion and this induction is partially responsible for the emerging resistance. Mechanistically, we find that the PARP1 protein directly binds to SNAI2 gene promoter and suppresses its transcription. Talazoparib treatment or PARP1 depletion lifts PARP1-mediated suppression and increases chromatin accessibility around SNAI2 promoters, thus driving SNAI2 transcription and drug resistance. We also find that depletion of the chromatin remodeler CHD1L suppresses SNAI2 expression and reverts acquired resistance to Talazoparib. The PARP1/CHD1L/SNAI2 transcription axis might be therapeutically targeted to re-sensitize Talazoparib in non-BRCA mutated tumors.
Project description:The SNAI1 and SNAI2 embryonic genes are reactivated in numerous cancer types, including carcinomas. They promote cancer cell dissemination by inducing an epithelial-to-mesenchymal transition (EMT) and by protecting cells from anoikis. We now have demonstrated that the sequentially related SNAI3 gene is aberrantly reactivated in human breast carcinomas. To compare the functional properties of the three SNAIL family members, the transcription factors were ectopically expressed in immortalized mammary epithelial cells.
Project description:The SNAI1 and SNAI2 embryonic genes are reactivated in numerous cancer types, including carcinomas. They promote cancer cell dissemination by inducing an epithelial-to-mesenchymal transition (EMT) and by protecting cells from anoikis. We now have demonstrated that the sequentially related SNAI3 gene is aberrantly reactivated in human breast carcinomas. To compare the functional properties of the three SNAIL family members, the transcription factors were ectopically expressed in immortalized mammary epithelial cells. Immortalized human mammary epithelial cells (HMEC-hTERT cells) or MCF10A cells were infected with SNAIL retroviral expression constructs. The gene expression profiles of the resulting cell lines, cultured in standard conditions or after plating them 24h in low-adherent (LA) conditions, were performed.
Project description:Analyses of the effect of CRISPR/CAS9 mediated knock out of the EMT-transcription factor SNAI2 on the mRNA expression profile of human neuroblastoma SH-SY5Y cells to identify genes that are differentially expressed upon loss of SNAI2. Results provide insight into genes that are repressed by SNAI2 in neuroblastoma cells under normal culture conditions, where loss of SNAI2 enhances the expression of genes involved in biological processes such as neuron development and neuron differentiation.
Project description:The synthetic lethal association between BRCA deficiency and poly (ADP-ribose) polymerase (PARP) inhibition supports PARP inhibitor (PARPi) clinical efficacy in BRCA-mutated tumors. PARPis also demonstrate activity in non-BRCA mutated tumors presumably through induction of PARP1-DNA trapping. Despite pronounced clinical response, therapeutic resistance to PARPis inevitably develops. An abundance of knowledge has been built around resistance mechanisms in BRCA-mutated tumors, however, parallel understanding in non-BRCA mutated settings remains insufficient. In this study, we find a strong correlation between the epithelial-mesenchymal transition (EMT) signature and resistance to a clinical PARPi, Talazoparib, in non-BRCA mutated tumor cells. Genetic profiling demonstrates that SNAI2, a master EMT transcription factor, is transcriptionally induced by Talazoparib treatment or PARP1 depletion and this induction is partially responsible for the emerging resistance. Mechanistically, we find that the PARP1 protein directly binds to SNAI2 gene promoter and suppresses its transcription. Talazoparib treatment or PARP1 depletion lifts PARP1-mediated suppression and increases chromatin accessibility around SNAI2 promoters, thus driving SNAI2 transcription and drug resistance. We also find that depletion of the chromatin remodeler CHD1L suppresses SNAI2 expression and reverts acquired resistance to Talazoparib. The PARP1/CHD1L/SNAI2 transcription axis might be therapeutically targeted to re-sensitize Talazoparib in non-BRCA mutated tumors.
Project description:The synthetic lethal association between BRCA deficiency and poly (ADP-ribose) polymerase (PARP) inhibition supports PARP inhibitor (PARPi) clinical efficacy in BRCA-mutated tumors. PARPis also demonstrate activity in non-BRCA mutated tumors presumably through induction of PARP1-DNA trapping. Despite pronounced clinical response, therapeutic resistance to PARPis inevitably develops. An abundance of knowledge has been built around resistance mechanisms in BRCA-mutated tumors, however, parallel understanding in non-BRCA mutated settings remains insufficient. In this study, we find a strong correlation between the epithelial-mesenchymal transition (EMT) signature and resistance to a clinical PARPi, Talazoparib, in non-BRCA mutated tumor cells. Genetic profiling demonstrates that SNAI2, a master EMT transcription factor, is transcriptionally induced by Talazoparib treatment or PARP1 depletion and this induction is partially responsible for the emerging resistance. Mechanistically, we find that the PARP1 protein directly binds to SNAI2 gene promoter and suppresses its transcription. Talazoparib treatment or PARP1 depletion lifts PARP1-mediated suppression and increases chromatin accessibility around SNAI2 promoters, thus driving SNAI2 transcription and drug resistance. We also find that depletion of the chromatin remodeler CHD1L suppresses SNAI2 expression and reverts acquired resistance to Talazoparib. The PARP1/CHD1L/SNAI2 transcription axis might be therapeutically targeted to re-sensitize Talazoparib in non-BRCA mutated tumors.
Project description:The synthetic lethal association between BRCA deficiency and poly (ADP-ribose) polymerase (PARP) inhibition supports PARP inhibitor (PARPi) clinical efficacy in BRCA-mutated tumors. PARPis also demonstrate activity in non-BRCA mutated tumors presumably through induction of PARP1-DNA trapping. Despite pronounced clinical response, therapeutic resistance to PARPis inevitably develops. An abundance of knowledge has been built around resistance mechanisms in BRCA-mutated tumors, however, parallel understanding in non-BRCA mutated settings remains insufficient. In this study, we find a strong correlation between the epithelial-mesenchymal transition (EMT) signature and resistance to a clinical PARPi, Talazoparib, in non-BRCA mutated tumor cells. Genetic profiling demonstrates that SNAI2, a master EMT transcription factor, is transcriptionally induced by Talazoparib treatment or PARP1 depletion and this induction is partially responsible for the emerging resistance. Mechanistically, we find that the PARP1 protein directly binds to SNAI2 gene promoter and suppresses its transcription. Talazoparib treatment or PARP1 depletion lifts PARP1-mediated suppression and increases chromatin accessibility around SNAI2 promoters, thus driving SNAI2 transcription and drug resistance. We also find that depletion of the chromatin remodeler CHD1L suppresses SNAI2 expression and reverts acquired resistance to Talazoparib. The PARP1/CHD1L/SNAI2 transcription axis might be therapeutically targeted to re-sensitize Talazoparib in non-BRCA mutated tumors.
Project description:Pancreatic cancer is a common malignant tumor with poor prognosis. Accumulating evidence indicates that sirtuin 1 (SIRT1) exerts biological functions in various cancers.SIRT1 plays an important role in tumorigenesis, development, and drug resistance by blocking aging and apoptosis, also promoting cell growth and angiogenesis.However, how SIRT1 functions in the development of pancreatic cancer stem cells (CSCs) is currently poorly understood. Here, we showed that SIRT1 inhibits the differentiation of cancer cells by inhibiting various genes expression , including GRHL3, thus promoting the stemness and tumorigenesis of pancreatic cancer.
Project description:Pancreatic cancer is a common malignant tumor with poor prognosis. Accumulating evidence indicates that sirtuin 1 (SIRT1) exerts biological functions in various cancers.SIRT1 plays an important role in tumorigenesis, development, and drug resistance by blocking aging and apoptosis, also promoting cell growth and angiogenesis.However, how SIRT1 functions in the development of pancreatic cancer stem cells (CSCs) is currently poorly understood. Here, we showed that SIRT1 is involved in regulating various pathways closely related to tumor growth, autophagy and stemness, as well as promoting pancreatic CSC development.