RESUMO
The major types of non-small-cell lung cancer (NSCLC)-squamous cell carcinoma and adenocarcinoma-have distinct immune microenvironments. We developed a genetic model of squamous NSCLC on the basis of overexpression of the transcription factor Sox2, which specifies lung basal cell fate, and loss of the tumor suppressor Lkb1 (SL mice). SL tumors recapitulated gene-expression and immune-infiltrate features of human squamous NSCLC; such features included enrichment of tumor-associated neutrophils (TANs) and decreased expression of NKX2-1, a transcriptional regulator that specifies alveolar cell fate. In Kras-driven adenocarcinomas, mis-expression of Sox2 or loss of Nkx2-1 led to TAN recruitment. TAN recruitment involved SOX2-mediated production of the chemokine CXCL5. Deletion of Nkx2-1 in SL mice (SNL) revealed that NKX2-1 suppresses SOX2-driven squamous tumorigenesis by repressing adeno-to-squamous transdifferentiation. Depletion of TANs in SNL mice reduced squamous tumors, suggesting that TANs foster squamous cell fate. Thus, lineage-defining transcription factors determine the tumor immune microenvironment, which in turn might impact the nature of the tumor.
Assuntos
Diferenciação Celular/imunologia , Regulação Neoplásica da Expressão Gênica/imunologia , Fatores de Transcrição SOXB1/imunologia , Microambiente Tumoral/imunologia , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Diferenciação Celular/genética , Linhagem Celular Tumoral , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Células Cultivadas , Modelos Animais de Doenças , Feminino , Perfilação da Expressão Gênica , Células HEK293 , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Neutrófilos/imunologia , Neutrófilos/metabolismo , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Fator Nuclear 1 de Tireoide/genética , Fator Nuclear 1 de Tireoide/metabolismo , Microambiente Tumoral/genéticaRESUMO
OBJECTIVE: Pancreatic ductal adenocarcinoma (PDAC) is an aggressive malignancy with a 5-year survival of less than 5%. Transcriptomic analysis has identified two clinically relevant molecular subtypes of PDAC: classical and basal-like. The classical subtype is characterised by a more favourable prognosis and better response to chemotherapy than the basal-like subtype. The classical subtype also expresses higher levels of lineage specifiers that regulate endodermal differentiation, including the nuclear receptor hepatocyte nuclear factor 4 α (HNF4α). The objective of this study is to evaluate the role of HNF4α, SIX4 and SIX1 in regulating the growth and molecular subtype of PDAC. DESIGN: We manipulate the expression of HNF4α, SIX4 and SIX1 in multiple in vitro and in vivo PDAC models. We determine the consequences of manipulating these genes on PDAC growth, differentiation and molecular subtype using functional assays, gene expression analysis and cross-species comparisons with human datasets. RESULTS: We show that HNF4α restrains tumour growth and drives tumour cells toward an epithelial identity. Gene expression analysis of murine models and human tumours shows that HNF4α activates expression of genes associated with the classical subtype. HNF4α also directly represses SIX4 and SIX1, two mesodermal/neuronal lineage specifiers expressed in the basal-like subtype. Finally, SIX4 and SIX1 drive proliferation and regulate differentiation in HNF4α-negative PDAC. CONCLUSION: Our data show that HNF4α regulates the growth and molecular subtype of PDAC by multiple mechanisms, including activation of the classical gene expression programme and repression of SIX4 and SIX1, which may represent novel dependencies of the basal-like subtype.
Assuntos
Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Fator 4 Nuclear de Hepatócito/genética , Proteínas de Homeodomínio/genética , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Animais , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Transativadores/genética , Neoplasias PancreáticasRESUMO
Cell-cell fusion is an essential event during life. Throughout human pregnancy, the syncytiotrophoblast (STB) layer of the placenta is formed by continuous fusion of the underlying villous cytotrophoblasts, thus maintaining placental functionality. Defects in this process are associated with pathologies like pre-eclampsia and intrauterine growth restriction. Krüppel-like factor 6 (KLF6) is a transcription factor highly expressed in human and murine placenta. However, KLF6 functions in trophoblast cells remain largely unexplored. The aim of this work was to address the role of KLF6 during STB formation. KLF6 knockdown through small interfering RNA experiments hindered cell-cell fusion revealed by immunofluorescence microscopy in human primary villous cytotrophoblast as well as in the human placental-derived BeWo cell line. Furthermore, KLF6 silencing led to a decrease in the expression of the fusogenic protein Syncytin-1 and the cell cycle regulator p21 CIP1/WAF1: measured by quantitative RT-PCR and western blot assays. On the contrary, transcript levels of genes that encode for proteins involved in STB formation such as Syncytin-1, Syncytin-2, Connexin-43 and Zonula Occludens-1 increased when KLF6 was overexpressed in differentiating villous cytotrophoblasts and in non-fusing placental-derived JEG-3 cells. Interestingly, the expression of two trophoblast biochemical differentiation markers, ßhCG and PSG3, were not reduced after KLF6 silencing in differentiating trophoblast cells. Present results support the notion that KLF6 is a relevant participant in cytotrophoblast fusion.
Assuntos
Vilosidades Coriônicas/metabolismo , Fatores de Transcrição Kruppel-Like/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Trofoblastos/metabolismo , Adulto , Fusão Celular , Gonadotropina Coriônica Humana Subunidade beta/genética , Gonadotropina Coriônica Humana Subunidade beta/metabolismo , Vilosidades Coriônicas/crescimento & desenvolvimento , Conexina 43/genética , Conexina 43/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Feminino , Regulação da Expressão Gênica , Produtos do Gene env/genética , Produtos do Gene env/metabolismo , Humanos , Fator 6 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/antagonistas & inibidores , Fatores de Transcrição Kruppel-Like/genética , Gravidez , Proteínas da Gravidez/genética , Proteínas da Gravidez/metabolismo , Cultura Primária de Células , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Proteínas Proto-Oncogênicas/genética , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Trofoblastos/citologia , Proteína da Zônula de Oclusão-1/genética , Proteína da Zônula de Oclusão-1/metabolismoRESUMO
Cancer cells undergo lineage switching during natural progression and in response to therapy. NKX2-1 loss in human and murine lung adenocarcinoma leads to invasive mucinous adenocarcinoma (IMA), a lung cancer subtype that exhibits gastric differentiation and harbors a distinct spectrum of driver oncogenes. In murine BRAFV600E-driven lung adenocarcinoma, NKX2-1 is required for early tumorigenesis, but dispensable for established tumor growth. NKX2-1-deficient, BRAFV600E-driven tumors resemble human IMA and exhibit a distinct response to BRAF/MEK inhibitors. Whereas BRAF/MEK inhibitors drive NKX2-1-positive tumor cells into quiescence, NKX2-1-negative cells fail to exit the cell cycle after the same therapy. BRAF/MEK inhibitors induce cell identity switching in NKX2-1-negative lung tumors within the gastric lineage, which is driven in part by WNT signaling and FoxA1/2. These data elucidate a complex, reciprocal relationship between lineage specifiers and oncogenic signaling pathways in the regulation of lung adenocarcinoma identity that is likely to impact lineage-specific therapeutic strategies.
When cells become cancerous they grow uncontrollably and spread into surrounding healthy tissue. As the cancer progresses different genes are switched on and off which can cause tumor cells to change their identity and transition into other types of cell. How closely tumor cells resemble the healthy tissue they came from can influence how well the cancer responds to treatment. Many lung cancers have an identity similar to normal lung cells. However, some turn off a gene that codes for a protein called NKX2-1, which leads to a type of cancer called invasive mucinous adenocarcinoma (or IMA for short). Cells from this type of cancer develop an identity similar to mucous cells that line the surface of the stomach. But it was unclear how IMA tumor cells that developed from a mutation in the BRAF gene are affected by this loss in NKX2-1, and how transitioning to a different cell type impacts their response to treatment. To investigate this, Zewdu et al. studied lung cells from patients with IMA tumors driven by a mutation in BRAF and cells from mice that have been genetically engineered to have a similar form of cancer. This revealed that the NKX2-1 protein is needed to initiate the formation of cancer cells but is not required for the growth of already established BRAF-driven tumors. Further experiments showed that removing the gene for NKX2-1 made these cancer cells less responsive to drugs known as BRAF/MEK inhibitors that are commonly used to treat cancer. These drugs caused the IMA cancer cells to change their identity and become another type of stomach cell. This identity change was found to depend on two signaling pathways which cells use to communicate. This study provides some explanation of how IMA lung cancers that lack the gene for NKX2-1 resist treatment with BRAF/MEK inhibitors. It also shows new relationships between key genes in these cancers and systems for cell communication. These findings could lead to better therapies for lung cancer, particularly for patients whose tumor cells are deficient in NKX2-1 and therefore require specialized treatment.
Assuntos
Adenocarcinoma de Pulmão/tratamento farmacológico , Antineoplásicos/farmacologia , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Fator Nuclear 1 de Tireoide/metabolismo , Proteínas Wnt/metabolismo , Adenocarcinoma de Pulmão/enzimologia , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Animais , Animais Geneticamente Modificados , Linhagem Celular Tumoral , Linhagem da Célula , Retroalimentação Fisiológica , Humanos , Neoplasias Pulmonares/enzimologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos NOD , Camundongos SCID , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Terapia de Alvo Molecular , Mutação , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Fator Nuclear 1 de Tireoide/genética , Células Tumorais Cultivadas , Via de Sinalização WntRESUMO
In the version of this article initially published, the label over the bottom schematic in Fig. 1a was "pH > 5.0"; it should have been "pH < 5.0". Further, the original article misspelt the surname of Katrin P. Guillen as "Gullien". These errors have been corrected in the print, PDF and HTML versions of the article.
RESUMO
Pancreatic ductal adenocarcinoma (PDA) was responsible for ~ 44,000 deaths in the United States in 2018 and is the epitome of a recalcitrant cancer driven by a pharmacologically intractable oncoprotein, KRAS1-4. Downstream of KRAS, the RAFâMEKâERK signaling pathway plays a central role in pancreatic carcinogenesis5. However, paradoxically, inhibition of this pathway has provided no clinical benefit to patients with PDA6. Here we show that inhibition of KRASâRAFâMEKâERK signaling elicits autophagy, a process of cellular recycling that protects PDA cells from the cytotoxic effects of KRAS pathway inhibition. Mechanistically, inhibition of MEK1/2 leads to activation of the LKB1âAMPKâULK1 signaling axis, a key regulator of autophagy. Furthermore, combined inhibition of MEK1/2 plus autophagy displays synergistic anti-proliferative effects against PDA cell lines in vitro and promotes regression of xenografted patient-derived PDA tumors in mice. The observed effect of combination trametinib plus chloroquine was not restricted to PDA as other tumors, including patient-derived xenografts (PDX) of NRAS-mutated melanoma and BRAF-mutated colorectal cancer displayed similar responses. Finally, treatment of a patient with PDA with the combination of trametinib plus hydroxychloroquine resulted in a partial, but nonetheless striking disease response. These data suggest that this combination therapy may represent a novel strategy to target RAS-driven cancers.
Assuntos
Autofagia/efeitos dos fármacos , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Quinases de Proteína Quinase Ativadas por Mitógeno/antagonistas & inibidores , Neoplasias Pancreáticas/enzimologia , Neoplasias Pancreáticas/patologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas ras/metabolismo , Animais , Antígeno CA-19-9/metabolismo , Linhagem Celular Tumoral , Cloroquina/farmacologia , Humanos , Camundongos SCID , Quinases de Proteína Quinase Ativadas por Mitógeno/metabolismo , Proteínas Proto-Oncogênicas B-raf/metabolismo , Piridonas/farmacologia , Pirimidinonas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto , Neoplasias PancreáticasRESUMO
Over the last decade, multiple genomics studies have led to the identification of discrete molecular subtypes of pancreatic ductal adenocarcinoma. A general theme has emerged that most pancreatic ductal adenocarcinoma (PDAC) can be grouped into two major subtypes based on cancer cell autonomous properties: classical/pancreatic progenitor and basal-like/squamous. The classical/progenitor subtype expresses higher levels of lineage specifiers that regulate endodermal differentiation than the basal-like/squamous subtype. The basal-like/squamous subtype confers a worse prognosis, raising the possibility that loss of these lineage specifiers might enhance the malignant potential of PDAC. Here, we discuss several of these differentially expressed lineage specifiers and examine the evidence that they might play a functional role in PDAC biology.
RESUMO
Changes in cancer cell identity can alter malignant potential and therapeutic response. Loss of the pulmonary lineage specifier NKX2-1 augments the growth of KRAS-driven lung adenocarcinoma and causes pulmonary to gastric transdifferentiation. Here, we show that the transcription factors FoxA1 and FoxA2 are required for initiation of mucinous NKX2-1-negative lung adenocarcinomas in the mouse and for activation of their gastric differentiation program. Foxa1/2 deletion severely impairs tumor initiation and causes a proximal shift in cellular identity, yielding tumors expressing markers of the squamocolumnar junction of the gastrointestinal tract. In contrast, we observe downregulation of FoxA1/2 expression in the squamous component of both murine and human lung adenosquamous carcinoma. Using sequential in vivo recombination, we find that FoxA1/2 loss in established KRAS-driven neoplasia originating from SPC-positive alveolar cells induces keratinizing squamous cell carcinomas. Thus, NKX2-1, FoxA1 and FoxA2 coordinately regulate the growth and identity of lung cancer in a context-specific manner.
Assuntos
Adenocarcinoma de Pulmão/genética , Biomarcadores Tumorais/genética , Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica , Fator 3-alfa Nuclear de Hepatócito/genética , Fator 3-beta Nuclear de Hepatócito/genética , Neoplasias Pulmonares/genética , Neoplasias Gástricas/genética , Fator Nuclear 1 de Tireoide/genética , Adenocarcinoma de Pulmão/metabolismo , Adenocarcinoma de Pulmão/mortalidade , Adenocarcinoma de Pulmão/patologia , Animais , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/patologia , Adesão Celular , Diferenciação Celular , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Transformação Celular Neoplásica/patologia , Modelos Animais de Doenças , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Fator 3-beta Nuclear de Hepatócito/metabolismo , Humanos , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/mortalidade , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Transgênicos , Fenótipo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/mortalidade , Neoplasias Gástricas/patologia , Análise de Sobrevida , Fator Nuclear 1 de Tireoide/deficiência , Células Tumorais CultivadasRESUMO
BACKGROUND: Lysine acetylation is an important post-translational modification that plays a central role in eukaryotic transcriptional activation by modifying chromatin and transcription-related factors. Human pregnancy-specific glycoproteins (PSG) are the major secreted placental proteins expressed by the syncytiotrophoblast at the end of pregnancy and represent early markers of cytotrophoblast differentiation. Low PSG levels are associated with complicated pregnancies, thus highlighting the importance of studying the mechanisms that control their expression. Despite several transcription factors having been implicated as key regulators of PSG gene family expression; the role of protein acetylation has not been explored. METHODOLOGY/PRINCIPAL FINDINGS: Here, we explored the role of acetylation on PSG gene expression in the human placental-derived JEG-3 cell line. Pharmacological inhibition of histone deacetylases (HDACs) up-regulated PSG protein and mRNA expression levels, and augmented the amount of acetylated histone H3 associated with PSG 5'regulatory regions. Moreover, PSG5 promoter activation mediated by Sp1 and KLF6, via the core promoter element motif (CPE, -147/-140), was markedly enhanced in the presence of the HDAC inhibitor trichostatin A (TSA). This effect correlated with an increase in Sp1 acetylation and KLF6 nuclear localization as revealed by immunoprecipitation and subcellular fractionation assays. The co-activators PCAF, p300, and CBP enhanced Sp1-dependent PSG5 promoter activation through their histone acetylase (HAT) function. Instead, p300 and CBP acetyltransferase domain was dispensable for sustaining co-activation of PSG5 promoter by KLF6. CONCLUSIONS/SIGNIFICANCE: Results are consistent with a regulatory role of lysine acetylation on PSG expression through a relaxed chromatin state and an increase in the transcriptional activity of Sp1 and KLF6 following an augmented Sp1 acetylation and KLF6 nuclear localization.
Assuntos
Histonas/genética , Placenta/metabolismo , Glicoproteínas beta 1 Específicas da Gravidez/genética , Regulação para Cima/fisiologia , Acetilação/efeitos dos fármacos , Linhagem Celular , Feminino , Inibidores de Histona Desacetilases/farmacologia , Histona Desacetilases/genética , Histona Desacetilases/metabolismo , Histonas/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Fator 6 Semelhante a Kruppel , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Lisina/genética , Lisina/metabolismo , Placenta/efeitos dos fármacos , Gravidez , Glicoproteínas beta 1 Específicas da Gravidez/metabolismo , Regiões Promotoras Genéticas/efeitos dos fármacos , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Fator de Transcrição Sp1/genética , Fator de Transcrição Sp1/metabolismo , Ativação Transcricional , Regulação para Cima/efeitos dos fármacos , Fatores de Transcrição de p300-CBP/genética , Fatores de Transcrição de p300-CBP/metabolismoRESUMO
The effects of organophosphate pesticides on human placenta remain poorly investigated although an increased risk of pregnancy alterations has been reported in women chronically exposed to these pesticides. Here, we have addressed whether chlorpyrifos (CPF) modifies the expression of genes relevant for placental function. Human placental JEG-3 cells were exposed to increasing CPF concentrations up to 100 µM for 24 and 48 h and cell viability, mRNA, protein and hormone levels were analyzed. Quantitative RT-PCR assays revealed that CPF increased the expression of ABCG2, GCM1 and, even more significantly, ßhCG mRNAs in conditions where cell viability and morphology were not compromised. In addition, ßhCG protein synthesis and secretion were time-dependently augmented. Present results may reflect a CPF nocive effect on placenta cells or a placental-defense mechanism to preserve its function. These novel CPF trophoblast target genes should be considered in future studies of pregnancy outcomes associated with in vivo exposures.
Assuntos
Clorpirifos/toxicidade , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Inseticidas/toxicidade , Placenta/efeitos dos fármacos , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/genética , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Gonadotropina Coriônica Humana Subunidade beta/genética , Proteínas de Ligação a DNA , Feminino , Humanos , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Placenta/metabolismo , Gravidez , RNA Mensageiro/metabolismo , Fatores de Transcrição/genéticaRESUMO
BACKGROUND: Krüppel-like factor-6 (KLF6) is a widely expressed member of the Sp1/KLF family of transcriptional regulators involved in differentiation, cell cycle control and proliferation in several cell systems. Even though the highest expression level of KLF6 has been detected in human and mice placenta, its function in trophoblast physiology is still unknown. METHODOLOGY/PRINCIPAL FINDINGS: Herein, we explored KLF6 expression and sub-cellular distribution in human trophoblast cells differentiating into the syncytial pathway, and its role in the regulation of genes associated with placental development and pregnancy maintenance. Confocal immunofluorescence microscopy demonstrated that KLF6 is expressed throughout human cytotrophoblast differentiation showing no evident modifications in its nuclear and cytoplasmic localization pattern. KLF6 transcript and protein peaked early during the syncytialization process as determined by qRT-PCR and western blot assays. Overexpression of KLF6 in trophoblast-derived JEG-3 cells showed a preferential nuclear signal correlating with enhanced expression of human ß-chorionic gonadotropin (ßhCG) and pregnancy-specific glycoprotein (PSG) genes. Moreover, KLF6 transactivated ßhCG5, PSG5 and PSG3 gene promoters. Deletion of KLF6 Zn-finger DNA binding domain or mutation of the consensus KLF6 binding site abolished transactivation of the PSG5 promoter. CONCLUSIONS/SIGNIFICANCE: Results are consistent with KLF6 playing a role as transcriptional regulator of relevant genes for placental differentiation and physiology such as ßhCG and PSG, in agreement with an early and transient increase of KLF6 expression during trophoblast syncytialization.