RESUMO
Activation of Akt/Protein Kinase B (PKB) by phosphatidylinositol-3-kinase (PI3K) controls several cellular functions largely studied in mammalian cells, including preimplantation embryos. We previously showed that early mouse embryos inherit active Akt from oocytes and that the intracellular localization of this enzyme at the two-cell stage depends on the T-cell leukemia/lymphoma 1 oncogenic protein, Tcl1. We have now investigated whether Akt isoforms, namely Akt1, Akt2 and Akt3, exert a specific role in blastomere proliferation during preimplantation embryo development. We show that, in contrast to other Akt family members, Akt2 enters male and female pronuclei of mouse preimplantation embryos at the late one-cell stage and thereafter maintains a nuclear localization during later embryo cleavage stages. Depleting one-cell embryos of single Akt family members by microinjecting Akt isoform-specific antibodies into wild-type zygotes, we observed that: (a) Akt2 is necessary for normal embryo progression through cleavage stages; and (b) the specific nuclear targeting of Akt2 in two-cell embryos depends on Tcl1. Our results indicate that preimplantation mouse embryos have a peculiar regulation of blastomere proliferation based on the activity of the Akt/PKB family member Akt2, which is mediated by the oncogenic protein Tcl1. Both Akt2 and Tcl1 are essential for early blastomere proliferation and embryo development.
Assuntos
Desenvolvimento Embrionário/genética , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas/genética , Animais , Blastocisto/metabolismo , Blastômeros/metabolismo , Proliferação de Células/genética , Embrião de Mamíferos , Feminino , Masculino , Camundongos , Gravidez , Isoformas de ProteínasRESUMO
Sézary syndrome (SS) is an incurable leukemic variant of cutaneous T-cell lymphoma characterized by recurrent chromosomal alterations, among which, chromosome 10q deletion is very frequent. In this study, we investigated the PTEN status, on locus 10q23, in 44 SS patients; our findings show that PTEN is deleted in 36% of SS cases, whereas PTEN downregulation is observed in almost all of the samples evaluated by quantitative reverse-transcriptase polymerase chain reaction and Western blotting analysis. Neither DNA sequence mutation nor promoter hypermethylation were found at the PTEN locus, but we demonstrate that PTEN level can be also reduced by a group of miRs previously found upregulated and of prognostic relevance in SS; particularly, miR-21, miR-106b, and miR-486 were able to control PTEN abundance either in vitro or in vivo. Finally, because reduced PTEN activates the PI3/AKT-mediated pathway of cell growth and survival, we demonstrate that PTEN deficiency is associated with activated AKT in skin resident but not circulating SS cells, suggesting that the cutaneous milieu may strongly contribute to the SS cell growth. To our knowledge, this is the first study fully exploring the PTEN status in a large cohort of SS patients, unveiling potential elements of clinical utility in this malignancy.
Assuntos
Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/fisiologia , PTEN Fosfo-Hidrolase/fisiologia , Síndrome de Sézary/metabolismo , Idoso , Idoso de 80 Anos ou mais , Cromossomos Humanos Par 10/ultraestrutura , Metilação de DNA , Análise Mutacional de DNA , Regulação para Baixo , Feminino , Deleção de Genes , Dosagem de Genes , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Proteínas de Neoplasias/análise , Proteínas de Neoplasias/genética , PTEN Fosfo-Hidrolase/análise , PTEN Fosfo-Hidrolase/genética , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Proto-Oncogênicas c-akt/fisiologia , RNA Mensageiro/biossíntese , RNA Neoplásico/biossíntese , Análise de Sequência de DNA , Síndrome de Sézary/genética , Transdução de Sinais , Pele/metabolismo , Pele/patologiaRESUMO
BACKGROUND: Circulating cytokines can represent non-invasive biomarkers to improve prediction of clinical outcomes of cancer patients. Here, plasma levels of IL-8, CCL4, osteopontin, LIF and BDNF were determined at baseline (T0), after 2 months of therapy (T2) and, when feasible, at progression (TP), in 70 melanoma patients treated with BRAF and MEK inhibitors. The association of baseline cytokine levels with clinical response, progression-free survival (PFS) and overall survival (OS) was evaluated. METHODS: Cytokine concentrations were measured using the xMAP technology. Their ability to discriminate between responding (Rs) and non-responding (NRs) patients was assessed by Receiver Operating Characteristics analysis. PFS and OS were estimated with the Kaplan-Meier method. The Cox proportional hazard model was used in the univariate and multivariate analyses to estimate crude and adjusted hazard ratios with 95% confidence intervals. RESULTS: CCL4 and LIF were undetectable in the majority of samples. The median osteopontin concentration at T0 and T2 was significantly higher in NRs than in Rs. The median T0 and T2 values of IL-8 were also higher in NRs than in Rs, although the statistical significance was not reached. No differences were detected for BDNF. In 39 Rs with matched T0, T2, and TP samples, osteopontin and IL-8 significantly decreased from T0 to T2 and rose again at TP, while BDNF levels remained unchanged. In NRs, none of the cytokines showed a significant decrease at T2. Only osteopontin demonstrated a good ability to discriminate between Rs and NRs. A high IL-8 T0 level was associated with significantly shorter PFS and OS and higher risk of progression and mortality, and remained an independent negative prognostic factor for OS in multivariate analysis. An elevated osteopontin T0 concentration was also significantly associated with worse OS and increased risk of death. Patients with high IL-8 and high osteopontin showed the lowest PFS and OS, and in multivariate analysis this cytokine combination remained independently associated with a three- to six-fold increased risk of mortality. CONCLUSION: Circulating IL-8 and osteopontin appear useful biomarkers to refine prognosis evaluation of patients undergoing targeted therapy, and deserve attention as potential targets to improve its clinical efficacy.
Assuntos
Biomarcadores Tumorais , Interleucina-8 , Melanoma , Osteopontina , Humanos , Osteopontina/sangue , Interleucina-8/sangue , Masculino , Feminino , Melanoma/tratamento farmacológico , Melanoma/sangue , Melanoma/mortalidade , Melanoma/patologia , Pessoa de Meia-Idade , Biomarcadores Tumorais/sangue , Idoso , Adulto , Terapia de Alvo Molecular , Resultado do Tratamento , Idoso de 80 Anos ou maisRESUMO
Cutaneous T-cell lymphomas are characterized by heterogeneity of clinical variants, further complicated by genomic and microenvironmental variables. Furthermore, in vitro experiments are hampered by the low culture efficiency of these malignant cells. Animal models are essential for understanding the pathogenetic mechanisms underlying malignancy and for discovering new anticancer treatments. They are divided into two main categories: those in which tumors arise in the host owing to genetic modifications and those that use tumor cell transplantation. In this review, we summarize the attempts to decipher the complexity of the pathogenesis of cutaneous T-cell lymphoma by exploiting genetically modified and xenograft models.
Assuntos
Linfoma Cutâneo de Células T , Neoplasias Cutâneas , Animais , Modelos Animais de Doenças , Humanos , Linfoma Cutâneo de Células T/genética , Linfoma Cutâneo de Células T/patologia , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/patologiaRESUMO
Sézary syndrome (SS) is an aggressive variant of cutaneous t-cell lymphoma characterized by the accumulation of neoplastic CD4+ lymphocytes-the SS cells-mainly in blood, lymph nodes, and skin. The tumor spread pattern of SS makes this lymphoma a unique model of disease that allows a concurrent blood and skin sampling for analysis. This review summarizes the recent studies highlighting the transcriptional programs triggered by the crosstalk between SS cells and blood-skin microenvironments. Emerging data proved that skin-derived SS cells show consistently higher activation/proliferation rates, mainly driven by T-cell receptor signaling with respect to matched blood SS cells that instead appear quiescent. Biochemical analyses also demonstrated an hyperactivation of PI3K/AKT/mTOR, a targetable pathway by multiple inhibitors currently in clinical trials, in skin SS cells compared with a paired blood counterpart. These results indicated that active and quiescent SS cells coexist in this lymphoma, and that they could be respectively treated with different therapeutics. Finally, this review underlines the more recent discoveries into the heterogeneity of circulating SS cells, highlighting a series of novel markers that could improve the diagnosis and that represent novel therapeutic targets (GPR15, PTPN13, KLRB1, and ITGB1) as well as new genetic markers (PD-1 and CD39) able to stratify SS patients for disease aggressiveness.
RESUMO
Sézary syndrome (SS) is a rare and aggressive variant of cutaneous T-cell lymphoma. It is characterized by the copresence of CD4+ neoplastic lymphocytes, named Sezary cells, mainly in the blood, lymph nodes, and skin where they induce chronic inflammation that in turn impairs the patient's QOL and fuels neoplastic cells. SS is not readily cured, but immunotherapy is becoming an effective option for this lymphoma. In this study, we investigated, in a large cohort of patients with SS, the expression and function of the immune checkpoint molecule CD39, which degrades proinflammatory extracellular adenosine triphosphate. We showed that the SNP rs10748643 A/G within the ENTPD1 gene coding for the CD39 protein controls its expression level. Patients carrying the A/GâG/G genotype showed a significantly higher frequency of clonal CD4+CD39+ SS cells than those carrying the A/A genotype. Different from other cancers, high CD39 expression correlates with a better prognosis. Comparing primary G/G with A/A lymphoma cells, we observed that G/G SS cells have a higher ability to degrade adenosine triphosphate, increased apoptotic susceptibility, and upon activation, reduced IL-2 production. Accordingly, CD39 enzymatic inhibition enhances SS cell viability and IL-2 production on activation. These results strongly suggest a special caution for SS treatment with therapeutic inhibitors of CD39.
Assuntos
Apirase , Síndrome de Sézary , Neoplasias Cutâneas , Humanos , Trifosfato de Adenosina/metabolismo , Apirase/genética , Sobrevivência Celular/genética , Proteínas de Checkpoint Imunológico , Interleucina-2/genética , Linfócitos/metabolismo , Prognóstico , Qualidade de Vida , Síndrome de Sézary/genética , Síndrome de Sézary/metabolismo , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/metabolismo , Linfócitos T ReguladoresRESUMO
OBJECTIVE: To investigate whether a significantly aberrant expression of circulating placental mRNA genes related with cardiogenesis can be detected at the second trimester of pregnancy. METHODS: The study was performed in two stages. First stage (development model group): match of 14 placental tissues at delivery of fetuses with congenital heart disease versus 20 controls. Second stage (validation model group): mRNA amplification of abnormal expressed genes in maternal blood samples from 26 women bearing a fetus with a congenital heart disease matched with 28 controls. RESULTS: We identified four functional categories of genes possibly involved in abnormal heart development: cardiac morphogenesis: tenascin, thioredoxin, salvador homolog 1 protein; extracellular matrix (ECM) and valvular tissue biosynthesis; placental-associated plasma protein, collagen, type I, alpha 2, fibulin-1, heparanase, procollagen-proline, 2-oxoglutarate 4-dioxygenase, alpha polypeptide II, Jumonji, AT rich interactive domain 1B RBP2-like; normal contractile activity: actinin, alpha 4, fascin homolog 1, actin-bundling protein; and congestive heart failure. CONCLUSION: Altered placental genetic expression was found at term delivery in affected fetuses. The aberration was also confirmed in maternal blood at the second trimester of women bearing a fetus with congenital heart disease. Sensitivity for the most aberrant genes ranged between 42% and 95% at a false positive rate (FPR) of 10%.
Assuntos
Doenças Fetais/sangue , Testes Genéticos/métodos , Cardiopatias Congênitas/sangue , Técnicas de Diagnóstico Molecular/métodos , Placenta/metabolismo , RNA Mensageiro/sangue , Biomarcadores/sangue , Feminino , Doenças Fetais/genética , Perfilação da Expressão Gênica , Cardiopatias Congênitas/genética , Humanos , Troca Materno-Fetal , Análise de Sequência com Séries de Oligonucleotídeos , Placenta/química , Valor Preditivo dos Testes , Gravidez , Segundo Trimestre da Gravidez/sangue , Estudos RetrospectivosRESUMO
The phosphoinositide 3-kinase(PI3K)/protein kinase B (AKT)/ mammalian target of rapamycin (mTOR) pathway is hyperactivated in many tumors, as well as in cutaneous T-cell lymphoma (CTCL), which includes the mycosis fungoides and the aggressive variant known as Sezary syndrome (SS). TORC1 signaling is activated in SS cells by cytokines and chemokines, which are overexpressed in SS tissues. Furthermore, the recurrent copy number variation of genes belonging to this cascade, such as PTEN, LKB1, and P70S6K, contributes to the hyperactivation of the pathway. The aim of this study was to investigate the therapeutic potential of mTOR inhibitors in CTCL. We compared the efficacy of three rapalogs (rapamycin, temsirolimus, and everolimus) and the dual-mTOR/PI3K inhibitor PF-04691502 (hereinafter PF-502) in four CTCL cell lines. PF-502 was revealed to be the most effective inhibitor of cell growth. Interestingly, PF-502 also exerted its antitumor activity in patient-derived CTCL cells and in a xenograft mouse model, where it induced significant apoptosis and increased survival of treated mice. Furthermore, we found an inverse correlation between PTEN gene expression and the ability of PF-502 to induce apoptosis in SS cells. Our data strongly support the therapeutic potential of dual PI3K/mTOR inhibitors in CTCL.
Assuntos
Antineoplásicos/uso terapêutico , Linfoma Cutâneo de Células T/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Piridonas/uso terapêutico , Pirimidinas/uso terapêutico , Linfócitos T/imunologia , Animais , Linhagem Celular , Avaliação Pré-Clínica de Medicamentos , Everolimo/uso terapêutico , Feminino , Humanos , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Camundongos Nus , Terapia de Alvo Molecular , Fosfatidilinositol 3-Quinases/metabolismo , Transdução de Sinais , Sirolimo/análogos & derivados , Sirolimo/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Sezary Syndrome is an aggressive T-cell Lymphoma involving blood, skin and lymphonodes Involvement of the CXCR4-SDF1 has been previously shown. We here present evidence also of the involvement of B-arrestin a downstream regulator of CXCR4, that is depleted and downregulated as well as a potential functional role for this depletion.
Assuntos
Linfoma de Células T/genética , Síndrome de Sézary/genética , Neoplasias Cutâneas/genética , beta-Arrestina 2/genética , beta-Arrestina 2/fisiologia , Células Cultivadas , Estudos de Coortes , Variações do Número de Cópias de DNA , Deleção de Genes , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Linfoma de Células T/patologia , Invasividade Neoplásica , RNA Interferente Pequeno/farmacologia , Receptores CXCR4/genética , Síndrome de Sézary/patologia , Neoplasias Cutâneas/patologia , beta-Arrestina 2/antagonistas & inibidoresRESUMO
Sézary syndrome (SS) is a rare and aggressive variant of Cutaneous T-Cell Lymphoma characterized by neoplastic distribution mainly involving blood, skin, and lymph-node. Although a role of the skin microenvironment in SS pathogenesis has long been hypothesized, its function in vivo is poorly characterized. To deepen this aspect, here we compared skin to blood-derived SS cells concurrently obtained from SS patients highlighting a greater proliferation-index and a PI3K/AKT/mTORC1 pathway activation level, particularly of mTOR protein, in skin-derived-SS cells. We proved that SDF-1 and CCL21 chemokines, both overexpressed in SS tissues, induce mTORC1 signaling activation, cell proliferation and Ki67 up-regulation in a SS-derived cell line and primary-SS cells. In a cohort of 43 SS cases, we observed recurrent copy number variations (CNV) of members belonging to this cascade, namely: loss of LKB1 (48%), PTEN (39%) and PDCD4 (35%) and gains of P70S6K (30%). These alterations represent druggable targets unraveling new therapeutic treatments as metformin here evaluated in vitro. Moreover, CNV of PTEN, PDCD4, and P70S6K, evaluated individually or in combination, are associated with reduced survival of SS patients. These data shed light on effects in vivo of skin-SS cells interaction underlying the prognostic and therapeutic relevance of mTORC1 pathway in SS.
Assuntos
Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Síndrome de Sézary/metabolismo , Síndrome de Sézary/patologia , Transdução de Sinais , Neoplasias Cutâneas/metabolismo , Neoplasias Cutâneas/patologia , Biomarcadores , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Proliferação de Células , Variações do Número de Cópias de DNA , Humanos , Imuno-Histoquímica , Imunofenotipagem , Metformina/farmacologia , Modelos Biológicos , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patologia , Prognóstico , Síndrome de Sézary/mortalidade , Neoplasias Cutâneas/mortalidadeRESUMO
T Cell Leukemia/Lymphoma 1A is expressed during B-cell differentiation and, when over-expressed, acts as an oncogene in mouse (Tcl1a) and human (TCL1A) B-cell chronic lymphocytic leukemia (B-CLL) and T-cell prolymphocytic leukemia (T-PLL). Furthermore, in the murine system Tcl1a is expressed in the ovary, testis and in pre-implantation embryos, where it plays an important role in blastomere proliferation and in embryonic stem cell (ESC) proliferation and self-renewal. We have also observed that Tcl1-/- adult mice exhibit alopecia and deep ulcerations. This finding has led us to investigate the role of TCL1 in mouse skin and hair follicles. We have found that TCL1 is expressed in the proliferative structure (i.e. the secondary hair germ) and in the stem cell niche (i.e. the bulge) of the hair follicle during regeneration phase and it is constitutively expressed in the basal layer of epidermis where it is required for the correct proliferative-differentiation program of the keratinocytes (KCs). Taking advantage of the murine models we have generated, including the Tcl1-/- and the K14-TCL1 transgenic mouse, we have analysed the function of TCL1 in mouse KCs and the molecular pathways involved. We provide evidence that in the epidermal compartment TCL1 has a role in the regulation of KC proliferation, differentiation, and apoptosis. In particular, the colony-forming efficiency (CFE) and the insulin-like growth factor 1 (IGF1)-induced proliferation are dramatically impaired, while apoptosis is increased, in KCs from Tcl1-/- mice when compared to WT. Moreover, the expression of differentiation markers such as cytokeratin 6 (KRT6), filaggrin (FLG) and involucrin (IVL) are profoundly altered in mutant mice (Tcl1-/-). Importantly, by over-expressing TCL1A in basal KCs of the K14-TCL1 transgenic mouse model, we observed a significant rescue of cell proliferation, differentiation and apoptosis of the mutant phenotype. Finally, we found TCL1 to act, at least in part, via increasing phospho-ERK1/2 and decreasing phospho-P38 MAPK. Hence, our data demonstrate that regulated levels of Tcl1a are necessary for the correct proliferation and differentiation of the interfollicular KCs.
Assuntos
Proliferação de Células/fisiologia , Fator de Crescimento Insulin-Like I/metabolismo , Queratinócitos/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Apoptose/fisiologia , Diferenciação Celular/fisiologia , Modelos Animais de Doenças , Epiderme/metabolismo , Epiderme/patologia , Proteínas Filagrinas , Regulação Neoplásica da Expressão Gênica/fisiologia , Folículo Piloso/metabolismo , Folículo Piloso/patologia , Queratinócitos/patologia , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Sistema de Sinalização das MAP Quinases/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pele/metabolismo , Pele/patologia , Nicho de Células-Tronco/fisiologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Cutaneous T-cell lymphoma is a group of incurable extranodal non-Hodgkin lymphomas that develop from the skin-homing CD4+ T cell. Mycosis fungoides and Sézary syndrome are the most common histological subtypes. Although next-generation sequencing data provided significant advances in the comprehension of the genetic basis of this lymphoma, there is not uniform consensus on the identity and prevalence of putative driver genes for this heterogeneous group of tumors. Additional studies may increase the knowledge about the complex genetic etiology characterizing this lymphoma. We used SNP6 arrays and GISTIC algorithm to prioritize a list of focal somatic copy-number alterations in a dataset of multiple sequential samples from 21 Sézary syndrome patients. Our results confirmed a prevalence of significant focal deletions over amplifications: single well-known tumor suppressors, such as TP53, PTEN, and RB1, are targeted by these aberrations. In our cohort, ZEB1 (TCF8, ZFHX1A) spans a deletion having the highest level of significance. In a larger group of 43 patients, we found that ZEB1 is affected by deletions and somatic inactivating mutations in 46.5% of cases; also, we found potentially relevant ZEB1 germline variants. The survival analysis shows a worse clinical course for patients with ZEB1 biallelic inactivation. Multiple abnormal expression signatures were found associated with ZEB1 depletion in Sézary patients we verified that ZEB1 exerts a role in oxidative response of Sézary cells. Our data confirm the importance of deletions in the pathogenesis of cutaneous T-cell lymphoma. The characterization of ZEB1 abnormalities in Sézary syndrome fulfils the criteria of a canonical tumor suppressor gene. Although additional confirmations are needed, our findings suggest, for the first time, that ZEB1 germline variants might contribute to the risk of developing this disease. Also, we provide evidence that ZEB1 activity in Sézary cells, influencing the reactive oxygen species production, affects cell viability and apoptosis.
Assuntos
Regulação Neoplásica da Expressão Gênica , Predisposição Genética para Doença , Mutação em Linhagem Germinativa , Síndrome de Sézary/genética , Neoplasias Cutâneas/genética , Homeobox 1 de Ligação a E-box em Dedo de Zinco/genética , Apoptose , Linhagem Celular Tumoral , Sobrevivência Celular , Variações do Número de Cópias de DNA , Humanos , Análise de Sequência com Séries de Oligonucleotídeos , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/imunologia , Polimorfismo de Nucleotídeo Único , Espécies Reativas de Oxigênio/imunologia , Espécies Reativas de Oxigênio/metabolismo , Proteínas de Ligação a Retinoblastoma/genética , Proteínas de Ligação a Retinoblastoma/imunologia , Síndrome de Sézary/imunologia , Síndrome de Sézary/mortalidade , Síndrome de Sézary/patologia , Pele/imunologia , Pele/patologia , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologia , Análise de Sobrevida , Linfócitos T/imunologia , Linfócitos T/patologia , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/imunologia , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/imunologia , Homeobox 1 de Ligação a E-box em Dedo de Zinco/deficiência , Homeobox 1 de Ligação a E-box em Dedo de Zinco/imunologiaRESUMO
The involvement of microRNAs (miRNAs) in chronic lymphocytic leukemia (CLL) pathogenesis suggests the possibility of anti-CLL therapeutic approaches based on miRNAs. Here, we used the Eµ-TCL1 transgenic mouse model, which reproduces leukemia with a similar course and distinct immunophenotype as human B-CLL, to test miR-181b as a therapeutic agent.In vitro enforced expression of miR-181b mimics induced significant apoptotic effects in human B-cell lines (RAJI, EHEB), as well as in mouse Eµ-TCL1 leukemic splenocytes. Molecular analyses revealed that miR-181b not only affected the expression of TCL1, Bcl2 and Mcl1 anti-apoptotic proteins, but also reduced the levels of Akt and phospho-Erk1/2. Notably, a siRNA anti-TCL1 could similarly down-modulate TCL1, but exhibited a reduced or absent activity in other relevant proteins, as well as a reduced effect on cell apoptosis and viability. In vivo studies demonstrated the capability of miR-181b to reduce leukemic cell expansion and to increase survival of treated mice.These data indicate that miR-181b exerts a broad range of actions, affecting proliferative, survival and apoptotic pathways, both in mice and human cells, and can potentially be used to reduce expansion of B-CLL leukemic cells.
Assuntos
Terapia Genética/métodos , Leucemia Linfocítica Crônica de Células B/terapia , MicroRNAs/genética , Proteínas Proto-Oncogênicas/genética , Animais , Apoptose , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Sobrevivência Celular , Modelos Animais de Doenças , MAP Quinases Reguladas por Sinal Extracelular/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Regulação Neoplásica da Expressão Gênica , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/metabolismo , Leucemia Linfocítica Crônica de Células B/patologia , Camundongos Transgênicos , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Interferência de RNA , Transdução de Sinais , Baço/imunologia , Baço/metabolismo , Baço/patologia , Fatores de Tempo , TransfecçãoRESUMO
Sézary syndrome (SS) is a rare form of cutaneous T-cell lymphoma (CTCL) characterized by a distinct metastatic pattern mainly involving blood and skin. Chemokines and their receptors play a critical role in cellular recruitment and homing to tissues and in the metastatic process of several tumors including non-Hodgkin T-cell lymphomas (NHLs). Here we report that SS cells express a functionally active CXCR4 and that its ligand SDF-1 is abundantly produced in the skin, which represents the main destination of SS cell spreading. SDF-1 is normally inactivated by proteolytic cleavage by the CD26/dipeptidylpeptidase IV (DPPIV). The lack of CD26 from the cell surface is a hallmark of circulating SS cells. We also show that the CD26(-) phenotype is maintained also in skin-infiltrating neoplastic T lymphocytes and that SS-affected individuals exhibit a reduced activity of plasma soluble CD26. Finally, we observe that the addition of soluble CD26 reduces the migratory response of SS cells to SDF-1 whereas the inhibition of the CD26 peptidase activity in Hut78, a CD26(+) CTCL cell line, enhances the SDF-1-induced migration of these cells. Our findings suggest that the SDF-1-CXCR4 axis could play an important role in skin homing of SS through the regulatory activity of CD26.
Assuntos
Adenosina Desaminase/metabolismo , Quimiocinas CXC/farmacologia , Dipeptidil Peptidase 4/metabolismo , Regulação Leucêmica da Expressão Gênica/efeitos dos fármacos , Glicoproteínas/metabolismo , Receptores CXCR4/metabolismo , Síndrome de Sézary/metabolismo , Transdução de Sinais/efeitos dos fármacos , Linhagem Celular Tumoral , Movimento Celular/efeitos dos fármacos , Quimiocina CXCL12 , Quimiocinas CXC/metabolismo , Regulação para Baixo/efeitos dos fármacos , Humanos , Metástase Neoplásica , Síndrome de Sézary/patologia , Pele/metabolismo , Pele/patologia , Linfócitos T/metabolismo , Linfócitos T/patologiaRESUMO
TCL1, the overexpression of which may result in T-cell leukemia, is normally expressed in early embryonic tissues, the ovary, and lymphoid lineage cells. Our analysis of mouse B-lineage cells indicates that Tcl1 expression is initiated in pro-B cells and persists in splenic marginal zone and follicular B cells. T-lineage Tcl1 expression begins in thymocyte progenitors, continues in CD4(+)CD8(+) thymocytes, and is extinguished in mature T cells. In Tcl1-deficient mice, we found B lymphopoiesis to be compromised at the pre-B cell stage and T-cell lymphopoiesis to be impaired at the CD4(+)CD8(+) thymocyte stage. A corresponding increase was observed in thymocyte susceptibility to anti-CD3epsilon-induced apoptosis. Reduced numbers of splenic follicular and germinal center B cells were accompanied by impaired production of immunoglobulin G1 (IgG1) and IgG2b antibodies in response to a T-dependent antigen. The marginal zone B cells and T-cell-independent antibody responses were also diminished in Tcl1(-/-) mice. This analysis indicates a significant role for Tcl1, a coactivator of Akt signaling, in normal T- and B-cell development and function.