RESUMO
Stathmin 1 (STMN1) is a microtubule-destabilizing protein highly expressed in hematological malignancies and involved in proliferation and differentiation. Although a previous study found that the PML-RARα fusion protein, which contributes to the pathophysiology of acute promyelocytic leukemia (APL), positively regulates STMN1 at the transcription and protein activity levels, little is known about the role of STMN1 in APL. In this study, we aimed to investigate the STMN1 expression levels and their associations with laboratory, clinical, and genomic data in APL patients. We also assessed the dynamics of STMN1 expression during myeloid cell differentiation and cell cycle progression, and the cellular effects of STMN1 silencing and pharmacological effects of microtubule-stabilizing drugs on APL cells. We found that STMN1 transcripts were significantly increased in samples from APL patients compared with those of healthy donors (all p < 0.05). However, this had no effect on clinical outcomes. STMN1 expression was associated with proliferation- and metabolism-related gene signatures in APL. Our data confirmed that STMN1 was highly expressed in early hematopoietic progenitors and reduced during cell differentiation, including the ATRA-induced granulocytic differentiation model. STMN1 phosphorylation was predominant in a pool of mitosis-enriched APL cells. In NB4 and NB4-R2 cells, STMN1 knockdown decreased autonomous cell growth (all p < 0.05) but did not impact ATRA-induced apoptosis and differentiation. Finally, treatment with paclitaxel (as a single agent or combined with ATRA) induced microtubule stabilization, resulting in mitotic catastrophe with repercussions for cell viability, even in ATRA-resistant APL cells. This study provides new insights into the STMN1 functions and microtubule dynamics in APL.
Assuntos
Leucemia Promielocítica Aguda , Diferenciação Celular , Proliferação de Células , Humanos , Leucemia Promielocítica Aguda/tratamento farmacológico , Leucemia Promielocítica Aguda/genética , Leucemia Promielocítica Aguda/patologia , Mitose , Proteínas de Fusão Oncogênica/genética , Paclitaxel , Estatmina/genéticaRESUMO
Adrenocortical carcinoma (ACC) is an aggressive endocrine cancer with few molecular predictors of malignancy and survival, especially in paediatric patients. Stathmin 1 (STMN1) regulates microtubule dynamics and has been involved in the malignant phenotype of cancer cells. Recently, it was reported that STMN1 is highly expressed in ACC patients, and STMN1 silencing reduces the clonogenicity and migration of ACC cell lines. However, the prognostic significance of STMN1 and its therapeutic potential remain undefined in ACC. In the present study, STMN1 mRNA levels were significantly higher (p < 0.05) in ACC patients, especially in an advanced stage, and correlated with BUB1B and PINK1 expression, the prognostic-related genes in ACC. In paediatric tumours, high STMN1 expression was observed in both adrenocortical carcinoma and adrenocortical adenoma patients. Among the adult malignant tumours, STMN1 level was an independent predictor of survival outcomes (overall survival: hazard ratio = 6.08, p = 0.002; disease-free survival: hazard ratio = 4.65, p < 0.0001). Paclitaxel, a microtubule-stabilizing drug, reduces the activation of STMN1 and significantly decreases cell migration and invasion in ACC cell lines and ACC cells from secondary cell culture (all p < 0.0001). In summary, STMN1 expression may be of great value to clinical and pathological findings in therapeutic trials and deserves future studies in ACC.
Assuntos
Neoplasias do Córtex Suprarrenal/genética , Neoplasias do Córtex Suprarrenal/mortalidade , Carcinoma Adrenocortical/genética , Carcinoma Adrenocortical/mortalidade , Movimento Celular/genética , Estatmina/genética , Neoplasias do Córtex Suprarrenal/tratamento farmacológico , Carcinoma Adrenocortical/tratamento farmacológico , Carcinoma Adrenocortical/patologia , Adulto , Biomarcadores Tumorais/genética , Linhagem Celular Tumoral , Pré-Escolar , Intervalo Livre de Doença , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Masculino , Paclitaxel/uso terapêutico , Prognóstico , RNA Mensageiro/genéticaRESUMO
SUMMARY: Uterine smooth muscle tumors (USMT) are common, behavior-distinct gynecological tumors; including: leiomyoma (ULM), leiomyosarcoma (ULMS), and smooth muscle tumors of undetermined malignant potential (STUMP). Pre-operative distinction is difficult, thus diagnosis relies on histopathology. Immunohistochemistry (IHC) had been used to help in distinction. We studied two markers (stathmin-1 and CD147) to demonstrate whether they have diagnostic/ prognostic assist. Sixty seven USMT are studied. Age, follow up, and recurrence/metastasis data were collected. Representative slides were stained and Histologic score (HS) calculated as stain intensity (SI) X percentage of positive tumor cells (PP). Results were grouped as low expression (LE) and high expression (HE); then correlated to tumor types, and risk of recurrence/ metastasis. Statistical analysis (P < 0.05); Sensitivity, specificity, positive and negative predictive values and confidence intervals in diagnosing ULMS were calculated. Stathmin-1 HS (p= 0.000) and HE (p=0.002) were different among groups. Same as for CD147 HS and HE (both p=0.000), with a gradient increase from LM to STUMP to ULMS. Sensitivity, specificity, positive and negative predictive values and confidence intervals in diagnosing ULMS were as following: For stathmin-1 HS: 92 %; 20 %; 42 %; and 80 % (CI= 44-96 %). For Stathmin-1 HE: 80 %; 66 %; 60 %; and 84 % (CI=66-94 %). For CD147 HS: 85 %; 22 %; 41 %; and 69 %. For CD147 HE: 58 %; 49 %; 42 %; and 65 % (CI= 45-80 %), respectively. Recurrence / metastasis were documented in 6 cases (4 ULMS; 2 STUMP) with follow up ranging from 6 months to 102 months. 5 tumors had stathmin-1 HE (p=0.099); 2 had CD147 HE (p=0.393) in the primary tumors. STMN1 and CD147 are helpful diagnostic tests for USMT sub-typing, especially for ULMS. Gradient increase of expression from LM, to STUMP, to ULMS may indicate a role in malignant transformation in USMT, and in increased risk of recurrences/metastasis.
RESUMEN: Los tumores del músculo liso uterino (USMT, por sus siglas en inglés) son tumores ginecológicos comunes y de comportamiento distinto; incluyendo: leiomioma (ULM), leiomiosarcoma (ULMS) y tumores de músculo liso de potencial maligno indeterminado (STUMP). La distinción preoperatoria es difícil, por lo que el diagnóstico se basa en la histopatología. La inmunohistoquímica (IHQ) se había utilizado para ayudar en la distinción. Estudiamos dos marcadores (stathmin-1 y CD147) para demostrar si había efecto diagnóstico / pronóstico. Se estudiaron 67 USMT. Se recopilaron los datos de edad, seguimiento y recurrencia / metástasis. Las muestras representativas se tiñeron y la puntuación histológica (HS) se calculó como la intensidad de la tinción (IS) x porcentaje de células tumorales positivas (PP). Los resultados se agruparon como expresión baja (EB) y expresión alta (EA); luego se correlacionaeon con los tipos de tumores y el riesgo de recurrencia / metástasis. Análisis estadístico (P <0,05); se calcularon la sensibilidad, la especificidad, los valores predictivos positivos y negativos y los intervalos de confianza en el diagnóstico de ULMS. Stathmin-1 HS (p = 0,000) y HE (p = 0,002) fueron diferentes entre los grupos. Igual que para CD147 HS y HE (ambos p = 0,000), con un aumento de gradiente de LM a STUMP a ULMS. La sensibilidad, la especificidad, los valores predictivos positivos y negativos y los intervalos de confianza en el diagnóstico de ULMS fueron los siguientes: Para stathmin-1 HS: 92 %; 20 %; 42 %; y 80 % (IC = 44-96 %). Para Stathmin-1 HE: 80 %; 66 %; 60 %; y 84 % (IC = 66-94 %). Para CD147 HS: 85 %; 22 %; 41 %; y el 69 %. Para CD147 HE: 58 %; 49 %; 42 %; y 65 % (IC = 45-80 %), respectivamente. La recurrencia / metástasis se documentaron en 6 casos (4 ULMS; 2 STUMP) con un seguimiento que osciló entre 6 meses y 102 meses. Cinco tumores tenían stathmin-1 HE (p = 0,099); dos tenían CD147 HE (p = 0,393) en los tumores primarios. STMN1 y CD147 son pruebas de diagnóstico útiles para la subclasificación de USMT, especialmente para ULMS. El aumento en el gradiente de la expresión de LM, a STUMP, a ULMS puede indicar un papel en la transformación maligna en USMT y en un mayor riesgo de recurrencias / metástasis.
Assuntos
Humanos , Feminino , Adulto , Pessoa de Meia-Idade , Neoplasias Uterinas/diagnóstico , Tumor de Músculo Liso/diagnóstico , Estatmina/metabolismo , Basigina/metabolismo , Neoplasias Uterinas/metabolismo , Neoplasias Uterinas/patologia , Imuno-Histoquímica , Intervalos de Confiança , Valor Preditivo dos Testes , Sensibilidade e Especificidade , Tumor de Músculo Liso/metabolismo , Tumor de Músculo Liso/patologia , Leiomioma/diagnóstico , Leiomioma/patologia , Leiomiossarcoma/diagnóstico , Leiomiossarcoma/patologiaRESUMO
The JAK/STAT pathway is constitutively activated in myeloproliferative neoplasms and can be inhibited by ruxolitinib, a selective JAK1/2 inhibitor. The JAK2(V617F) mutation leads to constitutive STAT3 phosphorylation and potentially leads to inhibition of Stathmin 1 activity via STAT3. In support of this hypothesis, we found that, in HEL JAK2(V617F) cells, ruxolitinib treatment decreased STAT3 and Stathmin 1 association, induced Stathmin 1 activation and microtubule instability. Silencing of Stathmin 1 significantly reduced cell proliferation and clonal growth, and increased apoptosis induced by ruxolitinib. Stathmin 1 silencing also prevented ruxolitinib-induced microtubule instability. To phenocopy the effect of Stathmin 1 inhibition, cells were treated with paclitaxel, a microtubule-stabilizing drug, in association or not with ruxolitinib; combined treatment significantly increased apoptosis, when compared to monotherapy. Notably, Stathmin 1 mRNA levels were highly expressed in CD34(+) cells from primary myelofibrosis patients. We then proposed that an undesired effect of ruxolitinib treatment may constitute Stathmin 1 activation and microtubule instability in JAK2(V617F) cells. Induction of microtubule stability, through Stathmin 1 silencing or paclitaxel treatment, combined with ruxolitinib could be an effective strategy for promoting apoptosis in JAK2(V617F) cells.
Assuntos
Apoptose/efeitos dos fármacos , Janus Quinase 2/antagonistas & inibidores , Pirazóis/farmacologia , Estatmina/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose/genética , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Janus Quinase 2/genética , Janus Quinase 2/metabolismo , Leucemia Eritroblástica Aguda/genética , Leucemia Eritroblástica Aguda/metabolismo , Leucemia Eritroblástica Aguda/patologia , Microscopia Confocal , Pessoa de Meia-Idade , Mutação de Sentido Incorreto , Transtornos Mieloproliferativos/genética , Transtornos Mieloproliferativos/metabolismo , Nitrilas , Paclitaxel/farmacologia , Pirimidinas , Interferência de RNA , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estatmina/genética , Moduladores de Tubulina/farmacologia , Adulto JovemRESUMO
ANKHD1 is highly expressed in human acute leukemia cells and potentially regulates multiple cellular functions through its ankyrin-repeat domains. In order to identify interaction partners of the ANKHD1 protein and its role in leukemia cells, we performed a yeast two-hybrid system screen and identified SIVA, a cellular protein known to be involved in proapoptotic signaling pathways. The interaction between ANKHD1 and SIVA was confirmed by co-imunoprecipitation assays. Using human leukemia cell models and lentivirus-mediated shRNA approaches, we showed that ANKHD1 and SIVA proteins have opposing effects. While it is known that SIVA silencing promotes Stathmin 1 activation, increased cell migration and xenograft tumor growth, we showed that ANKHD1 silencing leads to Stathmin 1 inactivation, reduced cell migration and xenograft tumor growth, likely through the inhibition of SIVA/Stathmin 1 association. In addition, we observed that ANKHD1 knockdown decreases cell proliferation, without modulating apoptosis of leukemia cells, while SIVA has a proapoptotic function in U937 cells, but does not modulate proliferation in vitro. Results indicate that ANKHD1 binds to SIVA and has an important role in inducing leukemia cell proliferation and migration via the Stathmin 1 pathway. ANKHD1 may be an oncogene and participate in the leukemia cell phenotype.
Assuntos
Movimento Celular/genética , Proliferação de Células/genética , Leucemia/patologia , Proteínas de Ligação a RNA/genética , Estatmina/metabolismo , Sequência de Aminoácidos , Animais , Feminino , Inativação Gênica , Células HEK293 , Humanos , Células Jurkat , Leucemia/genética , Leucemia/metabolismo , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Dados de Sequência Molecular , Estatmina/antagonistas & inibidores , Células U937RESUMO
Stathmin 1 is an important cytoplasmic microtubule-destabilizing protein that plays critical roles in proliferation and accurate chromosome segregation through regulation of microtubule dynamics. High levels of Stathmin 1 expression have been reported in leukemia and solid tumors. However, Stathmin 1 has not been studied in myelodysplastic syndrome cells. We, herein, report that significantly higher Stathmin 1 levels were observed in proliferating hematopoietic cells, in high-risk MDS and acute leukemia cells. In addition, Stathmin 1 silencing in U937 and Namalwa leukemia cells reduced cell proliferation and clonogenicity. Our data suggest that Stathmin 1 expression may be related to the highly proliferative phenotype of hematopoietic cells and add new insights into the participation of Stathmin 1 in hematological malignancies.