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1.
Gynecol Oncol ; 156(1): 233-242, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31711657

RESUMO

OBJECTIVE: Epithelial ovarian cancer (EOC) is usually diagnosed at advanced stages with highly variable clinical outcomes, even among patients with similar clinical characteristics and treatments. Host immune system plays a pivotal role in EOC pathogenesis and progression. Here, we assessed the clinical significance of 192 single nucleotide polymorphisms (SNPs) on 34 immune-system related genes in EOC patients. METHODS: Two hundred and thirty advanced EOC patients treated with platinum-based chemotherapy were included. Germ-line DNA was analyzed with Illumina GoldenGate Genotyping Assay. RESULTS: Nineteen polymorphisms were significantly associated with overall survival (OS), 17 with progression free survival (PFS) and 20 with platinum-free interval (PFI). Of the 8 polymorphisms associated with all three outcomes, 7 SNPs belonged to genes involved in the TGF-ß pathway. A genetic score was built considering the unfavourable genotypes (UGs) of these 7 polymorphisms (group 0-2 UGs: presence of 0, 1, or 2 UGs; group 3-4 UGs: 3 or 4 UGs; group 5-7: 5, 6, or 7 UGs). According to this score, OS decreased as the number of UGs increased (median OS: 0-2 UGs = not reached, 3-4 UGs = 44.6 and 5-7 UGs = 19.3 months, p < 0.0001). The same trend was observed also for PFS (median PFS: 0-2 UGs = 21.5, 3-4 UGs = 17.3 and 5-7 UGs = 11 months, p < 0.0001) and PFI (median PFI: 0-2 UGs = 16.6, 3-4 UGs = 9.8 and 5-7 UGs = 3.8 months, p < 0.0001). The score was validated by permutation analysis. CONCLUSIONS: The proposed TGF-ß pathway score could be useful to define prognosis and platinum sensitivity of advanced EOC patients.

2.
Cancers (Basel) ; 11(10)2019 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-31618839

RESUMO

Immunotherapy by using immune checkpoint inhibitors (ICI) has dramatically improved the treatment options in various cancers, increasing survival rates for treated patients. Nevertheless, there are heterogeneous response rates to ICI among different cancer types, and even in the context of patients affected by a specific cancer. Thus, it becomes crucial to identify factors that predict the response to immunotherapeutic approaches. A comprehensive investigation of the mutational and immunological aspects of the tumor can be useful to obtain a robust prediction. By performing a pan-cancer analysis on gene expression data from the Cancer Genome Atlas (TCGA, 8055 cases and 29 cancer types), we set up and validated a machine learning approach to predict the potential for positive response to ICI. Support vector machines (SVM) and extreme gradient boosting (XGboost) models were developed with a 10×5-fold cross-validation schema on 80% of TCGA cases to predict ICI responsiveness defined by a score combining tumor mutational burden and TGF- ß signaling. On the remaining 20% validation subset, our SVM model scored 0.88 accuracy and 0.27 Matthews Correlation Coefficient. The proposed machine learning approach could be useful to predict the putative response to ICI treatment by expression data of primary tumors.

3.
Haematologica ; 2019 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-31289209

RESUMO

In chronic lymphocytic leukemia, the hypoxia-inducible factor 1 (HIF-1) regulates the response of tumour cells to hypoxia and their protective interactions with the leukemic microenvironment. In this study we demonstrate that chronic lymphocytic leukemia cells from TP53-disrupted (TP53dis) patients have constitutively higher expression levels of the α-subunit of HIF-1 (HIF-1 α) and increased HIF-1 transcriptional activity, compared to the wild type counterpart. In the TP53dis subset, HIF-1 α upregulation is due to reduced expression of the HIF-1 α ubiquitin ligase von Hippel-Lindau protein (pVHL). Hypoxia and stromal cells further enhance HIF-1α accumulation, independently from the TP53 status. Hypoxia acts through the downmodulation of pVHL and the activation of the PI3K/AKT and RAS/ERK1-2 pathways, whereas stromal cells induce an increased activity of the RAS/ERK1-2, RHOA/RHOA kinase and PI3K/AKT pathways, without affecting pVHL expression. Interestingly, we observed that higher levels of HIF-1A mRNA correlate with a lower susceptibility of leukemic cells to spontaneous apoptosis, and associate with the fludarabine resistance that mainly characterizes TP53dis tumour cells. The HIF-1α inhibitor BAY87-2243 exerts cytotoxic effects toward leukemic cells, regardless of the TP53 status, and has anti-tumour activity in Eµ-TCL1 mice. BAY87-2243 also overcomes the constitutive fludarabine resistance of TP53dis leukemic cells and elicits a strongly synergistic cytotoxic effect in combination with ibrutinib, thus providing preclinical evidences for its further investigation as a potential new drug in chronic lymphocytic leukemia.

4.
Expert Rev Clin Pharmacol ; 12(5): 453-470, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30907177

RESUMO

INTRODUCTION: The introduction of immune checkpoint inhibitors has been lately proposed for the treatment of hepatocellular carcinoma (HCC) with respect to other cancer types. Several immunotherapeutic approaches are now under evaluation for HCC treatment including: i) antibodies acting as immune checkpoint inhibitors; ii) antibodies targeting specific tumor-associated antigens; iii) chimeric antigen receptor redirected T (CAR-T) cells targeting specific tumor-associated antigens; iv) vaccination strategies with tumor-specific epitopes. Areas covered: The review provides a wide description of the clinical trials investigating the efficacy of the main immunotherapeutic approaches proposed for the treatment of patients affected by HCC. Expert opinion: The balancing between immunostimulative and immunosuppressive factors in the context of HCC tumor microenvironment results in heterogeneous response rates to immunotherapeutic approaches such as checkpoint inhibitors, among HCC patients. In this context, it becomes crucial the identification of predictive factors determining the treatment response. A multiple approach using different biomarkers could be useful to identify the subgroup of HCC patients responsive to the treatment with a checkpoint inhibitor (as an example, nivolumab) as single agent, and to identify those patients in which other treatment regimens, such as the combination with sorafenib, or with locoregional therapies, could be more effective.


Assuntos
Carcinoma Hepatocelular/terapia , Imunoterapia/métodos , Neoplasias Hepáticas/terapia , Animais , Antineoplásicos Imunológicos/administração & dosagem , Antineoplásicos Imunológicos/farmacologia , Carcinoma Hepatocelular/imunologia , Carcinoma Hepatocelular/patologia , Humanos , Neoplasias Hepáticas/imunologia , Neoplasias Hepáticas/patologia , Terapia de Alvo Molecular , Resultado do Tratamento , Microambiente Tumoral
8.
Haematologica ; 103(5): 849-856, 2018 05.
Artigo em Inglês | MEDLINE | ID: mdl-29472356

RESUMO

Mantle cell lymphoma patients have variable clinical courses, ranging from indolent cases that do not require immediate treatment to aggressive, rapidly progressing diseases. Thus, diagnostic tools capable of stratifying patients according to their risk of relapse and death are needed. This study included 83 samples from the Fondazione Italiana Linfomi MCL-0208 clinical trial. Through gene expression profiling and quantitative real-time PCR we analyzed 46 peripheral blood and 43 formalin-fixed paraffin-embedded lymph node samples. A prediction model to classify patients was developed. By analyzing the transcriptome of 27 peripheral blood samples, two subgroups characterized by a differential expression of genes from the B-cell receptor pathway (B-cell receptorlow and B-cell receptorhigh) were identified. The prediction model based on the quantitative real-time PCR values of six representative genes (AKT3, BCL2, BTK, CD79B, PIK3CD, and SYK), was used to classify the 83 cases (43 B-cell receptorlow and 40 B-cell receptorhigh). The B-cell receptorhigh signature associated with shorter progression-free survival (P=0.0074), selected the mantle cell lymphoma subgroup with the shortest progression-free survival and overall survival (P=0.0014 and P=0.029, respectively) in combination with high (>30%) Ki-67 staining, and was an independent predictor of short progression- free survival along with the Mantle Cell Lymphoma International Prognostic Index-combined score. Moreover, the clinical impact of the 6- gene signature related to the B-cell receptor pathway identified a mantle cell lymphoma subset with shorter progression-free survival intervals also in an external independent mantle cell lymphoma cohort homogenously treated with different schedules. In conclusion, this 6-gene signature associates with a poor clinical response in the context of the MCL- 0208 clinical trial. (clinicaltrials.gov identifier: 02354313).


Assuntos
Biomarcadores Tumorais/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/mortalidade , Receptores de Antígenos de Linfócitos B/genética , Adulto , Idoso , Feminino , Seguimentos , Humanos , Linfoma de Célula do Manto/patologia , Linfoma de Célula do Manto/terapia , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Prospectivos , Taxa de Sobrevida
9.
J Exp Med ; 215(2): 681-697, 2018 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-29301866

RESUMO

The Bruton's tyrosine kinase (BTK) inhibitor ibrutinib, which antagonizes B cell receptor (BCR) signals, demonstrates remarkable clinical activity in chronic lymphocytic leukemia (CLL). The lymphocytosis experienced by most patients under ibrutinib has previously been attributed to inhibition of BTK-dependent integrin and chemokine cues operating to retain the tumor cells in nodal compartments. Here, we show that the VLA-4 integrin, as expressed by CD49d-positive CLL, can be inside-out activated upon BCR triggering, thus reinforcing the adhesive capacities of CLL cells. In vitro and in vivo ibrutinib treatment, although reducing the constitutive VLA-4 activation and cell adhesion, can be overcome by exogenous BCR triggering in a BTK-independent manner involving PI3K. Clinically, in three independent ibrutinib-treated CLL cohorts, CD49d expression identifies cases with reduced lymphocytosis and inferior nodal response and behaves as independent predictor of shorter progression-free survival, suggesting the retention of CD49d-expressing CLL cells in tissue sites via activated VLA-4. Evaluation of CD49d expression should be incorporated in the characterization of CLL undergoing therapy with BCR inhibitors.


Assuntos
Integrina alfa4beta1/metabolismo , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Pirazóis/uso terapêutico , Pirimidinas/uso terapêutico , Tirosina Quinase da Agamaglobulinemia/antagonistas & inibidores , Tirosina Quinase da Agamaglobulinemia/metabolismo , Adesão Celular/efeitos dos fármacos , Humanos , Imunoglobulina M/metabolismo , Estimativa de Kaplan-Meier , Linfonodos/efeitos dos fármacos , Linfonodos/metabolismo , Linfonodos/patologia , Linfocitose/metabolismo , Linfocitose/patologia , Análise Multivariada , Fosfatidilinositol 3-Quinases/metabolismo , Intervalo Livre de Progressão , Modelos de Riscos Proporcionais , Inibidores de Proteínas Quinases/farmacologia , Pirazóis/farmacologia , Pirimidinas/farmacologia , Receptores de Antígenos de Linfócitos B/metabolismo
12.
Hematol Oncol ; 35(4): 472-479, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27781290

RESUMO

Low-dose radiotherapy (LDRT) given in 2 × 2 Gy is a highly effective and safe treatment for palliation of indolent lymphomas. Otherwise, very little regarding the use of LDRT for diffuse large B-cell lymphoma (DLBCL) has been investigated. We designed a phase 2 trial of LDRT in patients with DLBCL with indication for palliative radiation. Low-dose radiotherapy was administered on symptomatic areas only. Clinical response was assessed 21 days after LDRT and defined as reduction >50% of maximum diameter of the radiated lesions. Quality of life was scored by the European Organisation for Research and Treatment of Cancer QLQ-C30 questionnaire. Tumor subtype (germinal center B-cell type versus activated B-cell type) and the presence of TP53 mutations in pathologic specimens of the target lesion were also evaluated. Twenty-three of twenty-five radiated patients were evaluable for response, and 2 died of disease before the visit at 21 days. The overall response rate was 70% (16 of 23 patients), with 7 complete responses and 9 partial responses (mean duration of response, 6 months; range, 1-39 months). Fifteen patients answered to the QLQ-C30 questionnaires, and an improved quality of life was documented in 9 cases. TP53 mutations were detected in 2 of 6 (33%) nonresponders and in none of the responders (P = .12). Germinal center B-cell type responded better than activated B-cell type (response rate was 83% and 29%, respectively, P = .01). These findings indicate that LDRT is effective for palliation in patients with DLBCL.


Assuntos
Linfoma Difuso de Grandes Células B/radioterapia , Qualidade de Vida/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Feminino , Humanos , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos
13.
Curr Cancer Drug Targets ; 16(8): 659-668, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27514846

RESUMO

Chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease characterized by the accumulation/expansion of a clonal population of neoplastic cells with the morphological appearance of small mature B lymphocytes in blood, bone marrow, and lymphoid organs. CD49d, the α chain of the α4ß1 integrin heterodimer, is one of the main interactors between CLL cells and accessory cells in the microenvironmental sites and one of the main predictors of overall survival. In particular, CD49d is known to play a pivotal role in mediating both cell-cell and cell-matrix interactions in CLL-involved tissues eventually delivering prosurvival signals and protecting CLL cells from drug-induced damages. Treatment strategies targeting the α4ß1 integrin could represent an interesting option in CLL. In this context, the recombinant anti-CD49d antibody natalizumab demonstrated the potential to overcome stromal cell-induced resistance of B cell lymphoma cells against cytotoxic drugs and rituximab in vitro. Moreover, a specific interest for the CD49d molecule raises from the clinical activity of the recently proposed inhibitors of kinases downstream the BCR that has been recently related with the inside-out activation of the α4ß1 integrin. In the review, we addressed in detail the role of CD49d in CLL cells, including clinical impact, relationship with specific cytogenetic features, and CD49d-dependent interactions in lymph node and bone marrow microenvironment responsible for growth- and survival- supporting signals, eventually influencing CLL prognosis and therapeutic options.


Assuntos
Cadeias alfa de Integrinas/metabolismo , Integrina alfa4/metabolismo , Leucemia Linfocítica Crônica de Células B/metabolismo , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Humanos , Integrina alfa4beta1/metabolismo , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico
14.
Haematologica ; 101(1): 77-85, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26565002

RESUMO

In chronic lymphocytic leukemia the balance between the pro-apoptotic and anti-apoptotic members of the bcl-2 family is involved in the pathogenesis, chemorefractoriness and clinical outcome. Moreover, the recently proposed anti-bcl-2 molecules, such as ABT-199, have emphasized the potential role of of bcl-2 family proteins in the context of target therapies. We investigated bax/bcl-2 ratio by flow cytometry in 502 patients and identified a cut off of 1.50 to correlate bax/bcl-2 ratio with well-established clinical and biological prognosticators. Bax/bcl-2 was 1.50 or over in 263 patients (52%) with chronic lymphocytic leukemia. Higher bax/bcl-2 was associated with low Rai stage, lymphocyte doubling time over 12 months, beta-2 microglobulin less than 2.2 mg/dL, soluble CD23 less than 70 U/mL and a low risk cytogenetic profile (P<0.0001). On the other hand, lower bax/bcl-2 was correlated with unmutated IGHV (P<0.0001), mutated NOTCH1 (P<0.0001) and mutated TP53 (P=0.00007). Significant shorter progression-free survival and overall survival were observed in patients with lower bax/bcl-2 (P<0.0001). Moreover, within IGHV unmutated (168 patients) and TP53 mutated (37 patients) subgroups, higher bax/bcl-2 identified cases with significant longer PFS (P=0.00002 and P=0.039). In multivariate analysis of progression-free survival and overall survival, bax/bcl-2 was an independent prognostic factor (P=0.0002 and P=0.002). In conclusion, we defined the prognostic power of bax/bcl-2 ratio, as determined by a flow cytometric approach, and highlighted a correlation with chemoresistance and outcome in chronic lymphocytic leukemia. Finally, the recently proposed new therapies employing bcl-2 inhibitors prompted the potential use of bax/bcl-2 ratio to identify patients putatively resistant to these molecules.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Leucemia Linfocítica Crônica de Células B , Proteínas Proto-Oncogênicas c-bcl-2/sangue , Proteína X Associada a bcl-2/sangue , Adulto , Idoso , Idoso de 80 Anos ou mais , Clorambucila/administração & dosagem , Intervalo Livre de Doença , Feminino , Humanos , Leucemia Linfocítica Crônica de Células B/sangue , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Leucemia Linfocítica Crônica de Células B/mortalidade , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prednisolona/administração & dosagem , Estudos Retrospectivos , Rituximab/administração & dosagem , Taxa de Sobrevida , Vidarabina/administração & dosagem , Vidarabina/análogos & derivados
15.
Oncotarget ; 6(23): 19381-92, 2015 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-26305986

RESUMO

MicroRNAs (miRNAs) represent a class of small non-coding single-stranded RNA molecules acting as master regulators of gene expression post transcriptionally by inhibiting the translation or inducing the degradation of target messenger RNAs (mRNAs). In particular, the miR-17-92 cluster is widely expressed in many different cell types and is essential for many developmental and pathogenic processes. As a strong oncogene, miR-17-92 can regulate multiple cellular processes that favor malignant transformation, promoting cell survival, rapid cell proliferation, and increased angiogenesis. The miR-17-92 cluster has been reported to be involved in hematopoietic malignancies including diffuse large B-cell lymphoma, mantle cell lymphoma, Burkitt's lymphoma, and chronic lymphocytic leukemia. Given the multiple and potent effects on cellular proliferation and apoptosis exerted by the miR-17-92 cluster, miRNAs belonging to the cluster surely represent attractive targets for cancer therapy also in the context of lymphoproliferative disorders. In the present review, we focus on the role of the miR-17-92 cluster in lymphoproliferative disorders, including diagnostic/prognostic implications, and on the potential applications of anti-miRNAs based therapies targeting miRNAs belonging to the cluster.


Assuntos
Transtornos Linfoproliferativos/genética , MicroRNAs/genética , Proteínas Proto-Oncogênicas c-myc/genética , Animais , Proliferação de Células/fisiologia , Humanos , Transtornos Linfoproliferativos/metabolismo , Transtornos Linfoproliferativos/patologia , MicroRNAs/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo
16.
Oncotarget ; 6(22): 19102-17, 2015 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-26036258

RESUMO

The B-cell receptor (BCR) plays an important role in the pathogenesis and progression of chronic lymphocytic leukemia (CLL). By global microRNA profiling of CLL cells stimulated or not stimulated by anti-IgM, significant up-regulation of microRNAs from the miR-132~212 cluster was observed both in IGHV gene unmutated (UM) and mutated (M) CLL cells. Parallel gene expression profiling identified SIRT1, a deacetylase targeting several proteins including TP53, among the top-ranked miR-132 target genes down-regulated upon anti-IgM exposure. The direct regulation of SIRT1 expression by miR-132 was demonstrated using luciferase assays. The reduction of SIRT1 mRNA and protein (P = 0.001) upon anti-IgM stimulation was associated with an increase in TP53 acetylation (P = 0.007), and the parallel up-regulation of the TP53 target gene CDKN1A. Consistently, miR-132 transfections of CLL-like cells resulted in down-regulation of SIRT1 and an induction of a TP53-dependent apoptosis. Finally, in a series of 134 CLL samples, miR-132, when expressed above the median value, associated with prolonged time-to-first-treatment in patients with M CLL (HR = 0.41; P = 0.02). Collectively, the miR-132/SIRT1/TP53 axis was identified as a novel pathway triggered by BCR engagement that further increases the complexity of the interactions between tumor microenvironments and CLL cells.


Assuntos
Leucemia Linfocítica Crônica de Células B/metabolismo , MicroRNAs/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Sirtuína 1/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Linfócitos B/metabolismo , Linfócitos B/patologia , Estudos de Casos e Controles , Proliferação de Células/fisiologia , Genes p53 , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/patologia , MicroRNAs/genética , Receptores de Antígenos de Linfócitos B/genética , Transdução de Sinais , Sirtuína 1/genética , Transfecção , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/genética , Regulação para Cima
18.
J Hematol Oncol ; 7: 79, 2014 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-25339346

RESUMO

Recently it was reported that microRNA from the miR-17 ~ 92 family may have a key role in chronic lymphocytic leukemia (CLL). Here, we designed specific oligonucleotides to target endogenous miR-17 (antagomiR17). In-vitro administration of antagomiR17 effectively reduced miR-17 expression and the proliferation of CLL-like MEC-1 cells. When injected in-vivo in tumor generated by the MEC-1 cells in SCID mice, antagomiR17 dramatically reduced tumor growth and significantly increase survival. Altogether, our results provide the rationale for the use of antagomiR17 as a novel potential therapeutic tool in CLL and in other lymphoproliferative disorders where miR-17 has a driver role in tumor progression.


Assuntos
Antineoplásicos/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , MicroRNAs/antagonistas & inibidores , Oligorribonucleotídeos/farmacologia , Animais , Linhagem Celular Tumoral , Humanos , Camundongos , Camundongos SCID , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Semin Hematol ; 51(3): 168-76, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25048781

RESUMO

Chronic lymphocytic leukemia (CLL) is a clinically heterogeneous disease characterized by the accumulation/expansion of a clonal population of neoplastic cells with the morphologic appearance of small mature B lymphocytes in blood, bone marrow, and lymphoid organs. A combination of genetic lesions is primarily responsible for the first step(s) of neoplastic transformation, along with microenvironmental signals, which concurrently operate by enhancing proliferation and/or inhibiting apoptosis. In this context, CD49d is known to play a pivotal role in mediating both cell-cell and cell-matrix interactions in CLL-involved tissues, eventually delivering pro-survival signals and protecting CLL cells from drug-induced damages. In the present review, we address, in detail, CD49d activities in the CLL microenvironment, CD49d functional and physical interactions with other microenvironmental receptors (including CD38 and B-cell receptor), and the relationship of CD49d expression with specific cytogenetic features in CLL.


Assuntos
Integrina alfa4/metabolismo , Leucemia Linfocítica Crônica de Células B/metabolismo , ADP-Ribosil Ciclase 1/metabolismo , Linfócitos B/imunologia , Humanos , Leucemia Linfocítica Crônica de Células B/mortalidade , Leucemia Linfocítica Crônica de Células B/patologia , Transdução de Sinais , Trissomia , Microambiente Tumoral
20.
J Hematol Oncol ; 6: 83, 2013 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-24283248

RESUMO

BACKGROUND: TP53 defects, i.e., 17p13 deletion and/or nucleotide mutations, associate with short survival and chemorefractoriness in chronic lymphocytic leukemia (CLL). In this context, since direct sequencing of the TP53 gene does not evaluate TP53 functionality, a functional assessment of TP53 pathway may be of interest to identify high risk CLL. By taking advantage of a training cohort of 100 CLL and a validation cohort of 40 CLL with different patterns of TP53 mutation/deletion by FISH and sequencing, we propose an in-vitro assay in which the modulation of TP53 protein and CDKN1A mRNA were investigated upon 24-hour exposure of CLL cells to Nutlin-3. METHODS: The functional assay was set-up on cell lines recapitulating all TP53 genotypes (EHEB, TP53(wt/wt); RAJI, TP53(mut/wt); MEC-1 and MAVER1, TP53(mut/del); HL-60, TP53(del/del)) and evaluated in two multi-institutional cohorts, purposely enriched in CLL bearing TP53 disruption: a training cohort of 100 cases and a validation cohort of 40 cases, both characterized by FISH and TP53 direct sequencing. Cells were exposed to 10 µM Nutlin-3 for 24 hours; TP53 accumulation was evaluated by Western blotting; TP53 transcriptional activity was determined by quantitative realtime PCR (qRT-PCR) of the TP53 target gene CDKN1A. RESULTS: According to TP53 protein modulation, in the training cohort we identified: (i) 63 cases (51 TP53wt/wt, 12 TP53del/wt) with absence of basal TP53 and induction after treatment (normal pattern); (ii) 18 cases (3 TP53(mut/wt), 15 TP53(mut/del)) with high basal TP53 without increase after treatment (mutant pattern); (iii) 19 cases (5 TP53(mut/wt); 3 TP53(mut/del); 11 TP53(wt/wt)) with basal TP53 that increases upon treatment (intermediate pattern). Evaluation of CDKN1A mRNA levels upon Nutlin-3 exposure showed that the 26 TP53 mutated (TP53(mut/del) or TP53(mut/wt)) cases had lower induction levels than the majority (57/63) of cases with normal pattern, and 10/12 cases with intermediate pattern without evidence of TP53 derangement by FISH and sequencing. These results were confirmed in the independent validation cohort of 40 cases (13 TP53(wt/wt), 3 TP53(del/wt), 12 TP53(mut/del), 12 TP53(mut/wt)). CONCLUSIONS: The proposed functional assay may integrate the conventional analyses for the identification of TP53 dysregulated CLL.


Assuntos
Genes p53 , Imidazóis/farmacologia , Leucemia Linfocítica Crônica de Células B/tratamento farmacológico , Piperazinas/farmacologia , Proteína Supressora de Tumor p53/metabolismo , Western Blotting , Estudos de Coortes , Genótipo , Células HL-60 , Humanos , Leucemia Linfocítica Crônica de Células B/genética , Leucemia Linfocítica Crônica de Células B/metabolismo , Prognóstico , Proteína Supressora de Tumor p53/genética
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