RESUMO
INTRODUCTION: Inhibitors of the phosphatidylinositol-3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/AKT/mTOR) pathway can overcome endocrine resistance in estrogen receptor (ER) α-positive breast cancer, but companion diagnostics indicating PI3K/AKT/mTOR activation and consequently endocrine resistance are lacking. PIK3CA mutations frequently occur in ERα-positive breast cancer and result in PI3K/AKT/mTOR activation in vitro. Nevertheless, the prognostic and treatment-predictive value of these mutations in ERα-positive breast cancer is contradictive. We tested the clinical validity of PIK3CA mutations and other canonic pathway drivers to predict intrinsic resistance to adjuvant tamoxifen. In addition, we tested the association between these drivers and downstream activated proteins. METHODS: Primary tumors from 563 ERα-positive postmenopausal patients, randomized between adjuvant tamoxifen (1 to 3 years) versus observation were recollected. PIK3CA hotspot mutations in exon 9 and exon 20 were assessed with Sequenom Mass Spectometry. Immunohistochemistry was performed for human epidermal growth factor receptor 2 (HER2), phosphatase and tensin homolog (PTEN), and insulin-like growth factor 1 receptor (IGF-1R). We tested the association between these molecular alterations and downstream activated proteins (like phospho-protein kinase B (p-AKT), phospho-mammalian target of rapamycin (p-mTOR), p-ERK1/2, and p-p70S6K). Recurrence-free interval improvement with tamoxifen versus control was assessed according to the presence or absence of canonic pathway drivers, by using Cox proportional hazard models, including a test for interaction. RESULTS: PIK3CA mutations (both exon 9 and exon 20) were associated with low tumor grade. An enrichment of PIK3CA exon 20 mutations was observed in progesterone receptor- positive tumors. PIK3CA exon 20 mutations were not associated with downstream-activated proteins. No significant interaction between PIK3CA mutations or any of the other canonic pathway drivers and tamoxifen-treatment benefit was found. CONCLUSION: PIK3CA mutations do not have clinical validity to predict intrinsic resistance to adjuvant tamoxifen and may therefore be unsuitable as companion diagnostic for PI3K/AKT/mTOR inhibitors in ERα- positive, postmenopausal, early breast cancer patients.
Assuntos
Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Resistencia a Medicamentos Antineoplásicos/genética , Fosfatidilinositol 3-Quinases/genética , Tamoxifeno/uso terapêutico , Idoso , Sequência de Bases , Biomarcadores Tumorais/genética , Quimioterapia Adjuvante , Classe I de Fosfatidilinositol 3-Quinases , Intervalo Livre de Doença , Feminino , Humanos , Mutação , PTEN Fosfo-Hidrolase/biossíntese , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase , Pós-Menopausa , Proteínas Proto-Oncogênicas c-akt/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-akt/genética , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor ErbB-2/biossíntese , Receptor IGF Tipo 1/biossíntese , Receptores de Estrogênio/metabolismo , Estudos Retrospectivos , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Análise de Sequência de DNA , Serina-Treonina Quinases TOR/antagonistas & inibidores , Serina-Treonina Quinases TOR/genética , Serina-Treonina Quinases TOR/metabolismo , Pesquisa Translacional BiomédicaRESUMO
INTRODUCTION: Activation of the phosphatidylinositol-3-kinase (PI3K) and/or mitogen-activated protein kinase (MAPK) pathways results in anti-estrogen resistance in vitro, but a biomarker with clinical validity to predict intrinsic resistance has not been identified. In metastatic breast cancer patients with previous exposure to endocrine therapy, the addition of a mammalian target of rapamycine (mTOR) inhibitor has been shown to be beneficial. Whether or not patients on adjuvant endocrine treatment might benefit from these drugs is currently unclear. A biomarker that predicts intrinsic resistance could potentially be used as companion diagnostic in this setting. We tested the clinical validity of different downstream-activated proteins in the PI3K and/or MAPK pathways to predict intrinsic tamoxifen resistance in postmenopausal primary breast cancer patients. METHODS: We recollected primary tumor tissue from patients who participated in a randomized trial of adjuvant tamoxifen (1-3 years) versus observation. After constructing a tissue micro-array, cores from 563 estrogen receptor α positive were immunostained for p-AKT(Thr308), p-AKT(Ser473), p-mTOR, p-p706SK and p-ERK1/2. Cox proportional hazard models for recurrence free interval were used to assess hazard ratios and interactions between these markers and tamoxifen treatment efficacy. RESULTS: Interactions were identified between tamoxifen and p-AKT(Thr308), p-mTOR, p-p70S6K and p-ERK1/2. Applying a conservative level of significance, p-p70S6K remained significantly associated with tamoxifen resistance. Patients with p-p70S6K negative tumors derived significant benefit from tamoxifen (HR 0.24, P < 0.0001), while patients whose tumor did express p-p70S6K did not (HR = 1.02, P =0.95), P for interaction 0.004. In systemically untreated breast cancer patients, p-p70S6K was associated with a decreased risk for recurrence. CONCLUSIONS: Patients whose tumor expresses p-p70S6K, as a marker of downstream PI3K and/or MAPK pathway activation, have a favorable prognosis, but do not benefit from adjuvant tamoxifen. A potential benefit from inhibitors of the PI3K/Akt/mTOR pathway in these patients needs to be further explored.
Assuntos
Antineoplásicos Hormonais/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Resistencia a Medicamentos Antineoplásicos , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Tamoxifeno/uso terapêutico , Idoso , Neoplasias da Mama/genética , Quimioterapia Adjuvante , Antagonistas de Estrogênios/uso terapêutico , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Feminino , Humanos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Recidiva Local de Neoplasia/epidemiologia , Fosfatidilinositol 3-Quinase/metabolismo , Fosforilação , Pós-Menopausa , Proteínas Proto-Oncogênicas c-akt/metabolismo , Estudos Retrospectivos , Serina-Treonina Quinases TOR/metabolismo , Resultado do TratamentoRESUMO
The distinction between T-cell-mediated rejection (TCMR) and other causes of kidney transplant dysfunction such as tubular necrosis requires biopsy. Subclinical rejection (SCR), an established risk factor for chronic allograft dysfunction, can only be diagnosed by protocol biopsy. A specific non-invasive biomarker to monitor immunological graft status would facilitate diagnosis and treatment of common transplantation-related complications. To identify possible markers, we measured urinary mRNA levels of several cytolytic proteins by quantitative PCR. Our cohort of 70 renal transplant recipients had biopsy proven type I and type II TCMR, acute tubular necrosis, SCR, calcineurin inhibitor-toxicity, cytomegalovirus infection, and stable graft function with normal histology. Granzyme A (GzmA) mRNA was significantly higher in subclinical and acute cellular rejection compared to patients with stable grafts or those with tubular necrosis with 80% sensitivity and up to 100% specificity. Granzyme B and perforin mRNA levels could significantly discriminate acute rejection from stable or tubular necrosis, but were not significantly elevated during SCR. Importantly, only GzmA mRNA remained below detection limits from grafts that were stable and most with tubular necrosis. Hence, the presented data indicate that urinary GzmA mRNA levels may entail a diagnostic non-invasive biomarker to distinguish patients with subclinical and acute cellular rejection from those with tubular necrosis or stable grafts.
Assuntos
Rejeição de Enxerto/diagnóstico , Rejeição de Enxerto/urina , Granzimas/genética , Transplante de Rim , RNA Mensageiro/urina , Adulto , Idoso , Biomarcadores/urina , Biópsia , Estudos de Coortes , Diagnóstico Diferencial , Feminino , Humanos , Túbulos Renais/patologia , Masculino , Pessoa de Meia-Idade , Necrose/diagnóstico , Necrose/urina , Perforina/genética , Estudos Retrospectivos , Sensibilidade e EspecificidadeRESUMO
In human B cells, effective major histocompatibility complex (MHC) class II-antigen presentation depends not only on MHC class II, but also on the invariant chain (CD74 or Ii), HLA-DM (DM) and HLA-DO (DO), the chaperones regulating the antigen loading process of MHC class II molecules. We analysed immediate ex vivo expression of HLA-DR (DR), CD74, DM and DO in B cell chronic lymphocytic leukaemia (B-CLL). Real-time reverse transcription polymerase chain reaction demonstrated a highly significant upregulation of DRA, CD74, DMB, DOA and DOB mRNA in purified malignant cells compared to B cells from healthy donors. The increased mRNA levels were not translated into enhanced protein levels but could reflect aberrant transcriptional regulation. Indeed, upregulation of DRA, DMB, DOA and DOB mRNA correlated with enhanced expression of class II transactivator (CIITA). In-depth analysis of the various CIITA transcripts demonstrated a significant increased activity of the interferon-gamma-inducible promoter CIITA-PIV in B-CLL. Comparison of the aberrant mRNA levels with clinical outcome identified DOA mRNA as a prognostic indicator for survival. Multivariate analysis revealed that the prognostic value of DOA mRNA was independent of the mutational status of the IGHV genes. Thus, aberrant transcription of DOA forms a novel and additional prognostic indicator for survival in B-CLL.
Assuntos
Regulação Neoplásica da Expressão Gênica , Antígenos HLA-D/genética , Leucemia Linfocítica Crônica de Células B/genética , Proteínas Nucleares/genética , RNA Mensageiro/análise , Transativadores/genética , Transcrição Gênica , Idoso , Apresentação de Antígeno/genética , Antígenos de Diferenciação de Linfócitos B/genética , Estudos de Casos e Controles , Eletroforese em Gel de Poliacrilamida/métodos , Feminino , Antígenos HLA-DR/genética , Antígenos de Histocompatibilidade Classe II/genética , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Regiões Promotoras Genéticas , Modelos de Riscos Proporcionais , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodosRESUMO
BACKGROUND: Clinical outcome in patients with diffuse large B cell lymphomas (DLBCL) is highly variable and poorly predictable. Microarray studies showed that patients with DLBCL with a germinal centre B cell-like (GCB) phenotype have a better prognosis than those with an activated B cell-like (ABC) phenotype. The BMI1 proto-oncogene was identified as one of the genes present in the signature of the ABC type of DLBCL, associated with a poor prognosis. OBJECTIVES: (1) To investigate, in primary nodal DLBCL, the expression of BMI1 and its association with clinical outcome and DLBCL signature; (2) to look for an association between BMI1 expression and the expression of its putative downstream targets p14ARF and p16INK4a. RESULTS: BMI1 expression was found to be associated with poor clinical outcome, but not clearly with an ABC-like phenotype of DLBCL. Expression of BMI1 was frequently, but not always, related to low levels of expression of p14ARF and p16INK4a. CONCLUSION: Expression of BMI1 is associated with an unfavourable clinical outcome of primary nodal DLBCL.
Assuntos
Biomarcadores Tumorais/metabolismo , Linfoma de Células B/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , Proteínas Nucleares/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Repressoras/metabolismo , Adulto , Idoso , Idoso de 80 Anos ou mais , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Feminino , Humanos , Técnicas Imunoenzimáticas , Ativação Linfocitária , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/metabolismo , Proteínas Nucleares/genética , Complexo Repressor Polycomb 1 , Prognóstico , Proto-Oncogene Mas , Proteínas Proto-Oncogênicas/genética , Proteínas Repressoras/genética , Análise de Sobrevida , Proteína Supressora de Tumor p14ARF/metabolismoRESUMO
PURPOSE: There have been reports of successful treatment of metastatic melanoma patients with active specific immunotherapy (ASI) using irradiated autologous tumor cell vaccination. It is still unknown why some patients respond and others do not. Tumor cells can evade the immune system, for example through interference with antigen presentation by down-regulation of MHC molecules or expressing proteins interfering with cytotoxic lymphocyte-induced apoptosis like the granzyme B antagonist protease inhibitor 9 (PI-9). EXPERIMENTAL DESIGN: PI-9 expression was detected in melanoma cell lines. To investigated if PI-9 is important in the response to ASI, paraffin-embedded tissues from stage III or IV melanoma patients were stained. RESULTS: PI-9 is expressed in melanoma cells and expression in metastasized melanoma cells is, in this group of patients, an adverse prognostic marker with regard to overall and disease-free survival. Moreover, loss of MHC-1 expression frequently occurs during tumor progression but is not associated with poor clinical outcome. Interestingly, melanoma patients with a favorable clinical outcome after ASI therapy usually have high percentages of activated (granzyme B-positive) tumor-infiltrating lymphocytes at time of first diagnosis and low percentages of activated lymphocytes at time of recurrent tumor. CONCLUSIONS: Expression of PI-9 in metastatic melanoma cells is associated with unfavorable clinical outcome whereas MHC-1 down-regulation is not. Although it cannot be proven that PI-9 expression is directly responsible for failure of immunotherapy, these data suggest that expression of PI-9 could be an important immune escape mechanism and that modulation of this inhibitor may enhance the efficacy of immunotherapy.
Assuntos
Apoptose , Vacinas Anticâncer/uso terapêutico , Linfócitos do Interstício Tumoral/patologia , Melanoma/imunologia , Serpinas/metabolismo , Neoplasias Cutâneas/imunologia , Adulto , Idoso , Western Blotting , Intervalo Livre de Doença , Feminino , Genes MHC Classe I/fisiologia , Granzimas , Humanos , Técnicas Imunoenzimáticas , Imunoterapia , Ativação Linfocitária , Masculino , Melanoma/secundário , Melanoma/terapia , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Serina Endopeptidases/química , Neoplasias Cutâneas/secundário , Neoplasias Cutâneas/terapia , Taxa de Sobrevida , Resultado do Tratamento , Células Tumorais CultivadasRESUMO
Invasive lobular carcinoma (ILC) is the second most frequently occurring histological breast cancer subtype after invasive ductal carcinoma (IDC), accounting for around 10% of all breast cancers. The molecular processes that drive the development of ILC are still largely unknown. We have performed a comprehensive genomic, transcriptomic and proteomic analysis of a large ILC patient cohort and present here an integrated molecular portrait of ILC. Mutations in CDH1 and in the PI3K pathway are the most frequent molecular alterations in ILC. We identified two main subtypes of ILCs: (i) an immune related subtype with mRNA up-regulation of PD-L1, PD-1 and CTLA-4 and greater sensitivity to DNA-damaging agents in representative cell line models; (ii) a hormone related subtype, associated with Epithelial to Mesenchymal Transition (EMT), and gain of chromosomes 1q and 8q and loss of chromosome 11q. Using the somatic mutation rate and eIF4B protein level, we identified three groups with different clinical outcomes, including a group with extremely good prognosis. We provide a comprehensive overview of the molecular alterations driving ILC and have explored links with therapy response. This molecular characterization may help to tailor treatment of ILC through the application of specific targeted, chemo- and/or immune-therapies.
Assuntos
Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Carcinoma Lobular/genética , Carcinoma Lobular/metabolismo , Genômica , Proteoma , Transcriptoma , Biomarcadores Tumorais , Neoplasias da Mama/diagnóstico , Neoplasias da Mama/mortalidade , Carcinoma Lobular/diagnóstico , Análise por Conglomerados , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Transição Epitelial-Mesenquimal/genética , Feminino , Perfilação da Expressão Gênica , Genômica/métodos , Humanos , Imuno-Histoquímica , Taxa de Mutação , Polimorfismo de Nucleotídeo Único , Prognóstico , Proteômica , Reprodutibilidade dos Testes , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Triple negative (TN) breast cancers make up some 15% of all breast cancers. Approximately 10-15% are mutant for the tumor suppressor, BRCA1. BRCA1 is required for homologous recombination-mediated DNA repair and deficiency results in genomic instability. BRCA1-mutated tumors have a specific pattern of genomic copy number aberrations that can be used to classify tumors as BRCA1-like or non-BRCA1-like. BRCA1 mutation, promoter methylation, BRCA1-like status and genome-wide expression data was determined for 112 TN breast cancer samples with long-term follow-up. Mutation status for 21 known DNA repair genes and PIK3CA was assessed. Gene expression and mutation frequency in BRCA1-like and non-BRCA1-like tumors were compared. Multivariate survival analysis was performed using the Cox proportional hazards model. BRCA1 germline mutation was identified in 10% of patients and 15% of tumors were BRCA1 promoter methylated. Fifty-five percent of tumors classified as BRCA1-like. The functions of genes significantly up-regulated in BRCA1-like tumors included cell cycle and DNA recombination and repair. TP53 was found to be frequently mutated in BRCA1-like (P < 0.05), while PIK3CA was frequently mutated in non-BRCA1-like tumors (P < 0.05). A significant association with worse prognosis was evident for patients with BRCA1-like tumors (adjusted HR = 3.32, 95% CI = 1.30-8.48, P = 0.01). TN tumors can be further divided into two major subgroups, BRCA1-like and non-BRCA1-like with different mutation and expression patterns and prognoses. Based on these molecular patterns, subgroups may be more sensitive to specific targeted agents such as PI3K or PARP inhibitors.
Assuntos
Genes BRCA1 , Terapia de Alvo Molecular/tendências , Transcriptoma , Neoplasias de Mama Triplo Negativas/classificação , Neoplasias de Mama Triplo Negativas/genética , Adulto , Idoso , Idoso de 80 Anos ou mais , Hibridização Genômica Comparativa , Metilação de DNA , Análise Mutacional de DNA , Feminino , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Análise em Microsséries , Pessoa de Meia-Idade , Regiões Promotoras Genéticas , Neoplasias de Mama Triplo Negativas/diagnóstico , Neoplasias de Mama Triplo Negativas/terapiaRESUMO
Diffuse large B-cell lymphomas (DLBCL) represent the most common type of adult malignant lymphoma in western countries and are treated with high dose combination chemotherapy. Although initially the majority of patients respond to this therapy, many do not achieve complete remission and others experience an early relapse. Several studies have shown that prediction of the clinical response to chemotherapy is possible before the start of chemotherapy treatment. Apparently, DLBCL are intrinsically either resistant or sensitive to chemotherapy-induced cell death. Differences in functional integrity of the apoptosis cascade are an important factor predicting outcome in DLBCL. In this review we discuss the possible mechanisms leading to intrinsic resistance to apoptosis and provide an explanation why strong differences in apoptosis sensitivity between DLBCL are observed. Subsequently we will focus on how differences in this intrinsic apoptosis resistance provide an explanation for the variable response to combination chemotherapy and how this can be used for further therapy tailoring.
Assuntos
Apoptose , Linfoma de Células B/metabolismo , Linfoma Difuso de Grandes Células B/metabolismo , Animais , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Apoptose/efeitos dos fármacos , Humanos , Linfoma de Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Recidiva , Indução de Remissão , Resultado do TratamentoRESUMO
Resistance to chemotherapy in therapy-refractory diffuse large B-cell lymphomas (DLBCL) is related to inhibition of the intrinsic apoptosis pathway. Human soluble tumour necrosis factor (TNF)-related apoptosis-inducing ligand (hsTRAIL/Apo2L) induces apoptosis via the alternative, death-receptor mediated apoptosis pathway and might be an effective alternative form of therapy for these lymphomas. This study investigated whether hsTRAIL/Apo2L could actually induce apoptosis in isolated lymphoma cells of DLBCL biopsies of patients with chemotherapy-refractory DLBCL. Twelve out of a total of 22 DLBCL samples were sensitive to hsTRAIL/Apo2L. These sensitive lymphomas included seven clinically chemotherapy-refractory lymphomas. Furthermore, hsTRAIL/Apo2L induced apoptosis in DLBCL cells and in B-cell lines that showed high expression levels of inhibitors of the intrinsic apoptosis pathway: Bcl-2 and/or X-linked inhibitor of apoptosis (XIAP). hsTRAIL/Apo2L-sensitive lymphoma cells showed expression of the TRAIL receptors R1 and/or R2 and absence of R3 and R4. We conclude that hsTRAIL/Apo2L induced apoptosis in a subpopulation of chemotherapy-refractory nodal DLBCL and that disruption of the intrinsic apoptosis-mediated pathway and expression of Bcl-2 and XIAP did not confer resistance to hsTRAIL/Apo2L-induced apoptosis in DLBCL. Thus, based on our results, further exploration of hsTRAIL/Apo2L as an alternative treatment for patients with chemotherapy-refractory DLBCL should be considered.
Assuntos
Proteínas Reguladoras de Apoptose/uso terapêutico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Glicoproteínas de Membrana/uso terapêutico , Fator de Necrose Tumoral alfa/uso terapêutico , Apoptose/efeitos dos fármacos , Western Blotting/métodos , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD , Caspase 3 , Caspases/metabolismo , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Fluorometria , Humanos , Imuno-Histoquímica/métodos , Peptídeos e Proteínas de Sinalização Intracelular/análise , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Metástase Linfática , Proteínas Proto-Oncogênicas c-bcl-2/análise , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Receptores do Ligante Indutor de Apoptose Relacionado a TNF , Receptores do Fator de Necrose Tumoral/análise , Receptores do Fator de Necrose Tumoral/metabolismo , Ligante Indutor de Apoptose Relacionado a TNF , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/análise , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismoRESUMO
Clinical response to chemotherapy in patients with diffuse large B-cell lymphomas is poorly predictable. We demonstrated that an expression profile consistent with inhibition of the stress-induced, caspase 9 mediated apoptosis pathway predicts poor clinical response to chemotherapy, whereas an expression profile consistent with inhibition of only the death-receptor induced, caspase 8 mediated pathway was associated with an excellent response to chemotherapy and favorable outcome. Furthermore, functional analysis of apoptosis sensitivity showed that lymphomas with a caspase 9 inhibition profile were indeed relatively resistant to Etoposide induced apoptosis. Determining the functional status of both apoptosis signaling pathways may accurately identify patients at high risk for fatal outcome and may have implications for alternative therapies triggering the death receptor mediated apoptosis pathway.
Assuntos
Antineoplásicos/farmacologia , Apoptose , Inibidores de Caspase , Resistencia a Medicamentos Antineoplásicos , Linfoma de Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Animais , Caspase 8 , Caspase 9 , Inibidores Enzimáticos , Etoposídeo/farmacologia , Humanos , Linfoma de Células B/patologia , Linfoma Difuso de Grandes Células B/patologia , Modelos Biológicos , Risco , Transdução de Sinais , Resultado do TratamentoRESUMO
Loss of both HLA class I and class II expression in B cell lymphomas is a mechanism of escape from a cytotoxic T lymphocyte (CTL) immune response and will therefore give a strong selective survival advantage in tumours expressing strong immunogenic antigens. We investigated loss of HLA expression using specific antibodies on tissue sections from 254 B cell lymphomas originating from nodal and different extranodal sites in relation to numbers of tumour-infiltrating T cells. Complete loss of HLA class I and II was observed in a minority of the nodal, stomach, and skin lymphomas but in the majority of the lymphomas originating from the testis and the CNS. Interestingly, relatively high percentages of activated CTLs were detected in both primary testicular and CNS lymphomas compared to lymphomas at other sites, with highest percentages in the testis (p < 0.0001). We conclude that loss of both HLA class I and II expression occurs very frequently in lymphomas originating from the testis and the CNS as compared to nodal and some other extranodal sites. The presence of high percentages of activated CTLs in the testicular and CNS lymphomas suggests that loss of HLA expression provides a strong growth advantage for lymphoma cells in these immune-privileged sites.
Assuntos
Neoplasias Encefálicas/genética , Antígenos HLA/genética , Linfoma de Células B/genética , Linfoma Difuso de Grandes Células B/genética , Linfócitos T Citotóxicos/imunologia , Neoplasias Testiculares/genética , Neoplasias Encefálicas/imunologia , Complexo CD3/genética , Complexo CD3/imunologia , Antígenos CD4/análise , Antígenos CD4/genética , Antígenos CD8/análise , Antígenos CD8/genética , Regulação Neoplásica da Expressão Gênica/genética , Regulação Neoplásica da Expressão Gênica/imunologia , Antígenos HLA/imunologia , Antígenos de Histocompatibilidade Classe I/genética , Antígenos de Histocompatibilidade Classe I/imunologia , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/imunologia , Humanos , Contagem de Linfócitos/métodos , Linfócitos do Interstício Tumoral/imunologia , Linfoma de Células B/imunologia , Linfoma Difuso de Grandes Células B/imunologia , Masculino , Fenótipo , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/imunologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/imunologia , Subpopulações de Linfócitos T/imunologia , Neoplasias Testiculares/imunologiaRESUMO
We used biopsy specimens of primary nodal diffuse large B-cell lymphoma (DLBCL) to investigate whether the inhibition of caspase 8 and/or 9 apoptosis signaling pathways predicts clinical outcome. Expression levels of cellular FLICE inhibitory protein (c-Flip) and numbers of active caspase 3-positive lymphoma cells were used to determine the status of the caspase 8-mediated pathway. Expression levels of Bcl-2 and X-linked inhibitor of apoptosis (XIAP) were used to determine the status of the caspase 9-mediated pathway. Expression of c-Flip, XIAP, Bcl-2, and caspase 3 activity all provided prognostic information. According to these immunohistochemical parameters, inhibition of either or both caspase signaling pathways was detected in all patients. Three groups of patients were identified, one with a caspase 8 inhibition profile, one with caspase 8 and 9 inhibition profiles, and one with a caspase 9 inhibition profile. Caspase 9 inhibition was strongly associated with poor response to chemotherapy and usually with fatal outcome, whereas caspase 8 inhibition was associated with excellent clinical outcome. Thus, our data strongly suggest that inhibition of the caspase 9-mediated pathway, but not the caspase 8-mediated pathway, is a major cause for therapy resistance in patients with nodal DLBCL.
Assuntos
Antineoplásicos Fitogênicos/administração & dosagem , Caspases/metabolismo , Etoposídeo/administração & dosagem , Linfoma de Células B/tratamento farmacológico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Transdução de Sinais/fisiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Proteína Reguladora de Apoptosis Semelhante a CASP8 e FADD , Caspase 3 , Caspase 8 , Caspase 9 , Feminino , Humanos , Imuno-Histoquímica , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Linfoma de Células B/metabolismo , Linfoma de Células B/mortalidade , Linfoma de Células B/patologia , Linfoma Difuso de Grandes Células B/metabolismo , Linfoma Difuso de Grandes Células B/mortalidade , Linfoma Difuso de Grandes Células B/patologia , Masculino , Pessoa de Meia-Idade , Poli(ADP-Ribose) Polimerases/metabolismo , Proteínas/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Resultado do Tratamento , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo XRESUMO
In tumor cells, the serine protease granzyme B is the primary mediator of apoptosis induced by cytotoxic T lymphocytes (CTLs)/natural killer (NK) cells. The human intracellular serpin proteinase inhibitor 9 (PI9) is the only known human protein able to inhibit the proteolytic activity of granzyme B. When present in the cytoplasm of T lymphocytes, PI9 is thought to protect CTLs against apoptosis induced by their own misdirected granzyme B. Based on the speculation that tumors may also express PI9 to escape CTL/NK cell surveillance, immunohistochemical studies on the expression of PI9 in various lymphomas were performed. Ninety-two cases of T-cell non-Hodgkin lymphoma (NHL), 75 cases of B-cell NHL, and 57 cases of Hodgkin lymphomas were stained with a PI9-specific monoclonal antibody. In T-cell NHL, highest PI9 expression was found in the extranodal T-cell NHL. In nearly 90% of enteropathy-type T-cell NHLs and 80% of NK/T-cell, nasal-type lymphomas, the majority of the tumor cells expressed PI9. In nodal T-anaplastic large cell lymphomas and peripheral T-cell lymphomas (not otherwise specified), PI9 expression occurred less frequently. In B-cell NHL, PI9 expression was associated with high-grade malignancy; 43% of diffuse large B-cell lymphomas showed PI9(+) tumor cells. Finally, PI9 expression was also found in 10% of Hodgkin lymphomas. This is the first report describing the expression of the granzyme B inhibitor PI9 in human neoplastic cells in vivo. Expression of this inhibitor is yet another mechanism used by tumor cells to escape their elimination by cytotoxic lymphocytes.