RESUMO
The cancer phenotype is usually characterized by deregulated activity of a variety of cellular kinases, with consequent abnormal hyper-phosphorylation of their target proteins. Therefore, antibodies that allow the detection of phosphorylated versions of proteins have become important tools both preclinically in molecular cancer research, and at the clinical level by serving as tools in pathological analyses of tumors. In order to ensure reliable results, validation of the phospho-specificity of these antibodies is extremely important, since this ensures that they are indeed able to discriminate between the phosphorylated and unphosphorylated versions of the protein of interest, specifically recognizing the phosphorylated variant. A recommended validation approach consists in dephosphorylating the target protein and assessing if such dephosphorylation abrogates antigen immunoreactivity when using the phospho-specific antibody. In this chapter, we describe a protocol to validate the specificity of a phospho-specific antibody that recognizes a phosphorylated variant of the Retinoblastoma (Rb) protein in lung cancer cell lines. The protocol consists in the dephosphorylation of the Rb-containing protein lysates by treating them with bovine intestinal phosphatase, followed by assessment of the dephosphorylation by immunoblot.
Assuntos
Anticorpos Antineoplásicos/química , Anticorpos Fosfo-Específicos/química , Immunoblotting , Neoplasias Pulmonares/metabolismo , Fosfoproteínas/metabolismo , Proteína do Retinoblastoma/metabolismo , Linhagem Celular Tumoral , Humanos , Neoplasias Pulmonares/patologiaRESUMO
BACKGROUND: T cell therapy for cancer involves genetic introduction of a target-binding feature into autologous T cells, ex vivo expansion and single large bolus administration back to the patient. These reprogrammed T cells can be highly effective in killing cells, but tumor heterogeneity results in regrowth of cells that do not sufficiently express the single antigen being targeted. We describe a cell-based therapy that simultaneously targets multiple tumor-specific antigens. METHODS: High-affinity polyclonal rabbit antibodies were generated against nine different surface-related tumor-specific mutations on B16F10 cells. Unsorted splenic effector cells from syngeneic mice were incubated with a cocktail of the nine anti-B16F10 antibodies. These 'armed' effector cells were used to treat mice previously inoculated with B16F10 melanoma cells. RESULTS: The cocktail of nine antibodies resulted in dense homogeneous binding to histological sections of B16F10 cells. Five treatments with the armed effector cells and PD1 inhibition inhibited tumor growth and improved survival. Shortening the interval of the five treatments from every three days to every day increased survival. Arming effector cells with the four antibodies showing best binding to B16F10 cells even further increased survival. CONCLUSIONS: This study demonstrates that ex vivo arming a mixed population of immune effector cells with antibodies targeting multiple tumor-specific mutated proteins in conjunction with PD1 inhibition delayed tumor growth and prolonged survival in mice inoculated with an aggressive melanoma. A remarkably low total antibody dose of less than 5 µg was sufficient to accomplish tumor inhibition. Scaling up to clinical level may be feasible.
Assuntos
Anticorpos Antineoplásicos/uso terapêutico , Antígenos de Neoplasias/imunologia , Imunoterapia Adotiva/métodos , Leucócitos/imunologia , Melanoma Experimental/terapia , Neoplasias Cutâneas/terapia , Carga Tumoral , Animais , Antígenos de Neoplasias/genética , Melanoma Experimental/imunologia , Melanoma Experimental/patologia , Camundongos , Proteínas Mutantes/genética , Proteínas Mutantes/imunologia , Mutação , Receptor de Morte Celular Programada 1/antagonistas & inibidores , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Baço/citologia , Taxa de SobrevidaRESUMO
Testicle tumors are a rare entity among men population, accounting for only 1-1.5% of all can-cers among men. The stromal tumors of the sexual cord correspond just 4% of all testicular cancers. Only 10% of them are malignant. The major representative of the sex cord-stromal tumors is the Leydig cell tumor, corresponding to 75 to 80% of the total. It has bimodal age incidence, involving children and adults between 30 and 60 years. We report the caso of a 91-year-old man with malignant Leydig cell tumor, presenting increase of the volume of scrotum, local pain and hyperemia. The are few cases in the literature, only 1 with pacient above 85 years old.
Assuntos
Tumor de Células de Leydig/patologia , Neoplasias Testiculares/patologia , Idoso de 80 Anos ou mais , Anticorpos Antineoplásicos , Humanos , Tumor de Células de Leydig/imunologia , Masculino , Doenças Raras , Escroto/patologia , Neoplasias Testiculares/imunologiaRESUMO
ABSTRACT Testicle tumors are a rare entity among men population, accounting for only 1-1.5% of all cancers among men. The stromal tumors of the sexual cord correspond just 4% of all testicular cancers. Only 10% of them are malignant. The major representative of the sex cord-stromal tumors is the Leydig cell tumor, corresponding to 75 to 80% of the total. It has bimodal age incidence, involving children and adults between 30 and 60 years. We report the caso of a 91-year-old man with malignant Leydig cell tumor, presenting increase of the volume of scrotum, local pain and hyperemia. The are few cases in the literature, only 1 with pacient above 85 years old.
Assuntos
Humanos , Masculino , Neoplasias Testiculares/patologia , Tumor de Células de Leydig/patologia , Escroto/patologia , Neoplasias Testiculares/imunologia , Doenças Raras , Tumor de Células de Leydig/imunologia , Anticorpos AntineoplásicosRESUMO
The antitumor properties of ticks salivary gland extracts or recombinant proteins have been reported recently, but little is known about the antitumor properties of the secreted components of saliva. The goal of this study was to investigate the in vitro effect of the saliva of the hard tick Amblyomma sculptum on neuroblastoma cell lines. SK-N-SK, SH-SY5Y, Be(2)-M17, IMR-32, and CHLA-20 cells were susceptible to saliva, with 80% reduction in their viability compared to untreated controls, as demonstrated by the methylene blue assay. Further investigation using CHLA-20 revealed apoptosis, with approximately 30% of annexin-V positive cells, and G0/G1-phase accumulation (>60%) after treatment with saliva. Mitochondrial membrane potential (m) was slightly, but significantly (p 0.05), reduced and the actin cytoskeleton was disarranged, as indicated by fluorescent microscopy. The viability of human fibroblast (HFF-1 cells) used as a non-tumoral control decreased by approximately 40%. However, no alterations in cell cycle progression, morphology, and m were observed in these cells. The present work provides new perspectives for the characterization of the molecules present in saliva and their antitumor properties.(AU)
As propriedades antitumorais de extratos de glândulas salivares de carrapatos ou proteínas recombinantes foram relatadas recentemente, mas pouco se sabe sobre as propriedades antitumorais dos componentes secretados da saliva. O objetivo deste estudo foi investigar o efeito in vitro da saliva bruta do carrapato duro Amblyomma sculptum sobre as linhagens celulares de neuroblastoma. Células SK-N-SK, SH-SY5Y, Be(2)-M17, IMR-32 e CHLA-20 foram suscetíveis à saliva, com redução de 80% na sua viabilidade em comparação com controles não tratados, como demonstrado pelo ensaio de Azul de Metileno. Investigações posteriores utilizando CHLA-20 revelaram apoptose, com aproximadamente 30% de células positivas para anexina-V, e G0/G1 (> 60%) após tratamento com saliva. O potencial de membrana mitocondrial (m) foi reduzido significativamente (p 0,05), e o citoesqueleto de actina foi desestruturado, como indicado pela microscopia de fluorescência. A viabilidade do fibroblasto humano (células HFF-1), usado como controle não tumoral, diminuiu em aproximadamente 40%. No entanto, não foram observadas alterações na progressão do ciclo celular, morfologia e m nestas células. O presente trabalho fornece novas perspectivas para a caracterização das moléculas presentes na saliva e suas propriedades antitumorais.(AU)
Assuntos
Animais , Ixodidae/parasitologia , Anticorpos Antineoplásicos/análise , Neuroblastoma , CitoesqueletoAssuntos
Terapêutica , Aloe , Anticorpos Antineoplásicos , Benzopirenos , Células Swiss 3T3 , CamundongosRESUMO
B7 homolog 1 (B7-H1) is the most potent immunoinhibitory molecule in the B7 family. In this study, we examined the effects of tumor-associated B7-H1 on T-cell proliferation in lung cancer. The expression of B7-H1 in human adenocarcinoma A549 and mouse Lewis lung carcinoma (LLC) cells were examined by flow cytometry. To assess the in vitro effect of tumor-associated B7-H1 on T-cell proliferation, we isolated T cells from peripheral blood mononuclear cells (PBMCs) of healthy individuals, labeled them with carboxyfluorescein succinimidyl ester, and co-cultured them with A549 cells in the absence or presence of anti-B7-H1 antibody. For in vivo analysis, LLC cells were subcutaneously injected into mice treated or not with anti-B7-H1 antibody. T-cell proliferation in both in vitro and in vivo assays was analyzed by flow cytometry. In vitro, co-culturing T cells with A549 cells significantly inhibited the proliferation of the former compared with the proliferation of T cells alone (P<0.01), and the addition of B7-H1 blocking antibody dramatically reversed the inhibition of T-cell proliferation by A549 cells. Similarly, in mice bearing LLC-derived xenograft tumors, in vivo administration of anti-B7-H1 antibody significantly increased the total number of spleen and tumor T cells compared to levels in control mice that did not receive anti-B7-H1 antibody. Functionally, in vivo administration of anti-B7-H1 antibody markedly reduced tumor growth. Tumor-associated B7-H1 may facilitate immune evasion by inhibiting T-cell proliferation. Targeting of this mechanism offers a promising therapy for cancer immunotherapy.
Assuntos
Adenocarcinoma/patologia , Antígeno B7-H1/análise , Proliferação de Células , Neoplasias Pulmonares/patologia , Linfócitos T/patologia , Células A549 , Animais , Anticorpos Antineoplásicos/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Células Cultivadas , Citometria de Fluxo , Humanos , Imunoterapia/métodos , Camundongos , Camundongos Endogâmicos C57BL , Neoplasias Experimentais , Neoplasias Esplênicas/patologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Cervical cancer is one of the most common female cancers and is caused by human papillomavirus (HPV). Viral infection leads to cell cycle deregulation by inactivating p53 and retinoblastoma protein by viral oncoproteins E6 and E7, respectively. Then, nuclear proteins such as DNA topoisomerase type IIa (TOP2A) and Ki-67 show increased expression because of increased cell division. These molecules are used as biomarkers for immunohistochemistry analysis of cervical tissue. METHODS: In this cross-sectional study, we recruited 110 women receiving regular gynecological surveillance at public health centers in Olinda - PE, Brazil. Cervicovaginal cells were collected to determine the presence of cytological abnormalities and HPV infection. Pap smear slides were used to evaluate the expression of TOP2A and Ki-67 using immunocytochemistry techniques. RESULTS: Of the 110 women, 75.4 % showed HPV-DNA(+) infection (83/110) and 29.1 % showed cellular abnormalities (32/110). Two atypical cells of undetermined significance, one low-grade squamous intraepithelial lesion, and one high-grade squamous intraepithelial lesion samples showed no HPV-DNA. TOP2A was positive in 71.9 % of samples, while Ki-67 was positive in 81.2 %. Immunocytochemistry results were positive in 4 of 5 atypical cells of undetermined significance samples. In HPV-DNA(+) samples with cytological abnormalities, immunocytochemistry results were positive 96.4 % of samples (p < 0.0001; odds ratio = 28.0). Among the samples infected with HR-HPV, TOP2A(+) was effective in 71 % samples, while and Ki-67(+) was 77.4 %. Ki-67 and TOP2A were positive for all samples infected with HPV6, HPV11, and HPV18. Ki-67 was also positive for all HPV16 samples, except for one negative sample in cytopathology analysis. CONCLUSIONS: TOP2A and Ki-67 antibodies may be used in combination for cervical cancer screening in immunocytochemistry assays.
Assuntos
Alphapapillomavirus , Antígenos de Neoplasias/metabolismo , DNA Topoisomerases Tipo II/metabolismo , Proteínas de Ligação a DNA/metabolismo , Antígeno Ki-67/metabolismo , Proteínas de Neoplasias/metabolismo , Infecções por Papillomavirus/metabolismo , Neoplasias do Colo do Útero/metabolismo , Esfregaço Vaginal , Adolescente , Adulto , Idoso , Anticorpos Antineoplásicos/química , Feminino , Humanos , Imuno-Histoquímica , Pessoa de Meia-Idade , Infecções por Papillomavirus/patologia , Proteínas de Ligação a Poli-ADP-Ribose , Neoplasias do Colo do Útero/patologiaRESUMO
B7 homolog 1 (B7-H1) is the most potent immunoinhibitory molecule in the B7 family. In this study, we examined the effects of tumor-associated B7-H1 on T-cell proliferation in lung cancer. The expression of B7-H1 in human adenocarcinoma A549 and mouse Lewis lung carcinoma (LLC) cells were examined by flow cytometry. To assess the in vitro effect of tumor-associated B7-H1 on T-cell proliferation, we isolated T cells from peripheral blood mononuclear cells (PBMCs) of healthy individuals, labeled them with carboxyfluorescein succinimidyl ester, and co-cultured them with A549 cells in the absence or presence of anti-B7-H1 antibody. For in vivo analysis, LLC cells were subcutaneously injected into mice treated or not with anti-B7-H1 antibody. T-cell proliferation in both in vitro and in vivo assays was analyzed by flow cytometry. In vitro, co-culturing T cells with A549 cells significantly inhibited the proliferation of the former compared with the proliferation of T cells alone (P<0.01), and the addition of B7-H1 blocking antibody dramatically reversed the inhibition of T-cell proliferation by A549 cells. Similarly, in mice bearing LLC-derived xenograft tumors, in vivo administration of anti-B7-H1 antibody significantly increased the total number of spleen and tumor T cells compared to levels in control mice that did not receive anti-B7-H1 antibody. Functionally, in vivo administration of anti-B7-H1 antibody markedly reduced tumor growth. Tumor-associated B7-H1 may facilitate immune evasion by inhibiting T-cell proliferation. Targeting of this mechanism offers a promising therapy for cancer immunotherapy.
Assuntos
Humanos , Animais , Camundongos , Adenocarcinoma/patologia , Antígeno B7-H1/análise , Proliferação de Células , Neoplasias Pulmonares/patologia , Linfócitos T/patologia , Células A549 , Anticorpos Antineoplásicos/uso terapêutico , Antígeno B7-H1/antagonistas & inibidores , Células Cultivadas , Citometria de Fluxo , Imunoterapia/métodos , Camundongos Endogâmicos C57BL , Neoplasias Experimentais , Neoplasias Esplênicas/patologia , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Pediatric neuroectodermal malignancies express N-glycolylated gangliosides including N-glycolyl GM3 (NeuGcGM3) as targets for immunotherapy. PROCEDURE: We evaluated the toxicity and maximum tolerated dose and immunological response of racotumomab, an anti-idiotype vaccine targeting NeuGcGM3 through a Phase I study enrolling children with relapsed or resistant tumors expressing NeuGcGM3. MATERIALS AND METHODS: Drug dose was escalated to three levels (0.15-0.25-0.4 mg) of racotumomab administered intradermally. Each drug level included three patients receiving a total of three doses, every 14 days. A confirmation cohort was added to the highest dose level. Antibody response was assessed upon study entry and at 4-week intervals for at least three immunological determinations for each patient. RESULTS: Fourteen patients were enrolled (10 with neuroblastoma, one with retinoblastoma, one with Wilms' tumor, and two with brainstem glioma). Three patients completed the three drug levels and three were enrolled in the confirmation cohort. One patient died of tumor progression before completing the three applications. Racotumomab was well tolerated. The only side effect observed was grade 1-2 toxicity at the injection site. Racotumomab elicited an IgM and/or IgG antibody response directed against NGcGM3 in nine patients and IgM against racotumomab in 11 of 13 evaluable patients. The maximum tolerated dose was not reached and no dose-limiting toxicity was seen. CONCLUSIONS: Racotumomab vaccination has a favorable toxicity profile up to a dose of 0.4 mg, and most patients elicited an immune response. Its activity as immunotherapy for neuroectodermal malignancies will be tested in further clinical trials.