Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 12 de 12
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Eur J Surg Oncol ; : 108370, 2024 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-38734494

RESUMO

Post neoadjuvant chemotherapy tumor localization is a challenge in LMI economy countries. Various options are available in High economy countries. Pre-chemotherapy clinically guided skin tattooing and post chemotherapy USG guided skin marking is a valid technique. In patients with complete clinic-radiological response larger volume resection may be an issue. Head-to-head comparison between skin marking and parenchymal marking is needed to make a conclusive statement.

2.
Cancer Immunol Res ; 11(3): 364-380, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36574614

RESUMO

B cells are an essential component of humoral immunity. Their primary function is to mount antigen-specific antibody responses to eliminate pathogens. Despite an increase in B-cell number, we found that serum-IgG levels were low in patients with breast cancer. To solve this conundrum, we used high-dimensional flow cytometry to analyze the heterogeneity of B-cell populations and identified a tumor-specific CD19+CD24hiCD38hi IL10-producing B regulatory (Breg)-cell subset. Although IL10 is a Breg-cell marker, being an intracellular protein, it is of limited value for Breg-cell isolation. Highly expressed Breg-cell surface proteins CD24 and CD38 also impede the isolation of viable Breg cells. These are hurdles that limit understanding of Breg-cell functions. Our transcriptomic analysis identified, CD39-negativity as an exclusive, sorting-friendly surface marker for tumor-associated Breg cells. We found that the identified CD19+CD39‒IL10+ B-cell population was suppressive in nature as it limited T helper-cell proliferation, type-1 cytokine production, and T effector-cell survival, and augmented CD4+FOXP3+ regulatory T-cell generation. These tumor-associated Breg cells were also found to restrict autologous T follicular helper-cell expansion and IL21 secretion, thereby inhibiting germinal transcript formation and activation-induced cytidine deaminase expression involved in H-chain class-switch recombination (CSR). This isotype-switching abnormality was shown to hinder B-cell differentiation into class-switched memory B cells and subsequent high-affinity antibody-producing plasma B cells, which collectively led to the dampening of IgG-mediated antibody responses in patients with cancer. As low IgG is associated with poor prognosis in patients with cancer, Breg-cell depletion could be a promising future therapy for boosting plasma B cell-mediated antibody responses.


Assuntos
Interleucina-10 , Neoplasias , Humanos , Formação de Anticorpos , Antígenos CD19 , Linfócitos T CD4-Positivos , Imunoglobulina G
3.
Front Immunol ; 13: 740588, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35222362

RESUMO

Infiltrating T-regulatory cells in the tumor microenvironment is a key impediment to immunotherapy and is linked to a poor prognosis. We found that tumor-infiltrating Tregs express a higher expression of the chemokine receptor CCR4 than peripheral Tregs in breast cancer patients. CCL22 and CCL17 are released by tumor cells and tumor-associated macrophages, attracting CCR4+ Tregs to the tumor site. The Treg lineage-specific transcription factor FOXP3 changes the CCR4 promoter epigenetically in conjunction with HAT1 to provide a space for FOXP3 binding and activation of the CCR4 gene. To increase CCR4 expression in Tregs, the FOXP3/HAT1 axis is required for permissive (K23 and K27) or repressive (K14 and K18) acetylation of histone-3. In murine breast and melanoma tumor models, genetic ablation of FOXP3 reduced CCR4+ Treg infiltration and tumor size while also restoring anti-tumor immunity. Overexpression of FOXP3, on the other hand, increased CCR4+ Treg infiltration, resulting in a decreased anti-tumor immune response and tumor progression. These findings point to FOXP3 playing a new role in the tumor microenvironment as a transcriptional activator of CCR4 and a regulator of Treg infiltration.


Assuntos
Neoplasias da Mama , Linfócitos T Reguladores , Animais , Neoplasias da Mama/patologia , Feminino , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Histona Acetiltransferases , Humanos , Camundongos , Receptores CCR4/metabolismo , Microambiente Tumoral
4.
Eur J Immunol ; 51(5): 1206-1217, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33555624

RESUMO

Plasticity between Th17 and Treg cells is regarded as a crucial determinant of tumor-associated immunosuppression. Classically Th17 cells mediate inflammatory responses through production of cytokine IL17. Recently, Th17 cells have also been shown to acquire suppressive phenotypes in tumor microenvironment. However, the mechanism by which they acquire such immunosuppressive properties is still elusive. Here, we report that in tumor microenvironment Th17 cell acquires immunosuppressive properties by expressing Treg lineage-specific transcription factor FOXP3 and ectonucleotidase CD73. We designate this cell as Th17reg cell and perceive that such immunosuppressive property is dependent on CD73. It was observed that in classical Th17 cell, GFI1 recruits HDAC1 to change the euchromatin into tightly-packed heterochromatin at the proximal-promoter region of CD73 to repress its expression. Whereas in Th17reg cells GFI1 cannot get access to CD73-promoter due to heterochromatin state at its binding site and, thus, cannot recruit HDAC1, failing to suppress the expression of CD73.


Assuntos
Proteínas de Ligação a DNA/metabolismo , Histona Desacetilase 1/metabolismo , Imunomodulação , Linfócitos do Interstício Tumoral/imunologia , Linfócitos do Interstício Tumoral/metabolismo , Células Th17/imunologia , Células Th17/metabolismo , Fatores de Transcrição/metabolismo , 5'-Nucleotidase/metabolismo , Citocinas/metabolismo , Fatores de Transcrição Forkhead/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Regiões Promotoras Genéticas , Transdução de Sinais , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Microambiente Tumoral/genética , Microambiente Tumoral/imunologia
5.
Sci Signal ; 13(654)2020 10 20.
Artigo em Inglês | MEDLINE | ID: mdl-33082288

RESUMO

The high abundance of drug efflux pumps in cancer stem cells (CSCs) contributes to chemotherapy resistance. The transcriptional regulator SMAR1 suppresses CSC expansion in colorectal cancer, and increased abundance of SMAR1 is associated with better prognosis. Here, we found in breast tumors that the expression of SMAR1 was decreased in CSCs through the cooperative interaction of the pluripotency factors Oct4 and Sox2 with the histone deacetylase HDAC1. Overexpressing SMAR1 sensitized CSCs to chemotherapy through SMAR1-dependent recruitment of HDAC2 to the promoter of the gene encoding the drug efflux pump ABCG2. Treating cultured CSCs or 4T1 tumor-bearing mice with the nonsteroidal anti-inflammatory drug aspirin restored SMAR1 expression and ABCG2 repression and enhanced tumor sensitivity to doxorubicin. Our findings reveal transcriptional mechanisms regulating SMAR1 that also regulate cancer stemness and chemoresistance and suggest that, by restoring SMAR1 expression, aspirin might enhance chemotherapeutic efficacy in patients with stem-like tumors.


Assuntos
Aspirina/farmacologia , Neoplasias da Mama/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ligação a DNA/genética , Resistencia a Medicamentos Antineoplásicos/genética , Células-Tronco Neoplásicas/metabolismo , Proteínas Nucleares/genética , Fatores de Transcrição/genética , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/metabolismo , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proteínas de Ligação a DNA/metabolismo , Feminino , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histona Desacetilase 1/genética , Histona Desacetilase 1/metabolismo , Humanos , Células MCF-7 , Camundongos Endogâmicos BALB C , Camundongos Nus , Células-Tronco Neoplásicas/efeitos dos fármacos , Proteínas Nucleares/metabolismo , Fator 3 de Transcrição de Octâmero/genética , Fator 3 de Transcrição de Octâmero/metabolismo , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Fatores de Transcrição/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto/métodos
6.
Front Immunol ; 10: 1878, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31440253

RESUMO

Plasmacytoid dendritic cells are the most efficient producers of type I interferons, viz. IFNα, in the body and thus have the ability to influence anti-tumor immune responses. But repression of effective intra-tumoral pDC activation is a key immuno-evasion strategy exhibited in tumors-tumor-recruited pDCs are rendered "tolerogenic," characterized by deficiency in IFNα induction and ability to expand regulatory T cells in situ. But the tumor-derived factors that drive this functional reprogramming of intra-tumoral pDCs are not established. In this study we aimed at exploring if intra-tumoral abundance of the oncometabolite lactate influences intra-tumoral pDC function. We found that lactate attenuates IFNα induction by pDCs mediated by intracellular Ca2+ mobilization triggered by cell surface GPR81 receptor as well as directly by cytosolic import of lactate in pDCs through the cell surface monocarboxylate transporters, affecting cellular metabolism needed for effective pDC activation. We also found that lactate enhances tryptophan metabolism and kynurenine production by pDCs which contribute to induction of FoxP3+ CD4+ regulatory T cells, the major immunosuppressive immune cell subset in tumor microenvironment. We validated these mechanisms of lactate-driven pDC reprogramming by looking into tumor recruited pDCs isolated from patients with breast cancers as well as in a preclinical model of breast cancer in mice. Thus, we discovered a hitherto unknown link between intra-tumoral abundance of an oncometabolite resulting from metabolic adaptation in cancer cells and the pro-tumor tolerogenic function of tumor-recruited pDCs, revealing new therapeutic targets for potentiating anti-cancer immune responses.


Assuntos
Neoplasias da Mama/imunologia , Neoplasias da Mama/metabolismo , Células Dendríticas/imunologia , Ácido Láctico/imunologia , Evasão Tumoral/fisiologia , Animais , Reprogramação Celular/imunologia , Células Dendríticas/metabolismo , Feminino , Humanos , Ácido Láctico/metabolismo , Camundongos , Linfócitos T Reguladores/imunologia , Microambiente Tumoral/imunologia
7.
Indian J Radiol Imaging ; 27(2): 229-236, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28744085

RESUMO

OBJECTIVE: To evaluate the role of exponential apparent diffusion coefficient (ADC) as a tool for differentiating benign and malignant breast lesions. PATIENTS AND METHODS: This prospective observational study included 88 breast lesions in 77 patients (between 18 and 85 years of age) who underwent 3T breast magnetic resonance imaging (MRI) including diffusion-weighted imaging (DWI) using b-values of 0 and 800 s/mm2 before biopsy. Mean exponential ADC and ADC of benign and malignant lesions obtained from DWI were compared. Receiver operating characteristics (ROC) curve analysis was undertaken to identify any cut-off for exponential ADC and ADC to predict malignancy. P value of <0.05 was considered statistically significant. Histopathology was taken as the gold standard. RESULTS: According to histopathology, 65 lesions were malignant and 23 were benign. The mean ADC and exponential ADC values of malignant lesions were 0.9526 ± 0.203 × 10-3 mm2/s and 0.4774 ± 0.071, respectively, and for benign lesions were 1.48 ± 0.4903 × 10-3 mm2/s and 0.317 ± 0.1152, respectively. For both the parameters, differences were highly significant (P < 0.001). Cut-off value of ≤0.0011 mm2/s (P < 0.0001) for ADC provided 92.3% sensitivity and 73.9% specificity, whereas with an exponential ADC cut-off value of >0.4 (P < 0.0001) for malignant lesions, 93.9% sensitivity and 82.6% specificity was obtained. The performance of ADC and exponential ADC in distinguishing benign and malignant breast lesions based on respective cut-offs was comparable (P = 0.109). CONCLUSION: Exponential ADC can be used as a quantitative adjunct tool for characterizing breast lesions with comparable sensitivity and specificity as that of ADC.

8.
Cancer Res ; 76(7): 2000-12, 2016 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-26842876

RESUMO

Acquired chemoresistance has curtailed cancer survival since the dawn of chemotherapy. Accumulating evidence suggests a major role for cancer stem cells (CSC) in chemoresistance, although their involvement in acquired resistance is still unknown. The use of aspirin has been associated with reduced cancer risk and recurrence, suggesting that the anti-inflammatory drug may exert effects on CSCs. In this study, we investigated the contribution of CSCs to acquired chemoresistance of breast cancer and the avenues for reversing such effects with aspirin. We observed that the residual risk of recurrence was higher in breast cancer patients who had acquired chemoresistance. Treatment of preexisting CSCs with a genotoxic drug combination (5-fluorouracil, doxorubicin, and cyclophosphamide) generated an NFκB-IL6-dependent inflammatory environment that imparted stemness to nonstem cancer cells, induced multidrug resistance, and enhanced the migration potential of CSCs. Treatment with aspirin prior to chemotherapy suppressed the acquisition of chemoresistance by perturbing the nuclear translocation of NFκB in preexisting CSCs. Therefore, disruptions to the NFκB-IL6 feedback loop prevented CSC induction and sensitized preexisting CSCs to chemotherapy. Collectively, our findings suggest that combining aspirin and conventional chemotherapy may offer a new treatment strategy to improve recurrence-free survival of breast cancer patients. Cancer Res; 76(7); 2000-12. ©2016 AACR.


Assuntos
Aspirina/farmacologia , Interleucina-6/metabolismo , NF-kappa B/metabolismo , Aspirina/metabolismo , Neoplasias da Mama/tratamento farmacológico , Linhagem Celular Tumoral , Estudos de Coortes , Feminino , Humanos , Microscopia Confocal , Células-Tronco Neoplásicas/efeitos dos fármacos , Estudos Prospectivos , Estudos Retrospectivos , Transfecção
9.
Transl Res ; 165(5): 558-77, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25468484

RESUMO

Chemotherapy resistance is a major clinical challenge for the management of locally advanced breast cancer. Accumulating evidence suggests a major role of cancer stem cells (CSCs) in chemoresistance evoking the requirement of drugs that selectively target CSCs in combination with chemotherapy. Here, we report that mithramycin A, a known specificity protein (Sp)1 inhibitor, sensitizes breast CSCs (bCSCs) by perturbing the expression of drug efflux transporters, ATP-binding cassette sub-family G, member 2 (ABCG2) and ATP-binding cassette sub-family C, member 1 (ABCC1), survival factors, B-cell lymphoma 2 (Bcl-2) and X-linked inhibitor of apoptosis (XIAP), and, stemness regulators, octamer-binding transcription factor 4 (Oct4) and Nanog, which are inherently upregulated in these cells compared with the rest of the tumor population. In-depth analysis revealed that aberrant overexpression of Sp1 in bCSCs transcriptionally upregulates (1) resistance-promoting genes to protect these cells from genotoxic therapy, and (2) stemness regulators to sustain self-renewal potential of these cells. However, mithramycin A causes transcriptional suppression of these chemoresistant and self-renewal genes by inhibiting Sp1 recruitment to their promoters. Under such antisurvival microenvironment, chemotherapeutic agent doxorubicin induces apoptosis in bCSCs via DNA damage-induced reactive oxygen species generation. Cumulatively, our findings raise the possibility that mithramycin A might emerge as a promising drug in combinatorial therapy with the existing chemotherapeutic agents that fail to eliminate CSCs. This will consequently lead to the improvement of therapeutic outcome for the treatment-resistant breast carcinomas.


Assuntos
Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/uso terapêutico , Células-Tronco Neoplásicas/efeitos dos fármacos , Plicamicina/análogos & derivados , Adulto , Idoso , Antineoplásicos/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica , Apoptose/efeitos dos fármacos , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Feminino , Humanos , Células MCF-7 , Pessoa de Meia-Idade , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Plicamicina/uso terapêutico , Fator de Transcrição Sp1/antagonistas & inibidores , Fator de Transcrição Sp1/genética , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/patologia , Pesquisa Translacional Biomédica , Células Tumorais Cultivadas , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/genética
10.
Immunology ; 144(4): 561-73, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25284464

RESUMO

Tumour progression is associated with immune-suppressive conditions that facilitate the escape of tumour cells from the regimen of immune cells, subsequently paralysing the host defence mechanisms. Induction of CD4(+)  CD25(+)  FoxP3(+) T regulatory (Treg) cells has been implicated in the tumour immune escape mechanism, although the novel anti-cancer treatment strategies targeting Treg cells remain unknown. The focus of this study is to define the interaction between tumour and immune system, i.e. how immune tolerance starts and gradually leads to the induction of adaptive Treg cells in the tumour microenvironment. Our study identified hyperactivated mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) -signalling as a potential target for reversing Treg cell augmentation in breast cancer patients. In more mechanistic detail, pharmacological inhibitors of MEK/ERK signalling inhibited transforming growth factor-ß (TGF-ß) production in tumour cells that essentially blocked TGF-ß-SMAD3/SMAD4-mediated induction of CD25/interleukin-2 receptor α on CD4(+) T-cell surface. As a result high-affinity binding of interleukin-2 on those cells was prohibited, causing lack of Janus kinase 1 (JAK1)/JAK3-mediated signal transducer and activator of transcription 3 (STAT3)/STAT5 activation required for FoxP3 expression. Finally, for a more radical approach towards a safe MEK inhibitor, we validate the potential of multi-kinase inhibitor curcumin, especially the nano-curcumin made out of pure curcumin with greater bioavailability; in repealing tumour-shed TGF-ß-induced Treg cell augmentation.


Assuntos
Antineoplásicos Fitogênicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Curcumina/farmacologia , MAP Quinase Quinase Quinases/antagonistas & inibidores , Comunicação Parácrina/efeitos dos fármacos , Inibidores de Proteínas Quinases/farmacologia , Linfócitos T Reguladores/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismo , Microambiente Tumoral , Animais , Neoplasias da Mama/enzimologia , Neoplasias da Mama/genética , Neoplasias da Mama/imunologia , Neoplasias da Mama/patologia , Estudos de Casos e Controles , Química Farmacêutica , Técnicas de Cocultura , Relação Dose-Resposta a Droga , Feminino , Fatores de Transcrição Forkhead/metabolismo , Humanos , Subunidade alfa de Receptor de Interleucina-2/metabolismo , MAP Quinase Quinase Quinases/genética , MAP Quinase Quinase Quinases/metabolismo , Camundongos Endogâmicos BALB C , Nanopartículas , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteínas Smad/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Fatores de Tempo , Fator de Crescimento Transformador beta/genética , Células Tumorais Cultivadas , Evasão Tumoral/efeitos dos fármacos
11.
Indian J Surg ; 74(3): 242-7, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23730051

RESUMO

Surgery has increasingly become a technology-driven specialty. Robotic assistance is considered one innovation within abdominal surgery over the past decade that has the potential to compensate for the drawbacks of conventional laparoscopy. The dramatic evolution of robotic surgery over the past 10 years is likely to be eclipsed by even greater advances over the next decade. We review the current status of robotic technology in surgery. The Medline database was searched for the terms "robotic surgery, telesurgery, and laparoscopy." A total of 2,496 references were found. All references were considered for information on robotic surgery in advanced laparoscopy. Further references were obtained through cross-referencing the bibliography cited in each work. There is a paucity of control studies on a sufficient number of subjects in robot-assisted surgeries in all fields. Studies that meet more stringent clinical trials criteria show that robot-assisted surgery appears comparable to traditional surgery in terms of feasibility and outcomes but that costs associated with robot-assisted surgery are higher because of longer operating times and expense of equipment. While a limited number of studies on the da Vinci robotic system have proven the benefit of this approach in regard to patient outcomes, including significantly reduced blood loss, lower percentage of postoperative complications, and shorter hospital stays, there are mechanical and institutional risks that must be more fully addressed. Robotic assistance will remain an intensively discussed subject since clinical benefits for most procedures have not yet been proven. While the benefit still remains open to discussion, robotic systems are spreading and are available worldwide in tertiary centers.

12.
Indian J Surg Oncol ; 1(1): 37-9, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22930616

RESUMO

BACKGROUND: To assess the validity of estrogen receptor (ER) status of breast tumor as a prognostic marker in clinical practice in the Indian perspective. MATERIALS AND METHODS: Sixty-three patients of breast cancer attending breast clinic IPGMER, Kolkata were included in this study. All patients underwent surgery. Metastatic status and tumor were done. Immunohistochemistry was also used for further analysis. RESULTS: Statistically we have proved that advancing course of the disease, there is a tendency of the tumors to become hormone insensitive. CONCLUSIONS: ER has a strong prognostic importance in early breast cancer and can play a major role in optimizing treatment modalities in node negative early breast cancer.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...