Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 6 de 6
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Lancet Oncol ; 23(9): 1189-1200, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35952709

RESUMO

BACKGROUND: TGF-ß is an immunosuppressive cytokine that is upregulated in colorectal cancer. TGF-ß blockade improved response to chemoradiotherapy in preclinical models of colorectal adenocarcinoma. We aimed to test the hypothesis that adding the TGF-ß type I receptor kinase inhibitor galunisertib to neoadjuvant chemoradiotherapy would improve pathological complete response rates in patients with locally advanced rectal cancer. METHODS: This was an investigator-initiated, single-arm, phase 2 study done in two medical centres in Portland (OR, USA). Eligible patients had previously untreated, locally advanced, rectal adenocarcinoma, stage IIA-IIIC or IV as per the American Joint Committee on Cancer; Eastern Cooperative Oncology Group status 0-2; and were aged 18 years or older. Participants completed two 14-day courses of oral galunisertib 150 mg twice daily, before and during fluorouracil-based chemoradiotherapy (intravenous fluorouracil 225 mg/m2 over 24 h daily 7 days per week during radiotherapy or oral capecitabine 825 mg/m2 twice per day 5 days per week during radiotherapy; radiotherapy consisted of 50·4-54·0 Gy in 28-30 fractions). 5-9 weeks later, patients underwent response assessment. Patients with a complete response could opt for non-operative management and proceed to modified FOLFOX6 (intravenous leucovorin 400 mg/m2 on day 1, intravenous fluorouracil 400 mg/m2 on day 1 then 2400 mg/m2 over 46 h, and intravenous oxaliplatin 85 mg/m2 on day 1 delivered every 2 weeks for eight cycles) or CAPEOX (intravenous oxaliplatin 130 mg/m2 on day 1 and oral capecitabine 1000 mg/m2 twice daily for 14 days every 3 weeks for four cycles). Patients with less than complete response underwent surgical resection. The primary endpoint was complete response rate, which was a composite of pathological complete response in patients who proceeded to surgery, or clinical complete response maintained at 1 year after last therapy in patients with non-operative management. Safety was a coprimary endpoint. Both endpoints were assessed in the intention-to-treat population. This study is registered with ClinicalTrials.gov, NCT02688712, and is active but not recruiting. FINDINGS: Between Oct 19, 2016, and Aug 31, 2020, 38 participants were enrolled. 25 (71%) of the 35 patients who completed chemoradiotherapy proceeded to total mesorectal excision surgery, five (20%) of whom had pathological complete responses. Ten (29%) patients had non-operative management, three (30%) of whom ultimately chose to have total mesorectal excision. Two (67%) of those three patients had pathological complete responses. Of the remaining seven patients in the non-operative management group, five (71%) had clinical complete responses at 1 year after their last modified FOLFOX6 infusion. In total, 12 (32% [one-sided 95% CI ≥19%]) of 38 patients had a complete response. Common grade 3 adverse events during treatment included diarrhoea in six (16%) of 38 patients, and haematological toxicity in seven (18%) patients. Two (5%) patients had grade 4 adverse events, one related to chemoradiotherapy-induced diarrhoea and dehydration, and the other an intraoperative ischaemic event. No treatment-related deaths occurred. INTERPRETATION: The addition of galunisertib to neoadjuvant chemoradiotherapy in patients with locally advanced rectal cancer improved the complete response rate to 32%, was well tolerated, and warrants further assessment in randomised trials. FUNDING: Eli Lilly via ExIST program, The Providence Foundation.


Assuntos
Adenocarcinoma , Segunda Neoplasia Primária , Neoplasias Retais , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Capecitabina , Quimiorradioterapia/efeitos adversos , Diarreia/etiologia , Fluoruracila , Humanos , Terapia Neoadjuvante/efeitos adversos , Estadiamento de Neoplasias , Segunda Neoplasia Primária/patologia , Oxaliplatina , Pirazóis , Quinolinas , Neoplasias Retais/tratamento farmacológico , Neoplasias Retais/patologia , Fator de Crescimento Transformador beta
2.
N Engl J Med ; 386(22): 2112-2119, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35648703

RESUMO

A patient with progressive metastatic pancreatic cancer was treated with a single infusion of 16.2×109 autologous T cells that had been genetically engineered to clonally express two allogeneic HLA-C*08:02-restricted T-cell receptors (TCRs) targeting mutant KRAS G12D expressed by the tumors. The patient had regression of visceral metastases (overall partial response of 72% according to the Response Evaluation Criteria in Solid Tumors, version 1.1); the response was ongoing at 6 months. The engineered T cells constituted more than 2% of all the circulating peripheral-blood T cells 6 months after the cell transfer. In this patient, TCR gene therapy targeting the KRAS G12D driver mutation mediated the objective regression of metastatic pancreatic cancer. (Funded by the Providence Portland Medical Foundation.).


Assuntos
Terapia Genética , Neoplasias Pancreáticas , Proteínas Proto-Oncogênicas p21(ras) , Receptores de Antígenos de Linfócitos T , Genes Codificadores dos Receptores de Linfócitos T/genética , Terapia Genética/métodos , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/uso terapêutico , Neoplasias Pancreáticas
3.
Sci Rep ; 5: 8566, 2015 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-25858503

RESUMO

Exposure to high levels of ionizing radiation (IR) leads to debilitating and dose-limiting gastrointestinal (GI) toxicity. Using three-dimensional mouse crypt culture, we demonstrated that p53 target PUMA mediates radiation-induced apoptosis via a cell-intrinsic mechanism, and identified the GSK-3 inhibitor CHIR99021 as a potent radioprotector. CHIR99021 treatment improved Lgr5+ cell survival and crypt regeneration after radiation in culture and mice. CHIR99021 treatment specifically blocked apoptosis and PUMA induction and K120 acetylation of p53 mediated by acetyl-transferase Tip60, while it had no effect on p53 stabilization, phosphorylation or p21 induction. CHIR99021 also protected human intestinal cultures from radiation by PUMA but not p21 suppression. These results demonstrate that p53 posttranslational modifications play a key role in the pathological and apoptotic response of the intestinal stem cells to radiation and can be targeted pharmacologically.


Assuntos
Apoptose/efeitos dos fármacos , Apoptose/genética , Intestinos/citologia , Radiação Ionizante , Protetores contra Radiação/farmacologia , Células-Tronco/efeitos dos fármacos , Células-Tronco/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Acetilação , Animais , Proteínas Reguladoras de Apoptose/deficiência , Proteínas Reguladoras de Apoptose/genética , Células Cultivadas , Modelos Animais de Doenças , Gastroenteropatias/etiologia , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos da radiação , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Humanos , Camundongos , Camundongos Knockout , Piridinas/farmacologia , Pirimidinas/farmacologia , Lesões Experimentais por Radiação , Tolerância a Radiação/efeitos dos fármacos , Tolerância a Radiação/genética , Radioterapia/efeitos adversos , Receptores Acoplados a Proteínas G/metabolismo , Células-Tronco/efeitos da radiação , Proteína Supressora de Tumor p53/genética , Proteínas Supressoras de Tumor/deficiência , Proteínas Supressoras de Tumor/genética
4.
PLoS One ; 10(3): e0118792, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25751518

RESUMO

The intestine is composed of an epithelial layer containing rapidly proliferating cells that mature into two regions, the small and the large intestine. Although previous studies have identified stem cells as the cell-of-origin for intestinal epithelial cells, no studies have directly compared stem cells derived from these anatomically distinct regions. Here, we examine intrinsic differences between primary epithelial cells isolated from human fetal small and large intestine, after in vitro expansion, using the Wnt agonist R-spondin 2. We utilized flow cytometry, fluorescence-activated cell sorting, gene expression analysis and a three-dimensional in vitro differentiation assay to characterize their stem cell properties. We identified stem cell markers that separate subpopulations of colony-forming cells in the small and large intestine and revealed important differences in differentiation, proliferation and disease pathways using gene expression analysis. Single cells from small and large intestine cultures formed organoids that reflect the distinct cellular hierarchy found in vivo and respond differently to identical exogenous cues. Our characterization identified numerous differences between small and large intestine epithelial stem cells suggesting possible connections to intestinal disease.


Assuntos
Biomarcadores/metabolismo , Peptídeos e Proteínas de Sinalização Intercelular/farmacologia , Intestino Grosso/embriologia , Intestino Delgado/embriologia , Células-Tronco/citologia , Técnicas de Cultura de Células , Diferenciação Celular , Proliferação de Células , Separação Celular , Células Cultivadas , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Intestino Grosso/citologia , Intestino Grosso/metabolismo , Intestino Delgado/citologia , Intestino Delgado/metabolismo , Células-Tronco/fisiologia
5.
Cell Rep ; 9(2): 701-11, 2014 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-25373907

RESUMO

Because the esophageal epithelium lacks a defined stem cell niche, it is unclear whether all basal epithelial cells in the adult esophagus are functionally equivalent. In this study, we showed that basal cells in the mouse esophagus contained a heterogeneous population of epithelial cells, similar to other rapidly cycling tissues such as the intestine or skin. Using a combination of cell-surface markers, we separated primary esophageal tissue into distinct cell populations that harbored differences in stem cell potential. We also used an in vitro 3D organoid assay to demonstrate that Sox2, Wnt, and bone morphogenetic protein signaling regulate esophageal self-renewal. Finally, we labeled proliferating basal epithelial cells in vivo to show differing cell-cycle profiles and proliferation kinetics. Based on our results, we propose that a nonquiescent stem cell population resides in the basal epithelium of the mouse esophagus.


Assuntos
Células-Tronco Adultas/metabolismo , Proliferação de Células , Células Epiteliais/metabolismo , Esôfago/citologia , Células-Tronco Adultas/citologia , Células-Tronco Adultas/fisiologia , Animais , Diferenciação Celular , Células Cultivadas , Células Epiteliais/citologia , Células Epiteliais/fisiologia , Esôfago/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Transcrição SOXB1/genética , Fatores de Transcrição SOXB1/metabolismo , Proteínas Wnt/genética , Proteínas Wnt/metabolismo
6.
Stem Cell Res ; 13(1): 164-171, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24950307

RESUMO

The PTP4A3 gene is highly expressed in human colon cancer and often associates with enhanced metastatic potential. Genetic disruption of the mouse Ptp4a3 gene reduces the frequency of colon tumor formation in mice treated in a colitis-associated cancer model. In the current study, we have examined the role of Ptp4a3 in the tumor-initiating cell population of mouse colon tumors using an in vitro culture system. Tumors generated in vivo following AOM/DSS treatment were isolated, dissociated, and expanded on a feeder layer resulting in a CD133(+) cell population, which expressed high levels of Ptp4a3. Tumor cells deficient for Ptp4a3 exhibited reduced clonogenicity and growth potential relative to WT cells as determined by limiting dilution analysis. Importantly, expanded tumor cells from WT mice readily formed secondary tumors when transplanted into nude mice, while tumor cells without Ptp4a3 expression failed to form secondary tumors and thus were not tumorigenic. These results demonstrate that Ptp4a3 contributes to the malignant phenotype of tumor-initiating cells and supports its role as a potential therapeutic target to inhibit tumor self-renewal and metastasis.


Assuntos
Colite/enzimologia , Colite/patologia , Neoplasias do Colo/enzimologia , Proteínas Imediatamente Precoces/metabolismo , Células-Tronco Neoplásicas/enzimologia , Proteínas Tirosina Fosfatases/metabolismo , Animais , Neoplasias do Colo/patologia , Modelos Animais de Doenças , Camundongos , Camundongos Knockout , Células-Tronco Neoplásicas/patologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA