Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 168
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
Nature ; 627(8004): 656-663, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38418883

RESUMO

Understanding the cellular processes that underlie early lung adenocarcinoma (LUAD) development is needed to devise intervention strategies1. Here we studied 246,102 single epithelial cells from 16 early-stage LUADs and 47 matched normal lung samples. Epithelial cells comprised diverse normal and cancer cell states, and diversity among cancer cells was strongly linked to LUAD-specific oncogenic drivers. KRAS mutant cancer cells showed distinct transcriptional features, reduced differentiation and low levels of aneuploidy. Non-malignant areas surrounding human LUAD samples were enriched with alveolar intermediate cells that displayed elevated KRT8 expression (termed KRT8+ alveolar intermediate cells (KACs) here), reduced differentiation, increased plasticity and driver KRAS mutations. Expression profiles of KACs were enriched in lung precancer cells and in LUAD cells and signified poor survival. In mice exposed to tobacco carcinogen, KACs emerged before lung tumours and persisted for months after cessation of carcinogen exposure. Moreover, they acquired Kras mutations and conveyed sensitivity to targeted KRAS inhibition in KAC-enriched organoids derived from alveolar type 2 (AT2) cells. Last, lineage-labelling of AT2 cells or KRT8+ cells following carcinogen exposure showed that KACs are possible intermediates in AT2-to-tumour cell transformation. This study provides new insights into epithelial cell states at the root of LUAD development, and such states could harbour potential targets for prevention or intervention.


Assuntos
Adenocarcinoma de Pulmão , Diferenciação Celular , Células Epiteliais , Neoplasias Pulmonares , Animais , Humanos , Camundongos , Adenocarcinoma de Pulmão/genética , Adenocarcinoma de Pulmão/patologia , Células Epiteliais Alveolares/metabolismo , Células Epiteliais Alveolares/patologia , Aneuploidia , Carcinógenos/toxicidade , Células Epiteliais/classificação , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Mutação , Organoides/efeitos dos fármacos , Organoides/metabolismo , Lesões Pré-Cancerosas/metabolismo , Proteínas Proto-Oncogênicas p21(ras)/genética , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , Taxa de Sobrevida , Produtos do Tabaco/efeitos adversos , Produtos do Tabaco/toxicidade
3.
Blood ; 140(5): 504-515, 2022 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-35512184

RESUMO

Patients with relapsed or refractory large B-cell lymphomas (rrLBCL) can achieve long-term remission after CD19 chimeric antigen receptor T-cell therapy (CART19). However, more than half of recipients will experience treatment failure. Thus, approaches are needed to identify high-risk patients who may benefit from alternative or consolidative therapy. We evaluated low-pass whole-genome sequencing (lpWGS) of cell-free DNA (cfDNA) before CART19 as a new approach for risk stratification. We performed lpWGS on pretreatment plasma samples from 122 patients at time of leukapheresis who received standard-of-care CART19 for rrLBCL to define DNA copy number alterations (CNAs). In multivariable selection, high focal CNA score (FCS) denoting genomic instability was the most significant pretreatment variable associated with inferior 3-month complete response rates (28% vs 56%, P = .0029), progression-free survival (PFS; P = .0007; hazard ratio, 2.11), and overall survival (OS; P = .0026; hazard ratio, 2.10). We identified 34 unique focal CNAs in 108 (89%) patients; of these, deletion 10q23.3 leading to loss of FAS death receptor was the most highly associated with poor outcomes, leading to inferior PFS (P < .0001; hazard ratio, 3.49) and OS (P = .0027; hazard ratio, 2.68). By combining FCS with traditional markers of increased tumor bulk (elevated lactate dehydrogenase and >1 extranodal site), we built a simple risk model that could reliably risk stratify patients. Thus, lpWGS of cfDNA is a minimally invasive assay that could rapidly identify high-risk patients and may guide patient selection for and targeted therapies to evaluate in future clinical trials.


Assuntos
Ácidos Nucleicos Livres , Imunoterapia Adotiva , Linfoma Difuso de Grandes Células B , Antígenos CD19 , Humanos , Linfoma Difuso de Grandes Células B/genética , Linfoma Difuso de Grandes Células B/terapia , Medição de Risco
4.
World J Surg Oncol ; 22(1): 42, 2024 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-38310233

RESUMO

AIMS: To present a case series of 11 rare uterine tumors resembling ovarian sex cord tumors (UTROSCTs), and review the literature on this topic to offer up-to-date treatment management for UTROSCTs. METHOD: Eight cases from Fujian Cancer Hospital between January 2017 and May 2023 and three patients from Fujian Union Hospital between October 2012 and October 2020 were retrospectively reviewed. All cases were pathologically confirmed as UTROSCTs by two senior and experienced pathologists. Clinical behaviors, medical data, histopathological features, therapy approaches, and survival outcomes were discussed. RESULTS: The median age at initial diagnosis was 53 years (29-70 years). 3 (27.3%) patients were under 40. Seven cases presented with abnormal vaginal bleeding, one with menstrual disorder, one with abnormal vaginal secretion, and two patients were accidentally found by physical examination without any symptoms. Three patients were initially misdiagnosed with endometrial cancer by MRI. Curettage was performed in all cases. Nine of them were well diagnosed by routine curettage, except for two samples, which were identified after surgery. Immunohistochemical biomarkers, such as CD99, Desmin, WT-1, CK, Vimentin, SMA, α-Inhibin, Ki67, CD56, ER, PR, and CR, tend to be positive in UTRO SCs patients. Six patients underwent hysterectomy with bilateral salpingo-oophorectomy. Two cases received a radical hysterectomy with bilateral salpingo-oophorectomy, retroperitoneal lymph node dissection, and omentum dissection. Three UTROSCTs were under observation after mass resection. The median PFS was 24 months (range 1-125 months). CONCLUSION: UTROSCT is a rare mesenchymal tumor with low malignant potential. Treatment modalities should be carefully considered to balance the therapy outcomes and patient needs. Surgery conservative management might be suitable for young women with fertility desires.


Assuntos
Neoplasias do Endométrio , Neoplasias Ovarianas , Neoplasias Uterinas , Humanos , Feminino , Pessoa de Meia-Idade , Estudos Retrospectivos , Neoplasias Uterinas/diagnóstico , Neoplasias Uterinas/cirurgia , Neoplasias do Endométrio/cirurgia , Neoplasias Ovarianas/diagnóstico , Neoplasias Ovarianas/cirurgia , Histerectomia
5.
Gut ; 72(4): 624-637, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36002248

RESUMO

OBJECTIVE: Many cancers engage embryonic genes for rapid growth and evading the immune system. SOX9 has been upregulated in many tumours, yet the role of SOX9 in mediating immunosuppressive tumour microenvironment is unclear. Here, we aim to dissect the role of SOX9-mediated cancer stemness attributes and immunosuppressive microenvironment in advanced gastric adenocarcinoma (GAC) for novel therapeutic discoveries. METHODS: Bulk RNAseq/scRNA-seq, patient-derived cells/models and extensive functional studies were used to identify the expression and functions of SOX9 and its target genes in vitro and in vivo. Immune responses were studied in PBMCs or CD45+ immune cells cocultured with tumour cells with SOX9high or knockout and the KP-Luc2 syngeneic models were used for efficacy of combinations. RESULTS: SOX9 is one of the most upregulated SOX genes in GAC and highly expressed in primary and metastatic tissues and associated with poor prognosis. Depletion of SOX9 in patient-derived GAC cells significantly decreased cancer stemness attributes, tumour formation and metastases and consistently increased CD8+ T cell responses when cocultured with PBMCs/CD45+ cells from GAC patients. RNA sequencing identified the leukaemia inhibitory factor (LIF) as the top secreted molecule regulated by SOX9 in tumour cells and was enriched in malignant ascites and mediated SOX9-induced M2 macrophage repolarisation and inhibited T cell function. CONCLUSION: Epithelial SOX9 is critical in suppressing CD8+ T cell responses and modified macrophage function in GAC through the paracrine LIF factor. Cotargeting LIF/LIFR and CSF1R has great potential in targeting SOX9-mediated cancer stemness, T cell immunosuppression and metastases suggesting the novel combination therapy against advanced GAC.


Assuntos
Adenocarcinoma , Neoplasias Gástricas , Humanos , Microambiente Tumoral , Adenocarcinoma/genética , Adenocarcinoma/patologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Imunossupressores , Terapia de Imunossupressão , Fatores de Transcrição SOX9/genética
6.
Toxicol Appl Pharmacol ; 477: 116691, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37708916

RESUMO

Ovarian cancer is known as the second leading cause of gynecologic cancer-associated deaths in women worldwide. Developing new and effective compounds to alleviate chemoresistance is an urgent priority in ovarian cancer. Here, we aimed to reveal the biological function and underlying mechanisms of phellopterin, a naturally sourced ingredient of Angelica dahurica, in ovarian cancer progression as well as evaluate the therapeutic potential of phellopterin in ovarian cancer patients. In this investigation, we found that phellopterin mitigated DNA replication and induced cell cycle arrest, apoptosis, and DNA damage, attenuating cell proliferation and chemoresistance of ovarian cancer. Interestingly, bioinformatics analyses of data from our RNA sequencing and The Cancer Genome Atlas ovarian cancer dataset suggested that phellopterin presented anti-cancer activities in ovarian cancer cells by modulating signals affecting ovarian cancer progression and identified phellopterin as a potential compound in improving ovarian cancer patients' prognosis. In addition, the C-Type Lectin Domain Containing 5A (CLEC5A) was demonstrated as a downstream effector of phellopterin and involved in a positive PU.1/CLEC5A/PI3K-AKT feedback loop. Interestingly, phellopterin might inactivate the positive feedback circuit to suppress ovarian cancer progression. Collectively, our investigation revealed that phellopterin mitigated ovarian cancer proliferation and chemoresistance through suppressing the PU.1/CLEC5A/PI3K-AKT feedback loop, and predicted phellopterin as a new and effective cytotoxic drug and CLEC5A as a potential target for the treatment of ovarian cancer.


Assuntos
Neoplasias Ovarianas , Proteínas Proto-Oncogênicas c-akt , Humanos , Feminino , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Retroalimentação , Linhagem Celular Tumoral , Neoplasias Ovarianas/tratamento farmacológico , Apoptose , Proliferação de Células , Receptores de Superfície Celular/genética , Lectinas Tipo C/genética
7.
Appl Opt ; 62(4): 1046-1056, 2023 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-36821162

RESUMO

A broadband and CMOS-compatible polarization beam splitter and rotator (PSR) built on the silicon nitride-on-silicon multilayer platform is presented. The PSR is realized by cascading a polarization beam splitter and a polarization rotator, which are both subtly constructed with an asymmetrical directional coupler waveguide structure. The advantage of this device is that the function of PSR can be directly realized in the SiN layer, providing a promising solution to the polarization diversity schemes in SiN photonic circuits. The chip is expected to have high power handling capability as the light is input from the SiN waveguide. The use of silicon dioxide as the upper cladding of the device ensures its compatibility with the metal back-end-of-line process. By optimizing the structure parameters, a polarization conversion loss lower than 1 dB and cross talk larger than 27.6 dB can be obtained for TM-TE mode conversion over a wavelength range of 1450 to 1600 nm. For TE mode, the insertion loss is lower than 0.26 dB and cross talk is larger than 25.3 dB over the same wavelength range. The proposed device has good potential in diversifying the functionalities of the multilayer photonic chip with high integration density.

8.
Gut ; 71(3): 467-478, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-33785559

RESUMO

BACKGROUND: Gastric adenocarcinoma (GAC) is a lethal disease with limited therapeutic options. Genetic alterations in chromatin remodelling gene AT-rich interactive domain 1A (ARID1A) and mTOR pathway activation occur frequently in GAC. Targeting the mechanistic target of rapamycin (mTOR) pathway in unselected patients has failed to show survival benefit. A deeper understanding of GAC might identify a subset that can benefit from mTOR inhibition. METHODS: Genomic alterations in ARID1A were analysed in GAC. Mouse gastric epithelial cells from CK19-Cre-Arid1Afl/fl and wild-type mice were used to determine the activation of oncogenic genes due to loss of Arid1A. Functional studies were performed to determine the significance of loss of ARID1A and the sensitivity of ARID1A-deficient cancer cells to mTOR inhibition in GAC. RESULTS: More than 30% of GAC cases had alterations (mutations or deletions) of ARID1A and ARID1A expression was negatively associated with phosphorylation of S6 and SOX9 in GAC tissues and patient-derived xenografts (PDXs). Activation of mTOR signalling (increased pS6) and SOX9 nuclear expression were strongly increased in Arid1A-/- mouse gastric tissues which could be curtailed by RAD001, an mTOR inhibitor. Knockdown of ARID1A in GAC cell lines increased pS6 and nuclear SOX9 and increased sensitivity to an mTOR inhibitor which was further amplified by its combination with fluorouracil both in vitro and in vivo in PDXs. CONCLUSIONS: The loss of ARID1A activates pS6 and SOX9 in GAC, which can be effectively targeted by an mTOR inhibitor. Therefore, our studies suggest a new therapeutic strategy of clinically targeting the mTOR pathway in patients with GAC with ARID1A deficiency.


Assuntos
Adenocarcinoma/etiologia , Proteínas de Ligação a DNA/fisiologia , Fatores de Transcrição SOX9/fisiologia , Transdução de Sinais/fisiologia , Neoplasias Gástricas/etiologia , Serina-Treonina Quinases TOR/fisiologia , Fatores de Transcrição/fisiologia , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Animais , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Proliferação de Células , Camundongos , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia
9.
Lancet Oncol ; 23(3): 406-415, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35074072

RESUMO

BACKGROUND: Induction with ibrutinib and rituximab provides an opportunity to minimise chemotherapy exposure, because upfront use of these targeted therapies could result in remission without chemotherapy and allow for consolidation with only four cycles of chemotherapy instead of the conventional eight. We aimed to determine the activity and safety of ibrutinib-rituximab induction followed by shortened chemoimmunotherapy (four cycles) with rituximab plus hyper-fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone (R-HCVAD) alternating with methotrexate-cytarabine in previously untreated patients with mantle cell lymphoma. METHODS: We did a single-centre, single-arm, phase 2 trial in previously untreated patients with mantle cell lymphoma. Eligible patients were aged 65 years or younger and had serum bilirubin of less than 1·5 mg/dL, creatinine clearance of 30 mL/min or more, Eastern Cooperative Oncology Group performance status of 2 or less, and cardiac ejection fraction 50% or more by echocardiogram. Patients received 12 cycles of ibrutinib-rituximab induction (part A; oral ibrutinib 560 mg daily and intravenous rituximab 375 mg/m2 weekly for the first 4 weeks and then on day 1 of cycles 3-12). As soon as patients had a complete response, four cycles of R-HCVAD alternating with methotrexate-cytarabine (part B) were administered. If they did not have a complete response or had a partial response, patients received two cycles of R-HCVAD alternating with methotrexate-cytarabine followed by reassessment, up to a total of eight cycles. Patients were taken off study if they had stable disease or progression during R-HCVAD. The primary outcome was the overall response rate after part A. The analyses were conducted on an intention-to-treat basis. This trial is registered with ClinicalTrials.gov, number NCT02427620. FINDINGS: 131 patients were enrolled between June 12, 2015, and Dec 6, 2018. The median age was 56 years (IQR 49-60). 58 (50%) of 117 patients had high Ki-67 (≥30%). 129 (98%, 95% CI 95-100) of 131 patients had an overall response in part A. The most common grade 3-4 adverse events were lymphocytopenia (19 [14%] of 131), skin rash (16 [12%]), thrombocytopenia (12 [9%]), infections (11 [8%]), and fatigue (ten [8%]) in part A and lymphocytopenia (96 [73%]), leukocytopenia (42 [32%]), thrombocytopenia (40 [30%]), and neutropenia (26 [20%]) in part B. There was one on-study death, which was not deemed to be treatment-related. INTERPRETATION: Induction with ibrutinib-rituximab in the frontline treatment of young patients with mantle cell lymphoma is active and safe. This approach allowed minimisation of the number of chemotherapy cycles, thereby reducing the adverse events associated with chemotherapy. Newer trials bringing the next-generation Bruton's tyrosine kinase inhibitors into the frontline setting might obviate the need for chemotherapy altogether in patients with mantle cell lymphoma. FUNDING: Pharmacyclics, Janssen.


Assuntos
Linfoma de Célula do Manto , Linfopenia , Trombocitopenia , Adenina/análogos & derivados , Adulto , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Ciclofosfamida , Citarabina , Doxorrubicina , Humanos , Linfoma de Célula do Manto/tratamento farmacológico , Linfoma de Célula do Manto/patologia , Linfopenia/induzido quimicamente , Metotrexato , Pessoa de Meia-Idade , Piperidinas , Rituximab , Trombocitopenia/induzido quimicamente , Resultado do Tratamento , Vincristina
10.
Mol Cancer ; 21(1): 185, 2022 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-36163179

RESUMO

BACKGROUND: Chimeric antigen receptor (CAR) T-cell therapy using brexucabtagene autoleucel (BA) induces remission in many patients with mantle cell lymphoma (MCL), and BA is the only CAR T-cell therapy approved by the FDA for MCL. However, development of relapses to BA is recognized with poor patient outcomes. Multiple CAR T-cell therapies have been approved for other lymphomas and the resistance mechanisms have been investigated. However, the mechanisms underlying BA relapse in MCL have not been investigated and whether any previously reported resistance mechanisms apply to BA-relapsed patients with MCL is unknown. METHODS: To interrogate BA resistance mechanisms in MCL, we performed single-cell RNA sequencing on 39 longitudinally collected samples from 15 BA-treated patients, and multiplex cytokine profiling on 80 serial samples from 20 patients. RESULTS: We demonstrate that after BA relapse, the proportion of T cells, especially cytotoxic T cells (CTLs), decreased among non-tumor cells, while the proportion of myeloid cells correspondingly increased. TIGIT, LAG3, and CD96 were the predominant checkpoint molecules expressed on exhausted T cells and CTLs; only TIGIT was significantly increased after relapse. CTLs expanded during remission, and then contracted during relapse with upregulated TIGIT expression. Tumor cells also acquired TIGIT expression after relapse, leading to the enhanced interaction of tumor cell TIGIT with monocyte CD155/PVR. In myeloid cells, post-relapse HLA-II expression was reduced relative to pretreatment and during remission. Myeloid-derived suppressor cells (MDSCs) were enriched after relapse with elevated expression of activation markers, including CLU (clusterin) and VCAN (versican). Extracellular chemokines (CCL4, CXCL9, CXCL13), soluble checkpoint inhibitors (sPD-L1, sTIM3, s4-1BB), and soluble receptors (sIL-2R, sTNFRII) were decreased during remission but elevated after relapse. CONCLUSIONS: Our data demonstrate that multiple tumor-intrinsic and -extrinsic factors are associated with T-cell suppression and BA relapse. Among these, TIGIT appears to be the central player given its elevated expression after BA relapse in not only CTLs but also MCL cells. The acquisition of TIGIT expression on tumor cells is MCL-specific and has not been reported in other CAR T-treated diseases. Together, our data suggest that co-targeting TIGIT may prevent CAR T relapses and thus promote long-term progression-free survival in MCL patients.


Assuntos
Linfoma de Célula do Manto , Receptores de Antígenos Quiméricos , Adulto , Antígenos CD , Clusterina , Citocinas/metabolismo , Humanos , Linfoma de Célula do Manto/genética , Linfoma de Célula do Manto/terapia , Recidiva Local de Neoplasia , Receptores Imunológicos/genética , Linfócitos T , Versicanas
11.
Appl Opt ; 61(26): 7798-7806, 2022 Sep 10.
Artigo em Inglês | MEDLINE | ID: mdl-36256383

RESUMO

A CMOS-compatible, broadband, and polarization-independent edge coupler for efficient chip coupling with standard single-mode fiber is proposed. Three layers of a silicon nitride waveguide array with the same structures are used in the top oxide cladding of the chip to achieve high coupling efficiency and to simplify the mode transformation structure. Optimal total coupling loss at the wavelength of 1550 nm, -0.49dB for TE mode polarization and -0.92dB for TM mode polarization is obtained. The -1dB bandwidth is beyond 160 nm for TE mode polarization and ∼130nm for TM mode polarization, respectively. A significant reduction in the packaging cost of silicon photonic chips is anticipated. Meanwhile, the structure holds vast potential for on-chip three-dimensional photonic integrations or fiber-to-chip, chip-to-chip optical interconnections.

12.
Sensors (Basel) ; 22(19)2022 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-36236285

RESUMO

Sensors that have low power consumption, high scalability and the ability of rapidly detecting multitudinous external stimulus are of great value in cyber-physical interactive applications. Herein, we reported the fabrication of ferroelectric barium strontium titanate ((Ba70Sr30)TiO3, BST) thin films on silicon substrates by magnetron sputtering. The as-grown BST films have a pure perovskite structure and exhibit excellent ferroelectric characteristics, such as a remnant polarization of 2.4 µC/cm2, a ferro-to-paraelectric (tetragonal-to-cubic) phase transition temperature of 31.2 °C, and a broad optical bandgap of 3.58 eV. Capacitor-based sensors made from the BST films have shown an outstanding average sensitivity of 0.10 mV·Pa-1 in the 10-80 kPa regime and work extremely steadily over 1000 cycles. More importantly, utilizing the Pockels effect, optical manipulation in BST can be also realized by a smaller bias and its electro-optic coefficient reff is estimated to be 83.5 pmV-1, which is 2.6 times larger than in the current standard material (LiNbO3) for electro-optical devices. Our work established BST thin film as a powerful design paradigm toward on-chip integrations with diverse electronics into sensors via CMOS-comparable technique.

13.
Angew Chem Int Ed Engl ; 61(47): e202212108, 2022 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-36196003

RESUMO

The first nickel-catalyzed highly enantioselective reductive Ullmann coupling of ortho-chlorinated aryl aldehyde was achieved under mild reaction conditions with a chiral 2,2'-bipyridine ligand (+)-DTB-SBpy, thus providing axially chiral biphenyl or binaphthyl dials with up to 99 % yield and 99.5:0.5 er. The versatility of the products as common synthetic intermediates for diverse axially chiral ligands, catalysts, and functional molecules was demonstrated by short-step transformations. This protocol also allowed the concise and highly enantioselective formal total synthesis of biologically active natural products (+)-kotanin, (-)-isoschizandrin and (+)-gossypol.


Assuntos
2,2'-Dipiridil , Aldeídos , Ligantes , Estereoisomerismo , Catálise
14.
Angew Chem Int Ed Engl ; 61(51): e202213943, 2022 12 19.
Artigo em Inglês | MEDLINE | ID: mdl-36300599

RESUMO

In contrast to previous approaches to chiral α-aryl carboxylic acids that based on reactions using hazardous gases, pressurized setup and mostly noble metal catalysts, in this work, a nickel-catalyzed general, efficient and highly enantioselective carboxylation reaction of racemic benzylic (pseudo)halides under mild conditions using atmospheric CO2 has been developed. A unique chiral 2,2'-bipyridine ligand named Me-SBpy featuring compact polycyclic skeleton enabled both high reactivity and stereoselectivity. The utility of this method has been demonstrated by synthesis of various chiral α-aryl carboxylic acids (30 examples, up to 95 % yield and 99 : 1 er), including profen family anti-inflammatory drugs and transformations using the acids as key intermediates. Based on mechanistic experimental results, a plausible catalytic cycle involving Ni-complex/radical equilibrium and Lewis acid-assisted CO2 activation has been proposed.


Assuntos
Compostos Heterocíclicos , Níquel , Ligantes , 2,2'-Dipiridil , Estereoisomerismo , Dióxido de Carbono , Catálise , Ácidos Carboxílicos
15.
Angew Chem Int Ed Engl ; 61(20): e202117843, 2022 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-35174597

RESUMO

A new class of chiral 2,2'-bipyridine ligands, SBpy, featuring minimized short-range steric hindrance and structural tunability was rationally designed and developed, and the effectiveness was demonstrated in the first highly enantioselective Ni-catalyzed addition of aryl halides to aldehydes. In comparison with known approaches using preformed aryl metallic reagents, this reaction is more step-economical and functional group tolerant. The reaction mechanism and a model of stereocontrol were proposed based on experimental and computational results.


Assuntos
Aldeídos , Compostos Heterocíclicos , 2,2'-Dipiridil , Aldeídos/química , Catálise , Ligantes , Níquel/química , Estereoisomerismo
16.
Gut ; 70(1): 55-66, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32345613

RESUMO

OBJECTIVE: Peritoneal carcinomatosis (PC; malignant ascites or implants) occurs in approximately 45% of advanced gastric adenocarcinoma (GAC) patients and associated with a poor survival. The molecular events leading to PC are unknown. The yes-associated protein 1 (YAP1) oncogene has emerged in many tumour types, but its clinical significance in PC is unclear. Here, we investigated the role of YAP1 in PC and its potential as a therapeutic target. METHODS: Patient-derived PC cells, patient-derived xenograft (PDX) and patient-derived orthotopic (PDO) models were used to study the function of YAP1 in vitro and in vivo. Immunofluorescence and immunohistochemical staining, RNA sequencing (RNA-Seq) and single-cell RNA-Seq (sc-RNA-Seq) were used to elucidate the expression of YAP1 and PC cell heterogeneity. LentiCRISPR/Cas9 knockout of YAP1 and a YAP1 inhibitor were used to dissect its role in PC metastases. RESULTS: YAP1 was highly upregulated in PC tumour cells, conferred cancer stem cell (CSC) properties and appeared to be a metastatic driver. Dual staining of YAP1/EpCAM and sc-RNA-Seq revealed that PC tumour cells were highly heterogeneous, YAP1high PC cells had CSC-like properties and easily formed PDX/PDO tumours but also formed PC in mice, while genetic knockout YAP1 significantly slowed tumour growth and eliminated PC in PDO model. Additionally, pharmacologic inhibition of YAP1 specifically reduced CSC-like properties and suppressed tumour growth in YAP1high PC cells especially in combination with cytotoxics in vivo PDX model. CONCLUSIONS: YAP1 is essential for PC that is attenuated by YAP1 inhibition. Our data provide a strong rationale to target YAP1 in clinic for GAC patients with PC.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Adenocarcinoma/secundário , Neoplasias Peritoneais/secundário , Neoplasias Gástricas/patologia , Animais , Técnicas de Cultura de Células , Humanos , Camundongos , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas de Sinalização YAP
17.
Gut ; 70(11): 2055-2065, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-33334899

RESUMO

OBJECTIVE: Prognosis of patients with advanced oesophagogastric adenocarcinoma (mEGAC) is poor and molecular determinants of shorter or longer overall survivors are lacking. Our objective was to identify molecular features and develop a prognostic model by profiling the genomic features of patients with mEGAC with widely varying outcomes. DESIGN: We profiled 40 untreated mEGACs (20 shorter survivors <13 months and 20 longer survivors >36 months) with whole-exome sequencing (WES) and RNA sequencing and performed an integrated analysis of exome, transcriptome, immune profile and pathological phenotypes to identify the molecular determinants, developing an integrated model for prognosis and comparison with The Cancer Genome Atlas (TCGA) cohorts. RESULTS: KMT2C alterations were exclusively observed in shorter survivors together with high level of intratumour heterogeneity and complex clonal architectures, whereas the APOBEC mutational signatures were significantly enriched in longer survivors. Notably, the loss of heterozygosity in chromosome 4 (Chr4) was associated with shorter survival and 'cold' immune phenotype characterised by decreased B, CD8, natural killer cells and interferon-gamma responses. Unsupervised transcriptomic clustering revealed a shorter survivor subtype with distinct expression features (eg, upregulated druggable targets JAK2, MAP3K13 and MECOM). An integrated model was then built based on clinical variables and the identified molecular determinants, which significantly segregated shorter and longer survivors. All the above features and the integrated model have been validated independently in multiple TCGA cohorts. CONCLUSION: This study discovered novel molecular features prognosticating overall survival in patients with mEGAC and identified potential novel targets in shorter survivors.


Assuntos
Adenocarcinoma/genética , Neoplasias Esofágicas/genética , Perfil Genético , Neoplasias Gástricas/genética , Variações do Número de Cópias de DNA , Feminino , Humanos , Masculino , Prognóstico , Medição de Risco , Análise de Sequência de RNA , Sequenciamento do Exoma
18.
Chemistry ; 27(18): 5754-5760, 2021 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-33458881

RESUMO

Catalytic carbene-transfer reactions constitute a class of highly useful transformations in organic synthesis. Although catalysts based on a range of transition-metals have been reported, the readily accessible nickel(II)-based complexes have been rarely used. Herein, an air-stable nickel(II)-carborane complex is reported as a well-defined, versatile and recyclable catalyst for selective carbene transfer reactions with low catalyst loading under mild conditions. This catalyst is effective for several types of reactions including diastereoselective cyclopropanation, epoxidation, selective X-H insertions (X = C, N, O, S, Si), particularly for the unprotected substrates. This represents a rare example of carborane ligands in base metal catalysis.

19.
Gut ; 69(1): 18-31, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31171626

RESUMO

OBJECTIVE: Peritoneal carcinomatosis (PC) occurs frequently in patients with gastric adenocarcinoma (GAC) and confers a poor prognosis. Multiplex profiling of primary GACs has been insightful but the underpinnings of PC's development/progression remain largely unknown. We characterised exome/transcriptome/immune landscapes of PC cells from patients with GAC aiming to identify novel therapeutic targets. DESIGN: We performed whole-exome sequencing (WES) and whole transcriptome sequencing (RNA-seq) on 44 PC specimens (43 patients with PC) including an integrative analysis of WES, RNA-seq, immune profile, clinical and pathological phenotypes to dissect the molecular pathogenesis, identifying actionable targets and/or biomarkers and comparison with TCGA primary GACs. RESULTS: We identified distinct alterations in PC versus primary GACs, such as more frequent CDH1 and TAF1 mutations, 6q loss and chr19 gain. Alterations associated with aggressive PC phenotypes emerged with increased mutations in TP53, CDH1, TAF1 and KMT2C, higher level of 'clock-like' mutational signature, increase in whole-genome doublings, chromosomal instability (particularly, copy number losses), reprogrammed microenvironment, enriched cell cycle pathways, MYC activation and impaired immune response. Integrated analysis identified two main molecular subtypes: 'mesenchymal-like' and 'epithelial-like' with discriminating response to chemotherapy (31% vs 71%). Patients with the less responsive 'mesenchymal-like' subtype had high expression of immune checkpoint T-Cell Immunoglobulin And Mucin Domain-Containing Protein 3 (TIM-3), its ligand galectin-9, V-domain Ig suppressor of T cell activation (VISTA) and transforming growth factor-ß as potential therapeutic immune targets. CONCLUSIONS: We have uncovered the unique mutational landscape, copy number alteration and gene expression profile of PC cells and defined PC molecular subtypes, which correlated with PC therapy resistance/response. Novel targets and immune checkpoint proteins have been identified with a potential to be translated into clinics.


Assuntos
Adenocarcinoma/secundário , Neoplasias Peritoneais/secundário , Neoplasias Gástricas/genética , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/genética , Adenocarcinoma/imunologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Antineoplásicos/uso terapêutico , Instabilidade Cromossômica , Variações do Número de Cópias de DNA/genética , DNA de Neoplasias/genética , Feminino , Perfilação da Expressão Gênica/métodos , Humanos , Masculino , Pessoa de Meia-Idade , Terapia de Alvo Molecular/métodos , Mutação , Neoplasias Peritoneais/tratamento farmacológico , Neoplasias Peritoneais/genética , Neoplasias Peritoneais/imunologia , Ploidias , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/imunologia , Sequenciamento do Exoma/métodos
20.
Am J Hematol ; 95(6): 623-629, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32239765

RESUMO

Venetoclax is effective in relapsed patients with mantle cell lymphoma (MCL). Mechanisms of resistance to venetoclax in MCL are poorly understood. We describe the clinical outcomes and genomic characteristics of 24 multiply relapsed patients (median of five prior lines of therapy) who received venetoclax-based therapies; 67% had progressed on BTK inhibitors (BTKi) and 54% had blastoid or pleomorphic histology. Median follow up after venetoclax treatment was 17 months. The overall response rate was 50% and complete response (CR) rate was 21%, 16 patients had progressed and 15 died. The median progression free, overall and post venetoclax survival were 8, 13.5 and 7.3 months respectively. Whole-exome sequencing (WES) was performed on samples collected from seven patients (including five pairs; before starting venetoclax and after progression on venetoclax). The SMARCA4 and BCL2 alterations were noted only after progression, while TP53, CDKN2A, KMT2D, CELSR3, CCND1, NOTCH2 and ATM were altered 2-4-fold more frequently after progression. In two patients with serial samples, we demonstrated clonal evolution of novel SMARCA4 and KMT2C/D mutations at progression. Mutation dynamics in venetoclax resistant MCL is demonstrated. Our data indicates that venetoclax resistance in MCL is predominantly associated with non-BCL2 gene mutations. Further studies are ongoing in MCL patients to evaluate the efficacy of venetoclax in combination with other agents and understand the biology of venetoclax resistance in MCL.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/administração & dosagem , Resistencia a Medicamentos Antineoplásicos/genética , Linfoma de Célula do Manto , Mutação , Proteínas de Neoplasias/genética , Sulfonamidas/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Linfoma de Célula do Manto/tratamento farmacológico , Linfoma de Célula do Manto/genética , Masculino , Pessoa de Meia-Idade , Recidiva
SELEÇÃO DE REFERÊNCIAS
Detalhe da pesquisa