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3.
J Med Imaging Radiat Oncol ; 67(1): 89-97, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36300564

RESUMO

INTRODUCTION: Tumour recurrences after treatment of head and neck squamous cell carcinoma (HNSCC) are more likely to originate from regions of high-baseline FDG-PET uptake. Mid-treatment functional imaging can potentially predict for higher risk of tumour recurrence. The aim of this study is to correlate the location of locoregional tumour recurrence with baseline FDG-PET metabolic volumes and mid-treatment FDG-PET metabolic volumes in patients with HNSCC following definitive radiotherapy. METHODS: A total of 23 patients with 26 local and/or regional recurrences underwent baseline (W0-PET) and mid-treatment (W3-PET) 18F-FDG PET scans as part of their radiotherapy. FDG-PET-based metabolic volumes (MTV20%, MTV40%, MTV60%, MTV80%, SUV2.5, SUVpeak and PET_EDGE) were delineated onto the FDG-PET scans. The recurrence nidus was identified on FDG-PET at the time of recurrence (REC-PET). DIR-based fusion was performed for REC-PET to W0-PET, and REC-PET to W3-PET. The location of the recurrence nidus was correlated with the FDG-PET volumes. Further analysis included a comparison of the recurrence density to FDG-PET metabolic volumes. RESULTS: Most recurrences occurred within the MTV20%, MTV40% and SUV 2.5 volumes. Sixty-nine per cent of recurrences (18 of 26) occurred within both the W0 MTV40% and W3 MTV40% volumes. A higher recurrence density was seen for iso-SUV contours closer to the maximum SUV for both W0 and W3. For a number of the FDG-PET volumes, including MTV20%, MTV40% and SUV2.5, the recurrence density was improved for W3 compared to W0, however, this improvement was small in magnitude. The average volume of MTV40% contours was considerably smaller than MTV20% and SUV2.5 contours. CONCLUSION: The metabolic parameters of SUV2.5, MTV20% and MTV40% delineated on the baseline and mid-treatment FDG-PET scans encompassed the majority of recurrences. The MTV40% is significantly smaller, hence, we prefer this volume for future dose escalation studies.


Assuntos
Fluordesoxiglucose F18 , Neoplasias de Cabeça e Pescoço , Humanos , Recidiva Local de Neoplasia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Tomografia por Emissão de Pósitrons/métodos , Compostos Radiofarmacêuticos , Recidiva , Carcinoma de Células Escamosas de Cabeça e Pescoço
4.
Radiother Oncol ; 186: 109794, 2023 09.
Artigo em Inglês | MEDLINE | ID: mdl-37414257

RESUMO

BACKGROUND AND PURPOSE: Previous studies on automatic delineation quality assurance (QA) have mostly focused on CT-based planning. As MRI-guided radiotherapy is increasingly utilized in prostate cancer treatment, there is a need for more research on MRI-specific automatic QA. This work proposes a clinical target volume (CTV) delineation QA framework based on deep learning (DL) for MRI-guided prostate radiotherapy. MATERIALS AND METHODS: The proposed workflow utilized a 3D dropblock ResUnet++ (DB-ResUnet++) to generate multiple segmentation predictions via Monte Carlo dropout which were used to compute an average delineation and area of uncertainty. A logistic regression (LR) classifier was employed to classify the manual delineation as pass or discrepancy based on the spatial association between the manual delineation and the network's outputs. This approach was evaluated on a multicentre MRI-only prostate radiotherapy dataset and compared with our previously published QA framework based on AN-AG Unet. RESULTS: The proposed framework achieved an area under the receiver operating curve (AUROC) of 0.92, a true positive rate (TPR) of 0.92 and a false positive rate of 0.09 with an average processing time per delineation of 1.3 min. Compared with our previous work using AN-AG Unet, this method generated fewer false positive detections at the same TPR with a much faster processing speed. CONCLUSION: To the best of our knowledge, this is the first study to propose an automatic delineation QA tool using DL with uncertainty estimation for MRI-guided prostate radiotherapy, which can potentially be used for reviewing prostate CTV delineation in multicentre clinical trials.


Assuntos
Aprendizado Profundo , Neoplasias da Próstata , Radioterapia Guiada por Imagem , Humanos , Masculino , Garantia da Qualidade dos Cuidados de Saúde , Imageamento por Ressonância Magnética , Incerteza , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/radioterapia
5.
Urol Oncol ; 40(1): 8.e1-8.e9, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34116935

RESUMO

BACKGROUND: Decisional conflict and post-treatment decisional regret have been documented in men with localised prostate cancer (LPC). However, there is limited evidence regarding decisional outcomes associated with the choice between robotic-assisted radical prostatectomy (RARP) and radiotherapy, when both treatment options are available in the public health system. There is increasing support for multidisciplinary approaches to guide men with LPC in their decision-making process. This study assessed decisional outcomes in men deciding between RARP or radiotherapy treatment before and after attending a LPC combined clinic (CC). METHODS: Quantitative longitudinal data were collected from 52 men who attended a LPC CC, where they saw both a urologist and radiation oncologist. Patients completed questionnaires assessing involvement in decision-making, decisional conflict, satisfaction and regret before and after the CC, three months, six months and 12 months post-treatment. Urologists and radiation oncologists also reported their perceptions regarding patients' suitability for, openness to, perceived preferences and appropriateness for each treatment. Data was analysed using paired/independent samples t-tests and McNemar's tests. RESULTS: Most participants (n = 37, 71%) opted for RARP over radiotherapy (n = 14, 27%); one participant deferred treatment (2%). Urologists and radiation oncologists reported low agreement (κ = 0.26) regarding the most appropriate treatment for each patient. Participants reported a desire for high levels of control over their decision-making process (77.5% patient-led, 22.5% shared) and high levels of decisional satisfaction (M = 4.4, SD = 0.47) after the CC. Decisional conflict levels were significantly reduced (baseline: M = 29.3, SD = 16.9, post-CC: M = 16.3, SD = 11.5; t = 5.37, P < 0.001) after the CC. Mean decisional regret scores were 'mild' at three-months (M = 16.0, SD = 17.5), six-months (M = 18.8, SD = 18.7) and 12-months (M = 18.2, SD = 15.1) post-treatment completion. CONCLUSION: This is the first Australian study to assess decisional outcomes when patients are offered the choice between RARP and radiotherapy in the public health system. A CC seems to support decision-making in men with LPC and positively impact some decisional outcomes. However, larger-scale controlled studies are needed to confirm these findings.


Assuntos
Tomada de Decisões , Satisfação do Paciente , Prostatectomia , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Procedimentos Cirúrgicos Robóticos , Idoso , Emoções , Humanos , Masculino , Pessoa de Meia-Idade , Prostatectomia/métodos , Autorrelato
6.
J Exp Psychol Appl ; 27(3): 529-545, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-33956477

RESUMO

A victim-centered approach to fighting sex trafficking can result in apprehension and prosecution of traffickers and offer needed services to survivors. However, law enforcement officers frequently arrest sex-trafficking survivors for prostitution in accordance with state law. This study examined the psychology of public reactions and judgments of sex-trafficking survivors demonstrating the importance of situational factors, cognitive stereotypes, and moral emotions. Using Stereotype Content Modeling to measure the stereotypes that 762 community members held about prostitutes, we found shared stereotypes that were low in competence (i.e., capable and skilled) and warmth (i.e., good-natured and friendly). These participants later read modified case facts from United States v. Bell (United States v. Bell, 761 F.3d (8th Cir. 2014)) that varied survivor history of prostitution, vulnerability, and prostitution as a subsequent livelihood. Participants who stereotyped prostitutes as low in warmth and competence were the ones most certain police should arrest the survivor. Moral emotion analyses further showed that a survivor with no prior prostitution history and who came from a nonvulnerable background invoked disgust and contempt, which predicted a higher certainty of the arrest. Moral emotions fully mediated the relationship between the interacting case facts and arrest certainty for the trafficking survivor. Future directions and policy implications are discussed. (PsycInfo Database Record (c) 2021 APA, all rights reserved).


Assuntos
Julgamento , Princípios Morais , Emoções , Feminino , Humanos , Polícia , Estereotipagem , Estados Unidos
7.
Phys Med Biol ; 66(19)2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34507305

RESUMO

Volume delineation quality assurance (QA) is particularly important in clinical trial settings where consistent protocol implementation is required, as outcomes will affect future as well current patients. Currently, where feasible, this is conducted manually, which is time consuming and resource intensive. Although previous studies mostly focused on automating delineation QA on CT, magnetic resonance imaging (MRI) is being increasingly used in radiotherapy treatment. In this work, we propose to perform automatic delineation QA on prostate MRI for both the clinical target volume (CTV) and organs-at-risk (OARs) by using delineations generated by 3D Unet variants as benchmarks for QA. These networks were trained on a small gold standard atlas set and applied on a multicentre radiotherapy clinical trial dataset to generate benchmark delineations. Then, a QA stage was designed to recommend 'pass', 'minor correction' and 'major correction' for each manual delineation in the trial set by thresholding its Dice similarity coefficient to the network generated delineation. Among all 3D Unet variants explored, the Unet with anatomical gates in an AtlasNet architecture performed the best in delineation QA, achieving an area under the receiver operating characteristics curve of 0.97, 0.92, 0.89 and 0.97 for identifying unacceptable (major correction) delineations with a sensitivity of 0.93, 0.73, 0.74 and 0.90 at a specificity of 0.93, 0.86, 0.86 and 0.95 for bladder, prostate CTV, rectum and gel spacer respectively. To the best of our knowledge, this is the first study to propose automated delineation QA for a multicentre radiotherapy clinical trial with treatment planning MRI. The methods proposed in this work can potentially improve the accuracy and consistency of CTV and OAR delineation in radiotherapy treatment planning.


Assuntos
Aprendizado Profundo , Próstata , Humanos , Imageamento por Ressonância Magnética , Masculino , Órgãos em Risco/diagnóstico por imagem , Planejamento da Radioterapia Assistida por Computador/métodos
8.
Bioorg Med Chem Lett ; 20(8): 2408-11, 2010 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-20346656

RESUMO

Efforts to identify potent small molecule inhibitors of PI3 kinase and mTOR led to the discovery of the exceptionally potent 6-aryl morpholino thienopyrimidine 6. In an effort to reduce the melting point in analogs of 6, the thienopyrimidine was modified by the addition of a methyl group to disrupt planarity. This modification resulted in a general improvement in in vivo clearance. This discovery led to the identification of GNE-477 (8), a potent and efficacious dual PI3K/mTOR inhibitor.


Assuntos
Inibidores Enzimáticos/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Inibidores de Fosfoinositídeo-3 Quinase , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Tiofenos/farmacologia , Animais , Cães , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Feminino , Camundongos , Pirimidinas/química , Ratos , Serina-Treonina Quinases TOR , Tiofenos/química
9.
Patient Educ Couns ; 102(7): 1364-1372, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30803903

RESUMO

OBJECTIVE: To understand how best to support men diagnosed with localised prostate cancer to decide which treatment option best suits their needs, when robotic prostatectomy and radiotherapy are equally appropriate to offer them. METHODS: Twenty-five men recently diagnosed with localised prostate cancer completed semi-structured interviews asking about information/decision-making needs before and/or after attending a combined clinic in which they consulted a urologist and a radiation oncologist regarding treatment options. Data was transcribed verbatim and thematically analysed. RESULTS: Most men preferred robotic prostatectomy pre-combined clinic and chose it afterwards. The thematic analysis revealed four themes: 1) trust in clinicians and the information they provide is critical for treatment choice, 2) perceived fit between treatment characteristics and personal circumstances, 3) additional considerations: specific side effects, socio-emotional and financial factors, and 4) need for tailored information delivery. Robotic prostatectomy was mistakenly believed to provide a more definitive cure than radiotherapy, which was seen as having a lesser lifestyle impact. CONCLUSIONS: Treatment choice is largely dependent on clinicians' (mainly urologists') recommendations. PRACTICE IMPLICATIONS: Patients need more balanced information about alternatives to robotic prostatectomy earlier in the treatment decision-making process. Referral to a radiation oncologist or combined clinic shortly after diagnosis is recommended.


Assuntos
Tomada de Decisão Compartilhada , Prostatectomia , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Procedimentos Cirúrgicos Robóticos , Idoso , Humanos , Entrevistas como Assunto , Masculino , Pessoa de Meia-Idade , Preferência do Paciente , Pesquisa Qualitativa
10.
J Med Imaging Radiat Oncol ; 63(2): 264-271, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30609205

RESUMO

INTRODUCTION: This study quantified inter-observer contouring variations for multiple male pelvic structures, many of which are of emerging relevance for prostate cancer radiotherapy progression and toxicity response studies. METHODS: Five prostate cancer patient datasets (CT and T2-weighted MR) were distributed to 13 observers for contouring. CT structures contoured included the clinical target volume (CTV), seminal vesicles, rectum, colon, bowel bag, bladder and peri-rectal space (PRS). MR contours included CTV, trigone, membranous urethra, penile bulb, neurovascular bundle and multiple pelvic floor muscles. Contouring variations were assessed using the intraclass correlation coefficient (ICC), Dice similarity coefficient (DSC), and multiple additional metrics. RESULTS: Clinical target volume (CT and MR), bladder, rectum and PRS contours showed excellent inter-observer agreement (median ICC = 0.97; 0.99; 1.00; 0.95; 0.90, DSC = 0.83 ± 0.05; 0.88 ± 0.05; 0.93 ± 0.03; 0.81 ± 0.07; 0.80 ± 0.06, respectively). Seminal vesicle contours were more variable (ICC = 0.75, DSC = 0.73 ± 0.14), while colon and bowel bag contoured volumes were consistent (ICC = 0.97; 0.97), but displayed poor overlap (DSC = 0.58 ± 0.22; 0.67 ± 0.21). Smaller MR structures showed significant inter-observer variations, with poor overlap for trigone, membranous urethra, penile bulb, and left and right neurovascular bundles (DSC = 0.44 ± 0.22; 0.41 ± 0.21; 0.66 ± 0.21; 0.16 ± 0.17; 0.15 ± 0.15). Pelvic floor muscles recorded moderate to strong inter-observer agreement (ICC = 0.50-0.97), although large outlier variations were observed. CONCLUSIONS: Inter-observer contouring variation was significant for multiple pelvic structures contoured on MR.


Assuntos
Pelve/anatomia & histologia , Pelve/diagnóstico por imagem , Neoplasias da Próstata/radioterapia , Planejamento da Radioterapia Assistida por Computador/métodos , Pontos de Referência Anatômicos , Humanos , Imageamento por Ressonância Magnética , Masculino , Variações Dependentes do Observador , Tomografia Computadorizada por Raios X
12.
J Med Imaging Radiat Oncol ; 61(5): 695-698, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28477339

RESUMO

Stereotactic body radiation therapy (SBRT) to treat spinal metastases has shown excellent clinical outcomes for local control. High dose gradients wrapping around spinal cord make this treatment technically challenging. In this work, we present a spine SBRT case where a dosimetric error was identified during pre-treatment dosimetric quality assurance (QA). A patient with metastasis in T7 vertebral body consented to undergo SBRT. A dual arc volumetric modulated arc therapy plan was generated on the Pinnacle treatment planning system (TPS) with a 6 MV Elekta machine using gantry control point spacing of 4°. Standard pre-treatment QA measurements were performed, including ArcCHECK, ion chamber in CTV and spinal cord (SC) region and film measurements in multiple planes. While the dose measured at CTV region showed good agreement with TPS, the dose measured to the SC was significantly higher than reported by TPS in the original and repeat plans. Acceptable agreement was only achieved when the gantry control point spacing was reduced to 3°. A potentially harmful dose error was identified by pre-treatment QA. TPS parameter settings used safely in conventional treatments should be re-assessed for complex treatments.


Assuntos
Radiocirurgia , Radioterapia de Intensidade Modulada , Neoplasias da Coluna Vertebral/radioterapia , Neoplasias da Coluna Vertebral/secundário , Idoso , Feminino , Humanos , Radiometria , Dosagem Radioterapêutica , Planejamento da Radioterapia Assistida por Computador , Carga Tumoral
14.
BMJ Open ; 7(11): e018403, 2017 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-29102996

RESUMO

BACKGROUND: Men diagnosed with localised prostate cancer (LPC) wanting curative treatment face a highly preference-sensitive choice between prostatectomy and radiotherapy, which offer similar cure rates but different side effects. This study aims to determine the information, decision-making needs and preferences of men with LPC choosing between robotic prostatectomy and standard external beam or stereotactic radiotherapy. METHODS AND ANALYSIS: This study will be conducted at a large public teaching hospital in Australia offering the choice between robotic prostatectomy and radiotherapy from early 2017. Men (20-30) diagnosed with LPC who want curative treatment and meet criteria for either treatment will be invited to participate. In this mixed-methods study, patients will complete semistructured interviews before and after attending a combined clinic in which they consult a urologist and a radiation oncologist regarding treatment and four questionnaires (one before treatment decision-making and three after) assessing demographic and clinical characteristics, involvement in decision-making, decisional conflict, satisfaction and regret. Combined clinic consultations will also be audio-recorded and clinicians will report their perceptions regarding patients' suitability for, openness to and preferences for each treatment. Qualitative data will be transcribed verbatim and thematically analysed and descriptive statistical analyses will explore quantitative decision-making outcomes, with comparison according to treatment choice. DISCUSSION: Results from this study will inform how to best support men diagnosed with LPC deciding which curative treatment option best suits their needs and may identify the need for and content required in a decision aid to support these men. ETHICS AND DISSEMINATION: All participants will provide written informed consent. Data will be rigorously managed in accordance with national legislation. Results will be disseminated via presentations to both scientific and layperson audiences and publications in peer-reviewed scientific journals.


Assuntos
Tomada de Decisões , Preferência do Paciente , Neoplasias da Próstata/psicologia , Neoplasias da Próstata/radioterapia , Neoplasias da Próstata/cirurgia , Austrália , Técnicas de Apoio para a Decisão , Hospitais de Ensino , Humanos , Masculino , Prostatectomia , Qualidade de Vida , Projetos de Pesquisa , Robótica , Inquéritos e Questionários
15.
Med Phys ; 44(2): 581-588, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27992058

RESUMO

PURPOSE: Conventionally in radiotherapy, a very heavy beam forming apparatus (gantry) is rotated around a patient. From a mechanical perspective, a more elegant approach is to rotate the patient within a stationary beam. Key obstacles to this approach are patient tolerance and anatomical deformation. Very little information on either aspect is available in the literature. The purpose of this work was therefore to design and test an MRI-compatible patient rotation system such that the feasibility of a patient rotation workflow could be tested. METHODS: A patient rotation system (PRS) was designed to fit inside the bore of a 3T MRI scanner (Skyra, Siemens) such that 3D images could be acquired at different rotation angles. Once constructed, a pelvic imaging study was carried out on a healthy volunteer. T2-weighted MRI images were taken every 45° between 0° and 360°, (with 0° equivalent to supine). The prostate, bladder, and rectum were segmented using atlas-based auto contouring. The images from each angle were registered back to the 0° image in three steps: (a) Rigid registration was based on MRI visible markers on the couch. (b) Rigid registration based on the prostate contour (equivalent to a rigid shift to the prostate). (c) Nonrigid registration. The Dice similarity coefficient (DSC) and mean average surface distance (MASD) were calculated for each organ at each step. RESULTS: The PRS met all design constraints and was successfully integrated with the MRI scanner. Phantom images showed minimal difference in signal or noise with or without the PRS in the MRI scanner. For the MRI images, the DSC (mean ± standard deviation) over all angles in the prostate, rectum, and bladder was 0.60 ± 0.11, 0.56 ± 0.15, and 0.76 ± 0.06 after rigid couch registration, 0.88 ± 0.03, 0.81 ± 0.08, and 0.86 ± 0.03 after rigid prostate guided registration, and 0.85 ± 0.03, 0.88 ± 0.02, 0.87 ± 0.02 after nonrigid registration. CONCLUSIONS: An MRI-compatible patient rotation system has been designed, constructed, and tested. A pelvic study was carried out on a healthy volunteer. Rigid registration based on the prostate contour yielded DSC overlap statistics in the prostate superior to interobserver contouring variability reported in the literature.


Assuntos
Imageamento por Ressonância Magnética/instrumentação , Posicionamento do Paciente/instrumentação , Rotação , Desenho de Equipamento , Humanos , Processamento de Imagem Assistida por Computador , Imagens de Fantasmas
16.
Radiother Oncol ; 119(1): 57-60, 2016 04.
Artigo em Inglês | MEDLINE | ID: mdl-26970675

RESUMO

This study investigates breast magnetic resonance imaging (MRI) image quality for 3 different breast radiotherapy positions (prone, supine flat and supine inclined) and associated choice of breast coils. Supine breast MRI has comparable image quality to prone breast MRI for the purposes of radiotherapy delineation for T2-weighted sequences.


Assuntos
Neoplasias da Mama/radioterapia , Imageamento por Ressonância Magnética/métodos , Postura , Planejamento da Radioterapia Assistida por Computador/métodos , Mama/patologia , Estudos de Viabilidade , Feminino , Humanos , Pessoa de Meia-Idade , Decúbito Ventral , Dosagem Radioterapêutica , Reprodutibilidade dos Testes , Decúbito Dorsal
17.
J Med Chem ; 54(21): 7579-87, 2011 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-21981714

RESUMO

The discovery of 2 (GDC-0980), a class I PI3K and mTOR kinase inhibitor for oncology indications, is described. mTOR inhibition was added to the class I PI3K inhibitor 1 (GDC-0941) scaffold primarily through the substitution of the indazole in 1 for a 2-aminopyrimidine. This substitution also increased the microsomal stability and the free fraction of compounds as evidenced through a pairwise comparison of molecules that were otherwise identical. Highlighted in detail are analogues of an advanced compound 4 that were designed to improve solubility, resulting in 2. This compound, is potent across PI3K class I isoforms with IC(50)s of 5, 27, 7, and 14 nM for PI3Kα, ß, δ, and γ, respectively, inhibits mTOR with a K(i) of 17 nM yet is highly selective versus a large panel of kinases including others in the PIKK family. On the basis of the cell potency, low clearance in mouse, and high free fraction, 2 demonstrated significant efficacy in mouse xenografts when dosed as low as 1 mg/kg orally and is currently in phase I clinical trials for cancer.


Assuntos
Antineoplásicos/síntese química , Compostos Bicíclicos Heterocíclicos com Pontes/síntese química , Classe I de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Pirimidinas/síntese química , Serina-Treonina Quinases TOR/antagonistas & inibidores , Administração Oral , Animais , Antineoplásicos/farmacocinética , Antineoplásicos/farmacologia , Compostos Bicíclicos Heterocíclicos com Pontes/farmacocinética , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular Tumoral , Cristalografia por Raios X , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Técnicas In Vitro , Isoenzimas/antagonistas & inibidores , Camundongos , Camundongos Nus , Microssomos Hepáticos/metabolismo , Modelos Moleculares , Transplante de Neoplasias , Conformação Proteica , Pirimidinas/farmacocinética , Pirimidinas/farmacologia , Ratos , Estereoisomerismo , Relação Estrutura-Atividade , Transplante Heterólogo
18.
Mol Cancer Ther ; 10(12): 2426-36, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21998291

RESUMO

Alterations of the phosphoinositide-3 kinase (PI3K)/Akt signaling pathway occur broadly in cancer via multiple mechanisms including mutation of the PIK3CA gene, loss or mutation of phosphatase and tensin homolog (PTEN), and deregulation of mammalian target of rapamycin (mTOR) complexes. The dysregulation of this pathway has been implicated in tumor initiation, cell growth and survival, invasion and angiogenesis, thus, PI3K and mTOR are promising therapeutic targets for cancer. We discovered GDC-0980, a selective, potent, orally bioavailable inhibitor of Class I PI3 kinase and mTOR kinase (TORC1/2) with excellent pharmacokinetic and pharmaceutical properties. GDC-0980 potently inhibits signal transduction downstream of both PI3K and mTOR, as measured by pharmacodynamic (PD) biomarkers, thereby acting upon two key pathway nodes to produce the strongest attainable inhibition of signaling in the pathway. Correspondingly, GDC-0980 was potent across a broad panel of cancer cell lines, with the greatest potency in breast, prostate, and lung cancers and less activity in melanoma and pancreatic cancers, consistent with KRAS and BRAF acting as resistance markers. Treatment of cancer cell lines with GDC-0980 resulted in G1 cell-cycle arrest, and in contrast to mTOR inhibitors, GDC-0980 induced apoptosis in certain cancer cell lines, including those with direct pathway activation via PI3K and PTEN. Low doses of GDC-0980 potently inhibited tumor growth in xenograft models including those with activated PI3K, loss of LKB1 or PTEN, and elicited an exposure-related decrease in PD biomarkers. These preclinical data show that GDC-0980 is a potent and effective dual PI3K/mTOR inhibitor with promise for the clinic.


Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes/uso terapêutico , Neoplasias/tratamento farmacológico , Pirimidinas/uso terapêutico , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Compostos Bicíclicos Heterocíclicos com Pontes/farmacologia , Linhagem Celular Tumoral , Células HCT116 , Humanos , Camundongos , Modelos Teóricos , Neoplasias/metabolismo , Fosfatidilinositol 3-Quinases/classificação , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositol 3-Quinases/fisiologia , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/classificação , Inibidores de Proteínas Quinases/uso terapêutico , Pirimidinas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/antagonistas & inibidores , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Cancer Res ; 70(3): 1164-72, 2010 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-20103642

RESUMO

Therapeutic inhibitors are being developed against the phosphoinositide 3-kinase (PI3K) pathway, the deregulation of which drives tumor growth and survival in many cancers. There are eight PI3Ks in mammals divided into three classes. Class IA PI3Ks (p110alpha, p110beta, and p110delta) are critical for cell growth and survival, with the p110alpha isoform implicated as the most important in carcinomas. In this study, we examined the effects of small-molecule inhibitors of class IA PI3Ks to explore the contributions of different isoforms in cancer cells. Similar responses were seen in cancer cells with wild-type or activated mutant PI3K genes treated with p110alpha/delta or p110alpha/beta/delta inhibitors in cell viability assays. In contrast, PTEN-negative cell lines tended to be less responsive (4-fold overall) to an inhibitor of p110alpha/delta versus p110alpha/beta/delta. Combining a p110alpha/delta inhibitor with a p110beta inhibitor resulted in comparable potency to the p110alpha/beta/delta inhibitor. The disparity in efficacy was confirmed in vivo. Pharmacodynamic biomarker analysis revealed that an inhibitor with insufficient potency against the p110beta isoform was less effective at inhibiting the PI3K pathway in PTEN-negative tumor xenografts. Our results imply that patients with PTEN-negative tumors may preferentially benefit from treatment with a class I PI3K inhibitor that is capable of inhibiting the p110beta isoform.


Assuntos
Inibidores de Fosfoinositídeo-3 Quinase , Neoplasias da Próstata/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Animais , Western Blotting , Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Citometria de Fluxo , Humanos , Indazóis/química , Indazóis/farmacologia , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Masculino , Camundongos , Camundongos Nus , Estrutura Molecular , Mutação , Proteína Oncogênica v-akt/metabolismo , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fosfatidilinositol 3-Quinases/genética , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Inibidores de Proteínas Quinases/química , Sulfonamidas/química , Sulfonamidas/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto
20.
J Med Chem ; 53(3): 1086-97, 2010 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-20050669

RESUMO

The PI3K/AKT/mTOR pathway has been shown to play an important role in cancer. Starting with compounds 1 and 2 (GDC-0941) as templates, (thienopyrimidin-2-yl)aminopyrimidines were discovered as potent inhibitors of PI3K or both PI3K and mTOR. Structural information derived from PI3K gamma-ligand cocrystal structures of 1 and 2 were used to design inhibitors that maintained potency for PI3K yet improved metabolic stability and oral bioavailability relative to 1. The addition of a single methyl group to the optimized 5 resulted in 21, which had significantly reduced potency for mTOR. The lead compounds 5 (GNE-493) and 21 (GNE-490) have good pharmacokinetic (PK) parameters, are highly selective, demonstrate knock down of pathway markers in vivo, and are efficacious in xenograft models where the PI3K pathway is deregulated. Both compounds were compared in a PI3K alpha mutated MCF7.1 xenograft model and were found to have equivalent efficacy when normalized for exposure.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Inibidores de Fosfoinositídeo-3 Quinase , Inibidores de Proteínas Quinases/farmacologia , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Pirimidinas/farmacologia , Tiofenos/farmacologia , Administração Oral , Animais , Proliferação de Células/efeitos dos fármacos , Classe Ib de Fosfatidilinositol 3-Quinase , Isoenzimas/antagonistas & inibidores , Camundongos , Camundongos Nus , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Pirimidinas/síntese química , Pirimidinas/química , Relação Estrutura-Atividade , Serina-Treonina Quinases TOR , Tiofenos/síntese química , Tiofenos/química , Ensaios Antitumorais Modelo de Xenoenxerto
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