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1.
J Pharmacokinet Pharmacodyn ; 51(1): 33-37, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37561265

RESUMO

Dense data can be classified into superdense information-poor data (type 1 dense data) and dense information-rich data (type 2 dense data). Arbitrary, random, or optimal thinning may be applied to type 1 dense data to minimise computational burden and statistical issues (such as autocorrelation). In contrast, a prospective or retrospective optimal design can be applied to type 2 dense data to maximise information gain from limited resources (capital and/or time). Here we describe a retrospective optimal selection strategy for quantification of unbound drug concentration from a discrete set of plasma samples where the total drug concentration has been measured.


Assuntos
Estudos Prospectivos , Estudos Retrospectivos
2.
J Pharmacokinet Pharmacodyn ; 51(4): 335-352, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38504032

RESUMO

The development of optimized dosing regimens plays a crucial role in oncology drug development. This study focused on the population pharmacokinetic modelling and simulation of docetaxel, comparing the pharmacokinetic exposure of oral docetaxel plus encequidar (oDox + E) with the standard of care intravenous (IV) docetaxel regimen. The aim was to evaluate the feasibility of oDox + E as a potential alternative to IV docetaxel. The article demonstrates an approach which aligns with the FDA's Project Optimus which aims to improve oncology drug development through model informed drug development (MIDD). The key question answered by this study was whether a feasible regimen of oDox + E existed. The purpose of this question was to provide an early GO / NO-GO decision point to guide drug development and improve development efficiency. METHODS:  A stepwise approach was employed to develop a population pharmacokinetic model for total and unbound docetaxel plasma concentrations after IV docetaxel and oDox + E administration. Simulations were performed from the final model to assess the probability of target attainment (PTA) for different oDox + E dose regimens (including multiple dose regimens) in relation to IV docetaxel using AUC over effective concentration (AUCOEC) metric across a range of effective concentrations (EC). A Go / No-Go framework was defined-the first part of the framework assessed whether a feasible oDox + E regimen existed (i.e., a PTA ≥ 80%), and the second part defined the conditions to proceed with a Go decision. RESULTS:  The overall population pharmacokinetic model consisted of a 3-compartment model with linear elimination, constant bioavailability, constant binding mechanics, and a combined error model. Simulations revealed that single dose oDox + E regimens did not achieve a PTA greater than 80%. However, two- and three-dose regimens at 600 mg achieved PTAs exceeding 80% for certain EC levels. CONCLUSION:  The study demonstrates the benefits of MIDD using oDox + E as a motivating example. A population pharmacokinetic model was developed for the total and unbound concentration in plasma of docetaxel after administration of IV docetaxel and oDox + E. The model was used to simulate oDox + E dose regimens which were compared to the current standard of care IV docetaxel regimen. A GO / NO-GO framework was applied to determine whether oDox + E should progress to the next phase of drug development and whether any conditions should apply. A two or three-dose regimen of oDox + E at 600 mg was able to achieve non-inferior pharmacokinetic exposure to current standard of care IV docetaxel in simulations. A Conditional GO decision was made based on this result and further quantification of the "effective concentration" would improve the ability to optimise the dose regimen.


Assuntos
Administração Intravenosa , Docetaxel , Modelos Biológicos , Docetaxel/farmacocinética , Docetaxel/administração & dosagem , Humanos , Administração Oral , Área Sob a Curva , Masculino , Simulação por Computador , Antineoplásicos/farmacocinética , Antineoplásicos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/farmacocinética , Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Equivalência Terapêutica , Feminino , Pessoa de Meia-Idade
3.
Int J Mol Sci ; 24(2)2023 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-36674782

RESUMO

The Δ133p53ß isoform is increased in many primary tumors and has many tumor-promoting properties that contribute to increased proliferation, migration and inflammation. Here we investigated whether Δ133p53ß contributed to some of the most aggressive tumors that had metastasized to the brain. Δ133p53ß mRNA expression was measured in lung, breast, melanoma, colorectal metastases and, where available, the matched primary tumor. The presence of Δ133p53ß expression was associated with the time for the primary tumor to metastasize and overall survival once the tumor was detected in the brain. Δ133p53ß was present in over 50% of lung, breast, melanoma and colorectal metastases to the brain. It was also increased in the brain metastases compared with the matched primary tumor. Brain metastases with Δ133p53ß expressed were associated with a reduced time for the primary tumor to metastasize to the brain compared with tumors with no Δ133p53ß expression. In-vitro-based analyses in Δ133p53ß-expressing cells showed increased cancer-promoting proteins on the cell surface and increased downstream p-AKT and p-MAPK signaling. Δ133p53ß-expressing cells also invaded more readily across a mock blood-brain barrier. Together these data suggested that Δ133p53ß contributes to brain metastases by making cells more likely to invade the brain.


Assuntos
Neoplasias Encefálicas , Proteína Supressora de Tumor p53 , Humanos , Neoplasias Encefálicas/metabolismo , Metástase Neoplásica , Isoformas de Proteínas/genética , Proteína Supressora de Tumor p53/genética , Deleção de Genes
4.
Br J Clin Pharmacol ; 87(12): 4670-4680, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-33960504

RESUMO

AIMS: Paclitaxel is a widely used anti-neoplastic agent but has low oral bioavailability due to gut extrusion by P-glycoprotein (P-gp). Oral paclitaxel could be more convenient, less resource intensive, and more tolerable than intravenous administration. Encequidar (HM30181A) is a novel, minimally absorbed gut-specific P-gp inhibitor. We tested whether administration of oral paclitaxel with encequidar (oPac+E) achieved comparable AUC to intravenous paclitaxel (IVP) 80 mg/m2 . METHODS: We conducted a multi-centre randomised crossover study with two treatment periods. Patients (pts) with advanced cancer received either oral paclitaxel 615 mg/m2 divided over 3 days and encequidar 15 mg orally 1 hour prior, followed by IVP 80 mg/m2 , or the reverse sequence. PK blood samples were taken up to Day 9 for oPac+E and Day 5 for IVP. RESULTS: Forty-two patients were enrolled; 35 completed both treatment periods. AUC0-∞ was 5033.5 ± 1401.1 ng.h/mL for oPac+E and 5595.9 ± 1264.1 ng.h/mL with IVP. The geometric mean ratio (GMR) for AUC was 89.50% (90% CI 83.89-95.50). Mean absolute bioavailability of oPac+E was 12% (CV% = 23%). PK parameters did not change meaningfully after 4 weeks administration of oPac+E in an extension study. G3 treatment-emergent adverse events occurred in seven (18%) pts with oPac+E and two (5%) with IVP. Seventy-five per cent of patients preferred oPac+E over IVP. CONCLUSIONS: GMR for AUC was within the predefined acceptable range of 80-125% for demonstrating equivalence. oPac+E is tolerable and there is no evidence of P-gp induction with repeat administration. With further study, oPac+E could be an alternative to IVP.


Assuntos
Neoplasias , Paclitaxel , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/antagonistas & inibidores , Administração Intravenosa , Administração Oral , Estudos Cross-Over , Humanos , Neoplasias/induzido quimicamente , Neoplasias/tratamento farmacológico , Paclitaxel/administração & dosagem
5.
Br J Cancer ; 121(5): 421-424, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31363168

RESUMO

Breast cancer can be diagnosed during pregnancy and in the peri-partum period, and the potential exposure of a foetus or neonate to chemotherapy is of concern to mothers and clinicians. Paclitaxel is a commonly used agent in breast cancer, but little is known about its excretion in breast milk. Breastfeeding during chemotherapy has been traditionally cautioned against due to the risk of neonatal exposure to chemotherapy agents, however, data are limited. We measured serum and breast milk concentrations of paclitaxel in a 33-year-old woman with an early breast cancer diagnosed during pregnancy and treated with weekly paclitaxel 80 mg/m2. We found breast milk paclitaxel levels drop below the minimum quantifiable dose at 72 h following chemotherapy, with a relative infant dose of 0.091%. Breast milk excretion of paclitaxel following a dose of 80 mg/m2 is negligible at 72 h, and this may be a safe time to recommence breastfeeding following exposure.


Assuntos
Antineoplásicos Fitogênicos/farmacocinética , Carcinoma Ductal de Mama/tratamento farmacológico , Mastectomia , Leite Humano/metabolismo , Paclitaxel/farmacocinética , Complicações Neoplásicas na Gravidez/tratamento farmacológico , Neoplasias de Mama Triplo Negativas/tratamento farmacológico , Administração Intravenosa , Adulto , Aleitamento Materno , Carcinoma Ductal de Mama/patologia , Quimioterapia Adjuvante , Feminino , Humanos , Gravidez , Complicações Neoplásicas na Gravidez/patologia , Radioterapia Adjuvante , Fatores de Tempo , Neoplasias de Mama Triplo Negativas/patologia
6.
J Pathol ; 246(1): 77-88, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-29888503

RESUMO

As tumor protein 53 (p53) isoforms have tumor-promoting, migration, and inflammatory properties, this study investigated whether p53 isoforms contributed to glioblastoma progression. The expression levels of full-length TP53α (TAp53α) and six TP53 isoforms were quantitated by RT-qPCR in 89 glioblastomas and correlated with TP53 mutation status, tumor-associated macrophage content, and various immune cell markers. Elevated levels of Δ133p53ß mRNA characterised glioblastomas with increased CD163-positive macrophages and wild-type TP53. In situ-based analyses found Δ133p53ß expression localised to malignant cells in areas with increased hypoxia, and in cells with the monocyte chemoattractant protein C-C motif chemokine ligand 2 (CCL2) expressed. Tumors with increased Δ133p53ß had increased numbers of cells positive for macrophage colony-stimulating factor 1 receptor (CSF1R) and programmed death ligand 1 (PDL1). In addition, cells expressing a murine 'mimic' of Δ133p53 (Δ122p53) were resistant to temozolomide treatment and oxidative stress. Our findings suggest that elevated Δ133p53ß is an alternative pathway to TP53 mutation in glioblastoma that aids tumor progression by promoting an immunosuppressive and chemoresistant environment. Adding Δ133p53ß to a TP53 signature along with TP53 mutation status will better predict treatment resistance in glioblastoma. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.


Assuntos
Biomarcadores Tumorais/metabolismo , Neoplasias Encefálicas/metabolismo , Glioblastoma/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Antineoplásicos Alquilantes/farmacologia , Antígeno B7-H1/metabolismo , Biomarcadores Tumorais/genética , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/patologia , Linhagem Celular , Quimiocina CCL2/metabolismo , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glioblastoma/patologia , Humanos , Macrófagos/metabolismo , Camundongos , Mutação , Estresse Oxidativo , Isoformas de Proteínas , Receptores de Superfície Celular/metabolismo , Receptores de Fator Estimulador das Colônias de Granulócitos e Macrófagos/metabolismo , Transdução de Sinais , Temozolomida/farmacologia , Hipóxia Tumoral , Microambiente Tumoral , Proteína Supressora de Tumor p53/genética , Regulação para Cima
8.
Mamm Genome ; 29(11-12): 831-842, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-29992419

RESUMO

This review paper outlines studies on the Δ122p53 mouse, a model of the human Δ133p53 isoform, together with studies in other model organisms, cell culture, and where available, clinical investigations. In general, these studies imply that, in contrast to the canonical p53 tumor suppressor, Δ133p53 family members have oncogenic capability. Δ122p53 is multi-functional, conferring survival and proliferative advantages on cells, promoting invasion, metastasis and vascularization, as does Δ133p53. Cancers with high levels of Δ133p53 often have poor prognosis. Δ122p53 mediates its effects through the JAK-STAT and RhoA-ROCK signaling pathways. We propose that Δ133p53 isoforms have evolved as inflammatory signaling molecules to deal with the consequent tissue damage of p53 activation. However, if sustained expression of the isoforms occur, pathologies may result.


Assuntos
Modelos Animais de Doenças , Inflamação/patologia , Neoplasias/patologia , Proteína Supressora de Tumor p53/metabolismo , Animais , Progressão da Doença , Humanos , Inflamação/etiologia , Inflamação/metabolismo , Camundongos , Neoplasias/etiologia , Neoplasias/metabolismo , Isoformas de Proteínas , Transdução de Sinais , Proteína Supressora de Tumor p53/genética
9.
Mod Pathol ; 29(3): 212-26, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26769142

RESUMO

Telomere maintenance is a hallmark of cancer and likely to be targeted in future treatments. In glioblastoma established methods of identifying telomerase and alternative lengthening of telomeres leave a significant proportion of tumors with no defined telomere maintenance mechanism. This study investigated the composition of these tumors using RNA-Seq. Glioblastomas with an indeterminate telomere maintenance mechanism had an increased immune signature compared with alternative lengthening of telomeres and telomerase-positive tumors. Immunohistochemistry for CD163 confirmed that the majority (80%) of tumors with an indeterminate telomere maintenance mechanism had a high presence of tumor-associated macrophages. The RNA-Seq and immunostaining data separated tumors with no defined telomere maintenance mechanism into three subgroups: alternative lengthening of telomeres like tumors with a high presence of tumor-associated macrophages and telomerase like tumors with a high presence of tumor-associated macrophages. The third subgroup had no increase in tumor-associated macrophages and may represent a distinct category. The presence of tumor-associated macrophages conferred a worse prognosis with reduced patient survival times (alternative lengthening of telomeres with and without macrophages P=0.0004, and telomerase with and without macrophages P=0.013). The immune signatures obtained from RNA-Seq were significantly different between telomere maintenance mechanisms. Alternative lengthening of telomeres like tumors with macrophages had increased expression of interferon-induced proteins with tetratricopeptide repeats (IFIT1-3). Telomerase-positive tumors with macrophages had increased expression of macrophage receptor with collagenous structure (MARCO), CXCL12 and sushi-repeat containing protein x-linked 2 (SRPX2). Telomerase-positive tumors with macrophages were also associated with a reduced frequency of total/near total resections (44% vs >76% for all other subtypes, P=0.014). In summary, different immune signatures are found among telomere maintenance mechanism-based subgroups in glioblastoma. The reduced extent of surgical resection of telomerase-positive tumors with macrophages suggests that some tumor-associated macrophages are more unfavorable.


Assuntos
Neoplasias Encefálicas/patologia , Glioblastoma/patologia , Macrófagos/imunologia , Telômero/fisiologia , Adulto , Idoso , Western Blotting , Neoplasias Encefálicas/imunologia , Neoplasias Encefálicas/mortalidade , Feminino , Glioblastoma/imunologia , Glioblastoma/mortalidade , Humanos , Imuno-Histoquímica , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase , Prognóstico
10.
Mod Pathol ; 28(10): 1369-82, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26293778

RESUMO

Viral infections are known to adversely affect pregnancy, but scant attention has been given to human papilloma virus (HPV) infection. We aimed to determine the molecular and histopathological features of placental HPV infection, in association with pregnancy complications including fetal growth restriction, pre-maturity, pre-eclampsia, and diabetes. Three hundred and thirty-nine placentae were selected based on the presence or absence of pregnancy complications. Five independent methods were used to identify HPV in the placenta, namely, immunohistochemistry for L1 viral capsid, in situ hybridization to high-risk HPV DNA, PCR, western blotting, and transmission electron microscopy. Pregnancy complications and uterine cervical smear screening results were correlated with placental HPV histopathology. In this study, which was deliberately biased towards complications, HPV was found in the decidua of 75% of placentae (253/339) and was statistically associated with histological acute chorioamnionitis (P<0.05). In 14% (35/253) of the HPV positive cases, HPV L1 immunoreactivity also occurred in the villous trophoblast where it was associated with a lymphohistiocytic villitis (HPV-LHV), and was exclusively of high-risk HPV type. HPV-LHV significantly associated with fetal growth restriction, preterm delivery, and pre-eclampsia (all P<0.05). All cases of pre-eclampsia (20/20) in our cohort had high-risk placental HPV. A further 55 cases (22%, 55/253) of HPV positive placentae had minimal villous trophoblast HPV L1 immunoreactivity, but a sclerosing pauci-immune villitis, statistically associated with diabetes (49.1%, 27/55, P<0.05). For women with placental HPV, 33% (69/207) had an HPV-related positive smear result before pregnancy compared with (9.4% 8/85) of women with HPV-negative placentae (P=0.0001). Our findings support further investigations to determine if vaccination of women and men will improve pregnancy outcomes.


Assuntos
Infecções por Papillomavirus/complicações , Placenta/virologia , Complicações Infecciosas na Gravidez/virologia , Adulto , Western Blotting , Estudos Transversais , Feminino , Humanos , Imuno-Histoquímica , Hibridização In Situ , Microscopia Eletrônica de Transmissão , Infecções por Papillomavirus/patologia , Placenta/patologia , Reação em Cadeia da Polimerase , Gravidez , Complicações Infecciosas na Gravidez/patologia , Resultado da Gravidez
11.
BMC Cancer ; 14: 159, 2014 Mar 06.
Artigo em Inglês | MEDLINE | ID: mdl-24602166

RESUMO

BACKGROUND: The molecular basis to overcome therapeutic resistance to treat glioblastoma remains unclear. The anti-apoptotic b cell lymphoma 2 (BCL2) gene is associated with treatment resistance, and is transactivated by the paired box transcription factor 8 (PAX8). In earlier studies, we demonstrated that increased PAX8 expression in glioma cell lines was associated with the expression of telomerase. In this current study, we more extensively explored a role for PAX8 in gliomagenesis. METHODS: PAX8 expression was measured in 156 gliomas including telomerase-negative tumours, those with the alternative lengthening of telomeres (ALT) mechanism or with a non-defined telomere maintenance mechanism (NDTMM), using immunohistochemistry and quantitative PCR. We also tested the affect of PAX8 knockdown using siRNA in cell lines on cell survival and BCL2 expression. RESULTS: Seventy-two percent of glioblastomas were PAX8-positive (80% telomerase, 73% NDTMM, and 44% ALT). The majority of the low-grade gliomas and normal brain cells were PAX8-negative. The suppression of PAX8 was associated with a reduction in both cell growth and BCL2, suggesting that a reduction in PAX8 expression would sensitise tumours to cell death. CONCLUSIONS: PAX8 is increased in the majority of glioblastomas and promoted cell survival. Because PAX8 is absent in normal brain tissue, it may be a promising therapeutic target pathway for treating aggressive gliomas.


Assuntos
Glioma/metabolismo , Fatores de Transcrição Box Pareados/metabolismo , Proliferação de Células , Sobrevivência Celular , Expressão Gênica , Inativação Gênica , Glioma/genética , Glioma/patologia , Humanos , Imuno-Histoquímica , Fator de Transcrição PAX5/metabolismo , Fator de Transcrição PAX8 , Fatores de Transcrição Box Pareados/genética , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Interferente Pequeno/genética
12.
Nephrology (Carlton) ; 19(6): 359-65, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24629073

RESUMO

BACKGROUND: Omeprazole is an important cause of drug-induced acute interstitial nephritis (AIN). How omeprazole induces injury is unknown. METHODS AND RESULTS: Detailed clinical assessment of 25 biopsy-proven cases of omeprazole-induced AIN showed that all patients presented with impaired renal function, sterile pyuria with varying amounts of proteinuria but no eosinophiluria and no systemic symptoms to suggest a vasculitis. Histological analyses were characteristic of an acute tubulitis with an inflammatory cellular infiltrate. Using modified Banff scheme criteria, mild tubulitis (t1) was present in 56% of cases, a moderate tubulitis (t2) in 24% of cases, and a severe tubulitis in 20% of cases. Most (78%) of cases had mononuclear cell infiltrates, no significant eosinophilic infiltrates were found, and glomeruli were not involved. Immunostaining for CD4, CD8, IL-17A, IL-17F, Foxp3 and T-bet (T cell subsets), CD20 and CD163 defined the cellular infiltrates. The predominant inflammatory cells were CD4+ lymphocytic aggregates (77% of cases), combined with co-staining of CD4 IL and 17A/F in 44-48% of all cases, suggesting a Th17-mediated inflammatory process. T-bet+ cell infiltrates were present to a lesser degree, suggesting additional Th1 involvement. How omeprazole induces this inflammatory response is unclear, but may include direct effects by IL-17 expressing CD4+ cells on renal tubular cells. CONCLUSION: This large biopsy series of omeprazole-induced AIN demonstrates the features of acute tubulitis, with significant interstitial infiltrates consistent with immunopathological Th17 and Th1 processes.


Assuntos
Nefrite Intersticial/induzido quimicamente , Nefrite Intersticial/imunologia , Omeprazol/efeitos adversos , Células Th1/efeitos dos fármacos , Células Th17/efeitos dos fármacos , Doença Aguda , Idoso , Idoso de 80 Anos ou mais , Biópsia , Eosinófilos/efeitos dos fármacos , Eosinófilos/imunologia , Feminino , Humanos , Imunofenotipagem , Masculino , Pessoa de Meia-Idade , Nefrite Intersticial/patologia , Inibidores da Bomba de Prótons/efeitos adversos , Células Th1/imunologia , Células Th17/imunologia
13.
Artigo em Inglês | MEDLINE | ID: mdl-38814342

RESUMO

PURPOSE: To determine the bioavailability, safety, and tolerability of a single dose of oral docetaxel plus encequidar (oDox + E) and compare its pharmacokinetic exposure with current standard of care IV docetaxel. INTRODUCTION: Docetaxel is a taxane widely used as an anti-neoplastic agent. Due to low oral bioavailability secondary to gut P-glycoprotein (P-gp) efflux, its current use is limited to intravenous administration. Oral docetaxel may provide a less resource intensive, more convenient, and tolerable alternative. Encequidar is a first in class, minimally absorbed, oral gut-specific P-gp inhibitor. We tested whether oDox + E can achieve comparable pharmacokinetic exposure to IV docetaxel. METHODS: A multicentre, phase I open-label, pharmacokinetic trial was undertaken to determine the bioavailability, safety, and tolerability of a single dose of oDox + E (at 75 mg/m2 + 15 mg, 150 mg/m2 + 15 mg, and 300 mg/m2 + 15 mg) in metastatic prostate cancer (mPC) patients compared to standard of care IV docetaxel as prescribed by their oncologists. The 15 mg of Encequidar at each dose level was given one hour prior to oral docetaxel. RESULTS: 11 patients were enrolled; 9 patients completed the study. Oral docetaxel exposure increased with dose, achieving the highest at 300 mg/m2 oDox + E (with AUC0 - infinity of 1343.3 ± 443.0 ng.h/mL compared to the IV docetaxel AUC0 - infinity of 2000 ± 325 ng.h/mL) and became non-linear at 300 mg/m2. The mean absolute bioavailability of oDox + E across all 3 dose levels was 16.14% (range: 8.19-25.09%). No patient deaths, dose limiting toxicity, treatment-related serious adverse event or grade 4 toxicity were observed. Maximal tolerated dose was not reached. CONCLUSION: oDox + E has a safe and tolerable adverse event profile in patients with metastatic prostate cancer. The increase in oral bioavailability of oDox + E suggests a multi-dose oDox + E regimen could theoretically achieve exposures comparable with standard of care IV docetaxel. Further development to examine the optimal multiple dose regimen of oDox + E is warranted. TRIAL REGISTRATION NUMBER: U1111-1173-5473.

14.
Pharmaceutics ; 16(5)2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38794263

RESUMO

INTRODUCTION: Docetaxel, a taxane used in the treatment of solid tumours, exerts pharmacological activity when in its unbound form. We report a sensitive assay to quantify unbound docetaxel after oral administration of docetaxel plus encequidar (oDox+E). Unbound drug quantification is important due to its direct correlation with drug-related toxicity and therapeutic efficacy. We improve on the sensitivity of current assay methods and demonstrate the utility of the assay on a novel formulation of oral docetaxel. METHODS: Ultrafiltration followed by high-performance liquid chromatography and tandem mass spectrometry (HPLC-MS/MS) was utilized. Long-term stability, precision, accuracy, and recovery experiments were conducted to validate the assay. Additionally, patient samples from a Phase I dose-escalation pharmacokinetic study were analyzed using the developed assay. RESULTS: The assay method exhibited long-term stability with an observed change between 0.8 and 6.9% after 131 days of storage at -60 °C. Precision and accuracy quality controls met the FDA acceptance criteria. An average recovery of 88% was obtained. Patient sample analysis demonstrated successful implementation of the assay. CONCLUSION: A validated sensitive assay was developed with an LLOQ of 0.084 ng/mL using 485 µL of human plasma. The sensitivity of the assay allowed quantification of unbound docetaxel concentrations in an early-phase oDox+E clinical study to compare it against IV docetaxel using pharmacokinetic modelling. Successful development of oDox+E represents an opportunity to replace the current IV docetaxel regimen with an oral regimen with lower cost, decreased side effects, and improve patient quality of life and experience.

15.
Blood ; 117(19): 5166-77, 2011 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-21411755

RESUMO

The p53 protein is a pivotal tumor suppressor that is frequently mutated in many human cancers, although precisely how p53 prevents tumors is still unclear. To add to its complexity, several isoforms of human p53 have now been reported. The Δ133p53 isoform is generated from an alternative transcription initiation site in intron 4 of the p53 gene (Tp53) and lacks the N-terminus. Elevated levels of Δ133p53 have been observed in a variety of tumors. To explore the functions of Δ133p53, we created a mouse expressing an N-terminal deletion mutant of p53 (Δ122p53) that corresponds to Δ133p53. Δ122p53 mice show decreased survival and a different and more aggressive tumor spectrum compared with p53 null mice, implying that Δ122p53 is a dominant oncogene. Consistent with this, Δ122p53 also confers a marked proliferative advantage on cells and reduced apoptosis. In addition to tumor development, Δ122p53 mice show a profound proinflammatory phenotype having increased serum concentrations of interleukin-6 and other proinflammatory cytokines and lymphocyte aggregates in the lung and liver as well as other pathologies. Based on these observations, we propose that human Δ133p53 also functions to promote cell proliferation and inflammation, one or both of which contribute to tumor development.


Assuntos
Proliferação de Células , Inflamação/genética , Neoplasias Experimentais/genética , Proteína Supressora de Tumor p53/genética , Sequência de Aminoácidos , Animais , Western Blotting , Imunofluorescência , Expressão Gênica , Perfilação da Expressão Gênica , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Dados de Sequência Molecular , Análise de Sequência com Séries de Oligonucleotídeos , Isoformas de Proteínas/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução Genética
16.
J Pathol ; 226(3): 509-18, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22250043

RESUMO

The alternative lengthening of telomeres (ALT) mechanism represents an alternative to the enzyme telomerase in the maintenance of mammalian telomeres in 25-60% of sarcomas and a minority of carcinomas (about 5-15%). ALT-positive cells are distinguished by long and heterogeneous telomere length distributions by terminal restriction fragment (TRF) Southern blotting. Another diagnostic marker of ALT is discrete nuclear co-localized signals of telomeric DNA and the promyelocytic leukaemia protein (PML), referred to as ALT-associated PML bodies (APBs). Recently, we detected smaller sized co-localized PML and telomere DNA (APB-like) bodies in endothelial cells adjacent to astrocytoma tumour cells in situ. In this study, we examined a wide variety of non-neoplastic tissues, and report that co-localized signals of PML and telomere DNA are present in endothelial, stromal, and some epithelial cells. Co-localized signals of PML and telomere DNA showed an increased frequency in non-neoplastic cells with DNA damage. These results suggest that a mechanism similar to that in ALT-positive tumours also operates in non-neoplastic cells, which may be activated by DNA damage.


Assuntos
Células Endoteliais/patologia , Células Epiteliais/patologia , Células Estromais/patologia , Homeostase do Telômero/fisiologia , Telômero/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Estudos de Casos e Controles , Células Cultivadas , DNA/análise , Humanos , Pessoa de Meia-Idade , Neoplasias/patologia , Proteínas Nucleares/metabolismo , Proteína da Leucemia Promielocítica , Telômero/genética , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Adulto Jovem
17.
Ther Adv Med Oncol ; 15: 17588359231183680, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37492633

RESUMO

Background: Paclitaxel is widely used for the treatment of metastatic breast cancer (MBC). However, it has a low oral bioavailability due to gut extrusion caused by P-glycoprotein (P-gp). Oral paclitaxel (oPAC) may be more convenient, less resource-intensive, and more tolerable than its intravenous form. Encequidar (E) is a first-in-class, minimally absorbed, gut-specific oral P-gp inhibitor that facilitates the oral absorption of paclitaxel. Objectives: To investigate the pharmacokinetics (PK), overall response rate (ORR), and safety of weekly oral paclitaxel with encequidar (oPAC + E) in patients with advanced breast cancer. Design: This is a multicenter, single-arm, open-label study in six medical centers in Taiwan. Methods: Patients with advanced breast cancer were administered 205 mg/m2 oPAC and 12.9 mg E for 3 consecutive days weekly for up to 16 weeks. Plasma samples were collected at weeks 1 and 4. PK, ORR, and safety were evaluated. Results: In all, 28 patients were enrolled; 27 had MBC; 23 had prior chemotherapy; and 14 had ⩾2 lines of prior chemotherapy. PK were evaluable in 25 patients. Plasma paclitaxel area under the curve (AUC)(0-52 h) at week 1 (3419 ± 1475 ng h/ml) and week 4 (3224 ± 1150 ng h/ml) were equivalent. Best overall response in 28 evaluable patients was partial response (PR) in 11 (39.3%), 13 (46.4%) stable disease (SD), and 1 (3.6%) with progressive disease (PD). No patient achieved complete response (CR). The clinical benefit rate (CR + PR + SD) was 85.7%. Major adverse events among the 28 treated patients were grade 3 neutropenia (25%), grade 4 neutropenia (18%), with febrile neutropenia in 4%, and grade 3 diarrhea (4%). No treatment-related deaths occurred. Grade 2 peripheral neuropathy occurred in 1 (4%) patient and grade 3 peripheral neuropathy in 1 (4%) patient. Conclusions: oPAC + E produced a consistent therapeutic plasma paclitaxel exposure during treatment. There was a high rate of radiologically assessed clinical benefit, and a low rate of neurotoxicity which may provide advantages over IV paclitaxel. Registration: ClinicalTrials.gov Identifier: NCT03165955.

18.
Am J Pathol ; 177(6): 2694-700, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21037079

RESUMO

Telomere maintenance by either telomerase activity or the recombination-mediated alternative lengthening of telomeres (ALT) mechanism is a hallmark of cancer. Tumors that use ALT as their telomere maintenance mechanism are characterized by long telomeres of great heterogeneity in length and by specific nuclear structures of co-localized promyelocytic leukemia protein and telomere DNA, called ALT-associated promyelocytic leukemia bodies (APBs). Recent advances have revealed a direct role for APBs in telomere recombination in ALT-positive cells. In this study, we investigated the possibility that APBs could occur before the long 'alternatively' lengthened telomeres arise, particularly in low-grade tumors. We measured APBs, telomere length, and telomerase activity in 64 astrocytomas inclusive of grade 1-4 tumors. Almost all grade 1-3 tumors (93%) were APB-positive using published criteria. Grade 2-3 APB-positive tumors also had long telomeres and were confirmed as ALT positive. However, grade 1 tumors lacked long telomeres and were therefore classified as ALT negative, but positive for telomere-associated promyelocytic leukemia bodies (TPB). This is the first report of a TPB-positive but ALT-negative tumor, and suggests that low-grade tumors have the foundation for recombinational telomere repair, as in ALT. Further work is warranted to characterize the TPB-positive phenotype in other early malignancies, as well as to determine whether TPBs predispose to telomere maintenance by ALT.


Assuntos
Astrocitoma/genética , Astrocitoma/metabolismo , Neoplasias Encefálicas/genética , Neoplasias Encefálicas/metabolismo , Proteínas Nucleares/metabolismo , Telômero/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Adolescente , Adulto , Astrocitoma/patologia , Neoplasias Encefálicas/patologia , Criança , Progressão da Doença , Humanos , Corpos de Inclusão/metabolismo , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Proteína da Leucemia Promielocítica , Telômero/química , Telômero/genética , Adulto Jovem
19.
Placenta ; 110: 16-23, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-34098319

RESUMO

INTRODUCTION: Pre-eclampsia (PE) is a dangerous placental condition that can lead to premature labour, seizures and death of mother and infant. Several studies have identified altered placental DNA methylation in PE; however, there is widespread inconsistency between studies and most findings have not been replicated. This study aimed to identify and validate consistent differences in methylation across multiple PE cohorts. METHODS: Seven publicly available 450K methylation array datasets were analysed to identify consistent differentially methylated positions (DMPs) in PE. DMPs were identified based on methylation difference (≥10%) and significance (p-value ≤ 1 × 10-7). Targeted deep bisulfite sequencing was then performed to validate a subset of DMPs in an additional independent PE cohort. RESULTS: Stringent analysis of the seven 450K datasets identified 25 DMPs (associated with 11 genes) in only one dataset. Using more relaxed criteria confirmed 19 of the stringent 25 DMPs in at least four of the remaining six datasets. Targeted deep bisulfite sequencing of eight DMPs (associated with three genes; CMIP, ST3GAL1 and DAPK3) in an independent PE cohort validated two DMPs in the CMIP gene. Seven additional CpG sites in CMIP were found to be significantly differentially methylated in PE. DISCUSSION: The identification and validation of significant differential methylation in CMIP suggests that the altered DNA methylation of this gene may be associated with the pathogenesis of PE, and may have the potential to serve as diagnostic biomarkers for this dangerous condition of pregnancy.


Assuntos
Metilação de DNA/fisiologia , Pré-Eclâmpsia/genética , Adolescente , Adulto , Estudos de Casos e Controles , Estudos de Coortes , Epigênese Genética/fisiologia , Feminino , Perfilação da Expressão Gênica , Humanos , Recém-Nascido , Masculino , Trabalho de Parto Prematuro/genética , Trabalho de Parto Prematuro/patologia , Pré-Eclâmpsia/patologia , Gravidez , Nascimento a Termo/genética , Nascimento a Termo/fisiologia , Adulto Jovem
20.
Clin Pharmacol Drug Dev ; 9(5): 610-620, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32468719

RESUMO

Fingolimod is indicated for the treatment of patients with the relapsing-remitting form of multiple sclerosis. The primary study objective was to evaluate the bioequivalence of a test formulation, 0.5 mg fingolimod HCl capsule (Lebrina, Asofarma Sociedad Anónima Industrial y Comercial, Argentina) relative to a reference formulation, 0.5 mg fingolimod capsule (Gilenya, Novartis Pharmaceutical, Australia). In a single-center, randomized, single-dose, single-blinded, 2-way crossover study, 33 New Zealand healthy subjects of both sexes were enrolled to receive a 0.5-mg dose of 3 capsules of each fingolimod formulation under fasting conditions, with a 42-day washout period between administrations. Additional pharmacokinetic information regarding its main active metabolite, fingolimod phosphate, was also provided. The point estimate and 90% confidence intervals of the ratios of maximum concentration and area under the plasma concentration-time curve from time 0 to 72 hours were 99.07 (95.83-102.41) and 97.64 (95.33-100.00) for fingolimod, and 95.60 (90.95-100.49) and 98.54 (96.19-100.96), for fingolimod phosphate. Primary parameters, maximum concentration and area under the plasma concentration-time curve from time 0 to 72 hours for fingolimod and fingolimod phosphate were found to have no significant difference when test and reference formulations were compared. Fingolimod and fingolimod phosphate of both formulations were within the accepted 90% confidence interval limits of 80.00% and 125.00%. No significant differences between the test and reference drug products were detected in any of the pharmacokinetic parameters estimated. Notwithstanding the primary conclusion of bioequivalence is focused on the measurement of the parent compound, compliance with the same criteria by the active metabolite reinforces the comparability between the pharmacokinetic profiles of both formulations (ClinicalTrials.gov Identifier: NCT03757338).


Assuntos
Família 4 do Citocromo P450/metabolismo , Composição de Medicamentos/métodos , Cloridrato de Fingolimode/farmacocinética , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Moduladores do Receptor de Esfingosina 1 Fosfato/farmacocinética , Administração Oral , Adulto , Área Sob a Curva , Índice de Massa Corporal , Estudos Cross-Over , Composição de Medicamentos/estatística & dados numéricos , Jejum/metabolismo , Feminino , Cloridrato de Fingolimode/administração & dosagem , Cloridrato de Fingolimode/sangue , Cloridrato de Fingolimode/metabolismo , Voluntários Saudáveis/estatística & dados numéricos , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla Recidivante-Remitente/sangue , Nova Zelândia/epidemiologia , Moduladores do Receptor de Esfingosina 1 Fosfato/administração & dosagem , Moduladores do Receptor de Esfingosina 1 Fosfato/sangue , Moduladores do Receptor de Esfingosina 1 Fosfato/metabolismo , Equivalência Terapêutica
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