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1.
Ann Oncol ; 34(3): 251-261, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36535566

RESUMEN

BACKGROUND: Pembrolizumab previously demonstrated robust antitumor activity and manageable safety in a phase Ib study of patients with heavily pretreated, programmed death ligand 1 (PD-L1)-positive, recurrent or metastatic nasopharyngeal carcinoma (NPC). The phase III KEYNOTE-122 study was conducted to further evaluate pembrolizumab versus chemotherapy in patients with platinum-pretreated, recurrent and/or metastatic NPC. Final analysis results are presented. PATIENTS AND METHODS: KEYNOTE-122 was an open-label, randomized study conducted at 29 sites, globally. Participants with platinum-pretreated recurrent and/or metastatic NPC were randomly assigned (1 : 1) to pembrolizumab or chemotherapy with capecitabine, gemcitabine, or docetaxel. Randomization was stratified by liver metastasis (present versus absent). The primary endpoint was overall survival (OS), analyzed in the intention-to-treat population using the stratified log-rank test (superiority threshold, one-sided P = 0.0187). Safety was assessed in the as-treated population. RESULTS: Between 5 May 2016 and 28 May 2018, 233 participants were randomly assigned to treatment (pembrolizumab, n = 117; chemotherapy, n = 116); Most participants (86.7%) received study treatment in the second-line or later setting. Median time from randomization to data cut-off (30 November 2020) was 45.1 months (interquartile range, 39.0-48.8 months). Median OS was 17.2 months [95% confidence interval (CI) 11.7-22.9 months] with pembrolizumab and 15.3 months (95% CI 10.9-18.1 months) with chemotherapy [hazard ratio, 0.90 (95% CI 0.67-1.19; P = 0.2262)]. Grade 3-5 treatment-related adverse events occurred in 12 of 116 participants (10.3%) with pembrolizumab and 49 of 112 participants (43.8%) with chemotherapy. Three treatment-related deaths occurred: 1 participant (0.9%) with pembrolizumab (pneumonitis) and 2 (1.8%) with chemotherapy (pneumonia, intracranial hemorrhage). CONCLUSION: Pembrolizumab did not significantly improve OS compared with chemotherapy in participants with platinum-pretreated recurrent and/or metastatic NPC but did have manageable safety and a lower incidence of treatment-related adverse events.


Asunto(s)
Neoplasias Nasofaríngeas , Platino (Metal) , Humanos , Neoplasias Nasofaríngeas/tratamiento farmacológico , Anticuerpos Monoclonales Humanizados , Docetaxel , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico
2.
Lung Cancer ; 159: 18-26, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34303276

RESUMEN

INTRODUCTION: Acquired resistance to TKI is an important unmet need in the management of EGFR mutated lung cancer. Recent clinical trial IMPower150 suggested that combination approach with VEGF inhibitor, check point inhibitor immunotherapy and platinum-based chemotherapy was effective in oncogene driven lung cancer. The current trial examined the efficacy of a modified regimen in an EGFR mutated cohort. METHODS: An open-labelled, single arm, phase II study was conducted in patients with EGFR mutated NSCLC who had progressed on at least one EGFR TKI. For those with T790M mutation, radiological progression on osimertinib was required for enrolment. Patients were treated with combination atezolizumab (1200 mg), bevacizumab (7.5 mg/kg), pemetrexed (500 mg/m2) and carboplatin (AUC 5) given once every 3 weeks until progression. RESULTS: Forty patients were enrolled. Median age was 62 (range 45-76) years. More than one half (23/40, 57.5%) had progressed on osimertinib. PD-L1 expression was < 1% in 52.5%. Median follow-up time was 17.8 months. ORR was 62.5%. Median PFS was 9.4 months (95% CI: 7.6 - 12.1). One year OS was 72.5% (95% CI: 0.56-0.83). Treatment related grade 3 or above adverse events (AE) occurred in 37.5% (15/40). Immune-related AE occurred in 32.5% (13/40) patients. Quality of life measures of function and symptoms did not change significantly throughout the course of treatments. Post-trial rechallenge with EGFR TKI containing regimen resulted in PFS of 5.8 months (95% CI 3.9-10.0 months). CONCLUSION: Combination approach of atezolizumab, bevacizumab, pemetrexed and carboplatin achieved promising efficacy in metastatic EGFR mutated NSCLC after TKI failure. The results were comparable with taxane based regimen of IMPower150 while toxicity profile was improved.


Asunto(s)
Receptores ErbB , Neoplasias Pulmonares , Anciano , Anticuerpos Monoclonales Humanizados , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Bevacizumab/uso terapéutico , Carboplatino/uso terapéutico , Receptores ErbB/genética , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Persona de Mediana Edad , Mutación , Pemetrexed/uso terapéutico , Inhibidores de Proteínas Quinasas/uso terapéutico , Calidad de Vida
3.
Clin Oncol (R Coll Radiol) ; 33(7): e305-e314, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33589348

RESUMEN

AIMS: Multiple studies have shown conflicting results on the correlation between the EGFR T790M quantitative level and survival outcomes in osimertinib-treated patients. We sought to validate such correlations using data from an osimertinib early access programme (EAP) providing access for metastatic non-small cell lung cancer patients with limited treatment options. PATIENTS AND METHODS: This observational, multicentre, retrospective analysis included EAP participants who received osimertinib until disease progression, intolerable toxicities or death. Digital droplet polymerase chain reaction-based quantitative plasma genotyping was carried out upon disease progression and data were analysed to explore the relationships between T790M mutant allele fraction (MAF), T790M copy number, MAF ratio and post-osimertinib overall survival. Real-world treatment outcomes and safety were also evaluated. RESULTS: Data from 156 EAP participants were analysed (median follow-up 37.7 months). The median age was 62 years, 62.2% were women, 79.5% were never-smokers, 60.9% had Eastern Cooperative Oncology Group performance status 0/1. In patients with available plasma data (n = 114), T790M MAF (%) showed no significant relationships with overall survival (hazard ratio 1.02; 95% confidence interval 0.99-1.04) or time to treatment discontinuation (TTD) (hazard ratio 1.01; 95% confidence interval 0.98-1.04). Absolute T790M copy number and T790M to activating EGFR mutation MAF ratio also showed no prognostic value. The investigator-assessed response rate was 42.3% and the disease control rate was 85.5%. The median TTD was 15.8 (95% confidence interval 12.5-18.5) months and the median overall survival was 22.3 (95% confidence interval 18.6-26.1) months. CONCLUSION: T790M MAF did not correlate with TTD or overall survival in this EAP cohort but limitations should not be overlooked. Observed survival outcomes and the toxicity profile were consistent with data from other real-world series.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas , Neoplasias Pulmonares , Inhibidores de Proteínas Quinasas , Acrilamidas , Alelos , Compuestos de Anilina , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/genética , Receptores ErbB/genética , Femenino , Humanos , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/genética , Persona de Mediana Edad , Mutación , Estudios Retrospectivos
4.
Clin Oncol (R Coll Radiol) ; 32(1): e1-e9, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31375307

RESUMEN

Lung cancer is a common cancer associated with high mortality rates worldwide. Unfortunately, it usually presents at a late stage, precluding the chance of curative therapy. The discovery of oncogenic driver mutations in patients with non-small cell lung cancer over the past 20 years has led to new molecular targeted therapies that have dramatically improved treatment efficacy and quality of life. New generations of therapy that target the drug-resistant mutations have also quickly evolved, benefiting patients who are refractory or intolerant to first-line targeted therapy. Eastern patients, from Southeast Asia, Japan and China, are known to have a higher incidence of epidermal growth factor receptor mutation. Therefore, compared with the West, more patients would benefit from these recent advances. In contrast, survival of patients without driver mutations has benefited from advances in novel therapeutics, including the immune checkpoint inhibitors. The current review aims to highlight the recent developments in the management of advanced-stage non-small cell lung cancer and to compare the differences in clinical practice between Eastern and Western countries.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/terapia , Inmunoterapia/métodos , Neoplasias Pulmonares/terapia , Calidad de Vida/psicología , Carcinoma de Pulmón de Células no Pequeñas/epidemiología , Carcinoma de Pulmón de Células no Pequeñas/mortalidad , Humanos , Neoplasias Pulmonares/epidemiología , Neoplasias Pulmonares/mortalidad , Análisis de Supervivencia
5.
Clin Oncol (R Coll Radiol) ; 31(8): 549-559, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31279432

RESUMEN

Managing head and neck cancers is an excellent example of the importance of teamwork, with head and neck surgeons, clinical oncologists, radiologists, pathologists and other allied health professionals specialised in this disease site working together. The reliable imaging and dedicated pretreatment work-up entailing the comprehensive anatomical description of tumour involvement by the radiologists, the expertise of surgeons in performing en-bloc gross tumour resection, the uneventful speedy postoperative rehabilitation and recovery by the speech therapists and nutritionists, as well as the dedicated treatment planning of clinical oncologists in delivering precise preoperative or postoperative (chemo)radiotherapy to maximise the therapeutic potentials are the pillars of treatment success. A multidisciplinary tumour board involving all of these key players is essential to provide the highest level of recommendation based on evidence-based medicine and to bring patients new hopes and the best chance of cure. This review illustrates the seamless collaborative teamwork within a well-established multidisciplinary tumour board in managing one of the most intractable cancers in the East, taking enlightenment and inspiration from the West.


Asunto(s)
Neoplasias de Cabeza y Cuello/terapia , Planificación de Atención al Paciente/normas , Asia Oriental , Neoplasias de Cabeza y Cuello/epidemiología , Humanos , Resultado del Tratamiento
6.
Clin Oncol (R Coll Radiol) ; 31(8): 560-569, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31279433

RESUMEN

Hepatocellular carcinoma (HCC) is a common malignancy worldwide, although its aetiologies vary significantly between the East and the West. About a half of HCC cases present with advanced unresectable HCC at the time of diagnosis, leading to a worse prognosis. Over the past 20 years, the treatment paradigm for advanced unresectable HCC has shifted from an entirely palliative approach to a multidisciplinary treatment, with continuous reassessment and possible repeat treatment attributed to the advent of novel and improved local, regional and systemic therapeutic options, contributed by both the East and the West. An individualised treatment plan should be determined for each patient, as there can be substantial differences in the decision-making and treatment response to the same treatment for different patients and different patient populations. This review provides a summary of the recent advances in management and compares Eastern and Western strategies for HCC.


Asunto(s)
Carcinoma Hepatocelular/epidemiología , Carcinoma Hepatocelular/terapia , Neoplasias Hepáticas/epidemiología , Neoplasias Hepáticas/terapia , Humanos
7.
8.
Clin Oncol (R Coll Radiol) ; 31(8): 589-594, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31230834

RESUMEN

Cancer is the most common cause of mortality worldwide. Although recent advances of multiple modality cancer management have significantly improved the cure and control rates, a significant proportion of patients are still refractory to the standard and available treatments. Early initiation of palliative care can reduce cancer suffering, improve health-related quality of life and possibly prolong survival. It also allows patients and their caretakers to perceive the trajectory of their cancer, so that better and advanced care planning can be contemplated and implemented. The traditional beliefs and perceptions of cancer also differ significantly between the East and the West, which may also affect the preferential approach to palliative care. This review provides an overview of palliative care services in Hong Kong, as compared with other parts of the world. In addition, we shall also explore how cancer perceptions affect the decision-making on palliative care.


Asunto(s)
Neoplasias/terapia , Cuidados Paliativos/métodos , Calidad de Vida/psicología , Asia Oriental , Hong Kong , Humanos
9.
Clin Oncol (R Coll Radiol) ; 31(8): 487-489, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31229380
10.
Clin Oncol (R Coll Radiol) ; 31(8): 570-577, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31178345

RESUMEN

Gastric cancers are highly prevalent in both the East and the West, although they differ in aetiology and prognostic outcome. Management of gastric cancer from screening to definitive treatment varies substantially between Eastern and Western countries and regions, owing to numerous factors, including government incentives to carry out population-wide screening programmes to detect early disease, differences in clinical and biological tumour behaviours and responsiveness to treatment, patient accessibility to effective treatment, etc. This review highlights and contrasts the differences in tumour aetiology and histology, as well as the management approaches between the East and the West, which gives important insights and inspirations on future international multicentre research collaboration to combat this dreadful malignancy.


Asunto(s)
Neoplasias Gástricas , Humanos , Pronóstico , Neoplasias Gástricas/epidemiología , Neoplasias Gástricas/etiología , Neoplasias Gástricas/patología , Neoplasias Gástricas/terapia
11.
Clin Oncol (R Coll Radiol) ; 31(8): 578-588, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31178347

RESUMEN

Chinese medicine therapies in cancer treatment are very common in the East. Although it is usually classified as a form of complementary and alternative therapy in the West, Chinese medicine is an independent medical profession in Hong Kong and mainland China. It has a different perspective in understanding health and diseases compared with Western medicine. In oncology practice, whereas Western medicine focuses on direct tumour eradication by surgery, radiation therapy and systemic therapies, Chinese medicine focuses on restoring body balance and enhancing the body's defences (immunity), in addition to some cytotoxic herbal therapies. Most often patients, especially those in the East, receive both treatments. Chinese medicine is also commonly used to reduce side-effects from chemotherapy or radiation therapy, to aid recovery after an operation, to palliate symptoms and to address survivorship issues. However, this raises concerns of drug-herb interactions and toxicity in combination therapies. Commonly used Chinese medicine treatment modalities include acupuncture, moxibustion, diet therapy, prescribed Chinese medicine herbal decoction, single Chinese medicine herbs or supplements and tai chi. Although there is an increasing trend of Chinese medicine use in cancer patients in both the East and the West, the scientific evidence of safety and efficacy is often questioned by oncologists. This article reviews the current evidence in different Chinese medicine therapies in cancer management in both the East and the West.


Asunto(s)
Medicina Tradicional China/métodos , Neoplasias/tratamiento farmacológico , Neoplasias/epidemiología , Humanos
12.
Clin Oncol (R Coll Radiol) ; 29(9): 568-575, 2017 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-28499791

RESUMEN

AIMS: Almost all patients with epidermal growth factor receptor (EGFR) mutations will develop resistance to first-line EGFR tyrosine kinase inhibitors (TKIs). The management of oligoprogression on EGFR TKI is controversial. Irradiating progressing tumours may potentially eradicate the resistant clone and allow continuation of EGFR TKI, but the clinical data remain sparse. We aimed to assess the effect of radiotherapy on survival outcomes in patients with oligoprogression in a matched-cohort study. MATERIALS AND METHODS: This was a retrospective matched-cohort study comparing patients with EGFR mutation-positive stage IV non-small cell lung cancer receiving radiotherapy versus chemotherapy for progression. Patients in the radiotherapy group received radiotherapy (mainly stereotactic ablative radiotherapy) for oligoprogression, whereas the chemotherapy group received only systemic chemotherapy upon progression. Key prognostic factors including gender, age, performance status, time to first progression and mutation subtypes were matched. RESULTS: Twenty-five patients with oligoprogression (radiotherapy group) were identified, and a matched chemotherapy group with the same number of patients was generated. The median duration of follow-up was 24.3 and 34 months for the radiotherapy and chemotherapy groups, respectively. The median overall survival of the radiotherapy group was significantly longer than the chemotherapy group, 28.2 versus 14.7 months (P = 0.026). The median progression-free survival (PFS) was 7.0 and 4.1 months after radiotherapy and chemotherapy, respectively (P = 0.0017). The use of radiotherapy was an independent predictive factor of overall survival and PFS in multivariate analysis. Only one patient had ≥grade 3 toxicity after radiotherapy. The frequency of secondary T790M mutation and subsequent Osimertinib exposure were similar in both groups. CONCLUSION: Radiotherapy may effectively extend EGFR TKI therapy for patients with oligoprogression on TKI. Improved PFS and overall survival were observed, although potential biases should not be overlooked. Further randomised studies are warranted.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Carcinoma de Pulmón de Células no Pequeñas/radioterapia , Receptores ErbB/genética , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/radioterapia , Inhibidores de Proteínas Quinasas/uso terapéutico , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Pulmón de Células no Pequeñas/patología , Estudios de Cohortes , Supervivencia sin Enfermedad , Femenino , Humanos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Mutación , Proyectos de Investigación , Estudios Retrospectivos , Análisis de Supervivencia
13.
Clin Oncol (R Coll Radiol) ; 28(1): 42-9, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26482452

RESUMEN

AIMS: We studied if post-radiation plasma Epstein-Barr virus (EBV) DNA predicted local clinical remission after radical intensity-modulated radiation therapy (IMRT) for nasopharyngeal carcinoma. MATERIALS AND METHODS: Patients with non-metastatic nasopharyngeal carcinoma with baseline and serial plasma EBV DNA were treated with radical IMRT ± adjunct chemotherapy. Eight weeks after IMRT, they had plasma EBV DNA and routine six-site random nasopharyngeal biopsies on the same day. A repeat biopsy was carried out every 2 weeks if residual tumours were noted in previous biopsies until 12 weeks after IMRT when local persistence was defined. Correlation of undetectable plasma EBV DNA with local clinical remission was carried out. RESULTS: Two hundred and sixty patients with serial plasma EBV DNA completed IMRT, after a median follow-up of 3.1 years. Only one (0.4%) suffered from local persistence. Area under the curve values of receiver operating characteristics of undetectable plasma EBV DNA for negative biopsy at 8 weeks and local persistence were 0.642 and 0.439, respectively. They increased to 0.856 (P = 0.007) and 0.952 (P = 0.119), respectively, when combined with age <65 years and T1/T2 stage. CONCLUSIONS: Post-treatment plasma EBV DNA was not useful to predict local clinical remission in this study, probably because of excellent local control after IMRT. However, it may serve as a reference for high-risk patients treated with older radiation techniques.


Asunto(s)
ADN Viral/sangre , Infecciones por Virus de Epstein-Barr/complicaciones , Neoplasias Nasofaríngeas/virología , Adulto , Anciano , Área Bajo la Curva , Carcinoma , Quimioterapia Adyuvante , Terapia Combinada , Infecciones por Virus de Epstein-Barr/sangre , Femenino , Herpesvirus Humano 4/genética , Humanos , Masculino , Persona de Mediana Edad , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas/sangre , Neoplasias Nasofaríngeas/radioterapia , Pronóstico , Curva ROC , Radioterapia de Intensidad Modulada
14.
Asian Pac J Cancer Prev ; 14(7): 4151-5, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23991968

RESUMEN

BACKGROUND: To compare response evaluation criteria in solid tumours (RECIST) and volumetric evaluation (VE) for colorectal cancer with liver-limited metastasis. PATIENTS AND METHODS: VE of liver metastases was performed by manual contouring before and after chemotherapy on 45 pairs of computed tomography (CT) images in 36 patients who suffered from metastatic colorectal cancer (mCRC) with liver metastasis only. Cohen kappa was used to compare the agreement between VE and RECIST. Pearson correlation was performed for their comparison after cubic root transformation of the aggregate tumor volumes. Logistic regression was done to identify clinical and radiographic factors to account for the difference which may be predictive in overall response (OR). RESULTS: There were 16 partial response (PR), 23 stable disease (SD) and 6 progressive disease (PD) cases with VE, and 14 PR, 23 SD and 8 PD with RECIST. VE demonstrated good agreement with RECIST (κ=0.779). Discordant objective responses were noted in 6 pairs of comparisons (13.3%). Pearson correlation also showed excellent correlation between VE and RECIST (r2=0.966, p<0.001). Subgroup analysis showed that VE was in slightly better agreement with RECIST for enlarging lesions than for shrinking lesions (r2=0.935 and r2=0.780 respectively). No factor was found predictive of the difference in OR between VE and RECIST. CONCLUSIONS: VE exhibited good agreement with RECIST. It might be more useful than RECIST in evaluation shrinking lesions in cases of numerous and conglomerate liver metastases.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/patología , Neoplasias Hepáticas/secundario , Tomografía Computarizada por Rayos X , Adulto , Anciano , Neoplasias Colorrectales/tratamiento farmacológico , Femenino , Estudios de Seguimiento , Humanos , Neoplasias Hepáticas/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Estudios Retrospectivos , Carga Tumoral
15.
Br J Cancer ; 104(6): 1000-6, 2011 Mar 15.
Artículo en Inglés | MEDLINE | ID: mdl-21364588

RESUMEN

BACKGROUND: Our recent work has shown the feasibility of using a refined immunomagnetic enrichment (IE) assay to detect cytokeratin 20-positive circulating tumour cells (CK20 pCTCs) in colorectal cancer (CRC) patients. We attempted to improve the sensitivity for CRC by detecting another intestinal-type differentiation marker, CDX2 pCTCs, using the same methodology. METHODS: CDX2 pCTCs were detected in patients with CRC, colorectal adenoma (CAD), benign colorectal diseases (BCD), other common cancers (OCC) and normal subjects (NS). Statistical analysis was used to correlate CDX2 pCTCs to the clinicohistopathological factors, recurrence, metastasis and survival after follow-up for 42 months in CRC patients. RESULTS: CDX2 pCTCs were detected in 81% CRC patients (73 out of 90, median number=21.5 CTCs), 7.5% CAD patients (3 out of 40), 0% patients with BCD (0 out of 90), 2.5% patients with OCC (2 out of 80) and 0% NS (0 out of 40). Furthermore, statistical analysis showed that CDX2 pCTC numbers were associated with tumour- node-metastasis stage and lymph node status. Using the median CDX2 pCTC numbers as the cutoff points, stratified groups of CRC patients had significant differences in their recurrence and survival. CONCLUSIONS: This study showed that the refined IE assay can detect CDX2 pCTCs with high sensitivity and that CDX2 pCTCs can generate clinically important information for CRC patients.


Asunto(s)
Adenoma/diagnóstico , Neoplasias Colorrectales/diagnóstico , Proteínas de Homeodominio/metabolismo , Células Neoplásicas Circulantes/metabolismo , Células Neoplásicas Circulantes/patología , Transactivadores/metabolismo , Adenoma/sangre , Adenoma/mortalidad , Adenoma/patología , Adulto , Anciano , Anciano de 80 o más Años , Biomarcadores de Tumor/análisis , Biomarcadores de Tumor/metabolismo , Factor de Transcripción CDX2 , Carcinoma/diagnóstico , Carcinoma/metabolismo , Carcinoma/patología , Neoplasias Colorrectales/sangre , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Femenino , Proteínas de Homeodominio/sangre , Humanos , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Pronóstico , Análisis de Supervivencia , Transactivadores/sangre , Adulto Joven
16.
Oncogene ; 26(21): 3069-80, 2007 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-17099724

RESUMEN

Epstein-Barr virus (EBV) infection is closely associated with nasopharyngeal carcinoma (NPC) and can be detected in early premalignant lesions of nasopharyngeal epithelium. The latent membrane protein 1 (LMP1) is an oncoprotein encoded by the EBV and is believed to play a role in transforming premalignant nasopharyngeal epithelial cells into cancer cells. RASSF1A is a tumor-suppressor gene commonly inactivated in many types of human cancer including NPC. In this study, we report a novel function of LMP1, in down-regulating RASSF1A expression in human epithelial cells. Downregulation of RASSF1A expression by LMP1 is dependent on the activation of intracellular signaling of NF-kappaB involving the C-terminal activating regions (CTARs) of LMP1. LMP1 expression also suppresses the transcriptional activity of the RASSF1A core promoter. RASSF1A stabilizes microtubules and regulates mitotic events. Aberrant mitotic spindles and chromosome aberrations are reported phenotypes in RASSF1A inactivated cells. In this study, we observed that LMP1 expression in human epithelial cells could induce aberrant mitotic spindles, disorganized interphase microtubules and aneuploidy. LMP1 expression could also suppress microtubule dynamics as exemplified by tracking movements of the growing tips of microtubules in live cells by transfecting EGFP-tagged EB1 into cells. The aberrant mitotic spindles and interphase microtubule organization induced by LMP1 could be rescued by transfecting RASSF1A expression plasmid into cells. Downregulation of RASSF1A expression by LMP1 may facilitate its role in transformation of premalignant nasopharyngeal epithelial cells into cancer cells.


Asunto(s)
Aberraciones Cromosómicas , Regulación hacia Abajo/genética , Células Epiteliales/metabolismo , Células Epiteliales/patología , Microtúbulos/metabolismo , Proteínas Supresoras de Tumor/antagonistas & inhibidores , Proteínas Supresoras de Tumor/genética , Proteínas de la Matriz Viral/fisiología , Línea Celular , Línea Celular Transformada , Línea Celular Tumoral , Células HeLa , Humanos , Microtúbulos/patología , FN-kappa B/fisiología , Proteínas Supresoras de Tumor/biosíntesis
17.
J Natl Cancer Inst Monogr ; (29): 41-4, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11694565

RESUMEN

This review focuses on epithelial drug transport mechanisms in mucosal drug delivery: the final step of a four-part process. Reference is made to the mucosae lining the oral cavity and the gastrointestinal tract, the two mucosae most often succumbing to the side effects of cytotoxic chemotherapeutic drugs. This review will be devoted to carrier-mediated transport, particularly as it relates to the intestinal dipeptide transporter PepT1. This transporter protein appears to be enriched in tumor epithelial cells, to be rather robust to the cytotoxic effects of chemotherapeutic drugs, and to lend itself to the molecular engineering of drugs that target this transporter in tumor epithelial cells. In contrast to the gastrointestinal tract, much less is known about the type and capacity of drug transport processes in the buccal epithelial cells and about how these processes may be altered in disease state (including cancer) and be manipulated pharmaceutically to optimize drug absorption.


Asunto(s)
Sistemas de Liberación de Medicamentos , Mucosa Intestinal/efectos de los fármacos , Mucosa Intestinal/patología , Simportadores , Animales , Antineoplásicos/farmacología , Transporte Biológico , Proteínas Portadoras/farmacología , Relación Dosis-Respuesta a Droga , Resistencia a Antineoplásicos , Células Epiteliales/metabolismo , Humanos , Modelos Biológicos , Modelos Químicos , Neoplasias/metabolismo , Neoplasias/patología , Transportador de Péptidos 1 , Factores de Tiempo
18.
Adv Drug Deliv Rev ; 46(1-3): 211-45, 2001 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-11259842

RESUMEN

This paper discusses the challenges to be met in designing delivery systems that maximize the absorption of peptide and protein drugs from the gastrointestinal and respiratory tracts. The ideal delivery system for either route of administration is one that will release its contents only at a favorable region of absorption, where the delivery system attaches by virtue of specific interaction with surface determinants unique to that region and where the delivery system travels at a rate independent of the transitory constraints inherent of the route of administration. Such a delivery system, which is as yet unavailable, will benefit not only peptide and protein drugs, but other poorly absorbed drugs.


Asunto(s)
Péptidos/administración & dosificación , Proteínas/administración & dosificación , Administración Oral , Animales , Sistemas de Liberación de Medicamentos , Humanos , Péptidos/farmacocinética , Proteínas/farmacocinética
19.
Gen Comp Endocrinol ; 120(2): 146-56, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11078626

RESUMEN

The in vitro effects of human chorionic gonadotropin (hCG) on ovarian connexin (Cx) 32.2 and 32.7 RNA levels and ovarian follicle maturation were assessed, and the cellular distribution of Cx transcripts in the ovary was determined. hCG caused a concentration-dependent induction of Cx32.2 RNA, which peaked coincidentally with the appearance of morphological indices of oocyte maturational competence (OMC). Cx32.2 RNA levels declined thereafter in all treatment groups, although this decline was not accompanied by the onset of germinal vesicle breakdown (GVBD) at the lowest hCG concentration used. The levels of Cx32.7 RNA initially declined and subsequently increased to preincubation values after hCG treatment, but these changes were not dependent on hCG concentration. In a separate experiment, the decline in Cx32.7 RNA occurred in the presence or absence of hCG and was prevented by low (physiological) concentrations of estradiol-17beta (E2) or by protein kinase C (PKC) inhibitor, but was enhanced in the presence of high E2 concentrations or of PKC activator. These changes in Cx32. 7 RNA abundance were not associated with any indices of oocyte maturation. In situ hybridization of tissue sections showed the presence of Cx32.2 and Cx32.7 RNA in somatic cells of the ovarian follicle but not in oocytes. Cx32.2 RNA seemed to be present in granulosa and thecal cells, but the assay resolution was insufficient to reliably determine the distribution of Cx32.7 transcript by somatic cell type. In view of earlier findings that Cx32.2-based (but not Cx32.7-based) connexons can form functional homotypic channels, these results indicate that Cx32.2 gene expression in granulosa cells is sufficient for the formation of homologous gap junctions (GJ). Northern blot of RNA extracts from ovulated eggs, which are free of follicle cells, showed the presence of relatively low levels of both Cx RNAs. Thus, it is possible that Cx32.2 is present in oocytes and that it participates in heterologous (homotypic) GJ formation between the oocyte and the granulosa cells. In conclusion, Cx32.2 RNA levels in somatic cells of the ovarian follicle correlated positively with morphological indices of OMC acquisition, but subsequently declined during GVBD. These changes in Cx32.2 RNA may function in the regulation of GJ contacts during follicular maturation.


Asunto(s)
Gonadotropina Coriónica/farmacología , Conexinas/genética , Peces/metabolismo , Ovario/química , ARN/metabolismo , Animales , Estradiol/farmacología , Femenino , Humanos , Hibridación in Situ/veterinaria , Folículo Ovárico/crecimiento & desarrollo , Ovario/efectos de los fármacos , Transcripción Genética , Proteína beta1 de Unión Comunicante
20.
Eur J Pharm Sci ; 11 Suppl 2: S41-50, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11033426

RESUMEN

Carrier-mediated drug transport is relatively unexplored in comparison with passive transcellular and paracellular drug transport. Yet, there is a host of transporter proteins that can be targeted for improving epithelial drug absorption. Generally, these are transport mechanisms for amino acids, dipeptides, monosaccharides, monocarboxylic acids, organic cations, phosphates, nucleosides, and water-soluble vitamins. Among them, the dipeptide transporter mechanism has received the most attention. Dipeptide transporters are H(+)-coupled, energy-dependent transporters that are known to play an essential role in the oral absorption of beta-lactam antibiotics, angiotensin-converting enzyme (ACE) inhibitors, renin inhibitors, and an anti-tumor drug, bestatin. Moreover, several investigators have demonstrated the utility of the dipeptide transporter as a platform for improving the oral bioavailability of drugs such as zidovudine and acyclovir through dipeptide prodrug derivatization. Thus far, at least four proton-coupled peptide transporters have been cloned. The first one cloned was PepT1 from the rabbit small intestine. The focus of this presentation will be structure-function, intracellular trafficking, and regulation of PepT1. Disease, dietary, and possible excipient influences on PepT1 function will also be discussed.


Asunto(s)
Proteínas Portadoras/farmacocinética , Dipéptidos/farmacocinética , Simportadores , Animales , Proteínas Portadoras/química , Membrana Celular/metabolismo , Dipéptidos/química , Interacciones Farmacológicas , Humanos , Mucosa Intestinal/metabolismo , Transportador de Péptidos 1 , Conejos , Transducción de Señal/fisiología , Relación Estructura-Actividad , Especificidad por Sustrato
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