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1.
J Neurooncol ; 162(1): 137-145, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36884201

RESUMO

PURPOSE: Cancer patients experience distress and anxiety when undergoing imaging studies to monitor disease status, yet these symptoms are not always appropriately identified or well-managed. This interim analysis of a phase 2 clinical trial explored feasibility and acceptability of a virtual reality relaxation (VR) intervention for primary brain tumor (PBT) patients at the time of clinical evaluation. METHODS: English speaking, adult PBT patients with previous reports of distress and upcoming neuroimaging were recruited between March of 2021 and March 2022. A brief VR session was done within 2 weeks prior to neuroimaging with patient-reported outcomes (PROs) collected before and immediately post-intervention. Self-directed VR use over the next 1 month was encouraged with additional PROs assessments at 1 and 4 weeks. Feasibility metrics included enrollment, eligibility, attrition, and device-related adverse effects with satisfaction measured with qualitative phone interviews. RESULTS: Fifty-five patients were approached via email, 40 (73%) responded and 20 (50%) enrolled (9 declines, 11 screen fails). 65% of participants were ≤ 50 years, 50% were male, 90% were White/non-Hispanic, 85% had good KPS (≥ 90), and most were on active treatment. All patients completed the VR intervention, PROs questionnaires, weekly check-ins, and qualitative interview. Most (90%) reported frequent VR use and high satisfaction and only 7 mild AEs were recorded (headache, dizziness, nausea, neck pain). CONCLUSION: This interim analysis supports feasibility and acceptability of a novel VR intervention to target psychological symptoms for PBT patients. Trial enrollment will continue to assess for intervention efficacy. TRIAL REGISTRATION: NCT04301089 registered on 3/9/2020.


Assuntos
Neoplasias Encefálicas , Terapia de Exposição à Realidade Virtual , Adulto , Humanos , Masculino , Feminino , Estudos de Viabilidade , Ansiedade/etiologia , Ansiedade/terapia , Neoplasias Encefálicas/complicações , Neoplasias Encefálicas/terapia
2.
Invest New Drugs ; 39(3): 821-828, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33405090

RESUMO

Background Preclinical evidence has suggested that a subset of pancreatic cancers with the G12R mutational isoform of the KRAS oncogene is more sensitive to MAPK pathway blockade than pancreatic tumors with other KRAS isoforms. We conducted a biomarker-driven trial of selumetinib (KOSELUGO™; ARRY-142886), an orally active, allosteric mitogen-activated protein kinase 1 and 2 (MEK1/2) inhibitor, in pancreas cancer patients with somatic KRASG12R mutations. Methods In this two-stage, phase II study (NCT03040986) patients with advanced pancreas cancer harboring somatic KRASG12R variants who had received at least one standard-of-care systemic therapy regimen received 75 mg selumetinib orally twice a day until disease progression or unacceptable toxicity occurred. The primary outcome of the study was best objective response (BOR). Results From August 2017 to February 2018 a total of 8 patients with confirmed somatic KRASG12R mutations and a median age of 61.5 years were treated with selumetinib. Seven out of eight (87.5%) had received two or more lines of prior systemic chemotherapy. After a median follow-up period of 8.5 months (range 2 to 20), three patients had stable disease for more than 6 months while receiving selumetinib. No patients achieved an objective partial response. Median progression-free survival (PFS) was 3.0 months (95% CI, 0.8-8.2) and median overall survival (OS) 9 months (95% CI, 2.5-20.9). Conclusion This study in heavily pre-treated pancreatic adenocarcinoma patients suggests alternative strategies beyond single agent MEK inhibition are required for this unique, molecular subset of pancreatic cancer patients. The trial was registered on February 2nd, 2017 under identifier NCT03040986 with ClinicalTrials.gov .


Assuntos
Adenocarcinoma/tratamento farmacológico , Antineoplásicos/uso terapêutico , Benzimidazóis/uso terapêutico , MAP Quinase Quinase 1/antagonistas & inibidores , MAP Quinase Quinase 2/antagonistas & inibidores , Neoplasias Pancreáticas/tratamento farmacológico , Inibidores de Proteínas Quinases/uso terapêutico , Adenocarcinoma/mortalidade , Administração Oral , Idoso , Antineoplásicos/efeitos adversos , Benzimidazóis/efeitos adversos , Feminino , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Neoplasias Pancreáticas/mortalidade , Intervalo Livre de Progressão , Inibidores de Proteínas Quinases/efeitos adversos
3.
BMC Gastroenterol ; 18(1): 94, 2018 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-29933761

RESUMO

BACKGROUND: Esophageal cancers accounted for nearly 16,000 deaths in 2016. The number of patients with esophageal cancers increases every year. Neoadjuvant chemoradiotherapy (nCRT) prior to esophagectomy is a standard treatment for esophageal cancers. The patients who have no residual tumor (pathological complete response (pCR)) at surgery are the most likely to experience long term survival. Accurately determining which patients will have a pCR will improve prognostic information for patients and families, confirm lack of response to nCRT, or avoid surgery if no residual tumor is present. Imaging, endoscopy, and liquid biomarkers have all failed to detect pCR without performing an esophagectomy. METHODS: In this study, we are enrolling patients with esophageal adenocarcinoma and squamous cell carcinoma. Patients will undergo standard evaluation including CT scans, laboratory tests, endoscopy with biopsies, and evaluation by a thoracic surgeon. Tissue biopsy is required for enrollment that will be sent for BH3 profiling and metabolomics. Patients will be treated with standard nCRT followed by surgery. Patients with metastatic disease are not eligible. Surgery at the National Cancer Institute will be minimally-invasive robotic surgery. Patients will remain on study indefinitely with regular clinic visits and imaging tests. DISCUSSION: The mitochondria are critically involved in the intrinsic pathway apoptosis. Bcl-2 homology domain 3 (BH3) profiling is a technique to measure a cell's susceptibility to apoptosis. BH3 profiling measures the relative interactions of proteins that induce or block apoptosis. The collective balance of these proteins determines whether a cell is near the threshold to undergo apoptosis. If the cell is near this threshold, then the tumor may be more likely to die when treated with nCRT. The mitochondria secrete metabolites that may be detectable as biomarkers. Metabolomics is a global assessment of all metabolite changes that has been performed for detection, monitoring, prognosis, and treatment response in cancers. Stratification of patients based on whether pCR occurs or not may elucidate metabolomic signatures that may be associated with response. We are asking whether BH3 profiling or a metabolomic signature will correlate with tumor death after nCRT for esophageal cancer. TRIAL REGISTRATION: NCT03223662 ; Clinicaltrials.gov. July 21, 2017.


Assuntos
Adenocarcinoma/genética , Adenocarcinoma/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Impressões Digitais de DNA , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/metabolismo , Genes bcl-2 , Metabolômica , Medicina de Precisão , Adenocarcinoma/patologia , Adenocarcinoma/terapia , Apoptose , Biópsia , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/terapia , Quimiorradioterapia , Neoplasias Esofágicas/patologia , Neoplasias Esofágicas/terapia , Genes p53 , Humanos , Mutação , Terapia Neoadjuvante , Estudos Prospectivos , Análise de Sobrevida
4.
Neurooncol Adv ; 6(1): vdae019, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38420614

RESUMO

Background: Glioblastoma (GBM) is the most aggressive primary brain malignancy with <45% living a year beyond diagnosis. Previously published investigations of long-term survivors (LTS) provided clinical data but rarely incorporated a comprehensive clinical and molecular analysis. Herein, we identify clinical, imaging, molecular, and outcome features for 23 GBM-LTS patients and compare them with a matched cohort of short-term survivors (STS). Methods: Molecularly confirmed Isocitrate Dehydrogenase (IDH) wildtype GBM patients living ≥3 years post-diagnosis (NLTS = 23) or <3 years (NSTS = 75) were identified from our Natural History study. Clinical and demographic characteristics were compared. Tumor tissue was analyzed with targeted next generation sequencing (NGS) (NLTS = 23; NSTS = 74) and methylation analysis (NLTS = 18; NSTS = 28). Pre-surgical MRI scans for a subset of LTS (N = 14) and STS control (N = 28) matched on sex, age, and extent of resection were analyzed. Results: LTS tended to be younger. Diagnostic MRIs showed more LTS with T1 tumor hypointensity. LTS tumors were enriched for MGMTp methylation and tumor protein 53 (TP53) mutation. Three patients with classic GBM histology were reclassified based on NGS and methylation testing. Additionally, there were LTS with typical poor prognostic molecular markers. Conclusions: Our findings emphasize that generalized predictions of prognosis are inaccurate for individual patients and underscore the need for complete clinical evaluation including molecular work-up to confirm the diagnosis. Continued accrual of patients to LTS registries that containcomprehensive clinical, imaging, tumor molecular data, and outcomes measures may pro\vide important insights about individual patient prognosis.

5.
Front Oncol ; 13: 1099618, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36741001

RESUMO

The uncommon MN1-altered primary central nervous system (CNS) tumors were recently added to the World Health Organization 2021 classification under the name Astroblastoma, MN1-altered. Another term used to describe them, "High-grade neuroepithelial tumor with MN1 alteration" (HGNET-MN1), makes reference to their distinct epigenetic profile but is currently not a recommended name. Thought to occur most commonly in children and predominantly in females, MN1-altered CNS tumors are associated with typical but not pathognomonic histological patterns and are characterized by a distinct DNA methylation profile and recurrent fusions implicating the MN1 (meningioma 1) gene. Diagnosis based on histological features alone is challenging: most cases with morphological features of astroblastoma (but not all) show these molecular features, whereas not all tumors with MN1 fusions show astroblastoma morphology. There is large variability in reported outcomes and detailed clinical and therapeutic information is frequently missing. Some patients experience multiple recurrences despite multimodality treatment, whereas others experience no recurrence after surgical resection alone, suggesting large clinical and biological heterogeneity despite unifying epigenetic features and recurrent fusions. In this report, we present the demographics, tumor characteristics, treatment, and outcome (including patient-reported outcomes) of three adults with MN1-altered primary CNS tumors diagnosed via genome-wide DNA methylation and RNA sequencing. All three patients were females and two of them were diagnosed as young adults. By reporting our neuropathological and clinical findings and comparing them with previously published cases we provide insight into the clinical heterogeneity of this tumor. Additionally, we propose a model for prospective, comprehensive, and systematic collection of clinical data in addition to neuropathological data, including standardized patient-reported outcomes.

6.
Res Sq ; 2023 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-36789426

RESUMO

Purpose: Cancer patients experience distress and anxiety when undergoing imaging studies to monitor disease status, yet these symptoms are not always appropriately identified or well-managed. This interim analysis of a phase 2 clinical trial explored feasibility and acceptability of a virtual reality relaxation (VR) intervention for primary brain tumor (PBT) patients at the time of clinical evaluation. Methods: English speaking, adult PBT patients with previous reports of distress and upcoming neuroimaging were recruited between March of 2021 and March 2022. A brief VR session was done within 2 weeks prior to neuroimaging with patient-reported outcomes (PROs) collected before and immediately post-intervention. Self-directed VR use over the next 1 month was encouraged with additional PROs assessments at 1 and 4 weeks. Feasibility metrics included enrollment, eligibility, attrition, and device-related adverse effects with satisfaction measured with qualitative phone interviews. Results: 55 patients were approached via email, 40 (73%) responded and 20 (50%) enrolled (9 declines, 11 screen fails). 65% of participants were ≤ 50 years, 50% were male, 90% were White/non-Hispanic, 85% had good KPS (≥ 90), and most were on active treatment. All patients completed the VR intervention, PROs questionnaires, weekly check-ins, and qualitative interview. Most (90%) reported frequent VR use and high satisfaction and only 7 mild AEs were recorded (headache, dizziness, nausea, neck pain). Conclusion: This interim analysis confirmed feasibility and acceptability of a novel VR intervention to target psychological symptoms for PBT patients. Trial enrollment will continue to assess for intervention efficacy. Trial Registration: NCT04301089 registered on 3/9/2020.

7.
Transl Lung Cancer Res ; 10(7): 3079-3092, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34430349

RESUMO

BACKGROUND: Although most malignancies express cancer-testis antigens (CTA), immune responses to these proteins are limited in thoracic oncology patients. This trial was undertaken to examine if a cancer cell lysate vaccine could induce immunity to CTA, and to ascertain if metronomic cyclophosphamide and celecoxib enhances vaccine-induced immune responses. METHODS: Eleven patients with primary thoracic malignancies and 10 patients with extrathoracic neoplasms metastatic to the chest rendered NED by conventional therapies were randomized to receive H1299 lung cancer cell lysates (10 mg protein/vaccine) with Iscomatrix™ adjuvant via deep intradermal injection q 4 weeks ×6 with or without daily oral metronomic cyclophosphamide/celecoxib. The primary endpoint was serologic response to purified CTA assessed 1 month after the 6th vaccination. Secondary endpoints included assessment of the effects of cyclophosphamide and celecoxib on frequency and magnitude of vaccine-induced immune responses to CTA. Exploratory endpoints included evaluation of the effects of the vaccine regimens on peripheral immune subsets. Standard of care imaging studies were obtained at baseline and 1 month after the 3rd and 6th vaccinations. RESULTS: All patients exhibited local and systemic inflammatory responses lasting 72-96 hours following vaccinations. There were no dose limiting treatment related toxicities. Fourteen patients (67%) completed all six vaccinations. Eight of 14 patients (57%) exhibited serologic responses to NY-ESO-1. One patient developed antibodies to GAGE7; several patients exhibited reactivity to XAGE and MAGE-C2. Vaccine therapy decreased the percent of Tregs (P=0.0068), PD-1 expression on Tregs (P=0.0027), PD-L1 expression on CD14+ monocytes (P=0.0089), PD-L1 expression on classical monocytes (P=0.016), and PD-L1 expression on intermediate monocytes (P=0.0031). Cyclophosphamide/celecoxib did not appear to increase immune responses or enhance vaccine-induced alterations in peripheral immune subsets. CONCLUSIONS: H1299 lysate vaccines with Iscomatrix™ induce immune responses to CTA and modulate peripheral immune subsets in a manner that may enhance antitumor immunity in patients with thoracic malignancies.

8.
Clin Cancer Res ; 14(1): 188-98, 2008 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-18172270

RESUMO

PURPOSE: Our preclinical experiments indicated that Romidepsin (Depsipeptide FK228; DP) mediates growth arrest and apoptosis in cultured lung cancer cells. A phase II trial was done to examine clinical and molecular responses mediated by this histone deacetylase inhibitor in lung cancer patients. EXPERIMENTAL DESIGN: Nineteen patients with neoplasms refractory to standard therapy received 4-h DP infusions (17.8 mg/m(2)) on days 1 and 7 of a 21-day cycle. Each full course of therapy consisted of two identical 21-day cycles. Plasma DP levels were evaluated by liquid chromatography-mass spectrometry techniques. A variety of molecular end points were assessed in tumor biopsies via immunohistochemistry techniques. Long oligo arrays were used to examine gene expression profiles in laser-captured tumor cells before and after DP exposure, relative to lung cancer cells and adjacent normal bronchial epithelia from patients undergoing pulmonary resections. RESULTS: Nineteen patients were evaluable for toxicity assessment; 18 were evaluable for treatment response. Myelosuppression was dose limiting in one individual. No significant cardiac toxicities were observed. Maximum steady-state plasma DP concentrations ranged from 384 to 1,114 ng/mL. No objective responses were observed. Transient stabilization of disease was noted in nine patients. DP enhanced acetylation of histone H4, increased p21 expression in lung cancer cells, and seemed to shift global gene expression profiles in these cells toward those detected in normal bronchial epithelia. CONCLUSION: Although exhibiting minimal clinical efficacy at this dose and schedule, DP mediates biological effects that may warrant further evaluation of this histone deacetylase inhibitor in combination with novel-targeted agents in lung cancer patients.


Assuntos
Antibióticos Antineoplásicos/uso terapêutico , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma de Células Pequenas/tratamento farmacológico , Depsipeptídeos/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Acetilação/efeitos dos fármacos , Adulto , Idoso , Antibióticos Antineoplásicos/farmacocinética , Depsipeptídeos/farmacocinética , Feminino , Expressão Gênica/efeitos dos fármacos , Perfilação da Expressão Gênica , Histonas/efeitos dos fármacos , Humanos , Imuno-Histoquímica , Lasers , Masculino , Microdissecção , Pessoa de Meia-Idade , Análise de Sequência com Séries de Oligonucleotídeos , Reação em Cadeia da Polimerase Via Transcriptase Reversa
9.
Clin Cancer Res ; 12(19): 5777-85, 2006 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-17020984

RESUMO

PURPOSE: The DNA methylation paradox, manifested as derepression of cancer-testis antigens, and silencing of tumor suppressors during malignant transformation, provides the rationale for the utilization of chromatin remodeling agents for cancer therapy. A phase I trial was done to examine pharmacokinetics, toxicities, and gene expression mediated by 5-aza-2'-deoxycytidine (DAC) in patients with thoracic malignancies. EXPERIMENTAL DESIGN: Thirty-five patients with cancers refractory to standard therapy received continuous 72-hour DAC infusions using a phase I dose-escalation schema. Each full course of therapy consisted of two identical 35-day cycles. Plasma DAC levels were evaluated by liquid chromatography-mass spectrometry techniques. Quantitative reverse transcription-PCR, methylation-specific PCR, and immunohistochemical techniques were used to evaluate NY-ESO-1, MAGE-3, and p16 expression in tumor biopsies. Long oligonucleotide arrays were used to evaluate gene expression profiles in laser-captured tumor cells before and after DAC exposure. RESULTS: Thirty-five patients were evaluable for toxicities; 25 were evaluable for treatment response. Myelosuppression constituted dose-limiting toxicity. The maximum tolerated dose of DAC was 60 to 75 mg/m(2) depending on the number of prior cytotoxic chemotherapy regimens. No objective responses were observed. Plasma DAC concentrations approximated thresholds for gene induction in cultured cancer cells. Target gene induction was observed in 36% of patients. Posttreatment antibodies to NY-ESO-1 were detected in three patients exhibiting NY-ESO-1 induction in their tumor tissues. Complex, heterogeneous gene expression profiles were observed in pretreatment and posttreatment tissues. CONCLUSION: Prolonged DAC infusions can modulate gene expression in primary thoracic malignancies. These findings support further evaluation of DNA-demethylating agents alone or in combination with other regimens targeting induced gene products for the treatment of these neoplasms.


Assuntos
Antimetabólitos Antineoplásicos/farmacologia , Azacitidina/análogos & derivados , Neoplasias Esofágicas/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Neoplasias Pulmonares/genética , Neoplasias Pleurais/genética , Adulto , Idoso , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Azacitidina/farmacologia , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Metilases de Modificação do DNA/antagonistas & inibidores , Decitabina , Neoplasias Esofágicas/tratamento farmacológico , Neoplasias Esofágicas/metabolismo , Feminino , Genes p16/fisiologia , Humanos , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/metabolismo , Masculino , Dose Máxima Tolerável , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Mesotelioma/tratamento farmacológico , Mesotelioma/genética , Mesotelioma/metabolismo , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Neoplasias Pleurais/tratamento farmacológico , Neoplasias Pleurais/metabolismo , Ativação Transcricional
10.
Chest ; 124(5): 1834-40, 2003 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-14605057

RESUMO

OBJECTIVES: Novel imaging modalities are currently available for the noninvasive evaluation of the tracheobronchial tree. This study was undertaken to compare the diagnostic potentials of conventional CT scanning, super high-resolution CT (SHR-CT) scanning, and virtual bronchoscopy (VB) directly with fiberoptic bronchoscopy (FB) for the detection of tracheobronchial neoplasms. DESIGN: Prospective observer study, in which 44 consecutive patients with thoracic malignancies were evaluated using several diagnostic imaging modalities. Images of the thorax were interpreted by individuals blind to the results of FB for the detection of endoluminal, obstructive, or mucosal lesions. MEASUREMENTS AND RESULTS: Image acquisition and simulation of the tracheobronchial anatomy were created successfully in all patients. Thirty-two patients who underwent both SHR-CT scanning and VB had correlative FBs within 1 month. In all nine patients who had a normal anatomy, SHR-CT scanning and VB accurately correlated with the FB findings. However, CT scanning demonstrated two false-positive obstructive lesions in one patient. Twenty-three patients had a total of 35 abnormal FB findings. The sensitivities of SHR-CT scanning and VB for the detection of endoluminal, obstructive, and mucosal lesions were 90%, 100%, and 16%, respectively. The overall sensitivities and specificities of SHR-CT scanning and VB were 83% and 100%, respectively. In contrast, CT scanning had sensitivities of 50%, 72%, and 0% for the detection of endoluminal, obstructive, and mucosal lesions with an overall sensitivity and specificity of 59%, and 85%, respectively. There was no case in which conventional CT scanning was better at detecting lesions than either SHR-CT scanning or VB. CONCLUSIONS: SHR-CT scanning and VB are accurate, noninvasive methods for identifying obstructions and endoluminal lesions within the respiratory tract. Thus, these novel imaging techniques are valuable as complementary modalities to FB, providing information that is useful for the detection and management of airway malignancies.


Assuntos
Neoplasias Brônquicas/diagnóstico , Broncoscopia , Tomografia Computadorizada por Raios X , Neoplasias da Traqueia/diagnóstico , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Brônquicas/diagnóstico por imagem , Broncoscopia/métodos , Reações Falso-Positivas , Feminino , Tecnologia de Fibra Óptica , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Intensificação de Imagem Radiográfica , Sensibilidade e Especificidade , Neoplasias da Traqueia/diagnóstico por imagem
11.
PLoS One ; 9(7): e101010, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24983628

RESUMO

BACKGROUND: Although implicated in the pathogenesis of several chronic inflammatory disorders and hematologic malignancies, telomerase mutations have not been thoroughly characterized in human cancers. The present study was performed to examine the frequency and potential clinical relevance of telomerase mutations in esophageal carcinomas. METHODS: Sequencing techniques were used to evaluate mutational status of telomerase reverse transcriptase (TERT) and telomerase RNA component (TERC) in neoplastic and adjacent normal mucosa from 143 esophageal cancer (EsC) patients. MTS, flow cytometry, time lapse microscopy, and murine xenograft techniques were used to assess proliferation, apoptosis, chemotaxis, and tumorigenicity of EsC cells expressing either wtTERT or TERT variants. Immunoprecipitation, immunoblot, immunofluorescence, promoter-reporter and qRT-PCR techniques were used to evaluate interactions of TERT and several TERT variants with BRG-1 and ß-catenin, and to assess expression of cytoskeletal proteins, and cell signaling. Fluorescence in-situ hybridization and spectral karyotyping techniques were used to examine telomere length and chromosomal stability. RESULTS: Sequencing analysis revealed one deletion involving TERC (TERC del 341-360), and two non-synonymous TERT variants [A279T (2 homozygous, 9 heterozygous); A1062T (4 heterozygous)]. The minor allele frequency of the A279T variant was five-fold higher in EsC patients compared to healthy blood donors (p<0.01). Relative to wtTERT, A279T decreased telomere length, destabilized TERT-BRG-1-ß-catenin complex, markedly depleted ß-catenin, and down-regulated canonical Wnt signaling in cancer cells; these phenomena coincided with decreased proliferation, depletion of additional cytoskeletal proteins, impaired chemotaxis, increased chemosensitivity, and significantly decreased tumorigenicity of EsC cells. A279T expression significantly increased chromosomal aberrations in mouse embryonic fibroblasts (MEFs) following Zeocin™ exposure, as well as Li Fraumeni fibroblasts in the absence of pharmacologically-induced DNA damage. CONCLUSIONS: A279T induces telomere dysfunction and inhibits non-canonical telomerase activity in esophageal cancer cells. These findings warrant further analysis of A279T expression in esophageal cancers and premalignant esophageal lesions.


Assuntos
Neoplasias Esofágicas/enzimologia , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Mutação de Sentido Incorreto , Proteínas de Neoplasias/biossíntese , Telomerase/biossíntese , Homeostase do Telômero , Substituição de Aminoácidos , Animais , Linhagem Celular Tumoral , Neoplasias Esofágicas/genética , Neoplasias Esofágicas/patologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Nus , Proteínas de Neoplasias/genética , RNA/biossíntese , RNA/genética , RNA Neoplásico/biossíntese , RNA Neoplásico/genética , Telomerase/genética , Telômero/enzimologia , Telômero/genética
12.
J Clin Invest ; 123(3): 1241-61, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23426183

RESUMO

MicroRNAs are critical mediators of stem cell pluripotency, differentiation, and malignancy. Limited information exists regarding microRNA alterations that facilitate initiation and progression of human lung cancers. In this study, array techniques were used to evaluate microRNA expression in normal human respiratory epithelia and lung cancer cells cultured in the presence or absence of cigarette smoke condensate (CSC). Under relevant exposure conditions, CSC significantly repressed miR-487b. Subsequent experiments demonstrated that miR-487b directly targeted SUZ12, BMI1, WNT5A, MYC, and KRAS. Repression of miR-487b correlated with overexpression of these targets in primary lung cancers and coincided with DNA methylation, de novo nucleosome occupancy, and decreased H2AZ and TCF1 levels within the miR-487b genomic locus. Deoxy-azacytidine derepressed miR-487b and attenuated CSC-mediated silencing of miR-487b. Constitutive expression of miR-487b abrogated Wnt signaling, inhibited in vitro proliferation and invasion of lung cancer cells mediated by CSC or overexpression of miR-487b targets, and decreased growth and metastatic potential of lung cancer cells in vivo. Collectively, these findings indicate that miR-487b is a tumor suppressor microRNA silenced by epigenetic mechanisms during tobacco-induced pulmonary carcinogenesis and suggest that DNA demethylating agents may be useful for activating miR-487b for lung cancer therapy.


Assuntos
Adenocarcinoma/genética , Transformação Celular Neoplásica/metabolismo , Neoplasias Pulmonares/genética , MicroRNAs/genética , Interferência de RNA , Fumaça/efeitos adversos , Adenocarcinoma/etiologia , Adenocarcinoma/metabolismo , Adenocarcinoma/secundário , Animais , Sequência de Bases , Sítios de Ligação , Linhagem Celular Tumoral , Transformação Celular Neoplásica/genética , Senescência Celular , Montagem e Desmontagem da Cromatina , Ilhas de CpG , Metilação de DNA , Epigênese Genética , Feminino , Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Genes Supressores de Tumor , Fator 1-alfa Nuclear de Hepatócito/metabolismo , Fator 1-alfa Nuclear de Hepatócito/fisiologia , Histonas/metabolismo , Humanos , Neoplasias Pulmonares/etiologia , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Masculino , Camundongos , Camundongos Nus , MicroRNAs/metabolismo , Pessoa de Meia-Idade , Proteínas de Neoplasias , Transplante de Neoplasias , Complexo Repressor Polycomb 1/genética , Complexo Repressor Polycomb 1/metabolismo , Complexo Repressor Polycomb 2/genética , Complexo Repressor Polycomb 2/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas c-myc/genética , Proteínas Proto-Oncogênicas c-myc/metabolismo , Proteínas Proto-Oncogênicas p21(ras) , Fumar/efeitos adversos , Nicotiana/química , Fatores de Transcrição , Fator de Crescimento Transformador beta1/fisiologia , Proteínas Wnt/genética , Proteínas Wnt/metabolismo , Proteína Wnt-5a , Proteínas ras/genética , Proteínas ras/metabolismo
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