Transcription Factor EB Expression in Early Breast Cancer Relates to Lysosomal/Autophagosomal Markers and Prognosis.
Clin Breast Cancer
; 17(3): e119-e125, 2017 06.
Article
em En
| MEDLINE
| ID: mdl-28017540
ABSTRACT
BACKGROUND:
Disrupting the autophagic balance to trigger autophagic death may open new strategies for cancer therapy. Transcription factor EB (TFEB) is a master regulator of lysosomal biogenesis and may play a role in cancer biology and clinical behavior.METHODS:
The expression of TFEB and the lysosomal cancer cell content (expression of lysosomal associated membrane protein 2a [LAMP2a] and cathepsin D) was studied in a series of 100 T1-stage breast carcinomas. Expression patterns were correlated with autophagy/hypoxia-related proteins, angiogenesis, and clinical outcome. The effect of hypoxic/acidic conditions on TFEB kinetics was studied in the MCF-7 cancer cell line.RESULTS:
Overexpression of TFEB in cancer cell cytoplasm and the perinuclear/nuclear area was noted in 23 (23%) of 100 cases. High LAMP2a and cathepsin D expression was noted in 30 (30%) of 100 and 28 (28%) of 100 cases, respectively. TFEB expression was directly linked with LAMP2a (P < .0001, r = 0.53), cathepsin D (P = .0002, r = 0.36), light chain 3A (LC3A) (P = .02, r = 0.22), and hypoxia-inducible factor 2-alpha (HIF-2α) (P = .01, r = 0.25) expression and inversely with progesterone receptor (P = .01, r = 0.22). High vascular density was directly linked with LAMP2a (P = .05, r = 0.18) and cathepsin D (P = .005, r = 0.28). In Kaplan-Meier survival analysis, TFEB and cathepsin D expression were related to an ominous prognosis (P = .001 and P = .03, respectively). In multivariate analysis, TFEB expression sustained its independent prognostic significance (P = .05, hazard ratio 2.1). In in vitro experiments, acidity triggered overexpression of TFEB and nuclear translocation.CONCLUSION:
Intense TFEB expression and lysosomal biogenesis, evident in one fourth of early breast carcinomas, define poor prognosis. Tumor acidity is among the microenvironmental conditions that trigger TFEB overactivity. TFEB is a sound target for the development of lysosomal targeting therapies.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Autofagia
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Neoplasias da Mama
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Biomarcadores
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Biomarcadores Tumorais
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Fatores de Transcrição de Zíper de Leucina e Hélice-Alça-Hélix Básicos
/
Lisossomos
Tipo de estudo:
Prognostic_studies
Limite:
Adult
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Aged
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Female
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Humans
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Middle aged
Idioma:
En
Ano de publicação:
2017
Tipo de documento:
Article