Reduced Smad4 expression and DNA topoisomerase inhibitor chemosensitivity in non-small cell lung cancer.
Lung Cancer
; 109: 28-35, 2017 07.
Article
em En
| MEDLINE
| ID: mdl-28577946
ABSTRACT
OBJECTIVE:
Smad4 is a tumor suppressor that transduces transforming growth factor beta signaling and regulates genomic stability. We previously found that Smad4 knockdown in vitro inhibited DNA repair and increased sensitivity to DNA topoisomerase inhibitors. In this study, we assessed the association between reduced Smad4 expression and DNA topoisomerase inhibitor sensitivity in human non-small cell lung cancer (NSCLC) patients and evaluated the relationship between genomic alterations of Smad4 and molecular alterations in DNA repair molecules. MATERIALS ANDMETHODS:
We retrospectively identified NSCLC patients who received etoposide or gemcitabine. Chemotherapeutic response was quantified by RECIST 1.1 criteria and Smad4 expression was assessed by immunohistochemistry. Relationships between Smad4 mutation and DNA repair molecule mutations were evaluated using publically available datasets.RESULTS:
We identified 28 individuals who received 30 treatments with gemcitabine or etoposide containing regimens for NSCLC. Reduced Smad4 expression was seen in 13/28 patients and was not associated with significant differences in clinical or pathologic parameters. Patients with reduced Smad4 expression had a larger response to DNA topoisomerase inhibitor containing regimens then patients with high Smad4 expression (-25.7% vs. -6.8% in lesion size, p=0.03); this relationship was more pronounced with gemcitabine containing regimens. The overall treatment response was higher in patients with reduced Smad4 expression (8/14 vs 2/16 p=0.02). Analysis of data from The Cancer Genome Atlas revealed that Smad4 mutation or homozygous loss was mutually exclusive with genomic alterations in DNA repair molecules.CONCLUSIONS:
Reduced Smad4 expression may predict responsiveness to regimens that contain DNA topoisomerase inhibitors. That Smad4 signaling alterations are mutually exclusive with alterations in DNA repair machinery is consistent with an important role of Smad4 in regulating DNA repair.Palavras-chave
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Protocolos de Quimioterapia Combinada Antineoplásica
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Carcinoma Pulmonar de Células não Pequenas
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Proteína Smad4
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Biomarcadores Farmacológicos
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Neoplasias Pulmonares
Tipo de estudo:
Observational_studies
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Prognostic_studies
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Risk_factors_studies
Limite:
Aged
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Female
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Humans
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Male
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Middle aged
Idioma:
En
Revista:
Lung Cancer
Assunto da revista:
NEOPLASIAS
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Estados Unidos