Expression of phosphorylated Hippo pathway kinases (MST1/2 and LATS1/2) in HER2-positive and triple-negative breast cancer patients treated with neoadjuvant therapy.
Cancer Biol Ther
; 18(5): 339-346, 2017 05 04.
Article
em En
| MEDLINE
| ID: mdl-28387539
ABSTRACT
The Hippo kinases MST1/2 and LATS1/2 inhibit the oncoproteins TAZ/YAP and regulate T cell function. Hippo kinases also cooperate with the ATR-Chk1 and ATM-Chk2 pathways, central orchestrators of the DNA damage response (DDR). We hypothesized that MST1/2 and LATS1/2 localization differently impacts the efficacy of neoadjuvant therapy (NAT) in breast cancer, being protective when expressed in the cytoplasm of tumor cells and in tumor-infiltrating lymphocytes, whereas representing molecular determinants of chemoresistance when present in the nucleus as a consequence of their cooperation with the DDR. Diagnostic biopsies from 57 HER2-positive and triple-negative breast cancer patients treated with NAT were immunostained for evaluating the expression of phosphorylated MST1/2 (pMST1/2) and LATS1/2 (pLATS1/2) in tumor-infiltrating lymphocytes (TILs) and in cancer cells. TAZ and Chk1 immunostaining was exploited for investigating subcellular compartment-dependent activity of Hippo kinases. Nuclear pMST1/2 (pMST1/2nuc) expression was significantly associated with nuclear expression of Chk1 (p = 0.046), whereas cytoplasmic pMST1/2 (pMST1/2cyt) expression was marginally associated with cytoplasmic TAZ staining (p = 0.053). Patients whose tumors expressed pMST1/2nuc were at increased risk of residual disease after NAT (pCR ypT0/is ypN0 OR 4.91, 95%CI 1.57-15.30; pCR ypT0 ypN0 OR 3.59, 95%CI 1.14-11.34). Conversely, exclusive cytoplasmic localization of pMST1/2 (pMST1/2cyt)seemed to be a protective factor (pCR ypT0/is ypN0 OR 0.34, 95%CI 0.11-1.00; pCR ypT0 ypN0 OR 0.31, 95%CI 0.10-0.93). The subcellular localization-dependent significance of pMST1/2 expression suggests their involvement in different molecular networks with opposite impact on NAT efficacy. Larger studies are warranted to confirm these novel findings.
Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Proteínas Proto-Oncogênicas
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Proteínas Serina-Treonina Quinases
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Fator de Crescimento de Hepatócito
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Terapia Neoadjuvante
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Neoplasias de Mama Triplo Negativas
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
Revista:
Cancer Biol Ther
Assunto da revista:
NEOPLASIAS
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TERAPEUTICA
Ano de publicação:
2017
Tipo de documento:
Article
País de afiliação:
Itália