Integrin α3ß1 can function to promote spontaneous metastasis and lung colonization of invasive breast carcinoma.
Mol Cancer Res
; 12(1): 143-154, 2014 Jan.
Article
en En
| MEDLINE
| ID: mdl-24002891
UNLABELLED: Significant evidence implicates α3ß1 integrin in promoting breast cancer tumorigenesis and metastasis-associated cell behaviors in vitro and in vivo. However, the extent to which α3ß1 is actually required for breast cancer metastasis remains to be determined. We used RNA interference to silence α3 integrin expression by approximately 70% in 4T1 murine mammary carcinoma cells, a model of aggressive, metastatic breast cancer. Loss of α3 integrin reduced adhesion, spreading, and proliferation on laminin isoforms, and modestly reduced the growth of orthotopically implanted cells. However, spontaneous metastasis to lung was strikingly curtailed. Experimental lung colonization after tail vein injection revealed a similar loss of metastatic capacity for the α3-silenced (α3si) cells, suggesting that critical, α3-dependent events at the metastatic site could account for much of α3ß1's contribution to metastasis in this model. Reexpressing α3 in the α3si cells reversed the loss of metastatic capacity, and silencing another target, the small GTPase RhoC, had no effect, supporting the specificity of the effect of silencing α3. Parental, α3si, and α3-rescued cells, all secreted abundant laminin α5 (LAMA5), an α3ß1 integrin ligand, suggesting that loss of α3 integrin might disrupt an autocrine loop that could function to sustain metastatic growth. Analysis of human breast cancer cases revealed reduced survival in cases where α3 integrin and LAMA5 are both overexpressed. IMPLICATIONS: α3 integrin or downstream effectors may be potential therapeutic targets in disseminated breast cancers, especially when laminin α5 or other α3 integrin ligands are also over-expressed.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Neoplasias de la Mama
/
Laminina
/
Integrina alfa3beta1
/
Neoplasias Pulmonares
Límite:
Animals
/
Female
/
Humans
Idioma:
En
Revista:
Mol Cancer Res
Asunto de la revista:
BIOLOGIA MOLECULAR
/
NEOPLASIAS
Año:
2014
Tipo del documento:
Article
Pais de publicación:
Estados Unidos