RESUMO
The 25-kDa heat shock protein (Hsp25) is associated with various malignancies and is expressed at high levels in biopsies as well as circulating in the serum of breast cancer patients. In this study, we used RNA interference technology to silence the hsp25 gene in 4T1 breast adenocarcinoma cells, known as a poorly immunogenic, highly metastatic cell line. We demonstrate that transfection of 4T1 cells with short interference RNA-Hsp25 dramatically inhibits proliferation as compared with control transfected cells. In addition, we show that 4T1 cells transfected with short interference RNA-Hsp25 abrogates tumor migration potential by a mechanism that is in part due to the repression of matrix metalloproteinase 9 expression and a concomitant upregulation of its antagonist, tissue inhibitor metalloproteinase 1. Taken together, these findings provide a model system for the study of metastatic potential of tumors and are suggestive of an earlier unrecognized role for Hsp25 in tumor migration.
Assuntos
Adenocarcinoma/genética , Adenocarcinoma/patologia , Neoplasias da Mama/genética , Neoplasias da Mama/patologia , Proteínas de Choque Térmico/biossíntese , Proteínas de Choque Térmico/genética , Metástase Neoplásica/fisiopatologia , Proteínas de Neoplasias/biossíntese , Proteínas de Neoplasias/genética , Interferência de RNA , Sequência de Bases , Movimento Celular , Proliferação de Células , Feminino , Proteínas de Choque Térmico HSP27 , Proteínas de Choque Térmico/fisiologia , Humanos , Metaloproteinase 9 da Matriz/metabolismo , Chaperonas Moleculares , Dados de Sequência Molecular , Proteínas de Neoplasias/fisiologia , Transfecção , Células Tumorais CultivadasRESUMO
The expression of unique surface structures on tumors that allow for recognition and activation of host immunocompetent cells plays an important role in determining tumor growth and/or metastasis. Recent studies have identified an important role for heat shock proteins (Hsp) in antitumor surveillance; however, the exact role of Hsp expressed on the surface of tumors has not been fully addressed. In this study, we show that 4T1 mammary adenocarcinoma cells sorted for high Hsp25 surface expression (Hsp25(high)) grow significantly faster than cells sorted for intermediate Hsp25 surface expression (Hsp25(intermediate)) or wild-type 4T1 cells implanted into the abdominal breast gland of female BALB/c mice (p < 0.05). In addition, histological examination of lung tissues revealed that Hsp25(high) 4T1 cells metastasized to the lungs more aggressively than either Hsp25(intermediate) or wild-type 4T1 cells (p < 0.05). Exposure of 4T1 cells to nonlethal heat shock (43 degrees C, 30 min) induced the surface expression of Hsp72 and a concomitant reduction in Hsp25 surface expression. The growth and metastastic potential of Hsp72(+) 4T1 cells was significantly less than that of Hsp25(high), Hsp25(intermediate) or wild-type 4T1 cells (p < 0.05). Taken together, these studies identify an important role for expression of Hsp25 and Hsp72 during tumor growth and metastatic spread which might be helpful in the design of antimetastatic therapies.
Assuntos
Adenocarcinoma/secundário , Biomarcadores Tumorais/sangue , Perfilação da Expressão Gênica , Proteínas de Choque Térmico/biossíntese , Neoplasias Pulmonares/secundário , Neoplasias Mamárias Animais/patologia , Metástase Neoplásica/fisiopatologia , Proteínas de Neoplasias/biossíntese , Animais , Proliferação de Células , Progressão da Doença , Feminino , Proteínas de Choque Térmico HSP27 , Proteínas de Choque Térmico HSP72 , Proteínas de Choque Térmico/farmacologia , Humanos , Neoplasias Pulmonares/fisiopatologia , Camundongos , Camundongos Endogâmicos BALB C , Chaperonas Moleculares , Proteínas de Neoplasias/farmacologia , Neoplasias Experimentais , Células Tumorais CultivadasRESUMO
The expression of unique surface structures on tumors that allow for recognition and activation of host immunocompetent cells plays an important role in determining tumor growth and/or metastasis. Recent sutdies have identified an important role for heat shock proteins (Hsp) in antitumor surveillance; however, the exact role of Hsp expressed on the surface of tumors has not been fully addressed. In this study, we show that 4T1 mammary adenocarcinoma cells sorted for high Hsp25 surface expression (Hsp25 high) grow significantly faster than cells sorted for intermediate Hsp 25 surface expression (Hsp25 intermediate) or wild-type 4T1 cells implanted into the abdominal breast gland of female BALB/c mice (p<0.05). In addition, histological examination of lung tissues reveales that Hsp25 high 4T1 cells metastasized to the lung more aggresively than either Hsp25intermediate or wild-type 4T1 cells (p<0.05). Exposure of 4T1 cells to nonlethal heat shock (43ºC, 30 min) induced the surface expression of Hsp72 and a concomitant reduction in Hsp surface expression. The growth and metastatic potential of Hsp72+ 4T1 cells was significantly less than that of Hsp25 high, Hspintermediate or wild-type 4T1 cells (p<0.05). Taken together, these studies identify an important role for expression of Hsp25 and Hsp72 during tumor growth and metastatic spread which might be helpful in the design of antimetastatic therapies