ABSTRACT
O câncer de mama é uma doença extremamente heterogênea compreendendo diferentes subtipos moleculares que resultam em evoluções clínicas e condutas terapêuticas distintas. A maior gravidade desta patologia está associada a sua capacidade de formação de metástases Mudanças no padrão de expressão gênica têm sido associadas à manifestação do fenótipo metastático. Neste trabalho, utilizamos microarranjos de tecido (TMAs) para investigar a expressão de 8 biomarcadores candidatos (CIP4, PPIL1, ITGAV, AKAP14, MICA, FXYD1, ARPC3, ABG1) e avaliar seu potencial prognóstico em pacientes com carcinoma ductal invasivo da mama. Destes, ARPC3 PPIL1 e CIP4 mostraram associações estatisticamente significativas com a sobrevida câncer específica e/ou a probabilidade de desenvolvimento de metástases. Determinamos que a expressão aumentada de CIP4 nos tumores está associada a maior probabilidade de desenvolvimento de metástases. CIP4 é uma proteína adaptadora descrita na literatura como moduladora de migração e invasão celular e portanto selecionamos este candidato para caracterização funcional detalhada. Observamos que a expressão de CIP4 encontra-se aumentada em linhagens tumorais com características invasivas. A partir do silenciamento estável e regulado de CIP4 na linhagem metastática MDA-MB-231, determinamos que CIP4 modula positivamente a ativação de MAPK-p38 e a expressão de MMP2 , sugerindo que CIP4 participe em vias de sinalização importantes para a transição epitélio-mesenquima (EMT). O silenciamento de CIP4 resultou em uma redução de aproximadamente 50% da capacidade migratória e invasiva das células tumorais in vitro , e na diminuição da formação de metástases pulmonares in vivo. Coletivamente, nossos resultados indicam que CIP4 tem potencial como marcador de prognóstico assim como um possível alvo terapêutico no controle da disseminação de metástases nos tumores da mama
Breast cancer is an extremely heterogeneous disease comprising different molecular subtypes that result in different clinical outcomes and therapeutic procedures. The severity of this disease is mainly associated with its ability to produce metastasis. Changes in gene expression profile have been associated with the manifestation of the metastatic phenotype. In this study, we used tissue microarrays (TMAs) to investigate the expression of 8 candidate biomarkers (CIP4, PPIL1, ITGAV, AKAP14, MICA, FXYD1, ARPC3 e ABG1) and to evaluate their prognostic potential in patients with invasive ductal breast carcinoma. Among these, ARPC3, PPIL1 and CIP4 showed statistically significant associations with cancer specific survival and/or the patient's probability to develop metastasis. We found that increased expression of CIP4 in tumors is associated with a higher probability of developing metastasis. CIP4 is an adaptor protein described in the literature as a modulator of cell migration and invasion and therefore we selected this candidate for detailed functional characterization. We observed that CIP4 expression is increased in tumor cell lines with invasive characteristics. Following the stable and regulated knockdown of CIP4 in the metastatic line MDA-MB-231, we determined that it modulates positively the activation of MAPK-p38 and the expression of MMP2, suggesting that CIP4 participates in important signaling pathways required for the epithelial mesenchymal transition (EMT). CIP4 silencing resulted in an approximate 50% reduction of the migratory and invasive capacity of tumor cells in vitro and decreased the generation of lung metastases in vivo. Collectively, our results indicate that CIP4 has potential as a prognostic marker as well as a potential therapeutic target to control the metastatic dissemination of breast tumors
Subject(s)
Biomarkers, Tumor/analysis , Breast Neoplasms/diagnosis , Prognosis , Fluorescent Antibody Technique/statistics & numerical data , Microarray Analysis/methods , Neoplasm Metastasis , Neoplastic Stem Cells , Real-Time Polymerase Chain Reaction/methods , Tissue Array Analysis/instrumentationABSTRACT
Objective To observe the effect of CIP4(Cdc42 interacting protein 4)on human renal tubular epithelial to mesenchymal transition(EMT)induced by transforming growth factor β1(TGF-β1)and to study the associated mechanism. Methods Human proximal tubular epithelial cells (HK-2 cell line) were cultured with TGF-β1 (10μg/L) for 72 hours. The protein expressions of E-cadherin and α-SMA were measured by Western blotting. One set of siRNA oligos specific for CIP4 and CIP4 construction of the entire coding sequence were designed based on the full CIP4 sequence in GenBank. Then HK-2 cells were transfected with CIP4-siRNA or pcDNA3.1-hCIP4 via lipofactamine 2000. The protein expressions of CIP4, E-cadherin and α-SMA were evaluated respectively in control cells, TGF-β1 treated cells, siRNA transfected cells, pcDNA3.1-hCIP4-transfected cells by Western blotting. The distribution of E-cadherin and α-SMA was observed by confocal microscope. After TGF-β1-treated HK-2 cells were interferenced with specific inhibitor of PI3K-Akt (wortmannin) 1μmol/L for 48 hours, Western blotting was used to detect the CIP4 protein in control cells and interferenced cells. Results With TGF-β1 stimulation, the expression of E-cadherin protein was decreased markedly (P＜0.05), and in contract, the expression of α-SMA were increased notably (P＜0.05), which revealed that TGF-β1 could induce EMT. After transfected with CIP4-siRNA, the protein expression of E-cadherin was increased (P＜0.05), and the protein expression of α-SMA was decreased (P＜0.05). The EMT induced by TGF-β1 was effectively reversed. After transfected with pcDNA3.1-hCIP4, the expression of E-cadherin protein was down-regnlated (P＜0.05), and the expression of α-SMA protein was up-regulated compared with control group (P＜0.05), leading to EMT. After HK-2 cells were interferenced with wortmannin for 48 hours, the expression of CIP4 was decreased (P＜0.05). Conclusion TGF-β1 upregulates the expression of CIP4 via PI3K-Akt pathway, and CIP4 may participate in EMT induced by TGF-β1.