RESUMO
Gallbladder cancer (GBC) is a particularly deadly type of cancer with a 5-year survival rate of only 10%. New effective therapeutic strategies are greatly needed. Recently, we have shown that Hedgehog (Hh) signaling is reactivated in various types of cancer and is a potential therapeutic target. However, little is known about the biological significance of Hh signaling in human GBC. In this study, we determined whether Hh signaling could be a therapeutic target in GBC. The Hh transcription factor Gli1 was detected in the nucleus of GBC cells but not in the nucleus of normal gallbladder cells. The expression levels of Sonic Hh (Shh) and Smoothened (Smo) in human GBC specimens (n = 37) were higher than those in normal gallbladder tissue. The addition of exogenous Shh ligand augmented the anchor-dependent and anchor-independent proliferation and invasiveness of GBC cells in vitro. In contrast, inhibiting the effector Smo decreased the anchor-dependent and anchor-independent proliferation. Furthermore, the suppression of Smo decreased GBC cell invasiveness through the inhibition of MMP-2 and MMP-9 expression and inhibited the epithelial-mesenchymal transition. In a xenograft model, tumor volume in Smo siRNA-transfected GBC cells was significantly lower than in control tumors. These results suggest that Hh signaling is elevated in GBC and may be involved in the acquisition of malignant phenotypes, and that Hh signaling may be a potential therapeutic target for GBC.
Assuntos
Neoplasias da Vesícula Biliar/metabolismo , Proteínas Hedgehog/metabolismo , Receptores Acoplados a Proteínas G/genética , Transdução de Sinais/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células , Transição Epitelial-Mesenquimal , Feminino , Vesícula Biliar/metabolismo , Neoplasias da Vesícula Biliar/patologia , Neoplasias da Vesícula Biliar/terapia , Técnicas de Silenciamento de Genes , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/metabolismo , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Transplante de Neoplasias , RNA Interferente Pequeno/genética , Receptores Acoplados a Proteínas G/metabolismo , Receptor Smoothened , Alcaloides de Veratrum/farmacologiaRESUMO
BACKGROUND/AIM: The prognosis for triple-negative breast cancer (TNBC) is poor. In the present study, we evaluated whether NOTCH4 receptor is a potential new therapeutic target for TNBC. MATERIALS AND METHODS: In vitro proliferation and invasiveness were evaluated in TNBC cells with or without small-interfering RNA (siRNA) for NOTCH4, and with or without NOTCH4 plasmid transfection. In vivo, MDA-MB-231 cells with or without NOTCH4 siRNA were subcutaneously implanted into the flank regions of mice. The frequency of nuclear translocation of NOTCH4 was assessed by immunohistochemistry in 21 TNBC samples and 46 non-TNBC samples. RESULTS: NOTCH4 inhibition in TNBC cells reduced proliferation and invasiveness, and NOTCH4 overexpression in TNBC cells increased proliferation and invasiveness. NOTCH4 inhibition reduced tumour volume and tumourigenicity of mouse xenografts. TNBC cells had a higher frequency of nuclear translocation of NOTCH4 than other cells. CONCLUSION: NOTCH4 is a new potential therapeutic target for triple-negative breast cancer.