Jagged 1 Regulates The Proliferation and Metastasis of Human MDA-T68 Thyroid Cancer Cells

Abstract

Objective: The current study evaluated the expression profile and explored the therapeutic implications of Jagged 1in human thyroid cancer.Materials and Methods: This experimental study was conducted in 60 paired specimens of papillary thyroid andadjacent normal tissues. Gene expression was determined by quantitative real time polymerase chain reaction(qRT-PCR) and western blotting. Transfection of cancer cells was performed by using Lipofectamine 2000. The cellproliferation of PTC cells was estimated by MTT assay. Clonogenic assay was performed for analysis of colony formingpotential of cancer cells. The apoptosis of PTC cells was studied by using AO/EB and Annexin V-FITC/PI stainingmethods. Flow cytometry was done to analyze the cell cycle phase distribution of cancer cells. Migration and invasionPTC cells were determined respectively with the wound-healing and transwell assays. The impact of Jagged 1 silencingwas investigated in vivo in a xenografted mice model followed by Immunohistochemistry (IHC) analysis.Results: We found significant (P<0.05) upregulation of Jagged 1 in human thyroid cancer. Silencing of Jagged 1 causedsignificant (P<0.05) reduction in proliferation and colony formation of MDA-T68 cells. The inhibitory effects of Jagged1 silencing were found to be due to the induction of apoptosis. We also found enhancement of Bax and repression ofBcl-2 protein levels in MDA-T68 cells. Wound healing assay indicated significant (P<0.05) inhibition of cell migration ofMDA-T68 thyroid cancer cells. Additionally, we found that invasion of the thyroid cancer cells was reduced by 55% uponsilencing of Jagged 1. Moreover, Jagged 1 silencing was found to cause inhibition of the Notch intracellular domain(NICD) and Notch target gene, Hes-1 expression. Finally, Jagged 1 silencing inhibited the xenografted tumors in vivo.Conclusion: The findings suggest that Jagged 1 regulates the development of thyroid cancer that may act as atherapeutic target for managing thyroid cancer.

Keywords

• apoptosis
• invasion
• migration
• proliferation
• thyroid cancer