7286

TUFT1

Pancreatic cancer (PC) is usually lethal because of late diagnosis and early metastasis. Analysis of data from online database showed that TUFT1 is highly expressed in liver metastases of PC, and was associated with shorter overall survival. However, the role of TUFT1 in PC remains unknown. In this study, we show for the first time that TUFT1 is overexpressed in PC tissues compared with adjacent normal pancreas tissues, and TUFT1 expression is significantly associated with lymph node metastasis and advanced PC stage (P <0.05). Depletion or overexpression of endogenous TUFT1 correspondingly inhibited or promoted PC cell migration and metastasis in vitro and in vivo, and affected expression of epithelial-mesenchymal transition (EMT)-related proteins, E-cadherin and vimentin. We also provide evidence that TUFT1 induced EMT by altering the expression of Snail; that TUFT1 is associated with expression and activity of HIF1; and that TUFT1 might affect HIF1-Snail signaling in regulating EMT. Collectively, these results indicate that TUFT1 could be a novel diagnostic and therapeutic target for PC.CI - Copyright (c) 2016 Elsevier Ireland Ltd. All rights reserved.

Tuftelin1 (TUFT1), an acidic protein constituent of developing and mineralizing tooth tissues, is regulated by hypoxia and the Hedgehog signaling pathway. We investigated the role of TUFT1 in hepatocellular carcinoma (HCC). qRT-PCR, immunohistochemistry and western blot were employed to evaluate TUFT1 level in HCC. MTT, BrdU, 3D culture and Transwell assays were used to assess cell viability, proliferation, in vitro growth, migration, and invasion. Subcutaneous and tail vein injection models were established to investigate in vivo growth and metastasis. Chromatin immunoprecipitation was performed to assess binding of hypoxia-inducible factor 1alpha (HIF-1alpha) to TUFT1 promoter. A microRNA array was used to identify hypoxia-related microRNAs. TUFT1 was elevated in HCC, and correlated with unfavorable clinicopathologic characteristics and poor survival. TUFT1 promoted HCC cell growth, metastasis and epithelial-mesenchymal transition in vitro and in vivo via activation of Ca(2+)/PI3K/AKT pathway. Hypoxia induced TUFT1 expression in an HIF-1alpha dependent manner, and TUFT1 expression was positively correlated with HIF-1alpha level in HCC tissues. Hypoxiaenhanced TUFT1 expression by downregulating miR-671-5p rather than by directly promoting the binding of HIF-1alpha to TUFT1 promoter. MiR-671-5p interacted with the 3'-UTR of TUFT1 mRNA and subsequently inhibited TUFT1 expression. Consequently, knockdown of TUFT1 blocked the effects of hypoxia in promoting HCC progression. TUFT1 promoted the growth, metastasis and EMT of HCC cells through activating Ca(2+)/PI3K/AKT pathway. The hypoxic microenvironment increased the expression of TUFT1 via downregulation of miR-671-5p. TUFT1 may function as a potential therapeutic target for the intervention and treatment of HCC.