ABSTRACT
Hepatocellular carcinoma (HCC) is one of the most aggressive malignant tumors, of which treatment options are limited especially in advanced stage. Bufalin, the major digoxin-like component of the traditional Chinese medicine Chansu, exhibits significant antitumor activities in hepatoma cells, but the potential mechanism is obscure. Cell cycle-related kinase (CCRK) is recently identified to be a crucial oncogenic master regulator to drive hepatocarcinogenesis. Here we investigated the molecular function of bufalin on CCRK-regulated signaling pathway, and expounded the underlying mechanism in HCC suppression. In vitro with PLC5 HCC cells and human immortal LO2 cells, proliferation, malignant transformation and cell cycle progression assays were performed to evaluate the antitumor effect of bufalin. In vivo with xenograft and orthotopic mice models, tumor growths with weight and volume change were assessed with or without bufalin treatment. Western blot, RT-qPCR, immunofluorescence and immunohistochemistry were conducted to examine the expression level of CCRK and ß-catenin/TCF signaling cascade. We revealed that bufalin suppresses PLC5 HCC cell proliferation, transformation and cell cycle progression rather than LO2 cells, which is correlated with CCRK-mediated ß-catenin/TCF signaling. It was also confirmed in mice model. Thus, bufalin is a potential anti-HCC therapeutic candidate through the inhibition of CCRK-driven ß-catenin/TCF oncogenic signaling pathway.
Subject(s)
Bufanolides/pharmacology , Carcinoma, Hepatocellular/metabolism , Cyclin-Dependent Kinases/drug effects , Animals , Bufanolides/metabolism , Carcinogenesis/drug effects , Cell Cycle/drug effects , Cell Line, Tumor , Cell Proliferation/drug effects , Cyclin-Dependent Kinases/metabolism , Female , Gene Expression Regulation, Neoplastic/drug effects , Glycogen Synthase Kinase 3/metabolism , Glycogen Synthase Kinase 3 beta/metabolism , Humans , Liver Neoplasms/metabolism , Medicine, Chinese Traditional/methods , Mice , Mice, Nude , Signal Transduction/drug effects , T Cell Transcription Factor 1/drug effects , Xenograft Model Antitumor Assays , beta Catenin/drug effects , Cyclin-Dependent Kinase-Activating KinaseABSTRACT
Epidemiological and experimental studies have indicated selenium could reduce the risk of some cancers. In our present study, growth inhibition and apoptosis were detected upon methylseleninic acid (MSA) treatment in human esophageal squamous cell carcinoma cell lines EC9706 and KYSE150. MSA reduced beta-catenin protein levels, while there was no significant change observed on transcriptional levels. Moreover, we found MSA accelerated the degradation of beta-catenin and activated glycogen synthase kinase 3beta (GSK-3beta). Some targets of beta-catenin/TCF pathway and apoptosis-related genes altered after MSA treatment. Notably, utilizing the inducible 293-TR/beta-catenin cell line, we found the apoptotic phenotypes induced by MSA were partially reversed by the overexpression of beta-catenin. Overall, our data indicate the effects induced by MSA in ESCC cells may act on the inhibition of beta-catenin/TCF pathway.
