Galectin-1 from cancer-associated fibroblasts induces epithelial–mesenchymal transition through β1 integrin-mediated upregulation of Gli1 in gastric cancer

Abstract

BackgroundGastric cancer (GC) is characterized by the excessive deposition of extracellular matrix, which is thought to contribute to this tumor’s malignant behavior. Epithelial-mesenchymal transition (EMT) is regarded as a crucial contributing factor to cancer progression. Galectin-1 (Gal-1), a β-galactoside-binding protein abundantly expressed in activated cancer-associated fibroblasts (CAFs), has been reported to be involved in GC progression and metastasis by binding to β1 integrin, which, in turn, can bind to matrix proteins and activate intracellular cascades that mediate EMT. Increasing evidence suggests that abnormal activation of the hedgehog (Hh) signaling pathway enhances GC cell migration and invasion. The purpose of our study is to explore the role of Gal-1 in the GC progression and metastasis as well as the regulatory mechanism.MethodsWe hypothesized that Gal-1 binding to β1 integrin would lead to paracrine signaling between CAFs and GC cells, mediating EMT by upregulating Gli1. Invasion and metastasis effects of the Gal-1 and Gli1 were evaluated using wound healing and invasion assay following transfection with mimics. Additionally, to facilitate the delineation of the role of the Hh signaling in GC, we monitored the expression level of associated proteins. We also evaluated the effects of β1 integrin on these processes. Furthermore, Gal-1 and Gli1 expression in GC patient samples were examined by immunohistochemistry and western blot to determine the correlation between their expression and clinicopathologic characteristics. The Kaplan-Meier method and Cox proportional hazards model were used to analyze the relationship of expression with clinical outcomes.ResultsGal-1 was found to induce EMT, GC cell migration and invasion. Further data showed that Gal-1 up-regulated Gli1 expression. β1 integrin was responsible for Gal-1-induced Gli1 expression and EMT. In clinical GC tissue, it confirmed a positive relationship between Gal-1 and Gli1 expression. Importantly, their high expression is correlated to poor prognosis.ConclusionGal-1 from CAFs binds to a carbohydrate structure in β1 integrin and plays an important role in the development of GC by inducing GC metastasis and EMT through targeting Gli1. This study highlights the potential therapeutic value of Gal-1 for suppression of GC metastasis.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-016-0449-1) contains supplementary material, which is available to authorized users.

Galectin-1 promotes the invasion of bladder cancer urothelia through their matrix milieu

“…This observation is congruent with increasing evidence of aberrant cancer cell-surface glycosylations, and cognate changes in lectins: proteins that sense, interact, and signal through, these aberrant glycans (11). The association of one such galactose-binding lectin: GAL-1 with cancer progression has been widely reported in different tumors type (12)(13)(14)(15)(16)(17).…”

Nicotinamide N-methyltransferase promotes epithelial-mesenchymal transition in gastric cancer cells by activating transforming growth factor-β1 expression

“…EMT is an important process in carcinogenesis since it increases the invasive ability of cancer cells (26,27). As a result of EMT, epithelial-derived tumor cells lose their features and obtain mesenchymal-like characteristics (28,29), and tumor cells invade the surrounding tissue and break through the capillary into the circulatory system, leading to distant metastasis (30).…”

Mechanisms of the Epithelial–Mesenchymal Transition and Tumor Microenvironment in Helicobacter pylori-Induced Gastric Cancer

“…CAFs also promote EMT and gastric carcinogenesis via activation of erythropoietin-producing hepatocellular A2 receptor (EphA2) and IL-6-JAK2-STAT3 signaling pathways [258,259]. CAFs release a significant amount of galectin-1, which promotes EMT and gastric cancer progression by binding to β1 integrin [260]. EMT is also promoted by CAFs-derived IL-33 through the activation of the ERK1/2-SP1-ZEB2 pathway [261].…”