CD44 stimulation by fragmented hyaluronic acid induces upregulation of urokinase‐type plasminogen activator and its receptor and subsequently facilitates invasion of human chondrosarcoma cells

Abstract

It has been established that fragmented hyaluronic acid (HA), but not native high molecular weight HA, can induce angiogenesis, cell proliferation and migration. We have studied the outside-in signal transduction pathways responsible for fragmented HA-mediated cancer cell invasion. In our study, we have studied the effects of CD44 stimulation by ligation with HA upon the expression of matrix metalloproteinases (MMPs)-2 and -9 as well as urokinase-type plasminogen activator (uPA), its receptor (uPAR) and its inhibitor (PAI-1) and the subsequent induction of invasion of human chondrosarcoma cell line HCS-2/8. Our study indicates that CD44; hyaluronic acid; invasion; MAP kinase; uPA receptor (uPAR) Tumor cell invasion is a complex, multistep process that involves cell adhesion and the controlled degradation of the extracellular matrix (ECM) by tumor cell-associated proteases. 1 Among these proteases, MMPs-2 and -9, also known as gelatinases, 2 and urokinase-type plasminogen activator (uPA), a serine protease that activates plasminogen to plasmin enabling the degradation of the ECM, have a main role in the metastatic proteolytic cascade. 3 Tissue inhibitors of gelatinase activity (e.g., TIMP-2) are involved in the MMP-2 activation process; in concert with membrane type 1-MMP (MT1-MMP) and in the inhibition of gelatinolytic activity. uPA bound to its cell-surface receptor, uPAR, is the principal participant in ECM degradation. 4 Plasminogen activator inhibitors (PAI) also regulate the catalytic activity of PA. Therefore proteolysis, the central step for cancer metastasis, should occur as a result of an imbalance between proteinases and their specific inhibitors. 2 The cellular functions are dependent upon a number of cell surface adhesion proteins and CD44 has been implicated as one such molecule. 5 CD44 has been shown to promote tumor cell adhesion, migration, invasion and angiogenesis, crucial steps in the process of metastasis. CD44 is a transmembrane glycoprotein known to bind hyaluronic acid (HA) in its extracellular domain. 6 CD44 is known to exist in many different isoforms arising by alternative splicing events. 7 HA is a nonsulfated, linear glycosaminoglycan consisting of repeating unit of (␤,1-4)-D-glucuronic acid-(␤,1-3)-N-acethyl-D-glucosamine. 8 Several studies have suggested that high and low molecular weight species of HA exhibit different biologic effects on cells: low molecular weight but not native HA has been shown to stimulate the expression of cytokines, proinflammatory chemokines and cell adhesion molecules (IL-1␤, TNF-␣ and insulin-like growth factor, inducible NO synthase, metalloelastase, VCAM-1 and ICAM-1) possibly through a mechanism involving the cellular HA receptor, CD44. 9 -17 Fragmented HA can also induce cell proliferation, migration and angiogenesis. 9,18 The mechanisms through which fragmented HA exerts its biologic functions have been only partially elucidated. There is a growing body of evidence that the CD44-induced signals are dependent on protein kinase C (PKC) activation 1...

Hyaluronan oligosaccharides are potential stimulators to angiogenesis via RHAMM mediated signal pathway in wound healing

“…A cascade of main signal pathway was selected for cell activation study: p-Src, c-myc, and p42/44 (extracellular signal-regulated kinase, ERK1/2). o-HA promotes EC signal transduction as reported previously 17 ( Fig. 6-7).…”

Coexpression of invasive markers (uPA, CD44) and multiple drug-resistance proteins (MDR1, MRP2) is correlated with epithelial ovarian cancer progression

“…One of the interesting findings in this study is the colocalisation of uPA and CD44, uPA and MDR1, uPA and MRP2, CD44 and MDR1 or CD44 and MRP2 in primary and metastatic EOC cells. Kobayashi et al (2002) reported that CD44 stimulation by fragmented HA can activate MAP kinase (MAPK) proteins and upregulate the expression of uPA mRNA and protein in human chondrosarcoma cell line HCS-2/8, which supports the role of uPA as an invasion-promoting factor. Sheridan et al (2006) showed that breast cancer cell lines with a significant CD44 þ /CD24À subpopulation express higher levels of the uPA gene associated with cancer invasion (Sheridan et al, 2006).…”

RNAi targeting urokinase‐type plasminogen activator receptor inhibits metastasis and progression of oral squamous cell carcinoma in vivo

“…13 In our study, the expression of MDR-1 of oral cancer cells was greatly inhibited by RNAi targeting u-PAR, which may be induced by the CD44-MAPK-PI3K signaling. 13,62 This result suggests that u-PAR is involved with tumor drug resistance. In addition, some recent studies have demonstrated that ligand engagement of u-PAR can counteract the proapoptotic effect triggered by cisplatin through the upregulation of the antiapoptotic factor Bcl-XL.…”