PAR-3 knockdown enhances adhesion rate of PANC-1 cells via increased expression of integrinαv and E-cadherin.
The balance between the adhesion of cancer cells to extracellular matrix and their migratory potential, as well as their proteolytic activity, are important parameters that determine cancer cells invasiveness and metastasis. Since thrombin has been implicated in cancer progression, we studied the role(s) of thrombin-activated receptors in the adhesion process. We stably knocked down proteinase-activated receptors (PARs) -1, or -3 in human pancreatic adenocarcinoma PANC-1 cells. PANC-1 cells exhibit rapid adhesion to cell culture treated plastic and much faster kinetics of adhesion to Matrigel coated surface. Knockdown of PAR-1 had no effect on cells' adhesiveness, while PAR-3 knockdowns (KDs) exhibited much faster adhesion kinetics. PAR-3 KDs also exhibited slower in vitro wound closure than vector-control and PAR-1 KD cells. To study the molecular mechanism(s) of PAR-3 KD cells' enhanced rate of adhesion, we assayed the expression of the molecules that mediate cell-surface and cell-cell adhesion. ITGαv, as well as ITGα6 and ITGα10 mRNAs, were greatly enriched (>40-fold) in a rapidly-adhering sub-population of PAR-3 KD cells. The whole population of both PAR-1 and -3 KDs exhibited enhanced expression of a number of integrins (ITGs) mRNAs. However, ITGαv mRNA and protein expression was increased in PAR-3 KD and markedly decreased in PAR-1 KD. PAR-3 KD cells also expressed more E-cadherin mRNA and protein. The enhanced adhesion kinetics of PAR-3 KDs was almost fully inhibited by calcium chelation, or by a HAV-motive decapeptide that affects E-cadherin intermolecular interactions. We propose that the enhanced rate of adhesion of PAR-3 KDs results from enhanced expression of E-cadherin, leading to a greater adhesion of free-floating cells to cells rapidly bound to the surface via their integrins, and particularly ITGαv.
Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
Liora
L
Segal
Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
Liora S
LS
Katz
Institute of Pathology, Central Lab, Maccabi, Rehovot, Israel.
Hagit
H
Shapira
Assaf Harofe Hospital Institute of Pathology and the Department of Pathology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
Judith
J
Sandbank
Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
Elizabeth
E
Geras-Raaka
Laboratory of Endocrinology and Receptor Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, Maryland, United States of America.
Marvin C
MC
Gershengorn
Department of Physiology and Pharmacology, Sackler Faculty of Medicine, Tel Aviv University, Ramat Aviv, Israel.
Yoram
Y
Oron
D000230:Adenocarcinoma / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D015820:Cadherins / Q000235:genetics / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D045744:Cell Line, Tumor; D006801:Humans; D039564:Integrin alphaV / Q000235:genetics / Q000378:metabolism*; D010190:Pancreatic Neoplasms / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D044463:Receptor, PAR-1 / Q000235:genetics / Q000378:metabolism*; D018179:Receptors, Thrombin / Q000235:genetics / Q000378:metabolism*
D015820:Cadherins; D039564:Integrin alphaV; D044463:Receptor, PAR-1; D018179:Receptors, Thrombin; C105295:protease-activated receptor 3; D002118:Calcium