Tumor Cells Enhance Their Own CD44 Cleavage and Motility by Generating Hyaluronan Fragments

Abstract

Hyaluronan (HA) is an extracellular matrix glycosaminoglycan that interacts with cell-surface receptors, including CD44. Although HA usually exists as a high molecular mass polymer, HA of a much lower molecular mass that shows a variety of biological activities can be detected under certain pathological conditions, particularly in tumors. We previously reported that low molecular weight HAs (LMW-HAs) of a certain size range induce the proteolytic cleavage of CD44 from the surface of tumor cells and promote tumor cell migration in a CD44-dependent manner. Here, we show that MIA PaCa-2, a human pancreatic carcinoma cell line, secreted hyaluronidases abundantly and generated readily detectable levels of LMW-HAs ranging from ∼10- to 40-mers. This occurred in the absence of any exogenous stimulation. The tumor-derived HA oligosaccharides were able to enhance CD44 cleavage and tumor cell motility. Inhibition of the CD44-HA interaction resulted in the complete abrogation of these cellular events. These results are consistent with the concept that tumor cells generate HA oligosaccha-rides that bind to tumor cell CD44 through the expression of their own constitutive hyaluronidases. This enhances their own CD44 cleavage and cell motility, which would subsequently promote tumor progression. Such an autocrine/paracrine-like process may represent a novel activation mechanism that would facilitate and promote the malignant potential of tumor cells. Hyaluronan (HA) is an extracellular matrix glycosaminoglycan that interacts with cell-surface receptors, including CD44. Although HA usually exists as a high molecular mass polymer, HA of a much lower molecular mass that shows a variety of biological activities can be detected under certain pathological conditions, particularly in tumors. We previously reported that low molecular weight HAs (LMW-HAs) of a certain size range induce the proteolytic cleavage of CD44 from the surface of tumor cells and promote tumor cell migration in a CD44-dependent manner. Here, we show that MIA PaCa-2, a human pancreatic carcinoma cell line, secreted hyaluronidases abundantly and generated readily detectable levels of LMW-HAs ranging from ∼10- to 40-mers. This occurred in the absence of any exogenous stimulation. The tumor-derived HA oligosaccharides were able to enhance CD44 cleavage and tumor cell motility. Inhibition of the CD44-HA interaction resulted in the complete abrogation of these cellular events. These results are consistent with the concept that tumor cells generate HA oligosaccha-rides that bind to tumor cell CD44 through the expression of their own constitutive hyaluronidases. This enhances their own CD44 cleavage and cell motility, which would subsequently promote tumor progression. Such an autocrine/paracrine-like process may represent a novel activation mechanism that would facilitate and promote the malignant potential of tumor cells. Hyaluronan (HA), 2The abbreviations used are: HA, hyaluronan; LMW-HA, low molecular weight hyaluronan; pAb, polyclonal antibody; mAb, monoclonal antibody; HRP, horseradish peroxidase; HABP, hyaluronan-binding protein; M-sup/conc, concentrated MIA PaCa-2 culture supernatant; M-sup, MIA PaCa-2 culture supernatant; M-HA, MIA PaCa-2 cell-derived hyaluronan oligosaccharides; ELISA, enzyme-linked immunosorbent assay; PBS, phosphate-buffered saline; hyaluronidase SD, hyaluronidase from Streptococcus dysgalactiae. 2The abbreviations used are: HA, hyaluronan; LMW-HA, low molecular weight hyaluronan; pAb, polyclonal antibody; mAb, monoclonal antibody; HRP, horseradish peroxidase; HABP, hyaluronan-binding protein; M-sup/conc, concentrated MIA PaCa-2 culture supernatant; M-sup, MIA PaCa-2 culture supernatant; M-HA, MIA PaCa-2 cell-derived hyaluronan oligosaccharides; ELISA, enzyme-linked immunosorbent assay; PBS, phosphate-buffered saline; hyaluronidase SD, hyaluronidase from Streptococcus dysgalactiae. one of the major components of the extracellular matrix, is a high molecular weight linear glycosaminoglycan consisting of repeating disaccharide units of d-glucuronic acid and N-acetyl-d-glucosamine, whose molecular size can reach 107 kDa (1Laurent T.C. Fraser J.R. FASEB J. 1992; 6: 2397-2404Crossref PubMed Scopus (2041) Google Scholar, 2Toole B.P. Nat. Rev. Cancer. 2004; 4: 528-539Crossref PubMed Scopus (1603) Google Scholar). Despite its simple composition, HA possesses a number of functions. It influences the hydration and physical properties of tissues (1Laurent T.C. Fraser J.R. FASEB J. 1992; 6: 2397-2404Crossref PubMed Scopus (2041) Google Scholar, 3Toole B.P. J. Clin. Investig. 2000; 106: 335-336Crossref PubMed Scopus (136) Google Scholar), interacts with other extracellular matrix macromolecules such as aggrecan (4Kiani C. Chen L. Wu Y.J. Yee A.J. Yang B.B. Cell Res. 2002; 12: 19-32Crossref PubMed Scopus (452) Google Scholar) and versican (5LeBaron R.G. Zimmermann D.R. Ruoslahti E. J. Biol. Chem. 1992; 267: 10003-10010Abstract Full Text PDF PubMed Google Scholar), and interacts with cell-surface receptors, notably CD44 (6Aruffo A. Stamenkovic I. Melnick M. Underhill C.B. Seed B. Cell. 1990; 61: 1303-1313Abstract Full Text PDF PubMed Scopus (2123) Google Scholar). Through these functions, HA forms a pericellular coat around cells (2Toole B.P. Nat. Rev. Cancer. 2004; 4: 528-539Crossref PubMed Scopus (1603) Google Scholar, 7Toole B.P. Glycobiology. 2002; 12: 37R-42RCrossref PubMed Scopus (180) Google Scholar) and participates in physiological events such as cell adhesion, migration, and proliferation (8Toole B.P. J. Intern. Med. 1997; 242: 35-40Crossref PubMed Scopus (277) Google Scholar). It is also involved in pathological conditions, including cancer (7Toole B.P. Glycobiology. 2002; 12: 37R-42RCrossref PubMed Scopus (180) Google Scholar). An increased synthesis of HA has been reported in various malignant tumors such as breast and ovarian carcinomas, and predicts a poor prognosis (9Ropponen K. Tammi M. Parkkinen J. Eskelinen M. Tammi R. Lipponen P. Ågren U. Alhava E. Kosma V.M. Cancer Res. 1998; 58: 342-347PubMed Google Scholar, 10Auvinen P. Tammi R. Parkkinen J. Tammi M. Ågren U. Johansson R. Hirvikoski P. Eskelinen M. Kosma V.M. Am. J. Pathol. 2000; 156: 529-536Abstract Full Text Full Text PDF PubMed Scopus (409) Google Scholar). HA enhances tumor cell adhesion and migration (11Itano N. Atsumi F. Sawai T. Yamada Y. Miyaishi O. Senga T. Hamaguchi M. Kimata K. Proc. Natl. Acad. Sci. U. S. A. 2002; 99: 3609-3614Crossref PubMed Scopus (261) Google Scholar) and influences several signaling pathways, including some that promote tumor cell growth and survival, such as ErbB2, Ras, mitogen-activated protein kinase, and phosphatidylinositol 3-kinase/Akt (12Ghatak S. Misra S. Toole B.P. J. Biol. Chem. 2005; 280: 8875-8883Abstract Full Text Full Text PDF PubMed Scopus (199) Google Scholar, 13Sohara Y. Ishiguro N. Machida K. Kurata H. Thant A.A. Senga T. Matsuda S. Kimata K. Iwata H. Hamaguchi M. Mol. Biol. Cell. 2001; 12: 1859-1868Crossref PubMed Scopus (89) Google Scholar, 14Turley E.A. Noble P.W. Bourguignon L.Y. J. Biol. Chem. 2002; 277: 4589-4592Abstract Full Text Full Text PDF PubMed Scopus (853) Google Scholar). Hyaluronidases play critical roles in HA metabolism (15Stern R. Eur. J. Cell Biol. 2004; 83: 317-325Crossref PubMed Scopus (304) Google Scholar). Six human hyaluronidase-like sequences are present in the human genome. These are HYAL1, HYAL2, HYAL3, HYAL4, SPAM1, and PHYAL1, which, respectively, encode Hyal-1, Hyal-2, Hyal-3, Hyal-4, PH-20, and a pseudogene that is transcribed but not translated (16Csoka A.B. Frost G.I. Stern R. Matrix Biol. 2001; 20: 499-508Crossref PubMed Scopus (462) Google Scholar). Of these hyaluronidases, only Hyal-1 and Hyal-2 have been characterized well. Hyal-1 is an acid-active lysosomal enzyme that can utilize HA of any size as a substrate, generating predominantly tetrasaccharides (15Stern R. Eur. J. Cell Biol. 2004; 83: 317-325Crossref PubMed Scopus (304) Google Scholar). Hyal-2 is an acid-active enzyme anchored to the plasma membrane by a glycosylphosphatidylinositol link, and can digest high molecular mass HA to a limit product of ∼20 kDa, or about 50 disaccharide units (15Stern R. Eur. J. Cell Biol. 2004; 83: 317-325Crossref PubMed Scopus (304) Google Scholar). These two hyaluronidases appear to co-operate in HA degradation and both have been implicated in tumor invasion and metastasis. Hyal-1 is highly expressed in an active form in the tissue and urine specimens of patients with bladder (17Pham H.T. Block N.L. Lokeshwar V.B. Cancer Res. 1997; 57: 778-783PubMed Google Scholar) or prostate (18Lokeshwar V.B. Rubinowicz D. Schroeder G.L. Forgacs E. Minna J.D. Block N.L. Nadji M. Lokeshwar B.L. J. Biol. Chem. 2001; 276: 11922-11932Abstract Full Text Full Text PDF PubMed Scopus (250) Google Scholar) cancers. It is associated with the appearance of detectable levels of low molecular weight HAs (LMWHAs) (17Pham H.T. Block N.L. Lokeshwar V.B. Cancer Res. 1997; 57: 778-783PubMed Google Scholar, 19Lokeshwar V.B. Öbek C. Soloway M.S. Block N.L. Cancer Res. 1997; 57: 773-777PubMed Google Scholar); whereas Hyal-2 is expressed in mammary tumors (20Bertrand P. Girard N. Duval C. d'Anjou J. Chauzy C. B. J. Cancer. 1997; PubMed Scopus Google Scholar). that LMW-HAs have from high molecular and that HA of have T. T. M. 2004; Scopus Google Scholar). HA induce expression in cells J. U. T. P. J. 2000; PubMed Scopus Google Scholar) and promote their C. F. J. C. U. T. K. M. C. J. Med. 2002; PubMed Scopus Google Scholar), HA induce expression in cells M. C. Noble P.W. J. Clin. Investig. PubMed Scopus Google Scholar), and HA induce F. S. PubMed Scopus Google Scholar). LMW-HAs have been to play a in tumor levels of LMW-HAs have been in several human such as bladder V.B. Öbek C. Soloway M.S. Block N.L. Cancer Res. 1997; 57: 773-777PubMed Google Scholar) and prostate (17Pham H.T. Block N.L. Lokeshwar V.B. Cancer Res. 1997; 57: 778-783PubMed Google Scholar) tumor S. J. Cancer. PubMed Scopus Google Scholar), and T.C. Cancer. PubMed Scopus Google Scholar). HA tumor cell in the of cell to adhesion T. Y. K. S. K. Yamada S. U. T. S. Cancer Res. Google Scholar). HA enhance CD44 cleavage and promote the migration of tumor cells in a CD44-dependent T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar), in with the that can tumor cells the cell-surface CD44. CD44 is a that as one of the cell-surface HA (6Aruffo A. Stamenkovic I. Melnick M. Underhill C.B. Seed B. Cell. 1990; 61: 1303-1313Abstract Full Text PDF PubMed Scopus (2123) Google Scholar). CD44 participates in a number of biological such as tumor cell invasion and migration D. D. Cancer Res. 1997; PubMed Google Scholar). CD44 is the extracellular by such as M. Y. T. H. A. H. M. J. Cell Biol. 2001; PubMed Scopus Google Scholar), and O. D. D. B. P. T. M. M. H. J. Cell Biol. 2004; PubMed Scopus Google Scholar), by cleavage its that may to the of CD44 expression I. Y. D. T. N. T. A.J. H. J. Cell Biol. 2001; PubMed Scopus Google Scholar). CD44 cleavage has been reported in various human including breast cell and ovarian carcinoma I. H. D.R. M. A. M. Y. H. A.J. Am. J. Pathol. 2002; Full Text Full Text PDF PubMed Scopus (136) Google Scholar), that cleavage an in tumor progression. these we that tumor cells may generate LMW-HAs of a certain size and that the LMW-HAs may in the tumor cells by with CD44. Here, we that LMW-HAs ranging from ∼10- to are generated by the of hyaluronidases in a human pancreatic carcinoma cell line, MIA PaCa-2, and that the generated LMW-HAs the cells by CD44 cleavage and cell in a CD44-dependent manner. results an process that a novel activation mechanism that to the and of the malignant properties of tumor cells. polyclonal pAb, which is the of CD44 by of and of I. Y. H. J. M. M. M. M. M. H. PubMed Scopus Google Scholar). An CD44 monoclonal from the and the of as previously T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). An and were from and and were from HA oligosaccharides and HA were by A. T. Y. A. Y. A. Glycobiology. 2002; 12: PubMed Scopus Google Scholar). HA, consisting of HA, from hyaluronidases and were generated by one of L.Y. F. Stern R. E. J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar). hyaluronidase and hyaluronidase from Streptococcus were from and from the Cell human pancreatic carcinoma cell MIA PaCa-2 T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar) from the Cell of and The cells were in with 50 and in an of MIA PaCa-2 PaCa-2 cells were in a and with the cells were in the The culture and by The used in the of hyaluronidase activities and the of hyaluronidase concentrated through a and the used in other not concentrated but through a the of and from MIA PaCa-2 cells by and transcribed an and and by of and by a The and were by and by the or in the absence of in the of levels present in the were an (17Pham H.T. Block N.L. Lokeshwar V.B. Cancer Res. 1997; 57: 778-783PubMed Google Scholar, M. Stern R. 1992; 12: PubMed Scopus Google Scholar, V.B. Öbek C. H.T. D. Soloway M.S. Block N.L. J. 2000; PubMed Scopus Google Scholar). The in a were with The were with various of hyaluronidase in the culture of tumor cells in hyaluronidase ranging from to with the were with protein The to the an by the the of the HA that not by the hyaluronidases, and the hyaluronidase activities in were some the were or with of to the of and PaCa-2 cells were cells and with 50 and from of cells were by a under conditions, and to a some of or of cell The in and with pAb, pAb, or The were with to the and or with to the The were detected of HA HA in the tumor cell culture and their were by an that is a V.B. Öbek C. H.T. D. Soloway M.S. Block N.L. J. 2000; PubMed Scopus Google Scholar, A.J. 1990; PubMed Scopus Google Scholar). The HA present in the with HA the to bind V.B. Öbek C. H.T. D. Soloway M.S. Block N.L. J. 2000; PubMed Scopus Google Scholar, A.J. 1990; PubMed Scopus Google Scholar). with HA were with of the culture of tumor the of the culture or HA and the were in The to the an by the the of HA, and the HA in and of MIA HA of the HA present in the tumor cell culture were by in which the of the HA were by the with HA, HA and HA The tumor cell culture were to a with The in and were the were HA by as HA oligosaccharides ranging from ∼10- to were and as MIA HA oligosaccharides HA in the of the tumor cell culture were with units of hyaluronidase and through a The were PBS, and HA by as some hyaluronidase by CD44 CD44 cleavage as reported previously T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). MIA PaCa-2 cells cells were and with to the cleavage of the CD44 I. Y. D. T. N. T. A.J. H. J. Cell Biol. 2001; PubMed Scopus Google Scholar). The cells were with various in the of The cells were with and from of cells were by an under and to a The in and with or with The with to the pAb, or with to the The were detected as reported previously T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). migration with a size T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). of the were with MIA PaCa-2 cells were to the and were that the cells to the The cells were with or or to and the migration various HA were to the of the a of 50 The were subsequently the cells the of the were the were in with and and that to the lower of the were under a The number of cells in and the MIA PaCa-2 Hyaluronidases and the have previously reported that HA oligosaccharides of a certain size range CD44 cleavage in pancreatic carcinoma cell line, MIA PaCa-2 T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). the MIA PaCa-2 cells show CD44 cleavage in the absence of any exogenous a readily detectable we the that these tumor cells may generate CD44 HA oligosaccharides by in the MIA PaCa-2 culture to which HA in a highly with the of These activities were by of the culture and by a hyaluronidase in with the that MIA PaCa-2 cells hyaluronidases. The of activities in the culture also by a not as in MIA PaCa-2 cells expressed two of the hyaluronidases, Hyal-1 Stern M. M. Stern R. PubMed Scopus Google Scholar) and Hyal-2 B. J. Biol. Chem. 1998; Full Text Full Text PDF PubMed Scopus Google Scholar), both the and protein levels and secreted both of these the culture with Hyal-1 and Hyal-2 expression were detected in a human prostate cancer cell line, (17Pham H.T. Block N.L. Lokeshwar V.B. Cancer Res. 1997; 57: 778-783PubMed Google Scholar) and in a human breast cancer cell line, L.Y. F. Stern R. E. J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar), respectively, both and protein levels not PaCa-2 cells hyaluronidases and the culture The expression levels of Hyal-1 and Hyal-2 were by and that both Hyal-1 and Hyal-2 were expressed the and the protein and M-sup/conc, in MIA PaCa-2 MIA PaCa-2 HA cells an of HA (9Ropponen K. Tammi M. Parkkinen J. Eskelinen M. Tammi R. Lipponen P. Ågren U. Alhava E. Kosma V.M. Cancer Res. 1998; 58: 342-347PubMed Google Scholar, 10Auvinen P. Tammi R. Parkkinen J. Tammi M. Ågren U. Johansson R. Hirvikoski P. Eskelinen M. Kosma V.M. Am. J. Pathol. 2000; 156: 529-536Abstract Full Text Full Text PDF PubMed Scopus (409) Google Scholar), and MIA PaCa-2 cells were in we high levels of HA in the MIA PaCa-2 culture We the size of the HA in the MIA PaCa-2 culture by in which the HA were by the with of HA HA, HA and HA in MIA PaCa-2 cells generated HA oligosaccharides ranging from ∼10- to which were in size to that have been to enhance CD44 cleavage in tumor cells T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). These results are consistent with the that MIA PaCa-2 cells HA by hyaluronidases and that the HA oligosaccharides that are generated have the to enhance CD44 cleavage and tumor cell T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). other pancreatic tumor cell we and also expressed levels of LMW-HAs not MIA PaCa-2 HA CD44 and Cell of the MIA PaCa-2 MIA PaCa-2 cells generate that can enhance CD44 cleavage in MIA PaCa-2 cells. in the of MIA PaCa-2 culture the of CD44 cleavage in MIA PaCa-2 as by an in the cleavage product in cleavage by the of the monoclonal T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, M. K. R. K. J. 2001; PubMed Scopus Google Scholar), that the CD44 cleavage of the interaction CD44 and its as in the of the MIA PaCa-2 culture and in MIA PaCa-2 cells to a with that by the of HA T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar). These which increased cell motility, were by the of that were also by the interaction of cell-surface CD44 and its as in the MIA PaCa-2 culture also the migration of MIA PaCa-2 cells in a migration assay; migration by the monoclonal but not by that the tumor cell also the CD44-HA The results that the and the increased cell were but not not the CD44 of these these results the that the HA oligosaccha-rides by the MIA PaCa-2 cells can CD44 cleavage and cell in the MIA PaCa-2 cells. We the HA oligosaccharides from the MIA PaCa-2 culture enhance CD44 in the MIA HA oligosaccharides the of CD44 cleavage in MIA PaCa-2 cells in a manner. The by the of T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar, M. K. R. K. J. 2001; PubMed Scopus Google Scholar) that the cleavage by the interaction CD44 and the HA by the hyaluronidase from S. and the MIA HA oligosaccharides their to enhance CD44 whereas the with hyaluronidase not and as in the MIA HA oligosaccharides the in the cell and of MIA PaCa-2 cells as by the of MIA culture the tumor cell-derived HA oligosaccharides and and tumor cell migration in were with HA and and as these in cell and were by and that were the interaction CD44 and The tumor-derived HA not appear to cell proliferation in not these results that the MIA PaCa-2 cells generate HA oligosaccharides that can enhance CD44 cleavage and tumor cell the of that the tumor cells also PaCa-2 cell-derived HA oligosaccharides promote tumor cell migration in MIA PaCa-2 cells. The of the and cell migration of MIA PaCa-2 cells were by and a migration as in the to and respectively, that 50 used of we a novel activation mechanism tumor cells. We that human pancreatic carcinoma MIA PaCa-2 cells active hyaluronidases and HA oligosaccharides of and that the tumor-derived HA oligosaccharides enhance CD44 cleavage and tumor cell interaction with CD44 tumor cells appear to generate HA oligosaccharides that bind to their own tumor cell CD44 by hyaluronidases This in enhances their own CD44 cleavage and cell that subsequently tumor and Six human hyaluronidase have been and of are translated hyaluronidase (16Csoka A.B. Frost G.I. Stern R. Matrix Biol. 2001; 20: 499-508Crossref PubMed Scopus (462) Google Scholar). Hyal-1 and Hyal-2 as the major hyaluronidases HA degradation in tissues (15Stern R. Eur. J. Cell Biol. 2004; 83: 317-325Crossref PubMed Scopus (304) Google Scholar). Hyal-1 and Hyal-2 are reported to be involved in tumor progression. Hyal-1 is detected in bladder cancer (17Pham H.T. Block N.L. Lokeshwar V.B. Cancer Res. 1997; 57: 778-783PubMed Google Scholar) and prostate cancer whereas the Hyal-2 expression is increased in breast tumor (20Bertrand P. Girard N. Duval C. d'Anjou J. Chauzy C. B. J. Cancer. 1997; PubMed Scopus Google Scholar), and the of Hyal-2 tumor in cells U. Cancer Res. Google Scholar). the present we that both Hyal-1 and Hyal-2 were secreted by MIA PaCa-2 tumor cells and of the hyaluronidase activities resulted in complete abrogation of the activities of the culture These that degradation a major in HA in MIA PaCa-2 cells. such as by P.W. Matrix Biol. 2002; PubMed Scopus Google Scholar) or the synthesis of low molecular mass HA N. Sawai T. M. P. Yamada Y. M. T. Hamaguchi M. Y. Y. S. Kimata K. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar), may play only a in MIA PaCa-2 cells. that the HA oligosaccharides detected in the culture from to Hyal-1 or hyaluronidase (18Lokeshwar V.B. Rubinowicz D. Schroeder G.L. Forgacs E. Minna J.D. Block N.L. Nadji M. Lokeshwar B.L. J. Biol. Chem. 2001; 276: 11922-11932Abstract Full Text Full Text PDF PubMed Scopus (250) Google Scholar) may be the enzyme involved in HA degradation in these tumor the of the hyaluronidases to the of hyaluronidase we the that the HA oligosaccharides by the tumor cells hyaluronidase expression by the cell-surface HA Although we that the exogenous of HA oligosaccharides in hyaluronidase expression levels in the tumor cells not the expression high that to a or It the tumor-derived HA oligosaccharides to the of the hyaluronidase expression in MIA PaCa-2 cells. Hyaluronidases are acid-active It reported that in breast tumor the interaction which an extracellular matrix to Hyal-2 and activation L.Y. F. Stern R. E. J. Biol. Chem. 2004; Full Text Full Text PDF PubMed Scopus Google Scholar). It is to that such a mechanism also in MIA PaCa-2 an hyaluronidases can the cells to generate HA oligosaccharides molecular weight HA oligosaccharides induce various biological activities T. T. M. 2004; Scopus Google Scholar). HA enhance the expression of and in tumor cells C. P. R. C. M. P. P. J. Cell Sci. 2004; PubMed Scopus Google Scholar), HA induce in the membrane F. S. PubMed Scopus Google Scholar), and HA expression in human cells K. Y. S. Y. J. 2001; PubMed Scopus Google Scholar) and in human cancer cells T. Y. K. S. K. Yamada S. U. T. S. Cancer Res. Google Scholar). An HA the in growth of human carcinoma cells S. Misra S. Toole B.P. J. Biol. Chem. 2002; 277: Full Text Full Text PDF PubMed Scopus Google Scholar) and the in growth of C. Toole B.P. Stamenkovic I. J. Cancer. 1998; PubMed Scopus Google Scholar), mammary carcinoma S. Misra S. Toole B.P. J. Biol. Chem. 2002; 277: Full Text Full Text PDF PubMed Scopus Google Scholar), and human carcinoma S. Misra S. Toole B.P. J. Biol. Chem. 2002; 277: Full Text Full Text PDF PubMed Scopus Google Scholar). We of the tumor-derived HA oligosaccharides MIA PaCa-2 cells. The results that the tumor-derived HA oligosaccharides CD44 cleavage and cell in MIA PaCa-2 and these activities were by a not These results the of an activation mechanism in which tumor cells generate HA oligosaccharides by hyaluronidases, and the HA degradation bind to tumor cell CD44 to enhance the CD44 cleavage and of the tumor cells. This would subsequently promote tumor and tumor cell of the CD44-HA interaction resulted in complete abrogation of the increased CD44 cell motility, and These results are consistent with the concept that the CD44-HA interaction an in the of tumor cell and invasion (2Toole B.P. Nat. Rev. Cancer. 2004; 4: 528-539Crossref PubMed Scopus (1603) Google Scholar) and may be to that the tumor-derived HA interaction an autocrine/paracrine-like mechanism in the of cell and tumor cells may their own activities through the of hyaluronidases, and HA The of CD44 that results from CD44 cleavage has been reported to with tumor in patients with and Y.J. D. Wu M. J. M.S. Cancer Res. Google Scholar). CD44 cleavage reported in tumors such as breast cell and ovarian carcinoma I. H. D.R. M. A. M. Y. H. A.J. Am. J. Pathol. 2002; Full Text Full Text PDF PubMed Scopus (136) Google Scholar). that CD44 such as I. Y. M. M. K. M. H. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar) and HA oligosaccharides T. H. H. H. M. J. Biol. Chem. Full Text Full Text PDF PubMed Scopus Google Scholar), promote tumor cell the proteolytic cleavage of CD44 has been implicated in tumor progression. The of CD44 cleavage by tumor cell such as HA oligosaccharides would the tumor cells with in the process of invasion and metastasis. a mechanism consisting of high hyaluronidase constitutive of HA CD44 and the of tumor and invasion may represent a novel activation mechanism in tumor which would to the and of their own malignant HA oligosaccharides show by to CD44 and HA of not only tumor cells but also the cells (2Toole B.P. Nat. Rev. Cancer. 2004; 4: 528-539Crossref PubMed Scopus (1603) Google Scholar), of their and may novel the of We and the and the We also with in and and with and We and critical of and Ruoslahti