title: Fragmented hyaluronan is an autocrine chemokinetic motility factor supported by the HAS2-HYAL2/CD44 system on the plasma membrane.
abstract: Hyaluronan (HA) is synthesized by HA synthase (HAS) 1, HAS2 and HAS3, and degraded by hyaluronidase (HYAL) 1 and HYAL2 in a CD44-dependent manner. HA and HYALs are intricately involved in tumor growth and metastasis. Random cell movement is generally described as chemokinesis, and represents an important step at the beginning of tumor cell liberation from the primary site. To investigate the roles of HAS2 and HYAL2/CD44 in cell motility, we examined HeLa-S3 cells showing spontaneous chemokinesis. HeLa-S3 cells expressed HAS2 and HAS3. siRNA-mediated knockdown of HAS2 decreased spontaneous chemokinesis of HeLa-S3 cells. Although HeLa-S3 cells secreted 50 ng/ml of high molecular weight (HMW)-HA (peak: 990 kDa) into the culture supernatant after 6 h of culture, exogenously added HMW-HA did not enhance spontaneous chemokinesis of the cells. These observations suggested that HeLa-S3 cells may have a self-degrading system for HA to regulate their spontaneous chemokinesis. To examine this possibility, we investigated the effects of siRNA-mediated knockdown of HYAL2 or CD44 on the spontaneous chemokinesis of HeLa-S3 cells. Knockdown of either molecule decreased the spontaneous chemokinesis of the cells. Low molecular weight (LMW)-HA (23 kDa) reversed the HYAL2 siRNA-mediated reduction in spontaneous chemokinesis of HeLa-S3 cells to the level in control cells stimulated with the same HA. These findings indicate that the HAS2-HYAL2/CD44 system may support spontaneous chemokinesis of human cancer cells through self-degradation of HMW-HA to produce LMW-HA by an autocrine mechanism. Consequently, our study may further expand our understanding of HA functions in cancer.
authors: Department of Molecular and Tumor Pathology, Graduate School of Medicine, Chiba University, 1-8-1 Inohana, Chuo-ku, Chiba 260-8670, Japan.
authors: Teruyoshi
authors: T
authors: Saito
authors: Hidetada
authors: H
authors: Kawana
authors: Kazuhiko
authors: K
authors: Azuma
authors: Akihiro
authors: A
authors: Toyoda
authors: Hiroshi
authors: H
authors: Fujita
authors: Motoo
authors: M
authors: Kitagawa
authors: Kenichi
authors: K
authors: Harigaya
mesh_terms: D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002462:Cell Membrane / Q000378:metabolism*; D002465:Cell Movement / Q000187:drug effects; D049109:Cell Proliferation; D058851:GPI-Linked Proteins / Q000235:genetics / Q000378:metabolism; D055785:Gene Knockdown Techniques; D014453:Glucuronosyltransferase / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D018960:Hyaluronan Receptors / Q000235:genetics / Q000378:metabolism*; D000076002:Hyaluronan Synthases; D006820:Hyaluronic Acid / Q000378:metabolism* / Q000494:pharmacology; D006821:Hyaluronoglucosaminidase / Q000235:genetics / Q000378:metabolism*; D008970:Molecular Weight
chemical_list: D015815:Cell Adhesion Molecules; D058851:GPI-Linked Proteins; D018960:Hyaluronan Receptors; D006820:Hyaluronic Acid; D014453:Glucuronosyltransferase; C101754:HAS2 protein, human; D000076002:Hyaluronan Synthases; C473096:Hyal2 protein, human; D006821:Hyaluronoglucosaminidase