Inducible macropinocytosis of hyaluronan in B16-F10 melanoma cells.

Publication/Presentation Date

7-1-2010

Abstract

Hyaluronan (HA) is a glycosaminoglycan composed of N-acetylglucosamine and glucuronic acid subunits. Endocytosis is thought to play an essential role in the catabolism of HA due to the intracellular compartmentalization of the HA degrading hyaluronidase enzymes. Previous investigations have shown that keratinocytes, chondrocytes and breast tumor cell lines endocytose HA via the cell surface glycoprotein, CD44. However, other cell types endocytose HA using a CD44-independent mechanism that remains to be defined. The purpose of this study was to investigate HA endocytosis in B16-F10 melanoma cells. We found that B16-F10 melanoma cells expressed CD44 on their surfaces. Unexpectedly, CD44 did not play a role in the endocytosis of HA. Electron microscopy studies revealed that B16-F10 melanoma cells exhibited membrane ruffling, a characteristic feature of macropinocytosis, only after incubating the cells with the HA co-polymer. Moreover, B16-F10 melanoma cells endocytosed HA via macropinocytosis as assessed by drug inhibition studies and the co-localization of fluorescently labeled HA with fluorescent tracers under confocal microscopy. Based on these results, we conclude that induced macropinocytosis may provide a previously unrecognized avenue for HA endocytosis in some cell types.

Volume

29

Issue

6

First Page

503

Last Page

510

ISSN

1569-1802

Disciplines

Medicine and Health Sciences

PubMedID

20600893

Department(s)

Department of Medicine

Document Type

Article

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