TITLE:
Uptake of Cystatin by Melanoma Cells in Culture
AUTHORS:
Lauren Deady, James L. Cox
KEYWORDS:
Cystatin; Melanoma; Endocytosis; Fluorescent
JOURNAL NAME:
CellBio,
Vol.2 No.2,
June
5,
2013
ABSTRACT: The cystatins are a super family of cysteine
protease inhibitors which are ubiquitous in their biologic occurrence. Cystatin C, a
type II cystatin, is primarily a secreted protein found in most biological
fluids. Besides acting as inhibitors of cathepsin, the cystatins have been
found to have some non-inhibitor related functions and multiple physiological
roles. Much interest has been generated for the cystatins as metastasis “suppressor-like” proteins,
as they have been shown to inhibit metastasis for multiple cancer types. The
sites and actions of the cystatins related to tumor suppressor actions are
still unclear, however. In this work, we have examined the uptake of cystatin by
metastatic melanoma cells in culture. Our results indicate cystatin uptake is
mediated by a non-canonical endocytotic pathway in B16 murine melanoma
cells.