PMID- 8316334
OWN - NLM
STAT- MEDLINE
DCOM- 19930728
LR  - 20190920
IS  - 0305-1846 (Print)
IS  - 0305-1846 (Linking)
VI  - 19
IP  - 2
DP  - 1993 Apr
TI  - Secretion of cathepsin B by human gliomas in vitro.
PG  - 146-51
AB  - There is evidence from investigations of non-CNS neoplasms that secreted 
      proteolytic enzymes may facilitate tumour invasion by partially degrading 
      extracellular matrix (ECM). Among the enzymes which may be involved are members 
      of the cysteine proteinase superfamily and especially cathepsin B (CB). In the 
      present investigation we have studied CB in human gliomas in vitro, concentrating 
      particularly on CB secretion, as extracellular enzyme is of prime importance in 
      this context. We have found that CB is secreted by gliomas in vitro as a latent 
      zymogen, requiring activation. This has been confirmed by gel chromatography 
      which indicated that CB is secreted as a 42 kDa proenzyme which may be 
      proteolytically processed to an enzymatically active 29 kDa molecule. The 
      inactive, high molecular weight, latent CB is stable at extracellular pH in 
      contrast to the activated low molecular weight form which rapidly loses activity 
      at this pH. We have also measured secretion of cysteine proteinase inhibitors 
      (CPI), as their presence would have a direct influence on the effective activity 
      of CB, and found that all of the gliomas secreted significant amounts of a CPI as 
      assessed by papain inhibition. Our experiments suggest that a number of factors 
      are involved in the regulation of extracellular glioma-derived CB activity. These 
      include: rate of secretion of pro-CB, rate of CB activation, destabilization of 
      CB at neutral pH and the presence of cysteine proteinase inhibitors.
FAU - McCormick, D
AU  - McCormick D
AD  - Neuropathology Laboratory, Queen's University of Belfast.
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - England
TA  - Neuropathol Appl Neurobiol
JT  - Neuropathology and applied neurobiology
JID - 7609829
RN  - 0 (Cysteine Proteinase Inhibitors)
RN  - EC 3.4.22.1 (Cathepsin B)
RN  - EC 3.4.22.2 (Papain)
SB  - IM
MH  - Brain Neoplasms/*enzymology
MH  - Cathepsin B/*metabolism
MH  - Cysteine Proteinase Inhibitors/metabolism
MH  - Extracellular Matrix/enzymology
MH  - Glioma/*enzymology
MH  - Humans
MH  - Hydrogen-Ion Concentration
MH  - Molecular Weight
MH  - Papain/metabolism
MH  - Tumor Cells, Cultured
EDAT- 1993/04/01 00:00
MHDA- 1993/04/01 00:01
CRDT- 1993/04/01 00:00
PHST- 1993/04/01 00:00 [pubmed]
PHST- 1993/04/01 00:01 [medline]
PHST- 1993/04/01 00:00 [entrez]
AID - 10.1111/j.1365-2990.1993.tb00420.x [doi]
PST - ppublish
SO  - Neuropathol Appl Neurobiol. 1993 Apr;19(2):146-51. doi: 
      10.1111/j.1365-2990.1993.tb00420.x.