HPP1 Ectodomain Shedding is Mediated by ADAM17 and is Necessary for Tumor Suppression in Colon Cancer.
Colorectal cancer
EGF-like ligand
Ectodomain shedding
TMEFF2
Journal
The Journal of surgical research
ISSN: 1095-8673
Titre abrégé: J Surg Res
Pays: United States
ID NLM: 0376340
Informations de publication
Date de publication:
10 2020
10 2020
Historique:
received:
07
10
2019
revised:
10
04
2020
accepted:
15
04
2020
pubmed:
26
5
2020
medline:
3
11
2020
entrez:
26
5
2020
Statut:
ppublish
Résumé
Hyperplastic polyposis protein 1 (HPP1) encodes a tumor-suppressive transmembrane cleavable epidermal growth factor-like ligand. It is unclear as to whether cleavage and shedding of HPP1 are essential steps in achieving its tumor suppressive properties. ADAM proteins are key players in cellular ectodomain shedding processes with ADAM17 being well characterized and representing the most likely sheddase for HPP1. In this study, we explore the mechanisms and importance of ectodomain shedding in contributing to HPP1-mediated tumor suppression. Baseline characterization of HPP1 ectodomain shedding and ADAM family member expression was performed in HCT116 colon cancer cells with forced overexpression of HPP1 and controls. Subsequent impact of attenuation of ADAM expression by short interfering RNA on HPP1 shedding was evaluated. Furthermore, we examined the functional impact of an uncleavable HPP1 mutant construct (HPP1-Δstalk) generated by site-directed mutagenesis. Cellular growth potential functions were analyzed by MTT and soft agar assays. Select proinflammatory cytokines enhanced HPP1 ectodomain shedding, whereas short interfering RNA-mediated knockdown of ADAM17 resulted in abrogation of HPP1 ectodomain shedding. ADAM17 knockdown concomitantly resulted in increased cell proliferation and anchorage-independent growth. HPP1-Δstalk-transfected cells exhibited significantly higher proliferation and reduced STAT1 activation relative to full-length HPP1, further suggesting a critical role for ectodomain shedding in HPP1-mediated tumor suppression. The tumor-suppressive properties of HPP1 in colorectal cancer require cleavage and shedding of its ectodomain which in turn are mediated by ADAM17. Further investigations into the regulation of HPP1 may lead to a greater understanding of epidermal growth factor-like ligand family biology and potential novel therapeutic strategies.
Sections du résumé
BACKGROUND
Hyperplastic polyposis protein 1 (HPP1) encodes a tumor-suppressive transmembrane cleavable epidermal growth factor-like ligand. It is unclear as to whether cleavage and shedding of HPP1 are essential steps in achieving its tumor suppressive properties. ADAM proteins are key players in cellular ectodomain shedding processes with ADAM17 being well characterized and representing the most likely sheddase for HPP1. In this study, we explore the mechanisms and importance of ectodomain shedding in contributing to HPP1-mediated tumor suppression.
METHODS
Baseline characterization of HPP1 ectodomain shedding and ADAM family member expression was performed in HCT116 colon cancer cells with forced overexpression of HPP1 and controls. Subsequent impact of attenuation of ADAM expression by short interfering RNA on HPP1 shedding was evaluated. Furthermore, we examined the functional impact of an uncleavable HPP1 mutant construct (HPP1-Δstalk) generated by site-directed mutagenesis. Cellular growth potential functions were analyzed by MTT and soft agar assays.
RESULTS
Select proinflammatory cytokines enhanced HPP1 ectodomain shedding, whereas short interfering RNA-mediated knockdown of ADAM17 resulted in abrogation of HPP1 ectodomain shedding. ADAM17 knockdown concomitantly resulted in increased cell proliferation and anchorage-independent growth. HPP1-Δstalk-transfected cells exhibited significantly higher proliferation and reduced STAT1 activation relative to full-length HPP1, further suggesting a critical role for ectodomain shedding in HPP1-mediated tumor suppression.
CONCLUSION
The tumor-suppressive properties of HPP1 in colorectal cancer require cleavage and shedding of its ectodomain which in turn are mediated by ADAM17. Further investigations into the regulation of HPP1 may lead to a greater understanding of epidermal growth factor-like ligand family biology and potential novel therapeutic strategies.
Identifiants
pubmed: 32450419
pii: S0022-4804(20)30230-4
doi: 10.1016/j.jss.2020.04.010
pmc: PMC7483406
mid: NIHMS1588582
pii:
doi:
Substances chimiques
Membrane Proteins
0
Neoplasm Proteins
0
STAT Transcription Factors
0
TMEFF2 protein, human
0
Tumor Suppressor Proteins
0
ADAM17 Protein
EC 3.4.24.86
ADAM17 protein, human
EC 3.4.24.86
Types de publication
Journal Article
Research Support, N.I.H., Extramural
Langues
eng
Sous-ensembles de citation
IM
Pagination
183-190Subventions
Organisme : NCI NIH HHS
ID : R01 CA131398
Pays : United States
Informations de copyright
Published by Elsevier Inc.