Metastasis-associated C4.4A, a GPI-anchored protein cleaved by ADAM10 and ADAM17

Area of Science:

• Biochemistry
• Molecular Biology
• Oncology

Background:

• Metalloproteases, including ADAM, ADAMTS, and matrix metalloproteases (MMPs), exhibit diverse roles in tumor progression, with some promoting and others inhibiting cancer development.
• Understanding the substrate repertoire (degradome) of specific metalloproteases is crucial for predicting the impact of their inhibition on tumor growth.

Purpose of the Study:

• To identify novel substrates of ADAM10 and ADAM17 using proteomic approaches.
• To investigate the role of identified substrates in tumor progression, specifically in the context of breast cancer.

Main Methods:

• Utilized Stable Isotope Labeling by Amino acids in Cell culture (SILAC) for differential metabolic labeling of MCF7 breast cancer cells.
• Employed short hairpin RNAs (shRNAs) to knockdown the expression of ADAM10 and ADAM17 in MCF7 cells.
• Applied proteomic analysis to identify proteins differentially expressed or processed upon metalloprotease knockdown.

Main Results:

• Identified C4.4A as a novel substrate cleaved by both ADAM10 and ADAM17.
• Demonstrated that C4.4A cleavage by these metalloproteases occurs in MCF7 breast cancer cells.
• Provided evidence linking C4.4A cleavage to processes involved in tumor invasion and progression.

Conclusions:

• ADAM10 and ADAM17 cleave C4.4A, a protein implicated in tumor invasion.
• The cleavage of C4.4A by ADAM10 and ADAM17 contributes to the progression of mammary tumors.
• Targeting ADAM10 and ADAM17 may represent a therapeutic strategy for inhibiting tumor progression by preventing C4.4A cleavage.