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Basal Cell Adhesion Molecule (BCAM) Promotes Mesothelial-to-mesenchymal Transition and Tumor Angiogenesis Through Paracrine Signaling

Abstract

Background: High expression of basal cell adhesion molecule (BCAM) is a hallmark of ovarian cancer (OC) progression. BCAM facilitates transcoelomic dissemination by promoting mesothelial cell clearance at peritoneal attachment sites of tumor cell spheroids. We investigated how BCAM mediates this effect and potentially drives other pro-metastatic functions.

Methods: The impact of BCAM on the tumor cell secretome and the mesothelial cell phenotype was analyzed by affinity proteomics, bulk and single-cell RNA sequencing, life-cell and multiphoton microscopy, biochemical and functional in vitro assays as well as a murine tumor model. BCAM manipulation involved ectopic overexpression, inducible expression and treatment with soluble BCAM.

Results: All forms of BCAM enhanced the secretion of cytokines that impact cell motility, mesenchymal differentiation and angiogenesis, including AREG, CXCL family members, FGF2, TGFB2, and VEGF. Notably, their levels in OC ascites were correlated with BCAM expression, and recombinant BCAM-induced cytokines triggered mesothelial-mesenchymal transition (MMT). Mesothelial cells undergoing MMT exhibited enhanced motility away from attaching tumor spheroids, leading to mesothelial clearance at spheroid attachment sites. BCAM-mediated MMT-associated transcriptional changes were also observed in subpopulations of omental mesothelial cells from OC patients, and were associated with poor survival. Consistent with the secretome data, BCAM induced endothelial tube formation in vitro and markedly promoted tumor angiogenesis in a mouse model.

Conclusion: We have identified previously unknown functions of the BCAM-induced secretome potentially impacting distinct stages of OC metastasis. While BCAM's impact on MMT may facilitate initiation of micrometastases, neo-angiogenesis is essential for tumor growth. Taken together with the observed clinical adverse association, our findings underscore the potential of BCAM as a therapeutic target.

References
1.
Eyler C, Telen M . The Lutheran glycoprotein: a multifunctional adhesion receptor. Transfusion. 2006; 46(4):668-77. DOI: 10.1111/j.1537-2995.2006.00779.x. View

2.
Finkernagel F, Reinartz S, Schuldner M, Malz A, Jansen J, Wagner U . Dual-platform affinity proteomics identifies links between the recurrence of ovarian carcinoma and proteins released into the tumor microenvironment. Theranostics. 2019; 9(22):6601-6617. PMC: 6771240. DOI: 10.7150/thno.37549. View

3.
Rahuel C, Le Van Kim C, Mattei M, Cartron J, Colin Y . A unique gene encodes spliceoforms of the B-cell adhesion molecule cell surface glycoprotein of epithelial cancer and of the Lutheran blood group glycoprotein. Blood. 1996; 88(5):1865-72. View

4.
Niiya D, Egawa N, Sakamoto T, Kikkawa Y, Shinkawa T, Isobe T . Identification and characterization of Lutheran blood group glycoprotein as a new substrate of membrane-type 1 matrix metalloproteinase 1 (MT1-MMP): a systemic whole cell analysis of MT1-MMP-associating proteins in A431 cells. J Biol Chem. 2009; 284(40):27360-9. PMC: 2785664. DOI: 10.1074/jbc.M109.029124. View

5.
Sivakumar S, Lieber S, Librizzi D, Keber C, Sommerfeld L, Finkernagel F . Basal cell adhesion molecule promotes metastasis-associated processes in ovarian cancer. Clin Transl Med. 2023; 13(1):e1176. PMC: 9842900. DOI: 10.1002/ctm2.1176. View