Effects of Alpha-Connexin Carboxyl-Terminal Peptide (aCT1) and Bowman-Birk Protease Inhibitor (BBI) on Canine Oral Mucosal Melanoma (OMM) Cells

Frontiers in Veterinary Science

Elizabeth Shinmay Yeh¹  Ayami Sato²  Tomohiro Yano²  Ivone Izabel Mackowiak da Fonseca³  Maria Lucia Zaidan Dagli³  Gabriela Fernandes de Toledo³  Francisco Javier Hernandez-Blazquez³  Márcia Kazumi Nagamine³  Rennan Olio³ 

[1] Department of Pharmacology and Toxicology, Simon Comprehensive Cancer Center, School of Medicine, Indiana University, Indianapolis, IN, United States;Institute of Life Innovation Studies, Toyo University, Tokyo, Japan;School of Veterinary Medicine and Animal Science of the University of São Paulo, São Paulo, Brazil;

关键词: melanoma;    connexin;    peptide;    viability;    aCT1;    Bowman-Birk inhibitor;   

DOI  :  10.3389/fvets.2021.670451

来源: DOAJ

【 摘 要 】

Oral mucosal melanomas (OMM) are aggressive cancers in dogs, and are good models for human OMM. Gap junctions are composed of connexin units, which may have altered expression patterns and/or subcellular localization in cancer cells. Cell-to-cell communication by gap junctions is often impaired in cancer cells, including in melanomas. Meanwhile, the upregulated expression of the gap junction protein connexin 43 (Cx43) inhibits melanoma progression. The α-connexin carboxyl-terminal (aCT1) peptide reportedly maintains Cx43 expression and cell-cell communication in human mammary cells and increases the communication activity through gap junctions in functional assays, therefore causing decreased cell proliferation. The Bowman-Birk protease inhibitor (BBI), a component of soybeans, induces Cx43 expression in several tumor cells as a trypsin–chymotrypsin inhibition function, with antineoplastic effects. This study investigated the effect of aCT1 peptide and BBI treatment, alone or in combination, on TLM1 canine melanoma cell viability. Cell viability after treatment with aCT1, the reverse sequence peptide (R-pep), and/or BBI for 5 days was analyzed by PrestoBlue assay. Immunofluorescence was used to observe Cx43 localization and expression. aCT1 (200 μM) alone did not significantly decrease cell viability in TLM1 cells, whereas BBI (400 μg/ml) alone significantly decreased the TLM1 viability. Combined treatment with both aCT1 (200 μM) and BBI (400 μg/ml) significantly decreased cell viability in TLM1 cells. Cx43 expression, as identified by immunostainings in TLM1 cells, was increased in the cell membrane after the combination treatment with BBI and aCT1. This dual treatment can be combined to achieve the anticancer activity, possibly by increasing Cx 43 expression and affecting Cx43 migration to the cell membrane. In conclusion, a treatment strategy targeting Cx43 with BBI and aCT1 may possibly lead to new effective therapies for canine OMM.

【 授权许可】

Unknown