Type VII collagen regulates expression of OATP1B3, promotes front-to-rear polarity and increases structural organisation in 3D spheroid cultures of RDEB tumour keratinocytes

J Cell Sci. 2014 Feb 15;127(Pt 4):740-51. doi: 10.1242/jcs.128454. Epub 2013 Dec 19.

Abstract

Type VII collagen is the main component of anchoring fibrils, structures that are integral to basement membrane homeostasis in skin. Mutations in the gene encoding type VII collagen COL7A1 cause recessive dystrophic epidermolysis bullosa (RDEB) an inherited skin blistering condition complicated by frequent aggressive cutaneous squamous cell carcinoma (cSCC). OATP1B3, which is encoded by the gene SLCO1B3, is a member of the OATP (organic anion transporting polypeptide) superfamily responsible for transporting a wide range of endogenous and xenobiotic compounds. OATP1B3 expression is limited to the liver in healthy tissues, but is frequently detected in multiple cancer types and is reported to be associated with differing clinical outcome. The mechanism and functional significance of tumour-specific expression of OATP1B3 has yet to be determined. Here, we identify SLCO1B3 expression in tumour keratinocytes isolated from RDEB and UV-induced cSCC and demonstrate that SLCO1B3 expression and promoter activity are modulated by type VII collagen. We show that reduction of SLCO1B3 expression upon expression of full-length type VII collagen in RDEB cSCC coincides with acquisition of front-to-rear polarity and increased organisation of 3D spheroid cultures. In addition, we show that type VII collagen positively regulates the abundance of markers implicated in cellular polarity, namely ELMO2, PAR3, E-cadherin, B-catenin, ITGA6 and Ln332.

Keywords: OATP1B3; Polarity; Type VII collagen.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism
  • Animals
  • Antigens, CD
  • Biomarkers, Tumor / genetics
  • Biomarkers, Tumor / metabolism
  • Cadherins / genetics
  • Cadherins / metabolism
  • Carcinoma, Squamous Cell / genetics
  • Carcinoma, Squamous Cell / metabolism*
  • Carcinoma, Squamous Cell / pathology
  • Cell Adhesion Molecules / genetics
  • Cell Adhesion Molecules / metabolism
  • Cell Cycle Proteins / genetics
  • Cell Cycle Proteins / metabolism
  • Cell Polarity*
  • Coculture Techniques
  • Collagen Type VII / physiology*
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism
  • Epidermolysis Bullosa Dystrophica / genetics
  • Epidermolysis Bullosa Dystrophica / metabolism*
  • Epidermolysis Bullosa Dystrophica / pathology
  • Gene Expression Regulation, Neoplastic
  • Humans
  • Integrin alpha6 / genetics
  • Integrin alpha6 / metabolism
  • Kalinin
  • Keratinocytes
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Mice
  • Neoplasm Transplantation
  • Organic Anion Transporters, Sodium-Independent / genetics
  • Organic Anion Transporters, Sodium-Independent / metabolism*
  • Promoter Regions, Genetic
  • Protein Transport
  • Skin Neoplasms / genetics
  • Skin Neoplasms / metabolism*
  • Skin Neoplasms / pathology
  • Solute Carrier Organic Anion Transporter Family Member 1B3
  • Transcription, Genetic
  • Tumor Cells, Cultured
  • beta Catenin / genetics
  • beta Catenin / metabolism

Substances

  • Adaptor Proteins, Signal Transducing
  • Antigens, CD
  • Biomarkers, Tumor
  • CDH1 protein, human
  • COL7A1 protein, human
  • CTNNB1 protein, human
  • Cadherins
  • Cell Adhesion Molecules
  • Cell Cycle Proteins
  • Collagen Type VII
  • Cytoskeletal Proteins
  • ELMO2 protein, human
  • ITGA6 protein, human
  • Integrin alpha6
  • Membrane Proteins
  • Organic Anion Transporters, Sodium-Independent
  • PARD3 protein, human
  • SLCO1B3 protein, human
  • Solute Carrier Organic Anion Transporter Family Member 1B3
  • beta Catenin