Haptoglobin expression in human colorectal cancer
Óscar Mariño-Crespo1, Elisa Cuevas-Álvarez2, Amy L. Harding3, Craig Murdoch3, Almudena Fernández-Briera1* and Emilio Gil-Martín1*
1Department of Biochemistry, Genetics and Immunology, Biomedical Research Centre (CINBIO, "Centro Singular de Investigación de Galicia"), University of Vigo, Vigo (Pontevedra), 2Pathology Service, University Hospital Complex of Ourense, Ourense, Spain and 3School of Clinical Dentistry, University of Sheffield, Sheffield, United Kingdom
*Contributed equally
Offprint requests to: Emilio Gil-Martín or Almudena Fernández-Briera, Departamento de Bioquímica, Genética e Immunología, Facultad de Biología, Universidad de Vigo, Campus As Lagoas-Marcosende, 36310 Vigo, Pontevedra, Spain. e-mail: egil@uvigo.es or abriera@uvigo.es
Summary. Aims and experimental design. The acute-phase protein haptoglobin (Hp) has been recently detected in colorectal cancer (CRC) tissue, where its expression correlates with metastasis. Recently, we identified Hp as a CDw75 antigen-expressing protein in colorectal tissue. To deepen the knowledge of this protein in CRC, we studied the expression of Hp in healthy and tumour tissue specimens from 62 CRC patients by immunohistochemistry and Western blotting, as well as in the Caco-2 and HT-29 CRC cell lines by quantitative PCR, immunofluorescence microscopy and flow cytometry. Results and discussion. Hp immuno-positive staining was absent in the 18 healthy colorectal specimens analysed, whereas it was observed in 24% (15/62) of the tumour specimens as cytoplasmic granules within cancer cells. Furthermore, Hp expression in CRC was associated with Dukes' stage and the presence of metastasis in our population of study. In vitro cultured Caco-2 and HT-29 cells expressed mRNA for Hp and the protein was detected at the cell surface. Conclusions. This study confirms the expression of Hp in CRC, both in vivo and in vitro, and provides further evidence of its association with disease progression and metastasis. Histol Histopathol 34, 953-963 (2019)
Key words: Haptoglobin, Human colorectal cancer tissue, Metastasis, Caco-2, HT-29
DOI: 10.14670/HH-18-100