The overexpression of Hsp90B1 is associated with tumorigenesis of canine mammary glands
Heat shock proteins (Hsp) are molecular chaperones that are responsible for protein folding and maintenance of cellular homeostasis. Hsp90, an important member of HSP family, has an important role in breast cancer. Glucose-regulated protein 94 (Grp94) is the endoplasmic reticulum paralog of Hsp90 encoded by Hsp90B1 gene. To test if this protein is overexpressed in dogs with mammary tumor, we estimated and compared its serum levels in healthy dogs and that of dogs with mammary tumors. Hsp90B1 mRNA expression was measured in tumorous and healthy mammary tissues (from age- and breed-matched dogs) by real-time PCR. The gene was found to be overexpressed in mammary tumors (3.586 ± 0.067 times). Further, it was heterologously expressed in a prokaryotic system as 90 kDa protein. A recombinant Grp94-based sandwich ELISA was developed to quantify serum Grp94 in dogs with mammary tumors. Based on receiver-operating characteristics’ analysis, the assay was found to be 90.62% sensitive and 93.75% specific for a cutoff value of 0.35 with respect to histopathological staining in diagnosing the disease. The t test showed that serum Grp94 levels were significantly elevated (92.97 ± 3.62 ng/ml) in dogs with mammary tumors compared with healthy controls (10.30 ± 0.79 ng/ml) (p < 0.0001). These findings suggest that Grp94 might act as a potential biomarker for prognosis of canine mammary tumors and monitoring its therapy.
KeywordsHsp90B1 Grp94 Endoplasmic reticulum Expression Canine mammary tumor Prognosis Sandwich ELISA
The authors are thankful to the Department of Biotechnology, India, for providing the funds to carry out the research work (BT/PR6434/GBD/27/414/2012).
Compliance with ethical standards
Conflict of interest
None of the authors of this paper has a financial or personal relationship with other people or organizations that could inappropriately influence or bias the content of the paper.
- 9.Cawthorn TR, Moreno JC, Dharsee M, Tran-Thanh D, Ackloo S, Zhu PH, Sardana G, Chen J, Kupchak P, Jacks LM, Miller NA, Youngson BJ, Iakovlev V, Guidos CJ, Vallis KA, Evans KR, McCready D, Leong WL, Done SJ (2012) Proteomic analyses reveal high expression of decorin and endoplasmin (HSP90B1) are associated with breast cancer metastasis and decreased survival. PLoS ONE 7(2):e30992CrossRefPubMedPubMedCentralGoogle Scholar
- 11.Tramentozzi E, Ruli E, Angriman I, Bardini R, Campora M, Guzzardo V, Zamarchi R, Rossi E, Rugge M, Finotti P (2016) Grp94 in complexes with IgG is a soluble diagnostic marker of gastrointestinal tumors and displays immune-stimulating activity on peripheral blood immune cells. Oncotarget 7(45):72923–72940CrossRefPubMedPubMedCentralGoogle Scholar
- 20.Sambrook J, Russel DW (2001) Molecular cloning: a laboratory manual, 3rd edn. Cold Spring Harbor Laboratory Press, New YorkGoogle Scholar
- 22.Talwar GP (1983) A handbook of practical immunology. Vikash Publishing House Pvt Ltd, New Delhi, pp 71–83Google Scholar
- 29.Cheng Q, Chang JT, Geradts J, Neckers LM, Haystead T, Spector NL, Lyerly HK (2012) Amplification and high-level expression of heat shock protein 90 marks aggressive phenotypes of human epidermal growth factor receptor 2 negative breast cancer. Breast Cancer Res 14(2):R62CrossRefPubMedPubMedCentralGoogle Scholar
- 30.Li W, Sahu D, Tsen F (1823) Secreted heat shock protein-90 (Hsp90) in wound healing and cancer. Biochim Biophys Acta 3:730–741Google Scholar