Sigma 2 receptor expression levels in blood and bladder from healthy and bladder cancer cattle

The expression of sigma-2 receptor (S2R) was assayed in blood and bladder samples from healthy cattle and in blood and bladder of cattle with deltapapillomavirus-associated urothelial tumors. Samples of bladder from cattle with neoplasia had significantly higher S2R than samples of bladder from healthy cattle (95% CI 0.31–0.82, P < 0.05). In addition, significantly higher S2R was detected in the blood of cattle with bladder cancer than blood from healthy cattle (95% CI 0.22–0.41, P < 0.05). The results provide evidence that increased expression of SR2 in blood could be useful as circulating biomarker for bladder cancer in cattle. PGRMC1 protein levels were also found to be increased in blood and bladder from cattle with cancer and increased expression of PGRMC1 transcripts was detected by quantitative real time PCR in samples from cattle neoplasia. Furthermore, electron microscopy revealed phagophores and numerous autophagosomes, ultrastructural hallmark of autophagy.