Abstract: Abstract：Objective To investigate the expression and clinical significance of α- actinin- 1 protein (ACTN1) in prostate cancer (PCa) and prostatic hyperplasia (BPH). Methods The clinical data of patients with PCa or BPH treated in our school affiliated hospital were collected between January 2007—October 2014, according to certain criteria. Immunohistochemistry method was used to detect the expression of ACTN1 in 30 samples of PCa and 30 samples of BPH tissues. Western blot assay was used to detect the relative expression of ACTN1 in 18 samples of PCa and 20 samples of BPH tissues in two groups. Results The result of immunohistochemistry showed that the positive expression rates of ACTN1 were 76.7% and 20% in PCa and BPH groups respectively. The difference was statistically significant (P < 0.01). Western blot assay showed that the relative expression of ACTN1was significantly higher in PCa group (0.591±0.182) than that in BPH group (0.037 ± 0.052, P < 0.05). There was no significant difference in expression level of ACTN1 betweendifferent age groups. There was no significant difference in serum prostate specific antigen (PSA) level between patients with or without bone metastasis, and patients with or without lymph node metastasis (P > 0.05). There were significant differences in ACTN1 levels between different Gleason score and T staging groups (P < 0.05). Conclusion The expression of α-actinin-1 is significantly higher in PCa tissues than that in BPH tissues. There is the relationship between expression of ACTN1, Gleason scores and T staging.

Key words: prostatic neoplasms, prostatic hyperplasia, actinin, immunohistochemistry, blotting, Western, prostate cancer, α-actinin-1