Elevated Expression of IRS-1 Associates with p-Akt Expression and Predicts Poor Prognosis of Breast Invasive Ductal Carcinoma

Publication date: Available online 15 March 2018
Source:Human Pathology
Author(s): Jiadi Luo, Juan Feng, Qiuyuan Wen, Christopher Qoyawayma, Weiyuan Wang, Lingjiao Chen, Junmi Lu, Yuting Zhan, Lina Xu, Hongjing Zang, Songqing Fan, Shuzhou Chu
Overexpression of Insulin Receptor Substrate 1 (IRS-1) has been reported to promote cell growth, atypical hyperplasia, and carcinogenesis. And phosphorylated Akt (p-Akt) is certified to be involved in many types of cancers such as breast invasive ductal carcinoma (BIDC). However, the relationship between IRS-1 and Akt, as well as the role of expression of IRS-1 in BIDC, has never been reported. The purpose of this research is to investigate the association between expression of IRS-1 and p-Akt proteins and clinicopathological features of BIDC by immunohistochemistry, as well as the survival status. The results showed that the percentage of either elevated expression of IRS-1 or positive p-Akt expression in BIDC is significantly higher than that in control breast tissue from non-cancer patients (P<.001, P=.001, respectively). Overexpression of IRS-1 was evidently associated with positive expression of p-Akt (r=.337, P<.001). Also, positive percentage of p-Akt expression was statistically different among different molecular subtypes of BIDC (highest in luminal B BIDC, P=.009). Furthermore, significantly worse overall survival was in BIDC patients with high expression of IRS-1 and p-Akt than patients with low expression (P=.006, P=.004, respectively). The multivariate Cox proportional hazard regression analysis showed that high expression of IRS-1 and positive expression of p-Akt protein were independent poor prognostic factors for patients with BIDC (P=.022, P=.046, respectively). In conclusion, we report for the first time that overexpression of IRS-1 protein associates with expression of p-Akt, and overexpression of IRS-1 and positive expression of p-Akt might be independent biomarkers for poor prognosis in BIDC.



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