Background and Objective: HER-2 (human epidermal growth factor receptor 2) is one such gene that can play a role in the development of breast cancer by making HER-2 proteins (receptorson breast cells). Normally, HER-2 receptors control breast cells grow and Division.  HER-2 protein over expression is the cause of up to 20% of breast cancers. The phosphoinositide 3 kinase (PI3K) pathway is important in the oncogenic function of HER-2. 

It has been reported compounds including Se, such as selenite significantly attenuated oxidative-stress-induced activation of the PI3K signaling pathways and can exhibit antitumor activity by downregulating PI3K activation.

 In this study, we evaluated Association of tissue selenium level and Human epidermal growth factor receptor 2 (HER-2) expression in breast cancer.

methods:

Se contents and expression of HER-2 were determined in 30 tissue collected from 30 women diagnosed with breast cancer based on immunohistochemistry (HER-2) and atomic absorption (Se).

Results:

About 30% of the samples were positive for HER-2 expression. Mean level of tissue selenium in tumors for positive and negative HER-2 was 268.15 µg/l and 206.43µg/l respectively. So, there was no significant association between selenium level and HER-2 expression. (p>0.005)

Conclusion:

There is no Association of tissue selenium level and HER-2 expression in breast cancer.

Keyword:

Selenium, HER-2, breast cancer

ABSTRACT
              Background and Objectives: Recently, the incidence of breast cancer has increased drastically worldwide. Therefore, the identification of novel diagnostic biomarkers is essential for improving treatment outcomes and prognosis. Estrogen receptor (ER) and progesterone receptor (PR) are routinely available in breast cancer specimens. Semi-quantitative assessment of ER and PR is important for prognosis. Even with the development of genomic tests, hormone receptor status remains the most significant predictive and prognostic biomarker. Selenium is known to protect mammary epithelial cells against oxidative DNA damage and early carcinogenetic events. Since overexpression of ER and PR is common in breast cancers, we aimed to evaluate association of tissue selenium level and ER and PR expression in breast cancer.
              Methods: Sixty tissue samples (30 tumors and 30 tumor margins) were collected from patients with breast cancer. Selenium level was measured using graphite furnace atomic absorption spectroscopy and ER/PR expression was evaluated using immunohistochemistry.
              Results: About 60% of the samples were positive for ER/PR expression. Mean level of tissue selenium was 209.54 µg/L in tumors and 185.04 µg/L in tumor margins that were ER/PR positive. In addition, mean selenium level was 243.39 µg/L and 168.06 µg/L in ER/PR-negative tumors and tumor margins, respectively. There was no significant association between selenium level and ER/PR expression (P>0.05).
              Conclusion: There is no association between tissue Se level and ER/PR expression in breast cancer.
              Keywords: Selenium, Estrogen receptor (ER), progesterone receptor (PR), breast cancer.