Abstract Objective To study the serine 118 phosphorylation in breast cancer tissue estrogen receptor α (p  Ser118  ERα) expression with ERα, PR expression and clinical value. The method of application of the method of immunohistochemical detection of five years ago, the treatment of 70 patients with primary breast cancer tissue p  the Ser118  of ERα expression of ERα, PR, correlation analysis, and Kaplan  Meier analysis with tamoxifen ( TAM) efficacy. Results in 70 cases ERα-positive breast cancer tissue, p   of ERα expression Ser118 and ERα expression was positively correlated (r = 0.348 P = 0.003), p  the Ser118  of ERα of expression and PR expression was positively correlated (r = 0.241 P = 0.044). the disease-free survival of the of p  Ser118  ERα-positive patients than negative patients (P = 0.013); PR-positive patients, the disease-free survival of patients of by p  Ser118-of ERα positive than negative patients (P = 0.021 ). Provide a more accurate detection of the conclusion p  Ser118  ERα joint PR tamoxifen efficacy evaluation of biological indicators.

Key words breast tumors; female hormone receptor α; phosphorylation; tamoxifen; immunohistochemistry

Expression of p  Ser118  ERα in Breast Cancer and Its Significance

    XU Dong  hong, FAN Zhong  lin, LI Yun  tao

    Department of The First General Surgery, Fourth Hospital of Hebei Medical University Shijiazhuang 050011, ChinaAbstract: Objective To study the expression of p  Ser118  ERα, ERα, PR of tissue in breast cancer by immunohistochemistry and the relationships among them.To explore the relationship between the expression of p  Ser118  ERα and the therapeutic efficacy of tamoxifen.Methods The expressions of p  Ser118  ERα, ERα, PR in 70 breast cancer tissues were examined by immunohistochemistry.The correlations among them were analyzed and the relationship between the expression of p  Ser118  ERα and the therapeutic efficacys of tamoxifen was analyzed by Kaplan  Meier.Results A significant correlation was found between the expression of p  Ser118  ERα and the expression of ERα (Spearman r = 0.348, P = 0.003) . A significant correlation was also found between the expression of p  Ser118  ERα and the expression of PR in breast cancer (Spearman r = 0.241 P = 0.044). Kaplan  Meier outcome analysis showed that patients with positive p  Ser118  ERα had a longer disease  free survival than those with negative p  Ser118  ERα (P = 0.013). And patients with positive p  Ser118  ERα had a longer disease  free survival than those with negative p  Ser118  ERα (P = 0.021 ) among the cases with positive PR.Conclusion The examination of p  Ser118  ERα and PR maybe a precise biomarker to evaluate the efficacys of tamoxifen.

    Key words: Breast neoplasma; Estrogen receptor α; Phosphorylation; Tamoxifen; Immunohistochemistry

The endocrine therapy ERα-positive breast cancer patients with treatment, tamoxifen (TAM) is still the most widely used selective estrogen receptor modulators (selective estrogen receptor modulators.SERMs). The study found that ERα is activated through phosphorylation of the receptor is a class, wherein the serine 118 is the most important one of the phosphorylation sites [1]. The subjects using immunohistochemical methods A retrospective analysis of p  Ser118  ERα expression in 70 cases of breast cancer tissue, are presented below.

    1 Materials and methods

    1.1 General Materials

    70 breast cancer patients were female, aged 31 to 83 years old, with a median age of 48 years; February 2000 to December 2001, ambulatory surgery, postoperative pathologically confirmed 50 cases of invasive ductal carcinoma, invasive lobular cancer, 16 cases, 2 cases of mucinous carcinoma, medullary carcinoma in 2 cases. All cases with immunohistochemical detection of cancerous tissue ERα positive after taking TAM 5-year follow-up to March 2007.

    1.2 Detection

    Take paraffin-embedded tissue, 4μm serial sections application peroxidase labeled streptomycin staining immunohistochemistry (SP method). An anti-Canada Cell signaling technology products, secondary antibody products Zymed are American companies.

    1.3 The results of judgment

    With PBS instead of primary antibody as a negative control, with positive sections known as a positive control. p  Ser118  ERα judgment brown particles to the tumor cell nuclei positive cells, staining score (IHC score) was graded product of staining intensity and high power field microscope, the number of positive cells. Staining intensity grading: 0 (none), 1 (weak), 2 (moderate), 3 (strong); percentage of positive cells were graded: 0 (none), 1 minute (<1/100 ), 2 points (1/100 to 1/10), 3 (1/10 to 1/3), 4 points (1/3 to 2/3), 5 (2/3). In addition to the number of positive cells> 1/100 given as positive, ≤ 1/100 given as negative.

    1.4 statistical methods

    Application SPSS13.0 statistical software for statistical analysis, using Spearman correlation analysis, Kaplan  Meier survival analysis, P <0.05 for the difference was statistically significant.

    2 Results

    70 cases ERα-positive breast cancer tissue specimens, p  Ser118  ERα positive in 41 cases (58.6%) and negative in 29 cases (41.4%), and the expression of p  Ser118  ERα and ERα expression was positively correlated (r = 0.348 , P = 0.003). p  Ser118  ERα expression and PR expression positively correlated (r = 0.241, P = 0.044).

    p  Ser118  ERα-positive and-negative patients with 5-year disease-free survival rates were 58.5% and 48.3%, p  the Ser118  of ERα-positive patients at each time point of the follow-up period, the survival rate was significantly higher than the negative group (P = 0.013) , as shown in Figure 1; PR-positive patients, p  Ser118  of ERα-positive and negative patients, 5-year disease-free survival rates were 56.5% and 44.4%, by p  Ser118-of ERα-positive patients at each time point of the follow-up period of survival were significantly higher than the negative group (P = 0.021), as shown in Figure 2.

    3 Discussion

    ERα expression in breast cancer tissue is the gold standard to select endocrine therapy, ERα from the amino end to the carboxyl terminus of AF  1 AF  two activation function area and A / B, C, the the C ~~ D, E, F five Ribbon, AF  1 in the A / B area AF  2 in the E Zone. Of ERα AF  1 zone is mainly to modulate its activity through the phosphorylation of several sites, common sites include Ser104, Ser106, Ser118, Ser167, etc., phosphorylation of Ser residues ERα mediated transcription activity is enhanced [1  2]. AF  2 through phosphorylation of tyrosine residues to enhance ERα transcriptional activity [3].

    Le Goff et al [4] reported that in COS  1 cell line, Ser104, Ser106, Ser118 were estradiol-induced phosphorylation sites associated with ER transactivation function, they are located in the A / B region, if the ER A / B-domain deleted or A / B region Ser residues alanine instead, the female hormone estrogen antagonist are not going to stimulate its phosphorylation and ERα transcriptional activity decreased by 30% to 40%. Another study reported that in fibroblasts and epithelial cells, Ser118 mutation into alanine, its transcriptional activity [5], also reduced. Ser118 phosphorylation may affect the transcriptional activity of ERα. Murphy et al [6  7] p  Ser118  ERα expression in breast cancer tissue immunohistochemical method proved no expression in normal breast tissue.

    The regulated synthesis by ER and PR, and therefore the expression of PR express functional pathway of ER, PR-positive often prompts the functional activity of the ER [8  11]. ER-positive and PR-positive breast cancer is considered true sex hormone-dependent tumors, an effective rate of 60% to 70% of such patients with endocrine treatment; ER-positive and PR-negative breast cancer is generally believed that the ER for non-functional or estrogen The stimulus is not sufficient to trigger the synthesis of PR, the effective rate of 20% to 30% of such patients with endocrine treatment; ER-negative, PR-negative breast cancer is not sensitive to endocrine therapy, there is generally less than 10% efficiency. Murphy et al [6] 117 breast cancer tissues using immunohistochemical methods to detect the PR level, state and p  Ser118  of ERα positive correlation. The experiment found that p  Ser118  ERα expression in breast cancer tissue (IHC score) and PR expression were also significantly positively correlated (r = 0.241, P = 0.044). p  Ser118  ERα and PR may jointly reflect the complete functional estrogen receptor signaling pathway, and at the same time regulating relations between of p  Ser118  ERα and PR.

    Generally believed that ERα-positive, tamoxifen is effective, but clinical also found that not all ERα positive expression patients can benefit from tamoxifen treatment. Murphy et al [6] this study, immunohistochemical method 117 axillary lymph node-negative breast cancer patients, cancer tissue for testing, of which 113 the ERα positive laws of postoperative oral tamoxifen, found p  Ser118  ERα positive patients with disease-free survival rate is better than of p  Ser118  ERα negative patients (P = 0.0118). The detection node-negative and-positive patients with breast cancer organization in this experiment, Kaplan  Meier analysis showed that the of p  Ser118  ERα positive patients with 5-year disease-free survival was significantly higher than the of p  Ser118  ERα negative patients (P = 0.013), indicating that ERα-positive patients, p  Ser118  ERα-positive patients benefit from tamoxifen treatment; PR-positive patients, Kaplan  Meier analysis showed that p  Ser118  ERα positive The disease-free survival rate was significantly higher than of p  Ser118  ERα-negative patients (P = 0.021). Thus, we believe that the joint detection of of p  Ser118  ERα and PR may become better predict endocrine therapy biomarkers.