Significance And Expression Of TXNIP And TrxR1 Protein In Breast Invasive Ductal Carcinoma

Objective: Breast cancer is one of the most common malignant tumors in women, and its morbidity rate account for 7-10% of all the malignant tumors. In recent years, breast cancer has already become the one of the malignant tumors that threatening the health of women. Therefore, it would be of great significance to investigate relevant factors with breast cancer and find efficient path to prevent and treat it for making prognosis judgment, guiding treatment and improving quality of life.Thioredoxin interaction protein(TXNIP) is a king of redox protein, and it can directly bind to the catalytic active center of reduced thioredoxin(Trx) and inhibits its ROS scavenging activity. Numerous studies have confirmed that the TXNIP gene contributed to many malignant tumors, and is an important index to judge the prognosis of tumor. Thioredoxin reductase 1( Trx R1) is a regulator of cellular redox state of the enzyme in mammalian cells, its important function is to keep the cell redox state of thioredoxin. Trx R1 was showed higher expression in many malignant tumors, and it may be become a therapeutic target. In this study, we investigated the expression of TXNIP and Trx R1 in breast cancer tissues, and to explore the relationship between expression of TXNIP and Trx R1 protein and the clinical pathological characteristics.Method: Immunohistochemical method(SP)was used to detect the expression of TXNIP and Trx R1 in 50 breast invasive ductal carcinoma specimens(including: lymph node metastasis, 30 cases and without lymph node metastasis, 20 cases) and 20 adjacent non-cancerous control breast tissues. And to analyze the correlation between TXNIP and Trx R1 expression in breast cancer tissues and the relationship between them and clinical pathological characteristics. SPSS13 statistical software was used in this study. Count data using chi square test. Spearman correlation analysis was used to analyse the expression of TXNIP and Trx R1 protein in breast cancer tissues. Statistical significance was defined as P< 0.05.Results:1 The expression of TXNIP in breast cancer tissuesThe TXNIP protein expression was localized in the cytoplasm or nucleus in breast cancer tissues. The TXNIP positive expression rate in adjacent non-cancerous control breast tissues was 80%(16/20); the TXNIP positive expression rate was 30%(15/50) in breast cancer tissues. The positive expression rate of TXNIP in breast cancer tissues was lower than that in adjacent non-cancerous control breast tissues, and the difference has statistical significance.2 The relationship between the TXNIP expression and clinical pathological characteristics in breast cancer tissuesThe positive expression rate of TXNIP protein was 29.2%(7/24) in age <50 years old group; the positive rate of TXNIP protein expression was 30.8%(8/26) in the age of over 50 years old group, there was no significant difference between the two groups. The positive rate of TXNIP protein was 29.6%(8/27) in diameter of tumor maximum diameter less than or equal to 2cm group; and the TXNIP protein positive rate was 30.4%(7/23) in diameter of tumor >2cm group, between the two groups showed no significant difference. In histological grade I group, the positive expression rate of TXNIP protein was 55%(11/20); the TXNIP protein positive expression rate was 13%(4/30) in histological grade II and III group, there was significant difference between them. The lymph node metastasis group, the positive rate of TXNIP protein was 26.7%(8/30); the TXNIP protein positive rate was 35%(7/20) in the group without lymph node metastasis, there was no significant difference of expression between the two groups. In TNM stage I group, the positive expression rate of TXNIP protein was 35.4%(11/31); the positive expression rate of TXNIP protein was 21.1%(1/19) in the stage II+III group, there was significant difference in expression between the two groups.The analysis results show that there was no relationship among the TXNIP protein expression in breast cancer patients with the age, tumor size and lymph node metastasis(P<0.05), and there were statistically significant differences of TXNIP expression among different histological grade and TNM staging(P<0.05).3 The expression of Trx R1 in breast cancer tissuesTrx R1 in breast cancer positive staining was mainly localized in the cytoplasm, a few expression localized in the nucleus. The weak expression of Trx R1 in adjacent non-cancerous control breast tissues, 2/20 cases(10%). The Trx R1 positive expression rate in breast cancer was 86%(43/50), far higher than the expression in in adjacent non-cancerous control breast tissues. There was statistically significant difference between the two groups.4 The relationship between the Trx R1 expression and clinical pathological characteristics in breast cancer tissuesThe positive expression rate of Trx R1 protein was 83.3%(20/24) in age<50 years old group, and the positive expression rate of Trx R1 protein was 88.4%(23/26) in over aged 50 years old group, there was no significant difference between the two groups. In the maximum diameter of the tumor is less than or equal to the 2cm group, the positive rate of Trx R1 protein was 88.9%(24/27), and the positive expression rate of Trx R1 protein was 82.6%(19/23) in diameter >2cm group, there was no significant difference between the two groups. In histological grade I group, the positive expression rate of Trx R1 protein was 85%(17/20), and he positive expression rate of Trx R1 was 86.7%(26/30) in histological grade II and III grade group. There was no statistically significant between the two groups. In lymph node metastatic group, the Trx R1 protein positive expression rate was 83.3%(25/30), and the group without lymph node metastasis, the positive rate of Trx R1 protein expression was 90%(18/20). There was no significant difference between between the two groups. In TNM stage I group, the positive expression rate of Trx R1 protein was 83.9%(26/31), and in the stage II and III group, the positive expression rate of Trx R1 protein was 89.5%(17/19). There was no significant difference between the two groups.The results showed that there was no relationship among the expression of Trx R1 protein in breast cancer tissues with the age of patients, tumor size, histological grade, lymph node metastasis and TNM staging.5 The correlation between TXNIP and Trx R1 expression in breast cancer tissuesThe correlation analysis showed that the expression of TXNIP protein had negative correlation with Trx R1 protein expression in breast cancer tissues.Conclusions:1 There was reduced TXNIP expression in breast cancer tissues. The expression of TXNIP has relationship with histological grade and TNM staging in breast cancer.2 Trx R1 protein expression was increased in breast cancer. The higher expression may be contribute to breast cancer.3 The expression of TXNIP protein has negative correlation with Trx R1 protein in breast cancer tissues. Hence, we infered that TXNIP and Trx R1 may be play important role in breast cancer.