Expression And Significance Of LAT1 And P-S6 In Breast Cancer

Backgroud: Breast cancer is one of the most common malignant tumors in women in the world.In 2012,there was an estimated 1.7 million invasive breast cancer cases and520,000 deaths in China.Breast cancer has become the most common malignant tumor in women in China.Research showed that L amino acid transporter 1(LAT1)and phosphorylated S6 ribosomal protein(p-S6)are upregulated in many tumors,promoting the occurrence and development of tumors.However,there are few reports on the role of both expression in breast cancer tissues.Purpose : To investigate the expression of LAT1 and p-S6 in breast cancer tissues,adjacent non-tumor tissues and breast benign lesions and to analyze its significance and their correlation in breast cancer,and to analyze their prognosis of breast cancer patients.Methods :(1)The expression of LAT1 proteins and p-S6 proteins was detected by immunohistochemistry En Vision two-step method in paraffin-embedded tissue section from 178 cases of breast cancer,53 cases of adjacent non-tumor tissues and 78 cases of benign breast lesions.(2)The expression of LAT1 m RNA was detected by in situ hybridization in paraffin-embedded tissue section from 60 cases of breast cancer,27 cases of adjacent non-tumor tissues and 40 cases of benign breast lesions.(3)Kaplan Meier survival analysis was used to analyze the relationship between LAT1 protein and p-S6 protein with the prognosis of breast cancer patients.Results:(1)Compared with the positive expression of LAT1 protein in adjacent non-tumor tissues(the positive rate was 18.9%),the positive expression of LAT1 protein(positive rate was 36.5%)was up-regulated in breast cancer tissues(P < 0.05).(2)Compared with the positive expression of LAT1 protein in benign breast lesions(the positive rate was 23.1%),the positive expression of LAT1 protein(positive rate was 36.5%)was up-regulated in breast cancer tissues(P < 0.05).(3)Compared with the positive expression of p-S6 protein in paracancerous breast tissues(the positive rate was 13.2%),the positive expression of LAT1 protein(positive rate was 33.2%)was up-regulated in breast cancer tissues(P < 0.05).(4)Compared with the positive expression of p-S6 protein in benign breast lesions(the positive rate was 12.8%),the positive expression of LAT1 protein(positive rate was33.2%)was up-regulated in breast cancer tissues(P < 0.05).(5)Univariate analysis shows that: The positive expression of LAT1 protein in breast cancer was correlated with tumor diameter,axillary lymph node metastasis,TNM staging,HER-2 level and Ki-67 level(P < 0.05).Multivariate analysis shows that : The positive expression of LAT1 protein in breast cancer was related to the tumor diameter,HER-2 level and Ki-67 level(P < 0.05).(6)Univariate analysis shows that: The positive expression of p-S6 protein in breast cancer was correlated with axillary lymph node metastasis,TNM staging,patients age,ER level(P < 0.05).Multivariate analysis shows that : The positive expression of p-S6 protein in breast cancer was correlated with axillary lymph node metastasis(P <0.05).(7)Pearson analysis shows that: There was a positive correlation between the expression of LAT1 protein and p-S6 protein in breast cancer tissues(P < 0.05).(8)Compared with the positive expression of LAT1 m RNA in paracancerous breast tissues(the positive rate was 28.6%),the positive expression of LAT1 m RNA(positive rate was 73.3%)was up-regulated in breast cancer tissues(P < 0.05).(9)Compared with the positive expression of LAT1 m RNA in benign breast lesions(the positive rate was 50.0%),the positive expression of LAT1 m RNA(positive rate was73.3%)was up-regulated in breast cancer tissues(P < 0.05).(10)Kaplan-Meier analyses shows that the overall 5-year survival rate was 82.2%.The5-year survival rate of LAT1 protein negative group and positive group were 86.7% and70.2,respectively.The difference was statistically significant(P =0.043).The 5-year disease-free survival rate of LAT1 negative group and positive group were 87.3% and62.5,respectively.The difference was statistically significant.The expression of p-S6 in breast cancer was not significantly different from that in breast cancer(P > 0.05).Conclusion: The expression of LAT1 and p-S6 was up-regulated in breast cancer.Both of them may be involved in the occurrence and development of breast cancer,and LAT1 can be used as a potential marker for evaluating the prognosis of breast cancer patients.