Expression of SP and neurokinin-1 receptor in patients with breast cancer and their correlations with clinicopathological features

Abstract

Objective To investigate the expression of substance P （ SP） and neurokinin-1 recep-tor （NK1R） in patients with breast cancer and to further understand the correlations of them with the clinico-pathological features and the prognosis of breast cancer.Methods SP levels in serum samples and superna-tants of breast cell culture were measured by ELISA.The expression of total NK1R, full-length NK1R （NK1R-FL） and truncted NK1R （NK1R-Tr） in 82 patients with breast cancer and 30 patients with breast hyperplasia were detected by using immunohistochemistry and Western blot.Results The levels of SP in patients with breast cancer were higher than those in patients with breast hyperplasia and healthy subjects （ P〈0.05） .The expression of NK1R-FL was inhibited, while the expression of NK1R-Tr was significantly en-hanced in breast cancer tissues as compared with those in normal and hyperplastic breast tissues （P〈0.01）. Compared with patients with ductal carcinoma in situ （ DCIS ） , patients with invasive ductal carcinoma （IDC） showed a decreased expression of NK1R-FL, but an increased expression of NK1R-Tr （P〈0.05）. The stages of breast cancer classified by using the TNM system showed a negative correlation with NK1R-FL expression, but positive correlations with the expression of NK1R-Tr and SP （P〈0.01）.Moreover, the en-hanced expression of NK1R-Tr and SP and suppressed expression of NK1R-FL were positively related to lymph node metastasis and high expression of vascular endothelial growth factor （ VEGF） , human epidermal growth factor receptor 2 （ HER2） and Ki-67, but negatively related to the expression of estrogen receptor （ER） and progesterone receptor （PR） in breast cancer tissues （P〈0.05）.The expression of NK1R-FL and NK1R-Tr showed no significant correlation with age, histological grades and the expression of P53 in breast cancer tissues （P〉0.05）.Conclusion The invasion and metastasis of breast cancer showed a negative cor-relation with the expression of NK1R-FL, but a positive correlation with the expression of NK1R-Tr and SP. Key words: Substance P Neurokinin Receptor Breast cancer