TITLE:
Neurotensin Receptor 1 (NTSR1) Overexpression in Breast Carcinomas Is Common and Independent of ER/PR/Her2 Expression
AUTHORS:
Xianyong Gui, Shuhong Liu, Ziran Meng, Zu-Hua Gao
KEYWORDS:
Neurotensin; Neurotensin Receptor; NTSR1; Breast Carcinoma; Estrogen Receptor; Progesterone Receptor; Her2
JOURNAL NAME:
Journal of Cancer Therapy,
Vol.4 No.7A,
July
17,
2013
ABSTRACT: Neurotensin (NT) is a 13-amino acid peptide with trophic effects on some neoplasms. Its bioactivities are mainly mediated by neurotensin receptor 1 (NTSR1). Both NT and NTSR1 were found to be upregulated in breast cancer. NT/NTSR1 thus becomes a potential therapeutic target. We studied whether any correlation exists between the expression of NTSR1 in breast carcinomas and the expression of ER, PR, and Her2. A total 85 cases of invasive ductal (62) and lobular (23) breast carcinomas were studied. Based on their ER/PR profiles, the ductal carcinomas (DCs) were subcategorized into ER+/PR+ (21), ER+/PR﹣ (20), and ER﹣/PR﹣ (21). All of the lobular carcinomas (LCs) were ER+/PR+. 21.57% of all DCs and 5.56% of LCs were Her2 positive. 77.78% of ER﹣/PR﹣ DCs were also Her2 negative (triple negative). The expression of NTSR1 was detected by immunohistochemistry and was semiquantitated (as negative, 1+, 2+, 3+). Both 2+ and 3+ were collectively defined as overexpression. The expression of NTSR1 was weak and focal in non-neoplastic mammary epithelial cells. It is increased in 74.19% of DCs (80.95% in ER+/PR+, 75% in ER+/PR﹣, and 66.67% in ER﹣/PR﹣ group), and in 95.65% of LCs. The overexpression of NTSR1 is similar between ER+ DCs and ER﹣ DCs (75% vs 66.67%, p > 0.05) as well as between PR+ DCs and PR﹣ DCs (80.95% in ER+/PR+ DCs vs 75% in ER+/PR﹣ DCs, p > 0.05). And it was seen in 77.78% of Her2+ DCs, 78.38% of Her2﹣ DCs, 94.12% of Her2﹣ LCs, and 78.57% of triple negative DCs. Overall, NTSR1 is commonly overexpressed in both ductal and lobular breast carcinomas and is independent of the ER/PR/Her2 profiles of the tumors. The present data supports the potential benefit of developing NTSR1 blockers in the adjuvant therapy of breast carcinomas, particularly for those “triple negative” tumors.