Immunolocalization of neurokinin 1 receptor in WHO grade 4 astrocytomas, oral squamous cell and urothelial carcinoma

Introduction: Neurokinin-1 receptor (NK-1R) induces inflammatory reactions in peripheral tissues but its regulatory effects in target tissues is dependent on receptor signalling. Substance P (SP) has a high affinity for the NK-1R, to which it binds preferentially. We aimed to investigate the expression of NK-1R in World Health Organization (WHO) grade 4 astrocytomas as well as in oral squamous cell carcinoma (OSCC) and urothelial carcinoma, and its association with disease progression. Material and methods: The study included tissue samples from 19 brain astrocytomas, 40 OSCCs and 10 urothelial carcinomas. NK-1R expression was quantitatively assessed in the tumour cells using immunohistochemistry. The relationship between NK-1R expression in astrocytomas and recurrence-free interval has been explored. Results: The results showed that the NK-1R was intensely expressed in patients with WHO grade 4 astrocytoma, OSCC and urothelial carcinoma. However, cases clinically diagnosed as a low-grade cancer showed reduced NK-1R expression. Conclusions: NK-1R is overexpressed in all cases of WHO grade 4 astrocytoma, OSCC and urothelial carcinoma. The ubiquitous presence of SP/NK-1R complex during tumour development and progression suggests a possible therapeutic key strategy to use NK-1R antagonist as an adjuvant therapy in the future.