Andrés Carranza

The substance P/neurokinin-1 receptor system in lung cancer: focus on the antitumor action of neurokinin-1 receptor antagonists.

The last decades have seen no significant progress in extending the survival of lung cancer patients and there is an urgent need to improve current therapies. The substance P (SP)/neurokinin-1 receptor (NK-1R) system plays an important role in the development of cancer: SP and NK-1R antagonists respectively induce cell proliferation and inhibition in human cancer cell lines. No study of the involvement of this system in non-small cell lung cancer (NSCLC) and small cell lung cancer (SCLC) cells has been carried out in depth. Here, we demonstrate the involvement of the SP/NK-1R system in human H-69 (SCLC) and COR-L23 (NSCLC) cell lines: (1) they express isoforms of the NK-1R and mRNA for the NK-1R; (2) they overexpress the tachykinin 1 gene; (3) the NK-1R is involved in their viability; (4) SP induces their proliferation; (5) NK-1R antagonists (Aprepitant (Emend), L-733,060, L-732,138) inhibit the growth of both cell lines in a concentration-dependent manner; (6) the specific antitumor action of these antagonists against such cells occurs through the NK-1R; and (7) lung cancer cell death is due to apoptosis. We also demonstrate the presence of NK-1Rs and SP in all the human SCLC and NSCLC samples studied. Our findings indicate that the NK-1R may be a promising new target in the treatment of lung cancer and that NK-1R antagonists could be new candidate antitumor drugs in the treatment of SCLC and NSCLC.

Antitumor activity of neurokinin-1 receptor antagonists in MG-63 human osteosarcoma xenografts

Osteosarcoma is a highly malignant bone tumor in children and adolescents. Aprepitant is a selective high‑affinity antagonist of the human neurokinin‑1 (NK‑1) receptor (NK1R) with robust antitumor activity. No data exist on the presence of NK1R in osteosarcoma and whether this tumor responds to NK1R antagonists. Here, we analyzed the expression of NK1R in the human osteosarcoma cell line MG-63 with western blot analysis and PCR and found significant expression both at the protein and mRNA levels. We further studied the growth inhibitory capacity of aprepitant and other NK1R antagonists on MG-63 in vitro using an MTS cytotoxicity assay and DAPI staining. All antagonists induced tumor growth inhibition and apoptosis. Synergism was observed for the combination of L-733,060 with common cytostatic drugs in MG-63, but not in non-malignant HEK293 cells. Pretreatment of HEK293 with L-733,060 prior to exposure to cytostatic drugs partially protected HEK293 cells from inhibition by these drugs. Furthermore, nanomolar concentrations of substance P (SP), the natural ligand of the NK1R, increased the growth rate of MG‑63 cells and micromolar concentrations of aprepitant inhibited SP-induced growth in a dose‑dependent manner. In vivo, a xenograft for MG-63 was created in nude mice and treated with peritumoral s.c. injections of fosaprepitant, which resulted in a significant reduction of tumor volume. Collectively, we demonstrated for the first time that the NK1R is expressed in human osteosarcoma cell line MG‑63 and that this receptor can be targeted with NK1R antagonists both in vitro as well as in vivo.

Uveal melanoma expresses NK-1 receptors and cyclosporin A induces apoptosis in human melanoma cell lines overexpressing the NK-1 receptor

Substance P and neurokinin-1 (NK-1) receptor antagonists respectively induce proliferation and growth inhibition in human melanoma cell lines. The presence of NK-1 receptors in human melanoma cell lines and samples has been reported, but the presence of NK-1 receptors has not been demonstrated in uveal melanomas. It is known that melanoma express the tachykinin 1 receptor (TAC1R) gene. This gene is overexpressed in several human cancer cell lines, but such overexpression is currently unknown in human malignant melanoma cell lines (COLO 858, MEL HO, COLO 679). In this study, we attempt to demonstrate the overexpression of the TAC1R gene in such cells. We performed an in vitro study by real-time quantitative RT-PCR for TAC1R and found that the NK-1 receptor was overexpressed in the three human melanoma cell lines studied. Using a knockdown method, we demonstrate that the NK-1 receptor is involved in the viability of the COLO 858 melanoma cell line. Immunohistochemistry was also used to demonstrate NK-1 receptors in uveal melanoma samples. We observed that NK-1 receptors were present in the 21/21 uveal melanomas. In addition, cyclosporin A inhibited the growth of the three melanoma cell lines studied in a dose-dependent manner, and after the administration of this immunosuppresive drug apoptosis was observed. This indicates at least that the antitumor action of cyclosporin A is mediated by the NK-1 receptor. Our findings suggest that the NK-1 receptor could be a promising target in the treatment of human melanomas.

Immunolocalization of substance P and NK‐1 receptor in hofbauer cells in human normal placenta

 Substance P (SP) after binding to the neurokinin‐1 (NK‐1) receptor regulates many biological functions. Both SP and the NK‐1 receptor are expressed in human normal placenta cells, monocytes, and macrophages. However, to our knowledge, the presence of both SP and the NK‐1 receptor in macrophages of the placenta, the Hofbauer cells, is unknown. We demonstrate by immunohistochemistry in human normal placenta samples the presence of both SP and NK‐1 receptors in the cytoplasm and in the nucleus of Hofbauer cells. The findings suggest a functional role of the SP/NK‐1 receptor system in the physiology and pathophysiology of Hofbauer cells in the human placenta. Microsc. Res. Tech. 76:1310‐1313, 2013.

Increased nuclear localization of substance P in human gastric tumor cells

Gastric cancer (GC) is an aggressive disease that remains the fourth most common type of cancer and is the second leading cause of cancer-related death worldwide. Treatment of advanced or metastatic GC has seen little progress and median overall survival in this group remains <1 year. It is urgent to investigate new mechanisms to understand GC progression. It is known that substance P (SP), after binding to the neurokinin-1 (NK-1) receptor, elicits GC proliferation; that GC cells and samples express NK-1 receptors; that NK-1 receptor antagonists, in a concentration dependent manner, inhibit the proliferation of GC cells and that these cells die by apoptosis. However, the presence of SP in GC and normal gastric cells is unknown. In order to know more on the involvement of the SP/NK-1 receptor system in GC, we studied in thirty human GC and normal gastric samples the immunolocalization of SP after using an immunohistochemical technique. SP was observed in the cytoplasm and in the nucleus of GC and normal gastric cells. The nuclear expression of SP was higher in GC cells than in normal cells. No significant difference was observed when the cytoplasmatic expression of SP in normal and GC cells was compared. The findings suggest that SP plays an important role in both nuclear function and GC.