NK-1 receptor antagonists induce apoptosis and counteract substance P-related mitogenesis in human laryngeal cancer cell line HEp-2

Abstract

It has been demonstrated that substance P (SP) induces cell proliferation and neurokinin-1 (NK-1) receptor antagonists inhibit growth in several human cancer cell lines, but it is currently unknown whether such actions are exerted on human laryngeal carcinoma cell line HEp-2. In addition, the presence of NK-1 receptor has not been demonstrated in this cell line. We carried out an in vitro study of the growth inhibitory capacity of the NK-1 receptor antagonists L-733,060 and L-732,138 against human laryngeal carcinoma cell line HEp-2. Coulter counter was used to determine viable cell numbers followed by application of the tetrazolium compound MTS. Furthermore, an immunoblot analysis was used to determine the NK-1 receptor, and the 4',6-diamidino-2-phenylindole (DAPI) method was applied to demonstrate apoptosis of the laryngeal carcinoma cells. We observed the presence of several NK-1 receptors isoforms (34, 46, 58 and 75 kDa). Nanomolar concentrations of SP increased the growth rate of the cell line and micromolar concentrations of L-733,060 and L-732,138 inhibited the growth of the HEp-2 cells in a dose-dependent manner, with and without previous administration of SP. The 50% inhibition concentration values were 21.34 microM and 37.97 (48 h) respectively for HEp-2. NK-1 receptor presence on HEp-2 cells was confirmed by western blotting. DAPI staining revealed the presence of apoptosis following NK-1 receptor antagonists treatment. We demonstrated that NK-1 receptors were present in this laryngeal cancer cell line; these findings demonstrate that SP acts as a mitogen on the human laryngeal carcinoma cell line HEp-2 through the NK-1 receptor, and also indicate that both NK-1 receptors antagonists induced apoptosis of the tumour cells. This new action, reported here for the first time, suggests that the NK-1 receptor is a new and promising target in the treatment of human laryngeal carcinoma.

The NK-1 receptor is expressed in human melanoma and is involved in the antitumor action of the NK-1 receptor antagonist aprepitant on melanoma cell lines

“…5 It has also been shown that activation of NK-1 receptors by SP induces mitogenesis in several melanoma cell lines 6,7 and others tumor cell lines. [8][9][10][11][12][13][14][15][16] SP is also a main mediator in the growth of capillary vessels in vivo and in the proliferation of cultured endothelial cells in vitro, and it has also been shown that NK-1 receptor agonists induced neoangiogenesis. 17 Moreover, the active migration of tumor cells, a crucial requirement for invasion and metastasis, is regulated by SP signals.…”

Paravertebral anesthesia: how substance P and the NK-1 receptor could be involved in regional block and breast cancer recurrence

“…(a) by inhibiting tumor cell proliferation in several tumor cell lines, including breast cancer cells [10,13,14]. NK-1 receptor antagonists induce cellular death by apoptosis [10,14]; (b) by inhibiting tumor neoangiogenesis [15]; and (c) by inhibiting the migration of tumoral cells (e.g., breast carcinoma cells) [9,16].…”

“…NK-1 receptor antagonists induce cellular death by apoptosis [10,14]; (b) by inhibiting tumor neoangiogenesis [15]; and (c) by inhibiting the migration of tumoral cells (e.g., breast carcinoma cells) [9,16]. NK-1 receptor antagonists also block the mitogenic action exerted by SP on tumor cells.…”

“…3. The presence of both SP [11] and NK-1 receptors in tumoral tissues, including breast carcinoma [10,12,13], has been demonstrated. This means that SP could act through an autocrine mechanism, through which SP is secreted from primary tumors.…”

“…Noxious stimuli enhance SP release from C-fibers and then SP depolarizes dorsal horn neurons in a similar manner to when electrical stimulation of C-fibers is carried out. [9,10]. Moreover, SP exerts an antiapoptotic effect [7].…”