substance-p--phe(5)-trp(7-9)-leu(11)- and Carcinoma--Non-Small-Cell-Lung

It is known that in human lung cancer samples, both small-cell lung cancer (SCLC) and non-small-cell lung cancer (NSCLC) cells express the neurokinin-1 (NK-1) receptor; that after binding to the NK-1 receptor the peptide substance P (SP) elicits tumour cell proliferation and an antiapoptotic effect. By contrast, it has been demonstrated that non-peptide NK-1 receptor antagonists, after binding to the NK-1 receptor and hence by blocking the SP action in SCLC/NSCLC, exert an antiproliferative action (inhibit lung cancer cell proliferation and induce the death of tumour cells by apoptosis). It is also known that SP peptide NK-1 receptor antagonists also called SP analogue antagonists (broad-spectrum GPCR antagonists, broad-spectrum neuropeptide antagonists or synthetic analogues of SP), also exert antiproliferative actions against SCLC/NSCLC. However, the underlying mechanisms involved in this antiproliferative action remain unknown. By using competition assays with SP, here we demonstrate that the antiproliferative action exerted by the [D-Arg(1), D-Phe(5), D-Trp(7,9), Leu(11)] SP analogue on human H-69 SCLC and COR-L23 NSCLC cell lines, occurs at least through the NK-1 receptor.

Topics: Antineoplastic Agents; Apoptosis; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Cell Line, Tumor; Cell Proliferation; Humans; Lung Neoplasms; Neurokinin-1 Receptor Antagonists; Receptors, Neurokinin-1; Substance P

The broad spectrum antagonist [D-Arg1, D-Phe5, D-Trp7,9, Leu11] substance P has been shown previously to inhibit the growth of small cell lung cancer cells both in vitro and in vivo. To elucidate further the pathways involved in the growth inhibitory actions of [D-Arg1, D-Phe5, D-Trp7,9, Leu11] substance P we have examined the effect of this agent on cell viability and the induction of apoptosis in small cell and non-small cell lung cancer cells. Treatment of lung tumor cells with [D-Arg1, D-Phe5, D-Trp7,9, Leu11] substance P caused a concentration-dependent loss of cell viability which was accompanied by the onset of apoptosis, as defined by cytological criteria and DNA fragmentation. This effect occurred in both small cell and non-small cell lung cancer cells and was not dependent on de novo protein synthesis. Such findings indicate that the antiproliferative action of [D-Arg1, D-Phe5, D-Trp7,9, Leu11] substance P involves a signal transduction pathway for apoptosis.

Topics: Adenocarcinoma; Antineoplastic Agents; Apoptosis; Carcinoma, Large Cell; Carcinoma, Non-Small-Cell Lung; Carcinoma, Small Cell; Carcinoma, Squamous Cell; Cell Line; Cell Survival; DNA Damage; DNA, Neoplasm; Flow Cytometry; Humans; Kinetics; Lung Neoplasms; Substance P; Time Factors; Tumor Cells, Cultured