Endocrine Abstracts

Small cell lung cancer (SCLC) is a common and devastating disease. SCLC tumours contain a neuroendocrine cell population that exhibit ectopic hormone production in a minority of patients. The aim of this study was to investigate a panel of neuroendocrine peptides as potential biomarkers of SCLC, including pro-opiomelanocortin, neuron specific enolase, chromogranin A and neural-cell adhesion molecule. Immunohistochemistry methods were used to examine neuroendocrine peptides in five human lung cancer cell lines (CORL24, CORL47, DMS79, H526, and A549) and a novel murine subcutaneous SCLC xenograft tumour. Liver, lung and brain samples were taken from xenograft mice to identify possible metastasis. ELISA measured POMC secretion and expression in cell lines during incubation and a western blot quantified chromogranin A levels in all cell lines and xenograft tumours. Results confirmed a significant neuroendocrine cell population within SCLC xenograft tumours and cell lines. Additionally, POMC secretion proved to be a marker of SCLC growth in vitro in CORL24 and DMS79. H526, CORL47 and A549 did not secrete POMC. Xenograft tumours appeared invasive with infiltration of surrounding connective tissue, but no metastases were present in liver, lung and brain samples. This study validates further investigation into the neuroendocrine phenotype in SCLC, and POMC as a potential biomarker for the disease.