Neuroendocrine Markers–Useful Predictors of Therapeutic Responses in Non-resectable Non-small Cell Lung Cancer

Effect of A549 neuroendocrine differentiation on cytotoxic immune response

The present study was designed to determine the effects of factors secreted by the lung adenocarcinoma cell line with the neuroendocrine phenotype, A549_NED, on cytotoxic T lymphocytes (CTLs) activity in vitro A perspective that integrates the nervous, endocrine and immune system in cancer research is essential to understand the complexity of dynamic interactions in tumours. Extensive clinical research suggests that neuroendocrine differentiation (NED) is correlated with worse patient outcomes; however, little is known regarding the effects of neuroendocrine factors on the communication between the immune system and neoplastic cells. The human lung cancer cell line A549 was induced to NED (A549_NED) using cAMP-elevating agents. The A549_NED cells showed changes in cell morphology, an inhibition of proliferation, an overexpression of chromogranin and a differential pattern of biogenic amine production (decreased dopamine and increased serotonin [5-HT] levels). Using co-cultures to determine the cytolytic CTLs activity on target cells, we showed that the acquisition of NED inhibits the decrease in the viability of the target cells and release of fluorescence. Additionally, the conditioned medium of A549_NED and 5-HT considerably decreased the viability and proliferation of the Jurkat cells after 24 h. Thus, our study successfully generated a neuroendocrine phenotype from the A549 cell line. In co-cultures with CTLs, the pattern of secretion by A549_NED impaired the proliferation and cytotoxic activity of CTLs, which might be partly explained by the increased release of 5-HT.

The prognostic significance of the circulating neuroendocrine markers chromogranin A, pro-gastrin-releasing peptide, and neuron-specific enolase in patients with small-cell lung cancer

Lung cancer is the most common cancer, and small-cell lung cancer (SCLC) accounts for around 20 % of lung cancers. SCLC has a neuroendocrine cellular origin, and the tumor cells usually express neuroendocrine markers. There have been major recent advances in the management of SCLC, and multimodal approaches are now the norm. An improved knowledge of the prognostic variables would assist in defining which patients were better candidates to receive these newer intensive therapies. This single-center retrospective study of 97 previously untreated and histologically proven SCLC patients analysed the circulating neuroendocrine markers chromogranin A (CGA), pro-gastrin-releasing peptide (ProGRP), and neuron-specific enolase (NSE) in addition to the other more classical variables. Fifty patients had limited-stage disease and 47 had extensive disease. Sixty patients had an ECOG performance status (PS) of 0-1 and 37 had PS 2-4. Median survival for the whole study population was 13 months. Univariate analysis and univariate Cox regression modeling found a statistically significant association between survival and PS, disease stage, and CGA, ProGRP, and NSE levels. Age and sex were not prognostic. A shorter survival time was found in patients with a PS equal to or >2, extensive stage disease, a serum CGA level >56 ng/ml, a serum ProGRP level >58 pg/ml, and a serum NSE level >19 ng/ml. This study has found that there is a potential role for ProGRP, NSE, and CGA in both staging and prognosing survival in SCLC patients.