Endocrine Abstracts

Introduction: Neuroendocrine neoplasms (NENs) comprise a heterogenous group of tumours with diverse clinical presentations and prognosis. Although significant progress has been made in treatment, a deeper understanding of somatostatin receptors (SSTRs) behaviour is essential to monitor disease progression and improve therapeutic strategies. This study investigates the effects of octreotide acetate (OA), lanreotide acetate (LA) and pasireotide (P) on LCC-18 cells, focusing on changes in SSTRs 2, 3, 4 and 5 and the proliferation marker Ki-67. Additionally, potential mechanisms behind drug resistance or loss of efficacy are explored.

Material and Methods: The LCC-18 cell line, derived grom a grade 3 NEN of colonic origin, was cultured and treated with increasing concentrations of OA, LA and P (6.25-100 μM) for 2 hours. Expression levels of SSTRs 2, 3, 4 and 5, and Ki-67 were evaluated using immunocytochemistry (ICC) and qRT-PCR. To assess potential cytotoxic effects, apoptosis induction was also examined following drug exposure.

Results: Preliminary results showed no significant induction of apoptosis with OA and LA treatment, while P demonstrated a mild apoptotic response at the highest concentration (100 μM). Early findings suggest differential effects of these analogues on SSTR and Ki-67 expression. However, detailed IC and qRT-PCR analysis are ongoing and will provide deeper insights into their respective mechanisms of action.

Conclusion: This study highlights the importance of evaluating early molecular changes following SSTR analogue treatment to identify biomarkers predictive of therapeutic efficacy. By elucidating alterations in SSTRs and Ki-67 expression, this research aims to enhance personalised treatment approaches for NEN patients. Such insights may lead to improved clinical outcomes by identifying early indicators of drug response and optimising future therapeutic strategies.