Endocrine Abstracts

Gastrointestinal neuroendocrine tumors (GI-NETs) present a challenging and diverse landscape, necessitating effective treatment strategies. Despite advancements, the demand for targeted therapies, particularly for advanced or metastatic cases, persists. Enhancing outcomes in GI-NETs management is crucial, emphasizing the need for ongoing research and development. In our laboratory, we conducted a multitarget compound screening, identifying FAK (BI-0319) and SYK (BI1002494) kinase inhibitors for their anti-proliferative effects on GI-NETs cell lines. SYK and FAK are pivotal in focal adhesions, influencing cell adhesion and migration. SYK, classically associated with immune responses, also impacts focal adhesions, influencing cell movement. FAK, a central adhesion complex component, activates during cell-ECM interactions, governing cell behaviour. Their interplay highlights the intricate relationship between immune signalling (SYK) and adhesion dynamics (FAK), contributing to a comprehensive understanding of cellular processes. Our objective was to characterize the mechanisms of action of FAK and SYK inhibitors in GI-NETs cell lines.

Methods: Using the Small intestine NET cell line GOT1 and colorectal cancer NET cell line COLO320DM as models, cells were cultivated in both 2D and 3D. Cell viability was assessed using crystal violet and cell-titer glo assays. Apoptosis was measured using the 3/7 caspase assay. Protein expression was detected by western blot and immunofluorescence. Gene expression was determined using QPCR.

Results: Both cell lines exhibited high levels of SYK and FAK. The IC50 of FAK (BI-0319) and SYK (BI1002494) was determined in both 2D and 3D. Apoptosis activation using the caspase 3/7 assay revealed limited engagement. Growth curve and real-time time-lapse analyses showed both compounds had significant anti-proliferative effects, delaying cell proliferation, and eventually leading to cell death.

Conclusion: FAK (BI-0319) and SYK (BI1002494) serve as valuable tools to understand the roles of SYK and FAK in GI-NETs biology. Further studies are warranted to investigate their roles in controlling the cell cycle and microtubule formation.