Spheroid Culture Methods to Study Pancreatic Cancer Cell Lines (pNEN)
Pancreatic neuroendocrine neoplasms (pNEN) comprise of a group of rare tumours that originates from the islets of langerhans (1). Diagnosis of pNEN is often complicated by hormone hyper secretion that culminates in early clinical manifestations. 85% of patients do not exhibit a specific syndrome and therefore the malignant stage tends to be diagnosed once it reaches an advanced stage (2). Although surgical resection remains an effective option, most tumours are unresectable once it reaches the advanced stage (3-4). A wide array of therapeutic measures are employed that includes biotherapy, targeted therapy, chemotherapy and radiation as well as peptide receptor radionuclide therapy, that helps with the symptoms and even stabilise tumor growth, but not as a cure (5). Therefore it is of importance to develop methods that enable us to understand disease progression especially in the early stages.
The value of 3D cultures over 2D monolayer cultures
For decades 3D cultures have helped to generate clinically relevant research models that mimic in vivo like cellular behaviour. 3D cultures when compared with 2D culture models, contain representative gene expression profiles and structures along with enhanced cell-cell interactions that are important for normal cell behaviour. All these benefits of 3D cultures have proved it to be indispensable for drug discovery research (6,7).
3D spheroid techniques adaptable for pNEN cell lines
3D cultures comprise of scaffold based and scaffold free cultures. pNEN cell lines are found compatible with scaffold free cultures such as hanging drop cultures, low attachment plate cultures as well as in ultra low attachment plates (ULA) plates albeit the latter proved most reliable. Spheroids formed on ULA plates was compact and round as a result of robust cell-cell aggregation. Spheroids grown in this manner were validated by its ease of use in drug screens, viability and reproducibility. Thus pNENE cell lines grown as spheroid cultures in ULA Plates presents an efficient platform to study the pathophysiology of the disease as well as investigate possible therapeutic measures in drug discovery processes.
References
1. Kim JY, Hong SM. Recent updates on neuroendocrine tumors from the gastrointestinal and pancreatobiliary tracts. Arch Pathol Lab Med. (2016) 140:437–48.
2. Karmazanovsky G, Belousova E, Schima W, Glotov A. Kalinin D, Kriger A. Nonhypervascular pancreatic neuroendocrine tumors: spectrum of MDCT imaging findings and differentiation from pancreatic ductal adenocarcinoma. Eur J Radiol. (2019) 110:66–73.
3. Jun E, Kim SC, Song KB, Hwang DW, Lee JH, Shin SH, et al. Diagnostic value of chromogranin A in pancreatic neuroendocrine tumors depends on tumor size: a prospective observational study from a single institute. Surgery. (2017) 162:120–30.
4. Wolin EM. The expanding role of somatostatin analogs in the management of neuroendocrine tumors. Gastrointest Cancer Res. (2012) 5:161–8.
5. Cives M, Strosberg JR. Gastroenteropancreatic neuroendocrine tumors. CA Cancer J Clin. (2018) 68:471–87.
6. Langhans SA. Three-dimensional. Front Pharmacol. (2018) 9:6.
7. Edmondson R, Broglie JJ, Adcock AF, Yang L. Three-dimensional cell culture systems and their applications in drug discovery and cell-based biosensors. Assay Drug Dev Technol. (2014) 12:207–18.
8. Bresciani G, Hofland LJ, Dogan F, Giamas G, Gagliano T and Zatelli MC (2019) Evaluation of Spheroid 3D Culture Methods to Study a Pancreatic Neuroendocrine Neoplasm Cell Line. Front. Endocrinol. 10:682.
