Metformin Treatment Induces Different Response in Pheochromocytoma/Paraganglioma Tumour Cells and in Primary Fibroblasts

Abstract

Pheochromocytoma/paragangliomas (PPGLs) are neuroendocrine tumours, often non-metastatic, but without available effective treatment for their metastatic form. Recent studies have shown that metformin exhibits antiproliferative activity in many human cancers, including PPGLs. Nevertheless, no data are available on the role of metformin on PPGL cells (two-dimension, 2D) and spheroids (three-dimension, 3D) migration/invasion. In this study, we observed that metformin exerts an antiproliferative effect on 2D and 3D cultures of pheochromocytoma mouse tumour tissue (MTT), either silenced or not for the SDHB subunit. However, metformin did not affect MTT migration. On the other hand, metformin did not have a short-term effect on the proliferation of mouse primary fibroblasts, but significantly decreased their ability to migrate. Although the metabolic changes induced by metformin were similar between MTT and fibroblasts (i.e., an overall decrease of ATP production and an increase in intracellular lactate concentration) the activated signalling pathways were different. Indeed, after metformin administration, MTT showed a reduced phosphorylation of Akt and Erk1/2, while fibroblasts exhibited a downregulation of N-Cadherin and an upregulation of E-Cadherin. Herein, we demonstrated that metformin has different effects on cell growth and spread depending on the cell type nature, underlining the importance of the tumour microenvironment in dictating the drug response.

Metabolomics in paraganglioma: applications and perspectives from genetics to therapy

“…Interestingly, metformin lowers the migratory capacity specifically in SDHB silenced cells cocultured with fibroblasts, but not in wildtype tumor cells (Martinelli et al, 2022). Since metformin activates AMP kinase by phosphorylation, it may counteract the inhibitory effect of succinate-dependent CDK5 activity on AMP kinase (Zhou et al, 2001, Gupta et al, 2022.…”

The 3D in vitro Adrenoid cell model recapitulates the complexity of the adrenal gland

“…Adrenoids and spheroids were maintained in DMEM supplemented with 10% FBS which was chosen after different experiments performed to optimize the medium for the mixed culture (Supplemental Data). This is the medium usually used for MTT-spheroid cultures 15,40 , and for monolayer experiments with H295R 41 , except for some growth supplementations 27 . To assess Adrenoid and spheroid growth, culture medium was replaced with fresh medium at T0, and images were acquired at different time points (T0, 3, 5, 7 and 10 days), and diameters were measured with ImageJ software 42 .…”

“…Given the physiological relevance of this complex interaction, it is also very likely an impact of the non-tumoral medullary and its cortical counterpart in adrenocortical carcinoma and in pheochromocytoma condition, respectively. To study the mechanisms underlying this intra-gland crosstalk as well as for drug testing, it is mandatory to develop a 3D multicellular spheroid structure consisting in both cortical and medullary cell types, which resembles the functionality of the organ and the complexity of interactions between the two cell types 7,15 .…”

Practical therapeutic approach in the management of diabetes mellitus secondary to Cushing’s syndrome, acromegaly and neuroendocrine tumours

“…When using GLP1-RA or DPP4-i alone or combined with metformin is not enough to adequately manage hyperglycaemia, we suggest adding pioglitazone. Metformin and pioglitazone, in addition to their metabolic effect, also have an inhibiting effect on pheochromocytomas cell proliferation ( 82 , 83 ). As a last step, basal insulin or a basal bolus insulin scheme should be used when glycaemic control is difficult to obtain.…”