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Updated: May 3, 2026
An In Ovo Model for Testing Insulin-mimetic Compounds
Published on: April 23, 2018
Classifying the adverse mitogenic mode of action of insulin analogues using a novel mechanism-based genetically
B ter Braak1, C L E Siezen, N Kannegieter
1Division of Toxicology, Leiden Academic Center for Drug Research, Leiden University, Einsteinweg 55, 2333 CC, Leiden, The Netherlands.
Abstract:
Insulin analogues are widely used in clinical practice. Modifications on the insulin molecular structure can affect the affinity and activation towards two closely related receptor tyrosine kinases: the insulin receptor (INSR) and the insulin-like growth factor 1 receptor (IGF1R). A switch towards higher IGF1R affinity is likely to emphasize mitogenesis rather than glucose metabolism. Relevant well-validated experimental tools to address the insulin analogue activation of either INSR or IGF1R are missing. We have established a panel of human MCF-7 breast cancer cell lines either ectopically expressing the INSR (A or B isoform) in conjunction with a stable knockdown of the IGF1R or ectopically expressing the IGF1R in conjunction with a stable knockdown of the INSR. In these cell lines, we systematically evaluated the INSR and IGF1R receptor activation and downstream mitogenic signalling of all major clinical relevant insulin analogues in comparison with insulin and IGF1R. While most insulin analogues primarily activated the INSR, the mitogenic activation pattern of glargine was highly similar to IGF1 and insulin AspB10, known to bind IGF1R and induce carcinogenesis. Yet, in a long-term proliferation assay, the proliferative effect of glargine was not much different from regular insulin or other insulin analogues. This was caused by the rapid enzymatic conversion into its two metabolic active metabolites M1 and M2, with reduced mitogenic signalling through the IGF1R. In summary, based on our new cell models, we identified a similar mitogenic potency of insulin glargine and AspB10. However, rapid enzymatic conversion of glargine precludes a sustained activation of the IGF1R signalling pathway.
Insights
Insulin glargine shows mitogenic potential similar to IGF1, activating the insulin-like growth factor 1 receptor (IGF1R). However, rapid conversion into metabolites limits sustained IGF1R signaling, reducing its long-term proliferative effect compared to other insulin analogues.
Area of Science:
- Endocrinology
- Molecular Biology
- Cancer Research
Background:
- Insulin analogues are widely used, but their molecular modifications can alter affinity for insulin receptor (INSR) and insulin-like growth factor 1 receptor (IGF1R).
- Higher IGF1R affinity may promote mitogenesis over glucose metabolism, necessitating tools to study receptor activation.
- Existing experimental tools to assess insulin analogue activation of INSR and IGF1R are limited.
Purpose of the Study:
- To establish and utilize novel cell models for evaluating insulin analogue activation of INSR and IGF1R.
- To compare the mitogenic signaling of clinical insulin analogues, insulin, and IGF1.
- To investigate the specific receptor activation patterns and downstream effects of insulin glargine.
Main Methods:
- Developed MCF-7 breast cancer cell lines with specific INSR/IGF1R expression or knockdown.
- Systematically evaluated receptor activation and downstream mitogenic signaling of insulin analogues.
- Conducted long-term proliferation assays to assess cellular response to insulin glargine.
Main Results:
- Insulin glargine exhibited a mitogenic activation pattern similar to IGF1 and insulin AspB10, suggesting IGF1R binding.
- Despite initial IGF1R activation, glargine's long-term proliferative effect was comparable to regular insulin due to rapid conversion to metabolites M1 and M2.
- Metabolites M1 and M2 showed reduced mitogenic signaling via IGF1R.
Conclusions:
- Novel cell models revealed insulin glargine's potential for mitogenic signaling through IGF1R, akin to AspB10.
- Rapid enzymatic conversion of insulin glargine into inactive metabolites prevents sustained IGF1R pathway activation.
- Understanding these mechanisms is crucial for assessing the oncogenic potential of insulin analogues.
