Toward Precision Medicine for CIC Syndrome Using Patient-Derived iPSC Models

Zoey R. Lorusso1,2, Daniel M. Fass1, PhD, Stephen J. Haggarty1, PhD

Harvard Medical School/Center for Genomic Medicine at Massachusetts General Hospital1

Biochemistry Discipline, Natural Sciences Collegium, Eckerd College, St. Petersburg, Florida2

Abstract:

This genetic study investigates CIC Haploinsufficiency Syndrome and potential therapeutics. Patients across the literature with CIC Syndrome have presented a wide variety of phenotypic symptoms, including intellectual disability, developmental delay, autism, and epilepsy. However, in the lens of this precision medicine project, the symptom this research is most concerned with is epilepsy. The therapeutics tested targeted upregulation of CIC to restore normal protein expression levels from the CIC gene. The model used to analyze CIC protein expression was patient-derived iPSC (induced pluripotent stem cells); this model was representative of the haploinsufficient disease and the diseased protein expression. The other cell model used for this study was a patient iPSC corrected to a wild-type cell line, which was representative of the wild-type protein expression. The last cell model used to research CIC was a CRISPR CIC-knockdown cell line, which was representative of no CIC protein expression. To study CIC haploinsufficiency protein expression in cell neurons, patient-derived iPSC were induced to differentiate into cortical glutamatergic neurons by overexpression of the pro-neural factor Ngn2. This cell line is representative of the disease within the patient's epileptic brain. After therapeutics were applied to the iPSC models in treatment time periods, whole cell protein lysates were made and used for gel electrophoresis and western blot analysis, which allowed for the visualization of CIC protein. This study found that multiple therapeutics could upregulate CIC protein expression; however, “Compound A” was found to upregulate CIC protein expression the most.