Molecular Examination of Differentially Expressed Genes in the Brains of Experimental Autoimmune Encephalomyelitis Mice Post Herceptin Treatment

Mena Al-Ani; Noha Mousaad Elemam; Ibrahim Y Hachim; Tom K Raju; Jibran Sualeh Muhammad; Mahmood Y Hachim; Riyad Bendardaf; Azzam A Maghazachi

doi:10.2147/JIR.S310535

Molecular Examination of Differentially Expressed Genes in the Brains of Experimental Autoimmune Encephalomyelitis Mice Post Herceptin Treatment

J Inflamm Res. 2021 Jun 17:14:2601-2617. doi: 10.2147/JIR.S310535. eCollection 2021.

Authors

Mena Al-Ani^#^{1

2}, Noha Mousaad Elemam^#^{1

2}, Ibrahim Y Hachim¹, Tom K Raju², Jibran Sualeh Muhammad^{1

2}, Mahmood Y Hachim³, Riyad Bendardaf^{1

4}, Azzam A Maghazachi^{1

2}

Affiliations

¹ Department of Clinical Sciences, College of Medicine, University of Sharjah, Sharjah, United Arab Emirates.
² The Immuno-Oncology Group, Sharjah Institute for Medical Research (SIMR), University of Sharjah, Sharjah, United Arab Emirates.
³ College of Medicine, Mohammed bin Rashid University of Medicine and Health Sciences, Dubai, United Arab Emirates.
⁴ University Hospital Sharjah, Sharjah, United Arab Emirates.

^# Contributed equally.

Abstract

Objective: Herceptin (trastuzumab) is an approved drug for treating HER2⁺ breast cancer patients, but its use for other diseases is not established. We sought to investigate the effects of Herceptin on ameliorating experimental autoimmune encephalomyelitis (EAE) and to examine its effects on the expression of various genes.

Methods: We used in-silico analysis of publicly available data, qRT-PCR, and immunohistochemistry (IHC) to determine the expression of HER2⁺ cells in the brains of EAE mice. IHC was also utilized to determine the anti-inflammatory effects of Herceptin. The ability of Herceptin to alleviate the EAE clinical score was measured in these mice. Bioinformatics analysis of publicly available data and qRT-PCR were performed to investigate the differentially expressed genes that were either up-regulated or down-regulated during the high clinical score (HCS) of the disease.

Results: We observed that HER2/Erbb2, the receptor for Herceptin is upregulated in the brains of EAE mice when the brains were examined at the HCS stage. Further, we demonstrated that Herceptin ameliorates the EAE disease, increasing re-myelination, reducing brain inflammation, CD3⁺ T cell accumulation, and HER2⁺ cells in the brains of these mice. Molecular analysis demonstrated the expression of different genes that were either up-regulated or down-regulated during the HCS of the disease. Our combined bioinformatics and qRT-PCR analyses show increased mRNA expression of Atp6v0d2, C3, C3ar1, Ccl3, Ccl6, Cd74, Clec7a, Cybb, H2-Aa, Hspb1, Lilr4b, Lilrb4a, Mpeg1, Ms4a4a, Ms4a6c, Saa3, Serpina3n and Timp1, at HCS. Except for the mRNA levels of Cd74 and Clec7a which were increased at HCS when Herceptin was used in both prophylactic and therapeutic regimens, the levels of other described mRNAs were reduced.

Conclusion: These novel findings show that Herceptin ameliorates the clinical score in EAE mice and are the first to investigate in detail the differential gene expression post-treatment with the drug.

Keywords: EAE; bioinformatics; differential gene expression; herceptin; high clinical score; immunohistochemistry; prophylactic; qRT-PCR; therapeutic.

Grants and funding

This work was supported by grants from Terry Fox Foundation and the Sharjah Research Academy. Mena Al-Ani is a recipient of the L’Oréal-UNESCO For Women in Science Middle East Young Talents Programme.