1. Academic Validation
  2. The underlying mechanisms of lorlatinib penetration across the blood-brain barrier and the distribution characteristics of lorlatinib in the brain

The underlying mechanisms of lorlatinib penetration across the blood-brain barrier and the distribution characteristics of lorlatinib in the brain

  • Cancer Med. 2020 Jun;9(12):4350-4359. doi: 10.1002/cam4.3061.
Wei Chen 1 Dujia Jin 2 Yafei Shi 1 Yujun Zhang 1 Haiyan Zhou 1 Guohui Li 1
Affiliations

Affiliations

  • 1 Department of Pharmacy, National Cancer Center/National Clinical Research Center for Cancer/Cancer Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
  • 2 Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China.
Abstract

Objective: To clarify the distribution of lorlatinib in the brain and elucidate the molecular mechanisms of lorlatinib penetration across the blood-brain barrier (BBB).

Methods: Cytological experiments were performed to investigate the growth inhibitory effect of lorlatinib on different cells (endothelial cells HUVEC, HMEC-1, and HCMEC/D3) and to investigate the protective effect of lorlatinib on neuronal cells after SH-SY5Y hypoxia/reoxygenation injury. Furthermore, rat brain tissue was sequenced, and the differentially expressed genes (secreted phosphoprotein 1 (SPP1), vascular endothelial growth factor (VEGF), transforming growth factor beta (TGF-β), Claudin, ZO-1 and P-gp) in several different drug treatment groups were verified by Real-Time PCR. Lorlatinib brain distribution was predicted by physiologically based pharmacokinetics (PBPK).

Results: Lorlatinib and crizotinib both had inhibitory effects on endothelial cells, however lorlatinib inhibited the growth of HCMEC/D3 more efficaciously than crizotinib. In the SH-SY5Y hypoxia model, lorlatinib had a greater protective effect on nerve cell damage caused by hypoxia and reoxygenation than crizotinib. The expression of SPP1, VEGF, TGF-β, and Claudin in brain tissue was significantly downregulated after lorlatinib administration, and the expression level of early growth transcription factor 1 (Egr-1) was significantly increased. The PBPK model successfully described lorlatinib concentrations in blood and brain tissue in the mouse model and gave a brain tissue partition coefficient of 0.7.

Conclusion: Lorlatinib can increase the permeability of the blood-brain barrier whereby we suggest its underlying working mechanism is related to downregulating SPP1, inhibiting VEGF, TGF-β, and Claudin subsequently reducing the number of tight junctions between BBB cells. Lorlatinib plays a protective role on injured nerve cells and does not change the amount of P-gp expression in brain tissue, which may be important for its ability to be efficacious across the BBB with a low incidence of resistance.

Keywords

Crizotinib; Lorlatinib; SPP1; blood-brain barrier.

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