Label-Free Delineation of Human Uveal Melanoma Infiltration With Pump-Probe Microscopy

Bohan Zhang; Tengteng Yao; Yaxin Chen; Chuqiao Wang; Yongyang Bao; Zhaoyang Wang; Keke Zhao; Minbiao Ji

doi:10.3389/fonc.2022.891282

Label-Free Delineation of Human Uveal Melanoma Infiltration With Pump-Probe Microscopy

Front Oncol. 2022 Jul 22:12:891282. doi: 10.3389/fonc.2022.891282. eCollection 2022.

Authors

Bohan Zhang¹, Tengteng Yao^{2

3}, Yaxin Chen¹, Chuqiao Wang^{2

3}, Yongyang Bao³, Zhaoyang Wang², Keke Zhao⁴, Minbiao Ji¹

Affiliations

¹ State Key Laboratory of Surface Physics and Department of Physics, Multiscale Research Institute of Complex Systems, Key Laboratory of Micro and Nano Photonic Structures (Ministry of Education), Academy for Engineering and Technology, Human Phenome Institute, Fudan University, Shanghai, China.
² Department of Ophthalmology, The Shanghai Tenth People's Hospital of Tongji University, Shanghai, China.
³ Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China.
⁴ Department of Ophthalmology, Shanghai Children's Medical Center, Shanghai Jiaotong University School of Medicine, Shanghai, China.

Abstract

Uveal melanoma (UM) is the most frequent primary intraocular malignancy in adults, characterized by melanin depositions in melanocytes located in the uveal tract in the eyes. Differentiation of melanin species (eumelanin and pheomelanin) is crucial in the diagnosis and management of UM, yet it remains inaccessible for conventional histology. Here, we report that femtosecond time-resolved pump-probe microscopy could provide label-free and chemical-specific detection of melanin species in human UM based on their distinct transient relaxation dynamics at the subpicosecond timescale. The method is capable of delineating the interface between melanoma and paracancerous regions on various tissue conditions, including frozen sections, paraffin sections, and fresh tissues. Moreover, transcriptome sequencing was conducted to confirm the active eumelanin synthesis in UM. Our results may hold potential for sensitive detection of tumor boundaries and biomedical research on melanin metabolism in UM.

Keywords: label-free imaging; melanin; multiphoton microscopy; pump-probe microscopy; uveal melanoma.