BackgroundMesothelin (MSLN) has been implicated in cancer migration, invasion, and prognosis, making it a potential tumor marker. However, the precise role of MSLN in the migration and invasion of malignant pleural mesothelioma (MPM) remains elusive, and effective noninvasive methods for assessing MSLN status are currently lacking. In this study, we focused on MSLN expression and elucidated the underlying mechanisms by which MSLN regulates migration and invasion in MPM. Building upon this knowledge, we developed an MRI nanoprobe that targets MSLN to assess its status in vitro and in vivo by comparing T2 signal intensity and T2 values on magnetic resonance imaging examinations. This nanoprobe combines the anatomical information obtained from MRI with biological information obtained from MSLN for comprehensive evaluation of MPM.ResultsNotably, we observed that MSLN expression in the epithelial type of MPM was higher and increased continuously with tumor growth than that in other types. In addition, MSLN upregulation promoted N-cadherin, matrix metalloproteinase-7, and MMP9 expression and resulted in higher migration/invasion ability and shorter survival. We synthesized MSLN-targeted nanoprobes (Fe3O4@SiO2-PEG-MSLN, FSPM) to assess MSLN expression by comparing the T2 signal intensity and T2 value of different cell lines and mice after 14, 28, and 42 days of modeling. Remarkably, MSLN-targeted nanoprobes demonstrated excellent targeting capabilities. In vitro studies revealed a pronounced reduction in T2 signal intensity and T2 values of the epithelial type as the probe concentration increased. In addition, in vivo experiments demonstrated a gradual decline in these parameters over time, particularly in the epithelial type as compared to the biphasic type, corresponding to the dynamic expression patterns of MSLN during different growth stages.ConclusionOur comprehensive research succeeded in confirming the regulatory mechanisms by which MSLN influences migration and invasion. Moreover, we introduced a promising method for monitoring MSLN expression that may help in facilitating the early detection, histological subtype identification, and assessment of migration, invasion, and prognosis in MPM.