The relationship of human tissue MicroRNAs with those from cerebrospinal fluid, tear, sweat, semen, and saliva

We previously revealed the relationships of human tissue microRNAs (miRNAs) with those from various body fluids including plasma, bile, urine, serum, and feces, which provided valuable clues for discovering miRNA-based biomarkers for specific diseases. However, it remains unknown for the relationships of human tissue miRNAs with those from other body fluids. Here, by analyzing miRNA expression data from 39 tissue types from healthy humans and various body fluids including cerebrospinal fluid, tear, sweat, semen, and saliva, we have uncovered the relationships of human healthy tissues with those body fluids. All miRNA expression data from body fluids were significantly positively correlated with total expression levels of miRNAs in 39 healthy tissues, and body fluids from different sources exhibited distinct patterns in their relationship with healthy tissues. Moreover, body fluids from different sources showed the highest correlation with different healthy tissues. Notably, saliva samples from patients with oral cavity squamous cell carcinoma showed higher correlations with all tissues than those from healthy controls. These findings together provide evidence for the application of body fluid miRNAs as biomarkers for the diagnosis and treatment of relevant human diseases.