Serum vault RNA1-1 levels reflect blood cells and bone marrow

Vault RNA1-1 (vtRNA1-1) exhibits antiviral and anti-apoptotic effects in infected and malignant cells. We observed that vtRNA1-1 levels in serum fluctuate in patients with hematological disorders, but its extracellular functions remain unclear. This study evaluates the potential of serum vtRNA1-1 levels as a biomarker for hematological disorders and investigates its association with bone marrow cell density (BMC).

Blood and serum samples were collected from patients with hematological disorders, patients who underwent bone marrow examination, PBSCT donors, and AML patients who received chemotherapy. VtRNA1-1 levels were measured using real-time quantitative RT-PCR. BMC was calculated by digital image analysis, and multiple regression analysis was performed using serum vtRNA1-1 and hematological and biochemical data as explanatory variables.

The vtRNA1-1 levels in the blood of 11 patients with hematological disorders averaged 10.8 log₁₀ cps/ml, significantly higher than 8.4 log₁₀ cps/ml in serum. Multiple regression analysis estimated the vtRNA1-1 expression levels of each blood cell. In 87 patients who underwent bone marrow examination, there was a significant correlation between serum vtRNA1-1 levels and BMC (Rs = 0.24, P = 0.023). In PBSCT donors, serum vtRNA1-1 levels increased after G-CSF administration (P < 0.001), and in AML patients, serum vtRNA1-1 levels decreased after the initiation of chemotherapy, fluctuating in parallel with white blood cell counts.

Our findings suggest that serum vtRNA1-1, derived from peripheral blood and bone marrow cells, can potentially serve as a clinical biomarker in specific diseases.