Plasma vesicle miRNAs for therapy response monitoring in Hodgkin lymphoma patients.

Monique A.J Van Eijndhoven,Nils J Groenewegen,Jan R.T Van Weering,Marca H.M Wauben,Lydia Visser,Stuart Van Niele,Renee X De Menezes,D Michiel Pegtel,Josée M Zijlstra,Esther E.E Drees,Danijela Koppers-Lalic,S Rubina Baglio,Sten F.W.M Libregts,Hans Van Der Voorn,Daphne De Jong,Rienk Nieuwland,Anke Van Den Berg

doi:10.1172/jci.insight.89631

Abstract

BACKGROUND. Cell-free circulating nucleic acids, including 22-nt microRNAs (miRNAs), represent noninvasive biomarkers for treatment response monitoring of cancer patients. While the majority of plasma miRNA is bound to proteins, a smaller, less well-characterized pool is associated with extracellular vesicles (EVs). Here, we addressed whether EV-associated miRNAs reflect metabolic disease in classical Hodgkin lymphoma (cHL) patients.METHODS. With standardized size-exclusion chromatography (SEC), we isolated EV-associated extracellular RNA (exRNA) fractions and protein-bound miRNA from plasma of cHL patients and healthy subjects. We performed a comprehensive small RNA sequencing analysis and validation by TaqMan qRT-PCR for candidate discovery. Fluorodeoxyglucose-PET (FDG-PET) status before treatment, directly after treatment, and during long-term follow-up was compared directly with EV miRNA levels.RESULTS. The plasma EV miRNA repertoire was more extensive compared with protein-bound miRNA that was heavily dominated by a few abundant miRNA species and was less informative of disease status. Purified EV fractions of untreated cHL patients and tumor EVs had enriched levels of miR24-3p, miR127-3p, miR21-5p, miR155-5p, and let7a-5p compared with EV fractions from healthy subjects and disease controls. Serial monitoring of EV miRNA levels in patients before treatment, directly after treatment, and during long-term follow-up revealed robust, stable decreases in miRNA levels matching a complete metabolic response, as observed with FDG-PET. Importantly, EV miRNA levels rose again in relapse patients.CONCLUSION. We conclude that cHL-related miRNA levels in circulating EVs reflect the presence of vital tumor tissue and are suitable for therapy response and relapse monitoring in individual cHL patients.FUNDING. Cancer Center Amsterdam Foundation (CCA-2013), Dutch Cancer Society (KWF-5510), Technology Foundation STW (STW Perspectief CANCER-ID).

Highlights

Most, if not all, human tumors shed nucleic acids that end up in circulation, including DNA and mRNA/ microRNAs, collectively called extracellular RNA [1, 2]
We conclude that classical Hodgkin lymphoma (cHL)-related miRNA levels in circulating extracellular vesicles (EVs) reflect the presence of vital tumor tissue and are suitable for therapy response and relapse monitoring in individual cHL patients
TARC levels are increased in the sera of cHL patients and may reflect tumor status, since elevated levels decrease during treatment in most clinical responders [13, 14]

Summary

Introduction

If not all, human tumors shed nucleic acids that end up in circulation, including DNA and mRNA/ microRNAs (mRNA/miRNAs), collectively called extracellular RNA (exRNA) [1, 2] This realization has prompted intensive studies to demonstrate the biomarker potential of exRNA in cancer patients, as it holds notable advantages over classic tissue biopsy sampling. Because fragmented ctDNA is likely derived from apoptotic/necrotic tumor cells, with a half-life estimated between 2 and 12 hours, ctDNA may or may not signify vital tumor [9] This is a major benefit of fluorodeoxyglucose–PET/CT (FDG-PET/CT) imaging, which is currently used in clinical practice for cHL, as it detects active tumor and stroma. We addressed whether EV-associated miRNAs reflect metabolic disease in classical Hodgkin lymphoma (cHL) patients

Methods

Results

Conclusion