The Role of MicroRNA in Graft-Versus-Host-Disease: A Review

Diagnosis of Cutaneous Acute Graft‑Versus‑Host Disease Through Circulating Plasma miR-638, miR-6511b-5p, miR-3613-5p, miR-455-3p, miR-5787, and miR-548a-3p as Prospective Noninvasive Biomarkers Following Allogeneic Hematopoietic Stem Cell Transplantation

BACKGROUND

There are currently no laboratory tests that can accurately predict the likelihood of developing acute graft-versus-host disease (aGVHD), a patient's response to treatment, or their survival chance. This research aimed to establish circulating miRNAs as diagnostic, prognostic, or predictive biomarkers of aGVHD.

METHODS

In a prospective cohort, we studied the incidence of cutaneous aGVHD in AML patients undergoing allo-HSCT at Shariati Hospital in Tehran, Iran during 2020-2023. Patients with cutaneous aGVHD were labeled as the case group, while patients without cutaneous aGVHD were selected as the control group. Accordingly, the expression levels of six significant miRNAs (miR-638, miR-6511b-5p, miR-3613-5p, miR-455-3p, miR-5787, miR-548a-3p) were evaluated by quantitative reverse transcription-polymerase chain reaction (RTqPCR) in three different time-points: before transplantation, on day 14 and day 21 after transplantation.

RESULTS

The levels of plasma miR-455-3p, miR-5787, miR-638, and miR-3613-5p were significantly downregulated, while miR-548a-3p, and miR-6511b-5p were significantly upregulated in individuals with cutaneous aGVHD in comparison to patients without GVHD. Additionally, the possibility for great diagnostic accuracy for cutaneous aGVHD was revealed by ROC curve analysis of differentially expressed miRNAs (DEMs).

CONCLUSION

The study findings encourage us to hypothesize that the aforementioned miRNAs may contribute to the predominance of aGVHD, particularly low-grade cutaneous aGVHD.

Using Targeted Transcriptome and Machine Learning of Pre- and Post-Transplant Bone Marrow Samples to Predict Acute Graft-versus-Host Disease and Overall Survival after Allogeneic Stem Cell Transplantation

Acute graft-versus-host disease (aGvHD) remains a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT). We performed RNA analysis of 1408 candidate genes in bone marrow samples obtained from 167 patients undergoing HSCT. RNA expression data were used in a machine learning algorithm to predict the presence or absence of aGvHD using either random forest or extreme gradient boosting algorithms. Patients were randomly divided into training (2/3 of patients) and validation (1/3 of patients) sets. Using post-HSCT RNA data, the machine learning algorithm selected 92 genes for predicting aGvHD that appear to play a role in PI3/AKT, MAPK, and FOXO signaling, as well as microRNA. The algorithm selected 20 genes for predicting survival included genes involved in MAPK and chemokine signaling. Using pre-HSCT RNA data, the machine learning algorithm selected 400 genes and 700 genes predicting aGvHD and overall survival, but candidate signaling pathways could not be specified in this analysis. These data show that NGS analyses of RNA expression using machine learning algorithms may be useful biomarkers of aGvHD and overall survival for patients undergoing HSCT, allowing for the identification of major signaling pathways associated with HSCT outcomes and helping to dissect the complex steps involved in the development of aGvHD. The analysis of pre-HSCT bone marrow samples may lead to pre-HSCT interventions including choice of remission induction regimens and modifications in patient health before HSCT.

Role of microRNAs in Immune Regulation with Translational and Clinical Applications

MicroRNAs (miRNAs) are 19-23 nucleotide long, evolutionarily conserved noncoding RNA molecules that regulate gene expression at the post-transcriptional level. In this review, involvement of miRNAs is summarized in the differentiation and function of immune cells, in anti-infective immune responses, immunodeficiencies and autoimmune diseases. Roles of miRNAs in anticancer immunity and in the transplantation of solid organs and hematopoietic stem cells are also discussed. Major focus is put on the translational clinical applications of miRNAs, including the establishment of noninvasive biomarkers for differential diagnosis and prediction of prognosis. Patient selection and response prediction to biological therapy is one of the most promising fields of application. Replacement or inhibition of miRNAs has enormous therapeutic potential, with constantly expanding possibilities. Although important challenges still await solutions, evaluation of miRNA fingerprints may contribute to an increasingly personalized management of immune dysregulation with a remarkable reduction in toxicity and treatment side effects. More detailed knowledge of the molecular effects of physical exercise and nutrition on the immune system may facilitate self-tailored lifestyle recommendations and advances in prevention.