PhD Scientific Days 2022

Pathology and Oncology III. (Poster discussion will take place in the Aula during the Coffee Break)

Investigation of miRNA Expression Patterns in Follicular Lymphoma Patients with Different Disease Outcomes

Text of the abstract

INTRODUCTION: Follicular lymphoma (FL) is the most common indolent non-Hodgkin lympoma, with an overall survival of 15 years. Although, the disease has an indolent biology, FL is characterized by a remitting, relapsing clinical course with the occurrence of high-grade transformation to a more aggressive lymphoma in around 20% of patients. Accurate patient prognostication at diagnosis is ineffective with current clinical indexes and histological methods. Recently, several attempts have been made to determine prognosis from diagnostic tissue samples at the molecular level (DNA, mRNA), but none could demonstrate clinical robustness. To date, only limited data is available of miRNA expression with regards to risk stratification in FL.

AIMS: In this study we aimed to investigate miRNA expression patterns in FL patients with poor and excellent outcome.

METHODS: We collected 40 diagnostic tissue samples from FL patients. Twenty-two patients had an excellent outcome (>10 years in remission, cured FL group: crFL) following first line immunochemotherapy (ICT), meanwhile eighteen patients transformed to aggressive lymphoma (trFL group) within five years after first line ICT. We isolated RNA from the diagnostic formalin fixed paraffin embedded samples, then we analyzed the expression of 798 miRNA genes with the nCounter NanoString platform (NanoString, USA). miRNA expression patterns were analyzed and visualized with the Rosalind webtool (Rosalind, USA).

RESULT: After normalization of miRNA expression counts to house-keeping controls, we detected 3-fold downregulation (p<0.05) of five miRNAs (miR-769-3p, miR-656-3p, miR-494-3p, miR-575, miR-630) in the crFL group compared to the trFL group. None of the investigated miRNAs were selectively upregulated in the trFL group.

CONCLUSION: In this study we describe five miRNAs, whose downregulation in the diagnostic tissue samples indicate excellent prognosis following ICT. Future studies are needed to elaborate the functional role of these miRNAs in FL.

Funding: NKFIH KDP-1022882, EFOP-3.6.3-VEKOP-16-2017-00009, ÚNKP-21-3, H2020-739593, K21_137948, TKP2021-EGA-24, TKP2021-NVA-15 and Elixir Hungary.