Emerging functions of FMNL1 in myeloid neoplasms: insights from bioinformatics to biological and pharmacological landscapes.

Background: Myeloid neoplasms encompass disorders characterized by abnormal myeloid cell proliferation and differentiation, including myelodysplastic syndromes (MDS), myeloproliferative neoplasms, acute myeloid leukemia (AML), and chronic myeloid leukemia (CML). Formin-like protein 1 (FMNL1) is involved in the regulation of the actin cytoskeleton and is predominantly expressed in hematopoietic cells. Given its role in leukemia cell proliferation, survival, migration, and invasion, this study investigates FMNL1 expression in normal hematopoiesis and myeloid neoplasms and explores associations with clinical-laboratory characteristics, mutational status, and survival outcomes in AML.

Methods: Transcript levels of FMNL1 from several blood-forming cell populations and myeloid neoplasms were extracted from publicly available databases. Myeloid neoplasm cell lines were used for gene/protein expression and cell differentiation studies. Functional genomics analysis was performed using RNA-seq data from The Cancer Genome Atlas (TCGA) AML study, and drug sensitivity predictions were investigated using Beat AML and Genomics of Drug Sensitivity in Cancer (GDSC) datasets. Statistical analyses assessed the impact of FMNL1 expression on clinical outcomes.

Results: FMNL1 was highly expressed in metamyelocytes, neutrophils, and monocytes compared to hematopoietic stem cells, and its expression increased with granulocytic differentiation. FMNL1 expression was elevated in AML and CML patients compared to healthy donors. FMNL1 expression was not significantly associated with clinical-laboratory characteristics or survival outcomes but showed a higher frequency of WT1 transcription factor (WT1) mutations with low FMNL1 expression in AML patients. High FMNL1 expression in AML correlated with immune response and inflammatory activity pathways. FMNL1 mRNA levels influenced drug sensitivity in AML models, with correlations observed for specific antineoplastic agents.

Conclusions: FMNL1 plays a potential role in granulocyte differentiation and function, and its differential expression is linked to critical signaling pathways in leukemogenesis and inflammation. These findings highlight FMNL1's potential therapeutic implications in myeloid neoplasia, warranting further investigation.