An international team of researchers published an article (“Identification of altered cell signaling pathways using proteomic profiling in stable and progressive chronic lymphocytic leukemia”) in the Journal of Leukocyte Biology that reportedly reveals that certain protein markers may indicate which patients have stable forms of CLL and which have more aggressive types.
Identifying these proteins may not only help determine patients’ prognoses but also point to potential therapeutic targets for investigators who are searching for new CLL treatments for the most common form of leukemia in the Western world.
“Chronic lymphocytic leukemia (CLL) is characterized by significant biologic and clinical heterogeneity. This study was designed to explore CLL B-cells’ proteomic profile in order to identify biologic processes affected at an early stage and during disease evolution as stable or progressive,” write the investigators.
“Purified B cells from 11 untreated CLL patients were tested at two time points by liquid chromatography–tandem mass spectrometry. Patients included in the study evolved to either progressive (n = 6) or stable disease (n = 5). First, at an early stage of the disease (Binet stage A), based on the relative abundance levels of 389 differentially expressed proteins (DEPs), samples were separated into stable and progressive clusters with the main differentiating factor being the RNA splicing pathway.
“Next, in order to test how the DEPs affect RNA splicing, a RNA-Seq study was conducted showing 4,217 differentially spliced genes between the two clusters. Distinct longitudinal evolutions were observed with predominantly proteomic modifications in the stable CLL group and spliced genes in the progressive CLL group. Splicing events were shown to be six times more frequent in the progressive CLL group. The main aberrant biologic processes controlled by DEPs and spliced genes in the progressive group were cytoskeletal organization, Wnt/β-catenin signaling, and mitochondrial and inositol phosphate metabolism with a downstream impact on CLL B-cell survival and migration.
“The results offer a meaningful biological approach into the protein composition of CLL cells at an early stage of the disease, when the clinical characteristics of patients are similar, and the course of the disease is difficult to predict. Our results showed that the protein profile can however predict how the disease will further evolve,” said lead author Cristina Bagacean, PhD, of CHU de Brest, in France. “This approach could identify putative therapeutic targets in order to prevent CLL progression.”