Bruno Lorusso

Generalized lymphatic anomaly (GLA) is a congenital, non-neoplastic vascular anomaly characterized by diffuse or multifocal involvement and infiltration of multiple organs. Most GLA cases harbor “hotspot” somatic missense single nucleotide mutations in the PIK3CA gene, whereas a minority involve mutations in other genes. Recently, rapamycin and its homologs have shown encouraging results in the treatment of alterations affecting the PI3K/AKT/mTOR pathway. Therefore, the present work aimed to expand the immunophenotypic characterization of the lymphatic lesion at the tissue level and to evaluate the in vitro viability, migration, and angiogenic capacity of endothelial cells freshly isolated from a PIK3CA-mutated GLA sample, following treatment with alpelisib, rapamycin, dactolisib, and buparlisib. We detected the p.Gln546Lys amino acid substitution in the PI3Kca helical domain in GLA-derived endothelial cells. Then, by immunohistochemical analysis, we documented altered expression of mTOR and its well-characterized downstream substrates, which regulate growth, proliferation, migration, angiogenesis, and survival of ECs. Finally, pharmacological treatment reduced GLA-EC functional properties and down-modulated the hyperactivated PI3K downstream substrates. Overall, our results suggest that routine immunohistochemistry, integrated with phospho-protein analysis and next-generation sequencing, might improve histopathological classification of vascular anomalies and facilitate the development of personalized targeted therapies, particularly in recurrent or surgically challenging cases.

Chromosome 1q21 copy number alterations (1q21+) are among the most frequent secondary events in multiple myeloma (MM), correlating with poor prognosis and therapy resistance. However, the molecular drivers of this lesion remain poorly defined. Here, we identify PYGO2, a Wnt/β-catenin co-activator located on 1q21, as a critical effector of MM progression. Analysis of primary CD138 ⁺ plasma cells and public datasets revealed that PYGO2 expression is significantly increased in 1q21+ patients and correlates with chromosome 1q copy number. High PYGO2 levels were associated with adverse cytogenetics and shorter progression-free and overall survival. Functional studies showed that PYGO2 knockdown (KD) in 1q21+ cell lines impaired proliferation, induced cell cycle perturbation coupled with CCND1 downregulation and reduced H3K4me3 enrichment, while increasing Carfilzomib and Bortezomib sensitivity. Conversely, PYGO2 overexpression enhanced cell growth and proteasome inhibitor resistance. RNA-seq profiling of KD cells revealed coordinated suppression of canonical Wnt/TCF target genes involved in proliferation and reshaped the replication stress and DNA damage response transcriptome, suggesting enhanced replication stress. RNA-seq profiling of KD cells also revealed suppression of oncogenic and immunomodulatory pathways, suggesting a broader role in tumor-microenvironment crosstalk. Overall, our data establish PYGO2 as a previously unrecognized effector of 1q21-driven aggressiveness in MM and suggest that it represents a therapeutic vulnerability in high-risk 1q21+ MM patients.

Technical parameters of CT volumes selected for segmentation

Blood immune-inflammatory features in patients developing acquired resistance to IO

Survival outcome within oligoAR and sysAR subgroups

Baseline immune-inflammatory profile of oligoAR and sysAR patients with NSCLC

List of antibodies employed for FACS analysis

Gating strategy adopted for flow cytometric (FACS) analyses

Delta radiomic profiling of oligoAR and sysAR patients

Statistically different baseline radiomic features in oligoAR vs sysAR patients