Functional genomics and tumor microenvironment analysis reveal prognostic biological subtypes in Mantle cell lymphoma.

Mantle cell lymphoma (MCL) is a genetically and clinically heterogeneous B-cell malignancy. We studied two MCL cohorts with differing treatment patterns: one enriched for immunochemotherapy, the other for chemotherapy alone. TP53 alterations are consistently associated with poor prognosis, whereas ATM mutations correlate with improved outcomes following rituximab-based chemotherapy. Based on recurrent genetic events, six clusters are identified and refined into three prognostic groups: high-risk (TP53 mutations and deletions at 17p13.3, 13q14.2, and 19p13.3), intermediate-risk (ATM and epigenetic regulator mutations, or gains at 8q/17q/15q), and low-risk (lacking TP53 alterations, rare ATM mutations without 11q deletions, gains at 3q, deletions at 6q). Transcriptomic analysis reveals enrichment of proliferation, metabolism-promoting gene signatures in high-risk; angiogenesis and NOTCH signaling in intermediate-risk; and proinflammatory-related (i.e., IFNα, TNFα) in low-risk MCLs. Multi-proteomic spatial profiling using imaging mass cytometry (IMC) demonstrates enrichment of CD4⁺ T cells with high expression of exhaustion markers and a dominant population of myeloid cells skewed toward an M2-like phenotype. Spatially, TP53-perturbed MCLs are immune-infiltrated yet exhausted, while ATM-perturbed cases remain immune-cold with dense tumors. Functional analysis shows that p53 represses BCR signaling through PTPN6 activation. Collectively, these findings highlight distinct molecular and immune landscapes and reveal therapeutic vulnerabilities in high-risk TP53-perturbed MCL.