Targeted next-generation sequencing analysis showed SOCS1 mutations in the 3 cases, and TNFAIP3 and XPO1 mutations in one, further supporting the diagnosis of PMBL.
Recurrent mutations of the exportin 1 gene (XPO1) and their impact on selective inhibitor of nuclear export compounds sensitivity in primary mediastinal B-cell lymphoma.
"Double-hit" (DH) lymphomas are B-cell neoplasms characterized by a translocation involving MYC and either BCL2 or BCL6 In the indexed literature, there are no reported cases of PMLBCL associated with DH or triple-hit events.
PD-L1 positive rates were all higher in PMBCL and DHL than in DLBCL-NOS by SP263, SP142, RNAscope, and FISH (P = 0.001, P < 0.001, P = 0.005 and P < 0.001, respectively).
Myelin and lymphocyte (MAL) protein has been previously reported as a highly specific marker for distinguishing primary mediastinal large B-cell lymphoma (PMBL) from diffuse large B-cell lymphoma, not otherwise specified (DLBCL, NOS).
In murine xenograft models of cHL and MLBCL with 9p24.1/JAK2 amplification, chemical JAK2 inhibition significantly decreased JAK2/STAT signaling and tumor growth and prolonged survival.
Herein, we integrate high-resolution copy number data with transcriptional profiles and identify the immunoregulatory genes, PD-L1 and PD-L2, as key targets at the 9p24.1 amplification peak in HL and MLBCL cell lines.
Integrative analysis reveals selective 9p24.1 amplification, increased PD-1 ligand expression, and further induction via JAK2 in nodular sclerosing Hodgkin lymphoma and primary mediastinal large B-cell lymphoma.
Taken together, these results suggest that JAK2 signaling in PMLBCLs occurs by mechanisms distinct from JAK2 (V617F) or JAK2 exon 12 activating mutations.
Because MAL protein is located in detergent-insoluble glycolipid-enriched membrane (GEM) domains involved in lymphocyte signal transduction, abnormal expression of MAL protein in the B-lymphoid lineage may have significant implications in PMBL lymphomagenesis.
Despite the few cases, these results demonstrate that this therapy, which includes anti-CD20, given in a multicenter setting, is feasible with acceptable toxicity in children with PMLBL.
PD-L2 staining was present in 78% of primary mediastinal large B-cell lymphoma but in fewer cases in all other categories including 40% of follicular dendritic cell sarcoma and 7% of anaplastic large cell lymphoma.
Despite the few cases, these results demonstrate that this therapy, which includes anti-CD20, given in a multicenter setting, is feasible with acceptable toxicity in children with PMLBL.