Classic Hodgkin lymphoma (cHL) has a rich immune infiltrate, which is an intrinsic component of the neoplastic process. Malignant Hodgkin Reed-Sternberg cells (HRSC) create an immunosuppressive microenvironment by the expression of regulatory molecules, preventing T-cell activation. It has also been demonstrated that mononuclear phagocytes (MNPs) in the vicinity of HRSC express similar regulatory mechanisms in parallel, and their presence in tissue is associated with inferior patient outcomes. MNPs in cHL have hitherto been identified with a small number of canonical markers and are usually described as 'tumor-associated macrophages'. The organization of MNP networks and interactions with HRSC remains unexplored at high resolution. Here, we defined the global immune cell composition of cHL and non-lymphoma lymph nodes, integrating data across single-cell RNA sequencing, spatial transcriptomics, and multiplexed immunofluorescence. We observed that MNPs comprise multiple subsets of monocytes, macrophages and dendritic cells (DCs). Classical monocytes, macrophages and conventional DC2 were enriched in the vicinity of HRSC, but plasmacytoid DCs and activated DCs were excluded. Unexpectedly, cDCs and monocytes expressed immunoregulatory checkpoints PD-L1, TIM-3, and the tryptophan-catabolizing protein IDO, at the same level as macrophages. Expression of these molecules increased with age. We also found that classical monocytes are important signaling hubs, potentially controlling the retention of cDC2 and ThExh via CCR1-, CCR4-, CCR5-, and CXCR3-dependent signaling. Enrichment of the cDC2-monocyte-macrophage network in diagnostic biopsies is associated with early treatment failure. These results reveal unanticipated complexity and spatial polarization within the MNP compartment, further demonstrating their potential roles in immune evasion by cHL.

Em 2014, o tofacitinibe, um medicamento modificador do curso da doença (MMCD) sintético, alvo‐específico, inibidor seletivo das Janus quinases (JAK), foi aprovado para uso no Brasil. Este documento de posicionamento tem o objetivo de atualizar as recomendações da Sociedade Brasileira de Reumatologia (SBR) sobre o tratamento da artrite reumatoide (AR) no Brasil, especificamente com relação ao uso de MMCD sintéticos alvo‐específicos. O método dessa recomendação incluiu revisão bibliográfica de artigos científicos, feita na base de dados Medline. Após a revisão, foi produzido um texto, que responde a perguntas na estrutura Pico, e considera questões de eficácia e segurança do uso do tofacitinibe para tratamento de AR em diferentes situações (como primeira linha de tratamento, após falha ao metotrexato [MTX] ou outros MMCD sintéticos convencionais, após falha da terapia biológica). Com base nas evidências existentes, e considerando os dados disponíveis sobre eficácia, segurança e custo das medicações disponíveis para tratamento da doença no Brasil, a Comissão de AR da SBR, após processo de discussão e votação de propostas, estabeleceu o seguinte posicionamento sobre o uso de tofacitinibe para o tratamento da AR no Brasil: “Tofacitinibe, em monoterapia ou em associação ao MTX, é uma opção para os pacientes com AR em atividade moderada ou alta, após falha de pelo menos dois esquemas com diferentes MMCD sintéticos e um esquema de MMCD biológico”. O grau de concordância com essa recomendação foi 7,5. Esse posicionamento poderá ser revisto nos próximos anos, com a maior experiência adquirida com o uso do medicamento.In 2014, tofacitinib, a target‐specific, synthetic disease modifying anti rheumatic drug (DMARD) and a selective inhibitor of Janus kinase (JAK) was approved for use in Brazil. This position paper aims to update the recommendations of the Brazilian Society of Rheumatology (SBR) on the treatment of rheumatoid arthritis (RA) in Brazil, specifically regarding the use of target‐specific synthetic DMARDs. The method of this recommendation consisted of a literature review of scientific papers held on the Medline database. After this review, a text was produced, answering questions in Pico structure, considering efficacy and safety issues of tofacitinib use for RA treatment in different scenarios (such as first‐line treatment after failure with methotrexate [MTX] or other conventional synthetic DMARDs after failure with biological therapy). Based on existing evidence, and considering the available data on efficacy, safety and cost of medications available to treat the disease in Brazil, the RA Commission of SBR, after a process of discussion and voting on proposals, established the following position on the use of tofacitinib for treatment of RA in Brazil: “Tofacitinib, alone or in combination with MTX, is an alternative for RA patients with moderate or high activity after failure of at least two different synthetic DMARDs and one biological DMARD.” The level of agreement with this recommendation was 7.5. This position may be reviewed in the coming years, in the face of a greater experience with the use of this medication.

Cutaneous T cell lymphomas (CTCL) represent rare extranodal non-Hodgkin’s lymphomas, which are characterised by pleomorphic skin lesions and distinct T-cell markers. CTCL is a relatively benign disease in its early stages, but survival rates decrease significantly with progression. Histone deacetylase inhibitors (HDACi) have recently emerged as a new class of targeted anticancer therapies for CTCL, which have been shown to induce growth inhibition, terminal differentiation and apoptosis in various cancers in vitro and in vivo. In addition to the intrinsic anticancer properties of HDACi, recent studies have demonstrated its ability to synergise with phototherapy. In particular, we examine the therapeutic potential of HDACi in combination with ultraviolet A (UV-A) phototherapy, employing a halogenated DNA minor groove binding ligand called UVASens as a photosensitiser. In vitro studies have demonstrated that UVASens is approximately 1000-fold more potent than current psoralens. The extreme photopotency of UVASens allows the use of lower radiation doses minimising the carcinogenic risks associated with the long-term use of phototherapy. Considering, previous findings using the photosensitiser UVASens and potential synergy of HDACi with phototherapy, it was hypothesised that HDACi will augment photochemotherapy-induced cytotoxicity in CTCL MyLa cells. The findings indicated that combinations of UVASens/UV-A photochemotherapy and HDACi significantly decreased cell viability and increased apoptosis and DNA double-strand breaks in MyLa cells.

Glioblastoma (GBM), the most common primary brain tumor, is the leading cause of deaths related to tumors in the central nervous system. The prognosis of GBM patients is currently poor, and the mechanisms underlying GBM genesis remain unclear. The expression of MUC4, a high-molecular-weight and highly glycosylated protein, has been studied in many cancers. However, information on MUC4 expression in GBM is limited. In this study, we found that MUC4 was overexpressed in GBM cell lines and tissues. The proliferation and invasive potential of GBM cells were significantly increased by the ectopic expression of MUC4. By contrast, RNA interference targeting MUC4 in GBM cells significantly decreased the proliferation and invasive potential of GBM cells. We also found that the expression of epidermal growth factor receptor (EGFR) was modulated by MUC4. EGFR inhibition by siRNA reversed the MUC4-induced proliferation and invasion. These results indicated that MUC4 expression in GBM was important in GBM cell proliferation and invasion, which may be partly associated with EGFR overexpression.

DDX3X is a ubiquitously expressed RNA helicase involved in multiple stages of RNA biogenesis. DDX3X is frequently mutated in Burkitt lymphoma, but the functional basis for this is unknown. Here, we show that loss-of-function DDX3X mutations are also enriched in MYC-translocated diffuse large B cell lymphoma and reveal functional cooperation between mutant DDX3X and MYC. DDX3X promotes the translation of mRNA encoding components of the core translational machinery, thereby driving global protein synthesis. Loss-of-function DDX3X mutations moderate MYC-driven global protein synthesis, thereby buffering MYC-induced proteotoxic stress during early lymphomagenesis. Established lymphoma cells restore full protein synthetic capacity by aberrant expression of DDX3Y, a Y chromosome homolog, the expression of which is normally restricted to the testis. These findings show that DDX3X loss of function can buffer MYC-driven proteotoxic stress and highlight the capacity of male B cell lymphomas to then compensate for this loss by ectopic DDX3Y expression.

Children with B-cell non-Hodgkin lymphoma (B-NHL) have an excellent chance of survival, however, current clinical risk stratification places as many as half of patients in a high-risk group receiving very intensive chemo-immunotherapy. TP53 alterations are associated with adverse outcome in many malignancies; however, whilst common in paediatric B-NHL, their utility as a risk classifier is unknown. We evaluated the clinical significance of TP53 abnormalities (mutations, deletion and/or copy number neutral loss of heterozygosity) in a large UK paediatric B-NHL cohort and determined their impact on survival. TP53 abnormalities were present in 54.7% of cases and were independently associated with a significantly inferior survival compared to those without a TP53 abnormality (PFS 70.0% vs 100%, p < 0.001, OS 78.0% vs 100%, p = 0.002). Moreover, amongst patients clinically defined as high-risk (stage III with high LDH or stage IV), those without a TP53 abnormality have superior survival compared to those with TP53 abnormalities (PFS 100% vs 55.6%, p = 0.005, OS 100% vs 66.7%, p = 0.019). Biallelic TP53 abnormalities were either maintained from the presentation or acquired at progression in all paired diagnosis/progression Burkitt lymphoma cases. TP53 abnormalities thus define clinical risk groups within paediatric B-NHL and offer a novel molecular risk stratifier, allowing more personalised treatment protocols.

FOXO1 has an oncogenic role in adult germinal center-derived lymphomas, in which mutations, predominately within the AKT recognition motif, cause nuclear retention of FOXO1, resulting in increased cell proliferation. To determine the prevalence and distribution of FOXO1 mutations in pediatric Burkitt lymphoma (BL), we sequenced a large number of sporadic and endemic BL patient samples. We report a high frequency of FOXO1 mutations in both sporadic and endemic BL at diagnosis, occurring in 23/78 (29%) and 48/89 (54%) samples, respectively, as well as 8/16 (50%) cases at relapse. Mutations of T24 were the most common in sporadic BL but were rare in endemic cases, in which mutations of residue S22, also within the AKT recognition motif, were the most frequent. FOXO1 mutations were almost always present in the major tumor cell clone but were not associated with outcome. Analysis of other recurrent mutations reported in BL revealed that FOXO1 mutations were associated with mutations of DDX3X and ARID1A, but not MYC, TCF3/ID3, or members of the phosphatidylinositol 3-kinase signaling pathway. We further show common nuclear retention of the FOXO1 protein, irrespective of mutation status, suggesting alternative unknown mechanisms for maintaining FOXO1 transcriptional activity in BL. CRISPR/Cas9 knockout of FOXO1 in an endemic cell line produced a significant decrease in cell proliferation, supporting an oncogenic role for FOXO1 in endemic BL. Thus, FOXO1 is frequently mutated in both sporadic and endemic BL and may offer a potential therapeutic target for pediatric BL patients worldwide.