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Diffuse large B-cell lymphoma (DLBCL) is the most common lymphoid malignancy in adults. Aberrant activation of Hedgehog (Hh) and nuclear factor (NF)-κB pathways is ubiquitously observed and known to mediate tumor growth, survival, and chemoresistance in DLBCL. Here, we find that activation of Hh signaling is positively correlated with NF-κB pathway in DLBCL tumors, and that smoothened (SMO), the signal transducer subunit of Hh pathway, contributes to NF-κB activation through recruiting G protein subunits Gai and Ga12 to activate PKCf}/CARMA1/TRAF6/NEMO signaling axis followed by assembling of the CARMA1/BCL10/MALT17TRAF6 complex to SMO. Moreover, functional inhibition of SMO enhances the cytotoxic effects of NF-κB inhibitor. Altogether, our study reveals a noncanonical Hh signaling pathway in which SMO activates trimeric G proteins and CARMA1-associated signaling complex, leading to NF-κB activation. This signaling cascade contributes to the survival of DLBCL and may serve as a potential target for combination therapies in DLBCL. [ABSTRACT FROM AUTHOR]

Primary central nervous system lymphoma (PCNSL) is a rare and aggressive non-Hodgkin's lymphoma that affects the brain, eyes, cerebrospinal fluid, or spinal cord without systemic involvement. The outcome of patients with PCNSL is worse compared to patients with systemic diffuse large B-cell lymphoma. Given potential mortality associated with severe immune effector cell-associated neurotoxicity syndrome (ICANS), patients with PCNSL have been excluded from most clinical trials involving chimeric antigen receptor T-cell (CAR-T) therapy initially. Here, we report for the first time to apply decitabine-primed tandem CD19/CD22 dual-targeted CAR-T therapy with programmed cell death-1 (PD-1) and Bruton's tyrosine kinase (BTK) inhibitors maintenance in one patient with multiline-resistant refractory PCNSL and the patient has maintained complete remission (CR) for a 35-month follow-up period. This case represents the first successful treatment of multiline resistant refractory PCNSL with long-term CR and without inducing ICANS under tandem CD19/ CD22 bispecific CAR-T therapy followed by maintenance therapy with PD-1 and BTK inhibitors. This study shows tremendous potential in the treatment of PCNSL and offers a look toward ongoing clinical studies. [ABSTRACT FROM AUTHOR]

The mammalian constitutive photomorphogenesis 9 (COP9) signalosome (CSN), a protein complex involved in embryonic development, is implicated in cell cycle regulation and the DNA damage response. Its role in tumor development, however, remains unclear. Here, we have shown that the COP9 subunit 6 (CSN6) gene is amplified in human breast cancer specimens, and the CSN6 protein is upregulated in human breast and thyroid tumors. CSN6 expression positively correlated with expression of murine double minute 2 (MDM2), a potent negative regulator of the p53 tumor suppressor. Expression of CSN6 appeared to prevent MDM2 autoubiquitination at lysine 364, resulting in stabilization of MDM2 and degradation of p53. Mice in which Csn6 was deleted died early in embryogenesis (E7.5). Embryos lacking both Csn6 and p53 survived to later in embryonic development (E10.5), which suggests that loss of p53 could partially rescue the effect of loss of Csn6. Mice heterozygous for Csn6 were sensitized to γ-irradiation-induced, p53-dependent apoptosis in both the thymus and the developing CNS. These mice were also less susceptible than wild-type mice to γ-irradiation-induced tumorigenesis. These results suggest that loss of CSN6 enhances p53-mediated tumor suppression in vivo and that CSN6 plays an important role in regulating DNA damage-associated apoptosis and tumorigenesis through control of the MDM2-p53 signaling pathway. [ABSTRACT FROM AUTHOR]