<p>Supplemental methods Supplemental Figures Supplemental Figure S1. Overview of somatic copy number alterations in rrDLBCLs. Supplemental Figure S2. Consistent low coverage in the first exon of FOXO1. Supplemental Figure S3. Overview of FOXO1 mutations in rrDLBCLs. Supplemental Figure S4. VAFs corrected using purity estimates. Supplemental Figure S5. Somatic copy number alterations affecting lymphoma-related genes. Supplemental Figure S6: Recurrent deletions in NFKBIE. Supplemental Tables Supplemental Table S1. Clinical details and sample processing of 38 patients with relapsed or refractory DLBCL and TLy Supplemental Table S2. Characteristics of samples used for exome sequencing and targeted sequencing of selected genes.</p>
Inhibitors of the mammalian target of rapamycin (mTORi) have clinical activity; however, the benefits of mTOR inhibition by rapamycin and rapamycin-derivatives (rapalogs) may be limited by a feedback mechanism that results in AKT activation. Increased AKT activity resulting from mTOR inhibition can be a result of increased signaling via the mTOR complex, TORC2. Previously, we published that arsenic trioxide (ATO) inhibits AKT activity and in some cases, decreases AKT protein expression. Therefore, we propose that combining ATO and rapamycin may circumvent the AKT feedback loop and increase the anti-tumor effects. Using a panel of breast cancer cell lines, we find that ATO, at clinically-achievable doses, can enhance the inhibitory activity of the mTORi temsirolimus. In all cell lines, temsirolimus treatment resulted in AKT activation, which was decreased by concomitant ATO treatment only in those cell lines where ATO enhanced growth inhibition. Treatment with rapalog also results in activated ERK signaling, which is decreased with ATO co-treatment in all cell lines tested. We next tested the toxicity and efficacy of rapamycin plus ATO combination therapy in a MDA-MB-468 breast cancer xenograft model. The drug combination was well-tolerated, and rapamycin did not increase ATO-induced liver enzyme levels. In addition, combination of these drugs was significantly more effective at inhibiting tumor growth compared to individual drug treatments, which corresponded with diminished phospho-Akt and phospho-ERK levels when compared with rapamycin-treated tumors. Therefore, we propose that combining ATO and mTORi may overcome the feedback loop by decreasing activation of the MAPK and AKT signaling pathways.
Supplementary Data from Acquired Resistance to EZH2 Inhibitor GSK343 Promotes the Differentiation of Human DLBCL Cell Lines toward an ABC-Like Phenotype
Supplementary Data from Acquired Resistance to EZH2 Inhibitor GSK343 Promotes the Differentiation of Human DLBCL Cell Lines toward an ABC-Like Phenotype
Arsenic is a widespread environmental contaminant to which millions of people are exposed worldwide. Exposure to arsenic is epidemiologically linked to increased cardiovascular disease, such as atherosclerosis. However, the effects of moderate concentrations of arsenic on atherosclerosis formation are unknown. Therefore, we utilized an in vivo ApoE−/− mouse model to assess the effects of chronic moderate exposure to arsenic on plaque formation and composition in order to facilitate mechanistic investigations. Mice exposed to 200 ppb arsenic developed atherosclerotic lesions, a lower exposure than previously reported. In addition, arsenic modified the plaque content, rendering them potentially less stable and consequently, potentially more dangerous. Moreover, we observed that the lower exposure concentration was more atherogenic than the higher concentration. Arsenic-enhanced lesions correlated with several proatherogenic molecular changes, including decreased liver X receptor (LXR) target gene expression and increased proinflammatory cytokines. Significantly, our observations suggest that chronic moderate arsenic exposure may be a greater cardiovascular health risk than previously anticipated.
Abstract Relapsed and refractory Diffuse Large B Cell Lymphoma (rrDLBCL) presents a significant challenge in hematology-oncology, with approximately 30-40% of DLBCL patients experiencing relapse or resistance to treatment. This underscores the urgent need to better understand the molecular mechanisms governing therapeutic resistance. Signal Transducer and Activator of Transcription 6 (STAT6) has been previously identified as a gene with recurrent D419 gain-of-function mutations in rrDLCBL. When STAT6 D419 mutations are present in DLBCL tumour cells, we have demonstrated that transcription of the chemokine CCL17 (aka TARC) is increased, and tumours have increased infiltration of CD4+ T cells. However, the significance of increased T cell infiltration had not been determined. In the present study, we developed a mouse model of STAT6 D419N mutant DLBCL, that recapitulates the critical features of human STAT6 D419 mutant DLBCL, including increased expression of phospho-STAT6, increased CD4+ T cell invasion, and resistance to doxorubicin treatment. With this model, we found CD4+ T cells in STAT6 D419N tumours have higher expression of the receptor for CCL17, CCR4. Using ex vivo functional assays we demonstrate that STAT6 D419N tumour cells are directly chemoattractive to CCR4+ CD4+ T cells, and when CCR4 is inhibited using a small molecule antagonist, CD4+ T cells in STAT6 D419N tumours are reduced and STAT6 D419N tumours regain therapeutic sensitivity to doxorubicin. Using PhenoCycler imaging of human rrDLBCL samples, we find that STAT6 D419 tumours indeed have increased expression of phospho-STAT6+ and increased cellular interactions between phospho-STAT6+ tumour cells and CD4+/ CCR4+ CD4+ T cells. Thus, our data identify CCR4 as an attractive therapeutic target in STAT6 D419 mutant rrDLBCL.
