Managing early failures with R-CHOP in patients with diffuse large B-cell lymphoma

Reverse effect of Semaphorin-3F on rituximab resistance in diffuse large B-cell lymphoma via the Hippo pathway

BACKGROUND

Exploring the underlying mechanism of rituximab resistance is critical to improve the outcomes of patients with diffuse large B-cell lymphoma (DLBCL). Here, we tried to identify the effects of the axon guidance factor semaphorin-3F (SEMA3F) on rituximab resistance as well as its therapeutic value in DLBCL.

METHODS

The effects of SEMA3F on the treatment response to rituximab were investigated by gain- or loss-of-function experiments. The role of the Hippo pathway in SEMA3F-mediated activity was explored. A xenograft mouse model generated by SEMA3F knockdown in cells was used to evaluate rituximab sensitivity and combined therapeutic effects. The prognostic value of SEMA3F and TAZ (WW domain-containing transcription regulator protein 1) was examined in the Gene Expression Omnibus (GEO) database and human DLBCL specimens.

RESULTS

We found that loss of SEMA3F was related to a poor prognosis in patients who received rituximab-based immunochemotherapy instead of chemotherapy regimen. Knockdown of SEMA3F significantly repressed the expression of CD20 and reduced the proapoptotic activity and complement-dependent cytotoxicity (CDC) activity induced by rituximab. We further demonstrated that the Hippo pathway was involved in the SEMA3F-mediated regulation of CD20. Knockdown of SEMA3F expression induced the nuclear accumulation of TAZ and inhibited CD20 transcriptional levels via direct binding of the transcription factor TEAD2 and the CD20 promoter. Moreover, in patients with DLBCL, SEMA3F expression was negatively correlated with TAZ, and patients with SEMA3F low TAZ high had a limited benefit from a rituximab-based strategy. Specifically, treatment of DLBCL cells with rituximab and a YAP/TAZ inhibitor showed promising therapeutic effects in vitro and in vivo .

CONCLUSION

Our study thus defined a previously unknown mechanism of SEMA3F-mediated rituximab resistance through TAZ activation in DLBCL and identified potential therapeutic targets in patients.

Outcome of Patients with Diffuse Large B-Cell Lymphoma Relapsing after Autologous Transplant before Availability of CAR-T Cell Treatment

Introduction

Autologous stem cell transplantation (ASCT) following high-dose chemotherapy is applied as salvage therapy in patients with relapsed disease or as first-line consolidation in high-risk DLBCL with chemo-sensitive disease. However, the prognosis of relapsing DLBCL post-ASCT remained poor until the availability of CAR-T cell treatment. To appreciate this development, understanding the outcome of these patients in the pre-CAR-T era is essential.

Methods

We retrospectively analyzed 125 consecutive DLBCL patients who underwent HDCT/ASCT.

Results

After a median follow-up of 26 months, OS and PFS were 65% and 55%. Fifty-three patients (42%) had a relapse (32 patients, 60%) or refractory disease (21 patients, 40%) after a median of 3 months post-ASCT. 81% of relapses occurred within the first year post-ASCT with an OS of 19% versus 40% at the last follow-up in patients with later relapses (p=0.0022). Patients with r/r disease after ASCT had inferior OS compared to patients in ongoing remission (23% versus 96%; p<0.0001). Patients relapsing post-ASCT without salvage therapy (n=22) had worse OS than patients with 1-4 subsequent treatment lines (n=31) (OS 0% versus 39%; median OS 3 versus 25 months; p<0.0001). Forty-one (77%) of patients relapsing after ASCT died, 35 of which due to progression.

Conclusions

Additional therapies can extend OS but mostly cannot prevent death in DLBCL relapsing/refractory post-ASCT. This study may serve as a reference to emerging results after CAR-T treatment in this population.

Circulating long non-coding RNAs HOTAIR, Linc-p21, GAS5 and XIST expression profiles in diffuse large B-cell lymphoma: association with R-CHOP responsiveness

The reliable identification of diffuse large B-cell lymphoma (DLBCL)-specific targets owns huge implications for its diagnosis and treatment. Long non-coding RNAs (lncRNAs) are implicated in DLBCL pathogenesis; however, circulating DLBCL-related lncRNAs are barely investigated. We investigated plasma lncRNAs; HOTAIR, Linc-p21, GAS5 and XIST as biomarkers for DLBCL diagnosis and responsiveness to R-CHOP therapy. Eighty-four DLBCL patients and thirty-three healthy controls were included. Only plasma HOTAIR, XIST and GAS5 were differentially expressed in DLBCL patients compared to controls. Pretreatment plasma HOTAIR was higher, whereas GAS5 was lower in non-responders than responders to R-CHOP. Plasma GAS5 demonstrated superior diagnostic accuracy (AUC = 0.97) whereas a panel of HOTAIR + GAS5 superiorly discriminated responders from non-responders by ROC analysis. In multivariate analysis, HOTAIR was an independent predictor of non-response. Among patients, plasma HOTAIR, Linc-p21 and XIST were correlated. Plasma GAS5 negatively correlated with International Prognostic Index, whereas HOTAIR positively correlated with performance status, denoting their prognostic potential. We constructed the lncRNAs-related protein-protein interaction networks linked to drug response via bioinformatics analysis. In conclusion, we introduce plasma HOTAIR, GAS5 and XIST as potential non-invasive diagnostic tools for DLBCL, and pretreatment HOTAIR and GAS5 as candidates for evaluating therapy response, with HOTAIR as a predictor of R-CHOP failure. We provide novel surrogates for future predictive studies in personalized medicine.

TIMD4 exhibits regulatory capability on the proliferation and apoptosis of diffuse large B-cell lymphoma cells via the Wnt/β-catenin pathway

BACKGROUND

Prior studies have noted the importance of T cell immunoglobulin and mucin domain containing 4 (TIMD4) in various diseases and its functions on cell malignant behaviors. However, the biological function of TIMD4 in diffuse large B-cell lymphoma (DLBCL) is unknown.

METHODS

Relative expression of TIMD4 was analyzed based on the GSE56315 array including 88 cases of human tissues. TIMD4 expression in cells was detected using a quantitative reverse transcriptase-polymerase chain reaction and western blot experiments. Cell proliferation was measured using the cell counting kit-8 (CCK-8) assay and apoptotic properties were assessed through the detection of related proteins by western blotting. The underlying molecular mechanism of TIMD4 in DLBCL was predicted and confirmed using KEGG enrichment analysis and western blotting.

RESULTS

The results indicate that TIMD4 is overexpressed in DLBCL tissues and the poor prognosis of DLBCL patients is significantly linked with the higher TIMD4 expression. The loss-of-TIMD4 experiment in CYP6D reveals that knockdown of TIMD4 blocks cell growth and accelerates cell apoptosis, whereas the gain-of-TIMD4 experiment in Raji cells suggests that up-regulation of TIMD4 promotes cell proliferation and inhibits cell apoptosis. The activity of the Wnt/β-catenin pathway is mediated by the TIMD4 expression in DLBCL cells.

CONCLUSIONS

These findings demonstrate that TIMD4 is up-regulated in patients with DLBCL and the regulatory effects of TIMD4 on cell proliferation and apoptosis are associated with the Wnt/β-catenin pathway, posing a novel target for DLBCL therapy.

The opportunistic effect of exosomes on Non-Hodgkin Lymphoma microenvironment modulation

There has been a shift in the paradigm of Non-Hodgkin lymphomas, changing from the classical genetic aberration-based model to a more complex and dynamic model involving tumor microenvironment interactions. In this instance, exosomes have emerged as important mediators in intercellular communication by providing survival and proliferation signals, licensing immune evasion and acquisition of drug resistance. The capability to transfer molecular cargo made exosomes a focus of research to understand cancer pathogenesis and its progression pathways. Several studies identified exosomes transporting tumor-released components in peripheral blood and focused on understanding their clinical relevance in the diagnosis, prognostic and in monitoring cancer progression. Moreover, due to their biophysical properties and physiological function, exosomes have drawn attention as potential therapeutic target and drug delivery vehicles. This review will discuss the function of exosomes in Non-Hodgkin lymphomagenesis, highlight their potential as diagnosis and prognosis biomarkers, and as new therapeutic opportunities in lymphoma management.

CAR-T cell Therapy for Non-Hodgkin Lymphomas: A New Treatment Paradigm

The majority of patients with B-cell non-Hodgkin lymphoma (NHL) can be cured with standard chemoimmunotherapy. However, patients who fail first line therapy have dismal outcomes, particularly if they have disease that is resistant to salvage therapy, including chemoimmunotherapy, radiation and/or autologous stem cell transplantation. Indolent B-NHLs, such as follicular lymphoma (FL), although not generally considered curable may be treated over many years with good prognosis. However, a subset of B-NHLs can undergo histologic transformation into more aggressive subtypes with outcomes similar to aggressive B-NHLs. In recent years, T cells genetically modified with chimeric antigen receptors (CARs), have demonstrated a remarkable capacity to induce complete and durable clinical responses in patients with chemotherapy-refractory lymphomas. Indeed, two autologous CD19-directed CAR-modified T cell products have now been FDA-approved for the treatment of patients with relapsed or refractory diffuse large B-cell lymphoma (DLBCL), primary mediastinal B-cell lymphoma (PMBCL) and transformed FL, while a plethora of other CAR-T cell targets are being explored in ongoing clinical trials. The purpose of this review is to summarize the clinical efficacy and unique toxicities of individually developed CAR-T cell products for the treatment of lymphomas, and their evolution from the laboratory bench to commercialization.

Soluble CXCL16 promotes TNF-α-induced apoptosis in DLBCL via the AMAD10-NF-κB regulatory feedback loop

We had previously identified that the co-expression of transmembrane CXCL16 (TM-CXCL16) and its receptor CXCR6 is an independent risk factor for poor survival in patients with diffuse large B-cell lymphoma (DLBCL). However, the impact of the soluble form of CXCL16 (sCXCL16) on the pathogenesis of DLBCL remains unknown. In the present study, the synergistic effect of sCXCL16 and tumor necrosis factor α (TNF-α) on apoptosis in DLBCL cell lines (OCI-LY8 and OCI-LY10) was investigated in vitro. sCXCL16 reinforced TNF-α-mediated inhibition of DLBCL cell proliferation, as determined by the cell counting kit-8 assay. The results of annexin V staining showed that sCXCL16 enhanced TNF-α-induced apoptosis in OCI-LY8 and OCI-LY10 cells through a death receptor-caspase signaling pathway. The results of gene microarray suggested a significant upregulation of differentially expressed genes in the TNF signaling pathway. sCXCL16 increased the concentration of extracellular TNF-α by binding to CXCR6 to activate the nuclear factor-κB (NF-κB) signaling pathway. TNF-α also induced the secretion of sCXCL16 by increasing the expression of ADAM10, which is known to cleave TM-CXCL16 to yield sCXCL16. Moreover, bioinformatics analysis revealed that elevated TNF-α and ADAM10 expression levels in tumor tissues predicted better survival in patients with DLBCL. Thus, our study suggests that sCXCL16 enhances TNF-α-induced apoptosis of DLBCL cells, which may involve a positive feedback loop consisting of TNF-α, ADAM10, sCXCL16, and members of the NF-κB pathway. sCXCL16 and TNF-α may be used as prognostic markers in the clinic, and their combinational use is a promising approach in the context of DLBCL therapy.

Renal Infiltration by Diffuse Large B-Cell Lymphoma as a Rare Cause of Fanconi's Syndrome: A Case Report

We report the case of a 16-year-old female patient with a known history of coeliac disease, who presented with the complaints of diarrhea, vomiting and generalized body weakness. On examination, she was found to have dehydration, decreased power in all her limbs, cervical lymphadenopathy and hepatosplenomegaly. Investigations showed severe hypokalemia, hyponatremia, hypomagnesemia, hypoglycemia and mildly enlarged kidneys on ultrasonography. Biopsy of the duodenum confirmed the flare up of coeliac disease, while cervical lymph node biopsy was positive for atypical lymphoid infiltrate and a morphology suggestive of non-Hodgkin’s lymphoma. The immune profile performed on this sample confirmed the presence of activated/non-germinal center type of diffuse large B cell lymphoma (DLBCL), which was morphologically aggressive in type. The bone marrow biopsy was hypocellular and was negative for any infiltration. The patient was suspected to have developed infiltration of one or both kidneys leading to a rare presentation of Fanconi’s syndrome. She was given first dose of rituximab on the 14th day of her admission. Unfortunately, she developed cardiopulmonary arrest and expired on the next day. We recommend screening for a possible renal involvement in patients with DLBCL and in patients with unusually deranged serum electrolytes as seen in Fanconi’s syndrome. Renal biopsy is considered the gold standard modality for diagnosis and if possible, an earlier sample in a patient with newly developed acute kidney injury can save future complications.