Pathogenesis and biomarkers of natural killer T cell lymphoma (NKTL)

Molecular significance of circRNAs in malignant lymphoproliferative disorders: pathogenesis and novel biomarkers or therapeutic targets

Recent studies have shown that circular RNAs (CircRNAs) have the novel functions and molecular mechanisms in the pathogenesis of malignant diseases. CircRNAs have been found to be associated with the occurrence and development of lymphoproliferative diseases, impacting on lymphocyte proliferation. This article provides a review of the pathogenesis of circRNAs in malignant lymphoproliferative disorders, focusing on conditions such as acute lymphocytic leukemia (ALL), chronic lymphocytic leukemia (CLL), and lymphoma. Additionally, it discusses the potential value of circRNAs as novel biomarkers or therapeutic targets in these disorders.

Analysis of mutation profiles in extranodal NK/T-cell lymphoma: clinical and prognostic correlations

The molecular pathogenesis of extranodal NK/T-cell lymphoma (NKTCL) remains obscured despite the next-generation sequencing (NGS) studies explored on ever larger cohorts in the last decade. We addressed the highly variable mutation frequencies reported among previous studies with comprehensive amplicon coverage and enhanced sequencing depth to achieve higher genomic resolution for novel genetic discovery and comparative mutational profiling of the oncogenesis of NKTCL. Targeted exome sequencing was conducted to interrogate 415 cancer-related genes in a cohort of 36 patients with NKTCL, and a total of 548 single nucleotide variants (SNVs) and 600 Copy number variances (CNVs) were identified. Recurrent amplification of the MCL1 (67%) and PIM1 (56%) genes was detected in a dominant majority of patients in our cohort. Functional mapping of genetic aberrations revealed that an enrichment of mutations in the JAK-STAT signaling pathway, including the cytokine receptor LIFR (copy number loss) upstream of JAK3, STAT3 (activating SNVs), and downstream effectors of MYC, PIM1 and MCL1 (copy number gains). RNA in situ hybridization showed the significant consistence of MCL1 RNA level and copy number of MCL1 gene. We further correlated molecular and clinical parameters with overall survival (OS) of these patients. When correlations were analyzed by univariate followed by multivariate modelling, only copy number loss of LIFR gene and stage (III-IV) were independent prognostic factors of reduced OS. Our findings identified that novel loss of LIFR gene significantly correlated with the adverse clinical outcome of NKTCL patients and provided therapeutic opportunities for this disease through manipulating LIFR.

GPCR signaling contributes to immune characteristics of microenvironment and process of EBV-induced lymphomagenesis

Epstein-Barr virus (EBV) is the oncogenic driver of multiple cancers. However, the underlying mechanism of virus-cancer immunological interaction during disease pathogenesis remains largely elusive. Here we reported the first comprehensive proteogenomic characterization of natural killer/T-cell lymphoma (NKTCL), a representative disease model to study EBV-induced lymphomagenesis, incorporating genomic, transcriptomic, and in-depth proteomic data. Our multi-omics analysis of NKTCL revealed that EBV gene pattern correlated with immune-related oncogenic signaling. Single-cell transcriptome further delineated the tumor microenvironment as immune-inflamed, -deficient, and -desert phenotypes, in association with different setpoints of cancer-immunity cycle. EBV interacted with transcriptional factors to provoke GPCR interactome (GPCRome) reprogramming. Enhanced expression of chemokine receptor-1 (CCR1) on malignant and immunosuppressive cells modulated virus-cancer interaction on microenvironment. Therapeutic targeting CCR1 showed promising efficacy with EBV eradication, T-cell activation, and lymphoma cell killing in NKTCL organoid. Collectively, our study identified a previously unknown GPCR-mediated malignant progression and translated sensors of viral molecules into EBV-specific anti-cancer therapeutics.

Clinical analysis of 20 cases of cutaneous extranodal NK/T-Cell lymphoma

Background To investigate the clinical features, pathological features and prognostic factors of cutaneous extranodal natural killer/T-cell lymphoma (CENKTL). Methods A total of 20 cases with CENKTL from February 2013 to November 2021 were analysed retrospectively. Results The patients included 15 men and five women, and their ages ranged from 19 to 92 (median age of 61) years. The most common lesions were on the extremities, followed by the trunk. Histopathological examination showed atypical lymphocyte infiltrate in dermis and subcutaneous fat. The tumour tissue showed vascular proliferation, vascular occlusion, and coagulation necrosis. In situ hybridisation revealed that 20 patients were positive for Epstein-Barr virus-coding ribonucleic acid. Immunohistochemistry showed that the tumour cells were positive for CD3 (18/20 and 90%), CD56 (19/20 and 95%), T-cell intracellular antigen (TIA-1) (13/14 and 92.9%) and CD20 (5/20, 25%). About 20 patients were positive for Ki-67 with values of 30-90%. A total of 11 of the 20 patients died, and two patients were lost to follow-up. The 2-year overall survival was 24%, and the median overall survival was 17 months. Univariate analysis revealed that involvement of lymph nodes (P = 0.042) correlated with worse survival. Limitation This is a retrospective study design and has a limited number of patients. Conclusion CENKTL is rare and has a poor prognosis. Diagnosis is challenging due to non-specific clinical symptoms and histopathology results. A comprehensive judgement should be made based on related clinical manifestations and histopathological and molecular examination. Lymph node involvement is an independent prognostic factor for CENKTL.

Preclinical characterization of WB737, a potent and selective STAT3 inhibitor, in natural killer/T-cell lymphoma

Natural killer/T-cell lymphoma (NKTL) is an uncommon malignancy with poor prognosis and limited therapeutic options. Activating mutations of signal transducer and activator of transcription 3 (STAT3) are frequently found in patients with NKTL, suggesting that targeted inhibition of STAT3 is a potential therapeutic option for this disease. Here, we have developed a small molecule drug WB737 as a novel and potent STAT3 inhibitor that directly binds to the STAT3-Src homology 2 domain with high affinity. In addition, the binding affinity of WB737 to STAT3 is 250-fold higher than STAT1 and STAT2. Interestingly, WB737 is more selective for NKTL with STAT3-activating mutations in terms of growth inhibition and apoptotic induction when compared with Stattic. Mechanistically, WB737 inhibits both canonical and noncanonical STAT3 signaling via suppression of STAT3 phosphorylation at Tyr705 and Ser727, respectively, thereby inhibiting the expression of c-Myc and mitochondria-related genes. Moreover, WB737 inhibited STAT3 more potently than Stattic, resulting in a significant antitumor effect with undetectable toxicity, followed by almost complete tumor regression in an NKTL xenograft model harboring a STAT3-activating mutation. Taken together, these findings provide preclinical proof-of-concept for WB737 as a novel therapeutic strategy for the treatment of NKTL patients with STAT3-activating mutations.

Novel target and treatment agents for natural killer/T-cell lymphoma

The rapidly increasing use of high-throughput screening had produced a plethora of expanding knowledge on the molecular basis of natural killer/T-cell lymphoma (NKTCL), which in turn has revolutionized the treatment. Specifically, the use of asparaginase-containing regimens has led to substantial improvement in survival outcomes in NKTCL patients. Novel treatment strategies that are currently under development include cell-surface-targeted antibodies, immune checkpoint inhibitors, Epstein-Barr virus targeted cytotoxic T lymphocyte, immunomodulatory agents, chimeric antigen receptor T cells, signaling pathway inhibitors and epigenetic targeted agents. In almost all cases, initial clinical studies of newly developed treatment are conducted in patients relapsed, and refractory NKTCL due to very limited treatment options. This review summarizes the results of these novel treatments for NKTCL and discusses their potential for likely use in NKTCL in a wider setting in the future.

Epstein‒Barr virus-associated cellular immunotherapy

Epstein‒Barr virus (EBV) is a human herpes virus that is saliva-transmissible and universally asymptomatic. It has been confirmed that more than 90% of the population is latently infected with EBV for life. EBV can cause a variety of related cancers, such as nasopharyngeal carcinoma, diffuse large B-cell lymphoma, and Burkitt lymphoma. Currently, many clinical studies have demonstrated that EBV-specific cytotoxic T lymphocytes and other cell therapies can be safely and effectively transfused to prevent and treat some diseases caused by EBV. This review will mainly focus on discussing EBV-specific cytotoxic T lymphocytes and will touch on therapeutic EBV vaccines and chimeric antigen receptor T-cell therapy briefly.

Super-enhancer-driven TOX2 mediates oncogenesis in Natural Killer/T Cell Lymphoma

BACKGROUND

Extranodal natural killer/T-cell lymphoma (NKTL) is an aggressive type of non-Hodgkin lymphoma with dismal outcome. A better understanding of disease biology and key oncogenic process is necessary for the development of targeted therapy. Super-enhancers (SEs) have been shown to drive pivotal oncogenes in various malignancies. However, the landscape of SEs and SE-associated oncogenes remain elusive in NKTL.

METHODS

We used Nano-ChIP-seq of the active enhancer marker histone H3 lysine 27 acetylation (H3K27ac) to profile unique SEs NKTL primary tumor samples. Integrative analysis of RNA-seq and survival data further pinned down high value, novel SE oncogenes. We utilized shRNA knockdown, CRISPR-dCas9, luciferase reporter assay, ChIP-PCR to investigate the regulation of transcription factor (TF) on SE oncogenes. Multi-color immunofluorescence (mIF) staining was performed on an independent cohort of clinical samples. Various function experiments were performed to evaluate the effects of TOX2 on the malignancy of NKTL in vitro and in vivo.

RESULTS

SE landscape was substantially different in NKTL samples in comparison with normal tonsils. Several SEs at key transcriptional factor (TF) genes, including TOX2, TBX21(T-bet), EOMES, RUNX2, and ID2, were identified. We confirmed that TOX2 was aberrantly overexpressed in NKTL relative to normal NK cells and high expression of TOX2 was associated with worse survival. Modulation of TOX2 expression by shRNA, CRISPR-dCas9 interference of SE function impacted on cell proliferation, survival and colony formation ability of NKTL cells. Mechanistically, we found that RUNX3 regulates TOX2 transcription by binding to the active elements of its SE. Silencing TOX2 also impaired tumor formation of NKTL cells in vivo. Metastasis-associated phosphatase PRL-3 has been identified and validated as a key downstream effector of TOX2-mediated oncogenesis.

CONCLUSIONS

Our integrative SE profiling strategy revealed the landscape of SEs, novel targets and insights into molecular pathogenesis of NKTL. The RUNX3-TOX2-SE-TOX2-PRL-3 regulatory pathway may represent a hallmark of NKTL biology. Targeting TOX2 could be a valuable therapeutic intervene for NKTL patients and warrants further study in clinic.

Synergistic anticancer effect of a combination of chidamide and etoposide against NK/T cell lymphoma

Natural killer/T cell lymphoma (NKTCL) is a highly aggressive hematological malignancy. However, there is currently no consensus on therapies for refractory/relapsed patients. In this study, we investigated the synergistic anticancer effect and potential mechanism of combining chidamide, a histone deacetylases (HDACs) inhibitor, and etoposide, a DNA-damaging agent, in NKTCL. We demonstrated that chidamide or etoposide alone dose- and time-dependently inhibited the cell viability of NKTCL cell lines, YT, NKYS and KHYG-1. Functional experiments suggested that combined chidamide and etoposide treatment exerted synergistic antiproliferation effect and enhanced cell apoptotic death in vitro and in vivo. Furthermore, the expression of DNA damage related proteins was detected and we also examined the alternations in histone acetylation, cell cycle progression, and mitochondrial membrane potential (MMP). The results suggested that increased histone acetylation, cell cycle arrest at the G2/M phase and loss of MMP, converging to greater DNA damage, might account for the synergism of the combination of chidamide and etoposide in NKTCL. Taken together, our study provides an evident for possible application on combining HDACs inhibitors and DNA-damaging agents for the treatment of NKTCL.

Importance of STAT3 signalling in cancer, metastasis and therapeutic interventions

The Signal Transducer and Activator of Transcription 3 (STAT3) protein is encoded on chromosome 17q21. The SH2 and the DNA binding domains are critical structural components of the protein, together with tyrosine and serine residues that initiate phosphorylation. STAT3 interacts with DNA directly and functions in cells as both a signal transducer and a transcription factor. Its cytoplasmic activation results in dimerisation and nuclear translocation, where it is involved in the transcription of a large number of target genes. STAT3 is hyperactive in cancer cells as a result of upstream STAT3 mutations or enhanced cytokine production in the tumour environment. The STAT3 signalling pathway promotes many hallmarks of carcinogenesis and metastasis, including enhanced cell proliferation and survival, as well as migration and invasion into the extracellular matrix. Recent investigations into novel STAT3-based therapies describe a range of innovative approaches, such as the use of novel oligonucleotide drugs. These limit STAT3 binding to its target genes by attaching to SH2 and DNA-binding domains. Yet, despite these significant steps in understanding the underpinning mechanisms, there are currently no therapeutic agents that addresses STAT3 signalling in a clinically relevant manner.

The identification of gene signatures in patients with extranodal NK/T-cell lymphoma from a pair of twins

Background

There is no unified treatment standard for patients with extranodal NK/T-cell lymphoma (ENKTL). Cancer neoantigens are the result of somatic mutations and cancer-specific. Increased number of somatic mutations are associated with anti-cancer effects. Screening out ENKTL-specific neoantigens on the surface of cancer cells relies on the understanding of ENKTL mutation patterns. Hence, it is imperative to identify ENKTL-specific genes for ENKTL diagnosis, the discovery of tumor-specific neoantigens and the development of novel therapeutic strategies. We investigated the gene signatures of ENKTL patients.

Methods

We collected the peripheral blood of a pair of twins for sequencing to identify unique variant genes. One of the twins is diagnosed with ENKTL. Seventy samples were analyzed by Robust Multi-array Analysis (RMA). Two methods (elastic net and Support Vector Machine-Recursive Feature Elimination) were used to select unique genes. Next, we performed functional enrichment analysis and pathway enrichment analysis. Then, we conducted single-sample gene set enrichment analysis of immune infiltration and validated the expression of the screened markers with limma packages.

Results

We screened out 126 unique variant genes. Among them, 11 unique genes were selected by the combination of elastic net and Support Vector Machine-Recursive Feature Elimination. Subsequently, GO and KEGG analysis indicated the biological function of identified unique genes. GSEA indicated five immunity-related pathways with high signature scores. In patients with ENKTL and the group with high signature scores, a proportion of functional immune cells are all of great infiltration. We finally found that CDC27, ZNF141, FCGR2C and NES were four significantly differential genes in ENKTL patients. ZNF141, FCGR2C and NES were upregulated in patients with ENKTL, while CDC27 was significantly downregulated.

Conclusion

We identified four ENKTL markers (ZNF141, FCGR2C, NES and CDC27) in patients with extranodal NK/T-cell lymphoma.

CircADARB1 serves as a new biomarker in natural killer T-cell lymphoma and a potential regulator of p-Stat3

Background

Natural killer/T-cell lymphoma (NKTCL) is a rare and aggressive subtype of Non-Hodgkin’s Lymphoma. CircRNA has shown great potential to become a biomarker in plasma. In this study, we aimed to determine circRNA for its diagnostic and prognostic value and biological function in NKTCL.

Method

The circRNA microarray of plasma from NKTCL patients and healthy donors were conducted. The relative expressions of target circRNA were verified by qRT-PCR. We conducted function experiments in vitro and in vivo. Bioinformatics predicted the target miRNA of the target circRNA and the binding site was detected by the dual luciferase report assay. Downstream target protein was predicted and detected by western blot in vitro and immunohistochemistry in vivo.

Result

By analyzing the plasma circRNA microarrays in NKTCL, 6137 circRNAs were up-regulated and 6190 circRNAs were down-regulated. The relative expressions of circADARB1 were significantly higher in NKTCL patients. The knockdown of circADARB1 inhibited proliferation of NKTCL cells in vitro and in vivo. CircADARB1 could bind to miR-214-3p in the downstream and regulate the expression of p-Stat3. In nude mice tumor tissue, p-Stat3 was under-expressed in the circADARB1 knockdown group.

Conclusion

CircADARB1 was highly expressed in NKTCL plasma and circADARB1 was a potential biomarker to assist diagnosis and predict the response in NKTCL. CircADARB1 bound up to miR-214-3p and regulated p-Stat3.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02296-x.

Involvement of classic and alternative non-homologous end joining pathways in hematologic malignancies: targeting strategies for treatment

Chromosomal translocations are the main etiological factor of hematologic malignancies. These translocations are generally the consequence of aberrant DNA double-strand break (DSB) repair. DSBs arise either exogenously or endogenously in cells and are repaired by major pathways, including non-homologous end-joining (NHEJ), homologous recombination (HR), and other minor pathways such as alternative end-joining (A-EJ). Therefore, defective NHEJ, HR, or A-EJ pathways force hematopoietic cells toward tumorigenesis. As some components of these repair pathways are overactivated in various tumor entities, targeting these pathways in cancer cells can sensitize them, especially resistant clones, to radiation or chemotherapy agents. However, targeted therapy-based studies are currently underway in this area, and furtherly there are some biological pitfalls, clinical issues, and limitations related to these targeted therapies, which need to be considered. This review aimed to investigate the alteration of DNA repair elements of C-NHEJ and A-EJ in hematologic malignancies and evaluate the potential targeted therapies against these pathways.

Chemorefractory extranodal nasal-type natural-killer/T-cell lymphoma with great response to pembrolizumab in a young patient: a case report

Introduction

Extranodal, natural-killer/T-cell lymphoma of nasal type is a rare but aggressive disease usually presenting as progressive necrotic lesions in the nasal cavity that responds poorly to chemotherapy. In this paper, we report a relapsing, chemorefractory case of extranodal natural-killer/T-cell lymphoma responding to checkpoint inhibitor immunotherapy with pembrolizumab.

Case presentation

A 32-year-old Hispanic woman with a history of recurrent sinusitis and preseptal abscess presented with a hoarse voice, swelling around the right eye, and diplopia. Laryngoscopy showed infiltrating tissue extending to bilateral laryngeal ventricles and false vocal cords. On immunohistochemical examination of laryngeal biopsy, the neoplastic cells showed positivity for CD3 (cytoplasmic), CD7, CD56, granzyme B, CD30, and Epstein–Barr virus-encoded ribonucleic acid (RNA). Extranodal natural-killer/T-cell lymphoma, nasal type, was confirmed. In the absence of distant organ involvement, the decision was to perform chemotherapy with etoposide, ifosfamide, mesna, cisplatin, and dexamethasone (VIPD protocol) followed by concurrent chemoradiation with weekly doses of cisplatin and two cycles of VIPD as adjuvant treatment. However, 1 month after completion of the treatment; disease recurrence was demonstrated. The patient was scheduled to receive salvage chemotherapy with steroid, methotrexate, ifosfamide, L- asparaginase, and etoposide (SMILE) protocol and CD30-targeting monoclonal antibodies. However, the mass was chemorefractory without response to either l-asparaginase-based salvage chemotherapy in combination with high-dose methotrexate or brentuximab vedotin. However, this case of chemorefractory extranodal natural-killer/T-cell lymphoma, nasal type, responded well to the novel drug pembrolizumab, which was able to control the disease.

Conclusion

Checkpoint inhibitors are potential treatment option in selected chemorefractory extranodal natural-killer/T-cell lymphoma, nasal type, cases.

SLC1A1 mediated glutamine addiction and contributed to natural killer T-cell lymphoma progression with immunotherapeutic potential

BACKGROUND

Metabolic reprogramming plays an essential role on lymphoma progression. Dysregulation of glutamine metabolism is implicated in natural-killer T-cell lymphoma (NKTCL) and tumor cell response to asparaginase-based anti-metabolic treatment.

METHODS

To understand the metabolomic alterations and determine the potential therapeutic target of asparaginase, we assessed metabolomic profile using liquid chromatography-mass spectrometry in serum samples of 36 NKTCL patients, and integrated targeted metabolic analysis and RNA sequencing in tumor samples of 102 NKTCL patients. The biological function of solute carrier family 1 member 1 (SLC1A1) on metabolic flux, lymphoma cell growth, and drug sensitivity was further examined in vitro in NK-lymphoma cell line NK-92 and SNK-6, and in vivo in zebrafish xenograft models.

FINDINGS

In NKTCL patients, serum metabolomic profile was characterized by aberrant glutamine metabolism and SLC1A1 was identified as a central regulator of altered glutaminolysis. Both in vitro and in vivo, ectopic expression of SLC1A1 increased cellular glutamine uptake, enhanced glutathione metabolic flux, and induced glutamine addiction, leading to acceleration of cell proliferation and tumor growth. Of note, SLC1A1 overexpression was significantly associated with PD-L1 downregulation and reduced cytotoxic CD3+/CD8+ T cell activity when co-cultured with peripheral blood mononuclear cells. Asparaginase treatment counteracted SLC1A1-mediated glutamine addiction, restored SLC1A1-induced impaired T-cell immunity. Clinically, high EAAT3 (SLC1A1-encoded protein) expression independently predicted superior progression-free and overall survival in 90 NKTCL patients treated with asparaginase-based regimens.

INTERPRETATION

SLC1A1 functioned as an extracellular glutamine transporter, promoted tumor growth through reprogramming glutamine metabolism of NKTCL, while rendered tumor cells sensitive to asparaginase treatment. Moreover, SLC1A1-mediated modulation of PD-L1 expression might provide clinical rationale of co-targeting metabolic vulnerability and immunosuppressive microenvironment in NKTCL.

FUNDING

This study was supported, in part, by research funding from the National Natural Science Foundation of China (82130004, 81830007 and 81900192), Chang Jiang Scholars Program, Shanghai Municipal Education Commission Gaofeng Clinical Medicine Grant Support (20152206 and 20152208), Clinical Research Plan of SHDC (2020CR1032B), Multicenter Clinical Research Project by Shanghai Jiao Tong University School of Medicine (DLY201601), Shanghai Chenguang Program (19CG15), Shanghai Sailing Program (19YF1430800), Medical-Engineering Cross Foundation of Shanghai Jiao Tong University (ZH2018QNA46), and Shanghai Yi Yuan Xin Xing Program.

Autologous EBV-specific T cell treatment results in sustained responses in patients with advanced extranodal NK/T lymphoma: results of a multicenter study

We conducted a phase II clinical trial to develop an autologous EBV-specific T cell product (baltaleucel T) for advanced, relapsed ENKTL. Among 47 patients who provided whole blood starting material for manufacturing the product, 15 patients received a median of 4 doses of baltaleucel T. Thirty-two (68%) patients did not receive baltaleucel-T due to manufacturing failure, rapid disease progression, and death. Of the 15 patients, 10 patients had measurable disease at baseline (salvage cohort), and 5 patients had no disease at baseline assessment (adjuvant cohort). In the 15 patients, the median follow-up duration was 10.2 months (range 2.0-23.5 months), median progression-free survival (PFS) was 3.9 months, and the median overall survival (OS) was not reached. Patients in the salvage cohort achieved a 30% complete response (CR) and a 50% overall response rate (ORR). In the adjuvant cohort, disease progression was reported in three patients and two patients did not relapse during study follow-up. When we compared survival outcomes of seven responders and eight non-responders, the PFS (P = 0.001) and OS (P = 0.014) of responders proved statistically superior to that of non-responders. Baltaleucel-T was well tolerated. We have performed a phase II clinical trial of autologous EBV-specific T cell treatment (baltaleucel-T) in R/R ENKTL. Autologous EBV-specific T cells were well tolerated and demonstrated single-agent activity in R/R ENTKL.

Combined immune checkpoint blockade and radiotherapy induces durable remission in relapsed natural killer/T-cell lymphoma: a case report and review of the literature

BACKGROUND

Extranodal natural killer/T-cell lymphoma is a rare, aggressive non-Hodgkin lymphoma that is treated upfront mostly with L-asparaginase containing regimens. Relapsed extranodal natural killer/T-cell lymphoma is associated with a poor prognosis, and there is no established standard of care.

CASE PRESENTATION

We report the case of a 72 year-old white male with a distant extranasal relapse of extranodal natural killer/T-cell lymphoma that has been managed successfully with a combination of radiation and immune checkpoint blockade with pembrolizumab. Pseudoprogression with new skin and bone lesions on positron emission tomography imaging was encountered during this Caucasian patient's immunotherapy and was successfully managed with supportive care and continuation of immune checkpoint blockade.

CONCLUSIONS

The patient has been in complete clinical, radiologic, and molecular remission for close to 3 years and has not had any immune-related adverse effects. Pseudoprogression is a clinical challenge that can be encountered while patients are treated with immunotherapy, and astute clinical acumen is needed for accurate management. We believe this is the longest duration of response to immune checkpoint blockade in relapsed extranodal natural killer/T-cell lymphoma reported to date in literature. There is a strong biologic rationale in combining radiation with immunotherapy. The optimal timing, dose, and duration of radiation combined with immunotherapy in extranodal natural killer/T-cell lymphoma need to be prospectively evaluated.

Extra-Nodal, Nasal, Natural Killer T-Cell Lymphoma Treated With a Checkpoint Inhibitor: A Case Report of a Sustained Complete Response

Extra-nodal natural killer T-cell lymphoma (ENKTL) is a rare and aggressive hematologic malignancy found in the nasal cavity and adjacent locations in 80% of cases, accounting for approximately 10% of non-Hodgkin lymphoma (NHL) and 0.4% of all cancers. Prognosis is typically poor and depends on stage, location, age, and tumor markers for targeted therapy, which is reserved for relapsed/refractory ENKTL. Of those, advanced clinical stage, higher Prognostic Index (PI), nodal involvement, Ki-67 expression, large cells, local tumor invasiveness, and circulating Epstein-Barr virus (EBV)-DNA levels are predictive of worse survival. Here, we present a rare case of a patient in remission 30 months after diagnosis of ENKTL following a sustained complete response to pembrolizumab, an immune checkpoint inhibitor targeting the programmed death-1 (PD-1) receptor.

Comprehensive analysis of peripheral T-cell and natural killer/T-cell lymphoma in Asian patients: A multinational, multicenter, prospective registry study in Asia

Background

Peripheral T-cell lymphomas (PTCLs) are uncommon and their frequency is regionally heterogeneous. Several studies have been conducted to evaluate the clinical features and treatment outcomes of this disease entity, but the majority of these were conducted in limited areas, making it difficult to comprehensively analyze their relative frequency and clinical features. Furthermore, no consensus treatment for PTCLs has been established. Therefore, we conducted an Asia-specific study to understand the relative frequency of PTCLs and assess treatments and their outcomes in Asian patients.

Methods

We performed a multinational, multicenter, prospective registry of adult patients with PTCLs that was named as the International Cooperative non-Hodgkin T-cell lymphoma prospective registry study where thirty-two institutes from six Asian countries and territories (Korea, China, Taiwan, Singapore, Malaysia, and Indonesia) participated.

Findings

A total of 486 patients were registered between April 2016 and February 2019, and more than a half of patients (57%) had stage III or IV. Extranodal natural killer (NK)/T- cell lymphoma was the most common subtype (n = 139,28.6%), followed by angioimmunoblastic T-cell lymphoma (AITL, n = 120,24.7%), PTCL-not otherwise specified (PTCL-NOS, n = 101,20.8%), ALK-positive anaplastic large cell lymphoma (ALCL, n = 34,6.9%), and ALK-negative ALCL (n = 30,6.2%). The median progression-free survival (PFS) and overall survival (OS) were 21.1 months (95% CI,10.6-31.6) and 83.6 months (95% CI, 56.7-110.5), respectively. Upfront use of combined treatment with chemotherapy and radiotherapy showed better PFS than chemotherapy alone in localized ENKTL whereas consolidation with upfront autologous stem cell transplantation (SCT) provided longer PFS in advance stage ENKTL. In patients with PTCLs other than ENKTL, anthracycline-containing chemotherapies were widely used, but the outcome of those regimens was not satisfactory, and upfront autologous SCT was not significantly associated with survival benefit, either. The treatment outcome of salvage chemotherapy was disappointing, and none of the salvage strategies showed superiority to one another.

Interpretation

This multinational, multicenter study identified the relative frequency of each subtype of PTCLs across Asian countries, and the survival outcomes according to the therapeutic strategies currently used.

Funding

Samsung Biomedical Research Institute.

Is EBV Associated with Breast Cancer in Specific Geographic Locations?

Epstein-Barr virus (EBV) is a virus that establishes a life-long infection in people, and infection with EBV is nearly ubiquitous by adulthood. EBV was identified from biopsy material from a child with Burkitt's lymphoma (BL) in sub-Saharan Africa. EBV has a well-characterised role in the development of some cancers, notably, Burkitt's lymphoma (BL), Hodgkin's disease (HD), gastric carcinoma (GC), and nasopharyngeal carcinoma (NPC). Links have also been made between EBV and breast cancer (BC), but these have been controversial. For all EBV-associated cancers, the ubiquitous nature of infection with EBV, contrasted with the relatively rare development of cancer, highlights a problem of determining whether EBV is an aetiological agent of cancer. In addition, the geographic distributions of some EBV-associated cancers point to contributions from additional co-factors. Recent meta-analyses of the incidence of EBV within BC biopsies has revealed that the diversity in the conclusions remain, however, they also show more of an association between EBV and BC biopsies in some study locations. Here, we review the evidence linking EBV with BC, and conclude that the evidence for the presence of EBV in BC biopsies is concentrated in specific geographic regions but is currently insufficient to provide a causal link. We pose some questions that could help to resolve the question of whether EBV contributes to BC and probe the contribution EBV might make to the aetiology of BC.

PD-L1 expression in peripheral T-cell lymphomas is not related to either PD-L1 gene amplification or rearrangements

Nodal peripheral T-cell lymphomas (n-PTCL) are aggressive lymphomas with no specific treatment. Programmed death 1 (PD-1) inhibits T-cell activation and proliferation, and the expression of its ligand PD-L1 has been associated with worse prognosis in some tumors. We performed immunohistochemistry for PD-1, p-STAT3, and PD-L1 (Clones SP142/263/22C3/28.8) and FISH studies for PD-L1/2 genes in chromosome 9p in a series of 168 formalin-fixed, paraffin-embedded n-PTCL samples. PD-L1 (clone 263) was the most frequently detected in both tumor cells (especially in the ALCL subgroup) and the microenvironment (especially in the AITL subgroup). In five ALCL cases, 3-4 copies of the two loci of chromosome 9 were found, suggestive of polyploidy. PD-L1 correlated with p-STAT3 on tumor cells. PD-1 expression in tumor cells was related to expression of PD-L1 in microenvironment. The expression of PD-L1 on tumor cells or microenvironment suggests that some n-PTCL cases might benefit from immune check-point modulation therapy.

Selection of new immunotherapy targets for NK/T cell lymphoma

Extranodal NK/T cell lymphoma, nasal type, is a rare type of non-Hodgkin's lymphoma (NHL), and the aetiology is not fully understood. Although the clinical outcome of anthracycline-based chemotherapy was dismal because of multidrug resistance (MDR). Novel therapeutic strategies including L-asparaginase-containing regimens, radiotherapy, sequential chemotherapy and radiotherapy, and concurrent chemoradiotherapy (CCRT) have remarkably improved outcomes. However, the overall survival (OS) rate of advanced stage patients is not satisfactory compared with patients with non-advanced-stage disease. Immunotherapy is a promising treatment for ENKTCL. Indeed, it has been proven that targeted therapies such as anti-CD30 antibodies and naked anti-CD38 antibodies are effective. In addition to these therapies that target cell surface antigens, therapies targeting intracellular signalling pathways and the microenvironment are considerably beneficial. EBV-driven overexpression of latent membrane proteins [LMP1 and LMP2] activates the pro-proliferation NF-κB/MAPK signalling pathway and leads to high PD-L1 expression. Binding of PD-L1 to PD-1 expressing cytotoxic T cells causes apoptosis and inactivation of T lymphocytes, achieving immune escape. On the basis of this mechanism, a variety of small molecular inhibitors, such as anti-PD-1 antibodies, NF-κB inhibitors, EBV antigens, and LMP1 and LMP2 antigens, can be applied. Via another signalling pathway the JAK/STAT pathway, upregulation and activation and mutation of genes promotes proliferation and ENKTCL lymphomagenesis, and JAK inhibitors have thus been applied. This article reviews recent advances in ENKTCL immunotherapy as a promising treatment for this fatal disease.

sATP‑binding cassette subfamily G member 2 enhances the multidrug resistance properties of human nasal natural killer/T cell lymphoma side population cells

Extranodal natural killer (NK)/T cell lymphoma, nasal type (ENKL) is a rare type of non-Hodgkin's lymphoma that is associated with limited effective treatment options and unfavorable survival rate, which is partly the result of multidrug resistance (MDR). The presence of side population (SP) cells-SNK-6/ADM-SP (SSP) cells has been previously used to explore mechanisms of drug resistance. ATP-binding cassette subfamily G member 2 (ABCG2) is a gene involved in MDR and is closely associated with SPs. However, the function of ABCG2 in SSP cells is unclear. The present study verified the high expression of ABCG2 in SSP cells. The IC₅₀ values of doxorubicin, cytarabine, cisplatin, gemcitabine and l-asparaginase were tested to evaluate drug sensitivity in SSP cells with different levels of ABCG2 expression. ABCG2 was identified as a gene promoting in MDR. ABCG2 upregulated cell proliferation, increased clonogenicity, increased invasive ability and decreased apoptosis, in vivo and in vitro, when cells were treated with gemcitabine. To conclude, ABCG2 enhanced MDR and increased the typical biological characteristics associated with cancer cells in SP cells. With further investigation of the ABCG2 gene could have the potential to reverse MDR in ENKL.

Plasma circulating tumor DNA assessment reveals KMT2D as a potential poor prognostic factor in extranodal NK/T-cell lymphoma

Background

The early detection of tumors upon initial diagnosis or during routine surveillance is important for improving survival outcomes. Here, we investigated the feasibility and clinical significance of circulating tumor DNA (ctDNA) detection for Extranodal NK/T-cell lymphoma, nasal type (ENTKL).

Methods

The plasma ctDNA assessment was based on blood specimens collected from 65 newly diagnosed patients with ENKTL in the hematology medical center of Xinqiao Hospital. Longitudinal samples collected under chemotherapy were also included. The gene mutation spectrum of ENKTL was analyzed via next generation sequencing.

Results

We found that the most frequently mutated genes were KMT2D (23.1%), APC (12.3%), ATM (10.8%), ASXL3 (9.2%), JAK3 (9.2%), SETD2 (9.2%), TP53 (9.2%) and NOTCH1 (7.7%). The mutation allele frequencies of ATM and JAK3 were significantly correlated with the disease stage, and mutated KMT2D, ASXL3 and JAK3 were positively correlated with the metabolic tumor burden of the patients. Compared with the tumor tissue, ctDNA profiling showed good concordance (93.75%). Serial ctDNA analysis showed that treatment with chemotherapy could decrease the number and mutation allele frequencies of the genes. Compared with PET/CT, ctDNA has more advantages in tracking residual disease in patients. In addition, patients with mutated KMT2D had higher expression compared with those with wild type, and mutated KMT2D predicted poor prognosis.

Conclusion

Our results unveil the mutation spectrum of ENKTL patients' plasma, which can be used to monitor the disease status of the patients exactly, and KMT2D is the most frequently mutated gene with prognosis prediction value. The application of ctDNA sequencing can provide precision treatment strategies for patients.

Trial registration

This study is registered with chictr.org (ChiCTR1800014813, registered 7 February, 2018-Retrospectively registered).

Epstein-Barr Virus Infection in the Development of Neurological Disorders

Epstein-Barr Virus (EBV) is a ubiquitous human herpesvirus that contributes to the etiology of diverse human cancers and auto-immune diseases. EBV establishes a relatively benign, long-term latent infection in over 90 percent of the adult population. Yet, it also increases risk for certain cancers and auto-immune disorders depending on complex viral, host, and environmental factors that are only partly understood. EBV latent infection is found predominantly in memory B-cells, but the natural infection cycle and pathological aberrations enable EBV to infect numerous other cell types, including oral, nasopharyngeal, and gastric epithelia, B-, T-, and NK-lymphoid cells, myocytes, adipocytes, astrocytes, and neurons. EBV infected cells, free virus, and gene products can also be found in the CNS. In addition to the direct effects of EBV on infected cells and tissue, the effect of chronic EBV infection on the immune system is also thought to contribute to pathogenesis, especially auto-immune disease. Here, we review properties of EBV infection that may shed light on its potential pathogenic role in neurological disorders.