Oncogenic activation of JAK3-STAT signaling confers clinical sensitivity to PRN371, a novel selective and potent JAK3 inhibitor, in natural killer/T-cell lymphoma

Optimization of immune checkpoint inhibitor treatment planning for relapsed or refractory extranodal NK/T cell lymphoma

Pembrolizumab (anti-programmed cell death-ligand 1 inhibitor) is a promising salvage therapeutic option for relapsed/refractory extranodal NK/T-cell lymphoma (R/R ENKTL). However, the appropriate duration of pembrolizumab use in R/R ENKTL patients and the optimal timing for administering pembrolizumab remain undetermined. We collected and analyzed clinical information on R/R ENKTL 58 patients who received pembrolizumab to evaluate the optimal treatment durations and clinical information for considering treatment interruption. Treatment outcomes were assessed by 18F-fluorodeoxyglucose positron emission tomography/computed tomography (FDG PET/CT) and Epstein Barr virus DNA (EBV DNA) every 3 months. Nineteen (32.8%) patients had been treated with more than three chemotherapies before pembrolizumab administration. The best response rate towards the first try of pembrolizumab was 38.9% (31.5% complete response rate (CR), 7.4% partial response (PR)). During the 41.8-month median follow-up duration, the median progression-free survival (PFS) was 3.1 months, and the median overall survival (OS) was 7.1 months. The failure group, which was characterized by Deaville score (DS) 3-4 and circulating EBV detection, or DS 5 with/without EBV detection, had the worst PFS (p < 0.001) and OS (p < 0.001), followed by the high (DS 1-2 and EBV detection, or DS 3-4 and EBV not detected) and low-risk groups (DS 1-2 and EBV not detected). Among the 21 patients who achieved the best response at the first pembolizumab try, the patients who received planned 24 cycles presented better PFS than those who received incomplete cycles (57.6 months vs 20.9 months, P-value = 0.012). Among 13 patients who received avelumab or pembrolizumab in advance, a few who responded to the second trial of pembrolizumab administration had over one year of chemotherapy vacation. Determining the discontinuation or continuation of pembrolizumab would be considered in selected cases assessed by PET-CT and EBV monitoring. Disruption of pembrolizumab treatment may be advisable for the low-risk group(DS 1-2 and EBV not detected), whereas continuation could be warranted for the high-risk group (DS 1-2 and EBV detection, or DS 3-4 and EBV not detected). Moreover, it might be critical to maintain over 24 cycles to improve the survival outcome of R/R ENKTL.

Janus Kinase 3 (JAK3): A Critical Conserved Node in Immunity Disrupted in Immune Cell Cancer and Immunodeficiency

The Janus kinase (JAK) family is a small group of protein tyrosine kinases that represent a central component of intracellular signaling downstream from a myriad of cytokine receptors. The JAK3 family member performs a particularly important role in facilitating signal transduction for a key set of cytokine receptors that are essential for immune cell development and function. Mutations that impact JAK3 activity have been identified in a number of human diseases, including somatic gain-of-function (GOF) mutations associated with immune cell malignancies and germline loss-of-function (LOF) mutations associated with immunodeficiency. The structure, function and impacts of both GOF and LOF mutations of JAK3 are highly conserved, making animal models highly informative. This review details the biology of JAK3 and the impact of its perturbation in immune cell-related diseases, including relevant animal studies.

JAK/STAT defects and immune dysregulation, and guiding therapeutic choices

Inborn errors of immunity (IEIs) encompass a diverse spectrum of genetic disorders that disrupt the intricate mechanisms of the immune system, leading to a variety of clinical manifestations. Traditionally associated with an increased susceptibility to recurrent infections, IEIs have unveiled a broader clinical landscape, encompassing immune dysregulation disorders characterized by autoimmunity, severe allergy, lymphoproliferation, and even malignancy. This review delves into the intricate interplay between IEIs and the JAK-STAT signaling pathway, a critical regulator of immune homeostasis. Mutations within this pathway can lead to a wide array of clinical presentations, even within the same gene. This heterogeneity poses a significant challenge, necessitating individually tailored therapeutic approaches to effectively manage the diverse manifestations of these disorders. Additionally, JAK-STAT pathway defects can lead to simultaneous susceptibility to both infection and immune dysregulation. JAK inhibitors, with their ability to suppress JAK-STAT signaling, have emerged as powerful tools in controlling immune dysregulation. However, questions remain regarding the optimal selection and dosing regimens for each specific condition. Hematopoietic stem cell transplantation (HSCT) holds promise as a curative therapy for many JAK-STAT pathway disorders, but this procedure carries significant risks. The use of JAK inhibitors as a bridge to HSCT has been proposed as a potential strategy to mitigate these risks.

Role of cytokine in malignant T-cell metabolism and subsequent alternation in T-cell tumor microenvironment

T cells are an important component of adaptive immunity and T-cell-derived lymphomas are very complex due to many functional sub-types and functional elasticity of T-cells. As with other tumors, tissues specific factors are crucial in the development of T-cell lymphomas. In addition to neoplastic cells, T- cell lymphomas consist of a tumor micro-environment composed of normal cells and stroma. Numerous studies established the qualitative and quantitative differences between the tumor microenvironment and normal cell surroundings. Interaction between the various component of the tumor microenvironment is crucial since tumor cells can change the microenvironment and vice versa. In normal T-cell development, T-cells must respond to various stimulants deferentially and during these courses of adaptation. T-cells undergo various metabolic alterations. From the stage of quiescence to attention of fully active form T-cells undergoes various stage in terms of metabolic activity. Predominantly quiescent T-cells have ATP-generating metabolism while during the proliferative stage, their metabolism tilted towards the growth-promoting pathways. In addition to this, a functionally different subset of T-cells requires to activate the different metabolic pathways, and consequently, this regulation of the metabolic pathway control activation and function of T-cells. So, it is obvious that dynamic, and well-regulated metabolic pathways are important for the normal functioning of T-cells and their interaction with the microenvironment. There are various cell signaling mechanisms of metabolism are involved in this regulation and more and more studies have suggested the involvement of additional signaling in the development of the overall metabolic phenotype of T cells. These important signaling mediators include cytokines and hormones. The impact and role of these mediators especially the cytokines on the interplay between T-cell metabolism and the interaction of T-cells with their micro-environments in the context of T-cells lymphomas are discussed in this review article.

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.

Landscape of Genetic Mutations in Appendiceal Cancers

In appendiceal cancers, the most frequently mutated genes are (i) KRAS, which, when reactivated, restores signal transduction via the RAS-RAF-MEK-ERK signaling pathway and stimulates cell proliferation in the early stages of tumor transformation, and then angiogenesis; (ii) TP53, whose inactivation leads to the inhibition of programmed cell death; (iii) GNAS, which, when reactivated, links the cAMP pathway to the RAS-RAF-MEK-ERK signaling pathway, stimulating cell proliferation and angiogenesis; (iv) SMAD4, exhibiting typical tumor-suppressive activity, blocking the transmission of oncogenic TGFB signals via the SMAD2/SMAD3 heterodimer; and (v) BRAF, which is part of the RAS-RAF-MEK-ERK signaling pathway. Diverse mutations are reported in other genes, which are part of secondary or less critical signaling pathways for tumor progression, but which amplify the phenotypic diversity of appendiceal cancers. In this review, we will present the main genetic mutations involved in appendix tumors and their roles in cell proliferation and survival, and in tumor invasiveness, angiogenesis, and acquired resistance to anti-growth signals.

Aberrant JAK-STAT signaling-mediated chromatin remodeling impairs the sensitivity of NK/T-cell lymphoma to chidamide

BACKGROUND

Natural killer/T-cell lymphoma (NKTL) is a rare type of aggressive and heterogeneous non-Hodgkin's lymphoma (NHL) with a poor prognosis and limited therapeutic options. Therefore, there is an urgent need to exploit potential novel therapeutic targets for the treatment of NKTL. Histone deacetylase (HDAC) inhibitor chidamide was recently approved for treating relapsed/refractory peripheral T-cell lymphoma (PTCL) patients. However, its therapeutic efficacy in NKTL remains unclear.

METHODS

We performed a phase II clinical trial to evaluate the efficacy of chidamide in 28 relapsed/refractory NKTL patients. Integrative transcriptomic, chromatin profiling analysis and functional studies were performed to identify potential predictive biomarkers and unravel the mechanisms of resistance to chidamide. Immunohistochemistry (IHC) was used to validate the predictive biomarkers in tumors from the clinical trial.

RESULTS

We demonstrated that chidamide is effective in treating relapsed/refractory NKTL patients, achieving an overall response and complete response rate of 39 and 18%, respectively. In vitro studies showed that hyperactivity of JAK-STAT signaling in NKTL cell lines was associated with the resistance to chidamide. Mechanistically, our results revealed that aberrant JAK-STAT signaling remodels the chromatin and confers resistance to chidamide. Subsequently, inhibition of JAK-STAT activity could overcome resistance to chidamide by reprogramming the chromatin from a resistant to sensitive state, leading to synergistic anti-tumor effect in vitro and in vivo. More importantly, our clinical data demonstrated that combinatorial therapy with chidamide and JAK inhibitor ruxolitinib is effective against chidamide-resistant NKTL. In addition, we identified TNFRSF8 (CD30), a downstream target of the JAK-STAT pathway, as a potential biomarker that could predict NKTL sensitivity to chidamide.

CONCLUSIONS

Our study suggests that chidamide, in combination with JAK-STAT inhibitors, can be a novel targeted therapy in the standard of care for NKTL.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02878278. Registered 25 August 2016, https://clinicaltrials.gov/ct2/show/NCT02878278.

PRRX1 promotes colorectal cancer stemness and chemoresistance via the JAK2/STAT3 axis by targeting IL-6

Background

Stemness acquirement is one of the hallmarks of cancer and the major reason for the chemoresistance and poor prognosis of colorectal cancer (CRC). Previous research has revealed the stimulatory role of paired related homeobox 1 (PRRX1) on CRC metastasis. However, the role of PRRX1 in stemness acquirement and chemoresistance of CRC is still not clear.

Methods

A retrospective cohort study was performed to investigate the relationship between PRRX1 expression and multiple clinicopathological characteristics of CRC patients. The functional effects of PRRX1 on stemness and chemoresistance of CRC cells were validated by in vitro and in vivo assays. Gene set enrichment analysis (GSEA) and JASPAR software were performed to predict the underlying mechanisms. Enzyme-linked immunosorbent assay (ELISA), Western blot, immunofluorescence, and dual-luciferase reporter assays were used to confirm the PRRX1-mediated signaling and its downstream factors.

Results

The expression of PRRX1 was up-regulated in CRC tissues and cell lines compared to normal epithelial tissues and cell lines. High expression of PRRX1 was tightly associated with the metastasis, chemoresistance, and poor prognosis of CRC patients. Additionally, PRRX1 significantly promoted the proliferation, viability, stemness, and chemoresistance of CRC cells, as well as the activation of the interleukin-6 (IL-6)/JAK2/STAT3 axis. Inhibiting the expression of IL-6 dramatically eliminated the effects of PRRX1 on CRC cell stemness and chemoresistance.

Conclusions

PRRX1 plays a vital role in the stemness and chemoresistance of CRC cells via JAK2/STAT3 signaling by targeting IL-6. Further, PRRX1 may be a valid biomarker for predicting the effect of chemotherapy and prognosis of CRC patients.

Intravascular NK/T-Cell Lymphoma: What We Know about This Diagnostically Challenging, Aggressive Disease

Intravascular lymphoma is a form of lymphoid malignancy characterized by neoplastic cells growing almost exclusively within the lumina of small- to medium-sized blood vessels. Most cases are of B-cell origin with rare cases of natural killer or T-cell lineage. Extranodal sites are affected, mainly the skin and central nervous system, although any organ may be involved. Intravascular NK/T-cell lymphoma deserves special attention because of its clinicopathologic features and the need for adequate immunophenotyping combined with clonality test for a proper diagnosis. Moreover, intravascular NK/T-cell lymphoma is strongly linked to Epstein-Barr virus (EBV), which is considered to play a role in tumorigenesis and to be responsible for the aggressive behavior of the disease. In this paper, we review the current knowledge on this rare lymphoma and, in particular, the most recent advances about its molecular landscape. The main distinguishing features with other EBV-related entities, such as extranodal NK/T-cell lymphoma, EBV-positive primary nodal T/NK-cell lymphoma, and aggressive NK-cell leukemia, are discussed to help pathologists obtain the correct diagnosis and consequently develop an adequate and prompt therapy response.

Pharmacophore-Based Virtual Screening and Experimental Validation of Pyrazolone-Derived Inhibitors toward Janus Kinases

Janus kinases (JAKs) are nonreceptor protein tyrosine kinases that play a role in a broad range of cell signaling. JAK2 and JAK3 have been involved in the pathogenesis of common lymphoid-derived diseases and leukemia cancer. Thus, inhibition of both JAK2 and JAK3 can be a potent strategy to reduce the risk of these diseases. In the present study, the pharmacophore models built based on the commercial drug tofacitinib and the JAK2/3 proteins derived from molecular dynamics (MD) trajectories were employed to search for a dual potent JAK2/3 inhibitor by a pharmacophore-based virtual screening of 54 synthesized pyrazolone derivatives from an in-house data set. Twelve selected compounds from the virtual screening procedure were then tested for their inhibitory potency against both JAKs in the kinase assay. The in vitro kinase inhibition experiment indicated that compounds 3h, TK4g, and TK4b can inhibit both JAKs in the low nanomolar range. Among them, the compound TK4g showed the highest protein kinase inhibition with the half-maximal inhibitory concentration (IC₅₀) value of 12.61 nM for JAK2 and 15.80 nM for JAK3. From the MD simulations study, it could be found that the sulfonamide group of TK4g can form hydrogen bonds in the hinge region at residues E930 and L932 of JAK2 and E903 and L905 of JAK3, while van der Waals interaction also plays a dominant role in ligand binding. Altogether, TK4g, found by virtual screening and biological tests, could serve as a novel therapeutical lead candidate.

An in vivo model of glioblastoma radiation resistance identifies long non-coding RNAs and targetable kinases

Key molecular regulators of acquired radiation resistance in recurrent glioblastoma (GBM) are largely unknown, with a dearth of accurate preclinical models. To address this, we generated 8 GBM patient-derived xenograft (PDX) models of acquired radiation therapy–selected (RTS) resistance compared with same-patient, treatment-naive (radiation-sensitive, unselected; RTU) PDXs. These likely unique models mimic the longitudinal evolution of patient recurrent tumors following serial radiation therapy. Indeed, while whole-exome sequencing showed retention of major genomic alterations in the RTS lines, we did detect a chromosome 12q14 amplification that was associated with clinical GBM recurrence in 2 RTS models. A potentially novel bioinformatics pipeline was applied to analyze phenotypic, transcriptomic, and kinomic alterations, which identified long noncoding RNAs (lncRNAs) and targetable, PDX-specific kinases. We observed differential transcriptional enrichment of DNA damage repair pathways in our RTS models, which correlated with several lncRNAs. Global kinomic profiling separated RTU and RTS models, but pairwise analyses indicated that there are multiple molecular routes to acquired radiation resistance. RTS model–specific kinases were identified and targeted with clinically relevant small molecule inhibitors. This cohort of in vivo RTS patient-derived models will enable future preclinical therapeutic testing to help overcome the treatment resistance seen in patients with GBM.

A genomic-augmented multivariate prognostic model for the survival of Natural-killer/T-cell lymphoma patients from an international cohort

With lowering costs of sequencing and genetic profiling techniques, genetic drivers can now be detected readily in tumors but current prognostic models for Natural-killer/T cell lymphoma (NKTCL) have yet to fully leverage on them for prognosticating patients. Here, we used next-generation sequencing to sequence 260 NKTCL tumors, and trained a genomic prognostic model (GPM) with the genomic mutations and survival data from this retrospective cohort of patients using LASSO Cox regression. The GPM is defined by the mutational status of 13 prognostic genes and is weakly correlated with the risk-features in International Prognostic Index (IPI), Prognostic Index for Natural-Killer cell lymphoma (PINK) and PINK-Epstein-Barr virus (PINK-E). Cox-proportional hazard multivariate regression also showed that the new GPM is independent and significant for both progression-free survival (PFS, HR: 3.73, 95% CI 2.07-6.73; P<0.001) and overall survival (OS, HR: 5.23, 95% CI 2.57-10.65; P=0.001) with known risk-features of these indices. When we assign an additional risk-score to samples, which are mutant for the GPM, the Harrell's C-indices of GPM-augmented IPI, PINK and PINK-E improved significantly (P<0.001, χ² test) for both PFS and OS. Thus, we report on how genomic mutational information could steer towards better prognostication of NKTCL patients. This article is protected by copyright. All rights reserved.

Design, synthesis and structure-activity relationship studies of pyrido[2,3-d]pyrimidin-7-ones as potent Janus Kinase 3 (JAK3) covalent inhibitors

Aberrantly activated Janus kinase 3 (JAK3) has been constantly detected in various immune disorders and hematopoietic cancers, suggesting its potential of being an attractive therapeutic target for these indications. Clinical benefits of drugs selectively targeting JAK3 versus pan-JAK inhibitors remain unclear. In this study, we report the design and synthesis of a new series of JAK3 covalent inhibitors with a pyrido[2,3-d]pyrimidin-7-one scaffold. After the extensive SAR study, compound 10f emerged to be the most potent JAK3 inhibitor with an IC₅₀ value of 2.0 nM. It showed excellent selectively proliferation inhibitory activity against U937 cells harboring JAK3 M511I mutation, while remained weakly active to the other tested cancer cells. Compound 10f also dose-dependently inhibited the phosphorylation of JAK3 and its downstream signal STAT5 in U937 cells. Taken together, 10f may serve as a promising tool molecule for treating cancers with aberrantly activated JAK3.

Treatment Advances in EBV Related Lymphoproliferative Diseases

Epstein Barr virus (EBV) can affect 90% of the human population. It can invade B lymphocytes, T lymphocytes and natural killer cells of the host and remain in the host for life. The long latency and reactivation of EBV can cause malignant transformation, leading to various lymphoproliferative diseases (LPDs), including EBV-related B-cell lymphoproliferative diseases (EBV-B-LPDs) (for example, Burkitt lymphoma (BL), classic Hodgkin's lymphoma (cHL), and posttransplantation and HIV-related lymphoproliferative diseases) and EBV-related T-cell lymphoproliferative diseases (EBV-T/NK-LPDs) (for example, extranodal nasal type natural killer/T-cell lymphoma (ENKTCL), aggressive NK cell leukaemia (ANKL), and peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS). EBV-LPDs are heterogeneous with different clinical features and prognoses. The treatment of EBV-LPDs is usually similar to that of EBV-negative lymphoma with the same histology and can include chemotherapy, radiotherapy, and hematopoietic stem cell transplant (HSCT). However, problems such as serious toxicity and drug resistance worsen the survival prognosis of patients. EBV expresses a variety of viral and lytic proteins that regulate cell cycle and death processes and promote the survival of tumour cells. Based on these characteristics, a series of treatment strategies for EBV in related malignant tumours have been developed, such as monoclonal antibodies, immune checkpoint inhibitors, cytotoxic T lymphocytes (CTLs) and epigenetic therapy. These new individualized therapies can produce highly specific killing effects on tumour cells, and nontumour cells can be protected from toxicity. This paper will focus on the latest progress in the treatment of EBV-LPDs based on pathological mechanisms.

Identification of serum and glucocorticoid-regulated kinase 1 as a regulator of signal transducer and activator of transcription 3 signaling

Signal transducer and activator of transcription 3 (STAT3) plays key roles in cancer cell proliferation, invasion, and immunosuppression. In many human cancer cells, STAT3 is hyperactivated, which leads to tumor progression and drug resistance, and therefore STAT3 and its modulators are considered effective drug targets. However, the complex regulatory mechanisms of STAT3 have made it difficult to develop potent anticancer drugs that suppress its activity. Here, we report serum and glucocorticoid-regulated kinase 1 (SGK1) as a novel regulator of STAT3 signaling and an effective target for combination therapy with Janus kinase (JAK) inhibitors. We screened small molecules using a gain-of-function mutant of STAT3 resistant to JAK inhibition and found that an SGK1 inhibitor suppressed the constitutive activation of STAT3. Importantly, our results revealed that SGK1 also mediated the activation of wild-type STAT3. Further examination suggested that the tuberous sclerosis complex 2 and mammalian target of rapamycin signaling pathway were involved in STAT3 activation by SGK1. Finally, we demonstrated that SGK1 inhibition enhanced the inhibitory effect of a JAK inhibitor on STAT3 phosphorylation and cancer cell proliferation. Our findings provide new insights into the molecular mechanisms of STAT3 activation and suggest SGK1 as a potential target for STAT3-targeted combination cancer therapy.

MicroRNAs and JAK/STAT3 signaling: A new promising therapeutic axis in blood cancers

Blood disorders include a wide spectrum of blood-associated malignancies resulting from inherited or acquired defects. The ineffectiveness of existing therapies against blood disorders arises from different reasons, one of which is drug resistance, so different types of leukemia may show different responses to treatment. Leukemia occurs for a variety of genetic and acquired reasons, leading to uncontrolled proliferation in one or more cell lines. Regarding the genetic defects, oncogene signal transducer and activator of transcription (STAT) family transcription factor, especially STAT3, play an essential role in hematological disorders onset and progress upon mutations, dysfunction, or hyperactivity. Besides, microRNAs, as biological molecules, has been shown to play a dual role in either tumorigenesis and tumor suppression in various cancers. Besides, a strong association between STAT3 and miRNA has been reported. For example, miRNAs can regulate STAT3 via targeting its upstream mediators such as IL6, IL9, and JAKs or directly binding to the STAT3 gene. On the other hand, STAT3 can regulate miRNAs. In this review study, we aimed to determine the role of either microRNAs and STAT3 along with their effect on one another's activity and function in hematological malignancies.

Janus Kinase Signaling: Oncogenic Criminal of Lymphoid Cancers

Simple Summary

Janus kinases (JAKs) are transmembrane receptors that pass signals from extracellular ligands to downstream. Increasing evidence has suggested that JAK family aberrations promote lymphoid cancer pathogenesis and progression through mediating gene expression via the JAK/STAT pathway or noncanonical JAK signaling. We are here to review how canonical JAK/STAT and noncanonical JAK signalings are represented and deregulated in lymphoid malignancies and how to target JAK for therapeutic purposes.

Abstract

The Janus kinase (JAK) family are known to respond to extracellular cytokine stimuli and to phosphorylate and activate signal transducers and activators of transcription (STAT), thereby modulating gene expression profiles. Recent studies have highlighted JAK abnormality in inducing over-activation of the JAK/STAT pathway, and that the cytoplasmic JAK tyrosine kinases may also have a nuclear role. A couple of anti-JAK therapeutics have been developed, which effectively harness lymphoid cancer cells. Here we discuss mutations and fusions leading to JAK deregulations, how upstream nodes drive JAK expression, how classical JAK/STAT pathways are represented in lymphoid malignancies and the noncanonical and nuclear role of JAKs. We also summarize JAK inhibition therapeutics applied alone or synergized with other drugs in treating lymphoid malignancies.

Pseurotin D Induces Apoptosis through Targeting Redox Sensitive Pathways in Human Lymphoid Leukemia Cells

Chronic lymphocytic leukemia (CLL) is the most prevalent lymphoid malignancy in many geographical regions of the world. Pseurotin D, a secondary metabolite of fungi, represents a group of bioactive natural products with a newly ascribed range of interesting biological activities. The purpose of this study was to bring new insights into the mechanism behind the effects of pseurotin D on MEC-1 cells as a representative CLL cell line, with a particular focus on selected signaling pathways important in the proliferation of cells and targeting mitochondrial metabolism. Our results showed that pseurotin D was able to significantly inhibit the proliferation of MEC-1 cells and arrested them in the G2/M cell cycle phase. In addition, pseurotin D was able to induce apoptosis. We found that all of these effects were associated with a change in mitochondrial membrane potential and the production of mitochondrial reactive oxygen species (ROS). We showed for the first time that pseurotin D suppresses MEC-1 cell proliferation and induces apoptotic cell death via induction of the collapse of the mitochondria respiratory chain and the ROS-related caspase pathway. Our results show the pseurotins family as promising compounds which could serve as a basis for the development of new compounds in the treatment of lymphoma.

Therapeutic siRNAs Targeting the JAK/STAT Signalling Pathway in Inflammatory Bowel Diseases

BACKGROUND AND AIMS

Inflammatory bowel diseases are highly debilitating conditions that require constant monitoring and life-long medication. Current treatments are focused on systemic administration of immunomodulatory drugs, but they have a broad range of undesirable side-effects. RNA interference is a highly specific endogenous mechanism that regulates the expression of the gene at the transcript level, which can be repurposed using exogenous short interfering RNA [siRNA] to repress expression of the target gene. While siRNA therapeutics can offer an alternative to existing therapies, with a high specificity critical for chronically administrated drugs, evidence of their potency compared to chemical kinase inhibitors used in clinics is still lacking in alleviating an adverse inflammatory response.

METHODS

We provide a framework to select highly specific siRNA, with a focus on two kinases strongly involved in pro-inflammatory diseases, namely JAK1 and JAK3. Using western-blot, real-time quantitative PCR and large-scale analysis, we assessed the specificity profile of these siRNA drugs and compared their efficacy to the most recent and promising kinase inhibitors for Janus kinases [Jakinibs], tofacitinib and filgotinib.

RESULTS

siRNA drugs can reach higher efficiency and selectivity at lower doses [5 pM vs 1 µM] than Jakinibs. Moreover, JAK silencing lasted up to 11 days, even with 6 h pulse transfection.

CONCLUSIONS

The siRNA-based drugs developed hold the potential to develop more potent therapeutics for chronic inflammatory diseases.

Liquid biopsy in extranodal NK/T-cell lymphoma: a prospective analysis of cell-free DNA genotyping and monitoring

Satisfactory tumor material is often hard to obtain for molecular analysis in extranodal natural killer (NK)/T-cell lymphoma (NKTCL) at present. However, the accuracy and utility of circulating cell-free DNA (cfDNA) genotyping have not been adequately assessed in NKTCL. We therefore performed targeted next-generation sequencing on tumor tissues and a series of longitudinal plasma samples prospectively collected from a cohort of high-risk NKTCL patients. Concordance of genotyping results of paired baseline tumor and cfDNA and the predictive value of dynamic cfDNA monitoring were evaluated. At baseline, 59 somatic variants in 31 genes were identified in tumor and/or plasma cfDNA among 19 out of 24 high-risk NKTCL patients (79.2%). Plasma cfDNA had a sensitivity of 72.4% for detection of somatic variants identified in tumor biopsies before treatment. Plasma cfDNA also allowed the identification of mutations that were undetectable in tumor biopsies. These results were also verified in a validation cohort of an additional 23 high-risk NKTCL patients. Furthermore, longitudinal analysis showed that patients with rapid clearance of NKTCL-related mutations from plasma had higher complete remission rates (80.0% vs 0%; P = .004) and more favorable survival (1-year progression-free survival [PFS] rate, 79.0% vs 20.0%; P = .002) compared with those with persisting or emerging mutations in plasma. In addition, low cfDNA concentration before treatment was associated with favorable survival outcome for patients with NKTCL (1-year PFS, 90.0% vs 36.4%; P = .012). In conclusion, cfDNA mirrors tumor biopsy for detection of genetic alterations in NKTCL and noninvasive dynamic plasma cfDNA monitoring might be a promising approach for tracking response and survival outcome for patients with NKTCL.

Streptomyces hygroscopicus UFPEDA 3370: A valuable source of the potent cytotoxic agent nigericin and its evaluation against human colorectal cancer cells

Streptomyces hygroscopicus UFPEDA 3370 was fermented in submerged cultivation and the biomass extract was partitioned, obtaining a fraction purified named EB1. After purification of EB1 fraction, nigericin free acid was obtained and identified. Nigericin presented cytotoxic activity against several cancer cell lines, being most active against HL-60 (human leukemia) and HCT-116 (human colon carcinoma) cell lines, presenting IC₅₀ and (IS) values: 0.0014 μM, (30.0) and 0.0138 μM (3.0), respectively. On HCT-116, nigericin caused apoptosis and autophagy. In this study, nigericin was also screened both in vitro and in silico against a panel of cancer-related kinases. Nigericin was able to inhibit both JAK3 and GSK-3β kinases in vitro and its binding affinities were mapped through the intermolecular interactions with each target in silico.

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.

Extranodal NK/T-Cell Lymphomas: The Role of Natural Killer Cells and EBV in Lymphomagenesis

Natural killer (NK) cells are lymphocytes involved in innate and adaptive immune functions. They are the presumed cell of origin of distinct hematolymphoid malignancies, including aggressive NK-cell leukemia and extranodal NK/T-cell lymphoma (ENKTL). This review focuses on the role of NK cells and Epstein–Barr virus (EBV) in ENKTL pathogenesis.

Evaluation of the PIK3 pathway in peripheral T-cell lymphoma and NK/T-cell lymphoma

Peripheral T‐cell lymphomas (PTCL) and natural killer (NK)/T‐cell lymphomas (NKTCL) are a heterogeneous group of aggressive malignancies with dismal outcomes and limited treatment options. While the phosphatidylinositol 3‐kinase (PIK3) pathway has been shown to be highly activated in many B‐cell lymphomas, its therapeutic relevance in PTCL and NKTCL remains unclear. The aim of this study is to investigate the expression of PIK3 and phosphatase and tensin homolog (PTEN) in these subtypes of lymphoma and to identify potential therapeutic targets for clinical testing. Therefore, the expression of PIK3α, PIK3β, PIK3γ, PIK3δ and PTEN was analyzed in 88 cases of PTCL and NKTCL samples by immunohistochemistry. All PTCL and NKTCL samples demonstrated high expression of PIK3 isoforms. In particular, high PIK3α expression was significantly associated with poor survival, even after adjustment for age, International Prognostic Index (IPI) score and anthracycline‐based chemotherapy in first line. Notably, copanlisib, a pan‐class I inhibitor with predominant activities towards PIK3α and PIK3δ isoforms, effectively inhibited phosphorylation of AKT, 4E‐BP‐1 and STAT3, causing G₀/G₁ cell cycle arrest and resulting in suppression of tumour cell growth in vitro and in vivo. This study provides evidence that targeting the PIK3 pathway, particularly simultaneous inhibition of PIK3α and δ, could be a promising approach for the treatment of PTCL and NKTCL.

Identifying subpathway signatures for individualized anticancer drug response by integrating multi-omics data

Background

Individualized drug response prediction is vital for achieving personalized treatment of cancer and moving precision medicine forward. Large-scale multi-omics profiles provide unprecedented opportunities for precision cancer therapy.

Methods

In this study, we propose a pipeline to identify subpathway signatures for anticancer drug response of individuals by integrating the comprehensive contributions of multiple genetic and epigenetic (gene expression, copy number variation and DNA methylation) alterations.

Results

Totally, 46 subpathway signatures associated with individual responses to different anticancer drugs were identified based on five cancer-drug response datasets. We have validated the reliability of subpathway signatures in two independent datasets. Furthermore, we also demonstrated these multi-omics subpathway signatures could significantly improve the performance of anticancer drug response prediction. In-depth analysis of these 46 subpathway signatures uncovered the essential roles of three omics types and the functional associations underlying different anticancer drug responses. Patient stratification based on subpathway signatures involved in anticancer drug response identified subtypes with different clinical outcomes, implying their potential roles as prognostic biomarkers. In addition, a landscape of subpathways associated with cellular responses to 191 anticancer drugs from CellMiner was provided and the mechanism similarity of drug action was accurately unclosed based on these subpathways. Finally, we constructed a user-friendly web interface-CancerDAP (http://bio-bigdata.hrbmu.edu.cn/CancerDAP/) available to explore 2751 subpathways relevant with 191 anticancer drugs response.

Conclusions

Taken together, our study identified and systematically characterized subpathway signatures for individualized anticancer drug response prediction, which may promote the precise treatment of cancer and the study for molecular mechanisms of drug actions.

Electronic supplementary material

The online version of this article (10.1186/s12967-019-2010-4) contains supplementary material, which is available to authorized users.

What we should know about natural killer/T-cell lymphomas

Natural-killer/T cell lymphoma (NKTCL) is the most common extranodal lymphoma with highly aggressive clinical outcome. System biology techniques provide novel insights into the pathogenesis, risk stratification, and clinical management in NKTCL. Comparative genomic hybridization analysis reveal most frequent deletion of chromosome 6q21. Whole-exome sequencing studies identify recurrent somatic gene mutations, involving RNA helicases, tumor suppressors, JAK-STAT pathway molecules, and epigenetic modifiers. Genome-wide association study reports strongest association of HLA-DPB1 rs9277378 with lymphomagenesis. Alterations of oncogenic signaling pathways as well as epigenetic dysregulation of microRNA and long non-coding RNAs are also observed in NKTCL. Epstein-Barr virus (EBV) is the major etiology of NKTCL and the pathogenic mechanism remains unclear. Different risk stratification models are proposed based on clinical parameters (IPI, PINK, and PINK-E, etc.) or biomarkers (Ki67, C-reactive protein level, and EBV DNA, etc.). Therapeutic strategies vary according to disease stage, including radiotherapy, asparaginase-based chemotherapy, hematopoietic stem-cell transplantation, targeted therapy (immune checkpoints inhibitors, and histone deacetylation inhibitors, etc.). Future investigations will be emphasized on EBV-related pathogenesis of NKTCL, prognostic and therapeutic biomarkers, as well as multi-center clinical trials, so as to optimize personalized treatment of NKTCL in the era of precision medicine.

Epstein-Barr Virus-Positive Natural Killer/T-Cell Lymphoma

Extranodal natural killer/T-cell lymphoma, nasal type (ENKL), is a rare malignancy of Non-Hodgkin lymphoma characterized by an aggressive clinical course and poor prognosis. It shows strong association with Epstein-Barr virus infection and occurs more commonly in Asia and Latin America. Various genetic alterations have been identified in ENKL by gene expression profiling and sequencing techniques. The frequent deletion of chromosome 6q21 was reported to lead to the silence of several tumor suppressor genes. Also, there have been novel genetic mutations that were recently uncovered and were found to frequently activate several oncogenic pathways, including the JAK/STAT, NF-κB, and MAPK pathways. Besides, we believe that deregulated single genes and epigenetic dysregulation might be relevant to the mechanism of this disease and thus, may have the potential to shed lights on the development of new therapeutic strategies. The consensus on the standard treatment for ENKL has not yet been currently established. For localized ENKL patients, radiotherapy with concurrent chemotherapy and sequential patterns of chemotherapy and radiotherapy are recommended as first-line therapy. As for advanced or relapsed/refractory ENKL patients, the application of non-anthracycline-containing regimens have significantly improved the clinical outcome, contributing to higher response rate, longer overall survival and progression-free survival. Hematopoietic stem cell transplantation is widely recommended for consolidation after a complete remission or partial remission has been achieved. The anti-programmed death 1 antibody, an immune checkpoint inhibitor, has demonstrated favorable results in treating relapsed or refractory ENKL. Of the current ENKL treatment, researchers are still striving to validate how radiotherapy and chemotherapy should be optimally combined and which of the non-anthracycline-containing regimens is superior. In this review, we summarize the main genetic alterations frequently found in ENKL and their role in providing new insights into the therapeutic targets of this disease, and highlight the recent findings regarding new biologic markers, novel therapeutic strategies applied to this intriguing neoplasm.

JAK3/STAT3 oncogenic pathway and PRDM1 expression stratify clinicopathologic features of extranodal NK/T‑cell lymphoma, nasal type

The inactivation of tumor suppressor gene positive regulatory domain containing I (PRDM1) and activation of signal transducer and activator of transcription 3 (STAT3) have been detected in the majority of extranodal NK/T‑cell lymphoma, nasal type (EN‑NK/T‑NT) cases. In the present study, their association with and effects on the clinicopathologic features of EN‑NK/T‑NT are described. PRDM1 was revealed to be expressed in 19 out of 58 patients (32.8%) with EN‑NK/T‑NT, and phosphorylated STAT3 was overexpressed in 42 out of 58 (72.4%). Oncogenic pathways were investigated by NanoString encounter technology in 5 PRDM1(+) and 5 PRDM1(‑) EN‑NK/T‑NT specimens. Multiple oncogenic pathways involved in cell apoptosis, cellcycle (CC) and angiogenesis were discriminately activated in EN‑NK/T‑NT cases, and in PRDM1(+) cases in particular. The sustained activation of the Janus kinase 3 (JAK)/STAT3 pathway was more pronounced. In addition, missense mutations in the SRC homology 2 domain of STAT3 were detected in 7 out of 37 EN‑NK/T‑NT cases (18.92%), and the acquired mutation was related to the activation of the JAK3/STAT3 pathway. The downregulation of PRDM1 and upregulation of phospho‑STAT3 (Tyr705) were associated with angiocentric infiltration of EN‑NK/T‑NT (P=0.039). Notably, the prognosis of patients in the PRDM1(+)/STAT3 [mutated (mut‑)] group was considerably improved than that of patients in the STAT3(mut+)/PRDM(‑) group (P=0.037). In addition, the inhibition of NK/T cell lymphoma cell lines by Stattic and tofacitinib could suppress cell proliferation by inducing cell apoptosis or arresting the CC. The present results revealed that the JAK3/STAT3 oncogenic pathway and PRDM1 expression could stratify clinicopathologic features of EN‑NK/T‑NT. The inhibition of the JAK3/STAT3 pathway may serve as a treatment option for EN‑NK/T‑NT.

Molecular pathogenic pathways in extranodal NK/T cell lymphoma

Extranodal NK/T cell lymphoma, nasal type (ENKTL) is an aggressive malignancy with a dismal prognosis. Although L-asparaginase-based chemotherapy has resulted in improved response rates, relapse occurs in up to 50% of patients with disseminated disease. There is hence an urgent need for effective targeted therapy, especially for patients with relapsed or refractory disease. Novel insights gleaned from high-throughput molecular and genomic profiling studies in recent years have contributed significantly to the understanding of the molecular biology of ENKTL, which exemplifies many of the hallmarks of cancer. Deregulated pro-proliferative signaling pathways, such as the Janus-associated kinase/signal transducer and activator of transcription (JAK/STAT), platelet-derived growth factor (PDGF), Aurora kinase, MYC, and NF-κB, have been identified as potential therapeutic targets. The discovery of the non-canonical function of EZH2 as a pro-proliferative transcriptional co-activator has shed further light on the pathogenesis of ENKTL. Loss of key tumor suppressor genes located on chromosome 6q21 also plays an important role. The best-studied examples include PR domain zinc finger protein 1(PRDM1), protein tyrosine phosphatase kappa (PTPRK), and FOXO3. Promoter hypermethylation has been shown to result in the downregulation of other tumor suppressor genes in ENKTL, which may be potentially targeted through hypomethylating agents. Deregulation of apoptosis through p53 mutations and upregulation of the anti-apoptotic protein, survivin, may provide a further growth advantage to this tumor. A deranged DNA damage response as a result of the aberration of ataxia telangiectasia-related (ATR) kinases can lead to significant genomic instability and may contribute to chemoresistance of ENKTL. Recently, immune evasion has emerged as a critical pathway for survival in ENKTL and may be a consequence of HLA dysregulation or STAT3-driven upregulation of programmed cell death ligand 1 (PD-L1). Immunotherapy via inhibition of programmed cell death 1 (PD-1)/PD-L1 checkpoint signaling holds great promise as a novel therapeutic option. In this review, we present an overview of the key molecular and pathogenic pathways in ENKTL, organized using the framework of the "hallmarks of cancer" as described by Hanahan and Weinberg, with a focus on those with the greatest translational potential.

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

Natural killer T cell lymphoma (NKTL) is an aggressive disease with very poor treatment outcomes in the advanced stages. With chemotherapy, initial response rates to treatment are high but responses are short lived. A better understanding of the complex molecular pathogenesis of this disease is essential in order to design and develop better therapeutics with improved efficacy. This review aims to summarise the key pathogenic mechanisms in NKTL which may have significant prognostic and therapeutic implications.

CD30-positive primary cutaneous lymphoproliferative disorders: molecular alterations and targeted therapies

Primary cutaneous CD30-positive T-cell lymphoproliferative disorders are the second most common subgroup of cutaneous T-cell lymphomas. They include two clinically different entities with some overlapping features and borderline cases: lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma. Molecular studies of primary cutaneous anaplastic large cell lymphoma reveal an increasing level of heterogeneity that is associated with histological and immunophenotypic features of the cases and their response to specific therapies. Here, we review the most significant genetic, epigenetic and molecular alterations described to date in primary cutaneous CD30-positive T-cell lymphoproliferative disorders, and their potential as therapeutic targets.

Advances in multiple omics of natural-killer/T cell lymphoma

Natural-killer/T cell lymphoma (NKTCL) represents the most common subtype of extranodal lymphoma with aggressive clinical behavior. Prevalent in Asians and South Americans, the pathogenesis of NKTCL remains to be fully elucidated. Using system biology techniques including genomics, transcriptomics, epigenomics, and metabolomics, novel biomarkers and therapeutic targets have been revealed in NKTCL. Whole-exome sequencing studies identify recurrent somatic gene mutations, involving RNA helicases, tumor suppressors, JAK-STAT pathway molecules, and epigenetic modifiers. Another genome-wide association study reports that single nucleotide polymorphisms mapping to the class II MHC region on chromosome 6 contribute to lymphomagenesis. Alterations of oncogenic signaling pathways janus kinase-signal transducer and activator of transcription (JAK-STAT), nuclear factor-κB (NF-κB), mitogen-activated protein kinase (MAPK), WNT, and NOTCH, as well as epigenetic dysregulation of microRNA and long non-coding RNAs, are also frequently observed in NKTCL. As for metabolomic profiling, abnormal amino acids metabolism plays an important role on disease progression of NKTCL. Of note, through targeting multiple omics aberrations, clinical outcome of NKTCL patients has been significantly improved by asparaginase-based regimens, immune checkpoints inhibitors, and histone deacetylation inhibitors. Future investigations will be emphasized on molecular classification of NKTCL using integrated analysis of system biology, so as to optimize targeted therapeutic strategies of NKTCL in the era of precision medicine.

STAT3 antisense oligonucleotide AZD9150 in a subset of patients with heavily pretreated lymphoma: results of a phase 1b trial

Background

The Janus kinase (JAK) and signal transduction and activation of transcription (STAT) signaling pathway is an attractive target in multiple cancers. Activation of the JAK-STAT pathway is important in both tumorigenesis and activation of immune responses. In diffuse large B-cell lymphoma (DLBCL), the transcription factor STAT3 has been associated with aggressive disease phenotype and worse overall survival. While multiple therapies inhibit upstream signaling, there has been limited success in selectively targeting STAT3 in patients. Antisense oligonucleotides (ASOs) represent a compelling therapeutic approach to target difficult to drug proteins such as STAT3 through of mRNA targeting. We report the evaluation of a next generation STAT3 ASO (AZD9150) in a non-Hodgkin’s lymphoma population, primarily consisting of patients with DLBCL.

Methods

Patients with relapsed or treatment refractory lymphoma were enrolled in this expansion cohort. AZD9150 was administered at 2 mg/kg and the 3 mg/kg (MTD determined by escalation cohort) dose levels with initial loading doses in the first week on days 1, 3, and 5 followed by weekly dosing. Patients were eligible to remain on therapy until unacceptable toxicity or progression. Blood was collected pre- and post-treatment for analysis of peripheral immune cells.

Results

Thirty patients were enrolled, 10 at 2 mg/kg and 20 at 3 mg/kg dose levels. Twenty-seven patients had DLBCL. AZD9150 was safe and well tolerated at both doses. Common drug-related adverse events included transaminitis, fatigue, and thrombocytopenia. The 3 mg/kg dose level is the recommended phase 2 dose. All responses were seen among DLBCL patients, including 2 complete responses with median duration of response 10.7 months and 2 partial responses. Peripheral blood cell analysis of three patients without a clinical response to therapy revealed a relative increase in proportion of macrophages, CD4+, and CD8+ T cells; this trend did not reach statistical significance.

Conclusions

AZD9150 was well tolerated and demonstrated efficacy in a subset of heavily pretreated patients with DLBCL. Studies in combination with checkpoint immunotherapies are ongoing.

Trial registration

Registered at ClinicalTrials.gov: NCT01563302. First submitted 2/13/2012.

Electronic supplementary material

The online version of this article (10.1186/s40425-018-0436-5) contains supplementary material, which is available to authorized users.

The Long Noncoding RNA MEG3 and its Target miR-147 Regulate JAK/STAT Pathway in Advanced Chronic Myeloid Leukemia

Background

Long non-coding (lnc) RNAs plays an important role in chronic myeloid leukemia (CML). In this study, we aimed to uncover the mechanism of the lncRNA maternally expressed 3 (MEG3) and its target microRNA-147 (miR-147) in CML.

Methods

Sixty CML patients and 10 healthy donors were included in the study. The methylation of MEG3 and miR-147 promoter was determined by methylation-specific PCR. The relationship of MEG3 and miR-147 was explored by luciferase assay. The interactions of proteins were studied by RNA pull-down assay, RNA immunoprecipitation and co-immunoprecipitation.

Findings

Patients in accelerated phase CML (CML-AP) and blast phase CML (CML-BP) showed lower expressions of MEG3 and miR-147 and higher expressions of DNMT1, DNMT3B, MBD2, MECP2 and HDAC1 compared to the controls. These patients also showed a higher degree of methylation of MEG3 and miR-147 while there was a reduction after chidamide treatment. Furthermore, the overexpression of MEG3 and miR-147 inhibited cell proliferation both in vivo and in vitro, promoted apoptosis and decreased the expressions of DNMT1, DNMT3A, DNMT3B, MBD2, HDAC1 and MECP2. We also found MEG3 interacted with DNMT1, JAK2, STAT3, HDAC1, and TYK2, and JAK2 was bound to STAT3, STAT5 and MYC. More interestingly, JAK2 was bound to TYK2 by the bridge of MEG3.

Interpretation

LncRNA MEG3 and its target miR-147 may serve as a novel therapeutic target for CML blast crisis, and chidamide might have a potential clinical application in treating CML blast crisis.

The Genomics and Molecular Biology of Natural Killer/T-Cell Lymphoma: Opportunities for Translation

Extranodal NK/T-cell lymphoma, nasal type (ENKTL), is an aggressive malignancy with a poor prognosis. While the introduction of L-asparaginase in the treatment of this disease has significantly improved the prognosis, the outcome of patients relapsing after asparaginase-based chemotherapy, which occurs in up to 50% of patients with disseminated disease, remains dismal. There is hence an urgent need for effective targeted therapy especially in the relapsed/refractory setting. Gene expression profiling studies have provided new perspectives on the molecular biology, ontogeny and classification of ENKTL and further identified dysregulated signaling pathways such as Janus associated kinase (/Signal Transducer and activation of transcription (JAK/STAT), Platelet derived growth factor (PDGF), Aurora Kinase and NF-κB, which are under evaluation as therapeutic targets. Copy number analyses have highlighted potential tumor suppressor genes such as PR Domain Zinc Finger Protein 1 (PRDM1) and protein tyrosine phosphatase kappa (PTPRK) while next generation sequencing studies have identified recurrently mutated genes in pro-survival and anti-apoptotic pathways. The discovery of epigenetic dysregulation and aberrant microRNA activity has broadened our understanding of the biology of ENKTL. Importantly, immunotherapy via Programmed Cell Death -1 (PD-1) and Programmed Cell Death Ligand1 (PD-L1) checkpoint signaling inhibition is emerging as an attractive therapeutic strategy in ENKTL. Herein, we present an overview of the molecular biology and genomic landscape of ENKTL with a focus on the most promising translational opportunities.

Transcriptomic Abnormalities in Epstein Barr Virus Associated T/NK Lymphoproliferative Disorders

Epstein Barr virus positive T/NK lymphoproliferative disorders (EBV-TNKLPD) comprise a spectrum of neoplasms ranging from cutaneous lymphoid proliferations to aggressive lymphomas. The spectrum includes extranodal NK/T-cell lymphoma (ENKTL), aggressive NK-cell leukemia, and a group of EBV-TNKLPDs affecting children which are poorly characterized in terms of their molecular biology. Gene and miRNA expression profiling has elucidated RNA abnormalities which impact on disease biology, classification, and treatment of EBV-TNKLPD. Pathways promoting proliferation, such as Janus associated kinase/ Signal Transducer and Activator of Transcription (JAK/STAT) and nuclear factor kB, are upregulated in ENKTL while upregulation of survivin and deregulation of p53 inhibit apoptosis in both ENKTL and chronic active EBV infection (CAEBV). Importantly, immune evasion via the programmed cell death-1 and its ligand, PD-1/PD-L1 checkpoint pathway, has been demonstrated to play an important role in ENKTL. Other pathogenic mechanisms involve EBV genes, microRNA deregulation, and a variety of other oncogenic signaling pathways. The identification of EBV-positive Peripheral T-cell lymphoma not otherwise specified (PTCL-NOS) as a tumor with a distinct molecular signature and clinical characteristics highlights the important contribution of the knowledge derived from gene and miRNA expression profiling in disease classification. Novel therapeutic targets identified through the study of RNA abnormalities provide hope for patients with EBV-TNKLPD, which often has a poor prognosis. Immune checkpoint inhibition and JAK inhibition in particular have shown promise and are being evaluated in clinical trials. In this review, we provide an overview of the key transcriptomic aberrancies in EBV-TNKLPD and discuss their translational potential.