Blockade of phosphodiesterase 5 by sildenafil reduces tumor growth and potentiates tumor-killing ability of cisplatin in vivo against T cell lymphoma: Implication of modulated apoptosis, reactive oxygen species homeostasis, glucose metabolism, and pH regulation

In the past years, PDE5 has emerged as a promising therapeutic target for many cancers due to its highly upregulated expression. Interestingly, a recent in vitro study by our group has shown the antitumor and chemopotentiating action of sildenafil against T cell lymphoma. Our study showed that lower doses of sildenafil (50 μM) and cisplatin (0.5 μg/mL) exhibited 4% and 23% cytotoxicity against HuT78 cells, respectively, which was dramatically increased up to 50% when treated with both. Hence, the present study was designed to evaluate the antitumor and chemo-potentiating action of sildenafil in a murine model of T cell lymphoma (popularly called as Dalton's lymphoma [DL]). In the present study, DL-bearing mice were administered with vehicle (PBS), sildenafil (5 mg/kg bw), cisplatin (5 mg/kg bw), and sildenafil and cisplatin followed by evaluation of their impact on tumor growth by analyzing various parameters. The apoptosis was assessed by Wright-Giemsa, annexin-V, and DAPI staining. Reactive oxygen species (ROS) level was examined through DCFDA staining. The expression of genes and proteins were estimated by RT-PCR and Western blotting, respectively. The experimental findings of the study demonstrate for the first time that sildenafil inhibits tumor growth and potentiates tumor inhibitory ability of cisplatin by altering apoptosis, glycolysis, ROS homeostasis, and pH regulation in T cell lymphoma-carrying host. In addition, our investigation also showed amelioration of tumor-induced liver and kidney damage by sildenafil. Overall, the experimental data of our study strongly advocate the use and repurposing of SDF in designing promising chemotherapeutic regimens against malignancies of T cells.

The construction of modular universal chimeric antigen receptor T (MU-CAR-T) cells by covalent linkage of allogeneic T cells and various antibody fragments

BACKGROUND

Chimeric antigen receptor-T (CAR-T) cells therapy is one of the novel immunotherapeutic approaches with significant clinical success. However, their applications are limited because of long preparation time, high cost, and interpersonal variations. Although the manufacture of universal CAR-T (U-CAR-T) cells have significantly improved, they are still not a stable and unified cell bank.

METHODS

Here, we tried to further improve the convenience and flexibility of U-CAR-T cells by constructing novel modular universal CAR-T (MU-CAR-T) cells. For this purpose, we initially screened healthy donors and cultured their T cells to obtain a higher proportion of stem cell-like memory T (TSCM) cells, which exhibit robust self-renewal capacity, sustainability and cytotoxicity. To reduce the alloreactivity, the T cells were further edited by double knockout of the T cell receptor (TCR) and class I human leukocyte antigen (HLA-I) genes utilizing the CRISPR/Cas9 system. The well-growing and genetically stable universal cells carrying the CAR-moiety were then stored as a stable and unified cell bank. Subsequently, the SDcatcher/GVoptiTag system, which generate an isopeptide bond, was used to covalently connect the purified scFvs of antibody targeting different antigens to the recovered CAR-T cells.

RESULTS

The resulting CAR-T cells can perform different functions by specifically targeting various cells, such as the eradication of human immunodeficiency virus type 1 (HIV-1)-latenly-infected cells or elimination of T lymphoma cells, with similar efficiency as the traditional CAR-T cells did.

CONCLUSION

Taken together, our strategy allows the production of CAR-T cells more modularization, and makes the quality control and pharmaceutic manufacture of CAR-T cells more feasible.

Recommendations on prevention of infections in patients with T-cell lymphomas: a narrative review and synthesis

T/Natural killer (NK) cell lymphomas (TCL) represent a heterogenous subgroup of non-Hodgkin lymphoma, associated with poorer prognosis and higher treatment toxicity. A cohesive synthesis of infection outcomes among TCL patients is lacking. International guidelines offer no specific recommendations regarding prophylaxis or supportive infection care for TCL patients. This systematic narrative review highlights infection outcomes in TCL patients treated with conventional, and novel therapies. Recommendations for infection screening, antimicrobial prophylaxis and vaccination strategies are outined.

Central Nervous System Relapse in T and NK cell Lymphomas

PURPOSE OF REVIEW

T and NK cell lymphomas are relatively rare and heterogeneous forms of non-Hodgkin lymphoma that are associated with high rates of mortality. Central nervous system relapse carries significant morbidity, though management is largely extrapolated from literature in B cell neoplasms. As such, outcomes for central nervous system involvement in T/NK cell lymphomas are dismal with no standard of care. In this review, we discuss the epidemiology of central nervous system relapse in T/NK cell lymphomas and critically analyze available literature regarding prophylaxis and treatment.

RECENT FINDINGS

Retrospective studies of central nervous system involvement in T/NK cell lymphomas have been limited by small sample sizes and heterogeneity of subtypes, though sites of extranodal involvement and disease subtypes are consistently reported as risk factors. Compelling evidence for the use of central nervous system-directed prophylactic therapy has not yet been established, though recent reports of central nervous system activity with novel agents may suggest promising therapeutic options. The overall rarity of T and NK cell lymphomas has precluded adequate study of prophylaxis and treatment of central nervous system relapse. Collaborative efforts are needed to better define strategies to address CNS disease in T/NK cell lymphomas. These should involve the use of targeted agents, which may hold an advantage over traditional cytotoxic drugs.

Nanobody-derived bispecific CAR-T cell therapy enhances the anti-tumor efficacy of T cell lymphoma treatment

T cell lymphoma (TCL) is a highly heterogeneous group of diseases with a poor prognosis and low 5-year overall survival rate. The current therapeutic regimens have relatively low efficacy rates. Clinical studies of single-target chimeric antigen receptor T cell (CAR-T cell) therapy in T lymphocytes require large and multiple infusions, increasing the risks and cost of treatment; therefore, optimizing targeted therapy is a way to improve overall prognosis. Despite significant advances in bispecific CAR-T cell therapy to avoid antigen escape in treatment of B cell lymphoma, applying this strategy to TCL requires further investigation. Here, we constructed an alpaca nanobody (Nb) phage library and generated high-affinity and -specificity Nbs targeting CD30 and CD5, respectively. Based on multiple rounds of screening, bispecific NbCD30-CD5-CAR T cells were constructed, and their superior anti-tumor effect against TCL was validated in vitro and in vivo. Our findings demonstrated that Nb-derived bispecific CAR-T cells significantly improved anti-tumor efficacy in TCL treatment compared with single-target CAR-T cells and bispecific single chain variable fragment (scFv)-derived CAR-T cells. Because Nbs are smaller and less immunogenic, the synergistic effect of Nb-based bispecific CAR-T cells may improve their safety and efficacy in future clinical applications.

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.

Case Report: An unclassified T cell lymphoma subtype with co-expression of TCR αβ and γ chains revealed by single cell sequencing

Background

T cell lymphomas (TCL) are a group of heterogeneous diseases with over 40 subtypes. In this study, we identified a novel TCL subtype which was featured by a unique T cell receptor (TCR) presentation, α, β and γ chains were co-existing in a single malignant T cell.

Case presentation

A 45-year-old male patient was diagnosed T cell lymphoma after 2-month of abdominal distension and liver enlargement. Combining histology review, PET-CT scanning and immunophenotyes, the patient was not classified to any existing TCL subtypes. To better understand this unclassified TCL case, we performed single cell RNA sequencing paired with TCR sequencing on the patient's PBMC and bone marrow samples. To our surprise, we identified that the malignant T cells had a very rare TCR combination, by expressing two α chains, one β chain and one γ chain simultaneously. We further studied the molecular pathogenesis and tumor cell heterogeneity of this rare TCL subtype. A set of potential therapeutic targets were identified from the transcriptome data, such as CCL5, KLRG1 and CD38.

Conclusions

We identified the first TCL case co-expressing α, β and γ chains and dissected its molecular pathogenesis, providing valuable information for precision medicine options for this novel TCL subtype.

ITK degradation to block T cell receptor signaling and overcome therapeutic resistance in T cell lymphomas

Interleukin (IL)-2-inducible T cell kinase (ITK) is essential for T cell receptor (TCR) signaling and plays an integral role in T cell proliferation and differentiation. Unlike the ITK homolog BTK, no inhibitors of ITK are currently US Food and Drug Administration (FDA) approved. In addition, recent studies have identified mutations within BTK that confer resistance to both covalent and non-covalent inhibitors. Here, as an alternative strategy, we report the development of BSJ-05-037, a potent and selective heterobifunctional degrader of ITK. BSJ-05-037 displayed enhanced anti-proliferative effects relative to its parent inhibitor BMS-509744, blocked the activation of NF-kB/GATA-3 signaling, and increased the sensitivity of T cell lymphoma cells to cytotoxic chemotherapy both in vitro and in vivo. In summary, targeted degradation of ITK is a novel approach to modulate TCR signal strength that could have broad application for the investigation and treatment of T cell-mediated diseases.

Intraocular Metastasis of Large T-cell Lymphoma Transformed from Mycosis Fungoides

PURPOSE

To describe a rare case of intraocular lymphoma that metastasized from cutaneous mycosis fungoides and transformed to large cell T cell lymphoma resulting in vitreoretinal pathology.

METHODS

Retrospective case report.

RESULTS

A 57-year-old male presented with 3 months of blurred vision in the right eye. He reported only a medical history of psoriasis. Examination revealed keratic precipitates and dense vitritis in the right eye. He was taken for a diagnostic vitrectomy. Histopathology showed that atypical lymphoid cells and flow cytometry were consistent with transformed large cell T-cell lymphoma. During follow-up, pre- and inner retinal lesions were noted throughout the posterior pole. Histopathology of the psoriatic lesions was consistent with mycosis fungoides. He was initiated on systemic and intravitreal methotrexate with improvement in vision.

CONCLUSIONS

Ocular involvement in metastatic transformed T-cell lymphoma is extremely rare but can be present with vitritis and retinal deposits. Our patient responded well to intravitreal methotrexate therapy.

Clinical characteristics, treatment, and survival of 30 patients with gastrointestinal natural killer/T-cell lymphoma

BACKGROUND

The gastrointestinal (GI) tract is the second most frequent extranasal involvement site for ENKTL. This study aimed to explore the clinicopathological features, treatment models, survival outcomes, and prognosis of gastrointestinal ENKTL (GI-ENKTL).

METHODS

The clinical data of GI-ENKTL patients were extracted from the China Lymphoma Collaborative Group (CLCG) database and were analyzed retrospectively.

RESULTS

A total of 30 patients were enrolled, with a male/female ratio of 4:1 and a median age of 42 years. Twenty-nine patients received chemotherapy, of whom 15 patients received asparaginase-based (ASP-based) regimens. Moreover, seven received surgery and three received radiotherapy. The overall response an d complete remission rates were 50.0% and 30.0% for the whole cohort, 50.0% and 37.5% for patients treated with ASP-based regimens, and 50.0% and 25.0% for those treated with non-ASP-based regimens, respectively. The median follow-up was 12.9 months and the 1-year overall survival rate was 40.0% for the whole cohort. For those patients in an early stage, ASP-based regimens resulted in a superior 1-year progression-free survival rate compared to non-ASP-based regimens (100.0% vs. 36.0%, p = .07). However, ASP-based regimens did not improve survival in patients at an advanced stage.

CONCLUSION

GI-ENKTL still has a poor prognosis, even in the era of modern asparaginase-based treatment strategies.

Clinical advances in epigenetic therapies for lymphoma

BACKGROUND

Advances in understanding of cancer biology, genomics, epigenomics, and immunology have resulted in development of several therapeutic options that expand cancer care beyond traditional chemotherapy or radiotherapy, including individualized treatment strategies, novel treatments based on monotherapies or combination therapy to reduce toxicities, and implementation of strategies for overcoming resistance to anticancer therapy.

RESULTS

This review covers the latest applications of epigenetic therapies for treatment of B cell, T cell, and Hodgkin lymphomas, highlighting key clinical trial results with monotherapies and combination therapies from the main classes of epigenetic therapies, including inhibitors of DNA methyltransferases, protein arginine methyltransferases, enhancer of zeste homolog 2, histone deacetylases, and the bromodomain and extraterminal domain.

CONCLUSION

Epigenetic therapies are emerging as an attractive add-on to traditional chemotherapy and immunotherapy regimens. New classes of epigenetic therapies promise low toxicity and may work synergistically with other cancer treatments to overcome drug resistance mechanisms.

Epinephrine facilitates the growth of T cell lymphoma by altering cell proliferation, apoptosis, and glucose metabolism

In recent years, studies have reported the role of stress-regulatory hormones, including epinephrine, in regulating the progression of a few cancers. However, the tumor-promoting action of epinephrine is not yet investigated in T cell malignancy, a rare and complicated neoplastic disorder. More so, very little is known regarding the implication of epinephrine in the glucose metabolic rewiring in tumor cells. The present investigation showed that epinephrine enhanced the proliferation of T lymphoma cells through up- and down-regulating the expression of PCNA, cyclin D, and p53, respectively. In addition, epinephrine inhibited apoptosis in T lymphoma cells possibly by increasing the level of BCL2 (an anti-apoptotic protein) and decreasing PARP level (a pro-apoptotic protein). Intriguingly, epinephrine is reported to stimulate glycolysis in T lymphoma cells by increasing the expression of crucial glycolysis regulatory molecules, namely HKII and PKM2, in a HIF-1α-dependent manner. Moreover, augmented production of ROS has been observed in T lymphoma cells, which might be a central player in epinephrine-mediated T cell lymphoma growth. Taken together, our study demonstrates that epinephrine might have a significant role in the progression of T cell lymphoma.

Feasibility and preclinical efficacy of CD7-unedited CD7 CAR T cells for T cell malignancies

Chimeric antigen receptor (CAR)-mediated targeting of T lineage antigens for the therapy of blood malignancies is frequently complicated by self-targeting of CAR T cells or their excessive differentiation driven by constant CAR signaling. Expression of CARs targeting CD7, a pan-T cell antigen highly expressed in T cell malignancies and some myeloid leukemias, produces robust fratricide and often requires additional mitigation strategies, such as CD7 gene editing. In this study, we show fratricide of CD7 CAR T cells can be fully prevented using ibrutinib and dasatinib, the pharmacologic inhibitors of key CAR/CD3ζ signaling kinases. Supplementation with ibrutinib and dasatinib rescued the ex vivo expansion of unedited CD7 CAR T cells and allowed regaining full CAR-mediated cytotoxicity in vitro and in vivo on withdrawal of the inhibitors. The unedited CD7 CAR T cells persisted long term and mediated sustained anti-leukemic activity in two mouse xenograft models of human T cell acute lymphoblastic leukemia (T-ALL) by self-selecting for CD7-, fratricide-resistant CD7 CAR T cells that were transcriptionally similar to control CD7-edited CD7 CAR T cells. Finally, we showed feasibility of cGMP manufacturing of unedited autologous CD7 CAR T cells for patients with CD7+ malignancies and initiated a phase I clinical trial (ClinicalTrials.gov: NCT03690011) using this approach. These results indicate pharmacologic inhibition of CAR signaling enables generating functional CD7 CAR T cells without additional engineering.

Rhodanine Derivatives as Anticancer Agents: QSAR and Molecular Docking Studies

BACKGROUND

Rhodanine derivatives have a proven wide range of biological activities.

OBJECTIVE

The aim of this study was to evaluate the cytotoxic effect of a series of rhodanine derivatives and investigate the quantitative structure-activity relationships, as well as binding modes to tyrosine kinase.

METHODS

Cytotoxic effect on cell proliferation (CaCo-2, HeLa, MDCK-1, Hut-78, K562) in vitro was evaluated by the MTT viability assay. QSAR analysis was performed with Dragon descriptors using QSARINS software. Molecular docking was performed on the tyrosin kinase (c-Src) (PDB ID: 3G6H) using iGEMDOCK.

RESULTS

Compounds with the best inhibiting activity toward all cell lines were the ones possessing only one group in the C2 of the phenyl ring. QSAR study on the cytotoxic activity against Human T cell lymphoma achieved the model that satisfies the fitting and internal cross-validation criteria (R² = 0.75; Q² _LOO = 0.64). Descriptors included in the model (MATS2e, MATs7e, RDF060p) revealed the importance of the presence of atoms with higher polarizability in the outer region of molecules. The findings of the molecular docking study performed on the c-Src are in accordance with the results of the QSAR study. The key interactions with binding site residues were achieved through oxygen atoms from phenoxy and rhodanine groups and rhodanine sulphur atoms.

CONCLUSION

Rhodanine derivatives could be developed as novel tyrosine kinase inhibitors in the treatment of leukemia.

Challenges in nodal peripheral T-cell lymphomas: from biological advances to clinical applicability

T cell lymphomas are a heterogenous group with varying biological and clinical features that tend to have poor outcomes with a few exceptions. They account for 10-15% of all non-Hodgkin lymphomas (NHL), and 20% of aggressive NHL. There has been little change in the overall prognosis of T cell lymphomas over the last 2 decades. Most subtypes carry an inferior prognosis when compared to the B cell lymphomas, with a 5-year OS of 30%. Gene expression profiling and other molecular techniques has enabled a deeper understanding of these differences in the various subtypes as reflected in the latest 5th WHO and ICC classification of T cell lymphomas. It is becoming increasingly clear that therapeutic approaches that target specific cellular pathways are needed to improve the clinical outcomes of T cell lymphomas. This review will focus on nodal T cell lymphomas and describe novel treatments and their applicability to the various subtypes.

CAR-iNKT cells targeting clonal TCRVβ chains as a precise strategy to treat T cell lymphoma

Introduction

Most T cell receptor (TCR)Vβ chain-expressing T cell lymphomas (TCL) including those caused by Human T cell leukaemia virus type-1 (HTLV-1) have poor prognosis. We hypothesised that chimeric antigen receptor (CAR)-mediated targeting of the clonal, lymphoma-associated TCRβ chains would comprise an effective cell therapy for TCL that would minimally impact the physiological TCR repertoire.

Methods

As proof of concept, we generated CAR constructs to target four TCRVβ subunits. Efficacy of the CAR constructs was tested using conventional T cells as effectors (CAR-T). Since invariant NKT (iNKT) cell do not incite acute graft-versus-host disease and are suitable for 'off-the-shelf' immunotherapy, we generated anti-TCRVβ CAR-iNKT cells.

Results

We show that anti-TCRVβ CAR-T cells selectively kill their cognate tumour targets while leaving >90% of the physiological TCR repertoire intact. CAR-iNKT cells inhibited the growth of TCL in vivo, and were also selectively active against malignant cells from Adult T cell leukaemia/lymphoma patients without activating expression of HTLV-1.

Discussion

Thus we provide proof-of-concept for effective and selective anti-TCRVβ CAR-T and -iNKT cell-based therapy of TCL with the latter providing the option for 'off-the-shelf' immunotherapy.

Controversies in the Front-Line Treatment of Systemic Peripheral T Cell Lymphomas

Systemic peripheral T cell lymphomas (PTCL) are a rare and clinically and biologically heterogeneous group of disorders with scarce and generally low-quality evidence guiding their management. In this manuscript, we tackle the current controversies in the front-line treatment of systemic PTCL including (1) whether CNS prophylaxis should be administered; (2) whether CHOEP should be preferred over CHOP; (3) what role brentuximab vedotin should have; (4) whether stem cell transplant (SCT) consolidation should be used and whether autologous or allogeneic; (5) how should molecular subtypes (including DUSP22 or TP63-rearranged ALCL or GATA3 or TBX21 PTCL, NOS) impact therapeutic decisions; and (6) whether there is a role for targeted agents beyond brentuximab vedotin.

Indolent Lymphoproliferative T-Cell Disorders Associated With Gastrointestional Disease: Diagnostic Challenges and Outcomes

Lymphoproliferative diseases arise when the physiological mechanisms that control the proliferation of T and B lymphocytes are disrupted, resulting in an uncontrolled and autonomous increase in immune cells leading to lymphocytosis and lymphadenopathy, and often to the involvement of extranodal sites. The differential diagnosis of malignant T cell tumors involves other neoplasms and non-clonal T cell proliferations. Immunological markers are essential, as a first step, to distinguish between T-cell and non-T-cell disorders. It must be established based on the configuration of the genes of the TCR chain to rule out that the picture is not reactive to other underlying diseases. This clinical review and accompanying case reports highlight the diagnostic challenges associated with indolent lymphoproliferative T-cell disorders, which in many cases may represent the clinical manifestation of a single disease. Particularly we focus on gastrointestinal manifestations that could be expression either of lymphoproliferative disorder either of autoimmune disease either of both. The correct interpretation of the different clinical situations can help in the diagnostic and therapeutic process.

Genetic alterations and oxidative stress in T cell lymphomas

T cell lymphomas encompass a diverse group of Non-Hodgkin lymphomas with a wide spectrum of clinical, immunological and pathological manifestations. In the last two decades there has been a progress in our understanding of the cell of origin, genetic abnormalities and their impact on behaviour in T cell lymphomas. Genetic alterations are one of the critical drivers of the pathogenesis of T cell lymphoma. Disease progression has been correlated with multiple genetic abnormalities where malignant clones arise primarily out of the host immune surveillance arsenal. There are many cellular processes involved in disease development, and some of them are T cell signaling, differentiation, epigenetic modifications, and immune regulation. Modulation of these crucial pathways via genetic mutations and chromosomal abnormalities possessing either point or copy number mutations helps tumor cells to develop a niche favourable for their growth via metabolic alterations. Several metabolic pathways especially regulation of redox homeostasis is critical in pathogenesis of lymphoma. Disruption of redox potential and induction of oxidative stress renders malignant cells vulnerable to mitochondrial damage and triggers apoptotic pathways causing cell death. Targeting genetic abnormalities and oxidative stress along with current treatment regime have the potential for improved therapeutics and presents new combination approaches towards selective treatment of T cell lymphomas.

Phosphodiesterase 5 inhibitor sildenafil potentiates the antitumor activity of cisplatin by ROS-mediated apoptosis: a role of deregulated glucose metabolism

Cyclic nucleotide phosphodiesterase 5 (PDE5) has been recently identified to play a crucial role in the progression of many cancers. PDE5 promotes tumorigenesis by dysregulating various cellular processes such as proliferation, apoptosis, angiogenesis, and invasion and migration. Interestingly, multiple studies have reported the promising chemosensitizing potential of PDE5 inhibitor sildenafil in breast, colon, prostate, glioma, and lung cancers. However, to date, the chemosensitizing action of sildenafil is not evaluated in T cell lymphoma, a rare and challenging neoplastic disorder. Hence, the present investigation was undertaken to examine the chemosensitizing potential of sildenafil against T cell lymphoma along with elucidation of possible involvement of altered apoptosis and glucose metabolism. The experimental findings of this study showed that sildenafil enhances the cytotoxic ability of cisplatin by apoptosis induction through altering the levels of apoptosis regulatory molecules: Bcl-2, Bax, cytochrome c (Cyt c), cleaved caspase-3, and poly (ADP-ribose) polymerase (PARP). These molecular alterations were possibly driven by sildenafil through reactive oxygen species (ROS). Sildenafil deregulates glucose metabolism by markedly lowering the expression of glycolysis regulatory molecules, namely glucose transporter 1 (GLUT1), lactate dehydrogenase A (LDHA), hexokinase II (HKII), pyruvate kinase M2 (PKM2), and pyruvate dehydrogenase kinase 1 (PDK1) via suppressing hypoxia-inducible factor 1-alpha (HIF-1α) expression. Hence, sildenafil potentiates the tumor cell killing ability of cisplatin by augmenting ROS production through switching the glucose metabolism from glycolysis to oxidative phosphorylation (OXPHOS). Overall, our study demonstrates that sildenafil might be a promising adjunct therapeutic candidate in designing novel combinatorial chemotherapeutic regimens against T cell lymphoma.

Nimbolide retards T cell lymphoma progression by altering apoptosis, glucose metabolism, pH regulation, and ROS homeostasis

Nimbolide is reported as one of the potential anticancer candidates of the neem tree (Azadirachta indica A. Juss). The cytotoxic action of nimbolide has been well reported against a wide number of malignancies, including breast, prostate, lung, liver, and cervix cancers. Interestingly, only a few in vivo studies conducted on B cell lymphoma, glioblastoma, pancreatic cancer, and buccal pouch carcinoma have shown the in vivo antitumor efficacy of nimbolide. Therefore, it is highly needed to examine the in vivo antineoplastic activity of nimbolide on a wide variety of cancers to establish nimbolide as a promising anticancer drug. In the present study, we investigated the tumor retarding action of nimbolide in a murine model of T cell lymphoma. We noticed significantly augmented apoptosis in nimbolide- administered tumor-bearing mice, possibly due to down-regulated expression of Bcl2 and up-regulated expression of p53, cleaved caspase-3, Cyt c, and ROS. The nimbolide treatment-induced ROS production by suppressing the expression of antioxidant regulatory enzymes, namely superoxide dismutase and catalase. In addition, nimbolide administration impaired glycolysis and pH homeostasis with concomitant inhibition of crucial glycolysis and pH regulatory molecules such as GLUT3, LDHA, MCT1, and V-ATPase, CAIX and NHE1, respectively. Taken together, the present investigation provides novel insights into molecular mechanisms of nimbolide inhibited T cell lymphoma progression and directs the utility of nimbolide as a potential anticancer therapeutic drug for the treatment of T cell lymphoma.

Mature T-Cell leukemias: Challenges in Diagnosis

T-cell clones can frequently be identified in peripheral blood. It can be difficult to appreciate whether these are benign and transient or whether they signify a clonal disorder. We review factors that aid in understanding the relevance of T-cell clones. Conversely, obvious pathological T-cell clones can be detected in blood, but there is uncertainty in how to categorize this clonal T cell population, thus, we adopt a multidisciplinary review of the clinical features, diagnostic material and radiology before making the diagnosis. In this review we shall discuss some of these challenges faced when diagnosing mature T-cell leukemias.

Targeting lysophosphatidic acid receptor with Ki16425 impedes T cell lymphoma progression through apoptosis induction, glycolysis inhibition, and activation of antitumor immune response

Lysophosphatidic acid (LPA) is a small phospholipid that acts as an extracellular lipid mediator. It promotes cancer progression by altering a wide array of cellular processes, including apoptosis, survival, angiogenesis, invasion, and migration through binding with its cognate receptors. Intriguingly, our previous study showed that in vitro treatment of LPA induced survival of T lymphoma cells. Hence, the present investigation was designed to investigate the antitumor potential of Ki16425, an antagonist of LPA receptors, against T cell lymphoma. Our in vitro results showed inhibition of LPA-mediated survival and metabolic activity of T lymphoma cells by Ki16425. Further, in vivo experimental findings indicated the tumor retarding potential of Ki16425 against T cell lymphoma through apoptosis induction, glycolysis inhibition, and immunoactivation. The administration of Ki16425 triggered apoptosis by down-regulating the expression of Bcl2 and up-regulating p53, Bax, cleaved caspase-3, and Cyt c expression. Further, Ki16425 suppressed glycolytic activity with concomitantly decreased expression of GLUT3 and MCT1. Moreover, we also noticed an elevated level of NO and iNOS in tumor cells after Ki16425 administration which might also be responsible for apoptosis induction and suppressed glycolysis. Additionally, we observed an increased population of total leukocytes, lymphocytes, and monocytes along with increased thymocytes count and IL-2 and IFN-γ levels. Besides, we observed amelioration of tumor-induced kidney and liver damages by Ki16425. Taken together, this is the first study that demonstrates that LPA receptors could be potential future therapeutic targets for designing promising therapeutic strategies against T cell lymphoma.

An uncommon unilateral primary T cell adrenal lymphoma: A case report

Primary adrenal lymphoma (PAL) is a rare disease with rapid progression. We present a case of PAL with T cell lymphoma in an 81-year-old male who initially presented with altered mental status and extreme weight loss. It is important to consider PAL in patients found to have adrenal masses to allow for prompt diagnosis and initiation of treatment.

•

Primary adrenal lymphoma (PAL) is a rare disease with rapid progression that should be included in the differential diagnosis if imaging shows unilateral or bilateral adrenal masses.

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Patients with PAL can present with malaise, B symptoms, and rapid weight loss.

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Pathology-directed chemotherapy is the first line treatment modality.

Aberrant Expression of and Cell Death Induction by Engagement of the MHC-II Chaperone CD74 in Anaplastic Large Cell Lymphoma (ALCL)

Simple Summary

Anaplastic large cell lymphoma (ALCL) is a lymphoid malignancy considered to be derived from T cells. Currently, two types of systemic ALCL are distinguished: anaplastic lymphoma kinase (ALK)-positive and ALK-negative ALCL. Although ALK⁺ and ALK⁻ ALCL differ at the genomic and molecular levels, various key biological and molecular features are highly similar between both entities. We have developed the concept that both ALCL entities share a common principle of pathogenesis. In support of this concept, we here describe a common deregulation of CD74, which is usually not expressed in T cells, in ALCL. Ligation of CD74 induces cell death of ALCL cells in various conditions, and an anti-CD74-directed antibody-drug conjugate efficiently kills ALCL cell lines. Furthermore, we reveal expression of the proto-oncogene and known CD74 interaction partner MET in a fraction of ALCL cases. These data give insights into ALCL pathogenesis and might help to develop new treatment strategies for ALCL.

Abstract

In 50–60% of cases, systemic anaplastic large cell lymphoma (ALCL) is characterized by the t(2;5)(p23;q35) or one of its variants, considered to be causative for anaplastic lymphoma kinase (ALK)-positive (ALK⁺) ALCL. Key pathogenic events in ALK-negative (ALK⁻) ALCL are less well defined. We have previously shown that deregulation of oncogenic genes surrounding the chromosomal breakpoints on 2p and 5q is a unifying feature of both ALK⁺ and ALK⁻ ALCL and predisposes for occurrence of t(2;5). Here, we report that the invariant chain of the MHC-II complex CD74 or li, which is encoded on 5q32, can act as signaling molecule, and whose expression in lymphoid cells is usually restricted to B cells, is aberrantly expressed in T cell-derived ALCL. Accordingly, ALCL shows an altered DNA methylation pattern of the CD74 locus compared to benign T cells. Functionally, CD74 ligation induces cell death of ALCL cells. Furthermore, CD74 engagement enhances the cytotoxic effects of conventional chemotherapeutics in ALCL cell lines, as well as the action of the ALK-inhibitor crizotinib in ALK⁺ ALCL or of CD95 death-receptor signaling in ALK⁻ ALCL. Additionally, a subset of ALCL cases expresses the proto-oncogene MET, which can form signaling complexes together with CD74. Finally, we demonstrate that the CD74-targeting antibody-drug conjugate STRO-001 efficiently and specifically kills CD74-positive ALCL cell lines in vitro. Taken together, these findings enabled us to demonstrate aberrant CD74-expression in ALCL cells, which might serve as tool for the development of new treatment strategies for this lymphoma entity.

How to Sequence Therapies in Peripheral T Cell Lymphoma

OPINION STATEMENT

Peripheral T cell lymphoma (PTCL) represents a heterogeneous group of rare lymphoproliferative disorders. Historically, there has been a lack of pathobiological understanding of PTCL. With the exception of ALK-positive anaplastic large cell lymphoma, patients with PTCL have less favorable outcomes, with most patients relapsing shortly after conventional anthracycline-containing multi-agent chemotherapy. The standard management approach for PTCL involves induction therapy followed by autologous stem cell transplantation. Patients with relapsed/refractory PTCL have dismal outcomes and limited treatment options despite the available novel agents, therefore remaining a critical unmet need. By virtue of advancement in cancer biology over the recent years, the treatment landscape of PTCL has gradually evolved from conventional chemotherapy based on solely morphological diagnosis toward more individualized therapies by integrating molecular attributes of PTCL to the traditional treatment paradigm. We are at the edge of witnessing a paradigm shift in PTCL management.

Oral and oropharyngeal lymphomas: A multi-institutional collaborative study

BACKGROUND

Lymphomas in the oral and oropharyngeal regions are relatively uncommon, and their diagnosis is challenging and complex due to the myriad histopathological subtypes. Herein, we report a large series of oral and oropharyngeal lymphomas and compare our data with the currently available literature.

METHODS

All cases diagnosed as lymphomas affecting the oral and oropharyngeal regions were retrospectively retrieved from seven Brazilian institutions. Clinicodemographic data and histopathological features were evaluated and described, while a comprehensive literature review was undertaken in order to compare our findings.

RESULTS

A total of 304 cases of oral and oropharyngeal lymphomas were obtained, mostly affecting individuals aged 60-69 years (n = 68) with a mean age at diagnosis of 54.2 ± 20.1 years. Males and females were equally affected. Mature B-cell neoplasms (87.2%) were the most common group, followed by mature T- and NK-cell neoplasms (11.2%) and precursor lymphoid neoplasms (1.6%). The most frequent subtypes in each group were diffuse large B-cell lymphomas, not otherwise specified (n = 99), extranodal NK/T-cell lymphomas, nasal type (n = 12), and B-lymphoblastic leukaemia/lymphomas, not otherwise specified (n = 4). The most commonly involved sites were the palate (26.3%), mandible (13%), and maxilla (10.5%).

CONCLUSION

Diffuse large B-cell lymphoma, not otherwise specified, remains the most common subtype of lymphomas in the oral and oropharyngeal region. Older patients are the most affected, with no gender predilection and the palate and jaw are usually affected.

Molecular Characterization of a Rare Case of Bilateral Vitreoretinal T Cell Lymphoma through Vitreous Liquid Biopsy

Vitreoretinal lymphoma (VRL) is an uncommon eye malignancy, and VRLs of T cell origin are rare. They are difficult to treat, and their molecular underpinnings, including actionable genomic alterations, remain to be elucidated. At present, vitreous fluid liquid biopsies represent a valuable VRL sample for molecular analysis to study VRLs. In this study, we report the molecular diagnostic workup of a rare case of bilateral T cell VRL and characterize its genomic landscape, including identification of potentially targetable alterations. Using next-generation sequencing of vitreous-derived DNA with a pan-cancer 126-gene panel, we found a copy number gain of BRAF and copy number loss of tumor suppressor DNMT3A. To the best of our knowledge, this represents the first exploration of the T cell VRL cancer genome and supports vitreous liquid biopsy as a suitable approach for precision oncology treatments.

CD8-positive peripheral T cell lymphoma in a patient following long-term nivolumab for advanced lung adenocarcinoma: A case report

A 54-year-old male smoker presented with hemoptysis. Advanced lung adenocarcinoma, cT1cN3M1b, stage IVB, was diagnosed. Enlargement of multiple intraperitoneal and inguinal lymph nodes and peripheral atypical lymphocytosis appeared after 33 cycles of second-line treatment with nivolumab, and a specimen obtained by left inguinal lymph node biopsy showed peripheral T cell lymphoma (PTCL), not otherwise specified. Lymphoma cells expressed CD3+, CD8+, and CD56+, but not CD4+ or PD-1. Despite systemic chemotherapy with cyclophosphamide, hydroxydaunorubicin, oncovin, and prednisolone, the patient died of PTCL 864 days after the initial visit. The possible relationship between treatment with immune checkpoint inhibitors (ICIs) and PTCL development is discussed here.

Hematopoietic Stem Cell Transplantation in T Cell and Natural Killer Cell Lymphomas: Update on Recent Advances

Mature T and natural killer (NK) cell non-Hodgkin lymphoma (T-NHL) has a poor prognosis. Data from existing retrospective and prospective studies have suggested that high-dose chemotherapy followed by autologous hematopoietic cell transplantation (auto-HCT) may improve the survival in patients with chemosensitive disease, either in the upfront or salvage setting. Auto-HCT is currently recommended to be used as frontline consolidation in peripheral T cell lymphoma not otherwise specified, angioimmunoblastic T cell lymphoma, anaplastic large cell lymphoma-anaplastic lymphoma kinase negative, NK/T cell (disseminated), and enteropathy-associated T cell lymphoma. However, about one-third of patients never reach transplantation because of early relapse or refractory disease. Allogeneic hematopoietic cell transplantation (allo-HCT), via its immunologic graft-versus-lymphoma effect, has been used to salvage patients with relapsed or refractory disease, resulting in long-term disease-free survival in a fraction of patients. However, the higher risk of transplant-related mortality due to regimen-related toxicities, graft-versus-host disease, and post-transplant infectious complications continues to limit the mainstream adoption of allo-HCT for this disease. Despite that, allo-HCT has been incorporated as part of the frontline treatment for aggressive subtypes of T-NHL, such as γδ T cell lymphoma and aggressive NK cell leukemia. Recent attempts to incorporate novel targeted T cell directed therapies into the treatment pathway of T-NHL may enhance treatment response and enable more patients to reach transplant, offering an alternative means of treating this disease.

Nimbolide induces cell death in T lymphoma cells: Implication of altered apoptosis and glucose metabolism

Nimbolide is a tetranortriterpenoid derived from the leaves and flowers of Azadirachta indica (Neem). It exhibits anticancer activity against a variety of cancers by modulating various crucial features, including cell proliferation, apoptosis, and invasion and metastasis. More importantly, the cytotoxic effect of nimbolide has also been observed against T cell lymphoma, but the underlying mechanisms are still unexplored. So far, no study has been conducted to observe the effect of nimbolide on cancer cell metabolism. Therefore, the present investigation was designed to explore the molecular mechanisms of the antitumor potential of nimbolide against T cell lymphoma, a neoplastic disorder of thymic origin. In addition, we also unraveled the anti-glycolytic activity of nimbolide against T lymphoma cells with possible molecular mechanisms. Our results showed the cytotoxic action of nimbolide against three different cell lines of T cell lymphoma, namely Dalton's lymphoma, HuT-78, and J6. Nimbolide-induced apoptosis in T lymphoma cells by altering the level of reactive oxygen species, p53, Bcl2, Bax, and cytochrome c, with subsequent cleavage of caspase 3. Remarkably, nimbolide inhibited the expression of hypoxia-inducible factor-1α, glucose transporter 3, hexokinase II, and pyruvate dehydrogenase kinase 1, which led to the suppression of glycolysis with concomitant activation of oxidative phosphorylation. Hence, the results of the present investigation demonstrate that nimbolide exerts tumoricidal activity against T lymphoma cells via augmentation of apoptosis and reversal of altered cell metabolism. Thus, the present study provides a new insight for the therapeutic utilization of nimbolide against T cell lymphoma.

Allogeneic Stem Cell Transplantation in Mature T Cell and Natural Killer/T Neoplasias: A Registry Study from Spanish GETH/GELTAMO Centers

Despite advances in understanding the biology of mature T and natural killer (NK)/T cell neoplasia, current therapies, even the most innovative ones, are still far from ensuring its cure. The only treatment to date that has been shown to control aggressive T cell neoplasms in the long term is allogeneic stem cell transplantation (alloSCT). We aim to report the results of alloSCT for advanced mature T and NK/T neoplasias performed in centers from our national GELTAMO/GETH (Grupo Español de Linfoma y Trasplante de Médula Ósea/Grupo Español de Trasplante Hematopoyético y Terapia Celular) over the past 25 years. As a secondary objective, we analyzed the results of alloSCT from haploidentical donors. We performed a retrospective analysis of all patients who received an alloSCT in Spanish centers (n = 201) from September 1995 to August 2018. The 2-year overall survival (OS) and disease-free survival (DFS) were 65.5% and 58.2%, respectively. The univariate for OS and DFS showed statistically different hazard ratios for conditioning intensity, response pre-alloSCT, comorbidity index, donor/receptor cytomegalovirus status and Eastern Cooperative Oncology Group (ECOG) pre-alloSCT, but only a better ECOG pre-alloSCT remained significant in the multivariate analysis. There was an increased incidence of relapse in those patients who did not develop chronic graft-versus-host disease (GVHD) and an increased risk of death in those developing moderate to severe acute GVHD. The 1-year nonrelapse mortality was 21.9% and was mainly due to GVHD (30%) and bacterial infections (17%). When comparing unrelated donors with haploidentical donors, we found similar results in terms of OS and DFS. There was, however, a reduction of acute GVHD in the haploidentical group (P = .04) and trend to a reduction of chronic GVHD. In conclusion, alloSCT is the only curative option for most aggressive T cell neoplasias. Haploidentical donors offer similar results to related donors in terms of survival with a reduction of acute GVHD.

Trifarotene: A Current Review and Perspectives in Dermatology

Retinoids have numerous applications in inflammatory, dyskeratotic, and oncohematology diseases. Retinoids have now reached the fourth generation, progressively reducing toxicity whilst increasing their efficacy. Trifarotene is a new fourth-generation retinoid with a selective action on RAR-γ. In this review, we reported the trials—both concluded and in progress—including the use of trifarotene in dermatological diseases. Studies were identified by searching electronic databases (MEDLINE, EMBASE, PubMed, Cochrane, Trials.gov) from 2012 to today and reference lists of respective articles. Only articles published in English language were included. Randomized trials evaluating trifarotene tolerability, safety, and efficacy in congenital ichthyosis and acne have demonstrated great results and mild side effects, leading to the approval by the FDA of trifarotene for the treatment of lamellar ichthyosis in 2014, and of acne vulgaris in October 2019. No high-quality randomized clinical trials have evaluated the treatment of primary cutaneous lymphomas with trifarotene. Finally, we are hypothesizing future perspectives in the treatment of non-melanoma skin cancers, fungal infections, photoaging, and hand-foot skin reactions with trifarotene.

Treatment of Aggressive T Cell Lymphoblastic Lymphoma/leukemia Using Anti-CD5 CAR T Cells

While treatment for B-cell malignancies has been revolutionized through the advent of CAR immunotherapy, similar strategies for T-cell malignancies have been limited. Additionally, T-cell leukemias and lymphomas can commonly metastasize to the CNS, where outcomes are poor and treatment options are associated with severe side effects. Consequently, the development of safer and more effective alternatives for targeting malignant T cells that have invaded the CNS remains clinically important. CD5 CAR has previously been shown to effectively target various T-cell cancers in preclinical studies. As IL-15 strengthens the anti-tumor response, we have modified CD5 CAR to secrete an IL-15/IL-15sushi complex. In a Phase I clinical trial, these CD5-IL15/IL15sushi CAR T cells were tested for safety and efficacy in a patient with refractory T-LBL with CNS infiltration. CD5-IL15/IL15sushi CAR T cells were able to rapidly ablate the CNS lymphoblasts within a few weeks, resulting in the remission of the patient's lymphoma. Despite the presence of CD5 on normal T cells, the patient only experienced a brief, transient T-cell aplasia. These results suggest that CD5-IL15/IL15sushi CAR T cells may be a safe and useful treatment of T-cell malignancies and may be particularly beneficial for patients with CNS involvement.Graphical Abstract.

Breast Implant-associated Anaplastic Large Cell Lymphoma

Breast implant-associated anaplastic large cell lymphoma (BIA-ALCL) is an uncommon lymphoproliferative disorder, mainly associated with textured implants. The average time from the breast implants to the development of BIA-ALCL is about 7 to 10 years, and the median age at the time of diagnosis is in the mid-50s. The exact incidence and prevalence of BIA-ALCL are not known. The pathogenesis of BIA-ALCL remains unclear. Different theories have been postulated, including immune response to textured implants, subclinical bacterial infection, and genetic predisposition. However, none of those theories have yet been proven to be causal in the pathogenesis of BIA-ALCL. BIA-ALCL is histologically similar to but clinically distinct from other CD30-positive T-cell lymphomas such as anaplastic lymphoma kinase-positive, anaplastic lymphoma kinase-negative, and primary cutaneous ALCL. The revised World Health Organization classification of lymphoid neoplasm in 2016 recognized BIA-ALCL as a provisional entity. Suspected cases need proper evaluation and workup to confirm the diagnosis. Surgical resection should be considered for all the cases. However, adjuvant radiotherapy and anthracycline-based chemotherapy are warranted for locally advanced and advanced cases.

Advances and Perspectives in the Treatment of T-PLL

PURPOSE OF REVIEW

T cell prolymphocytic leukemia (T-PLL) is a rare mature T cell tumor. Available treatment options in this aggressive disease are largely inefficient and patient outcomes are highly dissatisfactory. Current therapeutic strategies mainly employ the CD52-antibody alemtuzumab as the most active single agent. However, sustained remissions after sole alemtuzumab-based induction are exceptions. Responses after available second-line strategies are even less durable. More profound disease control or rare curative outcomes can currently only be expected after a consolidating allogeneic hematopoietic stem cell transplantation (allo-HSCT) in best first response. However, only 30-50% of patients are eligible for this procedure. Major advances in the molecular characterization of T-PLL during recent years have stimulated translational studies on potential vulnerabilities of the T-PLL cell. We summarize here the current state of "classical" treatments and critically appraise novel (pre)clinical strategies.

RECENT FINDINGS

Alemtuzumab-induced first remissions, accomplished in ≈ 90% of patients, last at median ≈ 12 months. Series on allo-HSCT in T-PLL, although of very heterogeneous character, suggest a slight improvement in outcomes among transplanted patients within the past decade. Dual-action nucleosides such as bendamustine or cladribine show moderate clinical activity as single agents in the setting of relapsed or refractory disease. Induction of apoptosis via reactivation of p53 (e.g., by inhibitors of HDAC or MDM2) and targeting of its downstream pathways (i.e., BCL2 family antagonists, CDK inhibitors) are promising new approaches. Novel strategies also focus on inhibition of the JAK/STAT pathway with the first clinical data. Implementations of immune-checkpoint blockades or CAR-T cell therapy are at the stage of pre-clinical assessments of activity and feasibility. The recommended treatment strategy in T-PLL remains a successful induction by infusional alemtuzumab followed by a consolidating allo-HSCT in eligible patients. Nevertheless, long-term survivors after this "standard" comprise only 10-20%. The increasingly revealed molecular make-up of T-PLL and the tremendous expansion of approved targeted compounds in oncology represent a "never-before" opportunity to successfully tackle the voids in T-PLL. Approaches, e.g., those reinstating deficient cell death execution, show encouraging pre-clinical and first-in-human results in T-PLL, and urgently have to be transferred to systematic clinical testing.

Hodgkin Reed-Sternberg-Like Cells in Non-Hodgkin Lymphoma

Reed-Sternberg cells (RSCs) are hallmarks of classic Hodgkin lymphoma (cHL). However, cells with a similar morphology and immunophenotype, so-called Reed-Sternberg-like cells (RSLCs), are occasionally seen in both B cell and T cell non-Hodgkin Lymphomas (NHLs). In NHLs, RSLCs are usually present as scattered elements or in small clusters, and the typical background microenviroment of cHL is usually absent. Nevertheless, in NHLs, the phenotype of RSLCs is very similar to typical RSCs, staining positive for CD30 and EBV, and often for B cell lineage markers, and negative for CD45/LCA. Due to different therapeutic approaches and prognostication, it is mandatory to distinguish between cHL and NHLs. Herein, NHL types in which RSLCs can be detected along with clinicopathological correlation are described. Moreover, the main helpful clues in the differential diagnosis with cHL are summarized.

The effect of PD-1 expression on tumor-associated macrophage in T cell lymphoma

PURPOSE

Our study aimed to explore the programmed death 1 (PD-1) expression on tumor-associated macrophage (TAM) in T cell non-Hodgkin lymphoma (T-NHL) and its relationship with lymphoma prognosis. The effect of PD-1 expression on the function of macrophages was also studied.

METHODS

Multispectral image quantitative analysis was applied for detecting PD-1 expression on macrophages in T cell lymphoma tissues. The Kaplan-Meier analysis was performed to evaluate the value of PD-1 expression of TAM in predicting the overall survival of T-NHL. PD-1 overexpression THP-1-derived macrophage was constructed and was cocultured with Jurkat cells to explore the effect of PD-1 on macrophage function.

RESULTS

In 17 T cell lymphoma cases, the 1-year overall survival rate was significantly lower in patients with higher PD-1 expression on TAMs (0.25 vs 0.86, p < 0.05). After co-cultured with Jurkat cells, classically activated (M1)-related markers on PD-1 overexpressed macrophages were significantly lower than those on controls, while the expressions of alternatively activated (M2) related markers were similar. The PD-1 overexpressed macrophages showed inhibited phagocytosis (4.42% vs 40.7%, p < 0.001) and increased IL-10 secretion (144.48 pg/ml vs 32.32 pg/ml, p < 0.001).

CONCLUSION

High PD-1 expression on TAMs in T-NHL may predict poor prognosis. The PD-1 overexpression of macrophages significantly inhibited polarization of M1 macrophages and phagocytosis, and more IL-10 was excreted. These changes may enhance the pro-tumor effects of tumor microenvironment.

A Novel Approach for the Treatment of T Cell Malignancies: Targeting T Cell Receptor Vβ Families

Peripheral T cell lymphomas (PTCLs) are generally chemotherapy resistant and have a poor prognosis. The lack of targeted immunotherapeutic approaches for T cell malignancies results in part from potential risks associated with targeting broadly expressed T cell markers, namely T cell depletion and clinically significant immune compromise. The knowledge that the T cell receptor (TCR) β chain in human α/β TCRs are grouped into Vβ families that can each be targeted by a monoclonal antibody can therefore be exploited for therapeutic purposes. Here, we develop a flexible approach for targeting TCR Vβ families by engineering T cells to express a chimeric CD64 protein that acts as a high affinity immune receptor (IR). We found that CD64 IR-modified T cells can be redirected with precision to T cell targets expressing selected Vβ families by combining CD64 IR-modified T cells with a monoclonal antibody directed toward a specific TCR Vβ family in vitro and in vivo. These findings provide proof of concept that TCR Vβ-family-specific T cell lysis can be achieved using this novel combination cell–antibody platform and illuminates a path toward high precision targeting of T cell malignancies without substantial immune compromise.

Spotlight on Mogamulizumab-Kpkc for Use in Adults with Relapsed or Refractory Mycosis Fungoides or Sézary Syndrome: Efficacy, Safety, and Patient Selection

Advanced cutaneous T cell lymphomas (CTCL) including mycosis fungoides (MF) and Sézary syndrome (SS) are often difficult to manage once they become resistant to initial systemic treatment. Current systemic treatments usually provide a limited duration of disease control, leaving this an area in desperate need of new treatment options for better long-term control. These conditions often affect the older population where transplantation may not be a feasible option. Recent studies evaluated a novel CCR4 humanized monoclonal antibody, mogamulizumab, in relapsed/refractory MF and SS, which show a meaningful progression free survival (PFS) benefit. In August 2018, mogamulizumab was approved by the FDA for the treatment of patients with relapsed/refractory MF/SS who have failed at least one treatment. Approval was based on the Phase III MAVORIC study comparing mogamulizumab to vorinostat, an FDA approved drug for this indication, in 372 patients. In this trial, mogamulizumab was found to have a superior PFS with a median of 7.7 months compared to 3.1 months in the vorinostat arm, with a hazard ratio of 0.53, p<0.001. Mogamulizumab was well tolerated with the most common AE being infusion-related reactions (32%), drug rash (20%), diarrhea (23%), and fatigue (22%). We reviewed the literature leading to the development and approval of mogamulizumab and suggest which patients may benefit the most from this treatment.

Eosinophilia Associated With CD3-CD4+ T Cells: Characterization and Outcome of a Single-Center Cohort of 26 Patients

Background: Lymphocytic variant hypereosinophilic syndrome is characterized by marked over-production of eosinophilopoietic factor(s) by dysregulated T cells leading to eosinophil expansion. In most cases, these T cells are clonal and express a CD3^-CD4⁺ phenotype. As this is a rare disorder, presenting manifestations, disease course, treatment responses, and outcome are not well-characterized. Materials and Methods: In this retrospective single-center observational study, we reviewed medical files of all patients with persistent hypereosinophilia seen between 1994 and 2019 in whom CD3^-CD4⁺ T cells were detected. Data collection included clinical and biological findings at presentation, treatment responses, disease course, and serial CD3^-CD4⁺ T cell counts. Results: Our cohort comprises 26 patients, including 2 with hypereosinophilia of undetermined significance. All 24 symptomatic patients had cutaneous lesions and/or angioedema, and fasciitis was present in several cases. The aberrant T cell subset represented 2% or less total lymphocytes in 11 subjects. TCR gene rearrangement patterns on whole blood were polyclonal in these cases, while they all had serum CCL17/TARC levels above 1,500 pg/ml. Disease manifestations were mild and did not require maintenance therapy in roughly one third of the cohort, while two thirds required long-term oral corticosteroids and/or second-line agents. Among these, interferon-alpha was the most effective treatment option with a response observed in 8/8 patients, one of whom was cured of disease. Treatment had to be interrupted in most cases however due to poor tolerance and/or development of secondary resistance. Anti-interleukin-5 antibodies reduced blood eosinophilia in 5/5 patients, but clinical responses were disappointing. A sub-group of 5 patients had severe treatment-refractory disease, and experienced significant disease- and treatment-related morbidity and mortality, including progression to T cell lymphoma in three. Conclusions: This retrospective longitudinal analysis of the largest monocentric cohort of CD3^-CD4⁺ T cell associated lymphocytic variant hypereosinophilic syndrome published so far provides clinicians confronted with this rare disorder with relevant new data on patient presentation and outcome that should help tailor therapy and follow-up to different levels of disease severity. It highlights the need for novel therapeutic options, especially for the subset of patients with severe treatment-refractory disease. Future research efforts should be made toward understanding CD3^-CD4⁺ T cell biology in order to develop new treatments that target primary pathogenic mechanisms.

Indolent T-Cell Lymphoproliferative Disease of the GI Tract: Insights for Better Diagnosis, Prognosis, and Appropriate Therapy

Indolent T-cell lymphoproliferative disease of the gastrointestinal tract (indolent GI T-LPD) is a benign neoplasm of CD4⁺ or CD8⁺ T cells that form primary tumors in the GI tract. Indolent GI T-LPD has recently been provisionally recognized as a distinct entity by the 2016 revision of the WHO classification of lymphoid neoplasms. Appropriate diagnosis of these cases is challenging as they may be misdiagnosed as T cell lymphoma that has an aggressive clinical course. Consequently, aggressive therapeutic approaches were usually chosen to treat these cases with no obvious benefit for most of the patients and potential side effects. Moreover, inflammatory diseases of the GI tract with similar symptoms may lead to misdiagnosis that leads to delays in administration of proper therapeutics against these cases. Therefore, it is of utmost importance to identify prognostic genetic biomarkers at the time of diagnosis for optimal medical care of these patients. TCR clonality analyses may not be useful for distinguishing these benign neoplasms from aggressive gastrointestinal T cell lymphomas; however, molecular genetic tests may prove useful as recurrent STAT3-JAK2 fusions, which may have diagnostic, prognostic or therapeutic value, have recently been identified. However, there is still lack of comprehensive information on the genetic and epigenetic factors associated with pathogenesis of indolent GI T-LPD. In this mini-review, we focus on the so far reported literature on indolent GI T-LPD cases, and discuss future directions for better differential diagnosis, risk stratification, and therapeutic target discovery with a special focus on the genetic and epigenetic alterations.

Breakage-Fusion-Bridge Events Trigger Complex Genome Rearrangements and Amplifications in Developmentally Arrested T Cell Lymphomas

To reveal the relative contribution of the recombination activating gene (RAG)1/2 nuclease to lymphomagenesis, we conducted a genome-wide analysis of T cell lymphomas from p53-deficient mice expressing or lacking RAG2. We found that while p53^−/− lymphoblastic T cells harbor primarily ectopic DNA deletions, Rag2^−/−p53^−/− T cell lymphomas display complex genomic rearrangements associated with amplification of the chromosomal location 9qA4-5.3. We show that this amplicon is generated by breakage-fusion-bridge during mitosis and arises distinctly in T cell lymphomas originating from an early progenitor stage. Notably, we report amplification of the corresponding syntenic region (11q23) in a subset of human leukemia leading to the overexpression of several cancer genes, including MLL/KMT2A. Our findings provide direct evidence that lymphocytes undergo malignant transformation through distinct genome architectural routes that are determined by both RAG-dependent and RAG-independent DNA damage and a block in cell development.

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Lymphomas from RAG2/p53- and p53-deficient mice bear distinct genome architectures

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Block in T cell development leads to 9qA4-5.3 rearrangements and amplifications

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Breakage-fusion-bridge events trigger 9qA4-5.3 aberrations in early T cell lymphomas

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The syntenic region 11q23 is amplified in some human hematological cancers

Utility of bone marrow aspirate and biopsy in staging of patients with T-cell lymphoma in the PET-Era - tissue remains the issue

The role of 18F-fluoro-2-deoxy-D-glucose positron emission tomography combined with computerized tomography (PET-CT) in evaluation of bone marrow involvement (BMI) in patients with T-cell lymphoma (TCL) is poorly understood. We investigated whether PET-CT could replace bone marrow aspiration and biopsy (BMAB) in TCL. Sixty patients with newly diagnosed TCL who underwent both diagnostic PET-CT and BMAB were identified. BMI was tissue-confirmed in 15 (25%) cases, however only 8 of these 15 showed BMI on PET-CT (sensitivity of 53.3%, specificity of 100%). BMI by BMAB was associated with lower progression-free survival (PFS) (p = 0.038) and overall survival (OS) (p = 0.003) while PET-CT BMI was associated only with OS (p = 0.02). BMI detected by BMAB in the setting of a negative PET-CT had similar inferior prognosis as BMI identified on PET-CT. Thus, PET-CT in TCL misses BMI in almost half of the cases detected by BMAB and hence cannot substitute BMAB in evaluation of TCL.

DT2216-a Bcl-xL-specific degrader is highly active against Bcl-xL-dependent T cell lymphomas

BACKGROUND

Patients with advanced T cell lymphomas (TCLs) have limited therapeutic options and poor outcomes in part because their TCLs evade apoptosis through upregulation of anti-apoptotic Bcl-2 proteins. Subsets of TCL cell lines, patient-derived xenografts (PDXs), and primary patient samples depend on Bcl-xL for survival. However, small molecule Bcl-xL inhibitors such as ABT263 have failed during clinical development due to on-target and dose-limiting thrombocytopenia.

METHODS

We have developed DT2216, a proteolysis targeting chimera (PROTAC) targeting Bcl-xL for degradation via Von Hippel-Lindau (VHL) E3 ligase, and shown that it has better anti-tumor activity but is less toxic to platelets compared to ABT263. Here, we examined the therapeutic potential of DT2216 for TCLs via testing its anti-TCL activity in vitro using MTS assay, immunoblotting, and flow cytometry and anti-TCL activity in vivo using TCL cell xenograft and PDX model in mice.

RESULTS

The results showed that DT2216 selectively killed various Bcl-xL-dependent TCL cells including MyLa cells in vitro. In vivo, DT2216 alone was highly effective against MyLa TCL xenografts in mice without causing significant thrombocytopenia or other toxicity. Furthermore, DT2216 combined with ABT199 (a selective Bcl-2 inhibitor) synergistically reduced disease burden and improved survival in a TCL PDX mouse model dependent on both Bcl-2 and Bcl-xL.

CONCLUSIONS

These findings support the clinical testing of DT2216 in patients with Bcl-xL-dependent TCLs, both as a single agent and in rational combinations.

Contemporary strategies to improve outcomes for peripheral T-cell lymphoma patients following the failure of first-line therapy

INTRODUCTION

T cell lymphomas are a heterogeneous group, with varying incidences, geographic patterns, and risk factors. Although until recently approached in a manner similar to B cell lymphomas, the treatment outcomes are poor and this disease is characterized by high relapse rates. The treatment advances in PTCL have been slow compared to B cell lymphomas. The outcomes of patients who progress following stem cell transplantation are worse.

AREAS COVERED

This review focuses on the novel targeted agents that are approved and/or are under investigation for patients with relapsed/refractory PTCL. We conducted an electronic literature search of the studies using PubMed, clincaltrials.gov, MEDLINE, using the key words 'PTCL,' 'second line therapy,' and 'targeted agents.' Studies published before January 2020 were included in the search criteria.

EXPERT OPINION

Development of newer therapies such as HDAC inhibitors and kinases are promising new agents with activity in relapsed/refractory PTCL. Combination therapy using novel agents may be the future for treatment of PTCL. Therapies in the next few years may take a more personalized approach taking into consideration not just the histology, but also the epigenomic landscape.

Fluorescence in-situ hybridisation for TP63 rearrangements in T cell lymphomas: single-site experience of 470 patients and implications for clinical testing

AIMS

The aims of this study were to review our 5-year experience with clinical FISH testing for TP63 rearrangements using both TP63 break-apart (BAP) and TBL1XR1/TP63 dual-fusion (D-FISH) probes to evaluate the frequency of TP63 rearrangements and the distribution of TBL1XR1 vs. alternate partner loci, and to assess whether both probe sets are necessary in all cases undergoing FISH testing.

METHODS AND RESULTS

A retrospective review of the Mayo Clinic cytogenetic database identified 470 patients evaluated by FISH testing for TP63 rearrangements in formalin-fixed paraffin-embedded (FFPE) tissue using both BAP and D-FISH probes. Of these, 25 (5.3%) had TP63 rearrangements. All samples were being investigated for anaplastic large-cell lymphoma or other T cell lymphoma subtypes. A TBL1XR1 partner was identified by D-FISH in 12 (48%) of 25 cases. All cases positive by TBL1XR1/TP63 D-FISH were also positive by TP63 BAP FISH.

CONCLUSION

This is the largest series of TP63 rearrangements to date. The frequency of positive results among cases referred to a large reference laboratory for TP63 FISH testing was 5.3%. Approximately half of TP63 rearrangements have a TBL1XR1 partner. TP63 BAP FISH testing is sufficient for up-front testing of FFPE tissue samples. However, because of the genomic proximity of the TP63 and TBL1XR1 loci, we recommend reflex TBL1XR1/TP63 D-FISH testing in positive and equivocal cases.

Targeting T cell malignancies using CAR-based immunotherapy: challenges and potential solutions

Chimeric antigen receptor (CAR) T cell therapy has been successful in treating B cell malignancies in clinical trials; however, fewer studies have evaluated CAR T cell therapy for the treatment of T cell malignancies. There are many challenges in translating this therapy for T cell disease, including fratricide, T cell aplasia, and product contamination. To the best of our knowledge, no tumor-specific antigen has been identified with universal expression on cancerous T cells, hindering CAR T cell therapy for these malignancies. Numerous approaches have been assessed to address each of these challenges, such as (i) disrupting target antigen expression on CAR-modified T cells, (ii) targeting antigens with limited expression on T cells, and (iii) using third party donor cells that are either non-alloreactive or have been genome edited at the T cell receptor α constant (TRAC) locus. In this review, we discuss CAR approaches that have been explored both in preclinical and clinical studies targeting T cell antigens, as well as examine other potential strategies that can be used to successfully translate this therapy for T cell disease.

STAT3 Dysregulation in Mature T and NK Cell Lymphomas

Abstract: T cell lymphomas comprise a distinct class of non-Hodgkin's lymphomas, which include mature T and natural killer (NK) cell neoplasms. While each malignancy within this group is characterized by unique clinicopathologic features, dysregulation in the Janus tyrosine family of kinases/Signal transducer and activator of transcription (JAK/STAT) signaling pathway, specifically aberrant STAT3 activation, is a common feature among these lymphomas. The mechanisms driving dysregulation vary among T cell lymphoma subtypes and include activating mutations in upstream kinases or STAT3 itself, formation of oncogenic kinases which drive STAT3 activation, loss of negative regulators of STAT3, and the induction of a pro-tumorigenic inflammatory microenvironment. Constitutive STAT3 activation has been associated with the expression of targets able to increase pro-survival signals and provide malignant fitness. Patients with dysregulated STAT3 signaling tend to have inferior clinical outcomes, which underscores the importance of STAT3 signaling in malignant progression. Targeting of STAT3 has shown promising results in pre-clinical studies in T cell lymphoma lines, ex-vivo primary malignant patient cells, and in mouse models of disease. However, targeting this pleotropic pathway in patients has proven difficult. Here we review the recent contributions to our understanding of the role of STAT3 in T cell lymphomagenesis, mechanisms driving STAT3 activation in T cell lymphomas, and current efforts at targeting STAT3 signaling in T cell malignancies.