Receptor-type tyrosine-protein phosphatase κ directly targets STAT3 activation for tumor suppression in nasal NK/T-cell lymphoma

Crosstalk between CXCL12/CXCR4/ACKR3 and the STAT3 Pathway

The reciprocal modulation between the CXCL12/CXCR4/ACKR3 axis and the STAT3 signaling pathway plays a crucial role in the progression of various diseases and neoplasms. Activation of the CXCL12/CXCR4/ACKR3 axis triggers the STAT3 pathway through multiple mechanisms, while the STAT3 pathway also regulates the expression of CXCL12. This review offers a thorough and systematic analysis of the reciprocal regulatory mechanisms between the CXCL12/CXCR4/ACKR3 signaling axis and the STAT3 signaling pathway in the context of diseases, particularly tumors. It explores the potential clinical applications in tumor treatment, highlighting possible therapeutic targets and novel strategies for targeted tumor therapy.

Therapeutic challenges in peripheral T-cell lymphoma

Peripheral T-cell lymphoma (PTCL) is a rare and heterogeneous group of hematological malignancies. Compared to our knowledge of B-cell tumors, our understanding of T-cell leukemia and lymphoma remains less advanced, and a significant number of patients are diagnosed with advanced stages of the disease. Unfortunately, the development of drug resistance in tumors leads to relapsed or refractory peripheral T-Cell Lymphomas (r/r PTCL), resulting in highly unsatisfactory treatment outcomes for these patients. This review provides an overview of potential mechanisms contributing to PTCL treatment resistance, encompassing aspects such as tumor heterogeneity, tumor microenvironment, and abnormal signaling pathways in PTCL development. The existing drugs aimed at overcoming PTCL resistance and their potential resistance mechanisms are also discussed. Furthermore, a summary of ongoing clinical trials related to PTCL is presented, with the aim of aiding clinicians in making informed treatment decisions.

Biology and genetics of extranodal mature T-cell and NKcell lymphomas and lymphoproliferative disorders

The extranodal mature T-cell and NK-cell lymphomas and lymphoproliferative disorders represent a unique group of rare neoplasms with both overlapping and distinct clinicopathological, biological, and genomic features. Their predilection for specific sites, such as the gastrointestinal tract, aerodigestive tract, liver, spleen, and skin/soft tissues, underlies their classification. Recent genomic advances have furthered our understanding of the biology and pathogenesis of these diseases, which is critical for accurate diagnosis, prognostic assessment, and therapeutic decision-making. Here we review clinical, pathological, genomic, and biological features of the following extranodal mature T-cell and NK-cell lymphomas and lymphoproliferative disorders: primary intestinal T-cell and NK-cell neoplasms, hepatosplenic T-cell lymphoma, extranodal NK/T-cell lymphoma, nasal type, and subcutaneous panniculitis-like T-cell lymphoma.

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.

The response and resistance to drugs in ovarian cancer cell lines in 2D monolayers and 3D spheroids

Ovarian cancer is the most common type of gynecologic cancer. One of the leading causes of high mortality is chemoresistance, developed primarily or during treatment. Different mechanisms of drug resistance appear at the cellular and cancer tissue organization levels. We examined the differences in response to the cytotoxic drugs CIS, MTX, DOX, VIN, PAC, and TOP using 2D (two-dimensional) and 3D (three-dimensional) culture methods. We tested the drug-sensitive ovarian cancer cell line W1 and established resistant cell lines to appropriate cytotoxic drugs. The following qualitative and quantitative methods were used to assess: 1) morphology - inverted microscope and hematoxylin & eosin staining; 2) viability - MTT assay; 3) gene expression - a quantitative polymerase chain reaction; 4) identification of proteins - immunohistochemistry, and immunofluorescence. Our results indicate that the drug-sensitive and drug-resistant cells cultured in 3D conditions exhibit stronger resistance than the cells cultured in 2D conditions. A traditional 2D model shows that drug resistance of cancer cells is caused mainly by changes in the expression of genes encoding ATP-binding cassette transporter proteins, components of the extracellular matrix, "new" established genes related to drug resistance in ovarian cancer cell lines, and universal marker of cancer stem cells. Whereas in a 3D model, the drug resistance in spheroids can be related to other mechanisms such as the structure of the spheroid (dense or loose), the cell type (necrotic, quiescent, proliferating cells), drug concentrations or drug diffusion into the dense cellular/ECM structure.

Extranodal NK-/T-cell lymphoma, nasal type: what advances have been made in the last decade?

Extranodal NK-/T-cell lymphoma (ENKTCL) is a rare and highly aggressive malignancy with significant racial and geographic variations worldwide. In addition to the formerly "nasal-type" initial description, these lymphomas are predominantly extranodal in origin and typically cause vascular damage and tissue destruction, and although not fully understood, Epstein-Barr virus (EBV) has an important role in its pathogenesis. Initial assessment must include a hematopathology review of representative and viable tumor areas without necrosis for adequate immunohistochemistry studies, including EBV-encoded small RNA (EBER) in situ hybridization (ISH). Positron emission tomography with 18-fluorodeoxyglucose (¹⁸F-FDG-PET/CT) for accurate staging is essential, and most patients will have localized disease (IE/IIE) at diagnosis. Apart from other T-cell malignancies, the best treatment even for localized cases is combined modality therapy (chemotherapy plus radiotherapy) with non-anthracycline-based regimens. For advanced-stage disease, l-asparaginase-containing regimens have shown improved survival, but relapsed and refractory cases have very poor outcomes. Nowadays, even with a better understanding of pathogenic pathways, up-front therapy is completely based on chemotherapy and radiotherapy, and treatment-related mortality is not low. Future strategies targeting signaling pathways and immunotherapy are evolving, but we need to better identify those patients with dismal outcomes in a pre-emptive way. Given the rarity of the disease, international collaborations are urgently needed, and clinical trials are the way to change the future.

Rational Targets of Therapy in Extranodal NK/T-Cell Lymphoma

Extranodal NK/T-cell lymphoma (ENKTL) is an aggressive extranodal non-Hodgkin lymphoma (NHL) with poor outcomes, particularly in advanced-stage and relapsed/refractory disease. Emerging research on molecular drivers of ENKTL lymphomagenesis by next-generation and whole genome sequencing has revealed diverse genomic mutations in multiple signaling pathways, with the identification of multiple putative targets for novel therapeutic agents. In this review, we summarize the biological underpinnings of newly-understood therapeutic targets in ENKTL with a focus on translational implications, including epigenetic and histone regulatory aberrations, activation of cell proliferation signaling pathways, suppression of apoptosis and tumor suppressor genes, changes in the tumor microenvironment, and EBV-mediated oncogenesis. In addition, we highlight prognostic and predictive biomarkers which may enable a personalized medicine approach toward ENKTL therapy.

Mature T-cell and NK-cell lymphomas: updates on molecular genetic features

Mature T-cell and NK-cell lymphomas are a heterogeneous group of rare and typically aggressive neoplasms. Diagnosis and subclassification have historically relied primarily on the integration of clinical, histologic, and immunophenotypic features, which often overlap. The widespread application of a variety of genomic techniques in recent years has provided extensive insight into the pathobiology of these diseases, allowing for more precise diagnostic classification, improved prognostication, and development of novel therapies. In this review, we summarize the genomic features of the most common types of mature T-cell and NK-cell lymphomas with a particular focus on the contribution of genomics to biologic insight, classification, risk stratification, and select therapies in the context of the recently published International Consensus and updated World Health Organization classification systems.

R-PTP-κ Inhibits Contact-Dependent Cell Growth by Suppressing E2F Activity

Density-dependent regulation of cell growth is presumed to be caused by cell-cell contact, but the underlying molecular mechanism is not yet clearly defined. Here, we report that receptor-type protein tyrosine phosphatase-kappa (R-PTP-κ) is an important regulator of cell contact-dependent growth inhibition. R-PTP-κ expression increased in proportion to cell density. siRNA-mediated R-PTP-κ downregulation led to the loss of cell contact-mediated growth inhibition, whereas its upregulation reduced anchorage-independent cell growth in soft agar as well as tumor growth in nude mice. Expression profiling and luciferase reporter system-mediated signaling pathway analysis revealed that R-PTP-κ induced under cell contact conditions distinctly suppressed E2F activity. Among the structural domains of R-PTP-κ, the cytoplasmic domain containing the tandemly repeated PTP motif acts as a potent downregulator of the E2F pathway. Specifically, R-PTP-κ suppressed CDK2 activity through the induction of p21Cip1/WAF-1 and p27Kip1, resulting in cell cycle arrest at the G1 phase. In transcriptome-based public datasets generated from four different tumor types, R-PTP-κ expression was negatively correlated with the expression pattern and prognostic value of two known E2F1 target genes (CCNE1 and CDC25A). Therefore, our results indicate that the R-PTP-κ-E2F axis plays a crucial role in cell growth-inhibitory signaling arising from cell-cell contact conditions.

Host gene expression is associated with viral shedding magnitude in blue-winged teals (Spatula discors) infected with low-path avian influenza virus

Intraspecific variation in host infectiousness affects disease transmission dynamics in human, domestic animal, and many wildlife host-pathogen systems including avian influenza virus (AIV); therefore, identifying host factors related to host infectiousness is important for understanding, controlling, and preventing future outbreaks. Toward this goal, we used RNA-seq data collected from low pathogenicity avian influenza virus (LPAIV)-infected blue-winged teal (Spatula discors) to determine the association between host gene expression and intraspecific variation in cloacal viral shedding magnitude, the transmissible fraction of virus. We found that host genes were differentially expressed between LPAIV-infected and uninfected birds early in the infection, host genes were differentially expressed between shed level groups at one-, three-, and five-days post-infection, host gene expression was associated with LPAIV infection patterns over time, and genes of the innate immune system had a positive linear relationship with cloacal viral shedding. This study provides important insights into host gene expression patterns associated with intraspecific LPAIV shedding variation and can serve as a foundation for future studies focused on the identification of host factors that drive or permit the emergence of high viral shedding individuals.

Pan-cancer analyses of classical protein tyrosine phosphatases and phosphatase-targeted therapy in cancer

Protein tyrosine phosphatases function in dephosphorylating target proteins to regulate signaling pathways that control a broad spectrum of fundamental physiological and pathological processes. Detailed knowledge concerning the roles of classical PTPs in human cancer merits in-depth investigation. We comprehensively analyzed the regulatory mechanisms and clinical relevance of classical PTPs in more than 9000 tumor patients across 33 types of cancer. The independent datasets and functional experiments were employed to validate our findings. We exhibited the extensive dysregulation of classical PTPs and constructed the gene regulatory network in human cancer. Moreover, we characterized the correlation of classical PTPs with both drug-resistant and drug-sensitive responses to anti-cancer drugs. To evaluate the PTP activity in cancer prognosis, we generated a PTPscore based on the expression and hazard ratio of classical PTPs. Our study highlights the notable role of classical PTPs in cancer biology and provides novel intelligence to improve potential therapeutic strategies based on pTyr regulation.

Extranodal natural killer/T-cell lymphoma: An overview on pathology and clinical management

Natural killer (NK)/T-cell lymphomas arise mainly from NK-cells and occasionally T-cells, and are universally infected with Epstein Barr virus (EBV). They are uncommon lymphomas more prevalent in Asian and Central/South American populations. NK/T-cell lymphomas are clinically aggressive and predominantly extranodal. The most commonly involved sites are the nasal cavity, followed by non-nasal sites including the skin, gastrointestinal tract and testis. The diagnosis of extranodal NK/T-cell lymphoma is established with histological and immunohistochemical examination, together with the demonstration of EBV in the tumour cells. Staging by positron emission tomography computed tomography is essential to inform the optimal management. Plasma EBV DNA quantification should be performed as it serves as a marker for prognostication and treatment response. Survival outcomes of patients with early-stage disease are good following treatment with nonanthracycline based chemotherapy, together with sequential/concurrent radiotherapy. For advanced-stage disease, asparaginase-containing regimens are mostly used and allogeneic haematopoietic stem cell transplantation should be considered for those at high risk of relapse. Salvage chemotherapy is largely ineffective for relapsed/refractory disease, which has a grave prognosis. Novel therapeutic approaches including immune check-point blockade, EBV-specific cytotoxic T-cells, and monoclonal antibodies are being investigated to improve outcomes for those with high risk and relapsed/refractory disease.

The Profile of MicroRNA Expression and Potential Role in the Regulation of Drug-Resistant Genes in Doxorubicin and Topotecan Resistant Ovarian Cancer Cell Lines

Epithelial ovarian cancer has the highest mortality among all gynecological malignancies. The main reasons for high mortality are late diagnosis and development of resistance to chemotherapy. Resistance to chemotherapeutic drugs can result from altered expression of drug-resistance genes regulated by miRNA. The main goal of our study was to detect differences in miRNA expression levels in two doxorubicin (DOX)- and two topotecan (TOP)-resistant variants of the A2780 drug-sensitive ovarian cancer cell line by miRNA microarray. The next aim was to recognize miRNAs as factors responsible for the regulation of drug-resistance genes. We observed altered expression of 28 miRNA that may be related to drug resistance. The upregulation of miR-125b-5p and miR-935 and downregulation of miR-218-5p was observed in both DOX-resistant cell lines. In both TOP-resistant cell lines, we noted the overexpression of miR-99a-5p, miR-100-5p, miR-125b-5p, and miR-125b-2-3p and decreased expression of miR-551b-3p, miR-551b-5p, and miR-383-5p. Analysis of the targets suggested that expression of important drug-resistant genes such as the collagen type I alpha 2 chain (COL1A2), protein Tyrosine Phosphatase Receptor Type K (PTPRK), receptor tyrosine kinase—EPHA7, Roundabout Guidance Receptor 2 (ROBO2), myristoylated alanine-rich C-kinase substrate (MARCK), and the ATP-binding cassette subfamily G member 2 (ABCG2) can be regulated by miRNA.

Cellular Origins and Pathogenesis of Gastrointestinal NK- and T-Cell Lymphoproliferative Disorders

The intestinal immune system, which must ensure appropriate immune responses to both pathogens and commensal microflora, comprises innate lymphoid cells and various T-cell subsets, including intra-epithelial lymphocytes (IELs). An example of innate lymphoid cells is natural killer cells, which may be classified into tissue-resident, CD56bright NK-cells that serve a regulatory function and more mature, circulating CD56dim NK-cells with effector cytolytic properties. CD56bright NK-cells in the gastrointestinal tract give rise to indolent NK-cell enteropathy and lymphomatoid gastropathy, as well as the aggressive extranodal NK/T cell lymphoma, the latter following activation by EBV infection and neoplastic transformation. Conventional CD4+ TCRαβ+ and CD8αβ+ TCRαβ+ T-cells are located in the lamina propria and the intraepithelial compartment of intestinal mucosa as type 'a' IELs. They are the putative cells of origin for CD4+ and CD8+ indolent T-cell lymphoproliferative disorders of the gastrointestinal tract and intestinal T-cell lymphoma, NOS. In addition to such conventional T-cells, there are non-conventional T-cells in the intra-epithelial compartment that express CD8αα and innate lymphoid cells that lack TCRs. The central feature of type 'b' IELs is the expression of CD8αα homodimers, seen in monomorphic epitheliotropic intestinal T-cell lymphoma (MEITL), which primarily arises from both CD8αα+ TCRαβ+ and CD8αα+ TCRγδ+ IELs. EATL is the other epitheliotropic T-cell lymphoma in the GI tract, a subset of which arises from the expansion and reprograming of intracytoplasmic CD3+ innate lymphoid cells, driven by IL15 and mutations of the JAK-STAT pathway.

The Effect of Chronic Rhinosinusitis on the Staging and Prognosis of Extranodal Natural Killer/T-Cell Lymphoma: A Single-Center Retrospective Analysis

Clinically, extranodal natural killer/T-cell lymphoma (ENKTL) patients frequently had a history of chronic rhinosinusitis (CRS) before onset, and the correlation between the two diseases has not been systematically reported at present. In this study, we applied the method-retrospective analysis-to explore the relationship between CRS and ENKTL. We collected clinical data and the length of CRS history before onset in 214 patients diagnosed with ENKTL and found that the length of CRS history was correlated with the stage of 182 ENKTL patients whose primary sites were upper aerodigestive tract (UAT) (χ ² = 21.317, p = 0.046, n = 182); the Spearman correlation coefficient was 0.162 (p = 0.029). There was no significant difference in stage of the non-UAT-ENKTL patients (χ ² = 18.910, p = 0.091, n = 32). The COX multivariate regression analysis showed that CRS history was an independent prognostic predictor for PFS of the UAT-ENKTL patients (p = 0.004), and patients without CRS had significantly better PFS than the more than 15 years CRS history group (p = 0.001). Our findings suggested that we should not ignore the existence of chronic inflammation of the nasal cavity in ENKTL patients. It is better to treat CRS as soon as possible in clinical practice to reduce the possibility of the occurrence or progression of UAT-ENKTL.

The GNAQ T96S mutation abrogates the ability of wild-type GNAQ to induce apoptosis by phosphorylating ANXA2 in natural killer/T cell lymphoma

Our previous study identified Annexin A2 (ANXA2) as a Gaq-interacting partner in natural killer/T cell lymphoma (NKTCL) cells transfected with the GNAQ T96S mutation vector by immunoprecipitation and mass spectrometry; however, the detailed molecular mechanisms by which GNAQ T96S might regulate ANXA2 remain to be defined in NKTCL. Herein, we found that the GNAQ T96S mutation significantly promotes the phosphorylation of ANXA2 at the Y24 site, whereas phosphorylation of ANXA2 abolishes the ability of wild-type GNAQ to trigger cell apoptosis. Further investigation revealed that a GNAQ T96S peptide inhibitor induced apoptosis by competing with ANXA2 binding to GNAQ T96S in NKTCL cells. In vivo animal experiments demonstrated that a GNAQ T96S peptide inhibitor suppresses the growth of NKTCL cells carrying the GNAQ T96S mutation. Our current data suggest a role for GNAQ T96S/Src/ANXA2 in mediating the apoptosis of NKTCL cells, and the GNAQ T96S peptide may be a promising agent for therapy in NKTCL patients.

Differential gene expression reveals host factors for viral shedding variation in mallards (Anas platyrhynchos) infected with low-pathogenic avian influenza virus

Intraspecific variation in pathogen shedding impacts disease transmission dynamics; therefore, understanding the host factors associated with individual variation in pathogen shedding is key to controlling and preventing outbreaks. In this study, ileum and bursa of Fabricius tissues of wild-bred mallards (Anas platyrhynchos) infected with low-pathogenic avian influenza (LPAIV) were evaluated at various post-infection time points to determine genetic host factors associated with intraspecific variation in viral shedding. By analysing transcriptome sequencing data (RNA-seq), we found that LPAIV-infected wild-bred mallards do not exhibit differential gene expression compared to uninfected birds, but that gene expression was associated with cloacal viral shedding quantity early in the infection. In both tissues, immune gene expression was higher in high/moderate shedding birds compared to low shedding birds, and significant positive relationships with viral shedding were observed. In the ileum, expression for host genes involved in viral cell entry was lower in low shedders compared to moderate shedders at 1 day post-infection (DPI), and expression for host genes promoting viral replication was higher in high shedders compared to low shedders at 2 DPI. Our findings indicate that viral shedding is a key factor for gene expression differences in LPAIV-infected wild-bred mallards, and the genes identified in this study could be important for understanding the molecular mechanisms driving intraspecific variation in pathogen shedding.

Recent Advances in the Diagnosis and Treatment of Natural Killer Cell Malignancies

Simple Summary

Natural killer (NK)/T-cell lymphomas are aggressive extranodal Epstein–Barr virus (EBV)-positive malignancies. They can be divided into three subtypes: nasal (involving the nose and upper aerodigestive tract), non-nasal (involving skin, gastrointestinal tract, testis and other organs) and disseminated (involving multiple organs). Lymphoma cells are positive for CD3ε, CD56, cytotoxic molecules and EBV-encoded small RNA. There is a predilection for Asian and Central/South American populations. Genome-wide association studies have identified lymphoma susceptibility loci in Asians. Positron emission tomography computed tomography and plasma EBV DNA quantification are crucial at diagnosis and follow-up. Stage I/II patients receive non-athracycline asparaginse-containing regimens, together with sequential/concurrent radiotherapy. Anthracycline-containing regimens are ineffective. Stage III/IV patients receive asparaginase-containing regimens, followed by allogeneic haematopoietic stem cell transplantation (HSCT). Autologous HSCT does not improve outcome. In relapsed/refractory patients, novel approaches include PD1/PD-L1 targeting, EBV-specific cytotoxic T-cells, and monoclonal antibodies. Small molecules including histone deacetylase inhibitors may be beneficial.

Abstract

Natural killer (NK)/T-cell lymphomas are aggressive malignancies. Epstein–Barr virus (EBV) infection in lymphoma cells is invariable. NK/T-cell lymphomas are divided into nasal, non-nasal, and disseminated subtypes. Nasal NK/T-cell lymphomas involve the nasal cavity and the upper aerodigestive tract. Non-nasal NK/T-cell lymphomas involve the skin, gastrointestinal tract, testis and other extranodal sites. Disseminated NK/T-cell lymphoma involves multiple organs, rarely presenting with a leukaemic phase. Lymphoma cells are positive for CD3ε (not surface CD3), CD56, cytotoxic molecules and EBV-encoded small RNA. There is a predilection for Asian and Central/South American populations. Genome-wide association studies have identified lymphoma susceptibility loci in Asian patients. Positron emission tomography computed tomography and plasma EBV DNA quantification are crucial evaluations at diagnosis and follow-up. Stage I/II patients typically receive non-athracycline regimens containing asparaginse, together with sequential/concurrent radiotherapy. Anthracycline-containing regimens are ineffective. Stage III/IV patients are treated with asparaginase-containing regimens, followed by allogeneic haematopoietic stem cell transplantation (HSCT) in suitable cases. Autologous HSCT does not improve outcome. In relapsed/refractory patients, novel approaches are needed, involving PD1/PD-L1 targeting, EBV-specific cytotoxic T-cells, and monoclonal antibodies. Small molecules including histone deacetylase inhibitors may be beneficial in selected patients. Future strategies may include targeting of signalling pathways and driver mutations.

The Pathologic and Genetic Characteristics of Extranodal NK/T-Cell Lymphoma

Extranodal NK/T-cell lymphoma is a neoplasm of NK cells or cytotoxic T cells presenting in extranodal sites, most often in the nasal cavity. The typical immunophenotypes are cCD3+, sCD3-, CD4-, CD5-, CD8-, CD16-, and CD56+ with the expression of cytotoxic molecules. Tumor subsets express NK cell receptors, CD95/CD95L, CD30, MYC, and PDL1. Virtually all the tumor cells harbor the EBV genome, which plays a key role in lymphomagenesis as an epigenetic driver. EBV-encoded oncoproteins modulate the host-cell epigenetic machinery, reprogramming the viral and host epigenomes using host epigenetic modifiers. NGS analysis revealed the mutational landscape of ENKTL, predominantly involving the JAK-STAT pathway, epigenetic modifications, the RNA helicase family, the RAS/MAP kinase pathway, and tumor suppressors, which indicate an important role of these pathways and this group of genes in the lymphomagenesis of ENKTL. Recently, three molecular subtypes were proposed, the tumor-suppressor/immune-modulator (TSIM), MGA-BRDT (MB), and HDAC9-EP300-ARID1A (HEA) subtypes, and they are well-correlated with the cell of origin, EBV pattern, genomic alterations, and clinical outcomes. A future investigation into the function and interaction of discovered genes would be very helpful for better understanding the molecular pathogenesis of ENKTL and establishing better treatment strategies.

Tumor-derived exosomal miR-19b-3p facilitates M2 macrophage polarization and exosomal LINC00273 secretion to promote lung adenocarcinoma metastasis via Hippo pathway

Numerous reports have elucidated the important participation of exosomes in the communication between tumor cells and other cancer-related cells including tumor-associated macrophages (TAMs) in microenvironment. However, the interchange of exosomes between tumor cells and TAMs in the progression of lung adenocarcinoma (LUAD) remains largely enigmatic. Herein, we discovered that LUAD cells induced the M2 polarization of TAMs and the M2-polarized macrophages facilitated LUAD cell invasion and migration and tumor metastasis in vivo. In detail, LUAD cells secreted exosomes to transport miR-19b-3p into TAMs so that miR-19b-3p targeted PTPRD and inhibited the PTPRD-mediated dephosphorylation of STAT3 in TAMs, leading to STAT3 activation and M2 polarization. Also, the activated STAT3 transcriptionally induced LINC00273 in M2 macrophages and exosomal LINC00273 was transferred into LUAD cells. In LUAD cells, LINC00273 recruited NEDD4 to facilitate LATS2 ubiquitination and degradation, so that the Hippo pathway was inactivated and YAP induced the transcription of RBMX. RBMX bound to miR-19b-3p to facilitate the packaging of miR-19b-3p into LUAD cell-derived exosomes. Collectively, our results revealed the mechanism underlying the interactive communication between LUAD cells and TAMs through elucidating the exchange of exosomal miR-19b-3p and LINC00273 and proved the prometastatic effect of the interchange between two cells. These discoveries opened a new vision for developing LUAD treatment.

Piperine Targets Different Drug Resistance Mechanisms in Human Ovarian Cancer Cell Lines Leading to Increased Sensitivity to Cytotoxic Drugs

Our goal was to examine the anticancer effects of piperine against the resistant human ovarian cancer cells and to explore the molecular mechanisms responsible for its anticancer effects. Our study used drug-sensitive ovarian cancer cell line W1 and its sublines resistant to paclitaxel (PAC) and topotecan (TOP). We analyzed the cytotoxic effect of piperine and cytostatic drugs using an MTT assay. The impact of piperine on protein expression was determined by immunofluorescence and Western blot. We also examined its effect on cell proliferation and migration. We noticed a different level of piperine resistance between cell lines. Piperine increases the cytotoxic effect of PAC and TOP in drug-resistant cells. We observed an increase in PTPRK expression correlated with decreased pTYR level after piperine treatment and downregulation of P-gp and BCRP expression. We also noted a decrease in COL3A1 and TGFBI expression in investigated cell lines and increased COL3A1 expression in media from W1PR2 cells. The expression of Ki67 protein and cell proliferation rate decreased after piperine treatment. Piperine markedly inhibited W1TR cell migration. Piperine can be considered a potential anticancer agent that can increase chemotherapy effectiveness in cancer patients.

Diagnostic approach to T- and NK-cell lymphoproliferative disorders in the gastrointestinal tract

Most gastrointestinal NK and T cell lymphomas are aggressive in behavior, although in recent years a subset of indolent lymphoproliferative disorders have been described, which must be distinguished from their more malignant mimics. Intestinal T-cell lymphomas may arise from intra-epithelial lymphocytes and display epitheliotropism, such as enteropathy-associated T-cell lymphoma and monomorphic epitheliotropic intestinal T-cell lymphoma. They are both aggressive in behavior but differ in their clinic-pathological features. On the other hand, intra-epithelial lymphocytes are not prominent in intestinal T-cell lymphoma, NOS, which is a diagnosis of exclusion and probably represents a heterogeneous group of entities. Indolent lymphoproliferative disorders of NK- and T-cells of both CD8 and CD4 subsets share a chronic, recurring clinical course but display differences from each other. CD8+ T-cell lymphoproliferative disorder of GI tract has a low proliferative fraction and does not progress nor undergo large cell transformation. Whilst NK-cell enteropathy runs an indolent clinical course, it may display a high proliferation fraction. On the other hand, CD4+ indolent T-cell lymphoproliferative disorder displays variable proliferation rates and may progress or transform after a number of years. In Asia and South America, it is not uncommon to see involvement of the gastrointestinal tract by EBV-associated extranodal NK/T cell lymphoma, nasal type, which must be distinguished from NK cell enteropathy and EBV-associated mucocutaneous ulcers.

Extranodal NK/T cell lymphoma, nasal type: An updated overview

Extranodal NK/T-cell lymphoma, nasal type (ENKTCL-NT) is an aggressive malignancy associated with Epstein-Barr virus infection, with a geographic and racial predilection for some Asian and Latin American countries. ENKTCL-NT manifests as a necrotic process affecting nasal or upper aerodigestive structures and, rarely, extranasal sites such as skin, and the gastrointestinal tract. ENKTCL-NT was characterized by its poor prognosis irrespective of clinical stage and therapy. However, during the last two decades, advances in its clinicopathologic, genetic and molecular characterization have been achieved, as have changes in the chemotherapy regimens that, in combination with radiotherapy, are significantly improving the survival of these patients, especially in initial stages. For these reasons, we present an overview of the historical background of ENKTCL-NT along with an updated review of its potential etiological factors, clinicopathologic and molecular features, as well as its prognostic models, current treatment protocols, and future directions on potential promising therapeutic approaches.

Transcriptomic Profiling of the Adaptive and Innate Immune Responses of Atlantic Salmon to Renibacterium salmoninarum Infection

Bacterial Kidney Disease (BKD), which is caused by a Gram-positive, intracellular bacterial pathogen (Renibacterium salmoninarum), affects salmonids including Atlantic salmon (Salmo salar). However, the transcriptome response of Atlantic salmon to BKD remained unknown before the current study. We used a 44K salmonid microarray platform to characterise the global gene expression response of Atlantic salmon to BKD. Fish (~54 g) were injected with a dose of R. salmoninarum (H-2 strain, 2 × 10⁸ CFU per fish) or sterile medium (control), and then head kidney samples were collected at 13 days post-infection/injection (dpi). Firstly, infection levels of individuals were determined through quantifying the R. salmoninarum level by RNA-based TaqMan qPCR assays. Thereafter, based on the qPCR results for infection level, fish (n = 5) that showed no (control), higher (H-BKD), or lower (L-BKD) infection level at 13 dpi were subjected to microarray analyses. We identified 6,766 and 7,729 differentially expressed probes in the H-BKD and L-BKD groups, respectively. There were 357 probes responsive to the infection level (H-BKD vs. L-BKD). Several adaptive and innate immune processes were dysregulated in R. salmoninarum-infected Atlantic salmon. Adaptive immune pathways associated with lymphocyte differentiation and activation (e.g., lymphocyte chemotaxis, T-cell activation, and immunoglobulin secretion), as well as antigen-presenting cell functions, were shown to be differentially regulated in response to BKD. The infection level-responsive transcripts were related to several mechanisms such as the JAK-STAT signalling pathway, B-cell differentiation and interleukin-1 responses. Sixty-five microarray-identified transcripts were subjected to qPCR validation, and they showed the same fold-change direction as microarray results. The qPCR-validated transcripts studied herein play putative roles in various immune processes including pathogen recognition (e.g., tlr5), antibacterial activity (e.g., hamp and camp), regulation of immune responses (e.g., tnfrsf11b and socs1), T-/B-cell differentiation (e.g., ccl4, irf1 and ccr5), T-cell functions (e.g., rnf144a, il13ra1b and tnfrsf6b), and antigen-presenting cell functions (e.g., fcgr1). The present study revealed diverse immune mechanisms dysregulated by R. salmoninarum in Atlantic salmon, and enhanced the current understanding of Atlantic salmon response to BKD. The identified biomarker genes can be used for future studies on improving the resistance of Atlantic salmon to BKD.

Molecular insights into pathogenesis and targeted therapy of peripheral T cell lymphoma

Peripheral T-cell lymphomas (PTCLs) are biologically and clinically heterogeneous diseases almost all of which are associated with poor outcomes. Recent advances in gene expression profiling that helps in diagnosis and prognostication of different subtypes and next-generation sequencing have given new insights into the pathogenesis and molecular pathway of PTCL. Here, we focus on a broader description of mutational insights into the common subtypes of PTCL including PTCL not other specified type, angioimmunoblastic T-cell lymphoma, anaplastic large cell lymphoma, and extra-nodal NK/T cell lymphoma, nasal type, and also present an overview of new targeted therapies currently in various stages of clinical trials.

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

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

Novel anti-cancer candidates from a combinatorial peptide library

STAT3 is attractive target for development of anti-cancer therapeutics as it is implicated in nearly all forms of human tumors. To identify novel leads, we screened a combinatorial peptide library displayed on the surface of M13 bacteriophage. After three rounds of biopanning, a dodecapeptide with the YYVSWPPDMMHY sequence was found to be enriched by 36% while another with a short consensus motif was displayed in 20% of the phages. Binding analysis by isothermal titration calorimetry shows the most displayed peptide interacted with a K_d of 1.79 μM, which on modification of its structure to mimic the natural binding partners of STAT3 brought the affinity to high nanomolar range (K_d  = 500 nM). Using a panel of tumor cell lines, we show that the peptides prevented the proliferation of triple-negative breast cancer cells with a moderate activity (GI₅₀  = 50 μM). Furthermore, gene expression analysis shows the peptide reduced the expression of oncoproteins critical for tumor cell proliferation, angiogenesis, and metastasis. To find novel STAT3-interacting proteins, we searched the non-redundant sequences of the National Center for Biotechnology Information database which allowed us to identify potential binding partners of the protein. In sum, our data show the identified agents could serve as useful therapeutics candidates for further development.

The landscape of new drugs in extranodal NK/T-cell lymphoma

To date, much progress has been made in early-stage extranodal NK/T-cell lymphoma (ENKTCL), and risk-adapted therapy with radiotherapy (RT) alone for the low-risk group and RT combined with asparaginase-based chemotherapy (CT) for the high-risk group yields favorable outcomes. However, optimal treatment strategies have not been defined yet for advanced-stage ENKTCL. Historically, ENKTCL responded poorly to conventional anthracycline-based chemotherapy probably because of inherent multidrug resistance (MDR). The fact that ENKTCL cells lack asparagine synthetase (ASNS) activity warranted the use of L-asparaginase or pegaspargase as frontline chemotherapies. Even though, due to high mortality of the disease, approximately 50% patients failing the frontline therapy arrived at dismal clinical outcomes with a median progression-free survival (PFS) less than 8 months. As distinctive molecular and biological subgroups are increasingly discovered within the disease entity of ENKTCL, novel targeted therapies and immunotherapy are of the urgent need for those heterogeneous subgroups. In this review, we sought to summarize the preclinical and clinical results of 6 categories of promising targeted therapy and immunotherapy for the treatment of ENKTCL, including monoclonal antibodies, immune checkpoint inhibitors, small-molecular inhibitors, epigenetic therapy, immunomodulatory drugs, and adoptive T-cell therapy, and these might change the landscape of treatment for ENKTCL in the near future.

Regulation of signal transducer and activator of transcription 3 activation by dual-specificity phosphatase 3

Since cancer is the leading cause of death worldwide, there is an urgent need to understand the mechanisms underlying cancer progression and the development of cancer inhibitors. Signal transducer and activator of transcription 3 (STAT3) is a major transcription factor that regulates the proliferation and survival of various cancer cells. Here, dual-specificity phosphatase 3 (DUSP3) was identified as a regulator of STAT3 based on an interaction screening performed using the protein tyrosine phosphatase library. DUSP3 interacted with the C-terminal domain of STAT3 and dephosphorylated p-Y705 of STAT3. In vitro dephosphorylation assay revealed that DUSP3 directly dephosphorylated p-STAT3. The suppressive effects of DUSP3 on STAT3 were evaluated by a decreased STAT3-specific promoter activity, which in turn reduced the expression of the downstream target genes of STAT3. In summary, DUSP3 downregulated the transcriptional activity of STAT3 via dephosphorylation at Y705 and also suppressed the migratory activity of cancer cells. This study demonstrated that DUSP3 inhibits interleukin 6 (IL-6)/STAT3 signaling and is expected to regulate cancer development. Novel functions of DUSP3 discovered in IL-6/STAT3 signaling regulation would help expand the understanding of cancer development mechanisms.

Peripheral T cell lymphomas: from the bench to the clinic

Peripheral T cell lymphomas (PTCLs) are a heterogeneous group of orphan neoplasms. Despite the introduction of anthracycline-based chemotherapy protocols, with or without autologous haematopoietic transplantation and a plethora of new agents, the progression-free survival of patients with PTCLs needs to be improved. The rarity of these neoplasms, the limited knowledge of their driving defects and the lack of experimental models have impaired clinical successes. This scenario is now rapidly changing with the discovery of a spectrum of genomic defects that hijack essential signalling pathways and foster T cell transformation. This knowledge has led to new genomic-based stratifications, which are being used to establish objective diagnostic criteria, more effective risk assessment and target-based interventions. The integration of genomic and functional data has provided the basis for targeted therapies and immunological approaches that underlie individual tumour vulnerabilities. Fortunately, novel therapeutic strategies can now be rapidly tested in preclinical models and effectively translated to the clinic by means of well-designed clinical trials. We believe that by combining new targeted agents with immune regulators and chimeric antigen receptor-expressing natural killer and T cells, the overall survival of patients with PTCLs will dramatically increase.

HKDC1 C-terminal based peptides inhibit extranodal natural killer/T-cell lymphoma by modulation of mitochondrial function and EBV suppression

Extranodal nasal-type natural killer/T-cell lymphoma (ENKTL) is an Epstein–Barr virus (EBV) associated lymphoma that progresses rapidly and relapses frequently. Advanced ENKTL is multidrug chemoresistant and has a poor prognosis. In this study, we aim to develop a novel hexokinase domain component 1 (HKDC1)-based antitumor target for ENKTL that is involved with the antimetabolic signaling pathway, EBV replication, and P-glycoprotein (P-gp) expression. We showed that HKDC1 is highly upregulated in ENKTL cells and HKDC1 knockdown significantly suppresses ENKTL tumor growth. In addition, HKDC1 is highly identical with four other hexokinase isoforms, with the only difference being in the last eight amino acids (aa) at the C-terminal. Further investigation showed that peptide delivery of the last eight aa of HKDC1 at the C-terminal (HKC8) with D-configuration using transferrin (Tf) receptor internalization sequence (Tf-D-HKC8) inhibits HKDC1 association with vascular endothelial growth factor 1 (VDAC1), resulting in mitochondrial dysfunction and reactive oxygen species (ROS) overgeneration and subsequently suppressing EBV replication and P-gp expression, making it very effective in killing EBV-positive ENKTL cells. Further in vivo experiments showed that local injection of Tf-D-HKC8 peptide significantly suppresses ENKTL tumor growth and EBV replication in ENKTL xenograft mouse models. We conclude that HKDC1 C-terminal-based peptides inhibit ENKTL by modulation of mitochondrial function and EBV suppression.

Epigenetic aberrations in natural killer/T-cell lymphoma: diagnostic, prognostic and therapeutic implications

Natural killer/T-cell lymphoma (NKTCL) is an aggressive malignancy that usually presents in the upper aerodigestive tract. This malignancy shows substantial geographic variability in incidence, and is characterized by Epstein-Barr virus (EBV) infections. Epigenetic aberrations may dysregulate the expression of genes involved in different hallmarks of cancer. A growing body of evidence underscores the importance of epigenetic aberrations in the pathogenesis of NKTCL. Promoter hypermethylation is a common epigenetic mechanism for the inactivation of tumour suppressor genes. Several epigenetically silenced tumour suppressor candidates (e.g. PRDM1, BIM) were identified in this aggressive cancer using locus-specific and genome-wide promoter methylation analyses. Importantly, genes involved in epigenetic modifications were identified to be mutated (e.g. KMT2D) or methylated (e.g. TET2) in NKTCL patients, which may contribute to pathogenesis through global alterations in chromatin states. Cancer-associated microRNAs, some of which are expressed by EBV, and long noncoding RNAs have been observed to be dysregulated in NKTCL. This review focuses on studies investigating epigenetic aberrations in NKTCL to bolster our overall understanding of the role of these abnormalities in disease pathobiology. We also discuss the potential of these epigenetic aberrations to improve diagnosis and prognosis as well as reveal novel targets of therapy for NKTCL.

The tumor suppressor PTPRK promotes ZNRF3 internalization and is required for Wnt inhibition in the Spemann organizer

A hallmark of Spemann organizer function is its expression of Wnt antagonists that regulate axial embryonic patterning. Here we identify the tumor suppressor Protein tyrosine phosphatase receptor-type kappa (PTPRK), as a Wnt inhibitor in human cancer cells and in the Spemann organizer of Xenopus embryos. We show that PTPRK acts via the transmembrane E3 ubiquitin ligase ZNRF3, a negative regulator of Wnt signaling promoting Wnt receptor degradation, which is also expressed in the organizer. Deficiency of Xenopus Ptprk increases Wnt signaling, leading to reduced expression of Spemann organizer effector genes and inducing head and axial defects. We identify a '4Y' endocytic signal in ZNRF3, which PTPRK maintains unphosphorylated to promote Wnt receptor depletion. Our discovery of PTPRK as a negative regulator of Wnt receptor turnover provides a rationale for its tumor suppressive function and reveals that in PTPRK-RSPO3 recurrent cancer fusions both fusion partners, in fact, encode ZNRF3 regulators.

How human and other animals form distinct head- and tail-ends as embryos is a fundamental question in biology. The fertilized eggs of the African clawed frog (also known as Xenopus) become embryos and grow into tadpoles within two days. This rapid growth makes Xenopus particularly suitable as a model to study how animals with backbones form their body plans.

In Xenopus embryos, a small group of cells known as the Spemann organizer plays a pivotal role in forming the body plan. It produces several enzymes known as Wnt inhibitors that repress a signal pathway known as Wnt signaling to determine the head- and tail-ends of the embryo.

Chang, Kim et al. searched for new Wnt inhibitors in the Spemann organizer of Xenopus embryos. The experiments revealed that the Spemann organizer produced an enzyme known as PTPRK that was essential to permit the head-to-tail patterning of the brain. PTPRK inhibited Wnt signaling by activating another enzyme known as ZNRF3.

Previous studies have shown that defects in Wnt signaling and in the activities of PTPRK and ZNRF3 are involved in colon cancer in mammals. Thus, these findings may help to develop new approaches for treating cancer in the future.

Advancing Aptamers as Molecular Probes for Cancer Theranostic Applications-The Role of Molecular Dynamics Simulation

Theranostics cover emerging technologies for cell biomarking for disease diagnosis and targeted introduction of drug ingredients to specific malignant sites. Theranostics development has become a significant biomedical research endeavor for effective diagnosis and treatment of diseases, especially cancer. An efficient biomarking and targeted delivery strategy for theranostic applications requires effective molecular coupling of binding ligands with high affinities to specific receptors on the cancer cell surface. Bioaffinity offers a unique mechanism to bind specific target and receptor molecules from a range of non-targets. The binding efficacy depends on the specificity of the affinity ligand toward the target molecule even at low concentrations. Aptamers are fragments of genetic materials, peptides, or oligonucleotides which possess enhanced specificity in targeting desired cell surface receptor molecules. Aptamer-target binding results from several inter-molecular interactions including hydrogen bond formation, aromatic stacking of flat moieties, hydrophobic interaction, electrostatic, and van der Waals interactions. Advancements in Systematic Evolution of Ligands by Exponential Enrichment (SELEX) assay has created the opportunity to artificially generate aptamers that specifically bind to desired cancer and tumor surface receptors with high affinities. This article discusses the potential application of molecular dynamics (MD) simulation to advance aptamer-mediated receptor targeting in targeted cancer therapy. MD simulation offers real-time analysis of the molecular drivers of the aptamer-receptor binding and generate optimal receptor binding conditions for theranostic applications. The article also provides an overview of different cancer types with focus on receptor biomarking and targeted treatment approaches, conventional molecular probes, and aptamers that have been explored for cancer cells targeting.

DDIAS promotes STAT3 activation by preventing STAT3 recruitment to PTPRM in lung cancer cells

DNA damage-induced apoptosis suppressor (DDIAS) regulates cancer cell survival. Here we investigated the involvement of DDIAS in IL-6-mediated signaling to understand the mechanism underlying the role of DDIAS in lung cancer malignancy. We showed that DDIAS promotes tyrosine phosphorylation of signal transducer and activator of transcription 3 (STAT3), which is constitutively activated in malignant cancers. Interestingly, siRNA protein tyrosine phosphatase (PTP) library screening revealed protein tyrosine phosphatase receptor mu (PTPRM) as a novel STAT3 PTP. PTPRM knockdown rescued the DDIAS-knockdown-mediated decrease in STAT3 Y705 phosphorylation in the presence of IL-6. However, PTPRM overexpression decreased STAT3 Y705 phosphorylation. Moreover, endogenous PTPRM interacted with endogenous STAT3 for dephosphorylation at Y705 following IL-6 treatment. As expected, PTPRM bound to wild-type STAT3 but not the STAT3 Y705F mutant. PTPRM dephosphorylated STAT3 in the absence of DDIAS, suggesting that DDIAS hampers PTPRM/STAT3 interaction. In fact, DDIAS bound to the STAT3 transactivation domain (TAD), which competes with PTPRM to recruit STAT3 for dephosphorylation. Thus we show that DDIAS prevents PTPRM/STAT3 binding and blocks STAT3 Y705 dephosphorylation, thereby sustaining STAT3 activation in lung cancer. DDIAS expression strongly correlates with STAT3 phosphorylation in human lung cancer cell lines and tissues. Thus DDIAS may be considered as a potential biomarker and therapeutic target in malignant lung cancer cells with aberrant STAT3 activation.

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.

BMP10 suppresses hepatocellular carcinoma progression via PTPRS-STAT3 axis

Bone morphogenetic protein 10 (BMP10), one member of the BMP family, is involved in various development events. Dysregulation of BMP10 has been observed in several diseases, including hypertensive cardiac hypertrophy, Hirschsprung disease and blood vessel formation. However, its role in liver cancer remains largely unknown. In this study, we reported that BMP10 was significantly downregulated in HCC at both mRNA and protein level. Decreased BMP10 was associated with bigger tumor size, worse TNM stage, earlier recurrence and poorer survival. BMP10 negatively regulated HCC cell proliferation in vitro and in vivo. Mechanism study revealed that BMP10 suppressed tumor cell growth by inhibiting STAT3 signaling. Interestingly, we found that cytoplasmic BMP10 interacted with both receptor protein tyrosine phosphatase sigma (PTPRS) and STAT3, which facilitated dephosphorylation of STAT3 by PTPRS. Altogether, our study has revealed the clinical significance of BMP10 in HCC, and suppression of HCC cell growth by BMP10 via PTPRS-STAT3 axis, providing a potential therapeutic strategy for targeting STAT3 signaling in HCC.

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.

Non-coding RNAs in Natural Killer/T-Cell Lymphoma

Natural killer/T-cell lymphoma (NKTCL) is a rare and aggressive subtype of non-Hodgkin's lymphoma that is associated with a poor outcome. Non-coding RNAs (ncRNAs), which account for 98% of human RNAs, lack the function of encoding proteins but instead have the important function of regulating gene expression, including transcription, translation, RNA splicing, editing, and turnover. However, the roles and mechanisms of aberrantly expressed ncRNAs in NKTCL are not fully clear. Aberrant expressions of microRNA (miRNAs) affect the PI3K/AKT signaling pathways (miRNA-21, miRNA-155, miRNA-150, miRNA-142, miRNA-494), NF-κB (miRNA-146a, miRNA-155) and cell cycle signaling pathways to regulate cell function. Moreover, Epstein-Barr virus (EBV) encoded miRNAs and EBV oncoprotein LMP-1 regulated the expression of cellular genes that induce invasion, metastasis, cell cycle progression and cellular transformation. In addition, NKTCL-associated Long non-coding RNA (lncRNA) ZFAS1 regulated certain pathways and lncRNA MALAT1 acted as a predictive marker. This review article provides an overview of ncRNAs associated with NKTCL, summarizes the function of significantly differentially expressed hotspot non-coding RNAs that contribute to the pathogenesis, diagnoses, treatment and prognosis of NKTCL and discusses the relevance of these ncRNAs to clinical practice.

NK/T-cell lymphomas

NK/T-cell lymphomas are extranodal EBV-related malignancies, mostly of NK-cell and occasionally of T-cell lineage. They are divided into nasal, non-nasal, and disseminated subtypes. Nasal NK/T-cell lymphomas involve the nose, nasopharynx and the upper aerodigestive tract. Non-nasal NK/T-cell lymphomas involve the skin, gastrointestinal tract, testis and other sites. Disseminated NK/T-cell lymphoma involves multiple organs, and may present with a leukemic phase. Initial evaluation requires positron emission tomography computed tomography (PET/CT) and quantification of circulating EBV DNA. Radiotherapy alone is inadequate with frequent relapses. Anthracycline-containing regimens are ineffective. Regimens incorporating asparaginase are currently the standard. For stage I/II disease, combined chemotherapy and radiotherapy is recommended. For stage III/IV disease, asparaginase-containing regimens are needed. Autologous hematopoietic stem cell transplantation (HSCT) is of limited efficacy, whereas allogeneic HSCT may be useful in patients with stage III/IV and relapsed diseases. Immunotherapy with antibodies against CD30, programmed cell death protein 1 and CD38 is promising.

Negative regulators of STAT3 signaling pathway in cancers

STAT3 is the most ubiquitous member of the STAT family and involved in many biological processes, such as cell proliferation, differentiation, and apoptosis. Mounting evidence has revealed that STAT3 is aberrantly activated in many malignant tumors and plays a critical role in cancer progression. STAT3 is usually regarded as an effective molecular target for cancer treatment, and abolishing the STAT3 activity may diminish tumor growth and metastasis. Recent studies have shown that negative regulators of STAT3 signaling such as PIAS, SOCS, and PTP, can effectively retard tumor progression. However, PIAS, SOCS, and PTP have also been reported to correlate with tumor malignancy, and their biological function in tumorigenesis and antitumor therapy are somewhat controversial. In this review, we summarize actual knowledge on the negative regulators of STAT3 in tumors, and focus on the potential role of PIAS, SOCS, and PTP in cancer treatment. Furthermore, we also outline the STAT3 inhibitors that have entered clinical trials. Targeting STAT3 seems to be a promising strategy in cancer therapy.

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.

PTPRK Expression Is Downregulated in Drug Resistant Ovarian Cancer Cell Lines, and Especially in ALDH1A1 Positive CSCs-Like Populations

Background: Ovarian cancer is the 7th most common cancer and 8th most mortal cancer among woman. The standard treatment includes cytoreduction surgery followed by chemotherapy. Unfortunately, in most cases, after treatment, cancer develops drug resistance. Decreased expression and/or activity of protein phosphatases leads to increased signal transduction and development of drug resistance in cancer cells. Methods: Using sensitive (W1, A2780) and resistant ovarian cancer cell lines, the expression of Protein Tyrosine Phosphatase Receptor Type K (PTPRK) was performed at the mRNA (real-time PCR analysis) and protein level (Western blot, immunofluorescence analysis). The protein expression in ovarian cancer tissues was determined by immunohistochemistry. Results: The results showed a decreased level of PTPRK expression in ovarian cancer cell lines resistant to cisplatin (CIS), paclitaxel (PAC), doxorubicin (DOX), topotecan (TOP), vincristine (VIN) and methotrexate (MTX). Additionally, the lower PTPRK expression was observed in Aldehyde Dehydrogenase 1 Family Member A1 (ALDH1A1) positive cancer stem cells (CSCs) population, suggesting the role of PTPRK downregulation in primary as well as acquired resistance to cytotoxic drugs. Conclusions: These results provide important insights into the role of PTPRK in mechanism leading to drug resistance in ovarian cancer and has raised important questions about the role of imbalance in processes of phosphorylation and dephosphorylation.

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.

PD-1 Tumor Suppressor Signaling in T Cell Lymphomas

The inhibitory receptor PD-1 is critical to balancing antigen-induced T cell activation; its inhibition is currently being explored to enhance antitumor T cell immunity with certain successful outcomes. However, PD-1 has also emerged as a central tumor suppressor in T cell lymphomas, where the tumor cell originates from a T cell itself. These aggressive cancers are frequently characterized by oncogenic mutations in T cell receptor (TCR) signaling pathways. PD-1 activity within malignant T cells can negatively regulate the PI3K/AKT and PKCθ/NF-κB tumor survival pathways and PD-1 is frequently inactivated in this human malignancy. This review summarizes current insights into oncogenic T cell signaling, discusses tumor-suppressive functions and mechanisms of PD-1 in T cell lymphomagenesis, and addresses potential unwanted effects caused by PD-1 checkpoint inhibition.

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.