Pitfalls in diagnosing a case of extranodal NK/T-cell lymphoma with CD20 aberrant expression and IGH gene rearrangement

Extranodal NK/T-cell lymphoma (ENKTL) is a subtype of non-Hodgkin lymphoma mainly derived from NK cells and, uncommonly, T-cells. A diagnostic challenge is presented when an atypical phenotype and gene rearrangement are encountered. Herein, we report a case of ENKTL with CD20 expression and IGH gene rearrangement, which is extremely rare. A 57-year-old female patient was seen in 2021 due to a nodule on her left leg and simultaneously impaired eyesight for 6 months. Skin biopsy and immunohistochemistry were performed. The lymphoid cells were positive for CD3, CD56, granzyme B, and TIA-1, partially positive for CD2, and mildly positive for CD20. In situ hybridization for Epstein-Barr virus was positive. Molecular studies revealed immunoglobulin heavy chain (IGH) gene rearrangement, while no T-cell receptor gene rearrangement was detected. The positron emission tomography scan showed that the lymphoma affected bilateral adrenal glands, pelvic cavity, peritoneal cavity, small intestine, skin, and subcutis of the bilateral lower extremities of the patient. Her disease progressed despite eight cycles of chemotherapy and radiation therapy. The importance of this case lies in the atypical phenotype and IGH gene rearrangements, necessitating comprehensive interpretation of clinicopathological data.

Prognostic value of prognostic nutritional index on extranodal natural killer/T-cell lymphoma patients: A multicenter propensity score matched analysis of 1022 cases in Huaihai Lymphoma Working Group

Prognostic nutritional index (PNI), comprised of serum albumin level and lymphocyte count, is associated with the prognosis of several malignant diseases, while the prognostic value of PNI in extranodal natural killer/T cell lymphoma, nasal type (ENKTL) remains unclear. This retrospective multicenter study aimed to investigate the value of PNI in predicting the prognosis of newly diagnosed ENKTL patients by using propensity score matched analysis (PSM). A total of 1022 newly diagnosed ENKTL patients were retrieved from Huaihai Lymphoma Working Group and clinicopathological variables were collected. MaxStat analysis was used to calculate the optimal cut-off points of PNI and other continuous variables. The median age at diagnosis was 47 years and 69.4% were males, with the 5-year OS of 71.7%. According to the MaxStat analysis, 41 was the optimal cut-off point for PNI. The Pseudo R2 before matching was 0.250, and it decreased to less than 0.019 after matching. Confounding factors of the two groups were well balanced after PSM. Multivariable analysis revealed that PNI, Korean Prognostic Index (KPI), eastern cooperative oncology group performance status (ECOG PS), the prognostic index of natural killer lymphoma (PINK) and hemoglobin were independent prognostic factors for ENKTL. The results of subgroup analysis demonstrated that patients with low PNI could predict worse prognosis and re-stratify patients in ECOG PS ≥ 2, EBER-positive, the International Prognostic Index (IPI) (HIR + HR), and PINK (HR) groups. PNI combined with IPI, PINK and KPI could improve the prediction efficiency. In conclusion, PNI could accurately stratify the prognosis of ENKTL by PSM analysis and patients with low PNI had poorer prognosis.

T-cell dysfunction in natural killer/T-cell lymphoma

Natural killer/T-cell lymphoma (NKTCL) is an incurable aggressive T-cell lymphoma closely correlated with Epstein‒Barr virus (EBV) infection. Chronic and consistent viral infection induces T-cell exhaustion. Herein, we describe T-cell dysfunction in NKTCL patients for the first time. Peripheral blood mononuclear cells (PBMCs) from age-matched healthy donors (HDs) and NKTCL patients were collected, and lymphocyte distributions, multiple surface inhibitory receptors (IRs), effector cytokine production and cell proliferation were determined by flow cytometry. PBMCs from HDs were cocultured with NKTCL cell lines to verify the clinical findings. IR expression was further assessed in NKTCL tumor biopsies using multiplex immunohistochemistry (mIHC). NKTCL patients have higher frequencies than HDs of inhibitory T regulatory cells (Tregs) and myeloid-derived suppressor cells (MDSCs). T-cell distribution also varies between NKTCL patients and HDs. T cells from NKTCL patients demonstrated higher expression levels of multiple IRs than HDs. Meanwhile, T-cell proliferation and interferon-γ production was significantly reduced in NKTCL patients. More importantly, the number of EBV-specific cytotoxic cells was lower in NTKCL patients, and these cells demonstrated upregulation of multiple IRs and secreted fewer effector cytokines. Interestingly, NKTCL cells caused normal PBMCs to acquire T-cell exhaustion phenotypes and induced generation of Tregs and MDSCs. In line with ex vivo finding, mIHC results showed that CD8+ T cells from NKTCL tumor biopsies expressed much higher level of IRs compared with reactive lymphoid hyperplasia individuals. The immune microenvironment of NKTCL patients exhibited T-cell dysfunction and accumulation of inhibitory cell components, which may contribute to impaired antitumor immunity.

Comprehensive Analysis and Summary of the Value of Immunophenotypes of Mature NK Cell Tumors for Differential Diagnosis, Treatment, and Prognosis

Background

Few studies have been performed to comprehensively analyze and summarize the immunophenotype and differential diagnosis of mature NK cell tumors, and there is often overlap between tumorigenic and reactive NK cell phenotypes. Furthermore, the impact of different phenotypes on patient prognosis has rarely been reported.

Methods

The degree of expression of extracellular and intracellular markers of NK cells in each group was compared by FCM, and the differences in expression of various markers among different disease groups and their impact on prognosis have been analyzed and summarized.

Results

Compared with normal NK cells, tumor cells of ANKL and ENKTL had characteristics of being more activated and progressive with larger FSC, in contrast to NK-CLPD and RNKL. Differential diagnoses with RNKL, ANKL, and ENKTL have broader FCM clues. In contrast, the phenotypes of NK-CLPD and RNKL are not significantly different, and consistent phenotypic abnormalities require ongoing monitoring to confirm malignant clones. The sensitivity of differentiating malignant NK cells from reactive NK cells by KIRs alone was poor. The clustering results showed that CD5, CD16, CD56, CD57, CD94, CD45RA, CD45RO, HLA-DR, KIRs, Granzyme B, Perforin and Ki-67 were differentially distributed in the expression of three NK cell tumors and reactive NK cell hyperplasia, so a comprehensive judgment using a wide range of antibody combinations is required in disease staging diagnosis. The tumor cell loads in BM and PB were also compared, and there was a clear correlation between the two. Moreover, the sensitivity of PB for monitoring tumor cells was up to 87.10%, suggesting that PB could be used as an alternative to BM for the diagnosis and screening of NK cell tumors. Analysis of the phenotypic impact of ENKTL patients on prognosis showed that those with CD7 and CD45RO expression had a poor prognosis, while those with positive KIRs had a better prognosis.

Conclusion

This study systematically characterized the FCM of mature NK cell tumors, emphasizing the importance and clinical value of accurate immunophenotyping in diagnosing, classifying, determining prognosis, and guiding treatment of the disease.

Clinicopathologic and Genetic Features of Primary T-cell Lymphomas of the Central Nervous System: An Analysis of 11 Cases Using Targeted Gene Sequencing

Primary central nervous system lymphoma (PCNSL) of peripheral T-cell lineage (T-PCNSL) is rare, and its genetic and clinicopathologic features remain unclear. Here, we present 11 cases of T-PCNSL in immunocompetent individuals from a single institute, focusing on their genetic alterations. Seven cases were subject to targeted panel sequencing covering 120 lymphoma-related genes. Nine of the eleven cases were classified as peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), of which one was of γδT-cell lineage. There was one case of anaplastic lymphoma kinase-positive anaplastic large cell lymphoma and another of extranodal natural killer (NK)/T-cell lymphoma (ENKTL) of αβT-cell lineage. The male to female ratio was 7 : 4 and the age ranged from 3 to 75 years (median, 61 y). Most patients presented with neurological deficits (n=10) and showed multifocal lesions (n=9) and deep brain structure involvement (n=9). Tumor cells were mostly small-to-medium, and T-cell monoclonality was detected in all nine evaluated cases. PTCL-NOS was CD4-positive (n=4), CD8-positive (n=3), mixed CD4-positive and CD8-positive (n=1), or CD4/CD8-double-negative (n=1, γδT-cell type). Cytotoxic molecule expression was observed in 4 (67%) of the 6 evaluated cases. Pathogenic alterations were found in 4 patients: one PTCL-NOS case had a frameshift mutation in KMT2C, another PTCL-NOS case harbored a truncating mutation in TET2, and another (γδT-cell-PTCL-NOS) harbored NRAS G12S and JAK3 M511I mutations, and homozygous deletions of CDKN2A and CDKN2B. The ENKTL (αβT-cell lineage) case harbored mutations in genes ARID1B, FAS, TP53, BCOR, KMT2C, POT1, and PRDM1. In conclusion, most of the T-PCNSL were PTCL-NOS, but sporadic cases of other subtypes including γδT-cell lymphoma, anaplastic lymphoma kinase-positive anaplastic large cell lymphoma, and ENKTL were also encountered. Immunophenotypic analysis, clonality test, and targeted gene sequencing along with clinicoradiologic evaluation, may be helpful for establishing the diagnosis of T-PCNSL. Moreover, this study demonstrates genetic alterations with potential diagnostic and therapeutic utility in T-PCNSL.

Interleukin-6 reverses Adriamycin resistance in nasal NK/T-cell lymphoma via downregulation of ABCC4 and inactivation of the JAK2/STAT3/NF-κB/P65 pathway

Chemotherapy is generally effective for extranodal natural killer (NK)/T-cell lymphoma (ENKTCL), nasal type. Nevertheless, multidrug resistance (MDR) remains a key challenge in treating nasal NK/T-cell lymphoma. Interleukin-6 (IL-6) is reportedly an important regulator of MDR in many cancers, implicating a role of IL-6 in the chemotherapy response. However, the effects and mechanism of IL-6 in nasal NK/T-cell lymphoma remain unclear. Herein, we demonstrated that the IL-6 serum level was decreased in nasal NK/T-cell lymphoma patients compared to chronic rhinitis patients. Lower serum levels of IL-6 were closely correlated with Ki67 expression and patient survival. ATP-binding cassette (ABC) drug transporter ABCC4 in patients was abnormally upregulated. IL-6 significantly inhibited resistance to Adriamycin (ADM) in ADM-resistant SNK-6 cells (SNK-6/ADM). Moreover, IL-6 resulted in cell cycle arrest and led to apoptosis in SNK-6/ADM cells. Furthermore, IL-6 decreased ABCC4, p-JAK2, p-STAT3, and phospho-NF-κB p65 expression in SNK-6/ADM cells. IL-6 in combination with ADM inhibited tumor growth and increased the survival of SNK-6/ADM xenograft mice. In conclusion, our findings suggest that IL-6 can inhibit the upregulation of ABCC4 and inactivate the JAK2/STAT3/NF-κB/P65 pathway to sensitize NK/T-cell lymphoma to ADM, indicating that combination therapy with IL-6 and other chemotherapeutic drugs may be effective in reversing acquired resistance in nasal NK/T-cell lymphoma.

TP73-AS1 promotes malignant progression of NK/T cell lymphoma by regulating DKK1 methylation

PURPOSE

Long non-coding RNA (lncRNA) TP73-AS1 is abnormally expressed in multiple types of tumors, which is able to mediate tumor cell signals. This study aims to explore the role of TP73-AS1 in affecting biological functions of NK/T-cell lymphoma (NKTCL) and DKK1 methylation.

METHODS

TP73-AS1 levels in peripheral blood of NKTCL patients and healthy volunteers was detected by quantitative real-time polymerase chain reaction (qRT-PCR). After knockdown of TP73-AS1, proliferative and migratory abilities in SNK-6 and HANK-1 cells were assessed by cell counting kit-8 (CCK-8) and Transwell assay, respectively. Regulatory effect of TP73-AS1 on DKK1 methylation in NKTCL cells was evaluated through methylation-specific PCR (MSP), dual-luciferase reporter assay and RNA Binding Protein Immunoprecipitation (RIP). Rescue experiments were conducted to further validate the interaction between TP73-AS1 and DKK1.

RESULTS

TP73-AS1 level was higher in peripheral blood of NKTCL patients than that of healthy volunteers. Knockdown of TP73-AS1 in vitro weakened proliferative and migratory functions of NKTCL cells. TP73-AS1 induced methylation of DKK1 promoter through DNMT1/DNMT3, thus regulating NKTCL cell functions.

CONCLUSIONS

TP73-AS1 level was higher in peripheral blood of NKTCL patients. Through inducing methylation of DKK1 promoter, TP73-AS1 aggravates the malignant progression of NKTCL.

Primary Adrenal Lymphoma: Two Case Series From China

OBJECTIVE

Primary adrenal lymphoma (PAL) is a rare form of adrenal mass. We summarize our experience in its clinical presentation, biochemical indexes, radiological features, pathological information, therapy regimens, and outcomes.

METHODS

This was an institutional review board-approved retrospective review of medical records and surgical pathology specimens of patients with a diagnosis of PAL at the Chinese People's Liberation Army General Hospital and the First Affiliate Hospital of Xiamen University between July 2007 and July 2017.

RESULTS

Twenty-six patients were identified. The mean age at presentation was 60.84 ± 13.14 years with a male-to-female ratio of 2.25:1 (18:8). The most common presenting symptoms were loss of appetite (65%, 17/26), weight loss (62%, 16/26), abdominal pain (58%, 15/26), and fatigue (58%, 15/26). The levels of lactate dehydrogenase (75%, 15/20), β₂-microglobulin (100%, 10/10), C-reactive protein (82%, 14/17), and ferritin (88%, 7/8) and the erythrocyte sedimentation rate (83%, 10/12) were elevated. Bilateral involvement was seen in 21 of 26 patients (81%); 12 of 19 evaluated patients with bilateral lesions (63%) were confirmed to have adrenal insufficiency. On computed tomography (CT), the mean tumor diameter was 7.31 ± 3.35 cm and the median Hounsfield density was 37.0 HU (range: 31.0-45.0 HU); 67% (10/15) and 27% (4/15) of lesions presented with mild and moderate enhancement after injection of contrast medium. ¹⁸F-fluorodeoxyglucose positron emission tomography (FDG PET)-CT revealed not only an adrenal tumor but also extra-adrenal lesions. Diffuse large B-cell lymphoma (DLBCL) was the most common phenotype (92%, 24/26). Ninety-two percent (24/26) of patients received chemotherapy while 8% (2/26) received unilateral adrenalectomy plus chemotherapy. The prognosis of PAL was poor, with a general survival time of 7.20 ± 5.18 months.

CONCLUSION

PAL is a rare disease. The clinical characteristics of PAL include loss of appetite and weight loss. Endocrine evaluation should be performed to determine whether patients have adrenal insufficiency, especially patients with bilateral lesions. FDG-PET appears to be more accurate than other imaging modalities in revealing extra-adrenal sites. Better therapy is required to improve the poor prognosis of PAL.

Calreticulin increases growth and progression of natural killer/T-cell lymphoma

In this study, we investigated the role of calreticulin (CALR) in the pathogenesis of natural killer/T-cell lymphoma (NKTCL). CALR expression was significantly higher in the NKTCL tissues than normal control tissues in the GSE80632 dataset. High CALR expression correlated with poorer overall survival of NKTCL patients (P = 0.0248). CALR mRNA and protein levels were significantly higher in NKTCL cell lines (NK92, SNK6, and SNT8) than normal NK cells. CALR-silenced SNK6 cells generated significantly smaller xenograft tumors in immunodeficient NCG mice than control SNK6 cells. CALR-knockdown NKTCL cells showed significantly less in vitro proliferation and Transwell migration than the controls. CALR knockdown inhibited G1-to-S phase cell cycle progression by increasing the levels of p27 cell cycle inhibitor and reducing the levels of cyclin E2 and cyclin-dependent kinase 2 (CDK2). CALR knockdown inhibited epithelial-to-mesenchymal transition (EMT) by decreasing the levels of β-catenin and TCF/ZEB1 and upregulating E-cadherin. These data demonstrate that CALR regulates the growth and progression of NKTCL cells by modulating G1-to-S cell cycle progression and EMT.

Genetic risk of extranodal natural killer T-cell lymphoma: a genome-wide association study in multiple populations

BACKGROUND

Extranodal natural killer T-cell lymphoma (NKTCL; nasal type) is an aggressive malignancy with a particularly high prevalence in Asian and Latin American populations. Epstein-Barr virus infection has a role in the pathogenesis of NKTCL, and HLA-DPB1 variants are risk factors for the disease. We aimed to identify additional novel genetic variants affecting risk of NKTCL.

METHODS

We did a genome-wide association study of NKTCL in multiple populations from east Asia. We recruited a discovery cohort of 700 cases with NKTCL and 7752 controls without NKTCL of Han Chinese ancestry from 19 centres in southern, central, and northern regions of China, and four independent replication samples including 717 cases and 12 650 controls. Three of these independent samples (451 cases and 5301 controls) were from eight centres in the same regions of southern, central, and northern China, and the fourth (266 cases and 7349 controls) was from 11 centres in Hong Kong, Taiwan, Singapore, and South Korea. All cases had primary NKTCL that was confirmed histopathologically, and matching with controls was based on geographical region and self-reported ancestry. Logistic regression analysis was done independently by geographical regions, followed by fixed-effect meta-analyses, to identify susceptibility loci. Bioinformatic approaches, including expression quantitative trait loci, binding motif and transcriptome analyses, and biological experiments were done to fine-map and explore the functional relevance of genome-wide association loci to the development of NKTCL.

FINDINGS

Genetic data were gathered between Jan 1, 2008, and Jan 23, 2019. Meta-analysis of all samples (a total of 1417 cases and 20 402 controls) identified two novel loci significantly associated with NKTCL: IL18RAP on 2q12.1 (rs13015714; p=2·83 × 10-16; odds ratio 1·39 [95% CI 1·28-1·50]) and HLA-DRB1 on 6p21.3 (rs9271588; 9·35 × 10-26 1·53 [1·41-1·65]). Fine-mapping and experimental analyses showed that rs1420106 at the promoter of IL18RAP was highly correlated with rs13015714, and the rs1420106-A risk variant had an upregulatory effect on IL18RAP expression. Cell growth assays in two NKTCL cell lines (YT and SNK-6 cells) showed that knockdown of IL18RAP inhibited cell proliferation by cell cycle arrest in NKTCL cells. Haplotype association analysis showed that haplotype 47F-67I was associated with reduced risk of NKTCL, whereas 47Y-67L was associated with increased risk of NKTCL. These two positions are component parts of the peptide-binding pocket 7 (P7) of the HLA-DR heterodimer, suggesting that these alterations might account for the association at HLA-DRB1, independent of the previously reported HLA-DPB1 variants.

INTERPRETATION

Our findings provide new insights into the development of NKTCL by showing the importance of inflammation and immune regulation through the IL18-IL18RAP axis and antigen presentation involving HLA-DRB1, which might help to identify potential therapeutic targets. Taken in combination with additional genetic and other risk factors, our results could potentially be used to stratify people at high risk of NKTCL for targeted prevention.

FUNDING

Guangdong Innovative and Entrepreneurial Research Team Program, National Natural Science Foundation of China, National Program for Support of Top-Notch Young Professionals, Chang Jiang Scholars Program, Singapore Ministry of Health's National Medical Research Council, Tanoto Foundation, National Research Foundation Singapore, Chang Gung Memorial Hospital, Recruitment Program for Young Professionals of China, First Affiliated Hospital and Army Medical University, US National Institutes of Health, and US National Cancer Institute.

Specific Soft-Tissue Invasion and LMP1 Expression Are Potential Indicators of Extranodal NK/T Cell Lymphoma, Nasal Type

BACKGROUND Extranodal NK/T cell lymphoma, nasal type (ENKTL-NT) is difficult to distinguish from nasal polyps and inverted papilloma, leading to its high misdiagnosis ratio. The aim of this study was to investigate its potential prognostic indicators. MATERIAL AND METHODS Kaplan-Meier method was used to calculate overall survival (OS) rate. Cox proportional hazards regression was used to analyze risk ratios (ORs) with 95% confidence intervals (CIs). RESULTS Nasal ala infiltration and nasal floor thickness >2.0 mm or nasal septum thickness >2.5 mm were potential prognostic factors for OS (p=0.0323 and 0.0072, respectively). Cox proportional-hazards regression indicated that high LMP1 expression and the nasal floor thickness >2.0 mm or nasal septum thickness >2.5 mm were the independent risk factors for poor OS of ENKTL-NT (HR=3.0655, p=0.028; HR=2.3650, p=0.0452, respectively). In the subgroup analysis, the OS rate was lower when the nasal floor thickness >2.0 mm or nasal septum thickness >2.5 mm in the patients who had high expression of LMP1 (p=0.0651), whereas high LMP1 expression increased the risk of worse prognostic outcome in patients with deep infiltration thickness. Thus, high LMP1 expression may contribute to the tissue invasion of ENKTL-NT. CONCLUSIONS Any patient with nasal ala soft-tissue invasion, nasal floor thickness >2.0 mm/nasal septum thickness >2.5 mm on CT imaging or high LMP1 expression should prompt immediate histopathologic diagnosis to rule out ENKTL-NT in clinical practice.

Platelet-derived growth factor receptor alpha (PDGFRα) is overexpressed in NK/T-cell lymphoma and mediates cell survival

Nasal-type natural killer/T-cell lymphoma (NKTCL) is a subtype of non-Hodgkin lymphoma (NHL) that is clinically aggressive and has a poor prognosis. Platelet-derived growth factor receptors (PDGFRs) and their ligands (PDGFs) play important roles in angiogenesis, cancer cell proliferation, survival, migration and poor prognosis in various tumours. However, the significance of PDGFRs in NKTCL remains unknown. Herein, the present study aimed to investigate the important role of PDGFRα in pathogenesis, progression and prognisis of NKTCL. Firstly, we performed immunohistochemical staining, qRT-PCR and western blotting to determine PDGFRα expression in formalin-fixed, paraffin-embedded tissue sections from 78 NKTCL cases and in cell lines. Secondly, correlations between PDGFRα expression and NKTCL clinical parameters and prognosis were analysed. Moreover, a biological assessment of PDGFRα blockade in two NKTCL cell lines was conducted through proliferation assay, cell-cycle evaluation and apoptosis detection by flow cytometry analyses. Furthermore, we detected in vivo activity of imatinib in mouse model of NKTCL. We found that the expression of PDGFRα was significantly higher in NKTCL tissues compared to the reactive lymphoid hyperplasia of the nasopharynx (P = 0.028). High PDGFRα expression was strongly associated with a high LDH level (P = 0.028) and III-IV stage (P = 0.013). NKTCL patients with high PDGFRα expression displayed a reduced median overall survival time and progression-free survival time when compared with those with low PDGFRα expression (P = 0.011, P = 0.005, respectively). Cox multivariate analysis showed that III-IV stage (P = 0.024) and high PDGFRα expression (P = 0.003) were independent prognostic factors in NKTCL patients. Biological assessment assays in two NKTCL cell lines revealed that a specific PDGFR antagonist, imatinib, inhibited cell viability, blocked cell cycle progression at G0/G1 stage and induced apoptosis. Similarly, the in vivo assay showed that imatinib delayed mouse model tumour growth. In conclusion, NKTCL tumour cells have prominent PDGFRα expression, which can serve as a candidate prognostic marker. PDGFR antagonists have significant biological effect on NKTCL and may be useful therapeutic agents for treatment of NKTCL.

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

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

Programmed death-ligand 1 and its soluble form are highly expressed in nasal natural killer/T-cell lymphoma: a potential rationale for immunotherapy

Nasal natural killer/T-cell lymphoma (NNKTL) is an aggressive neoplasm with poor therapeutic responses and prognosis. The programmed death-1/programmed death-ligand 1 (PD-1/PD-L1) pathway plays an important role in immune evasion of tumor cells through T-cell exhaustion. The aim of the present study was to examine the expression of PD-L1 and PD-1 molecules in NNKTL. We detected the expression of PD-L1 in biopsy samples from all of the NNKTL patients studied. PD-L1 was found on both malignant cells and tumor-infiltrating macrophages, while PD-1-positive mononuclear cells infiltrated the tumor tissues in 36% of patients. Most significantly, soluble PD-L1 (sPD-L1) was present in sera of NNKTL patients at higher levels as compared to healthy individuals and the levels of serum sPD-L1 in patients positively correlated with the expression of PD-L1 in lymphoma cells of tumor tissues. In addition, the high-sPD-L1 group of patients showed significantly worse prognosis than the low-sPD-L1 group. Furthermore, we confirmed that membrane and soluble PD-L1 was expressed on the surface and in the culture supernatant, respectively, of NNKTL cell lines. The expression of PD-L1 was observed in tumor tissues and sera from a murine xenograft model inoculated with an NNKTL cell line. Our results suggest that sPD-L1 could be a prognostic predictor for NNKTL and open up the possibility of immunotherapy of this lymphoma using PD-1/PD-L1 axis inhibitors.

Phosphatase and tensin homolog (PTEN) is down-regulated in human NK/T-cell lymphoma and corrects with clinical outcomes

Nasal-type natural killer/T-cell (NK/T-cell) lymphoma is a more aggressive sub-group of non-Hodgkin lymphoma, which is more common in Asia. The phosphatase and tensin homolog (PTEN) was originally discovered as a candidate tumor suppressor mutated and lost in various cancers. However, its clinical value and role in NK/T-cell lymphoma remain to be further explored. In the present study, we analyzed PTEN protein expression in 60 cases of human NK/T-cell lymphoma tissues and 40 cases of control nasal mucosa tissues specimens by immunohistochemical analysis. As a result, positive rate of PTEN protein expression in NK/T-cell lymphoma tissues (33.3%) is significantly lower than that of control nasal mucosa tissues (85.0%) (P < .01). However, no significant association was found between PTEN protein expression and sex, age, tumor location, clinical staging (Ann Arbor staging), or serum lactate dehydrogenase level (P > .05). Instead, PTEN protein was inversely corrected with Ki-67 expression, indicating a functional role in PTEN in human NK/T-cell lymphoma (P < .05). For clinical outcomes, PTEN positive rate significantly increased in objective response group (CR+PR) (43.5%) compared with SD+PD group (18.9%). Furthermore, overexpression of PTEN contributed to chemotherapy sensitivity to different doses of cisplatin (DDP) in human NK/T-cell lymphoma SNK-6 cells. These results suggest that PTEN may regulate chemotherapy sensitivity of NK/T-cell lymphoma and contribute to clinical outcomes. These findings indicate PTEN to be a potential target anti-tumor therapeutics for NK/T-cell lymphoma.

Molecular basis of targeted therapy in T/NK-cell lymphoma/leukemia: A comprehensive genomic and immunohistochemical analysis of a panel of 33 cell lines

T and NK-cell lymphoma is a collection of aggressive disorders with unfavorable outcome, in which targeted treatments are still at a preliminary phase. To gain deeper insights into the deregulated mechanisms promoting this disease, we searched a panel of 31 representative T-cell and 2 NK-cell lymphoma/leukemia cell lines for predictive markers of response to targeted therapy. To this end, targeted sequencing was performed alongside the expression of specific biomarkers corresponding to potentially activated survival pathways. The study identified TP53, NOTCH1 and DNMT3A as the most frequently mutated genes. We also found common alterations in JAK/STAT and epigenetic pathways. Immunohistochemical analysis showed nuclear accumulation of MYC (in 85% of the cases), NFKB (62%), p-STAT (44%) and p-MAPK (30%). This panel of cell lines captures the complexity of T/NK-cell lymphoproliferative processes samples, with the partial exception of AITL cases. Integrated mutational and immunohistochemical analysis shows that mutational changes cannot fully explain the activation of key survival pathways and the resulting phenotypes. The combined integration of mutational/expression changes forms a useful tool with which new compounds may be assayed.

Establishment and Characterization of a CD20-Positive NK/T-Cell Lymphoma Cell Line

BACKGROUND

CD20 positive NK/T-cell lymphoma is extremely rare and difficult for clinical treatment. Due to the lack of an established cell model for this disease, less is known about its biological characterization and potential therapeutic options.

METHODS

A cell line of NK/T-cell lymphoma, which was enriched by magnetic sorting with proper cell surface markers (CD56) from peripheral blood mononuclear cells (PBMCs) drawn from a 21-year-old male patient with nasal angiocentric NK/T-cell lymphoma, was designated as ZQNK-29. Immunophenotypic analysis of ZQNK-29 was performed by flow cytometric and immunohistochemical analysis. Comparative genomic hybridization (CGH) analysis was used for cytogenetic analysis of ZQNK-29. Potential rearrangements of the immunoglobulin gene and Epstein-Barr virus (EBV) infection were examined by PCR and RT-PCR, respectively.

RESULTS

ZQNK-29 cells express the phenotypic T-cell marker (CD3), T cell activation markers (HLA-DR), markers for both NK and cytotoxic T lymphocytes (TIA-1), and B-lineage marker CD20; however, expression of CD56 was not detected in expanded ZQNK-29 cells although this NK cell surface marker was used as one of selective cell surface markers for the initial isolation of NK/T cells. RT-PCR analysis showed that the pattern of gene expressions for infected EBV was latency type III, with the expressions of LMP1, EBNA-1, and EBNA-2; no rearrangements were found in the heavy-chain of the immunoglobulin gene or in the y chain of the T cell receptors (TCRs) gene. CGH analysis demonstrated that ZQNK-29 possessed an abnormal karyotype, 46XY, 1p (dist)+, 4p (dist)+, 4q (mid)-, 5q (mid)-, 9q (dist)+, 16p (dist)+, 16q (dist)+, 17p+, 17q (dist)+, 19q (dist)+, 20p+, 20q+, 21q+, and 22q+. Of these, 1p (dist)+, which has been confirmed to be mitochondrial DNA amplification, is believed to be mainly caused by EBV infection.

CONCLUSIONS

ZQNK-29 is a well characterized premature human NK/T-cell lymphoma cell line with expression of the B-cell marker CD20 and will provide a useful pre-clinic model for characterization and potential therapeutic studies of the aggressive NK/T-cell lymphoma.

[Expressions of Maspin and Ki67 in extranodal nasal type NK/T-cell lymphoma and the significance]

OBJECTIVE

To analyze the expression of Maspin and Ki67 in EN-NK/TCL and the significance.

METHOD

The expressions of Maspin and Ki67 were detected by immunohistochemistry in 34 cases of EN-NK/TCL and 11 cases of chronic sinusitis.

RESULT

Maspin was low expressed in EN-NK/TCL, Ki67 was highly expressed in EN-NK/TCL. Negative correlation was found between the expression of Maspin and Ki67 in EN-NK/TCL.

CONCLUSION

The combined examination of Maspin and Ki67 has important significance in the diagnosis in EN-NK/ TCL.

[Effect of doxorubicin on TRAIL resistance and TRAIL receptor expression in lymphoma cell line SNK-6 cells]

OBJECTIVE

To investigate the effect of doxorubicin on TRAIL resistance and TRAIL receptor expression in lymphoma cell line SNK-6 cells.

METHODS

SNK-6 cells treated with doxorubicin at different concentrations alone or in combination with tumor necrosis factor related apoptosis inducing ligand (TRAIL). Cell proliferation was evaluated by MTT assay. Apoptosis and the expression of TRAIL receptors were determined by flow cytometry.

RESULTS

MTT assay showed that treatment with 100 and 1000 ng/ml doxorubicin for 24 h, the survival rates of SNK-6 cells were (80.9 ± 7.2)% and (53.7 ± 2.8)%, significantly higher than that by treatment combined with 500 ng/ml TRAIL (64.9 ± 1.1)% and (34.0 ± 3.9)%, respectively (P < 0.05). Flow cytometry showed that after treatment with 100 and 1000 ng/ml doxorubicin for 48 h, the survival rates of SNK-6 cells were (69.9 ± 6.1)% and (31.1 ± 1.9)%, while treated in combination with 500 ng/ml TRAIL, the cell survival rates were (37.5 ± 6.4)% and (15.0 ± 1.8)%, respectively. The early apoptosis rate was (14.8 ± 0.6)% and (30.8 ± 1.5)%, significantly lower than that [(28.7 ± 0.6)% and (46.6 ± 2.8)%] after treatment in combination with TRAIL (P < 0.05). The expressions of TRAIL receptors and decoy receptors were increased when SNK-6 cells were treated with 100 ng/ml doxorubicin for 24 hours.

CONCLUSIONS

Doxorubicin can overcome to a certain extent the TRAIL resistance of SNK-6 cells and induce upregulation of TRAIL death receptors and decoy receptors on the surface of SNK-6 cells. However, a higher dose is needed.

[Expression of microRNA in extranodal NK/T cell lymphoma, nasal type]

OBJECTIVE

To study the expression of microRNAs (miRNAs) in extranodal NK/T cell lymphoma, nasal type (EN-NK/T-NT).

METHODS

TaqMan low density arrays were used to assess the expression level of 665 miRNAs in one case of EN-NK/T-NT and one normal nasopharyngeal tissue. Ninety-five miRNAs were found to be aberrantly expressed (86 being up-regulated and 9 being down-regulated) in EN-NK/T-NT, compared with normal nasopharyngeal tissue. The aberrant expression was found to be most significant in 8 miRNAs. According to the literature and miRNA database, the expression patterns of these 8 miRNAs were further analyzed in 15 cases of EN-NK/T-NT and 3 normal nasopharyngeal specimens, using the single tube TaqMan microRNA assays.

RESULTS

Three of the 8 miRNAs showed statistically significant difference in the expression in EN-NK/T-NT and normal nasopharyngeal specimens. These 3 miRNAs (miR-223, 886-3p and 34c-5p) were considered to play crucial roles in hemopoiesis, cellular proliferation and apoptosis. MiR-223 and miR-886-3p were significantly over-expressed in EN-NK/T-NT (P = 0.002, P = 0.010) while miR-34c-5p was significantly under-expressed (P = 0.017).

CONCLUSIONS

Certain types of miRNAs, especially those related to hemopoiesis, cellular proliferation and apoptosis, are aberrantly expressed in EN-NK/T-NT. The potential role of miRNAs in the molecular genetics of EN-NK/T-NT requires further investigation.

[Clinicopathologic study of 963 cases of mature T-cell and natural killer/T-cell lymphoma with respect to 2008 WHO classification of lymphoid neoplasms]

OBJECTIVE

To study the clinicopathologic features of various types of mature T-cell and natural killer (NK)/T-cell lymphoma in Guangdong, China, with respect to the 2008 WHO classification of lymphoid neoplasms.

METHODS

Eleven hundred and thirty-seven (1137) cases of mature T-cell or NK/T-cell lymphoma diagnosed during the period from 2002 to 2006 in Guangzhou area were retrieved. The clinical data, histologic features and immunohistochemical findings were reviewed by a panel of experienced hematopathologists. Additional immunostaining was performed if indicated. The cases were re-classified according to the 2008 WHO classification of lymphoid neoplasms.

RESULTS

Nine hundred and sixty-three (963) cases fulfilled the diagnostic criteria of mature T-cell or NK/T-cell lymphoma and accounted for 20.1% of all cases of lymphoma encountered during the same period (963/4801). A predominance of extranodal involvement was noted in 644 cases (66.9%), while 319 cases (33.1%) showed mainly nodal disease. The prevalence of various lymphoma subtypes was as follows: peripheral T-cell lymphoma, unspecified (PTCL, NOS) 293 cases (30.4%), extranodal NK/T-cell lymphoma, nasal type 281 cases (29.2%), anaplastic large cell lymphoma (ALCL) 198 cases (20.6%), and angioimmunoblastic T-cell lymphoma (AILT) 46 cases (4.8%). The male-to-female ratio was 1.99. The median age of the patients was 44 years, with the peak age of PTCL, NOS, extranodal NK/T-cell lymphoma, nasal type and AILT being 55 to 64 years, 25 to 54 years and 65 to 74 years, respectively. ALK-positive ALCL occurred more frequently in young age, while the ALK-negative ALCL cases occurred mainly in the elderly.

CONCLUSIONS

Extranodal lesions predominate in mature T-cell and NK/T-cell lymphomas occurring in Guangzhou area. There is a male predominance and the overall incidence shows no increasing trend with age of the patient. The peak age of various subtypes however varies. The most common subtype was PTCL, NOS, followed by extranodal NK/T-cell lymphoma, nasal type, ALCL and AILT. The relatively frequent occurrence of extranodal NK/T-cell lymphoma, nasal type in Guangdong area is likely associated with the high incidence of Epstein-Barr virus infection there.

[Study on expression of natural killer (NK) cell C-type lectin-like receptors in nasal NK/T-cell lymphomas]

OBJECTIVE

To investigate the expression and possible role of C-type lectin-like natural killer cell receptors, including CD94 and NKG2s, in extranodal NK/T-cell lymphoma, nasal type (EN-NK/T-NT).

METHODS

Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the expression of CD94 and NKG2s in tissue sections of 21 cases of EN-NK/T-NT(confirmed by histology, immunohistochemistry, in-situ hybridization for Epstein-Barr virus(EBV) and PCR for T-cell receptor genes), eight midline B cell lymphomas (BCL), 10 peripheral T cell lymphoma of lymph nodes (PTCL), five spleens, five thymuses and five chronic nasopharyngitis.

RESULTS

All 21 cases of EN-NK/T-NT showed typical histological features, with expression of CD3epsilon, CD56, cytotoxic granules and positivity of EBV in 20 cases. The RT-PCR results showed a high level expression of CD94 (85.7%) and NKG2 members (95.2% totally, with NKG2A/2B in 85.7%, NKG2D in 61.9%, NKG2F in 14.3%, NKG2C/2E in 4.8%, respectively and sequentially) in EN-NK/T-NT. But in the controls, none of the receptors were detected in TCL (0%) and BCL (0%), while only a few cases of lymphoid tissues expressed one or two of these receptors (two spleens and two chronic nasopharyngitis mucosa for CD94, one spleen for NKG2A/2B and one thymus for NKG2D). The differences of CD94 and NKG2 expression between EN-NK/T-NT and BCL or TCL were statistically significant (P<0.01). Co-expression of CD94 and NKG2 was found in 17 out of 21 EN-NK/T-NT cases (81.0%).

CONCLUSIONS

The specific and sequential expression nature of CD94 and NKG2 in EN-NK/T-NT, mimics the developmental expression model in their normal counterparts, and suggests that the tumor cells of most cases are being activated and keeping in a stage as the functional NK cells. Detection of these molecules may provide a useful tool to confirm the diagnosis of NK cell lymphoma.

Extranodal natural killer/T-cell lymphoma, nasal-type

A 51-year-old previously healthy man, an ex-smoker, was admitted to the authors' medical department with a 3-month history of dry cough; intermittent fever; painless, ulcerated cutaneous lesions over the trunk and limbs (Figure 1); and progressive weight loss. He was of Greek descent. His medical history was remarkable for nasal polyps, which were surgically removed 15 years earlier. Initially, he had been treated with antibiotics, without improvement. Several days before admission, chest radiography revealed pulmonary infiltrates in the left lower lobe. On admission, physical examination revealed a well-orientated man in mild distress, with inspiratory rhonchi at the lower part of the left lung and scattered erythematous nodules of variable size, some of which were ulcerated. Laboratory values were notable for leukopenia, 3.3 x 10(9)/L; total protein, 5.9 g/dL; globulin, 2.2 g/dL; serum glutamic oxaloacetic transaminase, 86 IU/L; serum glutamic pyruvic transaminase, 71 IU/L; and lactate dehydrogenase, 519 U/L. Computed tomograph (CT) of the chest showed multiple alveolar opacities bilaterally (Figure 2). Fiberoptic bronchoscopy did not reveal any important pathologic findings. Results of bronchial biopsy, cytology of bronchoalveolar lavage, washing, brushing, and sputum following bronchoscopy were negative. CT of the brai and sinonasal area revealed an abnormal low-density mass in the left nasal area. CT findings of the abdomen were negative, as were results of a bone marrow biopsy. There was no evidence of immunosuppression. The differential diagnosis, considering the evidence described, included granulomatous or infectious diseases, angiocentric lymphoproliferative lesions, and lymphomas. Biopsy of a skin lesion showed lymphoproliferative infiltration of the dermis with a follicular and angiocentric growth pattern and regional epidermal necrosis. Immunohistochemical stains showed that the tumor cell were positive for CD56 and CD3 (cytoplasmic positivity) and expressed the cytotoxic proteins T-cell intracellular antigen and granzyme B (Figure 3) They lacked TdT, CD34, CD7, CD8, TCL-1, and CD123. Findings from an in situ hybridization study for Epstein-Barr virus were negative. Give this result, molecular analysis ofT-cell receptor (TCR) gene rearrangements was performed using polymerase chain reaction-based TCR-gamma gene, wit negative results. The morphology and the immunophenotype were consistent with natural killer/T-cell lymphoma, nasal-type. Nasal involvement must be first excluded to proceed to the diagnosis of nasal-type natural killer-cell lymphoma. Indeed, histologic examination of the nasal mass revealed its polypoid nature. Thus, the authors were led to the diagnosis of extranodal extranasal natural killer/T-cell lymphoma, nasal-type, CD56-positive, Ep stein-Barr virus-negative, TCR-negative. The patient received combination chemotherapy and completed 4 cycles of cyclophosphamide, doxorubicin vincristine, and prednisone every 14 days for 2 months. Skin lesions improved, and there was no fever soon after the initiation of therapy. Reevaluatio after the fourth cycle, however, disclosed pulmonary infiltrations as well as leukemic infiltration of the central nervous system. The patient had receive systemic salvage chemotherapy and intrathecal infusions of methotrexate. Although the lung lesions had diminished at that time, the patient develope paraplegia, his clinical course rapidly deteriorated, and he eventually died.

[Diagnosis of hematolymphoid malignancy by using effusion fluid cytology specimens: a study of 33 cases]

OBJECTIVE

To study the diagnostic accuracy of hematolymphoid malignancy by using effusion fluid cytology specimens and to evaluate the values of immunocytochemistry for this assay.

METHODS

The cytospin preparations/smears and cell block sections of effusion cytology specimens from 33 cases of hematolymphoid malignancy were retrospectively reviewed. Immunocytochemical study was performed. In selected cases, in-situ hybridization for Epstein-Barr virus-encoded RNA and immunoglobulin and T-cell receptor gene rearrangement study were carried out as indicated.

RESULTS

There were 33 cases of hematolymphoid malignancy, including 12 cases of T-lymphoblastic leukemia/lymphoma, 16 cases of mature B cell neoplasm (including 9 cases of diffuse large B-cell lymphoma, 2 cases of Burkitt lymphoma, 2 cases of plasmacytoma/multiple myeloma, 2 cases of B-small lymphocytic leukemia/lymphoma and 1 case of mantle cell lymphoma), 3 cases of mature T or NK-cell neoplasm (including 1 case of extranodal nasal NK/T-cell lymphoma, 1 case of angioimmunoblastic T-cell lymphoma and 1 case of T-cell prolymphocytic leukemia), 1 case of myeloid sarcoma and 1 case of mast cell sarcoma. Amongst the 33 cases studied, 16 represented disease relapses, including 8 cases of diffuse large B-cell lymphoma, 2 cases of plasmacytoma/multiple myeloma, 2 cases of B-small lymphocytic leukemia/lymphoma, 1 case of T-lymphoblastic leukemia/lymphoma, 1 case of angioimmunoblastic T-cell lymphoma, 1 case of mantle cell lymphoma and 1 case of mast cell sarcoma. The remaining 17 cases showed serous effusion as the primary manifestation, with the diagnosis primarily made upon cytologic examination. The cytologic findings seen in all the 33 cases studied were in agreement with the corresponding histologic diagnosis.

CONCLUSIONS

Diagnosis of hematolymphoid malignancy by effusion fluid cytology specimens is possible, especially when coupled with the clinical history, immunophenotype, in-situ hybridization and gene rearrangement study findings. This is especially so for cases with disease relapses.

Nasal-type NK/T-cell lymphoma with palatal ulcer as the earliest clinical manifestation: a case report with literature review

Extranodal nasal natural killer (NK)/T-cell lymphoma is a very rare kind of lymphoma, Oral cavity involvement of extranodal natural killer/T-cell lymphoma, nasal type is extremely rare, and its clinicopathologic features are also poorly understood. Recently, we experienced an unusual case of Epstein-Barr virus-associated, extranodal NK/T-cell type with a unhealed palatal ulcer as the earliest clinical feature. It is a challenge for oral medicine specialists to make the early diagnosis for this special type of tumor.

[Expression and significance of p53-related proteins and LMP-1 in nasal NK/T-cell lymphoma]

OBJECTIVE

To investigate the expression of murine double minute 2 (mdm2), p53, p21 and latent membrane protein 1 (LMP-1) in nasal NK/T-cell lymphoma (NKTL) and analyze their relationship with the clinical stage and prognosis.

METHODS

The clinicopathological and follow-up data of 62 patients with NKTL proven by pathology were collected. Paraffin-embedded tissue sections were examined for mdm2, p53, p21 and LMP-1 proteins by tissue microarray technique and immunohistochemistry. In situ hybridization was used to detect EBER1/2.

RESULTS

The positive expression rates of mdm2, p53, p21 and LMP-1 proteins in NKTL were 61.3%, 79.0%, 58.1% and 48.4%, respectively, and EBER1/2 was 90.3%. The positive expression rates of mdm2 in Ann Arbor stage I, II, III and IV NKTL were 43.5%, 62.5%, 73.3% and 87.5%, respectively; p53 were 69.6%, 75.0%, 86.7% and 100.0%; p21 were 47.8%, 56.3%, 60.0% and 87.5%; while those of LMP-1 were 60.9%, 50.0%, 26.7% and 50.0%, respectively. With the progression of tumor, the positive expression rates of mdm2, p53 and p21 proteins gradually increased. There were statistically significant differences between them (P<0.05). There were statistically positive correlations among those three genes (P<0.05). The prognosis of the positive expression group of these three genes was worse than that of negative expression group (P<0.05). No statistically significant difference was observed between the expression of LMP-1 protein and the clinical stage or prognosis (P>0.05). The expression of p53 protein was an independent prognostic factor.

CONCLUSION

The expression of mdm2, p53 and p21 proteins is closely related with the pathogenesis and progression of NKTL. They are good markers for judgement of the biological behavior of NKTL. The expression of p53 protein is an independent prognostic factor. Though no significant relationship was found between the expression of LMP-1 protein and the clinical stage or prognosis, it may play some role in tumor progression.

[Extranodal nasal type NK/T-cell lymphoma: clinicopathologic and prognostic study of 55 cases]

OBJECTIVE

To study the clinicopathologic features and prognostic factors of extranodal nasal type NK/T-cell lymphoma (EN-NK/TCL) in Chinese patients.

METHODS

Fifty-five cases of EN-NK/TCL diagnosed in Chinese patients during the period from 1998 to 2007 were studied by light microscopy, immunohistochemistry and in-situ hybridization. The follow-up information was analyzed.

RESULTS

The male-to-female ratio was 1.89:1. The median age of the patients was 38 years. The commonest sites of involvement included nasal cavity and adjoining tissue (85.5%). Histologically, EN-NK/TCL was composed of small to medium-sized lymphoid cells. Angiocentric and angiodestructive growth patterns, coagulative tumor necrosis and apoptotic bodies were frequently observed. Immunohistochemical study showed that CD20, the B-cell marker, was negative in all cases. The positivity rates for T-cell markers CD3epsilon, CD4, CD5 and CD8 were 100% (49/49), 7% (3/46), 8% (4/48) and 63% (29/46), respectively. Most cases were also positive for NK-cell marker CD56 (79% 42/53). All cases expressed cytotoxic granule-associated proteins TIA-1 and granzyme B. Only 17% (8/46) of the cases were positive for anti-apoptotic protein bcl-2. The proliferation index, as demonstrated by Ki-67 immunostain, varied: 30% (14/47) with a low Ki-67 expression level (< or = 29%), 28% (13/47) with a medium level (30%-59%) and 42% with a high level (> or = 60%). There was a significant positive correlation between the bcl-2 positive expression and a high Ki-67 expression level. In-situ hybridization for EBV-encoded RNA was positive in all cases. Amongst the 41 cases with clinical information available, 63.4% presented with Ann Arbor stage I to II. The performance status score was 1 in 87.8% cases. High lactate dehydrogenase level was demonstrated in some patients (31.8%). Amongst the 27 cases with follow-up data available, the median survival was 13 months. The overall 1-year, 2-year and 5-year survival rates were 52%, 31% and 20%, respectively. In general, cases with high proliferation index carried poor prognosis.

CONCLUSIONS

EN-NK/TCL is a mature T-cell and NK-cell neoplasm which can be accurately diagnosed by histologic examination, immunohistochemical study and in-situ hybridization. The prognosis is usually not favorable. Proliferation index of the tumor represents an independent prognostic factor.

[18F-FDG uptake of lymphoma lesions of various histological subtypes]

BACKGROUND AND OBJECTIVE

Malignant lymphoma has high 2-fluorine-18-fluoro-2-deoxy-D-glucose (18F-FDG) uptake. This study was to analyze 18F-FDG uptake of lymphoma lesions of various histological subtypes.

METHODS

FDG PET/CT images of 102 naive lymphoma patients were analyzed. The maximal standardized uptake value (SUVmax) of every single lesion and the SUVmax of mediastinal blood pool were measured and used to calculate the mean T/MB value (tumor SUVmax /mediastinal SUVmax) of every patient. The mean T/MB value of the patients with the same subtype of lymphoma was calculated. The differences in T/MB value between Hodgkin's lymphoma (HL) and non-Hodgkin's lymphoma (NHL) patients, between HL and indolent NHL, invasive NHL patients, between B-cell NHL and NK/T-cell NHL patients, and between diffuse large B-cell lymphoma (DLBCL) patients of different stages were analyzed. The expression of Ki-67 in lymph nodes from four patients with relative low T/MB value was detected.

RESULTS

The T/MB values were 4.50+/-1.54 in HL patients and 5.21+/-2.86 in NHL patients (P=0.154). The T/MB value was significantly higher in invasive NHL patients than in HL and indolent NHL patients (P<0.001). The T/MB values were 5.29+/-3.00 in B-cell NHL patients and 4.91+/-2.30 in NK/T-cell NHL patients (P=0.57). There was also no significant difference between DLBCL patients of different stages. The positive rate of Ki-67 was lower in the four patients with relative low T/MB value than in positive control group.

CONCLUSIONS

18F-FDG uptake of lymphoma lesions is related to lymphoma invasion, but not related to cell origin and clinical stage. The low 18F-FDG uptake in four patients may be related to low expression of Ki-67.

The heat-shock protein 90 inhibitor, geldanamycin, induces apoptotic cell death in Epstein-Barr virus-positive NK/T-cell lymphoma by Akt down-regulation

NK/T-cell lymphoma (NKTL) is strongly associated with latent Epstein-Barr virus (EBV) infection. Recently, latent membrane protein 1 (LMP1), an EBV oncoprotein, was reported to activate the phosphatidylinositol-3 kinase (PI3K)/Akt pathway for cell survival. Because geldanamycin (GA) and its derivative, 17-allylamino-17-demethoxygeldanamycin (17-AAG), exhibit anti-tumour activity by degrading HSP90 client proteins, including Akt, we investigated the effect of GA and 17-AAG on the survival of NKTL cell lines. EBV-positive NKTL cell lines, Hank-1 and NK-YS, and an EBV-negative NK leukaemia cell line, NK-L, were treated with PI3K and Akt inhibitors, GA, and 17-AAG, and were subjected to apoptosis and cell viability assays, and immunoblot analysis. EBV-positive B-lymphoblastoid cell lines IM9 and LMP1-transfected IM9 (IM9-LMP1) were also included. Hank-1 and NK-YS cell viability was compromised and apoptosis was induced by LY294002 (PI3K inhibitor) or Akt inhibitor II. GA or 17-AAG administration resulted in the apoptosis of NKTL cells, accompanied by Akt and pAkt down-regulation, caspase 3 activation, and mitochondrial membrane potential disruption. The intrinsic level of pAkt was higher in EBV-positive NKTL cells than in EBV-negative NK-L, and GA or 17-AAG decreased the viability of NKTL cells more efficiently than NK-L. Moreover, IM9-LMP1 was more sensitive to Akt inhibitor II or HSP90 inhibitors than IM9. Importantly, GA showed little effect on the viability of normal peripheral NK cells as non-neoplastic counterparts for comparison. In conclusion, this study suggests that the PI3K/Akt pathway is frequently activated in EBV-positive NKTL and that therapeutic modalities based on targeting the PI3K/Akt pathway with HSP90 inhibitors could be useful for achieving NKTL control.

[Primary pulmonary involvement of NK/T-cell lymphoma: report of two cases with literature review]

OBJECTIVE

To describe the imaging, clinical and pathological features of primary pulmonary involvement of NK/T-cell lymphoma.

METHODS

The imaging, clinical and pathological features of 2 patients with primary pulmonary involvement of NK/T-cell lymphoma were retrospectively analyzed.

RESULTS

The 2 cases (both young women) of NK/T-cell lymphoma were confirmed with CT-guided percutaneous needle lung biopsy and the lung was the primary involved site. They presented similar clinical features, including fever, dry cough, and progressive tachypnea with hypoxia. Bilateral pulmonary parenchymal nodular consolidations with bilateral pleural fluid were detected at admission chest CT scanning. Air bronchogram and halo signs were found in both the cases. The plasma Epstein-Barr virus (EBV) DNA level was 3.65 x 10(5) copies/ml and 1000 copies/ml respectively. The disease deteriorated progressively and the patients survived only 40d and 66d respectively.

CONCLUSION

The lungs may be the primary involved sites of NK/T-cell lymphoma and the prognosis is grim.

Ki-67 expression is predictive of prognosis in patients with stage I/II extranodal NK/T-cell lymphoma, nasal type

BACKGROUND

Localized extranodal natural killer (NK)/T-cell lymphoma, nasal type, commonly has a low or low-intermediate risk of the international prognostic index (IPI), so the IPI has shown inconsistency in predicting prognosis. Thus, we analyzed Ki-67 expression and proposed a new prognostic model including Ki-67 expression for stage I/II extranodal NK/T-cell lymphoma.

PATIENTS AND METHODS

We studied Ki-67 expression and its relationship with prognosis in 50 patients with extranodal NK/T-cell lymphoma.

RESULTS

The patients were dichotomized by the median value: low (<65%) versus high Ki-67 (> or =65%). High Ki-67 was associated with a worse overall survival (OS; P = 0.021) and disease-free survival (DFS; P = 0.044). In multivariate analysis, Ki-67 expression and primary site of involvement were found to be an independent prognostic factor for OS and DFS (P < 0.05). Based on these results, we proposed a new clinico-pathological prognostic model with Ki-67 expression and the primary site of involvement. It showed a high degree of correlation with worse OS and DFS (P < 0.001).

CONCLUSIONS

Ki-67 expression is predictive of prognosis, and our prognostic model may become a useful tool for predicting prognosis in patients with stage I/II extranodal NK/T-cell lymphoma, nasal type.

[Expression and correlation of Skp2 and p27(kip1) in 92 cases of non-Hodgkin's lymphoma]

OBJECTIVE

To investigate the expression and correlation of Skp2 and p27kipl in non-Hodgkin's lymphoma.

METHODS

The expression of Skp2, p27(kip1) and Ki-67 (the proliferation index)were detected in sections of 92 cases of non-Hodgkin's lymphoma (NHL) and 14 cases of reactive lymph nodes by immunohistochemistry and histopathology. The expression of Skp2 and p27(kip1) in 4 NHL cell lines were detected by Western blot.

RESULTS

The expression of Skp2 in NHL cases were significantly higher than that in reactive lymph nodes (except the germinal centers), positively correlated with proliferation activity, and an increasing tumor aggressiveness was associated with the increased expression of Skp2. The expression of p27(kip1) protein in NHL cases were significantly lower than that in reactive lymph nodes (except the germinal centers), negatively correlated with proliferation activity, and an increasing tumor aggressiveness was associated with decreased expression of p27(kip1). The statistical analysis indicated that there was no obvious correlation between Skp2 and p27(kip1) expression in NHL tissues.

CONCLUSION

The higher expression of Skp2 and lower expression of p27(kip1) in NHL tissues may play a role in the tumorigenesis and development of NHL.

[Nasal and pharyngeal non-Hodgkin lymphomas and their relationship with Epstein-Barr virus: a report of 158 cases]

OBJECTIVE

To study the clinical features, immunophenotypes and the significance of Epstein-Barr virus infection in primary nasal and pharyngeal non-Hodgkin's lymphomas in Shenyang.

METHODS

One hundred and fifty eight cases of primary nasal and pharyngeal non-Hodgkin's lymphomas were included in this study. The samples were stained with haematoxylin and eosin for histological examination. Immunohistochemistry studies were performed using monoclonal antibodies, including CD3 for T-lymphocytes, CD20 for B-lymphocytes, and CD56 and CD57 for NK cells. All cases were reclassified according to the new WHO classification of lymphomas (2001). In situ hybridization detection of EBV-encoded small nuclear RNA (EBER-1) was performed in 99 cases.

RESULTS

Overall, 101 (63.9%) of the 158 NHL were extranodal NK/T cell lymphomas (nasal type), 23 (14.6%) were nonspecific peripheral T cell lymphomas and the remaining 34 cases (21.5%) were B cell lymphomas. The primary sites of involvement were the nasal cavity (53.2%, 84/158), the tonsil (24.7%, 39/158) and the pharynx (22.1%, 35/158). Among 99 cases studied by EBER-1 in situ hybridization, a positive detection was seen in 70/71 cases (98.6%) of extranodal NK/T cell lymphoma (nasal type), 8/12 cases (66.7%) of T cell lymphoma, and 7/16 cases (43.8%) of B cell lymphoma.

CONCLUSIONS

Among primary nasal and pharyngeal NK lymphomas, extranodal NK/T cell lymphoma (nasal type) is the most common type and is strongly associated with EBV infection. The pathological diagnosis of nasal and pharyngeal lymphomas should take considerations of the anatomic sites and immunophenotypical features.

[Expression and its significance of STAT3, STAT5, Survivin and Ki67 in nasal NK/T cell lymphoma]

OBJECTIVE

To study the expression and its significance of STAT3, STAT5, Survivin and Ki67 in the Epstein-Barr virus associated nasal NK/T cell lymphoma.

METHOD

The expression of STAT3, STAT5, Survivin and Ki67 were detected with immunohistochemistry in 25 cases of nasal NK/T cell lymphoma, and their relationship was analyzed. Nasal cavity tissues from 20 cases of chronic sinusitis were as the control group.

RESULT

The positive rates of STAT3 in the lymphoma and in control group were 56% and 10%, respectively (P <0.01). The positive rates of STAT5 in the lymphoma and in control group were 68% and 15%, respectively (P <0.01). The positive rates of Survivin and Ki67 of nasal NK/T cell-lymphoma were 68% and 72%, respectively; but it in the control group was 0% and 20%, respectively, P <0.01. The expression of STAT3 was positively related to that of Survivin and Ki67(r =0. 428, P <0. 05 and r =0. 704, P <0. 01); The expression of STAT5 was not related to that of Survivin and Ki67.

CONCLUSION

The pathway of STAT may play a role in the development of nasal NK/T cell lymphoma. STAT maybe take part in the formation of nasal NK/T cell lymphoma through induction of Survivin and Ki67.