A dual program for translation regulation in cellular proliferation and differentiation.

A dichotomous choice for metazoan cells is between proliferation and differentiation. Measuring tRNA pools in various cell types, we found two distinct subsets, one that is induced in proliferating cells, and repressed otherwise, and another with the opposite signature. Correspondingly, we found that genes serving cell-autonomous functions and genes involved in multicellularity obey distinct codon usage. Proliferation-induced and differentiation-induced tRNAs often carry anticodons that correspond to the codons enriched among the cell-autonomous and the multicellularity genes, respectively. Because mRNAs of cell-autonomous genes are induced in proliferation and cancer in particular, the concomitant induction of their codon-enriched tRNAs suggests coordination between transcription and translation. Histone modifications indeed change similarly in the vicinity of cell-autonomous genes and their corresponding tRNAs, and in multicellularity genes and their tRNAs, suggesting the existence of transcriptional programs coordinating tRNA supply and demand. Hence, we describe the existence of two distinct translation programs that operate during proliferation and differentiation.

Cardiovascular diseases after high-dose chemotherapy and autologous stem cell transplant for lymphoma: A Danish population-based study.

Cardiovascular diseases, especially congestive heart failure (CHF), are known complications of anthracyclines, but the risk for patients undergoing high-dose chemotherapy and autologous stem cell transplant (HDT-ASCT) is not well established. With T-cell therapies emerging as alternatives, studies of long-term complications after HDT-ASCT are warranted. Danish patients treated with HDT-ASCT for aggressive lymphoma between 2001 and 2017 were matched 1:5 on sex, birth year and Charlson comorbidity score to the general population. Events were captured using nationwide registers. A total of 787 patients treated with HDT-ASCT were identified. Median follow-up was 7.6 years. The risk of CHF was significantly increased in the HDT-ASCT population compared to matched comparators with an adjusted hazard ratio (HR) of 5.5 (3.8-8.1). The 10-year cumulative incidence of CHF was 8.0% versus 2.0% (p < 0.001). Male sex, ≥2 lines of therapy, hypertension and cumulative anthracycline dose (≥300 mg/m2 ) were risk factors for CHF. In a separate cohort of 4089 lymphoma patients, HDT-ASCT was also significantly associated with increased risk of CHF (adjusted HR of 2.6 [1.8-3.8]) when analysed as a time-dependent exposure. HDT-ASCT also increased the risk of other cardiac diseases. These findings are applicable for the benefit/risk assessment of HDT-ASCT versus novel therapies.

Expanding the understanding of telomere biology disorder with reports from two families harboring variants in ZCCHC8 and TERC.

Telomere biology disorder (TBD) can present within a wide spectrum of symptoms ranging from severe congenital malformations to isolated organ dysfunction in adulthood. Diagnosing TBD can be challenging given the substantial variation in symptoms and age of onset across generations. In this report, we present two families, one with a pathogenic variant in ZCCHC8 and another with a novel variant in TERC. In the literature, only one family has previously been reported with a ZCCHC8 variant and TBD symptoms. This family had multiple occurrences of pulmonary fibrosis and one case of bone marrow failure. In this paper, we present a second family with the same ZCCHC8 variant (p.Pro186Leu) and symptoms of TBD including pulmonary fibrosis, hematological disease, and elevated liver enzymes. The suspicion of TBD was confirmed with the measurement of short telomeres in the proband. In another family, we report a novel likely pathogenic variant in TERC. Our comprehensive description encompasses hematological manifestations, as well as pulmonary and hepatic fibrosis. Notably, there are no other reports which associate this variant to disease. The families expand our understanding of the clinical implications and genetic causes of TBD.

MYC protein is a high-risk factor in mantle cell lymphoma and identifies cases beyond morphology, proliferation and TP53/p53 - a Nordic Lymphoma Group study.

The transcription factor MYC is a well-described oncogene with an important role in lymphomagenesis, but its significance for clinical outcome in mantle cell lymphoma (MCL) remains to be determined. We performed an investigation of the expression of MYC protein in a cohort of 251 MCL patients complemented by analyses of structural aberrations and mRNA, in a sub-cohort of patients. Fourteen percent (n=35) of patients showed high MYC protein expression with >20% positive cells (MYChigh), among whom only one translocation was identified, and 86% (n=216) of patients showed low MYC protein expression. Low copy number gains of MYC were detected in ten patients, but with no correlation to MYC protein levels. However, MYC mRNA levels correlated significantly to MYC protein levels with a R2 value of 0.76. Patients with a MYChigh tumor had both an independent inferior overall survival and an inferior progression-free survival (hazard ratio [HR]=2.03, 95% confidence interval [95% CI]: 1.2-3.4 and HR=2.2, 95% CI: 1.04-4.6, respectively) when adjusted for additional high-risk features. Patients with MYChigh tumors also tended to have additional high-risk features and to be older at diagnosis. A subgroup of 13 patients had concomitant MYChigh expression and TP53/p53 alterations and a substantially increased risk of progression (HR=16.9, 95% CI: 7.4-38.3) and death (HR=7.8, 95% CI: 4.4-14.1) with an average overall survival of only 0.9 years. In summary, we found that at diagnosis a subset of MCL patients (14%) overexpressed MYC protein, and had a poor prognosis but that MYC rearrangements were rare. Tumors with concurrent MYC overexpression and TP53/p53 alterations pinpointed MCL patients with a dismal prognosis with a median overall survival of less than 3 years. We propose that MYC needs to be assessed beyond the current high-risk factors in MCL in order to identify cases in need of alternative treatment.

Overexpression of the key metabolic protein CPT1A defines mantle cell lymphoma patients with poor response to standard high-dose chemotherapy independent of MIPI and complement established highrisk factors.

The variable outcome to standard immunochemotherapy for mantle cell lymphoma (MCL) patients is a clinical challenge. Established risk factors, including high MCL International Prognostic Index (MIPI), high proliferation (Ki-67), non-classic (blastoid/pleomorphic) morphology, and mutated TP53, only partly identify patients in need of alternative treatment. Deepened understanding of biological factors that influence time to progression and relapse would allow for an improved stratification, and identification of novel targets for high-risk patients. We performed gene expression analyses to identify pathways and genes associated with outcome in a cohort of homogeneously treated patients. In addition to deregulated proliferation, we show that thermogenesis, fatty acid degradation and oxidative phosphorylation are altered in patients with poor survival, and that high expression of carnitine palmitoyltransferase 1A (CPT1A), an enzyme involved in fatty acid degradation, can specifically identify high-risk patients independent of the established high-risk factors. We suggest that complementary investigations of metabolism may increase the accuracy of patient stratification and that immunohistochemistry- based assessment of CPT1A can contribute to defining high-risk MCL.

ProGraME: A novel flow cytometry algorithm for the diagnosis of low-risk myelodysplastic syndromes in patients with cytopenia.

OBJECTIVES: Flow cytometry (FC) is, together with morphology, genetics, and cytogenetics, used in the diagnostic assessment of cytopenia, as its value in evaluating bone marrow dysplasia been highlighted by several studies. However, despite the development of algorithms and guidelines, there is still a lack of standardization of the FC assessment of bone marrow dysplasia. METHODS: By combining FC, together with morphological analysis and cytogenetic/molecular assessment in a training cohort of 209 patients, we created a novel score, ProGraME, which includes four parameters, each from a different cell lineage (Progenitor cells, Granulocytes, Monocytes, Erythroid precursors), solely based on relevant population gating. Points for ProGraME were attained for: lymphoid precursors ≤5% of all CD34+ cells (1.5 point); a granulocyte-to-lymphocyte side-scatter ratio ≤6 (1 point); a monocyte CD33-CV% ≥ 63 (2 points), and an erythroid precursor CD36-CV% ≥ 65 (2 points). RESULTS: Using a cutoff of ≥2 as suggestive of dysplasia, ProGraME showed a sensitivity of 91% and a specificity of 81% in the training cohort and 95% and 75%, respectively, in an independent validation cohort of 159 patients. In addition, ProGraME had a very high negative predictive value of 97.1% and 97.8% in the training and validation cohorts, respectively, offering a useful tool for excluding bone marrow dysplasia. Finally, among the 23 CCUS patients that scored positive for dysplasia with ProGraME in the training cohort, 16 of them (69%) carried high-risk mutations, suggesting that FC might help identify early changes of dysplasia. CONCLUSIONS: ProGraME can potentially optimize the FC diagnosis of low-risk myelodysplasia without minimal requirements of flow analysis other than accurate population gating.

Monocytosis in primary care and risk of haematological malignancies.

Monocytosis (≥0.5 × 109 /L in peripheral blood) is the hallmark of chronic myelomonocytic leukaemia (CMML) but may be present in a spectrum of diseases including other haematological malignancies. In the primary care sector, monocytosis is a relatively common finding, but its predictive value for haematological malignancy is unknown. We included 663 184 adult primary care patients from the greater Copenhagen area with one or more differential cell counts registered between 2000 and 2016 and followed them in the extensive nationwide Danish health data registers for 3 years after blood sampling. We used logistic regression to model the risk of haematological malignancy and death following monocytosis. Monocytosis was associated with an increased risk of all types of haematological malignancy with the greatest relative risk increase observed in CMML with an OR of 105.22 (95% confidence interval: 38.27-289.30). Sustained monocytosis (at least two requisitions in 3 months) further increased CMML risk, although the diagnosis was still very rare, that is, observed in only 0.1% of these individuals. Outside the haematological setting, the absolute risk of haematological malignancy associated with monocytosis is low and haematological malignancy should mainly be suspected when monocytosis is sustained or the clinical presentation raises suspicion of malignancy.

Humoral and cellular immune responses after three or four doses of BNT162b2 in patients with hematological malignancies.

OBJECTIVES: Initial responses to coronavirus disease 2019 vaccination are impaired in patients with hematological malignancies. We investigated immune responses after three or four doses of BNT162b2 in patients with myeloid and lymphoid malignancies compared to controls, and identified risk factors for humoral and cellular nonresponse 1 year after first vaccination. METHODS: In 407 hematological patients (45 myeloid, 362 lymphoid) and 98 matched controls, we measured immunoglobulin G (IgG) and neutralizing antibodies specific for the receptor-binding domain of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at baseline, 3 weeks, 2, 6, and 12 months, and interferon-γ release at 12 months. RESULTS: In patients with lymphoid malignancies, SARS-CoV-2 receptor-binding domain IgG concentration and mean neutralizing capacity was lower than in controls at all time points. A diagnosis of chronic lymphocytic B-cell leukemia (CLL) or lymphoma was associated with humoral nonresponse at 12 months compared to having multiple myeloma/amyloidosis (p < .001 and p = .013). Compared to controls, patients with lymphoid malignancies had increased risk of cellular nonresponse. A lymphoma diagnosis was associated with lower risk of cellular nonresponse compared to patients with multiple myeloma/amyloidosis, while patients with CLL had comparable response rates to patients with multiple myeloma/amyloidosis (p = .037 and p = .280). CONCLUSIONS: In conclusion, long-term humoral and cellular immune responses to BNT162b2 were impaired in patients with lymphoid malignancies.

Incidence of Positive Severe Acute Respiratory Syndrome Coronavirus Polymerase Chain Reaction After Coronavirus Disease 2019 Vaccination With up to 8 Months of Follow-up: Real-life Data From the Capital Region of Denmark.

BACKGROUND: Coronavirus disease 2019 (COVID-19) vaccines are implemented worldwide in efforts to curb the pandemic. This study investigates the risk of a positive severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) reverse transcriptase polymerase chain reaction (RT-PCR) test following BNT162b2 vaccination in a large real-life population in Denmark. METHODS: Vaccination status and positive SARS-CoV-2 RT-PCR results from adults in the Capital Region of Denmark (n = 1 549 488) were obtained from national registries. PCR testing was free and widely available. The number of positive PCR tests per individual at risk was calculated as weekly rates. Time to positive PCR test was modelled using Kaplan-Meier methods and hazard ratios (HRs) were calculated using Cox regression. RESULTS: A total of 1 119 574 individuals received the first dose of BNT162b2 and 1 088 879 received a second dose of BNT162b2. Individuals were followed up to 8.7 months after first dose (median: 5.5 months; interquartile ratio: 4.1-8.7). Rates of PCR-confirmed SARS-CoV-2 infection 2-4 months after the second dose were 0.21, 0.33, and 0.36 per 1000 individuals per week at risk for July, August, and September, respectively. Four or more months after the second dose, the rates were 0.56, 0.76, and 0.53 per 1000 individuals per week at risk for July, August, and September, respectively. HR of SARS-CoV-2 infection after the second dose was 0.2 (95% confidence interval, .05-.48; P = .001) for individuals with 8 months' follow-up. CONCLUSIONS: Individuals who received 2 doses of the BNT162b2 COVID-19 vaccine had a low risk of breakthrough infection after up to 8 months of follow-up. However, there was a tendency toward higher rates with longer follow-up.

Epigenetic therapy in combination with a multi-epitope cancer vaccine targeting shared tumor antigens for high-risk myelodysplastic syndrome - a phase I clinical trial.

BACKGROUND: Standard care for patients with high-risk myelodysplastic syndrome (MDS) is hypomethylating agents such as azacitidine (AZA), which can induce expression of methylated tumor-associated antigens and therefore potentiate immunotherapeutic targeting. METHOD: In this phase 1 trial, we combined AZA with a therapeutic peptide vaccine targeting antigens encoded from NY-ESO-1, MAGE-A3, PRAME, and WT-1, which have previously been demonstrated to be upregulated by AZA treatment. RESULT: Five patients who had responded to AZA monotherapy were included in the study and treated with the vaccine. The combination therapy showed only few adverse events during the study period, whereof none classified as serious. However, no specific immune responses could be detected using intracellular cytokine staining or ELISpot assays. Minor changes in the phenotypic composition of immune cells and their expression of stimulatory and inhibitory markers were detected. All patients progressed to AML with a mean time to progression from inclusion (TTP) of 5.2 months (range 2.8 to 7.6). Mean survival was 18.1 months (range 10.9 to 30.6) from MDS diagnosis and 11.3 months (range 4.3 to 22.2) from inclusion. Sequencing of bone marrow showed clonal expansion of malignant cells, as well as appearance of novel mutations. CONCLUSION: The patients progressed to AML with an average time of only five months after initiating the combination therapy. This may be unrelated to the experimental treatment, but the trial was terminated early as there was no sign of clinical benefit or immunological response. Why the manuscript is especially interesting This study is the first to exploit the potential synergistic effects of combining a multi-peptide cancer vaccine with epigenetic therapy in MDS. Although our results are negative, they emphasize challenges to induce immune reactivity in patients with high-risk MDS.

Humoral response to two doses of BNT162b2 vaccination in people with HIV.

BACKGROUND: People with HIV (PWH) are at increased risk of severe COVID-19. We aimed to determine humoral responses in PWH and controls who received two doses of BNT162b2. METHODS: In 269 PWH and 538 age-matched controls, we measured IgG and neutralizing antibodies specific for the receptor-binding domain of SARS-CoV-2 at baseline, 3 weeks and 2 months after the first dose of BNT162b2. RESULTS: IgG antibodies increased from baseline to 3 weeks and from 3 weeks to 2 months in both groups, but the concentrations of IgG antibodies were lower in PWH than that in controls at 3 weeks and 2 months (p = 0.025 and <0.001), respectively. The IgG titres in PWH with a humoral response at 2 months were 77.9% (95% confidence interval [62.5%-97.0%], age- and sex-adjusted p = 0.027) of controls. CONCLUSIONS: Reduced IgG antibody response to vaccination with BNT162b2 was found in PWH, and thus increased awareness of breakthrough infections in PWH is needed.

Clonal hematopoiesis in elderly twins: concordance, discordance, and mortality.

Clonal hematopoiesis (CH) of indeterminate potential (CHIP) is defined by mutations in myeloid cancer-associated genes with a variant allele frequency of at least 2%. Recent studies have suggested a possible genetic predisposition to CH. To further explore this phenomenon, we conducted a population-based study of 594 twins from 299 pairs aged 73 to 94 years, all with >20 years' follow-up. We sequenced DNA from peripheral blood with a customized 21-gene panel at a median coverage of 6179X. The casewise concordance rates for mutations were calculated to assess genetic predisposition. Mutations were identified in 214 (36%) of the twins. Whereas 20 twin pairs had mutations within the same genes, the exact same mutation was only observed in 2 twin pairs. No significant difference in casewise concordance between monozygotic and dizygotic twins was found for any specific gene, subgroup, or CHIP mutations overall, and no significant heritability could be detected. In pairs discordant for CHIP mutations, we tested if the affected twin died before the unaffected twin, as a direct measurement of the association of having CH when controlling for familial factors. A total of 127 twin pairs were discordant for carrying a mutation, and in 61 (48%) cases, the affected twin died first (P = .72). Overall, we did not find a genetic predisposition to CHIP mutations in this twin study. The previously described negative association of CHIP mutations on survival could not be confirmed in a direct comparison among twin pairs that were discordant for CHIP mutations.

Socioeconomic position and clinical outcomes in patients with myelodysplastic syndromes: A population-based cohort study.

Low socioeconomic position (SEP) may be associated with adverse outcomes in patients with myelodysplastic syndromes (MDS) inherent to for example, delayed diagnosis or reduced treatment intensity, but firm evidence is limited. In this study, we examined the association between SEP and clinical outcomes. We conducted a population-based cohort study (2010-2018) of 2233 Danish patients with MDS. SEP measures included individual-level information on education, cohabitation status and income retrieved from Statistics Denmark. Associations between SEP measures and disease severity at diagnosis were examined using binomial regression analysis. Using time-to-event analysis, we examined the association between SEP measures and treatment with allogeneic stem cell transplantation (allo-HSCT), risk of progression to acute myeloid leukemia (AML), and death. Estimates were adjusted for covariates selected based on direct acyclic graphs and reported with 95% confidence intervals. Patients with a short education were more likely to be transfusion-dependent at diagnosis (RR = 1.25, 95% CI: 1.04-1.45) and more likely to be diagnosed with higher risk MDS according to the International Prognostic Scoring System (RR = 1.29, 95% CI: 1.03-1.62), than patients with a long education. We found no clear association between SEP and risk of progression to AML. In adjusted models, the 1-year risk of dying was higher in patients with short versus long education (RR = 1.34, 95% CI: 1.08-1.65), in patients with low versus high income (RR = 1.42, 95% CI: 1.14-1.77), and among patients who lived alone compared to those who lived with a partner (RR = 1.15, 0.98-1.35). These associations persisted after 3 years and 5 years of follow-up. Notably, patients with a short education had a markedly lower rate of undergoing treatment with allo-HSCT compared to patients with a long education (HR = 0.51, 95% CI: 0.31-0.84). In conclusion, low SEP and especially short education, were poor prognostic factors for adverse clinical outcomes among patients with MDS.

Pre-treatment health-related quality of life parameters have prognostic impact in patients >65 years with newly diagnosed mantle cell lymphoma: The Nordic Lymphoma Group MCL4 (LENA-BERIT) experience.

Mantle cell lymphoma (MCL) is a rare, often aggressive type of B-cell lymphoma with poor survival and no cure. Cancer and cancer treatment has a negative impact on health-related quality of life (HRQOL) both during active disease and in the long term, and improvement of HRQOL is a crucial objective of cancer therapy in older patients and no curative intent. Baseline HRQOL has in other lymphoma populations been shown to be predictive of outcome. Here, we explored HRQOL, and its association with survival, by the EORTC QLQ-C30 questionnaire, before, during and after chemotherapy in a patient cohort with MCL, treated within the NLG-MCL4 trial, designed to evaluate the addition of lenalidomide (LEN) to rituximab-bendamustine (R-B) as first-line treatment. Fifty-one patients were enrolled, median age was 71 years (range 62-84), 37 were men (73%). Pre-treatment HRQOL was similar to scores from the reference population with healthy individuals. During treatment, HRQOL deteriorated, but reverted to the same level as the reference population after treatment. There was a correlation between physical function (p = 0.001) and role function (p = 0.006) at baseline and WHO performance status, but not with other clinical or genetic prognostic factors. None of the baseline factors were predictive for treatment related to HRQOL in this cohort. Pre-treatment physical (p = 0.011) and role function (p = 0.032) were independent factors associated with overall survival, and physical function (p = 0.002) was also associated with progression free survival. These findings may possibly be used to design support during treatment and improve rehabilitation. Further investigations are needed for assessment of long-term HRQOL.

Family caregiver ambassador support for caregivers of patients with newly diagnosed hematological cancer: a feasibility study.

PURPOSE: This study investigated the feasibility of a one-on-one peer support intervention in family caregivers of newly diagnosed patients with a hematological cancer during initial treatment. METHODS: The study was a one-arm feasibility study including family caregivers of newly diagnosed patients with hematological cancer (n = 26) and caregiver ambassadors who were family caregivers of previously treated patients as peer supporters (n = 17). The one-on-one peer support intervention consisted of three components: a caregiver ambassador preparatory course; 12 weeks of one-on-one peer support, and caregiver ambassador network meetings. RESULTS: Family caregivers reported high satisfaction with the delivery and flexibility of one-on-one peer support and improved in most psychosocial outcomes over time. Telephone and text messages were the most used form of contact between the peers. Caregiver ambassadors reported high satisfaction with the preparatory course and used the available support from the network meetings. No adverse events were reported. CONCLUSION: One-on-one peer support provided by a caregiver ambassador is feasible and safe in family caregivers of newly diagnosed hematological cancer patients during their initial treatment. Utilizing volunteer caregiver ambassadors has the potential to be a new support model in family caregivers of hematological cancer patients across diagnostic groups within a clinical setting. CLINICAL TRIAL REGISTRATION NUMBER: NCT04039100, July 29, 2019.

Protein phosphatase, Mg2+/Mn2+-dependent 1D (PPM1D) mutations in haematological cancer.

Until recently, the protein phosphatase, Mg2+/Mn2+-dependent 1D (PPM1D) gene had not been examined in haematological cancer, but several studies have now explored the functional role of this gene and its aberrations. It is often mutated in the context of clonal haemopoiesis (including in patients with lymphoma, myeloproliferative neoplasms and myelodysplastic syndrome) and mutations have been associated with exposure to cytotoxic and radiation therapy, development of therapy-related neoplasms and inferior survival. The vast majority of PPM1D mutations found in haematopoietic cells are of the nonsense or frameshift type and located within terminal exon 6. These genetic defects are rarely found in the blood of healthy individuals. PPM1D encodes the PPM1D phosphatase [also named wild-type p53-induced phosphatase 1 (WIP1)], which negatively regulates signalling molecules within the DNA damage response pathway, including tumour suppressor p53. Clonal expansion of PPM1D mutant haematopoietic cells can potentially be prevented with inhibitors; however, human trials are awaited. In the present review, we provide a review of the literature regarding PPM1D and its role in haematological cancer.

Risk of new malignancies among patients with CLL treated with chemotherapy: results of a Danish population-based study.

Patients with chronic lymphocytic leukaemia (CLL) have an increased risk of new malignancies. However, limited data have been published about the impact of CLL treatment on this risk. Here we followed a Danish population-based cohort of CLL patients for risks of new malignancies. Patients in the Danish CLL registry (2008-2017) were included. Up to 50 CLL-free matched comparators were identified. First-line treatment was categorized into four groups; bendamustine, chlorambucil, fludarabine or other. Patients were followed from CLL diagnosis for individual types of malignancy. Adjusted hazard ratios (HR) for new malignancies and 95% confidence intervals (95% CI) were calculated. Overall, 4286 CLL patients and 214 150 controls developed 594 and 20 565 new malignancies respectively. Risk of new malignancies was increased for CLL patients. Chemotherapy treatment was registered for 1064 (25%) patients with CLL. Chemotherapy was associated with increased HR (1·51, 95% CI: 1·3-1·8) of any new malignancy. Specifically, fludarabine was associated with an increased risk of myelodysplastic syndrome (MDS) (HR 4·93, 95% CI: 1·2-19·8). Patients with CLL are at increased risk of other haematological and solid malignancies compared to the general population. Chemotherapy exposure is associated with increased risk of second malignancies and fludarabine is associated with increased risk of MDS.

Structural aberrations are associated with poor survival in patients with clonal cytopenia of undetermined significance.

Not available.

A user's guide to multicolor flow cytometry panels for comprehensive immune profiling.

Multicolor flow cytometry is an essential tool for studying the immune system in health and disease, allowing users to extract longitudinal multiparametric data from patient samples. The process is complicated by substantial variation in performance between each flow cytometry instrument, and analytical errors are therefore common. Here, we present an approach to overcome such limitations by applying a systematic workflow for pairing colors to markers optimized for the equipment intended to run the experiments. The workflow is exemplified by the design of four comprehensive flow cytometry panels for patients with hematological cancer. Methods for quality control, titration of antibodies, compensation, and staining of cells for obtaining optimal results are also addressed. Finally, to handle the large amounts of data generated by multicolor flow cytometry, unsupervised clustering techniques are used to identify significant subpopulations not detected by conventional sequential gating.

The Thioredoxin-Interacting Protein TXNIP Is a Putative Tumour Suppressor in Cutaneous T-Cell Lymphoma.

BACKGROUND: The thioredoxin-interacting protein (TXNIP) is involved in cellular metabolism and cell proliferation, and recently, deficient expression of TXNIP has been associated with progression and poor outcome for cancer patients. OBJECTIVES: To assess TXNIP expression and function in malignant T cells from cutaneous T-cell lymphoma (CTCL). METHODS: CTCL-derived malignant (MyLa2059, PB2B) and non-malignant (MyLa1850) cell lines were analysed by Western blotting and qPCR for TXNIP expression. Subsequently, the malignant CTCL cell lines were treated with GSK126 - an inhibitor of enhancer of zeste homolog 2 (EZH2) methyltransferase activity or assessed by bisulphite sequencing for TXNIP promoter methylation. Methylation was also assessed with the demethylating agent 5-azacytidine (5AZA). Finally, TXNIP was overexpressed in the malignant PB2B cell line via plasmid transduction, and the effect of TXNIP was further analysed by flow cytometry. RESULTS: We report on low expression of TXNIP protein in all cell lines representing different subtypes and stages of CTCL when compared to non-malignant T cells. Epigenetic silencing and other mechanisms were involved in the repression of TXNIP whereas forced expression of TXNIP strongly inhibited proliferation of malignant T cells. CONCLUSIONS: Epigenetic silencing and other as yet unknown mechanisms repress TXNIP expression in malignant T cells. As forced expression of TXNIP inhibits malignant proliferation, we propose that TXNIP is a putative tumour suppressor in CTCL.