Chromosomal alterations among age-related haematopoietic clones in Japan.

The extent to which the biology of oncogenesis and ageing are shaped by factors that distinguish human populations is unknown. Haematopoietic clones with acquired mutations become common with advancing age and can lead to blood cancers1-10. Here we describe shared and population-specific patterns of genomic mutations and clonal selection in haematopoietic cells on the basis of 33,250 autosomal mosaic chromosomal alterations that we detected in 179,417 Japanese participants in the BioBank Japan cohort and compared with analogous data from the UK Biobank. In this long-lived Japanese population, mosaic chromosomal alterations were detected in more than 35.0% (s.e.m., 1.4%) of individuals older than 90 years, which suggests that such clones trend towards inevitability with advancing age. Japanese and European individuals exhibited key differences in the genomic locations of mutations in their respective haematopoietic clones; these differences predicted the relative rates of chronic lymphocytic leukaemia (which is more common among European individuals) and T cell leukaemia (which is more common among Japanese individuals) in these populations. Three different mutational precursors of chronic lymphocytic leukaemia (including trisomy 12, loss of chromosomes 13q and 13q, and copy-neutral loss of heterozygosity) were between two and six times less common among Japanese individuals, which suggests that the Japanese and European populations differ in selective pressures on clones long before the development of clinically apparent chronic lymphocytic leukaemia. Japanese and British populations also exhibited very different rates of clones that arose from B and T cell lineages, which predicted the relative rates of B and T cell cancers in these populations. We identified six previously undescribed loci at which inherited variants predispose to mosaic chromosomal alterations that duplicate or remove the inherited risk alleles, including large-effect rare variants at NBN, MRE11 and CTU2 (odds ratio, 28-91). We suggest that selective pressures on clones are modulated by factors that are specific to human populations. Further genomic characterization of clonal selection and cancer in populations from around the world is therefore warranted.

Metachronous Wilms Tumor, Glioblastoma, and T-cell Leukemia in an Child With Constitutional Mismatch Repair Deficiency syndrome due to Novel Mutation in MSH6 (c.2590G>T).

Constitutional mismatch repair deficiency (CMMRD) is an autosomal recessively inherited childhood cancer predisposition syndrome results from biallelic germline mutations affecting the key DNA mismatch repair gene: MLH1, MSH2, MSH6, or PMS2. CMMRD is associated with a high risk of developing early onset of central nervous system tumors, hematologic, and intestinal tract tumors. Clinical manifestations, genetic screening, and cancer prevention strategies are limited. In this report we present a patient with metachronous Wilms tumor, glioblastoma, and acute T-cell lymphoblastic leukemia. He had cutaneous features of neurofibromatosis type 1 (NF1). Molecular testing revealed a novel homozygous mutation in MSH6 (c.2590G>T; p.G864*) that has not been reported previously. CMMRD should be considered in patients with cutaneous features similar to NF1 if tumor is found other than expected tumors in NF, early onset cancer, and strong family history of cancer.

Cytotoxic Polyketide Metabolites from a Marine Mesophotic Zone Chalinidae Sponge-Associated Fungus Pleosporales sp. NBUF144.

Two new polyketide natural products, globosuxanthone F (1), and 2'-hydroxy bisdechlorogeodin (2), were isolated from the fungus Pleosporales sp. NBUF144, which was derived from a 62 m deep Chalinidae family sponge together with four known metabolites, 3,4-dihydroglobosuxanthone A (3), 8-hydroxy-3-methylxanthone-1-carboxylate (4), crosphaeropsone C (5), and 4-megastigmen-3,9-dione (6). The structures of these compounds were elucidated on the basis of extensive spectroscopic analysis, including 1D and 2D NMR and high-resolution electrospray ionization mass spectra (HRESIMS) data. The absolute configuration of 1 was further established by single-crystal X-ray diffraction studies. Compounds 1-5 were evaluated for cytotoxicity towards CCRF-CEM human acute lymphatic leukemia cells, and it was found that 1 had an IC50 value of 0.46 µM.

Induction of caspase-2 gene expression in carboxyl-functionalized carbon nanotube-treated human T-cell leukemia (Jurkat) cell line.

Carbon nanotubes (CNTs) have great potential as novel diagnostic or therapeutic tools in biomedicine but, cellular toxicity must be well considered before widespread application of CNTs. Many chemical agents exert their toxicity through apoptotic pathways by induction of caspase biomolecules. In the current study, effects of carboxyl-functionalized single-walled (SW) and multi-walled (MW) CNTs at a single dose of 100 µg ml-1 on the survival of Jurkat cells were examined using MTT assay. Additionally, the impacts of carboxylated CNTs on the gene expression levels of selected caspases were investigated. Jurkat cells were exposed to CNTs (100 µg ml-1 for 72 h) and then expression levels of selected caspase genes (Cas) were evaluated by qRT-PCR analysis. Housekeeping genes, ß-actin, and glyceraldehyde 3-phosphate dehydrogenase (GAPDH), were used as normalization controls. The results showed only a mild decrease in the viability of Jurkat cells treated with carboxylated MWCNT. The results of qRT-PCR analysis revealed the elevated level of Cas2 mRNA in the cells treated with carboxylated MWCNT (6.08-fold) and carboxylated SWCNT (1.20-fold). The expression levels of Cas4, Cas6, Cas8, and Cas10 genes were increased not significantly compared to the control untreated cells. Our findings suggested that exposure to carboxyl-functionalized CNTs could be resulted in up-regulation of the Cas2 gene and not initiator Cas8 and Cas10 genes. In addition, it seems that carboxylated MWCNT was more potent than SWCNT in activation of Cas2 gene expression and triggering cell death signal in a manner different from intrinsic or extrinsic apoptosis pathways.

Synthesis and screening of 6-alkoxy purine analogs as cell type-selective apoptotic inducers in Jurkat cells.

Purines are ubiquitous structures in cell biology involved in a multitude of cellular processes, because of which substituted purines and analogs are considered excellent scaffolds in drug design. In this study, we explored the key structural features of a purine-based proapoptotic hit, 8-tert-butyl-9-phenyl-6-benzyloxy-9H-purine (1), by setting up a library of 6-alkoxy purines with the aim of elucidating the structural requirements that govern its biological activity and to study the cell selectivity of this chemotype. This was done by a phenotypic screening approach based on cell cycle analysis of a panel of six human cancer cell lines, including T cell leukemia Jurkat cells. From this study, two derivatives (12 and 13) were identified as Jurkat-selective proapoptotic compounds, displaying superior potency and cell selectivity than hit 1.

Modulation of PTPN2/22 Function by Spermidine in CRISPR-Cas9-Edited T-Cells Associated with Crohn's Disease and Rheumatoid Arthritis.

Crohn's Disease (CD) and Rheumatoid Arthritis (RA) share some single nucleotide polymorphisms (SNPs) in protein tyrosine phosphatase non-receptor types 2 and 22 (PTPN2/22). Recently, we reported that clinical samples from CD and RA patients associated with PTPN2:rs478582 or PTPN22:rs2476601 genotypes were linked to overactive immune response and exacerbation of inflammation. Here, we investigated in vitro the effects of these SNPs in Jurkat T-cells using CRISPR-Cas9. All cells were evaluated for PTPN22/22 loss of function and effects on cell response. We measured gene expression via RT-qPCR and cytokines by ELISA. We also measured cell proliferation using a BrdU labeling proliferation ELISA, and T-cell activation using CD-25 fluorescent immunostaining. In PTPN2 SNP-edited cells, PTPN2 expression decreased by 3.2-fold, and proliferation increased by 10.2-fold compared to control. Likewise, expression of PTPN22 decreased by 2.4-fold and proliferation increased by 8.4-fold in PTPN22 SNP-edited cells. IFN-γ and TNF-α secretions increased in both edited cell lines. CD25 expression (cell activation) was 80.32% in PTPN2 SNP-edited cells and 85.82% in PTPN22 SNP-edited cells compared to 70.48% in unedited Jurkat T-cells. Treatment of PTPN2 and PTPN22-edited cells with a maximum 20 µM spermidine restored PTPN2/22 expression and cell response including cell proliferation, activation, and cytokines secretion. Most importantly, the effect of spermidine on edited cells restored normal expression and secretion of IFN-γ and TNF-α. The data clearly demonstrated that edited SNPs in PTPN2 or PTPN22 were associated with reduced gene expression, which resulted in an increase in cell proliferation and activation and overactive immune response. The data validated our earlier observations in CD and RA clinical samples. Surprisingly, spermidine restored PTPN2/22 expression in edited Jurkat T-cells and the consequent beneficial effect on cell response and inflammation. The study supports the use of polyamines dietary supplements for management of CD and in RA patients.

Pre-depletion of TRBC1+ T cells promotes the therapeutic efficacy of anti-TRBC1 CAR-T for T-cell malignancies.

Targeting T cell receptor ß-chain constant region 1 (TRBC1) CAR-T could specifically kill TRBC1+ T-cell malignancies. However, over-expressed CARs on anti-TRBC1 CAR transduced TRBC1+ T cells (CAR-C1) bound to autologous TRBC1, masking TRBC1 from identification by other anti-TRBC1 CAR-T, and moreover only the remaining unoccupied CARs recognized TRBC1+ cells, considerably reducing therapeutic potency of CAR-C1. In addition, co-culture of anti-TRBC1 CAR-T and TRBC1+ cells could promote exhaustion and terminal differentiation of CAR-T. These findings provide a rationale for pre-depleting TRBC1+ T cells before anti-TRBC1 CAR-T manufacturing.

Stage-specific roles for Zmiz1 in Notch-dependent steps of early T-cell development.

Notch1 signaling must elevate to high levels in order to drive the proliferation of CD4-CD8- double-negative (DN) thymocytes and progression to the CD4+CD8+ double-positive (DP) stage through ß-selection. During this critical phase of pre-T-cell development, which is also known as the DN-DP transition, it is unclear whether the Notch1 transcriptional complex strengthens its signal output as a discrete unit or through cofactors. We previously showed that the protein inhibitor of activated STAT-like coactivator Zmiz1 is a context-dependent cofactor of Notch1 in T-cell leukemia. We also showed that withdrawal of Zmiz1 generated an early T-lineage progenitor (ETP) defect. Here, we show that this early defect seems inconsistent with loss-of-Notch1 function. In contrast, at the later pre-T-cell stage, withdrawal of Zmiz1 impaired the DN-DP transition by inhibiting proliferation, like withdrawal of Notch. In pre-T cells, but not ETPs, Zmiz1 cooperatively regulated Notch1 target genes Hes1, Lef1, and Myc. Enforced expression of either activated Notch1 or Myc partially rescued the Zmiz1-deficient DN-DP defect. We identified residues in the tetratricopeptide repeat (TPR) domain of Zmiz1 that bind Notch1. Mutating only a single residue impaired the Zmiz1-Notch1 interaction, Myc induction, the DN-DP transition, and leukemic proliferation. Similar effects were seen using a dominant-negative TPR protein. Our studies identify stage-specific roles of Zmiz1. Zmiz1 is a context-specific cofactor for Notch1 during Notch/Myc-dependent thymocyte proliferation, whether normal or malignant. Finally, we highlight a vulnerability in leukemic cells that originated from a developmentally important Zmiz1-Notch1 interaction that is hijacked during transformation from normal pre-T cells.

Identification of inhibitors of the polo-box domain of polo-like kinase 1 from natural and semisynthetic compounds.

PLK1 has an important role in the regulation of cell cycle and represents an important target for cancer treatment. This enzyme belongs to the Polo-like kinases family, which is characterized by a regulatory domain named Polo-box domain (PBD). Rather than regular kinase inhibitors, this domain provides high selectivity to PLK1. Here, we report on four novel PLK1 PBD inhibitors identified by cytotoxicity screening and fluorescence polarization assay of a chemical library of natural and semisynthetic compounds. These compounds revealed two- to three-fold higher selectivity to the PDB of PLK1 than to those of the related family members, PLK2 and PLK3. These four substances inhibited tumor cell growth of sensitive CCRF-CEM and multidrug-resistant CEM/ADR5000 leukemia cells. The tested compounds increased the apoptotic cell fraction, which indicates apoptosis as a major mechanism of cell death. Cell cycle analysis showed compound (5) arrested the cell cycle of CCRF-CEM cells in the G2/M phase, while the other three molecules ((compound (3), compound (4), and compound (6)) exerted pronounced cytotoxicity with an increase of cells in the sub-G1 population. Molecular docking was performed for the understanding of ligand-protein interaction, the tested candidates showed strong binding affinity to PLK1 PBD. In conclusion, we identified four new chemical scaffolds that may serve as lead compounds for the development of selective PLK1 inhibitors in the future.

Crosstalk between Noxa, Bcl-2, and ceramide in mediating p53-dependent apoptosis in Molt-4 human T-cell leukemia.

Ionizing radiation induces apoptosis in human Molt-4 leukemia cells in a p53-dependent manner. The tumor suppressor p53 stimulates various downstream targets that presumably trigger, individually or in concert, de novo ceramide synthesis and intrinsic apoptosis via mitochondrial outer membrane permeabilization (MOMP). Among these targets, BH3-only protein Noxa was found to be promptly activated by p53 prior to ceramide accumulation and apoptosis in response to irradiation. To evaluate the relation between Noxa and ceramide in irradiation-induced apoptosis, Noxa was silenced in Molt-4 cells and apoptosis, p53 expression, and ceramide accumulation were assessed in response to irradiation. In the absence of Noxa, irradiation of Molt-4 cells still induced apoptosis in a p53-dependent manner however ceramide levels decreased significantly although they remained higher than untreated control. Upon irradiation, Noxa was found to translocate to the mitochondria where endogenous ceramide accumulation was observed. In contrast, overexpression of Bcl-2, another mitochondrial protein, in Molt-4 cells abolished the endogenous ceramide accumulation and apoptosis. In irradiation-induced, p53-dependent pathways of apoptosis, the pro-apoptotic Noxa represents one of several, yet to be identified, pathways simultaneously triggered by p53 to produce mitochondrial ceramide accumulation and apoptosis. In contrast, Bcl-2 functions as a broader inhibitor of both ceramide accumulation and apoptosis. Altogether, these results indicate that members of the Bcl-2 family differentially regulate ceramide accumulation and reveal the existence of crosstalk between Bcl-2 family members and ceramide in mediating p53-dependent apoptosis in Molt-4 human T-cell leukemia.

Synthesis and Biological Evaluation of Analogs of Didehydroepiandrosterone as Potential New Anticancer Agents.

The synthesis, cytotoxicity and inhibition of CDK8 by thirteen analogs of cortistatin A are reported. These efforts revealed that the analogs with either a 6- or 7-isoquinoline or 5-indole side chain in the 17-position are the most promising anti-proliferative agents. These compounds showed potent cytotoxic effects in CEM, HeLa and HMEC-1 cells. All three compounds exhibited IC50 values < 10µM. The most interesting 10l analog exhibited an IC50 value of 0.59 µM towards the human dermal microvascular endothelial cell line (HMEC-1), significantly lower than the reference standard 2-methoxyestradiol. At a concentration at 50 nM the most potent 10h compound reduced the activity of CDK8 to 35%.

Curcumin-1,2,3-Triazole Conjugation for Targeting the Cancer Apoptosis Machinery.

The burden of neoplastic diseases is widely recognized as a severe cause of mortality. The clinical inadequacy of most anticancer therapeutics urgently prompted intense drug discovery efforts toward the identification of new chemical entities endowed with a potent and safe antitumor profile. In this scenario, targeting cancer cells apoptosis machinery has emerged as a relevant strategy, useful for tackling the emergence of drug resistance. On this basis, a small library of naturally inspired hybrid molecules was obtained by combining, through a click chemistry approach, "privileged" synthons such as curcumin scaffold and 1,2,3-triazole building block. Compound 1, bearing a para-fluoro phenyl moiety, showed low-micromolar potency against T acute lymphoblastic leukemia cell growth. More in-depth biologic studies demonstrated, for this analog, cell death-inducing properties associated with its capability to simultaneously activate both the receptor and the mitochondrial apoptosis cascades. This peculiar behavior offers promises for achieving an expanded anticancer effect, namely intense cytotoxic response coupled with reduced predisposition of chemoresistance insurgence. Altogether, this study allowed the identification of compound 1 as a lead compound worth to be progressed as an anticancer drug candidate.

Central Nervous System Involvement of Natural Killer and T Cell Neoplasms.

PURPOSE OF REVIEW: Peripheral natural killer (NK) and T cell neoplasms comprise approximately 10-15% of non-Hodgkin lymphomas. There are 27 different subtypes of peripheral NK and T cell neoplasms, each of which is relatively uncommon. Treatment has been largely extrapolated from case series, retrospective reports, and paradigms developed for the aggressive B cell lymphomas. This review explores the current knowledge of the characteristics, outcome, and treatment of CNS T cell and NK neoplasms. RECENT FINDINGS: Primary and secondary CNS NK and T cell malignancies confer significant morbidity and poor prognosis. Despite clinical heterogeneity between the 27 subtypes, high-dose methotrexate-based regimens seem most effective overall. The role of prophylaxis against secondary CNS involvement remains controversial. Autologous stem cell transplant and immunotherapy are potential for promising future therapies. Current understanding of incidence, outcome, and optimal treatment strategies for CNS T cell and NK neoplasms is limited, in large part due to their diversity and rarity. Prognosis is poor, except in a few reports of long-term survival in patients most often treated with combination therapy including high-dose methotrexate. A future prospective study on treatment and outcome in CNS T cell and NK neoplasms is needed to better define these diseases.

Satureja hortensis induces cell death and inhibited cell cycle progression in K562 myelogenous and Jurkat T cell leukemia cell lines.

Several plants of Satureja genus have shown anti-tumor activity. We investigated the antileukemia effects of different fractions of Satureja hortensis (Summer savory). The growth inhibitory effect of S. hortensis fractions on K562 and Jurkat leukemia cells were determined by MTT assay. The most effective fractions were analyzed by flow cytometry and colorimetric assay for apoptosis induction and cell cycle changes. Various fractions from S. hortensis showed growth inhibitory effects on leukemia cells, among them two hexane and dichloromethane fractions with IC50 values of 32.1-47.8 µg/ml (K562) and 44.3-45.7 µg/ml (Jurkat) were the most effective. According to annexin V staining, both of these fractions significantly induced apoptosis at 50µg/ml in K562 (hexane; 73.06 ± 5.11% and dichloromethane; 96.14 ± 2.33%) and Jurkat cells (hexane; 78.85 ± 11.9% and dichloromethane; 94.05 ± 2.47%) 48 h after treatment. They increased cell accumulation in sub-G1 phase (>50%, p < .001) and decreased number of cells in G0-G1, S and G2M phases. The fractions significantly increased the caspase-3 activity in both cell lines (≈2.5-3.5 fold of untreated cells). Hexane and dichloromethane fractions of S. hortensis had the capacity to induce death and change the cell cycle distribution in leukemia cells; therefore they might be good candidates for more studies in regard to their possible therapeutic usefulness in leukemia.

FoxN1-dependent thymic epithelial cells promote T-cell leukemia development.

T-cell acute lymphoblastic leukemia (T-ALL) and T-lymphoblastic lymphomas (T-LBL) are aggressive malignancies of thymocytes. The role of thymic microenvironmental cells and stromal factors in thymocyte malignant transformation and T-ALL development remains little explored. Here, using the TEL-JAK2 transgenic (TJ2-Tg) mouse model of T-ALL/LBL, which is driven by constitutive JAK/STAT signaling and characterized by the acquisition of Notch1 mutations, we sought to identify stromal cell alterations associated with thymic leukemogenesis. Immunofluorescence analyses showed that thymic lymphomas presented epithelial areas characterized by keratin (Krt) 5 and Krt8 expression, adjacently to epithelial-free areas negative for Krt expression. Both areas contained abundant laminin (extracellular matrix) and ER-TR7+ (fibroblasts) CD31+ (endothelial) and CD11c+ (dendritic) cells. Besides Krt5, Krt-positive areas harbored medullary thymic epithelial cells (TECs) labeled by Ulex europaeus agglutinin-1. By performing flow cytometry and RNA sequencing analyses of thymic lymphomas, we observed an enrichment in medullary TEC markers in detriment of cortical TEC markers. To assess whether TECs are important for T-ALL/LBL development, we generated TJ2-Tg mice heterozygous for the FoxN1 transcription factor nude null mutation (Foxn1+/nu). Strikingly, in TJ2-Tg;Foxn1+/nu compound mice, both emergence of malignant cells in preleukemic thymi and overt T-ALL onset were significantly delayed. Moreover, in transplantation assays, leukemic cell expansion within the thymus of recipient Foxn1+/nu mice was reduced as compared with control littermates. Since thymopoesis is largely normal in Foxn1+/nu mice, these results indicate that FoxN1 haploinsufficiency in TECs has a more profound impact in thymic leukemogenesis.

Disparate effects of Shb gene deficiency on disease characteristics in murine models of myeloid, B-cell, and T-cell leukemia.

The Src homology-2 domain protein B is an adaptor protein operating downstream of tyrosine kinases. The Shb gene knockout has been found to accelerate p210 Breakpoint cluster region-cAbl oncogene 1 tyrosine kinase-induced leukemia. In human myeloid leukemia were tumors with high Src homology-2 domain protein B mRNA content, tumors were, however, associated with decreased latency and myeloid leukemia exhibiting immune cell characteristics. Thus, the aim of this study was to investigate the effects of Shb knockout on the development of leukemia in three additional models, that is, colony stimulating factor 3 receptor-T618I-induced neutrophilic leukemia, p190 Breakpoint cluster region-cAbl oncogene 1 tyrosine kinase-induced B-cell leukemia, and G12D-Kras-induced T-cell leukemia/thymic lymphoma. Wild-type or Shb knockout bone marrow cells expressing the oncogenes were transplanted to bone marrow-deficient recipients. Organs from moribund mice were collected and further analyzed. Shb knockout increased the development of CSF3RT618I-induced leukemia and increased the white blood cell count at the time of death. In the p190 Breakpoint cluster region-cAbl oncogene 1 tyrosine kinase B-cell model, Shb knockout reduced white blood cell counts without affecting latency, whereas in the G12D-Kras T-cell model, thymus size was increased without major effects on latency, suggesting that Shb knockout accelerates the development thymic lymphoma. Cytokine secretion plays a role in the progression of leukemia, and consequently Shb knockout bone marrows exhibited lower expression of granulocyte colony stimulating factor and interleukin 6 in the neutrophilic model and interleukin 7 and chemokine C-X-C motif ligand 12 (C-X-C motif chemokine 12) in the B-cell model. It is concluded that in experimental mouse models, the absence of the Shb gene exacerbates the disease in myeloid leukemia, whereas it alters the disease characteristics without affecting latency in B- and T-cell leukemia. The results suggest a role of Shb in modulating the disease characteristics depending on the oncogenic insult operating on hematopoietic cells. These findings help explain the outcome of human disease in relation to Src homology-2 domain protein B mRNA content.

Lewis-antigen-containing ICAM-2/3 on Jurkat leukemia cells interact with DC-SIGN to regulate DC functions.

Dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) is an important C-type lectin and plays a critical role in the recognition of pathogens and self-antigens. It has recently been shown that DC-SIGN directly interacts with acute T lymphoblastic leukemia cells. However, the mechanism regulating DC-SIGN-dependent DC association as well as related functions is still elusive. Here we showed that DC-SIGN preferentially bound to a set of malignant T lymphocytes, including Jurkat, CCRF-HSB2 and CCRF-CEM. ICAM-2/3 on Jurkat cells appeared to be the responsible ligands and the block of ICAM-2/3 dramatically impaired DC-SIGN association. We also found that ICAM-2/3 bear a considerable amount of Lewis X, Lewis Y and Lewis A residues, which are important for DC-SIGN recognition. Furthermore, transcriptome analysis revealed an upregulation of fucosyltransferase 4 (FUT4) in Jurkat cells and downregulating FUT4 limited DC-SIGN binding, indicating a previously unappreciated role of FUT4 in the control of Lewis antigens on malignant T lymphocytes. In addition, the presence of Jurkat cells impaired DC maturation and the block of DC-SIGN improved Jurkat cell-mediated effects on DC function and T cell differentiation. Together, we provide evidence that DC-SIGN orients DC association with acute T lymphoblastic leukemia cells and orchestrates DC functions.

The Effect of Over-Expression of miR-20a on Cell Proliferation of Human T Cell Leukemia Cell Line.

BACKGROUND: Acute T Cell Leukemia (ALL) is an aggressive and prevalent human malignancy. Chemotherapy is the most frequent therapeutic strategy; however, cytotoxicity and recurrence of cancer are the main concerns. The discovery of microRNA (miRNA) drew the attention of scientists who were working on targeted cancer therapy to use the potential of gene regulation by using this small RNAs. METHODS: miRanda, TargetScan, miRDB databases, and miRWalk software were applied to find probable miRNAs targeting 3'UTR of JAK1, STAT3, SOCS6, AKT1, APAF, BID, and Caspase9 mRNA. A lentiviral vector encoding miR-20a was used for overexpression of the miR-20a in C8166 cell lines to investigate the expression level of genes that are associated with the JAK/STAT signaling pathway and apoptosis using quantitative RTPCR. The effects of miR-20a overexpression also were examined on cell-cycle progression by flow cytometry. RESULTS: qRT-PCR results indicated that overexpression of miR-20a in C8166 cells resulted in significantly elevated expression of BID and Caspase9 (p-value < 0.01). Overexpression of miR-20a in C8166 cells led to cell cycle arrest at the G0/G1 phase. CONCLUSIONS: The results suggested miR-20a may act as a tumor suppressor in CD4+ T cells and also has a potential therapeutic in these kinds of cancers.

DCZ3301, a novel aryl-guanidino inhibitor, induces cell apoptosis and cell cycle arrest via suppressing the PI3K/AKT pathway in T-cell leukemia/lymphoma.

DCZ3301, a novel aryl-guanidino compound, was previously found to have potent anti-tumor activity in myeloma and B-cell lymphoma. In the present study, we investigated the effects of DCZ3301 on T-cell leukemia/lymphoma cells both in vitro and in vivo via cell proliferation, cell cycle analysis, apoptosis assay, mitochondrial membrane potential (MMP) assay, western blot analysis and tumor xenograft models. We found that DCZ3301 inhibited the viability of T-cell leukemia/lymphoma cells in a dose- and time-dependent manner. DCZ3301-induced G2/M cell cycle arrest, associated with downregulation of CDK1, cyclin B1, and cdc25C. DCZ3301 also induced cell apoptosis by decreasing MMP in T-cell leukemia/lymphoma cells, but had no significant pro-apoptotic effect on normal peripheral blood mononuclear cells (PBMCs). In addition, DCZ3301-induced apoptosis may be mediated by the caspase-dependent pathway and suppressing the phosphoinositide 3-kinase (PI3K)/AKT pathway. Finally, we showed that DCZ3301 treatment effectively inhibited tumor growth, with no significant side effects, in xenograft mouse models. In conclusion, these results suggest that DCZ3301 may be regarded as a new therapeutic strategy for T-cell leukemia/lymphoma patients.

Non-Structural Proteins from Human T-cell Leukemia Virus Type 1 in Cellular Membranes-Mechanisms for Viral Survivability and Proliferation.

Human T-cell leukemia virus type 1 (HTLV-1) is the causative agent of illnesses, such as adult T-cell leukemia/lymphoma, myelopathy/tropical spastic paraparesis (a neurodegenerative disorder), and other diseases. Therefore, HTLV-1 infection is a serious public health concern. Currently, diseases caused by HTLV-1 cannot be prevented or cured. Hence, there is a pressing need to comprehensively understand the mechanisms of HTLV-1 infection and intervention in host cell physiology. HTLV-1-encoded non-structural proteins that reside and function in the cellular membranes are of particular interest, because they alter cellular components, signaling pathways, and transcriptional mechanisms. Summarized herein is the current knowledge about the functions of the membrane-associated p8I, p12I, and p13II regulatory non-structural proteins. p12I resides in endomembranes and interacts with host proteins on the pathways of signal transduction, thus preventing immune responses to the virus. p8I is a proteolytic product of p12I residing in the plasma membrane, where it contributes to T-cell deactivation and participates in cellular conduits, enhancing virus transmission. p13II associates with the inner mitochondrial membrane, where it is proposed to function as a potassium channel. Potassium influx through p13II in the matrix causes membrane depolarization and triggers processes that lead to either T-cell activation or cell death through apoptosis.