Rhabdomyosarcoma (RMS) is the most common soft-tissue sarcoma in childhood. Here we studied 60 RMSs using whole-exome/-transcriptome sequencing, copy number (CN) and DNA methylome analyses to unravel ...the genetic/epigenetic basis of RMS. On the basis of methylation patterns, RMS is clustered into four distinct subtypes, which exhibits remarkable correlation with mutation/CN profiles, histological phenotypes and clinical behaviours. A1 and A2 subtypes, especially A1, largely correspond to alveolar histology with frequent PAX3/7 fusions and alterations in cell cycle regulators. In contrast, mostly showing embryonal histology, both E1 and E2 subtypes are characterized by high frequency of CN alterations and/or allelic imbalances, FGFR4/RAS/AKT pathway mutations and PTEN mutations/methylation and in E2, also by p53 inactivation. Despite the better prognosis of embryonal RMS, patients in the E2 are likely to have a poor prognosis. Our results highlight the close relationships of the methylation status and gene mutations with the biological behaviour in RMS.
Adult T-cell leukemia (ATL) is a heterogeneous tumor that is resistant to chemotherapy. Telomerase activity plays a critical role in tumorigenesis and is associated with the prognosis of ATL ...patients. Interleukin (IL)-2 commonly promotes tumor growth in chronic ATL cells. The signaling pathways involved in IL-2-regulated telomerase activation were studied in ATL cells derived from chronic ATL patients. IL-2 challenge enhanced tyrosine phosphorylation of Janus-activated kinase (JAK)1-3 and STAT5, and induced JAK1 and JAK2 to associate with STAT5 in IL-2-dependent ATL cells. Chromatin immunoprecipitation assays revealed that STAT5 directly bound to the human telomerase reverse transcriptase (hTERT) promoter. STAT5 short interfering RNA inhibited hTERT transcription in IL-2-stimulated ATL cells. Inhibitors of PI3K, HSP90, and mTOR reduced IL-2-induced hTERT mRNA, protein expression, and telomerase activity. AKT, HSP90, mTOR, S6 kinase, and hTERT immunoprecipitate from IL-2-stimulated cells contained telomerase activity, suggesting that hTERT directly interacts with, and is regulated by, these proteins. Binding of the p85 regulatory subunit of PI3K to JAK2 was enhanced in an IL-2-dependent manner, indicating that JAK2 propagates activation signals from the IL-2 receptor and links hTERT activation to both the STAT5 and PI3K pathways. Finally, IL-2-induced activation of telomerase and STAT5 was observed in primary leukemic cells. These results indicate that IL-2 stimulation induces hTERT activation through the JAK/STAT pathway and the JAK/PI3K/AKT/HSP90/mTORC1 pathway in IL-2-responsive ATL cells. These signaling proteins represent novel and promising molecular therapeutic targets for IL-2-dependent ATL.
Molecular mechanisms involved in the relapse of T‐cell acute lymphoblastic leukemia (T‐ALL) are not fully understood, although activating NOTCH1 signaling due to NOTCH1/FBXW7 alterations is a major ...oncogenic driver. To unravel the relevance of NOTCH1/FBXW7 mutations associated with relapse, we performed whole–exome sequencing in 30 pediatric T‐ALL cases, among which 11 diagnosis‐relapse paired cases were further investigated to track the clonal evolution of relapse using amplicon–based deep sequencing. NOTCH1/FBXW7 alterations were detected in 73.3% (diagnosis) and 72.7% (relapse) of cases. Single nucleotide variations in the heterodimerization domain were the most frequent (40.0%) at diagnosis, whereas proline, glutamic acid, serine, threonine–rich (PEST) domain alterations were the most frequent at relapse (54.5%). Comparison between non–relapsed and relapsed cases at diagnosis showed a predominance of PEST alterations in relapsed cases (P = .045), although we failed to validate this in the TARGET cohort. Based on the clonal analysis of diagnosis‐relapse samples, we identified NOTCH1 “switching” characterized by different NOTCH1 mutations in a major clone between diagnosis and relapse samples in 2 out of 11 diagnosis‐relapse paired cases analyzed. We found another NOTCH1 “switching” case in a previously reported Berlin‐Frankfurt‐Münster cohort (n = 13), indicating NOTCH1 importance in both the development and progression of T‐ALL. Despite the limitations of having a small sample size and a non–minimal residual disease–based protocol, our results suggest that the presence of NOTCH1 mutations might contribute to the disease relapse of T‐ALL.
As molecular mechanisms involved in the relapse of T‐ALL are not fully understood, we performed clonal analysis of diagnosis‐relapse samples using next–generation sequencing, specifically to establish the relevance of NOTCH1/FBXW7 mutations associated with relapse. We identified mutational “switching” of NOTCH1 showing different NOTCH1 mutations between diagnostic and relapsed specimens in multiple samples, which indicates the importance in development and progression of T‐ALL.
Ocular manifestations are known for non-Hodgkin lymphoma, but are rare for Hodgkin lymphoma. We report a case of Vogt-Koyanagi-Harada (VKH) disease presenting as serous retinal detachment and uveitis ...in both eyes in a child undergoing chemotherapy for Hodgkin lymphoma.
The patient was a 7-year-old boy with stage IIB Hodgkin lymphoma (nodular lymphocyte predominant type) who was undergoing chemotherapy, including 2 cycles of the OEPA regimen and 1 cycle of the COPDAC regimen. Two days after the end of the COPDAC regimen, the patient complained of headache and of blurred and decreased vision in both eyes. On the basis of optic symptoms, such as uveitis and serous retinal detachment in both eyes, increased cell counts in cerebrospinal fluid, and positivity for human leukocyte antigen (HLA)-DR4 in peripheral blood cells, incomplete VKH disease was diagnosed. Intravenous treatment with high-dose prednisolone (60mg/m
/day) for 7 days improved both visual acuity and serous retinal detachment and enabled the remains of the COPDAC chemotherapy cycle to be administered. With prednisolone treatment, visual acuity improved from 20/500 to 20/20 in the right eye and from 20/63 to 20/25 in the left eye. Because multiple vitiligo lesions later appeared in the abdomen, complete VKH disease was finally diagnosed.
The onset of VKH disease occurred during chemotherapy for Hodgkin lymphoma. The patient was HLA-DR4-positive and might have had a predisposition to develop autoimmune diseases, including VKH disease. However, the anticancer drugs administered to this patient have not been reported to cause uveitis. Whether Hodgkin lymphoma triggered the development of VKH remains unclear. Early diagnosis of VKH disease and prompt treatment with high-dose prednisone enabled the patient to maintain good visual function despite chemotherapy for Hodgkin lymphoma.
Central skull base osteomyelitis (CSBO) that has expanded to the middle cranial fossa is a rare complication of nasopharyngeal infection in children. Diagnosing CSBO is challenging in children, ...because specific symptoms are lacking and imaging findings can mimic skull base malignancy. We report on a 3-year-old girl who complained of pyrexia, headache, and vomiting and in whom a mass around the clivus was detected with magnetic resonance imaging. The patient received a diagnosis of CSBO based on characteristic imaging findings and the detection of a
Streptococcus milleri
group (SMG) in blood cultures. Clinical symptoms and abnormal imaging findings, including a mass lesion, were improved by prompt antibiotic treatment. The present patient had paranasal sinusitis with bacteremia of SMG, leading to the speculation of hematogeneous dissemination of SMG from the paranasal sinus. Awareness of CSBO, its early diagnosis, and aggressive management are required because CSBO is associated with high morbidity due to a life-threating infection involving multiple cranial nerves.
Abstract The cationic porphyrin TMPyP4 can bind to and stabilize DNA guanine-quadruplexes. We investigated the molecular mechanism of the antitumor activity of TMPyP4 in K562 cells and human telomere ...reverse transcriptase subunit (hTERT)-transfected K562 cells in which telomerase activity, followed by telomere elongation, was enhanced. Treatment with 100 μM TMPyP4 significantly inhibited the growth of both types of cell, with decreases of cells in the G1 phase and increases of those in the S and G2 /M phases after 48 h, preceding cell death after 72 h. cDNA microarray analysis revealed upregulation of 33 genes and downregulation of 54 genes in K562 cells treated with 100 μM TMPyP4 for 48 h. Moreover, TMPyP4 decreased c-Myc protein expression, increased the expression of p21CIP1 and p57KIP2 proteins, and activated p38 mitogen-activated protein kinase, c-Jun N-terminal kinase, and extracellular signal-regulated kinase. These findings may provide a rationale for the development of guanine-quadruplex–interactive agents as novel antileukemic therapies.
Hepatosplenic T-cell lymphoma (HSTCL) is a rare subtype of peripheral T-cell lymphoma that occurs most often in adolescents and young adults and is rare in children. Because of the aggressive ...clinical course, resistance to conventional chemotherapy and poor prognosis of HSTCL, an effective treatment has not been established. We report the case of a 3-year-old girl with HSTCL presenting with trilineage myelodysplasia. Although the HSTCL was refractory to conventional chemotherapy, remission was achieved with salvage chemotherapy that included fludarabine and cytarabine, which were shown to be effective in the drug sensitivity assay. After undergoing umbilical cord blood transplantation with a conditioning regimen consisting of etoposide, cyclophosphamide and total body irradiation, the patient has remained in complete remission for 8 years. Single-nucleotide polymorphism array analysis revealed heterozygous deletions of
PAX5
(9p),
ETV6
(12p) and homozygous deletions of
CDKN2A
(9p). Exome analysis showed a heterozygous nonsense c.2961C>G (p.Tyr987Ter) variant of the
KMT2C
gene. To improve the poor prognosis of HSTCL, the chemotherapeutic regimen can be selected for each patient on the basis of drug sensitivity and molecular genetic characteristics.
We have recently shown that proteasome inhibitor PS-341 induces apoptosis in drug-resistant multiple myeloma (MM) cells, inhibits binding of MM cells in the bone marrow microenvironment, and inhibits ...cytokines mediating MM cell growth, survival, drug resistance, and migration in vitro. PS-341 also inhibits human MM cell growth and prolongs survival in a SCID mouse model. Importantly, PS-341 has achieved remarkable clinical responses in patients with refractory relapsed MM. We here demonstrate molecular mechanisms whereby PS-341 mediates anti-MM activity by inducing p53 and MDM2 protein expression; inducing the phosphorylation (Ser15) of p53 protein; activating c-Jun NH2-terminal kinase (JNK), caspase-8, and caspase-3; and cleaving the DNA protein kinase catalytic subunit, ATM, and MDM2. Inhibition of JNK activity abrogates PS-341–induced MM cell death. These studies identify molecular targets of PS-341 and provide the rationale for the development of second-generation, more targeted therapies.
Insulin-like growth factors and their receptor (IGF-1R) have been implicated in cancer pathophysiology. We demonstrate that IGF-1R is universally expressed in various hematologic (multiple myeloma, ...lymphoma, leukemia) and solid tumor (breast, prostate, lung, colon, thyroid, renal, adrenal cancer, retinoblastoma, and sarcoma) cells. Specific IGF-1R inhibition with neutralizing antibody, antagonistic peptide, or the selective kinase inhibitor NVP-ADW742 has in vitro activity against diverse tumor cell types (particularly multiple myeloma), even those resistant to conventional therapies, and triggers pleiotropic antiproliferative/proapoptotic molecular sequelae, delineated by global transcriptional and proteomic profiling. NVP-ADW742 monotherapy or its combination with cytotoxic chemotherapy had significant antitumor activity in an orthotopic xenograft MM model, providing in vivo proof of principle for therapeutic use of selective IGF-1R inhibitors in cancer.
Summary
Thalidomide and immunomodulatory drugs (IMiDs), which target multiple myeloma (MM) cells and the bone marrow microenvironment, can overcome drug resistance. These agents also have ...immunomodulatory effects. Specifically, we have reported that thalidomide increased serum interleukin‐2 (IL‐2) levels and natural killer (NK) cell numbers in the peripheral blood of responding MM patients. In this study, we investigated the mechanisms whereby IMiDs augment NK cell cytotoxicity. NK cytotoxicity and antibody‐dependent cell‐mediated cytotoxicity (ADCC) of peripheral blood mononuclear cells cultured with IMiDs were examined in the presence or absence of anti‐IL‐2 antibody, ciclosporin A or depletion of CD56‐positive cells. IMiDs‐induced signalling pathways, triggering IL‐2 transcription in T cells, were also delineated. IMiDs facilitated the nuclear translocation of nuclear factor of activated T cells‐2 and activator protein‐1 via activation of phosphoinositide‐3 kinase signalling, with resultant IL‐2 secretion. IMiDs enhanced both NK cell cytotoxicity and ADCC induced by triggering IL‐2 production from T cells. These studies defined the mechanisms whereby IMiDs trigger NK cell‐mediated tumour‐cell lysis, further supporting their therapeutic use in MM.
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