Project description:Sézary syndrome (SS), an aggressive cutaneous T-cell lymphoma (CTCL) with poor prognosis, is characterized by the clinical hallmarks of circulating malignant T cells, erythroderma and lymphadenopathy. However, highly variable clinical skin manifestations and similarities with benign mimickers can lead to significant diagnostic delay and inappropriate therapy that can lead to disease progression and mortality. SS has been the focus of numerous transcriptomic-profiling studies to identify sensitive and specific diagnostic and prognostic biomarkers. Benign inflammatory disease controls (e.g., psoriasis, atopic dermatitis) have served to identify chronic inflammatory phenotypes in gene expression profiles, but provide limited insight into the lymphoproliferative and oncogenic roles of abnormal gene expression in SS. This perspective was recently clarified by a transcriptome meta-analysis comparing SS and lymphocytic-variant hypereosinophilic syndrome, a benign yet often clonal T-cell lymphoproliferation, with clinical features similar to SS. Here we review the rationale for selecting lymphocytic-variant hypereosinophilic syndrome (L-HES) as a disease control for SS, and discuss differentially expressed genes that may distinguish benign from malignant lymphoproliferative phenotypes, including additional context from prior gene expression studies to improve understanding of genes important in SS.
Project description:In a placebo-controlled study, denileukin diftitox (DD) was effective against cutaneous T-cell lymphoma (CTCL) expressing CD25. An open-label companion study examined the efficacy and safety of DD in 36 patients with skin biopsies containing < 20% CD25 cells by immunohistochemistry staining (CD25 low expression). Patients received DD 18 μg/kg/day for 5 consecutive days every 3 weeks for up to eight courses. The primary endpoint, overall response rate, was 30.6% (95% confidence interval: 16.3, 48.1), 33.3% for stage IIA or lower disease, and 26.7% for stage IIB or greater disease. Median progression-free survival (PFS) was > 487 days, and median time to treatment failure was 68.5 days. No difference in PFS by disease stage was observed. The safety profile of DD in CD25 low-expression disease was similar to that in CD25+ disease. These findings suggest that CD25 low expression does not preclude a meaningful clinical response to DD in patients with CTCL.
Project description:BackgroundMicroarray hybridization studies in Sézary syndrome (SS) have compared T lymphocytes from patients with cutaneous T-cell lymphoma with those of normal controls; a major limitation of this design is that significant inherent genetic variability of lymphocyte populations between individuals may produce differences in gene expression unrelated to disease state.ObjectiveThe objective of this study was to minimize the heterogeneity of information derived from whole-genome expression analysis and to identify specific genetic differences between highly purified malignant and nonmalignant (control) T cells from the same patient with SS.MethodsPeripheral blood mononuclear cells were obtained from a patient with SS, stained with anti-T-cell receptor Vb (TCR-Vb) antibodies, and sorted by multiparameter flow cytometry. Malignant cells expressed the dominant TCR-Vb; control T cells lacked the dominant TCR-Vb but were otherwise phenotypically identical (CD3+CD4+CD45RO+). These cell populations were compared using the Illumina Inc. Sentrix Human-6 expression BeadChip system.ResultsTranscriptome analysis using the J5 test, which was selected for data analysis based on an efficiency analysis of competing statistical methods, showed differential expression of 44 genes between the malignant and nonmalignant cell subsets. Promyelocytic leukaemia zinc finger protein (ZBTB16) was the most profoundly upregulated gene in the malignant cell population, while interferon regulatory factor 3 (IRF3) and interferon-induced protein 35 (IFI35), which are important elements of the cellular response to viral infection, were significantly downregulated.ConclusionsThe results of this study suggest the feasibility of this novel comparative approach to genomic profiling in SS. Using this method, we identified several differentially expressed genes and pathways not previously described in SS. While these findings require validation in larger studies, they may be important in SS pathogenesis.
Project description:MicroRNAs are commonly aberrantly expressed in many cancers. Very little is known of their role in T-cell lymphoma, however. We therefore elucidated the complete miRNome of purified T cells from 21 patients diagnosed with Sézary Syndrome (SzS), a rare aggressive primary cutaneous T-cell (CD4(+)) lymphoma. Unsupervised cluster analysis of microarray data revealed that the microRNA expression profile was distinct from CD4(+) T-cell controls and B-cell lymphomas. The majority (104 of 114) of SzS-associated microRNAs (P < .05) were down-regulated and their expression pattern was largely consistent with previously reported genomic copy number abnormalities and were found to be highly enriched (P < .001) for aberrantly expressed target genes. Levels of miR-223 distinguished SzS samples (n = 32) from healthy controls (n = 19) and patients with mycosis fungoides (n = 11) in more than 90% of samples. Furthermore, we demonstrate that the down-regulation of intronically encoded miR-342 plays a role in the pathogenesis of SzS by inhibiting apoptosis, and describe a novel mechanism of regulation for this microRNA via binding of miR-199a* to its host gene. We also provide the first in vivo evidence for down-regulation of the miR-17-92 cluster in malignancy and demonstrate that ectopic miR-17-5p expression increases apoptosis and decreases cell proliferation in SzS cells.
Project description:Special AT-rich sequence-binding protein-1 (SATB1) has been identified as a genome organizer that reprograms chromatin organization and transcription profiles. SATB1 promotes tumor growth and metastasis in breast cancer and is associated with poor prognosis in several cancer types. The association between SATB1 and colorectal cancer (CRC) has not been studied intensively. Therefore, this study aimed to investigate the effect of SATB1 on CRC growth and metastasis in vitro and in vivo and its correlation with overall survival and clinicopathological factors in CRC patients. Stable SATB1 knockdown and SATB1-overexpressing cell lines were established. SATB1 knockdown decreased cell growth, colony formation, migration, and invasion and increased apoptosis in CRC cells in vitro (p<0.05), whereas SATB1 overexpression had the opposite effect. SATB1 overexpression increased tumor growth and metastasis to lung and liver in vivo by using xenograft animal models (p<0.05). Thus, SATB1 promoted an aggressive CRC phenotype in vitro and in vivo. Immunohistochemical analysis of 560 CRC specimens showed that SATB1 expression was significantly higher in CRC tissues than in matched non-tumor mucosa (p<0.001). In addition, SATB1 expression was significantly higher in patients with poorly differentiated tumors, higher invasion depth, distant metastasis, and advanced TNM stage. SATB1-positive patients had a poorer prognosis than SATB1-negative patients, and SATB1 was identified as an independent prognostic factor for CRC (p = 0.009). Strikingly, we also evaluated SATB2 expression in CRC and found that SATB2 was more abundantly expressed in non-cancerous mucosa compared to colorectal cancer tissues (p<0.001). However, SATB2 expression had no influence on prognosis of CRC patients (p = 0.836). SATB1 expression was significantly associated with shorter survival time either in SATB2-positive patients or in SATB2-negative patients (p<0.001). In conclusion, our findings indicated an important role for SATB1 in CRC tumorigenesis and metastasis. Therefore, SATB1 may represent an important prognostic biomarker and therapeutic target for CRC.
Project description:Sézary syndrome (SS) is a rare variant of primary cutaneous T-cell lymphoma. Little is known about the underlying pathogenesis of S. To address this issue, we used Affymetrix 10K SNP microarray to analyse 13 DNA samples isolated from 8 SS patients and qPCR with ABI TaqMan SNP genotyping assays for the validation of the SNP microarray results. In addition, we tested the impact of SNP loss of heterozygosity (LOH) identified in SS cases on the gene expression profiles of SS cases detected with Affymetrix GeneChip U133A. The results showed: (1) frequent SNP copy number change and LOH involving 1, 2p, 3, 4q, 5q, 6, 7p, 8, 9, 10, 11, 12q, 13, 14, 16q, 17, and 20, (2) reduced SNP copy number at FAT gene (4q35) in 75% of SS cases, and (3) the separation of all SS cases from normal control samples by SNP LOH gene clusters at chromosome regions of 9q31q34, 10p11q26, and 13q11q12. These findings provide some intriguing information for our current understanding of the molecular pathogenesis of this tumour and suggest the possibility of presence of functional SNP LOH in SS tumour cells.
Project description:Sézary syndrome (SS) is an aggressive leukemic variant of cutaneous T-cell lymphoma (CTCL) with a median life expectancy of less than 4 years. Although initial treatment responses are often good, the vast majority of patients with SS fail to respond to ongoing therapy. We hypothesize that malignant T cells are highly heterogeneous and harbor subpopulations of SS cells that are both sensitive and resistant to treatment. Here, we investigate the presence of single-cell heterogeneity and resistance to histone deacetylase inhibitors (HDACi) within primary malignant T cells from patients with SS. Using single-cell RNA sequencing and flow cytometry, we find that malignant T cells from all investigated patients with SS display a high degree of single-cell heterogeneity at both the mRNA and protein levels. We show that this heterogeneity divides the malignant cells into distinct subpopulations that can be isolated by their expression of different surface antigens. Finally, we show that treatment with HDACi (suberanilohydroxamic acid and romidepsin) selectively eliminates some subpopulations while leaving other subpopulations largely unaffected. In conclusion, we show that patients with SS display a high degree of single-cell heterogeneity within the malignant T-cell population, and that distinct subpopulations of malignant T cells carry HDACi resistance. Our data point to the importance of understanding the heterogeneous nature of malignant SS cells in each individual patient to design combinational and new therapies to counter drug resistance and treatment failure.
Project description:The voltage-gated potassium channel Kv1.3 (KCNA3) is expressed by a subset of chronically activated memory T cells and plays an important role in their activation and proliferation. Here, we show that primary malignant T cells isolated from patients with Sézary syndrome (SS) express Kv1.3 and are sensitive to potent Kv1.3 inhibitors ShK and Vm24, but not sensitive to a less potent inhibitor [N17A/F32T]-AnTx. Kv1.3 blockade inhibits CD3/CD28-induced proliferation and IL-9 expression by SS cells in a concentration-dependent manner. In parallel, CD3/CD28-mediated CD25 induction is inhibited, whereas Kv1.3 blockade has no effect on apoptosis or cell death as judged by Annexin V and PI staining. In conclusion, we provide the first evidence that malignant T cells in SS express functional Kv1.3 channels and that Kv1.3 blockade inhibits activation-induced proliferation as well as cytokine and cytokine receptor expression in malignant T cells, suggesting that Kv1.3 is a potential target for therapy in SS.
Project description:Special AT-rich binding protein 1 (SATB1) is a global chromatin organizer and a transcription factor regulated by interleukin-4 (IL-4) during the early T helper 2 (Th2) cell differentiation. Here we show that SATB1 controls multiple IL-4 target genes involved in human Th cell polarization or function. Among the genes regulated by SATB1 is that encoding the cytokine IL-5, which is predominantly produced by Th2 cells and plays a key role in the development of eosinophilia in asthma. We demonstrate that, during the early Th2 cell differentiation, IL-5 expression is repressed through direct binding of SATB1 to the IL-5 promoter. Furthermore, SATB1 knockdown-induced up-regulation of IL-5 is partly counteracted by down-regulating GATA3 expression using RNAi in polarizing Th2 cells. Our results suggest that a competitive mechanism involving SATB1 and GATA3 regulates IL-5 transcription, and provide new mechanistic insights into the stringent regulation of IL-5 expression during human Th2 cell differentiation.
Project description:Posttransplant lymphoproliferative disorders (PTLDs) of T-cell orgin are rare biologically heterogeneous diseases of mature lymphoid cells manifesting in immunosuppressed patients. Only a few cases of mycosis fungoides diagnosed post allogeneic hematopoietic cell transplant (alloHSCT) have been described so far. We present a patient with myelodysplastic syndrome (MDS) post matched unrelated donor alloHSCT who was on long-term immunosuppressive therapy due to graft versus host disease. Three years after an alloHSCT, she developed generalized erythroderma and peripheral blood lymphocytosis. Both skin biopsy and peripheral blood flow cytometry revealed atypical CD4+ T-cell population consistent with diagnosis of Sezary syndrome. Chimerism studies revealed 100% donor engraftment. Therapy with extracorporeal photopheresis resulted in complete response in blood and skin.