Cutaneous T-cell Lymphoma Lesional Skin Research Articles

LAIR1 prevents excess inflammatory tissue damage in S. aureus skin infection and Cutaneous T-cell Lymphoma.

Patients with cutaneous T cell lymphoma (CTCL) experience high morbidity and mortality due to S. aureus skin infections and sepsis, but the causative immune defect is unclear. We previously identified high levels of LAIR2, a decoy protein for the inhibitory receptor LAIR1, in advanced CTCL. Mice do not have a LAIR2 homolog, so we used Lair1 knock-out (KO) mice to model LAIR2 overexpression. In a model of subcutaneous S. aureus skin infection, Lair1 KO mice had significantly larger abscesses and areas of dermonecrosis compared to WT. Lair1 KO exhibited a pattern of increased inflammatory responses in infection and sterile immune stimulation, including increased production of proinflammatory cytokines and myeloid chemokines, neutrophil ROS, and collagen/ECM remodeling pathways. Notably, Lair1 KO infected skin had a similar bacterial burden and neutrophils and monocytes had equivalent S. aureus phagocytosis compared to WT. These findings support a model in which lack of LAIR1 signaling causes an excessive inflammatory response that does not improve infection control. CTCL skin lesions harbored similar patterns of increased expression in cytokine and collagen/ECM remodeling pathways, suggesting that high levels of LAIR2 in CTCL recapitulates Lair1 KO, causing inflammatory tissue damage and compromising host defense against S. aureus infection.

CD25 expression could be a prognostic marker of bexarotene monotherapy for cutaneous T-cell lymphomas.

Bexarotene is often administered to phototherapy-resistant early cutaneous T-cell lymphoma (CTCL) patients as one of the first-line therapies in real-world practice. Since bexarotene reduces the expression of CCR4 in CTCL cells and CCL22 to decrease serum CCL22 levels, bexarotene inhibits the migration of CTCL cells, as well as other CCR4+ cells, such as cytotoxic T cells and regulatory T cells, in the lesional skin of CTCL. In this report, the efficacy of bexarotene in 28 cases of CTCL, as well as its correlations with immunohistochemical profiles of tumour-infiltrating leucocytes (TILs), was retrospectively investigated. The overall response rate at 1 and 4months for the total cohort was 70.8% (95% CI, 50.6%-86.3%) and 47.8% (95% CI, 29.2%-67.0%), respectively. The disease control rate for the total cohort at 4months was 65.2% (95% CI, 44.8%-81.3%). The mean event-free survival for all patients was 4.1months (0.3-68.5months). In addition, the immunoreactive cells were calculated using digital microscopy, suggesting that the ratio of CD25+ cells among TILs was significantly increased in patients who responded to bexarotene (p=0.0209), whereas there were no significant differences in the ratios of CD8+ cells, granulysin+ cells, and Foxp3+ cells among TILs between responder and non-responder patients. Collectively, the ratio of CD25 expression among TILs might be a predictive biomarker for the efficacy of bexarotene.

Targeting Immunosuppressive Macrophages in the Cutaneous T-Cell Lymphoma Microenvironment

Introduction: Immunosuppressive M2-like macrophages contribute to malignancy progression in cutaneous T-cell lymphoma (CTCL). Hence targeting M2-like macrophage differentiation and function may have potential therapeutic utility in CTCL. Targetable signaling pathways in M2 macrophages include the mannose receptor CD206 and the pattern recognition receptor Toll-like Receptor 4 (TLR4). Objective: To evaluate TLR4 and CD206 function in CTCL-associated macrophages and their therapeutic potential as targets of immunomodulation. Methods: We assessed TLR4 and CD206 expression in human CTCL lesional skin biopsies and in transwell co-cultures containing macrophages and CTCL cells. Using an established murine model of CTCL, we quantified tumor burden of mouse MBL2 cells after transplantation into immunocompetent mice with and without manipulating TLR4 or CD206 function. To abrogate TLR4 function we used TLR4 deficient mice and to stimulate CD206 signaling we used a novel CD206 binding peptide, RP-832c. Results: Human CTCL lesional skin biopsies and MBL2 tumors displayed co-localized expression of CD206 and TLR4 on macrophages. CTCL-associated macrophages in co-cultures exhibited an M2-like polarized phenotype as well as increased TLR4 expression. In contrast, when these co-cultures were treated with RP-832c, macrophages displayed the M1-like phenotype. In mice lacking TLR4, CTCL tumor growth was reduced (Figure 1) and M1 to M2 macrophage ratios were significantly higher compared to that of wild type. Similarly, CTCL tumors in mice treated with RP-832c displayed a shift from M2 macrophage phenotype to M1 and exhibited attenuated tumor growth (Figure 2). Conclusion: Our data suggest that both TLR4 inhibition and CD206 activation in the CTCL tumor microenvironment inhibit tumor growth by inducing a phenotypic shift from immunosuppressive M2-like to anti-tumor M1-like macrophages. Therefore, topical or systemic formulations of CD206 binding peptide, RP-832c, and small molecule TLR4 inhibitors present promising immunomodulatory therapeutic options in CTCL. Figure 1: MBL2 cells were injected s.c. into flanks of C57BL/6 and TLR4-/- recipients (5 mice /grp.) and tumor volumes monitored overtime. Shown are the mean and standard error for each group. Figure 2: MBL2 cells were injected s.c. into flanks of C57BL/6 recipients (5 mice /grp.) and mice were treated daily with i.p. injections of RP832c or saline starting 10 days post inoculation. Tumor volumes were monitored overtime. Shown are the mean and standard error for each group. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

110 Non-invasive molecular analysis for CTCL detection and differentiation from other skin conditions with adhesive smart sticker skin sample collection

Cutaneous T cell lymphoma (CTCL) is a complex and heterogenous disease with a range of pathogenic, diagnostic, prognostic and therapeutic courses. Broadly, CTCL is characterized by cutaneous infiltrates of aberrant monocolonal T-lymphocytes. Clinically and histopathologically, CTCL often mimics psoriasis, eczema and other benign dermatoses. Diagnosis of CTCL is often delayed by 4-6 years from the time lesions initially appear, and typically requires multiple skin biopsies and blood tests. In this study, we employed non-invasive adhesive patches to collect samples from lesional skin of CTCL (n=12) and psoriasis (n=10) patients as well as non-lesional skin from healthy (n=12) volunteers.

The Robust Tumoricidal Effects of Combined BET/HDAC Inhibition in Cutaneous T-Cell Lymphoma Can Be Reproduced by ΔNp73 Depletion

Combined BET inhibitor/histone deacetylase inhibitor treatment induces marked apoptosis of cutaneous T-cell lymphoma (CTCL) with minimal normal T-cell toxicity. At 96 hours when apoptosis was extensive, a majority of CTCL lines showed ≥2-fold suppression of T-cell survival factors (e.g., AKT1, BCL2 antiapoptotic factors, BIRC5, CD40, CD70, GADD45A, PRKCA, TNFRSF1B, ΔNp73) and ≥2-fold upregulation of proapoptotic factors and tumor suppressors (e.g., ATM, BAK, BIM, multiple caspases, FHIT, HIC1, MGMT, NOD1) (P < 0.05). The largest alterations were in TP73 isoform expression, resulting in increased TAp73/ΔNp73 ratios in CTCL lines and leukemic Sézary cells. Targeted ΔNp73 inhibition by small interfering RNA knockdown resulted in robust CTCL apoptosis comparable with that induced by BET inhibitor/histone deacetylase inhibitor with minimal normal T-cell toxicity. Chromatin immunoprecipitation analysis showed that BET inhibitor/histone deacetylase inhibitor treatment reduced RNA polymerase II binding to ΔNp73, MYC, and AKT1 while increasing its binding to TAp73. CTCL skin lesions expressed both TAp73 and ΔNp73 isoforms in situ. In aggregate, these findings implicate TAp73/ΔNp73 balance as a major factor governing CTCL survival, show that the expression of p73 isoforms can be altered by molecular biological and pharmaceutical means, show that p73 isoforms are expressed across the entire CTCL clinical spectrum, and identify the p73 pathway as a potential target for therapeutics.

IL-32 Supports the Survival of Malignant T Cells in Cutaneous T-cell Lymphoma

Cutaneous T-cell lymphoma (CTCL) is a heterogeneous collection of non-Hodgkin’s lymphomas derived from T cells that are tropic for the skin. Our understanding of this disease has been hampered by the fact that malignant T cells survive poorly in culture and do not survive well even in sophisticated xenograft models (Townsend et al., 2016). Isolation and culture of T cells from CTCL skin lesions lead to an overgrowth of benign infiltrating T cells and loss of the malignant T-cell clone. It is an inescapable irony that malignant T cells capable of killing patients die in even the most supportive in vitro and in vivo environments.

Abstract 2759: Reprogramming of PD1+ M2-like tumor-associated macrophages with anti-PD-L1 and Lenalidomide in cutaneous T cell lymphoma

Abstract M2-like tumor-associated macrophages (TAMs) are abundant and influence cutaneous T cell lymphoma (CTCL) development by inducing immunosuppression. Although it is well established that depletion of M2-like TAMs delays CTCL development, little is known about the underlying mechanisms that shape programmed cell death 1+ (PD1+) M2-like TAMs phenotype in CTCL. Here we identified PD1+ M2-like TAMs accumulated in CTCL lesional skin. Moreover, RNA-seq analysis of human CTCL tissues revealed an up-regulation of the TLR/NF-κB and JAK/STAT signaling pathways. In vitro, PD1+ TAMs exhibited an M2-like profile, with a significant increase in the expression of CD163, CD206, and IL-10, and a clear decrease in the expression of CD80, IL-1β, CXCL-10, and CXCL-11, and the activation of TLR/NF-κB and JAK/STAT signaling pathways. To determine whether PD1+ M2-like TAMs could be reprogrammed, anti-PD-L1 (durvalumab) and lenalidomide were used for treatment of MyLa-conditioned media induced human peripheral blood monocyte-derived PD1+ M2-like TAMs. The results show that anti-PD-L1 and lenalidomide synergistically reshaped M2-like TAMs to M1-like TAMs in vitro through ablation of the TLR/NF-κB and JAK/STAT signaling pathways, which was linked with functional changes in phagocytic activity and cell migration. In conclusion, TLR/NF-κB and JAK/STAT signaling pathways may drive PD1+ M2-like TAMs programming in the CTCL tumor microenvironment, anti-PD-L1 and lenalidomide may reshape PD1+ M2-like TAMs and induce functional changes through ablation of these specific pathways in CTCL. Corresponding author: Christiane Querfeld, MD, PhD. Div. of Dermatology and Beckman Research Institute, City of Hope. 1500 E. Duarte Road, Duarte, CA 91010. Email: cquerfeld@coh.org Phone: 626-634-4436 Fax: 626-218-6190 Citation Format: Zhen Han1,5, Chingyu Su1,5, Xiwei Wu2,5, Hanjun Qin2,5, Steven T. Rosen3,5, Christiane Querfeld1,3,4,5. Reprogramming of PD1+ M2-like tumor-associated macrophages with anti-PD-L1 and Lenalidomide in cutaneous T cell lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2759.

Ganglioside GD3 May Suppress the Functional Activities of Benign Skin T Cells in Cutaneous T-Cell Lymphoma.

In cutaneous T-cell lymphoma (CTCL), which arises from skin-tropic memory T cells, malignant T cells and benign T cells are confined in the same skin lesions. It is thus difficult to evaluate the phenotypic characteristics and functional activities of benign T cells in CTCL. Disialoganglioside with three glycosyl groups (GD3) is increasingly expressed on the surface of solid malignant tumor cells and takes part in tumor progression and suppression of tumor immunity. However, the role of GD3 in CTCL is not well-understood. In this study, the malignant and benign T cells in CTCL skin lesions were distinguished by flow cytometry and their phenotypic characteristics were compared with those of T cells from control skin specimens. In CTCL skin lesions, the benign T cells included limited resident memory T cells (TRM), which are sessile in skin and known to exert strong antitumor function. The benign T cells showed diminished Th17 property, and the expression of GD3 was high in the malignant T cells. The expression of GD3 in the malignant T cells inversely correlated with IL-17A production from the benign CD4 T cells. GD3 from the malignant T cells was implied to be involved in suppressing the Th17 activity of the benign T cells independent of the regulation of TRM differentiation in CTCL. Revealing the role of GD3 in inhibiting the production of IL-17A in CTCL would aid the understanding of the suppressive mechanism of the antitumor activity by malignant tumor cells.

Thrombospondin-1 promotes tumor progression in cutaneous T-cell lymphoma via CD47.

CD47 is highly expressed on various hematopoietic malignancies, and enables cancer cells to avoid immunosurveillance. Its ligand, thromobospondin-1 (TSP-1) is a multifunctional protein, and CD47/TSP-1 interactions promote tumor progression in various malignancies. In this study, we investigated roles of TSP-1 and CD47 in cutaneous T-cell lymphoma (CTCL). Flow cytometric analysis and immunohistochemistry showed that CTCL tumor cells and CTCL cell lines (Hut78, HH, and MyLa cells) overexpressed CD47 compared with normal CD4+ T cells. Overexpression of CD47 was partially induced by high c-Myc expression in CTCL tumor cells. TSP-1 mRNA expression levels in CTCL lesional skin were higher than those in normal skin and correlated with increased risk of disease-related death. Moreover, TSP-1 was expressed on CTCL tumor cells by immunohistochemistry. Serum soluble TSP-1 levels in patients with Sézary syndrome were significantly elevated. TSP-1 promotes proliferation and survival of CTCL tumor cells, which is inhibited by anti-CD47 neutralizing antibody or CD47 knockdown. Stimulation with TSP-1 also induces cell migration and in vivo growth. These effects were mediated by phosphorylation of ERK1/2 and AKT and expression of survivin. Collectively, our findings prompt a novel therapeutic approach to CTCL based on discovery that CD47/TSP-1 interactions play important roles in progression of CTCL.

YKL-40 Promotes Proliferation of Cutaneous T-Cell Lymphoma Tumor Cells through Extracellular Signal–Regulated Kinase Pathways

YKL-40, one of the chitinase-like proteins, is associated with the pathogenesis of a wide variety of human diseases through modulation of inflammation and tissue remodeling by its diverse roles in cell proliferation, differentiation, and survival. Emerging evidence shows that aberrantly expressed YKL-40 promotes the development of malignancies by inducing proliferation of tumor cells, cytokine production, and angiogenesis by acting on various stromal cells, immune cells, and tumor cells. In this study, we investigated the expression and function of YKL-40 in cutaneous T-cell lymphoma (CTCL). We first revealed that serum YKL-40 levels were increased in patients with CTCL and correlated with disease severity markers. We also found that YKL-40 was expressed by epidermal keratinocytes and tumor cells in lesional skin of CTCL by immunohistochemistry. Although YKL-40 did not affect cytokine production from CTCL cell lines, YKL-40 promoted the proliferation of Hut78 cells and HH cells invitro, which was dependent on extracellular signal-regulated kinase 1/2 pathways. Moreover, exogenous YKL-40 administration enhanced tumor growth of HH cells invivo. Our study has suggested that YKL-40 produced from epidermal keratinocytes and CTCL cells promoted the proliferation of CTCL cells through extracellular signal-regulated kinase 1/2 pathways in autocrine and paracrine manners, leading to development of CTCL.

Possible therapeutic applicability of galectin-9 in cutaneous T-cell lymphoma

BackgroundGalectin-9, a member of the galectin family, can promote tumor growth through inducing apoptosis in anti-tumor immune cells via T cell immunoglobulin and mucin domain 3 (TIM-3). On the other hand, galectin-9 also induces tumor cell apoptosis in many malignancies and thought to have potential as an anti-cancer agent. ObjectiveTo examine the expression and therapeutic applicability of galectin-9 in cutaneous T-cell lymphoma (CTCL). MethodsGalectin-9 expression in lesional skin and sera was measured using CTCL samples. The effect of galectin-9 on CTCL cell lines was investigated in vitro. We also examined effect of galectin-9 on tumor growth of CTCL cells in immune-deficient mice. Moreover, we examined the efficacy of galectin-9, anti-TIM-3 blocking antibody, or their combination on tumor growth of EL-4 cells in wild-type mice. ResultsGalectin-9 was expressed on tumor cells in lesional skin of CTCL and the expression levels were associated with decreased CD8+ T-cell infiltration. Serum galectin-9 levels were correlated with disease severity markers. High-dose galectin-9 induced cell death of CTCL cell lines through activation of caspase-3 and caspase-9, independently of TIM-3. High-dose galectin-9 suppressed the growth of CTCL cells and EL-4 cells in vivo. Furthermore, additional anti-TIM-3 blocking antibody administration to galectin-9 achieved greater inhibition of tumor growth compared to single administration. ConclusionGalectin-9 expression on tumor cells may be associated with CTCL progression through attenuating anti-tumor immunity. On the other hand, exogenous high-dose galectin-9 administration can be a therapeutic strategy for CTCL and anti-TIM-3 blocking antibody can augment the efficacy of galectin-9.

Targeting Phosphorylation of p21-activated Kinase 1 at Thr423 Induces Cell Cycle Arrest and Apoptosis in Cutaneous T-cell Lymphoma Cells.

Cutaneous T-cell lymphoma (CTCL) represents a rare group of extranodal T-cell lymphoproliferative diseases. Due to poor clinical outcome of CTCL, there is an urgent need for new and improved therapies. A small molecule, IPA-3, which inhibits p21-activated kinase 1 (PAK1), has shown therapeutic potential in various types of malignancies. In the present study, the anti-tumor effect of IPA-3 and its underlying molecular mechanism was evaluated. High expression of phosphorylated-PAK1 (pho-PAK1) was seen in CTCL lesional skin compared to benign inflammatory dermatoses. IPA-3 could significantly inhibit the proliferation of 3 CTCL lines in a dose- and time-dependent manner. The percentage of apoptotic cells was higher in the treatment group. Further, IPA-3 treatment caused increased EGR1 protein levels and decreased apoptosis-related BCL-2 and pho-BAD protein levels. In summary, inhibition of pho-PAK1 has significant anti-tumor effects in CTCL cells and it can be explored as a future therapeutic option.

Interleukin-25 is involved in cutaneous T-cell lymphoma progression by establishing a T helper 2-dominant microenvironment.

Interleukin (IL)-25 is a member of the IL-17 family, which can promote and augment T-helper (Th) type 2 responses. The expression of IL-25 and its cognate receptor, IL-25 receptor (IL-25R), is upregulated and correlated with disease activity in Th2-associated diseases. To examine the expression and function of IL-25 in cutaneous T-cell lymphoma (CTCL). Expression and location of IL-25 in lesional skin was investigated with immunohistochemistry. The effect of various cytokines on IL-25 production from normal human epidermal keratinocytes was assessed by quantitative reverse-transcription real-time polymerase chain reaction. Serum IL-25 levels were measured by enzyme-linked immunosorbent assay. The direct effect of IL-25 on tumour cells was also examined using CTCL cell lines and peripheral blood mononuclear cells in patients with Sézary syndrome. IL-25 expression was increased in epidermal keratinocytes in lesional skin of CTCL. Th2 cytokines, IL-4 and IL-13, and periostin induced IL-25 expression by normal human epidermal keratinocytes. Serum IL-25 levels were increased in patients with advanced CTCL and correlated with serum lactate dehydrogenase levels. MyLa cells expressed IL-25R and its expression was augmented by stimulation with IL-25. IL-25 enhanced IL-13 production from MyLa cells via phosphorylation of signal transducer and activator of transcription 6. Peripheral blood mononuclear cells from one patient with Sézary syndrome expressed IL-25R and showed increase of IL-13 production by IL-25. Th2 cytokines highly expressed in CTCL lesional skin induce IL-25 production by epidermal keratinocytes, which may, in turn, lead to formation of a Th2-dominant microenvironment through the direct induction of IL-13 by tumour cells.

Increased Soluble CD226 in Sera of Patients with Cutaneous T-Cell Lymphoma Mediates Cytotoxic Activity against Tumor Cells via CD155

Immune checkpoint therapy, which targets regulatory pathways in T cells to enhance antitumor immune responses, has led to important clinical advances. CD155 is expressed in various types of cancer, and this surface molecule on tumor cells functions either as a co-stimulatory molecule or a co-inhibitory molecule, depending on its receptor. CD226, a CD155 ligand, is mainly expressed on natural killer cells and CD8+ T cells, playing important roles in natural killer cell-mediated cytotoxicity. In this study, we investigated the expression and function of CD155 and CD226 in cutaneous T-cell lymphoma (CTCL). CD155 was strongly expressed on tumor cells and CD155 mRNA expression levels were increased in CTCL lesional skin. CD226 expression on natural killer cells and CD8+ cells in peripheral blood of CTCL patients was decreased. On the other hand, serum CD226 levels were significantly elevated in CTCL patients, strongly reflecting disease activity, suggesting that soluble CD226 in sera was generated by shedding of its membrane form. Recombinant CD226 itself showed cytotoxic activity against CD155-expressing CTCL cells invitro. These data suggest that soluble CD226 elevated in sera of CTCL patients would be important for tumor immunity by interacting with CD155 on tumor cells.

Thymic Stromal Chemokine TSLP Acts through Th2 Cytokine Production to Induce Cutaneous T-cell Lymphoma.

Thymic stromal lymphopoietin (TSLP) activates dendritic cells to induce Th2-mediated inflammation. Periostin, an extracellular matrix protein produced by fibroblasts, induces chronic inflammation by stimulating TSLP production. Recently, a reinforcing cycle linking Th2-type immune responses with periostin-induced keratinocyte activation has been proposed in atopic dermatitis pathogenesis. In this study, we investigated the role of TSLP and periostin in the development of cutaneous T-cell lymphoma (CTCL), where Th2 cytokines and chemokines are also dominant. TSLP and periostin mRNA expression levels were elevated in CTCL lesional skin, both of which correlated with IL4 expression levels. In vitro and ex vivo, IL4 or IL13 stimulated periostin expression by dermal fibroblasts, and fibroblasts from CTCL lesional skin expressed higher levels of periostin than those from control skin. Serum periostin levels of CTCL patients were also significantly higher than those of healthy individuals. Hut78 and MJ, CTCL cell lines, and peripheral blood mononuclear cells from leukemic CTCL patients expressed the TSLP receptor. TSLP induced production of IL4 and IL13 by Hut78 and MJ cells through the activation of STAT5. Moreover, TSLP induced proliferation of CTCL cells both in vitro and in vivo These data suggest that periostin-mediated TSLP production by keratinocytes directly stimulates CTCL tumor cell growth in addition to inducing a Th2-dominant tumor environment in CTCL. Cancer Res; 76(21); 6241-52. ©2016 AACR.

Ectopic expression of embryonic stem cell and other developmental genes in cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a potentially devastating malignancy. The pathogenesis of this cancer remains poorly elucidated. Previous studies focused on analysis of expression and function of known oncogenes and tumor suppressor genes. However, emerging reports highlight that it is also important to analyze the expression of genes that are ectopically expressed in CTCL (e.g., embryonic stem cell genes (ESC), cancer testis (CT) genes, etc.). Currently, it is not known whether ESC genes are expressed in CTCL. In the current work, we analyze by RT-PCR the expression of 26 ESC genes, many of which are known to regulate pluripotency and promote cancer stem cell-like phenotype, in a historic cohort of 60 patients from Boston and in a panel of 11 patient-derived CTCL cell lines and compare such expression to benign inflammatory dermatoses that often clinically mimic CTCL. Our findings document that many critical ESC genes including NANOG, SOX2, OCT4 (POU5F1) and their upstream and downstream signaling members are expressed in CTCL. Similarly, polycomb repressive complex 2 (PRC2) genes (i.e., EZH2, EED, and SUZ12) are also expressed in CTCL lesional skin. Furthermore, select ESC genes (OCT4, EED, TCF3, THAP11, CHD7, TIP60, TRIM28) are preferentially expressed in CTCL samples when compared to benign skin biopsies. Our work suggests that ESC genes are ectopically expressed together with CT genes, thymocyte development genes and B cell-specific genes and may be working in concert to promote tumorigenesis. Specifically, while ESC genes may be promoting cancer stem cell-like phenotype, CT genes may be contributing to aneuploidy and genomic instability by producing aberrant chromosomal translocations. Further analysis of ESC expression and function in this cancer will greatly enhance our fundamental understanding of CTCL and will help us identify novel therapeutic targets.

Analysis of STAT4 expression in cutaneous T-cell lymphoma (CTCL) patients and patient-derived cell lines

Deregulation of STAT signaling has been implicated in the pathogenesis for a variety of cancers, including CTCL. Recent reports indicate that loss of STAT4 expression is an important prognostic marker for CTCL progression and is associated with the acquisition of T helper 2 cell phenotype by malignant cells. However, little is known about the molecular mechanism behind the downregulation of STAT4 in this cancer. In the current work we test the expression of STAT4 and STAT6 via RT-PCR and/or Western Blot in CTCL lesional skin samples and in immortalized patient-derived cell lines. In these malignant cell lines we correlate the expression of STAT4 and STAT6 with the T helper (Th) phenotype markers and test the effect of Histone Deacetylase (HDAC) inhibitors and siRNA-mediated knock down of miR-155 on STAT4 expression. Our findings demonstrate that STAT4 expression correlates with Th1 phenotype, while STAT6 is associated with the Th2 phenotype. Our results further document that STAT4 and STAT6 genes are inversely regulated in CTCL. Treatment with HDAC inhibitors upregulates STAT4 expression, while at the same time decreases STAT6 expression in MyLa cells. Also, siRNA-mediated knock down of miR-155 leads to upregulation in STAT4 expression in MyLa cells. In summary, our results suggest that loss of STAT4 expression and associated switch to Th2 phenotype during Mycosis Fungoides progression may be driven via aberrant histone acetylation and/or upregulation of oncogenic miR-155 microRNA.

Treatment of cutaneous T-cell lymphoma with oral alitretinoin.

Cutaneous T-cell lymphoma (CTCL) is a potentially life-limiting malignant disease. Treatment strategies in CTCL aim at disease control and remission with the lowest possible side-effects. Recent reports suggest that the new vitamin A derivative alitretinoin might be a well-tolerated treatment option. We analysed the files of 11 CTCL patients with mycosis fungoides (n = 10) or Sézary syndrome (n = 1), who were treated with oral alitretinoin alone or in combination with standard treatment based on individual off-label treatment decisions. Patients had been monitored every 4-8 weeks with skin examination and laboratory analyses. Ten of 11 patients (90.9%) showed a marked improvement of their CTCL skin lesions and no progress of the disease during treatment with alitretinoin, one patient showed no response to the treatment (9.1%). Four of the responding patients (40.0%) had a complete response and 6 (60.0%) had a partial response. Average time to response was 2.5 months. Duration of treatment varied depending on whether patients had reached complete or partial remission. In general, alitretinoin was well tolerated. One of 11 patients developed high non-fasting average serum cholesterol (>300 mg/dL) and 1/11 a mean non-fasting triglyceride value >500 mg/dL. In 3/11 patients, thyroid-stimulating hormone declined without clinical symptoms during treatment, with one of the patients also showing a decreased thyroxin level. In our group of CTCL patients we noticed a low rate of side-effects and an overall good clinical response to treatment with alitretinoin. Further studies are required to substantiate this early clinical observation.

Serum Levels of Angiopoietin-2, but not Angiopoietin-1, are Elevated in Patients with Erythrodermic Cutaneous T-cell Lymphoma

Angiogenesis is a crucial process in the growth and progression of cancer, correlating with the metastatic potential of tumour cells. Angiopoietins are ligands for the endothelium-specific tyrosine kinase Tie2 receptor, which comprise 4 structurally related proteins, termed angiopoietin (Ang)-1, Ang-2, Ang-3 and Ang-4. The roles of Ang-1 and Ang-2 have recently been clarified as crucial in angiogenesis. In this report, we measured serum Ang-1 and Ang-2 levels in patients with cutaneous T-cell lymphoma (CTCL). Serum levels of Ang-2, but not Ang-1, in patients with Sézary syndrome were significantly higher than those in patch mycosis fungoides (MF), plaque/tumour MF, and healthy controls. In patients with CTCL, serum Ang-2 correlated with disease activity. Moreover, the numbers of Ang-2+ cells in lesional skin of CTCL were significantly larger than those in normal skin. These results suggest that Ang-2 may have important roles in the development of CTCL.

Skin Recurrence of Transformed Mycosis Fungoides Postumbilical Cord Blood Transplant despite Complete Donor Chimerism.

Background. Allogeneic stem cell transplant is the treatment of choice for systemic cutaneous T-cell lymphoma (CTCL) which provides graft-versus-lymphoma effect. Herein we discuss a case of recurrence of CTCL skin lesions after cord blood transplant in a patient who continued to have 100% donor chimerism in bone marrow. Case Presentation. A 48-year-old female with history of mycosis fungoides (MF) presented with biopsy proven large cell transformation of MF. PET scan revealed multiple adenopathy in abdomen and chest suspicious for lymphoma and skin biopsy showed large cell transformation. She was treated with multiple cycles of chemotherapy. Posttherapy PET scan showed resolution of lymphadenopathy. Later she underwent ablative preparative regimen followed by single cord blood transplant. Bone marrow chimerism studies at day +60 after transplant showed 100% donor cells without presence of lymphoma. However 5 months after transplant she had recurrence of MF with the same genotype as prior skin lesion. Bone marrow chimerism study continued to show 100% donor cells. Conclusion. A differential graft-versus-lymphoma effect in our case prevented lymphoma recurrence systemically but failed to do so in skin. We hypothesize that this response may be due to presence of other factors in the bone marrow and lymph node microenvironments preventing recurrence in these sites.