Mycosis Fungoides and Sézary Syndrome: Updates and Review of Current Therapy

Detecting T-cell receptor clonality in patients with severe atopic dermatitis refractory to dupilumab

BACKGROUND

Trials and real-life studies demonstrated clinically meaningful improvements of disease activity in the majority of patients with moderate to severe atopic dermatitis (AD) treated with the anti-IL-4RA-antibody dupilumab. However, misdiagnosis or confounding skin diseases in particular cutaneous T-cell lymphoma (CTCL) may lead to inadequate response.

OBJECTIVE

To investigate the clinical and pathological features of patients with AD who showed insufficient response to dupilumab.

METHODS

We reviewed the medical records of 371 patients treated with dupilumab for severe AD. Insufficient response was defined as failure to achieve an improvement of the eczema area severity index (EASI) of at least 50% (EASI-50) at Week 16 and of 75% (EASI-75) at Week 52. Among 46 patients with insufficient response, 35 patients consented to a re-evaluation including a full physical exam, biopsies and laboratory assessments including immunohistochemistry and T-cell receptor gene rearrangement analysis to differentiate CTCL.

RESULTS

Of the 371 patients treated with dupilumab, 46 (12.3%) patients showed insufficient response to dupilumab. Of these, 35 underwent further evaluation, and 19 (54.2% of inadequate responders) were finally diagnosed with mycosis fungoides (MF). In these patients, transition to or addition of conventional MF treatment led to clinical improvements.

CONCLUSION

Insufficient response to dupilumab treatment may help uncover early MF on an existing AD background.

As serious as Sézary

Sézary syndrome is a rare condition, with a very poor prognosis. This case highlights how important it is for clinicians to be cognizant of the impact that this condition and the various treatment regimens can have on patients’ lives.

Severe insulin resistance in a patient with diabetes after treatment with brentuximab vedotin

A man in his late 60s with a history of well-controlled type 2 diabetes and hepatic cirrhosis presented to the emergency department due to uncontrollable hyperglycaemia following the initial brentuximab vedotin (BV) infusion. BV was initiated as a treatment for mycosis fungoides, a form of cutaneous T-cell lymphoma. The patient was diagnosed with severe hyperglycaemia with ketosis. Empiric treatment with amoxicillin-clavulanic acid, hydration and intravenous insulin infusion was initiated. Hyperglycaemia persisted despite receiving massive amounts of insulin and was corrected only after treatment with high-dose methylprednisolone for suspected type B insulin resistance. Extremely high and difficult-to-treat hyperglycaemia is a rare side effect of BV. Unfortunately, the patient died of upper gastrointestinal bleeding 22 days after discharge. In patients with obesity and/or diabetes mellitus, the blood glucose levels should be carefully monitored when treated with BV.

Bilateral peripheral ulcerative keratitis in a patient with known Sézary syndrome

Purpose

To report a case of bilateral peripheral ulcerative keratitis (PUK) in a patient with underlying Sézary syndrome.

Observations

A 58-year-old male presented with bilateral corneal ulceration with stromal thinning and was diagnosed with PUK. He was actively being treated for Sézary syndrome, a cutaneous T-cell lymphoma. He had no lagophthalmos or other adnexal abnormalities that would lead to ocular surface breakdown. A systemic autoimmune and infectious workup for PUK was unremarkable. His keratitis resolved after treatment with oral prednisone.

Conclusions and importance

We describe a previously undocumented association of PUK with Sézary syndrome in a patient without adnexal disease.

JAK Inhibitors in Cutaneous T-Cell Lymphoma: Friend or Foe? A Systematic Review of the Published Literature

Cutaneous T-cell lymphomas (CTCLs) are a group of lymphoid neoplasms with high relapse rates and no curative treatment other than allogeneic stem cell transplantation (allo-SCT). CTCL is significantly influenced by disruption of JAK/STAT signaling. Therefore, Janus kinase (JAK) inhibitors may be promising for CTCL treatment. This study is a systematic review aiming to investigate the role of JAK inhibitors in the treatment of CTCL, including their efficacy and safety. Out of 438 initially searched articles, we present 13 eligible ones. The overall response rate (ORR) in the treatment with JAK inhibitors in clinical trials was 11-35%, although different subtypes of CTCL showed different ORRs. Mycosis fungoides showed an ORR of 14-45%, while subcutaneous-panniculitis-like T-cell lymphoma (SPTCL) displayed an ORR ranging from 75% to 100%. Five cases were reported having a relapse/incident of CTCL after using JAK inhibitors; of these, three cases were de novo CTCLs in patients under treatment with a JAK inhibitor due to refractory arthritis, and two cases were relapsed disease after graft-versus-host disease treatment following allo-SCT. In conclusion, using JAK inhibitors for CTCL treatment seems promising with acceptable side effects, especially in patients with SPTCL. Some biomarkers, like pS6, showed an association with better responses. Caution should be taken when treating patients with an underlying autoimmune disease and prior immunosuppression.

Clinical and Real-World Effectiveness of Mogamulizumab: A Narrative Review

Mogamulizumab (MOG) is an antibody targeting the CCR4 receptor, authorized for relapsed or refractory peripheral T-cell (PTCL) and cutaneous T-cell lymphomas (CTCL). Its adoption in guidelines and endorsement by FDA and EMA established it as a systemic treatment, especially for advanced disease stages due to its comparatively lower toxicity. Clinical trials and real-world evidence have underscored its efficacy in advanced CTCLs, including mycosis fungoides and Sézary syndrome; PTCLs; and adult T-cell leukemia/lymphoma (ATLL), showcasing positive outcomes. Notably, the drug has demonstrated significant response rates, disease stability, and extended periods of progression-free survival, suggesting its applicability in cases with multiple treatment lines. Its safety profile is generally manageable, with adverse events (AEs) primarily related to the skin, infusion-related reactions, drug eruptions, autoimmune diseases, and skin disorders. The latter seem to appear as CCR4 can promote the skin-specific homing of lymphocytes, and MOG is directed against this receptor. While combination with immunostimulatory agents like interferon alpha and interleukin 12 has shown promising results, caution is urged when combining with PD1 inhibitors due to the heightened risk of immune-mediated AEs. The introduction of MOG as a systemic treatment implies a significant advancement in managing these diseases, supported by its favorable safety profile and complementary mechanisms.

Transcriptomic and proteomic analysis of tumor suppressive effects of GZ17-6.02 against mycosis fungoides

Mycosis fungoides (MF) is the most common form of cutaneous T-cell lymphoma (CTCL). Despite having a wide variety of therapeutic agents available for the treatment of MF, patients often suffer from a significant decrease in quality of life and rarely achieve long-term remission or complete cure, highlighting a need to develop novel therapeutic agents for this disease. The present study was undertaken to evaluate the efficacy of a novel anti-tumor agent, GZ17-6.02, which is composed of curcumin, harmine, and isovanillin, against MF in vitro and in murine models. Treatment of HH and MyLa cells with GZ17-6.02 inhibited the growth of both cell lines with IC50 ± standard errors for growth inhibition of 14.37 ± 1.19 µg/mL and 14.56 ± 1.35 µg/mL, respectively, and increased the percentage of cells in late apoptosis (p = .0304 for HH; p = .0301 for MyLa). Transcriptomic and proteomic analyses revealed that GZ17-6.02 suppressed several pathways, including tumor necrosis factor (TNF)-ɑ signaling via nuclear factor (NF)-kB, mammalian target of rapamycin complex (mTORC)1, and Pi3K/Akt/mTOR signaling. In a subcutaneous tumor model, GZ17-6.02 decreased tumor volume (p = .002) and weight (p = .009) compared to control conditions. Proteomic analysis of tumor samples showed that GZ17-6.02 suppressed the expression of several proteins that may promote CTCL growth, including mitogen-activated protein kinase (MAPK)1, MAPK3, Growth factor receptor bound protein (GRB)2, and Mediator of RAP80 interactions and targeting subunit of 40 kDa (MERIT)40.

The implication of next-generation sequencing in the diagnosis and clinical management of non-Hodgkin lymphomas

Next generation sequencing (NGS) is a technology that broadens the horizon of knowledge of several somatic pathologies, especially in oncological and oncohematological pathology. In the case of NHL, the understanding of the mechanisms of tumorigenesis, tumor proliferation and the identification of genetic markers specific to different lymphoma subtypes led to more accurate classification and diagnosis. Similarly, the data obtained through NGS allowed the identification of recurrent somatic mutations that can serve as therapeutic targets that can be inhibited and thus reducing the rate of resistant cases. The article's purpose is to offer a comprehensive overview of the best ways of integrating of next-generation sequencing technologies for diagnosis, prognosis, classification, and selection of optimal therapy from the perspective of tailor-made medicine.

Non-cutaneous presentation of mycosis fungoides involving the penile corpora: Case report and review of current literature

Mycosis fungoides involvement of genitalia is rare. We present a 63-year-old man with history of cutaneous T cell lymphoma with large cell transformation status post multiple electron beam radiation cycles who presented with a new, enlarging penile mass. He underwent ultrasound, MRI, and excisional biopsy. Pathological results indicated hematogenous spread of T cell lymphoma with large cell transformation. Peri-operative radiation was performed, and the patient had significant reduction in penile mass size but some subsequent erectile dysfunction. In discussion of this case, we examine management of penile mycosis fungoides.

In the skin lesions of patients with mycosis fungoides, the number of MRGPRX2-expressing cells is increased and correlates with mast cell numbers

Background

Mycosis fungoides (MF) is an indolent T-cell lymphoma that mainly affects the skin and presents with itch in more than half of the patients. Recently, the expression of Mas-related G protein-coupled receptor X2 (MRGPRX2), a receptor of mast cell (MC) responsible for the IgE-independent non-histaminergic itch, has been shown in lesional skin of patients with pruritic skin diseases, including chronic urticaria, prurigo, and mastocytosis. As of yet, limited knowledge exists regarding the MRGPRX2 expression in the skin of patients with MF.

Objectives

To investigate the number of MRGPRX2-expressing (MRGPRX2+) cells in the skin of patients with MF and its correlation with clinical and laboratory characteristics of the disease.

Methods

MRGPRX2 was analyzed in lesional and non-lesional skin of MF patients and healthy skin tissues by immunohistochemistry. Co-localization of MRGPRX2 with the MC marker tryptase was assessed by immunofluorescence. Public single-cell RNAseq data was reanalyzed to identify the MRGPRX2 expression on the distinct cell types.

Results

In lesional skin of MF patients, MRGPRX2+ cell number was higher than in non-lesional skin and healthy control skin (mean:15.12 vs. 6.84 vs. 5.51 cells/mm2, p=0.04), and correlated with MC numbers (r=0.73, p=0.02). MC was the primary cell type expressing MRGPRX2 in MF patients. The ratio of MRGPRX2+ MCs to MRGPRX2+ cells in lesional and non-lesional skin correlated with the severity of disease (r=0.71, p=0.02 and r=0.67, p=0.03, respectively).

Conclusions

Our findings point to the role of MRGPRX2 and MC in the pathogenesis of MF that should be investigated in further studies.

Clinical Outcomes of COVID-19 in Mycosis Fungoides and Sezary Syndrome

INTRODUCTION

Haemato-oncologic patients are more susceptible to severe infections with SARS-CoV-2. We aimed to assess the clinical outcomes of SARS-CoV-2 infection among patients with Mycosis Fungoides and Sezary Syndrome (MF/SS).

METHODS

The data were retrieved from anonymized electronic medical records of Maccabi Healthcare Services (MHS), the second-largest healthcare organization in Israel. Patients diagnosed with MF/SS were included in the study. COVID-19 PCR test results together with sociodemographic and clinical data were extracted and analyzed to evaluate the association of COVID-19 with clinical outcomes.

RESULTS

In the period of 2020-2022, 1,472 MF/SS patients were included in the study. Among them, 768 (52%) had SARS-CoV-2 infection. The hospitalization rate was 2.9% and infection by the Delta variant was associated with the highest hospitalization rate (7.7%). The hospitalization rate was lower among fully vaccinated patients (p = 0.032) but higher for patients older than 65 (p < 0.001) and patients with SS (vs. MF) (p < 0.001) or COPD (p = 0.024) diagnosis. There was a tendency for decreased hospitalization among patients treated with nirmatrelvir + ritonavir within 5 days of infection, with a 79% risk reduction, although it was not statistically significant (p = 0.164).

CONCLUSION

Patients with MF/SS do not necessarily have worse COVID-19 outcomes compared to the general population.

Characterization of primary cutaneous T-cell lymphoma following solid organ transplantation

BACKGROUND

Immunosuppression following solid organ transplantation is a known risk factor for the development of posttransplant lymphoproliferative disorders (PTLD). Primary cutaneous T-cell lymphoma (CTCL) occurring in the posttransplant setting is rare, which has made comprehensive understanding of this disease challenging. This study aims to further characterize the spectrum of clinicopathologic features of CTCL in solid organ transplant recipients (SOTR).

METHODS

A retrospective chart review was performed for SOTR who were diagnosed with CTCL at a multi-site academic medical center from January 1, 1998, to December 31, 2013. Eight patients fulfilled the inclusion criteria and were included in this study. Data collected included patient demographics, transplanted organ, the time between transplant and CTCL diagnosis, clinical presentation and rash morphology, a histological subtype of CTCL, immunosuppression regimens, and patient status. Twelve diagnostic skin biopsies for five patients were examined and reviewed by a board-certified dermatopathologist.

RESULTS

Six (75%) out of the eight patients were men, two (25%) were women, and the median age was 53 years. The median time from the date of transplant to the diagnosis of CTCL was 8.2 years. Transplanted organs included the liver (4), kidney (3), and heart (1). Clinical presentation varied from papulonodules, comedone-like lesions, intense pruritis, and scaly erythematous eruptions. The most common histologic presentation was folliculotropic mycosis fungoides (FMF) (7/12). Epstein-Barr virus-in situ hybridization (EBV-ISH) was negative in all specimens.

CONCLUSIONS

We emphasize the rarity of CTCL among SOTR. Although rare in the general population, the FMF subtype appears to be disproportionately seen in SOTR compared with other CTCL.

Cutaneous Lymphoma and Antibody-Directed Therapies

The introduction of monoclonal antibodies such as rituximab to the treatment of cancer has greatly advanced the treatment scenario in onco-hematology. However, the response to these agents may be limited by insufficient efficacy or resistance. Antibody–drug conjugates are an attractive strategy to deliver payloads of toxicity or radiation with high selectivity toward malignant targets and limited unwanted effects. Primary cutaneous lymphomas are a heterogeneous group of disorders and a current area of unmet need in dermato-oncology due to the limited options available for advanced cases. This review briefly summarizes our current understanding of T and B cell lymphomagenesis, with a focus on recognized molecular alterations that may provide investigative therapeutic targets. The authors reviewed antibody-directed therapies investigated in the setting of lymphoma: this term includes a broad spectrum of approaches, from antibody–drug conjugates such as brentuximab vedotin, to bi-specific antibodies, antibody combinations, antibody-conjugated nanotherapeutics, radioimmunotherapy and, finally, photoimmunotherapy with specific antibody–photoadsorber conjugates, as an attractive strategy in development for the future management of cutaneous lymphoma.

Spotlight on hTERT Complex Regulation in Cutaneous T-Cell Lymphomas

As a major cancer hallmark, there is a sustained interest in understanding the telomerase contribution to carcinogenesis in order to therapeutically target this enzyme. This is particularly relevant in primary cutaneous T-cell lymphomas (CTCL), a malignancy showing telomerase dysregulation with few investigative data available. In CTCL, we examined the mechanisms involved in telomerase transcriptional activation and activity regulation. We analyzed 94 CTCL patients from a Franco-Portuguese cohort, as well as 8 cell lines, in comparison to 101 healthy controls. Our results showed that not only polymorphisms (SNPs) located at the promoter of human telomerase reverse transcriptase (hTERT) gene (rs2735940 and rs2853672) but also an SNP located within the coding region (rs2853676) could influence CTCL occurrence. Furthermore, our results sustained that the post-transcriptional regulation of hTERT contributes to CTCL lymphomagenesis. Indeed, CTCL cells present a different pattern of hTERT spliced transcripts distribution from the controls, mostly marked by an increase in the hTERT β+ variants proportion. This increase seems to be associated with CTCL development and progression. Through hTERT splicing transcriptome modulation with shRNAs, we observed that the decrease in the α-β+ transcript induced a decrease in the cell proliferation and tumorigenic capacities of T-MF cells in vitro. Taken together, our data highlight the major role of post-transcriptional mechanisms regulating telomerase non canonical functions in CTCL and suggest a new potential role for the α-β+ hTERT transcript variant.

The Role of TRL7/8 Agonists in Cancer Therapy, with Special Emphasis on Hematologic Malignancies

Toll-like receptors (TLR) belong to the pattern recognition receptors (PRR). TLR7 and the closely correlated TLR8 affiliate with toll-like receptors family, are located in endosomes. They recognize single-stranded ribonucleic acid (RNA) molecules and synthetic deoxyribonucleic acid (DNA)/RNA analogs-oligoribonucleotides. TLRs are primarily expressed in hematopoietic cells. There is compiling evidence implying that TLRs also direct the formation of blood cellular components and make a contribution to the pathogenesis of certain hematopoietic malignancies. The latest research shows a positive effect of therapy with TRL agonists on the course of hemato-oncological diseases. Ligands impact activation of antigen-presenting cells which results in production of cytokines, transfer of mentioned cells to the lymphoid tissue and co-stimulatory surface molecules expression required for T-cell activation. Toll-like receptor agonists have already been used in oncology especially in the treatment of dermatological neoplastic lesions. The usage of these substances in the treatment of solid tumors is being investigated. The present review discusses the direct and indirect influence that TLR7/8 agonists, such as imiquimod, imidazoquinolines and resiquimod have on neoplastic cells and their promising role as adjuvants in anticancer vaccines.

Cutaneous lymphomas—fast facts about an orphan disease—a short review

Cutaneous lymphomas are a rare group of primary skin lymphoproliferative disorders, divided into T and B cell lymphomas. They differ substantially in clinical course and therapy. The two main subtypes of primary cutaneous T‑cell lymphomas include mycosis fungoides, which is the most common, and Sézary syndrome, the rare leukemic variant. Skin lesions seen in mycosis fungoides patients are erythematous patches, plaques, or tumors. Most patients remain at patch/plaque (early) stage, while some progress to tumor (advanced) stage during their clinical course. Sézary syndrome is characterized by erythroderma and involvement of lymph nodes and the peripheral blood. Treatment is dependent on the disease stage. Therapeutic options include skin-directed and systemic therapies. In localized, early stage mycosis fungoides, prognosis is usually good which changes in advanced stages. Significant progress has been made in recent years in the clinical management of progressive or relapsed cutaneous T‑cell lymphomas by the approval of new targeted therapies. Although there are no curative treatment options apart from allogeneic transplantation, response rates are often encouraging, in particular when using combination therapies. Primary cutaneous B cell lymphomas are rare and three main subtypes are recognized: primary cutaneous marginal zone lymphoma, primary cutaneous follicle center lymphoma, and primary cutaneous diffuse large B‑cell lymphoma, leg type. An accurate diagnosis of the subtype is important for therapeutic management. The most common clinical presentations are red-to-violaceous cutaneous nodules and papules. Primary cutaneous marginal and follicle center lymphoma have excellent 5‑year survival rates of 95–99%.

Some New Aspects of Genetic Variability in Patients with Cutaneous T-Cell Lymphoma

AIM

Cutaneous T-cell lymphoma (CTCL) is a group of T-cell malignancies that develop in the skin. Though studied intensively, the etiology and pathogenesis of CTCL remain elusive. This study evaluated the survival of CTCL patients in the 1st Department of Dermatovenereology of St. Anne's University Hospital Brno. It included analysis of 19 polymorphic gene variants based on their expected involvement in CTCL severity.

MATERIAL AND METHODS

75 patients with CTCL, evaluated and treated at the 1st Department of Dermatovenereology of St. Anne´s University Hospital Brno, Faculty of Medicine, Masaryk University, were recruited for the study over the last 28 years (44 men and 31 women, average age 58 years, range 20-82 years). All patients were genotyped for 19 chosen gene polymorphisms by the conventional PCR method with restriction analysis. A multivariate Cox regression model was calculated to reveal genetic polymorphisms and other risk factors for survival.

RESULTS

The model identified MDR Ex21 2677 (rs2032582) as a significant genetic factor influencing the survival of the patients, with the T-allele playing a protective role. A multivariate stepwise Cox regression model confirmed the following as significant independent risk factors for overall survival: increased age at admission, clinical staging of the tumor, and male sex.

CONCLUSION

We showed that the TT genotype at position 2677 of the MDR1 gene exhibited statistically significant longer survival in CTCL patients. As such, the TT genotype of MDR1 confers a significant advantage for the CTCL patients who respond to treatment.

Italian Real-Life Experience on the Use of Mogamulizumab in Patients with Cutaneous T-Cell Lymphomas

Mycosis fungoides and Sèzary syndrome are the most studied subtypes common cutaneous T-cell lymphomas. The current treatment objective is to improve the clinical manifestations of the disease in the affected areas, to relieve symptoms and to halt disease progression. Patients with early-stage mycosis fungoides are usually managed with skin-directed therapies, whereas patients with resistant or advanced-stage mycosis fungoides or Sèzary syndrome often require systemic drugs. Over the last decade, new drugs have been developed, increasing the breadth of treatment options for cutaneous T-cell lymphomas patients. Mogamulizumab is a first-in-class defucosylated humanized IgG1 κ monoclonal antibody, which exerts its anti-tumour action by selectively binding to C-C chemokine receptor 4 and increasing antibody-dependent cellular cytotoxicity activity against malignant T-cells. Several clinical trials showed that mogamulizumab is able to effectively control the cutaneous T-cell lymphomas in each site (skin, blood, lymph nodes and viscera), improving patients' symptoms, function and overall quality of life with a manageable safety profile. In this report, we discuss 12 cases of patients with mycosis fungoides or Sèzary syndrome successfully treated with mogamulizumab in real-life clinical practice in Italy.

Ultrasound-guided microwave ablation as a palliative treatment for mycosis fungoides eyelid involvement: A case report

BACKGROUND

Mycosis fungoides (MF) is a form of lymphoma derived from heterogeneous T cells, and eyelid involvement is extremely rare. The common methods to treat eyelid involvement are radiotherapy and chemotherapy, but their efficacies are limited. Herein, we report a case of advanced-stage MF eyelid involvement, propose ultrasound (US)-guided microwave ablation (MWA) therapy and present a literature review.

CASE SUMMARY

A male patient was admitted to our hospital in June 2018 and diagnosed with MF via radiological and histopathological examinations. The patient’s condition was not well controlled by various conventional chemotherapies. US-guided MWA was performed to relieve the patient’s symptoms and improve his quality of life, showing satisfactory efficacy.

CONCLUSION

Eyelid involvement is one of the most troublesome clinical problems for advanced-stage MF patients. This is the first report on the use of US-guided MWA as a palliative therapy for MF eyelid involvement; the treatment successfully relieved the patient’s clinical symptoms and reduced his anxiety behaviours. Our study sheds new light on methods for improving the clinical management of eyelid involvement in MF.

Histamine H4 Receptor Agonism Induces Antitumor Effects in Human T-Cell Lymphoma

The discovery of the human histamine H4 receptor (H4R) has contributed to our understanding of the role of histamine in numerous physiological and pathological conditions, including tumor development and progression. The lymph nodes of patients with malignant lymphomas have shown to contain high levels of histamine, however, less is known regarding the expression and function of the H4R in T-cell lymphoma (TCL). In this work we demonstrate the expression of H4R isoforms (mRNA and protein) in three human aggressive TCL (OCI-Ly12, Karpas 299, and HuT78). Histamine and specific H4R agonists (VUF8430 and JNJ28610244) significantly reduced cell viability in a dose-dependent manner (p < 0.05). The combined treatment with the H4R antagonist (JNJ7777120, 10 µM) reversed the effects of the H4R ligands. Importantly, we screened a drug repurposing library of 433 FDA-approved compounds (1 μM) in combination with histamine (10 μM) in Hut78 cells. Histamine produced a favorable antitumor effect with 18 of these compounds, including the histone deacetylase inhibitor panobinostat. Apoptosis, proliferation, and oxidative stress studies confirmed the antitumoral effects of the combination. We conclude that the H4R is expressed in TCL, and it is involved in histamine-mediated responses.

Identification of Novel Anthracycline Resistance Genes and Their Inhibitors

Differentially expressed genes have been previously identified by us in multidrug-resistant tumor cells mainly resistant to doxorubicin. In the present study, we exemplarily focused on some of these genes to investigate their causative relationship with drug resistance. HMOX1, NEIL2, and PRKCA were overexpressed by lentiviral-plasmid-based transfection of HEK293 cells. An in silico drug repurposing approach was applied using virtual screening and molecular docking of FDA-approved drugs to identify inhibitors of these new drug-resistant genes. Overexpression of the selected genes conferred resistance to doxorubicin and daunorubicin but not to vincristine, docetaxel, and cisplatin, indicating the involvement of these genes in resistance to anthracyclines but not to a broader MDR phenotype. Using virtual drug screening and molecular docking analyses, we identified FDA-approved compounds (conivaptan, bexarotene, and desloratadine) that were interacting with HMOX1 and PRKCA at even stronger binding affinities than 1-(adamantan-1-yl)-2-(1H-imidazol-1-yl)ethenone and ellagic acid as known inhibitors of HMOX1 and PRKCA, respectively. Conivaptan treatment increased doxorubicin sensitivity of both HMOX1- and PRKCA-transfected cell lines. Bexarotene treatment had a comparable doxorubicin-sensitizing effect in HMOX1-transfected cells and desloratadine in PRKCA-transfected cells. Novel drug resistance mechanisms independent of ABC transporters have been identified that contribute to anthracycline resistance in MDR cells.

CD147-Cyclophilin a Interactions Promote Proliferation and Survival of Cutaneous T-Cell Lymphoma

CD147, a transmembrane glycoprotein that belongs to the immunoglobulin superfamily, and cyclophilin A (CypA), one of the binding partners of CD147, are overexpressed in tumor cells and associated with the progression of several malignancies, including both solid and hematological malignancies. However, CD147 and CypA involvement in cutaneous T-cell lymphoma (CTCL) has not been reported. In this study, we examined CD147 and CypA expression and function using clinical samples of mycosis fungoides (MF) and Sézary syndrome (SS) and CTCL cell lines. CD147 and CypA were overexpressed by tumor cells of MF/SS, and CypA was also expressed by epidermal keratinocytes in MF/SS lesional skin. Serum CypA levels were increased and correlated with disease severity markers in MF/SS patients. Anti-CD147 antibody and/or anti-CypA antibody suppressed the proliferation of CTCL cell lines, both in vitro and in vivo, via downregulation of phosphorylated extracellular-regulated kinase 1/2 and Akt. These results suggest that CD147-CypA interactions can contribute to the proliferation of MF/SS tumor cells in both a autocrine and paracrine manner, and that the disruption of CD147-CypA interactions could be a new therapeutic strategy for the treatment of MF/SS.