Mycosis fungoides and Sézary syndrome

Tape stripped stratum corneum samples are suitable for diagnosis and comprehensive proteomic investigation in mycosis fungoides

BACKGROUND

Mycosis Fungoides (MF) is a common cutaneous T-cell lymphoma. It can sometimes be challenging to diagnose MF using current clinico-histopathological criteria. Non-invasive molecular profiling analysis has the potential to aid the diagnosis and understanding of MF.

METHOD

Lesional and body site matched normal stratum corneum samples were obtained from the same MF patients (n = 28) using adhesive discs, followed by proteomic analyses using data-independent acquisition mass spectrometry (DIA-MS). Differential abundance analyses and bioinformatic analyses were performed to identify differentially abundant proteins and altered biofunctions between the MF and normal stratum corneum samples.

RESULTS

In total, 1303 proteins were identified, of which 290 proteins were significantly changed in the MF cohort compared to the normal stratum corneum. Ingenuity pathway analysis (IPA) predicted the significant inhibition of cell death of cancer cells and significant activation of immune-related activities and viral infection in the MF lesions. MF lesions were also associated with upstream regulators relating to immuno-oncologic dysfunctions. The top-250 variating proteins efficiently separated normal stratum corneum from matched MF samples.

CONCLUSION

Non-invasive proteomic analysis could transform the diagnosis of MF by reducing the need for invasive biopsy. The identification of altered biological functions may serve as useful biomarkers to predict MF progression.

Involvement of p53 Acetylation in Growth Suppression of Cutaneous T-Cell Lymphomas Induced by HDAC Inhibition

Cutaneous T-cell lymphomas (CTCLs) represent a rare form of non-Hodgkin lymphomas characterized by an accumulation of malignant CD4⁺ T cells in the skin. TP53 genetic alteration is one of the most prevalent genetic abnormalities in CTCLs. Therefore, it is a promising target for innovative therapeutic approaches. We found that p53 could physically interact with histone deacetylase (HDAC) 1 and HDAC8, and was subsequently deacetylated to lose its function in CTCL cells, and the p53 downstream apoptosis-associated genes were repressed. Thus, the anti-CTCL activity displayed by HDAC inhibitors depends on p53 status. However, recent studies have reported that HDAC inhibitors could induce a wide variety of drug-resistant characteristics in cancer cells by regulating ATP-binding cassette transporters. Moreover, we discovered that Baicalein, a natural product, exhibited an inhibitory effect on HDAC1 and HDAC8. Though the inhibition of HDAC1 was mild, Baicalein could induce the degradation of HDAC1 through the ubiquitin proteasome pathway, thereby markedly upregulating the acetylation of histone H3 without promoting ATP-binding cassette transporter gene expression. In terms of the mechanism, Baicalein showed better growth inhibition than traditional HDAC inhibitors in CTCLs. This study indicates a special mechanism of HDAC1 and HDAC8 and p53 in T-cell lymphoma cells and identifies a potential and safe natural HDAC inhibitor for the treatment of CTCLs.

MiR-23b-3p induces the proliferation and metastasis of esophageal squamous cell carcinomas cells through the inhibition of EBF3

MicroRNAs (miRNAs), some small non-coding RNAs that regulate gene expression at the posttranscriptional level, are always aberrantly expressed in carcinomas. In this study, we found that miR-23b-3p was remarkably up-regulated in human esophageal squamous cell carcinoma cells and tissues. Moreover, miR-23b-3p could induce the proliferation, invasion, and metastasis in vitro. EBF3 was identified as the direct downstream target gene of miR-23b-3p and ectogenic EBF3 could strongly inhibit the proliferation, invasion, and metastasis in vitro. Furthermore, it was found that miR-23b-3p could regulate epithelial-to-mesenchymal transition progress by blocking EBF3. Therefore, it was concluded that miR-23b-3p targeted EBF3 to accelerate the proliferation, invasion, and metastasis in ESCC.

Sézary Syndrome in a 17-Year-Old Boy: Clinicopathologic Features and Genomic Profile

We describe the case of a 17-year-old Hispanic boy who had had erythroderma and diffuse lymphadenopathy for approximately 6 months. A diagnosis of Sézary syndrome was made on the basis of the histologic features of the skin; the presence of the same T-cell clone on the skin, blood, and bone marrow; and the high CD4(+) lymphocyte count with an aberrant phenotype in peripheral blood; bone marrow involvement was also present. The patient was treated with systemic gemcitabine and achieved partial remission.

Hair follicle-derived IL-7 and IL-15 mediate skin-resident memory T cell homeostasis and lymphoma

The skin harbors a variety of resident leukocyte subsets that must be tightly regulated to maintain immune homeostasis. Hair follicles are unique structures in the skin that contribute to skin dendritic cell homeostasis via chemokine production. We demonstrate that CD4⁺ and CD8⁺ skin resident memory T cells (T_RM), responsible for long-term skin immunity, resided predominantly within the hair follicle epithelium of unperturbed epidermis. T_RM tropism for the epidermis and follicles was herein termed epidermotropism. Hair follicle-derived IL-15 was required for CD8⁺ T_RM, and IL-7 for CD8⁺ and CD4⁺ T_RM, to exert epidermotropism. The lack of either cytokine impaired hapten-induced contact hypersensitivity responses. In a model of cutaneous T cell lymphoma, epidermotropic CD4⁺ T_RM lymphoma cell localization depended on hair follicle-derived IL-7. These findings implicate hair follicle-derived cytokines as regulators of malignant and non-malignant T_RM cell tissue residence and suggest they may be targeted therapeutically in inflammatory skin disease and lymphoma.

Pathology of T-cell lymphomas: diagnosis and biomarker discovery

T-cell lymphomas are a group of predominantly rare hematologic malignancies that tend to recapitulate different stages of T-cell development, in a similar way that B-cell lymphomas do. As opposed to B-cell lymphomas, the understanding of the biology and the classification of T-cell lymphomas are somewhat rudimentary, and numerous entities are still included as 'provisional categories' in the World Health Classification of hematolopoietic malignancies. A relevant and useful classification of these disorders have been difficult to accomplish because of the rarity nature of them, the relative lack of understanding of the molecular pathogenesis, and their morphological and immunophenotypical complexity. Overall, T-cell lymphomas represent only 15 % of all non-Hodgkin lymphomas. This review is focused on addressing the current status of the categories of mature T-cell leukemias and lymphomas (nodal and extranodal) using an approach that incorporates histopathology, immunophenotype, and molecular understanding of the nature of these disorders, using the same philosophy of the most recent revised WHO classification of hematopoietic malignancies.