Molecular pathogenesis of cutaneous lymphomas

The cross-talk between miRNAs and JAK/STAT pathway in cutaneous T cell lymphoma: Emphasis on therapeutic opportunities

Mycosis Fungoides (MF) and Sézary Syndrome (SS) belong to a wide spectrum of T cell lymphoproliferative disorders collectively termed cutaneous T cell lymphomas (CTCL). CTCLs represent an archetype of heterogeneous and dynamically variable lymphoproliferative neoplasms typified by distinct clinical, histological, immunophenotypic, and genetic features. Owing to its complex dynamics, the pathogenesis of CTCL remains elusive. However, in recent years, progress in CTCL classification combined with next-generation sequencing analyses has broadened the genetic and epigenetic spectrum of clearly defined CTCL entities such as MF and SS. Several large-scale genome studies have identified the polygenic nature of CTCL and unveiled an idiosyncratic mutational landscape involving genetic aberrations, epigenetic alterations, cell cycle dysregulation, apoptosis, and the constitutive activation of T cell/NF-κB/JAK-STAT signaling pathways. In this review, we summarize the evolving insights on how the intrinsic epigenetic events driven by dysregulated miRNAs, including the oncogenic and tumor-suppressive miRNAs, influence the pathogenesis of MF and SS. We also focus on the interplay between the JAK/STAT pathway and miRNAs in CTCL as well as the significance of the miRNA/STAT axis as a relevant pathogenetic mechanism underlying CTCL initiation and progression. Based on these biologic insights, the current status and recent progress on novel therapies with a strong biological rationale, including miRNA-targeted molecules and JAK/STAT-targeted therapy for CTCL management, are discussed.

Determination of T-cell clonality and expression profiles of Toll-like receptors signaling pathway genes and related miRNAs in patients with mycosis fungoides

Cutaneous T-cell lymphomas (CTCL) encompass a group of diseases characterized by the presence of malignant clonal CD4+ T lymphocytes in the skin. Mycosis fungoides (MF) is the most prevalent form of CTCL, accounting for approximately 60 % of cutaneous T-cell lymphomas and 50 % of all primary cutaneous lymphomas. Despite ongoing research, the precise pathogenesis of MF remains incompletely understood. Toll-like receptors (TLRs) have the ability to specifically recognize ligands, subsequently induce the expression of diverse genes and activate innate immunity within the cell. Furthermore, miRNAs play a crucial role in regulating various aspects of immune cell function. The aim of our study was to explore the potential roles of TLRs and the genes implicated in their signal transduction, along with the expression status of miRNAs in the mechanisms underlying MF. Additionally, we assessed the clonal status and compared it with clinicopathological data using a T-cell clonality assay. To determine the expression status of TLR pathway genes and miRNAs, we conducted RT-PCR analysis on 52 MF samples and 50 control paraffin block materials. Pathway analysis were conducted using the KEGG database. T-cell receptor (TCR) gamma clonality changes were evaluated. Results from the study revealed increased expressions of TLR-1, -4, -8, IRF7, TRAF3, MEK1, MEK2, Elk1, NFkB, hsa-miR-21-5p, and hsa-miR-155-5p, as well as decreased expressions of hsa-miR-130a-3p, hsa-miR-210-3p, and hsa-let-7e-5p in the MF group. TCR gamma clonal change analysis demonstrated that 55.5 % of the analysed DNAs exhibited monoclonal and biallelic patterns, while 45.5 % displayed polyclonality. These findings collectively suggest the potential influence and therapeutic possibilities of the TLR signalling pathway in the molecular pathogenesis of MF.

Characteristics of Primary Cutaneous Lymphoma in Italy: A Tertiary Care, Single-Center Study

Data on primary cutaneous lymphomas (PCLs) patients in the Italian population are limited, and, despite the existence of several treatment options, the management of those patients remains challenging. Our study aimed to investigate the clinical and therapeutic features of PCL patients in a referral center in Italy. We conducted a retrospective study on 100 consecutive PCL patients between January 2017 and December 2022. The mean (SD) age of our cohort was 70.33 (14.14) years. Cutaneous T-cell lymphomas (CTCLs) represented 65% of all cases; the majority were mycosis fungoides (42%), followed by cases of Sezary syndrome (10%) and primary cutaneous anaplastic large cell lymphoma (4%). Cutaneous B-cell lymphomas (CBCLs) accounted for 35 % of PCLs, with 15 cases of primary cutaneous follicle center lymphoma, 10 cases of primary cutaneous diffuse large B-cell lymphoma leg type, and 9 cases of marginal zone B-cell lymphoma. A higher frequency of pruritus (p = 0.008) and higher peripheral blood levels of beta-2 microglobulin (p ≤ 0.001) and lactate dehydrogenase (p = 0.025) were found in CTCLs compared to those of CBCLs. Considering all therapeutic lines performed, treatments were extremely heterogeneous and skin-directed therapies represented the most frequently used approach. Our study confirms the distribution of PCL subtypes formerly reported in the literature and highlights the utility of real-life data in treatments to improve the current management of PCL patients.

Evaluation of Oxidative Stress by Thiol/Disulphide Homeostasis in Patients with Mycosis Fungoides: A Prospective Double-Centre Study

Background

Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma with unknown etiopathogenesis. Oxidant and antioxidant balance is important for cell function and normal metabolism. An imbalance between pro-oxidants and antioxidants causes oxidative stress. A recent focus has been on thiol/disulphide homeostasis as a novel marker of oxidative stress.

Aims and Objectives

This study aimed to evaluate the role of oxidative stress in MF by analysing thiol/disulphide homeostasis.

Materials and Methods

A total of 103 patients (48 female, 55 male) and a control group of 120 healthy individuals (48 female, 72 male) from two tertiary care hospitals were included in our study. Serum native thiol, total thiol and disulphide levels were evaluated using novel method developed by Erel and Neeliolu.

Results

Native thiol levels were 340.30 ± 87.44 in the patient group and 401.62 ± 69.45 in the control group. Total thiol value was 374.17 ± 87.78 in the patient group and 428.54 ± 70.05 in the control group. Native thiol and total thiol levels were significantly lower in the patient group compared to the control group (P < 0.001 and P < 0.001). The disulphide value was 16.93 ± 6.46 in the patient group and 13.46 ± 5.06 in the control group. Disulphide levels were found to be significantly higher in the patient group compared to the control group (P < 0.001).

Conclusions

In our study, thiol/disulphide balance shifted towards disulphide which indicates the presence of oxidative stress especially in the early stage while 93.2% of our patients had early-stage MF. We think that this may have pathogenetic and prognostic significance.

Potential Pathogenic Impact of Cow’s Milk Consumption and Bovine Milk-Derived Exosomal MicroRNAs in Diffuse Large B-Cell Lymphoma

Epidemiological evidence supports an association between cow’s milk consumption and the risk of diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin lymphoma worldwide. This narrative review intends to elucidate the potential impact of milk-related agents, predominantly milk-derived exosomes (MDEs) and their microRNAs (miRs) in lymphomagenesis. Upregulation of PI3K-AKT-mTORC1 signaling is a common feature of DLBCL. Increased expression of B cell lymphoma 6 (BCL6) and suppression of B lymphocyte-induced maturation protein 1 (BLIMP1)/PR domain-containing protein 1 (PRDM1) are crucial pathological deviations in DLBCL. Translational evidence indicates that during the breastfeeding period, human MDE miRs support B cell proliferation via epigenetic upregulation of BCL6 (via miR-148a-3p-mediated suppression of DNA methyltransferase 1 (DNMT1) and miR-155-5p/miR-29b-5p-mediated suppression of activation-induced cytidine deaminase (AICDA) and suppression of BLIMP1 (via MDE let-7-5p/miR-125b-5p-targeting of PRDM1). After weaning with the physiological termination of MDE miR signaling, the infant’s BCL6 expression and B cell proliferation declines, whereas BLIMP1-mediated B cell maturation for adequate own antibody production rises. Because human and bovine MDE miRs share identical nucleotide sequences, the consumption of pasteurized cow’s milk in adults with the continued transfer of bioactive bovine MDE miRs may de-differentiate B cells back to the neonatal “proliferation-dominated” B cell phenotype maintaining an increased BLC6/BLIMP1 ratio. Persistent milk-induced epigenetic dysregulation of BCL6 and BLIMP1 expression may thus represent a novel driving mechanism in B cell lymphomagenesis. Bovine MDEs and their miR cargo have to be considered potential pathogens that should be removed from the human food chain.

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.

Molecular pathogenesis of cutaneous lymphoma-Future directions

The pathogenesis of cutaneous T-cell lymphomas is not clear. In recent years, the genetic changes in CTCL were explored. The detected mutations showed a great deal of heterogeneity between individual patients. The studies documented various copy number variations (CNV) and single nucleotide variations (SNV) in multiple genes involved in multiple signalling pathways. Recurrently mutated signalling pathways include JAK-STAT, MAPK, T-cell receptor, TNF receptor and NFκB signalling. In the period between 2018 and today, additional studies towards the genetic changes in CTCL were carried out. Genetic changes in gamma delta T-cell lymphoma are also shown in genes of the JAK-STAT, MAPK, MYC and chromatin signalling pathways. These studies might indicate a shift away from targeted sequencing approaches towards whole-genome sequencing. This approach demands additional resources in terms of funding but has the advantage of finding mutations in non-coding regions. These mutations were neglected for a long time, but as shown in contemporary research these regions harbour highly recurrent mutations affecting gene expression and regulation. Nevertheless, the detection of specific molecular changes in known pathways enables considerations for targeted therapies.

Patient-reported quality of life in patients with relapsed/refractory cutaneous T-cell lymphoma: Results from the randomised phase III ALCANZA study

BACKGROUND

Brentuximab vedotin was approved for adult patients with CD30-expressing cutaneous T-cell lymphoma treated with prior systemic therapy based on improved response rates and progression-free survival with brentuximab vedotin (1.8 mg/kg once every 3 weeks; ≤16 cycles) versus physician's choice (methotrexate/bexarotene; ≤48 weeks) in the phase III ALCANZA study. Quality of life (QoL) in ALCANZA patients was also examined.

METHODS

QoL measures in ALCANZA were based on the Skindex-29, Functional Assessment of Cancer Therapy-General (FACT-G) and European QoL 5-dimension (EQ-5D) questionnaires.

RESULTS

Mean maximum reduction from the baseline Skindex-29 symptom domain score (key secondary end-point) was greater with brentuximab vedotin than physician's choice (-27.96 versus -8.62); the difference, -18.9 (95% confidence interval -26.6, -11.2; adjusted p < 0.001), exceeded the study-defined minimally important difference (9.0-12.3). Mean changes from baseline to end-of-treatment visit total FACT-G scores were similar with brentuximab vedotin and physician's choice (0.15 versus -2.29). EQ-5D changes were also comparable between arms. Among brentuximab vedotin-treated patients with peripheral neuropathy (PN), mean maximum reduction in Skindex-29 symptom domain was -35.54 versus -11.11 in patients without PN. PN had no meaningful effect on FACT-G and EQ-5D QoL scores.

CONCLUSIONS

In summary, brentuximab vedotin produced superior reductions in symptom burden compared with physician's choice, without adversely impacting QoL. QoL was unaffected by the presence of PN in brentuximab vedotin-treated patients.

CLINICAL TRIAL REGISTRATION

NCT01578499.

Low-dose total skin electron beam therapy: Quality of life improvement and clinical impact of maintenance and adjuvant treatment in patients with mycosis fungoides or Sezary syndrome

PURPOSE

Total skin electron beam therapy (TSEBT) has proved to be a safe and effective treatment for cutaneous T‑cell lymphomas. Here, we examined the impact of this treatment on patient quality of life and outcome.

PATIENTS AND METHODS

Forty-four patients with mycosis fungoides (MF) or Sezary syndrome (SS) received 48 TSEBT courses with a median dose of 12 Gy within the past 8 years at our institute. Patient and treatment characteristics for these cases as well as the impact of TSEBT on quality of life and duration of response were retrospectively analyzed and compared.

RESULTS

The median modified Severity-Weighted Assessment Tool score before the start of TSEBT was 44. The overall response rate was 88%, with a complete response (CR) rate of 33%. The median follow-up period was 13 months. The median duration of response (DOR) and progression-free survival (PFS) for the entire cohort were 10 months and 9 months, respectively. Patient-reported symptom burden was measured with the Dermatological Life Quality Index and Skindex-29 questionnaires. The mean symptom reductions were 6 ± 8 (P = 0.005) and 21 ± 24 (P = 0.002), respectively. In the Functional Assessment of Cancer Therapy-General Assessment, significant improvements in the emotional (P = 0.03) domains were observed after TSEBT. Patients who received maintenance or adjuvant treatments had a longer PFS (P = 0.01).

CONCLUSION

TSEBT improved disease symptoms and significantly improved emotional domains of patients' quality of life in patients with MF or SS. In addition, our results indicate that maintenance or adjuvant therapy after TSEBT may improve the PFS.