ABSTRACT
Objective:To determine lysophosphatidic acid receptor 6 (LPAR6) expression in patients with mycosis fungoides (MF) , a variant of cutaneous T-cell lymphoma (CTCL) , and to investigate its role and mechanism of action in the development and prognosis of CTCL.Methods:A total of 110 patients with confirmed MF were collected from Department of Dermatology, Peking University First Hospital from 2011 to 2020, including 24 with large-cell transformation (LCT) and 25 with non-large cell transformation (NLCT) in the discovery cohort, and 24 with LCT and 37 with NLCT in the validation cohort. RNA sequencing and RT-PCR were conducted to determine the LPAR6 expression in patients in the discovery cohort and validation cohort respectively. LPAR6 expression was compared between patients with LCT and those with NLCT, and its effect on the prognosis of patients was evaluated. Two LPAR6-overexpressing CTCL cell lines MyLa and Sz4 were constructed to evaluate the effect of LPAR6 overexpression on proliferative activity of MyLa and Sz4 cells, with the cells normally expressing LPAR6 as the control group; after the treatment with LPAR6-related ligand lysophosphatidic acid (LPA) , 2S-OMPT, adenosine triphosphate (ATP) or adenosine (ADO) , the effects of LPAR6 activation on the proliferative activity and apoptosis of LPAR6-overexpressing MyLa and Sz4 cells were evaluated by the MTS method and flow cytometry respectively. Log-rank test was used for prognostic analysis, and t test or Mann-Whitney U test was used for comparisons between two groups. Results:As RNA sequencing showed, LPAR6 was one of the significantly underexpressed genes in the LCT group in the discovery cohort; in the validation cohort, LPAR6 expression (median[ Q1, Q3]) was significantly lower in the LCT group (204.90[81.90, 512.70]) than in the NLCT group (809.40[417.50, 1 829.20], U= 242.00, P= 0.002) ; in the two cohorts, the underexpression of LPAR6 was significantly associated with increased risk of poor prognosis (both P < 0.01) . Cell proliferation assay showed no significant difference in the proliferative activity of MyLa or Sz4 cells between the LPAR6 overexpression group and control group at 0, 24, 48 and 72 hours during the experiment (all P > 0.05) ; 48 hours after activation of LPAR6 by LPA, 2S-OMPT, ATP and ADO in MyLa cells, the LPAR6 overexpression group showed significantly decreased cellular proliferative activity (1.38 ± 0.01, 1.04 ± 0.01, 1.09 ± 0.03, 1.23 ± 0.01, respectively) compared the control group (1.73 ± 0.04, 1.23 ± 0.01, 1.24 ± 0.01, 1.42 ± 0.03, t= 30.33, 18.38, 4.78, 5.75, respectively, all P < 0.05) , but significantly increased cell apoptosis rate (17.93% ± 0.88%, 17.75% ± 0.35%, 23.97% ± 0.57%, 31.44% ± 0.34%, respectively) compared the control group (3.98% ± 0.03%, 7.81% ± 0.59%, 11.95% ± 0.85%, 12.02% ± 0.48%, t= 15.93, 14.49, 11.74, 33.01, respectively, all P < 0.05) ; 48 hours after activation of LPAR6 by 2S-OMPT and ADO in Sz4 cells, compared with the control group, the LPAR6 overexpression group also showed significantly decreased cellular proliferative activity (2S-OMPT: 1.29 ± 0.04 vs. 1.48 ± 0.01; ADO: 1.27 ± 0.01 vs. 1.51 ± 0.02; both P < 0.05) , but significantly increased cell apoptosis rate (2S-OMPT: 41.70% ± 0.70% vs. 29.35% ± 0.55%; ADO: 37.05% ± 0.15% vs. 24.60% ± 1.00%; both P < 0.05) . Conclusions:LPAR6 was underexpressed in the patients with LCT, and its underexpression was significantly associated with increased risk of poor prognosis. In vitro activation of LPAR6 could inhibit the proliferation of CTCL cells and promote their apoptosis, suggesting that the decrease of LPAR6 expression may be one of the important mechanisms underlying disease progression in patients with LCT.
ABSTRACT
Objective:To investigate clinicopathological features and prognosis of transformed mycosis fungoides (TMF) .Methods:A retrospective analysis was performed on clinicopathological data collected from 24 patients with TMF, as well as on flow cytometry results of 16 peripheral blood samples obtained from 11 of the 24 patients, who visited Hospital of Dermatology, Chinese Academy of Medical Sciences between 2014 and 2020.Results:Among the 24 patients, 11 were males and 13 were females. Their average age at diagnosis of TMF was 50.0 years (range: 18 - 77 years), and patients with early-stage TMF (9 cases) and tumor-stage TMF (15 cases) were aged 44.8 and 52.6 years on average, respectively. The average time interval from diagnosis of MF to large cell transformation was 3.7 years, and 8 patients were diagnosed with TMF at the initial visit. Histopathologically, large cells infiltrated in a diffuse pattern in 20 cases, as well as in a multifocal pattern in 4, and the proportion of large cells in 7 cases was greater than 75%. Immunohistochemically, 18 patients showed positive staining for CD30, and the proportion of CD30-positive large cells was greater than 75% in 9; negative staining for CD30 was observed in 6. Flow cytometry of 16 peripheral blood samples showed the presence of cell subsets expressing clonal T cell receptor (TCR) -vβ in 2 of 4 patients with early-stage TMF and 10 of 12 with tumor-stage TMF, and tumor cells with higher forward scatter than normal lymphocytes were detected in 16 samples. During the follow-up, among the patients with early-stage TMF, 3 progressed to tumor-stage TMF 3.3 years on average after large cell transformation, 1 progressed to erythrodermic MF in stage IIIA, and the other 4 still showed an indolent course; among the patients with tumor-stage TMF, 1 progressed to stage-IV TMF, and 5 died 3.3 (1.5 - 6) years after large cell transformation.Conclusion:Large cell transformation may occur in patients with MF in any stage, some patients have poor prognosis, so close follow-up is needed for patients with TMF.
ABSTRACT
A 29-year-old Korean man presented with erythematous nodules on his right arm and left leg. He had been diagnosed with mycosis fungoides 10 years prior and was treated with phototherapy continuously. A diagnostic skin biopsy was performed, and the histopathologic findings of the specimen revealed dense infiltration of atypical large lymphoid cells through the entire dermis. These cells showed positive CD3 and CD30 staining. Despite the atypical finding that T cells represented less than 75% of the infiltrated cells, primary cutaneous CD30 positive anaplastic large cell lymphoma was ultimately diagnosed based on the overall consideration of the clinical features and favorable prognosis. Because primary cutaneous CD30 positive anaplastic large cell lymphoma has a favorable prognosis, it should be differentiated from large cell transformation of mycosis fungoides, which has a poor prognosis and requires aggressive treatment. However, this differential diagnosis is challenging. Herein, we report a rare case of primary cutaneous CD30 positive anaplastic large cell lymphoma with mycosis fungoides differentially diagnosed from large cell transformation.
Subject(s)
Adult , Humans , Arm , Biopsy , Dermis , Diagnosis, Differential , Leg , Lymphocytes , Lymphoma, Large-Cell, Anaplastic , Mycosis Fungoides , Phototherapy , Prognosis , Skin , T-LymphocytesABSTRACT
The clinical course of mycosis fungoides is indolent except when large cell transformation occurs. Large cell transformation of MF is rare and easy to misdiagnose. A case of large cell transformation of mycosis fungoides is reported. A 40-year-old man presented with a 10-year history of pruritic erythema and papules in the trunk and extremities as well as a 5-month history of nodules on the nape of the neck.Histopathologically, the erythematous patch showed typical changes of mycosis fungoides, while the tumor cells were small and expressed CD3 and CD4, and only a small number of tumor cells expressed CD30. Pathological examination of nodular lesions revealed the infiltration of large pleomorphic lymphoid cells expressing CD3 and CD4 throughout the entire dermis. There was an epidermotropism of large cells, and about 40% of these cells expressed CD30. Based on the medical history and histological findings, the patient was diagnosed with large cell transformation of mycosis fungoides. The lesions improved markedly after 3-week treatment with oral acitretin (30 mg once daily), subcutaneous interferon-alpha (2 × 106 IU thrice a week) and local superficial X-ray irradiation for nodular lesions. Up to the time of this writing, the patient had been followed.
ABSTRACT
Cutaneous T cell lymphoma (mycosis fungoides/Sezary syndrome) is a clonal malignacy of helper (CD4+) T lymphocytes usually first detected in the skin. In 8-55% of mycosis fungoides, the malignant T cell clone undergoes, cytologic transformation characterized by pleomorphic, large cells with prominent nucleoli, resulting in the morphologic appearance of a large cell lymphoma. The prognosis of large cell transformation of mycosis fungoides is poor; so detection of cytologic transformation is important to decide further treatment. We report a case of 22-year-old mycosis fungoides patient who developed large cell transformation during photochemotherapy (PUVA).