Effect of a retinoid derivative ECPIRM on proliferation and apoptosis of a cutaneous T-cell lymphoma cell line HH and its mechanisms: a preliminary investigation / 中华皮肤科杂志

Objective:To evaluate the inhibitory effect of a retinoid derivative ECPIRM on proliferation of a cutaneous T-cell lymphoma (CTCL) cell line HH, and to explore its potential mechanisms.Methods:Cultured HH cells were treated with ECPIRM at different concentrations of 0 (control group) , 5, 10 and 20 μmol/L separately for 72 hours, cell counting kit-8 (CCK8) assay was performed to evaluate the effect of ECPIRM on the proliferative activity of HH cells, and flow cytometry to investigate the effect of ECPIRM on apoptosis of HH cells. Some HH cells were treated with 10 μmol/L ECPIRM for 72 hours, transcriptome sequencing was performed to investigate gene expression changes triggered by ECPIRM in HH cells, and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis and gene ontology (GO) enrichment analysis were then performed to analyze differentially expressed genes in HH cells induced by ECPIRM. Reverse transcription-qPCR was subsequently conducted to verify changes in key gene expression in related pathways. Intergroup differences were analyzed by using one-way analysis of variance, and least significant difference (LSD) - t test was used for multiple comparisons. Results:CCK8 assay showed that the 50% inhibitory concentration (IC50) of ECPIRM on HH cells was 4.91 ± 2.48 μmol/L, the viability of HH cells significantly differed among the control group, and 5-, 10-and 20-μmol/L ECPIRM groups (100.00% ± 2.87%, 49.58% ± 4.53%, 48.36% ± 2.88%, 31.44% ± 2.46%, respectively, F=162.86, P < 0.001) , and was significantly lower in the 5-, 10-and 20-μmol/L ECPIRM groups than in the control group ( t=15.36, 15.73, 20.89, respectively, all P < 0.001) . Flow cytometry showed that there was a significant difference in the apoptosis rate among the 4 groups (11.51% ± 1.84%, 23.83% ± 5.72%, 36.19% ± 8.33%, 49.75% ± 4.10%, respectively, F=17.62, P < 0.001) , and the 10-and 20-μmol/L groups showed significantly increased apoptosis rates compared with the control group ( t=4.46, 6.92 respectively, both P < 0.01) . Transcriptomics analysis revealed that the inhibitory effect of ECPIRM on the cellular proliferative activity may be related to the metabolic regulation of steroids. As reverse transcription-qPCR revealed, the 10-μmol/L ECPIRM group showed significantly decreased mRNA expression of L-amino acid oxidase (IL4I1) , acetyl-coenzyme A acetyltransferase 2 (ACAT2) , 3-hydroxy-3-methylglutaryl-coenzyme A synthase 1 (HMGCS1) , mevalonate diphosphate decarboxylase (MVD) , 3-β-hydroxysteroid-8,7-isomerase (EBP) , very low-density lipoprotein receptor (VLDLR) , 3-hydroxy 3-methylglutaryl-CoA reductase (HMGCR) compared with the control group (all P < 0.05) . Conclusion:The retinoid derivative ECPIRM exerted marked anti-proliferative and apoptosis-inducing effects on HH cells, which may be related to the decreased expression of key genes involved in steroid metabolism.

The retinoid derivant ECPIRM selectively exhibited anti-proliferation effects in cutaneous T-Cell lymphoma via ITK-mediated signaling pathway.

BACKGROUND: The treatment of Cutaneous T-cell lymphoma (CTCL) met huge challenges because of the heterogeneity and the scarcity of targeted drugs. ECPIRM derived from isotretinoin exhibited strong anti-proliferation effects in Hut78 and MJ cells rather than Myla cells. However, there was no data regarding the potential target of ECPIRM for its selective activity. OBJECTIVES: To investigate the potential target of ECPIRM for its selective anti-proliferation activity. METHODS: We evaluated the cell viability of CTCL cells after ECPIRM treatment, and detected the effects of ECPIRM on the biomarker genes of CTCL. Subsequently, the mRNA and protein level of Interleukin-2-inducible T-cell kinase (ITK) was determined. Then the induction of apoptosis triggered by ITK inhibitor BMS-509744 and ITK siRNAs were detected, and the docking of ECPIRM interacted with ITK and the effects of ECPIRM on ITK-mediated signaling pathway were analyzed. Finally, we evaluated the anti-growth activity of ECPIRM in Hut78-xenografted nude mice, and the relative expression of cleaved caspase-3, ITK, p-ERK and p-Akt were determined. RESULTS: ITK was highly expressed in Hut78 and MJ cells rather than Myla cells, and targeted inhibition of ITK triggered cell apoptosis. ECPIRM efficiently bound the hydrophobic active pocket of ITK, and significantly inhibited ITK-mediated signaling pathway. In addition, ECPIRM suppressed tumor growth in Hut78-xenografted model, and upregulated the expression of cleaved caspase 3 and inhibited the expression of ITK, p-ERK and p-Akt in tumor tissues, which was consistent with in vitro study. CONCLUSION: ECPIRM might provide a novel strategy for CTCL by inhibiting ITK-mediated signaling pathway.

ECPIRM, a Potential Therapeutic Agent for Cutaneous T-Cell Lymphoma, Inhibits Cell Proliferation and Promotes Apoptosis via a JAK/STAT Pathway.

BACKGROUND: Retinoids are important agents for the treatment of cutaneous T-cell lymphomas (CTCL). But side effects and drug resistance caused by activation of RAR/RXR limited their clinical application. Therefore, it is urgent to develop new agents to fight against CTCL. ECPIRM, a 13-cis retinoic acid derivative, was reported that it inhibited proliferation and induced apoptosis of SCL-1 cells. OBJECTIVE: The aim of this study was to evaluate the biological activities and mechanisms of ECPIEM. METHODS: The effect of ECPIRM on cell proliferation was determined by MTT assay and Trypan blue exclusion assay while FACS analysis was used to detect changes in cell cycle and apoptosis in HUT78 cells. The influence of ECPIRM on RAR/RXR and JAK/STAT signaling was evaluated by western blot analysis. RESULTS: ECPIRM, better than other agents (all-trans retinoic acid,13-cis-retinoic acid or bexarotene), inhibited proliferation and induced apoptosis significantly in HUT78 cells, but with little cytotoxicity on normal lymphocytes. Then ECPIRM induced G0/G1 phase arrest by decreasing the expression of cyclinD1, cyclinE, CDK2 and CDK4 while increasing p21. Furthermore, the unaffected expression of RAR and RXR members suggested that ECPIRM acted independently of RAR/RXR pathway in HUT78 cells. But decreased phosphorylation of JAK1, STAT3, STAT5 and downregulated Bcl-xL, Cyclin D1 and c-Myc indicated that ECPIRM inhibited the activation of JAK/STAT signaling. CONCLUSION: ECPIRM inhibited proliferation, induced apoptosis and G0/G1 phase arrest in HUT78 cells through inhibiting JAK/STAT pathway but not RAR/RXR pathway, which presented ECPIRM as a promising candidate for the treatment of CTCL patients.

Effect of a tretinoin derivative ECPIRM on retinoic acid receptors and skin irritation responses to it in mice / 中华皮肤科杂志

Objective To estimate the effect of a tretinoin derivative ECPIRM on retinoic acid receptors (RARs),and to observe skin irritation responses to it in mice.Methods Cultured SCL-1 cells were divided into 2 groups to be treated with culture medium containing 10 μmol/L ECPIRM (ECPIRM group) or 10 μmol/L all-trans retinoic acid (ATRA) (ATRA group) for 24 hours,and those treated with drug-free culture medium served as the control group.Western blot analysis and real-time fluorescence-based quantitative PCR were performed to quantify the protein and mRNA expressions of RARs (RARα,RARβ,RARγ and RXRα) respectively.In addition,real-time fluorescence-based quantitative PCR was conducted to measure the mRNA expressions of two target genes of the activated RAR signaling pathway,i.e.,cytochrome P450 26A1 (CYP26A1) and tazarotene-induced gene 1 (TIG1).Eight BALB/c mice were equally divided into 2 groups to be topically treated with 0.075％ ECPIRM gel or 0.05％ ATRA cream at equal molar concentrations on the shaved skin once daily for 21 successive days.Skin irritation reactions were assessed in these mice.Results Compared with the control group,the ATRA group showed significantly increased protein and mRNA expressions of RARα,RARβ and RARγ (all P ＜ 0.05).The mRNA expressions of CYP26A1 and TIG1 genes in the ATRA group were 25.49 and 3.88 times that in the control group respectively (both P ＜ 0.01).However,there was no significant difference in the protein expressions of RARα,RARβ,RARγ and RXRα,or mRNA expressions of RARα,RARβ,RARγ CYP26A1 and TIG1 between the ECPIRM group and control group (all P ＞ 0.05).Obvious Skin irritation reactions such as erythema and desquamation were observed in BALB/c mice after 2-day topical treatment with ATRA cream,and their degree peaked after 5-day treatment.However,neither erythema nor desquamation was observed in BALB/c mice during 21-day treatment with 0.075％ ECPIRM gel.Conclusion Unlike ATRA,ECPIRM cannot activate the canonical RAR signaling pathway or cause skin irritation reactions.