MITF

MITF
  • 文章类型: Journal Article
    皮肤黑色素瘤是一种高度侵袭性的皮肤癌。据估计,5%至10%的潜在突变是遗传性的并且是家族性(或遗传性)黑素瘤的原因。这些患者容易早期发展和多发性黑色素瘤的风险较高。近年来,由于基因检测,越来越多的基因被鉴定出来,允许随后对处于危险中的个人进行监测,然而,在临床基础上预测这些突变的存在仍然很困难。在这种情况下,特定的表型和皮肤镜特征可以帮助临床医生进行鉴定.这项工作的目的是将突变与普遍的皮肤观察模式相关联,为临床实践中有用的参考模型铺平道路。在我们的队列中,在115名黑色素瘤遗传咨询患者中,25检测阳性(21.7%)的关键突变:CDKN2A(n=12),MITF(n=3),BAP1(n=1),MC1R(n=3),PTEN(n=1),TYR(n=2),OCA2(n=1),和SLC45A2(n=2)。通过数字采集获得的表型谱,分析,良性和恶性色素性病变的描述显示出II型皮肤表型的优势,平均总痣数升高(182摩尔,范围75-390)。至于皮肤特征,根据色素沉着描述了特定的突变相关模式,回归领域,和血管结构。尽管需要对更大的队列进行进一步的研究,我们的工作代表了研究和诊断家族性黑色素瘤的新方法的开始,强调临床和皮肤镜模式的重要性,这可能构成每个基因的参考模型,使能比较。
    Cutaneous melanoma is a highly aggressive skin cancer. It is estimated that 5% to 10% of the underlying mutations are hereditary and responsible for familial (or hereditary) melanoma. These patients are prone to the early development and higher risk of multiple melanomas. In recent years, an increasing number of genes have been identified thanks to genetic testing, allowing the subsequent surveillance of individuals at risk, yet it is still difficult to predict the presence of these mutations on a clinical basis. In this scenario, specific phenotypic and dermoscopic features could help clinicians in their identification. The aim of this work has been to correlate mutations to prevalent dermoscopic patterns, paving the way for reference models useful in clinical practice. In our cohort, out of 115 patients referred to genetic counseling for melanoma, 25 tested positive (21.7%) for critical mutations: CDKN2A (n = 12), MITF (n = 3), BAP1 (n = 1), MC1R (n = 3), PTEN (n = 1), TYR (n = 2), OCA2 (n = 1), and SLC45A2 (n = 2). The phenotype profiles obtained through the digital acquisition, analysis, and description of both benign and malignant pigmented lesions showed a predominance of the type II skin phenotype, with an elevated mean total nevus number (182 moles, range 75-390). As for dermoscopic features, specific mutation-related patterns were described in terms of pigmentation, areas of regression, and vascular structures. Although further studies with larger cohorts are needed, our work represents the beginning of a new approach to the study and diagnosis of familial melanoma, underlining the importance of clinical and dermoscopic patterns, which may constitute a reference model for each gene, enabling comparison.
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  • 文章类型: Journal Article
    背景:通过miRNA-155下调小眼症诱导的转录因子(MITF),单核细胞-巨噬细胞谱系细胞在体外致力于破骨细胞分化。因此,我们的目的是评估miRNA-155的表达,并探讨miRNA-155在牙周炎破骨细胞形成过程中对MITF的调控。
    方法:招募了98名受试者,并分为以下几类:I组(病例)-全身健康,局部III/IV期牙周炎(N=49)和II组(对照)-全身和牙周健康(N=49)。获取牙龈组织样品,并对相对基因表达进行qRT-PCR分析。
    结果:对于I组和II组,miRNA-155表达的平均ΔCT分别为-1.04±2.26和-0.01±1.4。各组miRNA-155表达差异有统计学意义(P≤0.01)。I组和II组MITF表达的平均ΔCT分别为4.15±2.16和3.51±1.57,组间差异无统计学意义(P>0.01)。在牙周炎组中,miRNA-155表达增加五倍(P≤0.01),而MITF表达在各组之间的倍数变化没有显着差异(P>0.01)。在总共98个样品中,位点特异性临床参数分别与miRNA-155的ΔCT和倍数变化值显示出统计学上显著的强负相关和正相关(P<0.01)。miRNA-155能够区分牙周健康和疾病,诊断准确率为96.9%(95CI:91.38-98.95),ROC分析AUC为0.98(95CI:0.97-1.0,SE=0.008,P<0.001),灵敏度为93.8%(95CI:83.48-97.9),特异性为100%(95CI:92.73-100)。
    结论:miRNA-155在牙周病中失调并上调五倍。它可以用作区分牙周健康和疾病的潜在生物标志物。在牙周健康和疾病之间,MITF基因表达没有差异。结果提示miRNA-155在本研究设计和局限性内不影响局部III/IV期牙周炎破骨细胞形成过程中MITF基因的表达。
    BACKGROUND: Monocyte-macrophage lineage cells are committed towards osteoclast differentiation in vitro by the downregulation of microphthalmia-induced transcription factor (MITF) by miRNA-155. Therefore, we aimed to evaluate miRNA-155 expression and explore the regulation of MITF by miRNA-155 during osteoclastogenesis in periodontitis.
    METHODS: Ninety-eight subjects were recruited and categorized into the following: group I (cases)-systemically healthy with localized stage III/IV periodontitis (N = 49) and group II (controls)-systemically and periodontally healthy (N = 49). Gingival tissue samples were procured and qRT-PCR analysis was carried out for relative gene expression.
    RESULTS: The mean ΔCT of miRNA-155 expression was -1.04 ± 2.26 and -0.01 ± 1.4 respectively for groups I and II. There was a statistically significant difference in the miRNA-155 expression (P ≤ 0.01) between the groups. The mean ΔCT of MITF expression for groups I and II was 4.15± 2.16 and 3.51± 1.57 respectively with no significant difference (P > 0.01) between the groups. In the periodontitis group, miRNA-155 expression increased by fivefolds (P ≤ 0.01) whereas MITF expression showed no significant difference in the fold change between the groups (P > 0.01). The site-specific clinical parameters showed a statistically significant strong negative and positive correlation with the ΔCT and fold change values of miRNA-155 respectively in the total 98 samples (P < 0.01). miRNA-155 was able to discriminate between periodontal health and disease with a diagnostic accuracy of 96.9% (95%CI: 91.38-98.95) and the AUC was 0.98 (95%CI: 0.97-1.0, SE = 0.008, P < 0.001) in ROC analysis with a sensitivity of 93.8% (95%CI: 83.48-97.9) and specificity of 100% (95%CI: 92.73-100).
    CONCLUSIONS: miRNA-155 was dysregulated and upregulated by fivefolds in periodontal disease. It can be used as a potential biomarker to discriminate between periodontal health and disease. No difference in the MITF gene expression was demonstrated between periodontal health and disease. The result suggested that miRNA-155 does not affect the expression of MITF gene in the process of osteoclastogenesis in localized stage III/IV periodontitis within this study design and limitations.
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  • 文章类型: Journal Article
    Background: Cutaneous melanoma is a heterogeneous tumor with a rapidly switching molecular and cellular phenotype. The invasive phenotype switching characterized by MITFlow/AXLhigh predicts early resistance to multiple targeted drugs in melanoma. Celecoxib proved to be a valuable adjuvant in cutaneous melanoma in preclinical studies. Our in vitro study evaluated for the first time whether celecoxib could prevent phenotype switching in two human melanoma cell lines treated with dabrafenib. Methods: All in vitro experiments were carried out on BRAF-V600E-positive A375 and SK-MEL-28 human melanoma cell lines, and subjected to a celecoxib and dabrafenib drug combination for 72 h. Melanoma cells were already in the MITFlow/AXLhigh end of the spectrum. Of main interest was the evaluation of the key proteins expressed in phenotype switching (TGF-β, MITF, AXL, YAP, TAZ), as well as cell death mechanisms correlated with oxidative stress production. Results: Celecoxib significantly enhanced the apoptotic effect of dabrafenib in each melanoma cell line compared to the dabrafenib group (p < 0.0001). Even though celecoxib promoted low MITF expression, this was correlated with high receptor tyrosine kinase AXL levels in A375 and SK-MEL-28 cell lines (p < 0.0001), a positive marker for the phenotype switch to an invasive state. Conclusion: This preliminary study highlighted that celecoxib might promote MITFlow/AXLhigh expression in cutaneous melanoma treated with dabrafenib, facilitating phenotype switching in vitro. Our results need further confirmation, as this finding could represent an important limitation of celecoxib as an antineoplastic drug.
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  • 文章类型: Journal Article
    目的:2014年首次描述,具有TFEB扩增(6p21)的肾细胞癌(RCC)是一种罕见的分子亚群,其诊断具有挑战性。预后和治疗意义仍不清楚。
    方法:我们在这里报告临床,组织学,免疫组织化学,和9个新病例的遗传特征。泌尿系专家对病理和免疫组织化学特征进行了集中审查。荧光原位杂交(FISH)证实了诊断,并进行了比较基因组杂交(CGH)以确定定量基因组改变。我们还对文献进行了详尽的回顾,并汇编了我们的数据。
    结果:TFEB扩增的肾癌局部晚期,1例初始淋巴结受累,另一例肝转移。它们是高度嗜酸性细胞肿瘤,伴有乳头状/假乳头状结构,黑素细胞标志物频繁阳性,和频繁的PDL1表达。FISH在6例中显示了高水平的TFEB扩增。1例合并TFEB易位。CGH分析确定了复杂的改变,频繁损失1便士,2q,3p,6p,以及频繁的6p和8q增益。在所有情况下,VEGFA共扩增的水平均低于TFEB。预后很差,5例患者有淋巴结或远处转移。
    结论:TFEB扩增的RCC是一种罕见的具有可变形态的分子亚群,其诊断通过FISH分析得到证实。CGH鉴定的复杂改变与侵袭性临床行为一致。VEGFA的共扩增和PDL1的表达可能表明抗血管生成素和靶向免疫疗法联合治疗这些侵袭性肿瘤的潜在益处。
    OBJECTIVE: First described in 2014, renal cell carcinoma (RCC) with TFEB amplification (6p21) is a rare molecular subgroup whose diagnosis is challenging. The prognosis and therapeutic implications remain unclear.
    METHODS: We report here the clinical, histological, immunohistochemical, and genetic features of nine novel cases. The pathological and immunohistochemical features were centrally reviewed by expert uropathologists. Fluorescence in situ hybridisation (FISH) confirmed the diagnosis and comparative genomic hybridisation (CGH) was performed to determine quantitative genomic alterations. We also performed an exhaustive review of the literature and compiled our data.
    RESULTS: TFEB-amplified RCC were locally advanced, with initial lymph node involvement in one case and liver metastasis in another case. They were high-grade eosinophilic tumours with papillary/pseudopapillary architecture, frequent positivity for melanocytic markers, and frequent PDL1 expression. FISH demonstrated high-level TFEB amplification in six cases. One case showed concomitant TFEB translocation. CGH analysis identified complex alterations with frequent losses of 1p, 2q, 3p, 6p, and frequent 6p and 8q gains. VEGFA coamplification was identified in all cases with a lower level than TFEB. The prognosis was poor, with five patients having lymph node or distant metastases.
    CONCLUSIONS: TFEB-amplified RCC is a rare molecular subgroup with variable morphology whose diagnosis is confirmed by FISH analysis. The complex alterations identified by CGH are consistent with an aggressive clinical behaviour. The coamplification of VEGFA and the expression of PDL1 could suggest a potential benefit from antiangiogenics and targeted immunotherapy in combination for these aggressive tumours.
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  • 文章类型: Journal Article
    恶性黑色素瘤仍然是一个严重的医学问题。死亡率相对较高,越来越多的新诊断病例,和不够有效的治疗方法需要黑色素瘤的研究。四环素是具有多效药理学性质的化合物。先前发表的关于黑色素黑素瘤细胞的研究确定米诺环素和多西环素发挥抗黑素瘤作用。该研究的目的是使用A375和C32人无色素性黑色素瘤细胞系评估米诺环素和多西环素的抗黑色素瘤潜力和作用机制。获得的结果表明,测试药物抑制增殖,细胞活力下降,并诱导无色素性黑色素瘤细胞凋亡。该治疗引起细胞周期谱的变化,并降低了还原硫醇和线粒体膜电位的细胞内水平。A375和C32细胞暴露于米诺环素和多西环素触发了细胞色素c和活化的起始物和效应物半胱天冬酶的释放。所分析药物的抗黑素瘤作用似乎与ERK1/2和MITF的上调有关。此外,人们注意到,米诺环素和多西环素增加了LC3A/B的水平,自噬标记,在A375细胞。总之,该研究表明,米诺环素和多西环素对无色素性黑色素瘤细胞具有多效性抗癌作用。考虑到所有的结果,可以得出结论,多西环素比米诺环素更有效。
    Malignant melanoma is still a serious medical problem. Relatively high mortality, a still-growing number of newly diagnosed cases, and insufficiently effective methods of therapy necessitate melanoma research. Tetracyclines are compounds with pleiotropic pharmacological properties. Previously published studies on melanotic melanoma cells ascertained that minocycline and doxycycline exerted an anti-melanoma effect. The purpose of the study was to assess the anti-melanoma potential and mechanisms of action of minocycline and doxycycline using A375 and C32 human amelanotic melanoma cell lines. The obtained results indicate that the tested drugs inhibited proliferation, decreased cell viability, and induced apoptosis in amelanotic melanoma cells. The treatment caused changes in the cell cycle profile and decreased the intracellular level of reduced thiols and mitochondrial membrane potential. The exposure of A375 and C32 cells to minocycline and doxycycline triggered the release of cytochrome c and activated initiator and effector caspases. The anti-melanoma effect of analyzed drugs appeared to be related to the up-regulation of ERK1/2 and MITF. Moreover, it was noticed that minocycline and doxycycline increased the level of LC3A/B, an autophagy marker, in A375 cells. In summary, the study showed the pleiotropic anti-cancer action of minocycline and doxycycline against amelanotic melanoma cells. Considering all results, it could be concluded that doxycycline was a more potent drug than minocycline.
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  • 文章类型: Journal Article
    Minocycline is a drug which induces skin hyperpigmentation. Its frequency reaches up to 50% of treated patients. The adverse effect diminishes the great therapeutic potential of minocycline, including antibacterial, neuroprotective, anti-inflammatory and anti-cancer actions. It is supposed that an elevated melanin level and drug accumulation in melanin-containing cells are related to skin hyperpigmentation. This study aimed to evaluate molecular and biochemical mechanism of minocycline-induced hyperpigmentation in human normal melanocytes, as well as the contribution of UV radiation to this side effect. The experiments involved the evaluation of cyto- and phototoxic potential of the drug using cell imaging with light and confocal microscopes as well as biochemical and molecular analysis of melanogenesis. We showed that minocycline induced melanin synthesis in epidermal melanocytes. The action was intensified by UV irradiation, especially with the UVB spectrum. Minocycline stimulated the expression of microphthalmia-associated transcription factor (MITF) and tyrosinase (TYR) gene. Higher levels of melanin and increased activity of tyrosinase were also observed in treated cells. Moreover, minocycline triggered the supranuclear accumulation of tyrosinase, similar to UV radiation. The decreased level of premelanosome protein PMEL17 observed in all minocycline-treated cultures suggests disorder of the formation, maturation or distribution of melanosomes. The study revealed that minocycline itself was able to enhance melanin synthesis. The action was intensified by irradiation, especially with the UVB spectrum. Demonstrated results confirmed the potential role of melanin and UV radiation minocycline-induced skin hyperpigmentation.
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  • 文章类型: Comparative Study
    Topical Tacrolimus, especially when combined with Nb-UVB, has been proven clinically to be effective in the treatment of vitiligo. However, no histological study has evaluated the repigmentation mechanism of tacrolimus ointment in combination therapy with Nb-UVB. In this study, the histological findings in patients receiving Nb-UVB were compared with those receiving topical tacrolimus combined with Nb-UVB. Twenty patients were recruited and received Nb-UVB treatment. The first ten patients were selected for the combination therapy and instructed to apply tacrolimus 0.1% ointment twice daily on the specified lesion of interest. The remaining ten patients did not receive any other topical treatments. Skin biopsy was performed at baseline from the depigmented area and 2-3 months post-treatment from the repigmented area. Biopsy specimens were stained with haematoxylin-eosin-safran (HES), Fontana Masson, HMB45, Melan A, MITF, SOX10 and Nestin. Clinically, in the combination therapy group, interfollicular repigmentation in addition to the perifollicular and marginal pattern was observed. Histologically, in the combination therapy group, besides the migration of melanocytes from the bulge of the hair follicle seen in the monotherapy group, for the first time, we observed dermal melanocyte precursors located in mid- and superficial dermis.
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  • 文章类型: Journal Article
    缺乏犬Y染色体的注释参考序列限制了进化研究,以及我们对Y连锁序列在具有性别偏见的表型中的作用的理解。在全基因组关联研究(GWAS)中,我们观察到病例对照队列中性别不平衡时与常染色体SNPs的虚假关联,并假设定位于常染色体的一部分SNPs事实上与性别相关.在GWAS中使用Illumina230KCanineHD阵列进行性爱,我们确定了在两性中扩增但在男性和女性之间具有显著等位基因频率差异的SNP.我们发现48个SNPs定位到8个常染色体的14个区域和Y连锁的X染色体,男性表现为杂合,女性表现为单态。在这14个区域中有8个基因:3个常染色体和5个X连锁。我们调查了常染色体基因(MITF,PPP2CB,和WNK1),并确定SNP是已转座Y染色体的逆转录病毒中的发散核苷酸。MITFY和WNK1Y最近在犬科谱系中表达和出现,而PPP2CBY代表一个更老的插入,在狗中没有表达的证据。这项工作揭示了新的犬科动物Y染色体序列,并为从常染色体和X到Y的基因转座提供了证据。
    The lack of an annotated reference sequence for the canine Y chromosome has limited evolutionary studies, as well as our understanding of the role of Y-linked sequences in phenotypes with a sex bias. In genome-wide association studies (GWASs), we observed spurious associations with autosomal SNPs when sex was unbalanced in case-control cohorts and hypothesized that a subset of SNPs mapped to autosomes are in fact sex-linked. Using the Illumina 230K CanineHD array in a GWAS for sex, we identified SNPs that amplify in both sexes but possess significant allele frequency differences between males and females. We found 48 SNPs mapping to 14 regions of eight autosomes and the X chromosome that are Y-linked, appearing heterozygous in males and monomorphic in females. Within these 14 regions are eight genes: three autosomal and five X-linked. We investigated the autosomal genes (MITF, PPP2CB, and WNK1) and determined that the SNPs are diverged nucleotides in retrocopies that have transposed to the Y chromosome. MITFY and WNK1Y are expressed and appeared recently in the Canidae lineage, whereas PPP2CBY represents a much older insertion with no evidence of expression in the dog. This work reveals novel canid Y chromosome sequences and provides evidence for gene transposition to the Y from autosomes and the X.
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  • 文章类型: Journal Article
    The E318K mutation in the MITF gene has been associated with a high risk of melanoma, renal cell carcinoma, and pancreatic cancer; the risk of other cancers has not been evaluated so far. Herein, we examined the possible association of E318K and a novel variant of the MITF gene, V320I, with the risk of cancers of different sites of origin in a Polish population. We assayed for the presence of the E318K and V320I missense mutations in 4,226 patients with one of six various cancers (melanoma or cancer of the kidney, lung, prostate, colon, or breast) and 2,114 controls from Poland. The E318K mutation was detected in 4 of 2,114 participants (0.19%) in the Polish control population, the V320I in 3 of 2,114 participants (0.14%) in the control group. We found no statistically significant differences in the prevalence of the E318K and V320I variants among cases and controls. We found two carriers of the E318K variant among melanoma patients (P = 0.95), one carrier among breast cancer patients (P = 0.77), one carrier among colorectal cancer patients (P = 0.82), and one carrier among kidney cancer patients (P = 0.64). Our study demonstrates a lack of strong association of E318K and V320I with increased risk of melanoma or cancers of the kidney, breast, prostate, lung, or colon.
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  • 文章类型: Journal Article
    背景:硫氧还蛋白系统通过硫氧还蛋白和硫氧还蛋白还原酶的作用维持氧化还原平衡。硫氧还蛋白调节各种底物的活性,包括那些能抵消细胞氧化应激的.这些包括过氧化物酶,甲硫氨酸亚砜还原酶A和特异性转录因子。特别相关的是氧化还原因子-1,其进而激活其他氧化还原调节的转录因子。
    方法:讨论了人类硫氧还蛋白和硫氧还蛋白还原酶基因启动子中实验定义的转录因子结合位点以及参与调节细胞氧化还原状态的主要硫氧还蛋白系统底物的启动子。使用计算机模拟方法来鉴定所有这些启动子中这些转录因子的潜在推定结合位点。
    结论:我们的分析表明许多氧化还原基因启动子含有相同的转录因子结合位点。这些转录因子中的几个依次是氧化还原调节的。ARE存在于这些启动子中的几个中,并且在各种氧化应激刺激期间被Nrf2结合以上调基因表达。在相同的氧化应激刺激过程中,其他转录因子也与这些启动子结合,这种冗余支持了抗氧化反应的重要性。推定的转录因子位点在计算机中鉴定,结合该基因启动子的特定调控知识,可以为未来的实验提供信息。
    结论:氧化还原蛋白参与许多细胞信号通路,异常表达可导致疾病或其他病理状况。因此,理解它们的表达如何被调节对于开发靶向这些途径的治疗剂是相关的。
    BACKGROUND: The thioredoxin system maintains redox balance through the action of thioredoxin and thioredoxin reductase. Thioredoxin regulates the activity of various substrates, including those that function to counteract cellular oxidative stress. These include the peroxiredoxins, methionine sulfoxide reductase A and specific transcription factors. Of particular relevance is Redox Factor-1, which in turn activates other redox-regulated transcription factors.
    METHODS: Experimentally defined transcription factor binding sites in the human thioredoxin and thioredoxin reductase gene promoters together with promoters of the major thioredoxin system substrates involved in regulating cellular redox status are discussed. An in silico approach was used to identify potential putative binding sites for these transcription factors in all of these promoters.
    CONCLUSIONS: Our analysis reveals that many redox gene promoters contain the same transcription factor binding sites. Several of these transcription factors are in turn redox regulated. The ARE is present in several of these promoters and is bound by Nrf2 during various oxidative stress stimuli to upregulate gene expression. Other transcription factors also bind to these promoters during the same oxidative stress stimuli, with this redundancy supporting the importance of the antioxidant response. Putative transcription factor sites were identified in silico, which in combination with specific regulatory knowledge for that gene promoter may inform future experiments.
    CONCLUSIONS: Redox proteins are involved in many cellular signalling pathways and aberrant expression can lead to disease or other pathological conditions. Therefore understanding how their expression is regulated is relevant for developing therapeutic agents that target these pathways.
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