MIA基因-RNAi对人黑素瘤A375细胞增殖的影响

目的探讨RNA干扰技术抑制恶性黑素瘤细胞株A375MIA基因表达后,对A375细胞增殖的影响。方法构建针对人黑素瘤A375细胞(MIA)基因3个不同靶序列的RNAi真核表达载体pLTE-hMIA-RNAi,用磷酸钙细胞转染法把构建的载体分别转染HEK293细胞,采用Western技术和RT-PCR技术分别检测MIA基因蛋白的表达和mRNA水平。选择对MIA基因表达抑制作用最强的RNAi载体转染A375细胞后,用细胞计数检测细胞增殖的变化。结果构建的3个RNAi质粒和对照组相比,pLTE-hMIA-RNAi352质粒对MIA的表达减少量>80%,hMIA的mRNA水平下降约83%,与对照组比较差异有显著性意义。而pLTE-hMIA-RNAi203、pLTE-hMIA-RNAi343质粒对MIA的表达及mRNA水平的影响,与对照组比较差异无显著性意义。转染pLTE-hMIA-RNAi352质粒的A375细胞增殖能力较对照组显著下降。结论构建的针对人MIA基因352位靶序列的RNAi质粒pLTE-hMIA-RNAi352可显著抑制MIA的表达及A375细胞增殖。     

腺病毒介导p27mt基因转移诱导恶性黑素瘤细胞凋亡的实验研究

目的:探讨突变型p27基因(p27mutant type gene;p27mt)对恶性黑素瘤A375细胞凋亡的调节作用。方法:利用重组腺病毒Ad-p27mt转染培养的人恶性黑素瘤A375细胞,用3H-TdR掺入法检测细胞增殖;流式细胞术、DNA片段分析法、TUNEL法检测细胞凋亡。结果:重组腺病毒Ad-p27mt在MOI≥50时,可达到100%的转导效率。Ad-p27mt转染恶性黑素瘤细胞A375后,3H-TdR掺入法检测发现细胞增殖抑制;流式细胞术检测在G1期前出现亚二倍体凋亡峰;细胞DNA抽提电泳后发现凋亡特征性梯带。TUNEL法检测凋亡指数分别为48.5±3.6(Ad-p27mt组)及4.2±0.8(空白对照组),差异有显著性(P<0.01)。结论:重组腺病毒介导的p27mt基因转移可诱导恶性黑素瘤A375细胞在Gl期阻滞并导致细胞凋亡。     

人黑素瘤细胞A375 MIA/CD-RAP基因启动子的克隆及其鉴定

目的:克隆MIA/CD-RAP的启动子序列并对其进行酶切和DNA测序鉴定。方法:从培养的人黑素瘤细胞A375基因组DNA中扩增出MIA/CD-RAP启动子序列,并将其克隆到载体pGL2-Ba-sic上,再经酶切及PCR扩增鉴定和测序。结果:酶切电泳和DNA测序结果表明,已成功克隆了人黑素瘤MIA/CD-RAP启动子序列。结论:人黑素瘤MIA/CD-RAP启动子序列的克隆,可为进一步研究MIA/CD-RAP基因的表达调控奠定基础。     

溶瘤腺病毒介导的IL-18在黑素瘤A375细胞中的表达

目的构建携带人IL-18基因的溶瘤腺病毒,观察在A375细胞中IL-18基因的表达情况。方法将pZD55-IL-18与含有腺病毒右臂的质粒pBHGE3共转染293细胞获得重组腺病毒。PCR鉴定条件增殖腺病毒ZD55- IL-18。以ZD55-IL-18感染人黑素瘤A375细胞系,通过逆转录-聚合酶链反应(RT-PCR)检测IL-18基因mRNA的表达;Western blot法检测腺病毒E1A的表达情况;结晶紫染色法检测细胞杀伤作用;MTY法检测细胞存活情况。结果PCR鉴定表明ZD55-IL-18构建成功;RT-PCR和Western blot结果表明,ZD55-IL-18能高效介导IL-18基因在A375细胞中的表达,并在肿瘤细胞内表达E1A;结晶紫染色和MTT结果表明,ZD55-IL-18对A375细胞有明显的杀伤作用。结论构建成功的溶瘤腺病毒ZD55-IL-18,可在A375细胞中高效表达IL-18基因,并能抑制黑素瘤细胞生长。     

骨桥蛋白在黑素瘤中的表达

目的研究骨桥蛋白(OPN)的表达与黑素瘤浸润、转移的关系。方法采用免疫组化SP法检测OPN在黑素瘤(30例)、黑素细胞痣(30例)、正常皮肤组织(15例)以及在黑素瘤A375细胞株和不同浓度乙酰肝素酶反义寡核苷酸转染的裸鼠黑素瘤移植瘤中的表达。结果 OPN在黑素瘤、黑素细胞痣及正常皮肤组织中阳性表达率分别为86.67%(26/30),13.33%(4/30)和0(0/15),黑素瘤组与黑素细胞痣组及正常皮肤组OPN的阳性表达率比较差异有统计学意义(P=0.000)。3种不同浓度的乙酰肝素酶反义寡核苷酸在转染的裸鼠体内恶性黑素瘤移植瘤中表达表现出不同程度的抑制作用,30μmol/L实验组的抑制作用最强。OPN在人黑素瘤A375细胞株中呈强阳性表达。结论 OPN在黑素瘤中的表达明显高于其在黑素细胞痣和正常皮肤中的表达;乙酰肝素酶反义寡核苷酸对裸鼠体内黑素瘤移植瘤中OPN的表达有显著抑制作用;OPN在A375细胞株中呈强阳性表达。     

皮肤黑素瘤中miRNA-34c的表达对促血管新生因子VEGF-A、VEGFR-1的影响

目的探讨皮肤黑素瘤中miRNA-34c的表达以及其对促血管新生因子VEGF-A和VEGFR-1的影响。方法 Northern blotting检测原代人黑素瘤细胞、黑素瘤细胞株A375和原代人表皮黑素细胞miRNA-34c表达。构建miRNA-34c基因过表达与基因敲低的黑素瘤细胞株A375细胞系即高表达miRNA-34c组和低表达miRNA-34c组,以空载体转染黑素瘤细胞株A375作为空载体对照组。CCK-8法检测各组细胞增殖活性。qRT-PCR和Western blotting分别检测各组VEGF-A、VEGFR-1 mRNA和蛋白表达。结果与原代人表皮黑素细胞相比,黑素瘤细胞株A375和原代人黑素瘤细胞中miRNA-34c的表达降低(P<0.05)。高表达miRNA-34c组、低表达miRNA-34c组和空载体对照组细胞增殖活性无明显差异(P>0.05)。高表达miRNA-34c组VEGF-A、VEGFR-1的mRNA和蛋白表达较空载体对照组降低(P<0.05)。低表达miRNA-34c组VEGF-A、VEGFR-1的mRNA和蛋白表达较空载体组升高(P<0.05)。结论 miRNA-34c在皮肤黑素瘤中呈现特异性下调,miRNA-34c可能通过对促血管新生因子VEGF-A、VEGFR-1的下调参与皮肤黑素瘤的发生与发展。     

RNAi沉默c-Met基因对黑素瘤A375细胞生物学行为的影响

目的探讨c-MetshRNA表达载体对人黑素瘤A375细胞增殖、侵袭能力的影响。方法以pGenesil-1质粒为载体,以c-Met为靶基因,构建shRNA表达载体,并将其转染至体外培养的人黑素瘤A375细胞中。倒置相差显微镜下观察经干扰后瘤细胞的形态学变化;采用反转录聚合酶链反应(RT-PCR)和Western blot法分别检测转染细胞c-Met基因和蛋白的表达水平;四甲基偶氮唑盐微量酶反应比色法(MTT法)检测转染后细胞的生长活力;Transwell小室法测定转染细胞体外侵袭能力。结果构建了pGenesil-1-c-MetshRNA重组质粒,并成功转染A375细胞。转染后A375细胞缩小,变圆。RT-PCR显示转染后c-Met mRNA的表达显著降低,以48h为著,下降近64%;Western blot证实转染后蛋白的表达下降近65%;MTT法显示细胞的活力降低为(68.25±4.4)%;Transwell小室测定转染细胞体外侵袭能力明显下降。结论 pGenesil-1-c-MetshRNA重组质粒明显下调c-Met在黑素瘤细胞中的表达,并抑制肿瘤细胞增殖及其侵袭能力。     

微小RNA let-7a下调黑素瘤A375细胞系BRAF蛋白的表达

目的:评价微小RNA let-7a对黑素瘤A375细胞系BRAF蛋白表达的影响。方法:采用蛋白印迹法检测BRAF蛋白在A375细胞及黑素细胞的表达;用微小RNA let-7a的模拟物及阴性对照分别转染A375细胞,CCK-8实验检测细胞增殖情况。结果:与黑素细胞相比,BRAF蛋白在黑素瘤A375细胞表达升高;与阴性对照相比,微小RNA let-7a的模拟物转染A375细胞后,抑制细胞增殖,BRAF蛋白表达下降。结论:微小RNA let-7a可抑制黑素瘤A375细胞增殖,下调BRAF蛋白表达。     

皮肤科学基础

诱导皮肤免疫抑制和表没食子儿茶素没食子酸酯光保护作用;中波紫外线对皮肤免疫系统影响的某些研究进展（综述）;全反式维甲酸和阿达帕林对中波紫外线诱导的melan-α黑素细胞黑素合成的影响;人黑素瘤细胞A375MIA／CD-RAP基因启动子的克隆及其鉴定;过氧化氢对黑素细胞生物学作用的研究……[第一段]     

微小RNA-let-7a对黑素瘤细胞系A375细胞凋亡的影响

目的 研究微小RNA（microRNA）-let-7a对黑素瘤细胞系A375细胞凋亡的影响及其作用机制。方法 采用实时荧光定量PCR法（TaqMan探针法）检测microRNA-let-7a在A375细胞及黑素细胞的表达差异;然后用microRNA-let-7a的模拟物转染A375细胞,流式细胞仪检测其凋亡的改变;最后采用Western印迹检测转染后半胱天冬酶-3（caspase-3）蛋白的变化。结果 与黑素细胞相比,microRNA-let-7a在A375细胞中表达下降了0.462倍;采用microRNA-let-7a的模拟物转染后,与阴性对照（细胞凋亡率16.9%）相比,A375细胞凋亡（细胞凋亡率47.4%）增加;转染后caspase-3蛋白表达下调。结论 microRNA-let-7a可促进黑素瘤细胞系A375的凋亡,同时下调caspase-3蛋白的表达。     

Nucleofection is a highly effective gene transfer technique for human melanoma cell lines

Abstract:  Despite the increasing use of gene transfer strategies in the study of cellular and molecular biology, melanoma cells have remained difficult to transfect in a safe, efficient, and reproducible manner. In the present study, we report the successful use of nucleofector technology to transfect human melanoma cell lines. This technology uses an empirically derived combination of cell line-specific solutions and nucleofector programmes to electroporate nucleic acid substrates directly into the cell nucleus. Using a colorimetric β-galactosidase assay, we optimized nucleofection parameters for 13 melanoma cell lines, leading to maximum transfection efficiency and cell survival. The combinations of cell solutions NHEM or T and nucleofector programmes A-24 or U-20 produced the best results. We compared nucleofection with two commercially available lipid-based gene transfer systems, effectene and lipofectamine 2000 using a green fluorescent protein reporter vector. Nucleofection demonstrated a 3- to 40-fold improvement in transfection efficiency when compared with the lipid-based counterparts. Nucleofection was also superior in transfecting small-interfering RNA (siRNA) as determined by Western blot analysis. Lastly, we applied nucleofection to the simultaneous transfection of a p53-dependent luciferase plasmid and p53-siRNA. Experiments using dual transfection showed knockdown of p53 expression and silencing of the reporter plasmid. In conclusion, nucleofection is highly effective for the transfer of nucleic acid substrates, singly or in combination, into human melanoma cell lines.     

Xeroderma pigmentosum group C in a French Caucasian patient with multiple melanoma and unusual long-term survival

We report the case of an 83-year-old French woman with multiple melanomas showing a severe DNA repair deficiency, corrected after transfection by XPC cDNA. Two biallelic mutations in the XPC gene are reported: an inactivating frameshift mutation in exon 15 (c.2544delG, p.W848X) and a missense mutation in exon 11 (c.2108 C>T, P703L). We demonstrate that these new mutations are involved in the DNA repair deficiency and confirm the diagnosis of xeroderma pigmentosum from complementation group C (XP-C). We speculate that the coexistence of a MC1R variant may be involved in the phenotype of multiple melanomas and that the unusual long-term survival may be related to a lower ultraviolet radiation exposure and to a regular clinical follow-up. This patient appears to be the first French Caucasian XP-C case and one of the oldest living patients with XP reported worldwide.     

Differential promoter activity in benign and malignant human cells of skin origin*

Abstract In order to develop systems to express mammalian proteins in human skin-derived cells, we tested 6 different viral and 1 eukaryotic promoter (pCMV, pRSV, pSV, pMMTV, pPoly E, pPoly L, pHMT) for their ability to drive the expression of the chloramphenicol acetyltrans-ferase (CAT) enzyme in different human skin-derived cells. DNA was transfected in human keratinocytes derived from normal foreskin and cervix, in the HPV-negative cervical cancer line HT-3 and in malignant melanoma cell lines (SK-Mcl 23, SK-Mcl 37) using a liposome-based technique or calcium precipitation. Transaction efficacy was controlled by cotrans-fection of a p-galactosidase gene construct. The enzymatic activity of the CAT-gene expression was determined by incubation of the cell extract prepared from the transfected cells with 14 C-labeled chloramphenicol. The CMV-promoter was highly active in all skin- or mucosal-derived cells. In contrast to the strong CMV-promoter, the RSV-, SV-, and HMT-promoter were less active and varied in dependence of the cell type. The pattern of the promoter activity differed between benign and transformed genital keratinocytes. Only the SV-promoter showed a comparable strong basal activity, which was restricted to the SK-Mel 37 cells. In conclusion, the promoter activity has to be tested for each cell type depending on the aims of the gene expression.     

黑素瘤相关MicroRNAs的研究进展

近年来发现MicroRNAs可通过膜受体酪氨酸蛋白激酶通路、P13K-AKT通路、P16INK4ACDK4/6-RB通路、小眼相关转录因子、p53-miR-149-3p-GSK3ix-Mcl-1通路影响黑素瘤的生物学行为,MicroRNAs及其靶基因相关通路的研究对黑素瘤的早期诊断、预后判断以及黑素瘤的靶向治疗具有重要的意义。     

Regression of established subcutaneous B16‐F10 murine melanoma tumors after gef gene therapy associated with the mitochondrial apoptotic pathway

Please cite this paper as: Regression of established subcutaneous B16‐F10 murine melanoma tumors after gef gene therapy associated with the mitochondrial apoptotic pathway. Experimental Dermatology 2009. Abstract: Novel treatment modalities, including gene therapy, are needed for patients with advanced melanoma. We evaluated whether the gef gene, a suicide gene from Escherichia coli, had a significant cytotoxic impact on melanoma in vivo. First, we used a non‐viral gene delivery approach (pcDNA3.1/gef) to study the inhibition of melanoma cells (B16‐F10) proliferation in vitro. Secondly, we used direct intra‐tumoral injection of pcDNA3.1/gef complexed with jetPEI to deliver gef cDNA to rapidly growing murine melanomas. We demonstrated that gef gene not only has an antiproliferative effect on B16‐F10 cells in vitro, but also induces an important decrease in melanoma tumor volume (77.7% in 8 days) in vivo. Interestingly, after gef gene treatment, melanoma showed apoptosis activation associated with the mitochondrial pathway, suggesting that the induction of this death mechanism may be an effective strategy for its treatment. Our in vivo results indicate that gef gene might become a suitable therapeutic strategy for patients with advanced melanoma.     

肢端黑素瘤合并骨髓增生异常综合征1例

患者男,67岁,发现右足底黑斑和肿物2个月,迅速增大10 d。患者1年前确诊骨髓增生异常综合征-EB1型。皮肤科情况:右足底单发肿物,表面颜色不均,伴糜烂,周围形状不规则的浅褐色至深褐色斑片。组织病理提示:黑素细胞瘤,梭形细胞型。免疫组织化学显示:S-100(+),SOX-10(+)。建议行右足底皮肤恶性肿瘤扩大切除术,患者拒绝。3个月后患者死亡,死因不详。     

Prognostic signs in melanoma: state of the art

Prognoses for melanoma patients are currently based on statistically confirmed parameters, above all the Breslow thickness and number of lymph node and/or distant metastases. However, metastases can develop even with "thin" melanomas (< 0.7 mm), while survival has been recorded in patients with tumours classified as "thick" (> 4 mm). This review of the literature examines the most recent advances in prognostic markers for melanoma (serological, immunohistochemical, histological, genetic and surgical). These markers offer interesting possibilities in terms of diagnostic certainty, identification of early growth phases and estimation of the tumour's potential for progression and metastasis. It is reasonable to assume that their combined use can provide useful information for formulating prognoses that are not only statistically valid but also individualized.