Vectors for gene therapy of skin diseases

The success of gene therapy mainly depends on the gene vector (GV) responsible for the efficient transport of genetic information. The qualities of a GV have a profound influence on the method of application, the efficiency of gene transfer in the target tissue, the amount and persistence of gene expression and the potential side effects and safety risks. Clinical gene therapy studies over the past 20 years have contributed to the development and testing of different GV systems, some of which also show great potential for the treatment of skin diseases. In this review the structures, methods of application, characteristics, clinical uses and possibilities for optimization of these GV will be discussed with regard to their cutaneous applications.     

CLINICAL AND IMMUNOLOGIC SEQUELAE OF AIDS RETROVIRUS INFECTION

The Sydney AIDS Project is a prospective immunoepidemiological study of 911 homosexual and bisexual men enrolled between February 1984 and January 1985. Clinical, immunological, and serological studies are performed on these subjects every six months. At enrolment, 39.9% of subjects were seropositive for antibodies to AIDS retrovirus (ARV). Of these 352 seropositive subjects, 28.1% were symptomless with normal immune profiles, 23.6% were symptomless with an immunodeficiency, 18.8% had a clinical illness but normal immune profile, and 29.6% had a clinical illness and immunodeficiency. Of the symptomless subjects, 27.8% were seropositive for antibodies to ARV. Clinically, seropositivity was significantly associated with enlargement of three or more non-inguinal lymph node groups, splenomegaly, and hepatomegaly. Immunologically, seropositivity was significantly associated with lower absolute numbers of lymphocytes and T4 + lymphocytes and a lower T4 +:T8 + ratio, compared with seronegative subjects. Seropositive subjects with a clinical illness had a significantly lower percentage of T4 + lymphocytes and lower T4 +:T8 + ratio than did those who were symptomless. However, the absolute number of T4 + cells was not significantly different between subjects with a clinical illness and those who were symptomless. Subjects whose sera were positive by immunofluorescence and enzyme-linked immunosorbent assay but were negative by radioimmune precipitation assay had a lower number and percentage of T4 + lymphocytes than subjects who were positive by all three tests. These results demonstrate a wide variety of clinical and immunological responses to ARV infection. Prospective study of these subjects will enable us to define further the natural history of ARV infection and factors associated with progression.     

Heme oxygenase-1 accelerates tumor angiogenesis of human pancreatic cancer

Angiogenesis is necessary for the continued growth of solid tumors, invasion and metastasis. Several studies clearly showed that heme oxygenase-1 (HO-1) plays an important role in angiogenesis. In this study, we used the vital microscope system, transparent skinfold model, lung colonization model and transduced pancreatic cancer cell line (Panc-1)/human heme oxygenase-1 (hHO-1) cells, to precisely analyze, for the first time, the effect of hHO-1 gene on tumor growth, angiogenesis and metastasis. Our results revealed that HO-1 stimulates angiogenesis of pancreatic carcinoma in severe combined immune deficient mice. Overexpression of human hHO-1 after its retroviral transfer into Panc-1 cells did not interfere with tumor growth in vitro. While in vivo the development of tumors was accelerated upon transfection with hHO-1. On the other hand, inhibition of heme oxygenase (HO) activity by stannous mesoporphyrin was able transiently to delay tumor growth in a dose dependent manner. Tumor angiogenesis was markedly increased in Panc-1/hHO-1 compared to mock transfected and wild type. Lectin staining and Ki-67 proliferation index confirmed these results. In addition hHO-1 stimulated in vitro tumor angiogenesis and increased endothelial cell survival. In a lung colonization model, overexpression of hHO-1 increased the occurrence of metastasis, while inhibition of HO activity by stannous mesoporphyrin completely inhibited the occurrence of metastasis. In conclusion, overexpression of HO-1 genes potentiates pancreatic cancer aggressiveness, by increasing tumor growth, angiogenesis and metastasis and that the inhibition of the HO system may be of useful benefit for the future treatment of the disease.     

Twist基因逆转录病毒载体的构建及其诱导正常乳腺上皮细胞发生上皮间质转化

目的 构建Twist基因逆转录病毒载体,研究其对人正常乳腺上皮细胞MCF10A的影响.方法 酶切pcDNA3/myc-Twist获得myc-Twist,克隆到逆转录病毒载体pBABE-puro中,构建重组质粒pB AB E-myc-Twist.通过酶切、测序鉴定Twist基因正确后,在体外将质粒pBABE-myc-Twist和其对照分别与包装质粒pAmpho共同转染人胚肾上皮细胞系293T细胞,进行逆转录病毒的包装,并感染人正常乳腺MCF10A上皮细胞,用嘌呤霉素(puromycin)筛选,获得成功转入Twist的MCF10A-Twist细胞和MCF10A-Vector对照细胞.通过RT-PCR和Western blot法验证Twist细胞在MCF10A-Twist和MCF10A-Vector细胞内的表达.免疫荧光技术和Western blot法检测细胞内上皮间质转化(EMT)标志蛋白的表达.Transwell(R)法检测细胞的迁移和侵袭能力.结果 重组逆转录病毒载体质粒pBABE-myc-Twist经酶切和测序鉴定构建正确;Twist基因被逆转录病毒成功导入MCF10A细胞,并在靶细胞内稳定表达,RT-PCR检测到Twist mRNA在MCF10A-Twist细胞中表达,Western blot法检测发现myc-Twist蛋白在MCF10A-Twist细胞中表达;免疫荧光和Western blot法检测显示在MCF10A-Twist细胞中E-cadherin表达显著下调、vimentin表达明显上调;与MCF10A-Vector细胞相比,Transwell(R)法检测发现MCF10A-Twist细胞迁移和侵袭能力明显增加(P＜0.01).结论 Twist诱导MCF10A细胞发生EMT转化,并促进其迁移和侵袭.     

人Notch1受体胞内段重组腺病毒构建及转染

目的构建人Notch1受体胞内段重组腺病毒并转染人肝癌细胞株HepG2,为Notch信号对肝癌侵袭转移的影响研究奠定实验基础。方法构建Notch1受体胞内段(notch intracellular domain,NICD)基因的重组质粒pDC316-CMV-EGFP-CMV-Notch1-Myc,采用AdMax腺病毒包装系统将重组质粒与骨架质粒pBHGlox_E1,3Cre共转染293细胞,同源重组产生重组腺病毒Ad-EGFP-NICD-Myc,RTPCR鉴定重组腺病毒EGFP及NICD基因表达。重组腺病毒转染人肝癌细胞株HepG2,荧光显微镜观察EGFP及NICD蛋白的表达。结果重组腺病毒Ad-EGFP-NICD-Myc经鉴定基因表达正确,此病毒转染人肝癌细胞株HepG2后阳性表达EGFP及NICD蛋白。结论人Notch1受体胞内段重组腺病毒成功构建,为进一步Notch信号对肝癌侵袭转移的影响研究奠定了实验基础。