This study aimed at investigating the inhibitory effects and the anti-tumor mechanisms of co-administration of fusion pro-teins gonadotropin-releasing hormone(GnRH)and hVEGF-GnRH3(VG)on B16F10 melanoma in C57BL/6J mice model.The metastasis of melanoma can be promoted by overexpression of the targeting antigens GnRH and VG.VG vaccine has been shown to elicit an immune inflammatory response against prostate cancer.Hence the authors hypothesized VG also has potential to prevent melanoma angiogenesis,progression and recurrence.Recombinant protein hVEGF-GnRH3 was extracted by E.coli expression system and purified by DEAE anion exchange chromatography to prepare protein vaccine.B16F10 melanoma cells were transplanted into male C57BL/6J mice(1 x 106 cells per mouse)to construct a melanoma model.The tumor-bearing mice were immunized with VG protein vaccine for three cycles.Thereafter,the tumor suppressing effect of the vaccine was evaluated from the aspects of tumor growth,angiogenesis and tumor histology,periphery and splenocytes humoral,cellular,and intracellular immunomodulation also included.The results showed that the volumes and angiogenesis of melanoma were significantly inhibited in VG group(P＜0.01).Compared to the PBS group,VG increased the levels of anti-GnRH,anti-VEGF IgG and circulating interferon-gamma(IFN-γ)in mice serum,while the level of IL-6 was significantly decreased.In the spleen-related experiments,the MTT assay showed that VG vaccine promoted splenocytes prolife-ration and cytotoxicity.At the same time,further analysis of intracellular cytokines revealed a significant increase in CD3+CD4+INF-γ+cells.The results above indicate that VEGF-GnRH3 is a promising vaccine for the treat-ment of melanoma.
实验探究了重组Monellin菌株的最佳培养条件,并对其进行了甜味阈值确认和血糖值影响实验.实验所用菌种为实验室构建保存的BL21(DE3)-pET28a Monellin菌种,利用不同浓度的乳糖和IPTG诱导该菌种生成目的蛋白,探究其最佳诱导条件,利用镍柱亲和层析纯化目的蛋白后进行相对甜度和甜味阈值实验,随后设置甜度梯度,对小鼠进行灌胃比较蔗糖和Monellin的升血糖作用及不同浓度Monellin对血糖的影响.实验结果表明,0.9 mmol/L IPTG诱导5 h的Monellin表达量最多,其甜味阈值为100μg/mL,相对甜度为蔗糖的800倍.灌胃结果表明,Monellin升血糖作用不显著,并且在一定范围内对血糖的影响不随其浓度的改变而发生变化.该实验为Monellin在糖尿病等代糖食品市场上的应用提供了科学的理论依据.
前列腺六段跨膜上皮抗原(Six-segment transmembrane epithelial antigen of prostate,STEAP)家族属于跨膜蛋白,其在细胞与细胞之间的通讯方面起着重要作用.STEAP具有离子通道功能,在体内可发挥金属氧化还原酶活性,广泛参与调控细胞增殖、凋亡、迁移和侵袭等生命活动.在多数肿瘤细胞中STEAP均呈现过表达的趋势,与正常的组织细胞表达量形成显著差异,这种表达特异性,预示其可作为治疗癌症的潜在靶标.文章主要针对STEAP家族中的成员STEAP1,对其蛋白结构功能、正常细胞与肿瘤细胞之间的表达差异以及靶向策略作一简要综述,用以评估其作为肿瘤治疗靶点的可行性.
