Fam114A1蛋白对黑素细胞生物学功能影响的初步研究

【摘要】 目的 初步探讨Fam114A1对黑素细胞生物学功能的影响。方法 以黑素瘤细胞A375为工具细胞株，通过慢病毒转染的方式构建稳定过表达和抑制Fam114A1蛋白的细胞株，即过表达组和表达抑制组，以转染空载慢病毒的A375细胞作为对照组。实时荧光定量PCR检测Fam114A1对黑素合成相关基因酪氨酸酶（TYR）、酪氨酸酶相关蛋白1（TYRP1）、前黑素小体蛋白（PMEL）、小眼畸形相关转录因子（MITF）和多巴色素异构酶（DCT）mRNA表达的影响，Western印迹法检测TYR、MITF蛋白的表达，MTT法、Transwell迁移和黏附实验分别检测Fam114A1对A375细胞增殖活性、迁移细胞数及黏附能力的影响。统计分析采用单因素方差分析和Dunnett-t检验。结果 荧光显微镜观察慢病毒转染效率均在90%左右。与对照组A375细胞Fam114A1相对表达水平（0.850 ± 0.120）相比，过表达组显著升高（1.507 ± 0.170，t = 5.888，P = 0.001），而表达抑制组显著降低（0.397 ± 0.120，t = 4.065，P = 0.007），成功构建稳定过表达和抑制Fam114A1的A375细胞株。实时荧光定量PCR及Western印迹结果显示，表达抑制组TYR和MITF mRNA及蛋白表达均显著低于对照组（均P < 0.01），而过表达组TYR和MITF mRNA及蛋白表达与对照组差异无统计学意义（均P > 0.05）。与对照组相比，表达抑制组细胞增殖活性和黏附能力显著增强（P = 0.009、0.001），细胞迁移能力显著减弱（P = 0.005），而过表达组仅细胞迁移能力显著增强（P = 0.021）。结论 Fam114A1可影响A375的增殖活性、迁移和黏附能力，且影响黑素合成相关蛋白TYR和MITF的表达，可能是一种参与调控黑素细胞生物学活性的功能蛋白。     

Nicotine does not affect stem cell properties requisite for suicide gene therapy against glioma

ABSTRACT

Objective: 

Glioblastoma is one of the most lethal tumors in adult central nervous system with a median survival of a year and half and effective therapeutic strategy is urgently needed. For that reason, stem cell-based suicide gene therapies have attracted much interest because of potent tumor tropism of stem cells and bystander effect. In this current clinical situation, stem cells are promising delivery tool of suicide genes for glioma therapy. Since habitual cigarette smoking still prevails worldwide, we investigated the effect of nicotine on stem cell tropism toward glioma and gap junctional intercellular communication (GJIC) function between glioma and stem cells, both of which are important for suicide gene therapies. Methods: Mouse induced pluripotent stem cell-derived neural stem cells (iPS-NSCs) and human dental pulp mesenchymal stem cells (DPSCs) were used. The effect of nicotine on tumor tropism to glioma-conditioned medium (CM) at a non-cytotoxic concentration was assessed with Matrigel invasion assay. Nicotine effect on GJIC was assessed with the scrape loading/dye transfer (SL/DT) assay for co-culture of glioma and stem cells and the parachute assay among glioma cells using high-content analysis. Results: Tumor tropism of iPS-NSCs toward GL261-CM and DPSCs toward U251-CM was not affected by nicotine (0.1 and 1 µM). Nicotine at the concentrations equivalent to habitual smoking (1 µM) did not affect GJIC of iPS-NSC/GL261 and DPSC/U251 and GJIC among each glioma cells. Conclusions: The study demonstrated that non-cytotoxic concentrations of nicotine did not significantly change the stem cell properties requisite for stem cell-based suicide gene therapy.     

PP4R1 interacts with HMGA2 to promote non-small-cell lung cancer migration and metastasis via activating MAPK/ERK-induced epithelial-mesenchymal transition

Protein phosphatase 4 regulatory subunit 1 (PP4R1) has been shown to play a role in the regulation of centrosome maturation, apoptosis, DNA repair, and tumor necrosis factor signaling. However, the function of PP4R1 in non-small-cell lung cancer remains unclear. In this study, we identify PP4R1 as an oncogene through Oncomine database mining and immunohistochemical staining, and we showed that PP4R1 is upregulated in lung cancer tissues as compared with that in normal lung tissues and correlated with a poor prognosis in lung cancer patients. Furthermore, in vitro study by wound-healing and Transwell assay showed that PP4R1 could promote migration and invasion of lung cancer cells. Mechanistic investigations revealed that PP4R1 could cooperate with high mobility group AT-hook 2 and thereby promotes epithelial-mesenchymal transition via MAPK/extracellular receptor kinase activation. Taken together, our study provides a rich resource for understanding PP4R1 in lung cancer and indicates that PP4R1 may serve as a potential biomarker in lung cancer therapies.     

Location,location, location: Melanoma cells “living at the edge”

Abnormal cell migration and invasion underlie metastatic dissemination, one of the major challenges for cancer treatment. Melanoma is one of the deadliest and most aggressive forms of skin cancer due in part to its migratory and metastatic potential. Cancer cells use a variety of migratory strategies regulated by cytoskeletal remodelling. In particular, we discuss the importance of amoeboid invasive melanoma strategies, since they have been identified at the edge of human melanomas. We hypothesize that the presence of amoeboid melanoma cells will favour tumor progression since they are invasive and metastatic; they support immunosuppression; they harbour cancer stem cell properties and they are involved in therapy resistance. The Rho-ROCK-Myosin II pathway is key to maintain amoeboid melanoma invasion but this pathway is further regulated by pro-tumorigenic/pro-metastatic/pro-survival signalling pathways such as JAK-STAT3, TGFβ-SMAD, NF-κB, Wnt11/5-FDZ7 and BRAF^V600E-MEK-ERK. These pathways support amoeboid behaviour and are actionable in the clinic. After melanoma wide surgical margin removal, we propose that possible remaining melanoma cells should be eradicated using anti-amoeboid therapies.     

葫芦素抗肿瘤作用研究进展

癌症是全球主要的公共卫生问题，中国国家癌症中心的统计数据也表明癌症以逐年提升的发病率和死亡率成为威胁人类健康的重大疾病。癌症的发生发展机制复杂，涉及多阶段、多个基因及多条信号通路的异常，常规的放化疗及新兴的靶向治疗方法是肿瘤治疗的主要方式，但由于其毒副作用和耐药性的产生严重影响了患者的生活质量和持续有效的治疗效果，因此寻找安全有效的抗癌药物是全球关注的焦点。抗肿瘤植物药紫杉醇类、长春碱类、鬼臼素类、人参皂苷和多糖等的研发与应用给肿瘤治疗带来了新的希望。葫芦素是一种来源于中药葫芦科植物的高度氧化的四环三萜类化合物，药理作用广泛且机制复杂，在葫芦素家族中，目前针对葫芦素B，D，E，I抗肿瘤作用研究最多，已有大量研究证实，葫芦素B，D，E，I在治疗消化系统、呼吸系统、生殖系统、血液系统、泌尿系统等肿瘤疾病中发挥了重要作用，能够显著抑制肿瘤细胞增殖，而且在阻滞细胞周期、诱导细胞凋亡和自噬性死亡、抑制细胞迁移和侵袭、抑制肿瘤血管生成、调节活性氧的水平、调节免疫等方面作用显著，有望开发成为抗癌新药。基于当前国内外针对葫芦素抗多种肿瘤的作用及机制研究成果，笔者对葫芦素抗肿瘤作用研究进展进行了全方面综述，以期为葫芦素类抗肿瘤药物新药研发提供参考。     

circZBTB44通过调控AKT通路促进肾透明细胞癌增殖和迁移的研究

目的 探究circZBTB44在肾透明细胞癌中的表达情况及探讨circZBTB44在肾透明细胞癌中的生物学功能及促进肾透明细胞癌细胞进展的可能机制。方法 通过qRT-PCR法检测circZBTB44在我院21对肾透明细胞癌组织及细胞系786-O、ACHN中的表达水平;通过放线菌素D实验、RNase R实验、核浆分离实验鉴定circZBTB44的特征;通过siRNA下调circZBTB44的表达后,通过MTS细胞增殖实验、克隆形成实验及Transwell迁移实验来探究circZBTB44对肾透明细胞癌786-O、ACHN的生物学功能影响;通过蛋白免疫印迹实验来探究circZBTB44调控的下游通路。结果 circZBTB44在肾透明细胞癌组织和细胞株786-O和ACHN中明显高表达。下调circZBTB44的表达可明显抑制786-O和ACHN的增殖和迁移能力。下调circZBTB44可抑制肾透明细胞癌786-O和ACHN细胞中AKT的磷酸化。结论 circZBTB44在肾透明细胞癌中高表达。circZBTB44可能通过调控AKT信号通路促进肾透明细胞癌的增殖和迁移。     

Increased Expression of Macrophage Migration Inhibitory Factor and DJ-1 contribute to Cell Invasion and Metastasis of Nasopharyngeal Carcinoma

Background and aim: Both macrophage migration inhibitory factor (MIF) and DJ-1 protein have been shown to relate with cell invasion and metastasis in tumors. However, the role of DJ-1 in invasion and metastasis of nasopharyngeal carcinoma (NPC) and its relation to MIF expression in NPC are not fully understood. The aim of present study is to determine whether or not MIF and DJ-1 are correlated with tumor invasion and influence a worse outcome in NPC, as well as its related mechanism.Methods: 125 cases of NPC and 45 normal tissues of nasopharynx were collected. The expression of MIF and DJ-1 in tissue microarray was evaluated by immunohistochemical staining. Correlation between immunostainings and clinicopathological parameters, as well as the follow-up data of patients, was analyzed statistically. The association of MIF and DJ-1 with cell invasion and migration in NPC cell line were evaluated by small interfering RNA (siRNA) transfection, invasion assay and Western blotting.Results: MIF and DJ-1 staining was diffused and strong in tumor cells, whereas they were generally weaker and less common in normal lining epithelia of nasopharynx. High MIF expression in tumor cells (71.2%, 89/125 cases) were significantly associated with advanced clinical stage, lymph node metastasis, and worse prognosis of NPC patients. High expression of DJ-1 (75.2%, 94/125 cases) were closely correlated to lymph node metastasis and MIF high-expression. Only MIF high expression (P = 0.010) and lymph node metastasis (P = 0.004) emerged as strong independent prognostic factors for overall survival of NPC patients. In vitro, down-regulated expression of DJ-1 in NPC cell lines by siRNA was observed to reduce cell migration and invasion potential, however, exogenous MIF promoted cells invasion.Conclusions: The data provided evidence that increased expression of MIF and DJ-1 induced cell invasion and metastasis of NPC, supporting the idea that MIF and DJ-1 may play important roles as regulators in the progression of NPC.     

Rapidly Expanding Range of Highly Pathogenic Avian Influenza Viruses

The movement of highly pathogenic avian influenza (H5N8) virus across Eurasia and into North America and the virus’ propensity to reassort with co-circulating low pathogenicity viruses raise concerns among poultry producers, wildlife biologists, aviculturists, and public health personnel worldwide. Surveillance, modeling, and experimental research will provide the knowledge required for intelligent policy and management decisions.     

Amphiregulin enhances intercellular adhesion molecule-1 expression and promotes tumor metastasis in human osteosarcoma

Osteosarcoma is a common, high malignant, and metastatic bone cancer. Amphiregulin (AREG) has been associated with cancer cellular activities. However, the effect of AREG on metastasis activity in human osteosarcoma cells has yet to be determined. We determined that AREG increases the expression of intercellular adhesion molecule-1 (ICAM-1) through PI3K/Akt signaling pathway via its interaction with the epidermal growth factor receptor, thus resulting in the enhanced cell migration of osteosarcoma. Furthermore, AREG stimulation increased the association of NF-κB to ICAM-1 promoter which then up-regulated ICAM-1 expression. Finally, we observed that shRNA silencing of AREG decreased osteosarcoma metastasis in vivo. Our findings revealed a relationship between osteosarcoma metastatic potential and AREG expression and the modulating effect of AREG on ICAM-1 expression.