mTOR通路激活后上调SNCG表达水平抑制 乳腺癌细胞辐射 敏感性的研究

目的：探讨乳腺癌T47D细胞通过激活mTOR通路调控SNCG表达水平，从而抑制乳腺癌细胞辐射敏感性的分子机制。方法：检测不同剂量γ射线照射后的T47D乳腺癌细胞中mTOR蛋白表达水平。在细胞培养液中加入不用浓度磷脂酸（PA，mTOR通路激活剂）进行培养，以常规培养细胞为对照组，采用Western blot法检测对照组和激活剂组细胞SNCG蛋白的表达。对照组和激活组细胞采用4 Gy γ射线照射24 h，检测照射后SNCG mRNA和蛋白的表达情况，并采用平板细胞克隆形成实验检测克隆形成率。同时，将转染SNCG siRNA的乳腺癌T47D细胞株分成激活组和对照组，验证SNCG在乳腺癌细胞辐射敏感性抵抗中的生物学功能。结果：不同剂量射线照射后，mTOR蛋白表达水平显著升高。mTOR激活剂PA处理后的细胞对乳腺癌细胞放射敏感性具有明显的抑制作用，同时Western blot显示γ射线照射处理后的乳腺癌细胞中SNCG蛋白的表达水平异常。Western blot和qPCR方法检测发现，T47D对照组和干扰SNCG基因的T47D细胞实验组中，激活mTOR或γ射线照射均能引起SNCG蛋白和mRNA表达增加。克隆形成实验进一步证明，降低SNCG的表达可显著抑制T47D细胞克隆形成能力。结论：在乳腺癌细胞中，mTOR介导的SNCG表达调控对乳腺癌细胞抗辐射起着重要作用，降低SNCG的表达可提高辐射敏感性，提示在临床治疗中有可能通过使用SNCG抑制剂或mTOR抑制剂提高乳腺癌细胞在放化疗中的敏感性。     

CYP1B1 and hormone-induced cancer

Cancers in hormone-responsive tissues (e.g., breast, ovary, endometrium, prostate) occur at high incidence rates worldwide. However, their genetic basis remains poorly understood. Studies to date suggest that endogenous/exogenous oestrogen and environmental carcinogens may play a role in development and/or progression of hormone-induced cancers via oxidative oestrogen metabolism. Cytochrome P450 1B1 is a key enzyme in its oestrogen metabolism pathway, giving rise to hydroxylation and conjugation. Although CYP1B1 is expressed in many cancers, particularly high levels of expression are observed in oestrogen-mediated disease. CYP1B1 is more readily found in tumour tissue compared to normal. Given the role of CYP1B1 in pro-carcinogen and oestrogen metabolism, polymorphisms in CYP1B1 could result in modifications in its enzyme activity and subsequently lead to hormone-mediated carcinogenesis. CYP1B1 may also be involved in progression of the disease by altering the tissue response to hormones and clinical response to chemotherapy. The exact mechanism behind these events is complex and unclear. Only a few functional single nucleotide polymorphisms of CYP1B1 are known to result in amino acid substitutions and have been extensively investigated. Studies examining the contribution of different CYP1B1 alleles to hormone-mediated cancer risks are inconsistent. The main focus of this review is to appraise the available studies linking the pathogenesis of the hormone-induced cancers to various CYP1B1 polymorphisms. Additionally, we explore the role of a neuronal protein, γ-synuclein, in CYP1B1-mediated pathogenesis.     

γ突触核蛋白在口腔颌面部肿瘤中的表达及临床意义

目的 探讨神经γ突触核蛋白(SNCG)在口腔颌面部肿瘤、癌旁组织及正常组织中的表达。方法 采用免疫组化SP法检测80例口腔颌面部肿瘤组织、癌旁组织及37例正常对照组中SNCG的表达。结果 肿瘤组织中的SNCG的阳性率为68.75%(55/80),而癌旁组织中SNCG的阳性率为7.5%(6/80),正常组织中未见SNCG的表达。在低分化、中等分化及高分化的肿瘤组织中SNCG的阳性率分别为86.1%(31/36)、69.0%(20/29)及26.7%(4/15),肿瘤组织分化程度越低SNCG的阳性率越高(χ2=17.416,P=0.000);SNCG在Ⅲ-Ⅳ期肿瘤组织中表达阳性率为81.1%(43/53),Ⅱ期为63.2%(12/19),而Ⅰ期未见表达,肿瘤组织临床分期越晚SNCG的阳性率越高(χ2=21.658,P=0.000);在未见肿瘤转移的组织中SNCG的阳性率为47.2%(17/36),而在有转移肿瘤组织中SNCG的阳性率为86.4%(38/44),SNCG的表达与肿瘤的转移相关(χ2=14.119,P=0.000)。结论 SNCG蛋白过表达与口腔颌面部肿瘤的进程相关,肿瘤分期越晚阳性率越高,且在浸润性的肿瘤组织中较早期高表达。SNCG有望成为新的口腔颌面部肿瘤的肿瘤标志物,为预后判断和制定相应的治疗方案提供依据。     

SNCG基因转染对PC-3细胞抗肿瘤药物作用效果的影响

目的:观察转染了质粒PCI-NEO-SNCG后的前列腺癌激素非依赖性细胞系PC-3细胞对抗肿瘤药物顺铂(DDP)、5-氟尿嘧啶(5-FU)、阿霉素(ADM)、长春新碱(VCR)、紫杉醇(TAX)的敏感性,探讨SNCG的表达对各种抗肿瘤药物作用效果的影响。方法:转染质粒PCI-NEO和PCI-NEO-SNCG至PC-3细胞,采用RT-PCR法检测PC-3细胞中SNCG的表达;MTT法检测各抗肿瘤药物对转染后PC-3细胞的抑制作用;流式细胞术分析转染细胞经TAX作用后的细胞周期及凋亡。结果:5种抗肿瘤药物对转染了空载体PCI-NEO质粒及PCI-NEO-SNCG质粒细胞的生长抑制作用均存在时间依赖性;转染PCI-NEO的PC-3细胞组与转染PCI-NEO-SNCG的PC-3细胞组中各种抗肿瘤药物的抑制效果比较显示,DDP、5-FU、ADM、VCR的抑制效果两组间没有显著性差异(P>0.05),而TAX对转染PCI-NEO-SNCG的细胞的抑制率较转染PCI-NEO的细胞显著降低(P<0.01);经TAX处理48 h后,在转染PCI-NEO质粒的细胞中,停留在G2-M期的细胞比例显著高于转染PCI-NEO-SNCG质粒的细胞(P<0.01),而停留在G0-G1期及S期的细胞比例,在转染PCI-NEO质粒的细胞中显著低于转染PCI-NEO-SNCG质粒的细胞(P<0.01);在转染PCI-NEO质粒的细胞中Caspase-3的表达显著高于转染PCI-NEO-SNCG质粒的细胞(P<0.01)。结论:TAX对转染了SNCG基因的PC-3细胞中的生长抑制作用明显降低,提示SNCG的表达可抑制TAX的作用效果,这一发现可为前列腺癌的个体化治疗提供理论依据和指导。     

原位杂交法检测SNCG在乳腺组织中的表达

目的:检测乳腺癌相关基因SNCG在乳腺组织不同病变的阳性表达率,分析其表达规律,探讨其在乳腺癌发生、发展中的作用。方法:用原位杂交方法,以地高辛标记的SNCG反义mRNA作探针,检测167例乳腺不同病变组织中SNCG基因mRNA的表达情况,并进行统计学分析。结果:SNCG的阳性表达率在乳腺增生症为76.0%(38/50),纤维腺瘤为20.0%(3/15),非典型性增生为92.3%(12/13),乳腺癌组织为95.5%(85/89),并且表达强度不同。有淋巴结转移的乳腺癌中强阳性表达率为47.7%(21/44)。而乳腺增生症组中无强阳性表达者。SNCG在不同乳腺病变组织中的表达有统计学意义(P<0.001)。结论:SNCG作为一个新发现的乳腺癌相关基因,在乳腺不同病变中表达情况不同,随病变程度加重,表达率明显增高。有转移者表达强度明显增强。因而SNCG可作为判断乳腺癌恶性潜能的指标。     

Correlation between periostin and SNCG and esophageal cancer invasion,infiltration and apoptosis

ObjectiveTo investigate the correlation between periostin and SNCG and esophageal cancer invasion, infiltration and apoptosis.MethodsA total of 78 cases esophageal surgical resection specimens were collected, expression of periostin and SNCG in esophageal cancer were detected. Effect of periostin and SNCG in esophageal carcinoma invasion and infiltration was analyzed.ResultsThe upregulated rate of periostin had significant difference in esophageal cancer tissues (39.74%), adjacent tissues (17.86%) and normal tissues (0.00%); The positive expression rates of SNCG had significant difference in esophageal cancer tissues (61.54%), adjacent tissues (32.14%) and normal tissues (1.96%); The upregulated rate of periostin had a significant correlation with lymph node metastasis, adventitia invasion, TNM stage; The positive expression rates of SNCG had a significant correlation with differentiation degree, lymph node metastasis, adventitia invasion, TNM stage; Apoptosis index of the positive of expression of SNCG of esophageal cancer tissue (4.541±2.267) was significantly lower than that of the negative expression (7.316±2.582) (P<0.05).ConclusionsSNCG may play an important role in invasion, infiltration and apoptosis of esophageal cancer and serve as target spots in the targeted therapy of esophageal cancer.     

突触核蛋白-γ对乳腺癌雌激素受体表达的影响

目的探讨突触核蛋白-7（synuclein-7,SNCG）表达对乳腺癌雌激素受体（estrogen receptor,ER）表达的影响。方法构建慢病毒SNCG过表达及干扰栽体,分别转染人乳腺癌T47D（SNCG＋／ER＋）细胞株。在SNCG过表达和SNCG干扰细胞组中,RT-PCR方法栓泖lSNCG和ER的rflRNA水平表达,Western blot法检测SNCG和ER的蛋白水平表达,并做Pearson法相关统计分析。结果在mRNA水平,SNCG过表达组中ER基因的mRNA表达量显著增高,两者呈正相关（P=0．03,R=0．81）;SNCG干扰组中ER基因的mRNA表达量显著降低,两者呈正相关（P=0．01,R=0．82）。在蛋白表达水平,SNCG过表达组ER表达显著增强,两者呈正相关（P=0．03,R-0．85）;SNCG干扰组ER表达显著降低,两者呈正相关（P-0．04,R=0．83）。结论SNCG对ER表达有正向调节作用,为进一步研究SNCG与ER的相互作用机制及SNCG与乳腺癌内分泌治疗之间的关系奠定了实验基础。     

SNCG shRNA 对乳腺癌细胞种植瘤形成和生长的抑制作用

目的：SNCG为乳腺癌特异性基因,在进展的乳腺癌中过表达,并且预后较差,本研究应用小分子RNA干扰技术,检测SNCG-shRNA降低乳腺癌细胞SNCG的作用。方法：本实验设计4组SNCG shRNA及2组对照组,应用化学法构建动物实验媒介,应用转染后的稳定的基因降低乳腺癌细胞系MCF-7的SNCG的表达,用特异性siRNA和无关序列转染后的细胞及未处理的细胞注入裸鼠,并建立相应的裸鼠种植瘤模型,分析肿瘤生长抑制情况,采用半定量RT-PCR及免疫细胞化学、免疫组化SP法检测4组SNCG shRNA转染后的MCF-7细胞组和4组抑制瘤组织及各对照组中SNCG的mRNA和蛋白的表达情况。结果：与各对照组相比,SNCG-shRNA转染的4组细胞中SNCG的mRNA和蛋白表达均减弱,差异均有统计学意义（P均＜0.05）。SNCG在种植瘤乳腺癌组织中的表达率明显高于其他各组,SNCG-shRNA4组中SNCG的mRNA和蛋白的表达水平均降低,差异有统计学意义（P均＜0.05）;