乳腺癌组织中乳腺癌缺失基因1的表达研究进展

DBC1基因与乳腺癌密切相关。了解DBC1的分子机制及其与疾病的关系,深入探讨DBC1与乳腺癌的关系,揭示其在乳腺癌发生发展中的作用,对于相关乳腺癌的病因预防和治疗新靶点的探索有很重要的意义。本文针对国内外关于该基因的研究进行综述,了解其分子机制及在乳腺癌中的表达。     

DBC1的研究进展

DBC1是近年来新发现的一种蛋白,属于小GTP酶类Rho家族的非典型成员。最初因为在乳腺癌组织中杂合性缺失被鉴定出来的。目前关于DBC1在乳腺癌上的研究报道尚少。本文对国内外关于该基因的有关研究进行综述,了解其分子机制,基因表达情况。     

DBC1在结肠癌中的表达及其临床意义

目的:研究DBC1在结肠癌中的表达及潜在的临床意义.方法:利用免疫组织化学染色的方法检测DBC1在150例结肠癌及其相应癌旁组织中的表达,分析DBC1表达与年龄、性别、部位、组织学分化程度、TNM分期、淋巴结转移、临床预后等临床参数间的相关性.结果:DBC1在结肠癌中的表达明显高于相应的癌旁组织(71.3％ vs 24.7％,P＜0.05).DBC1表达水平与组织学分化程度、TNM分期、淋巴结转移密切相关(P＜0.000).DBC1表达与结肠癌的总体生存时间、结肠癌患者总体生存率密切相关,DBC1表达水平越高,患者的生存时间越短(P＜0.000).结论:DBC1在结肠癌中呈高表达,可作为结肠癌的预后判断指标,提示DBC1在结肠癌的发生发展中发挥重要作用.     

DBC1在卵巢癌中的表达及临床意义

目的:探讨乳腺癌缺失基因1（DBC1）在卵巢癌组织中的表达及与临床参数的相关性。方法:收集山东省聊城市人民医院手术切除的上皮性卵巢癌组织121例、交界性上皮性肿瘤组织40例和良性囊腺瘤组织55例,所有患者术前均未进行放疗、化疗等治疗。采用免疫组化技术检测DBC1在组织中的表达情况,并分析其与临床病理特征的相关性。结果:DBC1的阳性表达在卵巢癌组织中明显高于交界性囊腺瘤和良性囊腺瘤（P=0.001,P=0.000）,其表达水平与FIGO分期、分化程度及预后密切相关（P=0.033,P=0.022,P=0.037）。结论:DBC1在卵巢癌中可作为肿瘤促进因子发挥作用,并且与预后密切相关,可作为卵巢癌的肿瘤标志物之一。     

中国人群DBC2基因突变与乳腺癌的关系

目的:检测乳腺癌患者DBC2基因启动子和第7外显子及其两翼部分内含子区域的突变情况,探讨DBC2基因突变与乳腺癌发病风险的关系.方法:收集长海医院32例乳腺癌患者的组织标本,提取DNA后,对DBC2基因启动子、第7外显子及其侧翼部分内含子进行PCR扩增,通过直接测序法鉴定DNA突变位点.另取18例乳腺良性肿瘤组织标本作为对照.结果:研究组和对照组都没有发现启动子或第7外显子突变.在13例组织标本中发现DBC2第7内含子IVS7+53C>G突变,研究组和对照组的突变率分别为25.00%(8/32)和27.78%(5/18),2者差异无统计学意义(P>0.05).IVS7+53C>G突变患者与野生型患者在年龄分布上差异无统计学意义(P>0.05).DBC2基因IVS7+53C>G突变与肿瘤大小、淋巴结状态以及雌激素受体和孕激素受体表达与否等临床特征无统计学相关性(P>0.05). 但是IVS7+53C>G突变患者HER2和p53表达率显著高于野生型患者,提示IVS7+53C>G突变与HER2和p53表达相关(P<0.05). 结论:DBC2基因启动子及第7外显子突变可能在中国人群中并不常见,与乳腺癌发病风险无关.IVS7+53C>G突变是中国人群中一种常见的多态性,与乳腺癌发病风险的关系尚待今后更大样本量的研究予以论证.     

DBC2基因突变与上海地区早发性乳腺癌相关性的研究

目的:检测上海地区早发性乳腺癌患者DBC2基因启动子及第7外显子突变情况,探讨DBC2基因突变与早发性乳腺癌发病风险的关系.方法:提取45例家族史阴性的早发性乳腺癌患者和36名健康志愿者外周血基因组DNA,对DBC2基因启动子、第7外显子及其侧翼部分内舍子序列进行PCR扩增,通过直接测序法鉴定DNA突变位点.结果:研究组和对照组均未发现启动子或第7外显子突变;在第7内舍子发现IVS7+53C>G突变23例,研究组和对照组DNA的突变率分别为26.67%(12/45)和30.56%(11/36),两者差异无统计学意义,P>0.05.IVS7+53C>G突变患者平均发病年龄为38.33岁,比IVS7+53野生型患者大3.64岁,两者差异有统计学意义,P<0.05.结论:DBC2基因启动子及第7外显子突变可能在上海地区人群中不常见,与早发性乳腺癌发病风险无关.IVS7+53C>G突变是中国人群一种常见多态性,与早发性乳腺癌发病风险关系尚待进一步研究.     

新疆维吾尔族妇女子宫颈癌DBC1基因启动子甲基化分析

背景与目的：近年来,表观遗传学研究已经成为癌症研究的一个新方向。大量研究结果显示,表观遗传修饰的异常改变与癌症有着十分密切的联系,全基因组范围内的表观遗传修饰改变已经成为癌症的新标志。该研究旨在探讨膀胱癌缺失基因1(deleted in bladder cancer 1,DBC1)启动子甲基化与新疆维吾尔族妇女子宫颈癌的关系及与人类乳头瘤病毒(human papillomavirus,HPV)感染的相关性,分析其能否作为高敏感性及特异性的工具用于子宫颈癌筛选。方法：用聚合酶链反应(polymerase chain reaction,PCR)方法对43例正常子宫颈组织、35例子宫颈上皮内瘤样变(cervical intraepithelial neoplasia,CIN)组织以及54例子宫颈癌组织进行HPV16、HPV18感染的检测;运用甲基化特异性PCR方法检测上述组织DBC1基因启动子甲基化状况;采用实时荧光定量聚合酶链反应(real-time fluorescent quantitative polymerase chain reaction,RTFQ-PCR)方法检测10例甲基化阴性的正常子宫颈组织和10例甲基化阳性的子宫颈癌组织中DBC1基因mRNA表达情况。结果：正常子宫颈组织、CIN组织及子宫颈癌组织中HPV16的感染率分别为18.6%、34.3%和68.5%;HPV18的感染率分别为2.3%、8.6%和16.7%;DBC1基因发生甲基化率分别为23.3%、40.0%和87.0%;在79例高级别宫颈损伤及子宫颈癌样本中,其中50例HPV16/18感染阳性,29例HPV16/18感染阴性;阳性组中DBC1基因发生甲基化率88.0%,阴性组甲基化率为55.2%(P<0.05);10例甲基化阳性子宫颈癌组织中DBC1基因mRNA表达水平明显低于10例甲基化阴性正常子宫颈组织(P<0.05)。结论：DBC1基因甲基化可能作为新疆维吾尔族妇女子宫颈癌的分子标志物,结合HPV16/18感染检测有助于子宫颈癌的诊断。     

Sharp1在乳腺癌中作用机制的研究进展

乳腺癌是女性最常见的恶性肿瘤之一,其发病率在全球范围内逐年上升,且死亡率位于女性恶性肿瘤的前列,因此乳腺癌的治疗备受关注［1］。分化型胚胎软骨发育基因（ Sharp1,the en-hancer of split and hairy related protein-1）,又名DEC2（differentia-ted embryo-chondrocyte expressed gene）,在肿瘤的发生和进展中均发挥重要作用。新近研究显示Sharp1在不同类型乳腺癌的组织和细胞中表达不同,提示其可能在不同类型的乳腺癌中发挥的作用及机制也各不相同。目前全球范围内关于Sharp1与乳腺癌的相关实验研究较少,且多集中在体外细胞和动物实验水平,有报道提示Sharp1的表达情况可能与乳腺癌的发生发展具有一定的相关性,但具体通过何种方式和分子机制尚待深入研究。因此,检测Sharp1在不同分子类型乳腺癌组织中的表达情况,阐明其分子作用机制,对今后乳腺癌的临床诊治和预后评估都具有重要意义,作为新靶点Sharp1也有望成为乳腺癌临床治疗的新的希望。     

PD-1/PD-L1抑制剂联合曲妥珠单抗在HER2阳性乳腺癌中的研究进展

乳腺癌中有20%~30%的患者表达HER2基因,HER2阳性乳腺癌预后较差,易发生复发和转移。但HER2的表达为乳腺癌治疗提供了新方向。曲妥珠单抗是抗HER2治疗的经典基础药物,然而其原发继发耐药问题引起了大家的注意,研究发现其不敏感及耐药机制的发生可能与肿瘤细胞表面PD-L1上调相关。因此大量关于PD-1/PD-L1抑制剂联合曲妥珠单抗的研究展开意在提高其敏感度,改善其耐药问题。本文就PD-1/PD-L1抑制剂在HER2阳性乳腺癌的临床前及临床研究作一综述。     

RASSF1A基因与乳腺癌相关性的研究进展

目的:总结RASSF1A基因作为新型的肿瘤抑制因子与乳腺癌发生发展相关性的研究现状,探讨其高甲基化在乳腺癌的早期诊断和治疗方面的研究前景和临床价值.方法:应用PubMed数据库检索系统以“RASSF1A、methylation、breast cancer和epigenetics”为关键词.检索2000-01-2012-08关于RASSF1A基因与乳腺癌相关性研究.纳入标准:1)RASSF1A基因甲基化的相关研究;2)RASSF1A基因高甲基化与乳腺癌相关性的研究.根据纳入标准,符合分析的文献35篇.结果:RASSF1A高甲基化可能是乳腺癌发生和发展中一个早期事件.RASSF1A高甲基化水平在乳腺癌临床诊断中具有较高的阳性率(57％～85％);逆转RASSFIA基因启动子CpG岛高甲基化可成为乳腺癌药物治疗的新方向.RASSF1A基因在乳腺癌诊断和治疗等方面正在得到越来越广泛的研究和应用.结论:RASSF1A基因与乳腺癌的发生发展密切相关,可用于乳腺癌的早期诊断及治疗.     

Deleted in breast cancer 1 (DBC1) deficiency results in apoptosis of breast cancer cells through impaired responses to UV-induced DNA damage

DBC1 (deleted in breast cancer 1) participates in the regulation of cell survival and death in response to various stimuli. In particular, DBC1 promotes cell death upon DNA damage through inhibition of SIRT1 deacetylase. However, the SIRT1-independent functions of DBC1 in the regulation of DNA damage response are less well understood. Therefore, we analyzed the DNA damage response in Hs578T breast cancer cell line in which the DBC1–SIRT1 interaction is barely detectable. DBC1–siRNA transfected cells showed a failure in the DNA damage checkpoint and the accumulation of genomic damage following UV irradiation. In addition, DBC1-deficient cells exhibited less JNK activation. Finally, the interruptions of signaling in DBC1-depleted cells contributed to cell death in response to UV irradiation. Overall, these data suggest that DBC1 is essential for a fully efficient and effective response to UV irradiation. Therefore, DBC1 plays a critical role in maintaining genomic stability and cellular integrity following UV-induced genotoxic stress.     

CK2α phosphorylates DBC1 and is involved in the progression of gastric carcinoma and predicts poor survival of gastric carcinoma patients

CK2α has diverse effects on the tumorigenesis owing to its kinase activity, which phosphorylates various proteins involved in tumorigenesis. We, therefore, investigated the expression and role of CK2α in the phosphorylation of deleted in breast cancer 1 (DBC1) in gastric carcinomas. We used 187 gastric carcinomas and human gastric cancer cells to investigate the roles and relationship between CK2α and DBC1 in gastric carcinomas. Positive expression of CK2α and phospho‐DBC1 predicted shorter overall survival and relapse‐free survival by univariate analysis. Especially, CK2α expression was an independent prognostic indicator for gastric carcinoma patients. In gastric carcinoma cells, CK2α was bound to DBC1 and phosphorylated DBC1. The phosphorylation of DBC1 by CK2α was evidenced by co‐immunoprecipitation of CK2α and DBC1 in a GST pull‐down assay, an in vitro kinase assay, and immunofluorescence staining. Inhibition of both CK2α and DBC1 decreased proliferation and invasive activity of cancer cells. Decreased migration and invasive activity was associated with a downregulation of MMP2, MMP9 and the epithelial–mesenchymal transition. A mutation at the phosphorylation site of DBC1 also downregulated the signals related with the epithelial–mesenchymal transition. Our study demonstrated that CK2α is an independent prognostic indicator for gastric carcinoma patients and is involved in tumorigenesis by regulating the phosphorylation of DBC1. In addition, the blocking of CK2α and DBC1 inhibited the proliferation and invasive potential of gastric cancer cells. Therefore, our study suggests that CK2α–DBC1 pathway might be a new therapeutic target for the treatment of gastric carcinoma.     

Delayed breast cellulitis: an evolving complication of breast conservation

PURPOSE: Delayed breast cellulitis (DBC) is characterized by the late onset of breast erythema, edema, tenderness, and warmth. This retrospective study analyzes the risk factors and clinical course of DBC. METHODS AND MATERIALS: From 1985 through 2004, 580 sequential women with 601 stage T0-2N0-1 breast cancers underwent breast conserving therapy. Cases of DBC were identified according to accepted clinical criteria: diffuse breast erythema, edema, tenderness, and warmth occurring >3 months after definitive surgery and >3 weeks after radiotherapy. Potential risk factors analyzed included patient comorbidity, operative technique, acute complications, and details of adjunctive therapy. Response to treatment and long-term outcome were analyzed to characterize the natural course of this syndrome. RESULTS: Of the 601 cases, 16%, 52%, and 32% were Stage 0, I, and II, respectively. The overall incidence of DBC was 8% (50/601). Obesity, ecchymoses, T stage, the presence and aspiration of a breast hematoma/seroma, removal of >5 axillary lymph nodes, and arm lymphedema were significantly associated with DBC. The median time to onset of DBC from the date of definitive surgery was 226 days. Ninety-two percent of DBC patients were empirically treated with antibiotics. Fourteen percent required more invasive intervention. Twenty-two percent had recurrent episodes of DBC. Ultimately, 2 patients (4%) underwent mastectomy for intractable breast pain related to DBC. CONCLUSION: Although multifactorial, we believe DBC is primarily related to a bacterial infection in the setting of impaired lymphatic drainage and may appear months after completion of radiotherapy. Invasive testing before a trial of antibiotics is generally not recommended.     

Genetic analysis of the DBC2 gene in gastric cancer

The DBC2 (Deleted in breast cancer, RhoBTB2) has been identified as a tumor suppressor gene that has growth inhibitory function. To investigate whether genetic alterations of the DBC2 gene are involved in the development of gastric cancer, we analyzed mutations and allelic loss in the DBC2 gene in 95 primary gastric cancers by PCR-SSCP, sequencing and LOH analysis. In the mutational analysis, we found one missense somatic mutation (CGG-->TGG, R275W) in the BTB/POZ domain of the gene in a patient with advanced gastric cancer and lymph node metastasis. In addition, we found one known polymorphism and three novel polymorphisms in the coding region of DBC2, which showed an amino acid change, and was detected in both the cancer cells and corresponding normal cells. On LOH analysis, 62 cases were heterozygous for at least one marker and 18 cases (29.0%) showed allelic loss at these markers. In conclusion, the mutations and allelic loss in the DBC2 gene are uncommon in gastric cancers in Korean patients. Further studies to identify the target gene at 8q21 responsible for the development of gastric cancer should be explored.     

人类DBC2基因重组腺病毒的构建及其在膀胱癌中的表达(英文)

Objective: The aim of the study was to construct recombinant type 5 adenovirus expressing the human DBC2(deleted in breast cancer 2) gene for in vitro and in vivo assay in human bladder cancer research. Methods: The human DBC2gene was first subcloned into a shuttle plasmid pAdTrack-CMV. After recombining with pAdEasy-1 vector in BJ5183 cells, thenew recombinant vector pAdEasy-DBC2-CMV was transfected into HEK-293 cells to produce adenovirus. The human bladdercancer cell line T24 was infected with DBC2-containing adenovirus particles. Both RNA and protein were collected from cellsharvested at 72 h after infection. Real time quantitative PCR (qPCR) and Western blot were used to examine mRNA and proteinlevels. Fluorescence microscopy was utilized to observe the expression of reporter green fluorescence protein. Results:Electrophoresis showed there was a 2.2 kb size band produced from high fidelity PCR. Pac I digest of the final producedrecombinant vector yielded band sizes of approximately 30 kb and 4.5 kb. After virus infection with the pAdEasy-DBC2-CMVvector, the T24 cell line was observed to highly express green fluorescence protein under a fluorescence microscope. qPCRand Western blot assay identified that the DBC2 gene was overexpressed at both the mRNA and protein levels in virustransfected cells. Conclusion: By using the pAdEasy adenovirus system, we successfully constructed an adenovirus thatcould highly overexpress the tumor suppressor DBC2 gene in a bladder cancer cell line. This viral construct would be widelyused for our further research in gene functional assays and gene therapy in bladder cancer.