58. Susceptibility to lung cancer is associated with genetic polymorphisms of CYP1A1、GSTM1

Objective: To investigate the association of lung cancer susceptibility with genetic Polymorphism of CYP1A1 and GSTM1. Methods: The study was conducted on 65 lung cancer cases and 60 no-cancer controls. The genetic polymorphism both CYP1A1 and GSTM1 were performed in cancer tissues of all patients and peripheral blood leukocytes of no-cancer controls. First by RFLP-PCR, then after incubating with restriction enzyme Ncol and Hinfl. Results: ①There were no significant differences in the frequency distribution of CYP1A1 polymorphisms between lung cancer patients and controls, but the frequency of CYP1A1(Val/Val) was significant higher than that controls (P<0.05). ②If OR for CYP1A1 (Ile/Ile) genotype was 1.0, the OR of CYP1A1 (Ile/VaL)、CYP1A1 (Val/Val) was 1.68 (95%CI, 0.79～3.59) and 3.2 (95%CI, 1.06～10.26), respectively. ③The significant difference were observed that GSTM1(-) became markedly expressed (63.1%, 41/65) in elung cancer patients than in the corresponding controls (45%, 27/60) (P<0.05), OR was 2.09 (95%CI, 1.02～4.26); ④When analysis combined CYP1A1 and GSTM1 genotype, we found that individual who take along CYP1A1 (Ile/Ile)/GSTM1 (-) or CYP1A1 (Ile/Val+Val/Val)/GSTM1 (+) genotype had higher odds ratio than CYP1A1 (Ile/Ile)/GSTM1 (+) genotype, the OR was 3.82 (95%CI, 1.27～11.45) and 3.5 (95%CI 1.18～10.41), respectively, but the CYP1A1 (Val/Val) / GSTM1 (-) genotype was the hightest odds ratio, the OR was 10.5 (95%CI, 1.70～64.73). ⑤We observed that the individual who carry CYP1A1(Val/Val) genotype can increased risk of squamous cell carcinoma of lung (P<0.05), OR was 2.75 (95%CI, 1.24～6.17), there was no significant associated of pathologic with GSTM1 genotype. ⑥Stratified analysis suggested an interaction between cigarettes smoking and CYP1A1 (Ile/Val+Val/Val)、GSTM1 (-) genotype. Conclusion: ①The individuals who carried genotype of CYP1A1 (Val/Val) and GSTM1 (-) were susceptible to lung cancer. ②the individuals who carried CYP1A1 (Ile/Ile) /GSTM1 (-) or CYP1A1 (Ile/Val+Val/Val) /GSTM1 (+) genotype with higher risk of developing lung cancer than that CYP1A1 (Ile/Ile)/GSTM1 (+) genotype. ③There were interaction between smoking and CYP1A1 (Ile/Val+Val/Val)、GSTM1 (-)     

四川人群中CYP1A1基因Ile-Val和Msp1位点多态性与肺癌易感性的研究

目的　探讨细胞色素P45 0 (CYP1A1)基因异亮氨酸 (Ile) 缬氨酸 (Val)位点和Msp1位点多态性和肺癌易感性的相关关系。方法　以病例对照的研究方法 ,采用PCR RFLP和ASA PCR技术检测 82例原发性肺癌和 91例对照的CYP1A1基因Ile Val位点和Msp1位点多态性。 结果　Ile Val三种多态基因型在肺癌组和对照组分布差异有显著性 (P <0 .0 5 ) ,Ile/Val、Val/Val基因型在肺癌组的分布频率明显高于对照组 ;logistic回归分析结果显示Ile/Val、Val/Val基因型患肺癌的危险分别是Ile/Ile基因型的 1.969倍和3 .15 0倍 ;当按吸烟分层后 (将Ile/Val、Val/Val基因型合并分析 ) ,吸烟组中Ile/Val、Val/Val合并基因型患肺癌的危险是Ile/Ile基因型的 3 .0 5 9倍 ,而在不吸烟组其OR为 1.687;Msp1位点多态性在肺癌组和对照组差异无统计学意义。结论　CYP1A1第 7外显子的Ile/Val、Val/Val基因型与肺癌的易感性有关 ,可望作为肺癌易感人群筛选的重要指标 ;尚不能认为Msp1多态性与肺癌的易感性有关     

CYP1A1,GSTM1基因型与烟酒诱发人体内淋巴细胞微核的形成

目的: 探讨代谢酶CYP1A1和GSTM1等位基因型对烟酒诱发人体内淋巴细胞微核的影响.方法:分别应用等位基因特异性(AS)和多重差别(MD)-PCR检测CYP1A1和GSTM1的等位基因型,应用末梢血微核法检测体内淋巴细胞微核.结果:与无吸烟史健康人群的淋巴细胞平均微核率(MNF 0.24‰)相比,吸烟组MNF显著增加(0.65‰,P＜0.05),重度饮酒可增强这一效应(0.89‰,P＜0.01):与无吸烟史的非易感联合基因型(CYP1A1 I1e/I1e*GSTM1+(+/+和+/0),CYP1A1 I1e/I1e*GSTM1 0/0和CYP1A1 I1e/Val*GSTM1+)个体的MNF(0.42‰)相比,吸烟使GSTM1 0/0基因型个体的MNF显著上升(0.75‰,P＜0.05),并可使CYP1A1 Val/Val基因型和易感联合基因型(CYP1A1 I1e/Val*GSTM1 0/0,CYP1A1 Val/Val*GSTM1+和CYP1A1 Val/Val*GSTM1 0/0)个体的MNF均上升约1倍(0.83‰和0.85‰,0.10＞P＞0.05).结论:吸烟诱发体内淋巴细胞MNF显著增加,重度饮酒增强这一效应.烟酒诱发微核形成与个体CYP1A1和GSTM1的遗传多态性密切相关.     

CYP1A1多态性与肺癌遗传易感性的关系

目的探讨代谢酶基因CYP1A1基因多态性与中国汉族人群肺癌遗传易感性之间的相关性。方法应用AS-PCR技术检测150例中国四川汉族肺癌和152例中国四川汉族健康人的CYP1A1基因Exon7多态性分布频率,并分析了Exon7多态性与中国四川汉族人群肺癌遗传易感性之间的相关性。结果CYP1A1Exon73种多态基因型分布频率在两组间比较差异无统计学意义,χ2=0.634,P=0.728。携带突变Val基因型的个体较携带Ile/Ile基因型的个体患肺癌的危险性增加,OR=1.139,95%CI为0.635~2.042,P=0.662。携带突变Val基因型的个体较携带Ile/Ile基因型的个体患肺鳞癌的风险显著增加,OR=3.510,95%CI=1.326~9.293,P=0.011。结论Val突变等位基因可能是中国四川汉族人群的肺癌易感基因。CYP1A1基因Exon7多态性在肺鳞癌发生中起重要作用。     

CYP1A1 GSTM1基因多态性和吸烟与肺癌易感性关系的病例对照研究

目的:探讨天津市居民致癌物代谢酶CYP1A1和GSTM1基因多态性对肺癌易感性的影响。方法:利用限制性片断长度多态性-聚合酶链反应(RFLP-PCR)方法检测原发性肺癌患者和健康对照者细胞色素P450酶基因CYP1A1Msp位点和谷胱甘肽硫转移酶基因GSTM1的多态性情况。结果:肺癌组与对照组之间CYP1A1和GSTM1基因型分布差异均存在统计学显著意义(P<0.05)。携带CYP1A1变异基因型或GSTM1阴性基因型的个体患肺癌的危险性增高,比值比(OR)分别达到2.44(1.04～5.81)和1.84(1.03～3.29)。多因素分析结果显示具有CYP1A1变异基因型、GSTM1阴性基因型的吸烟个体患肺癌的风险较大。结论:CYP1A1Msp位点变异基因型和GSTM1阴性基因型可能是肺癌的易感因素,吸烟与肺癌易感基因之间具有协同作用。     

CYP1A1和GSTM1基因多态性与肺癌易感性的Meta分析

目的探讨CYP1A1和GSTM1基因多态性与个体肺癌易感性的关系。方法全面检索相关文献,应用Meta分析方法对各研究进行数据的合并与分析。结果共8篇文献入选,累计肺癌病例1067人,对照1416人,分别对CYP1A1*A和GSTM1-、CYP1A1*B/C和GSTM1+、CYP1A1*B/C和GSTM1-联合基因型进行统计分析。异质性检验χ2值分别为6.43、8.83与9.63,P>0.05,文献有同质性,各合并OR及95%CI分别为1.36(1.09~2.77)、1.65(1.26~2.15)和2.01(1.57~2.59)。结论CYP1A1和GSTM1突变基因型为罹患肺癌的易感基因型,且两者存在协同作用,在肿瘤防治方案中应加以重视从而采取相应措施达到有效预防肿瘤的目的。     

GSTM1和CYP2E1基因多态性与肺癌遗传易感性关系的研究

背景与目的肺癌是中国人群恶性肿瘤死因的首位，其发病可能与肺癌人群中某些肺癌相关基因的遗传多态性有关。本研究旨在探讨细胞色素P4502E1(CYP2E1)基因RsaⅠ／PstⅠ多态性和谷胱甘肽转移酶M1(GSTM1)基因多态性与肺癌易感性之间是否存在相关性。方法应用PCR-RFLP和PCR法检测99例人非小细胞肺癌患者和66例同期住院的肺良性疾病患者CYP2E1基因的RsaⅠ／PstⅠ多态性和GSTM1基因多态性，并分析其与肺癌遗传易感性的相关性。结果(1)CYP2E1基因RsaⅠ／PstⅠ多态性的三种基因型在肺癌组和对照组的频率差异没有统计学意义(χ^2=1．374，P=0．241)。(2)肺癌组GSTM1(-)基因型频率显著高于对照组(分别为57．6％和40．9％)(χ^2=4．401，P=0．036)。(3)携带GSTM1(-)基因型的个体患肺癌的危险性显著高于GSTM1( )基因型的个体(OR=1．96，95％CI=1．042～3．689，P=0．037)。(4)与携带c1／c2或c2／c2基因型的不吸烟个体比较，携带c1／c1基因型的吸烟者患肺癌的风险显著增加(OR=3．525，95％CI=1．168～10．638，P=0．025)。(5)联合分析CYP2E1基因RsaⅠ／PstⅠ多态性和GSTM1基因多态性，携带有c1／c1和GSTM1(-)基因型的个体患肺癌的风险显著高于携带GSTM1( )和c1／c2或c2／c2基因型的个体(OR=3．449，95％CO=1．001～11．886，P=0．050)。按照吸烟因素分层，携带有GSTM1(-)和c1／c1基因型的不吸烟个体患肺癌的风险显著高于携带GSTM1( )和c1／c2或c2／c2基因型的不吸烟个体(OR=11．553，95％CI=1．068-124．944，P=0．044)，携带有GSTM1(-)和c1／c2或c2／c2基因型的不吸烟个体患肺癌的风险同样显著高于携带GSTM1( )和c1／c2或c2／c2基因型的不吸烟个体(OR=13．374，95％CI=1．258～142．166，P=0．032)。结论(1)GSTM1(-)基因型增加人群患肺癌的风险；(2)CYP2E1的c1／c1基因型和GSTM1(-)基因型的联合可增加吸烟和不吸烟人群患肺癌的风险。     

CYP1A1、GSTM1基因多态性及其联合作用与食管癌的易感性

目的探讨CYP1A1、GSTM1基因多态性及其联合作用与新疆汉族人食管癌易感性的关系。方法采用聚合酶链式反应-连接酶检测反应分析方法检测107例食管癌患者和204例非食管癌患者的CYP1A1(rs1048943、rs4646421和rs4646903)和GSTM1(缺失型和rs2071487)的基因型。结果CYP1A1基因rs1048943位点的等位基因和基因型频率在病例组和对照组之间比较,总体分布差异有统计学意义(χ² =5.52,P=0.019)。与A/A基因型相比,GG+AG基因型可增加食管癌的发病风险(OR=1.79,OR95%CI:1.10~2.92);GSTM1基因缺失型和非缺失型在病例组和对照组中的分布频率分别为68.69%、31.31%和48.39%、51.61%,在两组间的分布差异有统计学意义(χ²=10.55,P=0.001;OR=2.34,OR95%CI:1.40~3.91)。结论CYP1A1基因rs1048943位点多态性和GSTM1基因缺失型与新疆地区汉族人食管癌易感性有相关性。     

CYP1A1基因多态性与卵巢上皮性癌遗传易感性的关系

目的:探讨细胞色素P450(CYP1A1)基因异亮氨酸(Ile)-缬氨酸(Val)位点和Msp Ⅰ位点多态性与卵巢癌的相关关系.方法:以病例对照的研究方法.采用PCR-RFLP和AS-PCR技术检测78例卵巢癌患者和90名健康者对照的CYP1A1基因Ile-Val位点和Msp Ⅰ位点多态性.结果:Ile-Va 3种多态基因型在卵巢癌组和对照组分布差异有统计学意义(P<0.05),Ile/Val、Val/Val基因型在卵巢癌组的分布频率明显高于对照组;Ile/Val、Val/Val基因型患卵巢癌的危险分别是Ile/Ile基因型的1.313和3.472倍;Msp Ⅰ位点多态性在卵巢癌和对照组差异无统计学意义.结论:CYP1A1第7外显子的Ile/Val,Val/Val基因型与卵巢癌的易感性有关,突变基因型增加了卵巢癌的患病风险;尚不能认为Msp Ⅰ多态性与卵巢癌的易感性有关.     

CYP1A1与GSTM1的多态性与原发性肝癌遗传易感性的关系研究

目的 :探讨细胞色素P4 5 0 1A1(cytochromeP4 5 0 1A1,CYP1A1)与谷胱苷肽S -转移酶M1(glu tathioneS transferaseM 1,GSTM 1)的多态性与原发性肝癌遗传易感性的关系。方法 :应用等位特异PCR和多重PCR技术对 5 2例原发性肝癌患者和 10 0名健康对照的CYP1A1和GSTM 1多态性进行分析。结果 :肝癌患者CYP1A1第 7外显子 4 62Val的等位变异频率为 0 .4 6,显著高于正常对照的变异频率(0 .2 2 ) ,病例组GSTM1的纯合型缺失频率 (0 .65 )也显著高于对照组 (0 .4 1) ,携带有CYP1A1Val/Val纯合变异和GSTM1纯合缺失基因型的人患肝癌的风险大大增加 ,前者的比值比 (oddsratio ,OR)及 95 %可信区间 (confidenceinterval,95 %CI)为 4 .13(1.2 8～ 13.35 ) ,后者的OR值及 95 %CI为 2 .72 (1.35～5 .4 6) ,二者联合OR值及 95 %CI为 8.5 0 (1.74～ 4 1.5 0 )。结论 :CYP1A1和GSTM 1的多态是原发性肝癌的遗传易感因素 ,二者的等位变异增加了患肝癌的风险     

Dideoxy fingerprinting assay for BRCA1 mutation analysis

Since the isolation of BRCA1, the familial breast/ovarian cancer predisposition gene, much effort has been invested in characterizing the mutation spectrum. The large size of the gene and the wide distribution of its more than 100 mutations has increased the challenge of this endeavor such that traditional mutation detection techniques are inadequate. We examined the sensitivity of dideoxy fingerprinting (DDF), which combine a Sanger sequencing reaction with multiple-fragment single-strand conformation analysis (SSCA), as a mutation detection technique to screen BRCA1. Here we describe the technique and compare its sensitivity with that of SSCA in detecting 21 previously described BRCA1 sequence variants. All the variants were detected by DDF, but only 17 of 21 (81%) were observed by SSCA under standard conditions. Three of four alterations missed by SSCA were base substitutions. As a BRCA1 mutation detection technique, DDF was more sensitive than SSCA and may prove to be a useful research tool in defining the mutation spectrum within this and other genes. Mol. Carcinog. 19:176–179, 1997. © 1997 Wiley-Liss, Inc.     

GSTM1, GSTT1 and GSTP1 polymorphisms and lung cancer risk

Previous studies have suggested that GST genotypes may play a role in determining susceptibility to lung cancer, though the data are often conflicting. In this study we investigated GSTM1, GSTT1 and GSTP1 status in relation to lung cancer risk in patients attending a Manchester bronchoscopy clinic. Cases were all patients (n=94) currently with, or with a history of, tumours of the lung, trachea or bronchus. The control group were all other patients (n=165) who were free of benign and malignant tumours both at the time of, or prior to, diagnosis. All patients were interviewed for information on lifestyle risk factors, and DNA extracted from bronchial lavage and blood samples was used for genotyping. GSTM1 null genotype was associated with decreased lung cancer risk (odds ratio (OR) 0.50, 95% confidence interval (CI) 0.29–0.87), particularly among men (OR 0.43, 95% CI 0.21–0.87) and those above the median age (OR 0.33, 95% CI 0.15–0.70). No difference in GSTT1 and GSTP1 genotype distribution was seen between cases and controls. The GSTM1 null genotype was associated with a decreased risk of squamous cell carcinoma: the OR, adjusted for age, sex and pack years was 0.32 (95% CI 0.12–0.82). As previous studies have reported that the GSTM1 null genotype is associated with an increased lung cancer risk, further work is required to determine whether the observed association is true, or whether it arises from bias or confounding factors.     

Correlation of hMLH1 and HPP1 hypermethylation in gastric, but not in esophageal and cardiac adenocarcinoma

Using methylation-specific real-time PCR, we determined the prevalence of aberrant methylation in the mismatch repair gene hMLH1 and in the recently described HPP1 gene among 50 esophageal, 50 cardiac and 50 gastric ADCs. Additionally, expression of hMLH1 protein was detected immunohistochemically and correlated with DNA MSI. Hypermethylation of hMLH1 was found in 14% of esophageal, 28% of cardiac and 32% of gastric ADCs, whereas HPP1 hypermethylation was found more frequently in the 3 tumor types (64% vs. 38% vs. 54%). In gastric ADC, HPP1 hypermethylation was found more frequently in tumors with concomitant hMLH1 hypermethylation (81%) than in those without hMLH1 hypermethylation (41%, p = 0.008). Complete loss of hMLH1 protein expression, which was present in 10 carcinomas (5 cardiac and 5 gastric), was invariably correlated with hMLH1 hypermethylation and MSI. In conclusion, our data indicate that MSI and loss of the mismatch repair protein hMLH1, which is mainly caused by hMLH1 gene hypermethylation, are more prevalent in stomach and cardia carcinogenesis than in that of the esophagus. Moreover, in gastric cancer, hMLH1 hypermethylation is correlated with hypermethylation of the HPP1 gene.     

Identification of a novel gene, DAM1, amplified at chromosome 1p13.3-21 region in human breast cancer cell lines

Screening for differentially expressed genes in cancer cell lines by the RNA differential display (DD) technique identified a novel mRNA that encodes a 26-kDa protein and is up-regulated in MCF-7 and BT-20 breast cancer cells. The predicted amino acid sequence showed 38% homology to Caenorhabditis elegans T12A2.7 protein, indicating that this is a possible human homologue for C. elegans T12A2.7 protein. The mRNA, designated DAM1 (DNA amplified in mammary carcinoma), was mapped at the 1p13.3-21 region, which is frequently altered in human breast cancer. By Southern blot analysis, we confirmed that the up-regulation of this novel gene is associated with gene amplification in MCF-7 (10-fold) and BT-20 (5-fold) cells. Our findings suggest that the DAM1 gene is a novel gene up-regulated by amplification in human breast cancer cell lines.     

BRCA1 deficiency induces protective autophagy to mitigate stress and provides a mechanism for BRCA1 haploinsufficiency in tumorigenesis

Stress adaptation has profound impacts on malignant progression and response to treatment. BRCA1 is an important modulator of cellular stress, but our understanding of its mechanisms of action remains incomplete. Here we identify autophagy as an essential mechanism protecting BRCA1 deficient cancer cells from metabolic stress and allow their survival, which may underlie its significant cancer-promoting properties. We showed that targeted inhibition of endogenous BRCA1 using small interfering RNA caused significant autophagy in response to serum starvation and endoplasmic reticulum stress, whereas overexpression of BRCA1 did not, confirming that the effect was BRCA1 specific. We demonstrated that Beclin 1 was activated in BRCA1 deficient cells, suggesting involvement of a canonical pathway. Importantly, BRCA1 deficient cells were highly dependent on autophagy for survival, and rapidly underwent cell death upon disruption of autophagy. Notably, this dependence on protective autophagy extended to their tissue of origin, as ovarian surface epithelial cells from women testing positive for BRCA1 mutations, in contrast to those with no mutations, robustly induced autophagy to mitigate the stress and promote their survival. These findings highlight a novel role for BRCA1 in protective autophagy, which may make its essential contribution to tumorigenesis and prognosis.     

以PD-1/PD-L1为靶点的肺癌免疫治疗临床研究进展

免疫检查点的研究在近几年实现突破性进展,PD-1/PD-L1信号通路与免疫逃逸机制密切相关,针对阻断PD-1/PD-L1 通路免疫检查点的治疗在肺癌中取得明显效果。从Checkmate-017、Checkmate-057研究到KEYNOTE-010研究和OAK研究,逐 步奠定了PD1/PD-L1抑制剂作为化疗失败晚期NSCLC的标准治疗的地位;PD-1/PD-L1抑制剂可联合其他治疗方式,包括放疗、 化疗、靶向治疗以及其他免疫治疗等方式,在肺癌综合治疗中起到协同作用,从而提高了疗效。免疫检查点抑制剂带来了肺癌治 疗模式的改变,也对肿瘤疗效评价模式、治疗相关不良反应的处理带来挑战。另外,免疫检查点抑制剂的研发也有力地推动了精 准医疗的进展。     

Nuclear CSPP1 expression defined subtypes of basal-like breast cancer

Background:

The multi-exon CSPP1 gene, encoding for centrosome and microtubule-associated proteins involved in ciliogenesis and cell division, is a candidate oncogene in luminal breast cancer but expression of CSPP1 proteins remained unexplored.

Methods:

CSPP1 gene and protein expression was examined in normal mammary tissue, human breast cancer cell lines, and primary breast cancer biopsies from two patient cohorts. Cell type and epitope-dependent subcellular-specific CSPP1 staining pattern in normal mammary gland epithelium and cancer biopsies were correlated to molecular and clinical parameters.

Results:

A novel, nuclear localised CSPP1 isoform was exclusively detected in luminal epithelial cells, whereas cytoplasmic CSPP-L was generally expressed in normal mammary epithelium. Luminal cell-related nuclear CSPP1 expression was preserved in type-matched cell lines and carcinomas, and correlated to gene copy number and mRNA expression. In contrast, basal-like carcinomas displayed generally lower CSPP1 mRNA expression. Yet, a subgroup of basal-like breast carcinomas depicted nuclear CSPP1 expression, displayed luminal traits, and differed from nuclear CSPP1 devoid counterparts in expression of eight genes. Eight-gene signature defined groups of basal-like tumours from an independent cohort showed significant differences in survival.

Conclusions:

Differential expression of a nuclear CSPP1 isoform identified biologically and clinically distinct subgroups of basal-like breast carcinoma.