Oncogenic Potential of CYP24A1 in Lung Adenocarcinoma

IntroductionWe have previously demonstrated that a subset of lung cancer cells express higher CYP24A1 mRNA, a metabolizing enzyme for 1,25-D3, compared to benign tumors or surrounding normal lung and that high CYP24A1 mRNA expression is associated with poor prognosis in resected lung adenocarcinoma (AC). We hypothesized that CYP24A1 has oncogenic potential and increased CYP24A1 expression may contribute to tumor growth, whereas, CYP24A1 targeting may reduce tumor burden.MethodsTwo low CYP24A1 expressing human lung cancer cell lines (SK-LU-1 and Calu-6) were stably transfected either with an empty lentiviral vector or with the CYP24A1 expressing vector. Over-expression of mRNA and protein levels of CYP24A1 in SK-LU-1 and Calu-6 were confirmed using qRT-PCR and immunoblotting respectively. Next, effects of targeting CYP24A1 were examined in lung cancer cells (A549 and H441), which express higher basal levels of CYP24A1. Finally, we studied the effects of stable knockdown of CYP24A1 in xenograft models.ResultsOver-expression of CYP24A1 correlated with accelerated cell growth and invasion compared to control vector-transfected cells. CYP24A1 over-expression also increased RAS protein expression. Knockdown of CYP24A1 using either si- or shRNA reduced CYP24A1 mRNA and protein expression and significantly decreased cell proliferation (30-60%) and reduced mitochondrial DNA content compared to non-targeting (NT) si-/shRNA transfected/transduced cells. Transfection with CYP24A1 siRNA also decreased total RAS protein, thus reducing phosphorylated AKT. Importantly, stable knockdown of CYP24A1 in A549 and H441 lung tumor xenograft models resulted in tumor growth delay and smaller tumor size as evident from tumor bioluminescence and tumor volume measurement studies. Such observations were correlated with decreased tumor cell proliferation as evidenced by reduced Ki67 and Cyclin D staining.ConclusionsOur data suggest that CYP24A1 has oncogenic properties mediated by increasing RAS signaling, targeting of which may provide an alternate strategy to treat a subset of lung AC.     

Impact of CYP24A1 overexpression on growth of colorectal tumour xenografts in mice fed with vitamin D and soy

Our previous studies showed that the 1,25‐dihydroxyvitamin D (1,25‐D₃) catabolizing enzyme, 1,25‐dihydoxyvitamin D 24 hydroxylase (CYP24A1) was overexpressed in colorectal tumours and its level correlated with increased proliferation. We hypothesised that cells overexpressing CYP24A1 have growth advantage and a diet rich in vitamin D and soy would restore sensitivity to the anti‐tumourigenic effects of vitamin D. Soy contains genistein, a natural CYP24A1 inhibitor. To determine causality between CYP24A1 and tumour growth, we established xenografts in male SCID mice with HT29 cells stably overexpressing either GFP‐tagged CYP24A1 or GFP. Mice were fed with either high (2500 IU D₃/kg) or low vitamin D (100 IU D₃/kg) diet in the presence or absence of soy (20% diet). In vitro, cells overexpressing CYP24A1 grew faster than controls. 1,25‐D₃, the active vitamin D metabolite, reduced cell number only in the presence of the CYP24A1 inhibitor VID400. Regardless of the amount of vitamin D in the diet, xenografts overexpressing CYP24A1 grew faster, were heavier and more aggressive. Soy reduced tumour volume only in the control xenografts, while the tumours overexpressing CYP24A1 were larger in the presence of dietary soy. In conclusion, we demonstrate that CYP24A1 overexpression results in increased aggressiveness and proliferative potential of colorectal tumours. Irrespective of the dietary vitamin D₃, dietary soy is able to increase tumour volume when tumours overexpress CYP24A1, suggesting that combination of vitamin D₃ and soy could have an anti‐tumourigenic effect only if CYP24A1 levels are normal.     

CYP1A1基因多态性在子宫内膜异位症中的表达

目的　探讨CYP1A1基因多态性在子宫内膜异位症中的表达 ,了解其与子宫内膜异位症之间的关系。方法　采用PCR方法对子宫内膜异位症患者基因组DNA进行CYP1A1基因分型。结果　在 17例子宫内膜异位症标本中 ,CYP1A1I/I型频率为 0 .1176 ,CYP1A1V/V型频率为 0 .176 5 ,CYP1A1I/V型频率为 0 .70 5 9,含至少一个Val等位基因 (I/V +V/V )的频率为 0 .882 4 ,是I/I基因频率 (0 .1176 )的 7.5倍。结论　CYP1A1基因多态性中Val基因突变在子宫内膜异位症中占有很高的比例 ,提示该基因突变也许与子宫内膜异位症的发生之间有着密切联系。     

CYP1 A1 mRNA在大鼠脑内的分布以及溴氰菊酯对其影响的研究

目的 :研究CYP1A1mRNA在大鼠脑内的分布以及溴氰菊酯对其影响。方法 :采用RT -PCR及cDNAdotblot方法检测大鼠不同脑区CYP1A1mRNA的表达。结果 :大鼠脑区CYP1A1mRNA分布不一致 ,在所检测的脑区中 ,下丘脑最丰富 ,其次是皮层、小脑 ;在溴氰菊酯 1/ 10LD50 (12 .5mg .kg-1.d-1)腹腔注射连续 5d的作用下 ,溴氰菊酯对大鼠脑内CYP1A1mRNA有明显的抑制作用 ,并以皮层和下丘脑为甚。结论 :CYP1A1mRNA在大鼠脑内的分布不一致 ,溴氰菊酯抑制脑内CPY1A1mRNA的表达     

外周血中亲环素AmRNA的表达水平测定

目的探讨外周血中亲环素A（CyPA）mRNA表达水平与恶性肿瘤及非恶性肿瘤疾病的关系。方法采用实时荧光定量聚合酶链反应（RT—FQ—PCR）测定恶性肿瘤组、非恶性肿瘤组及对照组外周血中CyPA mRNA相对表达水平。结果外周血中CyPA mRNA相对表达水平从高到低依次为非恶性肿瘤组、恶性肿瘤组及对照组,非恶性肿瘤组与恶性肿瘤组比较差异无统计学意义（P〉0．05）,非恶性肿瘤组及恶性肿瘤组均高于对照组（P〈0．05）。结论外周血中CyPA mRNA相对表达水平升高与疾病的发生发展有关。     

外周血中亲环素A mRNA的表达水平测定

目的 探讨外周血中亲环素A (CyPA) mRNA表达水平与恶性肿瘤及非恶性肿瘤疾病的关系.方法 采用实时荧光定量聚合酶链反应(RT-FQ-PCR)测定恶性肿瘤组、非恶性肿瘤组及对照组外周血中CyPA mRNA相对表达水平.结果 外周血中CyPAmRNA相对表达水平从高到低依次为非恶性肿瘤组、恶性肿瘤组及对照组,非恶性...     

CYPlAl和CYPlA2基因多态性与汉族女性乳腺癌的关系

目的 探讨CYP1A1基因MspⅠ位点与CYP1A2基因C734A位点多态性与汉族女性乳腺癌的关系.方法 应用聚合酶链反应-限制性片段长度多态性技术和限制性核酸内切酶酶切的方法,检测2011年9月至2012年8月在四川省医学科学院四川省人民医院确诊的144例女性乳腺癌患者（乳腺癌组）和152例同期健康体检正常女性（对照组）CYP1A1基因MspⅠ与CYP1A2基因C734A多态性位点的基因型,用χ2检验比较两组等位基因频率的差异.结果 在乳腺癌组与对照组中,CYP1A1基因MspⅠ位点T等位基因频率分别为0.73和0.65,两者差异有统计学意义（χ2=4.94,P=0.03）,C等位基因与T等位基因相比,乳腺癌发病风险OR为0.67 （95%CI：0.47～0.96）;CYP1A2基因C734A位点C等位基因频率分别为0.26和0.29,两者差异无统计学意义 （χ2=0.63,P=0.43）.将乳腺癌组按照ER、PR表达与否进一步分组后,CYP1A1基因MspⅠ与CYP1A 2基因C734A 2个多态性位点的等位基因频率在ER（＋）与ER（-）组之间以及PR（＋）与PR（-）组之间差异均无统计学意义[ER（＋）组比ER（-）组：χ2=0.34、0.01;PR（＋）组比PR（-）组：χ2=0.60、0.68;P均〉0.05].结论 汉族女性CYP1A1基因MspⅠ位点多态性与乳腺癌相关联.     

Association of CYP1A1 rs1048943 Polymorphism with Prostate Cancer in Iraqi Men Patients

Objective: The purpose of this study was to evaluate the relationship between CYP1A1 gene rs1048943 polymorphism and the risk of Iraqi men with prostate cancer. Methods: In this research, we conducted a population-based approach that intersects high-throughput genotype information from  different population of Iraq to estimate the frequency of genotypes associated with prostate cancer responsivenessOur study included a total of 100 patients and 150 healthy controls. rs1048943 genotyping has been investigated in Iraqi men in connection with prostate cancer. Results: We observed that individuals with the rs1048943 GA genotype had an increased risk of prostate cancer relative to those with the AA genotype  ( OR 95% CI of 0.449 :95%CI 0.23-0.90; P = 0.002). We found in the dominant model that the rs1048943 GA and GG genotype displayed an increased risk of prostate cancer relative to the AA genotype   ( OR 95% CI of 0.680 :95%CI 0.4-1.17; P = 0.018). Conclusion: Polymorphism RS 1048943 in the CYP1A1 gene is associated with the risk of developing prostate cancer and is possibly one of the most significant factors in its development.     

Expression of CYP1A1 and GSTP1 in Human Brain Tumor Tissues in Pakistan

Most of the exogenous and endogenous chemical compounds are metabolized by enzymes of xenobioticprocessing pathways, including the phase I cytochrome p450 species. Carcinogens and their metabolites aregenerally detoxified by phase II enzymes like glutathione-S-transferases (GST). The balance of enzymesdetermines whether metabolic activation of pro-carcinogens or inactivation of carcinogens occurs. Under certainconditions, deregulated expression of xenobiotic enzymes may also convert endogenous substrates to metabolitesthat can facilitate DNA adduct formation and ultimately lead to cancer development. In this study, we aimed totest the association between deregulation of metabolizing genes and brain tumorigenesis. The expression profile ofmetabolizing genes CYP1A1 and GSTP1 was therefore studied in a cohort of 36 brain tumor patients and controlsusing Western blotting. In a second part of the study we analyzed protein expression of GSTs in the same studycohort by ELISA. CYP1A1 expression was found to be significantly high (p<0.001) in brain tumor as comparedto the normal tissues, with ~4 fold (OR=4, 95%CI=0.43-37) increase in some cases. In contrast, the expressionof GSTP1 was found to be significantly low in brain tumor tissues as compared to the controls (p<0.02). Thisdown regulation was significantly higher (OR=0.05, 95%CI=0.006-0.51; p<0.007) in certain grades of lesions.Furthermore, GSTs levels were significantly down-regulated (p<0.014) in brain tumor patients compared tocontrols. Statistically significant decrease in GST levels was observed in the more advanced lesions (III-IV,p<0.005) as compared to the early tissue grades (I-II). Thus, altered expression of these xenobiotic metabolizinggenes may be involved in brain tumor development in Pakistani population. Investigation of expression of thesegenes may provide information not only for the prediction of individual cancer risk but also for the preventionof cancer.     

CYP17 &; SULT1A1 gene polymorphisms in Indian breast cancer

BACKGROUND: Breast cancer is the most common cancer among women worldwide. Life-time exposure to steroid hormones, especially estrogen, is a major risk factor for breast cancer. Functional polymorphisms in genes encoding steroid metabolizing enzymes may thus be important as biomarkers of individual susceptibility to breast cancer. The CYP17 and SULT1A1 genes encode for two enzymes involved in hormone biosynthesis and metabolism. Single nucleotide polymorphisms of these genes may result in inter-individual variability in steroid hormone biosynthesis and metabolism thus influence the development of breast cancer. METHODS: We tested this hypothesis by conducting a case - control study on a group of 140 breast cancer cases and 140 healthy age-matched controls. Analysis of CYP17 and SULT1A1 genotypes were done by polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP). RESULTS: The genetic polymorphisms of the estrogen-related genes SULT1A1(OR=2.5, 95% CI=1.28-4.98) and CYP17 (OR=4.1, 95= CI=1.78-9.63) were associated with an increased risk of breast cancer among postmenopausal women. Our data also showed evidence for the genetic regulation of serum 17 beta estradiol (E2) levels as measured by ELISA among the premenopausal women with a significant increase in the serum E2 level for the CYP17 A2 variants. CONCLUSION: These results suggest that both CYP17 and SULT1A1 genotypes could be important determinants of breast cancer risk in Indian women and may help in early identification of high risk subjects. Such genotype analysis resulting in a high-risk profile holds considerable promise for individualizing screening, diagnosis and therapeutic intervention in breast cancer.     

紫杉醇作用卵巢癌细胞系HO-8910后CYP1B1 mRNA及蛋白表达差异的研究

背景与目的:用紫杉醇(paclitaxel,PTX)对卵巢癌细胞系HO-8910进行体外化疗后,观察CYP1B1表达的变化,以期探讨CYP1B1基因表达与肿瘤细胞耐药的关系. 材料与方法:以不同浓度PTX(分别为30、15、7.5、3.75、1.88、0.94、0.47 μg/mi)处理H0-8910细胞.采用四甲基偶氮唑蓝(MTT)比色法检测PTX对HO-8910细胞体外生长的抑制作用,实验同时设只加培养液的对照组.以5 μg/ml PTX分别处理HO-8910细胞24 h、48 h、72 h和50#g/ml PTX处理细胞24 h后,用RT-PCR技术检测存活的卵巢癌细胞中CYP1B1 mRNA的表达水平,用Western blot检测细胞CYP1B1蛋白表达.结果:PTX能抑制HO-8910细胞生长,7种不同浓度的PTX作用72 h后,细胞的抑制率分别为89.10%、76.82%、67.39%、57.27%、46.21%、37.02%、17.56%,随着药物浓度的下降,其抑制率明显降低,各浓度组细胞抑制率间的差异具有统计学意义(P<0.05).经PTX处理后存活的HO-8910细胞中CYP1B1 mRNA及蛋白的表达量增加,高于对照组;5 μg/ml PTX处理HO-8910细胞48 h、72 h和50 μg/ml的PTX处理24 h组,CYP1B1蛋白的表达量高于5 μg/ml PTX处理24 h组(P<0.05).结论:CYP1B1在卵巢癌细胞系中呈高表达,CYP1B1基因在卵巢癌细胞系H0-8910体外PTX化疗中起抑制作用.     

CYP1A1 Genetic Polymorphisms and Risk for Esophageal Cancer: a Case-control Study in Central China

The purpose of this study was to evaluate the associations of CYP1A1 genetic polymorphisms with the riskof developing esophageal cancer (EC). A case-control study was carried out in a Chinese population in which157 hospital based EC cases and 157 population based healthy controls with 1:1 match by age and sex wereincluded. PCR based restriction fragment length polymorphisms (PCR-RFLP) were used to detect genotypes incase and control groups. For the CYP1A1 Ile/Val polymorphism, comparing with wild genotype Ile/Ile, both theheterozygote genotype Ile/Val and the combined variant genotype Ile/Val+Val/Val increased the risk of esophagealcancer (OR: 2.05, 95%CI: 1.19-3.54, OR: 1.86, 95%CI: 1.11-3.12). No significant association was found betweenthe CYP1A1 MspI polymorphism and EC. According to analysis of combined genotypes, the TC/AG combinedgenotype which contained both variant alleles of these two polymorphisms increased the risk of developing EC(OR: 2.12, 95%CI: 1.16-3.85). Our results suggested that genetic polymorphisms of CYP1A1 may increase thesusceptibility to EC.     

高氡暴露地区人群中代谢酶CYP1A1基因多态性与肺癌易感性的关系

背景与目的:研究高氡暴露地区人群中CYP1A1基因多态性与肺癌易感性的关系.材料与方法:采用病例,对照研究方法,以基因体外扩增限制性片段长度多态性分析(RFLP-PCR)技术,对高氡暴露地区53例肺癌患者和72例对照人员进行了代谢酶CYP1A1(MSP Ⅰ)基因多态性检测,并分析了不同人群中该基因多态性与肺癌发病风险的关系.结果:在氡暴露地区CYP1A1(MAP Ⅰ)基因杂合型人群的肺癌发病的OR(优势比)值为1.03(95%可信限0.468～2.30).分层分析:有效剂量＜50 mSv的人群中CYP1A1(MSP Ⅰ)基因杂合型的肺癌发病风险增至4.29倍(95%可信限0.582～88.2),年龄在40～59岁人群中CYP1A1(MSP)基因杂合型的肺癌发病风险是野生型的1.22倍(95%可信限0.145～3.65).结论:CYPIAI(MSP Ⅰ)基因多态性与肺癌易感性无显著关联.但CYP1A1(MSP Ⅰ)基因杂合型对观察人群的肺鳞癌发病风险、有效剂量＜50 mSv的人群肺癌发病风险、非吸烟人群的肺癌发病风险和40～59岁人群肺癌发病风险均有增高的趋势.     

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和GSTM1基因多态性与内蒙古人群肺癌易感性的关系

背景与目的 肺癌是严重危害人类健康的恶性肿瘤之一，其发病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P4501A1（CYP1A1）基因多态性和谷胱甘肽硫转移酶M1（GSTM1）基因多态性与内蒙古人群肺癌易感性的关系。方法 用PCR-RFLP技术分析了原发性肺癌组和住院对照组（各163例）的CYP1A1、GSTM1基因的多态性、基因型分布频率和交互作用。结果 CYP1A1突变型和GSTM1基因缺陷型EGSTM1（-）]频率分布分别为36．8％、65．0％（病例组）和19．0％、48．9％（对照组），二者经χ^2检验差异有显著性（χ^2=12．82，P=0．000；χ^2=9．78，P=0．002）。CYP1A1突变型患肺癌的风险显著增加（OR=2．48，95％CI为1．51～4．08）。GSTM1（-）者患肺癌的风险也显著增加（OR=2．03，95％CI为1．30～3．17）。基因突变的协同分析发现CYP1A1突变型／GSTM1（-）在肺癌组和对照组中的分布频率分别为28．8％和8．0％，二者经χ^2检验有显著性差异（χ^2=23．883，P=0．000）。CYP1A1突变型／GSTM1（-）患肺癌的风险显著增加（OR=4．90，95％CI为2．50～9．83）。无论是在肺癌组还是在对照组，CYP1A1突变型／GSTM1（-）和CYP1A1非突变型／GSTM1（-）在性别间分布频率的差异均无显著性（肺癌组χ^2=0．797，P=0．372；对照组χ^2=0．670，P=0．761）。吸烟与肺癌易感性的统计学分析，结果显示吸烟与肺癌易感性有关（χ^2=14．197，P=0．000），吸烟者患肺癌的风险显著增加（OR=2．33，95％CI为1.50～3．62）。CYP1A1突变型与吸烟关系的协同分析发现，携带CYP1A1突变型基因的吸烟者较携带CYP1A1突变型基因不吸烟者易患肺癌（OR=4．44，95％CI为2．40～8．32，χ^2=23．843，P=0．000）。GSTM1（-）与吸烟关系的协同分析中也发现，携带GSTM1（-）的吸烟者患肺癌的风险显著增加（OR=7．32，95％CI为3．39～15．50，χ^2=36．708，P=0．000）。结论 CYP1A1突变型和GSTM1（-）是内蒙古地区肺癌的易患因素，二者对肺癌的发生有协同作用，吸烟与肺癌的易感性也有关，CYP1A1突变型、GSTM1（-）与吸烟在肺癌的发生上也有相互促进作用。     

胃癌组织Cystatin SN mRNA表达及其临床意义的探讨

目的:研究半胱氨酸蛋白酶抑制剂1 (Cystatin SN)在胃癌组织中的表达及临床意义.方法:荧光定量PCR方法检测40例胃癌组织和40例癌旁组织中Cystatin SN的表达.结果:胃癌组织中Cystatin SN mRNA的表达水平为5.370 0±3.034 5,相应的癌旁组织为1.705 0±0.738 8,癌组织显著高于癌旁组织,t=8.297,P=0.000.Cystatin SN的表达与肿瘤大小(t=-0.646,P=0.001)、淋巴转移(t=3.393,P=0.002)、TNM分期(t=-3.798,P=0.001)和浸润程度(t=4.904,P=0.000)相关,与肿瘤的分化程度、患者年龄和性别无关,P＞0.05.结论:Cystatin SN在胃癌组织中的高表达与胃癌的发生发展密切相关.     

Association of CYP3A5*3 and CYP1A1*2C Polymorphism with Development of Acute Myeloid Leukemia in Egyptian Patients

Aim: Cytochrome P450 (CYP) enzyme catalyzes the phase I metabolism reaction which metabolize endogenous and exogenous DNA-reactive chemical compounds and xenobiotics which could induce genotoxicity and increase the risk for leukemia. We aimed to detect frequency of CYP3A5*3 and CYP1A1*2C polymorphisms in Egyptian acute myeloid leukemia (AML) patients and to determine role of allele’s variants as a risk factor for developing leukemia. Patients and Methods: A case-control study was conducted on seventy acute myeloid leukemia patients and thirty control subjects. Samples were analyzed for prevalence of CYP3A5*3 and CYP1A1*2C polymorphisms using PCR - restriction fragment length polymorphism method. Results: CYP3A5*3 polymorphism (3/3) and (1/3) genotype were significantly elevated in AML group compared to control group (p=0.002). However, no statistical significant differences were found between patients and control group as regard CYP1A1*2C polymorphism. Conclusion: Our results suggest that Egyptians carrying CYP3A5*3 polymorphism might have an increased risk of AML emphasizing the significance of effective phase I detoxification in carcinogenesis.