Miller Spencer O, Ewing Gideon P, Howard Carol, Tachikawa Hiroyasu, Bigler Steven A, Barber W Henry, Angel Michael, McDaniel D Olga
Departments of Surgery and Pathology, University of Mississippi Medical Center, Departments of Biology and Chemistry, Jackson State University, Jackson, Mississippi, USA.
Biomed Sci Instrum. 2003;39:24-9.
We have evaluated the use of cytochrome P450 (CYP), 3A4 genotype and Fourier transform-infrared (RT-IR)/Raman spectroscopy as diagnostic tools for detection of breast tumors. CYP is involved in catalytic activity of oxidative metabolism of many chemicals in fatty tissues, and it plays a major role in biotransformation and detoxication of environmental contaminants. FT-IR and Raman spectroscopy have been used to develop methods for cancer assessment. Thus, the hypothesis was that a) CYP 3A4 gene expression level may have effect on the clinical presentation of breast cancer; and b) a combination spectroscopy and genotype analysis may strengthen the level of diagnosis. In parallel studies we compared by reverse-transcription-polymerase chain reaction (RT-PCR), the CYP 3A4 mRNA transcript levels, and by FT-IR the pathology of breast tissues. RNA was isolated from human breast biopsies and cultured tumor cells (MCF-7). A comparison of the levels of RT-PCR was made between CYP 3A4 genotype and 1B1, a genotype associated with human tumors, testing 3 normal breast tissues, 2 specimen from breast reduction and 7 breast tumors. Two variants of CYP 3A4 mRNA were observed, of which a 380-bp was displayed in 4 out of 5 pathologically determined tumors, and a 260-bp fragment was associated with normal tissues. The predictive value of the CYP 3A4 for the detection of tumor tissues was greater than that observed with the CYP 1B1. FT-IR signal patterns were distinct for tumor tissues as compared with that of normal tissue. Our findings demonstrated the importance of CYP 3A4 as molecular biomarker for determining the presence of breast tumors. This data in association with FT-IR/Raman spectroscopy and pathology, it can be an ideal test for predicting the clinical presentation of breast cancer.
我们评估了细胞色素P450(CYP)3A4基因型以及傅里叶变换红外(FT-IR)/拉曼光谱作为检测乳腺肿瘤诊断工具的应用。CYP参与脂肪组织中多种化学物质氧化代谢的催化活性,在环境污染物的生物转化和解毒过程中起主要作用。FT-IR和拉曼光谱已被用于开发癌症评估方法。因此,我们提出以下假设:a)CYP 3A4基因表达水平可能对乳腺癌的临床表现有影响;b)光谱学与基因型分析相结合可能会提高诊断水平。在平行研究中,我们通过逆转录聚合酶链反应(RT-PCR)比较了CYP 3A4 mRNA转录水平,并通过FT-IR比较了乳腺组织的病理学特征。从人乳腺活检组织和培养的肿瘤细胞(MCF-7)中分离RNA。比较了CYP 3A4基因型与1B1(一种与人类肿瘤相关的基因型)的RT-PCR水平,检测了3个正常乳腺组织、2个乳房缩小术标本和7个乳腺肿瘤。观察到CYP 3A4 mRNA的两种变体,其中在5个经病理确定的肿瘤中有4个显示出380 bp的片段,而260 bp的片段与正常组织相关。CYP 3A4对肿瘤组织检测的预测价值高于CYP 1B1。与正常组织相比,肿瘤组织的FT-IR信号模式明显不同。我们的研究结果证明了CYP 3A4作为确定乳腺肿瘤存在的分子生物标志物的重要性。这些数据与FT-IR/拉曼光谱和病理学相结合,可能是预测乳腺癌临床表现的理想检测方法。