Parrella P, Xiao Y, Fliss M, Sanchez-Cespedes M, Mazzarelli P, Rinaldi M, Nicol T, Gabrielson E, Cuomo C, Cohen D, Pandit S, Spencer M, Rabitti C, Fazio V M, Sidransky D
Department of Otolaryngology, Head and Neck Surgery, Division of Head and Neck Cancer Research, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA.
Cancer Res. 2001 Oct 15;61(20):7623-6.
To determine the frequency and distribution of mitochondrial DNA mutations in breast cancer, 18 primary breast tumors were analyzed by direct sequencing. Twelve somatic mutations not present in matched lymphocytes and normal breast tissues were detected in 11 of the tumors screened (61%). Of these mutations, five (42%) were deletions or insertions in a homopolymeric C-stretch between nucleotides 303-315 (D310) within the D-loop. The remaining seven mutations (58%) were single-base substitutions in the coding (ND1, ND4, ND5, and cytochrome b genes) or noncoding regions (D-loop) of the mitochondrial genome. In three cases (25%), the mutations detected in coding regions led to amino acid substitutions in the protein sequence. We then screened an additional 46 primary breast tumors with a rapid PCR-based assay to identify poly-C alterations in D310, and we found seven more cancers with alterations. Using D310 mutations as clonal marker, we detected identical changes in five of five matched fine-needle aspirates and in four of four metastases-positive lymph nodes. The high frequency of D310 alterations in primary breast cancer combined with the high sensitivity of the PCR-based assays provides a new molecular tool for cancer detection.
为了确定乳腺癌中线粒体DNA突变的频率和分布，通过直接测序对18例原发性乳腺肿瘤进行了分析。在筛查的11例肿瘤（61%）中检测到12种在匹配的淋巴细胞和正常乳腺组织中不存在的体细胞突变。在这些突变中，5种（42%）是D环内核苷酸303 - 315（D310）之间同聚C序列的缺失或插入。其余7种突变（58%）是线粒体基因组编码区（ND1、ND4、ND5和细胞色素b基因）或非编码区（D环）的单碱基替换。在3例（25%）中，编码区检测到的突变导致蛋白质序列中的氨基酸替换。然后，我们用基于快速PCR的检测方法对另外46例原发性乳腺肿瘤进行筛查，以鉴定D310中的多聚C改变，我们又发现了7例有改变的癌症。以D310突变作为克隆标记，我们在5例匹配的细针穿刺抽吸物中的5例以及4例转移阳性淋巴结中的4例中检测到相同的变化。原发性乳腺癌中D310改变的高频率与基于PCR检测方法的高灵敏度相结合，为癌症检测提供了一种新的分子工具。
