Yee C J, Roodi N, Verrier C S, Parl F F
Department of Pathology, Vanderbilt University, Nashville, Tennessee 37232.
Cancer Res. 1994 Apr 1;54(7):1641-4.
Microsatellite instability (MSI) has been described in colorectal and other cancers. The purpose of this study was to determine the presence of MSI in breast cancer and to correlate its occurrence with clinicopathological parameters. For microsatellite markers we examined mono-, di-, tri-, and tetranucleotide repeats that, due to their polymorphic nature, may also be used to investigate loss of heterozygosity. In 20 paired breast cancer-peripheral blood DNA samples we identified four tumors (20%) with somatic MSI. All four tumors were stage I or II, grade 1 or 2, and estrogen receptor positive. To study MSI in relation to tumor progression we also examined paired DNA samples from two ipsilateral and three contralateral breast cancers, as well as two matched tumor-metastatic lymph node specimens. None of these seven cases showed MSI, but two of the contralateral tumors revealed allelic loss of polymorphic repeats. These data suggest that MSI is an early event in mammary tumorigenesis while loss of heterozygosity may occur at a later stage.
微卫星不稳定性（MSI）已在结直肠癌和其他癌症中被描述。本研究的目的是确定乳腺癌中MSI的存在情况，并将其发生与临床病理参数相关联。对于微卫星标记，我们检测了单核苷酸、二核苷酸、三核苷酸和四核苷酸重复序列，由于它们的多态性，也可用于研究杂合性缺失。在20对乳腺癌-外周血DNA样本中，我们鉴定出4例（20%）存在体细胞MSI的肿瘤。所有4例肿瘤均为I期或II期、1级或2级，且雌激素受体阳性。为了研究MSI与肿瘤进展的关系，我们还检测了来自2例同侧和3例对侧乳腺癌的配对DNA样本，以及2例匹配的肿瘤-转移淋巴结标本。这7例病例均未显示MSI，但2例对侧肿瘤显示多态性重复序列的等位基因缺失。这些数据表明，MSI是乳腺肿瘤发生的早期事件，而杂合性缺失可能发生在后期。
