乳腺导管内增生性病变的克隆性分析

Clonality analysis of intraductal proliferative lesions in the mammary gland

目的检测乳腺导管内增生性病变的克隆性起源。方法采用激光捕获显微切割技术精确分离增生组织和周围正常组织中的导管上皮细胞，抽提其基因组DNA。以限制性内切酶HpaⅡ消化前后的基因组DNA为模板，荧光PCR法扩增人雄激素受体（HUMARA）外显子1，在DNA测序仪上毛细管电泳，并分析HUMARA两个位点的荧光强度。结果101例组织标本中，有68例PCR扩增HUMARA外显子1成功，并且该位点为杂合性，其中9例普通导管内增生（UDH）和5例导管上皮内肿瘤（DIN）1A在HpaⅡ消化前后的PCR产物均有2条，且荧光强度相近，即它们的X染色体失活是随机的，呈多克隆性。3例UDH、13例DIN1A、28例DIN1B和10例原位癌在HpaⅡ消化前后扩增出1条或2条强度差别较大的条带，提示它们为单克隆起源。结论DIN1A、1B和原位癌为单克隆起源，属于肿瘤性增生。

Objective To detect the clonal origin of intraductal proliferative lesions in the mammary gland. Methods Lesional and normal breast gland cells were microdissected from paraffin-embedded tissues using a laser capture microdissection （LCM） system. The genomic DNA was extracted. After digestion by restriction enzyme HpaⅡ , human androgen receptor （ HUMARA ） exonl was amplified by a fluorescent nested-PCR procedure and the PCR products were separated by a DNA sequencer and the fluorescent intensity of the two HUMARA alleles was analyzed. Results DNA from 88 of 101 （ 87. 1% ） patients could be amplified at the HUMARA locus and 68 of them （77.3%） were heterozygous and informative. 9/12 usual ductal hyperplasia （UDH） and 5/18 ductal intraepithelial neoplasia （DIN） 1A showed a polyclonal inactivation. 3/12 UDH, 13/18 DIN1A, 28/28 DIN1B, 10/10 carcinoma in situ were monoclonal origin. Conclusion DIN 1A, 1B and carcinoma in situ are of monoclonal origin and real tumors.