Analysis of clonality in odontogenic tumors by PCR assay of X chromosome gene

成釉细胞瘤是最常见的牙源性肿瘤，属于良性肿瘤。但它呈浸润性生长，破坏周围骨结构或软组织。基因组学技术的最新进展使得能够通过X染色体连锁基因的PCR测定来评估病变中的克隆性。为探讨雄激素受体基因多态性在成釉细胞瘤中的克隆性，从我所组织档案中选取9例女性成釉细胞瘤（均为滤泡型）标本，采用聚合酶链反应（PCR）技术检测雄激素受体基因多态性。将福尔马林固定、石蜡包埋的组织切片并分离肿瘤区域。用蛋白酶K和Hpa Ⅱ分别对标本进行酶切，以Hpa Ⅱ酶切产物和未酶切DNA为模板，PCR扩增雄激素受体基因外显子1，包括多态性三核苷酸重复序列。将PCR产物上样到聚丙烯酰胺凝胶上并进行电泳。凝胶银染，9例中3例无多态性等位基因。其余6例在凝胶上显示两条带，因此评价为多克隆。

Ameloblastoma, the most popular odontogenic tumor, is classified as benign tumor. However, it shows infiltrative growth and destroy surrounding bony structure or soft tissues. Namely, "generally benign, but locally aggressive".Recent advances in genomic technology enable the assesment of clonality in a lesion by PCR assay of X chromosome-linked gene. The aim of this study is to evaluate the clonality in ameloblastomas by PCR assay of human androgen receptor gene polymorphism.From tissue-archive in our institute, 9 cases of ameloblastoma (all follicular type) arisen in female were selected as the specimens. Formalin-fixed, paraffin-embedded tissues were sliced and tumor area was isolated. The specimens were digested with proteinase-K and a part of them were digested with HpaII.The HpaII digested product and remaining undigested DNA were used as templates for PCR amplification for androgen receptor gene exonl including polymorphic trinucleotide repeat. The PCR product was loaded on polyacrylamide gel and phoresed. The gel was stained with silver staining.Three of 9 cases did not have polymorhic allele. Remaining 6 cases showed two bands on the gel so that were evaluated as polyclonal.