Development of the diagnostic method to evaluate the risks for carcinogenesis, micro-metastasis, and malignant grade of oral cancer using in-house cDNA microarray

我们的cDNA微阵列系统，它携带的cDNA来源于人口腔癌细胞系的寡聚帽cDNA文库，确定了几个差异表达的基因在舌鳞状细胞癌（SCC）。与正常组织相比，在4例独立病例的舌鳞癌标本中，有几个基因共同上调2倍或更高。半定量RT-PCR分析证实了这些cDNA微阵列的结果。上调基因为C20 orf 21（AK 000398）、白细胞介素1 β（X56087）、Centaurin γ 2（AB 029022）、腺苷酸环化酶相关蛋白（M98474）、Rh C型糖蛋白（AF 081497）、精胺合成酶（AD 001528）、Copine 1（U83246）、KIAA 0251（AK 025504）、Clorf 10和Rab 1a。最大的差异表达基因Rab 1a属于Ras癌基因家族成员，并对其在原发性舌鳞状细胞癌或白斑、癌前病变和相应的正常舌上皮组织中的蛋白表达进行了化学染色研究。免疫组化结果显示Rab 1a在舌鳞癌和白斑组织中的表达明显高于正常口腔黏膜组织。这些结果表明，Rab 1a是一个很好的肿瘤生物标志物的候选人，以评估致癌，微转移和恶性程度的风险。

Our in-house cDNA microarray system, which carries cDNAs derived from oligo-capped cDNA library of human oral cavity cancer cell lines, identified several differentially expressed genes in tongue squamous cell carcinoma (SCC). Several genes were up-regulated 2-fold or higher in common among four tongue SCC specimens of independent cases, compared with normal tissues. Semiquantitative RT-PCR analysis confirmed these cDNA microarray findings. The up-regulated genes were C20orf21(AK000398), Interleukin 1 β (X56087), Centaurin gamma 2(AB029022), Adenylyl cyclase-associated protein (M98474), Rh type C glycoprotein (AF081497), Spermine syntase (AD001528), Copine 1 (U83246), KIAA0251 (AK025504), Clorf10, and Rab1a. The most differentially expressed gene, Rab1a, belongs to the member of the Ras oncogene family and was immunohistochemically studied for its protein expression in primary tongue SCC or leukoplakia, precancerous lesion, and corresponding normal tongue epithelium tissues. Immunohistochemical staining showed that Rab1a was differentially over-expressed in tongue SCC and leukoplakia tissues compared with normal oral epithelium ones. These results suggested that Rab1a is a candidate for an excellent tumor biomarker to evaluate the risks for carcinogenesis, micrometastasis, and malignant grade.