Department of Legal Medicine, Graduate School of Medicine, Gunma University, Maebashi, Japan.
Department of Innovative Cancer Immunotherapy, Graduate School of Medicine, Gunma University, Maebashi, Japan.
Clin Chim Acta. 2023 Jan 1;538:181-188. doi: 10.1016/j.cca.2022.11.006. Epub 2022 Nov 17.
The antigenic determinant of CA19-9 is synthesized by the α1,3/4fucosyltransferase encoded by the Le gene in the Lewis blood group system. Accordingly, a diagnosis with CA19-9 is not appropriate forLe-negative patients who possess the Le gene-mutated le alleles homozygously.
A Le gene-specific PCR was undertaken to determine c59T>G by using a set of tag-sense and biotin-labeled anti-sense primers and a peptide nucleic acid-le-clamp which bound to G59 in the le alleles. Following mixing with streptavidin-coatedbluelatex beads, the PCR products were developed on a strip on which the complementary tag oligonucleotide to theLe gene-specific amplicon was immobilized.
When the PCR products were developed on the strip, a clear line was rapidly observed in Le-positive but not in Le-negative individuals. In contrast, a significant number of cancer patients with Lewis-negative phenotype were found to possess CA19-9, while they were specifically genotyped asLe/-. No contradictory results were observed in cancer patients (n = 315) with respect to their Lewis genotypes and CA19-9 levels.
c59T>G occurred commonly in the le alleles could be specifically and rapidly identified by the present method. This method appeared to be relevant forselecting cancer patientsto bediagnosed with CA19-9.
CA19-9 的抗原决定簇由 Lewis 血型系统中 Le 基因编码的 α1,3/4 岩藻糖基转移酶合成。因此，对于具有 Le 基因突变等位基因纯合子的 Le 阴性患者，CA19-9 诊断并不合适。
采用一组标记 sense 和生物素标记 anti-sense 引物以及与 le 等位基因中 G59 结合的肽核酸-Le-夹，进行 Le 基因特异性 PCR，以确定 c59T>G。将 PCR 产物与链霉亲和素包被的蓝色乳胶珠混合后，在一条带有 Le 基因特异性扩增子互补标记寡核苷酸的条带上进行开发。
当 PCR 产物在条带上进行开发时，Le 阳性个体中迅速观察到清晰的线条，但 Le 阴性个体中则没有。相比之下，许多Lewis 阴性表型的癌症患者被发现具有 CA19-9，但它们被特异性地鉴定为 Le/ -。在具有 Lewis 基因型和 CA19-9 水平的癌症患者（n=315）中未观察到相反的结果。
本方法可特异性、快速地鉴定出 Le 等位基因中常见的 c59T>G。该方法似乎与选择癌症患者进行 CA19-9 诊断有关。
