Sutherlin M E, Nishimori I, Caffrey T, Bennett E P, Hassan H, Mandel U, Mack D, Iwamura T, Clausen H, Hollingsworth M A
Eppley Institute for Cancer and Allied Disease, University of Nebraska Medical Center, Omaha 68198-6805, USA.
Cancer Res. 1997 Nov 1;57(21):4744-8.
The levels of mRNA expression of three UDP-N-acetyl-alpha-D-galactosamine:polypeptide GalNAc N-acetylgalactosaminyltransferases (GalNAc-transferases) were quantified for human adenocarcinoma cell lines from pancreas, colon, stomach, and breast. Two of the GalNAc-transferases, GalNAc-T1 and GalNAc-T2, were expressed constitutively and at low levels in most or all cell lines examined. A third GalNAc-transferase, GalNAc-T3, was differentially expressed. Well-differentiated adenocarcinoma cell lines expressed high levels and moderately differentiated cell lines expressed lower levels of GalNAc-T3. Cell lines classified as poorly differentiated failed to express GalNAc-T3 mRNA at levels that could be detected by Northern blot analysis. Differential expression of the GalNAc-T3 protein was confirmed in these cell lines by Western blotting. We propose that glycosylation in tumor cell lines may be regulated in part by differential expression of GalNAc-transferases, and we suggest that GalNAc-T3 gene expression may be a molecular indicator of differentiated adenocarcinoma.
对来自胰腺、结肠、胃和乳腺的人腺癌细胞系，定量检测了三种UDP-N-乙酰-α-D-半乳糖胺：多肽N-乙酰半乳糖胺基转移酶（GalNAc-转移酶）的mRNA表达水平。在所检测的大多数或所有细胞系中，两种GalNAc-转移酶，即GalNAc-T1和GalNAc-T2，组成性表达且表达水平较低。第三种GalNAc-转移酶GalNAc-T3则呈差异表达。高分化腺癌细胞系表达高水平的GalNAc-T3，中等分化细胞系表达较低水平的GalNAc-T3。分类为低分化的细胞系未能表达通过Northern印迹分析可检测到水平的GalNAc-T3 mRNA。通过蛋白质印迹法在这些细胞系中证实了GalNAc-T3蛋白的差异表达。我们提出肿瘤细胞系中的糖基化可能部分受GalNAc-转移酶差异表达的调控，并且我们认为GalNAc-T3基因表达可能是分化型腺癌的分子指标。
