Effects of mutation in Cosmc non-coding region on the transcription level of Cosmc mRNA in Tn antigen positive tumor cells

Abstract

Objective To explore the mutation in corel β3-galactosyl-transferase specific molecular chaperone(Cosmc、no-coding region and it's effects on the transcription level of Cosmc in Tn antigen positive tumor cells.Methods The Tn antigen positive(Tn+)and negative(Tn-)cells were separated from tumor tissues by immune magnetic bead,then the genomic DNA(gDNA),total RNA were prepared by Qiagen AllPrep DNA/RNA mini kit. In these cells.the transcription levels of T-synthase and Cosmc mRNA were tested by RT-PCR.the DNA of Cosmc non-coding region was amplified by PCR,the mutation in Cosmc non-coding region were further detected by sequencing.Results There are no mutation appearing in Tn-cells,one or more mosaic sequence allele appearing in portion of patient's Tn-cells.Almost of the Tn+cells which separated from tumor tissues and Jurkat T cell exists mutation.but the mutation style and mutation point were not saine in different tumor.Thtee patient's Tn+cells have loss of hetemzygosity(LOH),four patient's Tn+cells and Jurkat T cell have point mutation.Although no difference of transcription level of T-synthase mRNA in Tn+ and Tn-cells.but the transcription level of Cosmc mRNA in Tn+ cell was much lower than that in Tn-cell.The ratio of T-synthase/Cosmc mRNA in Tn+ tumor cells was hiigher than that in Tn-cell.Conclusion The tumor Tn antigen arise from mutation in Cosmc non-coding region maybe result from transcription level decreased of Cosmc mRNA. Key words: Tumor; Tn antigen; Cosmc; Mutation; Loss of heterozygosity(LOH)