The Expression Of Gene TSG101 And It's Splice Variants In Breast Cancer

Objective: To investigate the expression and mutation of tumour suppressor gene TSG101 and its 4 splice variants (V_A, V_B, V_C and V_D) in breast cancer in order to study the role of TSG101 in tumorigenesis and development of breast cancer.Methods: Total RNA of 24 surgical excised breast caner tissues was isolated. Full length of gene TSG101 and its splice variants V_A, V_B, V_C and V_D were tested by the assay of RT-PCR using 5 pairs of specific primers. Agarose electrophoresis was performed to identify the PCR products. Each product was directly sequenced with primers (covered 663bp~1276bp) and compared with the sequence of gene TSG101 issued in genebank. The products of the 4 splice variants were also verified by sequencing with the primers of PCR, respectively.Results: Full length and 4 splice variants of the gene TSG101 had been obtained by RT-PCR in all of the 24 breast cancer samples. Among them, the different expression was shown, with the most prominent difference in V_D, while lesser in V_A, V_B and full length TSG101, and least in V_C. Sequencing results showed that the sequence of 20 samples (20/24,83.3%) were 100% matching the sequence in genebank, while in other 4 samples (4/24,16.7%) a same "C→T" heterozygous point mutation, at 798bp of exon 4 of TSG101 mRNA, was detected.Conclusion: 1. The breast cancer expressed both of full length of gene TSG101 and its four splice vanriants (V_A, V_B, V_C and V_D ), but the differences of expression could be seen. It needs to further study on the relationship between these differences and the biological characters and behavior of breast cancer. 2. The "C→T" heterozygous point mutation locating at 798bp of gene TSG101 mRNA in breast cancer was firstly reported worldwidely. Our results might imply a new clue to the molecular genetic basis of oncogenesis of breast cancer.