Expression of ATP-binding cassette superfamily G member 2 and β-tubulin-III in human breast carcinomas and clinical significance

Abstract

Objective To investigate the correlations of ATP-binding cassette superfamily G mem-ber 2 (ABCG2) and β-tubulin-Ⅲ (TUBB3)mRNA expressions with formation and development of breast carcinomas.Methods 196 cases of invasive breast cancer tissue specimens and specimens with normal breast tissue were collected.Reverse transcription-polymerase chain reaction (RT-PCR) was used to detect the expressions of ABCG2 and TUBB3 gene.The relationship between gene expression and clinicopatholog-ical features was analyzed.Results The ABCG2 gene expression rate in 196 samples of invasive breast cancer was 58.7％ and the electrophoretic bands grayscale was 0.685 ± 0.126,and those in adjacent normal breast tissue were 30.1％ and 0.271 ±0.143,respectively (P ＜0.05).The TUBB3 gene expression rate was 67.9％ and electrophoretic bands grayscale was 0.793 ± 0.115 in the samples of invasive breast cancer,and those in adjacent normal breast tissue were 23.0％ and 0.463 ± 0.127,respectively (P ＜0.05).ABCG2 gene expression in tumor tissue was correlated with estrogen receptor (ER) and progester-one receptor (PR) (P ＜ 0.05),but not with human epidermal growth factor receptor-2 (Her-2),clinical stage,vascular invasion,lymph node metastasis,tumor size and proliferation cell nuclear antigen (Ki-67)(P ＞0.05).The TUBB3 expression in tumor tissue was correlated with axillary lymph node metastasis,vascular invasion,tumor size,histological grade,clinical stage,Ki-67 and Her-2 (P ＜ 0.05),but not with ER and PR (P ＞ 0.05).Conclusion The abnormal expression of ABCG2 and TUBB3 genes may play important roles in drug resistance and development of breast cancer. Key words: Breast carcinomas ; Resistance gene ; ATP-binding cassette superfamily G member 2 ; Molecular typing