Increased Expression of Twist and Trkb in Breast Cancer and Their Clinical Significance

Objective: To study the expression of Twist and Trkb in human breast cancers,and to investigate the role of Twist and Trkb in breast cancer progression,metastasis,and prognosis.Methods: The MCF-7 human breast cancer cell line was cultured under mammosphere forming conditions and implanted into nude mice.RT-PCR technique was used to measure the expression of Twist and Trkb mRNA in the tissue samples from 14 nude mice and 86 human human breast tumors.Results: In the nude mice implanted with breast cancer cells,the level of the Twist and Trkb mRNA in the samples from metastasis tissues was higher than that of primary tissues(the relative OD value of Twist and Trkb mRNA was 2.1±0.2 vs 1.4±0.2,2.3±0.4 vs 1.5±0.3;t=2.4,2.8;P=0.03,0.02 respectively).In human tumor samples,the level of the Twist and Trkb mRNA of lymph node metastasis was higher than that of breast tissues(1.67±0.32 vs 0.83±0.23,1.58±0.41 vs 0.65±0.24 respectively;t=2.6,P=0.02;t=3.01,P=0.01).The level of the Twist and Trkb mRNA of breast cancers was higher than that of primary tissues(2.38±0.22 vs 1.84±0.43,2.17±0.41 vs 1.62±0.32 respectively;t=3.23,P=0.01;t=2.84,P=0.03).The expression of Twist and Trkb was significantly correlated with clinical stages,tumor lymph node metastasis and loss of differentiation(all P0.05).However,there was no correlation between Twist or Trkb mRNA levels and age or tumor size(all P0.05).Increased expression of Twist correlated with shorter overall survival([28.4±2.2] vs [32.7±2.4] months,LogRank=3.88,P=0.037),while no significant correlations were observed between increased expression of Trkb and shorter overall survival([29.9±2.6] vs [31.5±2.5] months,LogRank=2.46,P=0.08).Conclusion: Expression of Twist and Trkb associate with breast cancer infiltration and metastasis,and increased expression of Twist may implicate in breast cancer prognosis.