To our knowledge, this is the first study to examine the relationship between guanine nucleotide binding protein β-1 (GNB1) mRNA expression and clinicopathological parameters. Furthermore, the correlations between GNB1, Rictor and the mammalian target of rapamycin (mTOR) were also investigated.
Materials and methods: Breast cancer tissues (n=136) and normal tissues (n=31) underwent reverse transcription and quantitative polymerase chain reaction. Transcript levels were correlated with clinicopathological data.
Results: Higher mRNA transcript levels of GNB1 were found in the breast cancer specimens in paired samples (p=0.0029). The mRNA expression of GNB1 increased with TNM stage (TNM1 vs. TNM2/3/4, p=0.036), tumour grade (grade 2 vs. 3, p=0.006), in ductal tumours (p=0.0081), and was associated with adverse patient outcomes (mortality vs. disease-free survival: 4.9 vs. 0.01, p=0.027). GNB1 was positively-correlated with mTOR (r=0.525, p<0.000001) and Rictor (r=0.388, p=0.0000606).
Conclusion: These observations may suggest that GNB1 plays an important role in the mTOR-related anti-apoptosis pathway and can potentially be targeted in the treatment of human breast cancer.