Effects of genistein on N-glycolylneuraminic acid content in rats and the interaction with sialyl transferase / 生物工程学报

To investigate the effects of genistein (Gen) on the biosynthesis of N-glycolylneuraminic acid (Neu5Gc) in rats, 80 4-week-old male SD rats were randomly equally into the control and genistein groups. The rats of control and genistein groups were fed 5% ethanol and 300 mg/(kg·d) genistein respectively by gavage. The contents of Neu5Gc in hind leg muscle, kidney and liver tissues of rats were measured by using high performance liquid chromatography coupled with fluorescence detector (HPLC/FLD), and the mechanism of inhibition of Neu5Gc synthesis was investigated by using the molecular docking of Gen and sialyltransferase. On the 15th day, the content of Neu5Gc in hind leg muscle and liver tissues decreased 13.77% and 15.45%, respectively, and there was no significant change in the content of Neu5Gc in kidney tissues. On the 30th day, the content of Neu5Gc in liver tissues decreased 13.35%, however, there was no significant change in the content of Neu5Gc in kidney tissues and Neu5Gc was not detected in hind leg muscle. The content of Neu5Gc in hind leg muscle, kidney and liver tissues decreased respectively 32.65%, 32.78%, 16.80% and 12.72%, 11.42%, 12.30% while rats fed on the 45th and the 60th days. Genistein has formed the hydrogen bond with sialyltransferase activity site residues His319, Ser151, Gly293, Thr328 and formed a hydrophobic interactions with the residues His302, His301, Trp300, Ser271, Phe292, Thr328, Ser325 and Ile274. The results of molecular docking indicated that the weak intermolecular interaction was the main cause of genistein inhibiting sialyltransferase activity. The research results provided an experimental basis for the subsequent reduction of Neu5Gc in red meat before slaughter.

Relationship between p16, p27 proteins and clinicopathological characteristics of breast cancer and their prognostic value / 肿瘤研究与临床

Objective To study the relationship between p16,p27 proteins and clinicopathological characteristics of breast cancer and their prognostic value.Methods p16 protein and p27 protein were detected by two step immunohistochemical method in 93 tissues of breast cancer.Results The positive rates of p16 protein and p27 protein were 46.2 ％ (43/93) and 54.8 ％ (51/93).The positive rate of p16 protein in different tumor location (left/right),the maximal diameter and histological type had no statistically significant difference (all P ＞ 0.05),but in the different age groups and axillary lymph node metastasis,the differences were statistically significant (both P ＜ 0.05).The positive rate of p27 protein in different age groups,tumor location (left/right) and the maximal diameter had no significant difference (all P ＞ 0.05),but was correlated with the infiltration and axillary lymph node metastasis (both P ＜ 0.05).Conclusions The negative expression of p16 and p27 is significantly related with the biological behaviors of breast cancer.Detection of both p16 protein and p27 protein may play an important role in predicting the prognosis of breast cancer.