miR-325-3p, a novel regulator of osteoclastogenesis in osteolysis of colorectal cancer through targeting S100A4.

BACKGROUND: To investigate effect of microRNA-325-3p (miR-325-3p) on bone metastasis of colorectal cancer (CRC) and the precise role on osteoclastogenesis. METHODS: CT-26 cells were injected into tibias to establish bone metastatic model of CRC in vivo. AgomiR-325-3p or antagomir-325-3p were injected in tail-veins of Balb/c mice to interfere the osteoclastogenesis and bone metastasis of CRC. Safranin O and Fast Green staining examined the changes of trabecular area and TRAP staining examined the osteoclast number in bone metastasis of CRC. Real-time PCR was conducted to test the RNA level of miR-325-3p and mRNA levels of TRAP and Cathepsin K in osteoclast precursors (OCPs). Dual-luciferase reporter system was utilized to identify the direct target of miR-325-3p. Conditioned medium from CT-26 cells was collected to stimulate the OCPs during osteoclastogenesis induced by RANKL and M-CSF in vitro. Western blot analysis was performed to examine the protein level of S100A4 in OCPs after interfered by agomiR-325-3p or antagomir-325-3p cultured in CM or not. RESULTS: miR-325-3p downregulated in OCPs in CRC microenvironment both in vivo and in vitro. By luciferase activity assay, S100A4 was the target gene of miR-325-3p and the protein level of S100A4 in OCPs upregulated in CRC microenvironment. Overexpression of miR-325-3p inhibited the osteoclastogenesis of OCPs and it can be reversed after transfection with plasmid containing S100A4. Treatment with miR-325-3p can preserve trabecular area in bone metastasis of CRC. CONCLUSION: miR-325-3p can prevent osteoclast formation through targeting S100A4 in OCPs. Overexpression of miR-325-3p efficiently decreased the osteoclast number and attenuated bone resorption in bone metastasis of CRC.

Study on the Structure and Function of Repetition in Doctor-patient Outpatient Conversation Based on Corpus / 中国医学伦理学

This paper explored the methods of corpus linguistics application based on the corpus of doctor-pa-tient outpatient conversation, which was built by the project team members. Under the framework of the theory of conversation analysis, it discussed the inductive characteristics of subjective and functional repetition, and com-pared the similarities and differences of the repetition strategy use between patients and doctors. This study con-cludes a new OIR mode, enriching the theory of conversation analysis. The corresponding countermeasures of the repetition strategy use that put forward in this article provided a reference to strengthen the doctor-patient commu-nication, enhance the communication effect, and establish the interacted, cooperated and equal doctor-patient re-lationship. Meanwhile, it offered a new viewpoint to the study of doctor-patient communication.