The Role of m6A in Osteoporosis and the Differentiation of Mesenchymal Stem Cells into Osteoblasts and Adipocytes.

Osteoporosis is a systemic disease in which bone mass decreases, leading to an increased risk of bone fragility and fracture. The occurrence of osteoporosis is believed to be related to the disruption of the differentiation of mesenchymal stem cells into osteoblasts and adipocytes. N6-adenylate methylation (m6A) modification is the most common type of chemical RNA modification and refers to a methylation modification formed by the nitrogen atom at position 6 of adenine (A), which is catalyzed by a methyltransferase. The main roles of m6A are the post-transcriptional level regulation of the stability, localization, transportation, splicing, and translation of RNA; these are key elements of various biological activities, including osteoporosis and the differentiation of mesenchymal stem cells into osteoblasts and adipocytes. The main focus of this review is the role of m6A in these two biological processes.

[Establishment of red fluorescent protein orthotopic transplantation nude mice metastasis model of pancreatic cancer and whole-body fluorescent imaging].

OBJECTIVE: To establish a stable high red fluorescent protein (RFP)-expressing orthotopic transplantation nude mice spontaneous metastasis model of pancreatic cancer. METHODS: Stable high RFP-expressing cells SW1990-RFP were injected subcutaneously into mice to establish subcutaneous implantation model. Fluorescent tumor piece from subcutaneous was transplanted into the body of the pancreas to establish surgical orthotopic implantation model. The growth of primary tumor, metastasis and micrometastasis were assessed by whole-body fluorescence imaging system. RESULTS: Twelve RFP orthotopic transplantation nude mice metastasis models of pancreatic cancer were established successfully, the percentage of success rate was 100%. RFP-labeled pancreatic cancer growth could be monitored in real time way. The micrometastasis of primary lesions were detected in early stage with whole-body fluorescence imaging system. CONCLUSIONS: The RFP orthotopic transplantation nude mice metastasis model of pancreatic cancer is stable and reliable, and can be observed dynamically in vitro in a noninvasive way, with much higher sensitivity and specificity.