Bone marrow mesenchymal stem cells(BMSCs) are a kind of non-hematopoietic cells living among bone marrow stroma,and are able to differentiate into mesoderm-type cells and non-mesoderm type cells.At present,there are three main methods for isolating and purifying BMSCs:bone marrow adherent culture,density gradient centrifugation and immune selection.This review listed many kinds of cells that BMSCs can differentiate into under certain conditions,discussed the related different directing conditions reported by researchers,analyzed the principle behind the artificial controlling conditions,and tried to find relatively uniform and effective directing conditions.The cells that BMSCs can differentiate into various types of cells including mesoderm-type cells,and non-mesoderm type cells:osteocytes,chondrocytes,adiocytes.As seed cells and a source of cell therapy in tissue engineering,BMSCs have been widely used in studying stem cells.

OBJECTIVETo observe the osteoclast differentiation of Raw264.7 strain stably expressing enhanced green fluorescent protein (EGFP).

METHODSRaw264.7 cells were transfected with EGFP-Lifeact gene via retrovirus. The G3 cell clone was obtained by limited dilution technique which stably expressed EGFP under the fluorescence microscope. The morphology of G3 cells were observed. The effects of transfection on receptor activator of nuclear factor kappaB ligand (RANKL)--induced osteoclastogenesis and bone resorbing function of G3 cells were examined by tartrate resistant acid phosphatase (TRAP) staining, immunoblotting detection of cathepsin K and bone pit resorption assay. The real-time images of podosome dynamics were taken by laser confocal microscopy during osteoclast differentiation of G3 cells.

RESULTSThe Raw264.7 cells were successfully transfected with EGFP-Lifeact gene. The G3-EGFP cloned strain which could stably express EGFP even after 20 passages was constructed. There was no significant difference in morphology between G3-EGFP and wild Raw264.7 cells. The fusion rates of the transfection group and of the wild control group were (35±5)% and (39±5)%, respectively, which were not significantly different (P>0.05). The semi-quantitative ratio of cathepsin K/β-actin in the wild control group and in the transfection group was 0.83±0.07 and 1.02±0.08 (P>0.05), respectively. Bone pit results showed that the total area of the bone resorption was respectively 272,252±36,193 and 262,408±23,243 (P>0.05) and the number of the bone pits was respectively 320±51 and 339±55 (P>0.05). The photos of laser confocal microscopy showed the constant cell-cell fusion during osteoclast differentiation of G3-EGFP cells. In addition, the dynamic self-organized podosome initially assembled podosome clusts, then dynamic rings, finally formed the characteristic podosome belt pattern in mature osteoclasts.

CONCLUSIONSEnhanced green fluorescent protein high effectively expressed in Raw264.7. Biological character does not change after transfection.

Acid Phosphatase ; Actins ; metabolism ; Bone Resorption ; physiopathology ; Cathepsin K ; metabolism ; Cell Differentiation ; Cell Line ; Gene Expression ; Green Fluorescent Proteins ; metabolism ; Humans ; In Vitro Techniques ; Isoenzymes ; Osteoclasts ; cytology ; metabolism ; RANK Ligand ; metabolism ; Receptor Activator of Nuclear Factor-kappa B ; Tartrate-Resistant Acid Phosphatase ; Transfection ; methods

Purpose: Previous report from the ASCEND-8 trial showed consistent efficacy with less gastrointestinal (GI) toxicity in patients with anaplastic lymphoma kinase-rearranged (ALK+) advanced/metastatic non–small cell lung cancer (NSCLC) treated with ceritinib 450-mg with food compared with 750-mg fasted. In this subgroup analysis, we report outcomes in Asian patients of the ASCEND-8 trial. Materials and Methods: Key efficacy endpoints were blinded independent review committee (BIRC)–assessed overall response rate (ORR) and duration of response (DOR) evaluated per Response Evaluation Criteria in Solid Tumors v1.1. Other efficacy endpoints were investigator-assessed ORR and DOR; BIRC- and investigator-assessed progression-free survival (PFS) and disease control rate; overall survival (OS). Safety was evaluated by frequency and severity of adverse events. Results: At final data cutoff (6 March 2020), 198 treatment-naïve patients were included in efficacy analysis, of which 74 (37%) comprised the Asian subset; 450-mg fed (n=29), 600-mg fed (n=19), and 750-mg fasted (n=26). Baseline characteristics were mostly comparable across study arms. At baseline, more patients in 450-mg fed arm (44.8%) had brain metastases than in 750-mg fasted arm (26.9%). Per BIRC, patients in the 450-mg fed arm had a numerically higher ORR, 24-month DOR rate and 24-month PFS rate than the 750-mg fasted arm. The 36-month OS rate was 93.1% in 450-mg fed arm and 70.9% in 750-mg fasted arm. Any-grade GI toxicity occurred in 82.8% and 96.2% of patients in the 450-mg fed and 750-mg fasted arms, respectively. Conclusion Asian patients with ALK+ advanced/metastatic NSCLC treated with ceritinib 450-mg fed showed numerically higher efficacy and lower GI toxicity than 750-mg fasted patients.