Objective:To explore the effect of miR-181a on chondrosarcoma cell growth through phosphatase and tensin homolog(PTEN) and its possible regulatory mechanism.Methods:From January to December 2022, 10 fresh chondrosarcoma and 10 chondroma tissues from orthopedic patients of Hunan Provincial People′s Hospital were collected, and the expression of miR-181a in chondrosarcoma and chondroma tissues was detected using real-time fluorescence quantitative polymerase chain reaction (qRT-PCR); Chondrosarcoma cell SW1353 was cultured in vitro and transfected with miR-181a inhibitor (miR-181a inhibition group) and control (miR-NC, control group), respectively. The effects of miR-181a on the growth and proliferation of SW1353 cells were detected by cell counting kit (CCK-8) and clone formation test, respectively; The binding sites between miR-181a and PTEN were predicted through the Target Scan database, and verified using dual luciferase reporter gene experiments; The mimetic miR-181a (miR-181a group) and its control (miR-NC, control group) were transfected into chondrosarcoma cell SW1353, respectively. The adenosine triphosphate (ATP) content, glucose consumption, and lactic acid production in the cells were measured, and the effect of miR-181a on glycolysis of SW1353 cells was analyzed. Results:The expression of miR-181a in chondrosarcoma tissues was significantly higher than that in chondroma tissues ( P<0.05). The cell growth and clonogenesis ability of miR-181a inhibition group were significantly lower than those of control group (all P<0.05). It was predicted by Target Scan online website that there might be binding sites between miR-181a and PTEN, and co-transfection of wild-type PTEN and miR-181a could significantly reduce luciferase activity by double luciferase reporter assay ( P<0.05). The ATP content, glucose consumption and lactic acid production of miR-181a group were significantly higher than those of miR-NC group (all P<0.05). Conclusions:MiR-181a promotes the growth of chondrosarcoma cells through PTEN-mediated glycolysis.

AIM: To explore the effect of endoplasmic reticulum stress on cardiac myocyte apoptosis in mouse congestive heart failure induced by myocardial infraction.METHODS: The mouse model of heart failure was established by ligating the left anterior descending coronary to produce acute myocardial infarction.Thirty-two mice were divided into 4 groups: sham group and groups of post-operation at time points of 2,4 or 6 weeks,respectively.The ventricular dilatation and left ventricular functions were assessed by echocardiography.The expression of GRP78,CHOP,caspase-12,cleaved caspase-12,JNK and phosphorylated-JNK was detected by Western blotting.The cardiac myocyte apoptosis was determined by terminal deoxynucleotidyl transferase mediated dUTP-biotin nick end labeling(TUNEL).RESULTS: The cardiac expression of endoplasmic reticulum chaperones GRP78 was significantly increased in the hearts with functional failure.The upregulated expression of CHOP,phosphorylated-JNK and cleaved caspase-12 illuminated that the CHOP-JNK-caspase-12 dependent pathways for endoplasmic reticulum-initiated apoptosis were activated in the heart with functional failure by myocardial infraction.CONCLUSION: These findings suggest that the congestive heart failure induced by myocardial infraction is associated with endoplasmic reticulum stress and activation of CHOP,JNK,caspase-12 dependent pathways for endoplasmic reticulum-initiated apoptosis.

AIM: To investigate the changes of intracellular calcium ion (Ca2+) concentration in mouse H9c2 (2-1) cells transfected with or without FK506 binding protein 12.6(FKBP12.6) gene by ultrasound mediated destruction of microbubbles. METHODS: The pcDNA3.1-FKBP12.6 plasmid, mingled with albumin-coated microbubbles agents, was transfected into H9c2 (2-1) cells by ultrasound-mediated destruction of microbubbles. The H9c2 (2-1) cell growth state was investigated by inverted microscope. The changes of intracellular Ca2+ concentration was determined by laser scanning confocal microscope. The FKBP12.6 protein expression was checked by immunohistochemistry. RESULTS: As compared with control cells, the H9c2 (2-1) cells, transfected with FKBP12.6 gene, grew better, had higher gross intracellular Ca2+ concentration. CONCLUSION: FKBP12.6 gene augments Ca2+ concentration in mouse H9c2 (2-1) cells, enhances the contractibility of the myocardial cell, which may be helpful to improve the myocardial dysfunction.