BACKGROUND:It has been proved that miR-34a plays an inhibitory role in the growth of lung cancer stem cels, but the underlying mechanism remains unclear.
OBJECTIVE:To explore the inhibitory effect of miR-34a on lung cancer stem celsand the underlying mechanism.
METHODS:The CD133+lung cancer stem cels were separated from lung cancer A549 cel lines using magnetic activated cel sorting method. And miR-34a-overexpressing CD133+lung cancer stem cels were established by liposome transfection technology. Besides,the targeted relationship between miR-34a and Notch1 was analyzed by the dual-luciferase reporter. Afterwards, Notch1 silencing was performed by gene knockout, and its effect on lung cancer stem cels was determined.
RESULTS AND CONCLUSION:After sorted and detected by immunomagetic selection and flow cytometry assay respectively, a high rate of CD133+lung cancer stem cel was obtained. And qRT-PCR detected that the expression level of miR-34a in CD133+lung cancer stem cels was significantly lower than that in CD133-lung cancer stem cels. Moreover, miR-34a-overexpressing CD133+lung cancer stem cels were successfuly constructedandmiR-34a significantly inhibited proliferation and induced apoptosis of lung cancer stemcels. Dual-luciferase reporter assay indicated that Notch1 mRNA was a target of miR-34a. In addition, Notch1 silencing obviously inhibited proliferation and induced apoptosis of lung cancer stem cels. These findings suggest that miR-34a can inhibite lungcancer stem celsviathe Notch1 signaling pathway.

BACKGROUND:Cel cryopreservation is required for clinical use of stem cel s, and the current process of cryopreservation however may be harmful to cel viability, pluripotency and differentiation capacity.
OBJECTIVE:To explore the effect of fructose and dithiothreitol on pluripotency and osteogenesis of cryopreserved bone marrow mesenchymal stem cel s.
METHODS:Bone marrow mesenchymal stem cel s were isolated from the bone marrow of Sprague-Dawley rats and pretreated with fructose (200μmol/L), dithiothreitol (500μmol/L) or combined components before cryopreservation. Then the cel s were cryopreseved for 6 months and the morphology of cel s was observed by inverted microscopy. The cel viability was evaluated by MTT, and real-time PCR was used to detect the mRNA expression of Nanog, OCT4 and Sox2. Alkaline phophatase activity assay and alizarin red staining were utilized to detect the osteogenic capacity of bone marrow mesenchymal stem cel s.
RESULTS AND CONCLUSION:Images captured by inverted microscopy showed no significant difference in cel morphology between groups. The MTT results indicated that fructose and combined pretreatment could promote the cel viability of bone marrow mesenchymal stem cel s after cryopreservation, while the real-time PCR results demonstrated that dithiothreitol significantly facilitated the expression of Naogo and Sox2 in bone marrow mesenchymal stem cel s. Moreover, ALP activity assay and alizarin red staining confirmed the positive effects of fructose, dithiothreitol and combined pretreatment on osteogenic capacity of bone marrow mesenchymal stem cel s after cryopreservation, and the best effects were found after pretreatment with dithiothreitol and combined components. Overal , these findings indicate that fructose pretreatment is beneficial for cel viability of cryopreseved bone marrow mesenchymal stem cel s, and dithiothreitol contributes to maintaining the pluripotency and osteogenesis capacity of cryopreseved bone marrow mesenchymal stem cel s.

Bone marrow derived mesenchymal stem cell (BMSC) is one of the crucial cell types which plays roles in wound healing of tissues. In the last decades, it was believed that BMSCs promoted wound healing by differentiating into multiple lineages and placing the wounded tissues. In recent years, a new viewpoint arose from evidences that the paracrine effect of BMSCs might play a more important role in the process of wound healing than differentiation. Understanding the role of BMSCs paracrine in wound healing would be vital to clarify the mechanism how BMSCs take part into the process of wound healing. In this paper, we review the new research processes of BMSCs paracrine in wound healing of tissues.
Animals ; Bone Marrow Cells ; cytology ; physiology ; Cell Differentiation ; physiology ; Cells, Cultured ; Humans ; Mesenchymal Stromal Cells ; cytology ; physiology ; Paracrine Communication ; physiology ; Wound Healing ; physiology

Objective:To explore the application of microfluidic chip in detection of hereditary deafness-associated hotspot mutations.Methods:The dedicatedly designed and fabricated microfluidic chip was integrated with kompetitive allele-specific polymerase chain reaction amplification system, scanned via laser-excited confocal fluorescence scanner, and finally analyzed programmatically to acquire the typing results of the 23 mutation sites of the four common genes associated with hereditary hearing loss. Dried blood spots were collected from 276 neonates containing the 131 cases with hearing loss who were born in 2019 in Chengdu (deafness group) and the 145 cases with normal hearing who were born in 2020 in Chengdu (control group), and analyzed by the microfluidic chip to evaluate its clinical performance.Results:By cluster analysis, the microfluidic chip correctly analyzed the 23 positive reference samples and acquired the same typing results as their actual results, with a limit of detection of 1 mg/L. For the 276 newborn blood spots, the detection results of the microfluidic chips were confirmed to be correct by the contrasting methods. Among Deafness Group, 66 (50.4%) tested positive for the selected 23 mutation hotspots; among Control Group, 40(27.6%) were positive. Among these mutations, c.109G>A of the GJB2 gene was the most prevalent one, whose carrier rate in deafness group and control group were 46.6%(61/131) and 23.4% (34/145), respectively.Conclusions:The micro-fluidic chip system was succeeded in fulfilling the hereditary deafness-related mutation detection, and offered many advantages including high specificity, avoiding the amplicon carryover contamination, simplifying the entire experimental operation process and short detection time, so as to better meet the detection requirement of genetic testing for deafness in newborn screening and other fields.

OBJECTIVE:Percutaneous sacroiliac screw internal fixation has become the main surgical procedure for the treatment of posterior pelvic ring fractures;however,the unassisted closure operation requires high operator experience and repeated fluoroscopy increases the radiation hazard for patients and medical personnel.This article compares the clinical efficacy of robot-assisted versus unassisted percutaneous sacroiliac screw placement for posterior pelvic ring fractures by meta-analysis. METHODS:Computer searches of CNKI,WanFang,VIP,CBM,PubMed,Embase,Cochrane Library and ClinicalTrials.gov were conducted from the time of database inception to December 2022.The literature on the clinical efficacy of robot-assisted versus freehand percutaneous sacroiliac screw placement in the treatment of posterior pelvic ring fractures was collected in and outside China.The data were independently screened and extracted by two investigators according to the inclusion and exclusion criteria,respectively.The quality of randomized controlled trials was evaluated using Cochrane risk assessment criteria.The quality of included cohort studies was assessed using the Newcastle-Ottawa Scale.Meta-analysis was performed using RevMan 5.4 software for inclusion metrics.Outcome metrics included operative time,intraoperative bleeding,fluoroscopy time,fluoroscopy frequency,number of holes drilled,Majeed postoperative function score,the excellent and good rates of Matta fracture reduction,the excellent and good rates of Gras screw position,fracture healing time and complications. RESULTS:(1)A total of 13 publications were included,2 were randomized controlled trials both referring to randomized methods,11 non-randomized controlled studies were evaluated for quality of literature according to the Newcastle-Ottawa Scale,1 scored 8,9 scored 7;and 1 scored 6;the quality of literature was good.A total of 748 patients were included,including 430 in the robot-assisted group and 318 in the freehand group.(2)The results of the meta-analysis showed that the operative time(MD=-28.30,95%CI:-40.20 to-16.40),intraoperative bleeding(MD=-6.36,95%CI:-10.06 to-2.66),intraoperative fluoroscopy time(MD=-12.13,95%CI:-19.54 to-4.72),intraoperative fluoroscopy frequency(MD=-17.39,95%CI:-29.00 to-5.78),number of intraoperative needle drillings(SMD=-9.50,95%CI:-14.27 to-4.73)and the excellent and good rates of Gras screw position(OR=8.65,95%Cl:3.26-22.92)in the robot-assisted group were significantly better than those in the freehand group(P<0.05).(3)In the robot-assisted group,the overall postoperative complication rate was significantly reduced(OR=0.10,95%Cl:0.02-0.48,P<0.05).(4)No significant difference was detected in fracture healing time(MD=-0.08,95%CI:-0.21,0.06),the excellent and good rates of Matta fracture repositioning rate(OR=2.06,95%Cl:0.97-4.39),and Majeed functional score(MD=0.91,95%CI:-0.31-2.13)between both groups(P>0.05). CONCLUSION:Compared with freehand sacroiliac joint nailing,robotic assistance shortens the operative time,reduces intraoperative bleeding,decreases radiation damage to patients and medical staff,improves the excellent and good rate of screw position,and reduces the overall incidence of postoperative complications in patients,but there was no significant improvement in fracture reduction quality,fracture healing time,and postoperative function.In the future,more large-sample,multicenter,and high-quality randomized controlled trials are still needed to verify.