Objective To establish and identify the induced pluripotent stem cell(iPSC) line reprogrammed from human umbilical cord mesenchymal cells(HuMSCs).Methods HuMSCs were cultured by adhesion method,and OCT4,SOX2,KLF4,c-Myc,NANOG,LIN-28 were transfected into HuMSCs with lentiviral victor to reprogramme HuMSCs into iPSC.Morphological observation,pluripotency genes (SOX2,TDGF1,THY-1,OCT4,REX1 and TERF1) expression,alkaline phosphatase detection,karyotype analysis,embryonic stem cells (ESC) specific proteins (NANOG,OCT4,SSEA-4,TRA-1-81) immunofluorescence staining,differentiated into teratomas in vivo(inject the iPSC into SCID mice) and embryniod bodies in vitro were performed to exam the pluripotency of the iPSC.Results Four days after being infected by lentivirus,the HuMSCs became round-shape; 10 days after infection,some embryonic stem(ESC)-like colonies appeared.Fourteen days after infection,picked up the regularly shaped colonies and cultured several passages.About 1.25％ HuMSCs were reprogrammed into iPSC.The iPSC presented clone-like growth like ESC.All the cells were positive to alkaline phosphatase staining and expressed the pluripotency genes.The iPSC also expressed the ESC specific proteins,and karyotype analysis showed normal chromosome caryotype (46,XY).Furthermore,the iPSC could form embryoid bodies in vitro,expressed alpha fetoprotein(AFP),smooth muscle actin(SMA) and β-tubulin.The iPSC could alsoform teratomas in vivo.Conclusion OCT4,SOX2,KLF4,c-Myc,NANOG,LIN-28 can reprogram HuMSCs into iPSC efficiently.

Objective To investigate the effect and mechanism of oxymatrine on invasion and metastasis of human pancreatic cancer line SW1990 in vitro. Methods Human pancreatic cancer cell line SW1990 was cultured in vitro. Oxymatrine was added into the culture media of SW1990 cells. Then MTT assay was used to determine the effect on proliferation. The adhesive capability, the mobile ability and invasive ability of SW1990 cells were detected by the adhesion assay, the crossing-river test, the transwell migration assay and the matrigel invasion method, respectively. RT-PCR was used to detect the mRNA expression of MMP-2 and VEGF. ELISA method was used to detect the protein levels of the VEGF. Results The growth of SW1990 cells was inhibited by oxymatrine in a dose and time-dependent manner. After 2 mg/ml of oxymatrine treatment for SW1990 cells for 1 h, the adhesive capability inhibitory rate was (35.23 ±8.56) % ; 24 h later, crossing-river time was (65.46 ±4.25) h, which was significantly longer than that in control group [ (34.50 ± 4.12) h, P <0.05)], the number of penetrating cells was 91.9 ±9.6, which was significantly lower than that in control group (144.2±17.2, P <0.05). The mRNA expression of MMP-2 and VEGF, expression of protein of VEGF in SW1990 cells was significantly down-regulated [0.515 ±0.063 vs. 0.817 ±0.054, 0.343 ± 0.072 vs. 0.650 ±0.068; (265.50 ±5.45) pg/ml vs. (441.06 ±16.70) pg/ml, P <0.05]. Conclusions Oxymoron can inhibit the invasion and metastasis ability of pancreatic cancer line SW1990 in vitro, and the mechanism is possibly related to the down-regulation of MMP-2 and VEGF expression.

BACKGROUND:Human umbilical cord mesenchymal stem cells (hUC-MSCs) may be mutated duringin vitro culture based on the spontaneous malignant transformation of adult stem cells and tumor stem cell theory, and there may be a risk of tumorigenesis after in vivo transplantation. Therefore, to establish and perfect the in vitro safety testing procedures will actively promote the clinical application of stem cells. OBJECTIVE:To investigate the tumorigenic mechanism of hUC-MSCs and the expression level of DNA methyltransferase (DNMTs) in hUC-MSCs. METHODS:Primary hUC-MSCs were isolated and expanded by tissue adherent culture. 3-Methycholanthrene was used to cause the malignant transformation in hUC-MSCs (experimental group), followed by morphological observation and tumorigenesis experiment in nude mice. Then, the tumor tissues were obtained and identified by pathological examination and primary cell culture, and the levels of DNMTs mRNA in hUC-MSCs treated with 3-methycholanthrene and dimethyl sulfoxide (control group) were detected by real-time RT-PCR and compared. RESULTS AND CONCLUSION:hUC-MSCs treated with 3-methycholanthrene led to malignant transformation, which showed malignant growth and non-integer ploidy changes in the cell nuclei, and formed a malignant tumor in immune-deficient mice after injection. Compared with the control group, the cells in the experimental group showed higher expression of DNMTs mRNA as detected by real-time RT-PCR. To conclude, hUC-MSCs can trigger malignant transformation in the morphology and the epigenetics under certain conditions. DNMTs can be a candidate for prevention against malignant transformation of transplanted stem cells.

ted in a loss of cell fusion,which suggests the 928 site on G2 is crucial for cell fusion and the fusion peptide is likely on G2.

Objective:To investigate the risk factors for organoid culture failure in colorectal cancer.Methods:This was a retrospective observational study. Tumor specimens were obtained from 1130 patients with colorectal cancer who had undergone surgery or biopsy and had no other concurrent malignancies at Nanfang Hospital of Southern Medical University from December 2021 to November 2022. Organoid culture was performed on 1231 tumor tissue samples. Univariate analysis and multivariate logistic regression were used to analyze the factors that might have influenced the rate of successful organoid culture of colorectal cancer tissue samples.Results:The median (range) duration of organoid culture was 7 (3–12) days. The overall rate of successful culture was 76.3% (939/1231). The rate of successful organoid cultures varied according to the sampling site, malignant ascites having the highest success rate (96.4%, 27/28), followed by liver metastases (83.1%, 54/65), lung metastases (8/10), primary tumors (76.0%, 816/1074), omental metastases (10/14), peritoneal metastases (61.5%, 16/26), ovarian metastases (3/5), and lymph node metastases (5/9). The difference in rates of successful organoid culture between primary tumors and malignant ascites was statistically significant ( P=0.012), whereas none of the other rates of successful organoid culture success differed significantly (all P>0.05). The rate of successful organoid culture was 96.4% (27/28) for malignant ascites obtained by abdominal puncture, 76.5% (864/1130) for surgical specimens, and 65.8% (48/73) for endoscopic biopsies; these differences are statistically significant (χ 2=10.773, P=0.005). The rate of successful organoid culture was 62.5% (40/64) in the neoadjuvant chemoradiotherapy group, which is significantly lower than in the non-adjuvant (76.9%, 787/1023) and chemotherapy groups (77.8%, 112/144) (χ 2=7.134, P=0.028). Multivariate logistic regression analysis revealed that endoscopic biopsy (OR=0.557, 95%CI: 0.335–0.924, P=0.024) and neoadjuvant chemoradiotherapy (OR=0.483, 95%CI: 0.285–0.820, P=0.007) were independent risk factors for failure of organoid culture of colorectal cancer samples. Malignant ascites (OR=8.537, 95%CI:1.154–63.131, P=0.036) and abdominal puncture (OR=8.294, 95% CI: 1.112–61.882, P=0.039) were identified as independent protective factors. Conclusions:The rate of successful organoid culture was influenced by the sampling site, sampling method, and chemoradiotherapy. The rate of successful organoid culture was lower for endoscopic biopsies and in patients receiving preoperative neoadjuvant chemoradiotherapy, and higher for malignant ascites. We consider that culture of malignant ascites is preferable when peritoneal metastases are suspected.

Objective:To investigate the risk factors for organoid culture failure in colorectal cancer.Methods:This was a retrospective observational study. Tumor specimens were obtained from 1130 patients with colorectal cancer who had undergone surgery or biopsy and had no other concurrent malignancies at Nanfang Hospital of Southern Medical University from December 2021 to November 2022. Organoid culture was performed on 1231 tumor tissue samples. Univariate analysis and multivariate logistic regression were used to analyze the factors that might have influenced the rate of successful organoid culture of colorectal cancer tissue samples.Results:The median (range) duration of organoid culture was 7 (3–12) days. The overall rate of successful culture was 76.3% (939/1231). The rate of successful organoid cultures varied according to the sampling site, malignant ascites having the highest success rate (96.4%, 27/28), followed by liver metastases (83.1%, 54/65), lung metastases (8/10), primary tumors (76.0%, 816/1074), omental metastases (10/14), peritoneal metastases (61.5%, 16/26), ovarian metastases (3/5), and lymph node metastases (5/9). The difference in rates of successful organoid culture between primary tumors and malignant ascites was statistically significant ( P=0.012), whereas none of the other rates of successful organoid culture success differed significantly (all P>0.05). The rate of successful organoid culture was 96.4% (27/28) for malignant ascites obtained by abdominal puncture, 76.5% (864/1130) for surgical specimens, and 65.8% (48/73) for endoscopic biopsies; these differences are statistically significant (χ 2=10.773, P=0.005). The rate of successful organoid culture was 62.5% (40/64) in the neoadjuvant chemoradiotherapy group, which is significantly lower than in the non-adjuvant (76.9%, 787/1023) and chemotherapy groups (77.8%, 112/144) (χ 2=7.134, P=0.028). Multivariate logistic regression analysis revealed that endoscopic biopsy (OR=0.557, 95%CI: 0.335–0.924, P=0.024) and neoadjuvant chemoradiotherapy (OR=0.483, 95%CI: 0.285–0.820, P=0.007) were independent risk factors for failure of organoid culture of colorectal cancer samples. Malignant ascites (OR=8.537, 95%CI:1.154–63.131, P=0.036) and abdominal puncture (OR=8.294, 95% CI: 1.112–61.882, P=0.039) were identified as independent protective factors. Conclusions:The rate of successful organoid culture was influenced by the sampling site, sampling method, and chemoradiotherapy. The rate of successful organoid culture was lower for endoscopic biopsies and in patients receiving preoperative neoadjuvant chemoradiotherapy, and higher for malignant ascites. We consider that culture of malignant ascites is preferable when peritoneal metastases are suspected.

Posterior tibial slope (PTS) is used to describe the sagittal alignment of the tibial plateau of the knee. As its values indicate the steepness or gentleness of the tibial platform, it is an important basis for knee surgery, such as total knee replacement (TKA), anterior cruciate ligament/posterior cruciate ligament reconstruction (RACL/RPCL) and tibia high-level osteotomy (HTO), and affects the indication and efficacy of knee surgery. Since there has been no consensus description of PTS at present in clinical practice in China, this paper intends to discuss PTS from perspectives of epidemiology, measurement, its influence on knee joint activity, relationship between subchondral bone and knee ligament, and its significance in various knee joint operations. This review hopes to contribute to the knee surgery after the surgeons have a comprehensive understanding of the clinical significance and applications of PTS.