Casticin Attenuates Stemness in Cervical Cancer Stem-Like Cells by Regulating Activity and Expression of DNMT1.

OBJECTIVE: To explore whether casticin (CAS) suppresses stemness in cancer stem-like cells (CSLCs) obtained from human cervical cancer (CCSLCs) and the underlying mechanism. METHODS: Spheres from HeLa and CaSki cells were used as CCSLCs. DNA methyltransferase 1 (DNMT1) activity and mRNA levels, self-renewal capability (Nanog and Sox2), and cancer stem cell markers (CD133 and CD44), were detected by a colorimetric DNMT activity/inhibition assay kit, quantitative real-time reverse transcription-polymerase chain reaction, sphere and colony formation assays, and immunoblot, respectively. Knockdown and overexpression of DNMT1 by transfection with shRNA and cDNA, respectively, were performed to explore the mechanism for action of CAS (0, 10, 30, and 100 nmol/L). RESULTS: DNMT1 activity was increased in CCSLCs compared with HeLa and CaSki cells (P<0.05). In addition, HeLa-derived CCSLCs transfected with DNMT1 shRNA showed reduced sphere and colony formation abilities, and lower CD133, CD44, Nanog and Sox2 protein expressions (P<0.05). Conversely, overexpression of DNMT1 in HeLa cells exhibited the oppositive effects. Furthermore, CAS significantly reduced DNMT1 activity and transcription levels as well as stemness in HeLa-derived CCSLCs (P<0.05). Interestingly, DNMT1 knockdown enhanced the inhibitory effect of CAS on stemness. As expected, DNMT1 overexpression reversed the inhibitory effect of CAS on stemness in HeLa cells. CONCLUSION: CAS effectively inhibits stemness in CCSLCs through suppression of DNMT1 activation, suggesting that CAS acts as a promising preventive and therapeutic candidate in cervical cancer.

The prognostic value of serum amyloid A in solid tumors: a meta-analysis.

BACKGROUND: Previous studies have demonstrated that serum amyloid A (SAA) levels are correlated with the clinical outcomes of solid tumors. However, the available data have not been systematically evaluated. The objective of the present meta-analysis was to explore the prognostic value of SAA levels in solid tumors. METHODS: Eligible studies were identified from the PubMed, EMBASE and Science Citation Index electronic databases. The clinical characteristics, disease/progression-free survival (DFS/PFS) and overall survival (OS) were extracted from the eligible studies. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with Stata 12.0 software. We also performed subgroup, meta-regression and sensitivity analyses. RESULTS: In total, 12 eligible studies including 2749 patients were enrolled in the present meta-analysis. The pooled HRs with 95% CIs showed that elevated levels of SAA were significantly associated with poor OS (HR = 3.01, 95% CI 1.96-4.63) and DFS/PFS (HR = 1.67, 95% CI 1.31-2.12) in patients with solid tumors. Although publication bias was seem found in the studies with regard to OS, a further trim and fill analysis revealed that the adjusted HR was 3.02 (95% CI 1.96-4.63), which was close to the original HR. Subgroup analysis confirmed an elevated level of SAA as a strong prognostic marker in patients with solid tumors, regardless of tumor type, detection method, cut-off value, sample size, area and variance analyses. CONCLUSION: Our meta-analysis indicated that elevated levels of SAA might be an unfavorable prognostic marker for OS in patients with solid tumors.

Silk structure and degradation.

To investigate the structure of silk and its degradation properties, we have monitored the structure of silk using scanning electron microscopy and frozen sections. Raw silk and degummed raw silk were immersed in four types of degradation solutions for 156 d to observe their degradation properties. The subcutaneous implants in rats were removed after 7, 14, 56, 84, 129, and 145 d for frozen sectioning and subsequent staining with hematoxylin and eosin (H.E.), DAPI, Beta-actin and Collagen I immunofluorescence staining. The in vitro weight loss ratio of raw silk and degummed raw silk in water, PBS, DMEM and DMEM containing 10% FBS (F-DMEM) were, respectively, 14%/11%, 12.5%/12.9%, 11.1%/14.3%, 8.8%/11.6%. Silk began to degrade after 7 d subcutaneous implantation and after 145 d non-degraded silk was still observed. These findings suggest the immunogenicity of fibroin and sericin had no essential difference. In the process of in vitro degradation of silk, the role of the enzyme is not significant. The in vivo degradation of silk is related to phagocytotic activity and fibroblasts may be involved in this process to secrete collagen. This study also shows the developing process of cocoons and raw silk.

[Mechanism of inhibitory effect of P7 on 3T3 cell proliferation induced by basic fibroblast growth factor].

To investigate the mechanism of inhibitory effect of a novel bFGF antagonist peptide isolated from the phage display random heptapeptide library on cell proliferation induced by basic fibroblast growth factor. The effect of P7 on cell morphology was observed under an inverted microscope. Flow cytometry was applied to analyze the effect of P7 on cell cycle progress of bFGF-stimulated cells. The effect of P7 on bFGF-induced activation of MEK and Erk1/2 in MAPK pathway was detected by Western blotting. The results showed that no significant cell morphology change was observed in the range of detected concentrations of P7. Cell cycle analysis showed that P7 decreased S-phase cell population and arrested cell cycle at the G0/G1 phase of bFGF-stimulated cells. The results of MAP kinase activation assay indicated that P7 decreased bFGF-induced MEK and Erk1/2 phosphorylation in a dose-dependent manner. P7 inhibited proliferation of bFGF-stimulated Balb/c 3T3 cells possibly via cell cycle arrest at the G0/G1 phase and down-regulation of signal molecular activation in MAPK pathway.

Characteristics of PLGA-gelatin complex as potential artificial nerve scaffold.

The segmentation lesion of peripheral nerve will seriously impair the motion and sensation of the patients, and the satisfactory recovery of segmented peripheral nerve by autograft or allograft is still a great challenge posing to the neurosurgery. Apart from autograft for nerve repair, different allograft has been studying. In this study, a scaffold fabricated with polylactic acid-co-glycolic acid (PLGA) copolymer and gelatin was evaluated to be a potential artificial nerve scaffold in vitro. The effect of different mass ratio between PLGA and gelatin upon the characteristics of PLGA-gelatin scaffolds such as microstructure, mechanical property, degradation behavior in PBS, cell adhesion property were investigated. The results showed the homogeneity and mechanical property of the scaffolds became poor with the increase of gelatin, and the rate of max water-uptake and the mass loss of scaffolds increases with the increase of gelatin, and the cells could adhere to the scaffolds. Those indicated the scaffolds fabricated by the PLGA-gelatin complex had excellent biocompatibility, suitable mechanical property and sustained-release characteristics, which would meet the requirements for artificial nerve scaffold.

[Effect of cell surface sialic acid and their linkages on adhesion of mammary carcinoma cells].

OBJECTIVE: To investigate the effect of cell surface sialic acid and its linkage on the cell-cell and cell-matrix adhesion of mammary carcinoma cells MD-MB-435. METHODS: MD-MB-435 cells were sense-transfected with ST6Gal I cDNA or antisense-transfected with part of the ST6Gal I sequence inserted in pcDNA 3.1 vector, with mock transfection with pcDNA3.1 vector as the control. The cell surface alpha2, 6-linked sialylation was determined by fluorescence-activated cell sorting (FACS) using lectin SNA (Sambucus nigra agglutinin specific to alpha2, 6-linked sialic acid on N-linked glycoprotein). A significantly increased alpha2, 6-sialylation subclone in sense-transfectants and a decreased alpha2, 6-sialylation subclone in antisense-transfectants were selected for further examination of cell-cell and cell-matrix (collagen IV) adhesion. The transfectants were also treated with sialidase to compare the capacity of cell adhesion affected by cell surface sialylation. RESULTS: Sense-transfection subclone showed a reduced cell-cell aggregation but enhanced cell-matrix adhesion. In contrast, the antisense-transfection subclone exhibited increased cell-cell aggregation and decreased cell-matrix adhesion. After treatment with sialidase, the cell-matrix adhesion of all the transfectants and the parental MDA-MB-435 cells were significantly reduced to the level of 31%-57% of untreated cells. CONCLUSION: Cell surface sialic acid and alpha2, 6-linked sialylation play an important role in cell-cell and cell-matrix adhesion of mammary carcinoma cell MDA-MB-435.