Analysis of transcriptome sequencing of sciatic nerves in Sprague-Dawley rats of different ages.

An aging-induced decrease in Schwann cell viability can affect regeneration following peripheral nerve injury in mammals. It is therefore necessary to investigate possible age-related changes in gene expression that may affect the biological function of peripheral nerves. Ten 1-week-old and ten 12-month-old healthy male Sprague-Dawley rats were divided into young (1 week old) and adult (12 months old) groups according to their ages. mRNA expression in the sciatic nerve was compared between young and adult rats using next-generation sequencing (NGS) and bioinformatics (n = 4/group). The 18 groups of differentially expressed mRNA (DEmRNAs) were also tested by quantitative reverse transcription polymerase chain reaction (n = 6/group). Results revealed that (1) compared with young rats, adult rats had 3608 groups of DEmRNAs. Of these, 2684 were groups of upregulated genes, and 924 were groups of downregulated genes. Their functions mainly involved cell viability, proliferation, differentiation, regeneration, and myelination. (2) The gene with the most obvious increase of all DEmRNAs in adult rats was Thrsp (log2FC = 9.01, P < 0.05), and the gene with the most obvious reduction was Col2a1 (log2FC = -8.89, P < 0.05). (3) Gene Ontology analysis showed that DEmRNAs were mainly concentrated in oligosaccharide binding, nucleotide-binding oligomerization domain containing one signaling pathway, and peptide-transporting ATPase activity. (4) Analysis using the Kyoto Encyclopedia of Genes and Genomes showed that, with increased age, DEmRNAs were mainly enriched in steroid biosynthesis, Staphylococcus aureus infection, and graft-versus-host disease. (5) Spearman's correlation coefficient method for evaluating NGS accuracy showed that the NGS results and quantitative reverse transcription polymerase chain reaction results were positively correlated (rs = 0.74, P < 0.05). These findings confirm a difference in sciatic nerve gene expression between adult and young rats, suggesting that, in peripheral nerves, cells and the microenvironment change with age, thus influencing the function and repair of peripheral nerves.

Downregulated miR-495 [Corrected] Inhibits the G1-S Phase Transition by Targeting Bmi-1 in Breast Cancer.

Bmi-1 (B cell-specific Moloney murine leukemia virus integration site 1) is upregulated in breast cancer and was involved in many malignant progressions of breast cells, including cell proliferation, stem cell pluripotency, and cancer initiation. However, the epigenetic regulatory mechanism of Bmi-1 in breast cancer remains unclear. After analysis of the ArrayExpress dataset GSE45666, we comparatively detected the expression levels of miR-495 in 9 examined breast cancer cell lines, normal breast epithelial cells and 8 pairs of fresh clinical tumor samples. Furthermore, to evaluate the effect of miR-495 on the progression of breast cancer, MCF-7 and MDA-MB-231 were transduced to stably overexpress miR-495. The 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyl-2-H-tetrazolium bromide assay, colony formation assays, 5-Bromo-2-deoxyUridine labeling and immunofluorescence, anchorage-independent growth ability assay, flow cytometry analysis, and luciferase assays were used to test the effect of miR-495 in MCF-7 and MDA-MB-231 cells in vitro. Xenografted tumor model was also used to evaluate the effect of miR-495 in breast cancer. Herein, we found that miR-495, a predicted regulator of Bmi-1, was frequently downregulated in malignant cells and tissues of breast. Upregulation of miR-495 significantly suppressed breast cancer cell proliferation and tumorigenicity via G1-S arrest. Further analysis revealed that miR-495 targeted Bmi-1 through its 3' untranslated region. Moreover, Bmi-1 could neutralize the suppressive effect of miR-495 on cell proliferation and tumorigenicity of breast cancer in vivo. These data suggested that miR-495 could inhibit the G1-S phase transition that leads to proliferation and tumorigenicity inhibition by targeting and suppressing Bmi-1 in breast cancer.

Stable transfection of estrogen receptor-alpha suppresses expression of cyclooxygenase-2 and vascular endothelial growth factor-C in MDA-MB-231 breast cancer cells.

BACKGROUND: Estrogen receptor (ER)-negative breast cancer cells are more aggressive than ER-positive cells. Elevated levels of cyclooxygenase-2 (COX-2) and vascular endothelial growth factor-C (VEGF-C) expression have been detected in cultured human breast cancer cells and are associated with negative hormone receptor status. In this study, we created ERalpha stable transfectants in MDA-MB-231 cells to explore the effect of ERalpha on cell growth and COX-2 and VEGF-C expression. METHODS: The green fluorescent protein (GFP)-ERalpha plasmids were stably transfected into ER-negative MDA-MB-231 cells. The proliferation and migration of untransfected MDA-MB-231 cells, ERalpha-transfected MDA-MB-231 cells and ER-positive MCF-7 cells were determined. The expression of COX-2, and the levels of VEGF-C mRNA and the VEGF-C secretion concentration were assayed in these cell lines. RESULTS: The proliferation and migration capacities of ERalpha-tranfected MDA-MB-231 cells were significantly decreased (P < 0.05). The expression of COX-2 was significantly lower in ERalpha-tranfected MDA-MB-231 cells than in untranfected MDA-MB-231 cells. The mRNA and protein levels of VEGF-C were lower in ERalpha-tranfected MDA-MB-231 cells than in untransfected MDA-MB-231 cells (P < 0.05). CONCLUSIONS: ERalpha stable transfection inhibits proliferation and migration capacities of MDA-MB-231 cells and decreases expression of COX-2 and VEGF-C. The decreases of proliferation and migration capacities may be related to suppression of COX-2 and VEGF-C expression.

[Construction of an expression vector carrying short hairpin RNA targeting hTERT gene and its effects on breast cancer cell telomerase activity and proliferation in vivo].

OBJECTIVE: To construct a RNA interference expression vector targeting human telomerase reverse transcriptase gene (hTERT) gene and investigate its effects on telomerase activity and proliferation in breast cancer cells in vitro. METHODS: The shRNA sequences targeting hTERT gene were designed and recombined into pSuper-retro-puro vector. The breast cancer cell lines MCF-7 and MDA-MB231 were transfected with the recombined vector, and the telomerase activity of the cells was tested by telomerase repeat sequence amplification-enzyme linked immunosorbent assay (TRAP-ELISA). The proliferation of the transfected cells was assessed using MTT and soft-agar clone formation assays. RESULTS: The recombinant plasmids pSuper-retro-puro-TERT RNAi#1 and #2 were successfully constructed as confirmed by enzymatic digestion and DNA sequencing. The telomerase activity in the transfected breast cancer cells were down-regulated significantly as compared with that in negative control cells (Plt;0.005). The transfection resulted in significant inhibition of the proliferation of both MCF-7 and MDA-MB231 cells as detected by MTT assay (Plt;0.05) and soft agar clone formation assay (Plt;0.001). CONCLUSION: Transfection with the recombinant plasmid containing the shRNA targeting hTERT gene can down-regulate telomerase activity and inhibit proliferation of breast cancer cells in vitro, suggesting the potential of gene therapy targeting telomerase in the treatment of breast cancer.

[Histopathology and ultrastructural characteristics of acellular allogenic dermal matrix engrafted with thin split-thickness skin autograft: mid- and long-term results].

OBJECTIVE: To observe mid- and long-term changes in the histopathology and electron microscopic characteristics of the acellular dermal matrix engrafted with thin split-thickness skin autograft. METHODS: Twenty-three biopsy samples were collected from 17 patients undergoing extremity scar resection, who received subsequent grafting using allogenic dermal matrix dressed with thin split-thickness skin autografts. Six months to 2 years after the grafting, the grafts were sampled for histopathological and electron microscopic observations of the layer of the epidermis, thickness of the basal membrane, structural components of the dermis, and infiltration of fibroblasts and revascularization. The data were compared with those of the normal skin samples from the patients. RESULTS: Only the number of epidermal layers showed statistically significant difference between the skin grafts and the normal skin (16.33-/+5.89 vs 26.57-/+3.46, P=0.007). The thickness of the basal membrane of the skin grafts was similar to that of normal skin, and no significant difference was found in the number of fibroblasts and newly generated capillaries between them. CONCLUSION: The mid- and long-term histopathology and ultrastructures of the composite skin graft in the extremities are similar to those of normal skin, suggesting satisfactory effect of the skin grafts.

[Removing breast foreign body resulted from augmentation with polyacrylamide hydrogel injection and silicone prosthesis implantation at one stage].

OBJECTIVE: This study was to investigate an operation, in which removing breast cysts of foreign body resulted from augmentation with polyacrylamide hydrogel injection was performed simultaneously with silicone prosthesis implantation under SEPS endoscope in order to relieve tissue injury and increase the accuracy of clearance. METHODS: Eight patients were included in this study. Preoperative type B ultrasound examination was performed to mark the mass. Through an axillary approach, the cysts of foreign body that were distributed in the subcutaneous tissue, breast or muscle were separated and ablated under SEPS endoscope. After removal of the foreign body, a silicone implant was located submuscularly for breast augmentation. RESULTS: The operations were completed without hematoma and infection. Follow-up of the eight patients for 3 to 12 months showed that preoperative symptoms relating to the injected material, such as breast pain, lump and asymmetry, have no longer existed. The shapes of the breasts were satisfactory. CONCLUSIONS: We believe that endoscope-assisted mammoplasty offers more satisfactory clinical results with less injury, less morbidity, less scars, more accuracy and greater patient acceptance.

[Clinical application of acellular allogenic dermis with autogenous epithelium in wound repair].

OBJECTIVE: To observe the clinical effect of acellular allogenic dermis with split-thickness autogenous skin graft for coverage of wound. METHODS: Acellular allogenic dermis with split-thickness autogenous skin graft was used to repair 34 wounds of head, neck, trunk and extremities. The area of wounds was from 5 cm x 10 cm to 12 cm x 19 cm. Out of 34 wounds, there were 2 due to old granulation, 4 due to excision of giant pigmented nevus, 6 due to excision of capillary hemangioma of skin and 22 due to excision of scar. RESULTS: All grafts survived and had the smooth surface without obvious pigmentation and with slight wound contraction. CONCLUSION: Acellular allogenic dermis with autologous epithelium for coverage of various wounds is an ideal procedure.