Long noncoding RNA Ftx regulates the protein expression profile in HCT116 human colon cancer cells.

BACKGROUND: The long noncoding RNA (lncRNA) five prime to Xist (Ftx) is involved in distant metastasis in colorectal cancer (CRC). This study aimed to investigate Ftx alteration-induced proteomic changes in the highly metastatic CRC cell line HCT116. METHODS: Tandem mass tag (TMT)-based proteomics analysis was performed to detect the differential protein expression in Ftx-overexpressing and Ftx-silenced HCT116 cells. The differentially expressed proteins were classified and characterized by bioinformatics analyses, including gene ontology (GO) annotation, GO/Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway/protein domain enrichment analyses, as well as hierarchical clustering. A total of 5471 proteins were quantified, and the proteins with |fold change|≥ 1.2 and p < 0.05 were identified as differentially expressed proteins in response to Ftx overexpression or silencing. RESULTS: The bioinformatics analyses revealed that the differentially expressed proteins were involved in a wide range of GO terms and KEGG signaling pathways and contained multiple protein domains. These terms, pathways, and protein domains were associated with tumorigenesis and metastasis in CRC. CONCLUSIONS: Our results indicate that the alteration of Ftx expression induces proteomic changes in highly metastatic HCT116 cells, suggesting that Ftx and its downstream molecules and signaling pathways could be potential diagnostic biomarkers and therapeutic targets for metastatic CRC.

RbAp48 Is Critical for the Proliferation of Hypopharyngeal Carcinoma.

BACKGROUND: Emerging evidence has indicated the significance of RbAp48 in tumorigenesis. Although many genetic and epigenetic factors have been found to be involved in the pathogenesis of hypopharyngeal carcinoma, the effect of RbAp48 in hypopharyngeal carcinoma is still unclear. METHODS: A stable cell line overexpressing RbAp48 was generated in FaDu cells. Cell proliferation and colony formation were detected using FaDu-RbAp48 cells. Next we utilized nude mouse xenografts to determine the role of RbAp48. Flow cytometry was employed to investigate the effect of RbAp48 in cell cycle distribution and apoptosis. Real-time PCR was used to detect the expression of tumor suppressors and apoptosis-related factors. RESULTS: The overexpression of RbAp48 inhibited cell proliferation, colony formation, and tumor formation in nude mice. The overexpression of RbAp48 affected cell cycle distribution and induced apoptosis. The expression of p53, Rb, Bax, caspase 3, caspase 8, and caspase 9 was upregulated, whereas the expression of Bcl-2 was downregulated resulting from the overexpression of RbAp48. CONCLUSION: RbAp48 was identified as critical in the proliferation of hypopharyngeal carcinoma in both in vitro and in vivo experiments. It is conceivable that the regulation of tumor suppressors (Bcl-2 family and caspase enzymes) by RbAp48 contributes, at least in part, to the RbAp48-mediated proliferation in hypopharyngeal carcinoma.

Interleukin-6 and JAK2/STAT3 signaling mediate the reversion of dexamethasone resistance after dexamethasone withdrawal in 7TD1 multiple myeloma cells.

We previously reported the establishment and characteristics of a DXM-resistant cell line (7TD1-DXM) generated from the IL6-dependent mouse B cell hybridoma, 7TD1 cell line. After withdrawing DXM from 7TD1-DXM cells over 90 days, DXM significantly inhibited the cell growth and induced apoptosis in the cells (7TD1-WD) compared with 7TD1-DXM cells. Additionally, IL-6 reversed while IL-6 antibody and AG490 enhanced the effects of growth inhibition and apoptosis induced by DXM in 7TD1-WD cells. Our study demonstrates that 7TD1-DXM cells become resensitized to DXM after DXM withdrawal, and IL-6 and JAK2/STAT3 pathways may regulate the phenomenon.

The study on biocompatibility of porous nHA/PLGA composite scaffolds for tissue engineering with rabbit chondrocytes in vitro.

OBJECTIVE: To examine the biocompatibility of a novel nanohydroxyapatite/poly[lactic-co-glycolic acid] (nHA/PLGA) composite and evaluate its feasibility as a scaffold for cartilage tissue engineering. METHODS: Chondrocytes of fetal rabbit were cultured with nHA/PLGA scaffold in vitro and the cell viability was assessed by MTT assay first. Cells adhering to nHA/PLGA scaffold were then observed by inverted microscope and scanning electron microscope (SEM). The cell cycle profile was analyzed by flow cytometry. RESULTS: The viability of the chondrocytes on the scaffold was not affected by nHA/PLGA comparing with the control group as it was shown by MTT assay. Cells on the surface and in the pores of the scaffold increased in a time-dependent manner. Results obtained from flow cytometry showed that there was no significant difference in cell cycle profiles between the coculture group and control (P > 0.05). CONCLUSION: The porous nHA/PLGA composite scaffold is a biocompatible and good kind of scaffold for cartilage tissue engineering.

Differentiation of human bone marrow precursor cells into neuronal-like cells after transplantation into canine spinal cord organotypic slice cultures.

BACKGROUND: Treatments to regenerate different tissue involving the transplantation of bone marrow derived mesenchymal precursor cells are anticipated. Using an alternative methods, in vitro organotypic slice culture method, would be useful to transplant cells and assessing the effects. This study was to determine the possibility of differentiating human bone marrow precursor cells into cells of the neuronal lineage by transplanting into canine spinal cord organotypic slice cultures. METHODS: Bone marrow aspirates were obtained from posterior superior iliac spine (PSIS) of patients that had undergone spinal fusion due to a degenerative spinal disorder. For cell imaging, mesenchymal precursor cells (MPCs) were pre-stained with PKH-26 just before transplantation to canine spinal cord slices. Canine spinal cord tissues were obtained from three adult beagle dogs. Spinal cords were cut into transverse slices of 1 mm using tissue chopper. Two slices were transferred into 6-well plate containing 3 ml DMEM with antibiotics. Prepared MPCs (1×10(4)) were transplanted into spinal cord slices. On days 0, 3, 7, 14, MPCs were observed for morphological changes and expression of neuronal markers through immunofluorescence and reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The morphological study showed: spherical cells in the control and experiment groups on day 0; and on day 3, cells in the control group had one or two thick, short processes and ones in the experiment group had three or four thin, long processes. On day 7, these variously-sized processes contacted each other in the experiment group, but showed typical spindle-shaped cells in the control group. Immunofluorescence showed that PKH-26(+) MPCs stained positive for NeuN(+) and GFAP(+) in experimental group only. Also RT-PCR showed weak expression of ß-tubulin III and GFAP. CONCLUSIONS: Human bone marrow mesenchymal precursor cells (hMPCs) have the potential to differentiate into the neuronal like cells in this canine spinal cord organotypic slice culture model. Furthermore, these findings suggested the possibility that these cells can be utilized to treat patients with spinal cord injuries.

Dynamic evaluation of cervical disc herniation using kinetic MRI.

We investigated the effects of cervical disc herniation on kinematics of adjacent segmental motion by evaluating 407 patients using kinetic MRI. For each patient, measurements for translational motion (mm), angular variation (degrees) and disc height (mm) were obtained at each segment from C2/C3 through C7/T1. The results show that the spinal levels above the disc herniation experienced, on average, a 7.2% decrease in translational motion per millimeter of disc herniation (p=0.0113), but no significant change in angular motion. Spinal levels below the herniation experienced a 5.2% decrease in angular motion per millimeter of disc herniation (p=0.0236) without significant change in translational motion. Disc herniation had no significant impact on disc height at adjacent levels, although disc degeneration at the level of herniation correlated with decreased disc height above and increased disc height below. This study indicates that although disc height, translational motion and angular variation are significantly affected at the level of a disc herniation, no significant changes are apparent within the adjacent segments. Herniated discs have no effect on the range of motion at adjacent levels regardless of the degree of disc degeneration or the size of disc herniation. The natural progression of disc herniation and adjacent segment disease within the cervical spine appear to be separate, unrelated processes.

Effect of sagittal alignment on kinematic changes and degree of disc degeneration in the lumbar spine: an analysis using positional MRI.

STUDY DESIGN: Retrospective analysis using positional MRI. OBJECTIVE: To determine the effects of total sagittal lordosis on spinal kinematics and degree of disc degeneration in the lumbar spine. SUMMARY OF BACKGROUND DATA: Changes in sagittal lordosis alter the load on the spine and may affect spinal mobility. There is increasing recognition of the clinical impact that sagittal alignment has on back pain, especially its possible role in accelerating adjacent segment degeneration after spinal fusion. However, its relationship to segmental mobility and degeneration of the lumbar spine has yet to be determined. METHODS: Four hundred and thirty patients who had low back pain with or without leg pain (241 males and 189 females) with a mean age of 42.98 years (range, 16-85 years) were included. Total sagittal lordosis (T12-S1) was divided into three groups; Group A: Straight or Kyphosis (<20°, n = 84), Group B: Normal lordosis (20-50°, n = 294), and Group C: Hyperlordosis (>50°, n = 52). The degree of disc degeneration was graded using midsagittal T2-weighted MR images. Segmental mobility, including translational motion and angular variation, was measured using positional MRI. Their relationship with total segmental lordosis was identified. RESULTS: When compared with group B, the segmental motion in group C tended to be lower at the border of lordosis and higher at the apex of lordosis, with a significant difference in angular motion at L2-L3. The contrary finding was identified in group A, which had a higher segmental motion at border segments and lower motion at apical segments of lordosis, with significant difference of translational motion at L3-L4 and angular motion at L1-L2. Apical segments contributed more, whereas border segments contributed less to the total angular mobility in more lordotic spines. The opposite was seen in more kyphotic spines. Disc degeneration tended to be greater at all levels in group C, and at L1-L2 and L5-S1 in group A. CONCLUSION: Changes in sagittal alignment may lead to kinematic changes in the lumbar spine. This may subsequently influence load bearing and the distribution of disc degeneration at each level. Sagittal alignment, disc degeneration, and segmental mobility likely have a reciprocal influence on one another.

Inflammatory characteristics of rhBMP-2 in vitro and in an in vivo rodent model.

STUDY DESIGN: In vivo and in vitro model. OBJECTIVE: Investigate soft-tissue inflammation caused by rhBMP-2. SUMMARY OF BACKGROUND DATA: Although rhBMP-2 produces excellent rates of fusion in the spine, dysphagia and respiratory compromise have occurred when used in the neck. The mechanism of the swelling and inflammatory response has yet to be fully elucidated. METHODS: ELISA kits (IL-6, IL-10, TNF-α) were used to measure cytokine levels at different concentrations of rhBMP-2. Absorbable collagen sponges were implanted with or without different concentrations of rhBMP-2 into the backs of rats subcutaneously (SC) and intramuscularly (IM). Magnetic resonance imaging was used to measure inflammation at 3 hours and 2, 4, and 7 days. The inflammatory volumes were measured and compared using MIPAV software. Rats were killed after 7 days and studied. RESULTS: IL-6, IL-10, and TNF-α release was dose-dependent. Soft-tissue edema after rhBMP-2 implantation was also dose-dependent, peaking at 3 hours SC, after SC and IM implantations, and on day 2 IM after IM implantation. All formed a granuloma-type mass after SC insertion. The mass was much larger in the 10 and 20 µg/10 µL (high-concentration) groups. The inflammatory response did not diffuse across physiologic barriers (subcutaneous fascia). Both high-dose groups were associated with encapsulated hematomas and a significant increase in the inflammatory zone. CONCLUSION: Swelling and inflammation after rhBMP-2 use are dose-dependent. Swelling may be due to direct contact as well as spread in the plane of access. The causes are a robust inflammatory reaction as well as sterile seroma and encapsulated hematoma formation.