Observation of radiobiological characteristics in a HepG2 cell line with mitochondrial DNA deletion / 南方医科大学学报

<p><b>OBJECTIVE</b>To study the radiobiological characteristics of a HepG2 cell line with mitochondrial DNA (mtDNA) deletion.</p><p><b>METHODS</b>HepG2 cells were cultured in a medium containing ethidium bromide, acetylformic acid and uracil. The HepG2 cell line with mtDNA deletion (ρ(0)HepG2 cells) were acquired after 30 subcultures by limited dilution cloning. The cell survival was then observed in the absence of acetylformic acid and uracil, and the total mtDNA deletion in the cells was confirmed by PCR. The radiosensitivity of HepG2 and ρ(0)HepG2 cells was evaluated by exposure to gradient doses of 6 MV X ray irradiation. The cell apoptosis was assessed following a 2 Gy X-ray exposure with Hochest33342 staining, and the invasiveness of ρ(0)HepG2 cells was measured by Transwell assay.</p><p><b>RESULTS</b>HepG2 cells could survive 30 subcultures in the presence of ethidium bromide, and massive cell death occurred after removal of acetylformic acid and uracil from the medium. PCR confirmed total mtDNA deletion from ρ(0)HepG2 cells, whose α/β value was significantly lower than that of HepG2 cells. ρ(0)Hep-G2 cells showed an obviously lowered cell apoptosis rate following X-ray exposure with enhanced cell invasiveness.</p><p><b>CONCLUSION</b>HepG2 cells can be induced by ethidium bromide into ρ(0)HepG2 cells with an increased radiation resistance, anti-apoptosis ability and cell invasiveness.</p>

Intra-articular injection of etanercept into the sacroiliac joint of ankylosing spondylitis / 中华风湿病学杂志

Objective To evaluated intra-articular injection of TNF-α inhibitors into the sacroiliac joint as an effective and viable alternative. Methods Sixteen patients with documented ankylosing spondylitis (AS), without steroids or disease modifying anti-rheumatic drugs (DMARDs) were performed CT-guided intra-articular injections of etanercept (TNF-α antagonist) at week 0, 4 and 8 (25 mg per dose). Similarly, 20 patients with AS in the control group received systemic etanercept therapy at a dose of 50 mg per week for 8 weeks. All patients were followed up clinically and evaluated periodically. Pathological features of sacroiliitis were observed with light microscopy and immunohistochemistry. Expression of cytokines in joint biopsy samples was estimated by RT-PCR. Image changes of sacroiliitis were observed by SPECT/CT and MRI. Ttest, t'tesr and χ2 Fisher's test were selected. Results All the 16 patients who received intra-articular etanercept, the mean value of radiological nuclide decrease of the SIJ ROI (region of interest) in the SPECT improved significantly after 8 weeks treatment [(1.38±0.16 vs 1.45±0.14) P<0.05] . Bone marrow edema and fat deposition in MRI were relieved significantly after 8 weeks (P<0.05). In 8 patients the expression of TNF-α and TGF-β mRNA in joint tissue decreased significantly after 8 weeks [(0.89±0.06, 0.84±0.05) vs (l.08± 0.19, 1.13±0.33) (P<0.05)]. The occurrence of gynonitis, enthesitis, chondritis, subehondral bony plate destruction, bone marrow inflammation and inflammatory cell index also decreased significantly (P<0.05). Participants given intra-articular injection showed significant clinical improvement after 8 weeks and 12 weeks treatment(P<0.01 ) in BASDAI score [(32±13) mm]. Conclusion This study has shown that intra-articular injection of etanercept in SIJ can improve joint function and quality of life. It has a satisfactory safety profile and is cost effective. This mode of treatment is most beneficial in local arthropathy of recent onset and in those patients who do not tolerate systemic etanercept therapy.