G226, a new epipolythiodioxopiperazine derivative,triggers DNA damage and apoptosis in human cancer cells in vitro via ROS generation

Aim:

G226 is a novel derivative of epipolythiodioxopiperazines with potent inhibitory activity against cancer cells. Here, we sought to identify potential targets involved in the anti-cancer activity of G226.

Methods:

Cell proliferation assay was conducted in a panel of 12 human cancer cell lines. The activities of topoisomerase I (Topo I) and Topo II were studied using supercoiled pBR322 DNA relaxation and kDNA decatenation assays. ROS production was assessed with probes DCFH-DA and H&E. Western blot analysis and flow cytometry were used to examine DNA damage, apoptosis and cell cycle changes.

Results:

G226 displayed potent cytotoxicity in the 12 human cancer cell lines with a mean IC₅₀ value of 92.7 nmol/L. This compound (1–100 μmol/L) selectively inhibited the activity of Topo II, and elevated the expression of phosphorylated-H2AX in a dose-dependent manner. In Topo II-deficient HL60/MX2 cells, however, G226-induced DNA damage, apoptosis and cytotoxicity were only partially reduced, suggesting that Topo II was not essential for the anti-tumor effects of G226. Furthermore, G226 (0.125–2 μmol/L) dose-dependently elevated the intracellular levels of H₂O₂ and in the cancer cells, and pretreatment with GSH, NAC or DTT not only blocked G226-induced intracellular accumulation of ROS, but also abrogated G226-mediated phosphorylation of H2AX, apoptosis and cytotoxicity.

Conclusion:

G226-mediated ROS production contributes to the anti-cancer activity of this compound.     

Comparison of post-operative intravesical recurrence and oncological outcomes after open versus laparoscopic nephroureterectomy for upper urinary tract urothelial carcinoma

Object

To retrospectively evaluate intravesical recurrence and oncological outcomes after open or laparoscopic radical nephroureterectomy (RNU) for the upper urinary tract urothelial carcinoma (UUT-UC).

Patients and methods

This study comprised 122 patients diagnosed UUT-UC and subsequently nephroureterectomy was performed on. Several clinical and pathological parameters were emphasized for comparison of clinical outcomes.

Results

Among 122 patients with UUT-UC, 101 (82.8 %) and 21 (17.2 %) underwent open or laparoscopic radical nephroureterectomy (ONU or LNU), respectively. In univariable and multivariable Cox regression models, the surgical procedure exerted an impact neither on post-operative intravesical recurrence rate (p = 0.179 and 0.213, respectively) nor on cancer-specific mortality rate (p = 0.561 and 0.159, respectively). The 1-, 2- and 5-year cancer-specific survival (CSS) rates of patients undergoing ONU or LNU were 92.1 versus 95.2 %, 87.1 versus 90.5 %, 79.2 versus 85.7 %, respectively, and the Kaplan–Meier plot illustrated that patients from two groups enjoyed an equivalent survival rate (p = 0.559). Moreover, we added that previous history of bladder tumor and pre-operative hydronephrosis was associated with intravesical recurrence, whereas three prognostic factors, including pathological tumor stage, grade, and lymphovascular invasion, showed possibility to be predictors of cancer-specific mortality.

Conclusion

There existed no significant difference of intravesical recurrence and CSS between patients after ONU and LNU. Conclusively, laparoscopic radical nephroureterectomy did not present superiority to open management for patients with UUT-UC.     

骨质疏松性椎体压缩骨折在退变性脊柱侧凸的分布及危险因素

 目的 总结骨质疏松性椎体压缩骨折在退变性脊柱侧凸中分布的规律性,分析退变性脊柱侧凸患者发生椎 体压缩骨折的危险因素。方法 回顾性分析2004年7月至2012年7月治疗136例退变性脊柱侧凸患者资料,根据术前是 否发生骨质疏松性椎体压缩骨折分为骨折组和无骨折组。骨折组34例,男9例,女25例;年龄(71.7±1.7)岁。无骨折组 102例,男23例,女79例;年龄(63.3±6.7)岁。采用视觉模拟评分(visual analogue scale, VAS)评估胸背部疼痛程度,采 用双能X线骨密度仪测定骨密度T值,测量侧凸Cobb角,观察侧凸范围内骨桥发生情况。采用二分类Logistic逐步回归分析方 法筛选出骨折发生的危险因素。结果 骨折组发生T₁₁骨折3例,T₁₂骨折12例,L₁骨折15例 ,T₁₂及L₁两个椎体骨折4例。 无骨折组平均年龄低于骨折组(t=17.20,P<0.001),两组的性别组成并无差异(χ²=0.218,P=0.641),胸背部 疼痛的VAS评分小于骨折组(t=9.30,P< 0.001),侧凸Cobb角与骨折组相比无差异(t=1.84,P=0.08),骨质疏松的严重程度 低于骨折组(t=5.63,P<0.001),骨桥发生率低于骨折组(χ²=12.333,P< 0.001)。Logistic回归分析显示外伤 史(OR=1.36;95%CI,1.09～2.11)、骨桥形成(OR=3.31;95%CI,2.10～5.38)、骨质疏松(OR=2.45;95%CI,1.58～4.36) 会增加退变性脊柱侧凸患者发生骨质疏松性椎体压缩骨折的机会。结论 在退变性脊柱侧凸患者中,骨质疏松性椎体压缩骨折好 发于胸腰段椎体,外伤 史、骨质疏松以及侧凸范围内骨桥形成是骨折发生的危险因素。     

Impact of Dietary Aromatic Amino Acids on Osteoclastic Activity

We had shown that aromatic amino acid (phenylalanine, tyrosine, and tryptophan) supplementation prevented bone loss in an aging C57BL/6 mice model. In vivo results from the markers of bone breakdown suggested an inhibition of osteoclastic activity or differentiation. To assess osteoclastic differentiation, we examined the effects of aromatic amino acids on early /structural markers as vitronectin receptor, calcitonin receptor, and carbonic anhydrase II as well as, late/functional differentiation markers; cathepsin K and matrix metalloproteinase 9 (MMP-9). Our data demonstrate that the aromatic amino acids down-regulated early and late osteoclastic differentiation markers as measured by real time PCR. Our data also suggest a link between the vitronectin receptor and the secreted cathepsin K that both showed consistent effects to the aromatic amino acid treatment. However, the non-attachment related proteins, calcitonin receptor, and carbonic anhydrase II, demonstrated less consistent effects in response to treatment. Our data are consistent with aromatic amino acids down-regulating osteoclastic differentiation by suppressing remodeling gene expression thus contributing initially to the net increase in bone mass seen in vivo.     

shRNA-mediated GSTP1 gene silencing enhances androgen-independent cell line DU145 chemosensitivity

Purpose

Design short hairpin RNA (shRNA) interference sequence to silence glutathione S-transferase P1 (GSTP1) gene of androgen-independent prostate cancer cell line DU145, and then to explore its effect on sensitivity to chemotherapeutics.

Methods

Target sequence was picked up to form the shRNA. DU145 cell was divided into five groups according to the shRNA added for transfection: shRNA255, shRNA554, shRNA593, negative-shRNA and blank group. Fluorescence microscope was used to pick up the shRNA with the highest transfection ratio. Western blotting and RT-PCR were taken to pick up the shRNA with the best gene silencing result. 3-(4,5-Dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide assay and terminal de-oxynucleotidyl transferase-mediated dUTP nick end-labeling assay were used to detect survival ratio and apoptosis ratio of DU145 administered of fluorouracil (5-FU) or paclitaxel (PA) at different concentrations before and after shRNA transfection.

Results

Three different shRNA oligonucleotides (shRNA255; shRNA554; shRNA593) targeting the coding sequence of GSTP1 mRNA and one negative control shRNA were constructed. The transfection ratio of shRNA554 (76.2 ± 0.68 %) was higher than that of shRNA255 (63.3 ± 1.04 %) (P < 0.01) or shRNA593 (72.7 ± 0.33 %) (P < 0.01). After transfection of shRNA554, the mRNA and protein of level were the lowest, P < 0.01. The survival ratio of DU145 administered with 5-FU of different concentrations (30, 60, 120, 240 μg/ml) declined after transfection (P < 0.01). Besides, the apoptosis ratio increased after transfection (P < 0.01). Similarly the survival ratio of DU145 administered with PA of different concentrations (0.2, 2, 10, 20 μg/ml) declined (P < 0.01) and the apoptosis ratio increased (P < 0.01) after transfection.

Conclusions

The gene GSTP1 silence via shRNA transfection to androgen-independent prostate cancer cell line DU145 enhances the sensitivity to chemotherapeutics.     

The potential role of heat shock proteins in acute spinal cord injury

Purpose

This study aims to investigate the differential expression proteins profile of spinal cord tissues after acute spinal cord injury (ASCI), provide preliminary results for further study and explore the secondary injury mechanisms underlying ASCI.

Methods

Using Allen’s frame to establish ASCI model of Sprague–Dawley rats, then a stable isotope-labelled strategy using isobaric tags for relative and absolute quantitation (iTRAQ) coupled with two-dimensional (2D) liquid chromatography tandem mass spectrometry (2D LC–MS/MS) was performed to separate and identify differentially expressed proteins.

Results

A total of 220 differentially expressed proteins were identified in the spinal cord tissues of H-8 group (acute spinal cord injury after 8 h) compared with H-0 group (acute spinal cord injury after 0 h); Up to 116 proteins were up-regulated, whereas 104 proteins were down-regulated in the spinal cord tissues. Three of the differentially expressed Heat shock proteins (HSPs) namely, Hsp90ab1, Hspa4 and Hspe1 were down-regulated.

Conclusion

The differentially expressed proteins of spinal cord tissues after ASCI will provide scientific foundation for further study to explore the secondary injury mechanism of ASCI.     

The early and mid-term results of mitral valve repair for mitral regurgitation in children

Purpose

To review the surgical techniques and mid-term results of mitral valve repair in children with moderate or severe mitral regurgitation (MR).

Methods

One hundred and seven children with moderate or severe MR, aged 19.6 ± 8.5 months, were enrolled in this study. The surgical techniques used for mitral valve repair varied according to the mitral valve morphology, and included annuloplasty, annuloplasty ring, cleft closure, reconstruction of the posterior leaflet, etc. The concomitant cardiac anomalies were treated simultaneously. The results of repair were evaluated by transesophageal echocardiography performed during the operation and by serial transthoracic echocardiography performed during the follow-up.

Results

One hundred and six cases had no more than mild regurgitation intraoperatively, whereas only one case had moderate regurgitation. This patient underwent redo repair immediately, and the subsequent regurgitation was trivial. The in-hospital mortality rate was 0.9 % (1/107). The average follow-up was 46.5 ± 8.2 months. One patient died of heart failure 10 months postoperatively. The freedom from moderate or severe regurgitation after mitral valve repair was 92.3 ± 3.3 %.

Conclusion

Pediatric patients with moderate or severe MR require early surgical treatment. The early and mid-term results of mitral valve repair in pediatric patients were satisfactory.     

胎儿小脑表面叶裂的产前超声研究

目的研究正常胎儿小脑表面叶裂随孕周的变化规律并建立孕16~32周正常胎儿小脑叶裂数目参考值。 方法选取2019年6月至2020年12月在南方医科大学附属深圳妇幼保健院行产前超声检查无结构异常的644名妊娠12~32周的单胎孕妇,按孕周分为2个时间段观察：孕12~15周为阶段1,孕16~32周为阶段2,在二维图像上观察原裂、水平裂的显示情况并计数孕16~32周小脑原裂之前、原裂与水平裂之间、水平裂之后的叶裂数目及总数目,并分析其形态变化。随机抽取40名阶段2胎儿行叶裂数目两测量者间的组内相关系数（ICC）分析;建立阶段2胎儿小脑叶裂数目的参考值范围,采用Spearman相关行叶裂数目与孕周的相关性分析并建立拟合方程。 结果叶裂数目的计数两观察者之间的重复性检验一致性较好（ICC=0.969,P＜0.001）。各散点图显示正常胎儿小脑原裂之前、原裂与水平裂之间、水平裂之后叶裂数目及总数目与孕周呈正相关（r=0.863、0.698、0.831、0.932,P均＜0.001）。建立了各区域叶裂数目及总数目与孕周的二次多项式回归方程,原裂之前、原裂与水平裂之间、水平裂之后叶裂数以及总数目与孕周的回归方程分别为：Y=0.974X-0.014X ² -12.65,Y=0.362X-0.005X ² -4.843,Y=-0.125X+0.006X ² +0.285,Y=1.800X-0.024X ² -22.904。 结论利用产前超声可以较好地观察胎儿小脑表面叶裂并对其发育情况作出初步评估。胎儿小脑表面叶裂数目的正常参考值以及形态变化规律能为产前超声评估小脑皮质发育作出参考。