BRD4770 inhibits vascular smooth muscle cell proliferation via SUV39H2, but not EHMT2 to protect against neointima formation

The behavior of vascular smooth muscle cells (VSMCs) contributes to the formation of neointima. We previously found that EHMT2 suppressed autophagy activation in VSMCs. BRD4770, an inhibitor of EHMT2/G9a, plays a critical role in several kinds of cancers. However, whether and how BRD4770 regulates the behavior of VSMCs remain unknown. In this study, we evaluate the cellular effect of BRD4770 on VSMCs by series of experiments in vivo and ex vivo. We demonstrated that BRD4770 inhibited VSMCs' growth by blockage in G2/M phase in VSMCs. Moreover, our results demonstrated that the inhibition of proliferation was independent on autophagy or EHMT2 suppression which we previous reported. Mechanistically, BRD4770 exhibited an off-target effect from EHMT2 and our further study reveal that the proliferation inhibitory effect by BRD4770 was associated with suppressing on SUV39H2/KTM1B. In vivo, BRD4770 was also verified to rescue VIH. Thus, BRD4770 function as a crucial negative regulator of VSMC proliferation via SUV39H2 and G2/M cell cycle arrest and BRD4770 could be a molecule for the therapy of vascular restenosis.

Effects of neuregulin-1 on autonomic nervous system remodeling post-myocardial infarction in a rat model

Sympathetic nerve and vagus nerve remodeling play an important part in cardiac function post-myocardial infarction (MI). Increasing evidence indicates that neuregulin-1 (NRG-1) improves cardiac function following heart failure. Since its impact on cardiac function and neural remodeling post-MI is poorly understood, we aimed to investigate the role of NRG-1 in autonomic nervous system remodeling post-MI. Forty-five Sprague-Dawley rats were equally randomized into three groups: sham (with the left anterior descending coronary artery exposed but without ligation), MI (left anterior descending coronary artery ligation), and MI plus NRG-1 (left anterior descending coronary artery ligation followed by intraperitoneal injection of NRG-1 (10 μg/kg, once daily for 7 days)). At 4 weeks after MI, echocardiography was used to detect the rat cardiac function by measuring the left ventricular end-systolic inner diameter, left ventricular diastolic diameter, left ventricular end-systolic volume, left ventricular end-diastolic volume, left ventricular ejection fraction, and left ventricular fractional shortening. mRNA and protein expression levels of tyrosine hydroxylase, growth associated protein-43 (neuronal specific protein), nerve growth factor, choline acetyltransferase (vagus nerve marker), and vesicular acetylcholine transporter (cardiac vagal nerve fiber marker) in ischemic myocardia were detected by real-time PCR and western blot assay to assess autonomous nervous remodeling. After MI, the rat cardiac function deteriorated significantly, and it was significantly improved after NRG-1 injection. Compared with the MI group, mRNA and protein levels of tyrosine hydroxylase and growth associated protein-43, as well as choline acetyltransferase mRNA level significantly decreased in the MI plus NRG-1 group, while mRNA and protein levels of nerve growth factor and vesicular acetylcholine transporters, as well as choline acetyltransferase protein level slightly decreased. Our results indicate that NRG-1 can improve cardiac function and regulate sympathetic and vagus nerve remodeling post-MI, thus reaching a new balance of the autonomic nervous system to protect the heart from injury.

Paclitaxel-coated balloons for the treatment of patients with in-stent restenosis: A meta-analysis of angiographic and clinical data

Paclitaxel-coated balloons (PCBs) have become attractive alternative treatment options for patients with in-stent restenosis (ISR); however, the safety and efficacy of PCBs in comparison with those of conventional therapies are less well defined. The aim of this meta-analysis was to systematically review the efficacy and safety of PCBs for patients with ISR using comparisons with control groups. Electronic databases, such as MEDLINE, Embase and the Cochrane Central Register of Controlled Trials, were searched, and eligible studies that compared PCBs with uncoated balloons (UCBs) or drug-eluting stents (DESs) in patients with ISR were considered. Subgroup analyses were performed with different control groups. Nine studies (1,488 patients, 1,608 lesions) were included in the meta-analysis. Compared with patients who underwent UCB angioplasty, those who underwent PCB angioplasty exhibited a clear superiority in late lumen loss (LLL) [weighted mean difference (WMD), -0.46; 95% confidence interval (CI), (-0.59)-(-0.34); P<0.00001] and major adverse cardiac events (MACEs) [odds ratio (OR), 0.21; 95% CI, 0.13-0.33; P<0.00001]. The OR for myocardial infarction (MI) (OR, 0.46; 95% CI, 0.15-1.47; P=0.19) did not reach statistical significance. PCBs were associated with similar outcomes when compared with DESs with regard to LLL (WMD, -0.04; 95% CI, -0.18-0.10; P=0.57), MACEs (OR, 0.74; 95% CI, 0.36-1.53; P=0.42) and the ORs for all endpoints, including total mortality, target lesion revascularization, MI, stent thrombosis and binary restenosis, and no statistically significant differences were found. This meta-analysis showed that PCBs are associated with superior outcomes when compared with UCBs in the management of ISR, and are at least as efficacious and as well tolerated as DESs.

EGFR tyrosine kinase inhibitor AG1478 inhibits cell proliferation and arrests cell cycle in nasopharyngeal carcinoma cells

Nasopharyngeal carcinoma (NPC), which occurs with a high incidence in southern China and southeast Asia, is of epithelial origin with overexpression of EGF receptor. To study the effect of inhibition of EGFR signaling on nasopharyngeal carcinoma cell proliferation and cell cycle distribution, EGFR tyrosine kinase inhibitor AG1478 was employed to treat Nasopharyngeal Carcinoma CNE2 cells. The results showed that AG1478 inhibited proliferation of CNE2 cells. Immunoblot showed that AG1478 inhibited EGFR phosphorylation in CNE2 cells without reduced expression of EGFR protein. The activation of Akt and MAPK which are downstream molecules of EGFR signaling pathway, were also inhibited by AG1478. AG1478 induced cell cycle arrest in G1 phase, and the levels of protein p27 were significantly up-regulated. We concluded that inhibition of the EGFR signaling induced cell cycle arrest in G1 phase in CNE2 cells and p27 up-regulation was involved in this process. The EGFR kinase specific inhibitor is of potential to be developed into drugs for NPC treatment.

[Mechanism of apoptosis induced by squamocin in leukemia cells]

AIM

To investigate the mechanism of apoptosis of HL60 cells induced by the annonaceous acetogenin, squamocin.

METHODS

Induction of apoptosis was determined through Hoechst33258 dye staining and DNA agarose gel electrophoresis. Expression of the proteins was detected using Western blot analysis. Caspase-3 activity was detected using caspase-3 kit.

RESULTS

Treatment of HL-60 cells with squamocin resulted in extensive nuclear condensation, DNA fragmentation, cleavage of the death substrate poly(ADP-ribose) polymerase (PARP) and induction of caspase-3 activity. Pretreatment of HL-60 cells with caspase-3 specific inhibitor DEVD-CHO prevented squamocin-induced DNA fragmentation, PARP cleavage and cell death. Stress-activated protein kinase (SAPK/JNK) was activated after treatment with squamocin in HL-60 cells.

CONCLUSION

These results suggest that apoptosis of HL-60 cells induced by squamocin require caspase-3 activation, and could be related to SAPK activation.

Anti-tumor effect of angiogenesis inhibitor TNP-470 on the human nasopharyngeal carcinoma cell line NPC/HK1

The efficacy and targeting cells of angiogenesis inhibitor TNP-470 on human squamous cell nasopharyngeal carcinoma (NPC) were investigated. The colorimetric MTT assay was used to evaluate the IC50 values of NPC/HK1 cells and human dermal microvascular endothelial cells (HDMEC) for TNP-470. An NPC human tumor model was built by tumor-bearing nude mice using the NPC cell line of NPC/HK1. TNP-470 (30 mg/kg s.c.) was injected every other day. The results showed that the IC50 of NPC/HK1 cells for TNP-470 was 3.8 times higher than that of HDMEC. A significant difference in tumor volume between control and treatment groups was found after 7 days of treatment and increased thereafter. At the end of the treatment, tumor volume was 773.7 +/- 287.1 mm3 (n = 8) in the control group versus 454.5 +/- 132.8 mm3 (n = 8) in the treatment group (p = 0. 013); the ratio of the mean tumor volume in treated animals to that of control animals was 0.587, resulting a 41.3% decrease in tumor growth. The necrotic area was larger in the treatment group. Physical toxicity did not result from the treatment. These studies suggest that angiogenesis inhibitor TNP-470 is effective in the treatment of squamous cell NPC without obvious toxicity.

Blood selenium levels in nasopharyngeal cancer patients in south China

Blood selenium concentrations in 111 nasopharyngeal cancer patients and 56 normal subjects were determined using a modified 2,3-diamino naphthalene fluorometric method. Cancer subjects in this study were divided into two groups and blood Se levels (mean +/- SD) were 0.105 +/- 0.024 for untreated cases, 0.113 +/- 0.034 for those who had received treatment, and 0.109 +/- 0.030 microgram/ml for all subjects. The results suggest that low blood Se levels in nasopharyngeal cancer patients are a consequence of their disease rather than the cause of the cancer.