Influence of SIRT6 regulation of cellular glycometabolism on radiosensitivity of non-small-cell lung cancer A549 cells

OBJECTIVE

To investigate the influence of SIRT6 mediated regulation of cellular glycometabolism on radiosensitivity of A549 non-small-cell lung cancer (NSCLC) cells.

METHODS

Ad-SIRT6 adenovirus vector overexpressed SIRT6 and was established and divided into a control group, a zero-load group (Ad-null), and an overexpression group (Ad-SIRT6). The virus concentration of the Ad-null group and the Ad-SIRT6 group was 200 pfu/cell. The survival factor (SF) after X-ray irradiation of 0, 2, 4, 6, 8, and 10 Gy in three groups was detected by clone formation and cell cycle and apoptosis after 4 Gy X-ray irradiation for 48 hours in the three groups was detected by flow cytometry. Expression levels of pyruvate kinase (PKM), lactate dehydrogenase (LDHA), and hexokinase (HK) after 4 Gy X-ray irradiation of 48 h were detected by qPCR. The glucose level after consumption of (1×10⁶) cells in the medium was detected by a glucose kit.

RESULTS

Compared with the control group and the Ad-null group, SFs after X-ray irradiation of 4-10 Gy in the Ad-SIRT6 group were decreased (P<0.05). A sensitization enhancement ratio of the Ad-SIRT group/the control group was 1.451. After 4 Gy X-ray irradiation of 48 h, the cell ratio and apoptosis rate in G₁ phase were increased in the Ad-SIRT6 group, with statistical significance when compared with the other two groups (P<0.05). Compared with the control group and the Ad-null group, levels of PKM, LDHA, and HK mRNA in Ad-SIRT6 group were decreased (P<0.05) and the remaining glucose in the medium was increased (P<0.05).

CONCLUSION

Overexpression of SIRT6 can inhibit key-enzyme generation in A549 cells to inhibit glycolysis, enhance the radiosensitivity, and lead to G₀/G₁ phase block as well as cell apoptosis.

Intra-aortic balloon pumping and thrombocytopenia in patients with acute coronary syndrome : Incidence, risk factors, and prognosis

BACKGROUND

Thrombocytopenia is a frequently encountered phenomenon during intra-aortic balloon pumping (IABP), which may limit its prolonged utilization. The aim of the study was to explore the risk factors and clinical implications of IABP-associated thrombocytopenia in patients with acute coronary syndrome (ACS).

METHODS

We retrospectively analyzed the data of 222 patients with ACS undergoing invasive treatment strategy supported by IABP. The incidence and risk factors of IABP-associated thrombocytopenia, and the association between thrombocytopenia and relevant clinical endpoints (in-hospital death, bleeding according to the TIMI scale, and thromboembolic events), were analyzed.

RESULTS

IABP-associated thrombocytopenia was observed in 54.5% (121/222) of the patients. The incidence of thrombocytopenia was higher and the magnitude of reduction in platelet count was greater in the Arrow balloon group (n = 89) compared with the Datascope balloon group (n = 133; 68.5% vs. 45.1%, p = 0.001; 48.7% vs. 33.2%, p < 0.001; respectively). Independent predictors of thrombocytopenia included older age and Arrow balloon utilization (odds ratio [OR]: 1.054; 95% confidence interval [CI]: 1.028-1.080; p<0.001; OR: 2.468; 95%CI: 1.375-4.431; p = 0.002; respectively). The incidence of in-hospital death was higher in patients who developed thrombocytopenia than those who did not (9.1% vs. 2.0%, p = 0.041), and thrombocytopenia was correlated with in-hospital death (OR: 5.932; 95%CI: 1.221-28.822; p = 0.027). However, the rates of TIMI bleeding and thromboembolic events were similar between the two groups (5.8% vs. 5.0%, p = 1.000; 3.2% vs. 6.0%, p = 0.518; respectively), and thrombocytopenia was not associated with TIMI bleeding or thromboembolic events (OR: 0.940; 95%CI: 0.267-3.307; p = 0.923; OR: 0.541, 95%CI: 0.148-1.974, p = 0.352; respectively).

CONCLUSION

IABP-associated thrombocytopenia occurred in 54.5% of patients with ACS undergoing an invasive strategy and it was correlated with increased in-hospital mortality. Older age and use of the Arrow balloon may predict IABP-associated thrombocytopenia.

Nonlinear Transition from Mitigation to Suppression of the Edge Localized Mode with Resonant Magnetic Perturbations in the EAST Tokamak

Evidence of a nonlinear transition from mitigation to suppression of the edge localized mode (ELM) by using resonant magnetic perturbations (RMPs) in the EAST tokamak is presented. This is the first demonstration of ELM suppression with RMPs in slowly rotating plasmas with dominant radio-frequency wave heating. Changes of edge magnetic topology after the transition are indicated by a gradual phase shift in the plasma response field from a linear magneto hydro dynamics modeling result to a vacuum one and a sudden increase of three-dimensional particle flux to the divertor. The transition threshold depends on the spectrum of RMPs and plasma rotation as well as perturbation amplitude. This means that edge topological changes resulting from nonlinear plasma response plays a key role in the suppression of ELM with RMPs.

Elevated Serum Concentration of Chitinase 3-Like 1 is an Independent Prognostic Biomarker for Poor Survival in Lung Cancer Patients

BACKGROUND/AIMS

The chitinase 3-like 1 (CHI3L1) has an important role in cancer progression, and high CHI3L1 expression is associated with the development and progression of cancers. Previous studies had been controversial with respect to the association between CHI3L1 expression and lung cancer prognosis. Thus, we performed a meta-analysis to investigate the prognostic value of CHI3L1 expression in lung cancer.

METHODS

We searched Pubmed, Embase, and Wanfang databases to identify eligible studies. Overall survival and disease free survival were collected from included studies. Pooled hazard ratios (HRs) with 95% confidence interval (95%CI) were calculated to estimate the association. Seven studies comprising 911 lung cancer patients were included in this meta-analysis.

RESULTS

The results showed high CHI3L1 expression was independently associated with poorer overall survival in lung cancer patients (HR = 1.71, 95%CI 1.24-2.37, P = 0.001). Subgroup analysis by histological type showed that high CHI3L1 expression was independently associated with poorer overall survival in both non small-cell lung cancer patients (HR = 2.23,95%CI 1.43-3.47, P < 0.001) and small-cell lung cancer patients (HR = 1.45, 95%CI 1.06-2.00, P = 0.021). In addition, sensitivity analysis by omitting single study by turns did not change the pooled outcomes obviously.

CONCLUSION

Our results suggest that elevated serum CHI3L1 concentration is an independent prognostic biomarker for poorer survival in lung cancer patients.

Effects of environmental factors on sperm motility and fertilization rate of Phascolosoma esculenta

The study investigated the effects of environmental factors (salinity, pH, ions and activation media) on sperm motility (activation rate, duration of quick movement, and lifespan) and fertilization rate of Phascolosoma esculenta. The results showed that spermatozoa in the coelom and nephridium are able to move quickly. The optimal salinity was 14.64 to 43.35 and the optimal pH was 6.46 to 9.53 for sperm activation and motility, whereas the ranges for fertilization were narrower (18.56 to 30.3 for salinity and 6.46 to 8.61 for pH). Of the ions studied, Na+ was indispensable for sperm motility and fertilization, and Ca2+ and Mg2+ were necessary for fertilization. P. esculenta sperm could not fertilize eggs and have short lifespans in 200 to 600 mmol/L NaCl and KCl solutions. Furthermore, they could not be activated or move in 200 to 600 mmol/L CaCl2, MgSO4, and sucrose solutions.

CMTM3 is frequently reduced in clear cell renal cell carcinoma and exhibits tumor suppressor activities

PURPOSE

CKLF-like MARVEL transmembrane domain containing member 3 (CMTM3) is silenced in many kinds of cancers and inhibits tumor cells growth. We investigated the expression and role of CMTM3 in clear cell renal cell carcinoma (ccRCC).

METHODS

The expression of CMTM3 was detected in ccRCC tissue microarray, specimens, and cell lines by immunohistochemistry, quantitative real-time polymerase chain reaction (qRT-PCR) and western blot, respectively. After transfected with CMTM3 plasmid or vector, the proliferation and migration of ccRCC 786-0 cells were determined by MTT assay and transwell assay, respectively. Furthermore, the anchorage-independent growth of transfected cells was assessed using soft agar colony formation assay.

RESULTS

CMTM3 was down-regulated in 84 % (63/75) of ccRCC tissues and its expression had no correlation with the gender, age, clinical staging and histologic grade. CMTM3 protein was undetectable by western blot in most detected ccRCC specimens and two RCC cell lines (786-0 and ACHN). qRT-PCR analysis showed that CMTM3 mRNA was dramatically down-regulated in 40 ccRCC cancer tissues as compared with the paired adjacent normal ones. Restoration of CMTM3 significantly suppressed the anchorage-independent growth, proliferation and migration of 786-0 cells.

CONCLUSION

These results indicate that CMTM3 is significantly down-regulated in ccRCC and exerts remarkable tumor-suppressive functions in 786-0 cells. Reduction of CMTM3 expression may contribute to the pathogenesis of ccRCC and CMTM3 may be a potentially target for therapeutic strategy.

[Analysis of prognostic factors in NSCLC patients with brain metastases diagnosed by constrast-enhanced MRI after whole brain radiotherapy]

背景与目的

肺癌脑转移约占脑转移瘤的20%-40%。本研究旨在探讨基于增强MRI诊断并行全脑放疗的非小细胞肺癌（non-small cell lung cancer, NSCLC）脑转移的预后因素。

方法

回顾性分析2007年4月-2008年10月241例NSCLC脑转移并接受全脑放疗的病例资料，采用Kaplan-Meier法计算生存率，Log-rank法进行单因素分析，Cox回归分析进行多因素分析。

结果

中位随访时间为19.1个月，全组中位生存时间为8.7个月。影响NSCLC脑转移生存的单因素包括女性、KPS（karnofsky performance score） > 70分、脑转移无症状、胸内病变控制、化疗3周期以上及合并靶向治疗。多因素分析显示性别、随访截止时胸内病变控制状态、靶向治疗是影响NSCLC脑转移生存的独立预后因素。

结论

对于基于增强MRI诊断并行全脑放疗的NSCLC脑转移患者，性别、胸内病变控制、靶向治疗是影响生存的独立预后因素。

Ethanol-induced neurodegeneration in NRSF/REST neuronal conditional knockout mice

The transcription regulator, neuron-restrictive silencer factor (NRSF), also known as repressor element-1 silencing transcription factor (REST), plays an important role in neurogenesis and various neuronal diseases such as ischaemia, epilepsy, and Huntington's disease. In these disease processes, neuronal loss is associated with abnormal expression and/or localization of NRSF. Previous studies have demonstrated that NRSF regulates the effect of ethanol on neuronal cells in vitro, however, the role of NRSF in ethanol-induced neuronal cell death remains unclear. We generated nrsf conditional knockout mice using the Cre-loxP system to disrupt neuronal expression of nrsf and its truncated forms. At postnatal day 6, ethanol significantly increased the expression of REST4, a neuron-specific truncated form of NRSF, in the brains of wild type mice, and this effect was diminished in nrsf conditional knockout mice. The apoptotic effect of ethanol was pronounced in multiple brain regions of nrsf conditional mutant mice. These results indicate that NRSF, specifically REST4, may protect the developing brain from ethanol, and provide new evidence that NRSF can be a therapeutic target in foetal alcohol syndrome (FAS).

Specific determinants of conantokins that dictate their selectivity for the NR2B subunit of N-methyl-D-aspartate receptors

Conantokins are naturally-occurring small peptide antagonists of ion flow through NMDA/glycine activated-N-methyl-d-aspartate receptor (NMDAR) ion channels. One member of the conantokin family, conantokin (con)-G, a 17-residue peptide, is selective for NMDARs containing the N-methyl-d-aspartate receptor subunit 2 B (NR2B), whereas the homologous peptides, con-T and con-R, show broader selectivity for NR2 subunits. In this study, con-G, con-R, and con-T variants were chemically synthesized and employed to investigate their subunit selectivities as inhibitors of agonist-evoked ion currents in human embryonic kidney-293 (HEK-293) cells expressing various combinations of NMDAR subunits that contain NR1a or NR1b combined with NR2A or NR2B. Using truncation and point mutants, as well as chimeric conantokins, we determined that the N-terminus of con-G contains all the determinants for NR2B selectivity. With this information, a large number of (con) variants were synthesized and used to establish minimal sequence determinants for selectivity. Tyr at position 5 broadens the NR2 selectivity, and recovery of NR2B selectivity in Tyr5 peptides was achieved by incorporating Ala or Gly at position 8. NR2B selectivity in con-R can be conferred through deletion of the Ala at position 10, thereby shifting the γ-carboxyglutamate (Gla) from position 11 to position 10, where a Gla naturally occurs in con-G and con-T. The nature of the amino acid at position 6 is also linked to subunit selectivity. Our studies suggest that the molecular determinants of conantokins that dictate NMDAR subunit selectivity are housed in specific residues of the N-termini of these peptides. Thus, it is possible to engineer desired NMDAR functional properties into conantokin-based peptides.

Study To Evaluate the Efficacy and Safety of Zoladex Combined with CEF Chemotherapy as Neo-Adjuvant Therapy in Hormone Responsive, Premenopausal, Operable Breast Cancer Patients

Purpose: To evaluate the efficacy and safety of Zoladex combined with CEF chemotherapy as neo-adjuvant therapy in hormone responsive, premenopausal, operable breast cancer patients.Patients and Methods: 119 patients with hormone responsive, premenopausal, operable breast cancer have been enrolled. Zoladex 3.6 mg was administered by subcutaneous injection per 4 weeks for 3 cycles, concurrently, CEF (CTX 600mg/m2, EPI 60-90 mg/m2, 5-Fu 500 mg/m2) were given per 3 weeks for 4 cycles as neo-adjuvant therapy. The primary objective was pathological complete response (PCR) rate in the breast. The secondary objectives included clinical complete response (CR) rate, clinical partial response (PR) rate, clinical overall response rate (ORR), safety and toxicity, change of biological marker status (ER, PR, HER-2) pre- and post-therapy.Results: 31 patients (26.1%) achieved clinical complete response and 76 patients (63.9%) achieved clinical partial response; the overall clinical response rate was 90.0%. 14 patients (11.8%) achieved pathologic complete response to T0/Tis, N0 and 20 patients (16.8%) achieved pathologic complete response to T0/Tis, Nx. When stratified by the clinical lymph-node status, the clinical partial response rate in clinical lymph-node negative group was significantly better than clinical lymph-node positive group (p=0.02). When stratified by the hormonal status, the clinical partial response rate in ER+PR+ group was significantly better than ER+PR- and ER-PR+ group (p=0.0471). There was no significant difference between HER-2+ group and HER-2- group when stratified by the HER-2 status. There was no treatment-related death and no grade 3 or grade 4 toxicity. The common adverse events were nausea (grade1 65.5%, grade2 18.5%), vomiting (grade1 58.8%, grade2 13.4%), alopecia (grade1 45.4%, grade2 54.6%). Other adverse events with more than 5% incidence included neutropenia (grade1 5.0%) and hepatic dysfunction (grade1 9.2%). There was no drug discontinuation and no drug delay or dose reduction occurred. Hormonal receptor became negative post-therapy in 11 patients' (9.2%), which clinical response rate significantly lower compared with post-therapy hormonal receptor positive group (p&lt;0.001). The change of HER-2 status had no relationship with clinical efficacy. 109(91.6%) patients achieved amenorrhea after the first cycle of Zoladex, 10(8.4%) patients achieved amenorrhea after the second cycle of Zoladex. Mean period of amenorrhea was 6 months (4–17 months). 43 patients have been followed up for more than 1 year after operation and among them 6(14.0%) patients still remain amenorrhea.Conclusion: Zoladex combined with CEF chemotherapy as neo-adjuvant therapy in hormone responsive, premenopausal breast cancer patients was more effective and had no more toxicity than CEF chemotherapy alone. This regimen was most effective especially in the clinical lymph-node negative group and ER/PR double positive group. The clinical response rate will be lower if the hormonal receptor became negative after therapy. The efficacy of this regimen has no relationship with HER-2 status.

Citation Information: Cancer Res 2009;69(24 Suppl):Abstract nr 4087.

Ischemia and reperfusion reduce the endogenous basic fibroblast growth factor in rat skeletal muscles: an immunohistochemical study

Polyclonal antibodies directed against human recombinant basic fibroblast growth factor were used in immunohistochemical studies to localize this growth factor in normal and wounded rat skeletal muscles. According to the intensity of the stain, three main classes of fibers could be identified: the strongly, moderately, and weakly stained fibers. Basic fibroblast growth factor immunoreactivity was found mainly in the extracellular matrix, primarily in the endomysium, which includes the heparin-containing basal lamina, and also in the capillary basal membrane of both normal and wounded muscles; however, the signal intensity was much stronger in normal muscles. The distribution of basic fibroblast growth factor in wounded muscles became markedly heterogeneous and sparse. After 4 hours of ischemia, about 40% of skeletal muscle fibers lost their basic fibroblast growth factor immuno-reactivity. Muscles which underwent 4 hours of ischemia and 24 hours of reperfusion had only a diminished basic fibroblast growth factor immunoreactivity. The pathologic results supported the concept of destroyed cell connection and fiber necrosis in ischemic and reperfused muscles. Potential mechanisms involved in this reduced concentration of basic fibroblast growth factor in wounded muscles may include oxygen free radical activation, a generalized effect of the inflammatory response, and reduced secretion of endogenous basic fibroblast growth factor. These results are only partially compatible with the established mitogenic role of this growth factor and suggest that a reduction of endogenous fibroblast growth factor may partly contribute to a delay in wound healing.

Acidic fibroblast growth factor reduces renal morphologic and functional indicators of injury caused by ischemia and reperfusion

Therapeutic effects of acidic fibroblast growth factor on postischemic renal injury were evaluated in a rat model of bilateral renal ischemia (60 minutes) and reperfusion (7 days). Twenty-four rats were randomly divided into two groups (12 rats each). After 60 minutes of ischemia and at the onset of reperfusion, rats in the acidic fibroblast growth factor-treated group received 2.6 microg of acidic fibroblast growth factor/rat in 50 microl of phosphate-buffered saline solution containing 0.1% heparin (w/v) through the jugular vein, whereas the rats in the phosphate-buffered saline solution-treated group received the same vehicle without acidic fibroblast growth factor. Compared with the phosphate-buffered saline solution-treated group, rats in the acidic fibroblast growth factor-treated group had significantly lower blood urea nitrogen (83.13 +/- 26.07 versus 176.36 +/- 62.36, p < 0.05) and serum creatinine (0.73 +/- 0.14 versus 1.14 +/- 0.36, p < 0.05) levels 1 day after occlusion. Histopathologic scores showed much less renal damage on day 1 in the acidic fibroblast growth factor-treated rats compared with the phosphate-buffered saline solution controls. We conclude that intravenous administration of acidic fibroblast growth factor offers significant protection against postischemic renal injury and these protective effects may come from its nonmitogenic effects such as the regulation of vessel tone and calcium concentration in the body.

Dedifferentiation of epidermal cells to stem cells in vivo

The effects of growth factors on wound healing have been studied extensively; however epidermal regeneration is not fully understood. We treated eight patients with leg ulcers with recombinant human epidermal growth factor (rhEGF) and compared biopsies of regenerating epidermis with those of controls who did not receive rhEGF. We used immunohistochemistry to identify cells expressing keratin 19 and beta1 integrin in regenerated epidermis from patients and controls. Patients treated with rhEGF had stem cells in the spinous and granular layers of regenerated epidermis. Histological analysis showed that these stem cells had reverted from differentiated to undifferentiated stem cells. Our findings provide evidence for epidermal cell reversion.

[Effect of sepsis on the expression of ubiquitin and ubiquitinated protein in rat skeletal muscle]

OBJECTIVE

To study the regularity of ubiquitin and ubiquitinated protein expression in rat skeletal muscle during sepsis, and the molecular mechanism of enhancement in skeletal muscle protein catabolism.

METHODS

Wistar rats with sepsis were administered endotoxin peritoneally. The rats were randomly divided into 4 groups rats: 2, 6, 12 and 24 h after administration of endotoxin; each group (16) included normal controls. In vitro muscle incubation system with sufficient oxygen supply was used with amino acid automatic analyzer for detecting the proteolytic rate of the extensor digitorium longus(EDL) and soleus(SOL) muscle in the sample. The expression of ubiquitin and ubiquitinated protein in rat EDL muscle was determined by western blot.

RESULTS

Total proteolytic rate in the EDL muscle increased slightly at 2 and 6 h after administering endotoxin into the peritoneal cavity, and no significant difference at 12 and 24 h was observed. There was a progressive increase of 155% and 220% in myofibrillar proteolytic rate at 2 and 6 h, and 40% at 12 h, respectively, as compared with that of the normal controls. The expression of ubiquitin and ubiquitinated protein in the EDL muscle rose by 46% and 2.4 fold at 2 h and 6 h after administering endotoxin, while the ubiquitinated protein of high molecular weight was determined. No significant changes were noted in the expression of ubiquitin and ubiquitinated protein at 12 and 24 h.

CONCLUSION

The results indicate that activation of ubiquitin-proteasome pathway occurs in rat skeletal muscle during sepsis, and high expression of ubiquitin and ubiquitinated protein means that the substrate flowing into ubiquitin-proteasome pathway increases markedly, and then leads to muscle wasting.