EFFECT OF DORSOMEDIAL HYPOTHALAMUS NEUROPEPTIDE Y KNOCKDOWN ON HEPATIC INSULIN SENSITIVITY

Objective

In this study we investigated the effect of dorsomedial hypothalamus (DMH) neuropeptide Y (NPY) knock-down on hepatic insulin sensitivity in high-fat (HF) diet-fed rats.

Methods

Forty-eight Sprague-Dawley rats were randomly assigned to receive bilateral DMH injections of adeno-associated virus AAVshNPY or AAVshCTL and then accessed to regular chow. Five weeks after viral injection, half rats in each group were given access to the HF diet. At 16 weeks, rat livers were collected. Insulin receptor substrate-1 (IRS-1) and phosphoinositide 3-kinase (PI3K) mRNA expression was measured by qRT-PCR. Blood glucose levels were measured by the oxidase method, serum insulin, triglyceride, and TC levels were measured by Elisa. Pathological changes in the liver were assessed by hematoxylin-eosin (HE) staining. AKT, p-AKT, and GSK-3 levels were measured by western blotting.

Results

Compared with AAVshCTL-injected rats, AAVshNPY-injected rats showed a significant decrease in blood glucose concentrations; serum insulin, triglyceride, and TC; HOMA-IR; and IRS-1 and PI3K mRNA levels (P<0.05). ISI, GSK-3, and p-AKT levels were significantly increased (P<0.05). HE staining showed that AAVshNPY-injected rats fed the HF diet had mild fatty degeneration.

Conclusion

These results suggest that DMH NPY knock-down improves hepatic insulin sensitivity in HF diet-fed rats by activating the hepatic PI3K/AKT insulin signalling pathway.

[Development of influenza control programs in children]

Based on the characteristics of influenza occurred in 2017 and 2018, we discussed the current development and update on the etiology, mechanism, clinical characteristics, laboratory examination, treatment and prevention for influenza in children, in order to draw attention on the awareness and capacity in prevention and treatment programs targeting child influenza among physicians and health workers.

Establishment of a new fish cell line from the caudal fin of golden pompano Trachinotus ovatus and its susceptibility to iridovirus

A new cell line derived from the caudal fin of golden pompano Trachinotus ovatus (TOCF) was successfully established and characterized. TOCF cells grew well at 28° C in L-15 medium supplemented with 10% foetal bovine serum (FBS). The cell line has been subcultured in more than 100 passages. Molecular characterization of 18S ribosomal (r)RNA and cytochrome oxidase subunit 1 (COI) confirmed that the TOCF cells were derived indeed from T. ovatus. TOCF cells have a modal chromosome number of 54. It was further showed that TOCF cells were transfected successfully with pEGFP-N3 and pDsRED-N1 plasmid, suggesting that TOCF cells could be used to research gene functions in vitro. Viral susceptibility tests showed that TOCF cells were susceptible to Singapore grouper iridovirus (SGIV), observed by the occurrence of the cytopathic effect (CPE) with the formation of inclusion bodies. In addition, the expression of major capsid protein (MCP) gene of SGIV changed during virus infection in TOCF cells. Thus, our present results described the characteristic of a TOCF cell line that could be a valuable tool for genetic manipulation, as well as isolation and propagation of iridovirus studies.

[Safety and efficacy of rotational atherectomy in the interventional treatment of coronary chronic total occlusion lesions]

Objective: To investigate the safety and efficacy of rotational atherectomy in the interventional treatment of coronary chronic total occlusion lesions. Methods: In this retrospective study,a total of 31 consecutive patients with coronary chronic total occlusion(CTO) lesions underwent rotational atherectomy in our hospital from February 2004 to December 2016 were enrolled,and the clinical features were analyzed. Coronary atherectomy was performed if balloon failed to cross the CTO lesions or balloon could not be fully dilated in the CTO lesions after wire crossing. The definition of procedure success was defined as residual stenosis less than 20% after implantation of drug eluting stent and rotational atherectomy. After the procedure, the patients were followed up to observe major adverse cardiac and cerebral vascular events which including cardiogenic death, myocardial infarction, cerebrovascular accident, and target lesion revascularization. Results: The 1.25 mm diameter burr was firstly selected in 80.6% (25/31) patients,and 96.8%(30/31) patients used only 1 burr to complete the rotational atherectomy procedure. The complication rate was 9.8% (3/31) including 1 patient with coronary dissection and 3 patients with slow flow or no flow. There was 1 patent with both coronary dissection and slow flow. The procedure success rate was 96.8%(30/31). Interventional treatment related myocardial infarction occurred in 3 patients during hospitalization.The 30 patients with procedure success were followed up 36(11, 96) months. The incidence rate of major adverse cardiac and cerebral vascular events was 13.3% (4/30), of which the cardiogenic death rate was 3.3% (1/30), the myocardial infarction rate was 6.7% (2/30), cerebrovascular accident rate was 3.3%(1/30),and the target lesion revascularization rate was 6.7% (2/30). Conclusion: Rotational atherectomy is safe and effective in the interventional treatment of coronary CTO lesions.

Impact of carbohydrates on autoinducer-2 secretion of Bifidobacterium longum subsp. longum BBMN68

In this study, the regularity of autoinducer-2 (AI-2) secretion during growth and the effect of the addition of various carbohydrates on AI-2 secretion in Bifidobacterium longum subsp. longum BBMN68 were investigated. The results indicated that the AI-2 concentration reached its highest level (2536·60 nmol l^-1 ) at the early stationary growth phase, and then decreased to 1263·72 nmol l^-1 at the late stationary growth phase in Bifidobacterium cultures. When the density of the cultures which mannose, fructose, sucrose and lactose had been added to reached an OD_600 nm of 1·0, the AI-2 concentrations in the cultures were 1953·84, 1637·34, 1200·99 and 1077·60 nmol l^-1 , respectively. These concentrations were all significantly higher than that of the control culture (1031·33 nmol l^-1 ). Similarly, the addition of fructooligosaccharide significantly increased the AI-2 concentrations to 2094·29 nmol l^-1 . This study provides the advanced evidence that certain carbohydrates promote the secretion of AI-2, and that this occurs at the single cell level and is therefore unaffected by cell density.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provided the advanced data of the regularity of autoinducer-2 (AI-2) secretion during growth and the promotion on AI-2 secretion of different added carbohydrates in Bifidobacterium, which may be a new potential strategy to improve the acid resistance of Bifidobacterium applied in the food industry.

Veliparib with temozolomide or carboplatin/paclitaxel versus placebo with carboplatin/paclitaxel in patients with BRCA1/2 locally recurrent/metastatic breast cancer: randomized phase II study

Background

Homologous recombination defects in BRCA1/2-mutated tumors result in sensitivity to poly(ADP-ribose) polymerase inhibitors, which interfere with DNA damage repair. Veliparib, a potent poly(ADP-ribose) polymerase inhibitor, enhanced the antitumor activity of platinum agents and temozolomide in early phase clinical trials. This phase II study examined the safety and efficacy of intermittent veliparib with carboplatin/paclitaxel (VCP) or temozolomide (VT) in patients with BRCA1/2-mutated breast cancer.

Patients and methods

Eligible patients ≥18 years with locally recurrent or metastatic breast cancer and a deleterious BRCA1/2 germline mutation were randomized 1 : 1 : 1 to VCP, VT, or placebo plus carboplatin/paclitaxel (PCP). Primary end point was progression-free survival (PFS); secondary end points included overall survival (OS) and overall response rate (ORR).

Results

Of 290 randomized patients, 284 were BRCA+, confirmed by central laboratory. For VCP versus PCP, median PFS was 14.1 and 12.3 months, respectively [hazard ratio (HR) 0.789; 95% CI 0.536-1.162; P = 0.227], interim median OS 28.3 and 25.9 months (HR 0.750; 95% CI 0.503-1.117; P = 0.156), and ORR 77.8% and 61.3% (P = 0.027). For VT (versus PCP), median PFS was 7.4 months (HR 1.858; 95% CI 1.278-2.702; P = 0.001), interim median OS 19.1 months (HR 1.483; 95% CI 1.032-2.131; P = 0.032), and ORR 28.6% (P < 0.001). Safety profile was comparable between carboplatin/paclitaxel arms. Adverse events (all grades) of neutropenia, anemia, alopecia, and neuropathy were less frequent with VT versus PCP.

Conclusion

Numerical but not statistically significant increases in both PFS and OS were observed in patients with BRCA1/2-mutated recurrent/metastatic breast cancer receiving VCP compared with PCP. The addition of veliparib to carboplatin/paclitaxel significantly improved ORR. There was no clinically meaningful increase in toxicity with VCP versus PCP. VT was inferior to PCP. An ongoing phase III trial is evaluating VCP versus PCP, with optional continuation single-agent therapy with veliparib/placebo if chemotherapy is discontinued without progression, in this patient population.

Clinical trial information

NCT01506609.

Rapid and sensitive detection of redspotted grouper nervous necrosis virus (RGNNV) infection by aptamer-coat protein-aptamer sandwich enzyme-linked apta-sorbent assay (ELASA)

Redspotted grouper nervous necrosis virus (RGNNV) is one of the most devastating pathogens in the aquaculture of the grouper, Epinephlus sp., worldwide. The early and rapid diagnosis of RGNNV is important for the prevention of RGNNV infection. In this study, an aptamer (A10)-based sandwich enzyme-linked apta-sorbent assay (ELASA) was developed for RGNNV diagnosis. This sandwich ELASA showed high specificity for the RGNNV coat protein (CP) and virions in virus-infected cells and tissues. At the optimized working concentration of 200 nM of aptamer, the ELASA could detect RGNNV in the lysates of as few as 4 × 10³ RGNNV-infected GB cells. Incubation for 10 min was sufficient to produce accurate results. The sandwich ELASA was most stable at incubation temperatures of 4-25°C, but could still distinguish RGNNV-infected samples from the controls at 37°C. It could detect RGNNV infection in brain lysates diluted 1/10, with results consistent with those of reverse transcription PCR, although with 10% less sensitivity. The main equipment required includes dissection tools, a water bath, Pierce™ Streptavidin Coated Plates and a microplate reader. The sandwich ELASA has great potential utility for the rapid and sensitive diagnosis of RGNNV in its early stages by fish farmers.

[Refractory kaposiform hemangioendothelioma with Kasabach-Merritt syndrome: clinical analysis of 10 cases]

Objective: To analyze the clinical value of sirolimus plus prednisone for the treatment of the refractory kaposiform hemangioendothelioma(RKHE) and Kasabach-Merritt syndrome(KMS). Method: Clinical retrospective analysis was carried out for 10 patients recruited in Children's Hospital Affiliated to Capital Institute of Paediatrics from January 2014 to January 2017 who were non responders to or relapsers after the treatment of propranolol, prednisone, pingyangmycin and lauromacrogol(5 cases RKHE, 5 cases RKHE plus KMS, age ranged from 6 days to 9 years); patients were treated with sirolimus at the dosage of 0.035 ml/(kg·d), once a day, for 6-410 days; the diagnosis of 10 patients were confirmed by pathological biopsy and immunohistochemical examination(IHC); the difference of the coagulation parameters and the platelet counts, the size of tumor and ecchymosis at different stages of treatment were recorded and measured by scale and ultrasonography; the side effects of sirolimus were recorded as well. Result: Clinical characteristics of 10 cases (6 male and 4 female) RKHE with KMS were refractory dark red hard hemangioma or ecchymosis, the platelet counts were lower than 30.0×10(9)/L, (15±7)×10(9)/L, coagulation tests were obviously abnormal, fibrinogens were significantly decreased(0.8±0.5)g/L, the fibrin lysates and D-dimer were significantly increased(100±23)mg/L, (10 000±2 200)ng/L, the prothrombin time and activated partial thromboplastin time were prolonged(25.0±2.1)s, (58.0±3.4)s. The pathologic characteristics of the tumors were similar: spindle tumor cells, mass distribution and deeply stained nuclei tumor cells. IHC revealed positive staining for D2-40, CD31 and CD34. Stainings for factor Ⅷ and GLUT-1 were negative. In five cases RKHE plus KMS were treated with sirolimus and prednisone, after (6.5±0.7) days treatment, the platelet counts were obviously increased(72.0±0.6)×10(9)/L, coagulation parameters were obviously improved, fibrinogen significantly increased(1.5±0.2)g/L, the fibrinlysates and D-dimer significantly decreased(7±3)mg/L, (2 300±200)ng/L, the prothrombin time and activated partial thromboplastin time were prolonged(15±2.3)s, (42±3.4) s, and the sizes of tumor and ecchymosis were slightly shrunken 18%±3%, 38%±5%; after (30±5.7) days treatment, the platelet counts and coagulation parameters returned to normal(146±36)×10(9)/L, and the size of tumor and ecchymosis were obviously shrunken 73%±3%, 97%±3%; after (3±0.4) months treatment, the tumor was obviously shrunken by 93%±2% and no longer palpable. In five cases with RKHE without KMS manifested stubborn dark red hard hemangiomatous plaques, coagulation tests and platelet were obviously normal, these patients were treated with sirolimus, after (2.0±0.6) months treatment, the tumor became shrunken 8%±3%, with continuous treatment the tumor shrunk gradually, after (4.0±3.2)months(2-18 mouths) the tumor was not eliminated 51%±7%. Conclusion: RKHE and KMS have typical clinical, laboratory and pathological characteristics, sirolimus plus prednisone have remarkable efficacy and minor side effects, it should be recommended for the treatment of KHE with KMS.

PDZK1 inhibits the development and progression of renal cell carcinoma by suppression of SHP-1 phosphorylation

Renal cell carcinoma (RCC) is one of the most aggressive urologic cancers, however, the mechanism on supporting RCC carcinogenesis is still not clear. By using gene expression profile analysis and functional clustering, PDZ domain-containing 1 (PDZK1) was revealed to be downregulated in human clear cell renal cell carcinoma (ccRCC) samples, which was also verified in several independent public ccRCC data sets. Using PDZK1 overexpression and knockdown models in ccRCC cell lines, we demonstrated that PDZK1 inhibited cell proliferation, cell cycle G1/S phase transition, cell migration and invasion, indicating a tumor-suppressor role in the development and progression of ccRCC. Our study further demonstrated that PDZK1 inhibited cell proliferation and migration of ccRCC via targeting SHP-1. PDZK1 was further identified to suppress cell proliferation by blocking SHP-1 phosphorylation at Tyr536 via inhibition of the association between SHP-1 and PLCβ3, and then retarding Akt phosphorylation and promoting STAT5 phosphorylation in ccRCC cells. Moreover, the inhibitive effects of PDZK1 on SHP-1 phosphorylation and the tumor growth were verified in vivo by xenograft tumor studies. Accordingly, PDZK1 expression was negatively correlated with SHP-1 activation and phosphorylation, advanced pathologic stage, tumor weight and size, and prognosis of ccRCC patients. These findings have provided first lines of evidences that PDZK1 expression is negatively correlated with SHP-1 activation and poor clinical outcomes in ccRCC. PDZK1 was identified as a novel tumor suppressor in ccRCC by negating SHP-1 activity.

Establishment and characterization of a cell line from the head kidney of golden pompano Trachinotus ovatus and its application in toxicology and virus susceptibility

A cell line derived from the head kidney of golden pompano Trachinotus ovatus (TOHK) was established and characterized in this study. The TOHK cells grew most rapidly at 28° C and the optimum foetal bovine serum concentration in L-15 medium was 10%. The TOHK cells have a diploid chromosome number of 2N = 54. The transfection efficiency of TOHK cells was 7·5% at the 15th passage and 72% at the 40th passage. The transfection efficiency in TOHK cells was high, so these cells are suitable for foreign gene expression. The cytotoxic effects of heavy metals and extracellular products from Vibrio anguillarum and Vibrio alginolyticus were demonstrated in TOHK cells, so this TOHK cell line could also be applied in environmental monitoring of heavy metals and pathogenic bacteria. TOHK cell line showed high virus susceptibility, such as grouper nervous necrosis virus (GNNV) and Singapore grouper iridovirus (SGIV). Then, TOHK cell line could be used for the study of viral pathogenesis and the development of antiviral strategies.

Abstract P4-22-02: Evaluation of veliparib (V) and temozolomide (TMZ) in a phase 2 randomized study of the efficacy and tolerability of V+TMZ or carboplatin (C) and paclitaxel (P) vs placebo (Plc)+C/P in patients (pts) with BRCA1 or BRCA2 mutations and metastatic breast cancer

Background: V is a potent, poly(ADP-ribose) polymerase (PARP) inhibitor that obstructs DNA damage repair. BRCA1/2 tumors are defective in homologous recombination, which leads to more error-prone mechanisms of DNA repair and increased sensitivity to PARP inhibition. V enhances the antitumor activity of alkylating agents such as TMZ in preclinical models. In addition, V+TMZ showed promising activity in a single-arm phase 2 study in pts with BRCA1/2 mutations. This phase 2 trial (NCT01506609) investigated the efficacy and tolerability of V+TMZ (or V+C/P) compared to Plc+C/P in pts with locally recurrent or metastatic breast cancer harboring a BRCA1 or BRCA2 mutation. Results from the primary analysis for the V+TMZ arm vs Plc+C/P are presented, and the V+C/P vs Plc+C/P results will be presented separately.

Methods: Male and female pts aged ≥18 years with histologically confirmed locally recurrent or metastatic breast cancer were randomized 1:1:1 to: 1) V 40 mg BID D1–7 + TMZ 150–200 mg/m2 QD D1–5, 28-D cycle; 2) V 120 mg BID D1–7 + C AUC 6, D3 and P 175 mg/m2, D3, 21-D cycle; 3) placebo BID D1–7 + C/P. Key eligibility criteria included known deleterious BRCA1/2 mutation, ≤2 prior chemotherapies for metastatic disease, no prior platinum agent, and no CNS metastases. Randomization was stratified by hormone receptor status, prior cytotoxic therapy (yes vs no), and ECOG PS (0–1 vs 2). The primary endpoint was progression-free survival (PFS) per RECIST 1.1 by independent review. Overall survival (OS), objective response rate (ORR), and safety/tolerability were also evaluated.

Results: A total of 290 pts (284 BRCA+ per central lab) were randomized (V+TMZ, n=94 [91 BRCA+]). Baseline demographics and disease characteristics were comparable among treatment arms; 41.3% of pts had triple-negative breast cancer (TNBC) and 31.7% had received &gt;2 prior regimens. Median study drug exposure was 6 cycles for the V+TMZ arm and 10 cycles for the Plc+C/P arm. Median PFS, median OS (interim), and ORR for V+TMZ were inferior to Plc+C/P (PFS 7.4 vs 12.3 mo, OS 19.1 vs 25.0 mo, and ORR 28.6% vs 61.3%). In pts with TNBC, median PFS was 5.5 (3.1–8.5) mo; 8.4 (6.8–10.6) mo for pts with non-TNBC. Treatment-emergent adverse events (AEs) of interest occurring differentially with V+TMZ are shown in Table 1. Grade ≥3 AEs in ≥30% of pts in the V+TMZ arm were thrombocytopenia (48%) and neutropenia (37%).

Conclusions: V+TMZ provided durable responses, with less neutropenia, alopecia, and neuropathy than Plc+C/P; however, PFS, OS, and ORR were inferior in the TMZ arm compared to C/P.

Table 1Treatment-Emergent AEs, n (%)V+TMZ, n=93Plc+C/P, n=96Neutropenia46 (50)71 (74)Alopecia10 (11)55 (57)Peripheral neuropathy11 (12)56 (58)Thrombocytopenia73 (79)67 (70)Nausea70 (75)56 (58)

Citation Format: Diéras V, Han HS, Robson ME, Palácová M, Marcom PK, Jager A, Bondarenko I, Citrin D, Campone M, Telli ML, Domchek SM, Friedlander M, Kaufman B, Ratajczak C, Coates A, Bonnet P, Qin Q, Qian J, Giranda VL, Shepherd SP, Puhalla S, Isakoff SJ. Evaluation of veliparib (V) and temozolomide (TMZ) in a phase 2 randomized study of the efficacy and tolerability of V+TMZ or carboplatin (C) and paclitaxel (P) vs placebo (Plc)+C/P in patients (pts) with BRCA1 or BRCA2 mutations and metastatic breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-22-02.

Sunitinib modulates the radiosensitivity of esophageal squamous cell carcinoma cells in vitro

This study aims to explore the radiosensitivity of sunitinib on esophageal cancer cell lines. For in vitro studies, human esophageal squamous cell carcinoma (ESCC) cell lines were treated with sunitinib 24 hours before irradiation. ESCC cell lines were treated with sunitinib with or without radiation. Cell proliferation was detected by Cell Counting Kit 8 assay. Radiosensitization was evaluated by clonogenic survival assay. Cell apoptosis and cell cycle analysis were detected by flow cytometry. Deoxyribonucleic acid (DNA) double-strand breaks were performed by immunocytofluorescence analysis. Western blot analysis was used to determine the effect of sunitinib on radiation induced signal transduction. Sunitinib potently sensitized ESCC cells to radiation with a sensitization enhancement ratio of 1.13-1.72. Furthermore, sunitinib increased radiation induced DNA double-strand breaks, promoted the apoptosis of ESCC cells and induced the G2/M arrest. Radiosensitization was accompanied with enhanced apoptosis and regulated by the intrinsic pathway of apoptosis. Sunitinib sensitized ESCC cells to the cytotoxic effects of radiation. This compound is promising for future clinical trials with chemoradiation in esophageal cancer.

Development and characterization of aptamer-based enzyme-linked apta-sorbent assay for the detection of Singapore grouper iridovirus infection

AIMS

Singapore grouper iridovirus (SGIV) is a devastating aquaculture virus responsible for heavy economic losses to grouper, Epinephelus sp. aquaculture. The aim of this study was to develop a rapid and sensitive detection method for SGIV infections in infected groupers.

METHODS AND RESULTS

We previously generated DNA aptamers against SGIV-infected cells. In this study, we established and characterized a novel aptamer (Q3)-based enzyme-linked apta-sorbent assay (ELASA) for the detection of SGIV infection in Epinephelus coioides. The Q3-based ELASA could detect SGIV infection rapidly in vitro and in vivo, with high specificity and stability. Q3-based ELASA specifically recognized SGIV-infected cells, but not other-virus-infected cells or uninfected cells. Q3-based ELASA detected SGIV infection in a dose-dependent manner at Q3 concentrations as low as 125 nmol l(-1) . The results in relation to SGIV-infected cells (5 × 10(4) ), incubation time (1 min) and incubation temperature (37°C) demonstrated that Q3-based ELASA could detect SGIV infection quickly and stably, superior to antibody-based enzyme-linked immunosorbent assay. Q3-based ELASA could detect the presence of SGIV infection in kidney, liver and spleen samples in vivo, at dilutions of 1/50, 1/100 and 1/50 respectively. The complete detection process took 1-2 h.

CONCLUSIONS

Q3-based ELASA could be a useful tool for diagnosing SGIV infection.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first developed aptamer-based ELASA for detecting SGIV infection, and is widely applicable in grouper aquaculture industry in light of its rapidity, and high specificity and stability.

Establishment of a new cell line from the snout tissue of golden pompano Trachinotus ovatus, and its application in virus susceptibility

A new marine-fish cell line, designated GPS, was established from the snout tissue of golden pompano Trachinotus ovatus. GPS cells multiplied well in Leibovitz's L-15 containing 10% foetal bovine serum (FBS) at 28° C and the cells have been subcultured for >60 passages. Polymerase chain reaction (PCR) amplification of 16S ribosomal (r)RNA confirmed the origin of this cell line from T. ovatus. Chromosome analysis showed that GPS cells exhibited chromosomal aneuploidy with a modal chromosome number of 54. Bright green fluorescence signal was observed in enhanced green fluorescent protein (EGFP)-N3 transfected cells, indicating that GPS cells could be used to investigate gene functions in vitro. The GPS cells were highly susceptible to Singapore grouper iridovirus (SGIV), which was demonstrated by the presence of severe cytopathic effect (CPE) and increased viral titres. Real-time quantitative PCR and Western blot analysis showed that the viral gene transcription and protein synthesis occurred during SGIV infection in GPS cells. Thus, this study described the characteristic of a new cell line from the snout tissue of T. ovatus that could be used as a tool for propagation of iridovirus and genetic manipulation to investigate host-pathogen interactions.

Novel poly (ADP-ribose) polymerase inhibitor, AZD2281, enhances radiosensitivity of both normoxic and hypoxic esophageal squamous cancer cells

Radiotherapy plays an important role in the treatment of esophageal squamous cell carcinoma (ESCC). However, the outcome of radiotherapy in ESCC remains unsatisfactory because esophageal squamous cancer cells, particularly those under hypoxic condition, exhibit radioresistance. The aim of this study was to determine whether or not AZD2281, a potent poly (ADP-ribose) polymerase (PARP) inhibitor, could enhance the radiation sensitivity of two ESCC cell lines, namely ECA109 and TE13. The radiosensitizing effect of AZD2281 was evaluated on the basis of cell death, clonogenic survival and tumor xenograft progression. AZD2281 alone was slightly toxic to ESCC cell lines. Apoptosis was increased and clonogenic survival was decreased in both cell lines when AZD2281 was combined with ionizing radiation (IR) under normoxic condition. AZD2281 enhanced IR-induced apoptosis to a more significant level under chronic hypoxic condition (0.2% O(2), 48 hour) than under normoxic condition. AZD2281 also slightly enhanced clonogenic cell death under chronic hypoxic condition compared with that under normoxic condition. This result could be associated with increased radiation-induced DNA double-strand breaks (DSB), decreased DSB repair and increased apoptosis of ESCC cells. Furthermore, homologous recombination (HR) protein Rad51 expression and focus formation were decreased in ESCC cells exposed to moderate chronic hypoxic condition (0.2% O(2), 48 hour); this result indicated that chronic hypoxic ESCC cells were HR deficient, possibly causing contextual synthetic lethality with PARP inhibitor in radiation sensitization. AZD2281 was also a radiation sensitizer in ESCC tumor xenograft models. Hence, in vitro and in vivo findings provide evidence that AZD2281 potently sensitizes ESCC cells to X-ray irradiation. The selective cell killing of HR-defective hypoxic cells contributes to radiosensitization by PARP inhibitor in ESCC cells under hypoxic condition.

Acupuncture at heterotopic acupoints facilitates distal colonic motility via activating M3 receptors and somatic afferent C-fibers in normal, constipated, or diarrhoeic rats

BACKGROUND

Previous studies have demonstrated the efficacy of somatic stimulation for patients with gastrointestinal motility disorders. However, little effort has been made to investigate the effects of acupuncture on colonic motility, particularly in pathological conditions. The precise mechanism employed in the regulation of acupuncture on colonic motility still remains unclear.

METHODS

We assessed the effect of acupuncture at heterotopic acupoints on distal colonic motility using a warm-water-filled manometric balloon inserted 5-6 cm into the rectum of anesthetized normal rats or rats with diarrhea or constipation. Choline chloride, 4-DAMP, cobra venom and capsaicin were separately applied to investigate the role of M3 receptors in the regulation of distal colonic motility by acupuncture at heterotopic acupoints, and whether Aδ- and/or C-fibers are required for triggering distal colonic motility by acupuncture.

KEY RESULTS

Acupuncture at heterotopic acupoints increased distal colonic motility not only in normal rats but also in rats with constipation or diarrhea. M3 receptors play an important role in the facilitation of distal colonic motility triggered by acupuncture at heterotopic acupoints. Afferent nerve Aδ- and C-fibers mediate the transduction of the acupuncture signal and C-fibers are essential for enhancing the effect of acupuncture at the heterotopic acupoint on distal colonic motility.

CONCLUSIONS & INFERENCES

Our results reveal that acupuncture at heterotopic acupoints increases distal colonic motility regardless of normal or pathological conditions via predominately activating C-fibers of somatic afferent nerve and M3 receptors.

Effect of melatonin on oncosis of myocardial cells in the myocardial ischemia/reperfusion injury rat and the role of the mitochondrial permeability transition pore

We aimed to evaluate the effect of melatonin on myo-cardial cell oncosis in the myocardial ischemia/reperfusion injury rat, and the role of the mitochondrial permeability transition pore (MPTP) therein. Sprague Dawley rats (N = 60) were randomly divided into five groups of 12 rats each: control, ischemia/reperfusion (I/R), melatonin treatment (MT), melatonin treatment + atractyloside (MT+ATR), and atractyloside (ATR). We prepared the myocardial ischemia/reperfusion model by reperfusion after the left anterior descending coronary artery was ligated for 30 min. The MT rats were given a 10 mg/kg MT intra-venous injection immediately thereafter; the MT+ATR rats were also given a 5 mg/kg ATR intravenous injection 15 min before the ischemia; the ATR rats were given the ATR injection only. After 2-h re-perfusion, myocardial tissue was extracted, the infarction size was determined, and myocardial ultrastructures were observed using electron microscopy. The expression level of the preoncosis receptor (porimin), which can induce membrane injury, was determined by western blot; the nicotinamide adenine dinucleotide (NAD(+)) content was determined spectrophotometrically. The four treatment groups showed upregulat-ed expression of myocardial porimin, increased myocardial infarction size, and reduced NAD(+) content (P < 0.05). Compared with the I/R and MT+ATR groups, MT rats showed downregulated expression of myo-cardial porimin, reduced myocardial infarct size, and increased myo-cardial cell NAD(+) content (P < 0.05). The above indices between the ATR and MT+ATR groups were not significantly different (P > 0.05). Thus, MT might protect myocardial ischemia/reperfusion rats by inhibiting MPTP opening and reducing myocardial cell oncosis.

TTAGG-repeat telomeres and characterization of telomerase in the beet armyworm, Spodoptera exigua (Lepidoptera: Noctuidae)

Telomeres are maintained usually by telomerase, a specialized reverse transcriptase that adds this sequence to chromosome ends. In this study, telomerase activity was detected in the in different somatic tissues, such as midgut and fat bodies, by the telomeric repeat amplification protocol (TRAP) in Spodoptera exigua. The structure of the telomeres of S. exigua was evaluated by sequence analysis of the TRAP products, revealing that the telomerase synthesized a (TTAGG)n repeat. The presence of a telomerase reverse transcriptase (TERT) subunit coding gene has been cloned, sequenced and expressed in vitro successively. Notably, the S. exigua telomerase (SpexTERT) gene structure lacks the N-terminal GQ motif. Telomerase contains a large RNA subunit, TER, and a protein catalytic subunit, TERT. Here we report an in vitro system that was reconstructed by all components of the telomerase complex, a purified recombinant SpexTERT without a N-terminal GQ motif and a mutant human telomerase RNA (TER), showed telomerase activity. Together, these results suggest the GQ motif is not essential for telomerase catalysis.