PagKNAT2/6b promotes shoot branching by attenuating auxin-strigolactone signalling in poplar.

Shoot branching from axillary bud (AB) directly determines plant architecture. However, the mechanism through which AB remains dormant or emerges to form branches as plants grow remains largely unknown. Here, the auxin-strigolactone (IAA-SL) pathway was first shown to regulate shoot branching in poplar, and we found that PagKNAT2/6b could modulate this pathway. PagKNAT2/6b was expressed mainly in the shoot apical meristem and AB and was induced by shoot apex damage. PagKNAT2/6b overexpressing poplar plants (PagKNAT2/6b OE) exhibited multiple branches that mimicked the branching phenotype of nontransgenic plants after decapitation treatment, while compared with nontransgenic controls, PagKNAT2/6b antisense transgenic poplar and Pagknat2/6b mutant lines exhibited a significantly decreased number of branches after shoot apex damage treatment. In addition, we found that PagKNAT2/6b directly inhibits the expression of the key IAA synthesis gene PagYUC6a, which is specifically expressed in the shoot apex. Moreover, overexpression of PagYUC6a in the PagKNAT2/6b OE background reduced the number of branches after shoot apex damage treatment. Overall, we conclude that PagKNAT2/6b responds to shoot apical injury and regulates shoot branching through the IAA-SL pathway. These findings may provide a theoretical basis and candidate genes for genetic engineering to create new forest tree species with different crown types.

Minisci-Type Dehydrogenative Coupling of N-Heteroaromatic Rings with Inert C(sp3)-H Enabled by a Visible-Light-Catalyzed Intermolecular Hydrogen Atom Transfer Process.

The Minisci-type dehydrogenative coupling of N-heteroaromatic rings with inert C-H or Si-H partners via visible-light-catalyzed hydrogen atom transfer has been reported. This methodology allows the coupling reactions to be carried out in water as a solvent under air atmospheric conditions with visible-light illumination. A wide range of inert C-H and Si-H partners could be directly coupled with various N-aromatic heterocycles to deliver products in good to excellent yields.

Elevated NOX4 promotes tumorigenesis and acquired EGFR-TKIs resistance via enhancing IL-8/PD-L1 signaling in NSCLC.

Epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs) have been widely used for human non-small-cell lung cancer (NSCLC) treatment. However, acquired resistance to EGFR-TKIs is the major barrier of treatment success, and new resistance mechanism remains to be elucidated. In this study, we found that elevated NADPH oxidase 4 (NOX4) expression was associated with acquired EGFR-TKIs resistance. Gefitinib is the first-generation FDA-approved EGFR-TKI, and osimertinib is the third-generation FDA-approved EGFR-TKI. We demonstrated that NOX4 knockdown in the EGFR-TKI resistant cells enabled the cells to become sensitive to gefitinib and osimertinib treatment, while forced expression of NOX4 in the sensitive parental cells was sufficient to induce resistance to gefitinib and osimertinib in the cells. To elucidate the mechanism of NOX4 upregulation in increasing TKIs resistance, we found that knockdown of NOX4 significantly down-regulated the expression of transcription factor YY1. YY1 bound directly to the promoter region of IL-8 to transcriptionally activate IL-8 expression. Interestingly, knockdown of NOX4 and IL-8 decreased programmed death ligand 1 (PD-L1) expression, which provide new insight on TKIs resistance and immune escape. We found that patients with higher NOX4 and IL-8 expression levels showed a shorter survival time compared to those with lower NOX4 and IL-8 expression levels in response to the anti-PD-L1 therapy. Knockdown of NOX4, YY1 or IL-8 alone inhibited angiogenesis and tumor growth. Furthermore, the combination of NOX4 inhibitor GKT137831 and gefitinib had synergistic effect to inhibit cell proliferation and tumor growth and to increase cellular apoptosis. These findings demonstrated that NOX4 and YY1 were essential for mediating the acquired EGFR-TKIs resistance. IL-8 and PD-L1 are two downstream targets of NOX4 to regulate TKIs resistance and immunotherapy. These molecules may be used as potential new biomarkers and therapeutic targets for overcoming TKIs resistance in the future.

Camrelizumab in different PD-L1 expression cohorts of pre-treated advanced or metastatic non-small cell lung cancer: a phase II study.

BACKGROUND: This phase II study evaluated camrelizumab in different PD-L1 expression cohorts of patients with previously treated advanced/metastatic non-small cell lung cancer (NSCLC; NCT03085069, registered March 21, 2017). METHODS: Patients who progressed during/after chemotherapy were enrolled and divided into four cohorts based on PD-L1 tumor proportion score (TPS). Patients with EGFR/ALK alterations and PD-L1 TPS ≥ 50% were also eligible. All enrolled patients received camrelizumab at 200 mg IV Q2W. The primary endpoint was objective response rate. RESULTS: A total of 146 patients were enrolled. As of data cutoff on Aug 20, 2020, the median follow-up was 29.5 months (95% CI 27.4-30.8). Objective response rate was 17.8% (95% CI 12.0-25.0) and improved with the increasing PD-L1 TPS (TPS < 1%, 12.2% [95% CI 5.7-21.8]; ≥ 1-< 25%, 19.4% [95% CI 7.5-37.5]; ≥ 25-< 50%, 36.4% [95% CI 10.9-69.2]; ≥ 50%, 23.3% [95% CI 9.9-42.3]). No response was observed in the five patients harboring EGFR mutations. Median progression-free survival was 3.2 months (95% CI 2.0-3.4), and patients with positive PD-L1 TPS had longer progression-free survival. Median overall survival was 14.8 months (95% CI 10.2-18.7). Treatment-related adverse events (TRAEs) of any grade occurred in 87.7% of patients, and 21.2% had grade ≥ 3 TRAEs. CONCLUSION: Camrelizumab showed improved efficacy compared with historical data of the second-line chemotherapy in pre-treated advanced/metastatic NSCLC. Patients with positive PD-L1 expression derived greater benefit from camrelizumab. Camrelizumab has a manageable safety profile.

Correlation between pre-treatment serum carcinoembryonic antigen levels and genotypes in a large population of Chinese people with advanced lung adenocarcinoma.

BACKGROUND: A positive correlation between serum carcinoembryonic antigen (CEA) levels and epidermal growth factor receptor (EGFR) mutations has been reported in lung adenocarcinoma patients. AIM: To investigate retrospectively whether serum CEA levels are also associated with genotypes in a large population of advanced lung adenocarcinoma. METHODS: A large cohort of 701 patients with advanced lung adenocarcinoma was studied retrospectively. RESULTS: EGFR mutations were found in 47.5% (333/701) of advanced lung adenocarcinoma patients, being identified at high frequencies in never-smokers, females, and in patients with abnormal pre-treatment serum CEA levels (53.1% vs 37.5%, P < 0.001). In contrast, anaplastic lymphoma kinase gene rearrangements were found in 7.8% (55/701) of patients, being identified at high frequencies in younger patients, and in patients with normal CEA levels (11.5% vs 5.8%, P = 0.012). Serum CEA levels were divided into four groups: <5, 5-19, 20-99 and ≥100 ng/mL. The rate of EGFR mutations significantly increased as the serum CEA levels increased (37.5%, 49.5%, 53.9% and 57.7%, respectively, P < 0.001). Anaplastic lymphoma kinase gene rearrangements showed the opposite result (11.5%, 7.1%, 5.7% and 4.1%, respectively, P = 0.044). A multivariate analysis revealed that higher pre-treatment serum CEA levels were independently associated with EGFR mutations (95% CI: 1.291-2.487, P < 0.001), but normal serum CEA levels were independently associated with anaplastic lymphoma kinase gene rearrangements (95% CI: 0.275-0.842, P = 0.010). CONCLUSION: Our study demonstrated that a significant association exists between the serum CEA levels and genotypes in patients with advanced lung adenocarcinoma.

Geraniin suppresses ovarian cancer growth through inhibition of NF-κB activation and downregulation of Mcl-1 expression.

This study investigated the anticancer effects of geraniin on ovarian cancer cells and the signaling pathways involved. Ovarian cancer cells were treated with different concentrations of geraniin for 48 h and examined for viability, apoptosis, mitochondrial membrane depolarization, and gene expression. Xenograft tumor studies were performed to determine the anticancer activity of geraniin in vivo. Geraniin significantly decreased cancer cell viability in a concentration-dependent fashion. Geraniin significantly triggered apoptosis, which was accompanied by loss of mitochondrial membrane potential and increased cytochrome c release and caspsase-3 activity. Mechanistically, geraniin significantly downregulated Mcl-1 and impaired NF-κB p65 binding to the mcl-1 promoter. Overexpression of Mcl-1 significantly reversed geraniin-induced apoptosis in OVCAR3 cells. In addition, geraniin retarded ovarian cancer growth and reduced expression of phospho-p65 and Mcl-1. Collectively, geraniin elicits growth suppression in ovarian cancer through inhibition of NF-κB and Mcl-1 and may provide therapeutic benefits for this malignancy.

New isocoumarins from a cold-adapted fungal strain mucor sp. and their developmental toxicity to zebrafish embryos.

Three new isocoumarin derivatives, mucorisocoumarins A-C (1-3, resp.), together with seven known compounds, 4-10, were isolated from the cold-adapted fungal strain Mucor sp. (No. XJ07027-5). The structures of the new compounds were identified by detailed IR, MS, and 1D- and 2D-NMR analyses. It was noteworthy that compounds 1, 2, 4, and 5 were successfully resolved by chiral HPLC, indicating that 1-7 should exist as enantiomers. In an embryonic developmental toxicity assay using a zebrafish model, compound 3 produced developmental abnormalities in the zebrafish embryos. This is the first report of isocoumarins with developmental toxicity to zebrafish embryos.

The novel HLA-C*15:02:58 allele, identified by Sanger dideoxy nucleotide sequencing in a Chinese individual.

HLA-C*15:02:58 differs from HLA-C*15:02:01:01 by one nucleotide in exon 1.

[Application of zebrafish models in drug screening].

Due to its small size, fast external development, transparent embryos, and amenability to genetic analysis, zebrafish has become an ideal vertebrate animal model. In addition to studies in genetics and developmental biology, zebrafish has also been widely used in human disease modeling and drug screening. As a small whole-organism model, zebrafish can be used to comprehensively test and evaluate the activity and side effect of a compound at the same time, fulfilling high content screening. Recently, new zebrafish disease models and screening technologies have been developed. A number of active compounds were identified and most of them have similar functions in mammal models. One compound prostaglandin E2 has been subjected to clinical trial to test if it can promote the growth of umbilical cord blood units after transplantation. Another compound leflunomide has also been approved in clinical trial to cure melanoma in combination with vemurafenib. These findings demonstrate that zebrafish model is appropriate for drug screening. This review summarizes the unique features of zebrafish model and the recent progresses of zebrafish based drug screening.

Effectiveness of platelet rich plasma in burn wound healing: a systematic review and meta-analysis.

BACKGROUND: To evaluate the efficacy of platelet-rich plasma (PRP) in the treatment of burn wounds. METHODS: A comprehensive literature survey was conducted in electronic medical journal databases to identify studies that examined the effect of PRP treatment to burn wounds and meta-analyses of mean differences (MD) standardized MD, or odds ratios were performed. RESULTS: The percentage of graft take was not significantly different between PRP-treated and control wound areas. Healing rate was significantly better in PRP-treated wounds. Healing time was also significantly less in PRP-treated wounds. There was no significant difference between PRP-treated and control wound areas in epithelialization or in the incidence of adverse events. Incidence of infection was also not different between PRP-treated and control wound areas. Scar assessment score was significantly better in PRP-treated than in control wound areas. CONCLUSION: PRP treatment to burn wounds is found to improve healing. Variations in study design and sample size, types of wounds, PRP preparation protocols, and high risk of bias in some of the included studies may have impact on these outcomes.

RUNX3 directly interacts with intracellular domain of Notch1 and suppresses Notch signaling in hepatocellular carcinoma cells.

RUNX3 takes a strong suppressive effect in many tumors including hepatocellular carcinoma (HCC). HES-1, a downstream target of Notch signaling, is shown to be decreased in human HCC cell line SMMC7721 with RUNX3 gene transfection. Since Notch signaling is oncogenic in HCC, RUNX3 might exert its inhibitory effect in HCC partly through the suppression on Notch signaling. To investigate the possible mechanism of the down-regulation of HES-1 by RUNX3, we performed Western blot and reporter assay and found that RUNX3 suppressed intracellular domain of Notch1 (ICN1)-mediated transactivation of Notch signaling while it did not alter the expression of ICN1 and recombination signal binding protein-J kappa (RBP-J) in SMMC7721 cells. Besides, confocal microscopy, co-immunoprecipitation and GST pull-down assays showed that RUNX3 could co-localize with ICN1 and RBP-J, forming a complex with these two molecules in nucleus of SMMC7721 cells by its direct interaction with ICN1. Furthermore, RUNX3 was recruited to RBP-J recognition motif of HES-1 promoter, which was identified by chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA). Taken together, these findings indicate that RUNX3 suppresses Notch signaling in HCC SMMC7721 cells by its interaction with ICN1 and thus recruitment to the RBP-J recognition motif of downstream genes of Notch signaling.

[Retracted] Bergamottin isolated from Citrus bergamia exerts in vitro and in vivo antitumor activity in lung adenocarcinoma through the induction of apoptosis, cell cycle arrest, mitochondrial membrane potential loss and inhibition of cell migration and invasion.

Following the publication of the above paper, a concerned reader drew to the Editor's attention that a number of figures (specifically, Figs. 6, 8, 9, 10 and 12) contained apparent anomalies, including repeated patternings of data within the same figure panels. After having conducted an independent investigation in the Editorial Office, the Editor of Oncology Reports has determined that this paper should be retracted from the Journal on account of a lack of confidence concerning the originality and the authenticity of the data. The authors were asked for an explanation to account for these concerns, but the Editorial Office never received any reply. The Editor regrets any inconvenience that has been caused to the readership of the Journal. [the original article was published in Oncology Reports 36: 324­332, 2016; DOI: 10.3892/or.2016.4833].

HB-EGF Activates the EGFR/HIF-1α Pathway to Induce Proliferation of Arsenic-Transformed Cells and Tumor Growth.

Arsenic was recently identified as a pollutant that is a major cause of lung cancer. Since heparin-binding EGF-like growth factor (HB-EGF) was reported to be a promising therapeutic target for lung cancer, we investigated the role and mechanism of HB-EGF during arsenic-induced carcinogenesis and development of lung cancer. HB-EGF expression were upregulated in As-T cells, lung cancer cell lines, and in most lung cancer tissue samples; and HB-EGF activated the EGFR/p-ERK/HIF-1α pathway and induced VEGF by regulating HIF-1α transcription. HIF-1α transcriptional stimulation by HB-EGF was facilitated by PKM2 and played an important role in HB-EGF's effect on cells. An HB-EGF inhibitor(CRM197, cross-reacting material 197) slowed cell proliferation and inhibited migration of As-T and A549 cells, and inhibited tumor growth. PKM2 also played an important role in the proliferation and migration in As-T cells. The positive staining ratios of EGFR phosphorylation (Y1068) and PKM2 were significantly higher in most cases of lung cancer than in paired normal tumor-adjacent lung tissues; and HB-EGF expression levels strongly correlated with p-EGFR expression levels. Thus, HB-EGF drives arsenic-induced carcinogenesis, tumor growth, and lung cancer development via the EGFR/PKM2/HIF-1α pathway.

Time-series analysis in imatinib-resistant chronic myeloid leukemia K562-cells under different drug treatments.

Chronic myeloid leukemia (CML) is characterized by the accumulation of active BCR-ABL protein. Imatinib is the first-line treatment of CML; however, many patients are resistant to this drug. In this study, we aimed to compare the differences in expression patterns and functions of time-series genes in imatinib-resistant CML cells under different drug treatments. GSE24946 was downloaded from the GEO database, which included 17 samples of K562-r cells with (n=12) or without drug administration (n=5). Three drug treatment groups were considered for this study: arsenic trioxide (ATO), AMN107, and ATO+AMN107. Each group had one sample at each time point (3, 12, 24, and 48 h). Time-series genes with a ratio of standard deviation/average (coefficient of variation) >0.15 were screened, and their expression patterns were revealed based on Short Time-series Expression Miner (STEM). Then, the functional enrichment analysis of time-series genes in each group was performed using DAVID, and the genes enriched in the top ten functional categories were extracted to detect their expression patterns. Different time-series genes were identified in the three groups, and most of them were enriched in the ribosome and oxidative phosphorylation pathways. Time-series genes in the three treatment groups had different expression patterns and functions. Time-series genes in the ATO group (e.g. CCNA2 and DAB2) were significantly associated with cell adhesion, those in the AMN107 group were related to cellular carbohydrate metabolic process, while those in the ATO+AMN107 group (e.g. AP2M1) were significantly related to cell proliferation and antigen processing. In imatinib-resistant CML cells, ATO could influence genes related to cell adhesion, AMN107 might affect genes involved in cellular carbohydrate metabolism, and the combination therapy might regulate genes involved in cell proliferation.

Down-regulated microRNA-375 expression as a predictive biomarker in non-small cell lung cancer brain metastasis and its prognostic significance.

Brain metastases (BM) are common among patients with non-small cell lung cancer (NSCLC) and have been associated with significant morbidity and limited survival. Early and sensitive detection of BM is essential for improving prognosis. Recently, microRNA-375(miR-375) which is specifically expressed in the brain has been found significantly dysregulated in many human cancers. However, there is still no data whether miR-375 is associated with higher risk of BM development in NSCLC. In this study, we detected the miR-375 expression using quantitative real-time PCR (qRT-PCR) and assessed its predictive and prognostic significance. Our result showed that miR-375 expression was significantly down-regulated in NSCLC patients with BM(BM+, N=30) compared with NSCLC without BM(BM-, N=30) (P<0.001). Statistical analysis indicated that low miR-375 expression was linked to advanced disease stage (P<0.001) and brain metastasis (P<0.001) in NSCLC patient. Survival analysis suggested that low-expression group had significantly shorter overall survival than high-expression group in NSCLC patients with BM(log-rank test: P<0.05) as well as the total cases(log-rank test: P<0.01). Multivariate Cox proportional hazards model analysis indicated that low miR-375 expression was independently linked to poor survival of patients with NSCLC (HR=5.48, 95% CI: 1.93-15.56, P=0.001). In addition, we found that VEGF and MMP-9 were over-expressed in down-regulated miR-375 expression cases. Collectively, this study demonstrated that miR-375 may play an important role as a predictive biomarker in brain metastasis and an independent prognostic factor in NSCLC. Over-expression of VEGF and MMP-9 may be the reason for poor prognosis of NSCLC patients with low miR-375 expression.

Bergamottin isolated from Citrus bergamia exerts in vitro and in vivo antitumor activity in lung adenocarcinoma through the induction of apoptosis, cell cycle arrest, mitochondrial membrane potential loss and inhibition of cell migration and invasion.

The objective of the present study was to investigate the in vitro and in vivo anticancer properties of bergamottin, a natural furanocoumarin, against human non-small cell lung carcinoma (NSCLC) A549 cells. We also studied its effect on cell proliferation, cell cycle arrest, cell invasion, cell migration as well as cell apoptosis. Antiproliferative activity of bergamottin was estimated by the MTT assay. Phase contrast and fluorescence microscopy as well as flow cytometry using Annexin V-FITC assay were used to study induction of apoptosis by bergamottin in these cells. The effects of bergamottin on cell cycle phase distribution as well as on mitochondrial membrane potential were also demonstrated using flow cytometry. In vitro wound healing assay was used to study the effect of bergamottin on cell migration. The effects of bergamottin on tumor progression were also observed using a nude mouse model. The mice were divided into 4 groups and treated with bergamottin injected intraperitoneally. Bergamottin induced dose-dependent as well as time-dependent cytotoxic effects as well as inhibition of colony formation in the A549 cancer cells. Bergamottin also suppressed cancer cell invasion as well as cancer cell migration. Phase contrast microscopy and fluorescence microscopy revealed that bergamottin induced cell shrinkage, chromatin condensation and the cells became rounded and detached from each other. Bergamottin also induced a potent cell cycle arrest at the G2/M phase of the cell cycle. Experiments in mice showed that 25, 50 and 100 mg/kg bergamottin injection reduced the tumor weight from 1.61 g in the phosphate-buffered saline (PBS)-treated group (control) to 1.21, 0.42 and 0.15 g in the bergamottin-treated groups, respectively. The results of the present study revealed that bergamottin was able to inhibit lung cancer cell growth both in a cell model and a xenograft mouse model by inducing apoptosis, mitochondrial membrane potential loss, G2/M cell cycle arrest as well as inhibiting cell migration and invasion.

miRNA-149* promotes cell proliferation and suppresses apoptosis by mediating JunB in T-cell acute lymphoblastic leukemia.

MicroRNA-149* (miRNA-149*) functions as an oncogenic regulator in human melanoma. However, the effect of miRNA-149* on T-cell acute lymphoblastic leukemia (T-ALL) is unclear. Here we aimed to analyze the effects of miRNA-149* on in vitro T-ALL cells and to uncover the target for miRNA-149* in these cells. The miRNA-149* level was determined in multiple cell lines and bone marrow cells derived from patients with T-ALL, B acute lymphoblastic leukemia (B-ALL), acute myelocytic leukemia (AML), and healthy donors. We found that miRNA-149* was highly expressed in T-ALL cell lines and T-ALL patients' bone marrow samples. JunB was identified as a direct target of miR-149*. miRNA-149* mimics downregulated JunB levels in Molt-4 and Jurkat cells, while miRNA-149* inhibitors dramatically upregulated JunB expression in these cells. miRNA-149* mimics promoted proliferation, decreased the proportion of cells in G1 phase, and reduced cell apoptosis in T-ALL cells, while miRNA-149* inhibitors prevented these effects. miRNA-149* mimics downregulated p21 and upregulated cyclinD1, 4EBP1, and p70s6k in Molt-4 and Jurkat cells. Again, inhibitors prevented these effects. Our findings demonstrate that miRNA-149* may serve as an oncogenic regulator in T-ALL by negatively regulating JunB.

[Effect of a hypothetical gene Af116609 on multi-drug resistance of gastric cancer cells].

OBJECTIVE: To investigate the effect of gene Af116609 on gastric cancer multi-drug resistance (MDR) by introducing it into gastric cancer multi-drug resistant (MDR) cell line SGC7901/VCR. METHODS: Gene Af116609 was cloned from SGC7901/VCR by RT-PCR and its differential expression between gastric cancer MDR cells and its parental cells was displayed by Northern blot. The gene was introduced to gastric cancer cells by transfection of recombinant eukaryotic expression vector by electroporation. MTT assay in vitro was applied to investigate its effect on multi-drug resistance phenotype of gastric cancer cells. RESULTS: The full length CDS of gene Af116609, as long as 327 bp, was cloned from gastric cancer MDR cell line SGC7901/VCR and its sequence was coincident with the hypothetical gene Af116609 in GenBank. It was overexpressed in MDR cells than its parental cells at mRNA level. In the MTT assay in vitro, the drug sensitive cells transfected with sense eukaryotic expression vector showed upregulated targeted gene, with increased resistance to vincristine, 5-fliorouracil and arabinoside, and decreased resistance to adriamycin, but no influence on resistance to methotrexate. However, the drug resistant cells transfected with anti-sense eukaryotic expression vector, showed down regulated targeted gene, with less resistance to all the five anticancer drugs to different degrees. CONCLUSION: Gene Af116609 is related to MDR phenotype of gastric cancer cells and may become a candidate molecular target to reverse the MDR of gastric cancer.

Effect of ZNRD1 gene antisense RNA on drug resistant gastric cancer cells.

AIM: To investigate the expression level of ZNRD1 gene in gastric cancer cells SGC7901 and gastric cancer MDR (multidrug resistant) cells SGC7901/VCR, and to observe the drug sensitizing and proliferation effect of ZNRD1 antisense nucleic acid transduction on SGC7901/VCR cells. METHODS: Amplification of sequences encoding ZNRD1 from SGC7901/VCR cDNA by PCR. The levels of ZNRD1 mRNA expression were demonstrated using semiquantitative reverse transcription polymerase chain reaction (RT-PCR). Eukaryotic expression vector pcDNA3.1-anti ZNRD1 was constructed and transfected into SGC7901/VCR cells by lipofectamine. Immunochemical method was used to detect the expression of protein in SGC7901/VCR cells and transfectants. The cell cycle alteration and the intracellular adriamycin (ADM) accumulation were observed by FACS. Growth curve and drug sensitization of cells for vincristine (VCR) were analyzed with MTT assay. RESULTS: We cloned the open reading frame of full-length ZNRD1. The expression of ZNRD1 showed higher in SGC7901/VCR than in SGC7901 cells. The antisense ZNRD1 drug-resistant clones were selected after gene transfection. Immunochemical results showed that the expression level of ZNRD1 protein was lower in anti ZNRD1-SGC7901/VCR cells than that in non-transfectants. Comparing to SGC7901/VCR and pcDNA3.1-SGC7901/VCR, anti ZNRD1-SGC7901/VCR showed gradually accumulated in G(1) phase, with a concomitant decrease of cell population in S phase. FACS also suggested intracellular ADM accumulation increased 2fold in SGC7901/VCR cells after transfected with antisense ZNRD1. MTT assay showed that transfectants cells proliferation was lagged and more sensitive to VCR than non-transfectants. CONCLUSION: ZNRD1 gene displayed highly expression in VCR resistant gastric cancer cells. Expression of ZNRD1 protein was effectively blocked in anti ZNRD1-SGC7901/VCR cells by gene transfection. ZNRD1 antisense nucleic acid transfection sensitized drug resistant gastric cancer cells to VCR, increased ADM accumulation and inhibited the cells proliferation. ZNRD1 antisense RNA transduction could reverse the MDR of human drug-resistant gastric cancer cell SGC7901/VCR to a degree.

Effect of L-NAME on nitric oxide and gastrointestinal motility alterations in cirrhotic rats.

AIM: To investigate the effect of L-NAME on nitric oxide and gastrointestinal motility alterations in cirrhotic rats. METHODS: Rats with cirrhosis induced by carbon tetrachloride were randomly divided into two groups, one n =13 receiving 0.5mg.kg(-1) per day of N(G)-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor, for 10 days, whereas the other group (n =13) and control (n =10) rats were administrated the same volume of 9g.L(-1) saline. Half gastric emptying time and 2h residual rate were measured by SPECT, using (99m)Tc-DTPA-labeled barium sulfate as test meal. Gastrointestinal transition time was recorded simultaneously. Serum concentration of nitric oxide (NO) was determined by the kinetic cadmium reduction and colorimetric methods. Immunohistochemical SABC method was used to observe the expression and distribution of three types of nitric oxide synthase (NOS) isoforms in the rat gastrointestinal tract. Western blot was used to detect expression of gastrointestinal NOS isoforms. RESULTS: Half gastric emptying time and trans-gastrointestinal time were significantly prolonged(124.0 +/- 26.4 min; 33.7 +/- 8.9 min; 72.1 +/- 15.3 min; P<0.01), (12.4 +/- 0.5h; 9.5 +/- 0.3h; 8.2 +/- 0.8h; P<0.01), 2h residual rate was raised in cirrhotic rats than in controls and cirrhotic rats treated with L-NAME (54.9 +/- 7.6%,13.7 +/- 3.2%, 34.9 +/- 10.3%, P<0.01). Serum concentration of NO was significantly increased in cirrhotic rats than in the other groups (8.20 +/- 2.48) micromol.L(-1), (5.94 +/-1.07) micromol.L(-1) and control (5.66 +/- 1.60 micromol.L(-1), P<0.01. NOS staining intensities which were mainly located in the gastrointestinal tissues were markedly lower in cirrhotic rats than in the controls and cirrhotic rats after treated with L-NAME. CONCLUSION: Gastrointestinal motility was remarkably inhibited in cirrhotic rats, which could be alleviated by L-NAME. Nitric oxide may play an important role in the inhibition of gastrointestinal motility in cirrhotic rats.