RESUMO
Human Noxin (hNoxin, C11Orf82), a homolog of mouse noxin, is highly expressed in colorectal and lung cancer tissues. hNoxin contains a DNA-binding C-domain in RPA1, which mediates DNA metabolic processes, such as DNA replication and DNA repair. Expression of hNoxin is associated with S phase in cancer cells and in normal cells. Expression of hNoxin was induced by ultraviolet (UV) irradiation. Knockdown of hNoxin caused growth inhibition of colorectal and lung cancer cells. The comet assay and western blot analysis revealed that hNoxin knockdown induced apoptosis through activation of p38 mitogen-activated protein kinase (MAPK)/p53 in non-small cell lung carcinoma A549 cells. Furthermore, simultaneous hNoxin knockdown and treatment with DNA-damaging agents, such as camptothecin (CPT) and UV irradiation, enhanced apoptosis, whereas Trichostatin A (TSA) did not. However, transient overexpression of hNoxin rescued cells from DNA damage-induced apoptosis but did not block apoptosis in the absence of DNA damage. These results suggest that hNoxin may be associated with inhibition of apoptosis in response to DNA damage. An adenovirus expressing a short hairpin RNA against hNoxin transcripts significantly suppressed the growth of A549 tumor xenografts, indicating that hNoxin knockdown has in vivo anti-tumor efficacy. Thus, hNoxin is a DNA damage-induced anti-apoptotic protein and potential therapeutic target in cancer.
Assuntos
Proteínas Reguladoras de Apoptose/metabolismo , Apoptose , Carcinoma Pulmonar de Células não Pequenas/patologia , Proteínas de Transporte/metabolismo , Dano ao DNA/fisiologia , Neoplasias Pulmonares/patologia , Fosfoproteínas/metabolismo , Animais , Proteínas Reguladoras de Apoptose/genética , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismo , Western Blotting , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/metabolismo , Proteínas de Transporte/genética , Ciclo Celular , Proteínas de Ciclo Celular , Proliferação de Células , Células Cultivadas , Ensaio Cometa , Dano ao DNA/efeitos da radiação , Citometria de Fluxo , Perfilação da Expressão Gênica , Humanos , Hibridização In Situ , Pulmão/citologia , Pulmão/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Camundongos , Camundongos Nus , Análise de Sequência com Séries de Oligonucleotídeos , Fosfoproteínas/antagonistas & inibidores , Fosfoproteínas/genética , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rodaminas , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo , Raios Ultravioleta , Proteínas Quinases p38 Ativadas por Mitógeno/genética , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Previously, we reported that overexpression of Opa (Neisseria gonorrhoeae opacity-associated)-interacting protein 5 (OIP5) caused multi-septa formation and growth defects, both of which are considered cancer-related phenotypes. To evaluate OIP5 as a possible cancer therapeutic target, we examined its expression level in 66 colorectal cancer patients. OIP5 was upregulated about 3.7-fold in tumors and over 2-fold in 58 out of 66 colorectal cancer patients. Knockdown of OIP5 expression by small interfering RNA specific to OIP5 (siOIP5) resulted in growth inhibition of colorectal and gastric cancer cell lines. Growth inhibition of SNU638 by siOIP5 caused an increase in sub-G1 DNA content, as measured by flow cytometry, as well as an apoptotic gene expression profile. These results indicate that knockdown of OIP5 may induce apoptosis in cancer cells. Therefore, we suggest that OIP5 might be a potential cancer therapeutic target, although the mechanisms of OIP5-induced carcinogenesis should be elucidated.
Assuntos
Proteínas Cromossômicas não Histona/metabolismo , Neoplasias Colorretais/metabolismo , Neoplasias Gástricas/metabolismo , Animais , Apoptose , Proteínas de Ciclo Celular , Proteínas Cromossômicas não Histona/genética , Neoplasias Colorretais/genética , Neoplasias Colorretais/patologia , Neoplasias Colorretais/terapia , Perfilação da Expressão Gênica , Humanos , Análise em Microsséries , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Neoplasias Gástricas/terapia , Regulação para CimaRESUMO
BACKGROUND: Multidrug-resistant Enterobacteriaceae is a worldwide problem. Although various resistance mechanisms have been recognized with increasing frequency, only a few cases of triple resistance of extended-spectrum beta-lactamase (ESBL)-producing Klebsiella pneumoniae have been reported. This study was designed to evaluate the coexistence of qnr (qnrA, qnrB, and qnrS) and 16S rRNA methylase (armA, rmtA, rmtB, and rmtC) in ESBL-producing K. pneumoniae. METHODS: We tested 44 isolates of ESBL-producing K. pneumoniae at Chungnam National University Hospital from March to September 2006. Antimicrobial susceptibilities were tested by broth microdilution method, and transconjugation test was performed using E. coli J53 with azide resistance. Search for qnr (qnrA, qnrB, and qnrS) and 16S rRNA methylase (armA, rmtA, rmtB, and rmtC) genes was conducted by PCR amplification, and the genotypes were determined by direct nucleotide sequence analysis of the amplified products. Epidemiologic study was performed by Enterobacterial repetitive intergenic consensus-PCR (ERIC-PCR). RESULTS: All ESBL-positive strains produced qnrB; however, armA was detected in 68.2%. The coproduction rate of qnrB and armA in ESBL-producing K. pneumoniae was 68.2%. Two types (A and B) were dominant in ERIC-PCR results. CONCLUSIONS: K. pneumoniae producing qnrB, armA, and ESBL are spreading widely.
Assuntos
Proteínas de Bactérias/genética , Klebsiella pneumoniae/genética , Metiltransferases/genética , beta-Lactamases/genética , Proteínas de Bactérias/biossíntese , Testes de Sensibilidade a Antimicrobianos por Disco-Difusão , Farmacorresistência Bacteriana/genética , Humanos , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/efeitos dos fármacos , Klebsiella pneumoniae/isolamento & purificação , Metiltransferases/biossíntese , beta-Lactamases/biossíntese , beta-Lactamases/efeitos dos fármacosRESUMO
A major impediment in the treatment of neurological diseases is the presence of the blood-brain barrier, which precludes the entry of therapeutic molecules from blood to brain. Here we show that a short peptide derived from rabies virus glycoprotein (RVG) enables the transvascular delivery of small interfering RNA (siRNA) to the brain. This 29-amino-acid peptide specifically binds to the acetylcholine receptor expressed by neuronal cells. To enable siRNA binding, a chimaeric peptide was synthesized by adding nonamer arginine residues at the carboxy terminus of RVG. This RVG-9R peptide was able to bind and transduce siRNA to neuronal cells in vitro, resulting in efficient gene silencing. After intravenous injection into mice, RVG-9R delivered siRNA to the neuronal cells, resulting in specific gene silencing within the brain. Furthermore, intravenous treatment with RVG-9R-bound antiviral siRNA afforded robust protection against fatal viral encephalitis in mice. Repeated administration of RVG-9R-bound siRNA did not induce inflammatory cytokines or anti-peptide antibodies. Thus, RVG-9R provides a safe and noninvasive approach for the delivery of siRNA and potentially other therapeutic molecules across the blood-brain barrier.
