MicroRNAs (miRNAs) belong to a class of noncoding, regulatory RNAs that are involved in oncogenesis and show remarkable tissue specificity.miRNAs are approximately 22 nt non-coding RNAs, which regulate gene expression...MicroRNAs (miRNAs) belong to a class of noncoding, regulatory RNAs that are involved in oncogenesis and show remarkable tissue specificity.miRNAs are approximately 22 nt non-coding RNAs, which regulate gene expression in a sequence-specific manner via translational inhibition or messenger RNA (mRNA) degradation, thus affecting various cellular processes.Since the discovery of their fundamental mechanisms of action, the field of miRNAs has opened a new era in the understanding of small noncoding RNAs.Recent evidence has shown that miRNA controls cell growth, apoptosis, and differentiation.Cancer is a complex genetic disease caused by abnormalities in gene structure and expression, moreover, miRNA expression correlates with cancers and could have a crucial function in tumor progression.Bioinformatic data indicate that each miRNA can control hundreds of target genes, but identification of the accurate miRNA targets will be crucial to exploit the emerging knowledge of miRNA contribution to cancer process.展开更多
MicroRNAs(miRNAs),which contains approximately 22 nt,belong to a small endogenous,non-coding regulatory single-stranded RNA molecules.They are posttranscriptional regulators of gene expression and highly conserved in ...MicroRNAs(miRNAs),which contains approximately 22 nt,belong to a small endogenous,non-coding regulatory single-stranded RNA molecules.They are posttranscriptional regulators of gene expression and highly conserved in evolution.Many researches show that miRNAs involved in many processes,including tumor formation,cell proliferation and apoptosis and proliferation and metastasis of cancer cells.Among that,the relationship between miRNAs and lung cancer is one of the most focal areas for the researchers,because the abnormal expressions of miRNAs were significantly associated with the occurrence and development of lung cancer.The expression level of different miRNAs in lung cancer cells exist differences,compared with normal lung tissue cells,there are two classes of expression:over-expression level and low expression level.In this review,we focused on studying the mechanism of overexpression miRNAs in lung cancer.展开更多
Guiding college students to acquire an adequate vocabularyis an important task that is often neglected. The morevocabulary hat is mastered, the higher level a learner of Englishwill have. But in China, the traditional...Guiding college students to acquire an adequate vocabularyis an important task that is often neglected. The morevocabulary hat is mastered, the higher level a learner of Englishwill have. But in China, the traditional method of teachingvocabulary is learning by rote, and learners of foreign languagesare inclined to learn as much vocabulary as possible this wayregardless of whether these vocabulary is useful or not. Indeed,there are some disadvantageous factors hindering the studentsfrom expanding vocabulary rapidly and efficiently. We have todevelop a scientific method of teaching vocabulary exploringmethods of which is the key to this article.展开更多
From the oligotrophic culture of a soft coral-associated actinomycetes strain, Streptomyces sp. OUCMDZ-1703, we isolated and identified two new chlorinated polyketides that we named strepchloritides A and B （1 and 2...From the oligotrophic culture of a soft coral-associated actinomycetes strain, Streptomyces sp. OUCMDZ-1703, we isolated and identified two new chlorinated polyketides that we named strepchloritides A and B （1 and 2）, three thiazole derivatives known as watasemycin A （3）, pulicatin G （4） and aerugine （5）, along with pyrrole- 2-carboxamide, furan-2-carboxamide and 1-（3,5-dihydroxyphenyl）ethanone. The new structures of 1 and 2 were determined by spectroscopic studies such as 1D- and 2D-NMR and MS analyses, while the known compounds were identified by comparison of the NMR data with those in literatures. The results showed that actinomycete strain OUCMDZ-1703 could use the relative high ratio of chlorine in the oligotrophic medium to synthesize chlorinated natural products. New compounds 1 and 2 displayed cytotoxicity against the MCF-7 ceils with ICs0 values of 9.9 and 20.2 ~tmoloL-1, respectively. Thiazole derivatives 3 and 5 were first found to be active against three clinical strains of methicillin-resistant Staphylococcus aureus （MRSA082, MRSA111 and MRSA234） with the same MIC/MBC values of 7.81/7.81 μg·mL-1.展开更多
文摘MicroRNAs (miRNAs) belong to a class of noncoding, regulatory RNAs that are involved in oncogenesis and show remarkable tissue specificity.miRNAs are approximately 22 nt non-coding RNAs, which regulate gene expression in a sequence-specific manner via translational inhibition or messenger RNA (mRNA) degradation, thus affecting various cellular processes.Since the discovery of their fundamental mechanisms of action, the field of miRNAs has opened a new era in the understanding of small noncoding RNAs.Recent evidence has shown that miRNA controls cell growth, apoptosis, and differentiation.Cancer is a complex genetic disease caused by abnormalities in gene structure and expression, moreover, miRNA expression correlates with cancers and could have a crucial function in tumor progression.Bioinformatic data indicate that each miRNA can control hundreds of target genes, but identification of the accurate miRNA targets will be crucial to exploit the emerging knowledge of miRNA contribution to cancer process.
文摘MicroRNAs(miRNAs),which contains approximately 22 nt,belong to a small endogenous,non-coding regulatory single-stranded RNA molecules.They are posttranscriptional regulators of gene expression and highly conserved in evolution.Many researches show that miRNAs involved in many processes,including tumor formation,cell proliferation and apoptosis and proliferation and metastasis of cancer cells.Among that,the relationship between miRNAs and lung cancer is one of the most focal areas for the researchers,because the abnormal expressions of miRNAs were significantly associated with the occurrence and development of lung cancer.The expression level of different miRNAs in lung cancer cells exist differences,compared with normal lung tissue cells,there are two classes of expression:over-expression level and low expression level.In this review,we focused on studying the mechanism of overexpression miRNAs in lung cancer.
文摘Guiding college students to acquire an adequate vocabularyis an important task that is often neglected. The morevocabulary hat is mastered, the higher level a learner of Englishwill have. But in China, the traditional method of teachingvocabulary is learning by rote, and learners of foreign languagesare inclined to learn as much vocabulary as possible this wayregardless of whether these vocabulary is useful or not. Indeed,there are some disadvantageous factors hindering the studentsfrom expanding vocabulary rapidly and efficiently. We have todevelop a scientific method of teaching vocabulary exploringmethods of which is the key to this article.
文摘From the oligotrophic culture of a soft coral-associated actinomycetes strain, Streptomyces sp. OUCMDZ-1703, we isolated and identified two new chlorinated polyketides that we named strepchloritides A and B （1 and 2）, three thiazole derivatives known as watasemycin A （3）, pulicatin G （4） and aerugine （5）, along with pyrrole- 2-carboxamide, furan-2-carboxamide and 1-（3,5-dihydroxyphenyl）ethanone. The new structures of 1 and 2 were determined by spectroscopic studies such as 1D- and 2D-NMR and MS analyses, while the known compounds were identified by comparison of the NMR data with those in literatures. The results showed that actinomycete strain OUCMDZ-1703 could use the relative high ratio of chlorine in the oligotrophic medium to synthesize chlorinated natural products. New compounds 1 and 2 displayed cytotoxicity against the MCF-7 ceils with ICs0 values of 9.9 and 20.2 ~tmoloL-1, respectively. Thiazole derivatives 3 and 5 were first found to be active against three clinical strains of methicillin-resistant Staphylococcus aureus （MRSA082, MRSA111 and MRSA234） with the same MIC/MBC values of 7.81/7.81 μg·mL-1.
