Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A better understanding of the regulatory network underlying cellular drug resistance and stress response may be helpful to overcome the phenomenon of therapy-induced cross-resistances against a variety of antineoplastic agents. Two new powerful molecular techniques, mRNA differential display reverse transcriptase polymerase chain reaction (DDRT-PCR) and subtractive suppressive hybridisation were applied for the comparative analysis of the gene expression profile of a doxorubicin resistant and its corresponding sensitive parental colon carcinoma cell line (LoVo H67P). DDRT-PCR generated partial cDNAs from the doxorubicin resistant, sensitive and stress (dexamethasone, doxorubicin, cadmium chloride or heat) exposed sensitive cells, were size-separated on polyacrylamide gels. The expression patterns of more than 9000 bands of the resistant, sensitive and stressed sensitive cell populations were identical by more than 95%. Of the differentially expressed mRNAs, 20 cDNA fragments were reamplified after isolation from the gel, used as probes for Northern blot analysis to verify their differential expression and sequenced after cloning. Among the differentially expressed cDNAs, homologies of 96% and 87%, respectively, were found to the human proto-oncogene PTI-1 and the human ribosomal protein L4. Subtractive suppressive hybridisation revealed overexpression of the ribosomal protein L5 in the doxorubicin resistant line. These data point to the control of gene expression at the translational level as an important mechanism involved in cellular stress response.
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PMID:Overexpression of ribosomal proteins L4 and L5 and the putative alternative elongation factor PTI-1 in the doxorubicin resistant human colon cancer cell line LoVoDxR. 971 82

Several virulence factors are involved in Listeria monocytogenes pathogenicity. L. monocytogenes internalins, particularly internalin A, are required for bacterial adhesion to and invasion of human intestinal epithelial cells. The expression of internalins is thus related to virulence. Identification of conditions involved in regulating the expression of L. monocytogenes virulence factors is essential for developing targeted strategies to control listeriosis incidence and improving therapeutic approaches. The primary aim of this study was to develop a quantitative real-time reverse transcriptase PCR platform to study the impact of environmental factors on L. monocytogenes Scott A virulence factor expression, particularly in potentially complex ecosystems. A Taqman PCR-based, rapid quantitative gene expression evaluation method was established with the L. monocytogenes ribosomal protein L4 encoding gene used as an internal standard. Our data suggest that inlA expression is influenced by food composition and temperature, indicating that certain food processing or storage conditions, such as the use of lactic and acetic acids at common storage temperatures, could affect the expression of L. monocytogenes virulence factor.
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PMID:Assessment of environmental factors on Listeria monocytogenes Scott A inlA gene expression by relative quantitative Taqman real-time reverse transcriptase PCR. 1713 22

Rapid and specific detection of viable Listeria monocytogenes cells, particularly in processed foods, is a major challenge in the food industry. To assess the suitability of using RNA-based detection methods to detect viable cells, several sets of PCR primers and florescent probes were designed targeting the 16S rRNA, internalin A, and ribosomal protein L4 genes. One-step real-time reverse transcriptase (RT) PCR assays were conducted using RNAs extracted from control and heat-treated L. monocytogenes samples. The cycle threshold values were significantly higher in heat-treated cells than in controls. However, real-time RT-PCR amplification signals were still detected even in samples stored at room temperature for 24 h after lethal treatments, and the intensity of the signals was correlated with the cell population. The 16S rRNA molecules were the most stable of the three targets evaluated, and the impact on detection efficacy of the relative positions of the PCR primers within the target genes was limited under the experimental conditions. These results suggest that real-time RT-PCR assays have advantages over conventional PCR assays for assessing viable L. monocytogenes cells, but the results are affected by the stability of the RNA molecules targeted. These findings could have a major impact on interpretation of RNA-based detection data and gene expression studies.
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PMID:Critical issues in detecting viable Listeria monocytogenes cells by real-time reverse transcriptase PCR. 2241 Feb 25