Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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 methacarn fixation permits an approach that comprises multiple techniques. In this study the procedure is used to examine 100 mesenteric lymph nodes from patients with colon cancer by means of histology, immunohistochemistry (IHC), and reverse transcriptase polymerase chain reaction (RT-PCR). The evaluated nodes are found to be grossly free of metastases. The combined expression of both messenger RNA (mRNA) and protein is investigated to validate the presence of structural (cytokeratin 20, or CK20) and tumor-specific (carcinoembryonic antigen, or CEA) markers. Histological analysis shows micrometastases on 4 nodes. IHC analysis identifies isolated (CK20 and CEA positive) tumor cells on 14 other nodes. In this group, none of the nodes that are positive for CK20 IHC express the related mRNA. RT-PCR confirms the CEA IHC positivity in 50% of the cases. The double CEA IHC/RT-PCR positivity would have up-staged 33% of the pN0 cases to pN1. This approach offers a technological framework for further studies that aim to validate the clinical significance of protein/mRNA expression of tumor markers in colorectal cancer sentinel lymph nodes.
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PMID:Added value of combined gene and protein expression of CK20 and CEA in non-macroscopically involved lymph nodes of colorectal cancer. 1907 66

Alterations in genes encoding transforming growth factor-beta-signaling components contribute to colon cancer in humans. Similarly, mice deficient in the transforming growth factor-beta signaling molecule, Smad3, develop colon cancer, but only after a bacterial trigger occurs, resulting in chronic inflammation. To determine whether Smad3-null lymphocytes contribute to increased cancer susceptibility, we crossed Smad3-null mice with mice deficient in both B and T lymphocytes (Rag2(-/-) mice). Helicobacter-infected Smad3/Rag2-double knockout (DKO) mice had more diffuse inflammation and increased incidence of adenocarcinoma compared with Helicobacter-infected Smad3(-/-) or Rag2(-/-) mice alone. Adoptive transfer of WT CD4(+)CD25(+) T-regulatory cells provided significant protection of Smad3/Rag2-DKO from bacterial-induced typhlocolitis, dysplasia, and tumor development, whereas Smad3(-/-) T-regulatory cells provided no protection. Immunohistochemistry, real-time reverse transcriptase-polymerase chain reaction, and Western blot analyses of colonic tissues from Smad3/Rag2-DKO mice 1 week after Helicobacter infection revealed an influx of macrophages, enhanced nuclear factor-kappaB activation, increased Bcl(XL)/Bcl-2 expression, increased c-Myc expression, accentuated epithelial cell proliferation, and up-regulated IFN-gamma, IL-1alpha, TNF-alpha, IL-1beta, and IL-6 transcription levels. These results suggest that the loss of Smad3 increases susceptibility to colon cancer by at least two mechanisms: deficient T-regulatory cell function, which leads to excessive inflammation after a bacterial trigger; and increased expression of proinflammatory cytokines, enhanced nuclear factor-kappaB activation, and increased expression of both pro-oncogenic and anti-apoptotic proteins that result in increased cell proliferation/survival of epithelial cells in colonic tissues.
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PMID:Bacterial infection of Smad3/Rag2 double-null mice with transforming growth factor-beta dysregulation as a model for studying inflammation-associated colon cancer. 1911 84

A 5443 Da peptide with sequence homology to defensins was purified from purple pole beans (Phaseolus vulgaris cv. 'Extra-long Purple Pole bean'). This peptide was isolated by adsorption on an affinity chromatographic medium Affi-Gel Blue gel and ion-exchange chromatographic media SP-Sepharose (sulfopropyl-Sepharose) and Mono S and by gel filtration on Superdex peptide. The peptide inhibited mycelial growth in Mycosphaerella arachidicola, Helminthosporium maydis, Fusarium oxysporum, Verticillium dahliae, Rhizoctonia solani, Candida albicans and Setosphaeria turcica with an IC50 of 0.8, 0.9, 2.3, 3.2, 4.3, 4.8 and 9.8 microM respectively. Its antifungal potency was higher than that of the plant defensin coccinin (IC50>50 microM). It induced membrane permeabilization in C. albicans as evidenced by SYTOX Green uptake, but did not affect erythrocyte membrane permeability. It inhibited growth in M. arachidicola by inducing chitin accumulation at hyphal tips as was shown by Congo Red staining. The antifungal activity was pH stable and thermostable. The peptide inhibited the proliferation of hepatoma (HepG2), breast cancer (MCF7), colon cancer (HT29) and cervical cancer (SiHa) cells but not that of human embryonic liver (WRL68) cells. Its anti-HepG2 activity (IC50=4.1+/-0.8 microM, n=3) was higher than that of another plant defensin, gymnin (IC50>50 microM). Its anti-MCF7 activity (IC50=8.3+/-0.3 microM, n=3) was similar to that of other plant defensins. It reduced the activity of HIV-1 reverse transcriptase with an IC50 of 0.5+/-0.1 microM, n=3, much more potently than other plant defensins (IC50>40 microM). There is the possibility of using the purple pole bean defensin for producing antifungal drugs and/or transgenic plants with fungal resistance.
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PMID:A defensin with highly potent antipathogenic activities from the seeds of purple pole bean. 1933 35

Metastasis to the regional lymph nodes is an important prognostic factor in colorectal cancer, and nodal evaluation is essential for accurate staging. In colorectal cancer, the aim of evaluating sentinel lymph nodes (SLNs) is the selection of patients for adjuvant therapy and the detection of aberrant lymphatic drainage patterns, leading to modification of the initial therapeutic plan. In a review of the literature, tracer, technique, tumor-related factors (location and size of tumor, T stage, status of lymph node metastasis), neoadjuvant chemoradiation therapy, and body mass index were important factors in the accurate diagnosis of SLNs in colorectal cancer. In recent multicenter SLN trials, ultrastaging has been possible in 10-38% of NO colon cancer patients. Most recently, the trial conducted by Bilchik et al., which investigated the prognostic significance of micrometastases in SLNs in colon cancer patients, found that all NO colon cancer patients with recurrence had positive SLN findings after reverse transcriptase-polymerase chain reaction (RT-PCR)-ultrastaging, whereas none of those with negative SLN findings in immunohistologic staining had recurrence, and there was only a significant correlation between recurrence and molecular markers in RT-PCR. However, further prospective multicenter trials are warranted to evaluate the ultimate clinical relevance of SLN diagnosis in colorectal cancer including anal cancer.
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PMID:[Current status of sentinel lymph node-based nodal ultrastaging in colorectal cancer]. 1934 97

Colostrum, a nutrient-rich fluid produced by female mammals immediately after giving birth, is loaded with several immune, growth, and tissue repair factors. However, it remains unknown whether bovine colostrum has anti-inflammatory effects on intestinal epithelial cells (IEC). In this study, we aimed to investigate the anti-inflammatory effects of colostrum on IEC and to elucidate its molecular mechanisms. Human colon cancer HT-29 cells were stimulated with interleukin (IL)-1beta with or without bovine colostrum. The effects of colostrum on nuclear factor kappaB (NF-kappaB) signaling in HT-29 cells were examined using real-time reverse transcriptase-polymerase chain reaction detect IL-8 and intracellar adhesion molecule-1 mRNA expression using a NF-kappaB-dependent reporter gene assay and an electrophoretic mobility shift assay. Furthermore, we assessed the expression levels of inhibitor protein of NF-kappaB-alpha, cyclooxygenase-2, and p65 proteins by Western blotting. Bovine colostrum significantly inhibited IL-1beta-induced IL-8 and intracellar adhesion molecule-1 mRNA expression. Moreover, it suppressed IL-1beta-induced NF-kappaB activation, including NF-kappaB dependent reporter gene expression in a dose-dependent manner. Finally, Western blotting revealed that colostrum decreased the cyclooxygenase-2 protein expression level, inhibited inhibitor protein of NF-kappaB-alpha degradation, and blocked translocation of p65 into the nucleus. These data demonstrated that bovine colostrum might protect against IEC inflammation by inhibiting the NF-kappaB pathway, suggesting colostrum has a therapeutic potential for intestinal inflammation.
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PMID:Bovine colostrum inhibits nuclear factor kappaB-mediated proinflammatory cytokine expression in intestinal epithelial cells. 1941 Sep 80

Although the biologic function of Reg IV is poorly understood, it has been reported that Reg IV is a potent activator of the epidermal growth factor receptor/Akt/AP-1 signaling pathway in colon cancer cells and closely linked with the inhibition of apoptosis. To clarify the role of Reg IV in gastric carcinogenesis and subsequent progression, we examined its expression by immunohistochemistry and in situ hybridization on tissue microarray containing gastric carcinoma, adjacent nonneoplastic mucosa, adenoma, intestinal metaplasia, or gastritis. Gastric carcinoma cell lines (MKN28, AGS, MKN45, KATO-III, and HGC-27) were studied for Reg IV expression by Western blot and reverse transcriptase-polymerase chain reaction followed by sequencing. Frozen samples of gastric carcinoma and adjacent nonneoplastic mucosa were subjected to Western blot, and patient serum, to enzyme-linked immunosorbent assay for Reg IV. Gastric carcinoma cell lines showed different levels of Reg IV mRNA and its encoding protein. The Reg IV protein expression was gradually decreased from intestinal metaplasia, adenoma, and carcinoma to gastritis (P < .05). The positive rate of its mRNA was higher in intestinal metaplasia than carcinoma or nonneoplastic mucosa (P < .05). Elevated serum Reg IV level in gastric carcinoma patients was detected in comparison with that in health individuals (P < .05). Reg IV expression was significantly correlated with the MUC-2 and MUC-5AC expression (P < .05). Among histologic subtypes of the World Health Organization, signet ring cell carcinoma more frequently expressed Reg IV than the others (P < .05), whereas it is the converse for the poorly differentiated group (P < .05). Our study indicated that Reg IV expression experienced up-regulation in gastric intestinal metaplasia and adenoma and then down-regulation with malignant transformation of gastric epithelial cells. It was suggested that Reg IV expression should be considered as a good biomarker for gastric precancerous lesions and was especially related to the histogenic pathway of signet ring cell carcinoma.
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PMID:The role of Reg IV gene and its encoding product in gastric carcinogenesis. 1974 May 14

The most important prognostic marker of survival and predictive marker of response to adjuvant chemotherapy in colon cancer patients is tumor cells in regional lymph nodes. Despite their importance, standard techniques to assess nodal metastases remain imperfect, as approximately 30% of patients with histology-negative lymph nodes (pN0) die of recurrent disease, reflecting occult metastases that escape detection. These observations highlight the clinical need for novel, accurate approaches to detect occult lymph node metastases in patients with colon cancer. GUCY2C is a biomarker whose expression normally is restricted to intestinal cells, but is near universally overexpressed by colorectal cancer cells. Recently, a prospective, multicenter, blinded clinical trial demonstrated for the first time that the prognostic utility of GUCY2C quantitative reverse transcriptase (qRT)-PCR to detect occult lymph node metastases in pN0 colorectal cancer patients. Molecular staging revealed that approximately 13% of pN0 patients were free of tumor cells, while approximately 87% had GUCY2C results that suggested occult metastases. The presence of occult lymph node metastases was the strongest independent predictor of time to recurrence and disease-free survival. These observations establish the utility of molecular detection of occult lymph node metastases for estimating prognostic risk in pN0 colorectal cancer patients. Advancing this molecular diagnostic into staging paradigms in clinical laboratories will require validation in independent patient populations, definition of the relationship between the quantity of occult tumor metastases and risk, and determination of the utility of GUCY2C qRT-PCR to identify pN0 patients who might benefit from adjuvant chemotherapy.
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PMID:GUCY2C reverse transcriptase PCR to stage pN0 colorectal cancer patients. 1989 23

By routinely and systematically being able to perform quantitative stem-loop reverse transcriptase followed by TaqMan PCR expression analysis on stool and tissue samples using fifteen human (Homo sapiens, hsa) micro(mi)RNA genes selected by careful analysis of the peer-reviewed literature, we were able to monitor changes at various stages of CRC, allowing for reliable diagnostic screening of colon cancer particularly at the early, pre-malignant stages, and for difficult-to-treat active ulcerative colitis (UC). Although the expression of some of the miRNA genes tested in tissue showed less variability in CRC or UC patients than in stool, the stool by itself appears well-suited to screening. A miRNA approach using stool samples promises to offer more sensitivity and specificity than currently used screening genomic, methylomic or proteomic methods for colon cancer. Larger prospective clinical studies utilizing stool derived from many control, colon cancer or UC patients, to allow for a statistically valid analysis, are now urgently required to standardize test performance and determine the true sensitivity and specificity of the miRNA screening approach, and to provide a numerical underpinning for these diseases as a function of total RNA. Moreover, when a miRNA screening test is combined with analysis of a messenger(m)RNA expression test, which has also been considered in earlier studies to be a highly sensitive and a very specific and reliable transcriptomic approach, as outlined in this article, bioinformatics can be used to correlate microRNA seed data with mRNA target data in order to gain a mechanistic understanding of how miRNAs regulate gene expression, enabling understanding of why these miRNA genes should be informative in a screening test.
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PMID:Diagnostic microRNA markers for screening sporadic human colon cancer and active ulcerative colitis in stool and tissue. 1999 34

We investigated whether natural killer (NK) cells in the tumor microenvironment have a radiosensitization effect. The radiosensitization effect of combined CpG and Herceptin((R)) (Genentech, Inc., South San Francisco, CA) (CpG/Herceptin), given before or after radiation, was evaluated by using a murine colon cancer cell line overexpressing human HER2/neu, CT26HER2/neu. In vitro radiosensitization effects were investigated by coculture of CT26HER2/neu with splenocytes, CpG, and Herceptin before applying radiation. Tumor cells, cocultured with CpG-pretreated splenocytes and Herceptin, were more vulnerable to radiation damage. In BALB/c mice injected with CT26HER2/neu, CpG/Herceptin administered before radiotherapy was associated with a better retardation of tumor growth than when administered after radiotherapy. The radiosensitization effect was significantly abrogated by NK-cell depletion, indicating that NK cells play an essential role in it. Further, surviving mice treated with CpG or CpG/Herceptin and reverse transcriptase were resistant to renewed tumor challenge, suggesting the presence of an induced immune response to the tumor. Neoadjuvant immunotherapy with CpG/Herceptin may improve response to radiotherapy of HER2/neu-expressing tumors.
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PMID:Neoadjuvant immunotherapy enhances radiosensitivity through natural killer cell activation. 2018 95

Colorectal cancer mortality largely reflects metastasis, the spread of the disease to distant organs. Matrix metalloproteinase 9 (MMP-9) is a key regulator of metastasis and a target for anticancer strategies in colon cancer. Here, the overexpression of MMP-9 in pure tumor epithelial, but nor stromal, cell populations was associated with metastatic progression of colorectal cancer, as defined by reverse transcriptase-polymerase chain reaction (qRT-PCR) and confirmed by immunostaining. Thus, cancer cell MMP-9 represents a novel, selective prognostic and predictive factor that may be exploited for more effective disease stage stratification and therapeutic regimen selection in patients with colorectal cancer.
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PMID:Overexpression of matrix metalloproteinase 9 in tumor epithelial cells correlates with colorectal cancer metastasis. 2044 34


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