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)

The question that transforming growth factor-beta (TGF-beta) provides a tumor-suppressive or a tumor promoting role is still unknown in hepatocellular carcinoma (HCC). In the present study, we quantitatively investigated the gene expression levels of TGF-beta in liver tissues from patients with HCC. We also evaluated the prognostic importance of TGF-beta gene in HCC patients. A total of 59 patients with primary HCC who underwent hepatectomy between 1993 and 2001 were enrolled. TGF-beta gene expression levels of tumors and of noncancerous livers were analyzed by real-time reverse transcriptase polymerase chain reaction (RT-PCR). The percentage of apoptotic cells in tumor cells (apoptotic index: AI) was evaluated with immunohistochemistry. Also the expression of survivin protein (apoptosis inhibitor) in tumors was detected by immunohistochemistry. TGF-beta gene expression levels of tumors were compared with clinicopathological findings of patients. The relative expression level of TGF-beta mRNA of 59 tumor tissues did not differ from those of 8 normal liver tissues or 59 noncancerous liver tissues. The mean AI of 29 tumors with normal expression levels of TGF-beta gene (4%) was significantly higher than that of 30 tumors with low expression levels of TGF-beta gene (2.5%, p = 0.03). Thirteen out of 30 tumors (43%) with low expression level of TGF-P gene showed survivin positive, while only 4 out of 29 tumors (14%) with preserved expression of TGF-beta gene showed survivin positive. This difference was significant (p = 0.012). The overall 5-year survival rate of 29 patients with tumors with preserved TGF-beta gene prolonged to 72% compared with that of 30 patients who had tumors with suppressed TGF-beta gene (58%, p = 0.156). In HCC, TGF-beta gene may play a defensive role against tumor progression by regulating survivin protein expression and by controlling occurrence of spontaneous apoptosis in tumors.
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PMID:The gene expression level of transforming growth factor-beta (TGF-beta) as a biological prognostic marker of hepatocellular carcinoma. 1627 May 28

Stathmin is an intracellular phosphoprotein that is overexpressed in a number of human malignancies. Our previous study using proteomic profiling showed that significant upregulation of stathmin occurs in oral squamous-cell carcinoma (OSCC)-derived cell lines. In the current study, to determine the potential involvement of stathmin in OSCC, we evaluated the state of stathmin protein and mRNA expression in OSCC-derived cell lines and human primary OSCCs. A significant increase in stathmin expression was observed in all OSCC-derived cell lines examined compared to human normal oral keratinocytes. In immunohistochemistry, 65% of the OSCCs were positive for stathmin, and no immunoreaction was observed in corresponding normal tissues. Real-time quantitative reverse transcriptase-polymerase chain reaction data were consistent with the protein expression status. Moreover, stathmin expression status was correlated with the TNM stage grading. Furthermore, we found a statistical correlation between the protein expression status and disease-free survival (P=0.029). These results suggest that expression of stathmin could contribute to cancer progression/prognosis, and that stathmin may have potential as a biomarker and a therapeutic target for OSCC.
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PMID:Overexpression of stathmin in oral squamous-cell carcinoma: correlation with tumour progression and poor prognosis. 1649 30

We used gene expression profiling to probe differences in transcriptional output between 15 panels of colon tumor and matched normal colon tissues. This analysis revealed that GPR49, an orphan G Protein-Coupled Receptor (GPCR) is overexpressed in 66% (10/15) colon tumors compared with normal colon tissues. Subsequent analysis of an additional 39 sets of matched normal and tumor colon tissues by real-time quantitative reverse transcriptase confirmed the upregulation of this receptor. The differential expression of GPR49 between normal and tumor tissue was significant (p > 0.001). GPR49 was upregulated in 25 of 39 (64%) colon primary tumor tissues. In addition to colon tumors, GPR49 was also found to be upregulated in 18 of 33 (53%) ovarian primary tumor tissues analyzed by RT-PCR. Moreover, the expression level of GPR49 in colon and ovarian tumors increased in more advanced tumors suggesting a role for the receptor in tumor progression. The selective overexpression of GPR49 in tumor tissues was further illustrated by specific immunohistochemical staining of colon and ovarian tumor tissues, a finding that correlates with the mRNA expression of the receptor. In addition, expression of GPR49 induced transformation in a ligand-dependent manner and Knockdown of GPR49 mRNA level induced apoptosis in colon tumor cells. These novel findings provide a foundation for further studies and suggest a potential role for GPR49 in tumorigenesis.
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PMID:Identification of overexpression of orphan G protein-coupled receptor GPR49 in human colon and ovarian primary tumors. 1657 8

We used cDNA microarrays to study gene expression in fresh frozen papillary thyroid carcinoma (PTC) specimens. Seven clinically aggressive carcinomas were included, comprising poorly differentiated PTC and tumors with extensive local invasion or synchronous distant metastases. Ten differentiated (classic) papillary thyroid carcinomas (PTC) and non-neoplastic thyroid tissues were also investigated. TaqMan quantitative reverse transcriptase-polymerase chain reaction (RT-PCR), in situ hybridization, and immunohistochemistry verified the differential gene expression. The B-Raf gene was mutated with a T-->A transversion at nucleotide 1799 (V600E) in 8 of 10 differentiated PTC, and in 4 of 7 aggressive carcinomas. Among genes markedly and equally over-expressed in carcinomas of both the aggressive and classic PtC groups, compared to normal thyroid tissue, were CBP/p300 transactivator (CItED1), fibronectin, growth/differentiation factor 15, potassium inwardly rectifying channel KCNJ2, glutaminyl peptide cyclotransferase, WNT7A, and dipeptidyl peptidase IV. A marked upregulation in carcinomas of P-cadherin mRNA and protein concomitant with E-cadherin downregulation, indicates a possible P-E cadherin "switch" in PTC. The growth factor homologue Nel-like 2, dual specificity phosphatase 5, the serine protease kallikrein 10, and also the tight junction genes claudin 1 and claudin 16, were upregulated in classic PTC but not in aggressive tumors, which may be consistent with altered cell polarity in the dedifferentiated PtC. The aggressive, poorly differentiated PtC group was specifically characterized by marked upregulation of several genes related to cell proliferation such as cell division cycle 2 (CDC2), CDC7, kinesin-like 5, ubiquitin conjugating enzyme E2C, and topoisomerase IIalpha, and by upregulation of genes encoding extracellular matrix proteins such as seprase, extracellular matrix protein 1, and several collagens. These aggressive tumors were also characterized by overexpression of the integrin ligand periostin, and in some biopsies also of osteopontin and of the upstream Rac-regulator dedicator of cytokinesis 10 (DOCK10). These data are interpreted to be consistent with altered cell motility, extracellular matrix remodeling and increased cell proliferation, as important processes in PTC tumor progression.
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PMID:Gene expression in poorly differentiated papillary thyroid carcinomas. 1667 2

The human endogenous retrovirus-K encodes two potential tumor proteins, Rec and Np9. Rec is related to the Rev protein of HIV-1 and has been shown to be associated with tumor development in nude mice. Having shown the expression of human endogenous retrovirus-K in human melanomas and melanoma cell lines, tools were developed to allow the expression of the transmembrane envelope, Rec and Np9 mRNA and proteins to be studied in more detail. The expression of spliced env, rec and np9 was investigated by reverse transcriptase-polymerase chain reaction using a set of primers developed to discriminate between full-length and spliced mRNA. Env-specific, Rec-specific and Np9-specific antisera were produced, characterized and used to study protein expression in melanomas and melanoma cell lines by immunohistochemistry, immunofluorescence and Western blot analyses. Existence of human endogenous retrovirus-K Rec and Np9-specific antibodies in the sera of melanoma patients were analyzed by Western blot of immunofluorescence studies. The expression of both spliced env and rec mRNA was detected in 39% of the melanomas and in 40% of the melanoma cell lines and np9 mRNA was detected in 29 and 21%, respectively. In normal neonatal melanocytes, spliced rec mRNA was detected in the absence of spliced env mRNA. Using antisera specific for Rec and Np9, Rec protein was found in 14% of the melanomas but Np9 in none. In addition, cell surface expression of the putatively immunosuppressive transmembrane envelope protein and release of virus particles were shown. Antibodies specific for neither Rec nor Np9 were detected. The transmembrane envelope protein, Rec and Np9 proteins are expressed in melanoma cells with a pattern similar to that seen in teratocarcinoma cell lines. Additional experiments are needed to determine their involvement, if any, in cell proliferation and tumor progression.
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PMID:Expression of the human endogenous retrovirus-K transmembrane envelope, Rec and Np9 proteins in melanomas and melanoma cell lines. 1671 69

The transmembrane metalloproteases angiotensin-converting enzyme (ACE) and tumor necrosis factor-alpha (TNF-alpha)-converting enzyme (TACE/ADAM-17) have been associated with inflammation, cancer progression and angiogenesis. Few investigations into the regulation of these enzymes by physiological stimuli have been reported. In this study, we investigated the influence of interferons (IFNs) type I (alpha, beta) and II (gamma) on ACE and TACE expression of human leukemic NB4 cells and monocytes. We assessed the expression of proteases by reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay and immunofluorescence analyses. IFNgamma, but not type I IFNs, upregulated membrane ACE in a dose- and time-dependency and this was reflected by the increase of ACE enzymatic activity and ACE mRNA. ACE upregulation was dependent on protein synthesis. Treatment of the interferon responsive factor 1 (IRF1)-unresponsive HepG2 cell line with IFNgamma did not affect ACE expression, thus suggesting the participation of the IRF1 signaling pathway in IFNgamma-mediated ACE upregulation in myeloid cells. In contrast, both types of IFNs, in a dose- and time-dependent manner, downregulated surface TACE without affecting TACE transcript. Soluble TACE was not detected in the medium of IFN-treated cells. IFNgamma-mediated decrease of surface TACE in NB4 cells was reversible, and correlated with an increase in intracellular TACE, suggesting that cell surface TACE was internalized in response to IFNs. These findings, showing the presence of IFN-dependent controlled mechanisms by which ACE and TACE levels are regulated in human normal and leukemic myeloid cells, may have implications in the context of current investigations on the therapeutic potential of IFNs.
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PMID:Differential regulation of tumor necrosis factor-alpha-converting enzyme and angiotensin-converting enzyme by type I and II interferons in human normal and leukemic myeloid cells. 1679 29

Detection of disseminated tumor cells in the blood circulation is important in assessing tumor progression. The objective of this examination was to develop a highly specific and sensitive quantitative realtime reverse transcriptase-polymerase chain reaction (qRT-PCR) assay for the detection of relevant tumor-associated transcripts in patients' blood. The qRT-PCR assays detect the human epidermal growth factor receptor 2 (HER2) and CK20 transcripts of two tumor cells spiked into 5 mL of blood after an immunomagnetic tumor cell enrichment. Furthermore, the HER2 assay is only specific when enrichment is included. This procedure is a useful alternative to fluorescence in situ hybridization and immunocytochemistry for gene alteration analysis in human tumors. The analysis of the studied molecular markers of tumor cells in blood may be useful in the detection of disseminated tumor cells as well as for monitoring treatment response, early detection of relapse, and for stratification of patients with carcinoma.
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PMID:Quantitative real-time RT-PCR of disseminated tumor cells in combination with immunomagnetic cell enrichment. 1694 67

Large cell calcifying Sertoli cell tumors (LCCSCT) are associated with Carney complex and Peutz-Jeghers syndrome. The mechanisms linking these 2 genetic defects to the genesis of this tumor are obscure. Studies of CYP19 (aromatase) and transforming growth factor (TGF)-beta1 messenger RNA (mRNA) abundance, estrogen receptor (ER), TGFbeta1, and TGFbeta type II receptor (R) immunochemistry were carried out in the testis of a patient with this tumor to gain information on possible mechanisms of cell tumor development. Testicular tissue of a prepubertal patient, collected at gonadectomy, was separated into 2 macroscopically distinct fractions: tumoral nodules (Tu) and extratumoral, normal-looking testicular tissue (ExTu). The patient was a 9.5-year-old boy with a 5-year history of bilateral gynecomastia (Tanner stage 4), no pubic hair, incipient genital development, and bilateral testicular nodules. Multiple pigmented lesions of the skin were present. Bilateral mammectomy and gonadectomy was performed. RNA was extracted from Tu and ExTu for semiquantitative reverse transcriptase-polymerase chain reaction of CYP19 and TGFbeta1. Protein expression of ER, TGFbeta1, and TGFbeta type II R in Tu and ExTu was detected by immunohistochemistry. Cell proliferation was estimated by Ki-67 antigen immunochemistry and apoptosis using a modified TUNEL assay. Mean expression of aromatase and TGFbeta1 mRNAs in Tu was 6- and 2.3-fold higher than in ExTu, respectively (P<0.05). Tumoral cells exhibited ER staining with a predominant extranuclear localization. Positive staining of Sertoli cells in Tu was higher than in ExTu. TGFbeta1 immunostaining of the interstitial cells in Tu was higher than in ExTu. TGFbeta type II R immunostaining was detected in most Sertoli and interstitial cells, but intensity in ExTu was lower than in Tu. No significant difference was detected in the proliferation index, but in Tu, the percentage of Sertoli cells in apoptosis (1.4%) was significantly lower (P<0.01) than in ExTu (14.0%). The following hypothesis is proposed. The congenital gene defects of Carney complex or of Peutz-Jeghers syndrome might trigger a cascade of intracellular events that leads to overexpression of aromatase in Sertoli cells, favoring the development of a LCCSCT. At some point in the evolution of the disease, a mutational event might induce a higher expression of the ER. Also, TGFbeta1 protein expression is increased in neighboring cells. In this environment, TGFbeta1 might switch from tumor suppressor to oncogenic factor and, along with estrogen-ER complexes, might favor tumor progression by inhibiting apoptosis.
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PMID:High TGFbeta1, estrogen receptor, and aromatase gene expression in a large cell calcifying sertoli cell tumor (LCCSCT): implications for the mechanism of oncogenesis. 1694 77

As breast cancer remains the most common cause of cancer death in women, there is a continuing need not only to further characterise the processes of cancer progression, but also to improve accuracy of prognostic markers. Breast epithelial cells express components of the renin angiotensin system and studies suggest that these may be altered in disease progression. In addition, altered integrin expression correlates with lymph node metastasis. The aim of this study was to investigate the relationship between angiotensin II (AII) and integrins in breast tissue and, in particular, their role in breast cancer cell metastasis. Using in vitro assays, AII (10(-6) M)-treated MCF-7 and T47D breast cancer cells both show reduced adhesion to extracellular matrix proteins collagen-, fibronectin- and laminin-coated wells (P<0.001) and reduced invasion through collagen-, fibronectin- and laminin-coated membranes (P<0.05). This action was inhibited by co-treatment with the angiotensin type 1 receptor (AT1R) antagonist losartan (10(-5) M). The addition of the AT2R inhibitor PD123319 (10(-5) M) to AII-treated cells had no significant effect. Semi-quantitative reverse transcriptase-PCR and western blotting revealed that cells treated with AII (10(-6) M) expressed lower levels of both integrin alpha3 and beta1. Using specific inhibitors, this was shown to occur through protein kinase C signalling. These data suggest that AII reduces cell adhesion and invasion through the type 1 receptor and that this effect may be due to reduced expression of integrins, and in particular alpha3 and beta1.
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PMID:The role of angiotensin II in the regulation of breast cancer cell adhesion and invasion. 1695 38

Molecular abnormalities in the epithelial cells of endometriosis and their relevance to carcinogenesis of the ovary have been well studied. On the other hand, the differences of proinflammatory microenvironments between endometriosis and ovarian carcinomas have not been well documented yet. In this study, the expression patterns of CXC chemokines (IL-8, ENA-78, GRO-alpha, I-TAC, Mig, and SDF-1) and their receptors (CXCR2, CXCR3, and CXCR4) were compared among 12 ovarian carcinomas, 8 endometriosis, and 6 normal ovaries using quantitative reverse transcriptase polymerase chain reaction and immunohistochemistry. The CXCR3-mediated signaling in ovarian carcinoma cells in vitro was also investigated. In quantitative reverse transcriptase polymerase chain reaction, ENA-78 was up-regulated both in endometriosis and carcinomas, whereas I-TAC was detected exclusively in carcinomas. CXCR3 was up-regulated both in carcinomas and endometriosis. However, immunohistochemical studies revealed that the localization of CXCR3 in carcinomas was distinctively different from that in endometriosis. In carcinoma-endometriosis coexisting cases, CXCR3-positive lymphocytes in benign lesions decreased in proportion as CXCR3-positive tumor cells replaced the tissues. CXCR3 was also detected in ovarian carcinoma cell lines in vitro. Administration of interferon gamma (IFN-gamma)-inducible chemokines induced extracellular signal-regulated kinase phosphorylation in these carcinoma cells. The results indicated that CXC chemokines might contribute to the progression of ovarian carcinomas and endometriosis in different manners. Aberrant expression of IFN-gamma-inducible chemokines and CXCR3 in carcinoma cells in association with reduced CXCR3-positive immune cells raised the possibility that IFN-gamma-inducible chemokines might not exert effective antitumor immune responses but that they might work in favor of tumor progression.
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PMID:Up-regulation of CXC chemokines and their receptors: implications for proinflammatory microenvironments of ovarian carcinomas and endometriosis. 1770 63


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