Hormonal influences on the expression of casein messenger RNA during mouse mammary tumorigenesis.
Explore the source record for details and available documents.
Animals↗
SEARCH · Search PubMed
Results for “RNA, MESSENGER”
Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Molecular cloning and expression of multiple isoforms of human prostaglandin E receptor EP3 subtype generated by alternative messenger RNA splicing: multiple second messenger systems and tissue-specific distributions.
Five distinct cDNA clones encoding four different isoforms of human prostaglandin (PG) E receptor EP3 subtype were isolated from a human kidney cDNA library. Two cDNA clones differed only in their 3'-untranslated regions. The four isoforms, tentatively named EP3-I, EP3-II, EP3-III, and EP3-IV, which were generated by alternative mRNA splicing, had identical amino acid sequences except for their different carboxyl-terminal tails. Transfection experiments revealed that all the four isoforms show high binding affinities to PGE2, PGE1, and M&B28767, an EP3-specific agonist, whereas their downstream signaling pathways are divergent. M&B28767 increased cAMP concentrations in cells expressing EP3-II and EP3-IV, whereas it inhibited forskolin-induced cAMP accumulations in cells expressing all EP3 isoforms. M&B28767 also stimulated phosphoinositide turnover in cells expressing EP3-I and EP3-II. Northern blot analysis revealed that the EP3 gene is expressed in a wide variety of human tissues. The human EP3 mRNA was present most abundantly in the kidney, pancreas, and uterus. A substantial expression was also detected in the heart, liver, skeletal muscle, small intestine, colon, prostate, ovary, and testis. Furthermore, reverse transcription-polymerase chain reaction analysis demonstrated tissue-specific expressions of the five different EP3 mRNA species. The present study suggests the presence of the multiple systems of PGE2/EP3 isoforms and leads to the better understanding of its physiological and pathophysiological implications in humans.
Alternative Splicing↗
Selective expression of CD44 messenger RNA splice variants in four high grade human brain tumour cell lines.
Changes in CD44 transcripts have been previously found to be associated with metastasis in animal models. The purpose of this study was to investigate CD44V changes in four well established high grade human brain tumor cell lines, known to possess prominent invasive behavior. In Northern blot analysis, CD44S and CD44V were expressed strongly in three high-grade glioblastoma multiforme cell lines (GBM 8401, GBM 8909, GBM 8804) and one malignant meningioma cell line (IOMM). By RT-PCR and blot hybridization, three variant transcripts (650 bps, 850 bps, and 1,000 bps) were detected in GBM 8804 and two isoform transcripts (650 bps, 850 bps) were recognized in GBM 8401 and 8909. Further, in a malignant meningioma cell line (IOMM), only one weak isoform (650 bps) was detected. However, by Northern blot analysis, neither CD44S or CD44V could be expressed in normal brain and meningeal tissue. These results indicate that discrete CD44 mRNA splice variants are expressed in high grade glial cell tumors and malignant meningioma and suggest a possible role in the invasion of malignant brain tumors.
Base Sequence↗
Molecular characterization of prostate-specific antigen messenger RNA expressed in breast tumors.
Prostate-specific antigen (PSA) is considered a highly specific biochemical marker of the prostate gland and is currently used for prostate cancer diagnosis and monitoring of patients with prostate adenocarcinoma. We recently demonstrated, however, that about 30% of female breast tumors produce a M(r) 33,000 protein that has striking similarities to seminal PSA. In this study we characterized the presence of PSA in 6 breast tumors and in the testosterone-stimulated T47D breast cancer cell line at the mRNA level. Using reverse transcriptase-polymerase chain reaction and DNA sequencing techniques we identified PSA mRNA in immunoreactive PSA-positive breast tumors but not in immunoreactive PSA-negative breast tumors. The sequence of the generated polymerase chain reaction products was identical to the sequence of the PSA complementary DNA derived from prostate tissue. The data presented here support the notion that breast tumors produce a M(r) 33,000 protein which is identical to PSA produced by the prostate gland. Our study suggests that the presence of PSA in breast tumors may be used as a new additional biochemical marker for breast cancer prognosis, for the spreading of hematogenous micrometastases, and/or for response to adjuvant treatment.
Base Sequence↗
[Quantification of messenger RNA expression in tumors: which standard should be used for best RNA normalization?].
Alterations in gene expression are frequently encountered in malignant tissues. Quantification of the often quite subtle changes in mRNA content is routinely performed by northern blot hybridization. Practical experience shows that the methodology is subject to considerable error, necessitating the use of an internal mRNA standard for quantification. Many different control mRNAs have been employed over the years, but no systematic study has proven their applicability to comparisons made between tumor cells and normal tissues. The validity of these control RNAs, usually housekeeping genes, must be established to exclude the possibility that they themselves are expressed at different levels in tumor and non-tumor cells. Our experience has revealed that serious discrepancies may arise when incorrect standard genes are used to compare tumor and normal tissues.
Actins↗
Deregulated alternative splicing of CD44 messenger RNA transcripts in neoplastic and nonneoplastic lesions of the human thyroid.
CD44 is a polymorphic family of immunologically related cell surface proteoglycans and glycoproteins implicated in cell-cell and cell-matrix adhesion interactions, lymphocyte activation and homing, cell migration, and tumor metastasis. CD44 exists as a standard form and as multiple isoforms, each generated by alternative splicing of up to 10 variant exons (termed v1-v10) encoding parts of the extracellular domain. Using semiquantitative reverse transcriptase-PCR and Southern hybridization, alternative CD44 mRNA splicing was examined in 10 papillary thyroid carcinomas, 8 nodular goiters, 9 adenomas, 2 cases of thyroiditis, and 3 histologically normal thyroid controls. The amount of input cDNA for the CD44 PCRs was standardized against an internal control gene (glyceraldehyde phosphate dehydrogenase). Four papillary carcinomas showed significant overexpression of CD44 transcripts migrating between 750 and 1000 bp. These cases demonstrated reduced levels of the 482-bp standard isoform transcript. In six papillary cancers, we found a prominent v6-containing isoform at 750 bp that was present in only trace amounts in normal thyroid tissue. It is of interest that similar findings were seen in the majority of the goiters and adenomas but not in the cases of thyroiditis. These results show that deregulation of alternative CD44 splicing is a common feature of disordered thyroid follicular cell growth, both in neoplastic and nonneoplastic lesions. The data imply an important role for CD44, including CD44v6, in the pathogenesis of various thyroid lesions.
Adenocarcinoma, Papillary↗
Expression of thymidine kinase messenger RNA and a related transcript is modulated by radioprotector WR1065.
Previous studies have shown that the radioprotector WR1065 protects against mutagenesis across a wide concentration range (i.e., 40 microM to 4 mM) but protects against cell killing by ionizing radiation at concentrations greater than 1 mM. Other work has demonstrated that many genes are induced or repressed after exposure of cells in culture to ionizing radiation, but the actual inducing agents for this gene modulation response are unknown. In these experiments, we set out to identify genes that would be modulated in response to two different concentrations of WR1065 (i.e., a lower dose that is incapable of protecting against cell killing but effective in protecting against mutation induction, and a high dose that is effective in protecting against both end points). Using differential display reverse transcription-PCR, we compared genes expressed in untreated cells to those expressed in cells treated with different concentrations of WR1065 (4 mM or 40 microM) with or without radiation exposure (7.5 Gy). One band, which showed a differential response, was sequenced and found to have homology in the 3'-untranslated region of the mouse thymidine kinase (tk) gene but not identity to the Chinese hamster ovary tk gene. Dot blot and Northern blot analyses confirmed the differential display results and also determined that regulation of the tk-like gene is similar to that of tk itself. These experiments established that in Chinese hamster ovary cells, radiation causes a repression in accumulation of tk mRNA and a related tk-like transcript. This repression is made less dramatic by the presence of 40 microM WR1065, and, in fact, expression becomes enhanced when cells are pretreated with 4 mM WR1065. This suggests a role for regulation of tk and its related gene in the survival response of cells after exposure to ionizing radiation.
Animals↗
Characterization and regulatory effect of gamma-glutamyltransferase messenger RNA untranslated regions in human leukemia.
In this paper we report the presence and function of the 5' untranslated region (5'UTR) from the mRNA encoding human gamma-glutamyltransferase (GGT) in three different hematopoietic cell lines (HL-60, U-937 and K-562) as well as in the RNA of the leukocyte fraction from six acute lymphoblastic leukemias (ALL). Results obtained by RNase protection analysis demonstrate the presence of a unique form of 5'UTR expressed in most human tissues. In order to investigate the possible role of this type of sequence on regulation of GGT in hematopoietic cells, plasmid constructs carrying human hepatoma GGT 5'UTR and a luciferase reporter gene were transfected into the three blood cell lines. Compared to control untransfected cells, transfected HL-60 and K-562 showed a decrease in reporter gene activity of 51 and 73%, respectively. In contrast, transfected U-937 showed a 139% increase of reporter gene activity. Results were compared to GGT activity in the relevant cells and we concluded that the 5'UTR appears to have a regulatory role in GGT expression as a tissue-specific modulator of translation.
Base Sequence↗
Fibroin messenger RNA and its genes.
Explore the source record for details and available documents.
Alleles↗
Cyclin D1 messenger RNA overexpression as a marker for mantle cell lymphoma.
In mantle cell lymphoma (MCL) a recurrent chromosomal rearrangement, t(11;14)(q13;q32), has been described. Most breakpoints have been detected within the 120 kb BCL-1 region, upstream of the cyclin D1 gene. To evaluate the association between BCL-1 rearrangement and expression of cyclin D1 in lymphoproliferative disorders, we analysed a series of 24 MCL, 56 other B-cell non-Hodgkin's lymphomas (NHL), 28 chronic B-cell leukemias, 18 hematopoietic cell lines and 10 normal lymphoid tissues at the RNA level. Hematopoietic cell lines with a known 11q13 translocation showed high expression of the 4.5 kb cyclin D1 transcript. Three B-cell lines without known 11q13 breakpoint showed low expression. We detected high expression in all (11/11) MCL with and in 11 out of 13 cases of MCL without detectable t(11;14) rearrangement. In three cases with a rearrangement at the 3' end of cyclin D1, two showed overexpression of the 1.5 kb transcript and one expression of an aberrant (3.0 kb) transcript. In other lymphoproliferative disorders, only 5/15 hairy cell leukemias, all without detectable t(11;14), and 5/8 B-cell leukemias suspected to be MCL in leukemic phase showed expression levels comparable to MCL, whereas no or only low expression were observed in 56 cases of other NHL, seven chronic B-cell leukemias and all (10/10) normal lymphoid tissues. Cell sorting experiments on fresh tonsils showed that this low expression was present in normal B-cells and not in T-cells. In contrast to other studies, our data indicate that cyclin D1 is expressed in many lymphoproliferative disorders and normal tissues, albeit at low levels. High levels of expression of cyclin D1 however is restricted to MCL and some hairy cell leukemias. We therefore propose that overexpression of cyclin D1 is a reliable marker for the classification of MCL.
Biomarkers, Tumor↗
[Expression of epidermal growth factor, transforming growth factor-alpha and epidermal growth factor receptor messenger RNA in human endometrium and endometrial carcinoma].
To study the regulation of c-erbB, EFG and TGF-alpha in endometrium, we examined the expression of their mRNA in 5 normal endometrial and 5 endometrial carcinoma tissues by Northern blot and reverse transcription-polymerase chain reaction (RT-PCR). By Northern blot with 10 micrograms of total RNA, c-erbB mRNA was not detected in the normal endometrium, but it was detected in 3 samples of endometrial carcinoma tissues. On the other hand RT-PCR identified c-erbB mRNA in all the normal endometrium and endometrial carcinoma tissues by amplifying cDNA derived from c-erbB mRNA. EGF mRNA was detected by RT-PCR in normal endometrium except in the early follicular phase. It was detected in all cases of endometrial carcinoma tissues. TGF-alpha mRNA was also detected in all the normal and endometrial carcinoma tissues by RT-PCR. Our study suggests that an autocrine/paracrine mechanism of EGF may regulate the endometrial cycle. Because some endometrial carcinoma tissues express the c-erbB mRNA much more than normal endometrium, disruption of the autocrine/paracrine mechanism may trigger subsequent endometrial carcinogenesis.
Adenocarcinoma↗
The dynamics of production and the sensitivity to cycloheximide and actinomycin D of interferon-inducing and interferon messenger RNA.
In the process of virus-induced interferon production, two kinds of RNA appear in the cells. One of them induces production by the recipient cells of interferon with the species-specificity of the latter cells (interferon-inducing RNA), and the other is translated by the recipient cells pre-treated with actinomycin D into interferon with the species-specificity of the donor cells of RNA (interferon mRNA). The interferon-inducing RNA appears 20-30 minutes after virus induction and shows maximal activity after 1 hour. Its formation is not influenced by cycloheximide or actinomycin D. This RNA is assumed to be a transcriptive intermediate form of viral RNA. Interferon mRNA appears in the cells 1 hour after virus induction and shows maximal activity after 6-8 hours. Its synthesis is inhibited by cycloheximide and actinomycin D.
Animals↗
[Rate of ribosome movement along messenger RNA in E. coli under normal and inhibited translation].
Considerable decrease of polysome number (22% as compared with 48% in normally grown culture) was observed under methionine starvation of E. coli Hfr (Met-)culture . At the same time the amount of 70S ribosomes increased up to 32%, while it was 2--6% in the control, the content of free ribosome subunits (50S+30S) being stable. The number of polysomes was the same (congruent to 50%) both in the control culture and under inhibition of protein synthesis in E. coli Hfr(Met-) cells with chloramphenicol, the content of 70S ribosomes was increased (30%) like in the case of methionine starvation, and the amount of free ribosome subunits was decreased (24% as compared with 46% in the control). The rate of ribosome movement in polysomes in the presence of chloramphenicol is comparable with that in the control. The rate of ribosome movement along mRNA under methionine starvation in 1.6 times lower than in normally grown E.coli culture. The level of (14)C-leucine incorporation into newly synthesizing polysome proteins under chloramphenicol inhibition of protein synthesis and methionine starvation comprised 20% and 12% of the incorporation level inthe control respectively. It suggested that ribosomes under inhibition of protein synthesis by chloramphenicol or amino acid starvation continue their movement along mRNA with the rate comparable with that in the control. However in this case no peptide bonds are formed ("abortive" translocation).
Bacterial Proteins↗
Expression and cellular localization of messenger RNA for plasminogen activator inhibitor type 1 in human astrocytomas in vivo.
We investigated the expression and cellular localization of plasminogen activator inhibitor type 1 (PAI-1) in human astrocytoma in vivo. Northern blot and densitometric quantitation of PAI-1 mRNA indicated that PAI-1 transcripts were significantly higher in human malignant astrocytomas and especially in glioblastomas than in low-grade gliomas and normal brain tissues in vivo. Using in situ hybridization with paraffin-embedded surgical specimens of human gliomas and normal brain tissues, PAI-1 mRNA was abundantly expressed in glioblastomas. PAI-1 mRNA was localized mainly in tumor cells and endothelial cells. The distribution of PAI-1 mRNA expression was particularly abundant around areas of vascular proliferation and in remnant tumor cells surrounding necrotic foci. PAI-1 mRNA was also expressed in both the tumor and endothelial cells of anaplastic astrocytomas, whereas it was not expressed or only weakly expressed in low-grade astrocytomas or normal brain tissues. These results suggest that high expression of PAI-1 is associated with the malignant progression of astrocytic tumors and that excessive PAI-1 expression might be associated with intratumoral necrosis in glioblastomas.
Astrocytoma↗
Analysis of multidrug resistance-associated protein (MRP) messenger RNA in normal and malignant hematopoietic cells.
The multidrug resistance-associated protein (MRP) gene is a member of the ATP-binding cassette transporter gene superfamily and may be partially responsible for clinical drug resistance. Reverse transcriptase-polymerase chain reaction was used to measure MRP mRNA in normal hematopoietic cells from bone marrow and peripheral blood as well as patients with high risk acute myelocytic leukemia and multiple myeloma. All normal peripheral blood cells, regardless of cell lineage (CD4, CD8, CD14, CD15, CD19, CD56), expressed a similar basal level of MRP mRNA. Specimens from bone marrow containing mixed lineages also expressed a similar basal level of MRP expression. In patients with acute myelocytic leukemia, 10 of 12 (83%) of the specimens had detectable MRP mRNA, but the level of expression was similar to that of normal blood cells and low compared to a cell line known to overexpress MRP (H69/AR). All myeloma patients (12 of 12) had detectable MRP mRNA expression at levels comparable to normal peripheral blood and bone marrow cells. We conclude that MRP is commonly expressed in normal hematopoietic cells as well as certain hematopoietic malignancies. The therapeutic relevance of MRP expression is unknown, but these studies emphasize the importance of measuring MRP expression in normal cells as a point of reference and comparison for detection in malignant cells. We also recommend obtaining sequential specimens from patients, which may reveal an increased expression of MRP from baseline as the disease progresses and becomes resistant.
Base Sequence↗
PRAD-1/cyclin D1 gene amplification correlates with messenger RNA overexpression and tumor progression in human laryngeal carcinomas.
PRAD-1 is a putative oncogene localized on chromosome 11q13 which encodes cyclin D1, a novel cyclin involved in cell cycle regulation. Amplification of this gene has recently been reported in several human tumors including breast and head and neck carcinomas. In this study we have analyzed the presence of PRAD-1/cyclin D1 gene amplification and mRNA overexpression in a series of 46 matched normal mucosas and squamous cell carcinomas of the larynx. PRAD-1/cyclin D1 was found to be amplified 2- to 12-fold in 17 carcinomas (37%). DNA amplification correlated with advanced local invasion (P = 0.0015), presence of lymph node metastases (P = 0.0078), and stage IV of the tumors (P = 0.0021). mRNA overexpression was found in 15 of the 43 (35%) cases examined and it was also significantly associated with advanced local invasion (P = 0.0025) and stage IV carcinomas (P = 0.0032). A significant association was observed between gene amplification and mRNA overexpression (P < 0.0001) with only 3 discordant cases (2 amplifications with no overexpression and 1 overexpressed carcinoma with no gene amplification). Furthermore, the degree of DNA amplification correlated with the levels of mRNA expression (r = 0.6; P = 0.024). These findings suggest that the PRAD-1/cyclin D1 gene may be an important target of 11q13 amplifications in laryngeal carcinomas and the activation of this gene may be involved in the progression of these tumors. Its association with advanced-stage tumors indicates that PRAD-1/cyclin D1 gene amplification and overexpression may be of prognostic significance.
Adult↗
Messenger RNA levels of five genes located at chromosome 11q13 in B-cell tumors with chromosome translocation t(11;14)(q13;q32).
To identify genes activated by chromosome translocation t(11;14)(q13;q32), mRNA levels of five genes (cyclin D1, EXP1, MB38, HST1, and INT2) at chromosome 11q13 were investigated. The cyclin D1 mRNA increased in BCL-1-rearranged B-cell tumor cell lines SP-49, NOP-2, FLAM-76, KMS-12-PE, and KMS-12-BM cells, while it was not detected in cell lines without the translocation, Raji, U266, and HEL cells. A significant amount of the MB38 mRNA was detected irrelevantly to the translocation in all of these cell lines. The mRNAs of EXP1, HST1, and INT2 were undetectable in these cells. The results suggested that the translocation activates cyclin D1 alone, while the mRNA levels of the other four genes are regulated independently of the translocation.
Blotting, Northern↗
Elevation of topoisomerase I messenger RNA, protein, and catalytic activity in human tumors: demonstration of tumor-type specificity and implications for cancer chemotherapy.
Topoisomerase I has been identified as an intracellular target of camptothecin, a plant alkaloid with anticancer activity. Various lines of evidence suggest that the sensitivity of cells to this drug is directly related to the topoisomerase I content. In humans, the levels of topoisomerase I have been shown to be elevated in colorectal tumors, compared to normal colon mucosa. The aim of our study was to determine whether (a) topoisomerase I levels are elevated in other solid tumors, (b) the elevated enzyme is catalytically active in these tumors, and (c) the increase in topoisomerase I levels in colorectal tumors is a result of increased transcription or translation. Topoisomerase I levels were quantitated in crude extracts from colorectal, prostate, and kidney tumors and their matched normal counterparts by Western blotting and by direct determination of catalytic activity, and mRNA levels were determined by Northern blotting. By Western blotting, colorectal tumors showed 5-35-fold increases in topoisomerase I levels, compared to their normal colon mucosa. In the case of prostate tumors, the increase was 2-10-fold, compared with benign hyperplastic prostate tissue from the same patients. However, no difference was observed in topoisomerase I levels in kidney tumors, compared to their normal counterparts. The catalytic activity of topoisomerase I was determined by a quantitative 32P-transfer assay in crude homogenates, without isolating nuclei. Colorectal and prostate tumors exhibited 11-40- and 4-26-fold increases, respectively, in catalytic activity. However, kidney tumors did not show any alteration in catalytic activity, compared to their normal matched samples. Thus, for all three tumor types there was a good correlation between enzyme levels and catalytic activity. Finally, colorectal tumors were analyzed for steady state mRNA levels. A 2-33-fold increase in mRNA levels was found in colorectal tumors, compared to normal colon mucosa. These results suggest that alterations in topoisomerase I expression in humans are tumor type specific and that the increase in topoisomerase I levels results from either increased transcription of the topoisomerase I gene or increased mRNA stability.
Amino Acid Sequence↗