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)

There is clear evidence that the occurrence of specific mRNAs in plasma and serum is associated with cancer, while the usefulness of other body fluids for nucleic acid-based cancer detection remains to be elucidated. Nevertheless, due to the principal advantages of urine (large sample quantities, easy to acquire), several attempts were made to use quantitative reverse transcriptase polymerase chain reaction (RT-PCR)-based detection of putative RNA tumor markers from urine as a tool for noninvasive tumor detection. Because most of the commercially available RNA isolation systems do not accommodate larger sample volumes, the majority of experiments were performed using urine pellets. During the centrifugation step, putative extracellular nucleic acids of low molecular weight as well as complexes containing nucleic acids with low density are lost. Furthermore, cells may be destroyed during this procedure, and the subsequently released nucleic acids will quickly be degraded by nucleases in the urine, which may give rise to inconsistent results. Therefore, we established an improved protocol for the isolation of RNA from urine and subsequent quantification steps. The isolation procedure was tested using a quantitative RT-PCR specific for Ki-67 RNA as well as a radioactive-based reverse transcription approach.
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PMID:Improved conditions for isolation and quantification of RNA in urine specimens. 1525 58

Alterations in the control of cell cycle progression have been implicated in a wide variety of malignant neoplasms, including prostate cancer. CDC25 phosphatases belong to the tyrosine phosphatase family and play a critical role in regulating cell cycle progression by dephosphorylating cyclin-dependent kinases at inhibitory residues. CDC25C plays an important role in the G2-M transition by activating Cdc2/Cyclin B1 complexes. To determine whether CDC25C activity is altered in prostate cancer, we have examined the expression of CDC25C and an alternatively spliced variant in human prostate cancer samples and cell lines. CDC25C protein is up-regulated in prostate cancer in comparison with normal prostate tissue and is present almost exclusively in its active dephosphorylated form. Expression of a biologically active alternatively spliced CDC25C isoform is also increased in prostate cancer and expression of alternatively spliced CDC25C is correlated to occurrence of biochemical (prostate-specific antigen) recurrence. We have also developed a quantitative reverse transcriptase-PCR analysis of Ki-67 expression as a method of measuring proliferative activity in prostate cancer from RNA samples. Based on this analysis of Ki67 expression, some but not all of this increase in CDC25C and its alternatively spliced variants is correlated with increased proliferation in prostate cancer. This data suggests that CDC25C might play an important role in prostate cancer progression and could be used to monitor and predict the aggressiveness of this disease.
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PMID:Increased expression and activity of CDC25C phosphatase and an alternatively spliced variant in prostate cancer. 1600 May 64

IGF-1, IGF-2, and type 1 IGF receptor (IGF-R1) mRNA expression and immunolocalization and cell proliferation index were studied in human adrenals from early infancy to late puberty. Adrenals were obtained from transplantation donors or from necropsies of endocrinologically normal subjects. Subjects were divided into three age groups: group 1, <3 mo of age, involution of fetal adrenals; group 2, 3 mo to 6 y of age, preadrenarche; and group 3, older than 6 y up to 20 y of age, postadrenarche. Cell proliferation index (Ki-67) in the outer, subcapsular, zona glomerulosa was significantly higher than in zona fasciculata of all groups and in zona reticularis or fetal zone. IGF-1 mRNA (semiquantitative reverse transcriptase-PCR and Northern blot) in group 2 was significantly higher than in group 1 and group 3 (p < 0.05). IGF2 mRNA in group 1 was significantly higher than in the other groups. IGF-R1 mRNA in group 3 was significantly higher than in group 2 but not different from group 1. Strong IGF-1, IGF-2, and IGF-R1 immunostaining signal was observed in the outer, subcapsular, zona glomerulosa and in zona fasciculata in the three groups, whereas a very weak IGF-1 and IGF-R1 immunostaining signal was found in fetal zone cells of group 1 and in zona reticularis of group 3. We propose that IGF-1 could be a factor involved in the postnatal mechanism of progenitor adrenal cell proliferation and migration. Our data also suggest that IGF-1 is not a direct regulatory factor of adrenal androgen production by zona reticularis cells.
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PMID:Expression of the IGF system in human adrenal tissues from early infancy to late puberty: implications for the development of adrenarche. 1614 56

Aurora kinases such as Aurora A and Aurora B are key regulators of mitosis and have been reported to be overexpressed in various malignancies. However, the expression and localization of Aurora kinases in normal and neoplastic endometrial tissues remain undetermined. In the present study, immunohistochemical expression of Aurora A and B was examined in 40 normal, 30 hyperplastic, and 73 malignant endometria. The data were compared with the expression of Ki-67 and patient survivals. The expression of Aurora A and B at protein and messenger RNA levels was also examined using Western blotting and the reverse transcriptase polymerase chain reaction. The expression of Aurora A in normal endometrium was observed mainly in the proliferative phase and was decreased in the secretory phase. The Aurora A expression was significantly increased in carcinomas compared with normal proliferative endometrium; however, there was no correlation of Aurora A expression with Ki-67 expression or patient survival. The expression of Aurora B in normal endometrium was significantly higher in the proliferative phase than in the secretory phase. In endometrial carcinomas, the expression of Aurora B was correlated with Ki-67 expression and was significantly increased in high-grade tumors. In addition, patients with Aurora B-positive carcinoma showed poor prognosis compared with those with Aurora B-negative carcinoma (P = .0135). Accordingly, the present study indicates the aberrant expression of Aurora A and Aurora B in endometrial carcinomas and the clinical importance of Aurora B expression in relationship to patient prognosis.
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PMID:Expression of Aurora kinases A and B in normal, hyperplastic, and malignant human endometrium: Aurora B as a predictor for poor prognosis in endometrial carcinoma. 1631 Nov 21

The prototypic pituitary hormone prolactin (PRL) exerts a wide variety of bioregulatory effects in mammals and is also found in extrapituitary sites, including murine skin. Here, we show by reverse transcriptase-polymerase chain reaction and immunohistology that, contrary to a previous report, human skin and normal human scalp hair follicles (HFs), in particular, express both PRL and PRL receptors (PRL-R) at the mRNA and protein level. PRL and PRL-R immunoreactivity can be detected in the epithelium of human anagen VI HFs, while the HF mesenchyme is negative. During the HF transformation from growth (anagen) to apoptosis-driven regression (catagen), PRL and PRL-R immunoreactivity appear up-regulated. Treatment of organ-cultured human scalp HFs with high-dose PRL (400 ng/ml) results in a significant inhibition of hair shaft elongation and premature catagen development, along with reduced proliferation and increased apoptosis of hair bulb keratinocytes (Ki-67/terminal dUTP nick-end labeling immunohistomorphometry). This shows that PRL receptors, expressed in HFs, are functional and that human skin and human scalp HFs are both direct targets and sources of PRL. Our data suggest that PRL acts as an autocrine hair growth modulator with catagen-promoting functions and that the hair growth-inhibitory effects of PRL demonstrated here may underlie the as yet ill-understood hair loss in patients with hyper-prolactinemia.
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PMID:Human scalp hair follicles are both a target and a source of prolactin, which serves as an autocrine and/or paracrine promoter of apoptosis-driven hair follicle regression. 1650 90

Claudins (CLDNs), a family of transmembrane proteins, are major constituents of tight junctions (TJs). They have been shown to be differentially regulated in malignant tumors and play a role in carcinogenesis and progression. We aimed to explain the molecular mechanism underlying the main epithelial components of hepatoblastomas (HBs) based on the composition of TJs. Fourteen formalin-fixed, paraffin-embedded surgical resection specimens were analyzed by immunohistochemistry for CLDN-1, -2, -3, -4, -7; proliferating cell nuclear antigen (PCNA); Ki-67; beta-catenin; cytokeratin-7 (CK-7); and hepatocyte-specific antigen; messenger RNA was isolated for real-time reverse transcriptase polymerase chain reaction analysis of the CLDNs from dissected fetal and embryonal cell types. Significantly increased protein and messenger RNA expression of CLDN-1 and -2 was detected in the fetal compared with the embryonal component. Both cell types displayed negative or weak immunostainings for CLDN-3, -4, and -7. Hepatocyte-specific antigen was dominantly expressed in the fetal component. PCNA and Ki-67 labeling indices were significantly higher in embryonal compared with fetal cells. beta-catenin cytoplasmic/nuclear immunoreaction was frequent, although not showing significant differences between fetal and embryonal cells. Mutational analysis of beta-catenin detected mutation in two cases. Our results suggest that increased expression of CLDN-1 and -2 characterizes the more differentiated fetal component in HBs and is a reliable marker for differentiating fetal and embryonal cell types in HBs. The results proved that the embryonal and fetal components of HBs differ in such important feature as the protein composition of TJs. The expression of CLDN-1 and -2 is inversely correlated with cell proliferation. The more aggressive, rapidly proliferating embryonal phenotype is associated with the decrease/loss of CLDN-1 and -2. However, there are no data indicating association with the nuclear translocation of beta-catenin.
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PMID:Claudin-1 and claudin-2 differentiate fetal and embryonal components in human hepatoblastoma. 1664 53

The main purpose of this retrospective study was to compare Ki-67 expression in operable breast cancer examined by immunostaining and real-time reverse transcriptase polymerase chain reaction (RT-PCR). Relations between Ki-67 and classic prognostic factors were also investigated, and the prognostic relevance of Ki-67 expression was examined. Expression of Ki-67 was analyzed in specimens of invasive ductal breast cancer tissue obtained from 131 women during radical mastectomy. There was a significant, but weakly positive, correlation between Ki-67 expression assessed by immunostaining and real-time RT-PCR (tau=0.154, p=0.005). Higher Ki-67 expression in immunostaining and RT-PCR was more often seen in grade 3 tumors (p<0.001 and p=0.026, respectively). No significant relationship with age, disease stage, nodal involvement, estrogen receptor or HER2 status was found. In a univariate and multivariate analysis of cancer-specific survival with a median follow-up of 56 months, Ki-67 expression determined by immunostaining or real-time RT-PCR was no prognostic factor. We demonstrated that Ki-67 expression levels measured by immunostaining and real-time RT-PCR were weakly concordant, and both were related to higher tumor grade. Ki-67 expression did not influence survival.
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PMID:Ki-67 expression in operable breast cancer: a comparative study of immunostaining and a real-time RT-PCR assay. 1667 80

Secretory carcinomas (SBC) are characterized by their characteristic histomorphology and more favorable prognosis compared to invasive ductal carcinoma of usual type (IDC). On this basis, 13 SBCs are evaluated by molecular and immunohistochemical (IH) methods. 13 SBCs and 4 IDCs were analyzed for ETV6-NTRK3 gene fusion by reverse transcriptase-polymerase chain reaction (RT-PCR) and by Fluorescence in situ Hybridization (FISH). 8 of 13 microdissected SBCs with evaluable DNA were evaluated for genetic alterations (GA) by comparative genomic hybridization (CGH). IH included estrogen-receptor (ER), progesterone-receptor (PR), Her-2/neu and Ki-67 (MIB-1) in all 13 cases. Molecular and immunohistochemical results in SBCs were compared with previous data regarding immunohistochemical and molecular characteristics of IDCs. 12 of 13 (92 %) SBC cases, but not IDCs expressed the ETV6-NTRK3 fusion gene which encodes a chimeric tyrosine kinase. Retroviral transfer of ETV6-NTRK3 (EN) into murine mammary epithelial cells resulted in transformed cells that readily formed epithelial tumors in nude mice. CGH revealed an average of 2.0 GAs (range 0-6), including recurrent gains of chromosome 8q and 1q and losses of 22q. Four SBCs were positive for ER and 2 were positive for PR. The mean MIB-1-labeling index was 11.4% (range: <1-34%). Her-2/ neu protein overexpression was detected in 1 case (score 3+). Compared to previous findings in IDCs, SBCs are characterized by the recurrent expression of ETV6-NTRK3 fusion gene, a relatively low number of GAs, low proliferative rate, infrequent Her-2/ neu protein overexpression and a lower rate of steroid hormone receptor expression. These results support the hypothesis that SBCs have immunohistochemical and genetic features that specifically distinguish them from IDCs.
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PMID:Secretory carcinoma of the breast: a genetically defined carcinoma entity. 1688 13

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

Pancreatic cancer (PanCa) is characterized by perineural invasion (PNI), early lymph node and liver metastasis, and poor prognosis. PNI is one of the important causes of local recurrence. Little is known about the mechanism of PNI in PanCa. We presented a novel model system that may shed light on the mystery of PNI in PanCa. In this study, mouse dorsal root ganglia (DRGs) and human PanCa cell line (MIA PaCa-2) were cocultured in Matrigel matrix (BD Biosciences, San Jose, CA) to build this PNI model. MIA PaCa-2 cell line alone (control 1) or DRG alone (control 2) was cultured with Matrigel matrix as controls. Neurite outgrowth, cell colony growth, neurite-colony contact, and retrograde extension were observed under inverted microscopy and then were photographed and quantitated with the Optimas imaging system (Optimas Corp., Bothell, MA). At day 14, both the experimental and control 2 samples were harvested and subjected to total RNA isolation and fixed in paraffin-embedded blocks. Slides cut from paraffin blocks were studied with Ki-67 immunostaining and TUNEL assay. Gene profiling was performed using complementary DNA microarray. Overexpressed target genes were verified by quantitative reverse transcriptase polymerase chain reaction. The results showed that reciprocity was observed between neurites and MIA PaCa colonies with 24 hours of coculture. Neurite outgrowth was stimulated in the presence of pancreatic carcinoma cells, which showed 2-fold more area than did control 2. After 72 hours, MIA PaCa colonies cocultured with DRG exhibited 58% more colony area than did control 1. The Ki-67 index of the DRG/MIA PaCa cells (mean, 5.02%) was significantly higher than that in control 1 (mean, 1.18%) (P < .05); in contrast, the apoptotic index in the DRG/MIA PaCa cells was significantly lower (mean, 0.45%) than that in the control 1 (mean, 1.85%) (P < .001). Prosurvival genes MALT1 and TRAF were increased 2-fold in DRG/MIA PaCa compared with controls. We demonstrated that neural-epithelial interaction is a mutually beneficial process for the growth of nerves and PanCa cells. It is possible that oncogenes and growth factors might act synergistically in promoting proliferation and/or inhibiting apoptosis, a survival strategy crucial to the development of PNI in PanCa.
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PMID:Enhanced survival in perineural invasion of pancreatic cancer: an in vitro approach. 1709 19


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