Expression pattern of matrix metalloproteinases-13 in a rat model of alcoholic liver fibrosis

BACKGROUND: Interstitial collagenase has been considered as an essential enzyme for collagenolysis in liver fi-brosis, because type Ⅰ and Ⅲ collagens increase predominantly in liver fibrosis. The present study aimed to demonstrate the gene expression of matrix metalloproteinases-13 (MMP-13) in the progressive phases of ethanol induced experimental liver fibrosis in rats. METHODS: Thirty-four Sprague-Dawley rats were randomly divided into two groups. The experimental group (24 rats) was given ethanol (44% , 7 g/kg) every day and the control group (10) was given normal saline. Liver samples were harvested from experimental rats at 4, 12 and 24 weeks respectively. The kinetics of MMP-13 mRNA expression was assayed by semi-quantity reverse transcriptase-poly-merase chain reaction (RT-PCR). RESULTS: In normal rat liver, a faint band for MMP-13 mRNA was observed by RT-PCR (0.24±0.41). The gene expression of MMP-13 was increased in the liver of the rats treated with ethanol for 4 weeks (0. 62 ±0. 54), but it was not considered statistically significant (P >0.05). And the livers from 12-week-treated rats showed a marked mRNA expression(1.65 ±0.47, P <0. 01). Once fibrosis became prominent (24 weeks), a faint band of MMP-13 mRNA was observed (0.39±0.25). CONCLUSION: MMP-13 participates in the degradation of newly-formed matrix in the early phase of rat liver fibrosis induced by ethanol, and it was induced in a distinct time frame.

Expression of Transforming Growth Factor-β in Cultured Normal Human Lens Epithelia Cells

Summary: In order to investigate whether cultured normal human lens epithelial cells (LEC) express transforming growth factor β (TGF-β), reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemical methods were used for detection of TGF-β mRNA and protein in cultured normal human LEC. The results showed that a single RT-PCR amplified product about 310bp was obtained, and the sequence was homologous to the known sequence. TGF-β immunostain was positive in the plasma of LEC. It was suggested that normal human LEC could produce TGF-β, and LEC could be affected by TGF-β through autocrine action.

Differential gene expression between asymptomatic HBV carriers and normal adults

BACKGROUND: There are more than 100 million wa symptomatic HBV carriers (ASCs) in China and they are at a high risk of developing liver disease, which creates a serious health problem. But more than 90% of normal adults clear virus from primary HBV infection, so the difference of gene expression between ASCs and normal adults determines the differential outcomes. To identify differentially expressed genes in ASCs compared to normal adults, we used suppression subtractive hybridization to compare gene expression. METHODS: cDNA subtracted libraries were constructed by suppression subtracted hybridization from peripheral blood monocytes of ASCs and normal adults, the subtracted clones were prescreened by dot blot hybridization, and the levels of genes of interest were confirmed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: One hundred and two and 96 positive clones were acquired from the A-N and N-A libraries, respectively, and 14 and 11 clones were identified by dot blot hybridization in the A-N and N-A libraries. Two genes were confirmed as differentially expressed between a set of ASC and normal adult samples by real-time RT-PCR. CONCLUSIONS: Differentially expressed genes in peripheral blood mononuclear cells between ASCs and normal adults were isolated by suppression subtractive hybridization, and included some new genes. Of the upregulated genes in ASCs, checkpoint suppressor I is associated with DNA damage-induced cell cycle arrest. Perforin I is associated with inflammation. The information about such alterations in gene expression could be useful for elucidating the mechanisms of ASC pathogenesis.

Quantified gene expression levels for phase Ⅰ/Ⅱ metabolizing enzyme and estrogen receptor levels in benign prostate from cohorts designated as high-risk （UK） versus low-risk （India）for adenocarcinoma at this organ site：a preliminary study

Risk of clinically significant prostate adenocarcinoma （CAP） varies worldwide,although there is a uniform prevalence of latent disease. A hormone-responsive tissue,the prostate possesses the metabolizing capacity to biotransform a variety of environmental procarcinogens or endogenous hormones. Whether such metabolizing capacity or estrogen receptor （ER） status underlies these demographic differences in susceptibility to CaP remains unclear. With appropriate ethical permission,verified-benign tissues were obtained following transurethral resection of the prostate from a high-risk region （n = 12 UK-resident Caucasians） and a typically low-risk region （n = 14 India-resident Asians）. Quantitative gene expression analysis was employed for cytochrome P450 （CYP）1B1,N-acetyltransferase （NAT）1,NAT2,catechol-O-methyl transferase （ COMT）,sulfotransferase （ SULT） 1A1,ERα,ERβ and aromatase （CYP To quantify the presence or absence of CYP1B1,ERα or ERβ,and to identify ther in situ localization,immunohistochemistry was carried out. The two cohorts had reasonably well-matched serum levels of prostate-specific antigen or hormones. Expression levels for the candidate genes investigated were similar.However,clear differences in protein levels for CYP1B1 and ERβ were noted. Staining for CYP1B1 tended to be nuclear-associated in the basal glandular epithelial cells,and in UK-resident Caucasian tissues was present at a higher （P = 0.006） level compared with that from India-resident Asians. In contrast,a higher level of positive ERβ staining was noted in prostates from India-resident Asians. These study findings point to differences in metabolizing capacity and ER status in benign prostate tissues that might modulate susceptibility to the emergence of clinically significant CaP in demographically distinct populations.

EXPRESSION AND SIGNIFICANCE OF PTEN IN ENDOMETRIAL CARCINOMA

Objective: To investigate the expression of PTEN in endometrial carcinoma and its clinical significance. Methods: Reverse transcriptase-polymerase chain reaction and Western-blot methods were used to detect PTEN expression in 28 cases of endometrial carcinoma. Results: mRNA and protein expression levels of PTEN in endometrial carcinomas were significantly lower than those in normal endometrium (P<0.01). Conclusion: PTEN may play an important role in the tumorigenesis of endometrial carcinoma.

Transforming Growth Factor-β_2 Gene Cloning and Protein Expression in Human Trabecular Meshwork Cells

Whether cultured human trabecular meshwork cells express transforming growth factor-β 2 (TGF-β 2) messenger RNA (mRNA) and protein was investigated. Total RNA of 10 6 cultured human trabecular meshwork cells was extracted with TRIZOL reagent, reverse transcriptase-polymerase chain reaction (RT-PCR) were used for detection of TGF-β 2 messenger RNA, and the PCR product was verified by sequencing. Immunohistochemical staining was used to detect TGF-β 2 protein. The results showed that a single RT-PCR amplified product was obtained, and the sequence was homologous to the known sequence. TGF-β 2 immunostaining was positive. It was concluded that trabecular meshwork cells could produce TGF-β 2 and contribute to the presence of TGF-β 2 in trabecular meshwork microenvironment as well as aqueous humor. Trabecular meshwork cells were affected by TGF-β 2 not only through paracrine, but also autocrine action. Whether abnormal changes in TGF-β 2 production contribute to the pathogenesis of primary open-angle glaucoma is worth further investigation.

Long-term culture of primary porcine mature hepatocytes in the medium supplemented with ascorbic acid 2-phosphate

In this study, the effect of ascorbic acid 2-phosphate (Asc2P) was tested on porcine and rat mature hepatocytes in vitro. a). Asc2P increased the porcine, but not rat, albumin secretion and mRNA expression. The enhancing effect of Asc2P on porcine C/EBP alpha mRNA was observed in porcine mature hepatocytes. These data suggested that Asc2P played an important role in the regulation of porcine albumin mRNA level. b). The enhancing effect of Asc2P on ammonium metabolic activity was also observed in porcine, but not rat, mature hepatocytes. The porcine ornithine transcarbamylase (OTC) and arginase mRNAs were augmented by Asc2P, indicating that Asc2P had a direct effect on the urea cycle. c). The porcine collagen type I and type III mRNA, but not type XII mRNA, were detected as well, sugessting that Asc2P did not have the effect on the non-parenchymal hepatocytes to induce collagen type I and III mRNA expression. d). Our RT-PCR analysis demonstrated that the porcine hepatocytes expressed the sodium-ascorbate co-transporters SVCT1 and SVCT2, however, the intensities of porcine sodium-ascorbate co-transporters SVCT1 and SVCT2 bands were not changed markedly. These findings indicated that the Asc2P had no effect on SVCT1 and SVCT2 mRNA expression. e). The enhancing effect of Asc2P on porcine albumin mRNA was inhibited by staurosporine, a portein kinase inhibitor. We conclude that the enhanced albumin mRNA by Asc2P might be due to activation of tyrosine protein kinase and/or PKC and the Asc2P enhanced porcine albumin mRNA mainly at the transcriptional step.

Molecular detection of EWS-Ets fusion transcripts and their clinicopathologic significance in Ewing’s sarcoma/peripheral primitive neuroectodermal tumor

Background Ewing＇s sarcoma/peripheral primitive neuroectodermal tumor （ES/pPNET） is often difficuh to distinguish from other small round cell tumors. The EWS-Ets gene fusions that result from chromosomal translocations in this tumor provide potential molecular diagnostic markers. To apply these molecular markers to commonly available archival materials, we evaluated the feasibility of detecting EWS-Ets including EWS-Flil and EWS-ERG fusion transcripts in paraffin-embedded tissues and its diagnostic value for detecting ES/pPNET. Methods Thirteen paraffin-embedded samples of ES/pPNETs were retrieved from archives. Thirteen cases of other tumors with small round cell features （including rhabdomyosarcoma, neuroblastoma, lymphoma, small ceil carcinoma, and desmoplastic small round cell tumor ） were used as negative controls. β-actin and β2- microglobulin were used as internal controls. A nested reverse transcriptase-polymerase chain reaction （RT- PCR）-based assay was performed to detect the EWS-Flil and EWS-ERG fusion transcripts. Results β-aetin and β2-mieroglobulin were detected in 10/13 and 13/13 ES/pPNETs, respectively. EWS- Flil fusion transcripts were detected in 11 of 13 （85%） ES/pPNETs. Three chimeric transcripts, all EWS-Flil, were detected in ES/pPNET samples. Among 11 EWS-Flil-positive cases, 7 eases had a type Ⅰ fusion transcript involving fusion of EWS exon 7 with Flil exon 6, 2 eases had a type Ⅱ fusion transcript involving EWS exon 7 with Flil exon 5, and 2 eases expressed fusion transcripts involving EWS exon 7 and Flil exon 8. Type Ⅰ EWS- Flil fusion predominated over other types. Fusion types could not be distinguished in the remaining 2 eases. Thirteen negative controls did not show detectable chimeric messages. There was a significant relationship between EWS-Flil fusion transcripts and CD99 expression. Conclusions Molecular detection of EWS-Flil fusion transcripts in formalin-fixed paraffin-embedded material by nested RT-PCR is feasible and is useful for the diagnosis and differential diagnosis of ES/pPNETs.