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Exp Mol Pathol [journal]
- Over expression of miR-10a and miR-375 and down regulation of YAP1 in medullary thyroid carcinoma. [JOURNAL ARTICLE]
- Exp Mol Pathol 2013 May 16.
MicroRNAs are a primordial mechanism of gene expression control that appear to be crucial to cellular development and may play an important role in tumor development. Much is known about the genetics of medullary thyroid carcinomas, as approximately 25% are hereditary and harbor germ line activating mutations in the RET gene. Somatic RET mutations are also seen in roughly 50% of sporadic medullary thyroid carcinomas. Few studies, however, have evaluated the role of microRNA expression in these tumors. DNA and RNA were extracted from formalin-fixed paraffin-embedded tissue blocks of 15 medullary thyroid carcinomas [10 with RET mutations (3 hereditary) and 5 without RET mutations] and 5 non-tumor thyroid glands. miRNA expression of 754 targets was quantitated by real time PCR using the ABI OpenArray miRNA assay. Three miRNAs showed significant differential expression and were validated in a larger cohort of 59 cases by real-time PCR. Expression of potential downstream targets and upstream regulators were also investigated by real-time PCR. miR-375 and miR-10a were significantly overexpressed, while miR-455 was underexpressed in medullary thyroid carcinomas. Expression of all 3 miRNAs were validated in the larger cohort of cases (miR-375, p = 3.3x10(-26); miR-10a, p = 5.6x10(-14); miR-455, p = 2.4x10(-4)). No significant differences in miRNA expression were found between RET mutation positive and negative tumors nor between sporadic and hereditary tumors. Expression of the potential downstream targets of miR-375, YAP1 (a growth inhibitor) and SLC16a2 (a transporter of thyroid hormone), was downregulated in the tumors suggesting that miR-375 is a negative regulator of the expression of these genes. Thus, differential expression of miR-375, miR-10a and miR-455 may be important for tumor development and/or the reflect c-cell lineage of medullary thyroid carcinoma. Furthermore, the growth inhibitor YAP1 is identified as a potential important downstream target of miR-375.
- Garcinol induces lysosome-dependent p300/FOXP3 degradation and limits Treg cell functions to enhance targeted therapy against cancers. [JOURNAL ARTICLE]
- Exp Mol Pathol 2013 May 2.
p300 is one of several acetyltransferases that regulate FOXP3 acetylation and functions. Our recent studies have defined a complex set of histone acetyltransferase interactions which can lead to enhanced or repressed changes in FOXP3 function. We have explored the use of a natural p300 inhibitor, Garcinol, as a tool to understand mechanisms by which p300 regulates FOXP3 acetylation. In the presence of Garcinol, p300 appears to become disassociated from the FOXP3 complex and undergoes lysosome-dependent degradation. As a consequence of p300's physical absence, FOXP3 becomes less acetylated and eventually degraded, a process that cannot be rescued by the proteasome inhibitor MG132. p300 plays a complex role in FOXP3 acetylation, as it could also acetylate a subset of four Lys residues that repressively regulate total FOXP3 acetylation. Garcinol acts as a degradation device to reduce the suppressive activity of regulatory T cells (Treg) and to enhance the in vivo anti-tumor activity of a targeted therapeutic anti-p185(her2/neu) (ERBB2) antibody in MMTV-neu transgenics implanted with neu transformed breast tumor cells. Our studies provide the rationale for molecules that disrupt p300 stability to limit Treg functions in targeted therapies for cancers.
- Annexin A3 is associated with a poor prognosis in breast cancer and participates in the modulation of apoptosis in vitro by affecting the Bcl-2/Bax balance. [JOURNAL ARTICLE]
- Exp Mol Pathol 2013 Apr 28; 95(1):23-31.
OBJECTIVE:Annexins are a family of intracellular proteins that bind membrane phospholipids in a Ca(2+) concentration-dependent manner. Several annexins play important roles during tumor progression. However, little is known about the clinical implications and biological functions of Annexin A3 in breast cancer.
METHODS:Using immunohistochemistry, we analyzed 60 breast cancers for the levels of annexin A3 and investigated the correlation of its expression change with patient's survival via Kaplan-Meier survival analysis. Furthermore, via knockdown of Annexin A3 expression in breast cancer cells with special siRNA, the role of Annexin A3 in the proliferation and apoptosis of breast cancer cells was examined.
RESULTS:Annexin A3 was expressed at higher level in breast cancer than that in normal breast tissue. The expression of Annexin A3 in human breast carcinoma closely correlated with tumor size and axillary lymph node metastasis. Kaplan-Meier survival analysis revealed a significant inverse correlation between strong Annexin A3 expression and overall patient survival. Moreover, Annexin A3 overexpression was inversely associated with Bax staining and the apoptosis index. Annexin A3 small interfering RNA in MCF-7 and MDA-MB-435 could inhibit cell proliferation, decrease Bcl-2 mRNA and protein expression, and increase Bax mRNA and protein expression.
CONCLUSION:Our findings indicated that Annexin A3 might be a novel and potential prognostic marker for patients with breast cancer and be involved in regulating apoptosis by affecting Bcl-2/Bax balance.
- Validation of a solid-phase electrochemical array for genotyping hepatitis C virus. [JOURNAL ARTICLE]
- Exp Mol Pathol 2013 Apr 11; 95(1):18-22.
Hepatitis C viral infection is a major cause of progressive liver disease. HCV genotype is one of the most significant baseline predictors of response to HCV antiviral therapy. The objective was to evaluate an HCV genotyping method that targets the 5'-untranslated region (UTR) to detect genotypes/subtypes using the GenMark eSensor® XT-8 system. The HCV amplicon of major genotypes/subtypes from the Roche TaqMan® HCV assay served as a template for the nested PCR followed by a direct analysis on the XT-8 detection system. The assay was validated for limit of detection (LOD), specificity, accuracy and precision. The LOD determined was below 175IU/ml for all the subtypes except 6ab. The genotypes detected using this assay were in concordance with the LiPA assay. The high performance characteristics (LOD, specificity, intra- and inter-assay precision, and accuracy), make this assay particularly well suited for clinical HCV genotyping in order to guide antiviral therapy.
- Combined multi-gene analysis at the RNA and protein levels in single FFPE tissue sections. [JOURNAL ARTICLE]
- Exp Mol Pathol 2013 Apr 9; 95(1):1-6.
Novel approaches of individualized medicine require rapid analyses of comprehensive multi-gene expression patterns both at the RNA and protein levels. Optimally these analyses are achieved with minimal amounts of tissues, which are derived from routine procedures of clinical diagnostics. We demonstrate the parallel analyses of gene expression of six different genes at the RNA and protein levels in two consecutive sections of routinely processed FFPE tissues. This was achieved by combination of multi-epitope-ligand cartography (MELC) and fully automatically magnetic bead-based RNA extraction and subsequent qRT-PCR analysis. Our work provides proof-of-principle that comprehensive analyses of multi-gene expression patterns can be achieved by the combination of these two high content technologies. This may provide new perspectives for the determination of pathogenic gene expression in the framework of individualized medicine.
- Perivascular, but not parenchymal, cerebral engraftment of donor cells after non-myeloablative bone marrow transplantation. [JOURNAL ARTICLE]
- Exp Mol Pathol 2013 Apr 6; 95(1):7-17.
Myeloablative (MyA) bone marrow transplantation (BMT) results in robust engraftment of BMT-derived cells in the central nervous system (CNS) and is neuroprotective in diverse experimental models of neurodegenerative diseases of the brain and retina. However, MyA irradiation is associated with significant morbidity and mortality and does not represent a viable therapeutic option for the elderly. Non-myeloablative (NMyA) BMT is less toxic, but it is not known if the therapeutic efficacy observed with MyA BMT is preserved. As a first step to address this important gap in knowledge, we evaluated and compared engraftment characteristics of BMT-derived monocytes/microglia using several clinically relevant NMyA pretransplant conditioning regimens in C57BL/6 mice. These included chemotherapy (fludarabine and cyclophosphamide) with or without 2Gy irradiation, and 5.5Gy irradiation alone. Each regimen was followed by transplantation of whole bone marrow from green fluorescent protein-expressing wild type (wt) mice. While stable hematopoietic engraftment occurred, to varying degrees, in all NMyA regimens, only 5.5Gy irradiation resulted in significant engraftment of BMT-derived cells in the brain, where these cells were exclusively localized to perivascular, leptomeningeal, and related anatomic regions. Engraftment in retina under 5.5Gy NMyA conditions was significantly reduced compared to MyA, but robust engraftment was identified in the optic nerve. Advancing the therapeutic applications of BMT to neurodegenerative diseases will require identification of the barrier mechanisms that MyA, but not NMyA, BMT is able to overcome.
- Epidemiological and phylogenetic analysis of institutional mouse parvoviruses. [JOURNAL ARTICLE]
- Exp Mol Pathol 2013 Mar 29.
Mouse parvoviruses (MPVs) are small, single-stranded, 5kb DNA viruses that can be subclinical and endemic in many laboratory mouse colonies. MPVs have more distinctive deleterious effects on immune-compromised or genetically-engineered mice than immuno-competent mice. At the University of Louisville (U of L), there was a sudden increase of MPV sero-positivity for MPV infections in mouse colonies between January 2006 and February 2007, resulting in strategic changes aimed at controlling MPV spread throughout the animal facility. To investigate these MPVs, VP2 genes of seven MPVs were cloned and sequenced from eight documented incidences by PCR technology. The mutations in these VP2 genes were compared to those found at the Genbank database (NCBI; http://www.ncbi.nlm.nih.gov) and an intra-institutional phylogenetic tree for MPV infections at U of L was constructed. We discovered that the seven MPV isolates were different from those in Genbank and were not identical to each other. These MPVs were designated MPV-UL1 to 7; none of them were minute virus of mice parvoviruses (MVMs). Four isolates could be classified as MPV1, one was classified as MPV2, and two were defined as novel types with less than 96% and 94% homology with existing MPV types. Considering that all seven isolates had mutations in their VP2 genes and no mutations were observed in VP2 genes of MPV during a four-month time period, we concluded that all seven MPVs isolated at U of L between 2006 and 2007 probably originated from different sources. Serological survey for MPV infections verified that each MPV outbreak was controlled without further contamination within the institution.
- Angiogenic and inflammatory markers in acute respiratory distress syndrome and renal injury associated to A/H1N1 virus infection. [Journal Article]
- Exp Mol Pathol 2013 Jun; 94(3):486-92.
Acute kidney injury (AKI) is often associated to acute respiratory distress syndrome (ARDS) due to influenza A/H1N1 virus infection. The profile of angiogenic and inflammatory factors in ARDS patients may be relevant for AKI. We analyzed the serum levels of several angiogenic factors, cytokines, and chemokines in 32 patients with A/H1N1 virus infection (17 with ARDS/AKI and 15 ARDS patients who did not developed AKI) and in 18 healthy controls. Significantly higher levels of VEGF, MCP-1, IL-6, IL-8 and IP-10 in ARDS/AKI patients were detected. Adjusting by confusing variables, levels of MCP-1 ≥150pg/mL (OR=12.0, p=0.04) and VEGF ≥225pg/mL (OR=6.4, p=0.03) were associated with the development of AKI in ARDS patients. Higher levels of MCP-1 and IP-10 were significantly associated with a higher risk of death in patients with ARDS (hazard ratio (HR)=10.0, p=0.02; HR=25.5, p=0.03, respectively) even taking into account AKI. Patients with influenza A/H1N1 infection and ARDS/AKI have an over-production of MCP-1, VEGF and IP-10 possibly contributing to kidney injury and are associated to a higher risk of death.
- Deregulated expression of urokinase and its inhibitor type 1 in prostate cancer cells: Role of epigenetic mechanisms. [Journal Article]
- Exp Mol Pathol 2013 Jun; 94(3):458-65.
Plasminogen activator inhibitor-1 (PAI-1) and urokinase-type plasminogen activator (uPA) play a crucial role in cancer progression. In the present study we examined the regulation of PAI-1 and uPA expressions in normal prostate epithelial cells (PrEC) and the prostate cancer cell lines LNCaP, DU-145, and PC-3. The antigen and mRNA levels of PAI-1 were down-regulated in cancer cells, especially in LNCaP and DU-145. In the presence of proinflammatory cytokines, an increase of PAI-1 mRNA levels was observed in PrEC, LNCaP and PC-3, but not in DU-145 cells. Treatment with demethylating agent, 5-aza-2'-deoxycytidine increased the level of PAI-1 transcript in DU-145 cells and restored the inducing effect of cytokines on PAI-1 expression. An aberrant methylation of PAI-1 promoter in DU-145 and LNCaP cells was shown by methylation-sensitive high resolution melting (MS-HRM) analysis. PAI-1 methylation was also significantly increased in tumor samples (23.2±1.7%) in comparison to adjacent non-tumor tissue (6.0±0.8%). Furthermore, the expression of uPA was increased in high invasive cell lines DU-145 and PC-3 in comparison to PrEC and low invasive LNCaP cells. MS-HRM analysis revealed aberrant methylation of uPA promoter in LNCaP cells, but not in PrEC, DU-145 and PC-3 cells, as well as in normal and prostate cancer tissue samples. In conclusion, the study shows that PAI-1 and uPA expressions were changed in opposite directions in high invasive prostate cancer cell lines resulting in a strong decrease of PAI-1/uPA ratio, which may indicate a shift towards proteolytic activities. Methylation of the PAI-1 gene is suggested as one of the molecular mechanisms involved in the cancer-associated down-regulation of the PAI-1 expression.