45 research outputs found
Fe y opinión
No full textThe reflexión about faith and opinión is one of the most interesting points jn
the thought of Prof. A. Millán-Puelles. The originality of his views on the
subject appears when the author puts them in relation with Kant's
Philosophy of Religión. Millán's critic points on Kant provides the
developpement of a new scheme for the distinction of the different
meanings of the words «faith» and «believe»; such scheme is proposed by
the Author
Snail in prostate cancer cells promotes neurite outgrowth, 2021
No full textMost men who die of prostate cancer suffer from distant organ metastatic disease. Epithelial mesenchymal transition (EMT) is characterized as a critical step for cell trans-differentiation and is involved in the migration or metastatic cascade of many solid tumors. EMT can be induced by Snail transcription factor, a zinc-finger protein that can down-regulate cell adhesion proteins such as E-cadherin and up-regulate mesenchymal proteins thus promoting tumor migration and metastasis. Recently, studies have focused on metastatic spread within the nervous system as a possible factor of prostate cancer metastasis; however, the potential underlying mechanisms are poorly understood. We hypothesized that cancer cell migration and interaction with nerve cells is mediated by Snail. Neurite outgrowth is a process where developing neurons produce new tentacle-like extensions as they grow in response to guidance cues. The projection can be an axon or a dendrite (nerve fibers). Therefore, the concept of neoneurogenesis includes the development of nerve endings (axons) towards the tumor. Neurite outgrowth involves reciprocal signaling interactions between tumor cells and nerves where invading tumor cells have acquired the ability to respond to pro-invasive signals within the peripheral nerve environment. To test our hypothesis, we utilized prostate cancer cell models engineered to express low or high expression of Snail, followed by neurite outgrowth assays, and analysis of mechanisms involved in the neurite outgrowth. Our results showed that C42 non silencing (NS) prostate cancer cells that express high levels of Snail, and LNCaP Snail (cells stably overexpressing Snail) conditioned media when added to PC12 and NS20Y nerve cells led to a higher neurite outgrowth from these nerve cells, compared to the Snail knockdown cells (C42 snail shRNA) and LNCaP Neo (control with low Snail). Additionally, C4-2 NS cells secreted microvesicles containing WD Repeat Domain 77 (MEP50) WDR77, and Talin1. We also observed that neurite outgrowth was blocked by C9, a drug that inhibits the WDR77/PRMT5 complex,10D2 anti-short Talin-antibody, and mH4 Talin protease inhibitors. In conclusion, Snail promotes neurite outgrowth, which can be inhibited by PRMT5 and Talin inhibitors. Therefore, targeting cancer cell interaction with nerve cells may be helpful in halting prostate cancer progression/metastasis
Novel roles for manganese superoxide dismutase polymorphisms in prostate cancer, 2021
No full textEpithelial Mesenchymal Transition (EMT), a key event in cancer metastasis, allows polarized epithelial cells to assume mesenchymal morphologies, enhancing invasiveness and migration, and can be induced by Reactive Oxygen Species (ROS). Val16A (Ala) Superoxide Dismutase (SOD2) polymorphism has been associated with increased prostate cancer (PCa) risk. We hypothesized that SOD2 Ala single nucleotide polymorphism (SNP) may promote EMT. SOD2 expression and genotype was analyzed in various prostate cell lines. Stable overexpression of Ala-SOD2 or Val-SOD2 allele was performed in LNCaP cells followed by analysis of intracellular ROS and EMT marker protein expression. Treatments were performed with muscadine grape skin extract (MSKE) antioxidant, with or without addition of H2O2 to provide further oxidative stress. Furthermore, MTS cell proliferation, cell migration, and apoptosis assays were completed. The results showed that SOD2 expression did not correlate with tumor aggressiveness nor SOD2 genotype. Ala-SOD2 allele was demonstrated to be associated with marked induction of EMT indicated by higher Snail and vimentin, lower E-Cadherin, and increased cell migration, when compared to Val-SOD2 allele or Neo control cells. Ala-SOD2 SNP cells exhibited increased levels of total ROS and superoxide and were more sensitive to co-treatment with H2O2 and MSKE, which led to reduced cell growth and increased apoptosis. Additionally, MSKE inhibited Ala-SOD2 SNP-mediated EMT. The data indicates that treatment with a combination of H2O2-generative drugs, such as certain chemotherapeutics, and antioxidants such as MSKE that targets superoxide, hold promising therapeutic potential to halt PCa progression in the future
Snail induction of nuclear erk 1/2 promotes epithelial-mesenchymal transition and chemotherapy resistance in breast cancer cells, 2013
No full textSnail is high in several cancers, correlates with poor clinical prognosis, and associated with increased tumor progression via epithelial-to-mesenchymal transition (EMT). EMT is a latent embryonic program that alters epithelial cells to appear more mesenchymal, regulates embryonic development and wound healing. Snail binds to enhancer box sequences on its target genes like E-cadherin, maspin, and estrogen receptor-alpha (ER-a) to increase EMT. MAP kinase (MAPK/ERK1/2) protein signaling regulates the effects of EMT during tumor progression by regulating cell proliferation, growth, migration, adhesion, invasion, and survival. Recent reports suggest that ERK1 and ERK2 isoforms may function differently although they share similar stimulants and substrates. We investigated the mechanism(s) of Snail-mediated EMT that may be regulated by ERK1/2 in breast cancer cells. Snail expression and phosphorylated ERK (pERK) were higher in breast cancer cells compared to normal breast epithelial cells. Snail siRNA in T47-D and MDA-MB-231 breast cancer cells led to p-ERK relocating from the nucleus to the cytoplasm, and MDA-MB-231 had decreased p-ERK expression. Snail overexpression in MCF-7 Snail cells had increased EMT in vitro and in vivo as compared to MCF-7 Neo (control) cells. MCF-7 Snail had less p-ERK than MCF-7 Neo, which was nuclear-localized. ERK2 isoform activity was also higher in the nucleus of MCF-7 Snail compared to MCF-7 Neo. p-ERK and import protein nucleoporin98 (NUP98) were colocalized at the nuclear membrane in MCF-7 Neo suggesting a shift to the nucleus as cancer progresses. MAPK inhibition decreased cell migration and increased cell adhesion in MCF-7 Snail cells, and also re-induced E-cadherin expression, but decreased adhesion and E-cadherin in MCF-7 Neo. ERK2 isoform regulates EMT because ERK2 siRNA decreased Snail in MCF-7 Snail, but decreased E-cadherin in MCF-7 Neo. MCF-7 cells overexpressing Snail decreased ER-a expression. MCF-7 Snail were less responsive to 4- hydroxytamoxifen (4-OHT) chemotherapy using mitochondrial membrane permeability and cytotoxicity assays. MCF-7 Snail were only sensitive after being treated with 4-OHT at lOuM plus UO126 at lOuM. Collectively, our data suggest that nuclear and cytoplasmic ERK1 isoform activity positively regulates cell adhesion and may have a suppressive role in preventing EMT and breast cancer progression. Conversely, nuclear ERK activity which is predominantly ERK2 isoform activity increases EMT, and promotes resistance to chemotherapy and may promote tumor progression
The Availability of Instructional Media for Teaching Mentally Retarded Students in Nyanza Region, Kenya
No full textLearners with mental retardation pose a unique problem to the education system, one not presented by any other exceptionality. In view of the challenges and limitations of these learners, modification of both social and educational environment is fundamental in-order to attain effective schooling for them. One of the best proven medium of teaching these special learners is the use of various instructional resources. The success or failure of learners with mental retardation is directly linked to the adequacy of these resources. This study thus aimed to establish the availability of instructional resources in special schools in the Nyanza region of Kenya. Simple random sampling was used to select a sample of 28 respondents (teachers and principals) for the study. Data was collected from the respondent using three instruments: the questionnaire for teachers, observation checklist and interview guide. The data collected were analyzed both quantitatively and qualitatively by the use of both descriptive and inferential statistics. According to the results, 43.6% of the respondents indicated that the listed visual resources were not available. 26.9% of the respondents indicated weighing scales and communication board were inadequate while 73.1% expressed the opinion that they were not available. Charts and picture boards were indicated by 65.4% as inadequate while substitution table was highly unavailable according to 88.5% of the respondents. Only 17.3% of the respondents said that the graphic materials were adequate while 34.1% indicated that they were not available. 91.2% indicate that the Audio-visual materials were not available while 8.8% indicated they were available but inadequate. The findings thus demonstrate that almost all basic instructional resources were either inadequate or not available in the special schools. The author recommends that there should be collaborative effort between the government and the schools in helping provide funds for the purchase of sufficient and up-to-date instructional resources for these special schools. Keywords: Instructional resources, Special schools, Mentally retarde
Role of High Mobility Group A2 (HMGA2) in Prostate Cancer, 2019
No full textHigh mobility group A2 (HMGA2) is a non-histone protein highly expressed during the development but is low or absent in most adult tissues. Epithelial-mesenchymal transition (EMT) plays a critical role in prostate cancer progression and metastasis. HMGA2 has been shown to promote EMT in separate studies. Interestingly, wild-type HMGA2 and truncated (lacking the 3UTR) HMGA2 isoforms are overexpressed in many cancers. However, there are no studies on the role of each isoform in prostate cancer progression. We hypothesized that wild-type and truncated HMGA2 promotes prostate cancer progression by different mechanisms. We analyzed the expression of HMGA2 in the prostate panel by western blot analysis and the localization in prostate tissue microarray by immunohistochemistry. We stably overexpressed wild-type and truncated HMGA2 cDNA in LNCaP cells and measured the expression and the localization of HMGA2 as well as EMT markers. We also performed the migration and cell viability assays. We analyzed phospho-ERK in cells overexpressing HMGA2 as well as inhibition with U0126 (MAPK inhibitor). To explore the role of truncated HMGA2, we measured the reactive oxygen species (ROS) concentration by DCFDA dye, as well as analyzing Jun-D as a putative downstream effector of HMGA2. Additionally, we knocked down Jun-D and performed the migration and cell viability assays. We treated ARCaP-M mesenchymal cells with camalexin, a 3-thizol-2-yl-indole (a natural product, as a candidate to target HMGA2) in vitro and in vivo in nude mice. Our results showed an increase in nuclear HMGA2 expression with prostate cancer progression as compared to normal tissue. LNCaP cells overexpressing wild-type but not truncated HMGA2 displayed nuclear localization and induced EMT via the ERK1/2 pathway, and this effect could be reversed by treating the cells with U0126. Conversely, truncated HMGA2 displayed cytoplasmic expression and increased prostate cancer migration via increasing Jun-D expression and ROS; this could be antagonized by Jun-D knockdown. Finally, treating ARCaP-M aggressive prostate cancer cells with camalexin reduce its expression in vitro and in vivo. In conclusion, both wild-type and truncated HMGA2 induce prostate cancer progression by different mechanisms which may be targeted by camalexin. KEYWORDS: Biology, Cell Biolog
Over-expression of Aryl Hydrocarbon Receptor (AHR) enhances src kinase activity to functionally induce ar signaling and promote prostate cancer progression, 2018
No full textThe aryl hydrocarbon receptor (AhR) has been reported to interact with multiple signaling pathways during prostate development including the androgen receptor. AhR was overexpressed in LNCaP using PLNCX2 retrovirus vector containing AhR cDNA to determine if ectopic overexpression induces castrate resistant phenotype. The highly overexpressed AhR clone illustrated further increase in transcriptional and promotor activity for AhR and AR compared to the moderately overexpressed AhR clone and control. Western blot analysis showed more AhR, AR, cSrc, and pSrc protein expression in clones. AhR overexpression was found to induce several biological properties such as migration, invasion, proliferation, and promotion of G1 to S phase during the cell cycle. Bicalutamide treatment had no effect on AR transcriptional activity in either clone, proving resistance to anti-androgen therapy. Our results confirm that overexpression of AhR induces constitutive activity and stimulates androgen receptor signaling. This suggests a role for AhR in the development of CRPC. KEY TERMS: Prostate cancer, Aryl Hydrocarbon Receptor (AhR), Androgen Receptor (AR), Src kinase, CRPC, Biolog
Epigenetic silencing of ID4 in prostate cancer: mechanistic insight, 2015
No full textInhibitor of DNA binding/differentiation protein 4 (ID4) is a dominant negative regulator of basic helix loop helix (bHLH) family of transcription factors. ID4 shares the homology of HLH domain with other ID proteins (ID1, ID2, and ID3) and lack the basic DNA binding region. Evidence suggested that unlike ID1, ID2 and ID3, ID4 acts as a tumor suppressor in prostate cancer by attenuating cell proliferation and promoting apoptosis. Consistent with these observations ID4 is epigenetically silenced in DU145 prostate cancer cell line. In this study we investigated whether ID4 is also epigenetically silenced in prostate cancer. We also examined association between ID4 promoter hyper-methylation and its expression in prostate cancer cell lines. ID4 protein expression was analyzed in human prostate adenocarcinoma samples by Immunohistochemistry (IHC). ID4 promoter methylation pattern on prostate cancer cell lines was examined by methylation specific PCR. In addition, we performed methylation specific PCR on the human prostate tissues and genomic DNA to correlate cell line studies with clinical studies. IHC demonstrated decreased ID4 protein expression in human prostate tissue samples, whereas higher nuclear ID4 expression was found in normal prostate tissues. ID4 methylation specific PCR (MSP) on prostate cancer cell lines, showed ID4 methylation in DU145, but not in LNCaP and C33 cells. C81 and PC3 cells showed partial methylation. Increased ID4 methylation in C81 as compared to LNCaP suggests its epigenetic silencing as cells acquire androgen independence. Tumors with ID4 promoter hyper-methylation showed distinct loss of ID4 expression. However, the underlying mechanism involved in epigenetic silencing of ID4 is currently unknown. We hypothesized that ID4 promoter methylation is initiated by an EZH2 dependent tri-methylation of histone 3 at lysine 27 (H3K27Me3). ID4 expressing (LNCaP) and non-expressing (DU145 and C81) prostate cancer cell lines were used to investigate EZH2, H3K27Me3 and DNMT1 enrichment on ID4 promoter by Chromatin immuno-precipitation (ChIP). Increased enrichment of EZH2, H3K27Me3 and DNMT1 in DU145 and C81 cell lines was compared to ID4 expressing LNCaP cell line. Knockdown of EZH2 in DU145 cell line led to re-expression of ID4 and decrease in enrichment of EZH2, H3K27Me3 and DNMT1 demonstrating that ID4 is regulated in an EZH2 dependent manner. ChIP on prostate cancer tissue specimens and cell lines suggested EZH2 occupancy and H3K27Me3 marks on the ID4 promoter. Collectively, our data indicate a PRC2 dependent mechanism in ID4 promoter silencing in prostate cancer through recruitment of EZH2 and a corresponding increase in H3K27Me3. Increased EZH2, but decreased ID4 expression in prostate cancer strongly supports this model. KEY TERMS: ID4, Epigenetic silencing, Prostate Cancer, Biology, Cancer Biology, Cell Biology, Genetics, Other Cell and Developmental Biolog
Loss of Id4 Promotes Stemness In Prostate Cancer Cells, 2019
No full textInhibitor of differentiation 4 (ID4), a member of the helix-loop-helix family of transcriptional regulators has emerged as a tumor suppressor in prostate cancer (PCa). Recent studies have shown that Id4 is highly expressed in the normal prostate and decreases in prostate cancer due to epigenetic silencing. Id4 knockdown in androgen sensitive LNCaP cells has been shown to lead to castration resistant prostate cancer (CRPC) in vitro and in vivo. Id4-/- mice leads to underdeveloped prostate with PIN like lesions without the loss of Androgen Receptor (AR) expression. In this study we demonstrate that the loss of ID4 expression in PCa cell line LNCaP and DU145 may promote tumorigenesis by promoting stemness. LNCaP cells with stably silenced ID4 ((-)ID4) using retroviral based shRNA and LNCaP transfected with non-specific shRNA were used to perform colony forming assay and prostatosphere formation using matrigel. Expression of cancer stem cell markers was determined using western blotting and immunocytochemistry (ICC). FACS analysis was used to sort stem cells and determine the ID4 expression. Xenograft study was performed on SCID mice using CD133 positive LNCaP cells. LNCaP(-)ID4 and DU145 cells lacking ID4 showed increased holoclone as well as decreased paraclone formation, which are believed to be derived from stem cells and differentiated cells respectively, as compared to non-silencing control in the colony forming assay. There was also an increase in prostatosphere development in the LNCaP (-) ID4 cells indicating that the loss of ID4 is responsible for promoting the LNCaP cells towards cancer stem cells. The results were further validated via western blotting and ICC using known cancer stem cell markers on the holoclones and paraclones formed by these cells. Xenograft study showed that 10,000 cells from CD133 positive LNCaP cells developed tumor on SCID mice. This study reports for the first time that loss of ID4 increases holoclone and prostatosphere formation indicating that Id4 may contribute to promoting stemness in prostate cancer cells. KEYWORDS: Biotechnology, Cancer Biology, Developmental Biology, Integrative Biolog
Association of Epithelial Mesenchymal Transition with prostate and breast health disparities
No full textAfrican Americans (AA) have higher death rates due to prostate and breast cancer as compared to Caucasian Americans (CA), and few biomarkers have been associated with this disparity. In our study we investigated whether epithelial-mesenchymal transition (EMT) with a focus on Snail and Cathepsin L (Cat L), could potentially be two markers associated with prostate and breast health disparities. We have previously shown that Snail can increase Cat L protein and activity in prostate and breast cancer. Western blot and real-time PCR analyses showed that mesenchymal protein expression (Snail, vimentin, Cat L) and Cat L activity (shown by zymography) was higher in AA prostate cancer cells as compared to CA normal transformed RWPE-1 prostate epithelial cells, and androgen-dependent cells, and comparable to metastatic CA cell lines. With respect to breast cancer, mesenchymal markers were higher in TNBC compared to non-TNBC cells. The higher mesenchymal marker expression was functionally associated with higher proliferative and migratory rates. Immunohistochemistry showed that both nuclear Snail and Cat L expression was significantly higher in cancer compared to normal for CA and Bahamas prostate patient tissue. Interestingly, AA normal tissue stained higher for nuclear Snail and Cat L that was not significantly different to cancer tissue for both prostate and breast tissue, but was significantly higher than CA normal tissue. AA TNBC tissue also displayed significantly higher nuclear Snail expression compared to CA TNBC, while no significant differences were observed with Luminal A cancer tissue. Therefore, increased EMT in AA compared to CA that may contribute to the more aggressive disease
