Absence of HTATIP2 Expression in A549 Lung Adenocarcinoma Cells Promotes Tumor Plasticity in Response to Hypoxic Stress

HIV-1 Tat Interactive Protein 2 (HTATIP2) is a tumor suppressor, of which reduced or absent expression is associated with increased susceptibility to tumorigenesis and enhanced tumor invasion and metastasis. However, whether the absent expression of HTATIP2 is a tumor-promoting factor that acts through improving tumor adaptation to hypoxia is unclear. Here, we established a stable HTATIP2-knockdown A549 human lung adenocarcinoma cell line (A549shHTATIP2) using lentiviral-delivered HTATIP2-targeting short hairpin RNA (shRNA), employed a double subcutaneous xenograft model and incorporated photoacoustic imaging and metabolomics approaches to elucidate the impact of the absent HTATIP2 expression on tumor response to hypoxic stress. Results from the in vivo study showed that A549shHTATIP2 tumors exhibited accelerated growth but decreased intratumoral oxygenation and angiogenesis and reduced sensitivity to sorafenib treatment as compared with their parental counterparts. Moreover, results of the immunoblot and real-time PCR analyses revealed that the HIF2α protein and mRNA levels in vehicle-treated A549shHTATIP2 tumors were significantly increased (p < 0.01 compared with the parental control tumors). Despite the strong HIF2α-c-Myc protein interaction indicated by our co-immunoprecipitation data, the increase in the c-Myc protein and mRNA levels was not significant in the A549shHTATIP2 tumors. Nonetheless, MCL-1 and β-catenin protein levels in A549shHTATIP2 tumors were significantly increased (p < 0.05 compared with the parental control tumors), suggesting an enhanced β-catenin/c-Myc/MCL-1 pathway in the absence of HTATIP2 expression. The finding of significantly decreased E-cadherin (p < 0.01 compared with vehicle-treated A549shHTATIP2 tumors) and increased vimentin (p < 0.05 compared with sorafenib-treated A549 tumors) protein levels in A549shHTATIP2 tumors implicates that the absence of HTATIP2 expression increases the susceptibility of A549 tumors to sorafenib-activated epithelial-mesenchymal transition (EMT) process. Comparison of the metabolomic profiles between A549 and A549shHTATIP2 tumors demonstrated that the absence of HTATIP2 expression resulted in increased tumor metabolic plasticity that enabled tumor cells to exploit alternative metabolic pathways for survival and proliferation rather than relying on glutamine and fatty acids as a carbon source to replenish TCA cycle intermediates. Our data suggest a mechanism by which the absent HTATIP2 expression modulates tumor adaptation to hypoxia and promotes an aggressive tumor phenotype by enhancing the HIF2α-regulated β-catenin/c-Myc/MCL-1 signaling, increasing the susceptibility of tumors to sorafenib treatment-activated EMT process, and improving tumor metabolic plasticity.

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YAP1 Overexpression Is Associated with Kidney Dysfunction in Lupus Nephritis

Pathobiology ◽

10.1159/000517575 ◽

2021 ◽

pp. 1-12

Author(s):

Ying Xie ◽

Yuanyuan Ruan ◽

Huimei Zou ◽

Yixin Wang ◽

Xin Wu ◽

...

Keyword(s):

Lupus Nephritis ◽

Epithelial Mesenchymal Transition ◽

Kidney Tissue ◽

Mouse Kidney ◽

Experimental Comparison ◽

Control Group ◽

Mrna Levels ◽

Mesenchymal Transition ◽

Protein Levels

Objective: The goal of the present study was to determine the expression of yes-associated protein 1 (YAP1) in renal tissues of mice with lupus nephritis (LN) and elucidate its role in the progression of renal fibrosis. Methods: C57BL/6 mice and MRL/lpr mice were selected for experimental comparison. Mouse kidney tissues were removed and sectioned for hematoxylin and eosin staining, Masson’s trichome staining, Sirius staining, and immunohistochemistry. The mRNA and protein levels of YAP1 in mouse kidney tissues were detected, and the correlation between YAP1 and fibronectin (FN) mRNA levels was analyzed. Mouse renal epithelial cells were used for in vitro experiments. After transfection and stimulation, the cells were divided into 4 groups, namely the C57BL/6 serum group (group 1), the MRL/lpr serum group (group 2), the MRL/lpr serum + siRNA-negative control group (group 3), and the MRL/lpr serum + siRNA-YAP1 group (group 4). Epithelial-mesenchymal transition (EMT) markers in each group were detected by Western blotting and immunofluorescence staining. Serum creatinine, blood urea nitrogen, and urinary protein levels were detected and assessed for their correlation with YAP1 mRNA levels by Spearman’s analysis. Results: Compared to C57BL/6 mice, MRL/lpr mice exhibited obvious changes in fibrosis in renal tissues. In addition, YAP1 expression was significantly higher in the renal tissues of MRL/lpr mice than in those of C57BL/6 mice, and YAP1 mRNA levels were positively correlated with those of FN. YAP1 silencing in lupus serum-stimulated cells could effectively relieve serum-induced EMT. Finally, we observed that YAP1 mRNA levels in mouse kidney tissue were significantly and positively correlated with the degree of renal function injury. Conclusion: YAP1 expression in the kidney tissues of LN mice was higher than that observed in normal mice, indicating that YAP1 may play an important role in the occurrence and development of LN.

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Erythropoietin Receptor is a Risk Factor for Prognosis: A Potential Biomarker in Lung Adenocarcinoma

10.21203/rs.3.rs-1211017/v1 ◽

2022 ◽

Author(s):

Ya-Jing Zhang ◽

Sen-Yu Wang ◽

Song-Tao Han ◽

Yao-Yao Huang ◽

Yang-Chun Feng

Keyword(s):

Lung Adenocarcinoma ◽

Gene Mutations ◽

Predictive Ability ◽

Erythropoietin Receptor ◽

Immunohistochemical Method ◽

Normal Lung ◽

Mrna Levels ◽

Protein Levels ◽

Potential Biomarker ◽

Epor Expression

Abstract Background: Lung cancer has the highest mortality rate of all cancers, and LUAD's survival rate is particularly poor. Erythropoietin receptor (EPOR) is a member of the cytokine class I receptor family and can be detected in cancers such as lung adenocarcinoma (LUAD), however, the expression levels and prognostic value of EPOR in LUAD are still unclear.Methods: Multiple bioinformatics databases such as TIMER, Kaplan-Meier Plotter and TCGA databases, immunohistochemical method, and clinicopathological data of 92 LUADpatients between January 2008 and June 2016 were used to explore the EPOR expression, gene mutations affecting EPOR expression, EPOR-interacting or coexpressed genes, potential biological functions and the correlation of EPOR expression with prognosis, immune microenvironment and so on.All statistical analyses were performed in the R version 4.1.1.Results: In this study, the EPOR mRNA expression in LUAD tissues was possibly downregulated compared with that in normal lung tissues, but the EPOR protein expression in LUAD tissues was higher than that in paired normal lung tissues. Mutations in five genes, DDX60L, LGR6, POTEB3, RIF1 and SOX5, resulted in downregulation of EPOR expression, mutations in 10 genes includingC1orf168, DBX2 and EIF5B, resulted in upregulation of EPOR expression. Erichment analyses showed that EPOR is involved in neural tissue ligand-receptor interactions, MAPK and PI3K/Akt signaling pathways and cancer pathways. The KM Plotter and PrognoScan databases consistently concluded that EPOR was associated with prognosis in LUAD patients. Our clinicopathological data showed that high EPOR expression was associated with poorer OS (29.5 vs 46 months) and had a good predictive ability for 5-year survival probability. Conclusions: EPOR expression might be downregulated at the mRNA levels and significantly upregulated at the protein levels in LUAD, which showed that the mRNA and protein levels of EPOR are inconsistent.The high expression of EPOR was associated with poor prognosis and is expected to be a potential new prognostic marker for LUAD.

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Induction of Oxidative Stress and Apoptosis in the Injured Brain: Potential Relevance to Brain Regeneration in Zebrafish.

10.21203/rs.3.rs-549302/v1 ◽

2021 ◽

Author(s):

Surendra Kumar Anand ◽

Manas Ranjan Sahu ◽

Amal Chandra Mondal

Keyword(s):

Oxidative Stress ◽

Mrna Levels ◽

Adult Zebrafish ◽

Zebrafish Model ◽

Stab Injury ◽

Zebrafish Brain ◽

Protein Levels ◽

Injured Brain ◽

Brain Regeneration ◽

The Impact

Abstract In the recent years, zebrafish, owing to its tremendous adult neurogenic capacity, has emerged as a useful vertebrate model to study brain regeneration. Recent findings suggest a significant role of the BDNF/TrkB signaling as a mediator of brain regeneration following a stab injury in the adult zebrafish brain. Since BDNF has been implicated in a plethora of physiological processes, we hypothesized that these processes are affected in the injured zebrafish brain. In this small study, we examined the indicators of oxidative stress and of apoptosis using biochemical assays, RT-PCR and IHC to reflect upon the impact of stab injury on oxidative stress levels and apoptosis in the injured adult zebafish brain. Our results indicate induction of oxidative stress in the injured adult zebrafish brain. Also, apoptosis was induced in the injured brain as indicated by increased protein levels of cleaved caspase3 as well as enhanced mRNA levels of both pro-apoptotic and anti-apoptotic genes. This knowledge contributes to the overall understanding of adult neurogenesis in the zebrafish model and raises new questions pertaining to the compensatory physiological mechanisms in response to traumatic brain injury in the adult zebrafish brain.

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UDP-glucuronosyltransferase 2B15 (UGT2B15) and UGT2B17 Enzymes Are Major Determinants of the Androgen Response in Prostate Cancer LNCaP Cells

Journal of Biological Chemistry ◽

10.1074/jbc.m703370200 ◽

2007 ◽

Vol 282 (46) ◽

pp. 33466-33474 ◽

Cited By ~ 76

Author(s):

Sarah Chouinard ◽

Olivier Barbier ◽

Alain Bélanger

Keyword(s):

Culture Media ◽

Cancer Cell Line ◽

Mrna Levels ◽

Uridine Diphosphate ◽

Lncap Cells ◽

Protein Levels ◽

Prostate Cells ◽

Target Probe ◽

Interfering Rna ◽

The Impact

Uridine diphosphate-glucuronosyltransferase 2 (UGT2)B15 and B17 enzymes conjugate dihydrotestosterone (DHT) and its metabolites androstane-3α, 17β-diol (3α-DIOL) and androsterone (ADT). The presence of UGT2B15/B17 in the epithelial cells of the human prostate has been clearly demonstrated, and significant 3α-DIOL glucuronide and ADT-glucuronide concentrations have been detected in this tissue. The human androgen-dependent cancer cell line, LNCaP, expresses UGT2B15 and -B17 and is also capable of conjugating androgens. To assess the impact of these two genes in the inactivation of androgens in LNCaP cells, their expression was inhibited using RNA interference. The efficient inhibitory effects of a UGT2B15/B17 small interfering RNA (siRNA) probe was established by the 70% reduction of these UGT mRNA levels, which was further confirmed at the protein levels. The glucuronidation of dihydrotestosterone (DHT), 3α-DIOL, and ADT by LNCaP cell homogenates was reduced by more than 75% in UGT2B15/B17 siRNA-transfected LNCaP cells when compared with cells transfected with a non-target probe. In UGT2B15/B17-deficient LNCaP cells, we observe a stronger response to DHT than in control cells, as determined by cell proliferation and expression of eight known androgen-sensitive genes. As expected, the amounts of DHT in cell culture media from control cells were significantly lower than that from UGT2B15/B17 siRNA-treated cells, which was caused by a higher conversion to its corresponding glucuronide derivative. Taken together these data support the idea that UGT2B15 and -B17 are critical enzymes for the local inactivation of androgens and that glucuronidation is a major determinant of androgen action in prostate cells.

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Abnormally High Levels of E- and N-Cadherin Expression Add to Altered Regulation of b-Catenin In Multiple Myeloma

Blood ◽

10.1182/blood.v116.21.2982.2982 ◽

2010 ◽

Vol 116 (21) ◽

pp. 2982-2982

Author(s):

Ya-Wei Qiang ◽

Peter Stewart ◽

Yu Chen ◽

Bo Hu ◽

John Shaughnessy ◽

...

Keyword(s):

Transcriptional Activity ◽

Target Genes ◽

Plasma Cells ◽

Expression System ◽

Mrna Levels ◽

Hematopoietic Stem ◽

Mesenchymal Transition ◽

Protein Levels ◽

Elevated Expression ◽

E Cadherin

Abstract Abstract 2982 Gene expression profiling (GEP) of normal and malignant plasma cells and B-cells, revealed that MM is uniquely characterized by elevated expression of E- or N-cadherin. Classical cadherins are integral plasma membrane proteins, that together with a- and b-catenin form calcium-dependent adherent junctions. Homotypic interaction of N-cadherin+ hematopoietic stem cells and N-cadherin+ bone lining cells in the endosteal niche regulates HSC function. Adherent junctions contribute to the regulation of Wnt/b-catenin signaling by modulating the balance between membrane-bound and free cytosolic b-catenin, the latter of which is required for TCF transcriptional activity. Overexpression of DKK1 and suppression of Wnt/b-catenin osteoblasts causes a loss in self-renewal of HSC and only stromal cells with active nuclear b-catenin can support hematopoiesis in-vitro. On the other hand, disruption of adherent junctions and release of b-catenin contributes to epithelial-to-mesenchymal transition and solid tumor metastases. We, and others, have demonstrated that Wnt/β-catenin signaling is active in MM. However, emerging evidence suggests that loss of Wnt/b-catenin activity, rather than its activation, is central to MM pathogenesis. Nearly 90% of primary MM cells express and secrete DKK1 and/or SFRP3 or SFRP2, potent inhibitors of Wnt/b-catenin signaling. Moreover, loss-of-function mutations of APC or axin genes or gain-of-function mutations in the β-catenin gene common in colon cancer have not been found in MM. We therefore hypothesized that elevated expression of N/E-cadherin in MM cells contributes to the abnormally increase of b-catenin in MM. We first assessed the steady-state levels of β-catenin protein in MMCL with immunoblotting analysis. β-Catenin protein was expressed in all tested MMCL, with variable levels in individual lines. Interestingly, relative levels of β-catenin protein were comparable to N-cadherin expression in all eight tested myeloma cell lines. CD138-enriched plasma cells from the BM of 72 patients newly diagnosed MM revealed β-catenin protein levels are highly variable. After normalization of β-catenin with β-tubulin levels we segregated cases into three groups: 39% had low, 23% moderate, and 38% high levels of β-catenin. Analysis of correlation of b-catenin protein levels with U133Plus microarray data revealed there are striking positive correlations between N- or E-cadherin mRNA levels with levels of b-catenin protein. Importantly, b-catenin levels were not correlated with known Wnt/b-catenin target genes. To evaluate the role of N-cadherin in regulating β-catenin signaling in MM, we used a lentiviral expression system to express wild-type N-cadherin (NCadW/MMS1) or empty vector (EV/MMS1) in MMS1 cells. Significant increases in total and free b-catenin correlated with N-cadherin protein expression. These results indicate that N-cadherin protein modulates b-catenin levels MM cells. Results of experiments to determine whether N-cadherin-mediated regulation of b-catenin translates into altered TCF/b-catenin transcriptional activity in MM cells will be reported. Disclosures: Shaughnessy: Myeloma Health LLC: Consultancy, Equity Ownership, Patents & Royalties; Novartis: Membership on an entity's Board of Directors or advisory committees, Patents & Royalties; Genzyme: Patents & Royalties; Millennium: Honoraria; Celgene: Honoraria; OrthoBiotech: Honoraria; Array BioPharma: Honoraria.

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LSD1 Impairs the Epithelial-Mesenchymal Transition (EMT) and Osteoclastogenesis Potency in Multiple Myeloma and Synergistically Induces Cytotoxicity with HDAC Inhibitors

Blood ◽

10.1182/blood.v124.21.3410.3410 ◽

2014 ◽

Vol 124 (21) ◽

pp. 3410-3410 ◽

Cited By ~ 2

Author(s):

Maria Gkotzamanidou ◽

Mariateresa Fulciniti ◽

Jesús Martín Sanchez ◽

Mehmet Kemal Samur ◽

Giovanni Parmigiani ◽

...

Keyword(s):

Multiple Myeloma ◽

Plasma Cells ◽

Epithelial Mesenchymal Transition ◽

Conflicts Of Interest ◽

Hdac Inhibitors ◽

Significant Inhibition ◽

Mrna Levels ◽

Mesenchymal Transition ◽

Migration Assay ◽

The Impact

Abstract Lysine-specific demethylase 1 (LSD1) is a FAD-dependent histone demethylase, which selectively removes mono- and di-methyl groups from histone 3 lysine 4 or 9 residues (H3K4, H3K9) leading to either repression or activation of transcriptome. Previous studies have shown that lenalidomide and pomalidomide cause cell cycle arrest in Multiple Myeloma (MM) by modifying the chromatin structure of the p21WAF-1 promoter through LSD1 demethylation. LSD1 forms a co-repression complex with HDAC1 and HDAC2, mSin3a, and MMSET. However, the functional role of LSD1 in MM and its contribution in aggressive traits of the disease is largely unknown. First, we evaluated the expression of LSD1 in different datasets of MM patients (GSE2113, GSE16122) and observed significant overexpression in patients with symptomatic MM and Plasma Cell Leukemia (PCL) (p<.001). The expression of LSD1 in a panel 45 HMCLs was also pronounced. We confirmed the expression and both its nuclear and cytoplasmic localization by immunoblotting analysis in 4 different HMCLs and primary bone marrow plasma cells from newly diagnosed, relapsed MM and PCL patients (N=8). We further evaluated the LSD1-mediated effect on proliferation and survival by performing loss- and gain of function studies. LSD1 knockdown in LP1 and MM1S cells resulted in modest cytotoxicity. After a combination silencing of JARID1 members and LSD1 we were able to observe a further significant decrease in survival of MM cells lacking JARID1C and LSD1, indicating that the overlapping demethylation of H3K4 is of high importance for the cell survival. We examined the post-translational histone modifications by immunobloting after LSD1 knockdown and as expected, we observed significant increase of K4me2/3 and K9me2 marks, but more interestingly, alteration of acetylation status of K9. Therefore, we performed cytotoxicity and proliferation experiments in MM after knockdown of LSD1 in combination with HDAC inhibitors (SAHA, LBH589) and we observed that LSD1 depletion enhances the cytotoxicity effect of HDACs inhibitors. LSD1 depletion resulted in significant reduction of mRNA levels by using real-time PCR and protein expression by immunoblotting of HDAC1 and HDAC2. Furthermore, based on findings of higher expression of LSD1 in more aggressive types of MM, we sought to investigate the impact of LSD1 in epithelial-mesenchymal transition (EMT). LSD1 depletion in MM1S and LP1 cells inhibited significantly the migratory ability estimated by transwell migration assay, invasion and wound healing assays. More importantly, MM cells lacking LSD1 expressed significant lower levels of E-cadherin, N-cadherin and Vimentin evaluated by immunoblotting and immunocytochemistry. We confirmed the suppression of EMT-involved gene expression by performing a PCR-microarray assay. Finally, given the presence of osteolytic lesions as a hallmark of disease, and consequent impact on outcome, we evaluated the impact of LSD1 on osteoblast differentiation and osteoclastogenesis. LSD1 depletion/ and pharmacological inhibition (S2101) resulted in significant inhibition of osteoclastogenesis and RANKL-induced resorption evaluated by double TRAP/ALP staining, survival of OCs, and mRNA expression level of osteoblast markers (APL, BSP, OC). In contrast, LSD1 overexpression confirmed the upregulation of Wnt/b-catenin pathway suggesting a possible underlying mechanism for the osteoclastogenesis potency in MM patients with high expression of LSD1. Taken together, our findings demonstrate a promising epigenetic approach in myeloma therapeutics by targeting the deregulated LSD1-methylome in MM patients earlier than aggressive disease phase. Disclosures No relevant conflicts of interest to declare.

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The Effect of Alpha Mangostin on Epithelial-Mesenchymal Transition on Human Hepatocellular Carcinoma HepG2 Cells Surviving Sorafenib via TGF-β/Smad Pathways

Advanced Pharmaceutical Bulletin ◽

10.34172/apb.2020.078 ◽

2020 ◽

Vol 10 (4) ◽

pp. 648-655

Author(s):

Syarinta Adenina ◽

Melva Louisa ◽

Vivian Soetikno ◽

Wawaimuli Arozal ◽

Septelia Inawati Wanandi

Keyword(s):

Hepatocellular Carcinoma ◽

Cell Viability ◽

Hepg2 Cells ◽

Transforming Growth Factor ◽

Epithelial Mesenchymal Transition ◽

Sorafenib Treatment ◽

Mesenchymal Transition ◽

The Impact ◽

Tgf Β1 ◽

E Cadherin

Purpose : This study was intended to find out the impact of alpha mangostin administration on the epithelial-mesenchymal transition (EMT) markers and TGF-β/Smad pathways in hepatocellular carcinoma Hep-G2 cells surviving sorafenib. Methods: Hepatocellular carcinoma HepG2 cells were treated with sorafenib 10 μM. Cells surviving sorafenib treatment (HepG2surv) were then treated vehicle, sorafenib, alpha mangostin, or combination of sorafenib and alpha mangostin. Afterward, cells were observed for their morphology with an inverted microscope and counted for cell viability. The concentrations of transforming growth factor (TGF)-β1 in a culture medium were examined using ELISA. The mRNA expressions of TGF-β1, TGF-β1-receptor, Smad3, Smad7, E-cadherin, and vimentin were evaluated using quantitative reverse transcriptase–polymerase chain reaction. The protein level of E-cadherin was also determined using western blot analysis. Results: Treatment of alpha mangostin and sorafenib caused a significant decrease in the viability of sorafenib-surviving HepG2 cells versus control (both groups with P<0.05). Our study found that alpha mangostin treatment increased the expressions of vimentin (P<0.001 versus control). In contrast, alpha mangostin treatment tends to decrease the expressions of Smad7 and E-cadherin (both with P>0.05). In line with our findings, the expressions of TGF-β1 and Smad3 are significantly upregulated after alpha mangostin administration (both with P<0.05) versus control. Conclusion: Alpha mangostin reduced cell viability of sorafenib-surviving HepG2 cells; however, it also enhanced epithelial–mesenchymal transition markers by activating TGF-β/Smad pathways.

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Mycobacterium tuberculosis Requires Cholesterol Oxidase to Disrupt TLR2 Signalling in Human Macrophages

Mediators of Inflammation ◽

10.1155/2019/2373791 ◽

2019 ◽

Vol 2019 ◽

pp. 1-17

Author(s):

Izabela Szulc-Kielbik ◽

Michal Kielbik ◽

Patrycja Przygodzka ◽

Anna Brzostek ◽

Jaroslaw Dziadek ◽

...

Keyword(s):

Mycobacterium Tuberculosis ◽

Cholesterol Oxidase ◽

Interleukin 10 ◽

Signalling Pathway ◽

Mrna Levels ◽

Dependent Manner ◽

Wild Type ◽

Human Macrophages ◽

Protein Levels ◽

The Impact

This study tested the hypothesis that Mycobacterium tuberculosis (Mtb) uses a cholesterol oxidase enzyme (ChoD) to suppress a toll-like receptor type 2- (TLR2-) dependent signalling pathway to modulate macrophages’ immune response. We investigated the impact of Mtb possessing or lacking ChoD as well as TBChoD recombinant protein obtained from Mtb on the expression and activation of two key intracellular proteins involved in TLR2 signalling in human macrophages. Finally, the involvement of TLR2-related signalling proteins in an inflammatory/immunosuppressive response of macrophages to Mtb was evaluated. We demonstrate that wild-type Mtb but not the ∆choD mutant decreased the cytosolic IRAK4 and TRAF6 protein levels while strongly enhancing IRAK4 and TRAF6 mRNA levels in macrophages. Our data show that the TLR2 present on the surface of macrophages are involved in disturbing the signalling pathway by wild-type Mtb. Moreover, recombinant TBChoD effectively decreased the cytosolic level of TRAF6 and lowered the phosphorylation of IRAK4, which strongly confirm an involvement of cholesterol oxidase in affecting the TLR2-related pathway by Mtb. Wild-type Mtb induced an immunosuppressive response of macrophages in an IRAK4- and TRAF6-dependent manner as measured by interleukin 10 production. In conclusion, ChoD is a virulence factor that enables Mtb to disturb the TLR2-related signalling pathway in macrophages and modulate their response.

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Tissue-specific induction of 17 beta-hydroxysteroid dehydrogenase type IV by peroxisome proliferator chemicals is dependent on the peroxisome proliferator-activated receptor alpha

Journal of Endocrinology ◽

10.1677/joe.0.1580237 ◽

1998 ◽

Vol 158 (2) ◽

pp. 237-246 ◽

Cited By ~ 44

Author(s):

LQ Fan ◽

RC Cattley ◽

JC Corton

Keyword(s):

Hydroxysteroid Dehydrogenase ◽

Peroxisome Proliferator ◽

Mrna Levels ◽

Ppar Alpha ◽

Peroxisome Proliferator Activated Receptor ◽

Receptor Alpha ◽

Protein Levels ◽

Type Iv ◽

Liver And Kidney ◽

The Impact

The 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) family of proteins regulates the levels of the active 17 beta-hydroxy forms of sex steroids. The expression of 17 beta-HSD type IV is induced by peroxisome proliferator chemicals (PPC) in rat liver. In order to characterize more generally the impact of PPC on 17 beta-HSD expression, we determined (1) if expression of other members of the 17 beta-HSD family was coordinately induced by PPC exposure, (2) the tissues in which 17 beta-HSD was induced by PPC, and (3) whether the induction of 17 beta-HSD by PPC was dependent on the peroxisome proliferator-activated receptor alpha (PPAR alpha), the central mediator of PPC effects in the mouse liver. The mRNA levels of 17 beta-HSD I, II, and III were not altered in the liver, kidney, and testis or uterus of rats treated with PPC. The mRNA or 80 kDa a full-length protein levels of 17 beta-HSD IV were strongly induced in liver and kidney, but not induced in adrenals, brown fat, heart, testis, and uterus of rats treated with diverse PPC. In liver and kidneys from treated rats, additional proteins of 66 kDa, 56 kDa, and 32 kDa were also induced which reacted with the anti-17 beta-HSD IV antibodies and were most likely proteolytic fragments of 17 bega-HSD IV. Treatment of mice which lack a functional form of PPAR alpha with PPC, demonstrated that PPC-inducibility of 17 beta-HSD IV mRNA or the 80 kDa protein was dependent on PPAR alpha expression in liver and kidney. Our results demonstrate that 17 beta-HSD IV is induced by PPC through a PPAR alpha-dependent mechanism and support the hypothesis that exposure to PPC leads to alterations in sex steroid metabolism.

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Annexin A1 Is Required for Efficient Tumor Initiation and Cancer Stem Cell Maintenance in a Model of Human Breast Cancer

Cancers ◽

10.3390/cancers13051154 ◽

2021 ◽

Vol 13 (5) ◽

pp. 1154

Author(s):

Cameron N. Johnstone ◽

Yan Tu ◽

Shenna Langenbach ◽

David Baloyan ◽

Andrew D. Pattison ◽

...

Keyword(s):

Breast Cancer ◽

Human Breast Cancer ◽

Epithelial To Mesenchymal Transition ◽

Mrna Levels ◽

Annexin A1 ◽

Human Breast ◽

Spontaneous Metastasis ◽

Mesenchymal Transition ◽

Patient Prognosis ◽

The Impact

Triple-negative breast cancer (TNBC) has a poor outcome compared to other breast cancer subtypes, and new therapies that target the molecular alterations driving tumor progression are needed. Annexin A1 is an abundant multi-functional Ca2+ binding and membrane-associated protein. Reported roles of Annexin A1 in breast cancer progression and metastasis are contradictory. Here, we sought to clarify the functions of Annexin A1 in the development and progression of TNBC. The association of Annexin A1 expression with patient prognosis in subtypes of TNBC was examined. Annexin A1 was stably knocked down in a panel of human and murine TNBC cell lines with high endogenous Annexin A1 expression that were then evaluated for orthotopic growth and spontaneous metastasis in vivo and for alterations in cell morphology in vitro. The impact of Annexin A1 knockdown on the expression of genes involved in mammary epithelial cell differentia tion and epithelial to mesenchymal transition was also determined. Annexin A1 mRNA levels correlated with poor patient prognosis in basal-like breast tumors and also in the basal-like 2 subset of TNBCs. Unexpectedly, loss of Annexin A1 expression had no effect on either primary tumor growth or spontaneous metastasis of MDA-MB-231_HM xenografts, but abrogated the growth rate of SUM149 orthotopic tumors. In an MMTV-PyMT driven allograft model of breast cancer, Annexin A1 depletion markedly delayed tumor formation in both immuno-competent and immuno-deficient mice and induced epithelial to mesenchymal transition and upregulation of basal markers. Finally, loss of Annexin A1 resulted in the loss of a discrete CD24+/Sca1− population containing putative tumor initiating cells. Collectively, our data demonstrate a novel cell-autonomous role for Annexin A1 in the promotion of tumor-forming capacity in a model of human breast cancer and suggest that some basal-like TNBCs may require high endogenous tumor cell Annexin A1 expression for continued growth.

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