bluuebunny/crossref_metadata_2025_split huggingface dataset:
Androgen Receptor Represses the Expression of Minichromosome Maintenance Proteins: a Mechanism for Androgen Therapy in Castration Resistant Prostate Cancer
Authors: Valencia Kevin , Han Dong , Gao Shuai , Han Wanting , Cai Changmeng 
Published: November 2023

Standard treatment for metastatic prostate cancer is androgen deprivation therapy (ADT). Though this is often efficacious, for many patients, this invariably leads to the development of a more aggressive form of prostate cancer that is Castration Resistant Prostate Cancer (CRPC). Previous studies have shown that restoration of Androgen Receptor (AR, a member of nuclear receptor transcription factor family) activity plays a critical role in prostate cancer development and progression to CRPC. We have reported that in prostate cancer AR can function as both transcription activator and repressor. The latter suppressive function of AR is mediated by the recruitment of hypophosphorylated Retinoblastoma Protein (Rb), which results in negative regulation of the expression of Minichromosome Maintenance Proteins (MCMs). This protein family is composed of six distinct subunits (MCM2‐7) that form pre‐replication complex and are essential for replication initiation. Preliminary data of AR ChIP‐seq and Rb ChIP‐seq in CRPC cells showed the co‐binding on the promoters of MCM genes. Therefore downregulation the expression and activity of MCMs may be a potential mechanism for Rb‐dependent AR growth suppressive function in CRPC. We hypothesized that in CRPC cells, the AR activity stimulated by androgen treatment can have a repressive effect on the function of MCMs through recruitment of Rb to promoters, can subsequently suppress DNA replication process, and can thereby repress cancer cell proliferation. We alter Rb expression and phosphorylation as well as the expression of MCMs in prostate cancer cell lines (VCaP, LNCaP, and C4‐2) and then measure DNA replication by labeling newly replicated DNA with halogenated nucleotide precursors (BrdU, CldU, IdU) in conjunction with the expression level of MCMs, to determine the role of MCMs in AR mediated growth repressive function in CRPC. This AR growth repressive function may be mediated by downregulation of the expression and activity of MCMs through recruitment of hypophosphorylated Rb.Support or Funding InformationR00CA166507 (PI: Cai) 06/01/2015‐05/31/2017 (R00) NCI/NIH Molecular Basis of Androgen Receptor Mediated Gene Transcriptional Repression Objective: The aims of this project are to determine the molecular basis and functional importance for AR mediated repression of genes in prostate cancer cells. Aim 1. Determine the mechanisms of AR‐mediated repression on the subset of DNA synthesis and repair genes. Aim 2. Assess treatment with high dose androgen in combination with metabolic inhibitors on castration‐resistant PCa cell lines. Contact: Martinson O. Owusu 240‐276‐6297 martinson.owusu@mail.nih.gov
TIMP‐2: A Novel Biologic Therapy for Triple Negative Breast Cancer
Authors: Castro Nadia Pereira , Chowdhury Ananda , Jensen Sandra Mae , Cuttitta Frank , Stetler‐Stevenson William George , Solomon David 
Published: November 2023

Triple‐negative breast cancer (TNBC) presents the poorest prognosis among the breast cancer subtypes, having no current standardized therapy. Here, we used an orthotopic mouse model that establishes spontaneous lung metastasis from JygMC(A) cells. These primary tumors resemble human TNBC both phenotypically and molecularly. Tissue inhibitor of metalloproteinase‐2 (TIMP‐2) belongs to a small family of low molecular weight proteins identified as endogenous metalloproteinase inhibitors. These proteins modulate growth, migration and invasion of tumor cells and inhibit tumor angiogenesis. The mechanisms involve both metalloproteinase‐dependent (inhibition of protease activity) and ‐independent activities. In our TNBC model, JygMC(A) cells were implanted into both sides of the 4th inguinal mammary fat pads of athymic nude mice (10 mice per experimental group). Ten days following tumor cell inoculation, a daily intraperitoneal (IP) injection of recombinant TIMP‐2 protein was given at doses ranging from 0.75/100ml to 6.0 mg/100ml. Tumor growth was measured biweekly by caliper measurement for a total of 4 weeks). In our TNBC model, preliminary results showed that recombinant TIMP‐2 protein inhibited tumor growth by 50% at day 34 post tumor cell injection at a dose concentration as low as 1.5 mg/100 ml. Taken together, our data show that recombinant TIMP‐2 contributes to reduction of mammary tumor size in this mouse model revealing a therapeutic potential of a biologic protein able to decrease mammary carcinoma progression. Further studies will examine the MMP‐dependent and MMP‐independent mechanisms responsible for reduced tumor growth in this model system. Moreover, these findings may lead to a more efficient clinical treatment strategy for TNBC.Support or Funding InformationThis work was funded by the NCI Center for Cancer Research Intramural Research Program Grant # ZIA SC009179‐24.
PAF/PAF‐R Expression and Effects of Cigarette Smoke Exposure in Human Breast Cancer
Authors: Kispert Shannon E , Schwartz Theresa , McHowat Jane 
Published: November 2023

Platelet activating factor (PAF), a potent inflammatory lipid mediator, was first suggested to play a role in smoking‐induced injury when the plasma taken from tobacco smokers was determined to have higher concentrations of PAF than the plasma obtained from nonsmokers. Recent studies from our lab have demonstrated that cigarette smoke extract (CSE) inhibits PAF‐AH activity, the enzyme responsible for PAF catabolism and inactivation. PAF is not only an important mediator of inflammation but is also involved in many phases of cancer progression that include tumor growth, metastasis, and angiogenesis. PAF has been shown to trigger a variety of intracellular pathways including those involving tumor angiogenesis. Inhibition of PAF‐AH activity by cigarette smoke extract (CSE) enhanced endothelial cell surface expression of PAF and increased breast cancer cell adherence. When breast cancer cells were incubated with CSE, expression of the PAF receptor was increased and resulted in enhanced adherence to the endothelium. Conversely, when breast cancer cells were treated with the PAF receptor antagonist ginkgolide B, their adherence to lung endothelial cells was inhibited. Human breast cancer tissue showed higher PAF receptor expression via immunohistochemistry and immunofluorescence when compared with normal human breast tissue. PAF was also increased in human breast cancer tissues when compared with surrounding normal tissue. Thus, increased PAF receptor expression and PAF accumulation may contribute to breast tumor development and progression. Additionally, we propose that cigarette smoking may contribute to breast cancer via facilitation of the PAF‐PAF receptor interaction.Support or Funding InformationPresidents Research Fund Saint Louis University
The Histone Deacetylase Sirt2 Regulates Slug in Basal‐like Breast Cancer
Authors: Zhou Wenhui , Kuperwasser Charlotte 
Published: November 2023

Basal‐like breast cancer (BLBC) represents the most aggressive and deadliest breast cancer subtype, affecting 20% of breast cancer patients. Unlike other subtypes, few driver mutations have been identified and, thus, no targeted therapies have been established. We previously observed the transcriptional repressor Slug/SNAI2 is frequently overexpressed in diseased breast tissues of women with inherited mutations in BRCA1; this aberrant expression of Slug represents an important determinant in the pathogenesis of aggressive BLBC. The mechanism by which Slug becomes deregulated in cancer, however, remains unknown. Using a small molecular inhibitor screen, we identified Sirt2 as a master regulator of Slug. Sirt2 inhibition leads to rapid turnover and depletion of Slug protein, whereas Sirt2 overexpression stabilizes Slug and increases its level and activity. Mechanistically, Sirt2 binds to and deacetylates Slug protein at specific lysine residues to prevent its proteasomal degradation, thereby stabilizing Slug protein. Analysis from human breast cancer patients revealed that Sirt2 is frequently amplified, overexpressed and strongly correlated with Slug status in basal‐like tumors. Importantly, Sirt2 is induced following BRCA1 inhibition and inactivation of Sirt2 in BRCA1‐associated breast cancer leads to rapid Slug turnover and loss of pathological features that are clinically relevant to BLBC tumors. Collectively, these observations revealed a regulatory mechanism controlling Slug abundance, whereby dysregulated Sirt2 manifests into Slug overexpression in human cancer. As such, targeting Sirt2 may be a rational strategy to molecularly dampen the Slug hyperactivity and malignant behaviors characteristic of BLBC and those associated with BRCA1 mutation.Support or Funding InformationThis work was supported by grants from the Breast Cancer Research Foundation, the NIH/NICHD (R01HD073035), and the NIH/NCI (P01CA092644)
FSTL1 Inhibits Tumor Growth and Metastatic Progression via Blocking Proteolytic Activation of SPP1 in Lung Adenocarcinoma
Authors: Chiou Jean , Su Chia‐Yi , Lin Yuan‐Feng , Hsiao Michael 
Published: November 2023

Follistatin‐related protein 1 (FSTL1) plays a critical role in lung development through the interaction with bone morphogenetic protein (BMP) 4 and transforming growth factor β1 (TGF‐β1) signaling pathways. Although the supplement of FSTL1 was appeared to inhibit the in vitro cell growth of lung cancer cells, the precise mechanism and its role in lung cancer aggressiveness remains unclear. Here we found that low‐level FSTL1 is extensively detected in tumor tissues and significantly correlates with poor prognosis in patients with non‐small cell lung cancer, particularly lung ademonocarcinoma. Moreover, the expression of FSTL1 was inversely associated with the in vitro migration ability of several lung adenocarcinoma cell lines. Robustly, the treatment with recombinant FSTL1 protein significantly decreased migration and invasion of highly metastatic CL1‐5 cells in a dose‐dependent manner. In contrast, the mobility of poorly metastatic CL1‐0 cells was dose‐dependently enhanced by neutralizing FSTL1 using its specific antibody. Furthermore, the enforced expression of exogenous FSTL1 gene suppressed but the knockdown of FSTL1 promoted the in vitro and in vivo metastatic potential of CL1‐5 and CL1‐0 cells, respectively. Importantly, the administration of FSTL1 effectively inhibited the lung metastasis of CL1‐5 cells in an orthotropic animal model. The mass spectrometric analysis of FSTL1‐interacting proteins revealed that FSTL1 is capable of binding to the secreted phosphoprotein 1 (SPP1), Furthermore our results showed that FSTL1 binds to the matrix metalloproteinase‐3/7 (MMP3/7)‐recognition site and thereby blocks the proteolytic activation of pro‐SPP1 and its downstream signaling to ultimately inhibit lung cancer cell invasion and metastasis.These results suggest that the downregulation of predicts a poor prognosis in lung adenocarcinoma and the administration of FSTL1 could be a new therapeutic strategy to inhibit tumor growth and combat metastatic progression in lung adenocarcinoma via preventing the proteolytically processing of pro‐SPP1 into its active form.
Analysis of the acetylcholine‐signaling pathway reveals differences between normal and malignant lung tissue
Authors: Brown Kathleen C , Lau Jamie K , Thornhill Brent A , Perry Haley E , Jones Dennie V , Pulliam Joseph F , Martin Jeremiah , Dasgupta Piyali 
Published: November 2023

NSCLC is characterized by aggressive clinical course, rapid doubling time and a dismal survival rate. The development of NSCLC is closely correlated with smoking habits. A small percentage of NSCLC cases also occur in non‐smokers. Targeted therapies like EGFR‐inhibitors, EML‐ALK4 inhibitors, and B‐Raf inhibitors show excellent therapeutic response in NSCLC patients who are non‐smokers. However, they do not work well in NSCLC patients who are smokers. Therefore, the identification of novel molecular targets in NSCLC patients who are exposed to cigarette smoke is urgently needed. Tobacco components like nicotine and NNK have been known to accelerate the progression of lung cancer. One of the major mechanisms underlying the proliferative actions of nicotine and NNK is that they upregulate the levels of the growth factor acetylcholine (ACh). This ACh binds back to its target receptors (on NSCLC cells) and stimulates the proliferation of NSCLC cells in an autocrine manner. The ACh signaling loop is amplified by exposure to tobacco components and cigarette smoke. With this background in mind, we aim to compare the ACh‐signaling machinery between normal lung cells and NSCLC cells. We find that both normal lung epithelial cells and NSCLC cells express all the components of the ACh‐signaling pathway, namely choline acetyltransferase (ChAT), vesicular acetylcholine transporter (VAChT), acetylcholinesterase (AChE) and choline transporter (ChT). Some of the ACh‐signaling proteins like ChAT, VAChT and AChE show differences in expression and activity between normal lung tissue and NSCLC cells. We believe that such differences may form the basis of targeted therapies in NSCLC patients who are exposed to cigarette smoke.Support or Funding InformationFunding for our study was supported by the an NIH R15‐AREA Grant (1R15HL113681‐01A1), ACTSI Grant from Marshall University, the Flight Attendant Medical Research Institute YCSA Grant (82115),and the West Virginia IDeA Network of Biomedical Research Excellence (P20RR016477 and P20GM103434).
Losartan Blocks the Recruitment of Mast Cells in the Lungs of Rats Subjected to Fat Embolism with or without a Second Hit with LPS
Authors: Poisner Alan , Hamidpour Sopheila , Ho Andrea , Skaria Priya , Fletcher Amanda , Simon Steve , Molteni Agostino 
Published: November 2023

In a rat model of pulmonary fat embolism (FE) using triolein (T), we have shown that the long term histopathological effects of triolein‐induced FE extend to 10 weeks and are inhibited by losartan (LOS), an angiotensin II type 1 receptor blocker1 and augmented by a second hit with LPS2. These effects are associated with an increase in renin staining at 6 weeks3. Since other workers have implicated pulmonary mast cells (MC) in local renin‐angiotensin (RAS)‐mediated pulmonary pathology4, we examined whether FE in our model was associated with an increase in MC number and if their appearance would be blocked by LOS and modified by a second hit with LPS. 36 Sprague‐Dawley rats were treated with T (0.2 ml i.v.) or saline. After 6 weeks, half of the groups were given saline or LPS 0.1 ml (3 mg/kg) i.p., followed 1 hour later with saline or LOS (10 mg/kg i.p.), followed by LOS in the drinking water (50 mg/l). 4 weeks later (10 weeks after T), the animals were necropsied after isoflurane anesthesia. Lungs were fixed in 10% formalin and stained with H&E for morphometric scoring and for mast cells using CD11 (c‐kit). Portions of the lungs were frozen and stained for fat using Oil Red O. Two pathologists unaware of the slides’ identity took 10 photographs at random in each slide at 400× and then counted the mast cell number.MC number increased in T‐treated rats compared to saline controls (57.2 +/− 2.5 vs 20.0 +/− 2.3) (mean+/− SEM) (p=0.005). The MC count when T was followed by LPS rose to 66.8 +/− 14.5 (p=0.001 compared to saline). LPS or LOS alone did not cause a significant increase in MC (35.0 +/− 8.5 and 28.2 +/− 2.6, respectively.) The increases in MC caused by T and T+LPS were both blocked by LOS: (T+LOS 14.9 +/− 2.9; T+LPS+LOS 32.5 +/− 4.6; p=0.75 and 0.99 compared to LOS alone.The appearance of fat globules at 10 weeks was greatly reduced from what we reported for rats at 6 weeks3 but they were increased in T‐treated rats compared to saline controls.The results support suggestions that MC‐associated renin through its eventual product angiotensin II plays an important role in the histopathological changes produced by FE and the second hit with LPS. In addition, the presence of fat globules in the lungs 10 weeks after the initial challenge with T suggests that their continued presence may be important for the enhanced presence of MC in response to low grade inflammation. A role for macrophage signaling in this sequence is also supported5.Support or Funding InformationMary Katherine Geldmacher Research Foundation, St. Louis, MO
Regulation of lysophosphatidic acid receptor 1 stability modulates cytokine release in lung injury
Authors: Zhao Yutong , Wei Jianxin , Dong Su , Bowser Rachel K , Zhang Lina , Jacko Anastasia M , Zhao Jing 
Published: November 2023

Lysophosphatidic acid receptor 1 (LPA1), a member of G‐protein‐coupled receptors (GPCRs), is a druggable target for treating pulmonary inflammatory diseases, such as acute lung injury and pulmonary fibrosis. However, the molecular regulation of LPA1 stability, a factor that critically impacts its biological activity, remains largely unknown.To investigate the molecular regulation of LPA1 stability, we focus on investigating ubiquitination of LPA1. We identified two enzymes that catalyze ubiquitination and deubiquitination of LPA1. The ubiquitin E3 ligase Nedd4L targets LPA1 for its site specific ubiquitination and degradation in the lysosome. Nedd4L negatively regulates LPA/LPA1‐mediated cytokine release, suggesting targeting LPA1 stability is potential strategy for regulating LPA signaling. The stability of LPA1 is up‐regulated by ubiquitin‐specific protease 11 (USP11), which deubiquitinates and stabilizes LPA1, thus enhancing LPA1‐mediated pro‐inflammatory effects. LPA1 is associated with USP11 in quiescent cells, while LPA treatment triggers LPA1 dis‐association with USP11 and in turn binding to Nedd4L. We have shown that LPA1 contributes to LPS‐induced cytokine release through interaction with CD14. Here, we show that knockdown of USP11 reduces LPA1 stability, levels of LPA1, and LPA1/CD14 interaction complex; thereby diminishing both LPA‐ and LPS‐induced inflammatory responses. C57/BL mice were infected with USP11 shRNA lentivirus for 7 days, and then mice were challenged with intratracheal LPS. USP11 shRNA reduced USP11 levels in lungs and attenuated LPS‐increased BAL protein, IL‐6, KC, and neutrophil infiltration.Our findings identify an ubiquitin E3 ligase and a deubiquitinating enzyme responsible for regulation of LPA1 stability and biological activities. This study provides new targets for the development of anti‐inflammatory molecules to lessen LPA1‐mediated lung injury.Support or Funding InformationThis work was supported by the US National Institutes of Health (R01HL091916 and R01HL112791 to Y.Z, R01GM115389 to J.Z.), American Heart Association 12SDG9050005 (J.Z.), and American Lung Association Biomedical Research Grant RG350146 (J.Z.).
Kinetics and Implications of Germinal Center Formation in Induced Bronchus‐Associated Lymphoid Tissue During Influenza Infection
Authors: Gibson‐Corley Katherine N. , Boyden Alexander W. , Tygrett Lorraine , Waldschmidt Thomas J. 
Published: November 2023

Induced bronchus‐associated lymphoid tissue (iBALT) develops within the lung of both humans and mice following an adaptive immune response upon exposure to certain classes of antigens. iBALT has been documented to develop with Influenza A virus (IAV) infection but the kinetics of this localized immune response have yet to be documented. Using both flow cytometry and immunohistochemistry we have identified the structure, composition and development of B cells and iBALT over time in mice intranasally infected with an H1N1 IAV. Early in infection (days 6–12) B cells accumulate within the lung, primarily around blood vessels, and are very loosely organized. By flow cytometry, these are mature B cells and there is no evidence of germinal center cells. As time progresses to days 18 and 24, B cells more tightly organize around medium to large airways and have a well‐defined lymphoid structures complete with Bcl‐6 positive, PNAhi, CD95hi, IgMhi germinal center B cells which persist up to and likely beyond day 50 of infection. These findings are of interest as Influenza viruses are constantly undergoing antigenic changes, which make the development of vaccines very challenging. Understanding the kinetics of iBALT development can help us identify key triggers for a protective adaptive immune response and novel targets for vaccine development.Support or Funding InformationDepartmental Funding; Department of Pathology, University of Iowa
Investigating the Mechanism Of Autoimmune Disease Associated LQTS; anti‐Ro52 IgG Decreases hERG Channel Density
Authors: Szendrey John Alexander , Zhang Shetuan 
Published: November 2023

BackgroundThe human ether‐a‐go‐go‐related gene (hERG) is the pore forming subunit of Kv11.1, which is responsible for the rapidly activating delayed rectifier potassium current (IKr). Reductions to IhERG through mutations or drug interactions can cause LQTS, which predisposes individuals to ventricular arrhythmia's and sudden cardiac death. hERG has been speculated to be involved in autoimmune disease‐associated LQTS, however the mechanism is poorly understood. In 2006, a Japanese group reported an anti‐Ro52 IgG positive patient with LQTS and accompanying torasdes de pointes. The patient's serum was found to reduce the human ether‐a‐go‐related gene (hERG) channel density in a stable cell line. The authors speculated that anti‐Ro52 underwent a cross reaction with hERG, leading the production of anti‐hERG IgG. Here we investigate in detail this proposed mechanism, and provide strong evidence that anti‐Ro52 IgG reduces hERG channel density and current.MethodsHuman embryonic kidney (HEK 293) cell lines stably expressing the channel of interest were treated with anti‐Ro52 IgG (Sigma, 4 μg/ml) for 24 h, while saline treated cells served as control. Western blot analysis was used to quantify changes in protein expression, and whole cell patch clamp was performed to quantify changes in current.ResultsWe report that anti‐Ro52 IgG reduced hERG channel density and current. This was unique to hERG in that Kv1.5 and EAG channel density and current were not affected by IgG. Replacing the extracellular S5‐pore linker with that of EAGs instilled immunity to IgG treatment. Furthermore, anti‐Ro52 IgG treatment reduced IKr in rat neonatal cardiomyocytes, significantly increased the APD90, but did not affect other native currents. Our data suggest that IgG decreased hERG membrane expression through inducing channel internalization. Digestion of anti‐Ro52 and isolation of the Fab and Fc fragments revealed that the Fc region of IgG is responsible for reducing hERG. Finally, we are currently testing the effects of IgG positive and negative autoimmune patient serum on the QTc interval of rabbits.ConclusionOur findings provide strong evidence that anti‐Ro52 IgG is responsible for autoimmune disease associated‐LQTS, which mechanistically occurs through a reduction of the hERG current due to IgG‐mediated channel internalization.Support or Funding InformationFunded by CIHR and Heart and Stroke