bluuebunny/crossref_metadata_2025_split huggingface dataset:
Keto-Mycolic Acid-Dependent Pellicle Formation Confers Tolerance to Drug-Sensitive Mycobacterium tuberculosis
Authors: Sambandan Dhinakaran , Dao Dee N. , Weinrick Brian C. , Vilchèze Catherine , Gurcha Sudagar S. , Ojha Anil , Kremer Laurent , Besra Gurdyal S. , Hatfull Graham F. , Jacobs William R. 
Published: May 2013

ABSTRACT

The chronic nature of tuberculosis (TB), its requirement of long duration of treatment, its ability to evade immune intervention, and its propensity to relapse after drug treatment is discontinued are reminiscent of other chronic, biofilm-associated bacterial diseases. Historically,
Mycobacterium tuberculosis
was grown as a pellicle, a biofilm-like structure, at the liquid-air interface in a variety of synthetic media. Notably, the most widely administered human vaccine, BCG, is grown as a pellicle for vaccine production. However, the molecular requirements for this growth remain ill defined. Here, we demonstrate that keto-mycolic acids (keto-MA) are essential for pellicle growth, and mutants lacking in or depleted of this MA species are unable to form a pellicle. We investigated the role of the pellicle biofilm in the reduction of antibiotic sensitivity known as drug tolerance using the pellicle-defective Δ
mmaA4
mutant strain. We discovered that the Δ
mmaA4
mutant, which is both pellicle defective and highly sensitive to rifampicin (RIF) under planktonic growth, when incorporated within the wild-type pellicle biofilm, was protected from the bactericidal activity of RIF. The observation that growth within the
M. tuberculosis
pellicle biofilm can confer drug tolerance to a drug-hypersensitive strain suggests that identifying molecular requirements for pellicle growth could lead to development of novel interventions against mycobacterial infections. Our findings also suggest that a class of drugs that can disrupt
M. tuberculosis
biofilm formation, when used in conjunction with conventional antibiotics, has the potential to overcome drug tolerance.

IMPORTANCE
Two of the most important questions in tuberculosis (TB) research are (i) how does
Mycobacterium tuberculosis
persist in the human host for decades in the face of an active immune response and (ii) why does it take six months and four drugs to treat uncomplicated TB. Both these aspects of
M. tuberculosis
biology are reminiscent of infections caused by organisms capable of forming biofilms.
M. tuberculosis
is capable of growing as a biofilm-like structure called the pellicle. In this study, we demonstrate that a specific cell wall component, keto-mycolic acid, is essential for pellicle growth. We also demonstrate that a strain of
M. tuberculosis
that is both drug sensitive and pellicle defective exhibits commensal behavior and becomes drug tolerant by becoming part of a heterogeneous pellicle, a characteristic of multispecies biofilms. These observations could have important implications for identifying novel pathways for
M. tuberculosis
drug tolerance and the design of new modalities to rapidly treat TB.
Fibroblast Growth Factor Receptor 3 Is a Rational Therapeutic Target in Bladder Cancer
Authors: Gust Kilian M. , McConkey David J. , Awrey Shannon , Hegarty Paul K. , Qing Jing , Bondaruk Jolanta , Ashkenazi Avi , Czerniak Bogdan , Dinney Colin P. , Black Peter C. 
Published: May 2013

Abstract
Activating mutations of fibroblast growth factor receptor-3 (FGFR3) have been described in approximately 75% of low-grade papillary bladder tumors. In muscle-invasive disease, FGFR3 mutations are found in 20% of tumors, but overexpression of FGFR3 is observed in about half of cases. Therefore, FGFR3 is a particularly promising target for therapy in bladder cancer. Up to now, most drugs tested for inhibition of FGFR3 have been small molecule, multityrosine kinase inhibitors. More recently, a specific inhibitory monoclonal antibody targeting FGFR3 (R3Mab) has been described and tested preclinically. In this study, we have evaluated mutation and expression status of FGFR3 in 19 urothelial cancer cell lines and a cohort of 170 American patients with bladder cancer. We have shown inhibitory activity of R3Mab on tumor growth and corresponding cell signaling in three different orthotopic xenografts of bladder cancer. Our results provide the preclinical proof of principle necessary to translate FGFR3 inhibition with R3Mab into clinical trials in patients with bladder cancer. Mol Cancer Ther; 12(7); 1245–54. ©2013 AACR.
Abstract A40: Association between smoking status and free, total, and percent free prostate-specific antigen
Authors: Li Jun , Thompson Trevor , Joseph Djenaba , Master Viraj 
Published: May 2013

Abstract
Background: There are scant data available on the relationship between smoking and total prostate-specific antigen (tPSA), free PSA (fPSA) and percent-free PSA (%fPSA). Given the high prevalence of smoking and frequency of PSA screening, it is important to determine any association between smoking and PSA values using nationally representative data.
Materials and Methods: Included in the final study population were 3,820 men aged ≥40 years who participated in the 2001-2006 National Health and Nutrition Examination Survey and met eligibility criteria for PSA testing. The distributions of tPSA, fPSA, and %fPSA were estimated by sociodemographic and clinical characteristics. Multivariate linear regression models were fit to determine the adjusted relationship between smoking and tPSA and %fPSA while controlling for these characteristics simultaneously.
Results: For all ages combined, the median tPSA and fPSA were 0.90 (0.81–0.90) ng/ml and 0.26 (0.25–0.28) ng/ml, respectively. The multivariate linear regression analysis showed that tPSA was 7.9% and 12.2% lower among current and former smokers, respectively, than that among never smokers. High body mass index and diabetes were also statistically significantly associated with lower tPSA level. About one third of the men had a %fPSA&lt;25. Current smokers had significantly lower %fPSA compared with former smokers.
Conclusions: Our findings that smoking is inversely associated with tPSA may have potential implications for the interpretation of PSA levels in men who are current or former smokers. Given the high prevalence of smoking, obesity, and diabetes, additional research on the combined effect of these health risk factors is warranted.
Citation Format: Jun Li, Trevor Thompson, Djenaba Joseph, Viraj Master. Association between smoking status and free, total, and percent free prostate-specific antigen [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A40.
Abstract A47: Akt mediates prostate cancer cell migration and invasion via affinity modulation of integrin αvβ3
Authors: Goc Anna , Liu Junxiu , Byzova Tatiana , Shenoy Somanath 
Published: May 2013

Abstract
Purpose: Prostate cancer cells often metastasize to the bones. The ability of prostate cancer cells to attach to several matrix proteins, migrate with a sense of direction in response to stimuli, invade to the adjacent tissue and enter the micro-circulation etc. are pre-requisites for them to metastasize to distant tissues. During this sojourn, prostate cancer cells keep transforming itself from one type to another by constantly changing the expression profile of its surface receptors and secreted factors, which in turn, helps them to respond to the cues from the micro-environment and mediate tumor progression. The current study is focused on the role of Akt kinase in the affinity modulation of integrin αvβ3 leading to prostate tumor invasion and metastasis.
Methods: We used a number of tumor cell functional assay methods, molecular biology and biochemistry tools, immunocytochemistry, electric cell impedance sensing technology etc. to establish a correlation between Akt activity and inside-out activation (affinity modulation) of integrin αvβ3 leading to prostate cancer cell invasion and metastasis.
Results: Our previous studies have shown that Akt is necessary for the affinity modulation of integrins in many normal cell types. Our results also implicated that Akt is necessary for prostate cancer cell functions such as proliferation, survival, invasion and migration. Current results revealed the involvement of Akt-mediated activation of integrin αvβ3 in human prostate cancer cells in vitro. We showed that Akt and integrin αvβ3 cooperation is required not only for tumor growth but also for invasion and further micro-metastasis to the blood vessels and eventually metastasis to the bone.
Conclusion: Our study indicated a causal relationship between Akt activity, expression of integrin αvβ3 (that are not at all expressed by normal prostatic epithelial cells) and its inside-out activation (affinity modulation). We also conclude that Akt-mediated activation of integrin αvβ3 is necessary to initiate the switch in prostate cancer cells to invade and metastasis to distant tissues such as bone. Our study projects Akt and integrin αvβ3 as potential therapeutic targets for prostate cancer therapy.
Citation Format: Anna Goc, Junxiu Liu, Tatiana Byzova, Somanath Shenoy. Akt mediates prostate cancer cell migration and invasion via affinity modulation of integrin αvβ3 [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A47.
Abstract A49: Characterization of pre-B-cell leukemia transcription factor 1 in prostate cancer
Authors: Ramberg Hakon , Alshbib Ayham , Berge Viktor , Wanzhong Wang , Svindland Aud , Taskén Kristin Austlid 
Published: May 2013

Abstract
The main purpose of our project is to determine the role of Pre-B Cell Leukemia Transcription Factor 1 (PBX1) in prostate cancer development and progression.
In this study of PBX1, we used immunohistochemical staining of benign and malignant prostate tissue as well as immunoblotting and Real-Time RT-PCR of different prostate cancer cell lines to characterize the expression pattern and regulation of PBX1. Furthermore, we transfected LNCaP with short interference RNA (siRNA) against PBX1 to determine its role in proliferation and differentiation of prostate cancer cells.
Our analyses of PBX1 expression in prostate cancer cell lines indicate that the level of PBX1 is higher in LNCaP and VCaP compared to LNCaP C4-2B and DU145, at both the mRNA and protein levels. Immunohistochemical analysis of PBX1 showed that the protein is mainly expressed in basal cells of benign tissue and in a minor sub-fraction of cells located in the luminal compartment. Tumor tissue lacks basal cells and the expression level of PBX1 was therefore down-regulated in malignant compared to benign tissue. In less differentiated tumor areas, the frequency of PBX1 positive cells was lower than in highly differentiated tumors. Thus, an inverse correlation between PBX1 staining and Gleason grade was observed. The TMAstudy included 42 patients radically operated for prostate cancer in 2004 (108 spots) and no significant correlations between PBX1 expression and clinical parameters were observed.
Cyclic AMP has previously been shown to induce growth arrest and neurite outgrowth of prostate cancer cells. We have shown that the level of PBX1 mRNA is down-regulated by cAMP. Transient transfection of PBX1 siRNA in LNCaP cells mimicked the morphological changes observed when LNCaP cells are stimulated with cAMP (forskolin) and both treatments reduced the growth rate of LNCaP cells. Several cell cycle regulated genes have been identified as cAMP target genes in LNCaP cells and we are currently investigating whether these are PBX target genes. Furthermore, preliminary studies indicate decreased expression of luminal differentiation markers in LNCaP cells transfected with PBX1 siRNA.
Based on these preliminary studies, we suggest that PBX1 might play a role in regulation of development and/or progression of prostate cancer, as suggested for other types of cancers, like ovarian and renal cancers.
Citation Format: Hakon Ramberg, Ayham Alshbib, Viktor Berge, Wang Wanzhong, Aud Svindland, Kristin Austlid Taskén. Characterization of pre-B-cell leukemia transcription factor 1 in prostate cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A49.
Abstract A58: Galbanic acid isolated from Ferula assafoetida exerts in vivo antitumor activity in association with antiangiogenesis and antiproliferation
Authors: Kim Sunghoon , Kim Kwanhyun , Jeong Soojin , Lee Hyojeong , Lu Junxuan 
Published: May 2013

Abstract
To investigate whether galbanic acid (GBA) exerts antiangiogenic and anticancer activities. Using human umbilical vein endothelial cell (HUVEC) model, we analyzed effects of GBA on cellular and molecular events related to angiogenesis. We tested its direct antiproliferative action on mouse Lewis lung cancer (LLC) cells and established its in vivo antiangiogenic and antitumor efficacy using LLC model.
GBA significantly decreased vascular endothelial growth factor (VEGF)-induced proliferation and inhibited VEGF-induced migration and tube formation of HUVECs. These effects were accompanied by decreased phosphorylation of p38-mitogen-activated protein kinase (MAPK), c-jun N-terminal kinase (JNK), and AKT, and decreased expression of VEGFR targets endothelial nitric oxide synthase (eNOS) and cyclin D1 in VEGF-treated HUVECs. GBA also decreased LLC proliferation with an apparent G2/M arrest, but did not induce apoptosis. In vivo, inclusion of GBA in Matrigel plugs reduced VEGF-induced angiogenesis in mice. Galbanic acid given by daily i.p. injection (1 mg/kg) inhibited LLC-induced angiogenesis in an intradermal inoculation model and inhibited the growth of s.c. inoculated LLC allograft in syngenic mice. Immunohistochemistry revealed decreased CD34 microvessel density index and Ki-67 proliferative index in GBA-treated tumors.
Overall, our findings suggest that GBA exerts anticancer activity in association with antiangiogenic and antiproliferative actions.
Citation Format: Sunghoon Kim, Kwanhyun Kim, Soojin Jeong, Hyojeong Lee, Junxuan Lu. Galbanic acid isolated from Ferula assafoetida exerts in vivo antitumor activity in association with antiangiogenesis and antiproliferation [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A58.
Abstract A61: Hexim-1 protein expression levels modulate TGFβ activity in prostate cancer
Authors: Dhar-Mascareno Manya , Mascareno Eduardo , Liu Fang 
Published: May 2013

Abstract
Hexim-1 is a highly conserved protein from human to mouse, and a well-established inhibitor of RNA polymerase II-dependent transcription elongation and cell proliferation. Others and we have proposed and provided evidence that changes in the expression and activity in Hexim-1 significantly influence the progression of cancer. Here we show that changes in expression levels of Hexim-1 modulate TGFβ1 signaling by inducing posttranslational modifications in the SMADs proteins (small mother against decapentaplegic) at the polylinker region of the Smad1 and Smad3 proteins. Cdk9 serine activity not only targets specific serine residues in the carboxyl terminus of RNA polymerase II during transcriptional elongation but also serine residues in the polylinker region of Smad3. Hexim-1 directly inhibits Cdk9 activity, and therefore, transcription elongation and TGFβ1/Smad3 activity. Our results indicate that prostate cancer accompanies significant changes in Hexim-1 expression as well as sub cellular redistribution. Similar observations were obtained in the TRAMP mouse model of prostate cancer. In order to understand the role of Hexim-1 during prostate cancer progression, we generated a TRAMP mouse model heterozygous for Hexim-1. Our studies in the TRAMP mouse model revealed that lowered levels in Hexim-1 protein expression triggered a more aggressive form of prostate cancer. TGFβ1/Smad3 plays a significant role during proliferation, cell migration, as well as in epithelial mesenchymal transition, which is critical during metastasis. To test the role of Hexim-1 as a modulator of TGF/Smad3 in vitro, we use the epithelial mouse prostate cancer cell line TRAMP-C2 and derived the TRAMP-C2 heterozygous for Hexim-1 (HT). We observed increased serine 208 phosphorylation of Smad3 as well as enhanced transcriptional activity of TGF β/Smad3 target genes involved in EMT such as SM22alpha and alpha smooth muscle actin in the HT-TRAMP-C2 cell line. These findings suggest that Hexim-1 is a critical regulator of prostate cancer progression.
Citation Format: Manya Dhar-Mascareno, Eduardo Mascareno, Fang Liu. Hexim-1 protein expression levels modulate TGFβ activity in prostate cancer [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr A61.
Abstract B10: Inactivation of androgen-induced coactivator ARD1 inhibits androgen receptor acetylation and prostate tumorigenesis
Authors: Wang Zehua , Wang Zemin , Guo Jianhui , Liu Wanguo 
Published: May 2013

Abstract
Androgen signaling through androgen receptor (AR) is critical for prostate tumorigenesis. Given that AR-mediated gene regulation is enhanced by AR coactivators, inactivation of those coactivators is emerging as a promising therapy for prostate cancer (PCa). Here, we show that the N-acetyltransferase Arrest-defect-1 protein (ARD1) functions as a novel AR coactivator in PCa cells. ARD1 is upregulated in human PCa cell lines, tumor biopsies, and in prostate tumor tissues of Pten null mouse. The expression of ARD1 was augmented by treatment with synthetic androgen (R1881) unless AR is deficient or is inhibited by AR-specific siRNA or androgen inhibitor bicalutamide (Casodex [CDX]). Depletion of ARD1 by shRNA suppressed PCa cell proliferation, anchorage-independent growth, and xenograft tumor formation in SCID mice, suggesting that AR-dependent ARD1 expression is biologically germane. Notably, ARD1 was necessary and sufficient to transcriptionally coactivate a number of AR-target genes that are involved in prostate tumorigenesis shown by qRT-PCR, reporter assay, and chromatin immunoprecipitation (ChIP) analysis. Furthermore, ARD1 but not ARD1-dead (acetylase activity null mutant) interacted physically with and acetylated the AR protein in vivo and in vitro. Moreover, the ARD1-mediated AR acetylating is p300 independent. Since ARD1-specific AR acetylation facilitated the AR binding to its targeted promoters for gene transcription, we propose that ARD1 functions as a unique AR coactivator and forms a positive feedback loop for AR-dependent prostate tumorigenesis. Disruption of AR-ARD1 interactions may be a potent intervention for androgen-dependent PCa therapy.
Citation Format: Zehua Wang, Zemin Wang, Jianhui Guo, Wanguo Liu. Inactivation of androgen-induced coactivator ARD1 inhibits androgen receptor acetylation and prostate tumorigenesis [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr B10.
Abstract B43: An accurate seven-gene signature plus Gleason score for prostate cancer prognosis
Authors: Chen Xin , Jia Zhenyu , Dan Mercola 
Published: May 2013

Abstract
One of the major problems in the development of prostate cancer prognostic biomarkers is the composition heterogeneity in tissue samples, which causes the inconsistency among different studies. To deal with this problem, we developed two-step strategy. In the first step, the proposed two-step cluster analysis model accounting for the cell-type composition percentage was used to identify 324 genes strongly associated with biochemical recurrence status and in the second step the 324 identified genes was further investigated by SAM (significance analysis of microarray) leading to a seven-gene classifier. The classifier was then validated on two independent data sets with overall accuracy and sensitivity of 71% and 76%, respectively. The seven-gene classifier stratified the test samples into two risk groups that are highly associated with biochemical relapse status (hazard ratio = 2.6 with p value = 0.03). The study also showed that the inclusion of the Gleason sum to the seven-gene classifier raised the sensitivity and accuracy to 76% and 83% respectively when tested on the independent data sets. These results indicated that our seven-gene classifier with the Gleason score can be used for predicting outcomes for prostate cancer patients.
Citation Format: Xin Chen, Zhenyu Jia, Mercola Dan. An accurate seven-gene signature plus Gleason score for prostate cancer prognosis [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr B43.
Abstract B5: Epigenetic modification of AR in PC3 cells negatively regulates mTORC1/2 activity
Authors: Ellis Leigh , Adelaiye Remi , Ku Shengyu , Godoy Alejandro , Pili Roberto 
Published: May 2013

Abstract
Wild type androgen receptor (AR) acts as a tumor suppressor and mediates the differentiation of non-malignant prostate epithelial cells. However, in the development of prostate cancer AR activity becomes critical for the development and progression of disease. Previous studies demonstrate that re-expressing wild type AR within an AR negative cell line (PC3) possesses tumor suppressor quality by reducing cell proliferation and tumorgenicity in mice. Further, it is documented that acetylation of AR in non-malignant cells is a post-translational modification associated with increased transcriptional activity of AR, whereas acetylation of AR in tumor cells results in negative regulation of AR transcriptional activity. We therefor are seeking to investigate the regulation of re-expressed AR within PC3 cells by induced acetylation post HDAC inhibition. Our preliminary data reveals that sensitivity to HDAC inhibition is increased with the re-expression of AR in PC3 cells. Further, epigenetic modification of AR in this model negatively regulates mTORC1 and mTORC2 expression and activity, independent of AR transcriptional activity. Ongoing experiments are being conducted to investigate further the role of epigenetic post-translational modification of AR and its negative regulation of mTORC1/2 signaling.
Citation Format: Leigh Ellis, Remi Adelaiye, Shengyu Ku, Alejandro Godoy, Roberto Pili. Epigenetic modification of AR in PC3 cells negatively regulates mTORC1/2 activity [abstract]. In: Proceedings of the AACR Special Conference on Advances in Prostate Cancer Research; 2012 Feb 6-9; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2012;72(4 Suppl):Abstract nr B5.