Medicine and Health Sciences Commons^™

Targeting Cell Cycle And Hormone Receptor Pathways In Cancer., C E S Comstock, M A Augello, J F Goodwin, R De Leeuw, M J Schiewer, W F Ostrander, R A Burkhart, A K Mcclendon, Peter Mccue, Edouard J. Trabulsi, Costas D. Lallas, Leonard G Gomella, Md, M M Centenera, Jonathan Brody, Md, L M Butler, W D Tilley, K E Knudsen, Phd

Department of Cancer Biology Faculty Papers

The cyclin/cyclin-dependent kinase (CDK)/retinoblastoma (RB)-axis is a critical modulator of cell cycle entry and is aberrant in many human cancers. New nodes of therapeutic intervention are needed that can delay or combat the onset of malignancies. The antitumor properties and mechanistic functions of PD-0332991 (PD; a potent and selective CDK4/6 inhibitor) were investigated using human prostate cancer (PCa) models and primary tumors. PD significantly impaired the capacity of PCa cells to proliferate by promoting a robust G1-arrest. Accordingly, key regulators of the G1-S cell cycle transition were modulated including G1 cyclins D, E and A. Subsequent investigation demonstrated the ability …

Igf-Ir Promotes Prostate Cancer Growth By Stabilizing Α5Β1 Integrin Protein Levels., Aejaz Sayeed, Carmine Fedele, Marco Trerotola, Kirat K Ganguly, Lucia R Languino

Department of Cancer Biology Faculty Papers

Dynamic crosstalk between growth factor receptors, cell adhesion molecules and extracellular matrix is essential for cancer cell migration and invasion. Integrins are transmembrane receptors that bind extracellular matrix proteins and enable cell adhesion and cytoskeletal organization. They also mediate signal transduction to regulate cell proliferation and survival. The type 1 insulin-like growth factor receptor (IGF-IR) mediates tumor cell growth, adhesion and inhibition of apoptosis in several types of cancer. We have previously demonstrated that β1 integrins regulate anchorage-independent growth of prostate cancer (PrCa) cells by regulating IGF-IR expression and androgen receptor-mediated transcriptional functions. Furthermore, we have recently reported that IGF-IR …

Cyclin D1 Determines Estrogen Signaling In The Mammary Gland In Vivo., Mathew C Casimiro, Chenguang Wang, Z Li, Gabriele Disante, Nicole E Willmart, Sankar Addya, Lei Chen, Yang Liu, Michael P. Lisanti, Richard Pestell

Department of Cancer Biology Faculty Papers

The CCND1 gene, which is frequently overexpressed in cancers, encodes the regulatory subunit of a holoenzyme that phosphorylates the retinoblastoma protein. Although it is known that cyclin D1 regulates estrogen receptor (ER)α transactivation using heterologous reporter systems, the in vivo biological significance of cyclin D1 to estrogen-dependent signaling, and the molecular mechanisms by which cyclin D1 is involved, are yet to be elucidated. Herein, genome-wide expression profiling conducted of 17β-estradiol-treated castrated virgin mice deleted of the Ccnd1 gene demonstrated that cyclin D1 determines estrogen-dependent gene expression for 88% of estrogen-responsive genes in vivo. In addition, expression profiling of 17β-estradiol-stimulated cyclin …

A Statement On Vemurafenib-Resistant Melanoma., Edward J Hartsough, A E Aplin

Department of Cancer Biology Faculty Papers

Despite recent advancements in the treatment of late-stage mutant BRAF (V600E/K) melanomas, a major hurdle continues to be acquired resistance to BRAF inhibitors such as vemurafenib. The mechanisms for resistance have proven to be heterogeneous, emphasizing the need to use broad therapeutic approaches. In this issue, the study "Stat3-targeted therapies overcome the acquired resistance to vemurafenib in melanomas" by Liu et al. proposes that signal transducer and activator of transcription 3 (STAT3)-paired box 3 (PAX3) signaling may be a mechanism that is used by melanomas to resist RAF inhibitors.

Breast Cancer Antiestrogen Resistance 3 (Bcar3) Promotes Cell Motility By Regulating Actin Cytoskeletal And Adhesion Remodeling In Invasive Breast Cancer Cells., Ashley L Wilson, Randy S Schrecengost, Michael S Guerrero, Keena S Thomas, Amy H Bouton

Department of Cancer Biology Faculty Papers

Metastatic breast cancer is incurable. In order to improve patient survival, it is critical to develop a better understanding of the molecular mechanisms that regulate metastasis and the underlying process of cell motility. Here, we focus on the role of the adaptor molecule Breast Cancer Antiestrogen Resistance 3 (BCAR3) in cellular processes that contribute to cell motility, including protrusion, adhesion remodeling, and contractility. Previous work from our group showed that elevated BCAR3 protein levels enhance cell migration, while depletion of BCAR3 reduces the migratory and invasive capacities of breast cancer cells. In the current study, we show that BCAR3 is …

Acetylation Of The Cell-Fate Factor Dachshund Determines P53 Binding And Signaling Modules In Breast Cancer., Ke Chen, Kongming Wu, Michael Gormley, Adam Ertel, Jing Wang, Wei Zhang, Jie Zhou, Gabriele Disante, Zhiping Li, Hallgeir Rui, Andrew A Quong, Steven B Mcmahon, Haiteng Deng, Michael P Lisanti, Chenguang Wang, Richard G Pestell

Department of Cancer Biology Faculty Papers

Breast cancer is a leading form of cancer in the world. The Drosophila Dac gene was cloned as an inhibitor of the hyperactive epidermal growth factor (EGFR), ellipse. Herein, endogenous DACH1 co-localized with p53 in a nuclear, extranucleolar compartment and bound to p53 in human breast cancer cell lines, p53 and DACH1 bound common genes in Chip-Seq. Full inhibition of breast cancer contact-independent growth by DACH1 required p53. The p53 breast cancer mutants R248Q and R273H, evaded DACH1 binding. DACH1 phosphorylation at serine residue (S439) inhibited p53 binding and phosphorylation at p53 amino-terminal sites (S15, S20) enhanced DACH1 binding. DACH1 …

The Tweak Receptor Fn14 Is A Therapeutic Target In Melanoma: Immunotoxins Targeting Fn14 Receptor For Malignant Melanoma Treatment., Hong Zhou, Suhendan Ekmekcioglu, John W Marks, Khalid A Mohamedali, Kaushal Asrani, Keeley K Phillips, Sharron A N Brown, Emily Cheng, Michele B Weiss, Walter N Hittelman, Nhan L Tran, Hideo Yagita, Jeffrey A Winkles, Michael G Rosenblum

Department of Cancer Biology Faculty Papers

Fibroblast growth factor-inducible protein 14 (Fn14), the cell surface receptor for tumor necrosis factor-like weak inducer of apoptosis (TWEAK), is overexpressed in various human solid tumor types and can be a negative prognostic indicator. We detected Fn14 expression in ∼60% of the melanoma cell lines we tested, including both B-Raf WT and B-Raf(V600E) lines. Tumor tissue microarray analysis indicated that Fn14 expression was low in normal skin, but elevated in 173/190 (92%) of primary melanoma specimens and in 86/150 (58%) of melanoma metastases tested. We generated both a chemical conjugate composed of the recombinant gelonin (rGel) toxin and the anti-Fn14 …

Dynamic Recruitment Of Micrornas To Their Mrna Targets In The Regenerating Liver., Jonathan Schug, Lindsay B Mckenna, Gabriel Walton, Nicholas Hand, Sarmistha Mukherjee, Kow Essuman, Zhongjie Shi, Yan Gao, Karen Markley, Momo Nakagawa, Vasumathi Kameswaran, Anastassios Vourekas, Joshua R Friedman, Klaus H Kaestner, Linda E Greenbaum

Department of Cancer Biology Faculty Papers

BACKGROUND: Validation of physiologic miRNA targets has been met with significant challenges. We employed HITS-CLIP to identify which miRNAs participate in liver regeneration, and to identify their target mRNAs.

RESULTS: miRNA recruitment to the RISC is highly dynamic, changing more than five-fold for several miRNAs. miRNA recruitment to the RISC did not correlate with changes in overall miRNA expression for these dynamically recruited miRNAs, emphasizing the necessity to determine miRNA recruitment to the RISC in order to fully assess the impact of miRNA regulation. We incorporated RNA-seq quantification of total mRNA to identify expression-weighted Ago footprints, and developed a microRNA …

Dual Fluorescent Molecular Substrates Selectively Report The Activation, Sustainability And Reversibility Of Cellular Pkb/Akt Activity., Duanwen Shen, Mingfeng Bai, Rui Tang, Baogang Xu, Xiaoming Ju, Richard Pestell, Samuel Achilefu

Department of Cancer Biology Faculty Papers

Using a newly developed near-infrared (NIR) dye that fluoresces at two different wavelengths (dichromic fluorescence, DCF), we discovered a new fluorescent substrate for Akt, also known as protein kinase B, and a method to quantitatively report this enzyme's activity in real time. Upon insulin activation of cellular Akt, the enzyme multi-phosphorylated a single serine residue of a diserine DCF substrate in a time-dependent manner, culminating in monophospho- to triphospho-serine products. The NIR DCF probe was highly selective for the Akt1 isoform, which was demonstrated using Akt1 knockout cells derived from MMTV-ErbB2 transgenic mice. The DCF mechanism provides unparalleled potential to …