Oncology Commons^™

Small Extracellular Vesicle-Mediated Itgb6 Sirna Delivery Downregulates The Αvβ6 Integrin And Inhibits Adhesion And Migration Of Recipient Prostate Cancer Cells, Shiv Ram Krishn, Vaughn Garcia, Nicole M Naranjo, Fabio Quaglia, Christopher D Shields, Maisha A Harris, Andrew V Kossenkov, Qin Liu, Eva Corey, Dario C Altieri, Lucia R Languino

Department of Cancer Biology Faculty Papers

The αVβ6 integrin, an epithelial-specific cell surface receptor absent in normal prostate and expressed during prostate cancer (PrCa) progression, is a therapeutic target in many cancers. Here, we report that transcript levels of ITGB6 (encoding the β6 integrin subunit) are significantly increased in metastatic castrate-resistant androgen receptor-negative prostate tumors compared to androgen receptor-positive prostate tumors. In addition, the αVβ6 integrin protein levels are significantly elevated in androgen receptor-negative PrCa patient derived xenografts (PDXs) compared to androgen receptor-positive PDXs. In vitro, the androgen receptor-negative PrCa cells express high levels of the αVβ6 integrin compared to androgen receptor-positive PrCa cells. Additionally, …

The Quandary Of Dna-Based Treatment Assessment In De Novo Metastatic Prostate Cancer In The Era Of Precision Oncology., Sigve Nakken, Wolfgang Lilleby, Marta D. Switlyk, Karen E Knudsen, Oscar Lilleby, Sen Zhao, Fatemeh Kaveh, Per O. Ekstrøm, Alfonso Urbanucci, Eivind Hovig

Department of Cancer Biology Faculty Papers

Guidelines for genetic testing have been established for multiple tumor types, frequently indicating the most confident molecularly targeted treatment options. However, considering the often-complex presentation of individual cancer patients, in addition to the combinatorial complexity and inherent uncertainties of molecular findings, deriving optimal treatment strategies frequently becomes very challenging. Here, we report a comprehensive analysis of a 68-year-old male with metastatic prostate cancer, encompassing pathology and MRI findings, transcriptomic results, and key genomics findings from whole-exome sequencing, both somatic aberrations and germline variants. We identify multiple somatic aberrations that are known to be enriched in prostate cancer, including a deletion …

The Bone Extracellular Matrix As An Ideal Milieu For Cancer Cell Metastases., Alexus D. Kolb, Karen M. Bussard

Department of Cancer Biology Faculty Papers

Bone is a preferential site for cancer metastases, including multiple myeloma, prostate, and breast cancers.The composition of bone, especially the extracellular matrix (ECM), make it an attractive site for cancer cell colonization and survival. The bone ECM is composed of living cells embedded within a matrix composed of both organic and inorganic components. Among the organic components, type I collagen provides the tensile strength of bone. Inorganic components, including hydroxyapatite crystals, are an integral component of bone and provide bone with its rigidity. Under normal circumstances, two of the main cell types in bone, the osteoblasts and osteoclasts, help to …

Mapk Reliance Via Acquired Cdk4/6 Inhibitor Resistance In Cancer., Renée De Leeuw, Christopher Mcnair, Matthew J. Schiewer, Neermala Poudel Neupane, Lucas J. Brand, Michael A. Augello, Zhen Li, Larry C. Cheng, Akihiro Yoshida, Sean M. Courtney, E. Starr Hazard, Gary Hardiman, Maha H. Hussain, J. Alan Diehl, Justin M. Drake, William Kevin Kelly, Karen E. Knudsen

Department of Cancer Biology Faculty Papers

Purpose: Loss of cell-cycle control is a hallmark of cancer, which can be targeted with agents, including cyclin-dependent kinase-4/6 (CDK4/6) kinase inhibitors that impinge upon the G₁-S cell-cycle checkpoint via maintaining activity of the retinoblastoma tumor suppressor (RB). This class of drugs is under clinical investigation for various solid tumor types and has recently been FDA-approved for treatment of breast cancer. However, development of therapeutic resistance is not uncommon.

Experimental Design: In this study, palbociclib (a CDK4/6 inhibitor) resistance was established in models of early stage, RB-positive cancer.

Results: This study demonstrates that acquired palbociclib resistance renders cancer …

Concurrent Regulation Of Lkb1 And Camkk2 In The Activation Of Ampk In Castrate-Resistant Prostate Cancer By A Well-Defined Polyherbal Mixture With Anticancer Properties., Amber F. Macdonald, Ahmed Bettaieb, Dallas R. Donohoe, Dina S. Alani, Anna Han, Yi Zhao, Jay Whelan

Department of Cancer Biology Faculty Papers

BACKGROUND: Zyflamend, a blend of herbal extracts, effectively inhibits tumor growth using preclinical models of castrate-resistant prostate cancer mediated in part by 5'-adenosine monophosphate-activated protein kinase (AMPK), a master energy sensor of the cell. Clinically, treatment with Zyflamend and/or metformin (activators of AMPK) had benefits in castrate-resistant prostate cancer patients who no longer responded to treatment. Two predominant upstream kinases are known to activate AMPK: liver kinase B1 (LKB1), a tumor suppressor, and calcium-calmodulin kinase kinase-2 (CaMKK2), a tumor promotor over-expressed in many cancers. The objective was to interrogate how Zyflamend activates AMPK by determining the roles of LKB1 and …

Differential Impact Of Rb Status On E2f1 Reprogramming In Human Cancer., Christopher Mcnair, Kexin Xu, Amy C. Mandigo, Matteo Benelli, Benjamin E. Leiby, Daniel Rodrigues, Johan Lindberg, Henrik Gronberg, Mateus Crespo, Bram De Laere, Luc Dirix, Tapio Visakorpi, Fugen Li, Felix Y. Feng, Johann De Bono, Francesca Demichelis, Mark A. Rubin, Myles Brown, Karen E. Knudsen

Department of Cancer Biology Faculty Papers

The tumor suppressor protein retinoblastoma (RB) is mechanistically linked to suppression of transcription factor E2F1-mediated cell cycle regulation. For multiple tumor types, loss of RB function is associated with poor clinical outcome. RB action is abrogated either by direct depletion or through inactivation of RB function; however, the basis for this selectivity is unknown. Here, analysis of tumor samples and cell-free DNA from patients with advanced prostate cancer showed that direct RB loss was the preferred pathway of disruption in human disease. While RB loss was associated with lethal disease, RB-deficient tumors had no proliferative advantage and exhibited downstream effects …

Β1 Integrin- And Jnk-Dependent Tumor Growth Upon Hypofractionated Radiation., Aejaz Sayeed, Huimin Lu, Qin Liu, David Deming, Alexander Duffy, Peter Mccue, Adam P. Dicker, Roger J. Davis, Dmitry Gabrilovich, Ulrich Rodeck, Dario C. Altieri, Lucia R. Languino

Department of Cancer Biology Faculty Papers

Radiation therapy is an effective cancer treatment modality although tumors invariably become resistant. Using the transgenic adenocarcinoma of mouse prostate (TRAMP) model system, we report that a hypofractionated radiation schedule (10 Gy/day for 5 consecutive days) effectively blocks prostate tumor growth in wild type (β1wt /TRAMP) mice as well as in mice carrying a conditional ablation of β1 integrins in the prostatic epithelium (β1pc-/- /TRAMP). Since JNK is known to be suppressed by β1 integrins and mediates radiation-induced apoptosis, we tested the effect of SP600125, an inhibitor of c-Jun amino-terminal kinase (JNK) in the TRAMP model system. Our results show …

Hormone Whodunit: Clues For Solving The Case Of Intratumor Androgen Production., Karen E Knudsen

Department of Cancer Biology Faculty Papers

One of the key mechanisms by which prostate cancer cells evade hormone therapy is through intratumor testosterone production. New evidence points toward androstenedione as a potential precursor of intratumor androgen production and furthers nomination of AKR1C3 as a therapeutic target in advanced disease. Clin Cancer Res; 20(21); 5343-5. ©2014 AACR.