Medicine and Health Sciences Commons^™

Induction Of Ampk Activation By N,N'-Diarylurea Fnd-4b Decreases Growth And Increases Apoptosis In Triple Negative And Estrogen-Receptor Positive Breast Cancers, Jeremy Johnson, Piotr G. Rychahou, Vitaliy M. Sviripa, Heidi L. Weiss, Chunming Liu, David S. Watt, B. Mark Evers

Markey Cancer Center Faculty Publications

Purpose

Triple negative breast cancer (TNBC) is the most lethal and aggressive subtype of breast cancer. AMP-activated protein kinase (AMPK) is a major energy regulator that suppresses tumor growth, and 1-(3-chloro-4-((trifluoromethyl)thio)phenyl)-3-(4-(trifluoromethoxy)phenyl)urea (FND-4b) is a novel AMPK activator that inhibits growth and induces apoptosis in colon cancer. The purpose of this project was to test the effects of FND-4b on AMPK activation, proliferation, and apoptosis in breast cancer with a particular emphasis on TNBC.

Materials and methods

(i) Estrogen-receptor positive breast cancer (ER+BC; MCF-7, and T-47D), TNBC (MDA-MB-231 and HCC-1806), and breast cancer stem cells were treated with FND-4b for 24h. …

Neurotensin Receptor 3/Sortilin Contributes To Tumorigenesis Of Neuroendocrine Tumors Through Augmentation Of Cell Adhesion And Migration, Ji Tae Kim, Dana L. Napier, Heidi L. Weiss, Eun Y. Lee, Courtney M. Townsend, B. Mark Evers

Markey Cancer Center Faculty Publications

Neurotensin (NTS), a 13–amino acid peptide which is distributed predominantly along gastrointestinal tract, has multiple physiologic and pathologic functions, and its effects are mediated by three distinct NTS receptors (NTSRs). Overexpression and activation of NTS signaling components, especially NTS and/or NTSR1, are closely linked with cancer progression and metastasis in various types of cancers including neuroendocrine tumors (NETs). Although deregulation of NTSR3/sortilin has been implicated in a variety of human diseases, the expression and role of NTSR3/sortilin in NETs have not been elucidated. In this study, we investigated the expression and oncogenic effect of NTSR3/sortilin in NETs. Increased protein levels …

Oxidative Stress-Induced Jnk/Ap-1 Signaling Is A Major Pathway Involved In Selective Apoptosis Of Myelodysplastic Syndrome Cells By Withaferin-A, Karine Z. Oben, Sara S. Alhakeem, Mary Kathryn Mckenna, Jason A. Brandon, Rajeswaran Mani, Sunil K. Noothi, Jinpeng Liu, Shailaja Akunuru, Sanjit Kumar Dhar, Inder P. Singh, Ying Liang, Chi Wang, Ahmed Abdel-Latif, Harold F. Stills Jr., Daret K. St Clair, Hartmut Geiger, Natarajan Muthusamy, Kaoru Tohyama, Ramesh C. Gupta, Subbarao Bondada

Markey Cancer Center Faculty Publications

Myelodysplastic syndromes (MDS) are a diverse group of malignant clonal hematopoietic stem cell disorders characterized by ineffective hematopoiesis, dysplastic cell morphology in one or more hematopoietic lineages, and a risk of progression to acute myeloid leukemia (AML). Approximately 50% of MDS patients respond to current FDA-approved drug therapies but a majority of responders relapse within 2-3 years. There is therefore a compelling need to identify potential new therapies for MDS treatment. We utilized the MDS-L cell line to investigate the anticancer potential and mechanisms of action of a plant-derived compound, Withaferin A (WFA), in MDS. WFA was potently cytotoxic to …

A Naturally Generated Decoy Of The Prostate Apoptosis Response-4 Protein Overcomes Therapy Resistance In Tumors, Nikhil Hebbar, Ravshan Burikhanov, Nidhi Shukla, Shirley Qiu, Yanming Zhao, Kojo S. J. Elenitoba-Johnson, Vivek M. Rangnekar

Radiation Medicine Faculty Publications

Primary tumors are often heterogeneous, composed of therapy-sensitive and emerging therapy-resistant cancer cells. Interestingly, treatment of therapy-sensitive tumors in heterogeneous tumor microenvironments results in apoptosis of therapy-resistant tumors. In this study, we identify a prostate apoptosis response-4 (Par-4) amino-terminal fragment (PAF) that is released by diverse therapy-sensitive cancer cells following therapy-induced caspase cleavage of the tumor suppressor Par-4 protein. PAF caused apoptosis in cancer cells resistant to therapy and inhibited tumor growth. A VASA segment of Par-4 mediated its binding and degradation by the ubiquitin ligase Fbxo45, resulting in loss of Par-4 proapoptotic function. Conversely, PAF, which contains this VASA …

Relb Expression Determines The Differential Effects Of Ascorbic Acid In Normal And Cancer Cells, Xiaowei Wei, Yong Xu, Fang Fang Xu, Luksana Chaiswing, David M. Schnell, Teresa Noel, Chi Wang, Jinfei Chen, Daret K. St. Clair, William H. St. Clair

Toxicology and Cancer Biology Faculty Publications

Cancer cells typically experience higher oxidative stress than normal cells, such that elevating pro-oxidant levels can trigger cancer cell death. Although pre-exposure to mild oxidative agents will sensitize cancer cells to radiation, this pre-exposure may also activate the adaptive stress defense system in normal cells. Ascorbic acid is a prototype redox modulator that when infused intravenously appears to kill cancers without injury to normal tissues; however, the mechanisms involved remain elusive. In this study, we show how ascorbic acid kills cancer cells and sensitizes prostate cancer to radiation therapy while also conferring protection upon normal prostate epithelial cells against radiation-induced …

Overcoming Treatment Resistance In Heterogeneous Tumors, Nikhil Hebbar

Theses and Dissertations--Toxicology and Cancer Biology

Most primary tumors are heterogeneous and are often composed of therapy-sensitive and emerging therapy-resistant cancer cells. Rather unexpectedly, treatment of therapy-sensitive tumor cells in heterogeneous tumor microenvironments resulted in apoptosis of the therapy-resistant cancer cells. We identified a novel Par-4 amino-terminal fragment (PAF, which includes amino acids 1-131 of Par-4) that is produced and released by therapy-sensitive cancer cells following therapy-induced caspase-dependent cleavage of the tumor suppressor Par-4. PAF caused paracrine apoptosis in therapy-resistant cancer cells. Unlike Par-4-inducible apoptosis, which is dependent on the cell surface GRP78 receptor, PAF produced cancer-selective apoptosis independent of cell surface GRP78 function. Par-4 contains …

Chronic Ethanol Exposure Enhances The Aggressiveness Of Breast Cancer: The Role Of P38Γ, Mei Xu, Siying Wang, Zhenhua Ren, Jacqueline A. Frank, Xiuwei H. Yang, Zhuo Zhang, Zun-Ji Ke, Xianglin Shi, Jia Luo

Pharmacology and Nutritional Sciences Faculty Publications

Both epidemiological and experimental studies suggest that ethanol may enhance aggressiveness of breast cancer. We have previously demonstrated that short term exposure to ethanol (12–48 hours) increased migration/invasion in breast cancer cells overexpressing ErbB2, but not in breast cancer cells with low expression of ErbB2, such as MCF7, BT20 and T47D breast cancer cells. In this study, we showed that chronic ethanol exposure transformed breast cancer cells that were not responsive to short term ethanol treatment to a more aggressive phenotype. Chronic ethanol exposure (10 days - 2 months) at 100 (22 mM) or 200 mg/dl (44 mM) caused the …

Motor Neuron Apoptosis And Neuromuscular Junction Perturbation Are Prominent Features In A Drosophila Model Of Fus-Mediated Als, Ruohan Xia, Yajuan Liu, Liuqing Yang, Jozsef Gal, Haining Zhu, Jianhang Jia

Markey Cancer Center Faculty Publications

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is progressive neurodegenerative disease characterized by the loss of motor function. Several ALS genes have been identified as their mutations can lead to familial ALS, including the recently reported RNA-binding protein fused in sarcoma (Fus). However, it is not clear how mutations of Fus lead to motor neuron degeneration in ALS. In this study, we present a Drosophila model to examine the toxicity of Fus, its Drosophila orthologue Cabeza (Caz), and the ALS-related Fus mutants.

RESULTS: Our results show that the expression of wild-type Fus/Caz or FusR521G induced progressive toxicity in multiple tissues of the …

Possible Role Of Death Receptor-Mediated Apoptosis By The E3 Ubiquitin Ligases Siah2 And Posh, Perry A. Christian, Michael V. Fiandalo, Steven R. Schwarze

Markey Cancer Center Faculty Publications

BACKGROUND: A functioning ubiquitin proteasome system (UPS) is essential for a number of diverse cellular processes and maintenance of overall cellular homeostasis. The ability of proteasome inhibitors, such as Velcade, to promote extrinsic apoptotic effects illustrates the importance of the ubiquitin proteasome system in the regulation of death receptor signaling. Here, we set out to define the UPS machinery, particularly the E3 ubiquitin ligases, that repress apoptosis through the extrinsic pathway. A cell-based genome-wide E3 ligase siRNA screen was established to monitor caspase-8 activity following the addition of TRAIL.

RESULTS: Data from the high-throughput screen revealed that targeting the RING-finger …