Neoplasms Commons^™

Targeting The Bcl2 Family: Advances And Challenges In Bh3 Mimetic-Based Therapies, Nabanita Mukherjee, James Sheetz, Yiqun Shellman

Student Papers, Posters & Projects

The BCL2 family of proteins plays a pivotal role in regulating apoptosis and cellular homeostasis, making them critical therapeutic targets in cancer and other diseases characterized by pathological cell survival. BH3 mimetics, small molecules that selectively inhibit anti-apoptotic BCL2 family members, have achieved significant clinical success, particularly in hematologic malignancies. However, several challenges remain, including resistance mechanisms, toxicity (such as MCL1 inhibitor-associated cardiotoxicity), and the intricate balance between apoptotic and non-apoptotic functions. This review provides a comprehensive overview of BCL2 family biology, the development and clinical application and outcomes of BH3 mimetics, and the emerging resistance mechanism known as double-bolt …

Bard1: A Friend Or Foe In Pancreatic Ductal Adenocarcinoma?, Lily Zekavat, Aditi Jain

Department of Surgery Faculty Papers

Pancreatic ductal adenocarcinoma (PDAC) is an aggressive solid malignancy with poor overall prognosis and limited response to standard treatments. Growing interest in the modulation of DNA repair mechanisms, including the homologous recombination (HR) repair pathway, has opened new avenues for therapeutic development. BARD1 (BRCA1-Associated RING Domain 1) plays a complex role in tumor biology, functioning either as a tumor suppressor or as an oncogenic driver, depending on isoform expression, cellular context, and regulatory environment. In this review, we examine the dual roles of BARD1, focusing on its regulation and paradoxical activities in PDAC. We summarize evidence that BARD1 and BARD1 …

Ks151 Synergizes With Venetoclax And Abt-737 In Aml: Efficacy In Both Flt3-Wildtype And Flt3-Mutant Models, Sahil Jethi, Arnold Rojas, Omar S. Al-Odat, Krishne Gowda, Subash C. Jonnalagadda, Manoj Pandey

Rowan-Virtua Research Day

Acute myeloid leukemia (AML) is the most common leukemia in adult patients, with a 5-year survival rate of less than 30 percent. Therefore, more effective therapeutic strategies are required to prolong the survival of AML patients. Importantly, anti-apoptotic proteins, especially B-cell lymphoma 2 (Bcl-2), overexpression in AML is associated with uncontrolled growth as well as chemoresistance. Unsurprisingly, Bruton’s tyrosine kinase (BTK) overexpresses in AML and associated with poor prognosis and chemoresistance. The FDA-approved BTK inhibitor, ibrutinib, has been successful in treating other hematologic malignancies, but a proportion of patients relapse mainly because of acquired mutations at Cys481Ser (C481S) in the …

Stanniocalcin 2 Governs Cancer Cell Adaptation To Nutrient Insufficiency Through Alleviation Of Oxidative Stress, Shuo Qie, Haijuan Xiong, Yaqi Liu, Chenhui Yan, Yalei Wang, Lifeng Tian, Chenguang Wang, Nianli Sang

Department of Pharmacology, Physiology, and Cancer Biology Faculty Papers

Solid tumours often endure nutrient insufficiency during progression. How tumour cells adapt to temporal and spatial nutrient insufficiency remains unclear. We previously identified STC2 as one of the most upregulated genes in cells exposed to nutrient insufficiency by transcriptome screening, indicating the potential of STC2 in cellular adaptation to nutrient insufficiency. However, the molecular mechanisms underlying STC2 induction by nutrient insufficiency and subsequent adaptation remain elusive. Here, we report that STC2 protein is dramatically increased and secreted into the culture media by Gln-/Glc- deprivation. STC2 promoter contains cis-elements that are activated by ATF4 and p65/RelA, two transcription factors activated by …

Investigating The Therapeutic Potential Of Soursop In Treating Hematologic Malignancies, Sabrina Marie Paparo, Rebeca Mendoza, Robert Chitren, Omar Al-Odat, Emily Nelson, Subash Jonnalagadda, Roger Strair, Manoj Pandey

Rowan-Virtua Research Day

Acute Myeloid Leukemia (AML) and Multiple Myeloma (MM) are hematologic malignancies that originate in the bone marrow and account for approximately 1.3% and 2% of cancer cases, respectively. AML is characterized by an accumulation of myeloblasts, or immature myeloid cells, that have the potential to spread to the peripheral blood. There is an uncontrolled proliferation of plasma cells in the bone marrow in MM. While the current treatment options for both AML and MM show promise in achieving initial remission, it is unfortunately common for patients to experience relapse and develop drug resistance. There is a theory that relapse and …

Induction And Modulation Of Apoptosis In Breast Cancer Cells Mda-Mb-157 And 93b By Chinese Medicinal Herbs Oldenlandia Diffusa And Bryophyllum Pinnatum, Sarah Wolf

Honors Theses

Chinese medicinal herbs have been found to contain bioactive phytochemicals with anti-cancer properties. Herbal extracts induce apoptosis in cancer cells by modulating levels of pro- and anti-apoptotic proteins. A previous study showed that a commonly used herb, Scutellaria barbata, significantly induced apoptosis in the breast cancer cell line MDA-MB-157 and the therapy-resistant breast cancer cell line 93B. However, the effects of two different Chinese herbs, Oldenlandia diffusa (OD) and Bryophyllum pinnatum (BP) on these breast cancer cells are not known. This project indicates the influence of the herbs OD and BP on apoptosis of breast cancer cell line MDA-MB-157 in …

Induction And Modulation Of Apoptosis In Breast Cancer Cells 93a And Mda-Mb-157 By Chinese Medicinal Herbs Oldenlandia Diffusa And Bryophyllum Pinnatum, Rekha Isaac

Honors Theses

Chinese medicinal herbs, such as Oldenlandia diffusa, contain phytochemicals that exhibit antitumor, chemopreventive, and antiangiogenic effects in cancer cells. In this study, both Oldenlandia diffusa and Bryophyllum pinnatum (a lesser-studied herb) were tested on breast cancer cell lines MDA-MB-157 and 93A by administering an aqueous extract. The effectiveness between cell lines was also compared. The apoptotic effect both herbs showed was quantified by the levels of pro and anti-apoptotic proteins expressed in each cell line. Both cell lines treated with Oldenlandia diffusa and Bryophyllum pinnatum showed significant differences in their levels of both pro and anti-apoptotic proteins when compared to …

Targeting The Pro-Survival Protein Bcl-2 To Prevent Breast Cancer, Adelaide Young, Wen Bu, Weiyu Jiang, Amy Ku, Jyoti Kapali, Sagar Dhamne, Lan Qin, Susan G Hilsenbeck, Yi-Chieh Nancy Du, Yi Li

Faculty, Staff and Students Publications

Current chemopreventive strategies require 3-5 years of continuous treatment and have the concerns of significant side effects; therefore, new chemopreventive agents that require shorter and safer treatments are urgently needed. In this study, we developed a new murine model of breast cancer that mimics human breast cancer initiation and is ideal for testing the efficacy of chemopreventive therapeutics. In this model, introduction of lentivirus carrying a PIK3CA gene mutant commonly found in breast cancers infects a small number of the mammary cells, leading to atypia first and then to ductal carcinomas that are positive for both estrogen receptor and progesterone …

Ckb Inhibits Epithelial-Mesenchymal Transition And Prostate Cancer Progression By Sequestering And Inhibiting Akt Activation, Zheng Wang, Mohit Hulsurkar, Lijuan Zhuo, Jinbang Xu, Han Yang, Samira Naderinezhad, Lin Wang, Guoliang Zhang, Nanping Ai, Linna Li, Jeffrey T Chang, Songlin Zhang, Ladan Fazli, Chad J Creighton, Fang Bai, Michael M Ittmann, Martin E Gleave, Wenliang Li

Faculty, Staff and Students Publications

Epithelial-mesenchymal transition (EMT) contributes to tumor invasion, metastasis and drug resistance. AKT activation is key in a number of cellular processes. While many positive regulators for either EMT or AKT activation have been reported, few negative regulators are established. Through kinase cDNA screen, we identified brain-type creatine kinase (CKB or BCK) as a potent suppressor for both. As a ubiquitously expressed kinase in normal tissues, CKB is significantly downregulated in several solid cancer types. Lower CKB expression is significantly associated with worse prognosis. Phenotypically, CKB overexpression suppresses, while its silencing promotes, EMT and cell migration, xenograft tumor growth and metastasis …

Role Of Nurd In Acute Leukemia Cell Survival, Javeria Aijaz

Theses and Dissertations

Depletion of the ATPase component of the Nucleosome Remodeling and Deacetylase (NuRD) complex, CHD4, reduces acute myeloid leukemia (AML) cell survival. This study identified other NuRD components, as potential therapeutic targets for disrupting protein-protein interactions within NuRD. In addition to AML, we established that T-cell Acute Lymphoblastic Leukemia (T-ALL) cell lines responded similarly to CHD4 depletion.

Greater than 90% depletion of either MBD2 or MBD3 (the mutually exclusive two DNA binding NuRD paralogues) – was unremarkable, but complete depletion of MBD3 increased apoptosis and genotoxic sensitivity. Combined depletion of MBD-NuRD proteins augmented apoptosis observed with complete MBD3 depletion - indicating …

An In Vitro And In Vivo Evaluation Of The Anticancer Potential Of Resveratrol And Pterostilbene Against Hpv-E6 Positive Cancers, Kaushiki Chatterjee

Dissertations, Theses, and Capstone Projects

Cervical cancer remains as one of the most prevalent cancers effecting women globally. Lack of awareness and affordable prophylactic and therapeutic options in developing countries drive the need for alternative low-cost approaches. Dietary polyphenols have gained increased attention as possible anti-cancer agents. Our study aims to investigate whether two natural structural analogs, resveratrol and pterostilbene, exhibit anti-HPV (Human papillomavirus) activity in cervical cancer. To determine the efficacy of these polyphenols, extensive in vitro and in vivo analyses were carried out. For the in vitro studies we utilized human HeLa cells (HPV18 positive) and murine TC1 cells (HPV 16 oncogene positive). …

Inhibition Of Geranylgeranyl Diphosphate Synthase Is A Novel Therapeutic Strategy For Pancreatic Ductal Adenocarcinoma, Staci L. Haney, Michelle L. Varney, Yashpal S. Chhonker, Simon Shin, Kamiya Mehla, Ayrianne J. Crawford, Heather Jensen Smith, Lynette M. Smith, Daryl J. Murry, Michael A. Hollingsworth, Sarah A. Holstein

Journal Articles: Eppley Institute

Rab proteins play an essential role in regulating intracellular membrane trafficking processes. Rab activity is dependent upon geranylgeranylation, a post-translational modification that involves the addition of 20-carbon isoprenoid chains via the enzyme geranylgeranyl transferase (GGTase) II. We have focused on the development of inhibitors against geranylgeranyl diphosphate synthase (GGDPS), which generates the isoprenoid donor (GGPP), as anti-Rab agents. Pancreatic ductal adenocarcinoma (PDAC) is characterized by abnormal mucin production and these mucins play important roles in tumor development, metastasis and chemo-resistance. We hypothesized that GGDPS inhibitor (GGDPSi) treatment would induce PDAC cell death by disrupting mucin trafficking, thereby inducing the unfolded …

Effects Of The Mortalin Inhibitor Mkt-077 On The Tumor Suppressor P53 In Neuroblastoma Imr-32 Cells, Yusuf Ebrahim

Honors Theses and Capstones

The tumor suppressor protein, p53, is an important cell cycle regulator in humans. Over half of all human cancers involve disruption of p53 function. One way this is achieved is by tethering p53 to the mitochondrial 70 kilodalton heat shock protein (Hsp70), mortalin, in the cytoplasm, and preventing p53 from entering the nucleus. The mortalin inhibitor, MKT-077, binds competitively to the p53 binding site in mortalin, and disrupts the p53-mortalin complex in cancer cell lines, allowing p53 to enter the nucleus and promote apoptotic cell death. Previous research reported that cytoplasmic tethering of p53 occurs in certain human neuroblastomas. Thus, …

Novel Insights Into The Contribution Of Cellular Senescence To Cancer Therapy: Reversibility, Dormancy And Senolysis., Tareq Saleh

Theses and Dissertations

Cellular senescence a specialized form of growth arrest that contributes to the pathogenesis of several aging-related disorders including cancer. While by definition tumor cells are considered immortalized, they can undergo senescence when exposed to conventional and targeted cancer therapy. Therapy-Induced Senescence (TIS) represents a fundamental response to therapy and impacts its outcomes. However, TIS has been considered a positive therapeutic goal since senescent tumor cells are expected to enter a state of permanent growth abrogation. In this work we examined the hypothesis that a subpopulation of senescent cells can re-acquire proliferative potential after a state of senescent dormancy, indicating that …

Tgfβ/Smad3 Regulates Proliferation And Apoptosis Through Irs-1 Inhibition In Colon Cancer Cells., Katie L. Bailey, Ekta Agarwal, Sanjib Chowdhury, Jiangtao Luo, Michael G. Brattain, Jennifer D. Black, J. Wang

Journal Articles: Eppley Institute

In this study, we have uncovered a novel crosstalk between TGFβ and IGF-1R signaling pathways. We show for the first time that expression and activation of IRS-1, an IGF-1R adaptor protein, is decreased by TGFβ/Smad3 signaling. Loss or attenuation of TGFβ activation leads to elevated expression and phosphorylation of IRS-1 in colon cancer cells, resulting in enhanced cell proliferation, decreased apoptosis and increased tumor growth in vitro and in vivo. Downregulation of IRS-1 expression reversed Smad3 knockdown-mediated oncogenic phenotypes, indicating that TGFβ/Smad3 signaling inhibits cell proliferation and increases apoptosis at least partially through the inhibition of IRS-1 expression and activation. …

Yap And The Hippo Pathway In Pediatric Cancer., Atif Ahmed, Abdalla D. Mohamed, Melissa Gener, Weijie Li, Eugenio Taboada

Manuscripts, Articles, Book Chapters and Other Papers

The Hippo pathway is an important signaling pathway that controls cell proliferation and apoptosis. It is evolutionarily conserved in mammals and is stimulated by cell-cell contact, inhibiting cell proliferation in response to increased cell density. During early embryonic development, the Hippo signaling pathway regulates organ development and size, and its functions result in the coordinated balance between proliferation, apoptosis, and differentiation. Its principal effectors, YAP and TAZ, regulate signaling by the embryonic stem cells and determine cell fate and histogenesis. Dysfunction of this pathway contributes to cancer development in adults and children. Emerging studies have shed light on the upregulation …

Elevated Mtss1 Expression Associated With Metastasis And Poor Prognosis Of Residual Hepatitis B-Related Hepatocellular Carcinoma, Xiu-Yan Huang, Zi-Li Huang, Bin Xu, Zi Chen

Dartmouth Scholarship

Background: Hepatectomy generally offers the best chance of long-term survival for patients with hepatocellular carcinoma (HCC). Many studies have shown that hepatectomy accelerates tumor metastasis, but the mechanism remains unclear.

Methods: An orthotopic nude mice model with palliative HCC hepatectomy was performed in this study. Metastasis-related genes in tumor following resection were screened; HCC invasion, metastasis, and some molecular alterations were examined in vivo and in vitro. Clinical significance of key gene mRNA expression was also analyzed.

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 …

Cyclin-Dependent Kinase Inhibitor P1446a Induces Apoptosis In A Jnk/P38 Mapk-Dependent Manner In Chronic Lymphocytic Leukemia B-Cells, Cody Paiva, J. Claire Godbersen, Ryan S. Soderquist, Taylor Rowland, Sumner Kilmarx

Dartmouth Scholarship

CDK (cyclin-dependent kinase) inhibitors have shown remarkable activity in CLL, where its efficacy has been linked to inhibition of the transcriptional CDKs (7 and 9) and deregulation of RNA polymerase and short-lived pro-survival proteins such as MCL1. Furthermore, ER (endoplasmic reticulum) stress has been implicated in CDK inhibition in CLL. Here we conducted a pre-clinical study of a novel orally active kinase inhibitor P1446A in CLL B-cells. P1446A inhibited CDKs at nanomolar concentrations and induced rapid apoptosis of CLL cells in vitro, irrespective of chromosomal abnormalities or IGHV mutational status. Apoptosis preceded inactivation of RNA polymerase, and was accompanied by …

In Vitro Growth Suppression Of Renal Carcinoma Cells By Curcumin, Santhi D. Konduri, Madhavi Latha Yadav Bangaru, Phu Thanh Do, Shenglin Chen, Jeffrey Woodliff, Sanjay Kansra

Journal of Patient-Centered Research and Reviews

Purpose

Malignant clear cell renal carcinoma (ccRCC) is an aggressive tumor highly resistant to chemotherapy and radiation. Current therapeutic approaches to management of ccRCC have not significantly improved patient survival, therefore novel therapies are needed. Activated NFκB and STAT3 expression is associated with ccRCC pathogenesis. The dietary polyphenol curcumin is a well-documented antitumor agent and a known inhibitor of NFκB and STAT3 activation. Given the lack of effective therapies that block ccRCC progression, our objective was to examine whether curcumin could suppress the growth and migration of ccRCC cells, and whether this suppression was mediated via inhibition of NFκB and …

In Vitro Growth Suppression Of Renal Carcinoma Cells By Curcumin, Santhi Konduri, Madhavi Latha Yadav Bangaru, Phu Thanh Do, Shenglin Chen, Jeffrey Woodliff, Sanjay Kansra

Journal of Patient-Centered Research and Reviews

Background: Malignant clear cell renal carcinoma (ccRCC) is an aggressive tumor that is highly resistant to chemotherapy and radiation. Current therapeutic approaches to management of ccRCC have not significantly improved patient survival, therefore novel therapies are needed. The von Hippel-Lindau tumor suppressor gene is frequently mutated in ccRCC resulting in unregulated transcriptional activity of hypoxia-inducible factors (HIF) 1α and 2α. HIF-mediated transcription leads to increased growth factor expression and growth factor receptor (GFR)-mediated signaling. NFκB and STAT3 are phosphorylated in response to GFR activation and modulate gene expression, which promotes cell growth and invasion. Activated NFκB and STAT3 expression is …

Selenoprotein P Influences Colitis-Induced Tumorigenesis By Mediating Stemness And Oxidative Damage., C. W. Barrett, V. K. Reddy, S. P. Short, A. K. Motley, M. K. Lintel, A. M. Bradley, T. Freeman, J. Vallance, W. Ning, B. Parang, Shenika Poindexter Toliver

Faculty and Staff Publications

Patients with inflammatory bowel disease are at increased risk for colon cancer due to augmented oxidative stress. These patients also have compromised antioxidant defenses as the result of nutritional deficiencies. The micronutrient selenium is essential for selenoprotein production and is transported from the liver to target tissues via selenoprotein P (SEPP1). Target tissues also produce SEPP1, which is thought to possess an endogenous antioxidant function. Here, we have shown that mice with Sepp1 haploinsufficiency or mutations that disrupt either the selenium transport or the enzymatic domain of SEPP1 exhibit increased colitis-associated carcinogenesis as the result of increased genomic instability and …

A Novel Caspase 8 Selective Small Molecule Potentiates Trail-Induced Cell Death, Octavian Bucur, Gabriel Gaidos, Achani Yatawara, Bodvael Pennarun, Chamila Rupasinghe, Jérémie Roux, Stefan Andrei, Bingqian Guo, Alexandra Panaitiu, Maria Pellegrini, Dale Mierke, Roya Khosravi-Far

Dartmouth Scholarship

Recombinant soluble TRAIL and agonistic antibodies against TRAIL receptors (DR4 and DR5) are currently being created for clinical cancer therapy, due to their selective killing of cancer cells and high safety characteristics. However, resistance to TRAIL and other targeted therapies is an important issue facing current cancer research field. An attractive strategy to sensitize resistant malignancies to TRAIL-induced cell death is the design of small molecules that target and promote caspase 8 activation. For the first time, we describe the discovery and characterization of a small molecule that directly binds caspase 8 and enhances its activation when combined with TRAIL, …

The Role Of Mammalian Cyclin C In Stress Response And Thyroid Disease Progression, Kun Wang

Graduate School of Biomedical Sciences Theses and Dissertations

The cellular response to stress involves changes in gene expression programs as well as the remodeling of subcellular organelles including the mitochondria. Important for this study, the mitochondria undergo extensive fragmentation when the cell is exposed to a variety of stressors. The cyclin C-Cdk8 kinase is a highly conserved transcription factor that associates with the RNA polymerase II holoenzyme. Using cyclin C knockout (CCNC^-/-) mouse embryonic fibroblast (MEF) cells, I revealed that cyclin C is required for the extensive mitochondrial fragmentation following treatment with pro-oxidants or the anti-cancer drug cisplatin. However, Cdk8 is not required for this process …

Id4 Deficiency Attenuates Prostate Development And Promotes Pin-Like Lesions By Regulating Androgen Receptor Activity And Expression Of Nkx3.1 And Pten, Pankaj Sharma, Ashley Knowell, Swathi Chinaranagari, Shravan Komaragiri, Peri Nagappan, Divya Patel, Mathew C. Havrda, Jaideep Chaudhary

Dartmouth Scholarship

Background: Inhibitor of differentiation 4 (Id4), a member of the helix-loop-helix family of transcriptional regulators has emerged as a tumor suppressor in prostate cancer. Id4 is expressed in the normal prostate where its expression is also regulated by androgens. In this study we investigated the effect of loss of Id4 (Id4-/-) on adult prostate morphology. Methods: Histological analysis was performed on prostates from 6-8 weeks old Id4-/-, Id4+/- and Id4+/+ mice. Expression of Id1, Sox9, Myc, androgen receptor, Akt, p-Akt, Pten and Nkx3.1 was investigated by immunohistochemistry. Androgen receptor binding on NKX3.1 promoter was studied by chromatin immuno-precipitation. Id4 was …

Functional Study Of Hemogen Knockout Mouse Model, Peng Gao

Theses and Dissertations (ETD)

Mouse Hemogen (Hemgn) is regarded as a homologue of human Erythroid Differentiation Associated Gene (EDAG). EDAG overexpression has been postulated for association with some leukemia cases. Meanwhile, Hemgn has been found to contribute to Hoxb4 mediated hematopoietic stem cell expansion. Based on these postulations and evidences, a Hemgn knockout mouse model has been generated to study its function in normal and stress hematopoiesis. I confirmed the Hemgn expression in hematopoietic organs including bone marrow and spleen, as well as round spematids in testis. Hemgn is expressed in mouse hematopoietic stem cells and erythroid progenitor cells. Moreover, Hemgn was also found …

Synergistic Effects Of Nanosecond Pulsed Electric Fields Combined With Low Concentration Of Gemcitabine On Human Oral Squamous Cell Carcinoma In Vitro, Jing Wang, Jinsong Guo, Shan Wu, Hongqing Feng, Shujun Sun, Jie Pan, Jue Zhang, Stephen J. Beebe

Bioelectrics Publications

Treatment of cancer often involves uses of multiple therapeutic strategies with different mechanisms of action. In this study we investigated combinations of nanosecond pulsed electric fields (nsPEF) with low concentrations of gemcitabine on human oral cancer cells. Cells (Cal-27) were treated with pulse parameters (20 pulses, 100 ns in duration, intensities of 10, 30 and 60 kV/cm) and then cultured in medium with 0.01 mu g/ml gemcitabine. Proliferation, apoptosis/necrosis, invasion and morphology of those cells were examined using MTT, flow cytometry, clonogenics, transwell migration and TEM assay. Results show that combination treatments of gemcitabine and nsPEFs exhibited significant synergistic activities …

Transforming Growth Factor-Β Suppresses Metastasis In A Subset Of Human Colon Carcinoma Cells., Neka A.K. Simms, Ashwani Rajput, Elizabeth A. Sharratt, Melanie Ongchin, Carol A. Teggart, J. Wang, Michael G. Brattain

Journal Articles: Eppley Institute

BACKGROUND: TGFβ signaling has typically been associated with suppression of tumor initiation while the role it plays in metastasis is generally associated with progression of malignancy. However, we present evidence here for an anti-metastatic role of TGFβ signaling.

METHODS: To test the importance of TGFβ signaling to cell survival and metastasis we compared human colon carcinoma cell lines that are either non-tumorigenic with TGFβ response (FET), or tumorigenic with TGFβ response (FETα) or tumorigenic with abrogated TGFβ response via introduction of dominant negative TGFβRII (FETα/DN) and their ability to metastasize. Metastatic competency was assessed by orthotopic transplantation. Metastatic colony formation …

Bim Mediates Imatinib-Induced Apoptosis Of Gastrointestinal Stromal Tumors: Translational Implications, David Reynoso

Dissertations and Theses (Open Access)

Gastrointestinal stromal tumors (GISTs) are oncogene-addicted cancers driven by activating mutations in the genes encoding receptor tyrosine kinases KIT and PDGFR-α. Imatinib mesylate, a specific inhibitor of KIT and PDGFR-α signaling, delays progression of GIST, but is incapable of achieving cure. Thus, most patients who initially respond to imatinib therapy eventually experience tumor progression, and have limited therapeutic options thereafter. To address imatinib-resistance and tumor progression, these studies sought to understand the molecular mechanisms that regulate apoptosis in GIST, and evaluate combination therapies that kill GISTs cells via complementary, but independent, mechanisms. BIM (Bcl-2 interacting mediator …

Insights Into P53-Dependent Apoptotic Signaling And Cell Fate Vis-A-Vis Functional Cooperation Among Bcl-Xl, Cytoplasmic P53, And Puma, John C. Fisher

Theses and Dissertations (ETD)

Following DNA damage, nuclear p53 induces the expression of PUMA (p53 upregulated modulator of apoptosis), a BH3‑only protein that binds and inhibits the anti‑apoptotic BCL‑2 repertoire, including BCL‑xL. Structural investigations of PUMA and the BCL‑xL×PUMA BH3 domain complex by X‑ray crystallography and nuclear magnetic resonance (NMR) spectroscopy reveal a novel, PUMA‑induced, domain‑swapped dimerization of BCL‑xL that requires a π‑stacking interaction between PUMA W71 and BCL‑xL H113. PUMA is an intrinsically disordered protein, but upon interaction with BCL‑xL, PUMA W71 and the PUMA BH3 domain residues fold into an alpha helix and subtly remodel BCL‑xL to trigger its dimerization. Wild type …