Oncology Commons^™

Epigenetic Targeting Of Mcl-1 Is Synthetically Lethal With Bcl-Xl/Bcl-2 Inhibition In Model Systems Of Glioblastoma, Enyuan Shang, Trang T. T. Nguyen, Chang Shu, Mike-Andrew Westhoff, Georg Karpel-Massler, Markus D. Siegelin

Publications and Research

Apoptotic resistance remains a hallmark of glioblastoma (GBM), the most common primary brain tumor in adults, and a better understanding of this process may result in more efficient treatments. By utilizing chromatin immunoprecipitation with next-generation sequencing (CHIP-seq), we discovered that GBMs harbor a super enhancer around the Mcl-1 locus, a gene that has been known to confer cell death resistance in GBM.We utilized THZ1, a known super-enhancer blocker, and BH3-mimetics, including ABT263, WEHI-539, and ABT199. Combined treatment with BH3-mimetics and THZ1 led to synergistic growth reduction in GBM models. Reduction in cellular viability was accompanied by significant cell death induction …

Inhibition Of Hdac1/2 Along With Trap1 Causes Synthetic Lethality In Glioblastoma Model Systems, Trang T. T. Nguyen, Yiru Zhang, Enyuan Shang, Chang Shu, Catarina M. Quinzii, Mike-Andrew Westhoff, Georg Karpel-Massler, Markus D. Siegelin

Publications and Research

The heterogeneity of glioblastomas, the most common primary malignant brain tumor, remains a significant challenge for the treatment of these devastating tumors. Therefore, novel combination treatments are warranted. Here, we showed that the combined inhibition of TRAP1 by gamitrinib and histone deacetylases (HDAC1/HDAC2) through romidepsin or panobinostat caused synergistic growth reduction of established and patient-derived xenograft (PDX) glioblastoma cells. This was accompanied by enhanced cell death with features of apoptosis and activation of caspases. The combination treatment modulated the levels of pro- and anti-apoptotic Bcl-2 family members, including BIM and Noxa, Mcl-1, Bcl-2 and Bcl-xL. Silencing of Noxa, BAK and …

Activation Of Lxrβ Inhibits Tumor Respiration And Is Synthetically Lethal With Bcl-Xl Inhibition, Trang Thi Thu Nguyen, Chiaki Tsuge Ishida, Enyuan Shang, Chang Shu, Consuelo Torrini, Yiru Zhang, Elena Bianchetti, Maria J. Sanchez-Quintero, Giulio Kleiner, Catarina M. Quinzii, Mike-Andrew Westhoff, Georg Karpel-Massler, Peter Canoll, Markus D. Siegelin

Publications and Research

Liver-X-receptor (LXR) agonists are known to bear anti-tumor activity. However, their efficacy is limited and additional insights regarding the underlying mechanism are necessary. By performing transcriptome analysis coupled with global polar metabolite screening, we show that LXR agonists, LXR623 and GW3965, enhance synergistically the anti-proliferative effect of BH3 mimetics in solid tumor malignancies, which is predominantly mediated by cell death with features of apoptosis and is rescued by exogenous cholesterol. Extracellular flux analysis and carbon tracing experiments (U-¹³C-glucose and U-¹³C-glutamine) reveal that within 5 h, activation of LXRβ results in reprogramming of tumor cell metabolism, leading …

Cc Chemokine Ccl1 Receptor Ccr8 Mediates Conversion Of Mesenchymal Stem Cells To Embryoid Bodies Expressing Foxp3+Ccr8+ Regulatory T Cells, Nasreen Haque, Tuteja Akaash, Niloufar Haque

Publications and Research

Embryoid bodies (EBs) are three dimensional aggregates of pluripotent stem cells primarily used to investigate morphogenesis and cell toxicity, are also attractive tools in regenerative medicine. While embryonic stem cells (ESCs) and induced pluripotent cells (IPSCs) have been shown to form EBs in mouse, primate and humans, EB formation have not been previously demonstrated in mesenchymal stem cells (MSCs). Here we show that rat MSCs form EBs; which express regulatory T cell (Treg) marker Foxp3 and CC chemokine CCL1 receptor CCR8. We show a novel method for formation of EBs from MSCs under stress and demonstrate that the induction of …

Activation Of Lxr Receptors And Inhibition Of Trap1 Causes Synthetic Lethality In Solid Tumors, Trang Thi Thu Nguyen, Chiaki Tsuge Ishida, Enyuan Shang, Chang Shu, Elena Bianchetti, Georg Karpel-Massler, Markus D. Siegelin

Publications and Research

Cholesterol is a pivotal factor for cancer cells to entertain their relentless growth. In this case, we provide a novel strategy to inhibit tumor growth by simultaneous activation of liver-X-receptors and interference with Tumor Necrosis Factor Receptor-associated Protein 1 (TRAP1). Informed by a transcriptomic and subsequent gene set enrichment analysis, we demonstrate that inhibition of TRAP1 results in suppression of the cholesterol synthesis pathway in stem-like and established glioblastoma (GBM) cells by destabilizing the transcription factor SREBP2. Notably, TRAP1 inhibition induced cell death, which was rescued by cholesterol and mevalonate. Activation of liver X receptor (LXR) by a clinically validated …

Effects Of Vitamin D3 And Its Chemical Analogs On The Growth Of Hodgkin’S Lymphoma, In Vitro, Rajendra Ghardbaran, Bo Zhang, Luis Valerio, Onyekwere Onwumere, Madeline Wong, Jason Mighty, Stephen Redenti

Publications and Research

Objective: Vitamin D receptor (VDR) activities have been noted for a number of B cell malignancies which showed varying sensitivities to vitamin D3 (1,25-dihydroxyvitamin D3, VD3, calcitriol) and its synthetic analogs. The objective of this study was to address the potential effects of VD3 and vitamin D3 analogs (VDAs) on the growth of Hodgkin’s lymphoma (HL), a malignant pathology of B cell origin, in vitro.

Results: Immunofluorescence staining showed the expression of VDR by primary Hodgkin’s (H) and Reed–Sternberg (RS)—HRS-tumor cells in HL histological sections. Western blot analyses revealed expression of VDR in the HL cell lines Hs445, HDLM2, KMH2, …

Antioxidants And Cancer: Theories, Techniques, And Trials In Preventing Cancer, Gloria M. Calaf, Francisco Aguayo, Consolato M. Sergi, Angeles Juarranz, Debasish Roy

Publications and Research

No abstract provided.

Non-Nad-Like Poly(Adp-Ribose) Polymerase-1 Inhibitors Effectively Eliminate Cancer In Vivo, Colin Thomas, Yingbiao Ji, Niraj Lodhi, Elena Kotova, Aaron Dan Pinnola, Konstantin Golovine, Peter Makhov, Kate Pechenkina, Vladimir Kolenko, Alexei V. Tulin

Publications and Research

The clinical potential of PARP-1 inhibitors has been recognized N10 years ago, prompting intensive research on their pharmacological application in several branches of medicine, particularly in oncology. However, natural or acquired resistance of tumors to known PARP-1 inhibitors poses a serious problemfor their clinical implementation. Present study aims to reignite clinical interest to PARP-1 inhibitors by introducing a new method of identifying highly potent inhibitors and presenting the largest known collection of structurally diverse inhibitors. The majority of PARP-1 inhibitors known to date have been developed as NAD competitors. NAD is utilized by many enzymes other than PARP-1, resulting in …

Flurbiprofen Benzyl Nitrate (Nbs-242) Inhibits The Growth Of A-431 Human Epidermoid Carcinoma Cells And Targets Β-Catenin, Niharika Nath, Xiaoping Liu, Lloydine Jacobs, Khosrow Kashfi

Publications and Research

Background: The Wnt/β-catenin/T cell factor (TCF) signaling pathway is important in the development of nonmelanoma skin cancers (NMSCs). Nitric-oxide-releasing nonsteroidal anti-inflammatory drugs (NO-NSAIDs) are chemopreventive agents consisting of a traditional NSAID attached to an NO-releasing moiety through a chemical spacer. Previously we showed that an aromatic spacer enhanced the potency of a particular NO-NSAID compared to an aliphatic spacer.

Methods: We synthesized an NO-releasing NSAID with an aromatic spacer (flurbiprofen benzyl nitrate, NBS-242), and using the human skin cancer cell line A-431, we evaluated its effects on cell kinetics, Wnt/β-catenin, cyclin D1, and caspase-3.

Results: NBS-242 inhibited the growth of …