Cancer Biology Commons^™

Immunohistochemical Localization Of Prolactin Receptor (Prlr) To Hodgkin's And Reed-Sternberg Cells Of Hodgkin's Lymphoma, Rajendra Gharbaran, Onyekwere Onwumere, Naomi Codrington, Latchman Somenarian, Stephen Redenti

Publications and Research

Prolactin receptor (PRLR), a type-1 cytokine receptor, is overexpressed in a number of cancer types. It has attracted much attention for putative pro-oncogenic roles, which however, remains controversial in some malignancies. In this study, we reported the localization of PRLR to the Hodgkin's and Reed-Sternberg (HRS) cells of Hodgkin's lymphoma (HL), a neoplasm of predominantly B cell origin. Immunohistochemistry performed on 5-μm thick FFPE sections revealed expression of PRLR in HRS cells. Cellular immunofluorescence experiments showed that the HL-derived cell lines, Hs445, KMH2 and L428 overexpressed PRLR. The PRLR immunofluorescent signal was depleted after treating the cell lines with 10 …

Luteolin Induces Cytotoxicity In Mix Cellularity Classical Hodgkin's Lymphoma Via Caspase Activated-Cell Death, Rajendra Gharbaran, Enyuan Shang, Onyekwere Onwumere, Naomi Codrington, Evangelina Dankwa Sarpong, Stephen M. Redenti

Publications and Research

Background/aim: We investigated the effects of luteolin (LUT) on classical Hodgkin's lymphoma (cHL), since such studies in malignant lymphomas are lacking.

Materials and methods: Effect of LUT on cell growth was assessed with water-soluble tetrazolium 1 (WST-1) cell proliferation assay and automated hemocytometry on trypan blue-exclusion assay. Cell death was investigated with acridine orange/ethidium bromide live-dead assay, propidium iodide (PI) flow cytometry, and Annexin-V-PI microscopy. Caspase activation was studied using CellEvent Caspase-3/7 Green detection reagent. High resolution immunofluorescence microscopy was used to detect cleaved-PARP-1.

Results: LUT induced a dose-dependent decrease in the growth of KMH2 and L428 cells, cellular models …

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 …

Metabolic Reprogramming By C-Met Inhibition As A Targetable Vulnerability In Glioblastoma, Trang Thi Thu Nguyen, Enyuan Shang, Georg Karpel-Massler, Markus D. Siegelin

Publications and Research

The elucidation of better treatments for solid tumors and especially malignant glial tumors is a priority. Better understanding of the molecular underpinnings of treatment response and resistance are critical determinants in the success for this endeavor. Recently, a battery of novel tools have surfaced that allow to interrogate tumor cell metabolism to more precise extent than this was possible in the earlier days. At the forefront of these developments are the extracellular flux and carbon tracing analyses. Through utilization of these techniques our group made the recent observation that acute and chronic c-MET inhibition drives fatty acid oxidation that in …

Modulation Of The Pol Ii Ctd Phosphorylation Code By Rac1 And Cdc42 Small Gtpases In Cultured Human Cancer Cells And Its Implication For Developing A Synthetic-Lethal Cancer Therapy, Bo Zhang, Xuelin Zhong, Moira Sauane, Yihong Zhao, Zhi-Liang Zheng

Publications and Research

Rho GTPases, including Rho, Cdc42, Rac and ROP subfamilies, are key signaling molecules in RNA polymerase II (Pol II) transcriptional control. Our prior work has shown that plant ROP and yeast Cdc42 GTPases similarly modulate Ser2 and Ser5 phosphorylation status of the C-terminal domain (CTD) of the Pol II largest subunit by regulating CTD phosphatase degradation. Here, we present genetic and pharmacological evidence showing that Cdc42 and Rac1 GTPase signaling modulates a similar CTD Ser2 and Ser5 phosphorylation code in cultured human cancer cells. While siRNA knockdown of Cdc42 and Rac1, respectively, in HeLa cells increased the level of CTD …