Biology subjects

El-Deiry, W.

Publications and source records attributed to El-Deiry, W..

4 recordsLinked to original sources

bioRxiv2023

miR-6883 downregulates HIF1α in colorectal and breast cancer cells

Colorectal cancer (CRC) and breast cancer (BC) are deadly diseases that rank as the second and fourth leading causes of cancer-related deaths, respectively. We have previously shown that miR-6883 targets CDK4/6 and that palbociclib-mediated CDK4/6 inhibition destabilizes HIF1. We hypothesize that miR-6883 downregulates HIF1 in CRC and BC cells. miR-6883 was transfected under normoxia or hypoxia and western blot analysis revealed that miR-6883 downregulates CDK4/6 and HIF1 in CRC and BC cells, pointing to miR-6883 as a promising therapeutic to target hypoxic cancers or HIF1-deregulated tumor cells. Future studies will further investigate miR-6883 as a cancer biomarker, effects on HIF-related proteins and therapeutic uses in vivo. O_FIG O_LINKSMALLFIG WIDTH=164 HEIGHT=200 SRC="FIGDIR/small/556385v1_fig1.gif" ALT="Figure 1"> View larger version (41K): org.highwire.dtl.DTLVardef@e0acadorg.highwire.dtl.DTLVardef@68b428org.highwire.dtl.DTLVardef@bc4dforg.highwire.dtl.DTLVardef@aa13ad_HPS_FORMAT_FIGEXP M_FIG O_FLOATNOFigure 1.C_FLOATNO miR-6883 downregulates CDK4/6 and HIF1 in colorectal and breast cancer cells A) Colorectal cancer cells were treated with doses of palbociclib ranging from 0-20 {micro}M. Cell viability was measured by imaging the bioluminescent signal after addition of CellTiter-Glo reagent. B) Percent viability of colorectal cancer cells treated with palbociclib was calculated and nonlinear regression analysis was completed using GraphPad Prism software. C-H) CRC cells were transfected with miR-6883 under normoxia or hypoxia (<0.5% O2) and protein levels of CDK4/6, HIF1, Glut1, and Ran were measured by Western blot. C_FIG

cancer biology↗

bioRxiv2020

P53-independent restoration of p53 pathway in tumors with mutated p53 through ATF4 transcriptional modulation by ERK1/2 and CDK9

A long-term goal in the cancer-field has been to develop strategies for treating p53-mutated tumors. A novel small-molecule, PG3-Oc, restores p53 pathway-signaling in tumor cells with mutant-p53, independently of p53/p73. PG3-Oc partially upregulates the p53-transcriptome (13.7% of public p53 target-gene dataset; 15.2% of in-house dataset) and p53-proteome (18%, HT29; 16%, HCT116-p53-/-). Bioinformatic analysis indicates critical p53-effectors of growth-arrest (p21), apoptosis (PUMA, DR5, Noxa), autophagy (DRAM1), and metastasis-suppression (NDRG1) are induced by PG3-Oc. ERK1/2- and CDK9-kinases are required to upregulate ATF4 by PG3-Oc which restores p53 transcriptomic-targets in cells without functional-p53. PG3-Oc represses MYC (ATF4-independent), and upregulates PUMA (ATF4-dependent) in mediating cell death. With largely nonoverlapping transcriptomes, induced-ATF4 restores p53 transcriptomic targets in drug-treated cells including functionally important mediators such as PUMA and DR5. Our results demonstrate novel p53-independent drug-induced molecular reprogramming involving ERK1/2, CDK9, and ATF4 to restore upregulation of p53 effector genes required for cell death and tumor suppression.

cancer biology↗

bioRxiv2020

HIF1α inhibition by dual targeting of CDK4/6 and HSP90 reduces cancer cell viability including Rb-deficient cells

Most cancers harbor intra-tumoral hypoxia which promotes tumor progression and therapy resistance. Hypoxia-inducible factor 1 (HIF1) mediates an adaptive response to hypoxia and contributes to multiple cancer hallmarks. We describe cancer therapeutic targeting of HIF1 by combination of CDK4/6 inhibitors (CDK4/6i) and heat-shock protein 90 inhibitors (HSP90i). CDK1 contributes to HSP90-mediated HIF1 stabilization whereas CDK1-knockdown enhances HIF1 reduction by HSP90i. Dual CDK1- and HSP90-inhibition increases apoptosis and synergistically inhibits cancer cell viability. To translate our findings, we use FDA-approved CDK4/6i in combination with HSP90i to reduce HIF1 expression and suppress viability of multiple cancer cell types, including Rb-deficient cancer cells. Overexpression of HIF1668E partially rescues the cell viability inhibition by combination CDK4/6i and HSP90i treatment under hypoxia. CDK4/6i and HSP90i suppresses tumor growth in vivo. Thus, combined targeting of CDK4/6 and HSP90, through a drug class effect, inhibits HIF1 and shows preclinical anti-cancer therapeutic efficacy, including with Rb-deficiency.

cancer biology↗

bioRxiv2020

Natural Killer cell activation, reduced ACE2, TMPRSS2, cytokines G-CSF, M-CSF and SARS-CoV-2-S pseudovirus infectivity by MEK inhibitor treatment of human cells

COVID-19 affects vulnerable populations including elderly individuals and patients with cancer. Natural Killer (NK) cells and innate-immune TRAIL suppress transformed and virally-infected cells. ACE2, and TMPRSS2 protease promote SARS-CoV-2 infectivity, while inflammatory cytokines IL-6, or G-CSF worsen COVID-19 severity. We show MEK inhibitors (MEKi) VS-6766, trametinib and selumetinib reduce ACE2 expression in human cells. In some human cells, remdesivir increases ACE2-promoter luciferase-reporter expression, ACE2 mRNA and protein, and ACE2 expression is attenuated by MEKi. In serum-deprived and stimulated cells treated with remdesivir and MEKi we observed correlations between pRB, pERK, and ACE2 expression further supporting role of proliferative state and MAPK pathway in ACE2 regulation. We show elevated cytokines in COVID-19-(+) patient plasma (N=9) versus control (N=11). TMPRSS2, inflammatory cytokines G-CSF, M-CSF, IL-1, IL-6 and MCP-1 are suppressed by MEKi alone or with remdesivir. We observed MEKi stimulation of NK-cell killing of target-cells, without suppressing TRAIL-mediated cytotoxicity. Pseudotyped SARS-CoV-2 virus with a lentiviral core and SARS-CoV-2 D614 or G614 SPIKE (S) protein on its envelope infected human bronchial epithelial cells, small airway epithelial cells, or lung cancer cells and MEKi suppressed infectivity of the pseudovirus. We show a drug class-effect with MEKi to stimulate NK cells, inhibit inflammatory cytokines and block host-factors for SARS-CoV-2 infection leading also to suppression of SARS-CoV-2-S pseudovirus infection of human cells. MEKi may attenuate SARS-CoV-2 infection to allow immune responses and antiviral agents to control disease progression.

cell biology↗