High-throughput simultaneous screen and counterscreen identifies homoharringtonine as synthetic lethal with von Hippel-Lindau loss in renal cell carcinoma

Abstract

Renal cell carcinoma (RCC) accounts for 85% of primary renal neoplasms, and is rarely curable when metastatic. Approximately 70% of RCCs are clear-cell type (ccRCC), and in >80% the von Hippel-Lindau (VHL) gene is mutated or silenced. We developed a novel, high-content, screening strategy for the identification of small molecules that are synthetic lethal with genes mutated in cancer. In this strategy, the screen and counterscreen are conducted simultaneously by differentially labeling mutant and reconstituted isogenic tumor cell line pairs with different fluorochromes and using a highly sensitive high-throughput imaging-based platform. This approach minimizes confounding factors from sequential screening, and more accurately replicates the in vivo cancer setting where cancer cells are adjacent to normal cells. A screen of ~12,800 small molecules identified homoharringtonine (HHT), an FDA-approved drug for treating chronic myeloid leukemia, as a VHL-synthetic lethal agent in ccRCC. HHT induced apoptosis in VHL-mutant, but not VHL-reconstituted, ccRCC cells, and inhibited tumor growth in 30% of VHL-mutant patient-derived ccRCC tumorgraft lines tested. Building on a novel screening strategy and utilizing a validated RCC tumorgraft model recapitulating the genetics and drug responsiveness of human RCC, these studies identify HHT as a potential therapeutic agent for a subset of VHL-deficient ccRCCs.

Genomic characterization of patient-derived xenograft models established from fine needle aspirate biopsies of a primary pancreatic ductal adenocarcinoma and from patient-matched metastatic sites

“…The principles of synthetic lethality allow us to treat a tumor with minimal toxicity to non-cancerous cells by exploiting vulnerabilities caused by oncogenic alterations. [ 20 – 23 ] Indeed, this approach has previously been utilized to discover synthetic lethal interactions in KRAS -mutant cells. [ 24 ] We devised an approach to identify compounds and experimental drugs that are synthetic lethal with increased RAS signaling caused by loss of the RAS-GTPase activating protein (RAS-GAP) NF1.…”

The Expression of VHL (Von Hippel-Lindau) After Traumatic Spinal Cord Injury and Its Role in Neuronal Apoptosis

“…This VHL protein encoded by the VHL gene is well known as an E3 ubiquitin [8]. It is widely accepted that the a-subunit of hypoxia-inducible factor(HIF-a) is the degradation target of VHL-containing E3 ligase in normal physiological conditions [13,14]. Moreover, the ligand stromal cell-derived factor (SDF)-1 and CXC chemokine receptor 4 (CXCR4) were also regarded as HIF targets, which suggests that HIF activation could lead to the potential metastasis of cancer cells [15,16].…”

VHL and Hypoxia Signaling: Beyond HIF in Cancer

“…For example, a focused shRNA library screening identified that CDK6, MET, or MEK1 shRNAs may be selectively toxic to VHL-deficient ccRCC cells, but the effect is mediated in an HIF-independent fashion [ 110 ]. In addition, a highly sensitive high-throughput imaging-based platform with 12,800 small molecules identified homoharringtonine (HHT), an FDA-approved drug that may be used to treat chronic myeloid leukemia (CML), as a synthetic lethality partner in VHL-loss tumors [ 111 ]. However, it remains to be determined as to whether HHT affects HIF signaling in this setting.…”