CUDC-101, a multitargeted inhibitor of histone deacetylase, epidermal growth factor receptor, and human epidermal growth factor receptor 2, exerts potent anticancer activity.

Receptor tyrosine kinase inhibitors have recently become important therapeutics for a variety of cancers. However, due to the heterogeneous and dynamic nature of tumors, the effectiveness of these agents is often hindered by poor response rates and acquired drug resistance. To overcome these limitations, we created a novel small molecule, CUDC-101, which simultaneously inhibits histone deacetylase and the receptor kinases epidermal growth factor receptor (EGFR) and human epidermal growth factor receptor 2 (HER2) in cancer cells. Because of its integrated histone deacetylase inhibition, CUDC-101 synergistically blocked key regulators of EGFR/HER2 signaling pathways, also attenuating multiple compensatory pathways, such as AKT, HER3, and MET, which enable cancer cells to escape the effects of conventional EGFR/HER2 inhibitors. CUDC-101 displayed potent antiproliferative and proapoptotic activities against cultured and implanted tumor cells that are sensitive or resistant to several approved single-targeted drugs. Our results show that CUDC-101 has the potential to dramatically improve the treatment of heterogeneous and drug-resistant tumors that cannot be controlled with single-target agents. Further, they provide a framework to create individual small molecules that simultaneously antagonize multiple biochemically distinct oncogenic targets, suggesting a general paradigm to surpass conventional, single-target cancer therapeutics. Cancer Res; 70(9); 3647-56. (c)2010 AACR.

Gene expression profiles of circulating leukocytes correlate with renal disease activity in IgA nephropathy.

BACKGROUND: The goal of these studies was to explore the possibility of using gene expression profiles of circulating leukocytes as a functional fingerprint of nephritic disease activity. METHODS: This feasibility study utilized IgA nephropathy (IgAN) as a model system. Genes differentially expressed in IgAN patients were identified by Affymetrix GeneChip microarrays, and compared with gene expression of focal segmental glomerulosclerosis (FSGS), minimal change disease, antineutrophil cytoplasmic antibody (ANCA) glomerulonephritis, and with healthy volunteers. Of the genes identified, 15 transcriptionally up-regulated were validated in a larger cohort of patients using TaqMan polymerase chain reaction (PCR). To test whether increased expression of these genes correlated with disease activity, cluster analyses were performed utilizing the TaqMan PCR values. Taking a mathematical approach, we tested whether gene expression values were correlative with kidney function, as reflected by serum creatinine and creatinine clearance values. RESULTS: We identified 15 genes significantly correlative with disease activity in IgAN. This gene signature of IgAN patients' leukocytes reflected kidney function. This was demonstrated in that mathematically generated theoretical values of serum creatinine and creatinine clearance correlated significantly with actual IgAN patient values of serum creatinine and creatinine clearance. There was no apparent correlation with hematuria and proteinuria. The expression levels of this same gene set in ANCA glomerulonephritis or Lupus nephritis patients were not correlative with serum creatinine or creatinine clearance values. CONCLUSION: These data indicate that leukocytes carry informative disease-specific markers of pathogenic changes in renal tissue.

Altered mRNA expression in renal biopsy tissue from patients with IgA nephropathy.

BACKGROUND: Immunoglobulin A (IgA) nephropathy (IgAN) is a renal disease characterized by glomerular deposition of IgA-dominant immune deposits that cause glomerular inflammation and sclerosis. Gene expression changes induced in renal tissues/cells as a result of the disease are largely uncharacterized. METHODS: A sensitive differential mRNA display technique, restriction endonucleolytic analysis of differentially expressed sequences (READS) compared similarly processed normal renal tissue to renal biopsy RNA from patients with IgAN, minimal change disease, and necrotizing crescentic glomerulonephritis. A subset of genes with altered expression in IgAN as identified by the READS technology was further characterized and expression levels confirmed using real-time quantitative polymerase chain reaction (RT-PCR) analysis (TaqMan) in all RNA. RESULTS: Initial READS analysis showed IgAN samples have lower mRNA levels relative to normal renal tissue mRNA samples based upon total RNA as measured by ribosomal RNA. One hundred seventy-five differentially expressed non-redundant fragments were found from 860 initial candidate fragments. Twenty genes were selected for additional TaqMan analysis, and 13 of 20 genes showed statistically different expression when comparing biopsies from normal individuals and IgAN patients. Expression differences were seen in these genes in biopsies of IgAN of differing clinical activities. Gene expression cluster analysis using the Ward method detailed disease- and gene-related clusters. Detailed examination of the promoter regions of the genes within two gene clusters revealed common gene transcriptional regulatory protein-binding sites. CONCLUSION: IgAN leads to significant changes in overall mRNA transcription levels within the renal tissue, in addition to gene-specific mRNA level changes. Disease-related patterns of expression were identified and gene-specific clusters suggest common mechanisms of transcriptional alteration.

Expression profile of leukocyte genes activated by anti-neutrophil cytoplasmic autoantibodies (ANCA).

BACKGROUND: Anti-neutrophil cytoplasmic autoantibodies (ANCA) induce neutrophil activation in vitro with release of injurious products that can mediate necrotizing vasculitis in vivo. The importance of ANCA IgG F(ab')2-antigen binding versus Fcgamma receptor engagement in this process is controversial. We propose that ANCA-antigen binding affects cell signaling pathways that can result in changes of gene expression. METHODS: Microarray GeneChip analysis and real-time, quantitative PCR (TaqMan(R)) was used to probe for transcripts in leukocytes from patients (in vivo gene expression study) and in leukocytes treated with ANCA IgG or ANCA-F(ab')2 (in vitro gene expression study). RESULTS: Microarray gene chip analysis showed that ANCA IgG and ANCA-F(ab')2 stimulate transcription of a distinct subset of genes, some unique to whole IgG, some unique to F(ab')2 fragments, and some common to both. DIF-2, COX-2, and IL-8 were identified as genes responsive to ANCA signaling and were selected for in depth evaluation. In vitro DIF-2 and IL-8 were increased by both ANCA IgG and F(ab')2, but COX-2 only by MPO-ANCA F(ab')2. In vivo DIF-2 levels were increased in leukocytes of ANCA patients, which correlated strongly with disease activity and ANCA titer. DIF-2 was not increased in patients in remission or in disease control patients (systemic lupus erythematosus and IgA nephropathy). COX-2 gene expression was significantly increased in patients with active disease, while IL-8 was increased in remission. CONCLUSIONS: The data indicate that leukocyte genes are activated in vitro by both ANCA Fc and ANCA F(ab')2 pathways and that in vitro activation mimics changes in circulating leukocytes of patients with ANCA disease. Increased levels of DIF-2 in patient leukocytes strongly correlate with severity of disease in kidney tissue. The observations indicate a previously unrecognized role for DIF-2 in ANCA-mediated inflammation, which raises the possibility that DIF-2 has an important role in other types of inflammation.