Therapeutic Targeting of TFE3/IRS-1/PI3K/mTOR Axis in Translocation Renal Cell Carcinoma.

PURPOSE: Translocation renal cell carcinoma (tRCC) represents a rare subtype of kidney cancer associated with various TFE3, TFEB, or MITF gene fusions that are not responsive to standard treatments for RCC. Therefore, the identification of new therapeutic targets represents an unmet need for this disease. EXPERIMENTAL DESIGN: We have established and characterized a tRCC patient-derived xenograft, RP-R07, as a novel preclinical model for drug development by using next-generation sequencing and bioinformatics analysis. We then assessed the therapeutic potential of inhibiting the identified pathway using in vitro and in vivo models. RESULTS: The presence of a SFPQ-TFE3 fusion [t(X;1) (p11.2; p34)] with chromosomal break-points was identified by RNA-seq and validated by RT-PCR. TFE3 chromatin immunoprecipitation followed by deep sequencing analysis indicated a strong enrichment for the PI3K/AKT/mTOR pathway. Consistently, miRNA microarray analysis also identified PI3K/AKT/mTOR as a highly enriched pathway in RP-R07. Upregulation of PI3/AKT/mTOR pathway in additional TFE3-tRCC models was confirmed by significantly higher expression of phospho-S6 (P < 0.0001) and phospho-4EBP1 (P < 0.0001) in established tRCC cell lines compared with clear cell RCC cells. Simultaneous vertical targeting of both PI3K/AKT and mTOR axis provided a greater antiproliferative effect both in vitro (P < 0.0001) and in vivo (P < 0.01) compared with single-node inhibition. Knockdown of TFE3 in RP-R07 resulted in decreased expression of IRS-1 and inhibited cell proliferation. CONCLUSIONS: These results identify TFE3/IRS-1/PI3K/AKT/mTOR as a potential dysregulated pathway in TFE3-tRCC, and suggest a therapeutic potential of vertical inhibition of this axis by using a dual PI3K/mTOR inhibitor for patients with TFE3-tRCC.

Common ELF1 deletion in prostate cancer bolsters oncogenic ETS function, inhibits senescence and promotes docetaxel resistance.

ETS family transcription factors play major roles in prostate tumorigenesis with some acting as oncogenes and others as tumor suppressors. ETS factors can compete for binding at some cis-regulatory sequences, but display specific binding at others. Therefore, changes in expression of ETS family members during tumorigenesis can have complex, multimodal effects. Here we show that ELF1 was the most commonly down-regulated ETS factor in primary prostate tumors, and expression decreased further in metastatic disease. Genome-wide mapping in cell lines indicated that ELF1 has two distinct tumor suppressive roles mediated by distinct cis-regulatory sequences. First, ELF1 inhibited cell migration and epithelial-mesenchymal transition by interfering with oncogenic ETS functions at ETS/AP-1 cis-regulatory motifs. Second, ELF1 uniquely targeted and activated genes that promote senescence. Furthermore, knockdown of ELF1 increased docetaxel resistance, indicating that the genomic deletions found in metastatic prostate tumors may promote therapeutic resistance through loss of both RB1 and ELF1.

EZH2 Modifies Sunitinib Resistance in Renal Cell Carcinoma by Kinome Reprogramming.

Acquired and intrinsic resistance to receptor tyrosine kinase inhibitors (RTKi) represents a major hurdle in improving the management of clear cell renal cell carcinoma (ccRCC). Recent reports suggest that drug resistance is driven by tumor adaptation via epigenetic mechanisms that activate alternative survival pathways. The histone methyl transferase EZH2 is frequently altered in many cancers, including ccRCC. To evaluate its role in ccRCC resistance to RTKi, we established and characterized a spontaneously metastatic, patient-derived xenograft model that is intrinsically resistant to the RTKi sunitinib, but not to the VEGF therapeutic antibody bevacizumab. Sunitinib maintained its antiangiogenic and antimetastatic activity but lost its direct antitumor effects due to kinome reprogramming, which resulted in suppression of proapoptotic and cell-cycle-regulatory target genes. Modulating EZH2 expression or activity suppressed phosphorylation of certain RTKs, restoring the antitumor effects of sunitinib in models of acquired or intrinsically resistant ccRCC. Overall, our results highlight EZH2 as a rational target for therapeutic intervention in sunitinib-resistant ccRCC as well as a predictive marker for RTKi response in this disease. Cancer Res; 77(23); 6651-66. ©2017 AACR.

Safety of a meningococcal group B vaccine used in response to two university outbreaks.

OBJECTIVE: To assess the safety of meningococcal group B (MenB)-4C vaccine. PARTICIPANTS: Undergraduates, dormitory residents, and persons with high-risk medical conditions received the MenB-4C vaccine two-dose series during mass vaccination clinics from 12/2013 through 11/2014. METHODS: Adverse events (AEs) were identified by 15 minutes of observation postvaccination, spontaneous reports, surveys, and hospital surveillance. Causality was assessed for serious adverse events (SAEs). RESULTS: 16,974 persons received 31,313 MenB-4C doses. The incidence of syncope during the 15-minutes post-dose 1 was 0.88/1000 persons. 2% of participants spontaneously reported an AE (most common were arm pain and fever). 3 SAEs were suspected of being caused by the vaccine, including one case of anaphylaxis. CONCLUSIONS: Most AEs reported were nonserious and consistent with previous clinical trial findings. Measures to prevent injury from syncope and to treat anaphylaxis should be available wherever vaccines are administered. Our safety evaluation supports the use of MenB-4C in response to outbreaks.

Understanding Factors Affecting University A Students' Decision to Receive an Unlicensed Serogroup B Meningococcal Vaccine.

PURPOSE: During March-November 2013, five cases of serogroup B meningococcal disease occurred among University A undergraduates. The Centers for Disease Control and Prevention used the unlicensed MenB-4C (Bexsero, Novartis Vaccines), a serogroup B meningococcal vaccine, to control the outbreak. All undergraduates (n = 19,257) were offered two doses; 51% of undergraduates received ≥1 dose of MenB-4C. We conducted a knowledge, attitudes, and practice survey to understand which factors and sources of information impacted their decision on whether or not to receive vaccine. METHODS: An anonymous online survey was sent to University A undergraduates. The survey was implemented in June 2-30, 2014, and covered demographics, MenB-4C vaccination decision, and sources of information. Descriptive analyses were conducted. RESULTS: A total of 1,341 students completed the survey (response rate = 7.0%), of these 873 received ≥1 dose of MenB-4C. Among vaccinated respondents, the predominant reasons for receiving vaccine were knowledge of disease severity, parental recommendation, and believing that vaccination offered the best protection. Among unvaccinated respondents, the predominant reasons for not receiving vaccine were perception of low disease risk and concern over vaccine newness and safety. Respondents' top primary sources of information were e-mails from the university followed by their parents. CONCLUSIONS: Reasons behind respondents' decision to receive an unlicensed vaccine were similar to those reported for routinely recommended vaccines. Given the challenges around communicating the importance of receiving a vaccine that is not routinely recommended, respondents' primary sources of information, the university and their parents, could be targeted to improve coverage rates.

Extracellular signal-regulated kinase signaling regulates the opposing roles of JUN family transcription factors at ETS/AP-1 sites and in cell migration.

JUN transcription factors bind DNA as part of the AP-1 complex, regulate many cellular processes, and play a key role in oncogenesis. The three JUN proteins (c-JUN, JUNB, and JUND) can have both redundant and unique functions depending on the biological phenotype and cell type assayed. Mechanisms that allow this dynamic switching between overlapping and distinct functions are unclear. Here we demonstrate that JUND has a role in prostate cell migration that is the opposite of c-JUN's and JUNB's. RNA sequencing reveals that opposing regulation by c-JUN and JUND defines a subset of AP-1 target genes with cell migration roles. cis-regulatory elements for only this subset of targets were enriched for ETS factor binding, indicating a specificity mechanism. Interestingly, the function of c-JUN and JUND in prostate cell migration switched when we compared cells with an inactive versus an active RAS/extracellular signal-regulated kinase (ERK) signaling pathway. We show that this switch is due to phosphorylation and activation of JUND by ERK. Thus, the ETS/AP-1 sequence defines a unique gene expression program regulated by the relative levels of JUN proteins and RAS/ERK signaling. This work provides a rationale for how transcription factors can have distinct roles depending on the signaling status and the biological function in question.

ETS1 is a genome-wide effector of RAS/ERK signaling in epithelial cells.

The RAS/ERK pathway is commonly activated in carcinomas and promotes oncogenesis by altering transcriptional programs. However, the array of cis-regulatory elements and trans-acting factors that mediate these transcriptional changes is still unclear. Our genome-wide analysis determined that a sequence consisting of neighboring ETS and AP-1 transcription factor binding sites is enriched near cell migration genes activated by RAS/ERK signaling in epithelial cells. In vivo screening of candidate ETS proteins revealed that ETS1 is specifically required for migration of RAS/ERK activated cells. Furthermore, both migration and transcriptional activation through ETS/AP-1 required ERK phosphorylation of ETS1. Genome-wide mapping of multiple ETS proteins demonstrated that ETS1 binds specifically to enhancer ETS/AP-1 sequences. ETS1 occupancy, and its role in cell migration, was conserved in epithelial cells derived from multiple tissues, consistent with a chromatin organization common to epithelial cell lines. Genome-wide expression analysis showed that ETS1 was required for activation of RAS-regulated cell migration genes, but also identified a surprising role for ETS1 in the repression of genes such as DUSP4, DUSP6 and SPRY4 that provide negative feedback to the RAS/ERK pathway. Consistently, ETS1 was required for robust RAS/ERK pathway activation. Therefore, ETS1 has dual roles in mediating epithelial-specific RAS/ERK transcriptional functions.

Prostate cancer ETS rearrangements switch a cell migration gene expression program from RAS/ERK to PI3K/AKT regulation.

BACKGROUND: The RAS/ERK and PI3K/AKT pathways induce oncogenic gene expression programs and are commonly activated together in cancer cells. Often, RAS/ERK signaling is activated by mutation of the RAS or RAF oncogenes, and PI3K/AKT is activated by loss of the tumor suppressor PTEN. In prostate cancer, PTEN deletions are common, but, unlike other carcinomas, RAS and RAF mutations are rare. We have previously shown that over-expression of "oncogenic" ETS transcription factors, which occurs in about one-half of prostate tumors due to chromosome rearrangement, can bypass the need for RAS/ERK signaling in the activation of a cell migration gene expression program. In this study we test the role of RAS/ERK and PI3K/AKT signaling in the function of oncogenic ETS proteins. RESULTS: We find that oncogenic ETS expression negatively correlates with RAS and RAF mutations in prostate tumors. Furthermore, the oncogenic ETS transcription factors only increased cell migration in the absence of RAS/ERK activation. In contrast to RAS/ERK, it has been reported that oncogenic ETS expression positively correlates with PI3K/AKT activation. We identified a mechanistic explanation for this finding by showing that oncogenic ETS proteins required AKT signaling to activate a cell migration gene expression program through ETS/AP-1 binding sequences. Levels of pAKT correlated with the ability of oncogenic ETS proteins to increase cell migration, but this process did not require mTORC1. CONCLUSIONS: Our findings indicate that oncogenic ETS rearrangements cause a cell migration gene expression program to switch from RAS/ERK control to PI3K/AKT control and provide a possible explanation for the high frequency of PTEN, but not RAS/RAF mutations in prostate cancer.

Oncogenic ETS proteins mimic activated RAS/MAPK signaling in prostate cells.

The aberrant expression of an oncogenic ETS transcription factor is implicated in the progression of the majority of prostate cancers, 40% of melanomas, and most cases of gastrointestinal stromal tumor and Ewing's sarcoma. Chromosomal rearrangements in prostate cancer result in overexpression of any one of four ETS transcription factors. How these four oncogenic ETS genes differ from the numerous other ETS genes expressed in normal prostate and contribute to tumor progression is not understood. We report that these oncogenic ETS proteins, but not other ETS factors, enhance prostate cell migration. Genome-wide binding analysis matched this specific biological function to occupancy of a unique set of genomic sites highlighted by the presence of ETS- and AP-1-binding sequences. ETS/AP-1-binding sequences are prototypical RAS-responsive elements, but oncogenic ETS proteins activated a RAS/MAPK transcriptional program in the absence of MAPK activation. Thus, overexpression of oncogenic ETS proteins can replace RAS/MAPK pathway activation in prostate cells. The genomic description of this ETS/AP-1-regulated, RAS-responsive, gene expression program provides a resource for understanding the role of these ETS factors in both an oncogenic setting and the developmental processes where these genes normally function.

The ETS gene ETV4 is required for anchorage-independent growth and a cell proliferation gene expression program in PC3 prostate cells.

Chromosomal abnormalities that give rise to elevated expression levels of the ETS genes ETV1, ETV4, ETV5, or ERG are prevalent in prostate cancer, but the function of these transcription factors in carcinogenesis is not clear. Previous work in cell lines implicates ERG, ETV1, and ETV5 as regulators of invasive growth but not transformation. Here we show that the PC3 prostate cancer cell line provides a model system to study the over-expression of ETV4. Migration assays, anchorage independent growth assays, and microarray analysis indicate that high ETV4 expression contributes to both transformation and cellular motility in PC3 cells. ETV4 directly bound the 5' and 3' MYC enhancers and modulated expression of both MYC and other cell proliferation genes, demonstrating a potential role in cell growth control. Despite this novel role for ETV4 in anchorage independent growth, ETV4 over-expression in normal prostate-derived RWPE-1 cells showed effects similar to ETV1 over-expression - increased cellular motility, and an up-regulation of genes encoding extracellular proteins as well as ones important for development, inflammation, and wound healing. Because ETV1 and ETV4 have similar roles when introduced to the same cellular background, we suggest that the requirement of high ETV4 expression for maintenance of the anchorage-independent growth in PC3 cells is due to a specific characteristic of this cell line rather than a function of ETV4 that is distinct from the other oncogenic ETS genes. Thus, the function of ETS genes in prostate cancer may differ based on other genetic alterations in a tumor.

Can easy-to-read immunization information increase knowledge in urban low-income mothers?

This article describes a pilot study that (1) assessed the self-report of highest grade completed in school and the actual reading and comprehension skills of low-income mothers whose children receive immunizations in urban public clinics and (2) tested the effectiveness of a nursing intervention on immunization knowledge using revised easy-to-read written education materials. Thirty-seven mothers were randomized either to a control group (asked to read the standard vaccine information sheets) or to an experimental group (asked to read the revised immunization pamphlets). Although there was a modest increase in immunization knowledge for both groups, it was not significant. Thus, simplifying information alone may not increase parental knowledge.

Global effect of PEG-IFN-alpha and ribavirin on gene expression in PBMC in vitro.

Using oligonucleotide microarrays, we have examined the expression of 22,000 genes in peripheral blood cells treated with pegylated interferon-alpha2b (PEG-IFN-alpha) and ribavirin. Treatment with ribavirin had very little effect on gene expression, whereas treatment with PEG-IFN-alpha had a dramatic effect, modulating the expression of approximately 1000 genes (at p < 0.001). In addition to genes previously reported to be induced by type I or type II IFNs, many novel genes were found to be upregulated, including transcription factors, such as ATF3, ATF4, properdin, a key regulator of the complement pathway, a homeobox gene (HESX1), and an RNA editing enzyme (apobec3). Chemokines CXCL10 and CXCL11 were upregulated, whereas CXCL5 was downregulated. Cytokines interleukin-15 (IL-15) and IL-18 were also significantly induced, whereas IL-1alpha and IL-1beta were downregulated. Most other interleukins were not affected. The results of the microarrays were confirmed by kinetic real-time PCR. These data indicate that IFN treatment causes upregulation of genes associated with the stress response, apoptosis, and signaling, and an equal number of genes are downregulated, including those associated with protein synthesis, specific cytokines and chemokines and other biosynthetic functions.

Induction of IL-1Ra in resistant and responsive hepatitis C patients following treatment with IFN-con1.

Hepatitis C virus (HCV) infection is resistant to interferon-alpha (IFN-alpha) in some patients. The mechanism of this resistance is unknown. Interleukin-1 receptor antagonist (IL-1Ra) is induced by IFN-alpha and is a good indicator of IFN activity. In the current study, we compared IL-1Ra levels in rapid virologic responders and flat responders who showed resistance to IFN. Three groups of patients were examined, including those who received a single dose of consensus IFN (IFN-con1), patients who received daily IFN-con1 for 1 week, and patients who received IFN-con1 daily for 24 weeks. Serum IL-1Ra, IL-6, and HCV RNA were measured serially in all groups. Serum IL-1Ra levels increased rapidly in all patients with hepatitis C after IFN-alpha administration, irrespective of their virologic response. IL-1Ra levels remained elevated at 1 week but were similar to baseline by week 2 of treatment in patients receiving continuous therapy. IL-6 levels also increased acutely but rose more slowly than IL-1Ra levels. The increase in IL-1Ra and IL-6 observed in both flat and rapid virologic responders indicates that IFN receptors are functioning in patients with IFN-resistant hepatitis C and that the lack of response is related to other virologic or immunologic factors.