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The lack of precision therapies combined with limited therapeutic access to intracranial tumor sites due to the presence of the blood-brain/blood-tumor barriers have contributed to glioblastoma (GBM) being one of the most difficult cancers to effectively treat. We have developed a novel precision medicine approach for GBM treatment that involves the use of brain-penetrant RNA interference (RNAi)-based spherical nucleic acids (SNAs). In this study, we used SNAs consisting of gold nanoparticle cores covalently conjugated with radially oriented and densely packed siRNA oligonucleotides. Based upon previous preclinical evaluation, we conducted toxicology and toxicokinetic studies in non-human primates, and a single-arm, open-label phase 0 first-in-human trial (NCT03020017) to determine safety, pharmacokinetics, intratumoral accumulation and gene-suppressive activity of systemically administered SNAs carrying siRNA specific for the GBM oncogene Bcl2Like12 (Bcl2L12). Patients with recurrent GBM were treated with intravenous administration of siBcl2L12-SNAs (drug moniker: NU-0129), at a dose corresponding to 1/50th of the no-observed-adverse-event-level (NOAEL), followed by tumor resection. Safety assessment revealed no significant treatment-related toxicities. Inductively coupled plasma mass spectrometry, X-ray fluorescence microscopy, and silver staining of resected GBM tissue demonstrated that intravenously administered SNAs reached patient tumors, with gold (Au) enrichment observed in the tumor-associated endothelium, macrophages and tumor cells. NU-0129 uptake into glioma cells correlated with significant reduction in tumor-associated Bcl2L12 protein expression, as indicated by comparison of NU-0129-treated recurrent vs. matched primary (i.e., untreated) tumor. Our results establish SNA nanoconjugates as a brain-penetrant precision medicine approach for the systemic treatment of GBM.

Widespread tumor cell invasion is a fundamental property of diffuse gliomas and is ultimately responsible for their poor prognosis. A greater understanding of basic mechanisms underlying glioma invasion is needed to provide insights into therapies that could potentially counteract them. While none of the currently available in vitro models can fully recapitulate the complex interactions of glioma cells within the brain tumor microenvironment, if chosen and developed appropriately, these models can provide controlled experimental settings to study molecular and cellular phenomena that are challenging or impossible to model in vivo. Therefore, selecting the most appropriate in vitro model, together with its inherent advantages and limitations, for specific hypotheses and experimental questions achieves primary significance. In this review, we describe and discuss commonly used methods for modeling and studying glioma invasion in vitro, including platforms, matrices, cell culture, and visualization techniques, so that choices for experimental approach are informed and optimal.

Prostate cancer is one of the most commonly diagnosed cancers and the second leading cause of cancer death in men in the United States. Although there are recently approved therapeutic options for men with advanced and metastatic disease, the unfortunate reality is that advanced prostate cancer is inevitably fatal. Hormonal androgen deprivation therapy (ADT) is the standard of care once a patient has recurrent disease following primary surgical or radiation therapy; however, the benefits from ADT are typically short lived. Recurrent disease that follows ADT treatment is termed castration-resistant prostate cancer (CRPC), which is the most aggressive and lethal form of prostate cancer. The current treatment regime for CRPC consists primarily of chemotherapy with docetaxel, but other agents such as the immunotherapy agent sipuleucel-T, the taxane cabazitaxel, the CYP17 inhibitor abiraterone acetate, and the androgen receptor (AR) antagonist enzalutamide are also Food and Drug Administration (FDA) approved for the treatment of CRPC. Although there are clinical trials testing the potential therapeutic benefits of many other compounds, CRPC remains an incurable disease. Recent advancements in our understanding of the biochemical and genetic pathways critical to CRPC progression have identified many novel potential druggable targets as well as biomarkers of disease progression. This review focuses on the biological aspects of aggressive prostate cancer, biomarkers, therapeutic targets, and future directions for the treatment of CRPC (Fig).

Glioblastoma (GBM) is a highly malignant primary brain tumor and has a poor prognosis and is resistant to the most advanced therapies. The development of highly hypoxic centrally located necrotic regions is strongly associated with accelerated GBM progression, yet mechanistic explanations are not complete. Hypoxic regions within GBM are highly enriched for glioma stem cells (GSC), which are critical for tumor initiation, recurrence and therapeutic resistance due to their self-renewing capabilites. While most GBM cells migrate outward, away from hypoxia, GSCs accumulate there, forming a hypercellular border called pseudopalisades that promote their survival. Mechanisms that mediate GSC accumulation within pseudopalisades are unknown. We hypothesize that GSCs are enriched in the pseudopalisades due to the homing of a subpopulation towards the supportive hypoxic microenvironment. This in turn activates critical hypoxia-induced drivers to promote stemness, survival and migratory behavior encouraging the recruitment of more GSCs. Using two genetically distinct patient-derived GBM cell lines, we found that exposure to hypoxia in vitro led to enrichment of GSCs among a heterogeneous population of GSCs and non-GSCs. We found that hypoxia enhanced the expression of stem cell, pro-survival and pro-migratory factors in GSCs, such as the pro-migratory chemokine SDF-1α, and its cognate receptor CXCR4. Importantly, we found hypoxia also induced upregulation of OLIG2, one of four core transcription factors necessary and sufficient to induce stemness, in GSCs and non-GSCs exposed to hypoxia. We determined that OLIG2 was necessary for the expression of stem cell markers, and that its knockdown reduced cellular migration in hypoxia vs normoxia in GSCs. This suggests a critical role for OLIG2 in both hypoxia-induced stemness and homing behavior. We also generated a unique model of localized hypoxia in one brain hemisphere through vaso-cclusion and observed the homing of xenografted GBM cells towards hypoxia, regulated by OLIG2 in vivo. These data shed light on how hypoxic tumor microenvironments facilitate mechanisms vital to GBM progression and therapeutic resistance. Citation Format: Nitya V. Sharma, Monica Chau, Subhas Mukherjee, James Ross, Brandon Miller, Changming Zhang, Jun Kong, Carol Tucker-Burden, Emily Kaissi, John W. Reitnauer, Bilge Dundar, Cheryl L. Olson, Gregory Bix, Daniel J. Brat. Hypoxic microenvironments promote stemness and enhance the directed migration of glioma stem cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1153.

Containment strategies for outbreaks of invasive Neisseria meningitidis disease are informed by serogroup assays that characterize the polysaccharide capsule. We sought to uncover the genomic basis of conflicting serogroup assay results for an isolate (M16917) from a patient with acute meningococcal disease. To this end, we characterized the complete genome sequence of the M16917 isolate and performed a variety of comparative sequence analyses against N. meningitidis reference genome sequences of known serogroups. Multilocus sequence typing and whole-genome sequence comparison revealed that M16917 is a member of the ST-11 sequence group, which is most often associated with serogroup C. However, sequence similarity comparisons and phylogenetic analysis showed that the serogroup diagnostic capsule polymerase gene ( synD ) of M16917 belongs to serogroup B. These results suggest that a capsule-switching event occurred based on homologous recombination at or around the capsule locus of M16917. Detailed analysis of this locus uncovered the locations of recombination breakpoints in the M16917 genome sequence, which led to the introduction of an ∼2-kb serogroup B sequence cassette into the serogroup C genomic background. Since there is no currently available vaccine for serogroup B strains of N. meningitidis , this kind capsule-switching event could have public health relevance as a vaccine escape mutant.

Background: Patients with locally advanced or recurrent prostate cancer typically undergo androgen deprivation therapy (ADT), but the benefits are often short-lived and the responses variable. ADT failure results in castration-resistant prostate cancer (CRPC), which inevitably leads to metastasis. We hypothesized that differences in tumor transcriptional programs may reflect differential responses to ADT and subsequent metastasis. Results: We performed whole transcriptome analysis of 20 patient-matched Pre-ADT biopsies and 20 Post-ADT prostatectomy specimens, and identified two subgroups of patients (high impact and low impact groups) that exhibited distinct transcriptional changes in response to ADT. We found that all patients lost the AR-dependent subtype (PCS2) transcriptional signatures. The high impact group maintained the more aggressive subtype (PCS1) signal, while the low impact group more resembled an AR-suppressed (PCS3) subtype. Computational analyses identified transcription factor coordinated groups (TFCGs) enriched in the high impact group network. Leveraging a large public dataset of over 800 metastatic and primary samples, we identified 33 TFCGs in common between the high impact group and metastatic lesions, including SOX4/FOXA2/GATA4, and a TFCG containing JUN, JUNB, JUND, FOS, FOSB, and FOSL1. The majority of metastatic TFCGs were subsets of larger TFCGs in the high impact group network, suggesting a refinement of critical TFCGs in prostate cancer progression. Conclusions: We have identified TFCGs associated with pronounced initial transcriptional response to ADT, aggressive signatures, and metastasis. Our findings suggest multiple new hypotheses that could lead to novel combination therapies to prevent the development of CRPC following ADT.

Patients with recurrent, aggressive prostate cancer typically undergo androgen-deprivation therapy (ADT), but the benefits are often short-lived, and responses are variable. Failure to respond to ADT invariably leads to metastatic disease, and ultimately death. To investigate differential responses to ADT, we performed whole-transcriptome analysis of 20 patient-matched pre-ADT biopsies and post-ADT prostatectomy specimens, and observed that all patients lost transcriptional signatures indicative of the androgen receptor (AR)-dependent subtype, after treatment. We also identified two subgroups of patients with either a strong or weak transcriptional response to ADT. The strong responders maintained the more aggressive subtype signal, while the weak responders lost expression of these genes and more resembled an AR-suppressed, basal subtype. We generated a strong responder transcriptional network using the PANDA program and integrated expression data from our cohort, protein-protein interaction, and DNA binding motif data. We also leveraged the expression data from a large public dataset of over 800 metastatic and primary samples to construct a metastatic lesion transcriptional network. We identified 20 common transcription factor coordinated groups (TFCGs) associated with both the strong responders and metastatic lesions, including GLI3/GLI2, SOX4/FOXA2/GATA4, ERF/ETV5/ETV3/ELF4, and a TFCG containing JUN, JUNB, JUND, FOS, FOSB, and FOSL1. Many TFCGs in the metastatic network were subsets of larger groups in the strong responders network, implicating these transcription factor associations as potentially critical for both the differential ADT response and metastatic disease progression. Citation Format: Nitya V. Sharma, Kathryn L. Pellegrini, Veronique Ouellet, Felipe O. Giuste, Selvi Ramalingam, Kenneth Watanabe, Eloise Adam-Granger, Lucresse Fossouo, Sungyong You, Michael R. Freeman, Paula Vertino, Karen Conneely, Adeboye O. Osunkoya, Dominique Trudel, Anne-Marie Mes-Masson, John A. Petros, Fred Saad, Carlos S. Moreno. Transcription factor relationships associated with androgen-deprivation therapy response and metastatic progression in prostate cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 2269.

Prostate cancer is the most commonly diagnosed malignancy and the second leading cause of cancer death among men in the United States, with an estimated 220,800 new cases and 27,540 deaths in 2015. Epidemiological studies have shown that dietary compounds have significant effects on prostate carcinogenesis. Among dietary agents, genistein, the major isoflavone in soybean, is of particular interest because high consumption of soy products has been associated with a low incidence of prostate cancer, suggesting a preventive role of genistein in prostate cancer. In spite of numerous studies to understand the effects of genistein on prostate cancer, the mechanisms of action have not been fully elucidated. Here, we investigated the differences in methylation and gene expression levels of prostate specimens from a clinical trial of genistein supplementation prior to prostatectomy (Lazarevic B, et al. Nutr Cancer 2011). This study was a randomized, placebo-controlled, double-blind clinical trial on forty-seven Norwegian patients who received 30 mg genistein or placebo capsules daily for 3-6 weeks before prostatectomy. Whole genome methylation and expression profiling identified significantly differentially methylated sites and expressed sites between placebo and genistein groups. Differentially regulated genes were involved in developmental processes, stem cell markers, proliferation, and transcriptional regulation. These findings highlight the effects of genistein on global changes in DNA methylation and gene expression in prostate cancer, and provide additional insight into the multiple molecular pathways involved in prostate tumorigenesis. Citation Format: Birdal Bilir, Jeongseok Edward Lee, Nitya V. Sharma, Bato Lazarevic, Aud Svindland, Omer Kucuk, Carlos S. Moreno. Effects of genistein supplementation on genome-wide DNA methylation and gene expression in patients with localized prostate cancer. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Sep 24-27, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2016;76(2 Suppl):Abstract nr A46.

Prostate cancer remains the most commonly diagnosed cancer in U.S. males, and ranks second in mortality with over 28,000 deaths per year. Prostate cancer mortality is typically due to metastases, necessitating the understanding of how metastatic disease develops. One major step for cancer cells to metastasize and acquire migratory and invasive capabilities is the epithelial to mesenchymal transition (EMT). EMT encompasses vast molecular changes in gene expression, mediated by aberrant developmental signaling pathway activation, leading to the loss of cell-cell junctions and planar and apical-basal polarity, increased motility, and resistance to apoptosis and anoikis (cell death due to the detachment from the extracellular matrix). The sex determining region Y-box 4 (SOX4) gene is a developmental transcription factor that is over expressed in prostate cancer and plays a critical role in many developmental pathways inappropriately activated during EMT, such as the transforming growth factor (TGF-beta) and epidermal growth factor receptor (EGFR) signaling pathways. Our data suggest that concomitant treatment of TGF-beta and EGF induces SOX4, and initiates the EMT program in prostate epithelial cell lines. We also demonstrate that SOX4 over expression is sufficient to induce EMT in prostate epithelial cell lines. Currently, the molecular mechanisms that govern how SOX4 initiates EMT via transcriptional activation of target genes are poorly understood. We identified candidate SOX4 targets using the Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNE) on 9755 Pan Cancer samples from The Cancer Genome Atlas (TCGA). Gene ontology analysis of the top 1000 candidate SOX4 targets revealed genes that were enriched for epigenetic processes such as chromatin modification and DNA methylation. One putative target gene, PCAF, is a subunit of a large histone acetyltransferase (HAT) complex. Interestingly, our preliminary data also suggest that SOX4 interacts not only with PCAF, but also with TRRAP, another subunit of the PCAF HAT complex. These data suggest that SOX4 may induce and recruit the PCAF/TRRAP HAT complex in order to transcriptionally activate downstream targets to initiate the EMT program. Citation Format: Nitya V. Sharma, Soma Sannigrahi, YuHeng Lai, Carlos Moreno. The role of SOX4 in epithelial to mesenchymal transition in prostate cancer. [abstract]. In: Proceedings of the AACR Special Conference on Chromatin and Epigenetics in Cancer; Sep 24-27, 2015; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2016;76(2 Suppl):Abstract nr A21.

Neisseria meningitidis is one of the main agents of bacterial meningitis, causing substantial morbidity and mortality worldwide. However, most of the time N. meningitidis is carried as a commensal not associated with invasive disease. The genomic basis of the difference between disease-associated and carried isolates of N. meningitidis may provide critical insight into mechanisms of virulence, yet it has remained elusive. Here, we have taken a comparative genomics approach to interrogate the difference between disease-associated and carried isolates of N. meningitidis at the level of individual nucleotide variations (i.e., single nucleotide polymorphisms [SNPs]). We aligned complete genome sequences of 8 disease-associated and 4 carried isolates of N. meningitidis to search for SNPs that show mutually exclusive patterns of variation between the two groups. We found 63 SNPs that distinguish the 8 disease-associated genomes from the 4 carried genomes of N. meningitidis , which is far more than can be expected by chance alone given the level of nucleotide variation among the genomes. The putative list of SNPs that discriminate between disease-associated and carriage genomes may be expected to change with increased sampling or changes in the identities of the isolates being compared. Nevertheless, we show that these discriminating SNPs are more likely to reflect phenotypic differences than shared evolutionary history. Discriminating SNPs were mapped to genes, and the functions of the genes were evaluated for possible connections to virulence mechanisms. A number of overrepresented functional categories related to virulence were uncovered among SNP-associated genes, including genes related to the category “symbiosis, encompassing mutualism through parasitism.”