Identification of new molecular markers has led to the molecular classification of prostate cancer based on driving genetic lesions. The translation of these discoveries for clinical use necessitates the development of simple, reliable and rapid detection systems to screen patients for specific molecular aberrations. We developed two dual color immunohistochemistry-based assays for the simultaneous assessment of ERG-PTEN and ERG-SPINK1 in prostate cancer. A total of 232 cases from 184 localized and 48 metastatic prostate cancers were evaluated for ERG-PTEN and 284 cases from 228 localized and 56 metastatic prostate cancers were evaluated for ERG-SPINK1. Of the 232 cases evaluated for ERG-PTEN, 81 (35%) ERG positive and 77 (33%) PTEN deleted cases were identified. Of the 81 ERG positive cases, PTEN loss was confirmed in 35 (15%) cases by fluorescence in situ hybridization. PTEN status was concordant in 203 cases (Sensitivity 90%; Specificity 87% (p<0.0001) by both immunohistochemisty and FISH, however, immunohistochemisty could not distinguish between heterozygous and homozygous deletion status of PTEN. Of the 284 cases evaluated for ERG-SPINK1, 111 (39%) cases were positive for ERG. In the remaining 173 ERG negative cases; SPINK1 was positive in 26 (9 %) cases. SPINK1 expression was found to be mutually exclusive with ERG expression; however, we identified two cases, of which, one showed concomitant expression of ERG and SPINK1 in the same tumor foci and in the second case ERG and SPINK1 was seen in two independent foci of the same tumor nodule. Unlike the homogenous ERG staining in cancer tissues, heterogeneous SPINK1 staining was observed in the majority of the cases. Further studies are required to understand the molecular heterogeneity of cases with concomitant ERG-SPINK1 expression. Automated dual ERG-PTEN and ERG-SPINK1 immunohistochemisty assays are simple, reliable and portable across study sites for the simultaneous assessment of these proteins in prostate cancer.
Prostate cancers; Immunohistochemistry; Fluorescent in situ hybridization; Tissue Microarray
TFE3 translocation renal cell carcinoma (tRCC) is defined by chromosomal translocations involving the TFE3 transcription factor at chromosome Xp11.2. Genetically proven TFE3 tRCCs have a broad histologic spectrum with overlapping features to other renal tumor subtypes. In this study, we aimed for characterizing RCC with TFE3 protein expression. Using next-generation whole transcriptome sequencing (RNA-Seq) as a discovery tool, we analyzed fusion transcripts, gene expression profile, and somatic mutations in frozen tissue of one TFE3 tRCC. By applying a computational analysis developed to call chimeric RNA molecules from paired-end RNA-Seq data, we confirmed the known TFE3 translocation. Its fusion partner SFPQ has already been described as fusion partner in tRCCs. In addition, an RNA read-through chimera between TMED6 and COG8 as well as MET and KDR (VEGFR2) point mutations were identified. An EGFR mutation, but no chromosomal rearrangements, was identified in a control group of five clear cell RCCs (ccRCCs). The TFE3 tRCC could be clearly distinguished from the ccRCCs by RNA-Seq gene expression measurements using a previously reported tRCC gene signature. In validation experiments using reverse transcription-PCR, TMED6-COG8 chimera expression was significantly higher in nine TFE3 translocated and six TFE3-expressing/non-translocated RCCs than in 24 ccRCCs (P < .001) and 22 papillary RCCs (P < .05–.07). Immunohistochemical analysis of selected genes from the tRCC gene signature showed significantly higher eukaryotic translation elongation factor 1 alpha 2 (EEF1A2) and Contactin 3 (CNTN3) expression in 16 TFE3 translocated and six TFE3-expressing/non-translocated RCCs than in over 200 ccRCCs (P < .0001, both).
Since the introduction of serum prostate specific antigen (PSA) screening twenty-five years ago, prostate cancer diagnosis and management have been guided by this biomarker. Yet, PSA has proven controversial as a diagnostic assay due to its limitations. The next wave of prostate cancer biomarkers has emerged, introducing new assays in serum and urine that may supplement or, in time, replace PSA due to higher cancer specificity. This expanding universe of biomarkers has been facilitated, in large part, by new genomic technologies that have enabled an unbiased look at cancer biology. Such efforts have produced several notable success stories, moving biomarkers from the bench to the clinic rapidly. However, biomarker research has centered on disease diagnostics, rather than prognosis and prediction, which could work toward disease prevention—an important focus moving forward. We review the current state of prostate cancer biomarker research, including the PSA revolution, its impact on early prostate cancer detection, the recent advances in biomarker discovery, and the future efforts that promise to improve clinical management of this disease.
The three-dimensional (3D) conformation of the genome is known to be structured and to affect gene transcription, but how chromatin conformation changes in diseases such as cancer is poorly understood. Similarly, oncogenic transcription factors bind to thousands of sites in the genome without a clear transcriptional role on nearby genes. Could these factors play a non-transcriptional role in promoting tumor progression by restructuring the shape of the genome? To address this question, we recently performed unbiased high-resolution mapping of intra- and inter-chromosome interactions upon overexpression of ERG, an oncogenic transcription factor frequently overexpressed in prostate cancer as a result of a gene fusion. By integrating data from genome-wide chromosome conformation capture (Hi-C), ERG binding and gene expression, we have demonstrated that oncogenic transcription factor overexpression is associated with global, reproducible and functionally coherent changes in chromatin organization. Perhaps more importantly, we have identified novel genomic alterations associated with ERG overexpression. These results suggest a yet unappreciated role for transcription factors in promoting genomic alterations through their effect on chromatin architecture.
ERG; chromatin topology; prostate cancer; oncogenic transcription factor; translocation
Spindle cell rhabdomyosarcoma (RMS) is a rare form of RMS with different clinical characteristics and behavior between children and adult patients. Its genetic hallmark remains unknown and it remains debatable if there is pathogenetic relationship between the spindle cell and the so-called sclerosing RMS. We studied two pediatric and one adult spindle cell RMS by next generation RNA sequencing and used FusionSeq for data analysis to detect novel fusions. An SRF-NCOA2 gene fusion was detected in a spindle cell RMS from the posterior neck in a 7 month-old child. The fusion matched the tumor karyotype and was further confirmed by fluorescence in situ hybridization (FISH) and by RT-PCR, which showed fusion of SRF exon 6 to NCOA2 exon 12. Additional 14 spindle cell (from 8 children and 6 adults) and 4 sclerosing (from 2 children and 2 adults) RMS were tested by FISH for the presence of abnormalities in NCOA2, SRF, as well as for PAX3 and NCOA1, identifying NCOA2 rearrangements in two additional spindle cell RMS from a 3 month-old and a 4 week-old child, both arising in the chest wall. In the latter tumor, TEAD1 was identified by rapid amplification of cDNA ends (RACE) to be the NCOA2 gene fusion partner. None of the adult tumors were positive for NCOA2 rearrangement. Despite similar histomorphology in adults and young children, these results suggest that spindle cell RMS is a heterogeneous disease genetically as well as clinically. Our findings also support a relationship between NCOA2-rearranged spindle cell RMS occurring in young childhood and the so-called congenital RMS, which often displays rearrangements at 8q13 locus (NCOA2).
rhabdomyosarcoma; spindle cell; NCOA2; SRF; TEAD1; translocation; infantile
More than 1,300,000 prostate needle biopsies are performed annually in the U.S. with up to 16% incidence of isolated high-grade prostatic intraepithelial neoplasia (HGPIN). HGPIN has low predictive value for identifying prostate cancer (PCA) on subsequent needle biopsies in PSA screened populations. In contemporary series, PCA is detected in about 20% of repeat biopsies following a diagnosis of HGPIN. Further, discrete histological subtypes of HGPIN with clinical implication in management have not been characterized. The TMPRSS2-ERG gene fusion that has recently been described in PCA has also been demonstrated to occur in a subset of HGPIN. This may have significant clinical implications given that TMPRSS2-ERG fusion PCA is associated with a more aggressive clinical course.
In this study we assessed a series of HGPIN lesions and paired PCA for the presence of TMPRSS2-ERG gene fusion.
Fusion positive HGPIN was observed in 16% of the 143 number of lesions, and in all instances the matching cancer shared the same fusion pattern. 60% of TMPRSS2-ERG fusion PCA had fusion negative HGPIN.
Given the more aggressive nature of TMPRSS2-ERG PCA, the findings of this study raise the possibility that gene fusion positive HGPIN lesions are harbingers of more aggressive disease. To date, pathological, molecular and clinical parameters do not help stratify which men with HGPIN are at increased risk for a cancer diagnosis. Our results suggest that the detection of isolated TMPRSS2-ERG fusion HGPIN would improve the positive predictive value of finding TMPRSS2-ERG fusion PCA in subsequent biopsies.
Fusion of the TMPRSS2 prostate-specific gene with the ERG transcription factor is a putatively oncogenic gene rearrangement that is commonly found in prostate cancer tissue from men undergoing prostatectomy. However, the prevalence of the fusion was less common in TURP samples from a Swedish cohort of incidental prostate cancer patients followed by watchful waiting, raising the question as to whether the high prevalence in prostatectomy specimens reflects selection bias. We sought to determine the prevalence of TMPRSS2-ERG gene fusion among PSA-screened men undergoing prostate biopsy in the United States.
We studied 140 prostate biopsies from the same number of patients for TMPRSS2-ERG fusion status with a FISH assay. 134 (100 cancer and 34 benign) were assessable.
ERG gene rearrangement was detected in 46% prostate biopsies that were found to have prostate cancer and in 0% of benign prostate biopsies (p<0.0001). Evaluation of morphological features showed that cribriform growth, blue-tinged mucin, macronucleoli and collagenous micronodules were significantly more frequent in TMPRSS2-ERG fusion positive prostate cancer biopsies than gene fusion negative prostate cancer biopsies (p≤0.04). No significant association with Gleason score was detected. In addition, non-Caucasian patients were less likely to have positive fusion status (p=0.02).
This is the first prospective North American multi-center study to characterize the TMPRSS2-ERG prostate cancer prevalence in a cohort of patients undergoing needle biopsy irrespective of whether or not they subsequently undergo prostatectomy. Our results show that this gene rearrangement is common among North American men who have prostate cancer on biopsy, is absent in benign prostate biopsy, and is associated with specific morphological features. These findings indicate a need for prospective studies to evaluate the relationship of TMPRSS2-ERG rearrangement with clinical course of screening-detected prostate cancer in North American men, and development of non-invasive screening tests to detect TMPRSS2-ERG rearrangement.
The use of 2-way audiovisual telemedicine technology for the delivery of acute stroke care is well established in the literature and is a growing practice. The use of such technology for neurologic consultation outside the cerebrovascular specialty has been reported to a variable extent across most disciplines within the field of neurology, including that of the neurohospitalist medicine. A systematic review of these reports is lacking. Hence, the main purpose of this study was to conduct a systematic review of the literature on teleneurologic consultation in hospital neurology. The databases Ovid MEDLINE, EMBASE, PsychINFO, CINAHL, and Cochrane were used as data sources and were searched with key words “teleneurology” and its numerous synonyms and cognates. These key words were cross-referenced with subspecialties of neurology. The studies were included for further review only if the title or the abstract indicated that the study made use of 2-way audiovisual communication to address a neurologic indication. This search yielded 6625 abstracts. By consensus between the 2 investigators, 688 publications met the criteria for inclusion and further review. Four of those citations directly pertained to the inpatient hospital neurologic consultation. Each of the 4 relevant articles was scored with a novel rubric scoring functionality, application, technology, and evaluation phase. A subspecialty category score was calculated by averaging those scores. The use of 2-way audiovisual technology for general neurologic consultation of hospital inpatients, beyond stroke-related care, is promising, but the evidence supporting its routine use is weak. Further studies on reliability, validity, safety, efficacy, and cost-effectiveness are encouraged.
neurohospitalist; clinical specialty; quality; techniques; safety; techniques; teleneurology; remote consultation
Castrate resistant prostate cancer (CRPC) and neuroendocrine carcinoma of the prostate are invariably fatal diseases for which only palliative therapies exist. As part of a prostate tumour sequencing program, a patient tumour was analyzed using Illumina genome sequencing and a matched renal capsule tumour xenograft was generated. Both tumour and xenograft had a homozygous 9p21 deletion spanning the MTAP, CDKN2 and ARF genes. It is rare for this deletion to occur in primary prostate tumours yet approximately 10% express decreased levels of MTAP mRNA. Decreased MTAP expression is a prognosticator for poor outcome. Moreover, it appears that this deletion is more common in CRPC than in primary prostate cancer. We show for the first time that treatment with methylthioadenosine and high dose 6-thioguanine causes marked inhibition of a patient derived neuroendocrine xenograft growth while protecting the host from 6-thioguanine toxicity. This therapeutic approach can be applied to other MTAP-deficient human cancers since deletion or hypermethylation of the MTAP gene occurs in a broad spectrum of tumours at high frequency. The combination of genome sequencing and patient-derived xenografts can identify candidate therapeutic agents and evaluate them for personalized oncology.
massively parallel sequencing; MTAP; patient-derived xenograft; genitourinary cancers: prostate; animal models of cancer; gene expression profiling; functional genomics; xenograft models
The current paradigm of cancer care relies on predictive nomograms which integrate detailed histopathology with clinical data. However, when predictions fail, the consequences for patients are often catastrophic, especially in prostate cancer where nomograms influence the decision to therapeutically intervene. We hypothesized that the high dimensional data afforded by massively parallel sequencing (MPS) is not only capable of providing biological insights, but may aid molecular pathology of prostate tumours. We assembled a cohort of six patients with high-risk disease, and performed deep RNA and shallow DNA sequencing in primary tumours and matched metastases where available. Our analysis identified copy number abnormalities, accurately profiled gene expression levels, and detected both differential splicing and expressed fusion genes. We revealed occult and potentially dormant metastases, unambiguously supporting the patients’ clinical history, and implicated the REST transcriptional complex in the development of neuroendocrine prostate cancer, validating this finding in a large independent cohort. We massively expand on the number of novel fusion genes described in prostate cancer; provide fresh evidence for the growing link between fusion gene aetiology and gene expression profiles; and show the utility of fusion genes for molecular pathology. Finally, we identified chromothripsis in a patient with chronic prostatitis. Our results provide a strong foundation for further development of MPS-based molecular pathology.
molecular pathology; massively parallel sequencing; neuroendocrine prostate cancer; REST repressor; chromothripsis
Limited survival benefit and excess treatment due to PSA screening in randomized trials suggests a need for more restricted selection of prostate biopsy candidates by discerning risk of histologically-aggressive versus indolent cancer before biopsy.
Subjects undergoing first prostate biopsy enrolled in a multi-center, prospective cohort of the NCI Early Detection Research Network (EDRN; N=635) were analyzed to develop a model for predicting histologically- aggressive prostate cancers. The control arm of the Prostate Cancer Prevention Trial (PCPT; N=3833) was used to validate the generalization of the predictive model.
The EDRN cohort was comprised of men among whom 57% had no cancer, 14% had indolent cancer and 29% had aggressive cancer. Age, body mass index, family history of prostate cancer, abnormal digital rectal exam (DRE) and prostate specific antigen density (PSAD) were associated with aggressive cancer (all P<0.001). The EDRN model outperformed PSA alone in predicting aggressive cancer (AUC=0.81 vs. 0.71, P<0.01). Model validation in the PCPT cohort accurately identified men at low (<10%) risk of aggressive cancer for whom biopsy could be averted (AUC=0.78; 95% CI .75–.80). Under criteria from the EDRN model, prostate biopsy can be restricted to men with PSAD > 0.1ng/ml/cc or abnormal DRE. When PSAD < 0.1ng/ml/cc, family history or obesity can identify biopsy candidates.
A predictive model incorporating age, family history, obesity, PSAD and DRE elucidates criteria whereby one-quarter of prostate biopsies can be averted while retaining high sensitivity in detecting aggressive prostate cancer.
prostate cancer; biopsy; clinically-significant; indolent
Although prostate cancer (PCa) is the second leading cause of cancer death among men worldwide, not all men diagnosed with PCa will die from the disease. A critical challenge, therefore, is to distinguish indolent PCa from more advanced forms to guide appropriate treatment decisions. We used Enhanced Reduced Representation Bisulfite Sequencing, a genome-wide high-coverage single-base resolution DNA methylation method to profile seven localized PCa samples, seven matched benign prostate tissues, and six aggressive castration-resistant prostate cancer (CRPC) samples. We integrated these data with RNA-seq and whole-genome DNA-seq data to comprehensively characterize the PCa methylome, detect changes associated with disease progression, and identify novel candidate prognostic biomarkers. Our analyses revealed the correlation of cytosine guanine dinucleotide island (CGI)-specific hypermethylation with disease severity and association of certain breakpoints (deletion, tandem duplications, and interchromosomal translocations) with DNA methylation. Furthermore, integrative analysis of methylation and single-nucleotide polymorphisms (SNPs) uncovered widespread allele-specific methylation (ASM) for the first time in PCa. We found that most DNA methylation changes occurred in the context of ASM, suggesting that variations in tumor epigenetic landscape of individuals are partly mediated by genetic differences, which may affect PCa disease progression. We further selected a panel of 13 CGIs demonstrating increased DNA methylation with disease progression and validated this panel in an independent cohort of 20 benign prostate tissues, 16 PCa, and 8 aggressive CRPCs. These results warrant clinical evaluation in larger cohorts to help distinguish indolent PCa from advanced disease.
Identification of specific somatic gene alterations is crucial for the insight into the development, progression, and clinical behavior of individual cancer types. The recently discovered recurrent ERG rearrangement in prostate cancer (PCa) might represent a PCa specific alteration that has not been systematically assessed in tumors other than PCa. Aim of this study was to assess, whether the ERG rearrangement and the distinct deletion site between TMPRSS2 and ERG, both predominantly resulting in a TMPRSS2-ERG fusion, occurs in tumors other than PCa.
We assessed 54 different tumor types (2942 samples in total) for their ERG rearrangement status by FISH. To calibrate, we analyzed 285 PCa samples for the ERG rearrangement frequency. Additionally, we interrogated a high-resolution SNP data set across 3131 cancer specimens (26 tumor types) for copy number alterations.
None of the 54 different tumor types assessed by FISH harbored an ERG rearrangement, whereas the PCa samples revealed an ERG rearrangement in 31.2%–49.5%, depending on the cohort. Furthermore, within the 26 tumor types assessed for copy number alterations by SNP, the distinct deletion site between TMPRSS2 and ERG (21q22.2-3) was detectable exclusively in PCa.
Although Ewing's sarcoma and AML have known rearrangements rarely involving ERG, we hypothesize that the ERG rearrangement as well as the distinct deletion site on 21q22.2-3 between TMPRSS2 and ERG, are PCa specific genomic alterations. These observations provide further insight into the oncogenesis of PCa and might be critical for the development of ERG rearrangement assessment as a clinical tool.
ERG rearrangement; prostate cancer; carcinoma
α-Methylacyl-CoA racemase (AMACR) is an enzyme that serves as a diagnostic biomarker of prostate cancer in clinical practice. Recent studies suggest that low AMACR expression is associated with biochemical recurrence and the development of fatal disease.
We conducted a prospective cohort study among 920 men aged 47–84 years, who were diagnosed with prostate cancer in the Physicians’ Health Study and the Health Professionals Follow-up Study cohorts, and whose resected tissue specimens were available for immunohistochemical analysis. We used Cox proportional hazards regression to evaluate the association of AMACR expression with lethal prostate cancer over a 20-year follow-up period.
In total, 68 men died from prostate cancer, and an additional 18 developed bony metastases during follow-up. We found that lower AMACR intensity was associated with higher prostate-specific antigen levels (p=0.003) and more advanced clinical stage (p=0.06) at diagnosis, and a non-significant trend for higher risk of lethal outcomes. The hazard ratio comparing the lowest to the highest quartile of AMACR expression intensity was 1.53 ((95% CI: 0.86, 2.73), p-for-trend across quartiles=0.07); this trend was further attenuated after adjustment for age, Gleason score, stage and cohort with a hazard ratio of 1.24 (95% CI 0.69, 2.22), p-for-trend=0.23.
Low AMACR expression in primary tumor specimens was not independently associated with the development of metastatic and lethal prostate cancer after treatment over a 20-year follow-up period, after adjustment for important clinical covariates at diagnosis.
Inherited Copy Number Variants (CNVs) can modulate the expression levels of individual genes. However, little is known about how CNVs alter biological pathways and how this varies across different populations. To trace potential evolutionary changes of well-described biological pathways, we jointly queried the genomes and the transcriptomes of a collection of individuals with Caucasian, Asian or Yoruban descent combining high-resolution array and sequencing data.
We implemented an enrichment analysis of pathways accounting for CNVs and genes sizes and detected significant enrichment not only in signal transduction and extracellular biological processes, but also in metabolism pathways. Upon the estimation of CNV population differentiation (CNVs with different polymorphism frequencies across populations), we evaluated that 22% of the pathways contain at least one gene that is proximal to a CNV (CNV-gene pair) that shows significant population differentiation. The majority of these CNV-gene pairs belong to signal transduction pathways and 6% of the CNV-gene pairs show statistical association between the copy number states and the transcript levels.
The analysis suggested possible examples of positive selection within individual populations including NF-kB, MAPK signaling pathways, and Alu/L1 retrotransposition factors. Altogether, our results suggest that constitutional CNVs may modulate subtle pathway changes through specific pathway enzymes, which may become fixed in some populations.
CNVs; Pathways; Pathway evolution; Population genetics; eQTL
Neuroendocrine prostate cancer (NEPC), also referred to as anaplastic prostate cancer, is a lethal tumor that most commonly arises in late stages of prostate adenocarcinoma (PCA) with predilection to metastasize to visceral organs. In the current study, we explore for evidence that Aurora kinase A (AURKA) and N-myc (MYCN) gene abnormalities are harbingers of treatment-related NEPC (t-NEPC). We studied primary prostate tissue from 15 hormone naïve PCAs, 51 castration-resistant prostate cancers, and 15 metastatic tumors from 72 patients at different stages of disease progression to t-NEPC, some with multiple specimens. Histologic evaluation, immunohistochemistry, and fluorescence in situ hybridization were performed and correlated with clinical variables. AURKA amplification was identified in overall 65% of PCAs (hormone naïve and treated) from patients that developed t-NEPC and in 86% of metastases. Concurrent amplification of MYCN was present in 70% of primary PCAs, 69% of treated PCAs, and 83% of metastases. In contrast, in an unselected PCA cohort, AURKA and MYCN amplifications were identified in only 5% of 169 cases. When metastatic t-NEPC was compared to primary PCA from the same patients, there was 100% concordance of ERG rearrangement, 100% concordance of AURKA amplification, and 60% concordance of MYCN amplification. In tumors with mixed features, there was also 100% concordance of ERG rearrangement and 94% concordance of AURKA and MYCN co-amplification between areas of NEPC and adenocarcinoma. AURKA and MYCN amplifications may be prognostic and predictive biomarkers, as they are harbingers of tumors at risk of progressing to t-NEPC after hormonal therapy.
We sought to develop a clinical algorithm combining serum PSA with detection of TMPRSS2:ERG fusion and PCA3 in urine collected after digital rectal exam (post-DRE urine) to predict prostate cancer on subsequent biopsy.
Materials and Methods
Post-DRE urine was collected in 48 consecutive patients before prostate biopsy at two centers; qRT-PCR was used to detect PCA3 and TMPRSS2:ERG fusion transcript expression. Serum PSA was measured by clinical assay. The performance of TMPRSS2:ERG fusion, PCA3, and serum PSA as biomarkers predicting prostate cancer at biopsy was measured; a clinically practical algorithm combining serum PSA with TMPRSS2:ERG and PCA3 in post-DRE urine to predict prostate cancer was developed.
Post-DRE urine sediment provided informative RNA in 45 patients; prostate cancer was present on subsequent biopsy in 15. TMPRSS2:ERG in post-DRE urine was associated with prostate cancer (OR = 12.02; p< 0.001). PCA3 had the highest sensitivity in predicting prostate cancer diagnosis (93%), whereas TMPRSS2:ERG had the highest specificity (87%). TMPRSS2:ERG had the greatest discriminatory value in predicting prostate cancer (AUC = 0.77 compared to 0.65 for PCA3 and 0.72 for serum PSA alone). Combining serum PSA, PCA3 and TMPRSS2:ERG in a multivariable algorithm optimized for clinical utility improved cancer prediction (AUC = 0.88; specificity = 90% at 80% sensitivity).
A clinical algorithm specifying biopsy for all patients with PSA ≥10ng/ml, while restricting biopsy among those with PSA <10ng/ml to only those with detectable PCA3 or TMPRSS2:ERG in post-DRE urine, performed better than the individual biomarkers alone in predicting prostate cancer.
Screening; DRE; Biomarkers; Cancer Detection; Gene Fusion
Background: The use of two-way audio-visual technology for delivery of acute stroke is supported by a well established literature base. The use of telemedicine for general neurologic consultation has been reported across most subspecialties within the field, but a comprehensive systematic review of these reports is lacking. Purpose: To conduct a systematic review of the published literature on teleneurologic consultation beyond stroke. Data sources: Databases Ovid MEDLINE, EMBASE, PsychINFO, CINAHL, and Cochrane were searched with keywords, “teleneurology,” and numerous synonyms and cross-referenced with neurology subspecialties. The search yielded 6,615 potentially eligible hits, which were independently reviewed by two investigators. Ultimately 375 unique studies met eligibility criteria and were included in the review. Study selection: Studies were included if the title or abstract expressed use of two-way AV communication for a clinical neurologic indication other than stroke. Data extraction: Each article was classified using a novel scoring rubric to assess the level of functionality, application, technology, and evaluative stage. Data analysis: Articles were hierarchized within a subspecialty category. Overall subspecialty scores were assigned based on aggregate of scores across papers in each category. Conclusion: Use of telemedicine for general and most subspecialty neurologic consultation, beyond stroke, appears very promising but the clinical science is nascent.
teleneurology; systematic review; telemedicine; neurology; telecommunications; remote consultation
Demethylation by the AlkB dioxygenases represents an important mechanism for repair of N-alkylated nucleotides. However, little is known about their functions in mammalian cells. We report the purification of the ALKBH3 complex and demonstrate its association with the Activating Signal Co-integrator Complex (ASCC). ALKBH3 is overexpressed in various cancers, and both ALKBH3 and ASCC are important for alkylation damage resistance in these tumor cell lines. ASCC3, the largest subunit of ASCC, encodes a 3′-5′ DNA helicase, whose activity is crucial for the generation of single-stranded DNA upon which ALKBH3 preferentially functions for dealkylation. In cell lines that are dependent on ALKBH3 and ASCC3 for alkylation damage resistance, loss of ALKBH3 or ASCC3 leads to increased 3-methylcytosine and reduced cell proliferation, which correlates with pH2A.X and 53BP1 foci formation. Our data provide a molecular mechanism by which ALKBH3 collaborates with ASCC to maintain genomic integrity in a cell type specific manner.
To test whether multiphoton microscopy (MPM) might allow identification of prostatic and periprostatic structures with magnification and resolution similar to gold standard histopathology.
Material and Methods
The present study included 95 robotic radical prostatectomy patients who consented to participate in an Institutional Review Board-approved study starting in 2007.
The types of specimens used for imaging were excised surgical margins and biopsies, and sections obtained from the excised prostate.
The specimens were imaged with a custom-built MPM system.
All images were compared with haematoxylin/eosin histopathology of the same specimen.
MPM of freshly excised, unprocessed and unstained tissue can identify all relevant prostatic and periprostatic structures, such as nerves, blood vessels, capsule, underlying acini and also pathological changes, including prostate cancer.
Histological confirmation and correlation of these structures and pathologies have validated the findings of MPM.
MPM shows great promise as a tool for real-time intra-surgical histopathology without needing excision or administration of contrast agents.
The results will, however, need to be confirmed in true surgical settings using a miniaturized MPM microendoscope.
robotic prostatectomy; multiphoton microscopy; prostate cancer; nerve sparing; histopathology; real-time imaging
Neuroendocrine prostate cancer (NEPC) is an aggressive subtype of prostate cancer that most commonly evolves from preexisting prostate adenocarcinoma (PCA). Using Next Generation RNA-sequencing and oligonucleotide arrays, we profiled 7 NEPC, 30 PCA, and 5 benign prostate tissue (BEN), and validated findings on tumors from a large cohort of patients (37 NEPC, 169 PCA, 22 BEN) using IHC and FISH. We discovered significant overexpression and gene amplification of AURKA and MYCN in 40% of NEPC and 5% of PCA, respectively, and evidence that that they cooperate to induce a neuroendocrine phenotype in prostate cells. There was dramatic and enhanced sensitivity of NEPC (and MYCN overexpressing PCA) to Aurora kinase inhibitor therapy both in vitro and in vivo, with complete suppression of neuroendocrine marker expression following treatment. We propose that alterations in Aurora kinase A and N-myc are involved in the development of NEPC, and future clinical trials will help determine from the efficacy of Aurora kinase inhibitor therapy.
neuroendocrine prostate cancer; aurora kinase A; n-myc; drug targets
Transcriptional repressors and corepressors play a critical role in cellular homeostasis and are frequently altered in cancer. C-terminal binding protein 1 (CtBP1), a transcriptional corepressor that regulates the expression of tumor suppressors and genes involved in cell death, is known to play a role in multiple cancers. In this study, we observed the overexpression and mislocalization of CtBP1 in metastatic prostate cancer and demonstrated the functional significance of CtBP1 in prostate cancer progression. Transient and stable knockdown of CtBP1 in prostate cancer cells inhibited their proliferation and invasion. Expression profiling studies of prostate cancer cell lines revealed that multiple tumor suppressor genes are repressed by CtBP1. Furthermore, our studies indicate a role for CtBP1 in conferring radiation resistance to prostate cancer cell lines. In vivo studies using chicken chorioallantoic membrane assay, xenograft studies, and murine metastasis models suggested a role for CtBP1 in prostate tumor growth and metastasis. Taken together, our studies demonstrated that dysregulated expression of CtBP1 plays an important role in prostate cancer progression and may serve as a viable therapeutic target.
Prostate-specific antigen screening has led to enormous overtreatment of prostate cancer because of the inability to distinguish potentially lethal disease at diagnosis. We reasoned that by identifying an mRNA signature of Gleason grade, the best predictor of prognosis, we could improve prediction of lethal disease among men with moderate Gleason 7 tumors, the most common grade, and the most indeterminate in terms of prognosis.
Patients and Methods
Using the complementary DNA–mediated annealing, selection, extension, and ligation assay, we measured the mRNA expression of 6,100 genes in prostate tumor tissue in the Swedish Watchful Waiting cohort (n = 358) and Physicians' Health Study (PHS; n = 109). We developed an mRNA signature of Gleason grade comparing individuals with Gleason ≤ 6 to those with Gleason ≥ 8 tumors and applied the model among patients with Gleason 7 to discriminate lethal cases.
We built a 157-gene signature using the Swedish data that predicted Gleason with low misclassification (area under the curve [AUC] = 0.91); when this signature was tested in the PHS, the discriminatory ability remained high (AUC = 0.94). In men with Gleason 7 tumors, who were excluded from the model building, the signature significantly improved the prediction of lethal disease beyond knowing whether the Gleason score was 4 + 3 or 3 + 4 (P = .006).
Our expression signature and the genes identified may improve our understanding of the de-differentiation process of prostate tumors. Additionally, the signature may have clinical applications among men with Gleason 7, by further estimating their risk of lethal prostate cancer and thereby guiding therapy decisions to improve outcomes and reduce overtreatment.
Using an integrative genomics approach called Amplification Breakpoint Ranking and Assembly (ABRA) analysis, we nominated KRAS as a gene fusion with the ubiquitin-conjugating enzyme UBE2L3 in the DU145 cell line, originally derived from prostate cancer metastasis to the brain. Interestingly, analysis of tissues revealed that 2 of 62 metastatic prostate cancers harbored aberrations at the KRAS locus. In DU145 cells, UBE2L3-KRAS produces a fusion protein, specific knock-down of which, attenuates cell invasion and xenograft growth. Ectopic expression of the UBE2L3-KRAS fusion protein exhibits transforming activity in NIH 3T3 fibroblasts and RWPE prostate epithelial cells in vitro and in vivo. In NIH 3T3 cells, UBE2L3-KRAS attenuates MEK/ERK signaling, commonly engaged by oncogenic mutant KRAS, and instead signals via AKT and p38 MAPK pathways. This is the first report of a gene fusion involving Ras family suggesting that this aberration may drive metastatic progression in a rare subset of prostate cancers.
KRAS; gene fusion; prostate cancer; genomic amplification; bioinformatics
Prostate cancer is a clinically and molecularly heterogeneous disease. Understanding the biologic underpinning of prostate cancer is necessary to best determine how biology is associated with the risk of disease progression and how this understanding might provide insight into the development of novel therapeutic approaches. The focus of this review is on the recently identified common ETS and non-ETS gene rearrangements in prostate cancer. Although multiple molecular alterations have been detected in prostate cancer, a basic understanding of gene fusion prostate cancer should help explain the clinical and biologic diversity, providing a rationale for a molecular subclassification of the disease.
ETS; gene fusion; next generation sequencing; prostate cancer; TMPRSS2:ERG; translocation