Selenocysteine tRNA methylation promotes oxidative stress resistance in melanoma metastasis.

Selenocysteine-containing proteins play a central role in redox homeostasis. Their translation is a highly regulated process and is dependent on two tRNASec isodecoders differing by a single 2'-O-ribose methylation called Um34. Here we characterized FTSJ1 as the Um34 methyltransferase and show that its activity is required for efficient selenocysteine insertion at the UGA stop codon during translation. Specifically, loss of Um34 leads to ribosomal stalling and decreased UGA recoding. FTSJ1-deficient cells are more sensitive to oxidative stress and show decreased metastatic colonization in xenograft models of melanoma metastasis. We found that FTSJ1 mediates efficient translation of selenoproteins essential for the cellular antioxidant response. Our findings uncover a role for tRNASec Um34 modification in oxidative stress resistance and highlight FTSJ1 as a potential therapeutic target specific for metastatic disease.

Defining the commonalities between post-transcriptional and post-translational modification communities.

Post-transcriptional modifications of RNA (PRMs) and post-translational modifications of proteins (PTMs) are important regulatory mechanisms in biological processes and have many commonalities. However, the integration of these research areas is lacking. A recent discussion identified the priorities, areas of emphasis, and necessary technologies to advance and integrate these areas of study.

Small-Molecule Ebselen Binds to YTHDF Proteins Interfering with the Recognition of N 6-Methyladenosine-Modified RNAs.

YTHDF proteins bind the N 6-methyladenosine (m6A)-modified mRNAs, influencing their processing, stability, and translation. Therefore, the members of this protein family play crucial roles in gene regulation and several physiological and pathophysiological conditions. YTHDF proteins contain a hydrophobic pocket that accommodates the m6A embedded in the RRACH consensus sequence on mRNAs. We exploited the presence of this cage to set up an m6A-competitive assay and performed a high-throughput screen aimed at identifying ligands binding in the m6A pocket. We report the organoselenium compound ebselen as the first-in-class inhibitor of the YTHDF m6A-binding domain. Ebselen, whose interaction with YTHDF proteins was validated via orthogonal assays, cannot discriminate between the binding domains of the three YTHDF paralogs but can disrupt the interaction of the YTHDF m6A domain with the m6A-decorated mRNA targets. X-ray, mass spectrometry, and NMR studies indicate that in YTHDF1 ebselen binds close to the m6A cage, covalently to the Cys412 cysteine, or interacts reversibly depending on the reducing environment. We also showed that ebselen engages YTHDF proteins within cells, interfering with their mRNA binding. Finally, we produced a series of ebselen structural analogs that can interact with the YTHDF m6A domain, proving that ebselen expansion is amenable for developing new inhibitors. Our work demonstrates the feasibility of drugging the YTH domain in YTHDF proteins and opens new avenues for the development of disruptors of m6A recognition.

Hidden codes in mRNA: Control of gene expression by m6A.

Information in mRNA has largely been thought to be confined to its nucleotide sequence. However, the advent of mapping techniques to detect modified nucleotides has revealed that mRNA contains additional information in the form of chemical modifications. The most abundant modified nucleotide is N6-methyladenosine (m6A), a methyl modification of adenosine. Although early studies viewed m6A as a dynamic and tissue-specific modification, it is now clear that the mRNAs that contain m6A and the location of m6A in those transcripts are largely universal and are influenced by gene architecture, i.e., the size and location of exons and introns. m6A can affect nuclear processes such as splicing and epigenetic regulation, but the major effect of m6A on mRNAs is to promote degradation in the cytoplasm. m6A marks a functionally related cohort of mRNAs linked to certain biological processes, including cell differentiation and cell fate determination. m6A is also enriched in other cohorts of mRNAs and can therefore affect their respective cellular processes and pathways. Future work will focus on understanding how the m6A pathway is regulated to achieve control of m6A-containing mRNAs.

Characterization of basal and estrogen-regulated antisense transcription in breast cancer cells: Role in regulating sense transcription.

Estrogen-responsive breast cancer cells exhibit both basal and estrogen-regulated transcriptional programs, which lead to the transcription of many different transcription units (i.e., genes), including those that produce coding and non-coding sense (e.g., mRNA, lncRNA) and antisense (i.e., asRNA) transcripts. We have previously characterized the global basal and estrogen-regulated transcriptomes in estrogen receptor alpha (ERα)-positive MCF-7 breast cancer cells. Herein, we have mined genomic data to define three classes of antisense transcription in MCF-7 cells based on where their antisense transcription termination sites reside relative to their cognate sense mRNA and lncRNA genes. These three classes differ in their response to estrogen treatment, the enrichment of a number of genomic features associated with active promoters (H3K4me3, RNA polymerase II, open chromatin architecture), and the biological functions of their cognate sense genes as analyzed by DAVID gene ontology. We further characterized two estrogen-regulated antisense transcripts arising from the MYC gene in MCF-7 cells, showing that these antisense transcripts are 5'-capped, 3'-polyadenylated, and localized to different compartments of the cell. Together, our analyses have revealed distinct classes of antisense transcription correlated to different biological processes and response to estrogen stimulation, uncovering another layer of hormone-regulated gene regulation.

Distinct Roles for BET Family Members in Estrogen Receptor α Enhancer Function and Gene Regulation in Breast Cancer Cells.

The bromodomain family member proteins (BRD; BET proteins) are key coregulators for estrogen receptor alpha (ERα)-mediated transcriptional enhancers. The use of BRD-selective inhibitors has gained much attention as a potential treatment for various solid tumors, including ER-positive breast cancers. However, the roles of individual BET family members have largely remained unexplored. Here, we describe the role of BRDs in estrogen (E2)-dependent gene expression in ERα-positive breast cancer cells. We observed that chemical inhibition of BET family proteins with JQ1 impairs E2-regulated gene expression and growth in breast cancer cells. In addition, RNAi-mediated depletion of each BET family member (BRDs 2, 3, and 4) revealed partially redundant roles at ERα enhancers and for target gene transcription. Furthermore, we found a unique role of BRD3 as a molecular sensor of total BET family protein levels and activity through compensatory control of its own protein levels. Finally, we observed that BRD3 is recruited to a subset of ERα-binding sites (ERBS) that are enriched for active enhancer features, located in clusters of ERBSs likely functioning as "super enhancers," and associated with highly E2-responsive genes. Collectively, our results illustrate a critical and specific role for BET family members in ERα-dependent gene transcription. IMPLICATIONS: BRD3 is recruited to and controls the activity of a subset ERα transcriptional enhancers, providing a therapeutic opportunity to target BRD3 with BET inhibitors in ERα-positive breast cancers.

Enhancer transcription reveals subtype-specific gene expression programs controlling breast cancer pathogenesis.

Noncoding transcription is a defining feature of active enhancers, linking transcription factor (TF) binding to the molecular mechanisms controlling gene expression. To determine the relationship between enhancer activity and biological outcomes in breast cancers, we profiled the transcriptomes (using GRO-seq and RNA-seq) and epigenomes (using ChIP-seq) of 11 different human breast cancer cell lines representing five major molecular subtypes of breast cancer, as well as two immortalized ("normal") human breast cell lines. In addition, we developed a robust and unbiased computational pipeline that simultaneously identifies putative subtype-specific enhancers and their cognate TFs by integrating the magnitude of enhancer transcription, TF mRNA expression levels, TF motif P-values, and enrichment of H3K4me1 and H3K27ac. When applied across the 13 different cell lines noted above, the Total Functional Score of Enhancer Elements (TFSEE) identified key breast cancer subtype-specific TFs that act at transcribed enhancers to dictate gene expression patterns determining growth outcomes, including Forkhead TFs, FOSL1, and PLAG1. FOSL1, a Fos family TF, (1) is highly enriched at the enhancers of triple negative breast cancer (TNBC) cells, (2) acts as a key regulator of the proliferation and viability of TNBC cells, but not Luminal A cells, and (3) is associated with a poor prognosis in TNBC breast cancer patients. Taken together, our results validate our enhancer identification pipeline and reveal that enhancers transcribed in breast cancer cells direct critical gene regulatory networks that promote pathogenesis.

Outcomes of patients older than 75 years with non-metastatic prostate cancer.

OBJECTIVE: Prostate cancer in elderly patients was formerly treated with androgen deprivation therapy. Since the latter of the 1990s new technologies were introduced into treatments, then strategies have varied. We aimed to observe the outcomes of elderly patients treated during transition period and compare each stage with others. METHODS: During 2008 and 2010, 255 patients with prostate cancer older than 75 years were sequentially treated. With exception of patients with bone and/or visceral metastasis, outcomes of 199 patients with localized and locally advanced stages were examined. Complete records were obtained by the end of 2015. RESULTS: In total, 122 (61%), 28 (14%), 37 (19%) and 12 (6%) of patients were in stages T1c-T2a, T2b-c, T3 and T4, respectively. Patients generally presented with abnormal screening or lower urinary tract symptom. Seventy-one percent of patients received androgen deprivation therapy as monotherapy and 22% of the radiation-treated patients added androgen deprivation therapy. Patients in stage T1c-T2a and T2b-c showed a favorable prognosis. Some cancer death appeared in patients with T3 and T4 during observation periods. Twenty-seven percent of patients died from prostate cancer-independent complications: pneumonia, heart disease, and brain vascular disease. Tendency is similar to that of Japanese elderly male population. No remarkable side effects from androgen deprivation therapy were noticed. CONCLUSION: Elderly patients with localized prostate cancer showed favorable prognosis by androgen deprivation therapy with/without radiation, thus efficacy of androgen deprivation therapy is suitable to elderly patients with applicable stages. Prognosis of patients with locally advanced stage is serious and remains to be improved.

Dynamic assembly and activation of estrogen receptor α enhancers through coregulator switching.

Although many features of active transcriptional enhancers have been defined by genomic assays, we lack a clear understanding of the order of events leading to enhancer formation and activation as well as the dynamics of coregulator interactions within the enhancer complex. Here, we used selective loss- or gain-of-function mutants of estrogen receptor α (ERα) to define two distinct phases of ligand-dependent enhancer formation. In the first phase (0-20 min), p300 is recruited to ERα by Mediator as well as p300's acetylhistone-binding bromodomain to promote initial enhancer formation, which is not competent for sustained activation. In the second phase (20-45 min), p300 is recruited to ERα by steroid receptor coregulators (SRCs) for enhancer maturation and maintenance. Successful transition between these two phases ("coregulator switching") is required for proper enhancer function. Failure to recruit p300 during either phase leads to abortive enhancer formation and a lack of target gene expression. Our results reveal an ordered and cooperative assembly of ERα enhancers requiring functional interplay among p300, Mediator, and SRCs, which has implications for hormone-dependent gene regulation in breast cancers. More broadly, our results demonstrate the unexpectedly dynamic nature of coregulator interactions within enhancer complexes, which are likely to be a defining feature of all enhancers.

Estrogen receptor coregulator binding modulators (ERXs) effectively target estrogen receptor positive human breast cancers.

The majority of human breast cancer is estrogen receptor alpha (ER) positive. While anti-estrogens/aromatase inhibitors are initially effective, resistance to these drugs commonly develops. Therapy-resistant tumors often retain ER signaling, via interaction with critical oncogenic coregulator proteins. To address these mechanisms of resistance, we have developed a novel ER coregulator binding modulator, ERX-11. ERX-11 interacts directly with ER and blocks the interaction between a subset of coregulators with both native and mutant forms of ER. ERX-11 effectively blocks ER-mediated oncogenic signaling and has potent anti-proliferative activity against therapy-sensitive and therapy-resistant human breast cancer cells. ERX-11 is orally bioavailable, with no overt signs of toxicity and potent activity in both murine xenograft and patient-derived breast tumor explant models. This first-in-class agent, with its novel mechanism of action of disrupting critical protein-protein interactions, overcomes the limitations of current therapies and may be clinically translatable for patients with therapy-sensitive and therapy-resistant breast cancers.

Treatment of locally advanced prostate cancer (Stage T3).

OBJECTIVE: Formerly, locally advanced prostate cancer exhibited poorly prognosis. In the late 1990s, new surgical and radiation technologies were introduced in combination with androgen deprivation. To evaluate respective strategies, outcomes were examined. PATIENTS AND METHODS: Between 2001 and 2010, 224 patients with T3N0M0 (10.9% of all prostate cancer cases) were treated with prostatectomy, external beam radiation therapy with/without androgen deprivation or hormone alone. Complete records were obtained by the end of 2015. RESULTS: Operation group first started without adjuvant treatment and prostate-specific antigen (PSA) relapse occurred in 39% of cases. Radiation therapy group was alternatively divided into two subgroups, that received either monotherapy or combination with androgen deprivation, and PSA relapse rates were 65 and 16%, respectively. High rates of PSA relapse in both the operation and radiation therapy groups were observed in patients without adjuvant therapy, but after relapse androgen deprivation proceeded favorable outcomes. In the radiation subgroups, PSA relapse rates were different, but both subsequent survival rates were the same. This may be due to the effect of androgen deprivation after relapse, indicating effect of delayed therapy. PSA relapse rate in the hormone therapy group was 25% and after relapse, patients applied to treatment with other hormonal and anticancer drugs. Overall survival rates were 91, 88 and 67% in the operation, radiation therapy and hormone therapy groups, respectively. CONCLUSION: Aggressive treatment with short-term androgen deprivation for locally advanced prostate cancer could be beneficial and not harmful when suitable candidates are selected. Delayed androgen deprivation was effective for no adjuvant patients after PSA relapse.

Computational Approaches for Mining GRO-Seq Data to Identify and Characterize Active Enhancers.

Transcriptional enhancers are DNA regulatory elements that are bound by transcription factors and act to positively regulate the expression of nearby or distally located target genes. Enhancers have many features that have been discovered using genomic analyses. Recent studies have shown that active enhancers recruit RNA polymerase II (Pol II) and are transcribed, producing enhancer RNAs (eRNAs). GRO-seq, a method for identifying the location and orientation of all actively transcribing RNA polymerases across the genome, is a powerful approach for monitoring nascent enhancer transcription. Furthermore, the unique pattern of enhancer transcription can be used to identify enhancers in the absence of any information about the underlying transcription factors. Here, we describe the computational approaches required to identify and analyze active enhancers using GRO-seq data, including data pre-processing, alignment, and transcript calling. In addition, we describe protocols and computational pipelines for mining GRO-seq data to identify active enhancers, as well as known transcription factor binding sites that are transcribed. Furthermore, we discuss approaches for integrating GRO-seq-based enhancer data with other genomic data, including target gene expression and function. Finally, we describe molecular biology assays that can be used to confirm and explore further the function of enhancers that have been identified using genomic assays. Together, these approaches should allow the user to identify and explore the features and biological functions of new cell type-specific enhancers.

Long-term outcomes of nonpalpable prostate cancer (T1c) patients treated with radical prostatectomy.

PURPOSE: Various strategies have been used to treat patients with nonpalpable prostate cancer (T1c). As one of the treatments for this stage, a radical prostatectomy was performed and the outcomes were evaluated. METHODS: Between 1993 and 2002, 117 patients with T1c received a radical prostatectomy and their follow-up were examined by the end of 2013. Patients were classified according to risk groups using prostate-specific antigen (PSA) and Gleasson score, and outcomes of respective groups were compared. RESULTS: Approximately 60% of patients were in low risk group, and the remaining patients were grouped into the intermediate or high risks in half. In 22% insignificant cancer was detected. Biochemical failure occurred in 14%. One patient exhibited bone metastasis, but no deaths from prostate cancer ware observed. The five and ten year overall survival rates were 92% and 75%, respectively, and the biochemical failure-free survival rates were 92% and 89%, respectively. No different outcomes were observed for the different risk groups in the overall and biochemical failure-free survival rates. T1c tumors contain a certain range of various stages of tumors, but most patients experienced favorable outcomes. CONCLUSION: Radical prostatectomy as monotherapy is one of the treatment option for T1c prostate cancer patients, who have a long life span and belong to intermediate or high risk groups.

Management of men with a suspicion of prostate cancer after negative initial prostate biopsy results.

INTRODUCTION: For men with elevated prostate-specific antigen (PSA), appropriate management after negative prostate biopsy remains controversial. After determining PSA kinetics, subsequent follow-up was considered. PATIENTS AND METHODS: A total of 115 cases with negative repeat biopsy were followed by evaluating PSA kinetics and ratio of percent free PSA (F/T) and by performing second repeat biopsy. RESULTS: Eighteen cancer cases were diagnosed. Shorter PSA doubling times and faster velocities were found in cancer cases compared with cases without cancer. We observed a clear decrease in F/T among cancer cases. CONCLUSIONS: To avoid unnecessary repeat biopsies, cases with a suspicion of cancer after negative biopsy can be divided into two groups: one that requires additional biopsies and one with an average change in PSA of <1 ng/ml/year and no change in F/T, which is recommended for surveillance as stable disease without biopsy over a specified time period.

Enhancer transcripts mark active estrogen receptor binding sites.

We have integrated and analyzed a large number of data sets from a variety of genomic assays using a novel computational pipeline to provide a global view of estrogen receptor 1 (ESR1; a.k.a. ERα) enhancers in MCF-7 human breast cancer cells. Using this approach, we have defined a class of primary transcripts (eRNAs) that are transcribed uni- or bidirectionally from estrogen receptor binding sites (ERBSs) with an average transcription unit length of ∼3-5 kb. The majority are up-regulated by short treatments with estradiol (i.e., 10, 25, or 40 min) with kinetics that precede or match the induction of the target genes. The production of eRNAs at ERBSs is strongly correlated with the enrichment of a number of genomic features that are associated with enhancers (e.g., H3K4me1, H3K27ac, EP300/CREBBP, RNA polymerase II, open chromatin architecture), as well as enhancer looping to target gene promoters. In the absence of eRNA production, strong enrichment of these features is not observed, even though ESR1 binding is evident. We find that flavopiridol, a CDK9 inhibitor that blocks transcription elongation, inhibits eRNA production but does not affect other molecular indicators of enhancer activity, suggesting that eRNA production occurs after the assembly of active enhancers. Finally, we show that an enhancer transcription "signature" based on GRO-seq data can be used for de novo enhancer prediction across cell types. Together, our studies shed new light on the activity of ESR1 at its enhancer sites and provide new insights about enhancer function.

Crucial elements that maintain the interactions between the regulatory TnaC peptide and the ribosome exit tunnel responsible for Trp inhibition of ribosome function.

Translation of the TnaC nascent peptide inhibits ribosomal activity in the presence of l-tryptophan, inducing expression of the tnaCAB operon in Escherichia coli. Using chemical methylation, this work reveals how interactions between TnaC and the ribosome are affected by mutations in both molecules. The presence of the TnaC-tRNA(Pro) peptidyl-tRNA within the ribosome protects the 23S rRNA nucleotide U2609 against chemical methylation. Such protection was not observed in mutant ribosomes containing changes in 23S rRNA nucleotides of the A748-A752 region. Nucleotides A752 and U2609 establish a base-pair interaction. Most replacements of either A752 or U2609 affected Trp induction of a TnaC-regulated LacZ reporter. However, the single change A752G, or the dual replacements A752G and U2609C, maintained Trp induction. Replacements at the conserved TnaC residues W12 and D16 also abolished the protection of U2609 by TnaC-tRNA(Pro) against chemical methylation. These data indicate that the TnaC nascent peptide in the ribosome exit tunnel interacts with the U2609 nucleotide when the ribosome is Trp responsive. This interaction is affected by mutational changes in exit tunnel nucleotides of 23S rRNA, as well as in conserved TnaC residues, suggesting that they affect the structure of the exit tunnel and/or the nascent peptide configuration in the tunnel.

Outcome of patients with localized prostate cancer treated by radiotherapy after confirming the absence of lymph node invasion.

OBJECTIVE: Management of lymph nodes in radiotherapy for prostate cancer is an issue for curative intent. To find the influence of lymph nodes, patients with T1-T3 prostate cancer and surgically confirmed negative nodes were treated with radiotherapy. METHODS: After lymphadenectomy, 118 patients received photon beam radiotherapy with 66 Gy to the prostate. No adjuvant treatment was performed until biochemical failure. After failure, hormone therapy was administered. Follow-up period was 57 months (mean). RESULTS: Biochemical failure occurred in 47 patients. Few failures were observed in patients with low (24%) and intermediate risks (14%). In contrast, 64% of high-risk patients experienced failure, 97% of whom showed until 36 months. Most patients with failure responded well to hormone therapy. After 15 months (mean), a second biochemical failure occurred in 21% of patients who had the first failure, most of them were high risk. Factors involving failure were high initial and nadir prostate-specific antigen, advanced stage, short prostate-specific antigen-doubling time and duration between radiation and first failure. Failure showed an insufficient reduction in prostate-specific antigen after radiotherapy. Factor for second failure was prostate-specific antigen-doubling time at first failure. CONCLUSIONS: Half of high-risk patients experienced biochemical failure, indicating one of the causes involves factors other than lymph nodes. Low-, intermediate- and the other half of high-risk patients did not need to take immediate hormone therapy after radiotherapy. After failure, delayed hormone therapy was effective. Prostate-specific antigen parameters were predictive factors for further outcome.

PSA doubling time as a predictive factor on repeat biopsy for detection of prostate cancer.

OBJECTIVE: Detection of prostate cancer needs a biopsy of the prostate. Suspecting cancer from an increase in prostate-specific antigen (PSA) has a high negative rate at an initial prostate biopsy. Cases with negative initial biopsy may be the candidates of subsequent biopsy. For lowering unnecessary repeat biopsy, the use of predictive factors before a repeat biopsy is applied for indication. METHODS: Seventy-seven cases with negative initial prostate biopsy received a repeat biopsy and factors for the detection of cancer were examined. RESULTS: PSA doubling time distinguished a part of cancer cases. Its sensitivity of 30, 50 and 70 months was 36.6%, 30.4% and 10%, respectively. Cancer case did not show PSA doubling time of >100 months in general. Values of PSA transition zone density, %Free/total PSA and PSA velocity were similar between cancer and no cancer cases. CONCLUSIONS: PSA doubling time was one of the predictive factors for the detection of prostate cancer and was valuable for avoiding unnecessary repeat biopsy in some cases.

[Primary carcinoid tumor of the testis metastatic to the para-aortic lymph nodes in six years after the first operation: a case report].

This is an additional report of a case which Kinsui, et al. reported in 2000. A primary testicular tumor metastasized to the para-aortic lymph node in 6 years after the first high orichietectomy. In this case, we performed retroperitoneal lymph node dissection. After 4 months, the levels of 5-hydroxy indole acetic acid (5-HIAA), serotonin, urinary 5-HIAA were normalized without recurrence. This indicates testicular carcinoid needs long-term follow up.