Inhibition of Cyclin-Dependent Kinase 8/Cyclin-Dependent Kinase 19 Suppresses Its Pro-Oncogenic Effects in Prostate Cancer.

Progression of prostate cancer (PCa) is characterized by metastasis and castration resistance after response to androgen deprivation. Therapeutic options are limited, causing high morbidity and lethality. Recent work reported pro-oncogenic implications of the Mediator subunits cyclin-dependent kinase (CDK) 8 and 19 for the progression of PCa. The current study explored the underlying molecular mechanisms of CDK8/CDK19 and tested effects of novel CDK8/CDK19 inhibitors. PC3, DU145, LNCaP, and androgen-independent LNCaP Abl were used for in vitro experiments. Two inhibitors and CDK19 overexpression were used to modify CDK8/CDK19 activity. MTT assay, propidium iodide staining, wound healing assay, Boyden chamber assay, and adhesion assay were used to investigate cell viability, cell cycle, migration, and adhesion, respectively. Peptide-kinase screen using the PamGene platform was conducted to identify phosphorylated targets. Combining CDK8/CDK19 inhibitors with anti-androgens led to synergistic antiproliferative effects and sensitized androgen-independent cells to bicalutamide. CDK8/CDK19 inhibition resulted in reduced migration and increased collagen I-dependent adhesion. Phosphorylation of multiple peptides linked to cancer progression was identified to be dependent on CDK8/CDK19. In summary, this study substantially supports recent findings on CDK8/CDK19 in PCa progression. These findings contribute to a better understanding of underlying pro-oncogenic effects, which is needed to develop CDK8/CDK19 as a therapeutic target in PCa.

Targeting cyclin-dependent kinase 7-association between CDK7 and pMED1 expression in prostate cancer tissue.

Cyclin-dependent kinase (CDK) 7-mediated phosphorylation of Mediator-complex subunit 1 (MED1) enhances androgen receptor (AR) activity in prostate cancer (PCa). Hyperactive AR-signalling plays a key role for the development of castration resistance. Several CDK7 inhibitors are currently under investigation in Phase I/II trials addressing solid tumours, including PCa. Aim of this study was to characterize the CDK7/phospho-(p)MED1 axis in human tissue. Immunohistochemistry was performed on 595 PCa samples including 394 primary tumour foci obtained by radical prostatectomy (RP), 64 advanced or recurrent tumours obtained by palliative transurethral resection of the prostate (pTUR), 65 lymph node metastases (LNM), 35 distant metastases (DM) and 36 benign samples. CDK7 is expressed in 79.3% of PCa tissues and protein levels are significantly higher in LNM, pTUR and DM and lower in benign tissues compared to primary tumours. CDK7 and pMED1 expression show strong positive correlation. High expression of CDK7 associated with shorter 5-year biochemical recurrence-free-survival (63.0% vs. 85.0%) and reduced survival persists when adjusted for T-Stage, nodal status, resection boundaries, grade group and pre-operative prostate-specific antigen in multivariate Cox-regression (hazard ratio 4.30; 95% CI, 1.43 to 12,40, P = 0.007). High CDK7 and pMED1 levels correlate with nuclear AR expression. CDK7 positive tumours harbour higher Ki67 expression indices and show more frequently positive ERG (ETS-related gene)-status. In conclusion, CDK7 is frequently expressed in human PCa and predicts disease recurrence after RP. Therapeutical inhibition of CDK7 might be a promising approach in treatment of advanced PCa.

Analysis of tripartite motif (TRIM) family gene expression in prostate cancer bone metastases.

Tripartite motif (TRIM) family proteins are post-translational protein modifiers with E3-ubiquitin ligase activity, thereby involved in various biological processes. The molecular mechanisms driving prostate cancer (PCa) bone metastasis (BM) are incompletely understood, and targetable genetic alterations are lacking in the majority of cases. Therefore, we aimed to explore the expression and potential functional relevance of 71 TRIM members in bone metastatic PCa. We performed transcriptome analysis of all human TRIM family members and 770 cancer-related genes in 29 localized PCa and 30 PCa BM using Nanostring. KEGG, STRING and Ubibrowser were used for further bioinformatic gene correlation and pathway enrichment analyses. Compared to localized tumors, six TRIMs are under-expressed while nine TRIMs are over-expressed in BM. The differentially expressed TRIM proteins are linked to TNF-, TGFß-, PI3K/AKT- and HIF-1-signaling, and to features such as proteoglycans, platelet activation, adhesion and ECM-interaction based on correlation to cancer-related genes. The identification of TRIM-specific E3-ligase-substrates revealed insight into functional connections to oncogenes, tumor suppressors and cancer-related pathways including androgen receptor- and TGFß signaling, cell cycle regulation and splicing. In summary, this is the first study that comprehensively and systematically characterizes the expression of all TRIM members in PCa BM. Our results describe post-translational protein modification as an important regulatory mechanism of oncogenes, tumor suppressors, and pathway molecules in PCa progression. Therefore, this study may provide evidence for novel therapeutic targets, in particular for the treatment or prevention of BM.

Tissue distribution of tetrabromobisphenol A and cadmium in mixture inhalation exposure.

Tetrabromobisphenol A (TBBPA) and cadmium chloride (CdCl2) are the typical representative pollutants of brominated flame retardants and heavy metals found in the air of e-waste recycling workshops. However, their metabolic kinetics through mixture inhalation is unknown. In the present study, 8-week old Institute of Cancer Research (ICR) male mice were whole-body exposed to TBBPA and CdCl2 mixtures by inhalation. Tissue samples were collected for TBBPA and cadmium (Cd) analysis at 2, 4, 6, and 8 weeks during exposure and at 4 and 8 weeks after the completion of the 8-week exposure period. TBBPA was mainly distributed to the lungs, liver, kidney, testis, and spleen, with a high amount accumulated in the brain, liver, and spleen. Cd was mainly distributed to the lungs, liver, and kidney, with a high amount accumulated in the liver, kidney, and testis and a low amount accumulated in brain and serum. Tissue burden of TBBPA and Cd in all organs increased in a dose- and time-dependent manner during the exposure period. However, 4 weeks after the completion of an 8-week exposure, TBBPA concentrations in the liver, testis, brain, and serum and Cd concentrations in the liver, testis, and kidney were higher than the corresponding tissue concentrations during the exposure period. The rapid accumulation of both TBBPA and Cd in the lungs after inhalation exposure indicated a high risk of the respiratory system diseases for workers in e-waste recycling workshops. In addition, the migration of both TBBPA and Cd from lungs to liver and testis may result in more complex toxic effects in vivo.

CEACAM6 Promotes Lung Metastasis via Enhancing Proliferation, Migration and Suppressing Apoptosis of Prostate Cancer Cells.

BACKGROUND/AIM: Metastatic prostate cancer (mPCa) results in high morbidity and mortality. Visceral metastases in particular are associated with a shortened survival. Our aim was to unravel the molecular mechanisms that underly pulmonary spread in mPCa. MATERIALS AND METHODS: We performed a comprehensive transcriptomic analysis of PCa lung metastases, followed by functional validation of candidate genes. Digital gene expression analysis utilizing the NanoString technology was performed on mRNA extracted from formalin-fixed, paraffin-embedded (FFPE) tissue from PCa lung metastases. The gene expression data from primary PCa and PCa lung metastases were compared, and several publicly available bioinformatic analysis tools were used to annotate and validate the data. RESULTS: In PCa lung metastases, 234 genes were considerably up-regulated, and 78 genes were significantly down-regulated when compared to primary PCa. Carcinoembryonic antigen-related cell adhesion molecule 6 (CEACAM6) was identified as suitable candidate gene for further functional validation. CEACAM6 as a cell adhesion molecule has been implicated in promoting metastatic disease in several solid tumors, such as colorectal or gastric cancer. We showed that siRNA knockdown of CEACAM6 in PC-3 and LNCaP cells resulted in decreased cell viability and migration as well as enhanced apoptosis. Comprehensive transcriptomic analyses identified several genes of interest that might promote metastatic spread to the lung. CONCLUSION: Functional validation revealed that CEACAM6 might play an important role in fostering metastatic spread to the lung of PCa patients via enhancing proliferation, migration and suppressing apoptosis in PC-3 and LNCaP cells. CEACAM6 might pose an attractive therapeutic target to prevent metastatic disease.

[Therapy sequences and duration in mCRPC: a retrospective review of the Lübeck mCRPC cohort]. / Therapiesequenzen und ­dauer beim mCRPC: Eine retrospektive Aufarbeitung der Lübecker mCRPC-Kohorte.

BACKGROUND: Prostate cancer is one of the most common cancers in men in Europe. Several classes of agents can be considered for the treatment of metastatic prostate carcinoma, and their use is supported by extensive guidelines. In the treatment of metastatic castration-resistant prostate cancer (mCRPC), it is currently unclear which sequence of systemic therapies is most effective. Currently approved system therapies in the castration-resistant setting generally include hormone-manipulating agents, taxane-based chemotherapies, radioactive agents, or inhibitiors of DNA repair mechanisms. This study aims to summarize real world data of mCRPC therapy. METHODS: Retrospectively, 90 mCRPC patients undergoing treatment at the University Hospital Schleswig-Holstein, Lübeck Campus between February 2006 and March 2020 were identified. The patient data were analyzed for their treatment sequence and disease progression. Due to the inclusion period, the mCRPC therapy sequences studied were limited to: Abiraterone, Cabazitaxel, Docetaxel, Enzalutamide, Lutetium-177-PSMA and Radium-223. The analysis includes the therapy sequences and their duration, clinical information of the respective cohort, overall and cancer-specific survival (OS/CSS) as well as time to second-line therapy in relation to the respective first-line therapy. RESULTS: Approximately two-thirds of patients underwent a true therapy sequence (at least two of the drugs listed above), with this proportion halving by the third line.The majority of patients received the sequence (first/second line) abiraterone/docetaxel (n=13), followed by docetaxel/abiraterone (n=12) and abiraterone/enzalutamid (n=10) and docetaxel/docetaxel (n=8).Within the different docetaxel sequences, first-line (mean 4.7 months ± SD 3.1; median 4.0) and rechallenge (mean 5.3 months ± SD 5.9; median 3.0) therapy durations were the longest. The subjective side effect rate of docetaxel was lower in the second line, so that a better tolerability can be assumed here.The abiraterone/docetaxel sequence was used mainly in patients with metachronous metastases. Among the different sequences of abiraterone, first-line (mean 10.8 months ± SD 10.2; median 9.0) and second-line (mean 10.6 months ± SD 9.0; median 7.0) therapy durations were the longest.The sequence abiraterone/enzalutamide was prescribed mainly to older patients with synchronous metastases. Among the different enzalutamide sequences first-line (mean 9.6 months ± SD 7.1; median 7.0) and rechallenge (mean 11.0 ± SD 0.0; median 11.0) therapy durations were the longest.In contrast, the sequence docetaxel/docetaxel was used mainly in younger patients with a high initial PSA.The evaluation shows a trend that both abiraterone and enzalutamide can account for a survival advantage in the first line. CONCLUSION: Ultimately, an optimal treatment sequence cannot be confidently derived from these data.However, it was found that only a small proportion of patients underwent fourth- or even fifth-line treatment at all. Thus, the focus on first- and second-line in this study seems reasonable. It could be shown in a trend that docetaxel as first-line therapy seems to be disadvantegous regarding OS as well as CSS when compared to abiraterone or enzalutamide. However, due to the small number of patients in this study, a clear significance cannot be derived. Moreover, the subjectively better tolerability of docetaxel in the second-line setting could provide an impetus for treatment planning in multimorbid elderly patients in the future. The sequence abiraterone/docetaxel may offer a beneficial option for initial mCRPC therapy.

Comprehensive transcriptomic analysis of prostate cancer lung metastases.

Metastatic prostate cancer (mPCa) is a widespread disease with high mortality. Unraveling molecular mechanisms of disease progression is of utmost importance. The microenvironment in visceral organs and the skeletal system is of particular interest as a harbinger of metastatic spread. Therefore, we performed a comprehensive transcriptomic analysis of prostate cancer lung metastases with a special focus on differentially expressed genes attributable to the microenvironment. Digital gene expression analysis using the NanoString nCounter analysis system was performed on formalin-fixed, paraffin-embedded (FFPE) tissue from prostate cancer (PCa) lung metastases (n = 24). Data were compared to gene expression data from primary PCa and PCa bone metastases. Bioinformatic analysis was performed using several publicly available tools. In comparison to prostate cancer bone metastases, 209 genes were significantly upregulated, and 100 genes were significantly downregulated in prostate cancer lung metastases. Among the up-regulated genes, the top 10 genes with the most significant P-value were HLA-DPB1, PTPRC, ITGB7, C3, CCL21, CCL5, ITGAM, SERPINA1, MFAP4, ARAP2 and among the down-regulated genes, the top 10 genes with the most significant P-value were FOXC2, TWIST1, CDK14, CHAD, IBSP, EPN3, VIT, HAPLN1, SLC44A4, TBX1. In PCa lung metastases genes associated with immunogenic responses were upregulated while genes associated with epithelial-mesenchymal transition were down-regulated. We also showed that CXCR3/CXCL10 axis plays a significant role in prostate cancer lung metastases in comparison to bone metastases. In this study, we comprehensively explored transcriptomic alterations in PCa lung metastases in comparison to primary PCa and PCa bone metastases. In PCa lung metastases genes associated with immunogenic responses are upregulated while genes associated with epithelial-mesenchymal transition are down-regulated. This points to a more immunogenic phenotype of PCa lung metastases thus potentially making patients more susceptible to immunotherapeutic approaches.

Cracking it - successful mRNA extraction for digital gene expression analysis from decalcified, formalin-fixed and paraffin-embedded bone tissue.

With the advance of precision medicine, the availability of tumor tissue for molecular analysis has become a limiting factor. This is particularly the case for bone metastases which are frequently occurring in cancer types such as prostate cancer. Due to the necessary decalcification process it was long thought that transcriptome analysis will not be feasible from decalcified formalin-fixed, paraffin-embedded (DFFPE) in a large manner. Here we demonstrate that mRNA extraction from DFFPE is feasible, quick, robust and reproducible and that decalcification does not hamper subsequent gene expression analysis. This might assist in implementing transcriptome analysis from DFFPE into every day practice.

Pressure-induced structural and spin transitions of Fe3S4.

Greigite (Fe3S4), isostructural with Fe3O4 has recently attracted great scientific interests from material science to geology due to its complicated structure and electronic and magnetic configurations. Here, an investigation into the structural, magnetic and electronic properties of Fe3S4 under high pressure has been conducted by first-principle calculations based on density functional theory. The results show that a first-order phase transition of Fe3S4 would occur from the inverse spinel (SP) structure to the Cr3S4-type (CS) structure at 3.4 GPa, accompanied by a collapse of 9.7% in the volume, a redistribution of iron cations, and a half-metal to metal transition. In the CS-Fe3S4, Fe2+ located at octahedral environment firstly undergoes a transition from high-spin (HS) state to low-spin (LS) state at 8.5 GPa and Fe3+ subsequently does at 17 GPa. The Equation of State for different phases of Fe3S4 are also determined. Our results not only give some clues to explore novel materials by utilizing Fe3S4 but also shed light on the fundamental information of Fe3O4, as well as those of other SP-AB2X4 compounds.

Tetrabromobisphenol A and heavy metal exposure via dust ingestion in an e-waste recycling region in Southeast China.

This study was designed to investigate a prevalent brominated flame retardant tetrabromobisphenol A (TBBPA) and four heavy metals of Pb, Cr, As, Cd in dust samples (52 indoor and 52 outdoor) collected from residential houses in an e-waste recycling area in Southeast China. For TBBPA, the mean concentration in indoor dust (3435 ng/g, dw) was higher than that in outdoor dust (1998 ng/g, dw). For heavy metals, the mean concentrations of Pb, Cr, As, Cd were 399, 151, 48.13, and 5.85 mg/kg in indoor dust, respectively, and were 328, 191, 17.59, and 4.07 mg/kg in outdoor dust, respectively. Except for As, concentrations of TBBPA and other metals decreased with the increased distance away from the e-waste recycling center, suggesting significant contribution of e-waste activities. The daily exposure doses of TBBPA ranged from 0.04 to 7.50 ng/kg-bw/day for adults and from 0.31 to 58.54 ng/kg-bw/day for children, representing the highest values reported to date for TBBPA exposure via dust ingestion. Daily exposure doses of Cr, As, and Cd were all below the reference doses. However, daily exposure dose of Pb for children in areas near the e-waste processing center was above the reference dose, posing significant health concern for children in that region.