CircFOXO3 mediates hypoxia-induced autophagy of endometrial stromal cells in endometriosis.

Endometriosis is a benign gynecological disease that shares some common features of malignancy. Autophagy plays vital roles in endometriosis and influences endometrial cell metastasis, and hypoxia was identified as the initiator of this pathological process through hypoxia inducible factor 1 alpha (HIF-1α). A newly discovered circular RNA FOXO3 (circFOXO3) is critical in cell autophagy, migration, and invasion of various diseases and is reported to be related to hypoxia, although its role in endometriosis remains to be elucidated up to now. In this study, a lower circFOXO3 expression in ectopic endometrium was investigated. Furthermore, we verified that circFOXO3 could regulate autophagy by downregulating the level of p53 protein to mediate the migration and invasion of human endometrial stromal cells (T HESCs). Additionally, the effects of HIF-1α on circFOXO3 and autophagy were examined in T HESCs. Notably, overexpression of HIF-1α could induce autophagy and inhibit circFOXO3 expression, whereas overexpressing of circFOXO3 under hypoxia significantly inhibited hypoxia-induced autophagy. Mechanistically, the direct combination between HIF-1α and HIF-1α-binding site on adenosine deaminase 1 acting on RNA (ADAR1) promoter increased the level of ADAR1 protein, which bind directly with circFOXO3 pre-mRNA to block the cyclization of circFOXO3. All these results support that hypoxia-mediated ADAR1 elevation inhibited the expression of circFOXO3, and then autophagy was induced upon loss of circFOXO3 via inhibition of p53 degradation, participating in the development of endometriosis.

Transcriptome-wide N6-methyladenosine (m6A) methylation profiling of long non-coding RNAs in ovarian endometriosis.

N6-methyladenosine (m6A) methylation is the most prevalent internal epigenetic posttranscriptional mechanism for regulating mammalian RNA. Despite recent advances in determining the biological functions of m6A methylation, its association with the pathology of ovarian endometriosis remains uncertain. Herein, we performed m6A transcriptome-wide profiling to identify key lncRNAs with m6A modification involved in ovarian endometriosis development by bioinformatics analysis. We found the total m6A level was lower in ovarian endometriosis than in normal endometrium samples, with 9663 m6A peaks associated with 8989 lncRNAs detected in ovarian endometriosis and 9902 m6A peaks associated with 9210 lncRNAs detected in normal endometrium samples. These m6A peaks were primarily enriched within AAACU motifs. Functional enrichment analysis indicated that pathways involving the regulation of adhesion and development were significantly enriched in these differentially methylated lncRNAs. The regulatory relationships among lncRNAs, microRNAs (miRNAs), and mRNAs were identified by competing endogenous RNA (ceRNA) analysis and determination of the network regulating lncRNA-mRNA expression. Several specific lncRNA, including LINC00665, LINC00937, FZD10-AS1, DIO3OS and GATA2-AS1 which were differently expressed and modified by m6A, were validated using qRT-PCR and its interaction with infiltrating immune cells was explored. Furthermore, we found LncRNA DIO3OS promotes the invasion and migration of Human endometrial stromal cells (THESCs) and ALKBH5 regulates the expression of the lncRNA DIO3OS through m6A modification in vitro. Our study firstly revealed the transcriptome-wide map of m6A modification in lncRNAs of ovarian endometriosis. These findings may enable the determination of the underlying mechanism governing the pathogenesis of ovarian endometriosis and provide theoretical basis for further deeper research on the role of m6A in the development of ovarian endometriosis.

Ultrasensitive Paper-Based Photoelectrochemical Biosensor for Acetamiprid Detection Enabled by Spin-State Manipulation and Polarity-Switching.

Efficient carrier separation is vitally crucial to improving the detection sensitivity of photoelectrochemical (PEC) biosensors. Here, we developed a facile strategy to efficiently regulate the carrier separation efficiency of the photoactive matrix BiOI and In2S3 signal label functionalized paper chip by manipulation of electrons spin-state and rational design of electron transport pathways. The spin-dependent electronic structures of BiOI and In2S3 were regulated via enhanced electron-spin parallel alignment induced by an external magnetic field, markedly retarding carrier recombination and extending their lifetime. Simultaneously, with the progress of the target-induced catalytic hairpin assembly process, the transfer path of photogenerated carriers was changed, leading to a switch in photocurrent polarity from cathode to anode. This reversed electron transport pathway not only boosted the separation ability of photogenerated electrons but also eliminated false-positive and false-negative signals, thereby further improving the detection sensitivity. As a proof of concept, the well-designed magnetic field-stimulated paper-based PEC biosensor showed highly selectivity and sensitivity for acetamiprid assay with a wide linear range of 1 fM to 20 nM and an ultralow detection limit of 0.73 fM. This work develops a universal strategy for improving the sensitivity of biosensors and exhibits enormous potential in the fields of bioanalysis and clinical diagnosis.

Feedforward cysteine regulation maintains melanoma differentiation state and limits metastatic spread.

The inherent ability of melanoma cells to alter the differentiation-associated transcriptional repertoire to evade treatment and facilitate metastatic spread is well accepted and has been termed phenotypic switching. However, how these facets of cellular behavior are controlled remains largely elusive. Here, we show that cysteine availability, whether from lysosomes (CTNS-dependent) or exogenously derived (SLC7A11-dependent or as N-acetylcysteine), controls melanoma differentiation-associated pathways by acting on the melanocyte master regulator MITF. Functional data indicate that low cysteine availability reduces MITF levels and impairs lysosome functions, which affects tumor ferroptosis sensitivity but improves metastatic spread in vivo. Mechanistically, cysteine-restrictive conditions reduce acetyl-CoA levels to decrease p300-mediated H3K27 acetylation at the melanocyte-restricted MITF promoter, thus forming a cysteine feedforward regulation that controls MITF levels and downstream lysosome functions. These findings collectively suggest that cysteine homeostasis governs melanoma differentiation by maintaining MITF levels and lysosome functions, which protect against ferroptosis and limit metastatic spread.

Rational design of type-I photosensitizer molecules for mitochondrion-targeted photodynamic therapy.

Photodynamic therapy (PDT) has emerged as a promising approach for tumor treatment. However, traditional type II PDT faces limitations due to its oxygen-dependent nature. Type-I photosensitizers (PSs) exhibit superiority over conventional type-II PSs owing to their diminished oxygen dependence. Nevertheless, designing effective type-I PSs remains a significant challenge. In this work, we provide a novel strategy to tune the PDT mechanism of an excited photosensitizer through aryl substituent engineering. Using S-rhodamine as the base structure, three PSs were synthesized by incorporating phenyl, furyl, or thienyl groups at the meso position. Interestingly, furyl- or thienyl-substituted S-rhodamine are type-I-dominated PSs that produce O2˙-, while phenyl S-rhodamine results in O2˙- and 1O2 through type-I and type-II mechanisms, respectively. Experimental analyses and theoretical calculations showed that the introduction of a five-membered heterocycle at the meso position promoted intersystem crossing (ISC) and electron transfer, facilitating the production of O2˙-. Furthermore, furyl- or thienyl-substituted S-rhodamine exhibited high phototoxicity at ultralow concentrations. Thienyl-substituted S-rhodamine showed promising PDT efficacy against hypoxic solid tumors. This innovative strategy provides an alternative approach to developing new type-I PSs without the necessity for creating entirely new skeletons.

Effect of ferulic acid incorporation on structural, rheological, and digestive properties of hot-extrusion 3D-printed rice starch.

The influence of ferulic acid (FA) on rice starch was investigated by incorporating it at various concentrations (0, 2.5, 5, 7.5, and 10 %, w/w, on dry starch basis) and subjecting the resulting composites to hot-extrusion 3D printing (HE-3DP) process. This study examined the effects of FA addition and HE-3DP on the structural, rheological, and physicochemical properties as well as the printability and digestibility of rice starch. The results indicated that adding 0-5 % FA had no significant effect; however, as the amount of FA increased, the printed product edges became less defined, the product's overall stability decreased, and it collapsed. The addition of FA reduced the elasticity and viscosity, making it easier to extrude the composite gel from the nozzle. Moreover, the crystallinity and short-range ordered structure of the HE-3D printed rice starch gel decreased with the addition of FA, resulting in a decrease in the yield stress and an increase in fluidity. Furthermore, the addition of FA reduced the digestibility of the HE-3D-printed rice starch. The findings of this study may be useful for the development of healthier modified starch products by adding bioactive substances and employing the 3D printing technology.

Presence of Multiple Genetic Mutations Related to Insecticide Resistance in Chinese Field Samples of Two Phthorimaea Pest Species.

Potatoes hold the distinction of being the largest non-cereal food crop globally. The application of insecticides has been the most common technology for pest control. The repeated use of synthetic insecticides of the same chemical class and frequent applications have resulted in the emergence of insecticide resistance. Two closely related pests that feed on potato crops are the potato tuber moth, Phthorimaea operculella, and the tomato leafminer, Phthorimaea absoluta (syn. Tuta absoluta). Previous studies indicated the existence of insecticide resistance to various classes of insecticides including organophosphates, carbamates, and pyrethroids in field populations of P. operculella and P. absoluta. However, the exact mechanisms of insecticide resistance in P. operculella and to a lesser extent P. absoluta remain still poorly understood. Detecting resistance genotypes is crucial for the prediction and management of insecticide resistance. In this study, we identified multiple genetic mutations related to insecticide resistance in two species of Phthorimaea. An unexpected genetic divergence on target-site mutations was observed between P. operculella and P. absoluta. Three mutations (A201S, L231V, and F290V) in Ace1 (acetylcholinesterase), four mutations (M918T, L925M, T928I, and L1014F) in VGSC (voltage-gated sodium channel), and one mutation (A301S) in RDL (GABA-gated chloride channel) have been detected with varying frequencies in Chinese P. absoluta field populations. In contrast, P. operculella field populations showed three mutations (F158Y, A201S, and L231V) in Ace1, one mutation (L1014F) in VGSC at a lower frequency, and no mutation in RDL. These findings suggest that pyrethroids, organophosphates, and carbamates are likely to be ineffective in controlling P. absoluta, but not P. operculella. These findings contributed to a deeper understanding of the presence of target-site mutations conferring resistance to commonly used (and cheap) classes of insecticides in two closely related potato pests. It is recommended to consider the resistance status of both pests for the implementation of resistance management strategies in potatoes.

Association of a low-inflammatory diet with survival among adults: The role of cardiometabolic diseases and lifestyle.

BACKGROUND & AIMS: Evidence on the association between dietary inflammation and longevity is limited. We aimed to examine the association of a low-inflammatory diet with mortality and longevity, and to explore whether cardiometabolic diseases (CMDs) and lifestyle factors may play a role in this association. METHODS: Within the UK Biobank, 188,443 participants aged 39-72 years (mean 56.07) were followed for up to 16 years to detect survival status from the death registry. At baseline, dietary intake was assessed with a 24-h dietary record. An inflammatory diet index (IDI) was calculated as weighted sum of 31 food groups (including 14 anti-inflammatory and 17 pro-inflammatory) based on plasma high-sensitivity C-reactive protein levels, and tertiled as low, moderate, and high IDI scores. Baseline lifestyle beyond diet was assessed by summing the number of healthy lifestyle factors (i.e., never smoking, regular physical activity, and normal BMI) and categorized as unfavorable (≤1) and favorable (≥2). Presence of CMDs was defined as having any one of type 2 diabetes, ischemic heart disease, atrial fibrillation, heart failure, and stroke. Data were analyzed using Cox regression, Laplace regression, and generalized structural equation modelling. RESULTS: During the follow-up (median 9.79 years, interquartile range: 9.68-10.57 years), 9178 (4.9%) participants died. In multi-adjusted Cox regression models, a low-inflammatory diet (i.e. low IDI score) was associated with lower risk of all-cause mortality [hazard ratio (HR) = 0.82, 95% confidence interval (CI): 0.78 to 0.86]. Laplace regression analysis showed that the multi-adjusted 10th percentile difference (10th PD, 95% CI) of death time was delayed by 0.80 (0.55, 1.06; P < 0.001) years for participants with a low IDI score compared to those with a high IDI score. In mediation analysis, 21.48% of the association between IDI and mortality was mediated by CMDs. In joint effect analysis, participants with a low IDI score and favorable lifestyle had a 42% lower risk of death (HR = 0.58, 95% CI: 0.54, 0.62) compared to those with a high IDI score and unfavorable lifestyle. There was a significant additive interaction between low IDI score and favorable lifestyle on decreased mortality. CONCLUSIONS: A low-inflammatory diet is associated with a lower risk of death and could prolong survival time. CMDs may partially mediate the IDI-mortality association. A favorable lifestyle beyond diet may augment the positive effect of a low-inflammatory diet on longevity.

Pan-genome insights into adaptive evolution of bacterial symbionts in mixed host-microbe symbioses represented by human gut microbiota Bacteroides cellulosilyticus.

Animal hosts harbor diverse assemblages of microbial symbionts that play crucial roles in the host's lifestyle. The link between microbial symbiosis and host development remains poorly understood. In particular, little is known about the adaptive evolution of gut bacteria in host-microbe symbioses. Recently, symbiotic relationships have been categorized as open, closed, or mixed, reflecting their modes of inter-host transmission and resulting in distinct genomic features. Members of the genus Bacteroides are the most abundant human gut microbiota and possess both probiotic and pathogenic potential, providing an excellent model for studying pan-genome evolution in symbiotic systems. Here, we determined the complete genome of an novel clinical strain PL2022, which was isolated from a blood sample and performed pan-genome analyses on a representative set of Bacteroides cellulosilyticus strains to quantify the influence of the symbiotic relationship on the evolutionary dynamics. B. cellulosilyticus exhibited correlated genomic features with both open and closed symbioses, suggesting a mixed symbiosis. An open pan-genome is characterized by abundant accessory gene families, potential horizontal gene transfer (HGT), and diverse mobile genetic elements (MGEs), indicating an innovative gene pool, mainly associated with genomic islands and plasmids. However, massive parallel gene loss, weak purifying selection, and accumulation of positively selected mutations were the main drivers of genome reduction in B. cellulosilyticus. Metagenomic read recruitment analyses showed that B. cellulosilyticus members are globally distributed and active in human gut habitats, in line with predominant vertical transmission in the human gut. However, existence and/or high abundance were also detected in non-intestinal tissues, other animal hosts, and non-host environments, indicating occasional horizontal transmission to new niches, thereby creating arenas for the acquisition of novel genes. This case study of adaptive evolution under a mixed host-microbe symbiosis advances our understanding of symbiotic pan-genome evolution. Our results highlight the complexity of genetic evolution in this unusual intestinal symbiont.

The association of the dietary inflammatory potential with risk of overall and site-specific cancers: A community-based longitudinal study in the UK Biobank.

OBJECTIVES: The association of the dietary inflammatory potential with cancer risk remains uncertain. We examined the relationship of the dietary inflammatory potential with risk of overall and site-specific cancers and explored its sex and age differences. DESIGN: A community-based longitudinal study. SETTING: Participants from the UK Biobank completed baseline surveys during 2006-2010 and were followed for up to 15 years to detect incident cancer. PARTICIPANTS: 170,899 cancer-free participants with dietary data available (mean age: 55.73 ± 7.95, 54.10% female). MEASUREMENTS: At baseline, dietary intake was assessed with a 24-h dietary record for up to 5 times. The inflammatory diet index (IDI) was calculated to assess the dietary inflammatory potential as a weighted sum of 31 food groups (including 14 anti-inflammatory and 17 pro-inflammatory) based on plasma high-sensitivity C-reactive protein (hsCRP) levels, and tertiled as low (indicating low-inflammatory diet), moderate, and high IDI (as reference). Overall and site-specific cancers were ascertained via linkage to routine hospital admission, cancer registry, and death certificate data. Data were analyzed using Cox regression and Laplace regression. RESULTS: During the follow-up (median 10.32 years, interquartile range: 9.95-11.14 years), 18,884 (11.05%) participants developed cancer. In multi-adjusted Cox regression, low IDI scores were associated with decreased risk of rectal cancer (hazard ratio [95% confidence interval, CI] 0.76 [0.61, 0.94]), thyroid cancer [0.45 (0.27, 0.74)], lung cancer [0.73 (0.61, 0.88)]. However, the association between IDI score and the risk of overall cancer was not significant. Laplace regression analysis showed that 10th percentile differences (95% CIs) of cancer onset time for participants with low IDI scores was prolonged by 1.29 (0.32, 2.27), 1.44 (0.58, 2.30), and 2.62 (0.98, 4.27) years for rectal cancer, thyroid cancer, and lung cancer, respectively, compared to those with high IDI scores. Stratified analysis revealed that low IDI scores were associated with a lower risk of rectal cancer (p interaction between IDI score and sex = 0.035) and lung cancer in males, but not in females, and with a reduced risk of thyroid cancer in females, but not in males. Moreover, low IDI scores were associated with a reduced risk of rectal cancer and lung cancer in the participants aged ≥60 years, but not in those <60 years, and with a reduced risk of thyroid cancer in those aged ≥60 years and <60 years. CONCLUSIONS: A low-inflammatory diet is associated with decreased risk and prolonged onset time of rectal cancer and lung cancer, especially among males and individuals aged ≥60 years, and thyroid cancer among females.

Zebrafish cobll1a regulates lipid homeostasis via the RA signaling pathway.

Background: The COBLL1 gene has been implicated in human central obesity, fasting insulin levels, type 2 diabetes, and blood lipid profiles. However, its molecular mechanisms remain largely unexplored. Methods: In this study, we established cobll1a mutant lines using the CRISPR/Cas9-mediated gene knockout technique. To further dissect the molecular underpinnings of cobll1a during early development, transcriptome sequencing and bioinformatics analysis was employed. Results: Our study showed that compared to the control, cobll1a -/- zebrafish embryos exhibited impaired development of digestive organs, including the liver, intestine, and pancreas, at 4 days post-fertilization (dpf). Transcriptome sequencing and bioinformatics analysis results showed that in cobll1a knockout group, the expression level of genes in the Retinoic Acid (RA) signaling pathway was affected, and the expression level of lipid metabolism-related genes (fasn, scd, elovl2, elovl6, dgat1a, srebf1 and srebf2) were significantly changed (p < 0.01), leading to increased lipid synthesis and decreased lipid catabolism. The expression level of apolipoprotein genes (apoa1a, apoa1b, apoa2, apoa4a, apoa4b, and apoea) genes were downregulated. Conclusion: Our study suggest that the loss of cobll1a resulted in disrupted RA metabolism, reduced lipoprotein expression, and abnormal lipid transport, therefore contributing to lipid accumulation and deleterious effects on early liver development.

Biodegradable and Ultra-High Expansion Ratio PPC-P Foams Achieved by Microcellular Foaming Using CO2 as Blowing Agent.

Poly(propylene carbonate-co-phthalate) (PPC-P) is an amorphous copolymer of aliphatic polycarbonate and aromatic polyester; it possesses good biodegradability, superior mechanical performances, high thermal properties, and excellent affinity with CO2. Hence, we fabricate PPC-P foams in an autoclave by using subcritical CO2 as a physical blowing agent. Both saturation pressure and foaming temperature affect the foaming behaviors of PPC-P, including CO2 adsorption and desorption performance, foaming ratio, cell size, porosity, cell density, and nucleation density, which are investigated in this research. Moreover, the low-cost PPC-P/nano-CaCO3 and PPC-P/starch composites are prepared and foamed using the same procedure. The obtained PPC-P-based foams show ultra-high expansion ratio and refined microcellular structures simultaneously. Besides, nano-CaCO3 can effectively improve PPC-P's rheological properties and foamability. In addition, the introduction of starch into PPC-P can lead to a large number of open cells. Beyond all doubt, this work can certainly provide both a kind of new biodegradable PPC-P-based foam materials and an economic methodology to make biodegradable plastic foams. These foams are potentially applicable in the packaging, transportation, and food industry.

Study on anti-inflammatory effect of Shangkehuangshui in vitro and in vivo based on TLR4/TLR2-NF-κB signaling pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Shangkehuangshui (SK) has been traditionally used to treat traumatic injury, soft tissue and bone injury in Foshan hospital of traditional Chinese medicine for more than 60 years, which composed of many Chinese herbs such as Coptis chinensis Franch., Gardenia jasminoides Ellis, Phellodendron chinense Schneid. and etc. SK exhibits heat-clearing and detoxifying, enhancing blood circulation to eliminate blood stasis properties, and demonstrates noteworthy clinical efficacy. Nevertheless, the underlying mechanism remains uncertain. AIM OF THE STUDY: The early study found that SK had good anti-inflammatory effects in acute soft tissue injury model. This research is to verify the anti-inflammatory properties of SK both in vitro and in vivo via TLR4/TLR2-NF-κB signaling pathway, to clarify the underlying mechanisms responsible for the curative effect of SK. METHODS: The RAW264.7 cells inflammatory model was established with lipopolysaccharide (LPS) in vitro. NO and TNF-α, IL-6, IL-1ß were determined with Griess method and ELISA method respectively. The mRNA and protein expression levels of TLR4/TLR2-NF-κB pathway were evaluated by qPCR and Western blot method. In vivo experiment, chronic soft tissue injury rat models were established by tracking gastrocnemius muscle with electrical stimulation, then local appearance and pathological changes were observed and recorded, the contents of inflammatory factors in serum and tissue were performed. Moreover, we also measured and contrasted the expression of TLR4/TLR2-NF-κB related factors. RESULTS: SK effectively inhibited the LPS-induced generation of inflammatory cytokines, including NO, TNF-α, IL-6 and IL-1ß in RAW264.7 cells, and significantly suppressed the expression of TLR4, TLR2, MyD88, IκB, and NF-κB. In vivo, SK remarkably decreased the damage appearance scores after 4 and 14 days of administration and inhibit the quantity of NO and leukocytes present in the serum. Additionally, the inflammatory infiltration in the pathological section was alleviated, myofibrillar hyperplasia and blood stasis were reduced. SK markedly downregulated NO, TNF-α, IL-6 and IL-1ß in injured tissues of rats, also declined the expression of TLR4, TLR2, MyD88, IκB, NF-κB, IL-6, TNF-α and IL-1ß. CONCLUSION: This study revealed that SK had obvious effects of anti-inflammatory actions in vivo and vitro, effectively reduced acute and chronic soft tissue injury in clinical, this might be attributed to inhibit the TLR4/TLR2-NF-κB pathway, further inhibit the expression of downstream relevant pro-inflammatory cytokines.

Zebrafish myo7aa affects congenital hearing by regulating Rho-GTPase signaling.

Introduction: myo7aa, the homolog of the human Usher 1B syndrome pathogenic gene, myo7A, plays an important role in stereociliary development and maintenance, therefore, is critical for hearing and balance. However, the molecular mechanisms that myo7aa regulate hearing and balance still need to be studied. Methods: In this study, we generated two independent zebrafish myo7aa knockout lines using CRISPR/Cas9 technology. To investigate the effects of myo7aa on hearing, YO-PRO-1 staining and startle response assay were used. To gain insight into the specific molecular mechanisms by which myo7aa affects hearing, transcriptome sequencing and bioinformatics analysis were employed. Results: Our study showed that hair cells of myo7aa-/- zebrafish can not take up YO-PRO-1 fluorescent dye and are insensitive to acoustic stimulation in myo7aa-/- zebrafish compared to wild type. Genes related to the Rho GTPase signaling pathway, such as arhgap33, dab2ip, and arghef40, are significantly down-regulated in myo7aa-/- zebrafish embryos at 3 dpf. GTP and ATP compensation can partially rescue the hair cell defects in myo7aa knockout zebrafish. Discussion: Our findings suggest that zebrafish myo7aa affects congenital hearing by regulating Rho GTPase signaling, and loss of myo7aa leads to abnormal Rho GTPase signaling and impairs hair cell function. myo7aa, myo7A, arhgap33, dab2ip, arghef40 and myo7aa-/- fonts in the abstract are italicized. -/- is a superscript format.

Mediator kinase inhibition reverses castration resistance of advanced prostate cancer.

Mediator kinases CDK19 and CDK8, pleiotropic regulators of transcriptional reprogramming, are differentially regulated by androgen signaling, but both kinases are upregulated in castration-resistant prostate cancer (CRPC). Genetic or pharmacological inhibition of CDK8 and CDK19 reverses the castration-resistant phenotype and restores the sensitivity of CRPC xenografts to androgen deprivation in vivo. Prolonged CDK8/19 inhibitor treatment combined with castration not only suppressed the growth of CRPC xenografts but also induced tumor regression and cures. Transcriptomic analysis revealed that Mediator kinase inhibition amplified and modulated the effects of castration on gene expression, disrupting CRPC adaptation to androgen deprivation. Mediator kinase inactivation in tumor cells also affected stromal gene expression, indicating that Mediator kinase activity in CRPC molded the tumor microenvironment. The combination of castration and Mediator kinase inhibition downregulated the MYC pathway, and Mediator kinase inhibition suppressed a MYC-driven CRPC tumor model even without castration. CDK8/19 inhibitors showed efficacy in patient-derived xenograft models of CRPC, and a gene signature of Mediator kinase activity correlated with tumor progression and overall survival in clinical samples of metastatic CRPC. These results indicate that Mediator kinases mediated androgen-independent in vivo growth of CRPC, supporting the development of CDK8/19 inhibitors for the treatment of this presently incurable disease.