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Hepatocellular carcinoma (HCC) remains challenging due to the lack of efficient therapy. Promoting degradation of certain cancer drivers has become an innovative therapy. The nuclear transcription factor sine oculis homeobox 1 (SIX1) is a key driver for the progression of HCC. Here, we explored the molecular mechanisms of ubiquitination of SIX1 and whether targeting SIX1 degradation might represent a potential strategy for HCC therapy. Through detecting the ubiquitination level of SIX1 in clinical HCC tissues and analyzing TCGA and GEPIA databases, we found that ubiquitin specific peptidase 1 (USP1), a deubiquitinating enzyme, contributed to the lower ubiquitination and high protein level of SIX1 in HCC tissues. In HepG2 and Hep3B cells, activation of EGFR-AKT signaling pathway promoted the expression of USP1 and the stability of its substrates, including SIX1 and ribosomal protein S16 (RPS16). In contrast, suppression of EGFR with gefitinib or knockdown of USP1 restrained EGF-elevated levels of SIX1 and RPS16. We further revealed that SNS-023 (formerly known as BMS-387032) induced degradation of SIX1 and RPS16, whereas this process was reversed by reactivation of EGFR-AKT pathway or overexpression of USP1. Consequently, inactivation of the EGFR-AKT-USP1 axis with SNS-032 led to cell cycle arrest, apoptosis, and suppression of cell proliferation and migration in HCC. Moreover, we showed that sorafenib combined with SNS-032 or gefitinib synergistically inhibited the growth of Hep3B xenografts in vivo. Overall, we identify that both SIX1 and RPS16 are crucial substrates for the EGFR-AKT-USP1 axis-driven growth of HCC, suggesting a potential anti-HCC strategy from a novel perspective.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/patologia , Sorafenibe/farmacologia , Sorafenibe/uso terapêutico , Neoplasias Hepáticas/patologia , Gefitinibe , Proteínas Proto-Oncogênicas c-akt/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Receptores ErbB , Proteínas Ribossômicas , Proteínas de Homeodomínio/metabolismoRESUMO
Cardiac hypertrophy, a compensatory response to various stimuli in the heart, independently predicts cardiovascular ailments and related deaths. Increasing evidence indicates ubiquitin-proteasome signaling contributes to cardiac hypertrophy regulation. Here, we identified ubiquitin-specific protease 14 (USP14), a 19S proteasome associated deubiquitinase (DUB), as a novel target for cardiac hypertrophy therapy via inhibition of the GSK-3ß pathway. Indeed, USP14 expression was increased in an animal model of abdominal aorta constriction. In an angiotensin II (AngII) induced primary neonatal rat cardiomyocyte hypertrophy model, USP14 expression was increased in a time-dependent manner, and reduced USP14 deubiquitinase activity or USP14 knockdown resulted in lower expression levels of the myocardial hypertrophy specific marker ß-MHC, and subsequent decreased GSK-3ß phosphorylation. In conclusion, USP14 mediates the development of cardiac hypertrophy by promoting GSK-3ß phosphorylation, suggesting that USP14 might represent a novel therapeutic target for cardiac hypertrophy treatment.
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Cardiomegalia/enzimologia , Cardiomegalia/patologia , Progressão da Doença , Glicogênio Sintase Quinase 3 beta/metabolismo , Ubiquitina Tiolesterase/metabolismo , Animais , Animais Recém-Nascidos , Aorta Abdominal/diagnóstico por imagem , Aorta Abdominal/patologia , Biomarcadores/metabolismo , Cardiomegalia/diagnóstico por imagem , Constrição Patológica , Modelos Animais de Doenças , Técnicas de Silenciamento de Genes , Ventrículos do Coração/patologia , Masculino , Miocárdio/metabolismo , Miocárdio/patologia , Cadeias Pesadas de Miosina/metabolismo , Fosforilação , Ratos Sprague-DawleyRESUMO
BACKGROUND: Obesity is a global concern, driving the search for alternative treatments beyond lifestyle changes and medications. Laser acupuncture (LA) shows promise in obesity management, yet few studies compare it with FDA-approved medications. This study aimed to assess and compare LA's impact with liraglutide on weight reduction in obese individuals. METHODS: Data from the Chang Gung Research Database (CGRD) (2013-2018) were analyzed. Primary outcomes included changes in body weight and BMI within 180 days, with secondary outcomes measuring the proportion achieving 5%, 10%, and 15% weight loss. Adverse events were also assessed. RESULTS: Of 745 subjects (173 LA users, 572 liraglutide users), LA users lost more weight by day 180 (5.82 ± 4.39 vs. 2.38 ± 5.75 kg; p < 0.001) and had a greater BMI reduction (-2.27 ± 1.73 vs. -0.93 ± 2.25 kg/m2; p < 0.001). More LA users achieved 5% and 10% weight loss compared to liraglutide users (64.2% vs. 22.7%, 26.6% vs. 4.2%; all p < 0.001). After balancing baseline differences, LA's benefits remained significant. No adverse events were reported with LA. CONCLUSIONS: LA may offer superior weight reduction compared to liraglutide. Future studies should explore LA alone or in combination with liraglutide for obesity management.
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YTH domain family 2 (YTHDF2) is the first identified N6-methyladenosine (m6 A) reader that regulates the status of mRNA. It has been reported that overexpressed YTHDF2 promotes carcinogenesis; yet, its role in hepatocellular carcinoma (HCC) is elusive. Herein, it is demonstrated that YTHDF2 is upregulated and can predict poor outcomes in HCC. Decreased ubiquitination levels of YTHDF2 contribute to the upregulation of YTHDF2. Furthermore, heat shock protein 90 beta (HSP90ß) and STIP1 homology and U-box-containing protein 1 (STUB1) physically interact with YTHDF2 in the cytoplasm. Mechanically, the large and small middle domain of HSP90ß is required for its interaction with STUB1 and YTHDF2. HSP90ß inhibits the STUB1-induced degradation of YTHDF2 to elevate the expression of YTHDF2 and to further boost the proliferation and sorafenib resistance of HCC. Moreover, HSP90ß and YTHDF2 are upregulated, while STUB1 is downregulated in HCC tissues. The expression of HSP90ß is positively correlated with the YTHDF2 protein level, whereas the expression of STUB1 is negatively correlated with the protein levels of YTHDF2 and HSP90ß. These findings deepen the understanding of how YTHDF2 is regulated to drive HCC progression and provide potential targets for treating HCC.
Assuntos
Carcinoma Hepatocelular , Proteínas de Choque Térmico HSP90 , Neoplasias Hepáticas , Humanos , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Proteínas de Ligação a RNA/metabolismo , Sorafenibe/farmacologia , Ubiquitina-Proteína Ligases/genética , Ubiquitinação , Regulação para Cima , Proteínas de Choque Térmico HSP90/metabolismoRESUMO
HER2 is a transmembrane receptor with intrinsic tyrosine kinase activity that is overexpressed in almost 25% of human breast cancers. Here, we report that the neddylation of HER2 is a new post-translational modification that controls its expression and oncogenic activity in human breast cancer. Two critical members in the neddylation pathway, NEDD8 and NEDD8-activating enzyme E1 subunit 1 (NAE1), are detected in human breast specimens. Overexpressed NEDD8 and NAE1 are positively correlated with HER2 expression in human breast cancer. Subsequent structure and function experiments show that HER2 directly interacts with NEDD8 and NAE1, whereas HER2 protein expression is decreased by neddylation depletion. Mechanistically, neddylation inhibition promotes the degradation of HER2 protein by improving its ubiquitination. HER2 overexpression abrogates neddylation depletion-triggered cell growth suppression. The inhibition of neddylation synergized with trastuzumab significantly suppresses growth of HER2 positive breast cancer. Collectively, this study demonstrates a previously undiscovered role of NEDD8-dependent HER2 neddylation promotes tumor growth in breast cancer.
Assuntos
Neoplasias da Mama , Proteína NEDD8 , Proteólise , Receptor ErbB-2 , Ubiquitinação , Feminino , Humanos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Processamento de Proteína Pós-Traducional , Receptor ErbB-2/metabolismo , Proteína NEDD8/metabolismo , Progressão da DoençaRESUMO
[This corrects the article DOI: 10.3389/fphar.2022.978814.].
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Prostate cancer (PC) remains a great medical challenge due to its high incidence and the development of castration resistance in patients treated with androgen deprivation therapy. Deubiquitinases, the enzymes that specifically hydrolyze ubiquitin chains on their substrates, were recently proposed as a serious of critical therapeutic targets for cancer treatment. Our previous study has been reported that the ubiquitin specific peptidase 1 (USP1) functionally acts as a deubiquitinase of sine oculis homeobox homolog 1 (SIX1) and contributes to the proliferation and castration resistance of PC. The stabilization of SIX1 by USP1 partially depends on the status of glucose-regulated protein 75 (GRP75). In this study, we aimed to identify a SIX1 degradation inducer via inhibiting the USP1-SIX1 axis. we screened a range of kinase inhibitors and showed that SNS-032 is the best candidate to trigger the ubiquitinated degradation of SIX1. SNS-032 not only restrains activity of the USP1-SIX1 axis and cell cycle progression, but also results in apoptosis of PC cells. Moreover, the combination of SNS-032 and enzalutamide synergistically induces apoptosis and downregulates expression of USP1, SIX1, and AR/AR-V7 in AR-V7 highly expressed 22Rv1 cells. Overall, our findings may develop a novel and effective strategy to overcome castration resistance in PC for the identification of a SIX1 degradation inducer via targeting the USP1-SIX1 axis.
Assuntos
Antagonistas de Androgênios , Neoplasias de Próstata Resistentes à Castração , Antagonistas de Androgênios/farmacologia , Antagonistas de Androgênios/uso terapêutico , Linhagem Celular Tumoral , Proliferação de Células/genética , Proteínas de Homeodomínio/genética , Humanos , Masculino , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Neoplasias de Próstata Resistentes à Castração/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismoRESUMO
Introduction: In Taiwan, many people receive Chinese herbal medicine (CHM) as an alternative choice to help control body weight. However, the clinical effectiveness of CHM on weight control has not been well studied, while potential risks and adverse effects are still unknown. The aim of our study is to find out a safe and efficient treatment model of CHM for weight control compared to liraglutide in a real-world setting. Methods: we retrospectively analyzed obese subjects [body mass index (BMI)â§25 kg/m2] from Chang Gung Research Database (2013-2018). We evaluated the effect on body weight and BMI changes in obese groups receiving CHM or western medicine (WM, represented liraglutide) within 180 days. The proportion of subjects who achieved 5 and 10% weight reduction was calculated as well. Furthermore, the potential adverse events were analyzed during the study period. Overlap weighting was used to balance the baseline differences between CHM and WM groups. Results: The full cohort comprised 1,360 participants: 701 in the CHM group and 659 in the WM group. At baseline, the CHM group was younger (42.75 ± 12.12 years old in CHM vs. 52.31 ± 11.7 years old in WM, p-value <0.001) and has more female subjects (77.6% in CHM vs. 53.0% in WM, p-value <0.001). On the other hand, CHM users had lower body weight (79.83 ± 15.66 kg vs. 84.68 ± 17.14 kg, p-value <0.001) and BMI (30.58 ± 5.20 vs. 32.84 ± 6.95, p-value <0.001). At day 180, CHM users lost more body weight (-4.5 ± 4.07 kg vs. -2.15 ± 4.05 kg, p-value <0.001) and higher reduction in BMI (-1.77 ± 1.73 vs. -0.9 ± 2.14, p-value <0.001). A total of 53.21% (n = 373) CHM users lost at least 5% of body weight (22.46% for WM users, p-value <0.001), and 18.97% (n = 132) lost at least 10% of body weight (4.55% for WM users, p-value <0.001). The benefit remained consistent with and without overlap weighting. For adverse events, 18 cases of hypertension occurred in 659 subjects in the WM group (2.7%) in comparison to 1 of 701 subjects in the CHM group (0.1%). Conclusion: CHM led to clinically meaningful weight loss without serious adverse events in a real-world setting. Further clinical trials are warranted to validate this result.
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Breast cancer has the highest incidence and mortality in women worldwide. There are 70% of breast cancers considered as estrogen receptor α (ERα) positive. Therefore, the ERα-targeted therapy has become one of the most effective solution for patients with breast cancer. Whereas a better understanding of ERα regulation is critical to shape evolutional treatments for breast cancer. By exploring the regulatory mechanisms of ERα at levels of post-translational modifications, we identified the deubiquitinase USP15 as a novel protector for preventing ERα degradation and a critical driver for breast cancer progression. Specifically, we demonstrated that USP15 promoted the proliferation of ERα+, but not ERα- breast cancer, in vivo and in vitro. Meanwhile, USP15 knockdown notably enhanced the antitumor activities of tamoxifen on breast cancer cells. Importantly, USP15 knockdown induced the downregulation of ERα protein via promoting its K48-linked ubiquitination, which is required for proliferative inhibition of breast cancer cells. These findings not only provide a novel treatment for overcoming resistance to endocrine therapy, but also represent a therapeutic strategy on ERα degradation by targeting USP15-ERα axis.
Assuntos
Neoplasias da Mama/metabolismo , Receptor alfa de Estrogênio/metabolismo , Proteases Específicas de Ubiquitina/metabolismo , Neoplasias da Mama/genética , Linhagem Celular Tumoral , Progressão da Doença , Receptor alfa de Estrogênio/genética , Feminino , Humanos , Células MCF-7 , Transdução de Sinais , Transfecção , UbiquitinaçãoRESUMO
Androgen receptor splice variant 7 (AR-V7), a form of ligand-independent and constitutively activating variant of androgen receptor (AR), is considered as the key driver to initiate castration-resistant prostate cancer (CRPC). Because AR-V7 lacks ligand-binding domain, the AR-targeted therapies that aim to inactivate AR signaling through disrupting the interaction between AR and androgen are limited in CRPC. Thus, the emergence of AR-V7 has become the greatest challenge for treating CRPC. Targeting protein degradation is a recently proposed novel avenue for cancer treatment. Our previous studies have been shown that the oncoprotein AR-V7 is a substrate of the proteasome. Identifying novel drugs that can trigger the degradation of AR-V7 is therefore critical to cure CRPC. Here we show that nobiletin, a polymethoxylated flavonoid derived from the peel of Citrus fruits, exerts a potent anticancer activity via inducing G0/G1 phase arrest and enhancing the sensitivity of cells to enzalutamide in AR-V7 positive PC cells. Mechanically, we unravel that nobiletin selectively induces proteasomal degradation of AR-V7 (but not AR). This effect relies on its selective inhibition of the interactions between AR-V7 and two deubiquitinases USP14 and USP22. These findings not only enrich our understanding on the mechanism of AR-V7 degradation, but also provide an efficient and druggable target for overcoming CRPC through interfering the stability of AR-V7 mediated by the interaction between AR-V7 and deubiquitinase.
Assuntos
Neoplasias de Próstata Resistentes à Castração/metabolismo , Proteólise , Receptores Androgênicos/metabolismo , Animais , Benzamidas/farmacologia , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Flavonas/farmacologia , Humanos , Lisina/metabolismo , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Modelos Biológicos , Nitrilas/farmacologia , Feniltioidantoína/farmacologia , Neoplasias de Próstata Resistentes à Castração/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Proteólise/efeitos dos fármacos , Ubiquitina Tiolesterase/metabolismo , UbiquitinaçãoRESUMO
BACKGROUND: Hepatocellular carcinoma (HCC) remains a medical challenge due to its high proliferation and metastasis. Although deubiquitinating enzymes (DUBs) play a key role in regulating protein degradation, their pathological roles in HCC have not been fully elucidated. METHODS: By using biomass spectrometry, co-immunoprecipitation, western blotting and immunofluorescence assays, we identify ribosomal protein S16 (RPS16) as a key substrate of ubiquitin-specific peptidase 1 (USP1). The role of USP1-RPS16 axis in the progression of HCC was evaluated in cell cultures, in xenograft mouse models, and in clinical observations. RESULTS: We show that USP1 interacts with RPS16. The depletion of USP1 increases the level of K48-linked ubiquitinated-RPS16, leading to proteasome-dependent RPS16 degradation. In contrast, overexpression of USP1-WT instead of USP1-C90A (DUB inactivation mutant) reduces the level of K48-linked ubiquitinated RPS16, thereby stabilizing RPS16. Consequently, USP1 depletion mimics RPS16 deficiency with respect to the inhibition of growth and metastasis, whereas transfection-enforced re-expression of RPS16 restores oncogenic-like activity in USP1-deficient HCC cells. Importantly, the high expression of USP1 and RPS16 in liver tissue is a prognostic factor for poor survival of HCC patients. CONCLUSIONS: These findings reveal a previously unrecognized role for the activation of USP1-RPS16 pathway in driving HCC, which may be further developed as a novel strategy for cancer treatment.
Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , Proteínas Ribossômicas/metabolismo , Proteases Específicas de Ubiquitina/metabolismo , Animais , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Camundongos , Camundongos Nus , Proteínas Ribossômicas/genética , Transfecção , Proteases Específicas de Ubiquitina/genéticaRESUMO
Prostate cancer (PC) is the second most common cancer with limited treatment option in males. Although the reactivation of embryonic signals in adult cells is one of the characteristics of cancer, the underlying protein degradation mechanism remains elusive. Here, we show that the molecular chaperone GRP75 is a key player in PC cells by maintaining the protein stability of SIX1, a transcription factor for embryonic development. Mechanistically, GRP75 provides a platform to recruit the deubiquitinating enzyme USP1 to inhibit K48-linked polyubiquitination of SIX1. Structurally, the C-terminus of GRP75 (433-679 aa) contains a peptide binding domain, which is required for the formation of GRP75-USP1-SIX1 protein complex. Functionally, pharmacological or genetic inhibition of the GRP75-USP1-SIX1 protein complex suppresses tumor growth and overcomes the castration resistance of PC cells in vitro and in xenograft mouse models. Clinically, the protein expression of SIX1 in PC tumor tissues is positively correlated with the expression of GRP75 and USP1. These new findings not only enhance our understanding of the protein degradation mechanism, but also may provide a potential way to enhance the anti-cancer activity of androgen suppression therapy.
Assuntos
Proteínas de Choque Térmico HSP70/genética , Proteínas de Homeodomínio/genética , Proteínas Mitocondriais/genética , Neoplasias de Próstata Resistentes à Castração/genética , Proteases Específicas de Ubiquitina/genética , Animais , Castração , Linhagem Celular Tumoral , Proliferação de Células/genética , Progressão da Doença , Regulação Neoplásica da Expressão Gênica/genética , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Células PC-3 , Próstata/patologia , Neoplasias de Próstata Resistentes à Castração/patologia , Proteólise , Receptores Androgênicos/genética , Transdução de Sinais/genética , Fatores de Transcrição/genética , Ubiquitinação/genéticaRESUMO
Melanoma, the most threatening cancer in the skin, has been considered to be driven by the carcinogenic RAF-MEK1/2-ERK1/2 signaling pathway. This signaling pathway is usually mainly dysregulated by mutations in BRAF or RAS in skin melanomas. Although inhibitors targeting mutant BRAF, such as vemurafenib, have improved the clinical outcome of melanoma patients with BRAF mutations, the efficiency of vemurafenib is limited in many patients. Here, we show that blood bilirubin in patients with BRAF-mutant melanoma treated with vemurafenib is negatively correlated with clinical outcomes. In vitro and animal experiments show that bilirubin can abrogate vemurafenib-induced growth suppression of BRAF-mutant melanoma cells. Moreover, bilirubin can remarkably rescue vemurafenib-induced apoptosis. Mechanically, the activation of ERK-MNK1 axis is required for bilirubin-induced reversal effects post vemurafenib treatment. Our findings not only demonstrate that bilirubin is an unfavorable for patients with BRAF-mutant melanoma who received vemurafenib treatment, but also uncover the underlying mechanism by which bilirubin restrains the anticancer effect of vemurafenib on BRAF-mutant melanoma cells.
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Foam cell formation process is involved in the pathogenesis of atherosclerosis (AS). Activation of this biological process depends on lipid uptake by scavenger receptors, such as CD36, SR-A and SR-B1. Among these receptors, CD36 is the principal one because it dominates roughly 50% lipid uptake in monocytes. In this study, our western blotting and RT-qPCR assays revealed that USP10 inhibition promotes the degradation of CD36 protein but does not change its mRNA level. In addition, Co-IP results showed that USP10 interacts with CD36 and stabilizes CD36 protein by cleaving poly-ubiquitin on CD36. Significantly, USP10 promotes foam cell formation. Immunofluorescence and Oil red O staining assays show that inhibition or knockdown of USP10 suppresses lipid uptake and foam cell formation by macrophages. In conclusion, USP10 promotes the development and progression of atherosclerosis through stabilizing CD36 protein expression. The regulation of USP10-CD36 may provide a significant therapeutic scheme in atherosclerosis.
Assuntos
Antígenos CD36/metabolismo , Células Espumosas/enzimologia , Lipoproteínas LDL/metabolismo , Macrófagos/enzimologia , Ubiquitina Tiolesterase/metabolismo , Linhagem Celular , Humanos , Ubiquitina Tiolesterase/genéticaRESUMO
Rationale: Androgen receptor splice variant 7 (AR-V7) is a leading cause of the development of castration-resistant prostate cancer (CRPC). However, the regulation and function of AR-V7 at levels of post-translational modifications in prostate cancer therapy remain poorly understood. Here, we conducted a library screen of natural products to identify potential small molecules responsible for AR-V7 protein degradation in human prostate cancer cell lines. Methods: A natural product library was used to screen the inhibitor of AR-V7. Co-IP and biomass spectrum assays were used to identify the AR-V7-interacting proteins, whereas western blot, confocal microscopy, RNA interfering, and gene transfection were used to validate these interactions. Cell viability, EDU staining, and colony formation assays were employed to detect cell growth and proliferation. Flowcytometry assays were used to detect the distribution of cell cycle. Mouse xenograft models were used to study the anti-CRPC effects in vivo. Results: This screen identified rutaecarpine, one of the major components of the Chinese medicine Evodia rutaecarpa, as a novel chemical that selectively induces AR-V7 protein degradation via K48-linked ubiquitination. Mechanically, this effect relies on rutaecarpine inducing the formation of a GRP78-AR-V7 protein complex, which further recruits the E3 ligase SIAH2 to directly promote the ubiquitination of AR-V7. Consequently, the genetic and pharmacological activation of the GRP78-dependent AR-V7 protein degradation restores the sensitivity of castration-resistant prostate cancer to anti-androgen therapy in cell culture and animal models. Conclusions: These findings not only provide a new approach for overcoming castration-resistance in prostate cancer therapy, but also increase our understanding about the interplay between molecular chaperones and ubiquitin ligase in shaping protein stability.
Assuntos
Alcaloides/uso terapêutico , Antagonistas de Receptores de Andrógenos/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Proteínas de Choque Térmico/antagonistas & inibidores , Neoplasias de Próstata Resistentes à Castração/tratamento farmacológico , Receptores Androgênicos/metabolismo , Animais , Castração , Linhagem Celular Tumoral , Chaperona BiP do Retículo Endoplasmático , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Proteínas Nucleares/metabolismo , Isoformas de Proteínas/antagonistas & inibidores , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Proteólise , Receptores Androgênicos/genética , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitinação , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Bcr-Abl is the primary cause as well as currently key therapeutic target of chronic myeloid leukemia (CML). SKP2, an E3 ligase, is a downstream factor of Bcr-Abl to motivate the cell cycle transition of CML and also found to bind and activate Bcr-Abl in reverse. Therefore, SKP2/Bcr-Abl pathway is an attractive target for CML treatment. This study aims to identify an inhibitor of the SKP2/Bcr-Abl pathway based on a large screening of the natural products. We demonstrate that Diosmetin, a kind of phytoestrogens, notably downregulates the expression of SKP2, Bcr-Abl phosphorylation, and moderately downregulates the Bcr-Abl level. Furthermore, Diosmetin displays a favorable anti-tumor activity in CML cells and xenograft models. Collectively, our study reveals a natural compound in the treatment of CML on the basis of SKP2/Bcr-Abl signaling pathway.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Proliferação de Células/efeitos dos fármacos , Flavonoides/farmacologia , Proteínas de Fusão bcr-abl/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases Associadas a Fase S/antagonistas & inibidores , Animais , Apoptose/efeitos dos fármacos , Regulação para Baixo , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Humanos , Mesilato de Imatinib/farmacologia , Células K562 , Leucemia Mielogênica Crônica BCR-ABL Positiva/enzimologia , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Leucemia Mielogênica Crônica BCR-ABL Positiva/patologia , Masculino , Camundongos Endogâmicos BALB C , Camundongos Nus , Fosforilação , Proteínas Quinases Associadas a Fase S/genética , Proteínas Quinases Associadas a Fase S/metabolismo , Transdução de Sinais , Carga Tumoral/efeitos dos fármacos , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Breast cancer (BCa) has the highest incidence and mortality among malignant diseases in female worldwide. BCa is frequently caused by estrogen receptor α (ERα), a ligand-dependent receptor that highly expressed in about 70% of breast tumors. Therefore, ERα has become a well-characterized and the most effective target for treating ERα-expressing BCa (ERα+ BCa). However, the acquire resistance was somehow developed in patients who received current ERα signaling-targeted endocrine therapies. Hence, discovery of novel anti-estrogen/ERα strategies is urgent. In the present study, we identified butein as a potential agent for breast cancer treatment by the use of a natural product library. We showed that butein inhibits the growth of ERα+ BCa both in vitro and in vivo which is associated with cell cycle arrest that partially triggered by butein-induced ERα downregulation. Mechanically, butein binds to a specific pocket of ERα and promotes proteasome-mediated degradation of the receptor. Collectively, this work reveals that butein is a candidate to diminish ERα signaling which represents a potentially novel strategy for treating BCa.
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The incidence and mortality of breast cancer (BCa) are the highest among female cancers. There are approximate 70% BCa that are classified as estrogen receptor alpha (ERα) positive. Therefore, targeting ERα is the most significantly therapeutic schedule. However, patients with breast cancer develop resistance to ERα or estrogen (E2) antagonists such as fulvestrant and tamoxifen. In the present study, we found that L-Tetrahydropalmatine (L-THP) significantly suppressed cell proliferation in ERα+ BCa cells via inducing cell cycle arrest rather than apoptosis. Additionally, L-THP enhanced the sensitivity of ERα+ BCa cells to tamoxifen and fulvestrant. Mechanically, the application of L-THP promotes ERα degradation through accumulating ubiquitin chains on ERα. Overexpressing ERα abrogates L-THP induced-antiproliferation in ERα+ BCa cells. Collectively, our work indicates that L-THP may represent a potentially novel therapeutic medicine for ERα+ breast cancer patient.
Assuntos
Alcaloides de Berberina/farmacologia , Neoplasias da Mama/tratamento farmacológico , Sobrevivência Celular/efeitos dos fármacos , Receptor alfa de Estrogênio/antagonistas & inibidores , Antineoplásicos Hormonais/farmacologia , Linhagem Celular Tumoral , Antagonistas de Dopamina/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Antagonistas de Estrogênios/farmacologia , Feminino , Fulvestranto/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Humanos , Modelos Moleculares , Conformação Proteica , Tamoxifeno/farmacologiaRESUMO
BACKGROUND: Our previous study in animal models revealed that bilirubin could induce Aß formation and deposition. Bilirubin may be important in neurodegenerative dementia with Aß deposition. Hence, lowering the concentration of the free bilirubin capable of crossing the blood brain-barrier may benefit the treatment of Alzheimer's disease (AD). OBJECTIVES: The objectives of this study were to examine the change in the serum bilirubin and albumin concentrations of dementia patients with Aß deposition, and to determine the effects of intravenous administration of albumin in the treatment of AD. METHODS: Bilirubin and albumin concentrations in dementia patients with Aß deposition were examined. Cell viability and apoptosis were determined in dopaminergic neuron-like cells MN9D treated with bilirubin in the presence of diverse concentrations of serum. Human albumin at a dose of 10 g every 2 weeks for 24 weeks was administered intravenously to AD patients to examine the effect of albumin on AD symptoms. RESULTS: Significantly higher indirect bilirubin (IBIL) concentrations, lower albumin concentrations, and higher ratio of IBIL to albumin (IBIL/ALB) were observed in dementia patients with Aß deposition, including AD, dementia with Lewy bodies, and general paresis of insane. In vitro assays showed that bilirubin-induced injury in cultured dopaminergic neuron-like cells negatively depends on the concentration of serum in the culture medium. General linear model with repeated measures analysis indicated a main effect of group on the change in albumin concentrations and Alzheimer's Disease Cooperative Study Activities of Daily Living Inventory scale (ADCS-ADL) scores, and the main effect of time and group, and group-by-time interaction on the change of Clinical Dementia Rating Scale-Sum of Boxes (CDR-SB) scores. Analysis of the combined data of the entire 28 weeks of assessment period using the area under curve convincingly showed significantly improvements in the change of albumin concentrations, ADCS-ADL scores, and CDR-SB scores. CONCLUSION: IBIL and the IBIL/ALB ratio are significantly higher in dementia patients with Aß deposition, and intravenous administration of albumin is beneficial to AD treatment. TRIAL REGISTRATION: The intervention study was registered at http://www.chictr.org.cn (ChiCTR-IOR-17011539). Date of registration: June 1, 2017.
RESUMO
BACKGROUND: Androgen receptor (AR) is expressed in approximately 70% of breast tumors. Recent studies increasingly support AR as a potential therapeutic target of AR-positive breast cancer. We have previously reported that deubiquitinase USP14 stabilizes AR proteins by deubiquitination and USP14 inhibition results in inhibition of cell growth and tumor progression in AR-positive prostate cancer and breast cancer. The current study aims to explore the anticancer effect of a treatment combining AR antagonist enzalutamide with USP14 inhibition on breast cancer cells. METHODS: The combining effects of enzalutamide and USP14 inhibition on breast cancer cell proliferation and apoptosis and associated cell signaling were evaluated in vitro and in vivo. RESULTS: USP14 inhibition via administration of IU1 or USP14-specific siRNA/shRNA enhanced cell growth inhibition and apoptosis induction by enzalutamide in breast cancer cell lines in vitro and in vivo. Additionally, the combination of enzalutamide with USP14 inhibition/knockdown induced significant downregulation of AR proteins and suppression of AR-related signaling pathways, including Wnt/ß-catenin and PI3K/AKT pathways. Moreover, AKT inhibition via MK2206 increased the antiproliferative and proapoptotic effects of enzalutamide+IU1 combined treatment. CONCLUSION: Collectively, our data suggest that USP14 inhibition in combination with enzalutamide represents a potentially new therapeutic strategy for breast cancer.