Search

Abstract Background Sentrin/SUMO-specific protease 3 (SENP3) is essential to regulate protein stability and function in normal and cancer cells. Nevertheless, its role and action mechanisms in prostate cancer (PCa) remain elusive. Thus, clarification of SENP3’s involvement and the SUMOylation process in PCa is pivotal for discovering potential targets and understanding SUMOylation dynamics. Methods Cell viability, EdU staining, live cell imaging, and cell cycle assays were used to determine proliferation of PCa cells. Transwell and wound-healing assays were used to detect migration of PCa cells. The interaction between SENP3 and SIX1 was determined by co-immunoprecipitation, western blotting, and immunofluorescence assays. Xenograft models established on NOD-SCID mice were used to evaluate in vivo effects post SENP3 knockdown. Immunohistochemistry was performed to investigate the expression of SENP3 in PCa tissues. Results This study found that SENP3 is highly expressed in PCa cell lines and tissues from PCa patients. Overexpressed SENP3 is associated with metastatic malignancy in PCa. Various in vivo and in vitro experiments confirmed that SENP3 promotes the proliferation and migration of PCa. In addition, SENP3 interacts with the SD domain of SIX1 and mediates its deSUMOylation and protein stability. Lys154 (K154) is required for the SUMOylation of SIX1. More importantly, SENP3 promotes the malignancy of PCa through the regulation of SIX1. Conclusions We unravel the significant role of SENP3 in regulating protein stability of SIX1 and progression of PCa, which may deepen our understanding of the SUMOylation modification and provide a promising target for management of metastatic PCa.

The abundance and activity of estrogen receptor alpha (ERα) are tightly regulated by ubiquitin-specific peptidase 22 (USP22) during the progression of breast cancer (BCa). However, the post-transcriptional modifications on the USP22-ERα axis remain elusive. N6-methyladenosine (m6A) is critical to modulate RNA status in eukaryotic cells. Here, we find that METTL14 positively regulates the mRNA expression of USP22 and ERα. Mechanistically, METTL14 potently binds to the USP22 and ERα mRNA, and thereby enhancing their stability through m6A modification. YTHDC1 and YTHDF1 function as readers for m6A-modified USP22 and ERα, respectively. Additionally, METTL14 promotes the growth and migration of ERα+ BCa via the USP22-ERα-Cyclin D1 axis. Enforced expression of USP22/ERα significantly reverses the METTL14 depletion-induced growth and migration inhibition in BCa. Moreover, our analysis of clinical samples shows that the expression of METTL14, USP22, and ERα is upregulated and correlated in BCa tissues. Overall, our findings reveal the key role of the METTL14-USP22-ERα axis in BCa progression, which further provides a druggable target to treat BCa.

Abstract YTH domain family 2 (YTHDF2) is the first identified N6‐methyladenosine (m6A) 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 (HSP90β) 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 HSP90β is required for its interaction with STUB1 and YTHDF2. HSP90β 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, HSP90β and YTHDF2 are upregulated, while STUB1 is downregulated in HCC tissues. The expression of HSP90β is positively correlated with the YTHDF2 protein level, whereas the expression of STUB1 is negatively correlated with the protein levels of YTHDF2 and HSP90β. These findings deepen the understanding of how YTHDF2 is regulated to drive HCC progression and provide potential targets for treating HCC.

Abstract It’s highly desired but challenging to synthesize self-supporting nanohybrid made of conductive nanoparticles with metal organic framework (MOF) materials for the application in the electrochemical field. In this work, we report the preparation of Ni2P embedded Ni-MOF nanosheets supported on nickel foam through partial phosphidation (Ni2P@Ni-MOF/NF). The self-supporting Ni2P@Ni-MOF/NF was directly tested as electrode for urea electrolysis. When served as anode for urea oxidation reaction (UOR), it only demands 1.41 V (vs RHE) to deliver a current of 100 mA cm−2. And the overpotential of Ni2P@Ni-MOF/NF to reach 10 mA cm−2 for hydrogen evolution reaction HER was only 66 mV, remarkably lower than Ni2P/NF (133 mV). The exceptional electrochemical performance was attributed to the unique structure of Ni2P@Ni-MOF and the well exposed surface of Ni2P. Furthermore, the Ni2P@Ni-MOF/NF demonstrated outstanding longevity for both HER and UOR. The electrolyzer constructed with Ni2P@Ni-MOF/NF as bifunctional electrode can attain a current density of 100 mA cm−2 at a cell voltage as low as 1.65 V. Our work provides new insights for prepare MOF based nanohydrid for electrochemical application.

Abstract 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.

Abstract Deubiquitinates (DUBs) have been suggested as novel promising targets for cancer therapies. Accumulating experimental evidence suggests that some metal compounds have the potential to induce cancer cell death via inhibition of DUBs. We previously reported that auranofin, a gold(I)-containing agent used for the treatment of rheumatoid arthritis in clinics, can induce cell death by inhibiting proteasomal DUBs in a series of cancer cell lines. Unfortunately, currently available gold compounds are not potent in inhibiting DUBs. Here, we report that: (i) aumdubin, a synthetic derivative of auranofin, exhibited stronger DUB-inhibiting and apoptosis-inducing activities than auranofin in lung cancer cells; (ii) aumdubin shows high affinity for mitochondrial DUB USP30; (iii) aumdubin induces apoptosis by increasing the ubiquitination and mitochondrial location of Bax protein; and (iv) USP30 inhibition may contribute to Bax-dependent apoptosis induced by aumdubin in lung cancer cells. These results suggest that gold(I)-containing agent aumdubin induces Bax-dependent apoptosis partly through inhibiting the mitochondrial DUB USP30, which could open new avenues for lung cancer therapy.

Abstract Background We aimed to analyse the oral health status of adolescents in Shandong province, including dental caries and gingivitis, and their associated factors. Methods Adolescents aged 12–15-years in Shandong province were recruited. Caries and gingival status were assessed following the World Health Organisation diagnostic criteria. Information including the sociodemographic, oral hygiene knowledge, attitudes and practices were collected through the questionnaire. Chi-square test and multivariate logistic regression analysis were used to investigate the oral diseases associated factors. Results In total, 3868 students (50.2% males) were enrolled. Of these, 39.9% of the participants experienced caries, and 81.7% and 31.3% had calculus and bleeding gingival, respectively. Multivariate logistic regression analysis revealed that there was an association between dental caries and toothaches, dental visits and sleeping troubles caused by oral problems (P

Abstract 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.

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.

Appropriate gene carriers are vital components of gene therapy for treating numerous intractable diseases. Compared with viral carriers, non-viral carriers exhibit lower immunogenicity and higher biosafety, which have received increasing attention. In particular, among non-viral vectors, gene vectors based on chitosan derivatives are considered a promising gene therapy tool and have been extensively studied due to the biocompatibility, biodegradability, and modifiability of chitosan. In this review, we first discussed the influence of chitosan parameters on the efficiency of gene therapy. More importantly, we summarized the recent research progress in various diseases of chitosan derivatives to deliver different gene therapy substances including plasmid (pDNA), short interfering RNA (siRNA), short hairpin RNA (shRNA), microRNA (miRNA), and clustered regularly interspaced short palindromic repeats-associated endonuclease 9 (CRISPER-Cas9) system. Finally, the current challenges and future directions of chitosan derivatives as gene carriers are also proposed. [ABSTRACT FROM AUTHOR]