Targeting LYPLAL1-mediated cGAS depalmitoylation enhances the response to anti-tumor immunotherapy.

Cyclic GMP-AMP synthase (cGAS) binds pathogenic and other cytoplasmic double-stranded DNA (dsDNA) to catalyze the synthesis of cyclic GMP-AMP (cGAMP), which serves as the secondary messenger to activate the STING pathway and innate immune responses. Emerging evidence suggests that activation of the cGAS pathway is crucial for anti-tumor immunity; however, no effective intervention method targeting cGAS is currently available. Here we report that cGAS is palmitoylated by ZDHHC9 at cysteines 404/405, which promotes the dimerization and activation of cGAS. We further identified that lysophospholipase-like 1 (LYPLAL1) depalmitoylates cGAS to compromise its normal function. As such, inhibition of LYPLAL1 significantly enhances cGAS-mediated innate immune response, elevates PD-L1 expression, and enhances anti-tumor response to PD-1 blockade. Our results therefore reveal that targeting LYPLAL1-mediated cGAS depalmitoylation contributes to cGAS activation, providing a potential strategy to augment the efficacy of anti-tumor immunotherapy.

ß-asarone inhibits the migration, invasion, and EMT of bladder cancer through activating ER stress.

BACKGROUND: ß-asarone (ß-as), a compound extracted from Acorus calamus, has been found to have anticancer effects on a variety of human cancers. However, the potential effect of ß-as on bladder cancer (BCa) remains unknown. METHODS: After exposure to ß-as, migration, invasion, and epithelial-mesenchymal transition (EMT) of BCa were determined by wound healing, transwell, and Western blot assays. Expression of proteins involved in the EMT and ER stress were explored by Western blot assays. Nude mouse xenograft model was served as the model system in vivo. RESULTS: The migration, invasion, and EMT of BCa were significantly inhibited after ß-as treatment. Further experiments revealed that endoplasmic reticulum (ER) stress is involved in ß-as-mediated metastasis inhibition. In addition, ß-as significantly up-regulated activating transcription factor 6 (ATF6), a branch of ER stress, and promoted its Golgi cleavage and nuclear localization. ATF6 silencing attenuated ß-as-mediated metastasis and EMT inhibition in BCa cells. CONCLUSION: Our data suggests that ß-as inhibits migration, invasion, and EMT of BCa by activating the ATF6 branch of ER stress. Thus, ß-as represents a potential candidate for BCa treatment.

ß-Ionone represses renal cell carcinoma progression through activating LKB1/AMPK-triggered autophagy.

ß-Ionone, the end ring analog of ß-carotenoids, has been proven to have an antitumor effect in a variety of cancers. In this study, we investigated the impact of ß-ionone on renal cell carcinoma (RCC) cell lines (786-O and ACHN) using colony formation assays, flow cytometry analysis, and western blot analysis. We found that ß-ionone effectively inhibited the proliferation of RCC cells in vitro, which was also confirmed in a xenograft model. Moreover, we found that ß-ionone could induce autophagy, as indicated by LC3 puncta in 786-O and ACHN cell lines and the expression of LC3 in ß-ionone-treated RCC cells. To further explore the underlying mechanism, we assessed liver kinase B1/AMP-activated protein kinase (LKB1/AMPK) signaling pathway activity, and the results showed that ß-ionone inhibited the proliferation of RCC cells by inducing autophagy via the LKB1/AMPK signaling pathway. In summary, our findings provide a new therapeutic strategy of ß-ionone-induced autophagy in RCC.

Silibinin inhibits the migration, invasion and epithelial-mesenchymal transition of prostate cancer by activating the autophagic degradation of YAP.

Silibinin (SB), a flavonoid extracted from milk thistle seeds, has been found to exert antitumor effects in numerous tumor types. Our previous study reported that SB had anti-metastatic effects in prostate cancer (PCa). However, the exact underlying molecular mechanisms remain to be determined. The present study aimed to investigate the effects of SB on the migration, invasion and epithelial-mesenchymal transition (EMT) of castration-resistant PCa (CRPC) cells using wound healing, Transwell assays, and western blotting. The results revealed that SB treatment significantly inhibited the migration and invasion of CRPC cell lines. Moreover, SB was confirmed to activate autophagy, as determined using LC3 conversion, LC3 turnover and LC3 puncta assays. Further mechanistic studies indicated that the expression levels of Yes-associated protein (YAP) were downregulated in an autophagy-dependent manner after SB treatment. In addition, the SB-induced autophagic degradation of YAP was associated with the anti-metastatic effects of SB in CRPC. In conclusion, the findings of the present study suggested that SB might inhibit the migration, invasion and EMT of PCa cells by regulating the autophagic degradation of YAP, thus representing a potential novel treatment strategy for metastatic CRPC.

Deubiquitinase OTUD5 modulates mTORC1 signaling to promote bladder cancer progression.

The mechanistic (formally "mammalian") target of rapamycin (mTOR) pathway serves as a crucial regulator of various biological processes such as cell growth and cancer progression. In bladder cancer, recent discoveries showing the cancer-promoting role of mTOR complex 1 have attracted wide attention. However, the regulation of mTOR signaling in bladder cancer is complicated and the underlying mechanism remains elusive. Here, we report that the deubiquitinating enzyme, ovarian tumor domain-containing protein 5 (OTUD5), can activate the mTOR signaling pathway, promote cancer progression, and show its oncogenic potential in bladder cancer. In our study, we found that OTUD5 deubiquitinated a RING-type E3 ligase, RNF186, and stabilized its function. In addition, the stabilization of RNF186 further led to the degradation of sestrin2, which is an inhibitor of the mTOR signaling pathway. Together, we provide novel insights into the pathogenesis of bladder cancer and first prove that OTUD5 can promote bladder cancer progression through the OTUD5-RNF186-sestrin2-mTOR axis, which may be exploited in the future for the diagnosis and treatment of this malignancy.

Capsaicin inhibits the migration, invasion and EMT of renal cancer cells by inducing AMPK/mTOR-mediated autophagy.

Capsaicin (CAP), extracted from Capsicum fruits, has been reported to exhibit antitumor effects in various lines of cancer cells. However, the mechanism underlying its antitumor efficiency is not fully understood. Autophagy is a fundamental self-degradation process of cells that maintains homeostasis and plays a controversial role in tumor initiation and progression. The EMT is defined as a system regulating cells transformed from an epithelial-like phenotype into a mesenchymal phenotype by several internal and external factors, following the metastatic performance of the cells developed. The present study aimed to investigate the potential role of autophagy in CAP-induced antitumor effects in renal cell carcinoma (RCC) 786-O and CAKI-1 cell lines. The results revealed that CAP remarkably inhibited the migration and invasion of RCC cells in vitro and metastasis in vivo. Moreover, we found that the CAP treatment increased the formation of autophagolysosome vacuoles and LC3 yellow and red fluorescent puncta in RCC cells and upregulated the expression of LC3, suggesting that autophagy was induced by CAP in 786-O and CAKI-1 cell lines. Our further results demonstrated that CAP-induced autophagy was mediated by the AMPK/mTOR pathway. In conclusion, our study provides new knowledge of the potential relationship between autophagy and metastasis inhibition induced by CAP, which might be a promising therapeutic strategy in RCC.

ERK1/2 inhibits Cullin 3/SPOP-mediated PrLZ ubiquitination and degradation to modulate prostate cancer progression.

The gene encoding the E3 ubiquitin ligase substrate-binding adaptor SPOP is frequently mutated in prostate cancer (PCa), but how SPOP functions as a tumor suppressor and contributes to PCa pathogenesis remains poorly understood. Prostate Leucine Zipper (PrLZ) serves as a prostate-specific and androgen-responsive gene, which plays a pivotal role in the malignant progression of PCa. However, the upstream regulatory mechanism of PrLZ protein stability and its physiological contribution to PCa carcinogenesis remain largely elusive. Here we report that PrLZ can be degraded by SPOP. PrLZ abundance is elevated in SPOP-mutant expressing PCa cell lines and patient specimens. Meanwhile, ERK1/2 might regulate SPOP-mediated PrLZ degradation through phosphorylating PrLZ at Ser40, which blocks the interaction between SPOP and PrLZ. In addition, we identify IL-6 might act as an upstream PrLZ degradation regulator via promoting its phosphorylation by ERK1/2, leading to its impaired recognition by SPOP. Thus, our study reveals a novel SPOP substrate PrLZ which might be controlled by ERK1/2-mediated phosphorylation, thereby facilitating to explore novel drug targets and improve therapeutic strategy for PCa.

ß-ionone Inhibits Epithelial-Mesenchymal Transition (EMT) in Prostate Cancer Cells by Negatively Regulating the Wnt/ß-Catenin Pathway.

BACKGROUND: ß-ionone is a terminal cyclic analog of beta-carotenoids widely found in plants. In recent years, accumulating evidence has shown that ß-ionone exerts antitumor effects on various malignant tumors. However, limited studies have revealed the role of ß-ionone in regulating the epithelial-mesenchymal transition (EMT) of prostate cancer (PCa) cells. This study aimed to investigate the effect of ß-ionone on the EMT process of PCa, focusing on Wnt/ß-catenin signaling pathway. METHODS: After exposure to ß-ionone, cell viability was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and the Brdu proliferation assay. The Transwell and wounding healing were used to investigate the migration and invasion abilities of PCa cells. Expression of proteins involved in the EMT process (E-cadherin, N-cadherin, vimentin) and proteins in the Wnt/ß-catenin pathway (ß-catenin, GSK3-ß, and p-GSK3-ß) were explored by western blotting. The effects of ß-ionone on ß-catenin degradation were explored by cycloheximide tracking assay and in vitro ubiquitination assay. Nude mouse xenograft model was served as the model system in vivo. RESULTS: The migration, invasion, and EMT process of PCa Human PC-3 prostate adenocarcinoma cells (PC3) and Human 22RV1 prostate adenocarcinoma cells (22RV1) cells were significantly inhibited after ß-ionone treatment. In addition, ß-ionone also inhibited the growth and EMT process of subcutaneous xenograft tumors in nude mice. The study also found that ß-catenin, which promotes EMT, was downregulated after ß-ionone treatment. Further mechanistic studies revealed that ß-ionone inhibited the Wnt/ß-catenin pathway by accelerating the ubiquitination and degradation of ß-catenin in PCa, thus inhibiting the downstream migration, invasion, and EMT processes. CONCLUSIONS: These findings demonstrate that ß-ionone may be a potential natural compound targeting the Wnt/ß-catenin pathway for the treatment of PCa.

Acetylation-dependent regulation of TPD52 isoform 1 modulates chaperone-mediated autophagy in prostate cancer.

Aberrant chaperone-mediated autophagy (CMA) activation has been suggested as a tumorigenesis-promoting event in various cancers, although its roles in prostate cancer (PCa) remain elusive. Emerging evidence indicates that TPD52 isoform 1, a prostate-specific and androgen-responsive gene, contributes to the malignant progression of PCa. Here, we demonstrate that TPD52 enhances CMA activation by interacting with HSPA8/HSC70 and enhancing substrate degradation in PCa. Elevation of TPD52 is essential for CMA-induced PCa cell proliferation and stress resistance in vitro and in vivo. Furthermore, TPD52 is acetylated by KAT2B at K163, which is a process that can be antagonized by HDAC2. Inactivation of HDAC2 results in elevated TPD52 acetylation, which compromises the interaction between TPD52 and HSPA8, leading to impaired CMA function and tumor growth in vivo. Taken together, our findings reveal that acetylation-dependent regulation of TPD52 modulates CMA oncogenic function in PCa, thereby suggesting the possibility of targeting the TPD52-mediated CMA pathway to control the progression of PCa.Abbreviations: CMA: chaperone-mediated autophagy; HDAC2: histone deacetylase 2; HSPA8/HSC70: heat shock protein family A (Hsp70) member 8; KAT2B: lysine acetyltransferase 2B; LAMP2A: lysosomal associated membrane protein 2A; PCa: prostate cancer; TPD52: tumor protein D52.

Silibinin inhibits epithelial­mesenchymal transition of renal cell carcinoma through autophagy­dependent Wnt/ß­catenin signaling.

Silibinin is a flavonoid extracted from milk thistle seeds which has been widely used as a hepatoprotective and antioxidant agent. Recently, accumulating evidence has demonstrated the anti­cancer effects of silibinin in various cancer models. It was previously reported that silibinin induced apoptosis and decreased metastasis by activating autophagy in renal cell carcinoma (RCC). However, the underlying molecular mechanisms by which silibinin regulates autophagy remain largely unknown. The aim of the present study was to investigate the effects of silibinin on RCC metastasis in vitro and in vivo, with a focus on autophagy­dependent Wnt/ß­catenin signaling. Human RCC 786­O and ACHN cell lines were used as the model system in vitro and RCC xenografts of nude mice were used for in vivo studies. Silibinin inhibited metastasis and epithelial­mesenchymal transition (EMT) of RCC in vitro and in vivo, by regulating the Wnt/ß­catenin signaling pathway. Furthermore, silibinin inhibited the Wnt/ß­catenin signaling pathway in an autophagy­dependent manner. Autophagic degradation of ß­catenin induced by silibinin was associated with the anti­metastatic effects of silibinin against RCC. These findings identify a novel mechanism by which silibinin inhibits EMT and metastasis of RCC, highlighting a potential novel strategy for treating metastatic RCC.

Chaperone-mediated autophagy in cancer: Advances from bench to bedside.

Chaperone-mediated autophagy (CMA), a selective form of autophagy, where cellular proteins with KFERQ-like motif are targeted to the lysosome for degradation, is necessary to maintain cellular homeostasis. The role of CMA in neurodegenerative diseases has been extensively studied in the past decades, with defects in the pathway being strongly associated with disease. Recently, accumulating evidence has demonstrated a consistent increase in basal CMA activity in a wide array of cancer cell lines and human tumor biopsies, suggesting a potential link between CMA and cancer. On the other hand, an anti-oncogenic role for CMA under physiological conditions in non-transformed cells is also proposed despite the pro-tumorigenic function of CMA in cancer cells. The growing number of connections between CMA and cancers has generated interest in modulating CMA activity for therapeutic purposes. Here, we describe recent advances in the understanding of the molecular regulation of CMA, and discuss the evidence in support of the contribution of CMA dysfunction to cancers.

Biocompatible carbon-doped MoSe2 nanoparticles as a highly efficient targeted agent for human renal cell carcinoma.

MoSe2 is a typical transition-metal dichalcogenide material, and many researches have been focused on using its property of near infrared strong absorption for laser mediated photothermal cancer treatment. However, the anti-canter effect of MoSe2 and its possible mechanism in renal cell carcinoma (RCC) is still unclear. RCC has high incidence of metastasis, which is known as one of the most lethal malignancies in the urological system. This study revealed that the carbon-doped MoSe2 particles can obviously inhibit proliferation for 786-O and ACHN cells. Meanwhile, the carbon-doped MoSe2 nanoparticles have little impact on the viability of KH-2 cells in vitro. The mechanism analysis revealed that the carbon-doped MoSe2 particles have hydrogen bond effect in aqueous solution, and the particle aggregation effect caused the KH-2 cells to have high viability. The carbon-doped MoSe2 nanoparticles with minimal toxicity may be a potential therapeutic candidate against RCC.

cDNA library construction of two human Demodexspecies.

The research of Demodex, a type of pathogen causing various dermatoses in animals and human beings, is lacking at RNA level. This study aims at extracting RNA and constructing cDNA library for Demodex. First, P. cuniculiand D. farinaewere mixed to establish homogenization method for RNA extraction. Second, D. folliculorumand D. breviswere collected and preserved in Trizol, which were mixed with D. farinaerespectively to extract RNA. Finally, cDNA library was constructed and its quality was assessed. The results indicated that for D. folliculorum& D. farinae, the recombination rate of cDNA library was 90.67% and the library titer was 7.50 × 104 pfu/ml. 17 of the 59 positive clones were predicted to be of D. folliculorum; For D. brevis& D. farinae, the recombination rate was 90.96% and the library titer was 7.85 x104 pfu/ml. 40 of the 59 positive clones were predicted to be of D. brevis. Further detection by specific primers demonstrated that mtDNA cox1, cox3and ATP6 detected from cDNA libraries had 96.52%-99.73% identities with the corresponding sequences in GenBank. In conclusion, the cDNA libraries constructed for Demodexmixed with D. farinaewere successful and could satisfy the requirements for functional genes detection.