Arsenic nano complex induced degradation of YAP sensitized ESCC cancer cells to radiation and chemotherapy

Potential of the nanoplatform and PROTAC interface to achieve targeted protein degradation through the Ubiquitin-Proteasome system

In eukaryotic cells, the ubiquitin-proteasome system (UPS) plays a crucial role in selectively breaking down specific proteins. The ability of the UPS to target proteins effectively and expedite their removal has significantly contributed to the evolution of UPS-based targeted protein degradation (TPD) strategies. In particular, proteolysis targeting chimeras (PROTACs) are an immensely promising tool due to their high efficiency, extensive target range, and negligible drug resistance. This breakthrough has overcome the limitations posed by traditionally "non-druggable" proteins. However, their high molecular weight and constrained solubility impede the delivery of PROTACs. Fortunately, the field of nanomedicine has experienced significant growth, enabling the delivery of PROTACs through nanoscale drug-delivery systems, which effectively improves the stability, solubility, drug distribution, tissue-specific accumulation, and stimulus-responsive release of PROTACs. This article reviews the mechanism of action attributed to PROTACs and their potential implications for clinical applications. Moreover, we present strategies involving nanoplatforms for the effective delivery of PROTACs and evaluate recent advances in targeting nanoplatforms to the UPS. Ultimately, an assessment is conducted to determine the feasibility of utilizing PROTACs and nanoplatforms for UPS-based TPD. The primary aim of this review is to provide innovative, reliable solutions to overcome the current challenges obstructing the effective use of PROTACs in the management of cancer, neurodegenerative diseases, and metabolic syndrome. Therefore, this is a promising technology for improving the treatment status of major diseases.

Association between circ_0004365 and cisplatin resistance in esophageal squamous cell carcinoma

Cisplatin is one of the most predominant drugs for the chemotherapy of esophageal squamous cell carcinoma (ESCC); however, the underlying resistance mechanisms are still almost unknown. The present study performed RNA sequencing of human circular RNA (circRNA) in TE11 cells and cisplatin-resistant TE11 cells (TE11R). The expression profiles determined using CIRCexplorer2 revealed that the expression of circ_0004365, mapped on the Semaphorin 3C gene, was significantly greater in TE11R compared with in TE11. In reverse transcription-quantitative PCR, circ_0004365 expression was observed in human ESCC and non-tumor tissues and was significantly upregulated in ESCC tumor tissues after chemotherapy. Circ_0004365 expression was significantly upregulated in patients with poor pathological response (P=0.02). Furthermore, patients with advanced pT stage showed an upregulation in circ_0004365 expression after chemotherapy (P=0.02). The MTT assay revealed that knockdown of circ_0003465 in TE11 significantly decreased resistance to cisplatin. In conclusion, the present study suggested that circ_0004365 was associated with cisplatin resistance in ESCC and can be used as both a novel biomarker and a therapeutic target.

Advances in the Theranostics of Oesophageal Squamous Carcinoma

Oesophageal squamous carcinoma (ESCC) is one of the most lethal human malignancies, and it is a more aggressive form of oesophageal cancer (EC) that comprises over 90% of all EC cases in China compared with oesophageal adenocarcinoma (EAC). The high mortality of ESCC is attributed to the late‐stage diagnosis, chemoradiotherapy resistance, and lack of appropriate therapeutic targets and corresponding therapeutic formulations. Recently, emerging clinical and translational investigations have involved genome analyses, diagnostic biomarkers, and targeted therapy for ESCC, and these studies provide a new horizon for improving the clinical outcomes of patients with ESCC. Here, the latest research advances in the theranostics of ESCC are reviewed and the unique features of ESCC (including differences from EAC, genomic alterations, and microbe infections), tissue and circulating biomarkers, chemoradiotherapy resistance, clinical targeted therapy for ESCC, identification of novel therapeutic targets, and designation of nanotherapeutic systems for ESCC are particularly focused on. Finally, the perspectives for future clinical and translational theranostic research of ESCC are discussed and the obstacles that must be overcome in ESCC theranostics are described.

Chaetocin exhibits anticancer effects in esophageal squamous cell carcinoma via activation of Hippo pathway

Dysfunction of the Hippo pathway is common in esophageal squamous carcinoma (ESCC). Chaetocin, a small molecular compound isolated from the marine fungus, exhibits potent anticancer effects. However, the anticancer effects of chaetocin on ESCC and its potential relationship to Hippo pathway remain unclear. Here, we demonstrated that chaetocin dramatically inhibited the proliferation in ESCC cells by causing cycle arrest in the M phase and activating the caspase-dependent apoptosis signaling pathway in vitro, and we also found that chaetocin induced the accumulation cellular reactive oxygen species (ROS). The RNA-seq analysis indicated that the Hippo pathway is one of the most enriched pathways after chaetocin treatment. We further revealed that chaetocin triggered the activation of Hippo pathway in ESCC cells, which is characterized by elevated phosphorylation levels of almost all core proteins in Hippo pathway, such as MST1 (Thr183), MST2 (Thr180), MOB1 (Thr35), LAST1 (Thr1079 and Ser909) and YAP (Ser127), ultimately leading to decreased nuclear translocation of YAP. Moreover, the MST1/2 inhibitor XMU-MP-1 not only partially rescued the inhibitory effect chaetocin-induced proliferation, but also rescued the chaetocin-induced apoptosis in ESCC cells. Furthermore, in vivo results confirmed the antitumor effect of chaetocin and its relationship with Hippo pathway. Taken together, our study demonstrates that chaetocin exhibits anticancer effects in ESCC via activation of Hippo pathway. These results provide an important basis for further research of chaetocin as a potential candidate for ESCC treatment.

Arsenic impairs stem cell differentiation via the Hippo signaling pathway

Arsenic is a ubiquitous toxic metalloid, with over 150 million people exposed to arsenic concentrations above the current 10 ppb drinking water standard through contaminated food and water. Arsenic is a known developmental toxicant as neuronal and muscle development are disrupted following arsenic exposure during embryogenesis. In this study, murine embryonic stem cells were chronically exposed to 0.1 μM (7.5 ppb) arsenic for 32 weeks. RNA sequencing showed that the Hippo signaling pathway, which is involved in embryonic development and pluripotency maintenance, is impaired following arsenic exposure. Thus, temporal changes in the Hippo pathway's core components and its downstream target genes Ctgf and c-Myc were investigated. Protein expression of the pathway's main effector YAP in its active form was significantly upregulated by 3.7-fold in arsenic-exposed cells at week 8, while protein expression of inactive phosphorylated YAP was significantly downregulated by 2.5- and 2-fold at weeks 8 and 16. Exposure to arsenic significantly increased the ratio between nuclear and cytoplasmic YAP by 1.9-fold at weeks 16 and 28. The ratio between nuclear and cytoplasmic transcriptional enhancer factor domain was similarly increased in arsenic-treated samples by 3.4- and 1.6-fold at weeks 16 and 28, respectively. Levels of Ctgf and c-Myc were also upregulated following arsenic exposure. These results suggest that chronic exposure to an environmentally relevant arsenic concentration might hinder cellular differentiation and maintain pluripotency through the impairment of the Hippo signaling pathway resulting in increased YAP activation.

Glioma-associated mesenchymal stem cells-mediated PD-L1 expression is attenuated by Ad5-Ki67/IL-15 in GBM treatment

Background

Glioblastoma (GBM) is a highly immunosuppressive and vascular malignant brain tumor. Current therapeutic strategies targeting tumor cells have limited efficacy because of the immunosuppressive microenvironment and vascularization. Glioma-associated mesenchymal stem cells (GA-MSCs) have been identified as important stromal components of the tumor microenvironment, owing to their contribution to tumor angiogenesis and their potential to drive glioma stem cells. However, there are no reports on the effect of oncolytic Ad5-Ki67/IL-15 on programmed death ligand 1 (PD-L1) expression and angiogenesis induced by GA-MSCs.

Methods

Flow cytometry was respectively performed to detect the PD-L1 of glioma cells and programmed death protein 1 (PD-1), CD3, CD4 and CD8 in lymphocytes, as well as distribution of the cell cycle. CCK-8 assay investigated the proliferation of glioma cells and GA-MSCs in vitro. Tumor-bearing nude mice were established with U87-Luc cells and treated with the viruses, and further the IVIS spectrum was utilized to obtain luciferase images. Finally, the expression of PD-L1 in tumor tissues was also investigated using western blotting.

Results

We found that GA-MSCs had potential to induce PD-L1 upregulation and involved in vascular mimicry in vitro. Importantly, Ad5-Ki67/IL-15 reduced PD-L1 expression of glioma cells and neovascularization by targeting GA-MSCs. Furthermore, despite the presence of GA-MSCs, the virus has the ability to generate potent antitumor efficacy in vitro and vivo.

Conclusions

These findings suggest the use of oncolytic Ad5-Ki67/IL-15 targeting GA-MSCs to treat GBM, indicating potential clinical applications.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02968-z.

Roles of YAP/TAZ in ferroptosis

Ferroptosis is a unique iron-dependent form of regulated cell death. Recently, researchers found that ferroptosis was sensitive to cell density, regulated by Hippo signaling. This article summarizes the roles of the Hippo pathway effectors Yes-associated protein (YAP) and transcriptional coactivator with PDZ-binding motif (TAZ) in ferroptosis and the therapeutic potential of activating ferroptosis in cancer.

LncRNA GATA2-AS1 suppresses esophageal squamous cell carcinoma progression via the mir-940/PTPN12 axis

Esophageal squamous cell carcinoma (ESCC) is a common malignant tumor worldwide. Long noncoding RNAs (lncRNAs) exhibit a regulatory role in the progression of ESCC. Our research was performed to investigate the potential molecular mechanism of lncRNA GATA2-AS1 in ESCC.

METHODS

The expression of GATA2-AS1 was identified by qRT-PCR. Cell function assays explored the potential effect of GATA2-AS1 on ESCC progression. The subcellular hierarchical localization method was executed to identify the subcellular localization of GATA2-AS1 in ESCC cells. A prediction website was utilized to discover the relationships among GATA2-AS1, miR-940 and PTPN12. Dual luciferase reporter gene, pull-down assays and RIP assays were executed to verify the binding activity among GATA2-AS1, miR-940 and PTPN12. Xenograft tumor experiments were performed to evaluate ESCC cell growth in vivo.

RESULTS

The expression of GATA2-AS1 and PTPN12 was reduced, while miR-940 expression was enhanced in ESCC tissues and cell lines. In vivo experiments showed that GATA2-AS1 inhibited the progression of ESCC cells toward malignancy. Bioinformatics analysis, dual luciferase and RIP assays revealed that GATA2-AS1 upregulated PTPN12 expression by competitively targeting miR-940. miR-940 reversed the inhibitory effect of GATA2-AS1 on the biological behavior of ESCC cells.

CONCLUSION

Our findings suggested that GATA2-AS1, expressed at low levels in ESCC, plays a crucial role in the progression of ESCC by targeting the miR-940/PTPN12 axis and could be a potential drug target to treat ESCC patients.

Clock-modified mesenchymal stromal cells therapy rescues molecular circadian oscillation and age-related bone loss via miR142-3p/Bmal1/YAP signaling axis

Age-related bone loss and disease strongly affect the quality of life of the elderly population. Cellular circadian rhythms have been reported to regulate bone aging, and micro RNAs (miRNAs) play crucial posttranscriptional regulatory roles in the peripheral clock network. Proliferation capability, osteogenic lineage commitment, senescence-associated secreted phenotype (SASP) and circadian oscillation of clock genes under osteogenic condition were assessed in bone marrow mesenchymal stromal cells (BMSCs) from young adult and aged adult mice. miRNAs targeting the core clock gene brain and muscle arntl-like protein 1 (Bmal1) were screened and verified in young and old BMSCs with RT-qPCR and Western Blot analysis. ChIP-seq and RNA-seq datasets were mined to define the downstream mechanism and gain- and loss-of-function genetic experiments were performed to confirm the hypothesis. To compare the therapeutic effect of these clock-engineered BMSCs, SASP and osteogenic capability of Bmal1-overexpressing and miR-142-3p-inhibited BMSCs were investigated in vitro and transplanted into bone defects and femur cavities of aged mice. Aged BMSCs displayed an abolished circadian rhythm, impaired self-renewal capability and decreased osteoblast differentiation. miR-142-3p was elevated with aging, which downregulated Bmal1 and diminished the osteogenic potential of BMSCs. In addition, Bmal1 inhibited YAP expression to promote BMSCs osteogenesis, which was independent from the activation of Hippo signaling pathway. Overexpression of Bmal1 or inhibition of miR-142-3p rescued the molecular temporal rhythm and osteoblast differentiation ex vivo. Cell-based circadian therapy showed improved bone formation and higher turnover levels in vivo. This study demonstrates that transcriptional and post-transcriptional level clock-modified BMSCs rescued circadian oscillation and age-related bone loss via miR-142-3p/Bmal1/YAP signaling axis. These data provide promising clinical prospects of circadian-mediated stromal cell-based therapy and bone tissue regeneration.

MicroRNA-624-mediated ARRDC3/YAP/HIF1α axis enhances esophageal squamous cell carcinoma cell resistance to cisplatin and paclitaxel

Development of chemoresistance remains a major challenge in treating patients suffering from esophageal squamous cell carcinoma (ESCC), despite treatment advances. MicroRNAs (miRNAs) have been shown to play critical roles in the regulation of ESCC cell chemoresistance. Here, we aimed to investigate the role of miR-624 in ESCC and its molecular mechanism in mediating the resistance of ESCC cells to two common chemotherapeutic drugs, cisplatin (CIS) and paclitaxel (PT). Expression patterns of miR-624, arrestin domain-containing 3 (ARRDC3), Yes-associated protein (YAP), and hypoxia-inducible factor-1α (HIF1α) in ESCC tissues and cell lines were identified using RT-qPCR and Western blot analysis. The binding affinities with the miR-624/ARRDC3/YAP/HIF1α axis were characterized. The chemotherapy-sensitive cell line KYSE150 and chemotherapy-resistant cell line KYSE410 were transfected with an overexpression plasmid or shRNA to study the effect of miR-624/ARRDC3/YAP/HIF1α axis on ESCC cell resistance to CIS and PT. Their in vivo effects on resistance to PT were assessed in tumor-bearing nude mice. High expression of miR-624, YAP and HIF1α, and low expression of ARRDC3 were observed in ESCC tissues and cell lines. miR-624 presented with higher expression in KYSE410 than in KYSE150 cells. miR-624 downregulated ARRDC3 to increase YAP and HIF1α expression so as to enhance ESCC cell resistance to CIS and PT in vitro and in vivo. Taken together, these data indicate an important role for miR-624 in promoting the chemoresistance of ESCC cells, highlighting a potential strategy to overcome drug resistance in ESCC treatment. miR-624 targets ARRDC3 to inhibit its expression, and consequently upregulates YAP expression by inhibiting degradation of YAP. By this mechanism, HIF1α expression is upregulated and the HIF1α signaling pathway is activated. ESCC cell chemotherapy resistance is eventually increased.

Immuno-oncological role of 20S proteasome alpha-subunit 3 in aggravating the progression of esophageal squamous cell carcinoma

PSMA3, a member of the proteasome subunit, has been shown to play a major player in protein degradation. Reportedly, PSMA3 functions as a negative regulator in various cancers including colon, pancreatic and gastric cancers. However, the contributions of PSMA3 to the progression of esophageal squamous cell carcinoma (ESCC) and the underlying mechanism remain unclear. Therefore, in this study, we investigated whether PSMA3 is involved in ESCC progression and the potential underlying mechanism. The results revealed that PSMA3 was highly expressed in the ESCC tumor tissues and functioned as a negative indicator according to the data from The Cancer Genome Atlas (TCGA)/Gene Expression Omnibus (GEO) datasets and clinical patients' samples. Pathway enrichment analysis showed that PSMA3 was closely correlated with ESCC cancer stemness and the inflammatory response; however, this correlation was absent after knockdown of PSMA3 in vitro. We further demonstrated that PSMA3 suppressed CD8⁺ T-cells infiltration depending on the C-C motif chemokine ligand 3 (CCL3)/C-C motif chemokine receptor 5 (CCR5) axis. Collectively, these results demonstrate the role of PSMA3 in ESCC cancer stemness and the negative regulation of CD8 T-cells infiltration mediated by PSMA3. The results of this study may provide a potential target for the immuno-oncology effect of PSMA3 in ESCC therapy.