TRIM21-mediated Sohlh2 ubiquitination suppresses M2 macrophage polarization and progression of triple-negative breast cancer.

Lung metastasis is the major cause of death in patients with triple-negative breast cancer (TNBC). Tumor-associated macrophages (TAMs) represent the M2-like phenotype with potent immunosuppressive activity, and play a pro-tumor role in TNBC lung metastasis. Sohlh2 belongs to the basic helix-loop-helix transcription factor family. However, its role in macrophages polarization remains unknown, especially in TNBC progression. Here we demonstrated that Sohlh2 overexpression promoted M2 macrophage polarization. Moreover, high expression of Sohlh2 in M2-like macrophage enhanced TNBC cell growth, migration and lung metastasis in vivo and in vitro. Mechanistically, we revealed that Sohlh2 functioned through up-regulating LXRα, ABCA1, ABCG1 expression and disturbing the lipid homeostasis on the membrane of macrophages. Sohlh2 could directly bind to the promoter of LXRα and promote its transcription activity. E3 ubiquitin ligase TRIM21 promoted Sohlh2 ubiquitination and degradation, and suppressed M2 macrophage polarization and TNBC progression. Collectively, our findings suggested that Sohlh2 in macrophage could be a novel therapeutic target for TNBC metastatic treatment.

Sohlh2 promotes pulmonary fibrosis via repression of p62/Keap1/Nrf2 mediated anti-oxidative signaling pathway.

Disturbance in the redox balance of alveolar epithelial cells (AECs) was considered as a causal factor for pulmonary fibrosis. The regulatory mechanisms of redox hemostasis in the development of pulmonary fibrosis remain largely unknown. Using a type II AEC-specific Sohlh2 conditional knock-in (CKI) mouse model, we found that Sohlh2, a basic HLH transcription factor, accelerated age-related pulmonary fibrosis. High-fat diet (HFD) resulted in a tremendous increase in lung inflammation and fibrotic changes in the lung tissues of Sohlh2 CKI mice. Sohlh2 overexpression led to a significant rise of intracellular ROS and apoptosis in the lung, mouse primary AECIIs, and human A549 cells, which was attenuated by ROS inhibitor (NAC). Sohlh2 enhanced oxidative stress via repressing p62/Keap1/Nrf2 mediated anti-oxidative signaling pathway. p62, a direct target of Sohlh2, mediated Sohlh2 effects on ROS generation and apoptosis in A549 cells. Hence, our findings elucidate a pivotal mechanism underlying oxidative stress-induced pulmonary fibrosis, providing a framework for aging-related disorder interventions.

A Clinically Translatable Ternary Platinum(IV) Prodrug for Synergistically Reversing Drug Resistance  .

Scalable production of a clinically translatable formulation with enhanced therapeutic efficacy against cisplatin-resistant tumors without the use of any clinically unapproved reagents and additional manipulation remains a challenge. For this purpose, we report herein the construction of TPP-Pt-acetal-CA based on all commercially available, clinically approved reagents consisting of a cinnamaldehyde (CA) unit for reactive oxygen species generation, a mitochondrially targeted triphenylphosphonium (TPP)-modified Pt(IV) moiety for mitochondrial dysfunction, and an intracellular acidic pH-cleavable acetal link between these two moieties. The resulting self-assembled, stabilized TPP-Pt-acetal-CA nanoparticles mediated an IC50 value approximately 6-fold lower than that of cisplatin in A549/DDP cells and a tumor weight reduction 3.6-fold greater than that of cisplatin in A549/DDP tumor-bearing BALB/c mice with insignificant systematic toxicity due to the synergistic mitochondrial dysfunction and markedly amplified oxidative stress. Therefore, this study presents the first example of a clinically translatable Pt(IV) prodrug with enhanced efficiency for synergistically reversing drug resistance.

Sohlh2 Regulates the Stemness and Differentiation of Colon Cancer Stem Cells by Downregulating LncRNA-H19 Transcription.

Colon cancer stem cells (CSC) are tumor-initiating cells that drive tumorigenesis and progression through self-renewal and various differentiation potency. Therefore, the identification of factors critical for colon CSC function is vital for the development of therapies. Sohlh2 belongs to the superfamily of bhlh transcription factors and serves as a tumor suppressor in several tumors. The role of Sohlh2 in CSCs remains unknown. Here we demonstrated that Sohlh2 was related to the inhibition of LncRNA-H19/miR-141/ß-catenin signaling and led to the consequent suppression of colon CSC stemness and the promotion of colon CSC differentiation in vitro and in vivo. Moreover, Sohlh2 could directly bind to the promoter of LncRNA-H19 and repress its transcription activity. LncRNA-H19 mediated the effects of Sohlh2 on colon CSC stemness and differentiation. Clinically, we observed a significant inverse correlation between Sohlh2 and LncRNA-H19, ß-catenin, Lgr5, CD133 expression levels, and positive correlation between Sohlh2 and MUC2, TFF2 expression in colon cancer tissues. Collectively, our findings suggest an important role of the Sohlh2/LncRNA-H19/miR-141/ß-catenin pathway in regulating colon CSC stemness and differentiation, suggesting potential therapeutic targets for colon cancer. IMPLICATIONS: This study identifies that Sohlh2 directly manipulates LncRNA-H19 transcription and suppresses the ß-catenin signaling pathway and the Sohlh2/LncRNA-H19/miR-141/ß-catenin signaling pathway plays an essential role in the stemness of colon CSCs.

Electrochemical Performance of MnO2/Graphene Flower-like Microspheres Prepared by Thermally-Exfoliated Graphite.

To enhance the electrochemical performance of MnO2/graphene composite, herein, thermally-exfoliated graphite (TE-G) is adopted as a raw material, and a hydrothermal reaction is conducted to achieve the exfoliation of TE-G and the loading of MnO2 nanosheets. Through optimizing the TE-G/KMnO4 ratio in the redox reaction between carbon and KMnO4, flower-like MnO2/G microspheres (MnO2/G-10) are obtained with 83.2% MnO2 and 16.8% residual graphene. Meanwhile, corresponding MnO2/rGO composites are prepared by using rGO as raw materials. Serving as a working electrode in a three-electrode system, MnO2/G-10 composite displays a specific capacitance of 500 F g-1 at 1 A g-1, outstanding rate performance, and capacitance retention of 85.3% for 5,000 cycles. The performance is much better than that of optimized MnO2/rGO composite. We ascribe this to the high carbon fraction in TE-G resulting in a high fraction of MnO2 in composite, and the oxygen-containing groups in rGO reduce the resulting MnO2 fraction in the composite. The superior electrochemical performance of MnO2/G-10 is dependent on the hierarchical porous structure constructed by MnO2 nanosheet arrays and the residual graphene layer in the composite. In addition, a supercapacitor assembled by TE-G negative electrode and MnO2/G positive electrode also exhibits superior performance. In consideration of the low cost of raw materials, the MnO2/G composite exhibits great application potential in the field of supercapacitors.

CHST4 might promote the malignancy of cholangiocarcinoma.

BACKGROUND: Cholangiocarcinoma (CCA) is reported as an aggressive cancer which leads to high mortality and no effective therapeutic target has yet been discovered. Surgical resection is the main method to treat patients with CCA. However, only one-third of CCA patients have the opportunity to accept the operation, leading to poor prognosis for CCA patients. Therefore, it is necessary to search for new therapeutic targets of CCA or core genes involved in the happening and growth of CCA. AIM: In this study, we utilized bioinformatics technology and accessed to several medical databases trying to find the core genes of CCA for the purpose of intervening CCA through figuring out an effective curative target. METHODS: Firstly, three differentially expressed genes (DEGs) were discovered from GEPIA, and by further observing the distribution and gene expression, CHST4 was obtained as the core gene. Afterwards, correlated genes of CHST4 in CCA were identified using UALCAN to construct a gene expression profile. We obtained PPI network by Search Tool for the Retrieval of Interacting Networks Genes (STRING) and screened core genes using cytoscape software. Functional enrichment analyses were carried out and the expression of CHST in human tissues and tumors was observed. Finally, a CCA model was established for qPCR and staining validation. RESULTS: Three differentially expressed genes (DEGs), CHST4, MBOAT4 and RP11-525K10.3, were obtained. All were more over-expressed in CCA samples than the normal, among which the change multiple and the gene expression difference of CHST4 was the most obvious. Therefore, CHST4 was selected as the core gene. We can see in our established protein-protein interaction (PPI) network that CHST4 had the highest degree of connectivity, demonstrating its close association with CCA. We found that genes were mainly enriched in CCs in the PPI networks genes which shows functional enrichment analysis results, including golgi lumen, extracellular space and extracellular region. CHST4 was found very specifically expressed in the bile duct and was significantly different from that in normal tissues. The overexpression of CHST4 was further verified in the established animal model of TAA-induced CCA in rats. Quantitative PCR (qPCR) demonstrated that CHST4 was significantly overexpressed in tumor tissues, verifying the role of CHST4 as the core gene of CCA. CONCLUSION: CHST4 was increasingly expressed in CCA and CHST4 is worth being studied much further in the intervention of CCA.

A2M is a potential core gene in intrahepatic cholangiocarcinoma.

BACKGROUND: Intrahepatic cholangiocarcinoma (ICC) is a type of malignant tumor ranking the second in the incidence of primary liver cancer following hepatocellular carcinoma. Both the morbidity and mortality have been increasing in recent years. Small duct type of ICC has potential therapeutic targets. But overall, the prognosis of patients with ICC is usually very poor. METHODS: To search latent therapeutic targets for ICC, we programmatically selected the five most suitable microarray datasets. Then, we made an analysis of these microarray datasets (GSE26566, GSE31370, GSE32958, GSE45001 and GSE76311) collected from the Gene Expression Omnibus (GEO) database. The GEO2R tool was effective to find out differentially expressed genes (DEGs) between ICC and normal tissue. Gene Ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis were executed using the Database for Annotation, Visualization and Integrated Discovery (DAVID) v 6.8. The Search Tool for the Retrieval of Interacting Genes (STRING) database was used to analyze protein-protein interaction of these DEGs and protein-protein interaction of these DEGs was modified by Cytoscape3.8.2. Survival analysis was performed using Gene Expression Profiling Interactive Analysis (GEPIA) online analysis tool. RESULTS: A total of 28 upregulated DEGs and 118 downregulated DEGs were screened out. Then twenty hub genes were selected according to the connectivity degree. The survival analysis results showed that A2M was closely related to the pathogenesis and prognosis of ICC and was a potential therapeutic target for ICC. CONCLUSIONS: According to our study, low A2M expression in ICC compared to normal bile duct tissue was an adverse prognostic factor in ICC patients. The value of A2M in the treatment of ICC needs to be further studied.

Sohlh2 Inhibits the Malignant Progression of Renal Cell Carcinoma by Upregulating Klotho via DNMT3a.

BACKGROUND: Renal cell carcinoma is the most common malignant tumor of the kidney. The 5-year survival of renal cell carcinoma with distant metastasis is very low. Sohlh2 is a newly discovered tumor suppressor gene playing inhibitory roles in a variety of tumors, but its role in renal cell carcinoma has not been reported. METHODS: To clarify the role of Sohlh2 in the occurrence and development of renal cell carcinoma, we constructed stably transfected human renal cell carcinoma cell lines with Sohlh2 overexpression and Sohlh2 knockdown, separately. First, we studied the effects of Sohlh2 on proliferation, migration, invasion, and epithelial-mesenchymal transition (EMT) of renal cell carcinoma cells in vitro and in vivo. Then, we detected whether Sohlh2 functions through DNMT3a/Klotho using Western blotting, qPCR, and Cell Counting Kit-8 (CCK-8) assay. Finally, we collected 40 resected renal cell carcinoma samples to study the relevance between Sohlh2, DNMT3a, and Klotho by immunohistochemistry. RESULTS: Our results showed that Sohlh2 was downregulated in renal cell carcinoma, and its expression level was negatively correlated with tumor staging. Both in vitro and in vivo experiments confirmed that Sohlh2 overexpression inhibited the proliferation, migration, invasion, metastasis, and EMT of renal cell carcinoma. Sohlh2 functions through demethylation of Klotho by downregulating the expression of DNA methyltransferase of DNMT3a. In renal cell carcinoma, Sohlh2 was positively correlated with Klotho and negatively correlated with DNMT3a. CONCLUSION: Sohlh2 functions as a tumor suppressor gene in renal cell carcinoma by demethylation of Klotho via DNMT3a. Sohlh2 correlated with Klotho positively and with DNMT3a negatively in renal cell carcinoma. Our study suggests that Sohlh2 and DNMT3a/Klotho can be used as potential targets for the clinical treatment of renal cell carcinoma.