Angiotensin II promotes EMT of hepatocellular carcinoma cells through high mobility group protein B1 mediated by E4F1

Ribosomal protein S3A (RPS3A), as a transcription regulator of colony-stimulating factor 1 (CSF1), promotes glioma progression through regulating the recruitment and autophagy-mediated M2 polarization of tumor-associated macrophages

Dysregulated expression of ribosomal protein S3A (RPS3A) is associated with the tissue infiltration of immune-related cells in a variety of cancers. However, the role of RPS3A in immune cell infiltration in glioma remains unclear. This study aimed to explore the role of RPS3A in the glioma immune microenvironment. RPS3A expression was detected in tumor tissues from patients with glioma. U251 cells were transfected with RPS3A shRNA (sh-RPS3A) and overexpression vector (pcDNA-RPS3A) and then co-cultured with PMA-induced THP-1 cells. Cell viability, invasion, and apoptosis were detected by Edu staining, Transwell, and flow cytometry, respectively. The expression of tumor-associated macrophage (TAM) M1 and M2 markers was detected with RT-qPCR. Next, the interaction between RPS3A and E4 transcription factor 1 (E4F1) was verified by Co-IP analysis, and the binding of E4F1 to colony-stimulating factor 1 (CSF1) promoter was verified by ChIP analysis. Overexpression vectors of CSF1 and E4F1 were used to treat sh-RPS3A-transfected U251 cells for reversal experiments. Finally, U251 cells transfected with sh-RPS3A adenovirus vectors were subcutaneously injected into nude mice to construct a xenograft tumor model, and the growth and metastasis of glioma in vivo were monitored. RPS3A was significantly upregulated in glioma tissues. Overexpression of RPS3A promoted glioma cell proliferation and invasion and inhibited apoptosis. Moreover, overexpression of RPS3A promoted TAM proliferation, invasion, and M2 polarization. Silencing RPS3A had the opposite effect. Silencing RPS3A inhibited autophagy in U251 cells, whereas rapamycin, an activator of autophagy, reversed the inhibitory effect of RPS3A silencing on TAM M2 polarization. Meanwhile, RPS3A promoted its expression by interacting with E4F1, and E4F1 promoted CSF1 transcriptional activation. Overexpression of CSF1 promoted the proliferation and invasion of U251 cells and reversed the inhibitory effect of RPS3A silencing on TAM proliferation and invasion, but had no effect on TAM M2 polarization. The results of in vivo experiments showed that knockdown of RPS3A significantly inhibited glioma tumor growth and metastasis in vivo. This study revealed that RPS3A recruited TAMs by upregulating E4F1-mediated transcription activation of CSF1, and promoted the M2 polarization of TAMs through autophagy, promoting glioma cell malignant growth and tumor progression.

The Chicken HDAC4 Promoter and Its Regulation by MYC and HIF1A

BACKGROUND

Histone deacetylase 4 (HDAC4) is a member of the class II histone deacetylase family, whose members play a crucial role in various biological processes. An in-depth investigation of the transcriptional characteristics of chicken HDAC4 can provide fundamental insights into its function.

METHODS

We examined HDAC4 expression in chicken embryonic stem cells (ESC) and spermatogonial stem cells (SSC) and cloned a 444 bp fragment from upstream of the chicken HDAC4 transcription start site. Subsequently, we constructed pEGFP-HDAC4 and a series of 5'-deletion luciferase reporter constructs, which we transfected into DF-1 cells to measure their transcriptional activity. The regulatory mechanisms of chicken HDAC4 expression were investigated by performing trichostatin A (TSA) treatment, deleting putative transcription factor binding sites, and altering transcription factor expression levels.

RESULTS

HDAC4 exhibited higher expression in SSC than in ESC. We confirmed that the upstream region from -295 bp to 0 bp is the core transcriptional region of HDAC4. TSA effectively inhibited HDAC4 transcription, and bioinformatics analysis indicated that the chicken core HDAC4 promoter sequence exhibits high homology with those of other avian species. The myelocytomatosis viral oncogene homolog (MYC) and hypoxia-inducible factor 1 α (HIF1A) transcription factors were predicted to bind to this core region. Treatment with TSA for 24 h resulted in the upregulation of MYC and HIF1A, which repressed HDAC4 transcription.

CONCLUSIONS

Our results provide a basis for subsequent investigations into the regulation of HDAC4 expression and biological function.

A Study of JUN's Promoter Region and Its Regulators in Chickens

Background: The Jun proto-oncogene (JUN), also referred to as C-JUN, is an integral component of the JNK signaling pathway, which is crucial for the formation and differentiation of spermatogonial stem cells (SSCs). Investigations into the transcriptional regulation of chicken JUN can offer a molecular foundation for elucidating its mechanistic role in SSCs. Methods: In this study, we successfully cloned a 2000 bp upstream sequence of the JUN transcription start site and constructed a series of pGL3 recombinant vectors containing JUN promoters of varying lengths. Results: We verified the promoter activity of the 2000 bp upstream sequence by assessing the fluorescence intensity of DF-1 and identified the promoter activities of different regions via dual-luciferase assays. The transcription of JUN and its promoter region spanning -700 to 0 bp was modulated by an activator of the JNK signaling pathway. Bioinformatics analysis revealed that this -700 to 0 bp region was highly conserved among avian species and predicted the presence of binding sites for Wilms tumor 1 (WT1) and CCAAT/enhancer binding protein alpha (CEBPA). The JNK signaling pathway activator was found to upregulate the expression of these transcription factors in DF-1 cells. Through the deletion of binding sites and the overexpression of WT1 and CEBPA, we demonstrated that WT1 inhibited the transcription of JUN, while CEBPA promoted it. Conclusions: In conclusion, the -700 to 0 bp region is the key region of the JUN promoter, with WT1 inhibiting JUN transcription. The results of the study not only provide ideas for exploring the regulatory mechanism of JUN in chicken SSCs, but also lay an important foundation for the study of avian SSCs.

Technological advancements in viral vector designing and optimization for therapeutic applications

Viral vector engineering is critical to the advancement of several sectors of biotechnology, gene therapy, and vaccine development. These vectors were produced from viruses, were employed to deliver therapeutic genes or to alter biological processes. The potential for viral vectors to improve the precision, safety, and efficiency of therapeutic interventions has boosted their demand. The dynamic interplay between technological advancements and computational tools in establishing the landscape of viral vector engineering and vector optimization for therapeutic reasons is discussed in this chapter. It also emphasizes the importance of in silico techniques in maximizing vector potential for therapeutics and many phases of viral vector engineering, from genomic analysis to computer modelling and advancements to improve precise gene delivery. High-throughput screening propels the expedited process of vector selection, and computational techniques to analyze complex omics data to further enhance vector capabilities have been discussed. As in silico models reveal insights into off-target effects and integration sites, vector safety (biodistribution and toxicity) remains a crucial part and bridges the gap between preclinical and clinical investigations. Despite the limitations, this chapter depicts a future in which technology and computing merge to catapult viral vector therapy into an era of boundless possibilities.

Transcription factor E4F1 as a regulator of cell life and disease progression

E4F transcription factor 1 (E4F1), a member of the GLI-Kruppel family of zinc finger proteins, is now widely recognized as a transcription factor. It plays a critical role in regulating various cell processes, including cell growth, proliferation, differentiation, apoptosis and necrosis, DNA damage response, and cell metabolism. These processes involve intricate molecular regulatory networks, making E4F1 an important mediator in cell biology. Moreover, E4F1 has also been implicated in the pathogenesis of a range of human diseases. In this review, we provide an overview of the major advances in E4F1 research, from its first report to the present, including studies on its protein domains, molecular mechanisms of transcriptional regulation and biological functions, and implications for human diseases. We also address unresolved questions and potential research directions in this field. This review provides insights into the essential roles of E4F1 in human health and disease and may pave the way for facilitating E4F1 from basic research to clinical applications.

Effect of PLC-β1/CaM signaling pathway mediated by AT1R on the occurrence and development of hepatocellular carcinoma

Objective

To study the roles of AT1R, PLC-β1, CaM and other related signal molecules in the formation and development of hepatocellular carcinoma (HCC) and their correlation.

Methods

ELISA and immunohistochemistry were used to analyze the expressions of target proteins in serum and liver tissue of HCC patients, and the correlation between AT1R, PLC-β1 and CaM and postoperative survival status of patients was followed up and determined. CCK-8 method was used to screen the doses of Ang II and candesartan sensitive to HepG2 and HCCLM3 cells. Transwell experiment was used to observe the effects of different drugs on the migration and invasion activity of HCC cells. Meanwhile, flow cytometry and Western blot were used to detect the expression levels of AT1R, PLC-β1 and CaM in the cells. Then PLC-β1 siRNA was selected to transfect HCC cells, so as to further clarify the mechanism of the above signal proteins. HepG2 cells were inoculated under the hepatic capsule of mice to induce the formation of HCC in situ. Ang II and candesartan were used to stimulate HCC mice to observe the difference in liver appearance and measure the liver index. Finally, ELISA and immunofluorescence experiments were selected to analyze the levels of target proteins in mouse serum and liver tissue.

Results

The expression levels of target proteins in serum and liver tissue of HCC patients were significantly increased, and the postoperative survival time of patients with high expression of AT1R, PLC-β1 or CaM was obviously shortened. Ang II and candesartan could significantly promote and inhibit the motility of HCC cells, and had different effects on the levels of AT1R, PLC-β1 and CaM in cells. However, in hepatocellular carcinoma cells transfected with PLC-β1 siRNA, the intervention ability of drugs was obviously weakened. Ang II could significantly promote the formation and progression of mouse HCC, while candesartan had the opposite effect. Meanwhile, medications could affect the expressions of target proteins in mouse serum and liver tissue.

Conclusion

AT1R, PLC-β1 and CaM may be risk factors affecting the formation and prognosis of HCC, and the PLC-β1/CaM signaling pathway mediated by AT1R is an important way to regulate the migration and invasion activity of HCC cells.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12935-021-02261-8.