Suppressing serum response factor inhibits invasion in cervical cancer cell lines via regulating Egr‑1 and epithelial-mesenchymal transition

Quercetin induces dual specificity phosphatase 5 via serum response factor

The phytochemical quercetin has gained attention for its antiinflammatory and anti-tumorigenic properties in various types of cancer. Tumorigenesis involves the aberrant regulation of kinase/phosphatase, highlighting the importance of maintaining homeostasis. Dual Specificity Phosphatase (DUSP) plays a crucial role in controlling the phosphorylation of ERK. The current study aimed to clone the DUSP5 promoter, and investigate its transcriptional activity in the presence of quercetin. The results revealed that quercetin-induced DUSP5 expression is associated with the serum response factor (SRF) binding site located in the DUSP5 promoter. The deletion of this site abolished the luciferase activity induced by quercetin, indicating its vital role in quercetin-induced DUSP5 expression. SRF protein is a transcription factor that potentially contributes to quercetin-induced DUSP5 expression at the transcriptional level. Additionally, quercetin enhanced SRF binding activity without changing its expression. These findings provide evidence of how quercetin affects anti-cancer activity in colorectal tumorigenesis by inducing SRF transcription factor activity, thereby increasing DUSP5 expression at the transcriptional level. This study highlights the importance of investigating the molecular mechanisms underlying the anti-cancer properties of quercetin, and suggests its potential use in cancer therapy. [BMB Reports 2023; 56(9): 508-513].

Inhibition of ANXA2 regulated by SRF attenuates the development of severe acute pancreatitis by inhibiting the NF-κB signaling pathway

BACKGROUND

Acute pancreatitis (AP) is an inflammatory process of the pancreas resulting from biliary obstruction or alcohol consumption. Approximately, 10-20% of AP can evolve into severe AP (SAP). In this study, we sought to explore the physiological roles of the transcription factor serum response factor (SRF), annexin A2 (ANXA2), and nuclear factor-kappaB (NF-κB) in SAP.

METHODS

C57BL/6 mice and rat pancreatic acinar cells (AR42J) were used to establish an AP model in vivo and in vitro by cerulein with or without lipopolysaccharide (LPS). Production of pro-inflammatory cytokines (IL-1β and TNF-α) were examined by ELISA and immunoblotting analysis. Hematoxylin and eosin (HE) staining and TUNEL staining were performed to evaluate pathological changes in the course of AP. Apoptosis was examined by flow cytometric and immunoblotting analysis. Molecular interactions were tested by dual luciferase reporter, ChIP, and Co-IP assays.

RESULTS

ANXA2 was overexpressed in AP and correlated to the severity of AP. ANXA2 knockdown rescued pancreatic acinar cells against inflammation and apoptosis induced by cerulein with or without LPS. Mechanistic investigations revealed that SRF bound with the ANXA2 promoter region and repressed its expression. ANXA2 could activate the NF-κB signaling pathway by inducing the nuclear translocation of p50. SRF-mediated transcriptional repression of ANXA2-protected pancreatic acinar cells against AP-like injury through repressing the NF-κB signaling pathway.

CONCLUSION

Our study highlighted a regulatory network consisting of SRF, ANXA2, and NF-κB that was involved in AP progression, possibly providing some novel targets for treating SAP.

EGR1 promotes stemness and predicts a poor outcome of uterine cervical cancer by inducing SOX9 expression

BACKGROUND

Early growth response-1 (EGR1) is a transcription factor involved in the progression of several cancer types. However, the expression and clinical significance of EGR1 in uterine cervical cancer (CC) have not been elucidated.

OBJECTIVE

To investigate the expression, clinical significance and prognostic value of EGR1 in CC.

METHODS

The expression of EGR1 was detected in 13 CCs and paired adjacent tissues with qRT-PCR and in 144 CC tissues with immunohistochemistry (IHC). The IHC scores were used to divide the patients into subsets with low and high EGR1 expression. The correlations between the EGR1 expression and clinicopathological factors were analyzed with the chi-square test, and the prognostic significance of EGR1 expression was evaluated with univariate and multivariate analyses. The functions of EGR1 in the proliferation, invasion and stemness of CC cells were investigated, and the molecular mechanism was assessed by in vitro experiments.

RESULTS

High expression of EGR1 was significantly associated with low survival rates of CC. EGR1 is an independent prognostic biomarker of CC, and its high expression predicted a poor outcome. EGR1 facilitated stemness and thus promoted proliferation and invasion of CC cells. SOX9 played an essential role in the EGR1-induced progression of CC cells.

CONCLUSIONS

EGR1 is an independent prognostic biomarker of CC. High EGR1 expression promoted proliferation, invasion and stemness by increasing SOX9 expression in CC cells. Our results suggested that the EGR1-SOX9 axis may be a potential drug target and that blocking the EGR1-SOX9 axis may be a possible approach to treating CC.

Clinical Significance and Potential Regulatory Mechanisms of Serum Response Factor in 1118 Cases of Thyroid Cancer Based on Gene Chip and RNA-Sequencing Data

Background

Thyroid cancer (TC) is one of the most prevalent endocrine malignancies and there may be many unclarified molecular events and gene types involved in TC. The objective of this study was to assess the clinical implications and potential mechanisms of serum response factor (SRF) in TC.

Material/Methods

RNA-sequencing and gene chip data with TC expression were collected from The Cancer Genome Atlas/Genotype-Tissue Expression, Gene Expression Omnibus, ArrayExpress, Sequence Read Archive, and Oncomine. SRF expression of all TC and adjacent non-cancerous tissue were calculated using the t test, STATA, and Meta-DiSc. The related pathways of the potential SRF target genes and target miRNAs were explored. Dual-luciferase reporter assay was performed to validate the association between SRF and its putative miRNA.

Results

One RNA-sequencing and 15 gene chips were collected, and the pooled standardized mean difference of SRF was −1.00. Furthermore, the area under the curve of sROC of SRF in TC was 0.8251, indicating a dramatic decreased expression of SRF in TC tissues based on 1118 cases. The intersection of differentially expressed genes in TC, SRF co-expressed genes, and SRF potential target genes achieved from Cistrome Cancer led to 169 overlapped genes. miR-330-5p was predicted to target SRF, which was further confirmed by dual-luciferase reporter assay.

Conclusions

The reduction of SRF appears to play a crucial role in the origin of TC. These properties are accomplished by the target genes of SRF, as a transcription factor, or by the axes with the associated miRNAs.