Suppression of CUL4A attenuates TGF-β1-induced epithelial-to-mesenchymal transition in breast cancer cells

MicroRNA-561-3p indirectly regulates the PD-L1 expression by targeting ZEB1, HIF1A, and MYC genes in breast cancer

Globally, breast cancer is the second most common cause of cancer-related deaths among women. In breast cancer, microRNAs (miRNAs) are essential for both the initiation and development of tumors. It has been suggested that the tumor suppressor microRNA-561-3p (miR-561-3p) is crucial in arresting the growth of cancer cells. Further research is necessary to fully understand the role and molecular mechanism of miR-561 in human BC. The aim of this study was to investigate the inhibitory effect of miR-561-3p on ZEB1, HIF1A, and MYC expression as oncogenes that have the most impact on PD-L1 overexpression and cellular processes such as proliferation, apoptosis, and cell cycle in breast cancer (BC) cell lines. The expression of ZEB1, HIF1A, and MYC genes and miR-561-3p were measured in BC clinical samples and cell lines via qRT-PCR. The luciferase assay, MTT, Annexin-PI staining, and cell cycle experiments were used to assess the effect of miR-561-3p on candidate gene expression, proliferation, apoptosis, and cell cycle progression. Flow cytometry was used to investigate the effects of miR-561 on PD-L1 suppression in the BC cell line. The luciferase assay showed that miRNA-561-3p targets the 3'-UTRs of ZEB1, HIF1A and MYC genes significantly. In BC tissues, the qRT-PCR results demonstrated that miR-561-3p expression was downregulated and the expression of ZEB1, HIF1A and MYC genes was up-regulated. It was shown that overexpression of miR-561-3p decreased PD-L1 expression and BC cell proliferation, and induced apoptosis and cell cycle arrest through downregulation of candidate oncogenes. Furthermore, inhibition of candidate genes by miR-561-3p reduced PD-L1 at both mRNA and protein levels. Our research investigated the impact of miR-561-3p on the expression of ZEB1, HIF1A and MYC in breast cancer cells for the first time. Our findings may help clarify the role of miR-561-3p in PD-L1 regulation and point to this miR as a potential biomarker and novel therapeutic target for cancer immunotherapy.

TGF-β1: is it related to the stiffness of breast lesions and can it predict axillary lymph node metastasis?

Background

This study aimed to explore whether transforming growth factor β1 (TGF-β1) is correlated with the stiffness of breast lesions and if it can predict axillary lymph node (ALN) metastasis.

Methods

A retrospective analysis was performed in our hospital. A total of 135 breast lesions in 130 patients who were to undergo vacuum-assisted excisional biopsy (VAEB) or surgery were enrolled between April 2018 and October 2018. Ultrasound (US) and shear wave elastography (SWE) examinations were performed for every lesion before VAEB or surgery. Pathology results obtained by VAEB or surgery were regarded as gold criteria. The elastic parameters and TGF-β1 expression level of malignant breast lesions were compared with those of benign lesions; the relationship between TGF-β1 expression level in breast lesions and the elastic parameters was analyzed; the TGF-β1 expression level in breast lesions with or without ALN metastasis were compared; and the efficacy of TGF-β1 expression level in predicting ALN metastasis was analyzed.

Results

The malignant breast lesions were different from benign lesions in the maximum and mean elasticity (Emax, Emean), standard deviation of elasticity (ESD), elastic ratio of the lesions to the peripheral tissue (Eratio), and the occurrence rate of "stiff rim sign" (P<0.001). The expression level of TGF-β1 in benign breast lesions was significantly lower than that in malignant lesions (P<0.001), and the TGF-β1 expression level was positively correlated with Emax, Emean, ESD, and Eratio (r=0.869, 0.840, 0.834, and 0.734, respectively). The expression level of TGF-β1 in breast lesions with or without "stiff rim sign" was significantly different (P<0.001), and the TGF-β1 expression level in malignant breast lesions with ALN metastasis was significantly higher than that in malignant lesions without ALN metastasis (P=0.0009). When TGF-β1 expression level >0.3138 was taken as the cut-off value, its efficacy in predicting ALN metastasis was 0.853, with a sensitivity of 86.67%, and a specificity 83.33%.

Conclusions

The expression level of TGF-β1 was positively correlated with the elastic parameters of breast lesions, and it could be useful for predicting ALN metastasis, especially for negative ALN diagnosis clinically.

CUL4A regulates endometrial cancer cell proliferation, invasion and migration by interacting with CSN6

Endometrial cancer (EC) is a common malignant gynecological tumor arising from the endometrium, with an annually increasing morbidity and mortality. The present study aimed to investigate the functions of cullin 4A (CUL4A) in EC, as well as the underlying mechanisms. CUL4A expression was assessed in several human EC cells and normal human endometrial epithelial cells (hEECs) via reverse transcription‑quantitative polymerase chain reaction and western blotting. Subsequently, short hairpin (sh)RNA‑CULA4 was transfected into cells, and cell proliferation, invasion and migration were detected using Cell Counting kit‑8, Transwell and wound healing assays, respectively. The STRING database identified that CSN6 interacted with CULA4, and immunoprecipitation was performed to verify the interaction. Subsequently, following CUL4A knockdown, pcDNA3.1‑CSN6 was transfected into cells and its effects on cell proliferation, invasion and migration were assessed. The expression levels of matrix metallopeptidase (MMP)2, MMP9 and p53 were evaluated via western blotting. The results indicated that CUL4A was highly expressed in EC cells, compared with hEECs. CULA4‑knockdown notably inhibited EC cell proliferation, invasion and migration. The expression levels of MMP2 and MMP9 were significantly decreased, while p53 expression was enhanced following CUL4A‑knockdown. The immunoprecipitation assay verified that COP9 signalosome subunit 6 (CSN6) interacted with CULA4. Furthermore, CSN6‑overexpression alleviated the inhibitory effects of CUL4A‑knockdown on EC cell proliferation, invasion and migration. Similarly, CSN6 overexpression reversed CUL4A‑knockdown‑mediated effects on the expression of MMP2, MMP9 and p53. In summary, the results demonstrated that CUL4A regulated EC cell proliferation, invasion and migration by interacting with CSN6.

WD Repeat Domain 5 Promotes Invasion, Metastasis and Tumor Growth in Glioma Through Up-Regulated Zinc Finger E-Box Binding Homeobox 1 Expression

Background

Glioma is one of the important diseases that threaten human survival in today’s society. WD repeat domain 5 (WDR5) belongs to the components of the lysine methyltransferase complex. WDR5 is involved in gene transcription regulation, cell senescence, cancer and other biological events through methylation modification. However, its expression and function in glioma are still unclear.

Materials and Methods

The expression of WDR5 was observed in glioma cells, and then a glioma cell line SW1783 knocked down WDR5 was established. The effects of the decrease of WDR5 expression on proliferation, migration, invasion and EMT of glioma cells were detected, respectively. The downstream regulators of WDR5 were identified by gene expression profiling technology, and the possible molecular mechanisms were identified.

Results

In this study, we found that WDR5 could promote glioma cell’s proliferation, migration, invasion and tumor metastasis. In glioma, especially in metastatic glioma tissues, WDR5 levels were significantly increased, the higher expression level could also cause a significant reduction in overall survival of glioma patients. Second, the ability of cells’ proliferation, migration, invasion and tumor metastasis was significantly reduced in WDR5 knockdown cell lines. We also found a significant change in the expression level of epithelial and mesenchymal markers in WDR5 knockdown cell lines. Furthermore, we found that knockdown of WDR5 could inhibit the expression of zinc finger E-box binding homeobox 1 (ZEB1), and knockdown of ZEB1 could inhibit invasion, migration and epithelial–mesenchymal transformation (EMT) in WDR5 over-expression cell line. We also found that WDR5 may regulate ZEB1’s expression through H3K4me3.

Conclusion

In summary, in this study, we have studied the relationship between WDR5 and glioma, and found that WDR5’s expression is positively correlated with the proliferation, migration, and invasion of glioma cells, which will help find the potential therapeutic target for glioma patients.

Fangjihuangqi Decoction inhibits MDA-MB-231 cell invasion in vitro and decreases tumor growth and metastasis in triple-negative breast cancer xenografts tumor zebrafish model

Triple-negative breast cancer (TNBC) is a basal-like cancer which is considered to be more intrusive, have a poorer prognosis and chemoresistance. TNBC is characterized by the presence of epithelial to mesenchymal transition (EMT) that plays a major role in the progression of the cancer. In the present study, we first use a classic prescription of Chinese medicine Fangjihuangqi Decoction to treat TGFβ1-induced MDA-MB-231 cells in vitro. Our data showed that TGFβ1-induced MDA-MB-231 cell morphology change, promoted MDA-MB 231 invasion, increased Vimentin expression, and decreased E-cadherin expression. Further, Fangjihuangqi Decoction-medicated serum (FHS) treated both MDA-MB 231 cells and TGFβ1-induced MDA-MB-231 cells. Results showed that Fangjihuangqi Decoction could inhibit cell proliferation, reduce cell invasion, increase E-cadherin expression, and decrease EMT markers. Secondly, we established a xenograft tumor zebrafish model to assess Fangjihuangqi Decoction inhibition of cancer cell proliferation and invasion. Our results indicated that Fangjihuangqi Decoction could inhibit tumor growth, restrain the sprouts number of tumor neovascularization, and reduce the length of tumor neoplastic lymphatics by increasing E-cadherin expression and decreasing EMT markers in TNBC xenograft tumor zebrafish model. Overall, our studies provide evidences that Fangjihuangqi Decoction could inhibit TNBC, reverse EMT, and contribute to antimetastasis by increasing E-cadherin expression and decreasing EMT markers, which provide an experimental basis for clinical application of Fangjihuangqi Decoction on TNBC treatment.

The cullin4A is up-regulated in chronic obstructive pulmonary disease patient and contributes to epithelial-mesenchymal transition in small airway epithelium

Background

Chronic obstructive pulmonary disease (COPD) is a common respiratory disease with high morbidity and mortality. The most important pathophysiological change of COPD is airway obstruction. Airway obstruction can cause airflow restriction and obstructive ventilation dysfunction. Currently, many studies have shown that there is EMT phenomenon in the process of airway remodeling of COPD. Cullin4A (CUL4A) is an E3 ubiquitin ligase that interacts with other factors to form the E3 complex. Studies have shown that CLU4A is associated with EMT in non-small cell lung cancer and other cancers. However, its relationship with EMT in COPD has not been reported systematically. In this study, we detected the expression of CUL4A in lung epithelium of COPD patients. In addition, the regulatory effect and mechanism of CUL4A on EMT in COPD were clarified in small airway epithelial cells.

Methods

The expression of CUL4A was assessed by immunohistochemistry in lung epithelium specimens from smokers, non-smokers and patients with chronic obstructive pulmonary disease. The role of CUL4A on cigarette smoke extract (CSE)-induced epithelial-mesenchymal transition (EMT) in human small airway epithelial cells (HSAEpiCs) was assessed by silencing or overexpression CUL4A in vitro. Cigarette smoke is recognized as a high-risk factor in the induction of COPD, and its damage to the airway involves airway damage, airway inflammation and airway remodeling.

Results

The results shown that CUL4A expression in small airway epithelium was significantly increased in patients with COPD. We also observed a significant negative association between CUL4A and FEV₁%, a useful clinical marker for the diagnosis and evaluation of COPD severity, in small airway epithelial cells. In vitro, CSE-induced EMT is associated with high expression of CUL4A, and targeted silencing of CUL4A with shRNA inhibits CSE-induced EMT in human small airway epithelial cells.

Conclusions

Our results showed that CUL4A was overexpressed in lung epithelium of COPD patients, and CUL4A could regulate EMT of human small airway epithelium, which revealed a new mechanism of remodeling of small airway epithelium of COPD patients.

Electronic supplementary material

The online version of this article (10.1186/s12931-019-1048-4) contains supplementary material, which is available to authorized users.

Sphingomyelin synthase 1 regulates the epithelial‑to‑mesenchymal transition mediated by the TGF‑β/Smad pathway in MDA‑MB‑231 cells

Breast cancer is the most common cancer in women and a leading cause of cancer‑associated mortalities in the world. Epithelial‑to‑mesenchymal transition (EMT) serves an important role in the process of metastasis and invasive ability in cancer cells, and transforming growth factor β1 (TGF‑β1) have been investigated for promoting EMT. However, in the present study, the role of the sphingomyelin synthase 1 (SMS1) in TGF‑β1‑induced EMT development was investigated. Firstly, bioinformatics analysis demonstrated that the overexpression of SMS1 negatively regulated the TGFβ receptor I (TβRI) level of expression. Subsequently, the expression of SMS1 was decreased, whereas, SMS2 had no significant difference when MDA‑MB‑231 cells were treated by TGF‑β1 for 72 h. Furthermore, the present study constructed an overexpression cells model of SMS1 and these cells were treated by TGF‑β1. These results demonstrated that overexpression of SMS1 inhibited TGF‑β1‑induced EMT and the migration and invasion of MDA‑MB‑231 cells, increasing the expression of E‑cadherin while decreasing the expression of vimentin. Furthermore, the present study further confirmed that SMS1 overexpression could decrease TβRI expression levels and blocked smad family member 2 phosphorylation. Overall, the present results suggested that SMS1 could inhibit EMT and the migration and invasion of MDA‑MB‑231 cells via TGF‑β/Smad signaling pathway.