Activation of GPER suppresses epithelial mesenchymal transition of triple negative breast cancer cells via NF-κB signals

Combretastatin A4 Regulates Proliferation, Migration, Invasion, and Apoptosis of Thyroid Cancer Cells via PI3K/Akt Signaling Pathway

Background

Combretastatin A4 (CA4) is a potential therapeutic candidate for a variety of human cancer treatments. However, the inhibitive effects of CA4 on thyroid cancer cells are still not well-clarified. This study aimed to investigate the potential effect of CA4 on thyroid cancer cells, as well as underlying mechanism.

Material/Methods

Human thyroid papillary carcinoma cell line TPC1 was pre-treated with 5 concentrations of CA4 (0, 1, 2, 5, or 10 μM) for 2 h. Cell proliferation was determined by 3-(4, 5-dimethyl-2- thiazolyl)-2, 5-diphenyl -2-H-tetrazolium bromide (MTT) assay. Cell migration and invasion were detected by a modified Boyden chamber assay. Moreover, cell apoptosis was detected by terminal deoxynucleotidyl (TUNEL) staining assay and flow cytometry method. Western blot analysis was performed to determine the expression changes of epithelial-mesenchymal transition (EMT)-related proteins and phosphatidylinositol-3-kinase/serine/threonine kinase (PI3K/Akt) signaling pathway proteins.

Results

CA4 significantly inhibited the cell proliferation, migration, and invasion, and significantly promoted cell apoptosis in a dose-dependent manner compared with the control group. The EMT-related protein levels of N-Cadherin, Vimentin, Snail1, Slug, Twist1, and ZEB1 were significantly decreased by CA4, while E-cadherin had no significant difference compared with the control group. Moreover, PI3K/Akt signaling pathway protein levels of p-PI3K and p-Akt were significantly decreased, whereas PI3K and Akt had no significant differences compared with the control group.

Conclusions

CA4 can inhibit proliferation, migration, and invasion and promote apoptosis of TPC1 cells. These effects might be through the PI3K/Akt signaling pathway. CA4 may be a potential therapeutic target for the treatment of thyroid cancer.

17β-estradiol-induced growth of triple-negative breast cancer cells is prevented by the reduction of GPER expression after treatment with gefitinib

Triple-negative breast cancers (TNBCs) are neither susceptible to endocrine therapy due to a lack of estrogen receptor α expression nor trastuzumab. TNBCs frequently overexpress epidermal growth factor receptor (EGFR) and membrane bound estrogen receptor, GPER. To a certain extent the growth of TNBCs is stimulated by 17β-estradiol via GPER. We analyzed whether inhibition of EGFR by gefitinib reduces the expression of GPER and subsequent signal transduction in TNBC cells. Dependence of proliferation on 17β-estradiol was determined using Alamar Blue assay. Expression of GPR30 and activation of c-src, EGFR and cAMP-responsive element binding (CREB) protein by 17β-estradiol was analyzed by western blotting. Expression of c-fos, cyclin D1 and aromatase was determined using RT-PCR. Gefitinib reduced GPER expression concentration‑ and time‑dependently. In HCC70 cells, GPER expression was reduced to 15±11% (p<0.05) after treatment with 200 nM gefitinib for four days, and in HCC1806 cells GPER expression was reduced to 39±5% (p<0.01) of the control. 17β-estradiol significantly increased the percentage of HCC1806 cells within 7 days to 145±29% of the control (HCC70, 110±8%). This increase in cell growth was completely prevented in both TNBC cell lines after GPR30 expression was downregulated by treatment with 200 nM gefitinib. In HCC1806 cells, activation of c-src was increased by 17β-estradiol to 350±50% (p<0.01), and gefitinib reduced src activation to 110%. Similar results were obtained in the HCC70 cells. Phosphorylation of EGFR increased to 240±40% (p<0.05) in the HCC1806 cells treated with 17β-estradiol (HCC70, 147±25%). Gefitinib completely prevented this activation. Phosphorylation of CREB and induction of c-fos, cyclin D1 and aromatase expression by 17β-estradiol were all prevented by gefitinib. These experiments conclusively show that reduction of GPER expression is a promising therapeutic approach for TNBC.

Activation of GPER suppresses migration and angiogenesis of triple negative breast cancer via inhibition of NF-κB/IL-6 signals

Triple-negative breast cancer (TNBC) is characterized by high vascularity and frequent metastasis. Here, we found that activation of G protein-coupled estrogen receptor (GPER) by its specific agonist G-1 can significantly inhibit interleukin 6 (IL-6) and vascular endothelial growth factor A (VEGF-A). TNBC tissue microarrays from 100 TNBC patients revealed GPER is negatively associated with IL-6 levels and higher grade and stage. Activation of GPER or anti-IL-6 antibody can inhibit both in vitro tube formation of human umbilical vein endothelial cells (HUVECs) and migration of TNBC cells. While recombinant IL-6 supplementary can significantly reverse the inhibitory effects of G-1, suggesting the essential role of IL-6 in G-1 induced suppression of angiogenesis and invasiveness of TNBC cells. G-1 treatment decreased the phosphorylation, nuclear localization, transcriptional activities of NF-κB and suppressed its binding with IL-6 promoter. BAY11-7028, the inhibitor of NF-κB, can mimic the effect of G-1 to suppression of IL-6 and VEGF-A. While over expression of p65 can attenuate the inhibitory effects of G-1 on IL-6 and VEGF expression. The suppression of IL-6 by G-1 can further inhibit HIF-1α and STAT3 signals in TNBC cells by inhibition their expression, phosphorylation and/or nuclear localization. Moreover, G-1 also inhibited the in vivo NF-κB/IL-6 signals and angiogenesis and metastasis of MDA-MB-231 xenograft tumors. In conclusion, our study demonstrated that activation of GPER can suppress migration and angiogenesis of TNBC via inhibition of NF-κB/IL-6 signals, therefore it maybe act as an important target for TNBC treatment.

Signals involved in the effects of bisphenol A (BPA) on proliferation and motility of Leydig cells: a comparative proteomic analysis

Recent studies indicated that bisphenol A (BPA) can disrupt spermatogenesis and then cause male infertility. The present study revealed that BPA greater than 10^-6 M inhibited the proliferation of Leydig TM3 cells via a concentration dependent manner. The proteomic study revealed that 50 proteins were modulated in TM3 cells following exposure to BPA, which was relevant to structure, motility, cell metabolism, protein and nucleotide processing, and cell proliferation. Furthermore, BPA increased the in vitro migration and invasion of Leydig TM3 cells, which might be due to the BPA's modulation of proteins related to cell structure and motility such as actin and heat shock protein (HSP). Silencing of galectin-1, which was up regulated by BPA, significantly abolished the BPA-induced migration of TM3 cells. BPA treatment obviously increased the phosphorylation of ERK1/2 and Akt, while only PD98509 (ERK1/2 inhibitor) significantly attenuated BPA induced up regulation of galectin-1. Furthermore, PD98509 also reversed BPA induced migration of TM3 cells. Our study demonstrated that xenoestrogen BPA at micromolar or greater concentrations can modulate protein profiles, inhibit cell proliferation, and promote the in vitro migration and invasion of Leydig TM3 cells. It provided new insight into the mechanisms responsible for BPA induced male infertility.

Long non-coding RNA AFAP1-AS1 facilitates tumor growth and promotes metastasis in colorectal cancer

BACKGROUND AND OBJECTIVE

Long non-coding RNAs can regulate tumorigenesis of various cancers. Dys-regulation of lncRNA-AFAP1-AS1 has not been studied in colorectal carcinoma (CRC). This study was to examine the function involvement of AFAP1-AS1 in tumor growth and metastasis of CRC.

METHODS

Relative expression of AFAP1-AS1 in CRC tissues and CRC cells lines was determined using quantitative real-time PCR (qRT-PCR). Functional involvement of AFAP1-AS1 in tumor proliferation and metastasis was evaluated in AFAP1-AS1-specific siRNA-treated CRC cells and in CRC cell xenograft. Expression of epithelial-mesenchymal transition (EMT)-related gene expression was determined using western blot.

RESULTS

Relative expression of AFAP1-AS1 was significantly elevated in CRC tissues and CRC HCT116 and SW480 cell lines. AFAP1-AS1 knock-down suppressed SW480 cell proliferation, colony formation, migration and invasion. Also AFAP1-AS1 knock-down inhibited tumor metastasis-associated genes expression in terms of EMT. This carcinostatic action by AFAP1-AS1 knock-down was further confirmed by suppression of tumor formation and hepatic metastasis of CRC cells in nude mice.

CONCLUSION

lncRNA-AFAP1-AS1 knock-down exhibits antitumor effect on colorectal carcinoma in respects of suppression of cell proliferation and metastasis of cancer cells.

Visfatin Triggers the Cell Motility of Non-Small Cell Lung Cancer via Up-Regulation of Matrix Metalloproteinases

High levels of visfatin are correlated with worse clinical prognosis of various cancers. Still, the effects and mechanisms of visfatin on progression of non-small cell lung cancer (NSCLC) remain unclear. This study revealed that plasma levels of visfatin in patients with NSCLC (585 ± 287 pg/ml) were significantly (p < 0.01) higher than those in healthy people (142 ± 61.1 pg/ml). The high level of plasma visfatin was found to be significantly (p < 0.05) correlated with TNM stage, lymph node metastasis and distant metastasis. Visfatin treatment can increase the migration and invasion of NSCLC cells via up-regulation of metalloproteinase-2 (MMP-2) and MMP-9. Both si-MMP-2 and si-MMP-9 attenuated visfatin-induced migration of NSCLC cells. The inhibitor of NF-κB, while not ERK1/2, p38-MAPK or PI3K/Akt, can significantly abolish visfatin-induced migration of A549 cells and up-regulation of MMP-2 and MMP-9. Furthermore, visfatin can increase the phosphorylation of IκBα and p65 and the transcription activities of NF-κB in NSCLC cells. ACHP, the inhibitor of IKK-β, blocked visfatin-induced activation of p65 and up-regulation of MMP-2 and MMP-9. Collectively, our data revealed that visfatin can trigger the in vitro migration and invasion of NSCLC cells via up-regulation of MMPs through activation of NF-κB.

Epidermal growth factor (EGF) triggers the malignancy of hemangioma cells via activation of NF-κB signals

Hemangioma (HA) is tumor formed by hyper-proliferation of vascular endothelial cells. However, the role and mechanisms of epidermal growth factor (EGF) on the progression of HA are not well illustrated. Our present study revealed that EGF can significantly promote the in vitro proliferation and motility of HA cells, which was confirmed by the up regulation of Bcl-2, proliferating cell nuclear antigen (PCNA), and metalloproteinase-2 (MMP-2) and MMP-9. The pharmacological inhibition of NF-κB, while not ERK1/2 or PI3K/Akt, attenuated EGF induced cell proliferation and expression of MMP-2 and MMP-9. EGF treatment also increased the phosphorylation, nuclear translocation and transcriptional activities of NF-κB in HA cells. These data suggested that NF-κB plays an essential role in EGF induced malignancy of HA cells. Furthermore, EGF treatment also increased the phosphorylation of IκB and IKKα, while not IKKβ or IKKγ. The knockdown of IKKα reversed EGF induced activation of NF-κB. EGF treatment also decreased the phosphorylation of GSK-3β and increased its activities in both HDEC and CRL-2586 EOMA cells. LiCl, a potent GSK-3β inhibitor, can obviously reverse EGF induced up regulation of p65 phosphorylation. Collectively, our study revealed that EGF can trigger the malignancy of HA cells via induction of proliferation and invasion. The activation of NF-κB through IKKα/IκBα and GSK-3β signal is essential for this process. It suggested that EGF/NF-κB signal may represent a novel therapeutic target for the treatment of human HA.

Activation of GPER suppresses epithelial mesenchymal transition of triple negative breast cancer cells via NF-κB signals

The targeted therapy for triple-negative breast cancer (TNBC) is a great challenge due to our poor understanding on its molecular etiology. In the present study, our clinical data showed that the expression of G-protein coupled estrogen receptor (GPER) is negatively associated with lymph node metastasis, high-grade tumor and fibronectin (FN) expression while positively associated with the favorable outcome in 135 TNBC patients. In our experimental studies, both the in vitro migration and invasion of TNBC cells were inhibited by GPER specific agonist G-1, through the suppression of the epithelial mesenchymal transition (EMT). The G-1 treatment also reduced the phosphorylation, nuclear localization, and transcriptional activities of NF-κB. While over expression of NF-κB attenuated the action of G-1 in suppressing EMT. Our data further illustrated that the phosphorylation of GSK-3β by PI3K/Akt and ERK1/2 mediated, at least partially, the inhibitory effect of G-1 on NF-κB activities. It was further confirmed in a study of MDA-MB-231 tumor xenografts in nude mice. The data showed that G-1 inhibited the in vivo growth and invasive potential of TNBC via suppression of EMT. Our present study demonstrated that an activation of GPER pathway elicits tumor suppressive actions on TNBC, and supports the use of G-1 therapeutics for TNBC metastasis.