p38α MAPK mediates 17β-estradiol inhibition of MMP-2 and -9 expression and cell migration in human lovo colon cancer cells

Epidemiological studies demonstrate that the incidence and mortality rates of colorectal cancer in women are lower than in men. However, it is unknown if 17β‐estradiol (E₂) treatment is sufficient to inhibit cell proliferation and cell migration in human colon cancer cells. Up‐regulation of urokinase plasminogen activator (uPA), tissue plasminogen activator (tPA), and matrix metallopeptidases (MMPs) is reported to associate with the development of cancer cell mobility, metastasis, and subsequent malignant tumor. In the present study, we treated human LoVo colon cancer cells with E₂ to explore whether E₂ down‐regulates cell proliferation and migration, and to identify the precise molecular and cellular mechanisms behind the down‐regulatory responses. Here, we found that E₂ treatment decreased cell proliferation and cell cycle‐regulating factors such as cyclin A, cyclin D1 and cyclin E. At the same time, E₂ significantly inhibited cell migration and migration‐related factors such as uPA, tPA, MMP‐2, and MMP‐9. However, E₂ treatment showed no effects on upregulating expression of plasminogen activator inhibitor‐1 (PAI‐1), tissue inhibitor of metalloproteinase‐1, ‐2, ‐3, and ‐4 (TIMP‐1, ‐2, ‐3, and ‐4). After administration of inhibitors including QNZ (NFκB inhibitor), LY294002 (Akt activation inhibitor), U0126 (ERK1/2 inhibitor), SB203580 (p38 MAPK inhibitor) or SP600125 (JNK1/2 inhibitor), E₂‐downregulated cell migration and expression of MMP‐2 and MMP‐9 in LoVo cells is markedly inhibited only by p38 MAPK inhibitors, SB203580. Application of specific target gene siRNA (ERα, ERβ, p38α, and p38β) to LoVo cells further confirmed that p38 MAPK mediates E₂/ERs inhibition of MMP‐2 and ‐9 expression and cell motility in LoVo cells. Collectively, these results suggest that E₂ treatment down‐regulates cell proliferation by modulating the expression of cyclin A, cyclin D1 and cyclin E. E₂ treatment simultaneously impaired cell migration by inhibiting the expression of uPA, tPA, MMP‐2, and MMP‐9 through E₂/ERs ? p38α MAPK signaling pathway in human LoVo colon cancer cells. J. Cell. Physiol. 227: 3648–3660, 2012. © 2012 Wiley Periodicals, Inc.     

VPA inhibits renal cancer cell migration by targeting HDAC2 and down-regulating HIF-1α

Cell migration plays major roles in human renal cancer-related death, but the molecular mechanisms remain unclear. Valproic acid (VPA) is a broad-spectrum inhibitor of class I and II histone deacetylases and shows great anticancer activity in a variety of human cancers. In this study, we found that VPA significantly inhibited cell migration but not proliferation of human renal cancer ACHN cells. Mechanistic studies found that VPA significantly inhibited the expression of HIF-1α. Knockdown of HIF-1α could obviously inhibited cell migration, while over-expression of HIF-1α markedly rescued the inhibition of VPA on cell migration. Further studies found that knockdown of HDAC2 completely mimicked the effects of VPA on HIF-1α and cell migration, and over-expression of HIF-1α could also rescue the effects of HDAC2 knockdown on cell migration. Collectively, these results indicated that the potential of specific inhibition of HDAC2 by small molecular chemicals may lead to future therapeutic agents in human renal cancer treatment.     

Retracted: KDM6B promotes ovarian cancer cell migration and invasion by induced transforming growth factor-β1 expression

KDM6B, also known as JMJD3, is a member of the family of histone lysine demethylase (KDMs), which is closely related to many types of cancers. However, its role and the underlying mechanisms in ovarian cancer remain unknown. Here we show that KDM6B is elevated in epithelial ovarian cancer and its expression level is closely related with metastasis and invasion. In addition, survival analysis showed that high expression of KDM6B was associated with low overall survival in ovarian cancer patients. Overexpression of KDM6B in epithelial ovarian cancer cells promoted proliferation, epithelial-mesenchymal transition (EMT), migration and invasion in vitro, and enhanced metastatic capacities in vivo. On the contrary, silencing KDM6B in invasive and metastatic ovarian cancer cells inhibited these processes. Mechanistically, we found that KDM6B exerts its function by modulating the transforming growth factor-β1 (TGF-β1) expression, and TGF-β1 signal pathway inhibitor LY2157299 significantly inhibited KDM6B-induced proliferation, migration, metastasis, and EMT in ovarian cancer cells. Our findings, for the first time, reveal the pivotal role of KDM6B in the invasion and metastatic behavior of epithelial ovarian cancer. Thus, targeting KDM6B may be a useful strategy to interfere with these behaviors of epithelial ovarian cancer.     

Activin and TGFβ regulate expression of the microRNA-181 family to promote cell migration and invasion in breast cancer cells

MicroRNA-181 (miR-181) is a multifaceted miRNA that has been implicated in many cellular processes such as cell fate determination and cellular invasion. While miR-181 is often overexpressed in human tumors, a direct role for this miRNA in breast cancer progression has not yet been characterized. In this study, we found this miRNA to be regulated by both activin and TGFβ. While we found no effect of miR-181 modulation on activin/TGFβ-mediated tumor suppression, our data clearly indicate that miR-181 plays a critical and prominent role downstream of two growth factors, in mediating their pro-migratory and pro-invasive effects in breast cancer cells miR-181 acts as a metastamir in breast cancer. Thus, our findings define a novel role for miR-181 downstream of activin/TGFβ in regulating their tumor promoting functions. Having defined miR-181 as a critical regulator of tumor progression in vitro, our results thus, highlight miR-181 as an important potential therapeutic target in breast cancer.     

Id-1 promotes migration and invasion of non-small cell lung cancer cells through activating NF-κB signaling pathway

Background

Numerous studies have shown that Id-1 (Inhibitor of differentiation 1) is upregulated in several cancers and associated with tumor malignant characters. However, the clinical significance and biological role of Id-1 in non-small cell lung cancer (NSCLC) remains unclear.

Methods

We used RT-PCR, Western blot and Immunohistochemistry to measure Id-1 expression in NSCLC tissues and matched adjacent noncancerous tissues. The expression pattern of Id-1 in NSCLC tissues was determined by scoring system of immunohistochemical analysis. The Kaplan-Meier method was used to calculate the survival curve, and log-rank test to determine statistical significance. The Id-1 gene was overexpressed or downreuglated with Lentiviral vectors in NSCLC cells. And, the migration ability of NSCLC cells was tested in a Transwell Boyden Chamber.

Results

We found that Id-1 is generally expressed higher in NSCLC tissues compared with matched adjacent noncancerous tissues. We also found that high Id-1 expression in tumor tissues is significantly correlated with tumor progression and poor survival in NSCLC patients. Furthermore, our experimental data revealed that knockdown of Id-1 significantly suppressed the proliferation, migration and invasion of NSCLC cells, whereas ectopic expression of Id-1 promoted the malignant phenotype of NSCLC cells. Mechanistic study showed that NF-κB signaling pathway contributed to the effects of Id-1 in NSCLC cells. Moreover, blocking the NF-κB pathway significantly inhibited the tumor-promoting actions of Id-1 in NSCLC cells.

Conclusions

We identified a tumorigenic role of Id-1 in NSCLC and provided a novel therapeutic target for NSCLC patients.

     

LIF upregulates poFUT1 expression and promotes trophoblast cell migration and invasion at the fetal–maternal interface

Trophoblast cell migration and invasion are crucial for the establishment of a successful pregnancy. Protein O-fucosyltransferases, such as poFUT1 and poFUT2, catalyze the O-fucosylation of proteins and have important roles in embryonic development. Leukemia inhibitory factor (LIF) is a critical cytokine in the regulation of embryonic development and implantation. However, the exact roles of poFUTs in embryo migration and invasion and the effects of LIF on the expression of poFUTs have not been studied in detail. In the current study, we showed that poFUT1 and LIF were highly expressed in human trophoblast cells and in the serum of women during the first trimester of a normal pregnancy. However, in patients with threatened abortion, poFUT1 and LIF levels were found to be reduced. There were no significant differences in the expression levels of poFUT2 between the two groups. The migration and invasion potential of trophoblasts in an explant culture and in an in vitro implantation model was decreased or increased upon altering poFUT1 expression levels by siRNA or cDNA transfection. Our results also revealed that LIF upregulated the expression of poFUT1. The upregulation of poFUT1 by LIF promoted trophoblast cell migration and invasion at the fetal–maternal interface by activating the PI3K/Akt signaling pathway. Taken together, these study findings suggest that poFUT1 may be used as a marker of embryo implantation.Human pregnancy is a complex biological process that requires synchrony between the develop embryo and the receptive uterine endometrium. The fertilized egg divides into a 2-, 4-, and 8-cell embryo before developing into the morula and then into the mature blastocyst.^{1, 2} In the mature blastocysts, the inner cell mass (ICM), which comprises embryonic stem cells, differentiates into various tissues in the fetus. The trophoblast is the outer layer of embryonic tissue (also called villi) that facilitates the adhesion and penetration of the blastocysts into the endometrium during implantation. During the implantation of a human embryo, the progenitor trophoblast cells differentiate into the syncytiotrophoblast (STB) and the invasive trophoblast (iCTB) by different developmental pathways. The STB covers the villi and develops into the placenta, which mediates the exchange of nutrients, oxygen, and waste between maternal and fetal blood. The iCTB, which is derived from the trophoblast by epithelial–mesenchymal transition (EMT), forms cell columns and has a highly invasive character, causing it to migrate away from the attached embryo, invade the uterine epithelium and uterine spiral arteries to establish the maternal–fetal linkage.^{3, 4, 5, 6} However, poor iCTB migration and invasion often results in a failure to establish the maternal–fetal connection and leads to abortion. Many factors at the maternal–fetal interface, such as hormones (e.g., progesterone), growth factors and their receptors (e.g., EGF and EGFR), and cytokines (e.g., leukemia inhibitory factor (LIF)), regulate trophoblast invasion.^{7, 8, 9} These molecules increase the invasion potential of the embryo by increasing the expression levels of matrix metalloproteinases (MMPs) and decreasing that of the tissue inhibitor of MMP (TIMP).Protein glycosylation has an important role in many physiological and pathological processes, including inflammation, cancer metastasis, and embryo implantation.^{10, 11, 12} Protein fucosylation is one of the important types of glycosylation. It is classified into two kinds, N-fucosylation and O-fucosylation, which are catalyzed by fucosyltransferases (FUTs) and protein O-fucosyltransferases (poFUTs), respectively.^{13, 14} It is known that FUTs are expressed at specific stages of the menstrual cycle and are associated with reproductive function.^{15, 16} Ponnampalam et al.¹⁷ reported an increased expression level of FUT4 in the secretory phase as compared with that observed in the proliferative phase. We had previously shown that FUT4 and FUT7, which are expressed in uterine epithelial cells, influence the adhesion potential of the embryo.^{18, 19} poFUTs include poFUT1 and poFUT2. poFUT1 transfers L-fucose directly to the glycoproteins with epidermal growth factor (EGF)-like repeats.²⁰ A mutation in poFUT1 caused embryonic lethality in mice; silencing poFUT1 led to abnormal development in Drosophilas.^{20, 21} poFUT2 catalyzes the O-fucosylation of the glycoproteins with thrombospondin type 1 repeats (TSRs). The disruption of poFUT2 in mice resulted in teratomas.^{22, 23} However, the exact roles of poFUT1 and poFUT2 in human trophoblast migration and invasion have not been studied in detail.LIF, a pleiotropic cytokine of the interleukin-6 family, is essential for the successful completion of human pregnancy.^{24, 25} LIF, secreted by both the trophoblast and the uterine endometrium, mediates embryonic development and implantation in an autocrine or paracrine manner at the maternal–fetal interface. In the mother, LIF level peaks during the secretory/postovulatory phase of the menstrual cycle and regulates uterine receptivity for blastocyst implantation. In the fetus, LIF promotes trophoblast proliferation, invasion, and differentiation. Reduced expression level of LIF led to incomplete embryonic development. A deficiency of LIF results in implantation failure and causes repeated abortions or unexplained infertility.^{26, 27, 28, 29} However, the role of LIF-mediated regulation of poFUT1 and poFUT2 in embryo implantation has not been elucidated.In this study, we report that the levels of poFUT1 and LIF were higher in trophoblasts obtained from women with a normal pregnancy than those from patients with threatened abortion. However, the expression level of poFUT2 was not significantly different between the two groups. The poFUT1 promoted the migration and invasion of trophoblasts in an explant culture and in an in vitro implantation model. The upregulation of poFUT1 by LIF facilitated trophoblast cell migration and invasion through activating the PI3K/Akt signaling pathway.     

BST2 promotes cell proliferation,migration and induces NF-κB activation in gastric cancer

Objectives

To investigate the functional roles of bone marrow stromal cell antigen 2 (BST2) in gastric cancer (GC) cells and its implications in the development of GC patients.

Results

BST2 was frequently overexpressed in GC tissues compared with the adjacent non-tumorous tissues, and high BST2 expression was correlated with tumor stage and lymphatic metastasis. Furthermore, in vitro experiments demonstrated that knockdown of BST2 by siRNA inhibited cell proliferation, induced apoptosis and repressed cell motility in GC cells. In addition, the pro-tumor function of BST2 in GC was mediated partly through the NF-κB signaling.

Conclusion

BST2 possesses the oncogenic potential in GC by regulating the proliferation, apoptosis, and migratory ability of GC cells, thereby BST2 could be a potential therapeutic target for the treatment of GC.

     

Prognostic value of HIF-1α expression in patients with gastric cancer

The role of hypoxia-inducible factors-1 alpha (HIF-1α) expression in gastric cancer remains controversial. We performed a systematic review of the literature with meta-analysis. Electronic databases were used to identify published studies before December 1, 2012. Pooled hazard ratio (HR) or odds ratio (OR) with 95 % confidence interval (95 % CI) was used to estimate the strength of the association between HIF-1α expression and survival of gastric cancer patients. Heterogeneity and publication bias were also assessed. Final analysis of 1,268 patients from 9 eligible studies was performed. High HIF-1α expression was significantly correlated with poor overall survival (OS) of gastric cancer patients (HR = 2.14, 95 % CI = 1.32–3.48). Subgroup analysis indicated that HIF-1α over-expression had an unfavorable impact on OS in Asian patients (HR = 2.35, 95 % CI = 1.41–3.92). Moreover, up-regulation of HIF-1α was significantly associated with the depth of invasion (OR = 2.49, 95 % CI = 1.28–4.83), lymph node metastasis (OR = 2.15, 95 % CI = 1.27–3.66), and vascular invasion (OR = 2.23, 95 % CI = 1.20–4.14). HIF-1α expression might be a predicative factor of poor prognosis for gastric cancer particularly in Asia.     

Extracellular heat shock protein (Hsp)70 and Hsp90α assist in matrix metalloproteinase-2 activation and breast cancer cell migration and invasion

Breast cancer is second only to lung cancer in cancer-related deaths in women, and the majority of these deaths are caused by metastases. Obtaining a better understanding of migration and invasion, two early steps in metastasis, is critical for the development of treatments that inhibit breast cancer metastasis. In a functional proteomic screen for proteins required for invasion, extracellular heat shock protein 90 alpha (Hsp90α) was identified and shown to activate matrix metalloproteinase 2 (MMP-2). The mechanism of MMP-2 activation by Hsp90α is unknown. Intracellular Hsp90α commonly functions with a complex of co-chaperones, leading to our hypothesis that Hsp90α functions similarly outside of the cell. In this study, we show that a complex of co-chaperones outside of breast cancer cells assists Hsp90α mediated activation of MMP-2. We demonstrate that the co-chaperones Hsp70, Hop, Hsp40, and p23 are present outside of breast cancer cells and co-immunoprecipitate with Hsp90α in vitro and in breast cancer conditioned media. These co-chaperones also increase the association of Hsp90α and MMP-2 in vitro. This co-chaperone complex enhances Hsp90α-mediated activation of MMP-2 in vitro, while inhibition of Hsp70 in conditioned media reduces this activation and decreases cancer cell migration and invasion. Together, these findings support a model in which MMP-2 activation by an extracellular co-chaperone complex mediated by Hsp90α increases breast cancer cell migration and invasion. Our studies provide insight into a novel pathway for MMP-2 activation and suggest Hsp70 as an additional extracellular target for anti-metastatic drug development.     

Upregulation of LASP2 inhibits pancreatic cancer cell migration and invasion through suppressing TGF-β-induced EMT

LASP2 (LIM and SH3 protein 2), a member of the LIM-protein subfamily of the nebulin group, was first identified as a splice variant of the nebulin gene. In the past, investigators mainly focused on the impact of LASP2 on cardiac diseases because of its identification in the myocardium. Recently, several studies have reported that LASP2 is associated with the progression of various cancers. However, there have been no investigations on the expression and function of LASP2 in pancreatic cancer (PC). In this study, we performed the quantitative real-time polymerase chain reaction and Western blot analysis to detect the expression of LASP2 in PC tissues and cell lines. PC cells were transfected with LASP2 overexpression plasmid or the negative control in the presence or absence of tumor growth factor-β (TGF-β). The transwell assays were used to measure the effects of LASP2 on PC cell migration and invasion. The protein expression of epithelial-mesenchymal transition (EMT) markers was detected using Western blot assay. Our results demonstrated that LASP2 was downregulated in PC tissues and cell lines. In addition, upregulation of LASP2 inhibited the PC cell migration and invasion. We also found that LASP2 upregulation reversed TGF-β-induced EMT in PC cells. Taken together, we provided novel evidence supporting the tumor-suppressor role of LASP2 in PC and suggested it as a potential therapeutic target in PC treatment.     

PI3K and ERK-induced Rac1 activation mediates hypoxia-induced HIF-1α expression in MCF-7 breast cancer cells

Background

Hypoxia-inducible factor 1 (HIF-1α) expression induced by hypoxia plays a critical role in promoting tumor angiogenesis and metastasis. However, the molecular mechanisms underlying the induction of HIF-1α in tumor cells remain unknown.

Methodology/Principal Findings

In this study, we reported that hypoxia could induce HIF-1α and VEGF expression accompanied by Rac1 activation in MCF-7 breast cancer cells. Blockade of Rac1 activation with ectopic expression of an inactive mutant form of Rac1 (T17N) or Rac1 siRNA downregulated hypoxia-induced HIF-1α and VEGF expression. Furthermore, Hypoxia increased PI3K and ERK signaling activity. Both PI3K inhibitor {"type":"entrez-nucleotide","attrs":{"text":"LY294002","term_id":"1257998346","term_text":"LY294002"}}LY294002 and ERK inhibitor U0126 suppressed hypoxia-induced Rac1 activation as well as HIF-1α expression. Moreover, hypoxia treatment resulted in a remarkable production of reactive oxygen species (ROS). N-acetyl-L-cysteine, a scavenger of ROS, inhibited hypoxia-induced ROS generation, PI3K, ERK and Rac1 activation as well as HIF-1α expression.

Conclusions/Significance

Taken together, our study demonstrated that hypoxia-induced HIF-1α expression involves a cascade of signaling events including ROS generation, activation of PI3K and ERK signaling, and subsequent activation of Rac1.     

Pharmacologic IL-6Rα inhibition in cholangiocarcinoma promotes cancer cell growth and survival

Biliary tract cancer (BTC) represents a malignant tumor of the biliary tract including cholangiocarcinoma (CCA) and the carcinoma of the gallbladder (GBC) with a 5-year survival rate between 5 and 18% due to late diagnosis and rapid disease progression. Chronic inflammation is one of the main risk factors for CCA and GBC in particular. IL-6, as a mediator of inflammation, can act through a membrane-bound receptor alpha-chain (mIL-6R, “IL-6 classic signaling”) or via soluble forms (sIL-6R, “IL-6 trans-signaling”). However, little is known about the impact on cellular responses of IL-6 trans-signaling on BTC. We analyzed primary tumors as whole sections and as tissue microarrays, and also searched The Cancer Genome Atlas database. Compared to non-neoplastic, non-inflamed gallbladder tissue, IL-6Rα was downregulated in GBC, and this correlated with the patients' overall survival. Furthermore, different CCA cell lines and compounds for activation (IL-6 and Hyper-IL-6) or inhibition (Tocilizumab and sgp130Fc) of IL-6 classic signaling and trans-signaling were used to determine their effects on cellular processes between the two modes of IL-6 signaling. Inhibition of IL-6 trans-signaling by sgp130Fc reduced CCA cell line viability and apoptosis, whereas migration and proliferation were increased. We conclude that IL-6Rα expression is a good prognostic marker for GBC, and that the blocking of IL-6 trans-signaling and activation of IL-6 classic signaling have tumor promoting activity. These findings warrant the exclusion of patients with GBC or other malignancies associated with bile metabolism from IL-6R inhibitor therapy.     

Upregulation of Rpn10 promotes tumor progression via activation of the NF-κB pathway in clear cell renal cell carcinoma

The ubiquitin-proteasome system (UPS) plays a central role in regulating protein homeostasis in tumor progression.The proteasome subunit Rpn10 is associated wit...