LASP1-S100A11 axis promotes colorectal cancer aggressiveness by modulating TGF?/Smad signaling.
ABSTRACT: LIM and SH3 protein 1(LASP1) can promote colorectal cancer (CRC) progression and metastasis, but the mechanism remains unclear. Here, we show that LASP1 interacts with S100 calcium binding protein A11(S100A11) and enhances its expression in CRC. LASP1-S100A11 axis is essential for TGF?-mediated epithelial-mesenchymal transition (EMT) and cell aggressive phenotype. Clinically, S100A11 is overexpressed in CRC tissues and localized in both the cytoplasm and the nucleus of CRC cells. Overexpression of S100A11 in cytoplasmic and nuclear subcellular compartments is associated with tumor metastasis and poor prognosis of CRC patients. Introduction of cytoplasmic and nuclear S100A11 promotes aggressive phenotypes of CRC cells in vitro as well as growth and metastasis of CRC xenografts, whereas suppressing S100A11 abrogates these effects. Furthermore, we identify flotillin-1 (FLOT1) and histone H1 as downstream factors for cytoplasmic and nuclear pathway of S100A11, which are required for LASP1-S100A11 axis-mediated EMT and CRC progression. These findings indicate S100A11, combined with LASP1, plays a critical role in promoting CRC metastasis via its subcellular effectors, FLOT1 and histone H1.
Project description:Aberrant expression of miR-1 has been implicated in various cancers. However, the mechanisms underlying the role of miR-1 in CRC progression still have not been clarified clearly. Here, we showed the decreased expression of miR-1 in colorectal carcinoma (CRC) tissues and cell lines. Ectopic introduction of miR-1 suppressed cell proliferation and migration, whereas miR-1 inhibitor performed contrary functions in CRC cells. Stable overexpression of miR-1 was sufficient to inhibit tumor growth and homing capacity in vivo. Proteomic analysis revealed that miR-1 modulated the expression of key cellular molecules and involved in the MAPK and PI3K/AKT pathways by inhibiting phosphorylation of ERK and AKT. Meanwhile, miR-1 also reversed epithelial-mesenchymal transition (EMT), which played a pivotal role in the initiation of metastasis. Further studies found that miR-1 can target the 3' untranslated region (3'UTR) of LIM and SH3 protein 1 (LASP1) mRNA and suppress the expression of LASP1, identified as a CRC-associated protein. In contrast to the phenotypes induced by miR-1 restoration, LASP1-induced cell proliferation and migration partly rescued miR-1-mediated biological behaviors. Our results illustrated that miR-1 play a critical role in CRC progression, which suggests its potential role in the molecular therapy of cancer.
Project description:Objective:Small cell lung carcinoma (SCLC) is considered one of the most aggressive types of lung cancer due to its rapid growth and early metastasis. No tumor markers or therapeutic targets have been demonstrated to be specific or effective in SCLC to date. This study aims to evaluate the potential of Flotillin1 (Flot1) as a target of SCLC treatment. Methods:Flot1 expression level in the tissue of SCLC and other tissue of lung disease was detected using immunohistochemical staining. Transwell and Matrigel assays were employed to examine migration and invasion of cancer cells. Flow cytometry and xCELLigence system were used to evaluate cell apoptosis and cell viability, respectively. Expression levels of Flot1, epithelial-mesenchymal transition (EMT) marker E-cadherin, vimentin, cyclinD1, TGF-?-Smad2/3, and p-AKT were examined using Western blot. Furthermore, xenograft tumor in nude mice was used to evaluate the growth and metastasis of NCI-H446 cells in vivo. Results:Our results demonstrated that Flot1 is highly expressed in SCLC samples and that its expression correlates strongly with clinical stage, distant metastasis, and poor survival. The knockdown of Flot1 decreased the growth, migration, and invasiveness of SCLC cells and reversed EMT phenotype in vitro and in vivo, while enhanced Flot1 expression exhibited the opposite behavior. Gene expression profile analysis demonstrated that Flot1-regulated genes frequently mapped to the AKT and TGF-?-Smad2/3 pathways. Our results further revealed that Flot1 affected the progression of SCLC via regulation of EMT progression. Conclusions:These findings indicated an oncogenic role of Flot1 via promoting EMT in SCLC and suggested its potential as a tumor marker and prognostic indicator.
Project description:Hypoxia regulates epithelial to mesenchymal transition (EMT) of cancer cells. However, the mechanism underlying hypoxia-mediated EMT remains largely unknow. Here, utilizing colorectal cell carcinoma (CRC) as a model, we find that HUNK inhibits EMT and suppresses metastasis of CRC cells via its substrate GEF-H1 in a kinase-dependent manner. Mechanistically, HUNK directly phosphorylates GEF-H1 at ser645 site, which activates RhoA and consequently leads to a cascade of phosphorylation of LIMK1/CFL-1, thereby stabilizing F-actin and inhibiting EMT. Moreover, hypoxia suppresses HUNK activity and dephosphorylates GEF-H1 to promote EMT. Clinically, the expression levels of both HUNK and phosphorylation of GEH-H1 ser645 are not only downregulated in CRC tissues with metastasis compared to that without metastasis, but also positively correlated among these tissues. Our findings highlight the importance of hypoxia-regulated HUNK kinase activity and phosphorylation of GEF-H1 in regulation of EMT and metastasis of CRC. Overall design: We conducted total RNA sequencing after HUNK genes were knocked out in SW480 cell lines. Totally 6 samples were generated.
Project description:LIM kinase 1 (LIMK1) is a key regulator of the cytoskeletal organisation involved in cell proliferation and migration. Even though LIMK1 is frequently dysregulated in epithelial cancers, the role and mechanisms of LIMK1 in colorectal cancer (CRC) remains unclear.Immunohistochemical analysis was performed to examine the expression and clinical significance of LIMK1 in CRC samples. Loss- and gain-of-function assay was performed to investigate the effects of aberrant expression on cellular biological behaviour of CRC cells in vitro and in vivo. Immunoblotting and immunoprecipitation was used to screen LIMK1-related signalling pathways and downstream factors.In this study, our results showed that LIMK1 was upregulated in CRC tissues and localised in both the cytoplasm and the nucleus of CRC cells. Overexpression of LIMK1 in cytoplasmic and nuclear subcellular compartments was closely related to tumour metastasis and poor prognosis of CRC patients. Enhanced expression of cytoplasmic and nuclear LIMK1 significantly increased cell proliferation and migration by driving epithelial-mesenchymal transition and activating the PI3K/Akt signal pathway in vitro as well as promoting growth and metastasis of CRC xenografts, whereas opposite effects were achieved in LIMK1-silenced cells. Furthermore, we identified two tumour metastasis-associated proteins, MYH9 and ACTN4, as direct targets of LIMK1, which were required for a LIMK1-mediated aggressive phenotype.These findings indicate that LIMK1 plays a critical role in promoting CRC progression at subcellular level. Our findings provide new insights into the metastasis of CRC and advocate for the development of clinical intervention strategies against advanced CRC.
Project description:LIM and SH3 protein 1 (LASP1) can promote colorectal cancer (CRC) progression and metastasis, but the direct evidence that elucidates the molecular mechanism remains unclear. Here, our proteomic data showed that LASP1 interacted with 14-3-3σ and decreased the expression of 14-3-3σ in CRC. Deletion of 14-3-3σ was required for LASP1-mediated CRC cell aggressiveness. In vitro gain- and loss-of-function assays showed that 14-3-3σ suppressed the ability of cell migration and decreased the phosphorylation of AKT in CRC cells. We further observed clearly co-localization between AKT and 14-3-3σ in CRC cells. Treatment of PI3K inhibitor LY294002 markedly prevented phosphorylation of AKT and subsequently counteract aggressive phenotype mediated by siRNA of 14-3-3σ. Clinically, 14-3-3σ is frequently down-regulated in CRC tissues. Down-regulation of 14-3-3σ is associated with tumor progression and poor prognosis of patients with CRC. Multivariate analysis confirmed low expression of 14-3-3σ as an independent prognostic factor for CRC. A combination of low 14-3-3σ and high LASP1 expression shows a worse trend with overall survival of CRC patients. Our research paves the path to future investigation of the LASP1-14-3-3σ axis as a target for novel anticancer therapies of advanced CRC.
Project description:The Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of Kaposi's sarcoma (KS), and the induction of an invasive cellular phenotype by KSHV following de novo infection is an important pathogenic component mediating tumor progression. The metastasis suppressor gene known as Nm23-H1 regulates tumor cell invasiveness, but whether KSHV itself regulates Nm23-H1 expression or subcellular localization, and whether this impacts cell invasiveness, has not been established. We found that KSHV increases expression and nuclear translocation of Nm23-H1 and that nuclear translocation of Nm23-H1 is regulated by the KSHV-encoded latency-associated nuclear antigen (LANA). Moreover, activation of the Ras-BRaf-MAPK (mitogen-activated protein kinase) signal transduction pathway, secretion of promigratory factors associated with this pathway, and cell invasiveness are dependent on KSHV regulation of Nm23-H1. Finally, induction of cytoplasmic overexpression of Nm23-H1 using a pharmacologic inhibitor of DNA methylation reduced KSHV-associated Ras-BRaf-MAPK pathway activation and suppressed KSHV-induced invasiveness. These data provide the first evidence for KSHV regulation of Nm23-H1 as a mechanism for KSHV induction of an invasive cellular phenotype and support the potential utility of targeting Nm23-H1 as a therapeutic approach for the treatment of KS.
Project description:The subcellular location of annexin A1 (ANXA1) determines the ultimate fate of neurons after ischemic stroke. ANXA1 nuclear translocation is involved in neuronal apoptosis after cerebral ischemia, and extracellular ANXA1 is also associated with regulation of inflammatory responses. As the factors and mechanism that influence ANXA1 subcellular translocation remain unclear, studies aiming to determine and clarify the role of ANXA1 as a cell fate 'regulator' within cells are critically needed. In this study, we found that intracerebroventricular injection of the recombinant adenovirus vector Ad-S100A11 (carrying S100A11) strongly improved cognitive function and induced robust neuroprotective effects after ischemic stroke in vivo. Furthermore, upregulation of S100A11 protected against neuronal apoptosis induced by oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro. Surprisingly, S100A11 overexpression markedly decreased ANXA1 nuclear translocation and subsequently alleviated OGD/R-induced neuronal apoptosis. Notably, S100A11 exerted its neuroprotective effect by directly binding ANXA1. Importantly, S100A11 directly interacted with ANXA1 through the nuclear translocation signal (NTS) of ANXA1, which is essential for ANXA1 to import into the nucleus. Consistent with our previous studies, ANXA1 nuclear translocation after OGD/R promoted p53 transcriptional activity, induced mRNA expression of the pro-apoptotic Bid gene, and activated the caspase-3 apoptotic pathway, which was almost completely reversed by S100A11 overexpression. Thus, S100A11 protects against cell apoptosis by inhibiting OGD/R-induced ANXA1 nuclear translocation. This study provides a novel mechanism whereby S100A11 protects against neuronal cells apoptosis, suggesting the potential for a previously unidentified treatment strategy in minimizing apoptosis after ischemic stroke.
Project description:Tanshinone IIA (Tan IIA) is a major active ingredient extracted from Salvia miltiorrhiza, which has been proved to be able to inhibit metastasis of various cancers including colorectal cancer (CRC). However, the mechanisms of anti-metastatic effect of Tan IIA on CRC are not well explored. A number of studies indicate that epithelial-to-mesenchymal transition (EMT) plays an important role in CRC metastasis, and our previous studies demonstrate that ?-arrestin1could regulate EMT in CRC partly through ?-catenin signaling pathway. In this work, we investigate whether Tan IIA could regulate EMT in CRC through ?-arrestin1-mediated ?-catenin signaling pathway both in vivo and in vitro. Our results showed that Tan IIA inhibited lung metastases of CRC cells in vivo and extended the survival time of mice with CRC. In vitro, Tan IIA increased the expression of E-cadherin, decreased the expression of Snail, N-cadherin and Vimentin, thus suppressed EMT and the migratory ability of CRC cells. Further study found that the mechanism of action of Tan IIA in regulating EMT and metastasis is associated with the suppression of ?-arrestin1 expression, resulting in the increase of GSK-3? expression, reduction of ?-catenin nuclear localization, thereby decreased the activity of ?-catenin signaling pathway. Our data revealed a new mechanism of Tan IIA on the suppression of EMT and metastasis in CRC via ?-arrestin1-mediated ?-catenin signaling pathway and provided support for using Tan IIA as anti-metastatic agents in CRC.
Project description:S100A11 is reported to associate with progression and poor prognosis in several tumors. We previously reported that S100A11 was highly expressed in intrahepatic cholangiocarcinoma (ICC) cells and promoted TGF-β1-induced EMT through SMAD2/3 signaling pathway. Here, we explored the prognostic role of S100A11 on ICC patients and preliminary molecular mechanisms how S100A11 regulated ICC cell proliferation. Our results showed that S100A11 was obviously increased in ICC tumor tissues. High expression of S100A11 was closely correlated with lymph node metastasis (LNM) and TNM stage and was an independent risk factor for patients' overall survival (OS) and recurrence-free survival (RFS). The nomograms comprising LNM and S100A11 achieved better predictive accuracy compared with TNM staging system for OS and RFS prediction. Silencing S100A11 significantly suppressed RBE cells and HCCC9810 cells proliferation, colony formation, and activation of P38/mitogen-activated protein kinase (MAPK) signaling pathway in vitro and inhibited tumor growth in vivo. In contrast, the overexpression of S100A11 in RBE cells and HCCC9810 cells achieved the opposite results. S100A11-induced proliferation was abolished after treatment with P38 inhibitor. Our findings suggest S100A11/P38/MAPK signaling pathway may be a potential therapeutic target for ICC patients.
Project description:The CXCL12-CXCR4 axis plays a vital role in many steps of breast cancer metastasis, but the molecular mechanisms have not been fully elucidated. We previously reported that activation of CXCR4 by CXCL12 promotes the nuclear localization of LASP1 (LIM and SH3 protein 1). The nuclear LASP1 then interacts with Snail1 in triple-negative breast cancer (TNBC) cell lines. In this study, we report that the nuclear accumulation and retention of Snail1 was dependent on an increase in nuclear LASP1 levels driven by active CXCR4. The CXCR4-LASP1 axis may directly regulate the stabilization of nuclear Snail1, by upregulating nuclear levels of pS473-Akt, pS9-GSK-3?, A20, and LSD1. Furthermore, the activation of CXCR4 induced association of LASP1 with Snail1, A20, GSK-3?, and LSD1 endogenously. Thus, nuclear LASP1 may also regulate protein-protein interactions that facilitate the stability of Snail1. Genetic ablation of LASP1 resulted in the mislocalization of nuclear Snail1, loss of the ability of TNBC cells to invade Matrigel and a dysregulated expression of both epithelial and mesenchymal markers, including an increased expression of ALDH1A1, a marker for epithelial breast cancer stem-like cells. Our findings reveal a novel role for the CXCR4-LASP1 axis in facilitating the stability of nuclear localized Snail1.