Sonic hedgehog signaling pathway induces cell migration and invasion through focal adhesion kinase/AKT signaling-mediated activation of matrix metalloproteinase (MMP)-2 and MMP-9 in liver cancer

Reappraisal of the Roles of the Sonic Hedgehog Signaling Pathway in Hepatocellular Carcinoma

HCC remains one of the leading causes of cancer-related death globally. The main challenges in treatments of hepatocellular carcinoma (HCC) primarily arise from high rates of postoperative recurrence and the limited efficacy in treating advanced-stage patients. Various signaling pathways involved in HCC have been reported. Among them, the Sonic hedgehog (SHH) signaling pathway is crucial. The presence of SHH ligands is identified in approximately 60% of HCC tumor tissues, including tumor nests. PTCH-1 and GLI-1 are detected in more than half of HCC tissues, while GLI-2 is found in over 84% of HCC tissues. The SHH signaling pathway (including canonical and non-canonical) is involved in different aspects of HCC, including hepatocarcinogenesis, tumor growth, tumor invasiveness, progression, and migration. The SHH signaling pathway also contributes to recurrence, metastasis, modulation of the cancer microenvironment, and sustaining cancer stem cells. It also affects the resistance of HCC cells to chemotherapy, target therapy, and radiotherapy. Reappraisal of the roles of the SHH signaling pathway in HCC may trigger some novel therapies for HCC.

Recently reported cell migration inhibitors: Opportunities and challenges for antimetastatic agents

Antimetastatic agents are highly desirable for cancer treatment because of the severe medical challenges and high mortality resulting from tumor metastasis. Having demonstrated antimetastatic effects in numerous in vitro and in vivo studies, migration inhibitors present significant opportunities for developing a new class of anticancer drugs. To provide a useful overview on the latest research in migration inhibitors, this article first discusses their therapeutic significance, targetable proteins, and developmental avenues. Subsequently it reviews over 20 representative migration inhibitors reported in recent journals in terms of their inhibitory mechanism, potency, and potential clinical utility. The relevance of the target proteins to cellular migratory function is focused on as it is crucial for assessing the overall efficacy of the inhibitors.

Molecular mechanism of angiogenesis for cerebral infarction rats by acupuncture intervention based on sonic hedgehog signaling pathway

BACKGROUND

To study the factors of the Sonic Hedgehog (Shh) signaling pathway after permanent cerebral ischemic and the effects by acupuncture.

METHODS

Male Wistar rats were divided into Electro-acupuncture (EA) group, Model Control (MC) group, and blank control (Control) group. EA and MC were divided into 9 phases, namely 1 h, 3 h, 6 h, 9 h, 12 h, 24 h, 3 d, 7 d, and 12 d after the operation. The neurological deficits and permanent cerebral ischemic volume were observed. The immunofluorescence method was used to examine the angiogenesis. (Polymerase Chain Reaction) PCR and (Immunohistochemistry) IHC were used to test the changes in Shh, Ptch, Smo, and Gli2 mRNA and proteins.

RESULTS

The neurological severity scores (NSS) of the Control was 0, the score of the EA group was less than that of the MC. The cerebral permanent ischemic volume of the Control was 0 %, and the EA group's was smaller than that of the MC. The expression of copositive cells in the EA group was higher than the MC's from 12 h to 12 d, and the EA group had more peripheral blood vessels. The rat brain expressions of Shh, Ptch, Smo and Gli2 mRNA and proteins in the MC was higher than that of the Control, the rat brain expression of the EA group was higher than that of the MC.

CONCLUSIONS

EA can upregulate the expression of the Shh signaling pathway factors, thereby promoting angiogenesis.

Targeting hedgehog-driven mechanisms of drug-resistant cancers

Due to the cellular plasticity that is inherent to cancer, the acquisition of resistance to therapy remains one of the biggest obstacles to patient care. In many patients, the surviving cancer cell subpopulation goes on to proliferate or metastasize, often as the result of dramatically altered cell signaling and transcriptional pathways. A notable example is the Hedgehog (Hh) signaling pathway, which is a driver of several cancer subtypes and aberrantly activated in a wide range of malignancies in response to therapy. This review will summarize the field's current understanding of the many roles played by Hh signaling in drug resistance and will include topics such as non-canonical activation of Gli proteins, amplification of genes which promote tolerance to chemotherapy, the use of hedgehog-targeted drugs and tool compounds, and remaining gaps in our knowledge of the transcriptional mechanisms at play.

Transcriptional regulation by the NSL complex enables diversification of IFT functions in ciliated versus nonciliated cells

Members of the NSL histone acetyltransferase complex are involved in multiorgan developmental syndromes. While the NSL complex is known for its importance in early development, its role in fully differentiated cells remains enigmatic. Using a kidney-specific model, we discovered that deletion of NSL complex members KANSL2 or KANSL3 in postmitotic podocytes led to catastrophic kidney dysfunction. Systematic comparison of two primary differentiated cell types reveals the NSL complex as a master regulator of intraciliary transport genes in both dividing and nondividing cells. NSL complex ablation led to loss of cilia and impaired sonic hedgehog pathway in ciliated fibroblasts. By contrast, nonciliated podocytes responded with altered microtubule dynamics and obliterated podocyte functions. Finally, overexpression of wild-type but not a double zinc finger (ZF-ZF) domain mutant of KANSL2 rescued the transcriptional defects, revealing a critical function of this domain in NSL complex assembly and function. Thus, the NSL complex exhibits bifurcation of functions to enable diversity of specialized outcomes in differentiated cells.

Hedgehog signaling in tissue homeostasis, cancers, and targeted therapies

The past decade has seen significant advances in our understanding of Hedgehog (HH) signaling pathway in various biological events. HH signaling pathway exerts its biological effects through a complex signaling cascade involved with primary cilium. HH signaling pathway has important functions in embryonic development and tissue homeostasis. It plays a central role in the regulation of the proliferation and differentiation of adult stem cells. Importantly, it has become increasingly clear that HH signaling pathway is associated with increased cancer prevalence, malignant progression, poor prognosis and even increased mortality. Understanding the integrative nature of HH signaling pathway has opened up the potential for new therapeutic targets for cancer. A variety of drugs have been developed, including small molecule inhibitors, natural compounds, and long non-coding RNA (LncRNA), some of which are approved for clinical use. This review outlines recent discoveries of HH signaling in tissue homeostasis and cancer and discusses how these advances are paving the way for the development of new biologically based therapies for cancer. Furthermore, we address status quo and limitations of targeted therapies of HH signaling pathway. Insights from this review will help readers understand the function of HH signaling in homeostasis and cancer, as well as opportunities and challenges of therapeutic targets for cancer.

Anticancer Potentials of the Lignan Magnolin: A Systematic Review

Magnolin is a naturally occurring, multi-bioactive lignan molecule with inherent anticancer effects. This study aims to summarize the botanical origins and anticancer properties of magnolin. For this, a recent (as of March 2023) literature review was conducted using various academic search engines, including PubMed, Springer Link, Wiley Online, Web of Science, Science Direct, and Google Scholar. All the currently available information about this phytochemical and its role in various cancer types has been gathered and investigated. Magnolin is a compound found in many different plants. It has been demonstrated to have anticancer activity in numerous experimental models by inhibiting the cell cycle (G1 and G2/M phase); inducing apoptosis; and causing antiinvasion, antimetastasis, and antiproliferative effects via the modulation of several pathways. In conclusion, magnolin showed robust anticancer activity against many cancer cell lines by altering several cancer signaling pathways in various non- and pre-clinical experimental models, making it a promising plant-derived chemotherapeutic option for further clinical research.

Brazilein inhibits epithelial-mesenchymal transition (EMT) and programmed death ligand 1 (PD-L1) expression in breast cancer cells

Triple-negative breast cancer (TNBC) exhibits high levels of Epithelial-mesenchymal transition (EMT) and Programmed death ligand 1 (PD-L1) expression, which promotes immune escape and metastasis. Brazilein is a natural compound extracted from Caesalpinia sappan L., and has been demonstrated to be an anti-inflammatory anti- proliferative and apoptosis-inducer in various cancer cells. Here, we investigated the effect of brazilein on EMT and PD-L1 expression in breast cancer cells and its related molecular mechanisms using MCF-7 and MDA-MB-231 cells as a model. Since the AKT, NF-κB, and GSK3β/β-catenin signaling were reported to be important mechanisms in immune escape and metastasis, the effect of brazilein on these signaling pathways were also found out in our study. Firstly, brazilein was treated on breast cancer cells at various concentrations to study cell viability, apoptosis, and apoptosis proteins. Then, breast cancer cells were treated with non-toxic concentrations of brazilein to study its influence on EMT and expression of PD-L1 protein using MTT, flow cytometry, western blot, and wound healing analysis, respectively. We found that brazilein exerts an anti-cancer effect by reducing cell viability via induction of apoptosis, while it also downregulated EMT and PD-L1 through suppression of phosphorylation of AKT, NF-κB, and GSK3β/β-catenin. Moreover, the migration ability was diminished by inhibiting the activation of MMP-9 and MMP-2. Taken together, brazilein might delay cancer progression through inhibition of EMT, PD-L1, and metastasis suggesting it might be a potential therapeutic option in breast cancer patients having a high level of EMT and PD-L1.

Macrophage-Derived MMP-9 and MMP-2 are Closely Related to the Rupture of the Fibrous Capsule of Hepatocellular Carcinoma Leading to Tumor Invasion

BACKGROUND

Hepatocellular carcinoma (HCC) is an aggressive tumor with a poor clinical prognosis. Rupture of the fibrous capsule (FC) is a very important clinical phenomenon in the invasion and metastasis of HCC. FC is mainly composed of type I collagen (COL1A1). However, it is not clear what caused the FC rupture. In this study, we aimed to determine whether the rupture of FC in HCC patients was related to macrophage-derived MMP-9 and MMP-2, and their clinical diagnostic value for FC rupture.

RESULTS

By performing immunohistochemical and immunofluorescence staining of ruptured FC and intact FC, the results showed that the ruptured area of FC aggregated a large number of macrophages with MMP-9 and MMP-2. Western blot analysis and Quantitative real-time PCR were used to assess the expression of MMP-9 and MMP-2 in the ruptured and relatively intact area of FC in ruptured FC patients, and the results revealed a significantly different expression of MMP-9 and MMP-2. ELISA experiments show that we could discriminate effectively between ruptured FC and intact FC by MMP-9 and MMP-2.

CONCLUSIONS

Taken together, macrophage-derived MMP-9 and MMP-2 were closely related to the rupture of the FC of HCC and subsequently led to the migration and invasion of the tumor cells through the ruptured area of FC to the para cancer. It is suggested that when performing surgical resection, it is necessary to expand the range of tumor resection for patients with ruptured FC and hence reduce the possibility of recurrence and metastasis in HCC patients.

PPARγ signaling in hepatocarcinogenesis: Mechanistic insights for cellular reprogramming and therapeutic implications

Liver cancer or hepatocellular carcinoma (HCC) is leading cause of cancer-related mortalities globally. The therapeutic approaches for chronic liver diseases-associated liver cancers aimed at modulating immune check-points and peroxisome proliferator-activated receptor gamma (PPARγ) signaling pathway during multistep process of hepatocarcinogenesis that played a dispensable role in immunopathogenesis and outcomes of disease. Herein, the review highlights PPARγ-induced effects in balancing inflammatory (tumor necrosis factor alpha (TNF-α), interleukin (IL)-6, IL-1) and anti-inflammatory cytokines (IL-10, transforming growth factor beta (TGF-β), and interplay of PPARγ, hepatic stellate cells and fibrogenic niche in cell-intrinsic and -extrinsic crosstalk of hepatocarcinogenesis. PPARγ-mediated effects in pre-malignant microenvironment promote growth arrest, cell senescence and cell clearance in liver cancer pathophysiology. Furthermore, PPARγ-immune cell axis of liver microenvironment exhibits an immunomodulation strategy of resident immune cells of the liver (macrophages, natural killer cells, and dendritic cells) in concomitance with current clinical guidelines of the European Association for Study of Liver Diseases (EASL) for several liver diseases. Thus, mechanistic insights of PPARγ-associated high value targets and canonical signaling suggest PPARγ as a possible therapeutic target in reprogramming of hepatocarcinogenesis to decrease burden of liver cancers, worldwide.

CSP I-plus modified rEndostatin inhibits hepatocellular carcinoma metastasis via down-regulation of VEGFA and integrinβ1

BACKGROUND

In our previous study, N end of the Circumsporozoite protein (CSP I-plus) modified recombinant human Endostatin (rEndostatin, endostar) (rES-CSP) was constructed, which had antiangiogenic capability and bound to hepatocellular carcinoma in vivo and in vitro. In this study, the inhibition of rES-CSP on hepatocellular carcinoma metastasis was verified in vivo and in vitro, and its possible mechanism was explored.

METHODS

Firstly, the impact of rES-CSP on the migration, adhesion of hepatoma cell HCCLM3 was identified by wound healing, transwell, and on metastasis of orthotopic xenograft model was identified in nude mouse. Then the expression of metastasis-associated molecules (MMP2, E-cadherin, integrinβ1) and angiogenesis-related factors (VEGFA) in vitro and in vivo were detected by real-time PCR, western blotting, immunohistochemistry.

RESULTS

Finally, we found that rES-CSP could inhibit the migration and invasion of HCCLM3, and decrease tumor metastasis and growth in nude mouse orthotopic xenograft models. The tumor inhibiting rates of rES-CSP and Endostar were 42.46 ± 5.39% and 11.1 ± 1.88%. The lung metastasis rates of the control, Endostar and rES-CSP were 71, 50, and 42.8%, respectively. Compared with Endostar, rES-CSP significantly down-regulated the expression of VEGFA and integrinβ1. Heparin, a competitive inhibitor of CSP I-plus, which can be bind to the highly-sulfated heparan sulfate proteoglycans (HSPGs) over-expressed in liver and hepatocellular carcinoma, alleviated the down-regulation of VEGFA and integrinβ1.

CONCLUSIONS

These indicate that rES-CSP may play a role in inhibiting tumor growth and metastasis by down-regulating the angiogenic factor VEGF and the metastasis-related molecules or by interfering with HSPGs-mediated tumor metastasis.

Potential Focal Adhesion Kinase Inhibitors in Management of Cancer: Therapeutic Opportunities from Herbal Medicine

Focal adhesion kinase (FAK) is a multifunctional protein involved in cellular communication, integrating and transducing extracellular signals from cell-surface membrane receptors. It plays a central role intracellularly and extracellularly within the tumor microenvironment. Perturbations in FAK signaling promote tumor occurrence and development, and studies have revealed its biological behavior in tumor cell proliferation, migration, and adhesion. Herein we provide an overview of the complex biology of the FAK family members and their context-dependent nature. Next, with a focus on cancer, we highlight the activities of FAK signaling in different types of cancer and how knowledge of them is being used for screening natural compounds used in herbal medicine to fight tumor development.

KDELR2-KIF20A axis facilitates bladder cancer growth and metastasis by enhancing Golgi-mediated secretion

Background

Bladder cancer (BCa) is a fatal form of cancer worldwide associated with a poor prognosis. Identifying novel drivers of growth and metastasis hold therapeutic potential for the disease. Transport homeostasis between the endoplasmic reticulum and Golgi and the secretion of matrix metalloproteinases (MMPs) mediated by Golgi have been reported to be closely associated with tumor progression. However, to date, mechanistic studies remain limited.

Results

Here, we identified KDELR2 as a potential risk factor with prognostic value in patients with BCa, especially those harbouring the KDELR2 amplification. In addition, we found that KDELR2 is a regulator of BCa cell proliferation and tumorigenicity based on bioinformatic analysis with functional studies. Mechanistically, we revealed that KDELR2 could regulate the expression of KIF20A, thus stimulating the expression of MMP2, MMP9 and MKI67. Functionally, the overexpression of KDELR2 and KIF20A markedly promoted proliferation, migration, and invasion in vitro and enhanced tumor growth in vivo, while knockdown of KDELR2 and KIF20A exerted the opposite effects. And the overexpression of KDELR2 also enhanced lymph node metastasis in vivo.

Conclusions

Collectively, our findings clarified a hitherto unexplored mechanism of KDELR2-KIF20A axis in increasing Golgi-mediated secretion of MMPs to drive tumor progression in BCa.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12575-022-00174-y.

MicroRNA-766-3p-mediated downregulation of HNF4G inhibits proliferation in colorectal cancer cells through the PI3K/AKT pathway

Nuclear receptors (NRs) are a class of transcription factors that play a pivotal role in carcinogenesis, but their function in colorectal cancer (CRC) remains unclear. Here, we investigate the role NRs play in CRC pathogenesis. We found that hepatocyte nuclear factor 4 gamma (HNF4G; NR2A2), hepatocyte nuclear factor 4α (HNF4A; NR2A1), and retinoid-related orphan receptor γ (RORC; NR1F3) were significantly upregulated in CRC tissues analyzed by GEPIA bioinformatics tool. The expression of HNF4G was examined in CRC samples and cell lines by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and immunohistochemistry. Increased expression of HNF4G was strongly associated with high tumor-node-metastasis stage and poor prognosis. Moreover, overexpression of HNF4G significantly promoted the proliferation of CRC cells in vitro. Next, we found that HNF4G promoted CRC proliferation via the PI3K/AKT pathway through targeting of GNG12 and PTK2. In addition, HNF4G was verified as a direct target of microRNA-766-3p (miR-766-3p). miR-766-3p inhibited the proliferation of CRC cells by targeting HNF4G in vitro and in vivo. Collectively, our study indicates that miR-766-3p reduces the proliferation of CRC cells by targeting HNF4G expression and thus inhibits the PI3K/AKT pathway. Therefore, development of therapies which target the miR-766-3p/HNF4G axis may aid in the treatment of CRC.

VLCAD inhibits the proliferation and invasion of hepatocellular cancer cells through regulating PI3K/AKT axis

PURPOSE

Very-long-chain acyl-CoA dehydrogenase (VLCAD) is an essential mediator in fatty acid metabolism. The progression of human hepatocellular carcinoma (HCC) is closely associated with the disorder of energy supply. Here, we aimed to investigate the role and underlying molecule mechanism of VLCAD in pathological process of HCC.

METHODS

In this study, VLCAD was induced silencing and overexpression using small hairpin RNA (shRNA) and lentiviral-mediated vector in HCC cell lines. The proliferation of HCC cells was determined using CCK-8 assay. Transwell assay and lung metastasis were performed to analysis cell metastasis in vitro and in vivo. ECAR and OCR were used to evaluate the activity of glycolysis and mitochondrial oxidative phosphorylation.

RESULTS

Our data indicated that VLCAD was downregulated in human HCC tissues and cells. VLCAD overexpression strongly suppressed the proliferation and metastasis of HCC cells associating with the decrease of ATP accumulation and glycolysis activity. Importantly, the PI3K/AKT inhibitor LY294002 strongly abolished the role of shVLCAD in HCC cells. Our results suggested that VLCAD suppressed the growth and metastasis in HCC cells by inhibiting the activities of glycolysis and mitochondrial oxidative phosphorylation metabolism via PI3K/AKT pathway.

CONCLUSIONS

Together, present findings not only demonstrated the protective role of and molecular network of VLCAD in HCC cells but also indicated its and potential use as a target in the therapy of HCC.

Target Therapy for Hepatocellular Carcinoma: Beyond Receptor Tyrosine Kinase Inhibitors and Immune Checkpoint Inhibitors

Simple Summary

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer and its incidence is steadily increasing. The development of HCC is a complex, multi-step process that is accompanied by alterations in multiple signaling cascades. Recent years have seen advancement in understanding molecular signaling pathways that play central roles in hepatocarcinogenesis. Aberrant activation of YAP/TAZ, Hedgehog, or Wnt/β-catenin signaling is frequently found in a subset of HCC patients. Targeting the signaling pathway via small molecule inhibitors could be a promising therapeutic option for the subset of patients. In this review, we will introduce the signaling pathways, discuss their roles in the development of HCC, and propose a therapeutic approach targeting the signaling pathways in the context of HCC.

Abstract

Hepatocellular carcinoma (HCC) is a major health concern worldwide, and its incidence is increasing steadily. To date, receptor tyrosine kinases (RTKs) are the most favored molecular targets for the treatment of HCC, followed by immune checkpoint regulators such as PD-1, PD-L1, and CTLA-4. With less than desirable clinical outcomes from RTK inhibitors as well as immune checkpoint inhibitors (ICI) so far, novel molecular target therapies have been proposed for HCC. In this review, we will introduce diverse molecular signaling pathways that are aberrantly activated in HCC, focusing on YAP/TAZ, Hedgehog, and Wnt/β-catenin signaling pathways, and discuss potential therapeutic strategies targeting the signaling pathways in HCC.

Intertwined Signaling Pathways Governing Tooth Development: A Give-and-Take Between Canonical Wnt and Shh

Teeth play essential roles in life. Their development relies on reciprocal interactions between the ectoderm-derived dental epithelium and the underlying neural crest-originated mesenchyme. This odontogenic process serves as a prototype model for the development of ectodermal appendages. In the mouse, developing teeth go through distinct morphological phases that are tightly controlled by epithelial signaling centers. Crucial molecular regulators of odontogenesis include the evolutionarily conserved Wnt, BMP, FGF and sonic hedgehog (Shh) pathways. These signaling modules do not act on their own, but are closely intertwined during tooth development, thereby outlining the path to be taken by specific cell populations including the resident dental stem cells. Recently, pivotal Wnt-Shh interaction and feedback loops have been uncovered during odontogenesis, showing conservation in other developing ectodermal appendages. This review provides an integrated overview of the interplay between canonical Wnt and Shh throughout mouse tooth formation stages, extending from the initiation of dental placode to the fully formed adult tooth.

Basal epidermis collective migration and local Sonic hedgehog signaling promote skeletal branching morphogenesis in zebrafish fins

Teleost fish fins, like all vertebrate limbs, comprise a series of bones laid out in characteristic pattern. Each fin's distal bony rays typically branch to elaborate skeletal networks providing form and function. Zebrafish caudal fin regeneration studies suggest basal epidermal-expressed Sonic hedgehog (Shh) promotes ray branching by partitioning pools of adjacent pre-osteoblasts. This Shh role is distinct from its well-studied Zone of Polarizing Activity role establishing paired limb positional information. Therefore, we investigated if and how Shh signaling similarly functions during developmental ray branching of both paired and unpaired fins while resolving cellular dynamics of branching by live imaging. We found shha is expressed uniquely by basal epidermal cells overlying pre-osteoblast pools at the distal aspect of outgrowing juvenile fins. Lateral splitting of each shha-expressing epidermal domain followed by the pre-osteoblast pools precedes overt ray branching. We use ptch2:Kaede fish and Kaede photoconversion to identify short stretches of shha+basal epidermis and juxtaposed pre-osteoblasts as the Shh/Smoothened (Smo) active zone. Basal epidermal distal collective movements continuously replenish each shha+domain with individual cells transiently expressing and responding to Shh. In contrast, pre-osteoblasts maintain Shh/Smo activity until differentiating. The Smo inhibitor BMS-833923 prevents branching in all fins, paired and unpaired, with surprisingly minimal effects on caudal fin initial skeletal patterning, ray outgrowth or bone differentiation. Staggered BMS-833923 addition indicates Shh/Smo signaling acts throughout the branching process. We use live cell tracking to find Shh/Smo restrains the distal movement of basal epidermal cells by apparent 'tethering' to pre-osteoblasts. We propose short-range Shh/Smo signaling promotes these heterotypic associations to couple instructive basal epidermal collective movements to pre-osteoblast repositioning as a unique mode of branching morphogenesis.

Multi-layered proteogenomic analysis unravels cancer metastasis directed by MMP-2 and focal adhesion kinase signaling

The role of matrix metalloproteinase-2 (MMP-2) in tumor cell migration has been widely studied, however, the characteristics and effects of MMP-2 in clinical sample of metastatic colorectal cancer (CRC) remain poorly understood. Here, in order to unveil the perturbed proteomic signal during MMP-2 induced cancer progression, we analyzed plasma proteome of CRC patients according to disease progression, HCT116 cancer secretome upon MMP-2 knockdown, and publicly available CRC tissue proteome data. Collectively, the integrative analysis of multi-layered proteomes revealed that a protein cluster containing EMT (Epithelial-to-Mesenchymal Transition)-associated proteins such as CD9-integrin as well as MMP-2. The proteins of the cluster were regulated by MMP-2 perturbation and exhibited significantly increased expressions in tissue and plasma as disease progressed from TNM (Tumor, Node, and Metastasis) stage I to II. Furthermore, we also identified a plausible association between MMP-2 up-regulation and activation of focal adhesion kinase signaling in the proteogenomic analysis of CRC patient tissues. Based on these comparative and integrative analyses, we suggest that the high invasiveness in the metastatic CRC resulted from increased secretion of MMP-2 and CD9-integrin complex mediated by FAK signaling activation.

PLD1 promotes tumor invasion by regulation of MMP-13 expression via NF-κB signaling in bladder cancer

Invasion of bladder cancer (BC) cells from the mucosa into the muscle layer is canonical for BC progression while phospholipase D isoform 1 (PLD1) is known to mediate development of cancer through phosphatidic acid (PA) production. We therefore used in silico, in vitro and in vivo approaches to detail the effect of PLD1 on BC invasion. In BC patients, higher levels of PLD1 expression were associated with poor prognoses. PLD1 knockdown significantly suppressed cellular invasion by human BC cells and matrix metalloproteinase-13 (MMP-13) was observed to mediate this effect. In our mouse bladder carcinogenesis model, the development of invasive BCs was suppressed by PLD1 knockout and a global transcriptomic analysis in this model indicated MMP-13 as a potential tumor invasion gene with NF-κB (nuclear factor-kB) as its transcriptional regulator. Furthermore, PA administration increased MMP-13 expression in line with NF-κB p65 phosphorylation levels. Collectively, we demonstrate that PLD1 promotes tumor invasion of BC by regulation of MMP-13 expression through the NF-κB signaling pathway and that PLD1 might be a potential therapeutic target to prevent clinical progression in BC patients.

Antiprostate Cancer Activity of Ineupatolide Isolated from Carpesium cernuum L

Objective

The aim of the study was to investigate the antiprostate cancer effects and mechanism of ineupatolide (T-21), a natural product isolated from the Compositae plant Carpesium cernuum L., on PC-3 human prostate cancer cells.

Methods

The effect of T-21 on the proliferation of PC-3 cells was detected by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, cell migration, and invasion experiments; the morphology of cell apoptosis was observed by Hoechst-propidium iodide staining; the effects of T-21 on PC-3 cell apoptosis and the cell cycle were evaluated by flow cytometry; and the effect of T-21 on the expression levels of phosphorylated protein kinase B (p-AKT), AKT, X-linked inhibitor of apoptosis protein (xlAP), procaspase-3, and poly (ADP-ribose) polymerase (PARP) in PC-3 cells was measured by western blotting.

Results

T-21 significantly inhibited the proliferation of cells, and its half-maximal inhibitory concentrations at 12, 24, and 48 h were 38.46 ± 1.01, 24.63 ± 0.70, and 7.36 ± 0.58 μM, respectively. T-21 may promote cell apoptosis in a concentration-dependent manner and block the cell cycle in the G2 and S phases. In addition, T-21 significantly reduced the protein expression levels of p-AKT, AKT, xlAP, procaspase-3, and PARP.

Conclusion

T-21 exhibits antiproliferation effects on PC-3 cells by promoting apoptosis and arresting the cell cycle in the G2 and S phases. The possible mechanism underlying its potential therapeutic effects against prostate cancer is related to the AKT/xlAP pathway.

Polylysine-bilirubin conjugates maintain functional islets and promote M2 macrophage polarization

Macrophage polarization is one of the main factors contributing to the proinflammatory milieu of transplanted islets. It causes significant islet loss. Bilirubin exhibits protective effects during the islet transplantation process, but the mode of delivering drugs along with the islet graft has not yet been developed. In addition, it remains unclear whether bilirubin or its derivatives can modulate macrophage polarization during islet transplantation. Therefore, this study aimed to develop an ε-polylysine-bilirubin conjugate (PLL-BR) to encapsulate the islets for protection and to explore its macrophage modulation activities. In in vitro studies, the PLL-BR was shown to tightly adhere to the islet surface. It also exhibited enhanced cytoprotective effects against oxidative and inflammatory conditions by promoting M2-type macrophage polarization. In in vivo studies, the PLL-BR-protected islets successfully prolonged the euglycemia period in diabetic mice and accelerated the blood glucose clearance rate by maintaining the insulin secretion function. Compared to the untreated islets, the PLL-BR-encapsulated islets induced anti-inflammatory responses that were characterized by elevated levels of M2 macrophage markers and local vascularization. In conclusion, PLL-BR can be used as a tool for reprograming macrophage polarization while providing a more efficient immune protection for transplanted islets. STATEMENT OF SIGNIFICANCE: Macrophage polarization is one main factor that caused significant loss of transplanted islets. Bilirubin possesses protective effects toward pancreatic islet, but how to deliver the drug along with the islet graft has not yet been harnessed. More importantly, whether bilirubin or its derivatives could modulate macrophage polarization during the host rejections has also not been answered. In this study, we developed an ε-polylysine-bilirubin conjugate (PLL-BR) to encapsulate the islets and explore its role in macrophage modulation activities. PLL-BR could attach to the surface of islets and exerted high oxidation resistance and anti-inflammatory effect. For the first time, we demonstrate that bilirubin and its derivatives effectively promoted the M2-type macrophage polarization, and optimize the immune microenvironment for islets survival and function.

Post-transcriptional regulation of MMP2 mRNA by its interaction with miR-20a and Nucleolin in breast cancer cell lines

Matrix-metalloproteinase-2 (MMP2) is a foremost MMP, governing invasion of breast cancer cells during metastasis. miR-20a was reported to induce mesenchymal to epithelial transition in MDA-MB-231 cells and its endogenous expression varies directly with invasiveness of breast cancer cells. The inverse and direct correlation of invasiveness with miR-20a and Nucleolin respectively led us to study the post-transcriptional regulation of MMP2 by miR-20a and mRNA stabilizing protein, Nucleolin. Thus, understanding the mechanism of its regulation will enable modification of the invasion potential. MMP2 was found to be higher in MDA-MB-231 than MCF-7 cells both at RNA and protein levels. RNA-protein co-immunoprecipitation assay with Argonaute 2 revealed that MMP2 undergoes miRNA-mediated post-transcriptional regulation. miR-20a decreased MMP2 expression as well as its enzymatic activity as found by zymogram assay. Reporter assay showed that miR-20a directly binds to its putative binding site in MMP2 3'-UTR as per in silico prediction. miR-20a additionally impeded MMP2 mRNA stability, and binding of stabilizing trans-factor Nucleolin to its 3'-UTR was confirmed by RNA-protein co-immunoprecipitation assay. Partial down-regulation of Nucleolin by Si-RNA resulted in the downregulation of MMP2 and Nucleolin over-expression rescued the inhibitory effect of miR-20a on MMP2 expression. Delineating the mechanism of post-transcriptional regulation of MMP2, two of its potent regulators, miR-20a and Nucleolin were identified. It was established for the first time that MMP2 is a direct target of miR-20a. The results also elucidated that Nucleolin binds to MMP2 3' UTR and its abundance affects MMP2 expression.

Cell-Intrinsic Tumorigenic Functions of PPARγ in Bladder Urothelial Carcinoma

The role of PPAR gamma (PPARγ) has been well characterized in the developmental process of adipogenesis, yet its aberrant expression patterns and functions in cancer subtypes are less understood. Although PPARγ has been recently demonstrated to play non-cell-autonomous roles in promoting bladder urothelial carcinoma (UC) progression, underlying mechanisms of the cell-intrinsic oncogenic activity remain unknown. Here, we report robust expression and nuclear accumulation of PPARγ in 47% of samples of patients with UC, exceeding mRNA expression patterns published by The Cancer Genome Atlas. In vitro assays revealed for the first time that treatment of UC cells with PPARγ inverse agonist or PPARG knockout by CRISPR-Cas9 reduces proliferation, migration, and invasion of multiple established UC cell lines, most strongly in those characterized by PPARG genomic amplification or activating mutations of RXRA, the obligate heterodimer of PPARγ. Through genome-wide approaches including chromatin immunoprecipitation sequencing and RNA sequencing, we define a novel set of PPARγ-regulated genes in UC, including Sonic Hedgehog (SHH). Similar to PPARγ, genetic inhibition of SHH reduces proliferation and motility. Finally, we demonstrate the PPARγ dependency of UC tumors in vivo by genetic and pharmacologic PPARγ inhibition in subcutaneous xenografts. Collectively, our data indicate that PPARγ promotes UC progression in a subset of patients, at least in part, through cell-autonomous mechanisms linked to SHH signaling. IMPLICATIONS: Genome-wide analysis of DNA-binding sites for oncogenic factor PPARγ revealed SHH as a novel downstream target involved in UC progression, providing important insight into the tumorigenic nature and molecular mechanism of PPARγ signaling in UC.

FAK displacement from focal adhesions: a promising strategy to target processes implicated in cancer progression and metastasis

BACKGROUND

Focal adhesion kinase (FAK) is a non-receptor tyrosine kinase that is overexpressed or activated in several advanced-stage solid cancers. It is known to play both kinase-dependent and -independent roles in promoting tumor progression and metastasis. Numerous inhibitors, targeting either the enzymatic or scaffolding activities of FAK have been generated, with varying degree of success. Here, we describe a novel approach to site-specifically target both kinase-dependent and -independent FAK functions at focal adhesions (FAs), the primary sites at which the kinase exerts its activity.

METHODS

We took advantage of the well-characterized interactions between the paxillin LD motifs and the FAK FAT domain and generated a polypeptide (LD2-LD3-LD4) expected to compete with interactions with paxillin. Co-immunoprecipitation experiments were performed to examine the interaction between the LD2-LD3-LD4 polypeptide and FAK. The effects of LD2-LD3-LD4 in the localization and functions of FAK, as well as FA composition, were evaluated using quantitative immunofluorescence, cell fractionation, FA isolation and Western Blot analysis. Live cell imaging, as well as 2-D migration and cell invasion assays were used to examine the effects on FA turnover and tumor cell migration and invasion.

RESULTS

Expression of the LD2-LD3-LD4 polypeptide prevents FAK localization at FAs, in a controlled and dose-dependent manner, by competing with endogenous paxillin for FAK binding. Importantly, the LD2-LD3-LD4 peptide did not otherwise affect FA composition or integrin activation. LD2-LD3-LD4 inhibited FAK-dependent downstream integrin signaling and, unlike existing inhibitors, also blocked FAK's scaffolding functions. We further show that LD2-LD3-LD4 expression markedly reduces FA turnover and inhibits tumor cell migration and invasion. Finally, we show that dimers of a single motif, linked through a flexible linker of the proper size, are sufficient for the displacement of FAK from FAs and for inhibition of tumor cell migration. This work raises the possibility of using a synthetic peptide as an antimetastatic agent, given that effective displacement of FAK from FAs only requires dimers of a single LD motif linked by a short flexible linker.

CONCLUSION

In conclusion, these results suggest that FAK displacement from FAs is a promising new strategy to target critical processes implicated in cancer progression and metastasis. Video abstract.

Upregulation of amplified in breast cancer 1 contributes to pancreatic ductal adenocarcinoma progression and vulnerability to blockage of hedgehog activation

Background: Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and devastating cancers without effective treatments. Amplified in breast cancer 1 (AIB1) is a member of the steroid receptor coactivator family that mediates the transcriptional activities of nuclear receptors. While AIB1 is associated with the initiation and progression of multiple cancers, the mechanism by which AIB1 contributes to PDAC progression remains unknown. In this study, we aimed to explore the role of AIB1 in the progression of PDAC and elucidate the underlying mechanisms. Methods: The clinical significance and mRNA level of AIB1 in PDAC were studied by database analysis. To demonstrate whether AIB1 mediates the malignant features of PDAC cells, namely, proliferation, migration, invasion, we performed real-time PCR and Western blot analysis, established xenograft models and used in vivo metastasis assay. With insights into the mechanism of AIB1, we performed RNA sequencing (Seq), ChIP-Seq, luciferase reporter assays and pull-down assays. Furthermore, we analyzed the relationship between AIB1 expression and its target expression in PDAC cells and patients and explored whether PDAC cells with high AIB1 levels are sensitive to inhibitors of its target. Results: We found that AIB1 was significantly upregulated in PDAC and associated with its malignancy. Silencing AIB1 impaired hedgehog (Hh) activation by reducing the expression of smoothened (SMO), leading to cell cycle arrest and the inhibition of PDAC cell proliferation. In addition, AIB1, via upregulation of integrin αv (ITGAV) expression, promoted extracellular matrix (ECM) signaling, which played an important role in PDAC progression. Further studies showed that AIB1 preferably bound to AP-1 related elements and served as a coactivator for enhancing the transcriptional activity of MafB, which promoted the expression of SMO and ITGAV. PDAC cells with high AIB1 levels were sensitive to Hh signaling inhibitors, suggesting that blocking Hh activation is an effective treatment against PDAC with high AIB1 expression. Conclusions: These findings reveal that AIB1 is a crucial oncogenic regulator associated with PDAC progression via Hh and ECM signaling and suggest potential therapeutic targets for PDAC treatment.

Diallyl trisulfide regulates cell apoptosis and invasion in human osteosarcoma U2OS cells through regulating PI3K/AKT/GSK3β signaling pathway

AIMS

To investigate the effects and the mechanisms of action of Diallyl trisulfide (DATS) on the proliferation and metastasis of human osteosarcoma (OS) U2OS.

METHODS

U2OS cells were treated by different concentrations of DATS at different time points. Cell proliferations were measured by MTT assay. DATS induced cell cycle distribution and apoptosis were evaluated by flow cytometry (FCM) with Annexin-V. Cell migration and invasion were detected by wound healing assay and transwell assay. The effects of DATS in U2OS cell growth and metastasis were also detected in a mouse OS xenograft model.

RESULTS

A time- and concentration-dependent cytotoxic effect of DATS was observed in U2OS cells. FCM with PI staining and Annexin-V -FITC indicated that DATS induces apoptosis and a G0/G1 cell cycle arrest of U2OS cells at all concentrations from 25 μmol/l to 100 μmol/l. DATS also inhibits the migration and invasion of U2OS cells. Western blot showed that the expression levels of p-AKT, p-GSK3β, Bcl-2, Vimentin and β-catenin were decreased, while the expression levels of Bad, Bax and E-cadherin were significantly increased in DATS treated U2OS cells. Analysis using a mouse xenograft model indicated that xenografts of DATS treatment group had a significant decrease in tumor volume and weight compared to the control group. Lung metastasis models in mice demonstrated that treatment of DATS inhibits lung metastasis of OS in vivo.

CONCLUSIONS

These data suggested that DATS inhibits OS development and progression through the regulation of PI3K/AKT/GSK3β signaling pathways, accompanied by downregulation of Bcl-2, Vimentin and β-catenin, as well as upregulation of Bad, Bax and E-cadherin. Therefore, our data demonstrated that DATS exerted its anticancer effects by inhibiting cell proliferation, migration and invasion in vitro and in vivo. These results provide evidence for the use of the natural product DATS either alone or in combination with standard therapy for OS.

Progress in the Development of Small Molecular Inhibitors of Focal Adhesion Kinase (FAK)

Focal adhesion kinase (FAK) is a nonreceptor intracellular tyrosine kinase that plays an essential role in cancer cell adhesion, survival, proliferation, and migration through both its enzymatic activities and scaffolding functions. Overexpression of FAK has been found in many human cancer cells from different origins, which promotes tumor progression and influences clinical outcomes in different classes of human tumors. Therefore, FAK has been considered as a promising target for small molecule anticancer drug development. Many FAK inhibitors targeting different domains of FAK with various mechanisms of functions have been reported, including kinase domain inhibitors, FERM domain inhibitors, and FAT domain inhibitors. In addition, FAK-targeting PROTACs, which can induce the degradation of FAK, have also been developed. In this Perspective, we summarized the progress in the development of small molecular FAK inhibitors and proposed the perspectives for the future development of agents targeting FAK.

Silencing glioma-associated oncogene homolog 1 suppresses the migration and invasion of hepatocellular carcinoma in vitro

Hepatocellular carcinoma (HCC) is the fourth most common cause of cancer-associated death worldwide. Glioma-associated oncogene homolog 1 (Gli1) is a key component and functions as a reliable marker of Hedgehog signaling pathway activation. Previous studies have demonstrated that Gli1 serves important roles in the progression of various types of cancer, including HCC. However, its effect on HCC invasion and metastasis and the underlying mechanism remain to be elucidated. Small interference RNA was employed to silence the Gli1 gene in liver cancer cells. Reverse transcription-quantitative PCR and western blot analysis were performed to evaluate the mRNA and protein expression of Gli1, respectively. A series of assays, including Cell Counting Kit-8, adhesion, wound healing and Matrigel invasion were performed to investigate cell viability, adhesive, migratory and invasive capabilities of liver cancer cells, respectively. In addition, immunofluorescence staining was performed to determine the cellular localization of focal adhesion kinase (FAK), phosphorylated (p-)FAK and p-AKT. The mRNA and protein expression of Gli1 in liver cancer cells (HepG2 and SK-Hep1) were markedly decreased in a dose-dependent manner following Gli1-knockdown. Gli1 silencing significantly inhibited the adhesion, migration and invasion of SK-Hep1 cells. Additionally, knockdown of Gli1 markedly suppressed the expression of metalloproteinase (MMP)-2 and MMP-9. Furthermore, downregulation of Gli1 blocked the FAK/AKT signaling pathway. Gli1 serves significant roles in the migration and invasion of HCC cells through activation of the FAK/AKT signaling pathway and subsequent upregulation of MMP-2 and MMP-9 expression. Thus, Gli1 may be a potential protein target for the regulation of HCC migration and invasion.

lncRNA SNHG1 Promotes Basal Bladder Cancer Invasion via Interaction with PP2A Catalytic Subunit and Induction of Autophagy

Although basal muscle-invasive bladder cancers (MIBCs) are predominant, are more aggressive, and have bad prognoses, molecular mechanisms underlying how basal MIBC formation/progression have been barely explored. In the present study, SNHG1, a long non-coding RNA, was shown to be expressed at higher levels in basal MIBC cells than in other types of bladder BC cells, and its presence could promote basal MIBC cell invasion. The results revealed that SNHG1 specifically induced MMP2 expression via increasing its transcription and mRNA stability. In one mechanism, SNHG1 directly bound with PP2A catalytic subunit (PP2A-c) to inhibit interactions of PP2A-c with c-Jun and then promoted c-Jun phosphorylation that, in turn, mediated MMP2 transcription. In another mechanism, SNHG1 markedly induced autophagy in the cells via induction of increases in the abundance of autophagy-related proteins. The latter initiated autophagy and further abolished miR-34a stability, which reduced overall miR-34a binding directly to the 3' UTR of MMP2 mRNA, thereby promoting MMP2 mRNA stabilization. These results provided novel insight into understanding the specific functions of SNHG1 in basal MIBC. Such findings may ultimately prove highly significant for the design/synthesis of new SNHG1-based compounds for the treatment of basal MIBC patients.

Role of microRNA-7 in liver diseases: a comprehensive review of the mechanisms and therapeutic applications

MicroRNA-7 (miR-7) is a small non-coding RNA, which plays critical roles in regulating gene expression of multiple key cellular processes. MiR-7 exhibits a tissue-specific pattern of expression, with abundant levels found in the brain, spleen, and pancreas. Although it is expressed at lower levels in other tissues, including the liver, miR-7 is involved in both the development of organs and biological functions of cells. In this review, we focus on the mechanisms by which miR-7 controls cell growth, proliferation, invasion, metastasis, metabolism, and inflammation. We also summarize the specific roles of miR-7 in liver diseases. MiR-7 is considered as a tumor suppressor miRNA in hepatocellular carcinoma and is involved in the pathogenesis of hepatic steatosis and hepatitis. Future studies to further define miR-7 functions and its mechanism in association with other types of liver diseases should be explored. An improved understanding from these studies will provide us a useful perspective leading to mechanism-based intervention by targeting miR-7 for the treatment of liver diseases.

Novel molecular targets in hepatocellular carcinoma

Globally, hepatocellular carcinoma (HCC) is a leading cause of cancer and cancer-related deaths. The therapeutic efficacy of locoregional and systemic treatment in patients with advanced HCC remains low, which results in a poor prognosis. The development of sorafenib for the treatment of HCC has resulted in a new era of molecular targeted therapy for this disease. However, the median overall survival was reported to be barely higher in the sorafenib treatment group than in the control group. Hence, in this review we describe the importance of developing more effective targeted therapies for the management of advanced HCC. Recent investigations of molecular signaling pathways in several cancers have provided some insights into developing molecular therapies that target critical members of these signaling pathways. Proteins involved in the Hedgehog and Notch signaling pathways, Polo-like kinase 1, arginine, histone deacetylases and Glypican-3 can be potential targets in the treatment of HCC. Monotherapy has limited therapeutic efficacy due to the development of inhibitory feedback mechanisms and induction of chemoresistance. Thus, emphasis is now on the development of personalized and combination molecular targeted therapies that can serve as ideal therapeutic strategies for improved management of HCC.

The Gli1-Snail axis contributes to Salmonella Typhimurium-induced disruption of intercellular junctions of intestinal epithelial cells

Salmonella enterica serovar Typhimurium (S. Typhimurium) is a facultative intracellular pathogen that damages gastrointestinal tissue and causes severe diarrhoea. The mechanisms by which Salmonella disrupts epithelial barrier and increases the paracellular permeability are incompletely understood. Our present study aims to determine the role of Gli1, a transcription factor activated in the sonic hedgehog (Shh) pathway, in decreasing the levels of apical junction proteins in a Salmonella-infected human colonic epithelial cancer cell line, Caco-2, and in the intestinal tissue of Salmonella-infected mice. Here, we report that S. Typhimurium increased the mRNA and protein levels of Gli1 and Snail, a downstream transcription factor that plays an important role in the epithelial-to-mesenchymal transition (EMT). S. Typhimurium also decreased the levels of E-cadherin and three tight junction proteins (ZO-1, claudin-1, and occludin). Gli1 siRNA and GANT61, a Gli1-specific inhibitor, blocked S. Typhimurium-induced Snail expression, restored the levels of E-cadherin and tight junction proteins, and prevented S. Typhimurium-increased paracellular permeability. Further study showed that Gli1 was cross-activated by the MAP and PI-3 kinase pathways. S. Typhimurium devoid of sopB, an effector of the Type 3 secretion system (T3SS) responsible for AKT activation, was unable to induce Snail expression and to decrease the expression of apical junction proteins. Our study uncovered a novel role of Gli1 in mediating the Salmonella-induced disruption of the intestinal epithelial barrier.

TP3, an antimicrobial peptide, inhibits infiltration and motility of glioblastoma cells via modulating the tumor microenvironment

Glioblastoma multiforme (GBM) is a cancer of the central nervous system with limited therapeutic outcomes. Infiltrating cancer cells are the contributing factor to high GBM malignancy. The intracranial brain cancer cell infiltration is a complex cascade involving adhesion, migration, and invasion. An arsenal of natural products has been under exploration to overcome GBM malignancy. This study applied the antimicrobial peptide tilapia piscidin 3 (TP3) to GBM8401, U87MG, and T98G cells. The cellular assays and microscopic observations showed that TP3 significantly attenuated cell adhesion, migration, and invasion. A live‐cell video clip showed the inhibition of filopodia protrusions and cell attachment. Probing at the molecular levels showed that the proteolytic activities (from secretion), the mRNA and protein expression levels of matrix metalloproteinases‐2 and ‐9 were attenuated. This result strongly evidenced that both invasion and metastasis were inhibited, although metastatic GBM is rare. Furthermore, the protein expression levels of cell‐mobilization regulators focal adhesion kinase and paxillin were decreased. Similar effects were observed in small GTPase (RAS), phosphorylated protein kinase B (AKT) and MAP kinases such as extracellular signal‐regulated kinases (ERK), JNK, and p38. Overall, TP3 showed promising activities to prevent cell infiltration and metastasis through modulating the tumor microenvironment balance, suggesting that TP3 merits further development for use in GBM treatments.

Polyphyllin II inhibits liver cancer cell proliferation, migration and invasion through downregulated cofilin activity and the AKT/NF-κB pathway

The morbidity and mortality of primary liver cancer is one of the highest amongst all cancers. Deficiency of effective treatment and characteristics of cancer metastasis are believed to be responsible for this situation, thus a great demand is required for new agent development. Polyphyllin II (PP2), an important steroidal saponin extracted from Rhizoma Paris, has emerged as a potential anti-cancer agent, but the effects of PP2 in liver cancers and its underlying mechanisms remain unexplored. In our study, we found that PP2 could remarkably suppress the proliferation of two liver cancer cell lines, HepG2 and BEL7402, resulting in significant cell death. Besides, low doses of PP2 have displayed properties that inhibit cellular motility and invasion of liver cancer cells. In addition, we have found that PP2-mediated cofilin activity suppression was implicated in the inhibition of liver cancer cell motility. Decreased expression of two major hydrolytic enzymes (MMP2/MMP9), through the AKT/NF-κB signaling pathway may also be also responsible for this process. Rescue experiments done with either non-phosphorylatable mutant cofilin-1 (S3A) transfection or an activator of the AKT pathway significantly reversed the inhibition effects of PP2 on liver cancer cells. Taken together, we report a potential agent for liver cancer treatment and reveal its underlying mechanisms.

Sonic Hedgehog Signaling in Organogenesis, Tumors, and Tumor Microenvironments

During mammalian embryonic development, primary cilia transduce and regulate several signaling pathways. Among the various pathways, Sonic hedgehog (SHH) is one of the most significant. SHH signaling remains quiescent in adult mammalian tissues. However, in multiple adult tissues, it becomes active during differentiation, proliferation, and maintenance. Moreover, aberrant activation of SHH signaling occurs in cancers of the skin, brain, liver, gallbladder, pancreas, stomach, colon, breast, lung, prostate, and hematological malignancies. Recent studies have shown that the tumor microenvironment or stroma could affect tumor development and metastasis. One hypothesis has been proposed, claiming that the pancreatic epithelia secretes SHH that is essential in establishing and regulating the pancreatic tumor microenvironment in promoting cancer progression. The SHH signaling pathway is also activated in the cancer stem cells (CSC) of several neoplasms. The self-renewal of CSC is regulated by the SHH/Smoothened receptor (SMO)/Glioma-associated oncogene homolog I (GLI) signaling pathway. Combined use of SHH signaling inhibitors and chemotherapy/radiation therapy/immunotherapy is therefore key in targeting CSCs.

Hedgehog Signaling for Urogenital Organogenesis and Prostate Cancer: An Implication for the Epithelial-Mesenchyme Interaction (EMI)

Hedgehog (Hh) signaling is an essential growth factor signaling pathway especially in the regulation of epithelial-mesenchymal interactions (EMI) during the development of the urogenital organs such as the bladder and the external genitalia (EXG). The Hh ligands are often expressed in the epithelia, affecting the surrounding mesenchyme, and thus constituting a form of paracrine signaling. The development of the urogenital organ, therefore, provides an intriguing opportunity to study EMI and its relationship with other pathways, such as hormonal signaling. Cellular interactions of prostate cancer (PCa) with its neighboring tissue is also noteworthy. The local microenvironment, including the bone metastatic site, can release cellular signals which can affect the malignant tumors, and vice versa. Thus, it is necessary to compare possible similarities and divergences in Hh signaling functions and its interaction with other local growth factors, such as BMP (bone morphogenetic protein) between organogenesis and tumorigenesis. Additionally, this review will discuss two pertinent research aspects of Hh signaling: (1) the potential signaling crosstalk between Hh and androgen signaling; and (2) the effect of signaling between the epithelia and the mesenchyme on the status of the basement membrane with extracellular matrix structures located on the epithelial-mesenchymal interface.

A tropomyosin-like Meretrix meretrix Linnaeus polypeptide inhibits the proliferation and metastasis of glioma cells via microtubule polymerization and FAK/Akt/MMPs signaling

Glioblastoma (GBM) represents the most common, aggressive and deadliest primary tumors with poor prognosis as available therapeutic approaches fail to control its aberrant proliferation and high invasiveness. Thus, the therapeutic agents targeting these two characteristics will be more effective. In present study, a novel polypeptide (MM15), which was originally purified from Meretrix meretrix Linnaeus and has been proven to possess potent antitumor activity by our laboratory, was recombinant expressed and identified as a tropomyosin homologous protein. The recombinant polypeptide (re-MM15) could induce the U87 cell cycle arrest in G2/M phase and cell apoptosis by inducing tubulin polymerization. Additionally, re-MM15 displayed the significant inhibition to the migration and invasion of U87 cells through downregulating FAK/Akt/MMPs signaling. Furthermore, the in vivo analysis suggested that re-MM15 significantly blocked tumor growth in U87 xenograft model. Collectively, our results indicated that re-MM15, with anti-GBM properties in vitro and in vivo, has promising potential as a new anticancer candidate for GBM.

Anti-cancer effects of ethanol extract of Reynoutria japonica Houtt. radix in human hepatocellular carcinoma cells via inhibition of MAPK and PI3K/Akt signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Reynoutria japonica Houtt. has been used as a traditional medicine of cancer in East Asia for thousands of years. However, the mechanism of the anti-cancer effect of R. japonica has not been investigated at the molecular level. The regulation of intracellular signaling pathways by the extract of R. japonica radix needs to be evaluated for a deeper understanding and application of the anti-cancer effect of R. japonica radix.

AIM OF THE STUDY

The purpose of this study was to evaluate the inhibitory effects of the ethanol extracts of R. japonica radix (ERJR) on cancer metastasis and the regulation mechanism of metastasis by ERJR in human hepatocellular carcinomas.

MATERIALS AND METHODS

Suppression of cancer metastasis by ERJR in SK-Hep1 and Huh7 cells were investigated. Prior to experiments, the cytotoxic effect of ERJR was examined by cell viability assays. To evaluate the inhibitory effects of ERJR on cancer metastasis, wound-healing assays, invasion assays, zymography, and multicellular tumor spheroids (MCTS) assays were performed. Molecular mechanisms in the suppressive regulation of metastasis by ERJR were verified by measuring the expression levels of metastatic markers, and the phosphorylation and protein levels of cancer metastasis-related signaling pathways.

RESULTS

In all experiments, ERJR was used at a maximum concentration of 20 μg/ml, which did not show cytotoxicity in SK-Hep1 and Huh7 cells. We examined the inhibitory effects of ERJR on cancer metastasis. In wound-healing and invasion assays, ERJR treatment effectively suppressed the wound-recovery of Huh7 cells and inhibited the invasion ability of SK-Hep1 cells. Also, ERJR treatment significantly decreased the enzymatic activity of matrix metalloproteinase-2 and -9 in SK-Hep1 cells. ERJR suppressed the growth of MCTS in SK-Hep1 cells in a dose-dependent manner. These results indicated that ERJR effectively inhibited the invasive and proliferative ability of SK-Hep1 and Huh7 cells. Moreover, ERJR treatment reduced the expression levels of Snail1, Twist1, N-cadherin, and Vimentin, which are metastatic markers, by inhibiting the activation of protein kinase B and mitogen-activated protein kinases in SK-Hep1 cells.

CONCLUSIONS

These results verified the molecular mechanism of ERJR that has been used in traditional anti-cancer remedy and suggest that it can be developed as a promising therapy for cancer metastasis in the future.

Overexpressed miR-200a promotes bladder cancer invasion through direct regulating Dicer/miR-16/JNK2/MMP-2 axis

Invasive bladder cancer (BC) is one of the most lethal malignant urological tumors. Although miR-200a has been reported as an onco-miRNA that targets the PTEN gene in endometrioid carcinoma, its biological significance in BC invasion has been poorly explored. In the current study, we found that miR-200a was markedly overexpressed in both human BC tissues and BBN-induced muscle-invasive BC tissues. We further showed that miR-200a overexpression specifically promoted human BC cell invasion, but not migration, via transcriptional upregulation of matrix metalloproteinase (MMP)-2. Mechanistic studies indicated that the increased phosphorylation of c-Jun mediated the increasing levels of MMP-2 mRNA transcription. Further investigation revealed that Dicer was decreased in miR-200a overexpressed BC cells; this resulted in inhibition of miR-16 maturation and consequently led to increased JNK2 protein translation and c-Jun activation. Taken together, the studies here showed that miR-200a overexpression inhibited Dicer expression, in turn, resulted in inhibition of miR-16 maturation, leading to upregulation of JNK2 expression, c-Jun phosphorylation, MMP-2 transcription and, ultimately, BC invasion. Collectively, these results demonstrate that miR-200a is an onco-miRNA that is a positive regulator for BC invasion. This finding could be very useful in the ongoing development of new strategies to treat invasive BC patients.

Crosstalk Between Signaling Pathways Involved in the Regulation of Airway Smooth Muscle Cell Hyperplasia

Increased ASM mass, primarily due to ASM hyperplasia, has been recognized as a hallmark of airway remodeling in asthma. Increased ASM mass is the major contributor to the airway narrowing, thus worsening the bronchoconstriction in response to stimuli. Inflammatory mediators and growth factors released during inflammation induce increased ASM mass surrounding airway wall via increased ASM proliferation, diminished ASM apoptosis and increased ASM migration. Several major pathways, such as MAPKs, PI3K/AKT, JAK2/STAT3 and Rho kinase, have been reported to regulate these cellular activities in ASM and were reported to be interrelated at certain points. This article aims to provide an overview of the signaling pathways/molecules involved in ASM hyperplasia as well as the mapping of the interplay/crosstalk between these major pathways in mediating ASM hyperplasia. A more comprehensive understanding of the complexity of cellular signaling in ASM cells will enable more specific and safer drug development in the control of asthma.

Circ_0015756 promotes proliferation, invasion and migration by microRNA-7-dependent inhibition of FAK in hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) afflicts more than half a million people each year worldwide. It was reported that circ_0015756 was up-regulated in HCC, but the mechanism did not extensively studied. Methods: we collected 24 paired cancerous and noncancerous liver tissues surgically resected from HCC patients. HCC cell proliferation, invasion, migration and apoptosis in vitro were evaluated using MTT assay, Transwell assay, scratch test and Annexin-V/PI staining respectively. Interactions between circ_0015756 and miR-7, miR-7 and FAK were further validated by the luciferase reporter assay. Tumor xenografts of HCC cells with circ_0015756 knockdown were established in nude mice. Results: The expression level of circ_0015756 was increased and the expression level of miR-7 was diminished in cancerous liver tissues relative to noncancerous liver tissues. Circ_0015756 knockdown was shown to increase the expression of miR-7, reduce the proliferation, invasion, migration and resistance to apoptosis, and down-regulate the expression of FAK in HCC. We found miR-7 impaired expression of FAK to inhibit HCC cells, suggesting that miR-7 is responsible for the dysfunction of FAK. Importantly, we showed circ_0015756 could up-regulate FAK via targeting miR-7. These in vitro findings were reproduced in vivo that circ_0015756 knockdown decreased HCC xenograft growth. Conclusion: Our present study reveals a model of HCC development that is composed of circ_0015756, miR-7 and FAK. Modulation of their levels exhibits a promise in the treatment of HCC. Abbreviations: HCC: hepatocellular carcinoma; circRNAs: circular RNAs; miRNA/miR: microRNA; miR-7: microRNA-7; FAK: focal adhesion kinase; KLF-4: kruppel like factor 4; DKK1: dickkopf WNT signaling pathway inhibitor 1; ccRCC: clear cell renal cell carcinoma; PI3K: phosphoinositide 3-kinase; Ct: comparative threshold cycle; RPMI: Roswell Park Memorial Institute; FBS: fetal bovine serum; RT: reverse transcription; qPCR: quantitative polymerase chain reaction; RIPA: radioimmunoprecipitation assay; SDS-PAGE: sodium dodecyl sulfate-polyacrylamide gel electrophoresis; PVDF: polyvinylidene difluoride; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; MTT: 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide; DMSO: dimethyl sulfoxide; DMEM: Dulbecco's modified Eagle's medium; PI: propidium iodide; SPF: specific pathogen-free; SD: standard deviation; p-Akt: phosphorylated-Akt; shRNAs: small hairpin RNAs; 3'UTR: 3'-untranslated regions.

Sonic Hedgehog signaling pathway as a potential target to inhibit the progression of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-associated mortality worldwide. Hepatocarcinogenesis involves numerous interlinked factors and processes, including the Sonic hedgehog (Shh) signaling pathway, which participates in the carcinogenesis, progression, invasiveness, recurrence and cancer stem cell maintenance of HCC. The Shh signaling pathway is activated by ligands that bind to their receptor protein, Protein patched homolog (Ptch). The process of Shh ligand binding to Ptch weakens the inhibition of smoothened homolog (SMO) and activates signal transduction via glioma-associated oncogene homolog (Gli) transcription factors. The overexpression of Shh pathway molecules, including Shh, Ptch-1, Gli and SMO has been indicated in patients with HCC. It has also been suggested that the Shh signaling pathway exhibits cross-talk between numerous other signaling pathways. The inactivation of the Shh signaling pathway reduces HCC growth, increases radio-sensitivity and increases the beneficial effect of chemotherapy in HCC treatment. Therefore, inhibition of the Shh pathway may be an effective target therapy that can be used in the treatment of HCC.

Stress-induced phosphoprotein 1 promotes pancreatic cancer progression through activation of the FAK/AKT/MMP signaling axis

BACKGROUND

Dependent on the extent of adenosine triphosphate (ATP) hydrolysis and/or ATP/ADP exchange, the stress-induced phosphoprotein 1 (STIP1) mediates molecular interaction and complex formation between the molecular chaperones heat shock protein (Hsp)70 and Hsp90. The overexpression of STIP1 is increasingly being documented in various human malignancies, including ovarian, cholangiocellular, renal and gastric cancers. However, the role of STIP1 in pancreatic cancer (PANC) and probable molecular mechanism remains largely unexplored.

METHODS & RESULTS

In the present study, using clinical samples (n = 88) and human PANC cell lines PANC-1, Capan-2, SW1990, and BxPC-3, we demonstrated that STIP1 is aberrantly expressed in human PANC tissues or cell lines compared to adjacent non-tumor pancreas samples or human pancreatic duct epithelial cells (HPDEC), respectively. Clinicopathological correlation studies revealed significant positive correlation between high STIP1 expression and lymph node involvement (p = 0.001), cancer metastasis (p = 0.002), microvascular invasion (p = 0.002), advance TNM stage (p = 0.024), perineural invasion (PNI; p = 0.013), and cancer-related death (p = 0.002) among patients with PANC. Univariate and multivariate analyses indicate that STIP1overexpression is an independent prognostic factor of PANC. Furthermore, STIP1 knockdown significantly inhibit the migration and invasive ability of PANC-1 and SW1990 cells, while downregulating N-cadherin and Vimentin, but upregulating E-cadherin mRNA expression levels, concurrently. We also demonstrated that STIP1 knockdown suppressed p-FAK, p-AKT, MMP2, MMP9, and Slug protein and mRNA expression levels, thus, indicating, at least in part, a role for STIP1 in the activation of FAK/AKT/MMP signaling.

CONCLUSION

Taken together, our results demonstrate a critical role for STIP1 in cancer metastasis, disease progression and poor prognosis, as well as, provide evidence suggestive of the therapeutic efficacy of STIP1-mediated targeting of the FAK/AKT/MMP signaling axis in patients with PANC.

Fibronectin promotes cervical cancer tumorigenesis through activating FAK signaling pathway

Cervical cancer is a cancer arising from the cervix, and it is the fourth most common cause of death in women. Overexpression of fibronectin 1 (FN1) was observed in many tumors and associated with the survival and metastasis of cancer cells. However, the mechanism by which FN1 promotes cervical cancer cell viability, migration, adhesion, and invasion, and inhibits cell apoptosis through focal adhesion kinase (FAK) signaling pathway remains to be investigated. Our results demonstrated that FN1 was upregulated in patients with cervical cancer and higher FN1 expression correlated with a poor prognosis for patients with cervical cancer. FN1 knockdown by small interfering RNA (siRNA) inhibited SiHa cell viability, migration, invasion, and adhesion, and promoted cell apoptosis. FN1 overexpression in CaSki cell promoted cell viability, migration, invasion, and adhesion, and inhibited cell apoptosis. Further, phosphorylation of FAK, a main downstream signaling molecule of FN1, and the protein expression of Bcl-2/Bax, matrix metalloproteinase 2 (MMP-2), matrix metalloproteinase 9 (MMP-9), and N-cadherin was upregulated in CaSki cells with FN1 overexpression, but caspase-3 protein expression was downregulated. The FAK phosphorylation inhibitor PF573228 inhibited FN1 overexpression-induced expression of those proteins in CaSki cells with FN1 overexpression. In vivo experiment demonstrated that FN1 knockdown significantly inhibited FN1 expression, phosphorylation of FAK, and tumor growth in xenograft from the nude mice. These results suggest that FN1 regulates the viability, apoptosis, migration, invasion, and adhesion of cervical cancer cells through the FAK signaling pathway and is a potential therapeutic target in the treatment of cervical cancer.

Stimulative role of ST6GALNAC1 in proliferation, migration and invasion of ovarian cancer stem cells via the Akt signaling pathway

Background

Ovarian cancer is known as one of the most common cancers in the world among women. ST6GALNAC1 is highly expressed in cancer stem cells (CSCs), which correlates to high tumor-initiating, self-renewal and differentiation abilities. This present study aims to investigate how ST6GALNAC1 affects ovarian cancer stem cells (OCSCs).

Methods

In order to identify the differentially expressed genes related to ovarian cancer, microarray-based gene expression profiling of ovarian cancer was used, and ST6GALANC1 was one of the identified targets. After that, levels of ST6GALNAC1 in OCSCs and ovarian cancer cells were examined. Subsequently, an Akt signaling pathway inhibitor LY294002 was introduced into the cluster of differentiation 90⁺ (CD90⁺) stem cells, and cell proliferation, migration and invasion, levels of CXCL16, EGFR, CD44, Nanog and Oct4, as well as tumorigenicity of OCSCs were examined.

Results

By using a comprehensive microarray analysis, it was determined that ST6GALNAC1 was highly expressed in ovarian cancer and it regulated the Akt signaling pathway. High levels of ST6GALNAC1 were observed in OCSCs and ovarian cancer cells. Silencing ST6GALNAC1 was shown to be able to reduce cell proliferation, migration, invasion, self-renewal ability, tumorigenicity of OCSCs. In accordance with these results, the effects of ST6GALNAC1 in OCSCs were dependent on the Akt signaling pathway.

Conclusions

When taken together, our findings defined the potential stimulative roles of ST6GALNAC1 in ovarian cancer and OCSCs, which relied on the Akt signaling pathway.

Upregulation of Twist is involved in Gli1 induced migration and invasion of hepatocarcinoma cells

Hedgehog (Hh) signaling is involved in the progression of hepatocellular carcinoma (HCC), while its detailed mechanisms are not well illustrated. Our present study revealed that the expression of Gli1, while not Gli2 or Gli3, is significantly increased in HCC cell lines and 20/28 (71.4%) HCC tissues as compared with their corresponding controls. Over expression of Gli1 can promote the migration, invasion and epithelial-mesenchymal transition (EMT) of HCC cells. Gli1 can increase the expression of Twist, while not other EMT transcription factors such as Snail, ZEB1 or Slug. Gli1 increases the transcription of Twist while it has no significant effect on the protein or mRNA stability. Chromatin immunoprecipitation-polymerase chain reaction confirms that Gli1 can directly bind to the promoter of Twist, in which the third binding site is essential for Gli1 induced transcription. Collectively, our data suggest that upregulation of Twist is involved in Gli1 induced migration and invasion of HCC cells.

Gli Proteins: Regulation in Development and Cancer

Gli proteins are transcriptional effectors of the Hedgehog signaling pathway. They play key roles in the development of many organs and tissues, and are deregulated in birth defects and cancer. We review the molecular mechanisms of Gli protein regulation in mammals, with special emphasis on posttranslational modifications and intracellular transport. We also discuss how Gli proteins interact with co-activators and co-repressors to fine-tune the expression of Hedgehog target genes. Finally, we provide an overview of the regulation of developmental processes and tissue regeneration by Gli proteins and discuss how these proteins are involved in cancer progression, both through canonical regulation via the Hedgehog pathway and through cross-talk with other signaling pathways.