Knockdown of galectin-1 suppresses the growth and invasion of osteosarcoma cells through inhibition of the MAPK/ERK pathway

Galectin-1: An important regulator in myeloid differentiation and acute myeloid leukemia as well as a promising prognostic indicator and therapeutic target

Acute myeloid leukemia (AML) is an aggressive and heterogeneous hematological malignancy with a low survival probability and limited therapeutic options. Although galectin-1 (LGALS1) has been implicated in tumor cell survival and immune evasion in solid tumor, its role in AML is still unclear. In this study, we found that LGALS1 presents prominent upregulation in AML patients at both mRNA and protein levels compared with the control samples. Bioinformatics analysis indicated that high expression of LGALS1 is a significant unfavorable prognostic factor for overall survival in AML, correlating with adverse clinical and genetic features as well as immune cell infiltration. Depletion of LGALS1 in AML cells impeded cell proliferation, induced apoptosis and promoted myeloid differentiation. Treatment with OTX008, an LGALS1 inhibitor, markedly diminished the viability of primary malignant bone marrow cells from AML patients. Notably, LGALS1 expression was significantly reduced exclusively in AML-M5 patients after treatment, which may be due to its higher expression in AML-M5 subtype compared to other FAB subtypes. In summary, our findings indicate that LGALS1 could serve as an independent prognostic risk factor and a promising therapeutic target in AML, providing novel insights into AML pathogenesis and laying the foundation for the development of new therapeutic strategies.

Cancer-associated fibroblasts as therapeutic targets for cancer: advances, challenges, and future prospects

Research into cancer treatment has been mainly focused on developing therapies to directly target cancer cells. Over the past decade, extensive studies have revealed critical roles of the tumour microenvironment (TME) in cancer initiation, progression, and drug resistance. Notably, cancer-associated fibroblasts (CAFs) have emerged as one of the primary contributors in shaping TME, creating a favourable environment for cancer development. Many preclinical studies have identified promising targets on CAFs, demonstrating remarkable efficacy of some CAF-targeted treatments in preclinical models. Encouraged by these compelling findings, therapeutic strategies have now advanced into clinical evaluation. We aim to provide a comprehensive review of relevant subjects on CAFs, including CAF-related markers and targets, their multifaceted roles, and current landscape of ongoing clinical trials. This knowledge can guide future research on CAFs and advocate for clinical investigations targeting CAFs.

Construction of a 5-gene prognostic signature based on oxidative stress related genes for predicting prognosis in osteosarcoma

BACKGROUND

The understanding of the complex biological scenario of osteosarcoma will open the way to identifying new strategies for its treatment. Oxidative stress is a cancer-related biological scenario. At present, it is not clear the oxidative stress genes in affecting the prognosis and progression of osteosarcoma, the underlying mechanism as well as their impact on the classification of osteosarcoma subtypes.

METHODS

We selected samples and sequencing data from TARGET data set and GSE21257 data set, and downloaded oxidative stress related-genes (OSRGs) from MsigDB. Univariate Cox analysis of OSRG was conducted using TARGET data, and the prognostic OSRG was screened to conduct unsupervised clustering analysis to identify the molecular subtypes of osteosarcoma. Through least absolute shrinkage and selection operator (LASSO) regression analysis and COX regression analysis of differentially expressed genes (DEGs) between subgroups, a risk assessment system for osteosarcoma was developed.

RESULTS

45 prognosis-related OSRGs genes were acquired, and two molecular subtypes of osteosarcoma were clustered. C2 cluster displayed prolonged overall survival (OS) accompanied with high degree of immune infiltration and enriched immune pathways. While cell cycle related pathways were enriched in C2 cluster. Based on DEGs between subgroups and Lasso analysis, 5 hub genes (ZYX, GJA5, GAL, GRAMD1B, and CKMT2) were screened to establish a robust prognostic risk model independent of clinicopathological features. High-risk group had more patients with cancer metastasis and death as well as C1 subtype with poor prognosis. Low-risk group exhibited favorable OS and high immune infiltration status. Additionally, the risk assessment system was optimized by building decision tree and nomogram.

CONCLUSIONS

This study defined two molecular subtypes of osteosarcoma with different prognosis and tumor immune microenvironment status based on the expression of OSRGs, and provided a new risk assessment system for the prognosis of osteosarcoma.

Research progress in the mechanism and treatment of osteosarcoma

ABSTRACT

Osteosarcoma (OS) is the most common primary malignant bone tumor that more commonly occurs in children and adolescents. The most commonly used treatment for OS is surgery combined with chemotherapy, but the treatment outcomes are typically unsatisfactory. High rates of metastasis and post-treatment recurrence rates are major challenges in the treatment of OS. This underlines the need for studying the in-depth characterization of the pathogenetic mechanisms of OS and development of more effective therapeutic modalities. Previous studies have demonstrated the important role of the bone microenvironment and the regulation of signaling pathways in the occurrence and development of OS. In this review, we discussed the available evidence pertaining to the mechanisms of OS development and identified therapeutic targets for OS. We also summarized the available treatment modalities for OS and identified future priorities for therapeutics research.

Inhibition of galectins in cancer: Biological challenges for their clinical application

Galectins play relevant roles in tumor development, progression and metastasis. Accordingly, galectins are certainly enticing targets for medical intervention in cancer. To date, however, clinical trials based on galectin inhibitors reported inconclusive results. This review summarizes the galectin inhibitors currently being evaluated and discusses some of the biological challenges that need to be addressed to improve these strategies for the benefit of cancer patients.

Targeting Signaling Pathway by Curcumin in Osteosarcoma

The most prevalent primary bone malignancy among children and adolescents is osteosarcoma. The high mortality rate of osteosarcoma is due to lung metastasis. Despite the development of multi-agent chemotherapy and surgical resection, patients with osteosarcoma have a high metastasis rate and poor prognosis. Thus, it is necessary to identify novel therapeutic agents to improve the 5-year survival rate of these patients. Curcumin, a phytochemical compound derived from Curcuma longa, has been employed in treating several types of cancers through various mechanisms. Also, in vitro studies have demonstrated that curcumin could inhibit cell proliferation and induce apoptosis in osteosarcoma cells. Development in identifying signaling pathways involved in the pathogenesis of osteosarcoma has provided insight into finding new therapeutic targets for the treatment of this cancer. Targeting MAPK/ERK, PI3k/AKT, Wnt/β-catenin, Notch, and MircoRNA by curcumin has been evaluated to improve outcomes in patients with osteosarcoma. Although curcumin is a potent anti-cancer compound, it has rarely been studied in clinical settings due to its congenital properties such as hydrophobicity and poor bioavailability. In this review, we recapitulate and describe the effect of curcumin in regulating signaling pathways involved in osteosarcoma.

Mechanism and Role of Endoplasmic Reticulum Stress in Osteosarcoma

Osteosarcoma is the most common malignant bone tumor, often occurring in children and adolescents. The etiology of most patients is unclear, and the current conventional treatment methods are chemotherapy, radiotherapy, and surgical resection. However, the sensitivity of osteosarcoma to radiotherapy and chemotherapy is low, and the prognosis is poor. The development of new and useful treatment strategies for improving patient survival is an urgent need. It has been found that endoplasmic reticulum (ER) stress (ERS) affects tumor angiogenesis, invasion, etc. By summarizing the literature related to osteosarcoma and ERS, we found that the unfolded protein response (UPR) pathway activated by ERS has a regulatory role in osteosarcoma proliferation, apoptosis, and chemoresistance. In osteosarcoma, the UPR pathway plays an important role by crosstalk with autophagy, oxidative stress, and other pathways. Overall, this article focuses on the relationship between ERS and osteosarcoma and reviews the potential of drugs or gene targets associated with ERS for the treatment of osteosarcoma.

Comprehensive analysis of potential cellular communication networks in advanced osteosarcoma using single-cell RNA sequencing data

Osteosarcoma (OS) is a common bone cancer in children and adolescents, and metastasis and recurrence are the major causes of poor treatment outcomes. A better understanding of the tumor microenvironment is required to develop an effective treatment for OS. In this paper, a single-cell RNA sequencing dataset was taken to a systematic genetic analysis, and potential signaling pathways linked with osteosarcoma development were explored. Our findings revealed 25 clusters across 11 osteosarcoma tissues, with 11 cell types including “Chondroblastic cells”, “Osteoblastic cells”, “Myeloid cells”, “Pericytes”, “Fibroblasts”, “Proliferating osteoblastic cells”, “Osteoclasts”, “TILs”, “Endothelial cells”, “Mesenchymal stem cells”, and “Myoblasts”. The results of Cell communication analysis showed 17 potential cellular communication networks including “COLLAGEN signaling pathway network”, “CD99 signaling pathway network”, “PTN signaling pathway network”, “MIF signaling pathway network”, “SPP1 signaling pathway network”, “FN1 signaling pathway network”, “LAMININ signaling pathway network”, “FGF signaling pathway network”, “VEGF signaling pathway network”, “GALECTIN signaling pathway network”, “PERIOSTIN signaling pathway network”, “VISFATIN signaling pathway network”, “ITGB2 signaling pathway network”, “NOTCH signaling pathway network”, “IGF signaling pathway network”, “VWF signaling pathway network”, “PDGF signaling pathway network”. This research may provide novel insights into the pathophysiology of OS’s molecular processes.

Molecular signaling pathways as potential therapeutic targets in osteosarcoma

Among primary bone malignancies, osteosarcoma (OS) is the most common form causing morbidity and mortality in both adults and children. The interesting point about this malignancy is that nearly 10-20% of its newly diagnosed cases have developed metastasis. This adds up to the fact that the survival rate of both metastatic and non-metastatic patients of osteosarcoma hasn't changed in the past 30 years and suggests that we need to revise our therapeutic options for OS. In recent years, diverse signaling pathways have drawn the attention of the scientific community since they can be great candidates for treating complicated diseases such as cancer. In this review, we have tried to explain the pathophysiology of osteosarcoma by the help of different signaling pathways taking part in its initiation/progression and investigate how this pathway can be targeted for providing more efficient methods.

Mechanisms, Diagnosis and Treatment of Bone Metastases

Bone and bone marrow are among the most frequent metastatic sites of cancer. The occurrence of bone metastasis is frequently associated with a dismal disease outcome. The prevention and therapy of bone metastases is a priority in the treatment of cancer patients. However, current therapeutic options for patients with bone metastatic disease are limited in efficacy and associated with increased morbidity. Therefore, most current therapies are mainly palliative in nature. A better understanding of the underlying molecular pathways of the bone metastatic process is warranted to develop novel, well-tolerated and more successful treatments for a significant improvement of patients' quality of life and disease outcome. In this review, we provide comparative mechanistic insights into the bone metastatic process of various solid tumors, including pediatric cancers. We also highlight current and innovative approaches to biologically targeted therapy and immunotherapy. In particular, we discuss the role of the bone marrow microenvironment in the attraction, homing, dormancy and outgrowth of metastatic tumor cells and the ensuing therapeutic implications. Multiple signaling pathways have been described to contribute to metastatic spread to the bone of specific cancer entities, with most knowledge derived from the study of breast and prostate cancer. However, it is likely that similar mechanisms are involved in different types of cancer, including multiple myeloma, primary bone sarcomas and neuroblastoma. The metastatic rate-limiting interaction of tumor cells with the various cellular and noncellular components of the bone-marrow niche provides attractive therapeutic targets, which are already partially exploited by novel promising immunotherapies.

PADI1 contributes to EMT in PAAD by activating the ERK1/2-p38 signaling pathway

Background

Peptidylarginine deiminase 1 (PADI1) has been reported to promote tumorigenesis in breast cancer. However, the functional role of PADI1 in pancreatic ductal adenocarcinoma (PAAD) has remained elusive until now.

Methods

The expression pattern of PADI1 in PAAD tissues and normal tissues was analyzed using The Cancer Genome Atlas (TCGA) dataset. A Kaplan-Meier curve analysis was performed to evaluate the prognostic value of PADI1 in PAAD patients. PADI1 was knocked down in CFPAN-1 and HPAC cells, and overexpressed in PANC-1 and Bxpc-3 cells by RNA interference. A wound-healing assay was performed to analyze relative cell migration distance. Cell migration and invasion were assessed by a Transwell assay. Related protein expression levels were measured by western blot and immunofluorescence.

Results

The bioinformatics analysis showed that PADI1 was overexpressed in PAAD tissues and associated with a poor survival prognosis. The knockdown of PADI1 suppressed cell migration and invasion, and activated the ERK1/2-p38 signaling pathway in CFPAN-1 and HPAC cells. The overexpression of PADI1 produced the opposite results in PANC-1 and Bxpc-3 cells. Additionally, treatment with an MEK1/2 inhibitor significantly attenuated the effects of PADI1 knockdown on cell migration, invasion, the epithelial-mesenchymal transition (EMT) process, and p-ERK1/2 and p38 expression in CFPAN-1 and HPAC cells.

Conclusions

Our data suggested that PADI1 may function as an oncogene in regulating metastasis in vitro in PAAD.

CircRNA_104889 promotes lung adenocarcinoma cell invasion via sponging miR4458

Background

Lung adenocarcinoma is metastatic cancer with a high mortality rate. Circular RNAs (circRNAs) are a type of noncoding RNA and play a vital role in cancer progression. However, the expression and function of circRNAs in lung adenocarcinoma are still mostly unknown.

Methods

In this study, we screened the differential expression of circRNAs in human bronchial epithelial cells (HBE) and A549 human lung adenocarcinoma cell line (A549) by human circRNA microarray and RT-qPCR. The role of overexpressed circRNA_104889 in A549 cell proliferation, apoptosis, migration, and invasion was studied extensively. Intracellular localization of circRNA_104889 was visualized by FISH assay. MiRNA sponging, ERK1/2 signaling, and caspase-3 expression were analyzed in siRNA-mediated circRNA_104889 knockdowned A549 cells.

Results

CircRNA microarray showed overexpression of circRNA_104889 (> 13-fold) in A459 cells compared to HBE. This finding was further corroborated by the RT-qPCR result. CircRNA_104889 was mainly localized in the cytoplasm of A549 cells. The knockdown of circRNA_104889 in A549 cells by si-RNA mediated RNA interference did not affect cell proliferation and apoptosis but significantly inhibited cell migration and invasion in vitro. Furthermore, knockdown of circRNA_104889 led to an increase of miR4458 expression. Overexpression of miR4458 inhibited A549 cell migration. Both the knockdown of circRNA_104889 and overexpression of miR4458 inhibited the caspase-3 expression and ERK1/2 phosphorylation in A549 cells.

Conclusions

CircRNA_104889 promotes lung adenocarcinoma cell migration and invasion by sponging miR4458 and targeting ERK1/2 signaling and caspase-3 expression.

Development of a novel immune-related genes prognostic signature for osteosarcoma

Immune-related genes (IRGs) are responsible for osteosarcoma (OS) initiation and development. We aimed to develop an optimal IRGs-based signature to assess of OS prognosis. Sample gene expression profiles and clinical information were downloaded from the Therapeutically Applicable Research to Generate Effective Treatments (TARGET) and Genotype-Tissue Expression (GTEx) databases. IRGs were obtained from the ImmPort database. R software was used to screen differentially expressed IRGs (DEIRGs) and functional correlation analysis. DEIRGs were analyzed by univariate Cox regression and iterative LASSO Cox regression analysis to develop an optimal prognostic signature, and the signature was further verified by independent cohort (GSE39055) and clinical correlation analysis. The analyses yielded 604 DEIRGs and 10 hub IRGs. A prognostic signature consisting of 13 IRGs was constructed, which strikingly correlated with OS overall survival and distant metastasis (p < 0.05, p < 0.01), and clinical subgroup showed that the signature's prognostic ability was independent of clinicopathological factors. Univariate and multivariate Cox regression analyses also supported its prognostic value. In conclusion, we developed an IRGs signature that is a prognostic indicator in OS patients, and the signature might serve as potential prognostic indicator to identify outcome of OS and facilitate personalized management of the high-risk patients.

Down-Regulation of Ribosomal Protein RPS21 Inhibits Invasive Behavior of Osteosarcoma Cells Through the Inactivation of MAPK Pathway

Objective

The goal of our present study was to explore the expression level, biological function, and underlying molecular mechanism of ribosomal protein s21 (RPS21) in human osteosarcoma (OS).

Methods

Firstly, we evaluated the expression of RPS21 in OS tissue samples based on the Gene Expression Omnibus (GEO) datasets and also measured the RPS21 expression of OS cell lines (MG63, and U2OS) by quantitative real-time polymerase chain reaction (qRT-PCR). siRNA interference method was used to reduce the expression of RSP21 in the OS cells. Cell Counting Kit-8 (CCK-8), colony formation, wound-healing, and transwell assays were conducted to measure the proliferation, migration, and invasion of OS cells. The mitogen-activated protein kinase (MAPK) pathway-related proteins levels were examined by Western blot.

Results

Our analyses showed that the expression of RPS21 was significantly increased in OS, compared with normal samples. Upregulation of RPS21 was associated with worse outcomes of OS patients. Knockdown of RPS21 suppressed OS cell proliferation, colony-forming ability, migration, and invasion capacities. Moreover, down-regulation of RPS21 inactivated the MAPK signaling pathway.

Conclusion

RPS21 plays an oncogenic candidate in OS development via regulating the activity of MAPK pathway; therefore, it may serve as a novel therapeutic target for OS treatment.

Galectins and Ovarian Cancer

Ovarian cancer is known for its aggressive pathological features, including the capacity to undergo epithelial to mesenchymal transition, promoting angiogenesis, metastatic potential, chemoresistance, inhibiting apoptosis, immunosuppression and promoting stem-like features. Galectins, a family of glycan-binding proteins defined by a conserved carbohydrate recognition domain, can modulate many of these processes, enabling them to contribute to the pathology of ovarian cancer. Our goal herein was to review specific galectin members identified in the context of ovarian cancer, with emphasis on their association with clinical and pathological features, implied functions, diagnostic or prognostic potential and strategies being developed to disrupt their negative actions.

Biomarkers for pediatric cancer detection: latest advances and future perspectives

Cancer is one of the major health problems of the modern world. With the development of novel biochemistry and analytical instrumentation, precancer diagnosis has become a major focus of clinical and preclinical research. Finding appropriate biomarkers is crucial to make an early diagnosis, before the disease fully develops. With the improvement of precancer studies, cancer biomarkers prove their usefulness in providing important data on the cancer type and the status of patients' progression at a very early stage of the disease. Due to the constant evolution of pediatric cancer diagnosis, which includes highly advanced molecular techniques, the authors have decided to focus on selected groups of neoplastic disease and these include brain tumors, neuroblastoma, osteosarcoma and Hodgkin lymphoma.

Human Galectin-1 and Its Inhibitors: Privileged Target for Cancer and HIV

Galectin 1(Gal-1), a β-galactoside binding mammalian lectin of 14KDa, is implicated in many signalling pathways, immune responses associated with cancer progression and immune disorders. Inhibition of human Gal-1 has been regarded as one of the potential therapeutic approaches for the treatment of cancer, as it plays a major role in tumour development and metastasis by modulating various biological functions viz. apoptosis, angiogenesis, migration, cell immune escape. Gal-1 is considered as a biomarker in diagnosis, prognosis and treatment condition. The overexpression of Gal-1 is well established and seen in many types of cancer progression like osteosarcoma, breast, lung, prostate, melanoma, etc. Gal-1 greatly accelerates the binding kinetics of HIV-1 to susceptible cells, leading to faster viral entry and a more robust viral replication by specific binding of CD4 cells. Hence, the Gal-1 is considered a promising molecular target for the development of new therapeutic drugs for cancer and HIV. The present review laid emphasis on structural insights and functional role of Gal-1 in the disease, current Gal-1 inhibitors and future prospects in the design of specific Gal-1 inhibitors.

Synthesis of 1-benzyl-1H-benzimidazoles as galectin-1 mediated anticancer agents

In our pursuit to develop novel non-carbohydrate small molecule Galectin-1 Inhibitors, we have designed a series of 1-benzyl-1H-benzimidazole derivatives and demonstrated their anticancer activity. The compound 6g, 4-(1-benzyl-5-chloro-1H-benzo[d]imidazol-2-yl)-N-(4-hydroxyphenyl) benzamide was found to be most potent with an IC₅₀ of 7.01 ± 0.20 µM and arresting MCF-7 cell growth at G2/M phase and S phase. Induction of apoptosis was confirmed by morphological changes like cell shrinkage, blebbing and cell wall deformation, dose dependent increase in the mitochondrial membrane potential (ΔΨm) and ROS levels. Further, dose dependent decrease in Gal-1 protein levels proves Gal-1 mediated apoptosis by 6g. Molecular docking studies were performed to understand the Gal-1 interaction with compound 6g. In addition, RP-HPLC studies showed 85.44% of 6g binding to Gal-1. Binding affinity studies by fluorescence spectroscopy and Surface Plasmon Resonance (SPR) showed that 6g binds to Gal-1 with binding constant (K_a) of 1.2 × 10⁴ M^-1 and equilibrium constant K_D value of 5.76 × 10^-4 M respectively.

Identification of Prognostic and Predictive Osteosarcoma Biomarkers

Both adolescents and children suffer from osteosarcoma, localized in the metaphysis of the long bones. This is the most common primary high-grade bone tumor in this patient group. Early tumor detection is the key to ensuring effective treatment. Improved osteosarcoma outcomes in clinical trials have been contingent on biomarker discovery and an evolving understanding of molecules and their complex interactions. In this review, we present a short overview of biomarkers for osteosarcoma, and highlight advances in osteosarcoma-related biomarker research. Many studies show that several biomarkers undergo critical changes with osteosarcoma progression. Growing knowledge about osteosarcoma-related markers is expected to positively impact the development of therapeutics for osteosarcoma, and ultimately of clinical care. It has also become important to develop new biomarkers, which can identify vulnerable patients who should be treated with more intensive and aggressive therapy after diagnosis.

CircRNA fibroblast growth factor receptor 3 promotes tumor progression in non-small cell lung cancer by regulating Galectin-1-AKT/ERK1/2 signaling

The dysregulation of circular RNA (circRNA) expression is involved in the progression of several cancers, including non-small cell lung cancer (NSCLC). However, the role and underlying molecular mechanisms of circRNA FGFR3 (circFGFR3) in NSCLC progression remains unknown. Here, we used quantitative real-time polymerase chain reaction to validate that circFGFR3 expression was higher in NSCLC tissues than in the paratumor tissues. Furthermore, our study indicated that the forced circFGFR3 expression promoted NSCLC cell invasion and proliferation. Mechanistically, we found that circFGFR3 promoted NSCLC cell invasion and proliferation via competitively combining with miR-22-3p to facilitate the galectin-1 (Gal-1), p-AKT, and p-ERK1/2 expressions. Clinically, we revealed that the high circFGFR3 expression correlates with the poor clinical outcomes in patients with NSCLC. Together, these data provide mechanistic insights into the circFGFR3-mediated regulation of both the AKT and ERK1/2 signaling pathways by sponging miR-22-3p and increasing Gal-1 expression.

Galectin-1 promotes an M2 macrophage response to polydioxanone scaffolds

Regulating soft tissue repair to prevent fibrosis and promote regeneration is central to creating a microenvironment conducive to soft tissue development. Macrophages play an important role in this process. The macrophage response can be modulated using biomaterials, altering cytokine and growth factor secretion to promote regeneration. Electrospun polydioxanone (PDO) fiber scaffolds promoted an M2 phenotype when macrophages were cultured on large diameter, highly porous scaffolds, but an M1 phenotype on smaller diameter fibers. In this study, we investigated whether incorporation of galectin-1, an immunosuppressive protein that enhances muscle regeneration, could promote the M2 response. Galectin-1 was incorporated into large and small fiber PDO scaffolds during electrospinning. Galectin-1 incorporation increased arginase-1 and reduced iNOS and IL-6 production in mouse bone-marrow derived macrophages compared with PDO alone for both scaffold types. Inhibition of ERK mitogen-activated protein kinase did not alter galectin-1 effects on arginase-1 and iNOS expression, but reversed IL-6 suppression, indicating that IL-6 is mediated by a different mechanism. Our results suggest that galectin-1 can be used to modulate macrophage commitment to a pro-regenerative M2 phenotype, which may positively impact tissue regeneration when using small diameter PDO scaffolds. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 2562-2571, 2017.

Decrease in stathmin expression by arsenic trioxide inhibits the proliferation and invasion of osteosarcoma cells via the MAPK signal pathway

Osteosarcoma (OS) is the most common type of malignant bone tumor in children and adolescents. In total, 40–50% of patients with OS experience metastasis, and thus have a poor prognosis. Our previous study demonstrated that arsenic trioxide (As₂O₃) combined with doxorubicin [also known as Adriamycin (ADM)] significantly inhibited OS cell proliferation by downregulating stathmin expression. The present study investigated the effect and mechanism of stathmin expression on OS cell invasion. It was identified that the expression of stathmin was increased in human ADM-resistant OS MG63 (MG63/dox) cells compared with the level in the normal osteoblast hFoB1.19cell line using western blot analysis. Lentiviral-mediated small hairpin RNA (shRNA) was constructed to silence stathmin expression of MG63/dox cells. In transwell assay, stathmin-knockdown significantly suppressed migration and invasion in MG63/dox cells. As₂O₃ combined with ADM inhibited the migration and invasion of MG63/dox cells, and was associated with the downregulation of phosphorylated-mitogen-activated protein kinase (MAPK) 1 and β-catenin, and upregulation of phosphorylated-MAPK8 and E-cadherin. In addition, stathmin-knockdown significantly suppressed tumor growth and increased E-cadherin expression in a xenograft nude mouse model. Taken together, these data suggested that As₂O₃ combined with ADM inhibited stathmin-mediated invasion via the MAPK pathway. Elucidation of the mechanism for stathmin downregulation by As₂O₃ may provide novel insights into the mechanism of OS metastasis.

TLR4-mediated galectin-1 production triggers epithelial-mesenchymal transition in colon cancer cells through ADAM10- and ADAM17-associated lactate production

Toll-like receptor 4 (TLR4) activation is a key contributor to the carcinogenesis of colon cancer. Overexpression of galectin-1 (Gal-1) also correlates with increased invasive activity of colorectal cancer. Lactate production is a critical predictive factor of risk of metastasis, but the functional relationship between intracellular lactate and Gal-1 expression in TLR4-activated colon cancer remains unknown. In this study, we investigated the underlying mechanism and role of Gal-1 in metastasis and invasion of colorectal cancer (CRC) cells after TLR4 stimulation. Exposure to the TLR4 ligand lipopolysaccharide (LPS) increased expression of Gal-1, induced EMT-related cytokines, triggered the activation of glycolysis-related enzymes, and promoted lactate production. Gene silencing of TLR4 and Gal-1 in CRC cells inhibited lactate-mediated epithelial-mesenchymal transition (EMT) after TLR4 stimulation. Gal-1-mediated activation of a disintegrin and metalloproteinase 10 (ADAM10) and ADAM 17 increased the invasion activity and expression of mesenchymal characteristics in LPS-activated CRC cells. Conversely, inhibition of ADAM10 or ADAM17 effectively blocked the generation of lactate and the migration capacity of LPS-treated CRC cells. Thus, the TLR4/Gal-1 signaling pathway regulates lactate-mediated EMT processes through the activation of ADAM10 and ADAM17 in CRC cells.

Deguelin Induces the Apoptosis of Lung Squamous Cell Carcinoma Cells through Regulating the Expression of Galectin-1

Lung cancer is the leading cause of cancer mortality around the world. Despite advances in the targeted therapy, patients with lung squamous cell carcinoma(SCC) still benefit few from it, and the search for potential effective therapies is imperative. Here, we demonstrated that deguelin induced significant apoptosis of lung SCC cells in vitro. Importantly, we found deguelin down-regulated the expression of galectin-1, which was involved in a wide range of tumorous physiologic process. Thus, we both over-expressed and down-regulated galectin-1 to perform its role in deguelin-induced apoptosis. We found that increased galectin-1 attenuated apoptosis of SCC cells exposed to deguelin, while galectin-1 knockdown sensitized lung cancer cells to deguelin treatment. Additionally, we observed that down-regulation of galectin-1 resulted in suppression of Ras/Raf/ERK pathway which was involved in deguelin-induced cell apoptosis. We also found that deguelin had a significant anti-tumor ability with decline of galectin-1 in vivo. In conclusion, these findings confirm that deguelin may act as a new chemo-preventive agent through inducing apoptosis of lung SCC cells in a galectin-1 dependent manner.

Identification of novel therapeutic target genes in acquired lapatinib-resistant breast cancer by integrative meta-analysis

Acquired resistance to lapatinib is a highly problematic clinical barrier that has to be overcome for a successful cancer treatment. Despite efforts to determine the mechanisms underlying acquired lapatinib resistance (ALR), no definitive genetic factors have been reported to be solely responsible for the acquired resistance in breast cancer. Therefore, we performed a cross-platform meta-analysis of three publically available microarray datasets related to breast cancer with ALR, using the R-based RankProd package. From the meta-analysis, we were able to identify a total of 990 differentially expressed genes (DEGs, 406 upregulated, 584 downregulated) that are potentially associated with ALR. Gene ontology (GO) function and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis of the DEGs showed that "response to organic substance" and "p53 signaling pathway" may be largely involved in ALR process. Of these, many of the top 50 upregulated and downregulated DEGs were found in oncogenesis of various tumors and cancers. For the top 50 DEGs, we constructed the gene coexpression and protein-protein interaction networks from a huge database of well-known molecular interactions. By integrative analysis of two systemic networks, we condensed the total number of DEGs to six common genes (LGALS1, PRSS23, PTRF, FHL2, TOB1, and SOCS2). Furthermore, these genes were confirmed in functional module eigens obtained from the weighted gene correlation network analysis of total DEGs in the microarray datasets ("GSE16179" and "GSE52707"). Our integrative meta-analysis could provide a comprehensive perspective into complex mechanisms underlying ALR in breast cancer and a theoretical support for further chemotherapeutic studies.

Small interfering RNA-induced silencing of galectin-3 inhibits the malignant phenotypes of osteosarcoma in vitro

Osteosarcoma (OS) is the most common malignant tumor of bone. It has recently been demonstrated that galectin-3, a multifunctional β-galactoside-binding, is significantly upregulated in OS tissues, and is correlated with its progression and metastasis. However, the detailed role of galectin‑3 in the regulation of cellular biological processes in OS cells has remained to be elucidated. The present study reported that the mRNA and protein levels of galectin‑3 were significantly increased in OS tissues compared to those in their matched normal adjacent tissues. Furthermore, galectin‑3 was upregulated in three OS cell lines, Saos‑2, MG63 and U2OS, when compared with that in the human osteoblast cell line hFOB1.19. Knockdown of galectin‑3 by galectin‑3‑specific small interfering RNA markedly inhibited OS‑cell proliferation and induced cell apoptosis. Furthermore, silencing of galectin‑3 expression significantly inhibited OS cell migration and invasion, accompanied with a marked decrease in the protein expression of matrix metalloproteinase 2 and ‑9. Mechanistic investigation suggested that the mitogen‑activated protein kinase kinase/extracellular signal‑regulated protein kinase signaling pathway may be involved in the galectin‑3‑mediated OS cell invasion. In conclusion, the present study was the first to report that silencing of galectin‑3 inhibited the malignant phenotypes of osteosarcoma in vitro. Therefore, galectin-3 may serve as a potential therapeutic target for OS.

Lectins with potential for anti-cancer therapy

This article reviews lectins of animal and plant origin that induce apoptosis and autophagy of cancer cells and hence possess the potential of being developed into anticancer drugs. Apoptosis-inducing lectins encompass galectins, C-type lectins, annexins, Haliotis discus discus lectin, Polygonatum odoratum lectin, mistletoe lectin, and concanavalin A, fucose-binding Dicentrarchus labrax lectin, and Strongylocentrotus purpuratus lectin, Polygonatum odoratum lectin, and mistletoe lectin, Polygonatum odoratum lectin, autophagy inducing lectins include annexins and Polygonatum odoratum lectin.