Wnt/β-catenin signaling pathway activation reverses gemcitabine resistance by attenuating Beclin1-mediated autophagy in the MG63 human osteosarcoma cell line

Tenovin-6 exhibits inhibitory effects on the growth of Sonic Hedgehog (SHH) medulloblastoma, as evidenced by both in vitro and in vivo studies

Medulloblastoma (MB) is the most common malignant brain tumor in children. Within MB, tumors driven by the Sonic Hedgehog (SHH) pathway represent the most heterogeneous subtype, known as SHH subtype medulloblastoma (SHH-MB). Tenovin-6, a recognized p53 activator, has been demonstrated to inhibit autophagy and modulate sirtuin activity, underscoring its potential as a novel therapeutic agent across various malignancies. However, its efficacy in treating SHH-MB remains unexplored. This study aims to investigate the inhibitory effects of tenovin-6 on SHH-MB and elucidate its underlying signaling pathways. We assessed the impact of tenovin-6 on cell proliferation through the CCK-8 and colony formation assays. The scratch and transwell invasion assays were utilized to evaluate the drug's effects on metastasis. Apoptosis and reactive oxygen species (ROS) levels were measured using flow cytometry. Potential signaling pathways were identified via transcriptomics and quantitative PCR (qPCR). Our in vivo studies involved a mouse xenograft model to explore tenovin-6's anticancer efficacy against SHH-MB. The findings indicate that tenovin-6 not only inhibits cell proliferation and metastasis in SHH-MB cell lines but also promotes apoptosis, which is closely linked to its proliferation-inhibiting properties. Additionally, animal experiments confirmed that tenovin-6 suppresses MB growth in vivo. We discovered that tenovin-6 reduces intracellular ROS levels and inhibits autophagy in SHH-MB by disrupting the fusion of autophagosomes with lysosomes, likely through inducing autophagosome formation.

Elucidating the crosstalk between endothelial-to-mesenchymal transition (EndoMT) and endothelial autophagy in the pathogenesis of atherosclerosis

Atherosclerosis, a chronic systemic inflammatory condition, is implicated in most cardiovascular ischemic events. The pathophysiology of atherosclerosis involves various cell types and associated processes, including endothelial cell activation, monocyte recruitment, smooth muscle cell migration, involvement of macrophages and foam cells, and instability of the extracellular matrix. The process of endothelial-to-mesenchymal transition (EndoMT) has recently emerged as a pivotal process in mediating vascular inflammation associated with atherosclerosis. This transition occurs gradually, with a significant portion of endothelial cells adopting an intermediate state, characterized by a partial loss of endothelial-specific gene expression and the acquisition of "mesenchymal" traits. Consequently, this shift disrupts endothelial cell junctions, increases vascular permeability, and exacerbates inflammation, creating a self-perpetuating cycle that drives atherosclerotic progression. While endothelial cell dysfunction initiates the development of atherosclerosis, autophagy, a cellular catabolic process designed to safeguard cells by recycling intracellular molecules, is believed to exert a significant role in plaque development. Identifying the pathological mechanisms and molecular mediators of EndoMT underpinning endothelial autophagy, may be of clinical relevance. Here, we offer new insights into the underlying biology of atherosclerosis and present potential molecular mechanisms of atherosclerotic resistance and highlight potential therapeutic targets.

The role of programmed cell death in osteosarcoma: From pathogenesis to therapy

Osteosarcoma (OS) is a prevalent bone solid malignancy that primarily affects adolescents, particularly boys aged 14-19. This aggressive form of cancer often leads to deadly lung cancer due to its high migration ability. Experimental evidence suggests that programmed cell death (PCD) plays a crucial role in the development of osteosarcoma. Various forms of PCD, including apoptosis, ferroptosis, autophagy, necroptosis, and pyroptosis, contribute significantly to the progression of osteosarcoma. Additionally, different signaling pathways such as STAT3/c-Myc signal pathway, JNK signl pathway, PI3k/AKT/mTOR signal pathway, WNT/β-catenin signal pathway, and RhoA signal pathway can influence the development of osteosarcoma by regulating PCD in osteosarcoma cell. Therefore, targeting PCD and the associated signaling pathways could offer a promising therapeutic approach for treating osteosarcoma.

Cross-validation of chemical and genetic disruption approaches to inform host cellular effects on Wolbachia abundance in Drosophila

Introduction

Endosymbiotic Wolbachia bacteria are widespread in nature, present in half of all insect species. The success of Wolbachia is supported by a commensal lifestyle. Unlike bacterial pathogens that overreplicate and harm host cells, Wolbachia infections have a relatively innocuous intracellular lifestyle. This raises important questions about how Wolbachia infection is regulated. Little is known about how Wolbachia abundance is controlled at an organismal scale.

Methods

This study demonstrates methodology for rigorous identification of cellular processes that affect whole-body Wolbachia abundance, as indicated by absolute counts of the Wolbachia surface protein (wsp) gene.

Results

Candidate pathways, associated with well-described infection scenarios, were identified. Wolbachia-infected fruit flies were exposed to small molecule inhibitors known for targeting those same pathways. Sequential tests in D. melanogaster and D. simulans yielded a subset of chemical inhibitors that significantly affected whole-body Wolbachia abundance, including the Wnt pathway disruptor, IWR-1 and the mTOR pathway inhibitor, Rapamycin. The implicated pathways were genetically retested for effects in D. melanogaster, using inducible RNAi expression driven by constitutive as well as chemically-induced somatic GAL4 expression. Genetic disruptions of armadillo, tor, and ATG6 significantly affected whole-body Wolbachia abundance.

Discussion

As such, the data corroborate reagent targeting and pathway relevance to whole-body Wolbachia infection. The results also implicate Wnt and mTOR regulation of autophagy as important for regulation of Wolbachia titer.

Galectin-3 and Autophagy in Renal Acute Tubular Necrosis

Acute kidney injury (AKI) is a public health burden with increasing morbidity and mortality rates and health care costs. Acute tubular necrosis (ATN) is the most common cause of AKI. Cisplatin (CIS) is a platinum-based chemotherapeutic agent used in the treatment of a wide variety of malignancies such as lung, breast, ovary, testis, bladder, cervix, and head and neck cancers. Autophagy plays an important role in AKI. Galectin-3 (Gal-3) is significantly increased in renal tubules in AKI; however, its role in autophagy is not well understood. Male C57B6/J and B6.Cg-Lgals3 /J Gal-3 knockout (KO) mice were used to induce AKI using a CIS mouse model of ATN. Renal Gal-3 and autophagy proteins' expression were measured using standard histologic, immunofluorescent, and enzyme-linked immunosorbent assay techniques. The data were presented as the mean ± S.E. Statistically significant differences (p < 0.05) were calculated between experimental groups and corresponding control groups by one-way analysis of variance. There was a significant increase in renal concentrations of Gal-3 in the Gal-3 wild-type CIS-treated mice when compared with sham control mice. There were significantly higher concentrations of renal LC3B, ATG13, Ulk-1, Beclin, ATG5, ATG12, ATG9A, and p-AMPK in the CIS-treated Gal-3 KO mice than in the Gal-3 wild-type CIS-treated mice. Further, there were significantly higher concentrations of mTOR, p- NF-κB, beta-catenin, and p62 in the kidneys of the Gal-3 wild-type CIS-treated mice than in the Gal-3 KO CIS-treated mice. Our findings affirm the connection between Gal-3 and autophagy, revealing its central role as a connector with prosurvival signaling proteins. Gal-3 plays a pivotal role in orchestrating cellular responses by interacting with prosurvival signal pathways and engaging with autophagy proteins. Notably, our observations highlight that the absence of Gal-3 can enhance autophagy in CIS-induced ATN.

Non-apoptotic cell death programs in cervical cancer with an emphasis on ferroptosis

BACKGROUND

Cervical cancer, a pernicious gynecological malignancy, causes the mortality of hundreds of thousands of females worldwide. Despite a considerable decline in mortality, the surging incidence rate among younger women has raised serious concerns. Immortality is the most important characteristic of tumor cells, hence the carcinogenesis of cervical cancer cells pivotally requires compromising with cell death mechanisms.

METHODS

The current study comprehensively reviewed the mechanisms of non-apoptotic cell death programs to provide possible disease management strategies.

RESULTS

Comprehensive evidence has stated that focusing on necroptosis, pyroptosis, and autophagy for disease management is associated with significant limitations such as insufficient understanding, contradictory functions, dependence on disease stage, and complexity of intracellular pathways. However, ferroptosis represents a predictable role in cervix carcinogenesis, and ferroptosis-related genes demonstrate a remarkable correlation with patient survival and clinical outcomes.

CONCLUSION

Ferroptosis may be an appropriate option for disease management strategies from predicting prognosis to treatment.

Wnt/β-catenin signaling pathway-a versatile player in apoptosis and autophagy

The Wnt/β-catenin signaling pathway is a highly conserved pathway that is involved in cell development, proliferation, differentiation, apoptosis and autophagy. Among these processes, apoptosis and autophagy occur physiologically during host defense and the maintenance of intracellular homeostasis. Mounting evidence suggests that the crosstalk between Wnt/β-catenin-regulated apoptosis and autophagy has broad functional significance in various diseases. Herein, we summarize the recent studies in understanding the role of the Wnt/β-catenin signaling pathway in apoptosis and autophagy, and draw the following conclusions: a) For apoptosis, the regulation of Wnt/β-catenin is generally positive. However, a small amount of evidence indicates the presence of a negatively regulated relationship between Wnt/β-catenin and apoptosis; b) Wnt/β-catenin influences the occurrence and development of autophagy by regulating autophagy-related factors, and these factors in turn affect Wnt/β-catenin pathway; c) Wnt/β-catenin always balances the molecular damage caused by the crosstalk between autophagy and apoptosis in a compensatory manner. Understanding the specific role of the Wnt/β-catenin signaling pathway during different stages of autophagy and apoptosis may provide new insights into the progression of related diseases regulated by the Wnt/β-catenin signaling pathway.

Autophagy and its role in osteosarcoma

Osteosarcoma (OS) is the most common bone malignancy and preferably occurs in children and adolescents. Despite significant advances in surgery and chemotherapy for OS over the past few years, overall survival rates of OS have reached a bottleneck. Thus, extensive researches aimed at developing new therapeutic targets for OS are urgently needed. Autophagy, a conserved process which allows cells to recycle altered or unused organelles and cellular components, has been proven to play a critical role in multiple biological processes in OS. In this article, we summarized the association between autophagy and proliferation, metastasis, chemotherapy, radiotherapy, and immunotherapy of OS, revealing that autophagy-related genes and pathways could serve as potential targets for OS therapy.

Superenhancers activate the autophagy-related genes Beclin1 and LC3B to drive metastasis and drug resistance in osteosarcoma

Metastasis and drug resistance are the leading causes of poor prognosis in patients with osteosarcoma. Identifying the relevant factors that drive metastasis and drug resistance is the key to improving the therapeutic outcome of osteosarcoma. Here, we reported that autophagy was highly activated in metastatic osteosarcoma. We found increased autophagolysosomes in metastatic osteosarcoma cell lines by using electron microscopy, Western blot, and immunofluorescence experiments. We further examined the expression of the autophagy-related genes Beclin1 and LC3B in 82 patients through immunohistochemistry and found that Beclin1 and LC3B were highly related to unfavorable prognosis of osteosarcoma. Knockdown of Beclin1 and LC3B reduced invasion, metastasis, and proliferation in metastatic osteosarcoma cells. In vitro and in vivo studies also demonstrated that inhibiting by 3-MA inhibited cell growth and metastasis. Moreover, we demonstrated that autophagy-related genes were activated by SEs and that the inhibition of SEs by JQ-1 decreased the metastasis of osteosarcoma. Overall, our findings highlighted the association of autophagy with osteosarcoma progression and shed new light on autophagy-targeting therapy for osteosarcoma.

Radix Actinidia chinensis Suppresses Renal Cell Carcinoma Progression: Network Pharmacology Prediction and In Vivo Experimental Validation

Background

Renal cell carcinoma (RCC) is a frequent disease with limited curative methods. This study is aimed at investigating the role and mechanism of Radix Actinidia chinensis (RAC) on RCC.

Methods

The ingredients, target, and crucial pathways of RAC in RCC therapy were analyzed by network pharmacology. Then, an RCC animal model was established by subcutaneously injecting A498 cell suspension to BALB/c nude mice. After 1 week, the mice in the RAC-L/M/H groups were administered with RAC at 5, 10, and 20 mg/kg/d, respectively. The histopathology of the tumor was evaluated. The contents of tumor inflammatory cytokines and serum oxidative stress factors were detected by ELISA. The apoptosis of tumor tissues was assessed by TUNEL staining. The expressions of apoptosis-, proliferate-, autophagy-, and MAPK-related proteins were measured.

Results

There were 13 active ingredients, and 20 RCC-relevant targets were selected from RAC; KEGG pathway indicated that these targets were enriched in the PI3K/AKT/mTOR and MAPK pathway. In in vivo experiments, RAC not only obviously damaged tumor cells and decreased the release of inflammatory cytokines and oxidative stress factors but also enhanced the apoptosis of the tumor cell in RCC mice. Besides, the expressions of apoptosis-, proliferate-, autophagy-, PI3K/AKT/mTOR path-, and MAPK path-related proteins were all affected by RAC.

Conclusion

RAC attenuated RCC by regulating inflammation response, oxidative stress, apoptosis, proliferation, and autophagy, and its effects were partly linked to the PI3K/AKT/mTOR and MAPK pathway, which indicated that RAC may be a candidate drug for RCC.

Strain-Specific Behavior of Mycobacterium tuberculosis in Interruption of Autophagy Pathway in Human Alveolar Type II Epithelial A549 Cells

Background:

Autophagy induction has been shown to differ in magnitude depending on the mycobacterial species. However, few studies have investigated the specific autophagic capacity of different Mtb strains in ATs. This study aimed to elucidate the host autophagic response to different Mtb strains in ATs responsible for TB in the capital of Iran, Tehran.

Methods:

A549 cells were infected with three different Mtb clinical isolates (Beijing, NEW1, and CAS1/Delhi) and the reference strain H37Rv. Following RNA extraction, the expression of eight ATG genes, four mycobacterial genes, and three miRNAs was evaluated using quantitative RT-PCR.

Results:

The results revealed that all four strains influenced the autophagy pathway in various ways at different magnitudes. The Beijing and H37Rv strains could inhibit autophagosome formation, whereas the CAS and NEW1 strains induced autophagosome formation. The expression of genes involved in the fusion of autophagosomes to lysosomes (LAMP1) indicated that all the studied strains impaired the autophagolysosomal fusion; this result is not unexpected as Mtb can block the autophagolysomal fusion. In addition, the Beijing and H37RV strains prevented the formation of autophagic vacuoles, besides mycobacterial targeting of lysosomes and protease activity.

Conclusion:

This preliminary study improved our understanding of how Mtb manages to overcome the host immune system, such as autophagy, and evaluated the genes used by specific strains during this process. Further studies with a large number of Mtb strains, encompassing the other main Mtb lineages, are inevitable.

Tanshinone IIA exerts autophagic cell death through down-regulation of β-catenin in renal cell carcinoma cells

Renal cell carcinoma (RCC), also called kidney cancer, is one of the most common malignancies worldwide, including the United States and China. Because of the characteristics of RCC that are both insidious and largely insensitive to chemo-radiation, the incidence and mortality of RCC are increasing every year. However, there are few studies describing anti-cancer effects of the natural compounds on RCC as compared to other cancers. Here, we analyzed the anti-neoplastic impact of Tanshinone IIA (TSN) on RCC cells. We noted that TSN increased the expression of LC3 proteins while having little effect on PARP and Alix protein expression. We found that TSN up-regulated the expression of autophagy-related proteins such as Atg7 and Beclin-1. Moreover, TSN promoted the formation of autophagic vacuoles such as autophagosomes and autolysosomes. However, treatment with 3-Methyladenine (3-MA) or Chloroquine (CQ), slightly decreased the ability of TSN to induce autophagy, but still autophagy occurred. In addition, TSN inhibited translocation of β-catenin into the nucleus, and β-catenin deletion and TSN treatment in RCC increased the expression of LC3 protein. Overall our findings indicate that TSN can exert significant anti-tumor effects through down-regulation of β-catenin to induce autophagic cell death.

The Key Role of the WNT/β-Catenin Pathway in Metabolic Reprogramming in Cancers under Normoxic Conditions

Simple Summary

The canonical WNT/β-catenin pathway is upregulated in cancers and plays a major role in proliferation, invasion, apoptosis and angiogenesis. Recent studies have shown that cancer processes are involved under normoxic conditions. These findings completely change the way of approaching the study of the cancer process. In this review, we focus on the fact that, under normoxic conditions, the overstimulation of the WNT/β-catenin pathway leads to modifications in the tumor micro-environment and the activation of the Warburg effect, i.e., aerobic glycolysis, autophagy and glutaminolysis, which in turn participate in tumor growth.

Abstract

The canonical WNT/β-catenin pathway is upregulated in cancers and plays a major role in proliferation, invasion, apoptosis and angiogenesis. Nuclear β-catenin accumulation is associated with cancer. Hypoxic mechanisms lead to the activation of the hypoxia-inducible factor (HIF)-1α, promoting glycolytic and energetic metabolism and angiogenesis. However, HIF-1α is degraded by the HIF prolyl hydroxylase under normoxia, conditions under which the WNT/β-catenin pathway can activate HIF-1α. This review is therefore focused on the interaction between the upregulated WNT/β-catenin pathway and the metabolic processes underlying cancer mechanisms under normoxic conditions. The WNT pathway stimulates the PI3K/Akt pathway, the STAT3 pathway and the transduction of WNT/β-catenin target genes (such as c-Myc) to activate HIF-1α activity in a hypoxia-independent manner. In cancers, stimulation of the WNT/β-catenin pathway induces many glycolytic enzymes, which in turn induce metabolic reprogramming, known as the Warburg effect or aerobic glycolysis, leading to lactate overproduction. The activation of the Wnt/β-catenin pathway induces gene transactivation via WNT target genes, c-Myc and cyclin D1, or via HIF-1α. This in turn encodes aerobic glycolysis enzymes, including glucose transporter, hexokinase 2, pyruvate kinase M2, pyruvate dehydrogenase kinase 1 and lactate dehydrogenase-A, leading to lactate production. The increase in lactate production is associated with modifications to the tumor microenvironment and tumor growth under normoxic conditions. Moreover, increased lactate production is associated with overexpression of VEGF, a key inducer of angiogenesis. Thus, under normoxic conditions, overstimulation of the WNT/β-catenin pathway leads to modifications of the tumor microenvironment and activation of the Warburg effect, autophagy and glutaminolysis, which in turn participate in tumor growth.

Targeting Wnt/β-catenin signaling by microRNAs as a therapeutic approach in chemoresistant osteosarcoma

Osteosarcoma (OS) is an adolescent and young adult malignancy that mostly occurs in long bones. The treatment of OS is still a big challenge for clinicians due to increasing chemoresistance, and many efforts are being made today to find more beneficial treatments. In this regard, the use of microRNAs has shown a high capacity to develop promising therapies. By targeting cancer-involved signaling pathways, microRNAs reduce the cellular level of these protein pathways; thereby reducing the growth and invasion of tumors, and even leading cancer cells to apoptosis. One of these oncogenic pathways that play an important role in OS development and can be targeted by microRNAs is the Wnt/β-catenin signaling pathway. Hence, the first goal of this review article is to explain the cross-talk of microRNAs and the Wnt/β-catenin signaling in OS and then discussing recent findings of the use of microRNAs as a therapeutic approach in OS.

Crosstalk of the Wnt/β-Catenin Signaling Pathway in the Induction of Apoptosis on Cancer Cells

The Wnt/β-catenin signaling pathway plays a major role in cell survival and proliferation, as well as in angiogenesis, migration, invasion, metastasis, and stem cell renewal in various cancer types. However, the modulation (either up- or downregulation) of this pathway can inhibit cell proliferation and apoptosis both through β-catenin-dependent and independent mechanisms, and by crosstalk with other signaling pathways in a wide range of malignant tumors. Existing studies have reported conflicting results, indicating that the Wnt signaling can have both oncogenic and tumor-suppressing roles, depending on the cellular context. This review summarizes the available information on the role of the Wnt/β-catenin pathway and its crosstalk with other signaling pathways in apoptosis induction in cancer cells and presents a modified dual-signal model for the function of β-catenin. Understanding the proapoptotic mechanisms induced by the Wnt/β-catenin pathway could open new therapeutic opportunities.

Exploration of Immune-Related Gene Expression in Osteosarcoma and Association With Outcomes

IMPORTANCE

Host immune dysregulation is associated with initiation and development of osteosarcoma. In addition, immunotherapy for osteosarcomas requires some knowledge of the immune state of patients.

OBJECTIVE

To perform an immunogenomic landscape analysis based on The Cancer Genome Atlas (TCGA) project, which provides osteosarcoma samples with clinical information.

DESIGN, SETTING, AND PARTICIPANTS

This genetic association study was conducted from July 20, 2020, to September 20, 2020, as a secondary analysis of public data. Cox regression and risk score analyses were used to construct signatures of immune-related genes (IRGs) in 84 patients with osteosarcoma from TCGA with corresponding clinical information. Patients were divided into high- and low-risk groups with 42 individuals in each group according to their risk scores. Data were analyzed from July 20 to September 20, 2020.

MAIN OUTCOMES AND MEASURES

Differentially expressed genes (DEGs) were analyzed between groups, and potential molecular mechanisms, expression regulation, and immune cell infiltration were also explored using bioinformation methods. A prognostic model based on independent risk factors selected from multivariate Cox hazard ratio regression was established to estimate 1-year overall survival.

RESULTS

In this genetic association study based on 84 samples from patients with osteosarcoma from TCGA (mean [SD] age, 15.0 [4.8] years; 47 [56.0%] men; mean [SD] follow-up time, 4.1 [2.8] years), a total of 14 survival-associated IRGs were identified. Patients assigned to the high-risk group had worse survival than patients from the low-risk group (1 death [2.4%] vs 26 deaths [61.9%%]; P < .001). The protein digestion and absorption pathway was one of the associated pathways in the functional enrichment analysis (gene ratio, 2:8; P < .001). The prognostic model based on metastases at diagnosis and risk score performed well in 1-year overall survival estimations (area under the curve, 0.947; 95% CI, 0.832-0.972). The risk score was correlated with immune cell infiltration (B cells: r = 0.331; P = .002; macrophages: r = 0.410; P < .001; CD8 T cells: r = 0.230; P = .04).

CONCLUSIONS AND RELEVANCE

This genetic association study developed a prognostic modeling tool for osteosarcoma based on IRG expression profiles, which could result in improved survival rates through more individualized therapies. Further research on IRG expression profiles could provide potential targets for future studies on immune treatment for osteosarcoma.

Role and mechanism of autophagy-regulating factors in tumorigenesis and drug resistance

A hallmark feature of tumorigenesis is uncontrolled cell division. Autophagy is regulated by more than 30 genes and it is one of several mechanisms by which cells maintain homeostasis. Autophagy promotes cancer progression and drug resistance. Several genes play important roles in autophagy-induced tumorigenesis and drug resistance including Beclin-1, MIF, HMGB1, p53, PTEN, p62, RAC3, SRC3, NF-2, MEG3, LAPTM4B, mTOR, BRAF and c-MYC. These genes alter cell growth, cellular microenvironment and cell division. Mechanisms involved in tumorigenesis and drug resistance include microdeletions, genetic mutations, loss of heterozygosity, hypermethylation, microsatellite instability and translational modifications at a molecular level. Disrupted or altered autophagy has been reported in hematological malignancies like lymphoma, leukemia and myeloma as well as multiple solid organ tumors like colorectal, hepatocellular, gall bladder, pancreatic, gastric and cholangiocarcinoma among many other malignancies. In addition, defects in autophagy also play a role in drug resistance in cancers like osteosarcoma, ovarian and lung carcinomas following treatment with drugs such as doxorubicin, paclitaxel, cisplatin, gemcitabine and etoposide. Therapeutic approaches that modulate autophagy are a novel future direction for cancer drug development that may help to prevent issues with disease progression and overcome drug resistance.

Construction and Validation of an Autophagy-Related Prognostic Model for Osteosarcoma Patients

While the prognostic value of autophagy-related genes (ARGs) in OS patients remains scarcely known, increasing evidence is indicating that autophagy is closely associated with the development and progression of osteosarcoma (OS). Therefore, we explored the prognostic value of ARGs in OS patients and illuminate associated mechanisms in this study. When the OS patients in the training/validation cohort were stratified into high- and low-risk groups according to the risk model established using least absolute shrinkage and selection operator (LASSO) regression analysis, we observed that patients in the low-risk group possessed better prognosis (P < 0.0001). Univariate/Multivariate COX regression and subgroup analysis demonstrated that the ARGs-based risk model was an independent survival indicator for OS patients. The nomogram incorporating the risk model and clinical features exhibited excellent prognostic accuracy. GO, KEGG, and GSVA analyses collectively indicated that bone development-associated pathway mediated the contribution of ARGs to the malignance of OS. Immune infiltration analysis suggested the potential pivotal role of macrophage in OS. In summary, the risk model based on 12 ARGs possessed potent capacity in predicting the prognosis of OS patients. Our work may assist clinicians to map out more reasonable treatment strategies and facilitate individual-targeted therapy in osteosarcoma.

Wnt/β-catenin Antagonists: Exploring New Avenues to Trigger Old Drugs in Alleviating Glioblastoma Multiforme

BACKGROUND

Glioblastoma multiforme is one of the most heterogenous primary brain tumor with high mortality. Nevertheless, of the current therapeutic approaches, survival rate remains poor with 12 to 15 months following preliminary diagnosis, this warrants the need for effective treatment modality. Wnt/β-catenin pathway is presumably the most noteworthy pathway up-regulated in almost 80% GBM cases contributing to tumor-initiation, progression and survival. Therefore, therapeutic strategies targeting key components of Wnt/β-catenin cascade using established genotoxic agents like temozolomide and pharmacological inhibitors would be an effective approach to modulate Wnt/β-catenin pathway. Recently, drug repurposing by means of effective combination therapy has gained importance in various solid tumors including GBM, by targeting two or more proteins in a single pathway, thereby possessing the ability to overcome the hurdle implicated by chemo-resistance in GBM.

OBJECTIVE

In this context, by employing computational tools, an attempt has been carried out to speculate the novel combinations against Wnt/β-catenin signaling pathway.

METHODS

We have explored the binding interactions of three conventional drugs namely temozolomide, metformin, chloroquine along with three natural compounds viz., epigallocatechin gallate, naringenin and phloroglucinol on the major receptors of Wnt/β-catenin signaling.

RESULTS

It was noted that all the experimental compounds possessed profound interaction with the two major receptors of Wnt/β-catenin pathway.

CONCLUSION

To the best of our knowledge, this study is the first of its kind to characterize the combined interactions of the afore-mentioned drugs on Wnt/β-catenin signaling in silico and this will putatively open up new avenues for combination therapies in GBM treatment.

miRNA-128 modulates bone neoplasms cells proliferation and migration through the WNT/β-catenin and EMT signal pathways

BACKGROUND

Bone neoplasms present poor prognosis due to recurrence and metastasis. Although the role microRNAs (miRNAs) in inhibiting growth and metastasis of bone neoplasms has been investigated, the underlying potential molecular mechanisms mediated by miRNA-128 (miR-218) for the invasiveness of bone neoplasms cells are still not completely understood. The purpose of this study was to identify the regulatory mechanisms of miR-218 in bone neoplasms cells.

METHODS

Western blotting, quantitative reverse transcription-polymerase chain reaction (qRT-PCR), Counting Kit-8 assay, terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining, luciferase activity assay immunofluorescence, and immunohistochemistry were used to analyze the regulatory effects of miR-218 on bone neoplasms cells.

RESULTS

Here, the results showed that transfection of miR-128 suppressed bone neoplasms cells proliferation, migration, and invasion. Genetic knockdown of miR-128 in bone neoplasms cells suppressed the activation of the Wnt/β-catenin and epithelial-mesenchymal transition (EMT) signaling pathways. Activation of Wnt or EMT blocked miR-128-inhibited cells proliferation and migration in bone neoplasms cells. Exogenously introduced miR-128 markedly inhibited tumor regeneration in bone neoplasms xenograft models.

CONCLUSIONS

These results define a tumor-regulated function for miR-128 in bone neoplasms by down-regulation of the Wnt/β-catenin and EMT signal pathways, which provided a potential target for bone neoplasms gene therapy.

The Dual Role of Autophagy in Cancer Development and a Therapeutic Strategy for Cancer by Targeting Autophagy

Autophagy is a delicate intracellular degradation process that occurs due to diverse stressful conditions, including the accumulation of damaged proteins and organelles as well as nutrient deprivation. The mechanism of autophagy is initiated by the creation of autophagosomes, which capture and encapsulate abnormal components. Afterward, autophagosomes assemble with lysosomes to recycle or remove degradative cargo. The regulation of autophagy has bipolar roles in cancer suppression and promotion in diverse cancers. Furthermore, autophagy modulates the features of tumorigenesis, cancer metastasis, cancer stem cells, and drug resistance against anticancer agents. Some autophagy regulators are used to modulate autophagy for anticancer therapy but the dual roles of autophagy limit their application in anticancer therapy, and present as the main reason for therapy failure. In this review, we summarize the mechanisms of autophagy, tumorigenesis, metastasis, cancer stem cells, and resistance against anticancer agents. Finally, we discuss whether targeting autophagy is a promising and effective therapeutic strategy in anticancer therapy.

Interplay Between Autophagy and Wnt/β-Catenin Signaling in Cancer: Therapeutic Potential Through Drug Repositioning

The widespread dysregulation that characterizes cancer cells has been dissected and many regulation pathways common to multiple cancer types have been described in depth. Wnt/β-catenin signaling and autophagy are among these principal pathways, which contribute to tumor growth and resistance to anticancer therapies. Currently, several therapeutic strategies that target either Wnt/β-catenin signaling or autophagy are in various stages of development. Targeted therapies that block specific elements that participate in both pathways; are subject to in vitro studies as well as pre-clinical and early clinical trials. Strikingly, drugs designed for other diseases also impact these pathways, which is relevant since they are already FDA-approved and sometimes even routinely used in the clinic. The main focus of this mini-review is to highlight the importance of drug repositioning to inhibit the Wnt/β-catenin and autophagy pathways, with an emphasis on the interplay between them. The data we found strongly suggested that this field is worth further examination.

Up-regulation of DRAM2 promotes tolerance of bladder transitional cell carcinoma to gemcitabine

INTRODUCTION

Bladder transitional cell carcinoma (BTCC) is one of the most prevalent human malignant diseases. Gemcitabine is commonly applied in the treatment of BTCC while acquired gemcitabine resistance has caused a severe impediment to recovery. This study aimed to investigate the function of DRAM2 in regulating gemcitabine resistance of BTCC.

MATERIAL AND METHODS

GSE77883 was introduced to screen out the differentially expressed autophagy-related genes in T24 cells and gemcitabine-resistant T24-GEM cells. After establishing T24-GEM cells ourselves, aberrant expression of DRAM2 was detected by qRT-PCR and Western blot. After stably manipulating the expression of DRAM2 in T24 and T24-GEM cells, the changes of cell biological functions under gemcitabine treatment were compared, including cell viability, apoptosis and autophagy, using colony formation, flow cytometry and electron microscopy respectively.

RESULTS

DRAM2 was up-regulated in gemcitabine-resistant T24-GEM cells. Silencing of DRAM2 in T24-GEM cells inhibited the cell autophagy induced by treatment with gemcitabine and contributed to attenuated gemcitabine resistance. Also, overexpression of DRAM2 in T24 cells enhanced the autophagy, strengthened the chemoresistance and decreased the cell apoptosis rate under the treatment with gemcitabine.

CONCLUSIONS

Our data suggested that downregulation of DRAM2 rescued the sensitivity of T24-GEM cells to gemcitabine, providing an appropriate therapeutic target for BTCC treatment.

Targeting PI3K/AKT/mTOR-mediated autophagy for tumor therapy

Autophagy is a highly conserved catabolic process and participates in a variety of cellular biological activities. The phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway, as a critical regulator of autophagy, is involved in the initiation and promotion of a series of pathological disorders including various tumors. Autophagy also participates in regulating the balance between the tumor and the tumor microenvironment. Natural products have been considered a treasure of new drug discoveries and are of great value to medicine. Mounting evidence has suggested that numerous natural products are targeting PI3K/AKT/mTOR-mediated autophagy, thereby suppressing tumor growth. Furthermore, autophagy plays a "double-edged sword" role in different tumors. Targeting PI3K/AKT/mTOR-mediated autophagy is an important therapeutic strategy for a variety of tumors, and plays important roles in enhancing the chemosensitivity of tumor cells and avoiding drug resistance. Therefore, we summarized the roles of PI3K/AKT/mTOR-mediated autophagy in tumorigenesis, progression, and drug resistance of tumors, which may be utilized to design preferably therapeutic strategies for various tumors.

Insight Into the Role of Autophagy in Osteosarcoma and Its Therapeutic Implication

Osteosarcoma is an aggressive bone cancer that frequently metastasizes to the lungs. The cytotoxicity of most chemotherapeutics and targeted drugs in the treatment of osteosarcoma is partially lessened. Furthermore, there is a poor response to current chemo- and radiotherapy for both primary lesions and pulmonary metastases of osteosarcoma. There is a clear need to explore promising drug candidates that could improve the efficacy of osteosarcoma treatment. Autophagy, a dynamic and highly conserved catabolic process, has dual roles in promoting cell survival as well as cell death. The role of autophagy has been investigated extensively in different tumor types, and a growing body of research has highlighted the potential value of using autophagy in clinical therapy. Here, we address significant aspects of autophagy in osteosarcoma, including its functions, modulation, and possible therapeutic applications.

Targeting autophagy is a promising therapeutic strategy to overcome chemoresistance and reduce metastasis in osteosarcoma

Osteosarcoma (OS) is the most common primary bone malignancy, mainly affecting children and adolescents. Currently, surgical resection combined with adjuvant chemotherapy has been standardized for OS treatment. Despite great advances in chemotherapy for OS, its clinical prognosis remains far from satisfactory; this is due to chemoresistance, which has become a major obstacle to improving OS treatment. Autophagy, a catabolic process through which cells eliminate and recycle their own damaged proteins and organelles to provide energy, can be activated by chemotherapeutic drugs. Accumulating evidence has indicated that autophagy plays the dual role in the regulation of OS chemoresistance by either promoting drug resistance or increasing drug sensitivity. The aim of the present review was to demonstrate thatautophagy has both a cytoprotective and an autophagic cell death function in OS chemoresistance. In addition, methods to detect autophagy, autophagy inducers and inhibitors, as well as autophagy‑mediated metastasis, immunotherapy and clinical prognosis are also discussed.

Local release of gemcitabine via in situ UV-crosslinked lipid-strengthened hydrogel for inhibiting osteosarcoma

Osteosarcoma is among the most common malignant bone tumors in human skeletal system. The conventional treatment of osteosarcoma mainly consists of combining neoadjuvant chemotherapy with surgical approach. However, it is crucial to design an artificial implant that possesses excellent biomechanical properties and is capable of sustaining local release of chemotherapeutics. In this study, we envision that the highly efficient combination of gemcitabine (GEM) hydrochloride loaded liposomes with gelatin methacryloyl (GelMA) of in situ photocrosslinkable hydrogel will lead to a multifunctional implant with unique antitumor, mechanical, and biodegradable properties. A sustained controlled release was observed; more specifically, the release of GEM in vitro lasted for 4 days long. Furthermore, its capability in killing MG63 cells was further explored by using the lixivium of GEM-Lip@Gel and GEM-GelMA hydrogel in vitro (composite hydrogel by GEM loaded liposomes blending with GelMA, short for GEM-Lip@Gel), which agreed with the drug release outcome. In addition, these hydrogel showed excellent ability in inhibiting osteosarcoma in vivo by Balb/c mice bearing MG63 cells. Therefore, GEM-loaded lipo-hydrogel certainly has presented itself as a promising strategy for the development of implant in the field of osteosarcoma treatment.

Wnt3a promotes radioresistance via autophagy in squamous cell carcinoma of the head and neck

The canonical Wnt/β‐catenin signalling pathway and autophagy play critical roles in cancer progression. However, the role of Wnt‐mediated autophagy in cancer radioresistance remains unclear. In this study, we found that irradiation activated the Wnt/β‐catenin and autophagic signalling pathways in squamous cell carcinoma of the head and neck (SCCHN). Wnt3a is a classical ligand that activated the Wnt/β‐catenin signalling pathway, induced autophagy and decreased the sensitivity of SCCHN to irradiation both in vitro and in vivo. Further mechanistic analysis revealed that Wnt3a promoted SCCHN radioresistance via protective autophagy. Finally, expression of the Wnt3a protein was elevated in both SCCHN tissues and patients' serum. Patients showing high expression of Wnt3a displayed a worse prognosis. Taken together, our study indicates that both the canonical Wnt and autophagic signalling pathways are valuable targets for sensitizing SCCHN to irradiation.

Autophagic flux modulation by Wnt/β-catenin pathway inhibition in hepatocellular carcinoma

Autophagy targets cellular components for lysosomal-dependent degradation in which the products of degradation may be recycled for protein synthesis and utilized for energy production. Autophagy also plays a critical role in cell homeostasis and the regulation of many physiological and pathological processes and prompts this investigation of new agents to effect abnormal autophagy in hepatocellular carcinoma (HCC). 2,5-Dichloro-N-(2-methyl-4-nitrophenyl) benzenesulfonamide (FH535) is a synthetic inhibitor of the Wnt/β-catenin pathway that exhibits anti-proliferative and anti-angiogenic effects on different types of cancer cells. The combination of FH535 with sorafenib promotes a synergistic inhibition of HCC and liver cancer stem cell proliferation, mediated in part by the simultaneous disruption of mitochondrial respiration and glycolysis. We demonstrated that FH535 decreased HCC tumor progression in a mouse xenograft model. For the first time, we showed the inhibitory effect of an FH535 derivative, FH535-N, alone and in combination with sorafenib on HCC cell proliferation. Our study revealed the contributing effect of Wnt/β-catenin pathway inhibition by FH535 and its derivative (FH535-N) through disruption of the autophagic flux in HCC cells.

Expression of DACT1 in children with asthma and its regulation mechanism

The aim of the present study was to detect DACT1 expression levels in the lungs of children with asthma, and to investigate its role and molecular mechanisms in regulating the expression of inflammatory factors in RAW264.7 cells. DACT1, DACT2 and DACT3 expression was analyzed in biopsy specimens from 10 cases of newly diagnosed children with asthma and 10 healthy controls by reverse transcription-quantitative polymerase chain reaction, and their expression was confirmed in RAW264.7 cells. DACT1 expression was silenced by small interfering RNA or enhanced by transfection of pcDNA-3.1-DACT1 in RAW264.7 cells, and expression of β-catenin and inflammatory factors, interleukin (IL) 5, IL6 and IL13, was analyzed. Nuclear translocation of β-catenin was detected by western blot analysis, and the effect of DACT1 on β-catenin was investigated with rescue experiments. Regulation of the Wnt signaling pathway by DACT1 and β-catenin was analyzed in RAW264.7 cells after recombinant Wnt5A stimulation. DACT1, DACT2 and DACT3 were significantly upregulated in specimens from children with asthma compared with controls (P<0.05) and the expression of DACT1 was significantly more increased compared with DACT2 and DACT3 (P<0.05). Inhibition of DACT1 expression significantly suppressed IL5, IL6 and IL13 mRNA expression levels compared with the control (P<0.05), while upregulated DACT1 expression significantly increased IL5, IL6 and IL13 mRNA expression (P<0.05). DACT1 inhibited the expression and nuclear translocation of β-catenin, while overexpression of β-catenin significantly inhibited the biological function of DACT1 (P<0.05). Overexpression of β-catenin also significantly suppressed the upregulation of IL5, IL6 and IL13 mRNA induced by pcDNA3.1-DACT1 transfection (P<0.05). Following the addition of Wnt5A, overexpression of DACT1 inhibited the expression and nuclear translocation of β-catenin, and upregulated IL5, IL6 and IL13 mRNA expression. In conclusion, DACT1 was indicated to be upregulated in lung tissues from children with asthma, which could induce higher pro-inflammatory factor expression. DACT1 may act via inhibiting the expression and nuclear translocation of β-catenin, a factor in the Wnt signaling pathway. The present results suggested that DACT1 may be a potential target for the treatment of asthma.