Tetrahydrocurcumin induces mesenchymal-epithelial transition and suppresses angiogenesis by targeting HIF-1α and autophagy in human osteosarcoma

The role of tetrahydrocurcumin in disease prevention and treatment

In recent decades, natural compounds derived from herbal medicine or dietary sources have played important roles in prevention and treatment of various diseases and have attracted more and more attention. Curcumin, extracted from the Curcumae Longae Rhizoma and widely used as food spice and coloring agent, has been proven to possess high pharmacological value. However, the pharmacological application of curcumin is limited due to its poor systemic bioavailability. As a major active metabolite of curcumin, tetrahydrocurcumin (THC) has higher bioavailability and stability than curcumin. Increasing evidence confirmed that THC had a wide range of biological activities and significant treatment effects on diseases. In this paper, we reviewed the research progress on the biological activities and therapeutic potential of THC on different diseases such as neurological disorders, metabolic syndromes, cancers, and inflammatory diseases. The extensive pharmacological effects of THC involve the modulation of various signaling transduction pathways including MAPK, JAK/STAT, NF-κB, Nrf2, PI3K/Akt/mTOR, AMPK, Wnt/β-catenin. In addition, the pharmacokinetics, drug combination and toxicology of THC were discussed, thus providing scientific basis for the safe application of THC and the development of its dietary supplements and drugs.

Hypoxia inducible factor-1ɑ as a potential therapeutic target for osteosarcoma metastasis

Osteosarcoma (OS) is a malignant tumor originating from mesenchymal tissue. Pulmonary metastasis is usually present upon initial diagnosis, and metastasis is the primary factor affecting the poor prognosis of patients with OS. Current research shows that the ability to regulate the cellular microenvironment is essential for preventing the distant metastasis of OS, and anoxic microenvironments are important features of solid tumors. During hypoxia, hypoxia-inducible factor-1α (HIF-1α) expression levels and stability increase. Increased HIF-1α promotes tumor vascular remodeling, epithelial-mesenchymal transformation (EMT), and OS cells invasiveness; this leads to distant metastasis of OS cells. HIF-1α plays an essential role in the mechanisms of OS metastasis. In order to develop precise prognostic indicators and potential therapeutic targets for OS treatment, this review examines the molecular mechanisms of HIF-1α in the distant metastasis of OS cells; the signal transduction pathways mediated by HIF-1α are also discussed.

Novel tetrahydrocurcumin integrated mucoadhesive nanocomposite κ-carrageenan/xanthan gum sponges: a strategy for effective local treatment of oral cancerous and precancerous lesions

Oral cancer is one of the leading causes of death worldwide. Oral precancerous lesions (OPL) are the precursors of oral cancer, with varying degrees of progression. Tetrahydrocurcumin (THC) is a major metabolite of curcumin with superior anticancer properties against various types of cancer. However, THC's clinical outcome is limited by its poor aqueous solubility. Herein, we developed novel mucoadhesive biopolymer-based composite sponges for buccal delivery of THC, exploiting nanotechnology and mucoadhesion for efficient prevention and treatment of oral cancer. Firstly, THC-nanocrystals (THC-NC) were formulated and characterized for subsequent loading into mucoadhesive composite sponges. The anticancer activity of THC-NC was assessed on a human tongue squamous carcinoma cell line (SCC-4). Finally, the chemopreventive activity of THC-NC loaded sponges (THC-NC-S) was examined in DMBA-induced hamster OPL. The selected THC-NC exhibited a particle size of 532.68 ± 13.20 nm and a zeta potential of -46.08 ± 1.12 mV. Moreover, THC-NC enhanced the anticancer effect against SCC-4 with an IC50 value of 80 µg/mL. THC-NC-S exhibited good mucoadhesion properties (0.24 ± 0.02 N) with sustained drug release, where 90% of THC was released over 4 days. Furthermore, THC-NC-S had a magnificent potential for maintaining high chemopreventive activity, as demonstrated by significant regression in the dysplasia degree and a decline in cyclin D1 (control: 40.4 ± 12.5, THC-NC-S: 12.07 ± 5.2), culminating in significant amelioration after 25 days of treatment. Conclusively, novel THC-NC-S represent a promising platform for local therapy of OPL, preventing their malignant transformation into cancer.

Autophagy Modulation as a Potential Therapeutic Strategy in Osteosarcoma: Current Insights and Future Perspectives

Autophagy, the process that enables the recycling and degradation of cellular components, is essential for homeostasis, which occurs in response to various types of stress. Autophagy plays an important role in the genesis and evolution of osteosarcoma (OS). The conventional treatment of OS has limitations and is not always effective at controlling the disease. Therefore, numerous researchers have analyzed how controlling autophagy could be used as a treatment or strategy to reverse resistance to therapy in OS. They highlight how the inhibition of autophagy improves the efficacy of chemotherapeutic treatments and how the promotion of autophagy could prove positive in OS therapy. The modulation of autophagy can also be directed against OS stem cells, improving treatment efficacy and preventing cancer recurrence. Despite promising findings, future studies are needed to elucidate the molecular mechanisms of autophagy and its relationship to OS, as well as the mechanisms underlying the functioning of autophagic modulators. Careful evaluation is required as autophagy modulation may have adverse effects on normal cells, and the optimization of autophagic modulators for use as drugs in OS is imperative.

Augmentation of Docetaxel-Induced Cytotoxicity in Human PC-3 Androgen-Independent Prostate Cancer Cells by Combination With Four Natural Apoptosis-Inducing Anticancer Compounds

Docetaxel (DTX) is the treatment of choice for metastatic castration-resistant prostate cancer. However, developing drug resistance is a significant challenge for achieving effective therapy. This study evaluated the anticancer and synergistic effects on DTX of four natural compounds (calebin A, 3^'-hydroxypterostilbene, hispolon, and tetrahydrocurcumin) using PC-3 androgen-resistant human prostate cancer cells. We utilized the CellTiter-Glo^® luminescent cell viability assay and human PC-3 androgen-independent prostate cancer cells to determine the antiproliferative effects of the four compounds alone and combined with DTX. Cytotoxicity to normal human prostate epithelial cells was tested in parallel using normal immortalized human prostate epithelial cells (RWPE-1). We used cell imaging and quantitative caspase-3 activity to determine whether these compounds induce apoptosis. We also measured the capacity of each drug to inhibit TNF-α-induced NF-kB using a colorimetric assay. Our results showed that all four natural compounds significantly augmented the toxicity of DTX to androgen-resistant PC-3 prostate cancer cells at IC₅₀. Interestingly, when used alone, each of the four compounds had a higher cytotoxic activity to PC-3 than DTX. Mechanistically, these compounds induced apoptosis, which we confirmed by cell imaging and caspase-3 colorimetric assays. Further, when used either alone or combined with DTX, the four test compounds inhibited TNF-α-induced NF-kB production. More significantly, the cytotoxic effects on normal immortalized human prostate epithelial cells were minimal and non-significant, suggesting prostate cancer-specific effects. In conclusion, the combination of DTX with the four test compounds could effectively enhance the anti-prostate cancer activity of DTX. This combination has the added value of reducing the DTX effective concentration. We surmise that calebin A, 3^'-hydroxypterostilbene, hispolon, and tetrahydrocurcumin were all excellent drug candidates that produced significant antiproliferative activity when used alone and synergistically enhanced the anticancer effect of DTX. Further in vivo studies using animal models of prostate cancer are needed to confirm our in vitro findings.

Effect of Curcumin on Attenuation of Liver Cirrhosis via Genes/Proteins and Pathways: A System Pharmacology Study

Background: Liver cirrhosis is a life-threatening seqsuel of many chronic liver disorders of varying etiologies. In this study, we investigated protein targets of curcumin in liver cirrhosis based on a bioinformatics approach. Methods: Gene/protein associations with curcumin and liver cirrhosis were probed in drug−gene and gene−diseases databases including STITCH/DGIdb/DisGeNET/OMIM/DISEASES/CTD/Pharos and SwissTargetPrediction. Critical clustering groups (MCODE), hub candidates and critical hub genes in liver cirrhosis were identified, and connections between curcumin and liver cirrhosis-related genes were analyzed via Venn diagram. Interaction of hub genes with curcumin by molecular docking using PyRx-virtual screening tools was performed. Results: MCODE analysis indicated three MCODEs; the cluster (MCODE 1) comprised 79 nodes and 881 edges (score: 22.59). Curcumin database interactions recognized 318 protein targets. Liver cirrhosis genes and curcumin protein targets analysis demonstrated 96 shared proteins, suggesting that curcumin may influence 20 candidate and 13 hub genes, covering 81% of liver cirrhosis critical genes and proteins. Thirteen shared proteins affected oxidative stress regulation, RNA, telomerase activity, cell proliferation, and cell death. Molecular docking analysis showed the affinity of curcumin binding hub genes (Binding affinity: ΔG < −4.9 kcal/mol). Conclusions: Curcumin impacted on several critical liver cirrhosis genes mainly involved in extracellular matrix communication, focal adhesion, and the response to oxidative stress.

Complexity of Tumor Microenvironment: Therapeutic Role of Curcumin and Its Metabolites

The tumor microenvironment (TME) is a complex network of cellular and non-cellular components surrounding the tumor. The cellular component includes fibroblasts, adipocytes, endothelial cells, and immune cells, while non-cellular components are tumor vasculature, extracellular matrix and signaling molecules. The tumor cells have constant close interaction with their surrounding TME components that facilitate their growth, survival, and metastasis. Targeting a complex TME network and its interaction with the tumor can offer a novel strategy to disrupt cancer cell progression. Curcumin, from turmeric rhizome, is recognized as a safe and effective natural therapeutic agent against multiple diseases including cancer. Here the effects of curcumin and its metabolites on tumor-TME interaction modulating ability have been described. Curcumin and its metabolites regulate TME by inhibiting the growth of its cellular components such as cancer-associated adipocytes, cancer-associated fibroblast, tumor endothelial cells, tumor-stimulating immune cells, and inducing anticancer immune cells. They also inhibit the interplay of tumor cells to TME by suppressing non-cellular components such as extracellular matrix, and associated tumor promoting signaling-pathways. In addition, curcumin inhibits the inflammatory environment, suppresses angiogenic factors, and increases antioxidant status in TME. Overall, curcumin has the capability to regulate TME components and their interaction with tumor cells.

The Multifaceted Therapeutic Mechanisms of Curcumin in Osteosarcoma: State-of-the-Art

Osteosarcoma is a major form of malignant bone tumor that typically occurs in young adults and children. The combination of aggressive surgical strategies and chemotherapy has led to improvements in survival time, although individuals with recurrent or metastatic conditions still have an extremely poor prognosis. This disappointing situation strongly indicates that testing novel, targeted therapeutic agents is imperative to prevent the progression of osteosarcoma and enhance patient survival time. Curcumin, a naturally occurring phenolic compound found in Curcuma longa, has been shown to have a wide variety of anti-tumor, anti-oxidant, and anti-inflammatory activities in many types of cancers including osteosarcoma. Curcumin is a highly pleiotropic molecule that can modulate intracellular signaling pathways to regulate cell proliferation, inflammation, and apoptosis. These signaling pathways include RANK/RANKL, Notch, Wnt/β-catenin, apoptosis, autophagy, JAK/STAT, and HIF-1 pathways. Additionally, curcumin can regulate the expression of various types of microRNAs that are involved in osteosarcoma. Therefore, curcumin may be a potential candidate for the prevention and treatment of osteosarcoma. This comprehensive review not only covers the use of curcumin in the treatment of osteosarcoma and its anti-cancer molecular mechanisms but also reveals the novel delivery strategies and combination therapies with the aim to improve the therapeutic effect of curcumin.

Effect of the Notch1-mediated PI3K-Akt-mTOR pathway in human osteosarcoma

Purpose: Osteosarcoma is one of the most common malignant bone tumours in early adolescence. The incidence rate of osteosarcoma has stagnated over the past 30 years, highlighting the need to develop novel therapies. In osteosarcoma cells, Notch1 expression is absent, and the Notch1 pathway is related to cancer cell proliferation, apoptosis and autophagy. Our study aimed to investigate the role of Notch1 in osteosarcoma development.

Methods: We measured NICD1 expression induced by doxycycline treatment at various concentrations. The viability of human osteosarcoma cells (MG-63) induced by doxycycline was measured. Flow cytometry and cell apoptosis analysis were conducted to measure the effect of Notch1 on the cell cycle of human osteosarcoma cells. We also used a GFP-LC3 plasmid to detect Notch1-induced autophagy in MG-63 cells. Western blotting was conducted to analyse expression of the PI3K/Akt/mTOR signalling pathway through Notch1 induction by doxycycline.

Results: In this study, we demonstrated that Notch1 activation by doxycycline potently suppressed cell proliferation by inducing S phase arrest in osteosarcoma cells. Doxycycline-induced Notch1 activation also induced apoptosis and autophagy in osteosarcoma cells. Moreover, we found that Notch1 inhibited PI3K/Akt/mTOR signalling to induce apoptosis and autophagy.

Conclusion: In summary, our results revealed that Notch1 activation by doxycycline induces S phase arrest, apoptosis and autophagy by blocking PI3K/Akt/mTOR signalling in human osteosarcoma cells. Notch1 may be a potential clinical antitumour target for osteosarcoma therapy.

Selected using bioinformatics and molecular docking analyses, PHA-793887 is effective against osteosarcoma

To identify novel prognostic and therapeutic targets for osteosarcoma patients, we compared the gene expression profiles of osteosarcoma and control tissues from the GSE42352 dataset in the Gene Expression Omnibus. Differentially expressed genes were subjected to Gene Ontology, Kyoto Encyclopedia of Genes and Genomes, Gene Set Enrichment and protein-protein interaction network analyses. Survival curve analyses indicated that osteosarcoma patients with lower mRNA levels of cyclin-dependent kinase 1 (CDK1) and topoisomerase II alpha had better prognoses. Various computer-aided techniques were used to identify potential CDK1 inhibitors for osteosarcoma patients, and PHA-793887 was predicted to be a safe drug with a high binding affinity for CDK1. In vitro, MTT and colony formation assays demonstrated that PHA-793887 reduced the viability and clonogenicity of osteosarcoma cells, while a scratch assay suggested that PHA-793887 impaired the migration of these cells. Flow cytometry experiments revealed that PHA-793887 dose-dependently induced apoptosis in osteosarcoma cells. Western blotting and enzyme-linked immunosorbent assays indicated that CDK1 expression in osteosarcoma cells declined with increasing PHA-793887 concentrations. These results suggest that PHA-793887 could be a promising new treatment for osteosarcoma.

Reductive metabolites of curcumin and their therapeutic effects

Curcumin, a secondary metabolite from the turmeric plant is one of the most promising natural products, which has been studied extensively for decades. It has demonstrated several pharmacological activities in vitro and in vivo. Various studies have indicated that the pharmacological activity of curcumin is contributed by its metabolites. The aim of this review is to present an overview of metabolic products of curcumin produced upon its reduction like di, tetra, hexa and octa-hydrocurcumin. In addition, this paper has systematically analyzed the current information regarding medicinal use of reduced metabolites of curcumin and identified the limitations which have hindered its widespread usage in the medical world. Several diverse therapeutic effects have shown to be exhibited by reduced metabolites of curcumin such as antioxidant, anti-cancerous, anti-inflammatory and immunoregulatory activities. The potential underlying molecular mechanisms of the biological activities of reduced metabolites of curcumin have also been highlighted, which may provide insight into the principle of effectiveness of curcumin.

The Cancer Chemopreventive and Therapeutic Potential of Tetrahydrocurcumin

In recent decades, cancer has been one of the leading causes of death worldwide. Despite advances in understanding the molecular basis of tumorigenesis, diagnosis, and clinical therapies, the discovery and development of effective drugs is an active and vital field in cancer research. Tetrahydrocurcumin is a major curcuminoid metabolite of curcumin, naturally occurring in turmeric. The interest in tetrahydrocurcumin research is increasing because it is superior to curcumin in its solubility in water, chemical stability, bioavailability, and anti-oxidative activity. Many in vitro and in vivo studies have revealed that tetrahydrocurcumin exerts anti-cancer effects through various mechanisms, including modulation of oxidative stress, xenobiotic detoxification, inflammation, proliferation, metastasis, programmed cell death, and immunity. Despite the pharmacological similarities between tetrahydrocurcumin and curcumin, the structure of tetrahydrocurcumin determines its distinct and specific molecular mechanism, thus making it a potential candidate for the prevention and treatment of cancers. However, the utility of tetrahydrocurcumin is yet to be evaluated as only limited pharmacokinetic and oral bioavailability studies have been performed. This review summarizes research on the anti-cancer properties of tetrahydrocurcumin and describes its mechanisms of action.

Alternagin-C (ALT-C), a disintegrin-like protein, attenuates alpha2beta1 integrin and VEGF receptor 2 signaling resulting in angiogenesis inhibition

Angiogenesis, a crucial process in tumor progression, is mainly regulated by vascular endothelial growth factor (VEGF) and its receptor, VEGFR2. Studies have shown the interaction between α₂β₁ integrin, a collagen receptor, and VEGFR2 in VEGF-driven angiogenesis in vitro and in vivo. Alternagin-C (ALT-C), an ECD-disintegrin-like protein from Bothrops alternatus snake venom, has high affinity for α₂β₁ integrin and shows antiangiogenic activity in concentrations higher than 100 nM. Despite previous results, its mechanism of action on angiogenic signaling pathways has not been addressed. Here we evaluate the antiangiogenic activity of ALT-C in human umbilical vein endothelial cells (HUVECs) associated or not with VEGF, as well as its interference in the α₂β₁/VEGFR2 crosstalk. ALT-C (1000 nM) affected actin cytoskeleton, decreased the number of cell filopodia, and strongly inhibited HUVEC tube formation, adhesion to type I collagen and cell migration. Down-regulation of α₂β₁/VEGFR2 crosstalk by ALT-C decreased the protein content and phosphorylation of VEGFR2 and β₁ integrin subunit, inhibited ERK 1/2 and PI3K signaling and regulated FAK/Src and paxillin pathways. Furthermore, ALT-C increased the content of the autophagic markers LC3B and Beclin-1 in the presence of VEGF, which is associated with decreased angiogenesis. In conclusion, we suggest that ALT-C, after binding to α₂β₁ integrin, inhibits VEGF/VEGFR2 signaling, which results in impaired angiogenesis. These results demonstrate that ALT-C may be a potential candidate for the development of antiangiogenic therapies for tumor and metastasis treatment and help to understand the complexity and fundamental role of integrin inhibition in the tumor microenvironment.

Anti-angiogenesis triggers exosomes release from endothelial cells to promote tumor vasculogenesis

Although anti-angiogenic therapies (AATs) have some effects against multiple malignancies, they are limited by subsequent tumor vasculogenesis and progression. To investigate the mechanisms by which tumor vasculogenesis and progression following AATs, we transfected microRNA (miR)-9 into human umbilical vein endothelial cells (HUVECs) to mimic the tumor-associated endothelial cells in hepatocellular carcinoma and simulated the AATs in vitro and in vivo. We found that administration of the angiogenesis inhibitor vandetanib completely abolished miR-9-induced angiogenesis and promoted autophagy in HUVECs, but induced the release of vascular endothelial growth factor (VEGF)-enriched exosomes. These VEGF-enriched exosomes significantly promoted the formation of endothelial vessels and vasculogenic mimicry in hepatocellular carcinoma and its progression in mice. Anti-autophagic therapy is proposed to improve the efficacy of AATs. However, similar effects by AATs were observed with the application of anti-autophagy by 3-methyladenine. Our results revealed that tumor vasculogenesis and progression after AATs and anti-autophagic therapies were due to the cross-talk between endothelial and tumor cells via VEGF-enriched exosomes.

The Chemopreventive Activity of Indonesia Medicinal Plants Targeting on Hallmarks of Cancer

Cancer remains a complex disease with increasing global mortality and morbidity. Numerous theories have been established to understand the biological mechanism underlying cancer. One of the most renowned frameworks is the hallmark of cancer proposed by Hanahan and Weinberg that covers ten eminent characteristics of cancer: (i) genome instability and mutation, (ii) sustaining proliferative signaling, (iii) evading growth suppressor, (iv) enabling replicative immortality, (v) resisting cell death, (vi) inducing angiogenesis, (vii) activating invasion and metastasis, (viii) avoiding immune destruction, (ix) tumor-promoting inflammation, and (x) deregulating cellular energetics. These hallmarks provide a rational approach to design an anticancer therapy. In the current review, we summarized specific target molecules on each hallmark of cancer. Further, we evaluated the biological activity of several Indonesia medicinal plants against those specific targets. We explicated the anticancer and chemopreventive activities of some medicinal plants that have been used for centuries by local communities in Indonesia, including Curcuma genus, Brucea javanica, Boesenbergia pandurata, Caesalpinia sappan, and Nigella sativa. Interestingly, these medicinal plants target several hallmarks of cancer, and even Curcuma genus exhibited biological activities that target all hallmarks of cancer. Further, we also discuss several strategies to develop those medicinal plants and/or their active compounds as anticancer and chemopreventive agents.

Cyclohexanone curcumin analogs inhibit the progression of castration-resistant prostate cancer in vitro and in vivo

Many prostate cancer patients develop resistance to treatment called castration‐resistant prostate cancer (CRPC) which is the major cause of recurrence and death. In the present study, four cyclohexanone curcumin analogs were synthesized. Additionally, their anticancer progression activity on CRPC cell lines, PC3 and PLS10 cells, was examined. We first determined their anti‐metastasis properties and found that 2,6‐bis‐(4‐hydroxy‐3‐methoxy‐benzylidene)‐cyclohexanone (2A) and 2,6‐bis‐(3,4‐dihydroxy‐benzylidene)‐cyclohexanone (2F) showed higher anti‐invasion properties against CRPC cells than curcumin. Analog 2A inhibited both MMP‐2 and MMP‐9 secretions and activities, whereas analog 2F reduced only MMP activities. These findings suggest that the compounds may inhibit CRPC cell metastasis by decreased extracellular matrix degradation. Analog 2A, the most potent analog, was then subjected to an in vivo study. Similar to curcumin, analog 2A was detectable in the serum of mice at 30 and 60 minutes after i.p. injections. Analog 2A and curcumin (30 mg/kg bodyweight) showed a similar ability to reduce tumor area in lungs of mice that were i.v. injected with PLS10 cells. Additionally, analog 2A showed superior growth inhibitory effect on PLS10 cells than that of curcumin both in vitro and in vivo. The compound inhibited PLS10 cells growth by induction of G1 phase arrest and apoptosis in vitro. Interestingly, analog 2A significantly decreased tumor growth with downregulation of cell proliferation and angiogenesis in PLS10‐bearing mice. Taken together, we could summarize that analog 2A showed promising activities in inhibiting CRPC progression both in vitro and in vivo.

The Kraken Wakes: induced EMT as a driver of tumour aggression and poor outcome

Epithelial mesenchymal transition (EMT) describes the shift of cells from an epithelial form to a contact independent, migratory, mesenchymal form. In cancer the change is linked to invasion and metastasis. Tumour conditions, including hypoxia, acidosis and a range of treatments can trigger EMT, which is implicated in the subsequent development of resistance to those same treatments. Consequently, the degree to which EMT occurs may underpin the entire course of tumour progression and treatment response in a patient. In this review we look past the protective effect of EMT against the initial treatment, to the role of the mesenchymal state, once triggered, in promoting disease growth, spread and future treatment insensitivity. In patients a correlation was found between the propensity of a treatment to induce EMT and failure of that treatment to provide a survival benefit, implicating EMT induction in accelerated tumour progression after treatment cessation. Looking to the mechanisms driving this detrimental effect; increased proliferation, suppressed apoptosis, stem cell induction, augmented angiogenesis, enhanced metastatic dissemination, and immune tolerance, can all result from treatment-induced EMT and could worsen outcome. Evidence also suggests EMT induction with earlier therapies attenuates benefits of later treatments. Looking beyond epithelial tumours, de-differentiation also has therapy-attenuating effects and reversal thereof may yield similar rewards. A range of potential therapies are in development that may address the diverse mechanisms and molecular control systems involved in EMT-induced accelerated progression. Considering the broad reaching effects of mesenchymal shift identified, successful deployment of such treatments could substantially improve patient outcomes.

Sinomenine Hydrochloride Inhibits the Metastasis of Human Glioblastoma Cells by Suppressing the Expression of Matrix Metalloproteinase-2/-9 and Reversing the Endogenous and Exogenous Epithelial-Mesenchymal Transition

As shown in our previous study, sinomenine hydrochloride (SH), the major bioactive alkaloid isolated from Sinomenium acutum Rehd. et Wils. (Fam. Menispermaceae), initiates the autophagy-mediated death of human glioblastoma cells by generating reactive oxygen species and activating the autophagy-lysosome pathway. However, its effects on the migration and invasion of human glioblastoma cells have not yet been elucidated. Therefore, human glioblastoma U87 and SF767 cells were treated with SH (0.125 and 0.25 mM) for 24 h, and cell migration and invasion were assessed using scratch wound healing, migration and invasion assays. SH promoted G0/G1 phase arrest, inhibited the migration and invasion of the two cell lines, suppressed the activation of nuclear factor kappa B (NFκB) and the expression of matrix metalloproteinase (MMP)-2/-9, triggered endoplasmic reticulum (ER) stress, reversed the exogenous epithelial-mesenchymal transition (EMT) induced by the inflammatory microenvironment and the endogenous EMT. Additionally, NFκB p65 overexpression blocked the SH-mediated inhibitory effects on MMP-2/-9 expression and cell invasion. SH-induced autophagy was reduced in CCAAT/enhancer binding protein (C/EBP) homologous protein (CHOP) or autophagy-related 5 (ATG5)-silenced human glioblastoma cells and cells treated with 4-phenylbutyric acid (4-PBA) or 3-methyladenine (3-MA), as shown by the decreased levels of the microtubule-associated protein light chain 3B (LC3B)-II and autophagic vacuoles (AVs) stained with monodansylcadaverine (MDC), respectively. Moreover, knockdown of CHOP or ATG5 and treatment with 4-PBA or 3-MA abolished the SH-mediated inhibition of mesenchymal markers (vimentin, Snail and Slug) expression and cell invasion, respectively. Importantly, SH also regulated the above related pathways in nude mice. Based on these findings, SH inhibited cell proliferation by inducing cell cycle arrest, and attenuated the metastasis of U87 and SF767 cells by suppressing MMP-2/-9 expression and reversing the endogenous and exogenous EMT in vitro and/or in vivo. Thus, SH might be a new potential anti-metastasis agent for the treatment of human glioblastoma.

Energy stress-induced lncRNA HAND2-AS1 represses HIF1α-mediated energy metabolism and inhibits osteosarcoma progression

During recent years, long noncoding RNAs (lncRNAs) have been recognized as key regulators in the development and progression of human cancers, however, their roles in osteosarcoma metabolism are still not well understood. The present study aims to investigate the expression profiles and potential modulation of specific lncRNA(s) in osteosarcoma metabolism. The high-throughput Hiseq sequencing was performed to screen for abnormally expressed lncRNAs in osteosarcoma cells cultured under glucose starvation condition, and lncRNA HAND2-AS1 was eventually identified as one that was significantly up-regulated when compared with normal cultured cells. Mechanistic investigations indicated that knockdown of HAND2-AS1 abrogated the energy stress-induced effect on cell apoptosis and proliferation, and promoted osteosarcoma progression. Moreover, knockdown of HAND2-AS1 promoted glucose uptake, lactate production, and the expression level of a serious of enzymes that involved in energy metabolism. Subsequently, RNA pull-down and RNA immuneprecipitation revealed that, upon energy stress, HAND2-AS1 regulated osteosarcoma metabolism through sequestering FBP1 from binding to HIF1α, thereby releasing HIF1α expression and promoting the protein level. Taken together, our integrated approach reveals a regulatory mechanism by lncRNA HAND2-AS1 to control energy metabolism and tumor development in osteosarcoma. Thus, HAND2-AS1 may be a potential biomarker and therapeutic target for the repression of osteosarcoma metabolism.