More expressions of BDNF and TrkB in multiple hepatocellular carcinoma and anti-BDNF or K252a induced apoptosis, supressed invasion of HepG2 and HCCLM3 cells

Epigenetic Perspectives and Their Prognostic Value in Early Recurrence After Hepatocellular Carcinoma Resection

BACKGROUND/OBJECTIVES

The post-hepatectomy survival of patients with hepatocellular carcinoma (HCC) faces challenges due to high recurrence rates, especially early recurrence (ER). We investigated DNA methylation in HCC and developed a methylation-based model for ER prediction (MER).

METHODS

We studied HCC patients with ER within a year post-hepatectomy, comparing them to those who remained recurrence-free (RF) for 5 years. In a testing set, we examined genome-wide methylation profiles to identify differences between ER and RF. Validation in an independent cohort confirmed candidate markers using real-time quantitative methylation-specific PCR (qMSP). We constructed MER by incorporating identified gene methylation, clinical information, and serum protein marker, and evaluated its predictive performance using ROC analysis and Cox regression.

RESULTS

Distinct signatures of hypermethylation and hypomethylation were observed between ER and RF, as well as between cirrhotic and non-cirrhotic groups. Significant aberrant methylation pathways, including FGFR signaling, the PI3K network, and the MAPK pathway, were observed in non-cirrhotic ER patients. Conversely, cirrhotic ER patients showed notable associations with Wnt/β-catenin signaling, cell adhesion, and migration mechanisms. Through qMSP analysis, we identified ER-associated genes, including BDNF, FOXL2, LMO7, NCAM1, NEIS3, PLA2G7, and LTB4R. MER demonstrated strong predictive ability for ER, with an AUC of 0.855, surpassing current indicators such as AFP, tumor size, and BCLC stage. Combining different predictors resulted in heightened AUC values. Importantly, the inclusion of MER yielded to the highest AUC of 0.952, underscoring the substantial contribution of MER to predictive accuracy.

CONCLUSIONS

This study discovered the involvement of aberrant DNA methylation in HCC with early recurrence. The MER outperforms clinicopathological predictors and achieves robust prediction capabilities in identifying patients at risk of ER.

Novel CAR-T cells targeting TRKB for the treatment of solid cancer

Chimeric antigen receptor (CAR) T-cell therapy is highly effective for treating blood cancers such as B-cell malignancies, however, its effectiveness as an approach to treat solid tumors remains to be further explored. Here, we focused on the development of CAR-T cell therapies targeting tropomyosin-related kinase receptor B (TRKB), a highly expressed protein that is significantly associated with tumor progression, malignancy, and drug resistance in multiple forms of aggressive solid tumors. To achieve this, we screened brain-derived neurotrophic factor (BDNF) and neurotrophin 4 (NTF4) ligand-based CAR-T cells for their efficiency in targeting the TRKB receptor in the context of solid tumors, particularly hepatocellular carcinoma and pancreatic cancer. We demonstrated that TRKB is overexpressed not only in hepatocellular carcinoma and pancreatic carcinoma cell lines but also in cancer stem-like cells (CSCs). Notably, BDNF-CAR T and NTF4-CAR T cells could not only effectively target and kill TRKB-expressing pan-cancer cell lines in a dose-dependent manner but also effectively kill CSCs. We also performed in vivo studies to show that NTF4-CAR T cells have a better potential to inhibit the tumor growth of hepatocellular carcinoma xenografts in mice, compared with BDNF-CAR T cells. Taken together, our findings suggest that CAR-T targeting TRKB may be a promising approach for developing novel therapies to treat solid cancers.

Developing a novel neutralizing monoclonal antibody against TrkB

The TrkB receptor, which is highly expressed in various human cancers and considered a pro-oncogene, was targeted to develop neutralizing monoclonal antibodies against its immunoglobulin-like (Ig-like) domains. Recombinant TrkB-IgL peptide, including the Ig-like C2 type 1 (Ig-C2-type 1) and Ig-like C2 type 2 (Ig-C2-type 2) domains, was expressed and purified from E. coli. Mice were immunized with this peptide, and hybridoma clones producing anti-TrkB-IgL antibodies were generated. Among 23 ELISA-positive TrkB-IgL hybridoma clones, four (TrkB-IgL 5.11, 4.11, 4.6, 4.3) showed anti-proliferative effects compared to the control on human breast cancer (MCF-7) and human colon cancer (HCT116) cells, as assessed using the xCELLigence system. Western blot analysis revealed that TrkB-IgL 5.11 and 4.11 significantly suppressed TrkB-mediated signaling pathways compared to the control. Purified TrkB-IgL monoclonal antibodies (mAbs) exhibited anti-proliferative effects compared to both positive and negative controls using the xCELLigence system. The TrkB-IgL 5.11 mAb notably suppressed phosphorylation of TrkB, Akt, and ERK and induced Caspase-3 and Caspase-9 activities in a dose-dependent manner, as determined by Western blotting. Additionally, immunostaining confirmed the localization of these mAbs on the SH-SY5Y cell membrane, which is known for high TrkB expression. In conclusion, the TrkB-IgL 5.11 antibody effectively inhibits cancer cell proliferation and induces apoptosis by suppressing key signaling pathways. These findings demonstrate the potential of this antibody as a therapeutic agent for cancers that overexpress TrkB. Additionally, it is considered a promising candidate for humanization, which would facilitate its application in cancer treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-024-04063-x.

TrkB inhibition of DJ-1 degradation promotes the growth and maintenance of cancer stem cell characteristics in hepatocellular carcinoma

Although TrkB may be associated with the pathogenesis of various cancer by upregulation, how upregulation of TrkB led to tumor progression in hepatocellular carcinoma (HCC) and the signaling mechanisms by which TrkB induces motility, invasion, metastasis, drug resistance, and acquisition of self-renewal traits has remained unclear. Here, we demonstrated that TrkB was significantly upregulated in highly metastatic HCC cells and HCC patients. Also, the increased TrkB levels were significantly correlated with tumor stages and poor survival of HCC patients. Furthermore, the upregulated TrkB expression enhances the metastatic ability of HCC cells through reduced anoikis sensitivity, induced migration, and colony formation. Most strikingly, TrkB markedly enhances the activation of STAT3 by preventing DJ-1 degradation through the formation of the TrkB/DJ-1 complex. This signaling mechanism is responsible for triggering cellular traits of highly aggressive HCC. The activation of the EMT program of HCC via increasing DJ-1 stability by TrkB induces the gain of cancer stem cell states and chemoresistance via the upregulation of stem cells cell markers and ABC transporters. Also, TrkB-mediated inhibition of DJ-1 degradation promotes tumor formation and metastasizes to other organs in vivo. Our observations illustrate that TrkB is a prognostic and therapeutic targeting in promoting aggressiveness and metastasis of HCC.

The Genomic and Proteomic Profiles of NTRK Genes and Trk Receptors in Liver Hepatocellular Carcinoma

Background

The neurotrophic tyrosine kinase (NTRK) gene family includes NTRK1, NTRK2, and NTRK3, which encode tropomyosin receptor kinases TrkA, TrkB, and TrkC, respectively. This study aimed to initially assess the genomic and proteomic profiles of NTRK genes and Trk receptors in liver hepatocellular carcinoma (LIHC).

Methods

The ONCOMINE, UALCAN, GEPIA, cBioPortal, FusionGDB, SurvivalMeth, and the Human Protein Atlas databases were searched for NTRK gene expression and protein data in LIHC. Immunohistochemistry was used to detect pan-Trk expression across a commercial microarray containing 96 hepatocellular carcinoma (HCC) and 94 para-cancerous tissue spots. A modified histological score (H-score) with a maximum score of 300 was used to quantify immunohistochemical staining for pan-Trk. Student's t- and chi-square tests were the main statistical analyses used.

Results

The transcriptional levels of NTRK genes in LIHC were not significantly different from healthy controls. Using UALCAN and GEPIA, only high expression of NTRK2 was significantly associated with longer disease-free survival (P = 0.004). The alteration frequencies were low (7% in NTRK1, 1.7% in NTRK2, and 2% in NTRK3). The methylation levels of NTRK genes were all significantly different as analyzed by UALCAN; the high-risk group displayed an unfavorable prognosis compared with the low-risk group for NTRK1 (P = 0.033) and NTRK3 (P = 0.005). The median H-score of pan-Trk in HCC and para-cancerous tissues was not statistically different (186.31 ± 23.86 and 192.38 ± 21.06, P = 0.065). No differences were observed in clinicopathological features of HCC with the median H-score for pan-Trk expression (p > 0.05). The survival rate of patients with pan-Trk expression was also not significantly different.

Conclusion

The alteration frequency was low in NTRK genes, including gene fusion and methylation levels. Therefore, pan-Trk expression in HCC tissue has limited value in clinicopathological features and prognosis.

BDNF-TrkB signaling pathway-mediated microglial activation induces neuronal KCC2 downregulation contributing to dynamic allodynia following spared nerve injury

Mechanical allodynia can be evoked by punctate pressure contact with the skin (punctate mechanical allodynia) and dynamic contact stimulation induced by gentle touching of the skin (dynamic mechanical allodynia). Dynamic allodynia is insensitive to morphine treatment and is transmitted through the spinal dorsal horn by a specific neuronal pathway, which is different from that for punctate allodynia, leading to difficulties in clinical treatment. K+-Cl- cotransporter-2 (KCC2) is one of the major determinants of inhibitory efficiency, and the inhibitory system in the spinal cord is important in the regulation of neuropathic pain. The aim of the current study was to determine whether neuronal KCC2 is involved in the induction of dynamic allodynia and to identify underlying spinal mechanisms involved in this process. Dynamic and punctate allodynia were assessed using either von Frey filaments or a paint brush in a spared nerve injury (SNI) mouse model. Our study discovered that the downregulated neuronal membrane KCC2 (mKCC2) in the spinal dorsal horn of SNI mice is closely associated with SNI-induced dynamic allodynia, as the prevention of KCC2 downregulation significantly suppressed the induction of dynamic allodynia. The over activation of microglia in the spinal dorsal horn after SNI was at least one of the triggers in SNI-induced mKCC2 reduction and dynamic allodynia, as these effects were blocked by the inhibition of microglial activation. Finally, the BDNF-TrkB pathway mediated by activated microglial affected SNI-induced dynamic allodynia through neuronal KCC2 downregulation. Overall, our findings revealed that activation of microglia through the BDNF-TrkB pathway affected neuronal KCC2 downregulation, contributing to dynamic allodynia induction in an SNI mouse model.

Interactions Among Brain-Derived Neurotrophic Factor and Neuroimmune Pathways Are Key Components of the Major Psychiatric Disorders

The purpose of this review is to summarize the current knowledge regarding the reciprocal associations between brain-derived neurotrophic factor (BDNF) and immune-inflammatory pathways and how these links may explain the involvement of this neurotrophin in the immune pathophysiology of mood disorders and schizophrenia. Toward this end, we delineated the protein-protein interaction (PPI) network centered around BDNF and searched PubMed, Scopus, Google Scholar, and Science Direct for papers dealing with the involvement of BDNF in the major psychosis, neurodevelopment, neuronal functions, and immune-inflammatory and related pathways. The PPI network was built based on the significant interactions of BDNF with neurotrophic (NTRK2, NTF4, and NGFR), immune (cytokines, STAT3, TRAF6), and cell-cell junction (CTNNB, CDH1) DEPs (differentially expressed proteins). Enrichment analysis shows that the most significant terms associated with this PPI network are the tyrosine kinase receptor (TRKR) and Src homology region two domain-containing phosphatase-2 (SHP2) pathways, tyrosine kinase receptor signaling pathways, positive regulation of kinase and transferase activity, cytokine signaling, and negative regulation of the immune response. The participation of BDNF in the immune response and its interactions with neuroprotective and cell-cell adhesion DEPs is probably a conserved regulatory process which protects against the many detrimental effects of immune activation and hyperinflammation including neurotoxicity. Lowered BDNF levels in mood disorders and schizophrenia (a) are associated with disruptions in neurotrophic signaling and activated immune-inflammatory pathways leading to neurotoxicity and (b) may interact with the reduced expression of other DEPs (CTNNB1, CDH1, or DISC1) leading to multiple aberrations in synapse and axonal functions.

Transcriptome Analysis Reveals the Anti-cancerous Mechanism of Licochalcone A on Human Hepatoma Cell HepG2

Hepatocellular carcinoma is a malignancy with a low survival rate globally, and there is imperative to unearth novel natural phytochemicals as effective therapeutic strategies. Licochalcone A is a chalcone from Glycyrrhiza that displayed various pharmacological efficacy. A globally transcriptome analysis was carried out to reveal the gene expression profiling to explore Licochalcone A's function as an anti-cancer phytochemical on HepG2 cells and investigate its potential mechanisms. Altogether, 6,061 dysregulated genes were detected (3,414 up-regulated and 2,647 down-regulated). SP1 was expected as the transcription factor that regulates the functions of most screened genes. GO and KEGG analysis was conducted, and the MAPK signaling pathway and the FoxO signaling pathway were two critical signal pathways. Protein-protein interaction (PPI) network analysis based on STRING platform to discover the hub genes (MAPK1, ATF4, BDNF, CASP3, etc.) in the MAPK signaling pathway and (AKT3, GADD45A, IL6, CDK2, CDKN1A, etc.) the FoxO signaling pathway. The protein level of essential genes that participated in significant pathways was consistent with the transcriptome data. This study will provide an inclusive understanding of the potential anti-cancer mechanism of Licochalcone A on hepatocellular, signifying Licochalcone A as a promising candidate for cancer therapy.

Salvianolic acid B targets mortalin and inhibits the migration and invasion of hepatocellular carcinoma via the RECK/STAT3 pathway

BACKGROUND

Tumor migration and invasion is a complex and diverse process that involves the epithelial-mesenchymal transition (EMT) of tumor cells and degradation of the extracellular matrix by matrix metalloproteases (MMPs). Mortalin is an important oncogene. It has been reported to play an important role in tumor migration and invasion through various signaling pathways, but the underlying mechanism is not fully understood.

METHODS

Here, we investigated the role of mortalin in the migration of the hepatocellular carcinoma (HCC) cell lines HepG2 and HCCLM3.

RESULTS

The overexpression of mortalin in HepG2 cells decreased the protein level of reversion-inducing cysteine-rich protein with Kazal motifs (RECK) and activated the phosphorylation and acetylation of STAT3, thereby up-regulating matrix metalloproteinase 9 (MMP9) and promoting cell migration and invasion. In contrast, in HCCLM3 cells, mortalin knockdown increased the expression of RECK, inhibited the STAT3 pathway and the activity of MMP9, and inhibited cell migration and invasion. Furthermore, we found that salvianolic acid B, a caffeic acid phenethyl ester analog, specifically bound to mortalin and increased the degradation of mortalin proteasomes through ubiquitination, thereby up-regulating RECK, inhibiting STAT3, and finally inhibiting the migration and invasion of HCC cells.

CONCLUSION

Our work suggested that mortalin is a potential therapeutic target for hepatocellular carcinoma.

BDNF expression in GISTs predicts poor prognosis when associated with PD-L1 positive tumor-infiltrating lymphocytes

Substantial evidence indicates that brain-derived neurotrophic factor (BDNF) plays an important role in tumorigenesis, in addition to its primary role in neuronal activity. Gastrointestinal stromal tumors (GISTs), which are the most common mesenchymal neoplasms of the gastrointestinal tract, contain multiple types of tumor-infiltrating lymphocytes (TILs) that express relevant immune checkpoint proteins. However, no data have been reported on the role of BDNF in GISTs. This study aimed to investigate the expression pattern and prognostic value of BDNF in GIST patients with different degrees of risk, as well as the relationship between BDNF expression and immune checkpoints. Immunohistochemistry (IHC) demonstrated that higher BDNF expression was more likely to be present in high-risk patients and suggested a poor prognosis. A similar phenomenon was demonstrated in plasma. Even more interesting was that a positive correlation was present between BDNF and PD-L1⁺ expression on TILs. Moreover, high BDNF expression levels in combination with a high PD-L1⁺ TIL count predict extremely poor survival. The combination of BDNF expression and TIL PD-L1⁺ expression as a single biomarker was a powerful significant independent predictor of prognosis. Taken together, BDNF expression may serve as a significant prognostic factor, as the combination of BDNF expression and the PD-L1⁺ TIL subset led to superior prediction of GIST prognosis. Furthermore, our research coupled a neurotrophin with immunity, which provides novel evidence of neural and immune regulation in a clinical study of GIST.

Serum Levels of BDNF in Patients with Adenoma and Colorectal Cancer

The present study is aimed at examining the serum levels of brain-derived neurotrophic factor (BDNF) and investigating its role in differential diagnosis of colorectal cancer (CRC). Materials and Methods. In a Chinese population, we conducted a case-control study to compare the diagnostic performance of serum levels of BDNF and carcinoembryonic antigen (CEA) for CRC. We enrolled 61 healthy controls, 31 patients with adenomas, and 81 patients with CRC. We explored the correlation between serum levels of BDNF and several pathological features, such as tumor differentiation and TNM staging. Results. The serum levels of BDNF were significantly (p < 0.0001) higher in patients with CRC (10.64 ± 3.84, n = 81) than in the healthy controls (4.69 ± 1.69 ng/mL, n = 61). Serum BDNF also correlated with tumor size, tumor differentiation, and TNM staging (p < 0.05). For early diagnosis, the combination of BDNF (AUC 0.719; 95% CI, 0.621–0.816) and CEA (AUC 0.733; 95% CI, 0.632–0.909) slightly improved the diagnostic performance for CRC (AUC 0.823; 95% CI, 0.737-0.909). Conclusions. Combined detection of serum BDNF and CEA may thus have the potential to become a new laboratory method for the early clinical diagnosis of CRC.

Nerves in the Tumor Microenvironment: Origin and Effects

Studies have reported the vital role of nerves in tumorigenesis and cancer progression. Nerves infiltrate the tumor microenvironment thereby enhancing cancer growth and metastasis. Perineural invasion, a process by which cancer cells invade the surrounding nerves, provides an alternative route for metastasis and generation of tumor-related pain. Moreover, central and sympathetic nervous system dysfunctions and psychological stress-induced hormone network disorders may influence the malignant progression of cancer through multiple mechanisms. This reciprocal interaction between nerves and cancer cells provides novel insights into the cellular and molecular bases of tumorigenesis. In addition, they point to the potential utility of anti-neurogenic therapies. This review describes the evolving cross-talk between nerves and cancer cells, thus uncovers potential therapeutic targets for cancer.

Multiplex coherent anti-Stokes Raman scattering microspectroscopy detection of lipid droplets in cancer cells expressing TrkB

For many years, scientists have been looking for specific biomarkers associated with cancer cells for diagnosis purposes. These biomarkers mainly consist of proteins located at the cell surface (e.g. the TrkB receptor) whose activation is associated with specific metabolic modifications. Identification of these metabolic changes usually requires cell fixation and specific dye staining. MCARS microspectroscopy is a label-free, non-toxic, and minimally invasive method allowing to perform analyses of live cells and tissues. We used this method to follow the formation of lipid droplets in three colorectal cancer cell lines expressing TrkB. MCARS images of cells generated from signal integration of CH₂ stretching modes allow to discriminate between lipid accumulation in the endoplasmic reticulum and the formation of cytoplasmic lipid droplets. We found that the number of the latter was related to the TrkB expression level. This result was confirmed thanks to the creation of a HEK cell line which over-expresses TrkB. We demonstrated that BDNF-induced TrkB activation leads to the formation of cytoplasmic lipid droplets, which can be abolished by K252a, an inhibitor of TrkB. So, MCARS microspectroscopy proved useful in characterizing cancer cells displaying an aberrant lipid metabolism.

LMP1 promotes nasopharyngeal carcinoma metastasis through NTRK2-mediated anoikis resistance

Anoikis resistance is an important mechanism that mediates tumor metastasis. Studies have found that Epstein-Barr virus (EBV)-encoded latent membrane protein 1 (LMP1) promotes the occurrence, development, and metastasis of nasopharyngeal carcinoma (NPC). However, the related mechanism, especially whether LMP1 is involved in NPC metastasis through anoikis resistance, has not yet been elucidated. In present study, we showed that LMP1 enhanced the ability of NPC cells to resist anoikis by upregulating neurotrophic tyrosine kinase receptor type 2 (NTRK2 or TrkB) expression through NF-κB signaling and promoted the migration and invasion of NPC cells. After knockdown of NTRK2, the p-ERK and p-AKT in NPC cells were inhibited, and twist expression was further reduced, resulting in upregulation of E-cadherin expression and downregulation of vimentin expression. Subsequently, the results of a xenograft experiment showed that inhibiting NTRK2 could reduce LMP1-mediated NPC metastasis in vivo. In summary, these findings demonstrated that EBV-LMP1 upregulates twist expression to promote epithelial-mesenchymal transition (EMT) through the NTRK2-mediated AKT/ERK signaling pathway, thus mediating anoikis resistance and promoting NPC metastasis. These data will provide new molecular markers and potential targets for NPC metastasis.

MiR-489-3p inhibits cell proliferation, migration, and invasion, and induces apoptosis, by targeting the BDNF-mediated PI3K/AKT pathway in glioblastoma

Among astrocyte tumors, glioblastoma (GBM) is the most malignant glioma, highly aggressive and invasive, with extremely poor prognosis. Previous research has reported that microRNAs (miRNAs) participate in the progression of many cancers. Thus, this study aimed to explore the role and the underlying mechanisms of microRNA (miR)-489-3p in GBM progression. The expression of miR-489-3p and brain-derived neurotrophic factor (BDNF) mRNA was measured by quantitative real-time polymerase chain reaction. Western blot analysis was used to detect BDNF protein and the PI3K/AKT pathway-related protein. Cell proliferation, apoptosis, migration, and invasion were analyzed using CKK-8 assay, flow cytometry, and transwell assay, respectively. The interaction between BDNF and miR-489-3p was explored by luciferase reporter assay and RNA immunoprecipitation (RIP) assay. MiR-489-3p was down-regulated and BDNF was up-regulated in GBM tissues and cells. MiR-489-3p re-expression or BDNF knockdown inhibited GBM cell proliferation, migration, and invasion, and promoted apoptosis. BDNF was a target of miR-489-3p, and BDNF up-regulation reversed the effects of miR-489-3p on GBM cells. The protein levels of p-AKT and p-PI3K were notably reduced in GBM cells by overexpression of miR-489-3p, but were rescued following BDNF up-regulation. Therefore, miR-489-3p inhibited proliferation, migration, and invasion, and induced apoptosis, by targeting the BDNF-mediated PI3K/AKT pathway in GBM, providing new strategies for clinical treatment of GBM.

Effect of catalpol on behavior and neurodevelopment in an ADHD rat model

Studies suggest that abnormal neurodevelopment of prefrontal striatal circuits is implicated in the pathogenesis of attention deficit hyperactivity disorder (ADHD). In the present study, we investigated the effect of catalpol, an active ingredient of Rehmanniae radix preparata, which is the most frequently used Chinese medicinal herb for the treatment of ADHD, on behavior and neurodevelopment in spontaneously hypertensive rats (SHR). SHR were divided into SHR group (vehicle, i.g.), methylphenidate (MPH) group (2 mg/kg/day, i.g.), and catalpol group (50 mg/kg/day i.g.), and Wistar-Kyoto (WKY) rats were used as control group (vehicle, i.g.). Open Field Test (OFT) and Morris water maze (MWM) test were performed to assess the effect of catalpol on behavior. Results revealed that both catalpol and MPH treatment decreased average speed, time spent in the central area, rearing times, and central area visits, increased the immobility time of SHR in OFT, and increased number of visits to the annulus, and time spent in target quadrant in the MWM test. Hematoxylin and eosin (H&E) staining showed that catalpol reduced irregular neuronal arrangement, ruptured nuclear membranes, and resulted in disappearance of the nucleolus in the prefrontal cortex (PFC) and striatum of SHR. Moreover, immuno-fluorescent staining of NeuN and myelin basic protein (MBP) indicated that catalpol ameliorated neuronal loss and contributed to myelination. Finally, western blot and immunostaining analysis suggested that several regulatory proteins involved in PFC development were up-regulated by catalpol treatment, such as brain-derived neurotrophic factor (BDNF), cyclin-dependent kinase 5 (Cdk5), p35, fibroblast growth factor (FGF) 21 and its receptor (FGFR)1. Taken together, catalpol can effectively ameliorate hyperactive and impulsive behavior, improve spatial learning and memory in SHR, likely through the neurodevelopmental pathways. Nonetheless, whether catalpol could attenuate inattention in SHR and the pathway by which catalpol reduces neuronal loss remain to be further studied.

miR-210 inhibits cell migration and invasion by targeting the brain-derived neurotrophic factor in glioblastoma

Recently, there is increasing evidence that microRNAs are related to the development, diagnosis, treatment, and prognosis of glioblastoma. microRNA-210 (miR-210) had been identified in many human cancers, but the specific function of miR-210 remains unclear in glioblastoma. The present study mainly focused on exploring its biological role and potential molecular mechanisms in glioblastoma. We found that miR-210 expression was decreased in glioblastoma, and downregulation of miR-210 was related to worse prognosis in glioblastoma patients. In addition, miR-210 overexpression inhibited the migration and invasion of human glioblastoma cells. At the same time, we found that miR-210 directly targets the brain-derived neurotrophic factor (BDNF) and reduces BDNF expression level. Consistently, BDNF silencing had the same effects as miR-210 overexpression in glioblastoma, and upregulation of BDNF counteracted the inhibitory effect of miR-210 in glioblastoma. In conclusion, miR-210 suppressed the migration and invasion of glioblastoma cells by targeting BDNF.

A selective c-Met and Trks inhibitor Indo5 suppresses hepatocellular carcinoma growth

Background

Human hepatocellular carcinoma (HCC) lacks effective curative therapy and there is an urgent need to develop a novel molecular-targeted therapy for HCC. Selective tyrosine kinase inhibitors have shown promise in treating cancers including HCC. Tyrosine kinases c-Met and Trks are potential therapeutic targets of HCC and strategies to interrupt c-Met and Trks cross-signaling may result in increased effects on HCC inhibition.

Methods

The effects of Indo5 on c-Met and Trks activity were determined with in vitro kinase activity assay, cell-based signaling pathway activation, and kinases-driven cell transformation. The in vivo anti-tumor activity was determined with xenograft mice and liver orthotopic mice models. The co-expression of c-Met and TrkB in 180 pairs of HCC and adjacent normal tissues were detected using immunohistochemical staining.

Results

Indo5, a novel lead compound displayed biochemical potency against both c-Met and Trks with selectivity over 13 human kinases. Indo5 abrogated HGF-induced c-Met signaling activation and BDNF/NGF-induced Trks signal activation, c-Met or TrkB-mediated cell transformation and migration. Furthermore, Indo5 significantly decreased the growth of HCC cells in xenograft mice and improved the survival of mice with liver orthotopic tumors. In addition, co-expression of c-Met and TrkB in HCC patients was a predictor of poor prognosis, and combined inhibition of c-Met and TrkB exerted a synergistic suppressive effect on HCC.

Conclusions

These findings indicate that Indo5 is associated with marked suppression of c-Met and Trks co-expressing HCC, supporting its clinical development as an antitumor treatment for HCC patients with co-active c-Met and Trks signaling.

Electronic supplementary material

The online version of this article (10.1186/s13046-019-1104-4) contains supplementary material, which is available to authorized users.

A Small Molecule TrkB Neurotrophin Receptor Partial Agonist as Possible Treatment for Experimental Nonarteritic Anterior Ischemic Optic Neuropathy

PURPOSE

Brain-derived neurotrophic factor (BDNF) and activation of its high affinity receptor tropomyosin kinase (Trk) B promote retinal ganglion cells (RGCs) survival following injury. In this study, we tested the effects of LM22A-4, a small molecule TrkB receptor-specific partial agonist, on RGC survival in vitro and in experimental nonarteritic anterior ischemic optic neuropathy (AION), the most common acute optic neuropathy in those older than 50 years.

METHODS

We assessed drug effects on immunopanned, cultured RGCs and calculated RGC survival and assessed TrkB receptor activation by mitogen-activated protein (MAP) kinase translocation. To assess effects in vivo, we induced murine AION and treated the animals with one intravitreal injection and three-week systemic treatment. We measured drug effects using serial spectral-domain optical coherence tomography (OCT) and quantified retinal Brn3A+ RGC density three weeks after ischemia.

RESULTS

In vitro, LM22A-4 significantly increased the survival of cultured RGCs at day 2 (95% CI control: 8.4-13.6; LM22A-4: 23.7-30.3; BDNF: 24.3-29.9; P ≤ 0.0001), similar to the effect of the endogenous TrkB receptor ligand BDNF. There was also significant nuclear and cytoplasmic translocation of MAP kinase (95% CI control: 0.9-6.8; LM22A-4: 38.8-84.4; BDNF: 64.0-93.0; P = 0.0002), a known downstream event of TrkB receptor activation. Following AION, LM22A-4 treatment led to significant preservation of the ganglion cell complex (95% CI: AION-PBS: 66.8-70.7%; AION-LM22A-4: 70.0-73.1; P = 0.03) and total retinal thickness (95% CI: AION-PBS: 185-196%; AION-LM22A-4: 195-203; P = 0.002) as measured by OCT compared with non-treated eyes. There was also significant rescue of the Brn3A+ RGC density on morphometric analysis of whole mount retinae (95% CI control: 2360-2629; AION-PBS: 1647-2008 cells/mm2; AION-LM22A-4: 1958-2216 cells/mm2; P = 0.02).

CONCLUSIONS

TrkB receptor partial agonist LM22A-4 promoted survival of cultured RGCs in vitro by TrkB receptor activation, and treatment in vivo led to increased survival of RGCs after optic nerve ischemia, providing support that LM22A-4 may be effective therapy to treat ischemic optic neuropathy.

ABBREVIATIONS

AION: anterior ischemic optic neuropathy, BDNF: Brain-derived neurotrophic factor, GCC: ganglion cell complex, MAP: mitogen-activated protein, OCT: spectral-domain optical coherence tomography, OD: right eye, ON: optic nerve, ONH: optic nerve head, OS: left eye, RGC: retinal ganglion cell; Trk: tropomyosin kinase.

Proliferative role of BDNF/TrkB signaling is associated with anoikis resistance in cervical cancer

Brain-derived neurotrophic factor (BDNF) is known as one of the members of the neurotropin family. BDNF-induced activation of its receptor tyrosine kinase B (TrkB) is associated with anoikis tolerance, tumor progression and poor prognosis in many types of malignancy. However, to the best of our knowledge, there are no reports describing the contribution of the BDNF/TrkB axis to cervical cancer. BDNF and TrKB expression in cervical cancer (CC) tissues and adjacent normal tissues from 87 patients were analyzed by immunohistochemistry, western blot analysis and quantitative PCR assays and the results showed that they were significantly higher in cancer tissues than that in normal adjacent tissues, respectively. Higher expression rates of BDNF and TrKB were observed in stage IIB or higher and BDNF expression was positively associated with lymph node metastasis. Notably, a high expression of TrKB may be contributed to poor survival time, which confirmed by Kaplan-Meier analysis. Compared to the corresponding CC cell lines, HeLa, SiHa, CASKI, C4-1 and C-33a, BDNF and TrKB expression was enhanced in anoikis-like apoptotic tolerance (AAT), a cell model established from cervical cancer cell lines. AAT cells showed a higher proliferation activity compared with CC cell lines, which was confirmed by a shorter G0/G1 phase, elevated cyclin A, cyclin D1 and c-myc, decreased caspase-3 and Bax, and increased Bcl-2. By contrast, the knockdown of TrKB expression reversed these changes in AAT cells, induced G0/G1 arrest and suppressed proliferation activity. The results of the present study show that PI3K/Akt signaling is involved in the BDNF/TrKB-induced proliferation of AAT cells in cervical cancer. These findings indicate that BDNF/TrKB pathway is a potential target for the treatment of cervical cancer.

Midkine promotes hepatocellular carcinoma metastasis by elevating anoikis resistance of circulating tumor cells

Midkine is overexpressed in hepatocellular carcinoma (HCC) and plays a role in tumor progression, but less is known about its role in resistance of circulating tumor cells (CTCs) to anoikis which leading to recurrence and metastasis. The aim of the present study was to analyze whether midkine was associated with HCC progression with anoikis resistance. We found that cultured HCC cells were more resistant to anoikis, which paralleled midkine expression, and midkine treatment significantly inhibited anoikis in a dose-dependent manner. Furthermore, in in vitro and in vivo assays, knockdown of midkine resulted in significant sensitivity to anoikis, decreased cell survival and significantly decreased tumor occurrence rate. Patients with midkine-elevated HCC had higher CTC counts and less apoptotic CTCs, as well as significantly higher recurrence rate and shorter recurrence-free interval. To understand the molecular mechanism underlying the midkine with HCC progression, we performed in vitro and in vivo studies. We found that midkine plays an important role in enhancement of HCC cell resistance to anoikis, thereby promoting subsequent metastasis. Activation of PI3K/Akt/NF-κB/TrkB signaling by midkine-activated anaplastic lymphomakinase (ALK) is responsible for anoikis resistance.

Nervous system and primary liver cancer

Recent advances have found irregular activities of the nervous system-associated factors in the development and progression of primary liver cancer. These factors contributed in the regulation of migration, proliferation, and apoptosis of cancer cells, and took a role in modulating invasion, metastasis, and recurrence after curative treatment. In clinical researches, neural-related factors were found to be significant prognostic factors, suggesting that the interactions between nervous system and primary liver cancer are indispensable in understanding underlying biological mechanisms. Herein, we reviewed up-to-date achievements in this area and the future perspectives of the interactions between the nervous system and primary liver cancer.

MicroRNA-10a-5p suppresses cancer proliferation and division in human cervical cancer by targeting BDNF

The aim of the present study was to investigate the effect and mechanism of microRNA (miR)-10a-5p in human cervical cancer. The expression level of miR-10-5p in cervical cancer lines was assessed using reverse transcription-quantitative polymerase chain reaction (RT-qPCR). In cervical cancer HeLa and SiHa cells, miR-10-5p was ectopically overexpressed by lentiviral transduction. Brain-derived neurotrophic factor (BDNF) was then overexpressed in HeLa and SiHa cells to evaluate its selective effect on miR-10-5p in cervical cancer modulation. The targeting of miR-10-5p on its downstream gene, BDNF, was evaluated using RT-qPCR and western blot analysis. Cervical cancer cell viability and cell cycle was evaluated using an MTT assay and flow cytometry, respectively. The results indicated that miR-10-5p expression was significantly lower in cervical cancer cell lines compared with normal cells (P<0.05). Ectopic overexpression of miR-10-5p significantly inhibited cancer cell viability and induced cell cycle arrest in HeLa and SiHa cells (both P<0.05). miR-10-5p overexpression significantly reduced BDNF gene expression (P<0.05) and also reduced BDNF protein levels in cervical cancer cells compared with the control. In conclusion, the current study indicated that miR-10-5p is a cervical cancer suppressor, which regulates BDNF expression in cervical cancer.

Long noncoding nature brain-derived neurotrophic factor antisense is associated with poor prognosis and functional regulation in non-small cell lung caner

In this study, we evaluated the prognostic potential and functional regulation of human nature antisense, brain-derived neurotrophic factor antisense, in non-small cell lung cancer. Non-small cell lung cancer carcinoma and adjacent non-carcinoma lung tissues were extracted from 151 patients. Their endogenous brain-derived neurotrophic factor antisense expression levels were compared by quantitative reverse transcription polymerase chain reaction. Clinical relevance between endogenous brain-derived neurotrophic factor antisense expression level and patients' clinicopathological variances or overall survival was analyzed. The potential of brain-derived neurotrophic factor antisense being an independent prognostic factor in non-small cell lung cancer was also evaluated. In in vitro non-small cell lung cancer cell lines, brain-derived neurotrophic factor antisense was upregulated through forced overexpression. The effects of brain-derived neurotrophic factor antisense upregulation on non-small cell lung cancer in vitro survival, proliferation, and migration were evaluated by viability, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide, and transwell assays. Brain-derived neurotrophic factor antisense is lowly expressed in non-small cell lung cancer carcinoma tissues and further downregulated in late-stage carcinomas. Brain-derived neurotrophic factor antisense downregulation was closely associated with non-small cell lung cancer patients' advanced tumor, lymph node, metastasis stage, and positive status of lymph node metastasis, and confirmed to be an independent prognostic factor for patients' poor overall survival. In non-small cell lung cancer A549 and H226 cell lines, forced overexpression of brain-derived neurotrophic factor antisense did not alter cancer cell viability but had significantly tumor suppressive effect in inhibiting in vitro non-small cell lung cancer proliferation and migration. Endogenous brain-derived neurotrophic factor antisense in non-small cell lung cancer carcinoma could be a potential biomarker for predicting patients' prognosis. Overexpressing brain-derived neurotrophic factor antisense may also have a therapeutic potential in inhibiting non-small cell lung cancer tumor growth.

Therapeutic Potentials of BDNF/TrkB in Breast Cancer; Current Status and Perspectives

Brain-derived neurotrophic factor (BDNF) is a potent neurotrophic factor that has been shown to stimulate breast cancer cell growth and metastasis via tyrosine kinase receptors TrkA, TrkB, and the p75^NTR death receptor. The aberrant activation of BDNF/TrkB pathways can modulate several signaling pathways, including Akt/PI3K, Jak/STAT, NF-kB, UPAR/UPA, Wnt/β-catenin, and VEGF pathways as well as the ER receptor. Several microRNAs have been identified that are involved in the modulation of BDNF/TrkB pathways. These include miR-206, miR-204, MiR-200a/c, MiR-210, MiR-134, and MiR-191; and these may be of value as prognostic and predictive biomarkers for detecting patients at high risk of developing breast cancer. It has been also been demonstrated that a high expression of genes involved in the BDNF pathway in breast cancer is associated with poor clinical outcome and reduced survival of patients. Several approaches have been developed for targeting this pathway, for example TKr inhibitors (AZD6918, CEP-701) and RNA interference. The aim of the current review was to provide an overview of the role of BDNF/TrkB pathways in the pathogenesis of breast cancer and its value as a potential therapeutic target. J. Cell. Biochem. 118: 2502-2515, 2017. © 2017 Wiley Periodicals, Inc.

Nardostachys jatamansi Targets BDNF-TrkB to Alleviate Ketamine-Induced Schizophrenia-Like Symptoms in Rats

OBJECTIVE

Schizophrenia, a common neurological disorder appearing in the late teens or early adulthood, is characterized by disorganized thinking, behaviour, and perception of emotions. Aberrant N-methyl-D-aspartate (NMDA) receptor-mediated synaptic plasticity is a major pathological event here due to dysfunction of dopamine and glutamate transmission at NMDA receptors. De-regulated brain-derived neurotrophic factor (BDNF), i.e., its signalling through the tropomyosin receptor kinase B (TrkB) receptor, is a major feature of schizophrenia. With recent global awareness of traditional plant medicines in reducing side effects, the aim of our study was to evaluate the efficacy of the ethanolic root extract of a herb belonging to the Valerianacea family, Nardostachys jatamansi, against ketamine-induced schizophrenia-like model in rats.

METHODS

The effect of the N. jatamansi drug (oral dosage of 500 mg/kg body weight for 14 days) in ketamine-administered male Wistar albino rats (30 mg/kg body weight for 5 days) on modulating behaviour and the level of neurotransmitters like dopamine and glutamate was studied in whole-brain homogenates, and its influence on BDNF and TrkB levels in 2 relevant brain regions, the hippocampus and prefrontal cortex, was assessed.

RESULTS

We observed that N. jatamansi treatment exhibited encouraging results in the modulation of ketamine-induced schizophrenia-like behaviours, principally the positive symptoms. Our drug both significantly upregulated the glutamate level and downregulated the dopamine level in whole-brain homogenates and retained the normal levels of BDNF (in the hippocampus but not in the prefrontal cortex) and TrkB (in both hippocampus and prefrontal cortex) induced by ketamine in rats.

CONCLUSION

These findings suggest a neuroprotective effect of the ethanolic root extract of N. jatamansi against ketamine-induced schizophrenia-like symptoms in rats; possibly, regarding its effect on TrkB signalling. Further research is warranted in the treatment of schizophrenic symptoms.

siRNA-mediated inhibition of endogenous brain‑derived neurotrophic factor gene modulates the biological behavior of HeLa cells

Brain-derived neurotrophic factor (BDNF) is expressed in a number of neural and non-neuronal tumors. The present study investigated the effect of endogenous BDNF on the biological behavior of cervix cancer cells using small interfering RNA (siRNA). HeLa, a cervix cancer cell line with high expression of BDNF, was used as a living model to screen out the effective sequences of short hairpin RNA of the BDNF gene, and the effects of RNA interference on proliferation, apoptosis, migration and invasion of these cells were evaluated. Among the 4 siRNAs examined, siRNA1 caused a 99% reduction in the relative BDNF mRNA level, while a 58% decrease in the relative BDNF protein level (p<0.01) was noted, and thus this siRNA was selected as the most efficient for use in the present study. In subsequent experiments, MTT assay revealed that BDNF silencing caused marked inhibition of HeLa cell proliferation while Hoechst 33258 staining assay demonstrated apoptosis-related changes in cell morphology. Downregulation of BDNF expression induced cell cycle arrest in the G1 phase as shown by flow cytometry. As indicated by Transwell migration and invasion assays, downregulation of BDNF expression suppressed the migratory and invasive capabilities of the HeLa cells. Together, our data revealed that BDNF modulates the proliferation, apoptosis, migratory and invasive capabilities of HeLa cells. BDNF siRNA may represent a novel therapy or drug target for preventing the tumorigenesis of cervical cancer.

PI3K and MAPK pathways mediate the BDNF/TrkB-increased metastasis in neuroblastoma

Brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor TrkB have been reported to be associated with poor prognosis in neuroblastoma (NB) patients. Our previous studies indicated that BDNF activation of TrkB induces chemo-resistance through activation of phosphoinositide-3-kinase (PI3K)/Akt pathway. In this study, we investigated the role of BDNF/TrkB on metastasis in NB. A tetracycline-regulated TrkB-expressing NB cell line (TB3) was used. Scratch wound healing assay, Boyden chamber migration, and invasion assays were performed to study the migration and invasion of TB3 cells. A tumor xenograft model using SCID-Beige mice was utilized to detect the metastasis of NB tumors in vivo. Inhibitors of PI3K, MAPK, Akt, and mTOR were used. Western blotting was performed to study the expressions of P-Akt, P-Erk, and P-mTOR. Our results showed that in TrkB-expressing NB cells, BDNF treatment significantly increased gap closing (P < 0.01) in scratch wound healing assay, also significantly enhanced the numbers of migrating cells (P < 0.01) and invading cells (P < 0.01) in the Boyden chamber migration and invasion assays. In vivo, NB distant metastases were significantly increased in mice with TrkB-expressing xenograft tumors compared to those with non-TrkB-expressing tumors (P < 0.05). Pre-treatment with any of the inhibitors for PI3K (LY294002), MAPK (PD98059), Akt (perifosine), or mTOR (rapamycin) blocked the BDNF/TrkB-induced increases of cell migration and invasion in TB3 cells, and also blocked the BDNF/TrkB-induced expressions of P-Akt, P-Erk, and P-mTOR. These data indicated that BDNF/TrkB increased metastasis in NB via PI3K/Akt/mTOR and MAPK pathways, and BDNF/TrkB and the downstream targets may be potential targets for the treatment of NB metastasis.

Expression and clinical significance of TrkB in sinonasal squamous cell carcinoma: a pilot study

Previous studies have confirmed that tropomyosin-related kinase B (TrkB) plays a critical role in the occurrence, development, and metastasis of many kinds of malignant tumour. More recently, TrkB was found to be overexpressed in head and neck squamous cell carcinoma (SCC) and to be involved in multistep tumour progression. In this study, the expression of TrkB was investigated in 27 cases of sinonasal SCC using an immunohistochemical method. The clinical significance and possible role of TrkB as a prognostic marker in these tumours was also explored. The results showed that TrkB was overexpressed in all cases of sinonasal SCC. A high level of expression of TrkB was significantly related with poor-to-moderate differentiation of SCC (P=0.026), high clinical stage (P=0.023), and the presence of local recurrence (P=0.004). Analysis by Kaplan-Meier method indicated that patients with high levels of TrkB expression had shorter overall survival (P=0.006) and disease-free survival (P=0.018). Multivariate analysis revealed that the level of TrkB expression was an independent prognostic factor for both overall and disease-free survival (P=0.019 and P=0.048, respectively). These data suggest that the overexpression of TrkB may play a significant role in sinonasal SCC and that TrkB may be used as a potential prognostic marker for the clinical outcome.

More expression of BDNF associates with lung squamous cell carcinoma and is critical to the proliferation and invasion of lung cancer cells

Background

Brain-derived neurotrophic factor (BDNF) has been reported to promote tumorigenesis and progression in several human malignancies. The purpose of this study was to explore the function of BDNF in lung squamous cell carcinoma (SCC) and adenocarcinoma (ADC).

Methods

The expression of BDNF was examined in 110 samples of lung SCC and ADC by immunohistochemistry. The protein level of BDNF was examined in 25 lung SCC or ADC samples and paired non-tumors by western blot. BDNF expression was also evaluated in human bronchial epithelial cells (HBE) and 4 lung cancer cell lines using western blot. Three BDNF mRNA variants containing exons IV, VI and IX were evaluated in HBE, two SCC (SK, LK2) and two ADC (A549, LTE) cell lines by RT-PCR. The expression and secretion of BDNF were also determined in cells using western blot and ELISA. Then the shRNA specific for BDNF was transfected into LK2 or A549 cells to further elucidate the BDNF knockdown on cell proliferation, apoptosis and invasion, which were confirmed by MTT, flow cytometry and transwell examinations.

Results

71.8 % (79 out of 110) of lung SCC and ADC samples were detected positive BDNF, and high expression of BDNF was significantly correlated with histological type and T stage. Compared with non-tumorous counterparts, BDNF was apparently overexpressed in SCC and ADC tissues. In cell studies, the extensive expression and secretion of BDNF were demonstrated in lung cancer cells compared with HBE cells. Interestingly, the expressions of BDNF mRNA variant IV and VI were identical in all cells examined. However, more expression of BDNF mRNA variant IX was found in SK and LK2 cells. The apoptotic cells were increased, and the cell proliferation and invasion were both attenuated once the expression of BDNF was inhibited. When retreated by rhBDNF, BDNF knockdown cells showed less apoptotic or more proliferative and invasive.

Conclusions

Our data show that BDNF probably facilitates the tumorigenesis of lung SCC and ADC. The expression of BDNF mRNA variant IX is probably more helpful to the upregulation of BDNF in SCC, and intervening the production of BDNF could be a possible strategy to lung cancer therapy.

Brain-derived neurotrophic factor regulates cell motility in human colon cancer

Brain-derived neurotrophic factor (BDNF) is a potent neurotrophic factor that has been shown to affect cancer cell metastasis and migration. In the present study, we investigated the mechanisms of BDNF-induced cell migration in colon cancer cells. The migratory activities of two colon cancer cell lines, HCT116 and SW480, were found to be increased in the presence of human BDNF. Heme oxygenase-1 (HO)-1 is known to be involved in the development and progression of tumors. However, the molecular mechanisms that underlie HO-1 in the regulation of colon cancer cell migration remain unclear. Expression of HO-1 protein and mRNA increased in response to BDNF stimulation. The BDNF-induced increase in cell migration was antagonized by a HO-1 inhibitor and HO-1 siRNA. Furthermore, the expression of vascular endothelial growth factor (VEGF) also increased in response to BDNF stimulation, as did VEGF mRNA expression and transcriptional activity. The increase in BDNF-induced cancer cell migration was antagonized by a VEGF-neutralizing antibody. Moreover, transfection with HO-1 siRNA effectively reduced the increased VEGF expression induced by BDNF. The BDNF-induced cell migration was regulated by the ERK, p38, and Akt signaling pathways. Furthermore, BDNF-increased HO-1 and VEGF promoter transcriptional activity were inhibited by ERK, p38, and AKT pharmacological inhibitors and dominant-negative mutants in colon cancer cells. These results indicate that BDNF increases the migration of colon cancer cells by regulating VEGF/HO-1 activation through the ERK, p38, and PI3K/Akt signaling pathways. The results of this study may provide a relevant contribution to our understanding of the molecular mechanisms by which BDNF promotes colon cancer cell motility.

Hypoxia inducible factor-1alpha mediates protection of DL-3-n-butylphthalide in brain microvascular endothelial cells against oxygen glucose deprivation-induced injury

Studies have demonstrated that DL-3-n-butylphthalide can significantly alleviate oxygen glucose deprivation-induced injury of human umbilical vein endothelial cells at least partly associated with its enhancement on oxygen glucose deprivation -induced hypoxia inducible factor-1α expression. In this study, we hypothesized that DL-3-n-butylphthalide can protect against oxygen glucose deprivation-induced injury of newborn rat brain microvascular endothelial cells by means of upregulating hypoxia inducible factor-1α expression. MTT assay and Hoechst staining results showed that DL-3-n-butylphthalide protected brain microvascular endothelial cells against oxygen glucose deprivation-induced injury in a dose-dependent manner. Western blot and immunofluorescent staining results further confirmed that the protective effect was related to upregulation of hypoxia inducible factor-1α. Real-time RT-PCR reaction results showed that DL-3-n-butylphthalide reduced apoptosis by inhibiting downregulation of pro-apoptotic gene caspase-3 mRNA expression and upregulation of apoptosis-executive protease bcl-2 mRNA expression; however, DL-3-n-butylphthalide had no protective effects on brain microvascular endothelial cells after knockdown of hypoxia inducible factor-1α by small interfering RNA. These findings suggest that DL-3-n-butylphthalide can protect brain microvascular endothelial cells against oxygen glucose deprivation-induced injury by upregulating bcl-2 expression and downregulating caspase-3 expression though hypoxia inducible factor-1α pathway.

TrkB inhibition by GNF-4256 slows growth and enhances chemotherapeutic efficacy in neuroblastoma xenografts

PURPOSE

Neuroblastoma (NB) is one of the most common and deadly pediatric solid tumors. NB is characterized by clinical heterogeneity, from spontaneous regression to relentless progression despite intensive multimodality therapy. There is compelling evidence that members of the tropomyosin receptor kinase (Trk) family play important roles in these disparate clinical behaviors. Indeed, TrkB and its ligand, brain-derived neurotrophic factor (BDNF), are expressed in 50-60 % of high-risk NBs. The BDNF/TrkB autocrine pathway enhances survival, invasion, metastasis, angiogenesis and drug resistance.

METHODS

We tested a novel pan-Trk inhibitor, GNF-4256 (Genomics Institute of the Novartis Research Foundation), in vitro and in vivo in a nu/nu athymic xenograft mouse model to determine its efficacy in inhibiting the growth of TrkB-expressing human NB cells (SY5Y-TrkB). Additionally, we assessed the ability of GNF-4256 to enhance NB cell growth inhibition in vitro and in vivo, when combined with conventional chemotherapeutic agents, irinotecan and temozolomide (Irino-TMZ).

RESULTS

GNF-4256 inhibits TrkB phosphorylation and the in vitro growth of TrkB-expressing NBs in a dose-dependent manner, with an IC₅₀ around 7 and 50 nM, respectively. Furthermore, GNF-4256 inhibits the growth of NB xenografts as a single agent (p < 0.0001 for mice treated at 40 or 100 mg/kg BID, compared to controls), and it significantly enhances the antitumor efficacy of irinotecan plus temozolomide (Irino-TMZ, p < 0.0071 compared to Irino-TMZ alone).

CONCLUSIONS

Our data suggest that GNF-4256 is a potent and specific Trk inhibitor capable of significantly slowing SY5Y-TrkB growth, both in vitro and in vivo. More importantly, the addition of GNF-4256 significantly enhanced the antitumor efficacy of Irino-TMZ, as measured by in vitro and in vivo growth inhibition and increased event-free survival in a mouse xenograft model, without additional toxicity. These data strongly suggest that inhibition of TrkB with GNF-4256 can enhance the efficacy of current chemotherapeutic treatment for recurrent/refractory high-risk NBs with minimal or no additional toxicity.

BDNF mediated TrkB activation contributes to the EMT progression and the poor prognosis in human salivary adenoid cystic carcinoma

BACKGROUND

The aim of the present study was to investigate whether the expression of Brain-Derived Neurotrophic Factor (BDNF) and its receptor Tropomyosin-related kinase B (TrkB) is correlated with the clinical progression of salivary adenoid cystic carcinoma (SACC) and whether the BDNF/TrkB axis is associated with the induction of epithelial-mesenchymal transition (EMT) in SACC cells.

METHOD

The expression of BDNF, TrkB, and E-cadherin (an EMT biomarker) in 76 primary SACC specimens and 20 normal salivary gland tissues was analyzed by immunohistochemistry. Additionally, the expression of BDNF, TrkB, and E-cadherin in SACC cell lines (SACC-83 and SACC-LM) was analyzed by RT-PCR and Western blotting. The biological role of the BDNF/TrkB axis in the EMT progression of SACC was evaluated after treatment with increased levels of BDNF and by inhibiting TrkB activity in SACC-83 cell line. The progression of SACC cells through EMT was assessed by RT-PCR, Western blotting, photography, migration and invasion assays.

RESULTS

Elevated expression of TrkB (92.1%) and BDNF (89.5%), and downregulated expression of E-cadherin (47.4%) was found in SACC specimens, which was significantly correlated with the invasion and metastasis in SACC (P<0.05). The high expression of TrkB and the low expression of E-cadherin was significantly correlated with the poor prognosis of SACC patients (P<0.05). The expression of TrkB was inversely correlated with the expression of E-cadherin in both SACC cases and cell lines (P<0.05). Increasing BDNF levels after treatment with exogenous recombinant human BDNF (rhBDNF) at 100 ng/ml significantly promoted the activation of TrKB and the progression of EMT in SACC cells. While obstruction of TrkB by its inhibitor, k252a (100 nM), significantly inhibited the EMT progression of SACC cells.

CONCLUSIONS

These results suggest that BDNF-mediated TrkB activation contributes to the EMT progression and the poor prognosis in SACC. The present study demonstrated that the BDNF/TrkB axis promotes the migration and invasion of SACC cells via EMT in vitro. Targeting the inactivation of the BDNF/TrkB axis may be a potential strategy for the treatment of SACC.

Suppression of choriocarcinoma invasion and metastasis following blockade of BDNF/TrkB signaling

Brain-derived neurotrophic factor (BDNF) acts through its cognate receptor tyrosine kinase-B (TrkB) to regulate diverse physiological functions in reproductive and other tissues. In normal and malignant trophoblastic cells, the BDNF/TrkB signaling promotes cell growth. Due to the highly malignant nature of choriocarcinoma, we investigated possible involvement of this system in choriocarcinoma cell invasion and metastasis. We demonstrated that treatment of cultured choriocarcinoma cells, known to express both BDNF and TrkB, with a soluble TrkB ectodomain or a Trk receptor inhibitor K252a suppressed cell invasion accompanied with decreased expression of matrix metalloproteinase-2, a cell invasion marker. In vivo studies using a tumor xenograft model in athymic nude mice further showed inhibition of cell invasion from tumors to surrounding tissues following the suppression of endogenous TrkB signaling. For an in vivo model of choriocarcinoma metastasis, we performed intravenous injections of JAR cells expressing firefly luciferase into severe combined immunodeficiency (SCID) mice. Treatment with K252a inhibited metastasis of tumors to distant organs. In vivo K252a treatment also suppressed metastatic tumor growth as reflected by decreased cell proliferation and increased apoptosis and caspases-3/7 activities, together with reduced tissue levels of a tumor marker, human chorionic gonadotropin-β. In vivo suppression of TrkB signaling also led to decreased expression of angiogenic markers in metastatic tumor, including cluster of differentiation 31 and vascular endothelial growth factor A. Our findings suggested essential autocrine/paracrine roles of the BDNF/TrkB signaling system in choriocarcinoma invasion and metastasis. Inhibition of this signaling could serve as the basis to develop a novel therapy for patients with choriocarcinoma.

Comparative effectiveness of radiofrequency ablation with or without transarterial chemoembolization for hepatocellular carcinoma

The aim of this study is to compare the overall survival in patients with hepatocellular carcinoma (HCC) treated with radiofrequency ablation (RFA) and transarterial chemoembolization (TACE) versus RFA alone. All eligible studies were collected from the PubMed, the Cochrane Library, and the Embase electronic databases. The outcomes were overall survival rates. We used odds ratios to assess the strength of the association, and 95% confidence intervals give a sense of the precision of the estimate. Statistical analyses were performed by Review Manager 5.0 and Stata 11.0. A total of 19 available studies were considered in the present meta-analysis. When all groups were pooled, meta-analysis showed that RFA plus TACE significantly improved the survival rates of patients with HCC at 1, 3, and 5 years compared with RFA alone. The combination of RFA with TACE has advantages in improving overall survival rate, and provides better prognosis for HCC patients.

Biological influence of brain-derived neurotrophic factor (BDNF) on colon cancer cells

Brain-derived neurotrophic factor (BDNF) has been observed to be elevated in solid tumors including colorectal cancer. The present study aimed to investigate the effect of modulation of BDNF at the transcription level on the cellular function of colorectal cells and to increase our understanding of its biological role in human colon cancer. An investigation of a cohort of human colorectal tissues (tumor n=66; normal n=88) using quantitative PCR and immunohistochemistry demonstrated that BDNF is aberrantly expressed in human colon cancer and a significantly raised level of BDNF is associated with its stage at diagnosis. The expression profile of BDNF in human colon cancer cell lines was evaluated using RT-PCR. A set of anti-BDNF ribozymes were used to transfect colon cancer cells in order to generate BDNF knockdown cells to evaluate the effect on growth and apoptosis. BDNF gene transcripts were successfully detected in the colon cancer cell lines, Caco-2 and HRT18. BDNF knockdown in Caco-2 and HRT18 cell lines resulted in decreased rates of growth and proliferation. Analysis of apoptosis showed that cell apoptosis was increased. It is concluded that BDNF, a neurotrophic growth factor aberrantly expressed in cancers such as colon cancer, has a profound impact on the cellular behavior of colon cancer cells and that BDNF is associated with a reduction in the apoptosis of colon cancer. BDNF is therefore a potential therapeutic target in colon cancer and its effect in human colon cancer requires further investigation.

Association of BDNF and BMPR1A with clinicopathologic parameters in benign and malignant gallbladder lesions

BACKGROUND

Neurotrophic factors such as brain derived neurotrophic factor (BDNF) are synthesized in a variety of neural and non-neuronal cell types and regulate survival, proliferation and apoptosis. In addition, bone morphogenetic proteins (BMPs) inhibit the proliferation of pulmonary large carcinoma cells bone morphogenetic protein receptor, type IA (BMPR1A). Little is known about the expression of BDNF or BMPR1A in malignant gall bladder lesions. This study was to evaluate BDNF and BMPR1A expression and evaluate the clinicopathological significance in benign and malignant lesions of the gallbladder.

METHODS

The BDNF and BMPR1A expression of gallbladder adenocarcinoma, peritumoral tissues, adenoma, polyp and chronic cholecystitis were Immunohistochemically determined.

RESULTS

BDNF expression was significantly higher in gallbladder adenocarcinoma than in peritumoral tissues, adenoma, polyps and chronic cholecystitis samples. However, BMPR1A expression was significantly lower in gallbladder adenocarcinoma than in peritumoral tissues, adenomas, polyps and chronic cholecystitis tissues. The specimens with increased expression of BDNF in the benign lesions exhibited moderate- or severe-dysplasia of gallbladder epithelium. BDNF expression was significantly lower in well-differentiated adenocarcinomas with maximum tumor diameter <2 cm, no metastasis to lymph nodes, and no invasion of regional tissues compared to poorly-differentiated adenocarcinomas with maximal tumor diameter >2 cm, metastasis of lymph node, and invasiveness of regional tissues in gallbladder adenocarcinoma. BMPR1A expression were significantly higher in the well-differentiated adenocarcinoma with maximal tumor diameter <2 cm, no metastasis of lymph node, and no invasion of regional tissues compared to poorly-differentiated adenocarcinomas with maximal tumor diameter >2 cm, metastasis of lymph node, and invasiveness of regional tissues in gallbladder. Univariate Kaplan-Meier analysis indicated increased expression of BDNF or decreased expression of BMPR1A was associated with decreased disease specific survival (DSS) rates. Similarly, multivariate Cox regression analysis showed increased expression of BDNF or decreased expression of BMPR1A are independent predictors of poor DSS rates in gallbladder adenocarcinoma.

CONCLUSIONS

In gallbladder malignancies, the increased expression of BDNF and decreased expression of BMPR1A were associated with increased risk of metastasis, regional invasion and mortality. They might serve as novel indicators of gallbladder adenocarcinoma outcomes, which may prove valuable for the development of personalized therapeutic paradigms.

Biological influence of brain-derived neurotrophic factor on breast cancer cells

Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin superfamily which has been indicated in the pathophysiology of the nervous system and is important in a number of neurological and psychological conditions. Recently, BDNF was also shown to play a role in the development and progression of solid tumour myeloma. It has been reported that BDNF is aberrantly expressed in human breast cancer and that a raised level of BDNF is associated with poor clinical outcome and reduced survival. The present study investigated the role of BDNF in human breast cancer. A panel of human breast cancer cells was used and the expression profile of BDNF was evaluated using RT-PCR. We constructed a set of anti-BDNF transgenes which were used to transfect breast cancer cells in order to generate BDNF knocked down cells. The impact of BDNF knockdown on growth and apoptosis was evaluated. Statistical analysis was performed using SPSS. P<0.05 was considered statistically significant. BDNF gene transcripts were successfully detected in the breast cancer cell lines MCF-7, MDA-MB-231 and ZR75-1 MDA-MB-231 and MCF-7 wild-type cells were subject to transfection of anti-BDNF transgenes, followed by the establishment of BDNF knocked down sublines. Knockdown of BDNF in MDA-MB-231 and MCF-7 cell lines resulted in decreased rates of growth and proliferation. Analysis of apoptosis showed that cell apoptosis was increased in cells stably transfected with ribozymes for BDNF compared with the vector control. It is concluded that BDNF, a neurotrophic growth factor aberrantly expressed in cancers such as breast cancer, has a profound impact on the cellular behaviour of breast cancer cells and that BDNF is associated with a reduction of the apoptosis of breast cancer. BDNF is, therefore, a potential therapeutic target in breast cancer and its effect in human breast cancer requires further investigation.