NDRG1 Controls Gastric Cancer Migration and Invasion through Regulating MMP-9

Molecular Insight into Gastric Cancer Invasion-Current Status and Future Directions

Gastric cancer (GC) is one of the most common malignancies worldwide. There has been no efficient therapy for stage IV GC patients due to this disease's heterogeneity and dissemination ability. Despite the rapid advancement of molecular targeted therapies, such as HER2 and immune checkpoint inhibitors, survival of GC patients is still unsatisfactory because the understanding of the mechanism of GC progression is still incomplete. Invasion is the most important feature of GC metastasis, which causes poor mortality in patients. Recently, genomic research has critically deepened our knowledge of which gene products are dysregulated in invasive GC. Furthermore, the study of the interaction of GC cells with the tumor microenvironment has emerged as a principal subject in driving invasion and metastasis. These results are expected to provide a profound knowledge of how biological molecules are implicated in GC development. This review summarizes the advances in our current understanding of the molecular mechanism of GC invasion. We also highlight the future directions of the invasion therapeutics of GC. Compared to conventional therapy using protease or molecular inhibitors alone, multi-therapy targeting invasion plasticity may seem to be an assuring direction for the progression of novel strategies.

A review on the role of NDRG1 in different cancers

NDRG1 is a member of the α/β hydrolase superfamily that resides in the cytoplasm and participates in the stress responses, hormone response, cell growth, and differentiation. Several studies have pointed to the importance of NDRG1 in the carcinogenesis. This gene has been found to be up-regulated in an array of cancer types such as bladder, esophageal squamous cell carcinoma, endometrial, lung and liver cancers, but being down-regulated in other types of cancers such as colorectal, gastric and ovarian cancers. The current study summarizes the evidence on the role of NDRG1 in the carcinogenic processes in different types of tissues.

Cortactin contributes to the tumorigenesis of gastric cancer by activating ERK/MMP pathway

Gastric cancer is a malignant tumor with high mortality and high incidence. This study aims to explore the function and molecular mechanism of Cortactin on gastric cancer progression in vitro and in vivo. A bioinformatics analysis from TCGA displayed that Cortactin was highly expressed in gastric cancer samples, and patients with a high Cortactin level had a worse survival rate. Subsequently, we investigated the specific mechanism of action of A in gastric cancer by collecting patient samples for immunohistochemistry, WB, qRT-PCR, cell transfection, cell invasion and metastasis, and constructing tumor xenografts in nude mice. Overexpression of Cortactin inhibited apoptosis and enhanced cellular proliferation and mobility in AGS cells, while those activities were reversed by the knockdown of MMP2 or MMP9. Conversely, the deletion of Cortactin induced apoptosis and suppressed cell growth and metastasis in SGC7901 cells, whereas those behaviors were inhibited by overexpression of MMP2 or MMP9. Additionally, the ERK pathway was activated by Cortactin upregulation. In vivo studies presented that overexpression of Cortactin promoted tumor growth, increased Ki67 expression, and reduced caspase 3 expression, which was reversed by ERK inhibitor treatment. In conclusion, Cortactin acted as an oncogene in gastric cancer and exerted its function by ERK/MMP2/MMP9 signaling pathway.

Antimetastatic Activity of Apoptolidin A by Upregulation of N-Myc Downstream-Regulated Gene 1 Expression in Human Colorectal Cancer Cells

Colorectal cancer (CRC) is one of the most prevalent tumors with high metastatic potential; consequently, finding new drug candidates that suppress tumor metastasis is essential. Apoptolidin A is a macrocyclic lactone produced by Amycolatopsis sp. DW02G. It exhibits significant cytotoxicity against several cancer cell lines, but its effects on CRC cells remain unknown. Therefore, the present study investigated the antiproliferative and antimetastatic activities of apoptolidin A and its underlying molecular mechanisms in CRC cells. Apoptolidin A effectively inhibited CRC cell growth and colony formation. The induction of G0/G1 phase cell cycle arrest was associated with the downregulation of cyclin D1 and CDK4/6 expression. Long-term exposure to apoptolidin A also induced apoptosis as confirmed by the downregulation and upregulation of Bcl-2 and Bax expression, respectively. Moreover, apoptolidin A effectively upregulated the suppressed expression of N-Myc downstream-regulated gene 1 (NDRG1), a tumor suppressor gene, in a concentration-dependent manner in CRC cells. The antimetastatic potential of apoptolidin A was also correlated with the expression of epithelial–mesenchymal transition (EMT) biomarkers, including the upregulation of E-cadherin and downregulation of N-cadherin, vimentin, snail, and MMP9 in CRC cells. These findings suggest that apoptolidin A exerts antiproliferative and antimetastatic activities by regulating the NDRG1-activated EMT pathway in CRC cells.

NDRG1 is induced by antigen-receptor signaling but dispensable for B and T cell self-tolerance

Peripheral tolerance prevents the initiation of damaging immune responses by autoreactive lymphocytes. While tolerogenic mechanisms are tightly regulated by antigen-dependent and independent signals, downstream pathways are incompletely understood. N-myc downstream-regulated gene 1 (NDRG1), an anti-cancer therapeutic target, has previously been implicated as a CD4⁺ T cell clonal anergy factor. By RNA-sequencing, we identified Ndrg1 as the third most upregulated gene in anergic, compared to naïve follicular, B cells. Ndrg1 is upregulated by B cell receptor activation (signal one) and suppressed by co-stimulation (signal two), suggesting that NDRG1 may be important in B cell tolerance. However, though Ndrg1^-/- mice have a neurological defect mimicking NDRG1-associated Charcot-Marie-Tooth (CMT4d) disease, primary and secondary immune responses were normal. We find that B cell tolerance is maintained, and NDRG1 does not play a role in downstream responses during re-stimulation of in vivo antigen-experienced CD4⁺ T cells, demonstrating that NDGR1 is functionally redundant for lymphocyte anergy.

A phase 1b study of andecaliximab in combination with S-1 plus platinum in Japanese patients with gastric adenocarcinoma

Andecaliximab (ADX) is a monoclonal antibody that inhibits matrix metalloproteinase 9 (MMP9), an extracellular enzyme involved in matrix remodeling, tumor growth, and metastasis. In preclinical models, MMP9 inhibitors have been shown to enhance the cytotoxic effects of chemotherapeutic agents and to suppress distant metastasis. In this phase Ib, multicenter study, the safety and efficacy of ADX combined with S-1 plus cisplatin (SP) or S-1 plus oxaliplatin (SOX) as a first-line treatment were evaluated in Japanese patients with advanced gastric or gastroesophageal junction (GEJ) adenocarcinoma. ADX was administrated at a dose of 800 mg every 2 weeks for the SP cohort and 1200 mg every three weeks for the SOX cohort. As of December 2019, 16 patients were enrolled (six patients in the SP cohort and 10 patients in the SOX cohort). Peripheral sensory neuropathy (69%), anorexia (63%), nausea (56%), and decreased neutrophil counts (44%) were the most common adverse events (AEs). The grade 3 or higher AEs attributed to ADX were stomatitis and abnormal hepatic function (each one patient) in the SP cohort and decreased neutrophil counts (two patients) in the SOX cohort. The objective response rate in 11 patients with measurable target lesions was 73% (8/11), based on the investigator's evaluation. Median progression-free survival was11.9 months (90% confidence interval, 5.6-16.6), and median overall survival was not reached. In conclusion, ADX combined with S-1 plus platinum demonstrated a manageable safety profile and promising clinical activity in the first-line treatment of patients with advanced gastric or GEJ adenocarcinoma.Clinical Trial Registration information: ClinicalTrials.gov Identifier: NCT02862535 (11/08/2016) and protocol ID: GS-US-296-1884.

Multifaceted and Intricate Oncogenic Mechanisms of NDRG1 in Head and Neck Cancer Depend on Its C-Terminal 3R-Motif

N-Myc downstream-regulated 1 (NDRG1) has inconsistent oncogenic functions in various cancers. We surveyed and characterized the role of NDRG1 in head and neck cancer (HNC). Cellular methods included spheroid cell formation, clonogenic survival, cell viability, and Matrigel invasion assays. Molecular techniques included transcriptomic profiling, RT-qPCR, immunoblotting, in vitro phosphorylation, immunofluorescent staining, and confocal microscopy. Prognostic significance was assessed by Kaplan–Meier analysis. NDRG1 participated in diverse oncogenic functions in HNC cells, mainly stress response and cell motility. Notably, NDRG1 contributed to spheroid cell growth, radio-chemoresistance, and upregulation of stemness-related markers (CD44 and Twist1). NDRG1 facilitated cell migration and invasion, and was associated with modulation of the extracellular matrix molecules (fibronectin, vimentin). Characterizing the 3R-motif in NDRG1 revealed its mechanism in the differential regulation of the phenotypes. The 3R-motif displayed minimal effect on cancer stemness but was crucial for cell motility. Phosphorylating the motif by GSK3b at serine residues led to its nuclear translocation to promote motility. Clinical analyses supported the oncogenic function of NDRG1, which was overexpressed in HNC and associated with poor prognosis. The data elucidate the multifaceted and intricate mechanisms of NDRG1 in HNC. NDRG1 may be a prognostic indicator or therapeutic target for refractory HNC.

DNMT family induces down-regulation of NDRG1 via DNA methylation and clinicopathological significance in gastric cancer

BACKGROUND

Aberrant DNA methylation of tumor suppressor genes is a common event in the development and progression of gastric cancer (GC). Our previous study showed NDRG1, which could suppress cell invasion and migration, was frequently down-regulated by DNA methylation of its promoter in GC.

PURPOSE AND METHODS

To analyze the relationship between the expression and DNA methylation of NDRG1 and DNA methyltransferase (DNMT) family. We performed a comprehensive comparison analysis using 407 patients including sequencing analysis data of GC from TCGA.

RESULTS

NDRG1 was down-regulated in GC, and was negatively correlative to DNMT1 (r = -0.11, p = 0.03), DNMT3A (r = -0.10, p = 0.01), DNMT3B (r = -0.01, p = 0.88), respectively, whereas the DNA methylation of NDRG1 was positively correlative to DNMT family (DNMT1 r = 0.20, p < 0.01; DNMT3A r = 0.26, p < 0.001; DNMT3B r = 0.03, p = 0.57, respectively). NDRG1 expression was significantly inverse correlated with invasion depth (p = 0.023), but DNMT1 was significantly positive correlated with invasion depth (p = 0.049). DNMT3B was significantly correlated with the degree of tumor cell differentiation (p = 0.030). However, there was no association between the expression of DNMT3A and clinicopathological features. The KM plotter showed that NDRG1 (HR = 0.95, 95% CI [0.8-1.12], p = 0.53) and DNMT1 (HR = 1.04, 95% CI [0.88-1.23], p = 0.67) had no association with prognosis of GC patients, while, DNMT3A (p = 0.0064) and DNMT3B (p = 0.00025) displayed significantly association. But the overall survival of high expression of NDRG1 tended to be prolonged.

CONCLUSION

These data suggest that down-regulation of NDRG1expression in GC may be due to its promoter DNA methylation via DNMT family. The demethylating agent maybe a potential target drug for GC patients.

CYLD Promotes Apoptosis of Nasopharyngeal Carcinoma Cells by Regulating NDRG1

Purpose

Nasopharyngeal carcinoma (NPC) is among the most common malignancies derived from the epithelium of the nasopharynx. To date, the regulatory networks involved in NPC have not been fully identified. Previous studies revealed multiple loss-of-function mutations in NPC and specifically in cylindromatosis lysine 63 deubiquitinase (CYLD); however, the exact role of CYLD in NPC progression and its potential mechanism remains unclear.

Methods

We performed immunohistochemical (IHC) staining and real-time quantitative polymerase chain reaction (qPCR) to measure CYLD expression in NPC tissues, and Western blot was conducted to determine CYLD levels in NPC cell lines. Cell proliferation was detected by CCK8 assay and colony formation analysis, and apoptosis was determined by Annexin V/propidium iodide staining. Potential targets of CYLD were verified by co-immunoprecipitation and mass spectrometry. Xenograft assay was conducted to confirm the role of CYLD in vivo.

Results

We found that CYLD levels were significantly decreased in both NPC tissues and cell lines, and that CYLD overexpression inhibited NPC cell proliferation and promoted apoptosis. Additionally, we revealed that CYLD bound and upregulated N-Myc downstream regulated 1 (NDRG1), and that silencing NDRG1 abolished the tumor-suppressor effect of CYLD on NPC cells. Furthermore, CYLD suppressed tumor growth in xenograft mice models.

Conclusion

These results suggest CYLD as a tumor suppressor, potential biomarker for diagnosing NPC, and therapeutic target.

USP19 Enhances MMP2/MMP9-Mediated Tumorigenesis in Gastric Cancer

Background

To investigate the clinical significance of ubiquitin-specific peptidase 19 (USP19) expression in gastric cancer (GC) compared with that in normal tissues and gastric cell lines.

Methods

USP19 protein expression was analyzed in 212 paired GC samples using immunohistochemical staining. Quantitative real-time PCR (qRT-PCR) and Western blotting were used to detect the level of USP19 in gastric cell lines. The biological functions of USP19 were investigated by MTT assay, colony-forming assay, wound healing assay and gelatin zymography, and apoptotic cells were detected by immunohistochemistry assays in SGC7901 xenograft models.

Results

USP19 expression was significantly increased in GC cells and tissues, and the high level of USP19 expression was positively correlated with the Lauren’s classification and poor prognosis. Moreover, USP19 was identified as a novel independent prognostic biomarker in GC patients. Enhanced USP19 expression promoted GC cell proliferation and metastasis through reduced cleaved caspase-3 and increased MMP2/MMP9 expression and promoted enzyme activity in the study, and verified the results through The Cancer Genome Atlas (TCGA) and bioinformatic websites from the Kaplan–Meier plotter (http://kmplot.com) and GEPIA (http://gepia2.cancer-pku.cn.).

Conclusion

Our study suggests that USP19 promoted tumor progression by inducing MMP2/MMP9 expression and related enzyme activity. Hence, USP19 may be a valuable prognostic predictor for GC, and the USP19-MMP2/MMP9 axis could serve as a therapeutic target.

Hsa_circ_0003159 inhibits gastric cancer progression by regulating miR-223-3p/NDRG1 axis

Background

Abnormally expressed circular RNAs (circRNAs) are implicated in the development and treatment of gastric cancer (GC). Previous study has reported that hsa_circ_0003159 is expressed in GC. However, the role and mechanism of hsa_circ_0003159 in GC progression remain unclear.

Methods

GC tissues and normal tissues were harvested from 55 patients in this study. The levels of hsa_circ_0003159, microRNA (miR)-223-3p and N-myc downstream regulated gene 1 (NDRG1) were measured by quantitative real-time polymerase chain reaction or western blot. Cell proliferation, migration, invasion and apoptosis were determined by cell counting kit (CCK)-8, transwell assay, flow cytometry and western blot, respectively. The target association of miR-223-3p-hsa_circ_0003159 and miR-223-3p-NDRG1 was explored by dual-luciferase reporter assay. Xenograft model was established to assess the roles of hsa_circ_0003159 in GC in vivo.

Results

Hsa_circ_0003159 was lowly expressed in GC tissues and cells and mainly presented in the cytoplasm. Low expression of hsa_circ_0003159 was associated with lower overall survival and disease-free survival. Hsa_circ_0003159 overexpression inhibited proliferation, migration and invasion but induced apoptosis in GC cells. MiR-223-3p was a target of hsa_circ_0003159 and abated the effect of hsa_circ_0003159 on proliferation, migration, invasion and apoptosis in GC cells. Hsa_circ_0003159 promoted NDRG1 expression by competitively sponging miR-223-3p. Knockdown of NDRG1 reversed the suppressive effect of hsa_circ_0003159 on GC progression. Besides, hsa_circ_0003159 decreased GC cell xenograft tumor growth by regulating miR-223-3p and NDRG1.

Conclusion

Hsa_circ_0003159 suppressed proliferation, migration, invasion and xenograft tumor growth but promoted apoptosis by decreasing miR-223-3p and increasing NDRG1 in GC, indicating a novel target for treatment of GC.

Fentanyl inhibits the progression of gastric cancer through the suppression of MMP-9 via the PI3K/Akt signaling pathway

BACKGROUND

Fentanyl is a drug commonly used for perioperative and postoperative analgesia. Previous studies have confirmed that fentanyl can affect the progression of gastric cancer; however, this effect has not yet been elucidated. The purpose of our study was thus to investigate the role of fentanyl in gastric cancer and clarify its potential mechanisms.

METHODS

A CCK-8 assay was used to determine the proliferation of MGC-803 cells, while Transwell assay and wound healing assay were used to determine the invasion and migration abilities, respectively. Apoptosis and the cell cycle were assessed by flow cytometry, and the ultrastructure of the cells was examined with a transmission electron microscope. The mRNA expression levels of serine-threonine protein kinase 1 (Akt-1), matrix metalloproteinase-9 (MMP-9), and death-associated protein kinase 1 (DAPK1) were evaluated by real-time (RT) quantitative PCR. The protein expression of p-Akt, MMP-9, and caspase-9 was detected by western blot analysis. To study the interaction of fentanyl with the phosphatidylinositol-3-kinase (PI3K)/Akt/MMP-9 pathway, PI3K inhibitor (LY294002) and MMP-9 inhibitor (SB-3CT) were used to treat the MGC-803 cells.

RESULTS

Findings indicated that fentanyl inhibits the proliferation, invasion, and migration of MGC-803 cells. Specifically, fentanyl inhibits the expression of MMP-9 and enhances the expression of apoptosis-promoting factors such as caspase-9 and DAPK1 through the PI3K/Akt signaling pathway. Cell cycle arrest was observed in the G0/G1 phase. Furthermore, the inhibition of PI3K/Akt/MMP-9 by LY294002 and SB-3CT enhanced the anticancer effects of fentanyl.

CONCLUSIONS

Fentanyl inhibits the proliferation, invasion and migration of gastric cancer cells by inhibiting the PI3K/Akt/MMP-9 pathway, which could be very useful for gastric cancer treatment.

Characterization of the prognostic values of the NDRG family in gastric cancer

BACKGROUND

The N-myc downstream-regulated gene (NDRG) family, NDRG1-4, has been involved in a wide spectrum of biological functions in multiple cancers. However, their prognostic values remain sparse in gastric cancer (GC). Therefore, it is crucial to systematically investigate the prognostic values of the NDRG family in GC.

METHODS

The prognostic values of the NDRG family were evaluated by Kaplan-Meier Plotter and SurvExpress. The mRNA of the NDRG family was investigated in The Cancer Genome Atlas (TCGA). Transcription factors (TFs) and miRNAs associated with the NDRG family were predicted by NetworkAnalysis. The prognostic values of DNA methylation levels were analyzed by MethSurv. The correlation between immune cells and the NDRG family was evaluated by the Tumor Immune Estimation Resource (TIMER) database.

RESULTS

High levels of mRNA expression of NDRG2 and NDRG3 were associated with a favorable prognosis in all GCs. In HER2 ^- GC, NDRG1 was significantly associated with a poor prognosis of GC [hazard ratio (HR) = 1.65, 95% confidence interval (CI) = 1.16-2.33, p = 0.0046]. In HER2 ⁺ GC, NDRG4 showed a poor prognosis (HR = 1.4, 95% CI: 1.06-1.85, p = 0.017). NDRG4 was an independent prognostic factor in recurrence-free survival by TCGA cohort. The low-risk NDRG-signature group displayed a significantly favorable survival outcome than the high-risk group (HR = 1.76, 95% CI: 1.2-2.59, p = 0.00385). The phosphorylated protein NDRG1 (NDRG1_pT346) displayed a favorable overall survival and was significantly associated with HER2 and phosphorylated HER2. Epidermis development was the top biological process (BP) for coexpressed genes associated with NDRG1 and NDRG4, while mitotic nuclear division and mitotic cell processes were the top BPs for NDRG2 and NDRG3, respectively. Overall, 6 CpGs of NDRG1, 4 CpGs of NDRG2, 3 CpGs of NDRG3 and 24 CpGs of NDRG4 were associated with significant prognosis. CD4⁺ T-cells showed the highest correlation with NDRG4 (correlation = 0.341, p = 2.14e^-11). Furthermore, BCL6 in follicular helper T-cells (Tfh) cells showed the highest association with NDRG4 (correlation = 0.438, p = 00e⁺00).

CONCLUSIONS

This study analyzed the multilevel prognostic values and biological roles of the NDRG family in GC.

Iron and Cancer

This review explores the multifaceted role that iron has in cancer biology. Epidemiological studies have demonstrated an association between excess iron and increased cancer incidence and risk, while experimental studies have implicated iron in cancer initiation, tumor growth, and metastasis. The roles of iron in proliferation, metabolism, and metastasis underpin the association of iron with tumor growth and progression. Cancer cells exhibit an iron-seeking phenotype achieved through dysregulation of iron metabolic proteins. These changes are mediated, at least in part, by oncogenes and tumor suppressors. The dependence of cancer cells on iron has implications in a number of cell death pathways, including ferroptosis, an iron-dependent form of cell death. Uniquely, both iron excess and iron depletion can be utilized in anticancer therapies. Investigating the efficacy of these therapeutic approaches is an area of active research that promises substantial clinical impact.

miR‑490‑5p regulates the proliferation, migration, invasion and epithelial‑mesenchymal transition of pharyngolaryngeal cancer cells by targeting mitogen‑activated protein kinase kinasekinase 9

MicroRNA (miRNA/miR) has been identified to be a promising tool in treating pharyngolaryngeal cancer. The present study aimed to investigate the role of miR‑490‑5p in the regulation of proliferation, migration, invasion and epithelial‑mesenchymal transition (EMT) of pharyngolaryngeal cancer cells. The data of miR‑490‑5p expression levels of 45 cases were obtained from the People's Hospital of Xinjiang Uygur Autonomous Region, and the prediction of the target of miR‑490‑5p was conducted by bioinformatics and verified using a luciferase assay. Cell viability was determined by cell counting kit‑8. Migration and invasion rates were measured by wound healing test and Transwell apparatus, respectively. Colony formation rate was measured by plate colony formation assay. mRNA and protein levels were determined by quantitative polymerase chain reaction and western blotting, respectively. miR‑490‑5p expression was significantly depressed in primary pharyngolaryngeal cancer tissues and cell lines, leading to an unfavorable prognosis. Evidently, miR‑490‑5p overexpression decreased the cell viabilities of BICR 18 and FaDu cells. Mechanically, miR‑490‑5p could target mitogen‑activated protein kinase kinasekinase 9 (MAP3K9). The overexpression of MAP3K9 could promote cell viability, migration and invasion rates, EMT process and ability of cloning, miR‑490‑5p could target MAP3K9 and further modulate the proliferation, migration, invasion and EMT of pharyngolaryngeal cancer cells. The results of the present study provide a novel entry point to the treatment of pharyngolaryngeal cancer.

Chrysin inhibit human melanoma A375.S2 cell migration and invasion via affecting MAPK signaling and NF-κB signaling pathway in vitro

Numerous evidences have shown that chrysin induced cytotoxic effects via induced cell cycle arrest and induction of cell apoptosis in human cancer cell lines, however, no information showed that chrysin inhibited skin cancer cell migration and invasion. In this study, we investigated anti-metastasis mechanisms of chrysin in human melanoma cancer A375.S2 cells in vitro. Under sub-lethal concentrations of chrysin (0, 5, 10, and 15 μM) which inhibits cell mobility, migration and invasion of A375.S2 cells that were assayed by wound healing and Transwell filter. That chrysin inhibited MMP-2 activity in A375.S2 cells was investigated by gelatin zymography assay. Western blotting was used to examine protein expression and results indicated that chrysin inhibited the expression of GRB2, SOS-1, PKC, p-AKT (Thr308), NF-κBp65, and NF-κBp50 at 24 and 48 hours treatment, but only at 10-15 μM of chrysin decreased Ras, PI3K, p-c-Jun, and Snail only at 48 hours treatment and only decrease p-AKT(Ser473) at 24 hours treatment. Furthermore, chrysin (5-15 μM) decreased the expression of uPA, N-cadherin and MMP-1 at 24 and 48 hours treatment but only decreased MMP-2 and VEGF at 48 hours treatment at 10-15 μM and 5-15 μM of chrysin, respectively, however, increased E-cadherin at 5-15 μM treatment. Results of confocal laser microscopy systems indicated that chrysin inhibited expression of NF-κBp65 in A375.S2 cells. Based on these observations, we suggest that chrysin can be used in anti-metastasis of human melanoma cells in the future.

Tetrandrine inhibits human brain glioblastoma multiforme GBM 8401 cancer cell migration and invasion in vitro

Tetrandrine (TET) has been reported to induce anti-cancer activity in many human cancer cells and also to inhibit cancer cell migration and invasion. However, there are no reports to show TET inhibits cell migration and invasion in human brain glioblastoma multiforme GBM 8401 cells. In this study, we investigated the anti-metastasis effects of TET on GBM 8401 cells in vitro. Under sub-lethal concentrations (from 1, 5 up to 10 μM), TET significantly inhibited cell mobility, migration and invasion of GBM 8401 cells that were assayed by wound healing and Transwell assays. Gelatin zymography assay showed that TET inhibited MMP-2 activity in GBM 8401 cells. Western blotting results indicated that TET inhibited several key metastasis-related proteins, such as p-EGFR_(Tyr1068) , SOS-1, GRB2, Ras, p-AKT_(Ser473) and p-AKT_(Thr308) , NF-κB-p65, Snail, E-cadherin, N-cadherin, NF-κB, MMP-2 and MMP-9 that were significant reduction at 24 and 48 hours treatment by TET. TET reduced MAPK signaling associated proteins such as p-JNK1/2 and p-c-Jun in GBM 8401 cells. The electrophoretic mobility shift (EMSA) assay was used to investigate NF-κB and DNA binding was reduced by TET in a dose-dependently. Based on these findings, we suggested that TET could be used in anti-metastasis of human brain glioblastoma multiforme GBM 8401 cells in the future.

Hemidesmosomal linker proteins regulate cell motility, invasion and tumorigenicity in oral squamous cell carcinoma derived cells

BPAG1e and Plectin are hemidesmosomal linker proteins which anchor intermediate filament proteins to the cell surface through β4 integrin. Recent reports indicate that these proteins play a role in various cellular processes apart from their known anchoring function. However, the available literature is inconsistent. Further, the previous study from our laboratory suggested that Keratin8/18 pair promotes cell motility and tumor progression by deregulating β4 integrin signaling in oral squamous cell carcinoma (OSCC) derived cells. Based on these findings, we hypothesized that linker proteins may have a role in neoplastic progression of OSCC. Downregulation of hemidesmosomal linker proteins in OSCC derived cells resulted in reduced cell migration accompanied by alterations in actin organization. Further, decreased MMP9 activity led to reduced cell invasion in linker proteins knockdown cells. Moreover, loss of these proteins resulted in reduced tumorigenic potential. SWATH analysis demonstrated upregulation of N-Myc downstream regulated gene 1 (NDRG1) in linker proteins downregulated cells as compared to vector control cells. Further, the defects in phenotype upon linker proteins ablation were rescued upon loss of NDRG1 in linker proteins knockdown background. These data together indicate that hemidesmosomal linker proteins regulate cell motility, invasion and tumorigenicity possibly through NDRG1 in OSCC derived cells.

N-myc downstream-regulated gene 1 promotes apoptosis in colorectal cancer via up-regulating death receptor 4

The aim of this study was to evaluate the clinical significance of N-myc downstream-regulated gene 1 (NDRG1) in colorectal cancer (CRC) patients and to explore the mechanisms governing the role of NDRG1 in apoptosis of CRC cells. In the current study, we found that NDRG1 was a prognostic marker of CRC patients. Moreover, NDRG1 expression negatively correlated to tumor size and clinical TNM stage, suggesting that NDRG1 might act as a tumor suppressor by inhibiting proliferation or inducing apoptosis in CRC. Consistently, substantial apoptosis was observed in vitro and in vivo in the presence of NDRG1. From a mechanistic standpoint, we discovered that NDRG1 was able to prevent death receptor 4 from degradation induced by MARCH-8, a member of the membrane-associated RING-CH (MARCH) ubiquitin ligase family. As a consequence, CRC cells expressing NDRG1 were more sensitive to reagents targeting death receptors such as tumor necrosis factor-related apoptosis-inducing ligands (TRAIL). Additionally, the pro-apoptotic effect of NDRG1 was also validated in mouse xenograft model. In conclusion, our results provided further insights of the pivotal role of NDRG1 in apoptosis initiated by death receptors and demonstrated a novel marker to predict the sensitivity of CRC to TRAIL treatment in future clinical study.

Tetrandrine inhibits migration and invasion of human renal cell carcinoma by regulating Akt/NF-κB/MMP-9 signaling

Renal cell carcinoma (RCC) is known as one of the most lethal malignancies in the urological system because of its high incidence of metastasis. Tetrandrine (Tet), a traditional Chinese herbal medicine, exerts a potent anti-cancer effect in a variety of cancer cells. However, the anti-metastatic effect of Tet and its possible mechanism in RCC is still unclear. The present study revealed that Tet significantly suppressed the migration and invasion of RCC 786-O and 769-P cells in vitro. Mechanistically, the protein levels of matrix metalloproteinases 9 (MMP-9), phosphorylated PI3K, PDK1, Akt and NF-κB were markedly reduced after Tet treatment. Moreover, co-treatment with LY294002 (PI3K inhibitor) could further enhance the Tet-inhibited migration and invasion, and the NF-κB and MMP-9 protein levels were further decreased. Similar results were observed after PDTC (NF-κB inhibitor) co-treatment. Conversely, SC79, an Akt activator, could partially reverse the anti-metastatic effects of Tet, accompanied by the restoration of NF-κB and MMP-9 protein levels. In conclusion, the current results indicated that Tet inhibited migration and invasion of RCC partially by regulating Akt/NF-κB/MMP-9 signaling pathway, suggesting that Tet may be a potential therapeutic candidate against metastatic RCC.

Tumor apelin, not serum apelin, is associated with the clinical features and prognosis of gastric cancer

BACKGROUND

To study the association between Apelin expression and the clinical features and postoperative prognosis in patients with gastric cancer (Int J Cancer 136:2388-2401, 2015).

METHODS

Tumor samples and matched adjacent normal tissues were collected from 270 patients with GC receiving surgical resection. The tumor and serum Apelin levels were determined by immunohistochemistry and ELISA methods, respectively. GC cell lines were cultured for migration and invasive assays.

RESULTS

Our data showed that tumor Apelin expression status, instead of serum Apelin level, was closely associated with more advance clinical features including tumor differentiation, lymph node and distant metastases. Moreover, patients with high tumor Apelin level had a significantly shorter overall survival period compared to those with low Apelin expression and those with or negative Apelin staining. Our in vitro study revealed that the Apelin regulated the migration and invasion abilities of GC cell lines, accompanied by up-regulations of a variety of cytokines associated with tumor invasiveness.

CONCLUSION

Our data suggest that tumor Apelin can be used as a marker to evaluate clinical characteristics and predict prognosis in GC patients.