Ag2 O-TiO2 -NTs enhance osteogenic activity in vitro by modulating TNF-α/ß-catenin signaling in bone marrow-derived mesenchymal stem cells.

The toxic effects of nanoparticles-silver oxide (Ag2 O) limited its use. However, loading Ag2 O nanoparticles into titanium dioxide (TiO2 ) nanotubes (Ag2 O-TiO2 -NTs) has more efficient biological activity and safety. The aim of this study was to observe the effect of Ag2 O-TiO2 -NTs on osteogenic differentiation of bone marrow-derived mesenchymal stem cells (BMSCs) and its mechanism. The enzyme activity of lactate dehydrogenase (LDH) and the expression of RUNX family transcription factor 2 (Runx2), OPN, OCN in BMSCs were detected by quantitative real time polymerase chain reaction. At 14 days of induction, the mineralization ability and alkaline phosphatase (ALP) activity of cells in each group were observed by Alizarin Red S staining and ALP staining. In addition, the protein levels of tumor necrosis factor-α (TNF-α) and ß-catenin in BMSCs of each group were observed by western blot. After 14 days of the induction, the mineralization ability and ALP activity of BMSCs in the Ag2 O-TiO2 -NTs group were significantly enhanced compared with those in the Ag2 O and TiO2 groups. Western blot analysis showed that the BMSCs in the Ag2 O-TiO2 -NTs group exhibited much lower protein level of TNF-α and higher protein level of ß-catenin than those in the Ag2 O and TiO2 groups.Ag2 O-TiO2 -NTs enhance the osteogenic activity of BMSCs by modulating TNF-α/ß-catenin signaling.

Protective effect of chicory and/or artichoke leaves extracts on carbon tetrachloride and gamma-irradiation-induced chronic nephrotoxicity in rats.

The prevalence of chronic kidney disease (CKD) is in progress that causes kidney failure, leading to global problems. This manuscript investigated the nephroprotective effects of chicory (CLE) and/or artichoke (ALE) leaves extracts on carbon tetrachloride (CCl4 ) and gamma-irradiation (Rad)-induced chronic nephrotoxicity in rats. Rats were divided into 10 groups (10 animals/group): group 1: control, groups 2-7 rats were treated with CLE, ALE, CLE/ALE, CCl4 , Rad, and CCl4 /Rad, respectively. Groups 8 to 10, rats were intoxicated with CCl4 /Rad, and treated with CLE, ALE, and CLE/ALE extracts, respectively, for 4 weeks. The data demonstrated that CCl4 administration or Rad exposure induced high levels of urea and creatinine, with low levels of total protein and albumin in the serum. However, high levels of malondialdehyde (MDA), nitric oxide (NO), hydrogen peroxide (H2 O2 ), some pro-inflammatory markers such as interleukins (IL-1ß, IL-2, IL-6), TNF-α, NF-κB, the fibrotic marker; TGF-ß1, calcium, and copper, low contents of reduced glutathione (GSH), iron, and zinc, and suppression of the antioxidant enzymes' activity, superoxide dismutase (SOD), and catalase (CAT) were observed. In addition, the Wnt and ß-catenin protein expression ratios were up-regulated in the kidney tissues of the CCl4 , and Rad intoxicated animals. However, the combined treatment CCl4 /Rad augmented these measurements. On the other hand, CLE, ALE, and CLE/ALE treatments demonstrated nephroprotection in the kidney tissues of CCl4 /Rad intoxicated animals, in the order of CLE/ALE>ALE>CLE by ameliorating the investigated parameters. Kidney tissues' histopathological examinations confirmed these results. In conclusion, CLE and/or ALE demonstrated nephroprotection against CCl4 /Rad co-toxicity mediated by down-regulation of renal Wnt/ß-catenin protein expressions.

Dinaciclib exerts a tumor-suppressing effect via ß-catenin/YAP axis in pancreatic ductal adenocarcinoma.

Dinaciclib, a cyclin-dependent kinase-5 (CDK5) inhibitor, has significant anti-tumor properties. However, the precise mechanism of dinaciclib requires further investigation. Herein, we investigated the anti-tumor functions and molecular basis of dinaciclib in pancreatic ductal adenocarcinoma (PDAC). PDAC and matched para-carcinoma specimens were collected from the patients who underwent radical resection. Immunohistochemistry was performed to assess CDK5 expression. Cell proliferation ability, migration, and invasion were measured using Cell Counting Kit-8, wound healing, and transwell assay, respectively. The cell cycle and apoptosis were assessed using flow cytometry. Gene expression was examined using RNA-seq and quantitative real-time PCR. Protein expression of proteins was measured by western blot analysis and immunofluorescence microscopy. Tumor-bearing mice were intraperitoneally injected with dinaciclib. CDK5 is highly expressed in PDAC. The expression level of CDK5 was significantly related to tumor size, T stage, and the American Joint Committee on Cancer stage. High CDK5 expression can predict poor survival in PDAC patients. In addition, the expression level of CDK5 might be an independent prognostic factor for PDAC patients. Dinaciclib inhibits the growth and motility of PDAC cells and induces apoptosis and cell cycle arrest in the G2/M phase. Mechanistically, dinaciclib down-regulated yes-associated protein (YAP) mRNA and protein expression by reducing ß-catenin expression. Moreover, dinaciclib significantly inhibited PDAC cell growth in vivo . Our findings reveal a novel anti-tumor mechanism of dinaciclib in which it decreases YAP expression by down-regulating ß-catenin at the transcriptional level rather than by activating Hippo pathway-mediated phosphorylation-dependent degradation.

APC and P53 mutations synergise to create a therapeutic vulnerability to NOTUM inhibition in advanced colorectal cancer.

OBJECTIVE: Colorectal cancer (CRC) is a leading cause of cancer-related deaths, with the majority of cases initiated by inactivation of the APC tumour suppressor. This results in the constitutive activation of canonical WNT pathway transcriptional effector ß-catenin, along with induction of WNT feedback inhibitors, including the extracellular palmitoleoyl-protein carboxylesterase NOTUM which antagonises WNT-FZD receptor-ligand interactions. Here, we sought to evaluate the effects of NOTUM activity on CRC as a function of driver mutation landscape. DESIGN: Mouse and human colon organoids engineered with combinations of CRC driver mutations were used for Notum genetic gain-of-function and loss-of-function studies. In vitro assays, in vivo endoscope-guided orthotopic organoid implantation assays and transcriptomic profiling were employed to characterise the effects of Notum activity. Small molecule inhibitors of Notum activity were used in preclinical therapeutic proof-of-principle studies targeting oncogenic Notum activity. RESULTS: NOTUM retains tumour suppressive activity in APC-null adenomas despite constitutive ß-catenin activity. Strikingly, on progression to adenocarcinoma with P53 loss, NOTUM becomes an obligate oncogene. These phenotypes are Wnt-independent, resulting from differential activity of NOTUM on glypican 1 and 4 in early-stage versus late-stage disease, respectively. Ultimately, preclinical mouse models and human organoid cultures demonstrate that pharmacological inhibition of NOTUM is highly effective in arresting primary adenocarcinoma growth and inhibiting metastatic colonisation of distal organs. CONCLUSIONS: Our findings that a single agent targeting the extracellular enzyme NOTUM is effective in treating highly aggressive, metastatic adenocarcinomas in preclinical mouse models and human organoids make NOTUM and its glypican targets therapeutic vulnerabilities in advanced CRC.

Honokiol inhibits epithelial-mesenchymal transition and hepatic fibrosis via activation of Ecadherin/GSK3ß/JNK and inhibition of AKT/ERK/p38/ß-catenin/TMPRSS4 signaling axis.

Though Honokiol was known to have anti-inflammatory, antioxidant, anticancer, antithrombotic, anti-viral, metabolic, antithrombotic, and neurotrophic activities, the underlying mechanisms of Honokiol on epithelial-mesenchymal transition (EMT) mediated liver fibrosis still remain elusive so far. Anti-EMT and antifibrotic effects of Honokiol were explored in murine AML-12 hepatocyte cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay, wound healing assay, Western blotting and also in CCl4-induced liver injury mouse model by immunohistochemistry. Honokiol significantly suppressed transforming growth factor ß1 (TGF-ß1)-induced EMT and migration of AML-12 cells along with decreased EMT phenotypes such as loss of cell adhesion and formation of fibroblast like mesenchymal cells in TGF-ß1-treated AML-12 cells. Consistently, Honokiol suppressed the expression of Snail and transmembrane protease serine 4 (TMPRSS4), but not p-Smad3, and activated E-cadherin in TGF-ß1-treated AML-12 cells. Additionally, Honokiol reduced the expression of ß-catenin, p-AKT, p-ERK, p-p38 and increased phosphorylation of glycogen synthase kinase 3 beta (GSK3ß) and JNK in TGF-ß1-treated AML-12 cells via TGF-ß1/nonSmad pathway. Conversely, GSK3ß inhibitor SB216763 reversed the ability of Honokiol to reduce Snail, ß-catenin and migration and activate E-cadherin in TGF-ß1-treated AML-12 cells. Also, Honokiol suppressed hepatic steatosis and necrosis by reducing the expression of TGF-ß1 and α-SMA in liver tissues of CCl4 treated mice. These findings provide scientific evidence that Honokiol suppresses EMT and hepatic fibrosis via activation of E-cadherin/GSK3ß/JNK and inhibition of AKT/ERK/p38/ß-catenin/TMPRSS4 signaling axis.

Ginsenoside Re Attenuates Cisplatin-Induced Intestinal Toxicity via Suppressing GSK-3ß-Dependent Wnt/ß-Catenin Signaling Pathway In Vivo and In Vitro.

Previous reports have confirmed that crude saponins (ginsenosides) in Panax ginseng have a preventive effect on chemotherapy-induced intestinal injury. However, the protective effects and possible mechanisms of ginsenoside Re (G-Re, a maker saponin in ginseng) against chemotherapy-induced intestinal damage have not been thoroughly studied. In this work, a series of experiments in vivo and in vitro on the intestinal toxicity caused by cisplatin have been designed to verify the improvement effect of G-Re, focusing on the levels of Wnt3a and [Formula: see text]-catenin. Mice were intragastric with G-Re for 10 days, and intestinal injury was induced by intraperitoneal administration of cisplatin at a dose of 20 mg/kg. Histopathology, gastrointestinal digestive enzyme activities, inflammatory cytokines, and oxidative status were evaluated to investigate the protective effect. Furthermore, in IEC-6 cells, G-Re statistically reverses cisplatin-induced oxidative damage and cytotoxicity. The TUNEL and Hoechst 33258 staining demonstrated that G-Re possesses protective effects in cisplatin-induced apoptosis. Additionally, pretreatment with G-Re significantly alleviated the apoptosis via inhibition of over-expressions of B-associated X (Bax), as well as the caspase family members, such as caspase 3 and 9, respectively, in vivo and in vitro. Notably, western blotting results showed that G-Re treatment decreased Wnt3a, Glycogen synthase kinase [Formula: see text] (GSK-[Formula: see text]), and [Formula: see text]-catenin expression, suggesting that nuclear accumulation of [Formula: see text]-catenin was attenuated, thereby inhibiting the activation of GSK-[Formula: see text]-dependent Wnt/[Formula: see text]-catenin signaling, which was consistent with our expected results. Therefore, the above evidence suggested that G-Re may be a candidate drug for the treatment of intestinal injury.

Acid sensor ASIC1a induces synovial fibroblast proliferation via Wnt/ß-catenin/c-Myc pathway in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune disease characterized by synovial hyperplasia and progressive joint destruction in the middle and late stages. Notably, activated rheumatoid arthritis synovial fibroblasts (RASFs) exhibit tumor-like features, including an increased proliferation rate that largely contributes to pannus formation and joint destruction. Our previous studies have demonstrated that acid-sensing ion channel 1a (ASIC1a) was highly expressed in RASFs, and acidic microenvironment of synovial fluid in patients with RA can activate ASIC1a to promote synovial inflammation, leading to the progression of RA. However, the role and possible mechanism of ASIC1a in RASF proliferation remains unclear. The present study aimed to investigate the effect of ASIC1a activation upon acidosis on RASF proliferation and its molecular mechanism in vivo and in vitro. The results of in vitro experiments showed that activation of ASIC1a upon acidosis promoted the proliferation of RASFs, which could be attenuated by the specific ASIC1a inhibitor Psalmotoxin-1 (PcTx-1) or specific siRNA for ASIC1a. Mechanistically, Wnt/ß-catenin/c-Myc signaling pathway was involved in ASIC1a-induced RASF proliferation. The results of in vivo experiments indicated that intra-articular injection of PcTx-1 reduced synovial hyperplasia and ameliorated cartilage degradation in rats with adjuvant arthritis (AA). Collectively, these results suggest that activation of ASIC1a upon acidosis promotes RASF proliferation, and the mechanism may be related to Wnt/ß-catenin/c-Myc pathway.

Effects of Stress on Osteoblast Proliferation and Differentiation Based on Endoplasmic Reticulum Stress and Wntß-Catenin Signaling Pathway.

In order to investigate the effect of fluid shear stress on the proliferation of osteoblasts and the regulatory role of the Wnt/ß-catenin signaling pathway in cell proliferation, a new method based on endoplasmic reticulum stress and Wnt/ß-catenin signaling pathway stress-mediated was proposed. Taking MG63 osteoblasts as the research object, they were inoculated on glass slides (G group), polished titanium sheets (P group), and sandblasted acid-base treated pure titanium sheets (S group). In addition, FSS of 0 dunes/cm2 (static group) and 12 dunes/cm2 (stress group) were given, respectively. Then, quantitative reverse transcription-PCR (RT-qPCR) and western blot were used to detect the mRNA and protein expressions of low-density lipoprotein receptor-related protein 5 (LRP5) and ß-catenin in MG63 cells. The results showed that the expression levels of ß-catenin mRNA and protein in cells in the stress group were significantly increased (P < 0.05), and the protein expression level of LRP5 was significantly decreased (P < 0.05). The expression level of LRP5 in group S was greatly inhibited, while the expression level of ß-catenin was significantly upregulated. Therefore, FSS can stimulate the expression of LRP5 and ß-catenin in osteoblasts. Fluid shear stress can promote osteoblast proliferation in vitro; the Wnt/ß-catenin signaling pathway is involved in regulating fluid shear stress to promote osteoblast proliferation.

Vitamin D receptor activation is a feasible therapeutic target to impair adrenocortical tumorigenesis.

OBJECTIVE: To evaluate the therapeutic potential of vitamin D receptor (VDR) signaling in adrenocortical carcinoma (ACC) cells. METHODS: We evaluated VDR's methylation pattern in H295R ACC cells, and investigated the effects of calcitriol and seocalcitol treatments on adrenocortical tumorigenesis. RESULTS: VDR was hypermethylated and underexpressed in basal H295R cells. Treatments with calcitriol and seocalcitol restored VDR signaling, resulted in antiproliferative effects, and impaired Wnt/B-catenin signaling. RNAseq of treated cells demonstrated VDR activation on steroid hormones biosynthesis and Rap1 signaling, among others. In vivo, seocalcitol constrained the growth of H295R xenografts and reduced autonomous tumor steroid secretion without hypercalcemia-associated side effects. CONCLUSIONS: H295R cells present VDR hypermethylation, which can be responsible for its underexpression and signaling inactivation under basal conditions. VDR signaling promoted antiproliferative effects in vitro and in vivo, suggesting that it may be a potential therapeutic target for ACC and a valuable tool for patient's clinical management.

Novel therapeutic diiminoquinone exhibits anticancer effects on human colorectal cancer cells in two-dimensional and three-dimensional in vitro models.

BACKGROUND: Colorectal cancer (CRC) is the second leading cause of cancer-related mortality. Cancer stem cells (CSCs) in CRC, which are spared by many chemotherapeutics, have tumorigenic capacity and are believed to be the reason behind cancer relapse. So far, there have been no effective drugs to target colon CSCs. Diiminoquinone (DIQ) has shown promising effects on targeting colon cancer. However, there is limited research on the effects of DIQ on eradicating CSCs in CRC. AIM: To investigate the anticancer potential of DIQ on colon CSCs in two-dimensional (2D) and three-dimensional (3D) models using colonospheres and patient-derived organoids. METHODS: Various 2D methods have been used to assess the effect and the mechanism of DIQ on HCT116 and HT29 cell lines including cell proliferation and viability assays, migration and invasion assays, immunofluorescence staining, and flow cytometry. The potency of DIQ was also assessed in 3D culture using the sphere formation assay and colon cancer patient-derived organoid model. RESULTS: Our results showed that DIQ significantly inhibited cell proliferation, migration, and invasion in HCT116 and HT29 cell lines. DIQ treatment induced apoptosis along with an accumulation of HCT116 and HT29 cancer cells in the sub-G1 region and an increase in reactive oxygen species in both CRC cell lines. DIQ reduced sphere-forming and self-renewal ability of colon cancer HCT116 and HT29 stem/progenitor cells at sub-toxic doses of 1 µmol/L. Mechanistically, DIQ targets CSCs by downregulating the main components of stem cell-related -catenin, AKT, and ERK oncogenic signaling pathways. Potently, DIQ displayed a highly significant decrease in both the count and the size of the organoids derived from colon cancer patients as compared to control and 5-fluorouracil conditions. CONCLUSION: This study is the first documentation of the molecular mechanism of the novel anticancer therapeutic DIQ via targeting CSC, a promising compound that needs further investigation.

KMT5A Knockdown Suppresses Osteosarcoma Cell Proliferation and Metastasis Through Ꞵ-Catenin Signalling.

PURPOSE: Osteosarcoma (OS) is the most common malignant solid bone tumor in children and young adults. We aimed to investigate the effects and cellular mechanisms of KMT5A on OS cell activity. METHODS: The protein expression was evaluated in the clinical normal, adjacent and OS osteogenic tissues. Knockdown of KMT5A was achieved by KMT5A siRNAs in a human OS cell line, MG63, to detect cell proliferation and metastasis. RESULTS: KMT5A expression was upregulated in clinical OS tissues. Knockdown of KMT5A inhibited cell proliferation but enhanced cell death, with significantly reduced cyclinD1 and Bcl2 and increased cleaved-caspase9 levels. KMT5A knockdown also suppressed OS cell migration and invasion capacity and deceased MMP3 and vimentin expression. ß-catenin levels were upregulated in OS tissues and blocking KMT5A resulted in a significant decline in ß-catenin expression in the OS cells. Further administration of ß-catenin activator remarkably increased protein levels of KMT5A, cyclinD1, Bcl2, MMP3, and vimentin, which showed reversed effects of KMT5A knockdown on OS cell activity. CONCLUSION: KMT5A knockdown plays an inhibitory role in OS cell proliferation and metastasis through ß-catenin signalling, which provides basic evidence and suggests potential targets for OS therapeutic research.

Umbelliferone Inhibits Migration, Invasion and Inflammation of Rheumatoid Arthritis Fibroblast-Like Synoviocytes and Relieves Adjuvant-Induced Arthritis in Rats by Blockade of Wnt/ß-Catenin Signaling Pathway.

Umbelliferone (UMB), a natural coumarin compound, has been reported to possess anti-rheumatic effects on rheumatoid arthritis (RA) experimental models, but its potential role of UMB in regulating migration, invasion and inflammation of RA fibroblast-like synoviocytes (FLS) remain unclear. Herein, MTT assay was performed to confirm the non-cytotoxic concentrations (10, 20, and 40[Formula: see text][Formula: see text]M) and the treatment time (24[Formula: see text]h) of UMB on TNF-[Formula: see text]-stimulated RA FLS (MH7A cells) in vitro. Results of wound-healing, transwell and phalloidin staining assays revealed that UMB inhibited TNF-[Formula: see text]-induced migration, invasion and F-actin cytoskeletal reorganization in MH7A. Results of ELISA, western blot and gelatin zymography indicated that UMB decreased the productions of pro-inflammatory factors, including IL-1[Formula: see text], IL-6, IL-8, MMP-2 and MMP-9, and inhibited MMP-2 activity in TNF-[Formula: see text]-stimulated MH7A cells. In vivo, UMB (25[Formula: see text]mg/kg and 50[Formula: see text]mg/kg) relieved the joint damage and synovial inflammation in rats with adjuvant-induced arthritis (AIA). Mechanistically, UMB could suppress Wnt/[Formula: see text]-catenin signaling both in TNF-[Formula: see text]-induced MH7A cells and in AIA rat synovium, evidenced by decreasing Wnt1 protein level, activating GSK-3[Formula: see text] kinase by blocking GSK-3[Formula: see text] (Ser9) phosphorylation, and reducing the protein level and nuclear translocation of [Formula: see text]-catenin. Importantly, combined use of lithium chloride (a Wnt/[Formula: see text]-catenin signaling agonist) eliminated the inhibitory effects of UMB on migration, invasion and inflammation in vitro and the anti-arthritic effects of UMB in vivo. We concluded that UMB inhibited TNF-[Formula: see text]-induced migration, invasion and inflammation of RA FLS and attenuated the severity of rat AIA through its ability to block Wnt/[Formula: see text]-catenin signaling pathway.

Inhibition of the Wnt/b-catenin pathway using PNU-74654 reduces tumor growth in in vitro and in vivo models of colorectal cancer.

BACKGROUND: Colorectal-cancer (CRC) is amongst the most lethal-cancers, mainly due to its metastatic spread and drug chemoresistance. Hence there is a need for new approaches to either increase the efficacy of current therapy or introduce new therapies that have greater efficacy. There is increasing evidence that dysregulation of WNT-signaling-pathway plays an essential role in the development and prognosis of CRC. Here we have investigated the therapeutic potential of targeting the WNT/b-catenin pathway using a novel Wnt/b-catenin inhibitor, PNU-74654, in combination with 5-FU in CRC. METHODS: The anti-proliferative-effect of PNU-74654 was evaluated in two-/three-dimensional cell models. The activity of agents on cell growth, migration, invasion, cell cycle and apoptosis was evaluated by MTT, wound healing assay, invasion, FACS, and annexin V staining, respectively. The oxidant/antioxidant levels were also assessed by determining the level of MDA, SOD, as well as using the DCFH-DA assay. We used a xenograft model of CRC to investigate PNU-74654 activity alone and in combination with 5-FU follow by histological staining and biochemical and gene expression analyses by RT-PCR and western blot. RESULTS: PNU-74654 inhibited cell-growth and synergistically affected the anti-tumor properties of 5-FU via modulation of Cyclin D1 and survivin. This agent inhibited the migration/invasion of colorectal cancer cells via perturbation of E-cadherin. Furthermore, PNU-74654 inhibited the tumor growth, which was more pronounced using the PNU-74654 plus 5-FU combination via induction of reactive oxygen species, down-regulation of SOD and modulation of MCP-1, P53, TNF-α. CONCLUSIONS: Our finding demonstrated that PNU-74654 can target Wnt-pathway, interfere with cell-proliferation, induced-cell death, reduced-migration and interact with 5-FU, supporting further investigations on this therapeutic-approach for colorectal cancer.

Mechanism of dact2 gene inhibiting the occurrence and development of liver fibrosis.

There are few reports about the relationship between dact2 and liver fibrosis. The inhibitory mechanism of dact2 in liver fibrosis is not clear, we need to further explore it. In this study has been shown that the dact2 gene can inhibit liver fibrosis. In this experiment, we used lentivirus as a vector to construct a lentivirus vector carrying the dact2 gene and packaged dact2 recombinant lentivirus and its control vector. HSC-T6 infected cells were observed. The effect of dact2 gene expression was activated by Wnt3a HSC-T6 cells. Immunoblot was used to detect α - SMA expression, TGF - ß 1, Smad3, Smad7, ß - Catenin and CyclinD1. The expression of MMP-2 and TIMP-1 was detected by real-time PCR. At the same time, dact2 recombinant lentivirus was injected into the tail vein. Carbon tetrachloride was used to establish the liver fibrosis model. After 7 weeks of modeling, the staining was used to observe the pathological changes of liver tissue, hydroxyproline was used to analyze the changes of collagen content in liver tissue, the expression of the protein was observed by immunohistochemistry, and the expression of fibrosis-related genes was detected by real-time PCR. Results showed that the dact2 gene expression could inhibit the activation of HSC-T6 cells and reduce the expression of TGF - ß 1. The percentage of Smad3, ß - Catenin and cyclinD1 protein was 50.02%, 46.73%, 47.58% and 37.50% respectively (P < 0.05).

p120-catenin suppresses proliferation and tumor growth of oral squamous cell carcinoma via inhibiting nuclear phospholipase C-γ1 signaling.

p120-catenin (p120) serves as a stabilizer of the calcium-dependent cadherin-catenin complex and loss of p120 expression has been observed in several types of human cancers. The p120-dependent E-cadherin-ß-catenin complex has been shown to mediate calcium-induced keratinocyte differentiation via inducing activation of plasma membrane phospholipase C-γ1 (PLC-γ1). On the other hand, PLC-γ1 has been shown to interact with phosphatidylinositol 3-kinase enhancer in the nucleus and plays a critical role in epidermal growth factor-induced proliferation of oral squamous cell carcinoma (OSCC) cells. To determine whether p120 suppresses OSCC proliferation and tumor growth via inhibiting PLC-γ1, we examined effects of p120 knockdown or p120 and PLC-γ1 double knockdown on proliferation of cultured OSCC cells and tumor growth in xenograft OSCC in mice. The results showed that knockdown of p120 reduced levels of PLC-γ1 in the plasma membrane and increased levels of PLC-γ1 and its signaling in the nucleus in OSCC cells and OSCC cell proliferation as well as xenograft OSCC tumor growth. However, double knockdown of p120 and PLC-γ1 or knockdown of PLC-γ1 alone did not have any effect. Immunohistochemical analysis of OSCC tissue from patients showed a lower expression level of p120 and a higher expression level of PLC-γ1 compared with that of adjacent noncancerous tissue. These data indicate that p120 suppresses OSCC cell proliferation and tumor growth by inhibiting signaling mediated by nuclear PLC-γ1.

[Prevention of senescence and stress by food composition].

  The high prevalence of dementia in aged individuals suggests that aging is the most important risk factor and that senescence further enhances dementia. We have searched for dietary factors that prevent brain senescence using a mouse model of age-related neurodegeneration (SAMP10). This mouse line is suitable for studying brain senescence because brain atrophy and cognitive dysfunction are observed with aging, similar to humans. The production of reactive oxygen species and oxidative damage are high in the brains of aged SAMP10. We found that green tea catechin and ß-cryptoxanthin in Japanese mandarin oranges prevented brain atrophy and cognitive dysfunction. In addition, psychosocially chronically stressed mice exhibited a shortened life span and accelerated cognitive dysfunction. These deficiencies were prevented by the ingestion of theanine, an amino acid in tea, under stressed conditions. While a number of factors affect brain senescence, our results suggest that non-nutritive food components such as catechin, ß-cryptoxanthin and theanine may be useful for preventing brain senescence.