X-Ray Triggered Coordination-Bond Breakage in Dysprosium-Organic Framework and its Impact on Magnetic Properties.

Photosensitive lanthanide-based single-molecule magnets (Ln-SMM) are very attractive for their potential applications in information storage, switching, and sensors. However, the light-driven structural transformation in Ln-SMMs hardly changes the coordination number of the lanthanide ion. Herein, for the first time it is reported that X-ray (λ=0.71073 Å) irradiation can break the coordination bond of Dy-OH2 in the three-dimensional (3D) metal-organic framework Dy2 (amp2 H2 )3 (H2 O)6 ⋅ 4H2 O (MDAF-5), in which the {Dy2 (OPO)2 } dimers are cross-linked by dianthracene-phosphonate ligands. The structural transformation proceeds in a single-crystal-to-single-crystal (SC-SC) fashion, forming the new phase Dy2 (amp2 H2 )3 (H2 O)4 ⋅ 4H2 O (MDAF-5-X). The phase transition is accompanied by a significant change in magnetic properties due to the alteration in coordination geometry of the DyIII ion from a distorted pentagonal bipyramid in MDAF-5 to a distorted octahedron in MDAF-5-X.

Exosomes Derived from Human Adipose-Derived Stem Cells Cannot Distinctively Promote Graft Survival in Cryopreservation Fat Grafting.

BACKGROUND: Cryopreserved fat has limited clinical applications due to its rapid absorption, high degree of fibrosis, and risk of complications after grafting. Many studies have verified that Adipose-derived mesenchymal stem cell-derived exosomes (ADSC-Exos) can improve fresh fat graft survival. This study assessed whether ADSC-Exos could improve the survival of cryopreserved fat grafts. METHODS: Exosomes were isolated from human ADSCs were subcutaneously engrafted with adipose tissues stored under different conditions (fresh; cryopreserved for 1 month) into the backs of BALB/c nude mice (n = 24), and exosomes or PBS were administered weekly. Grafts were harvested at 1, 2, 4, and 8 weeks, and fat retention rate, histologic, and immunohistochemical analyses were conducted. RESULTS: At 1, 2, and 4 weeks after the transfer, cryopreserved fat grafts in groups of exosome-treated showed better fat integrity, fewer oil cysts, and reduced fibrosis. Further investigations of macrophage infiltration and neovascularization revealed that those exosomes increased the number of M2 macrophages at 2 and 4 weeks (p<0.05), but had limited impact on vascularization (p>0.05). It's important to note that no significant differences (p>0.05) were observed between the two groups in both histological and immunohistochemical evaluations at 8 weeks post-transplantation. CONCLUSIONS: This study suggests that ADSC-Exos could improve the survival of cryopreserved fat grafts in the short term (within 4 weeks), but the overall improvement was poor (after 8 weeks). This suggests that the utility of using ADSC-Exos to treat cryopreserved adipose tissue grafts is limited. NO LEVEL ASSIGNED: This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Age-Related Changes of the Zygomatic Ligament: An Experimental Animal Study.

BACKGROUND: Facial aging is a multifactorial process involving the skin, fat, muscles, bones, and ligaments. The role of facial ligaments in the facial aging process remains elusive. OBJECTIVES: The aim of this study was to identify whether age-related changes in facial ligaments exist and how to best quantify such changes when investigating the zygomatic ligament in the rat. METHODS: A total of 30 male Sprague-Dawley rats (10 young, 10 middle-aged, 10 mature) were investigated to visualize the zygomatic ligament. Samples of the ligaments spanning the zygomatic arch and the skin were taken and histologically examined with hematoxylin-eosin, Masson, Verhoeff's elastic, and picrosirius red staining. Quantification of the Type I/III collagen ratio and collagen content was performed by color deconvolution and electron microscopic imaging. RESULTS: With increasing age, collagen fibers inside of the examined ligaments appeared thicker and more closely arranged. The Type I/III collagen ratio was measured to be 1.74 in young animals, 3.93 in middle-aged animals, and 5.58 in mature animals. The ultra-microstructure of the ligament was less coordinated in direction and orientation in young and middle-aged animals than in mature animals, in which collagen fibers were bundled together in a strong and oriented mesh. CONCLUSIONS: Ligaments appeared thinner, transparent, more elastic, and less robust in young animals, whereas ligaments in mature animals appeared thicker, more fascia-like, less elastic, and more robust. An increase in the Type I/III collagen ratio, indicating greater stiffness and reduced elasticity, was observed with higher age of the investigated animals. These findings indicate that ligaments might increase in stiffness and rigidity with age.

[The mechanism of tenuigenin for eliminating waste product accumulation in cerebral neurons of Alzheimer's disease rats via ubiquitin-proteasome pathway].

OBJECTIVE: To explore the scavenging action of tenuigenin (TEN) on intracerebral amyloid ß protein (Aß) aggregation and the abnormal phosphorylated tau protein and its mechanism in Alzheimer's disease (AD) rats' brain. METHODS: Aß1-40 was injected into the right CA1 region hippocampus to establish the AD model. Successfully modeled rats were divided into the model group, the low, middle, high TEN group. Rats were administered with TEN (18.5, 37.0, 74.0 mg/kg) by gastrogavage. Besides, a sham-operation group was set up. Expression levels of Aß1-40 and Tau p-Ser262 were detected by immunohistochemistry. Expression levels of ubiquitin (Ub) and Ub-protein ligase E3 were measured by Western blotting.The content of 26S proteasome was detected by ELISA. RESULTS: Immunohistochemical results showed that the number of Aß and Tau p-Ser262 positively reacted neurons significantly increased in model group, when compared with the sham-operation group (P < 0.01). Results of Western blot showed expression levels of ubiquitinated protein were up-regulated and those of Ub-protein ligase E3 were down-regulated in the model group (P < 0.01). ELISA results showed that the content of 26S proteasome significantly decreased in AD rats' brain (P < 0.01). Compared with the model group, expression levels of Aß1-40, Tau p-Ser262, and Ub significantly decreased; expression levels of Ub-protein ligase E3 apparently increased; the content of 26S proteasome significantly increased in each TEN treatment group (P < 0.05, P < 0.01). Best effect was shown in 37.0 mg/kg and 74.0 mg/kg TEN groups. CONCLUSIONS: Ub proteasome pathway (UPP) participated in the occurrence of AD. TEN could obviously reduce intracere- bral Aß1-40 accumulation and abnormal tau phosphorylation.

Estimating the Change in Facial Subunits During Positive and Negative Facial Expression Using Three-Dimensional Stereophotogrammetry Facial Analysis.

Background: A more refined and clinically related facial expression analysis is required for patients who wish to be perceived more emotionally positive. Objective: To measure the change in skin vector and volume in facial subunits when expressing positive expression (happiness) compared with negative expressions (sadness, fear, disgust, and anger), using three-dimensional (3D) stereophotogrammetry analysis. Methods: This study took 3D photographs of 20 volunteers' face at rest and during positive and negative expression. The directions of skin vector and volume changes in each facial subregion were recorded and calculated. Results: In the positive expression, 78.3% (95% confidence interval [CI] 66.8-89.9) of the medial midfacial subregions presented superolateral vector and volume increase, whereas volume decrease in 82.5% (95% CI 78.5-86.5) of the lip subregions could be observed. In the negative expression, the vector changes were predominantly inferomedial in 26.0% (95% CI 15.4-36.5) of the forehead and 36.8% (95% CI 33.2-40.3) of the upper eyelid subregions, whereas volume increases in 34.0% (95% CI 30.4-37.7) of the upper eyelid subregions were observed. Conclusions: This 3D stereophotogrammetry analysis presents the morphological difference between the positive and negative expression.

Relationship between serum concentration and clinical response of quetiapine in adolescents and adults with bipolar disorders in acute stage: a prospective observational study.

BACKGROUND: It is found that there are great differences in the efficacy of quetiapine at the same dose in many patients with bipolar disorders. Therefore, therapeutic drug monitoring (TDM) is a valuable tool for guiding treatment with quetiapine. The aims of this study were to assess the relationship between serum concentration and clinical response of quetiapine in adolescents and adults with bipolar disorders in acute stage. METHODS: The study design was prospective and observational. Within the naturalistic setting of a routine TDM service at the First Affiliated Hospital, Zhejiang University School of Medicine. Psychiatric symptoms were assessed using the HAMD (Hamilton Depression Scale), YRMS (Young manic rating scale) and CUDOS-M (Clinically Useful Depression Outcome Scale-Mixed Subscale). The decline of HAMD and YMRS scores was were used to assess clinical outcome of bipolar disorders respectively. RESULTS: 169 inpatients (23.7 % male, 76.3 % female) were enrolled in the study. We found that there was a strong correlation between quetiapine serum concentrations and clinical outcomes (rs = 0.702, p < 0.001). While, quetiapine daily dose was not correlated with clinical outcome. We found that when the quetiapine serum level is >146.85 ng/ml in depression episodes patients could obtain a satisfactory treatment effect after 2 weeks of hospitalization. CONCLUSIONS: We found a significant positive relationship between serum concentration and clinical outcome, and also determined the serum concentration of quetiapine for the treatment of bipolar depression.

Association between vitamin D and insulin resistance in adults with latent tuberculosis infection: Results from the National Health and Nutrition Examination Survey (NHANES) 2011-2012.

BACKGROUND: Evidence demonstrated that vitamin D insufficiency was involved in insulin resistance (IR) pathogenesis and associated with tuberculosis. However, the association of vitamin D and IR in patients with latent tuberculosis infection (LTBI) remains unclear. This study aims to evaluate the association between vitamin D and insulin resistance in US adults with LTBI. METHOD: National Health and Nutrition Examination Survey (NHANES) participants ≥ 20 years during the years 2011-2012 with positive QuantiFERON®-TB Gold-In-Tube (QFT) or tuberculin skin testing (TST) were enrolled in present study. Participants with LTBI were divided into 2 groups: (1) vitamin D insufficiency group (n = 267), and (2) vitamin D sufficiency group (n = 437). RESULTS: Weighted analysis of all the population in the study showed that serum 25(OH)D inversely correlated with HOMA-IR (r = -0.14, P = 0.008). The vitamin D insufficiency group had higher fasting insulin (17.5 (1.38) vs. 15.29 (3.1), respectively, P = 0.0013) and HOMA-IR (5.0 (0.4) vs. 4.5 (1), respectively, P = 0.013) than the vitamin D sufficiency group. In adjusted analysis, vitamin D levels was independently associated with insulin resistance (adjusted OR [aOR] 2.74; 95% CI, 1.01-7.48, p = 0.0489). CONCLUSIONS: Taken together, our study suggested that serum 25(OH) D concentrations were inversely and independently associated with HOMA-IR in LTBI.

Higher modified dietary inflammatory index is associated with increased risk of osteoporosis in US adults: Data from NHANES.

Objective: The aim of this study was to study the relationship between modified dietary inflammatory index (MDII) score with osteoporosis (OP) in adult Americans. Methods: Data were extracted from the United States National Health and Nutrition Examination Survey (NHANES) (2007-2008, 2009-2010, 2013-2014, and 2017-2018). In this cross-sectional study, 5,446 participants were included and analyzed. Potential dietary inflammatory was assessed by MDII score (24-h recall), a composite method computed according to the relationship between nutrients and systemic pro-inflammatory cytokine level, and was further classified into tertiles. Weighted multivariable logistic regression analysis was employed to examine the associations between OP and MDII scores. Results: In weighted multivariable-adjusted logistic regression models, the highest tertile of MDII score was associated with an increased risk of OP [odds ratio (OR): 1.73, 95% confidence interval (95 CI%): 1.14-2.63]. In participants aged above 59 years, a higher MDII score showed a higher risk of OP (OR: 1.92; 95 CI%: 1.16-3.15). In the sex-stratified models, the results remained significant only among women (OR: 1.80; 95% CI: 1.02-3.17). In the menopausal status stratified model, after adjusting potential confounding variables, the association between the MDII score, either as a categorical (OR: 1.88; 95% CI: 1.07-3.13) or continuous variables (OR: 1.19; 95%CI: 1.02-1.38), and OP risk was significant among postmenopausal women. Conclusion: Our study indicates that a higher MDII score (pro-inflammatory effect) is significantly associated with an increased risk of OP in US adults, especially among those postmenopausal women more than 60 years. This study further supports that those dietary changes have the potential to prevent OP.

[Spatiotemporal evolution of habitat quality in three basins of Hainan Island based on InVEST model]. / 基于InVEST模型的海南岛三大流域生境质量时空演变.

Based on land use data of five periods during 1980 to 2020, using the InVEST model and the methods of land use transfer, habitat quality change rate and spatial statistical analysis, we explored the changes of habitat quality and its spatial distribution characteristics in the three major basins of Hainan Island (Nandu River, Changhua River and Wanquan River). The results showed that woodlands were the main land use type in the three basins of Hainan Island, accounting for more than 70% of the total area. From 1980 to 2020, the area of construction land increased the most, reaching up to 169.09 km2, mainly from cultivated land and woodland. The spatial distribution pattern of habitat quality in the study area was higher in the upstream and head water areas and lower in the mid and downstream regions. Overall, habitat quality index increased slightly for a short period and then decreased significantly during the study period. Among the three basins, habitat quality of Wanquan River Basin was the highest, followed by Changhua River Basin, and Nandu River Basin was the lowest. The habitat quality of Nandu River Basin fluctuated greatly and was strongly affected by human disturbance. From 1980 to 2020, the change rate of habitat quality in the three basins generally decreased by 0.5%, which was significantly degraded from 2010 to 2020. From 1980 to 2020, the spatial distribution of habitat quality in the study area displayed strong autocorrelation and significant aggregation. The hot spot area of habitat quality was mainly concentrated near the head water and upstream areas of the three basins, while the cold spot area was mainly distributed in the estuary area of the three basins, along with the mid and downstream areas of the Nandu River. These results would provide scientific reference for biodiversity conservation and ecological restoration efforts in the three basins of Hainan Island.

Bipedicle Advancement Flap for Skin Coverage after Digital Mucous Cyst Excision: A Retrospective Study of 18 Cases.

OBJECTIVES: To assess the clinical outcomes of using a bipedicle advancement flap to cover the skin defects after digital mucous cyst (DMC) excision. METHODS: Data for 15 patients (18 fingers) with DMC, admitted to the Department of Orthopaedics and Surgery of the Affiliated Zhongshan Hospital of Dalian University from January 2016 to January 2018, were analyzed retrospectively. This study included 4 men and 11 women, with a mean age of 64 ± 7.8 years (range, 47-77 years). A total of 5 cases involved the thumb, 4 involved the index finger, 5 involved ithe middle finger, and 4 involved the ring finger. Among a total of 18 digital mucous cysts, 7 cases were in the left hand and 11 were in the right hand. Approximately 77.8% of cases had osteophytes. The cysts ranged in size from 0.5-1.0 cm to 0.7-1.2 cm. All patients underwent cyst and osteophyte excision and a bipedicle advancement flap to cover the resultant defect. The same surgical procedure was applied to all patients. Postoperative flap survival, healing, and infection were evaluated. The preoperative and postoperative ranges of motion (ROM) of the distal interphalangeal (DIP) and thumb interphalangeal joints (TIPJ) were recorded. Postoperative patient satisfaction was assessed by the visual analog scale (VAS, 0-10) during follow-up visits. The Shapiro-Wilk test was used to determine whether the data for the difference between the preoperative and postoperative ROM of the DIP/TIPJ were normally distributed or not. The homogeneity of variance was expressed as mean ± standard deviation. A paired t-test was used to compare the preoperative and postoperative ROM of the DIP/TIPJ. RESULTS: The patients were followed up for 20 ± 6.0 months (range, 12-36 months). All the flaps survived after surgery, and the incisions healed well. The sutures were removed 2 weeks postoperatively. No infections occurred and there was no cyst recurrence at follow up. After systemic physical therapy and functional exercises, the ROM of all the fingers was restored to the preoperative ROM by 1 month after surgery. The scores for patient satisfaction with surgery by means of the VAS were 8.5 ± 1.0 points, 2.8 ± 1.4 points, 2.0 ± 1.6 points, 1.5 ± 1.2 points, and 1.1 ± 1.3 points preoperatively, and 1, 3, 6, and 12 months postoperatively, respectively. The data for the difference between preoperative and postoperative VAS scores were normally distributed. There were significant differences between the preoperative and postoperative VAS scores. The preoperative DIP/TIPJ ROM was 71.7° ± 14.0°, and the postoperative ROM at 1, 3, 6, and 12 months were 69.3° ± 15.3°, 70.4° ± 12.7°, 71.5° ± 15.6°, and 71.8° ± 15.6°, respectively. The data for the difference between preoperative and postoperative ROM of the DIP/TIPJ were normally distributed. No difference was found between the preoperative and postoperative ROM. CONCLUSION: The bipedicle advancement flap provides a simple and effective technique for covering skin defects following DMC excision.

Delivery of Rapamycin by Liposomes Synergistically Enhances the Chemotherapy Effect of 5-Fluorouracil on Colorectal Cancer.

BACKGROUND: Rapamycin is a promising agent for treating tumors, but clinical applications of rapamycin are limited due to its poor water solubility and low bioavailability. This paper constructs a liposome delivery system for rapamycin to improve the effect in treating colorectal cancer. METHODS: We prepared the rapamycin liposomes using the ethanol injection method. The cellular uptake and biodistribution were detected by LC-MS and in vivo imaging system. MTT assay, transwell migration experiment, flow cytometry, and Western blot analysis evaluated the antitumor effect of rapamycin liposomes in vitro. Furthermore, HCT-116 tumor-bearing mice were used to assess the therapeutic efficacy of rapamycin liposomes in vivo. RESULTS: The prepared rapamycin liposomes had a particle size of 100±5.5 nm and with a narrow size distribution. In vitro cellular uptake experiments showed that the uptake of rapamycin liposomes by colorectal cells was higher than that of free rapamycin. Subsequently, in vivo imaging experiments also demonstrated that rapamycin liposomes exhibited higher tumor accumulation. Therefore, the ability of rapamycin liposomes to inhibit tumor proliferation, migration and to induce tumor apoptosis is superior to that of free rapamycin. We also demonstrated in vivo good antitumor efficacy of the rapamycin liposomes in HCT-116 xenograft mice. In addition, rapamycin liposomes and 5-FU can synergistically improve the efficacy of colorectal cancer via the Akt/mTOR and P53 pathways. CONCLUSION: Collectively, rapamycin liposomes are a potential treatment for colorectal cancer, as it not only improves rapamycin's antitumor effect but also synergistically enhances 5-FU's chemotherapy effect.

T-cell death-associated gene 8 accelerates atherosclerosis by promoting vascular smooth muscle cell proliferation and migration.

BACKGROUND AND AIMS: Atherosclerosis is a serious cardiovascular disease, featuring inflammation, abnormal proliferation and migration of vascular smooth muscle cells (VSMCs). During atherosclerosis, inflammation may cause low pH. T-cell death-associated gene 8 (Tdag8) is a proton-sensing receptor, however, the role of Tdag8 in VSMCs remains unknown. This study aimed to investigate the potential effects of Tdag8 in VSMCs during atherosclerosis. METHODS: We examined the expression of Tdag8 in an atherosclerotic model of high-fat-diet-fed ApoE-/- mice, while the role and mechanism of Tdag8 in phenotype transformation, proliferation and migration of VSMCs were investigated in a series of in vivo and in vitro experiments. RESULTS: We first found that Tdag8 expression at the mRNA and protein level was significantly increased in atherosclerotic ApoE-/- mice. Immunofluorescence staining showed that Tdag8 was primarily distributed in PCNA-positive VSMCs and the phenotype of VSMCs switching from contractile phenotype to synthetic phenotype. Additionally, the protein level of Tdag8 was upregulated in FBS-treated VSMCs. VSMCs proliferation and migration were inhibited by Tdag8 silencing and increased by Tdag8 overexpression. Further mechanistic studies showed that cAMP level was increased in Tdag8-overexpressing VSMCs and ApoE-/- mice. However, the PKA inhibitor H-89 reversed Tdag8-induced VSMC proliferation and migration. CONCLUSIONS: The results demonstrate that Tdag8 mediated phenotype transformation, proliferation and migration of VSMCs via the cAMP/PKA signaling pathway, thus partially contributing to atherosclerosis.

Collaborative activities of macrophage-stimulating protein and transforming growth factor-beta1 in induction of epithelial to mesenchymal transition: roles of the RON receptor tyrosine kinase.

Epithelial to mesenchymal transition (EMT) is a process occurring during embryonic development and cancer progression. Using recepteur d'origine nantais (RON)-expressing epithelial cells as a model, we showed that RON activation causes spindle-shaped morphology with increased cell motilities. These activities resemble those observed in EMT induced by transforming growth factor (TGF)-beta1 or by Ras-Raf signaling. By immunofluorescent and Western blot analyses, we found that constitutive RON expression results in diminished expression of E-cadherin, redistribution of beta-catenin, reorganization of actin cytoskeleton, and increased expression of vimentin, a mesenchymal filament. RON expression is also essential for TGF-beta1-induced expression of alpha-smooth muscle actin (alpha-SMA), a specialized mesenchymal marker. In the study of signaling pathways responsible for RON-mediated EMT, it was found that PD98059, a MAP kinase inhibitor, blocks the collaborative activities of RON and TGF-beta1 in induction of alpha-SMA expression and restores epithelial cells to their original morphology. Moreover, we showed that RON expression increases Smad2 gene promoter activities and protein expression, which significantly lowers TGF-beta1 threshold for EMT induction. These results suggest that persistent RON expression and activation cause the loss of epithelial phenotypes. These changes, collaborating with TGF-beta1 signaling, could play a critical role in epithelial transdifferentiation towards invasiveness and metastasis of certain cancers.

Targeted expression of the receptor tyrosine kinase RON in distal lung epithelial cells results in multiple tumor formation: oncogenic potential of RON in vivo.

RON, a member of the MET proto-oncogene family, has been implicated in the progression of certain epithelial cancers. The purpose of this study was to determine the oncogenic potential of RON in vivo in lung epithelial cells. Transgenic mice were established using surfactant protein C promoter to express human RON in the distal lung epithelial cells. These mice were born normal but developed multiple lung tumors with distinct morphology and growth patterns. Tumors appeared as a single mass in the lung around 2 months of age and gradually developed into multiple nodules located mostly in the peripheral portions of the lung. A transition from early adenomas to later adenocarcinomas was observed. Morphologically, tumors were characterized as cuboidal epithelial cells with a type II cell phenotype, grew along the alveolar walls, and projected into the alveolar septa. RON was highly expressed and constitutively activated in tumors. These results indicate that overexpression of human wild-type RON causes the formation of lung tumors with unique biological characteristics in vivo. This model provides opportunities to study the role of RON in the pathogenesis of lung tumors and to elucidate the mechanisms underlying this distinct lung tumor.

Altered expression of the RON receptor tyrosine kinase in primary human colorectal adenocarcinomas: generation of different splicing RON variants and their oncogenic potential.

The RON receptor tyrosine kinase is a member of the MET proto-oncogene family that has been implicated in regulating motile-invasive phenotypes in certain types of epithelial cancers. The purpose of this study was to determine if RON expression is altered in primary human colorectal adenocarcinomas. Results from immunohistochemical staining showed that RON is highly expressed in the majority of colorectal adenocarcinomas (29/49 cases). Accumulated RON is also constitutively active with autophosphorylation in tyrosine residues. Moreover, three splicing variants of RON, namely RONdelta165, RONdelta160, and RONdelta155 were detected and cloned from two primary colon cancer samples. These RON variants were generated by deletions in different regions in extracellular domains of the RON beta chain. Functional studies showed that expression of RONdelta160 or RONdelta155 in Martin-Darby canine kidney cells resulted in increased cell dissociation (scatter-like activity). RON variants, RONdelta160 and RONdelta155, also exerted the ability to induce multiple focus formation and sustain anchorage-independent growth of transfected NIH3T3 cells. Moreover, NIH3T3 cells expressing RONdelta160 or RONdelta155 formed tumors in athymic nude mice and colonized in the lungs. These data suggest that RON expression is altered in certain primary colon cancers. Abnormal accumulation of RON variants may play a role in the progression of certain colorectal cancers in vivo.

RNA-mediated gene silencing of the RON receptor tyrosine kinase alters oncogenic phenotypes of human colorectal carcinoma cells.

Altered expression of receptor tyrosine kinases contributes to tumorigenic behaviors of epithelial cancers. In this study, the pathogenic roles of receptor tyrosine kinase RON (recepteur d'origine nantais) in regulating oncogenic phenotypes in colorectal epithelial cells were studied. Increased expression of RON and its variants resulted in colony formation and motile activities of colonic epithelial AA/C1 cells as evident in soft-agar and migration assays, respectively. These results suggest that overexpression of wild-type RON mediates the transformed phenotypes in immortalized colon epithelial cells. In colorectal cancer cells (HT-29, HCT116, and SW620) that naturally express RON, the RON gene expression was silenced by RNA interference. The introduction of RON-specific small interfering (si) RNA significantly affected cancer cell proliferation, motility, and led to increased apoptotic cell death. Focus-forming activities and anchorage-independent growth of colon cancer cells were also dramatically reduced. Moreover, it was demonstrated in tumor growth assays that silencing RON gene expression significantly reduces tumorigenic activities of SW620 cells in vivo. By analysing signaling proteins involved in colon carcinogenesis, we found that the effect of RON-specific siRNA is associated with diminished expression of beta-catenin, a critical component in the Wnt signaling pathway. Taken together, our results demonstrate that altered expression of RON in colon cancer cells is required to maintain tumorigenic phenotypes. Thus, silencing RON gene expression could have potential to reverse malignant activities of colon tumors in vivo.

Activation of the RON receptor tyrosine kinase protects murine macrophages from apoptotic death induced by bacterial lipopolysaccharide.

RON is a receptor tyrosine kinase activated by macrophage-stimulating protein. We demonstrate here that RON activation inhibits LPS-induced apoptosis of mouse peritoneal macrophages and Raw264.7 cells expressing RON or a constitutively active RON mutant. The antiapoptotic effect of RON was accompanied with the inhibition of LPS-induced production of nitric oxide (NO), a molecule responsible for LPS-induced cell apoptosis. This conclusion is supported by experiments using a chemical NO donor GSNO, in which RON activation directly blocked GSNO-induced apoptotic death of Raw264.7 cells and inhibited LPS-induced p53 accumulation. Furthermore, we showed that treatment of cells with wortmannin, which inhibits phosphatidylinositol (PI)-3 kinase, prevents the inhibitory effect of RON on LPS-induced macrophage apoptosis. These results were confirmed further by expression of a dominant inhibitory PI-3 kinase p85 subunit. These data suggest that by activating PI-3 kinase and inhibiting p53 accumulation, RON protects macrophage from apoptosis induced by LPS and NO. The antiapoptotic effect of RON might represent a novel mechanism for the survival of activated macrophages during inflammation.