Ascitic autotaxin as a potential prognostic, diagnostic, and therapeutic target for epithelial ovarian cancer.

BACKGROUND: Malignant ascites contributes to the metastatic process by facilitating the multifocal dissemination of ovarian tumour cells onto the peritoneal surface. However, the prognostic and diagnostic relevance of ascitic fluid remains largely unknown. Herein, we investigated the potential clinical value and therapeutic utility of ascitic autotaxin (ATX) in epithelial ovarian cancer (EOC). METHODS: ATX expression was assessed in clinical samples. Spheroid-forming assay, real-time PCR, western blot analysis, invadopodia assay, and adhesion assays were performed. RESULTS: Ascitic ATX expression was highly elevated in patients with ovarian cancer compared to those with benign ascites and was associated with advanced stage, high grade, and a short disease-free period in patients with EOC. Combining the diagnostic ability of ascitic ATX and serum CA-125 levels significantly improved the area under the curve (AUC) value for EOC compared to serum CA125 level alone. This marker combination showed a large odds ratio for short disease-free period in high-risk EOC groups. Functional studies revealed that ascitic ATX was required for maintaining cancer stem cell-like characteristics and invadopodia formation. CONCLUSION: Ascitic ATX levels may serve as a useful prognostic indicator for predicting aggressive behaviour in EOC. ATX-linked invadopodia are a potential target to prevent peritoneal dissemination in ovarian cancer.

Nectin-4 as a Predictive Marker for Poor Prognosis of Endometrial Cancer with Mismatch Repair Impairment.

The adhesion molecule Nectin-4 is a new potential therapeutic target for different types of cancer; however, little is known about its diagnosis significance in endometrial cancer (EC). We found that Nectin-4 expression was significantly higher in EC tissues than in nonadjacent normal tissue. The area under the receiver operating characteristic curve value of 0.922 indicated good diagnostic accuracy for Nectin-4 expression in EC. Furthermore, Nectin-4 expression was associated with DNA mismatch repair (MMR) protein deficiency. Notably, the high Nectin-4 expression group of patients with MSH2/6-deficient EC had shorter progression-free survival than that of the low Nectin-4 expression group. The number of lymphovascular space invasion-positive patients in groups with MMR deficiency and high Nectin-4 expression was also increased compared with that in the low Nectin-4 expression group. Bioinformatics analysis revealed that alteration in Nectin-4 and MMR genes is associated with Nectin-4 expression in EC. To the best of our knowledge, this is the first study to show that Nectin-4 expression may be a potential biomarker for EC diagnosis and that high Nectin-4 expression in MMR-deficient patients with EC can predict short progression-free survival, thus providing clues to identify patients for adjuvant therapy.

High-Dose Selenium Induces Ferroptotic Cell Death in Ovarian Cancer.

Selenium is a promising multi-target chemotherapeutic agent with controversial clinical results. Hence, reassessing the anticancer effects of Se is necessary to clearly understand the potential of high-dose selenium in cancer treatment. Here, we observed that high-dose sodium selenite (SS) significantly decreased the proliferation and increased the death of ovarian cancer cells, mediated by an increased generation of reactive oxygen species. Notably, high-dose SS decreased the levels of glutathione peroxidase (GPx), a selenoprotein with antioxidant properties, without altering other selenoproteins. Furthermore, high-dose SS triggered lipid peroxidation and ferroptosis, a type of iron-dependent cell death, due to dysregulated GPx4 pathways. We demonstrated that intravenous high-dose SS significantly reduced the tumor growth and weight in SKOV3-bearing mice. Consistent with our in vitro results, mice with SKOV3 cells treated with high-dose SS showed decreased GPx4 expression in tumors. Therefore, we highlight the significance of high-dose SS as a potential chemotherapeutic agent for ovarian cancer. High-dose SS-mediated ferroptotic therapy integrating glutathione depletion and ROS generation is a promising strategy for cancer therapy.

Engineered Corynebacterium glutamicum as the Platform for the Production of Aromatic Aldehydes.

Aromatic aldehydes, including 4-hydroxybenzaldehyde (4-HB aldehyde), protocatechuic (PC) aldehyde, and vanillin, are used as important flavors, fragrances, and pharmaceutical precursors and have several biological and therapeutic effects. Production of aromatic aldehydes in microbial hosts poses a challenge due to its rapid and endogenous reduction to alcohols. To address this hurdle, prospecting of the genome of Corynebacterium glutamicum yielded 27 candidate proteins that were used in comprehensive screening with a 4-hydroxybenzyl (4-HB) alcohol-producing strain. We identified that NCgl0324 has aromatic aldehyde reductase activity and contributed to 4-HB aldehyde reduction in vivo since the NCgl0324 deletion strain HB-Δ0324 produced 1.36 g/L of 4-HB aldehyde, that is, about 188% more than its parental strain. To demonstrate that NCgl0324 knockout can also improve production of PC aldehyde and vanillin, first, a basal MA303 strain that produces protocatechuate was engineered from 4-hydroxybenzoate-synthesizing C. glutamicum APS963, followed by deletion of NCgl0324 to generate PV-Δ0324. The PC aldehyde/alcohol or vanillin/vanillyl alcohol biosynthetic pathways, respectively, were able to be expanded from protocatechuate upon introduction of carboxylic acid reductase (CAR) and catechol O-methyltransferase encoded by a mutated comt m gene. In shake flask culture, the resulting NCgl0324 deletion strains PV-IΔ0324 and PV-IYΔ0324 were shown to produce 1.18 g/L PC aldehyde and 0.31 g/L vanillin, respectively. Thus, modulation of the identified NCgl0324 gene was shown to have the potential to boost production of valuable aromatic aldehydes and alcohols.

Cervical Cancer Prevention Education Program for Rural Korean Immigrant Women.

The study aimed to evaluate the effectiveness of a cervical cancer prevention education program for rural Korean immigrant women. A total of 46 Korean immigrant women who had not been screened in the past three years participated. The experimental group participated in the intervention program once a week for four weeks and completed a post-program survey in week 12. Compared to the control group, significant increases were detected in level of knowledge of cervical cancer prevention (p = .001), behavioral attitude toward cervical cancer prevention (p = .029) and behavioral intention regarding cervical cancer prevention (p = .005) in the experimental group. Pap screening rate of the experimental group was significantly increased (p = .029), but the rate of change in the selection of primary care providers was not significant. The results suggest the need for a multilevel approach to address cultural and systemic barriers to Korean immigrant women in promotion of cervical cancer prevention behavior.

Factors Influencing Unmet Healthcare Needs among Older Korean Women.

The purpose of this study was to determine factors that influence the unmet healthcare needs of older women in Korea and to examine differences in the reasons for these unmet healthcare needs according to age and residential area. We analyzed data from the 2018 Korea Community Health Survey and enrolled 42,698 older Korean women in this study. Residential area, living arrangement, income, education, basic livelihood subsidy, activity of daily living, subjective health status, hypertension and diabetes, unmet healthcare needs, and the reasons healthcare needs were not met were assessed. Logistic regression analysis was performed to identify factors that influenced unmet healthcare needs. Chi-square tests were used to identify reasons for unmet healthcare needs according to age group and residential area. Of the participants, 4151 (9.7%) reported unmet healthcare needs over the past year. The primary reason participants could not use health services was "inconvenient transportation" (38.4%), followed by "financial burden" (28.4%) and "symptoms not severe" (16.8%). There were significant differences in "financial burden", "difficulty making appointments", "inconvenient transportation", and "symptoms not severe" according to both age group and residential area. Factors that influenced unmet healthcare needs were residential area, living alone, lower family income, lower educational level, basic livelihood subsidy, difficult activities of daily living, hypertension and diabetes, and poor subjective health. Older women in Korea living alone in urban and rural areas had more unmet healthcare needs of than those who lived with other people. To address the unmet healthcare needs of older Korean women, transportation and medical facilities need to be improved or established.

Clinical Significance of Tumor Infiltrating Lymphocytes in Association with Hormone Receptor Expression Patterns in Epithelial Ovarian Cancer.

Hormone receptor expression patterns often correlate with infiltration of specific lymphocytes in tumors. Specifically, the presence of specific tumor-infiltrating lymphocytes (TILs) with particular hormone receptor expression is reportedly associated with breast cancer, however, this has not been revealed in epithelial ovarian cancer (EOC). Therefore, we investigated the association between hormone receptor expression and TILs in EOC. Here we found that ERα, AR, and GR expression increased in EOC, while PR was significantly reduced and ERß expression showed a reduced trend compared to normal epithelium. Cluster analysis indicated poor disease-free survival (DFS) in AR+/GR+/PR+ subgroup (triple dominant group); while the Cox proportional-hazards model highlighted the triple dominant group as an independent prognostic factor for DFS. In addition, significant upregulation of FoxP3+ TILs, PD-1, and PD-L1 was observed in the triple dominant group compared to other groups. NanoString analyses further suggested that tumor necrosis factor (TNF) and/or NF-κB signaling pathways were activated with significant upregulation of RELA, MAP3K5, TNFAIP3, BCL2L1, RIPK1, TRAF2, PARP1, and AKT1 in the triple dominant EOC group. The triple dominant subgroup correlates with poor prognosis in EOC. Moreover, the TNF and/or NF-κB signaling pathways may be responsible for hormone-mediated inhibition of the immune microenvironment.

Anti-Inflammatory Effect of Artemisia argyi on Ethanol-Induced Gastric Ulcer: Analytical, In Vitro and In Vivo Studies for the Identification of Action Mechanism and Active Compounds.

Artemisia argyi is widely used as traditional medicine in East Asia. However, its effects against inflammation and gastric ulcers have not been reported yet. We analyzed anti-inflammatory activity and its molecular mechanisms of A. argyi using RAW264.7 cells line, then evaluated the curative efficacy in rats with acute gastric ulcers. Nitric oxide and IL-6 production was measured using Griess reagent and an ELISA kit. Inducible nitric oxide synthase (iNOS), interleukin (IL)-6, and mucin (MUC)1, MUC5AC, and MUC6 mRNA were determined by SYBR Green or Taqman qRT-PCR methods. The phosphorylation of ERK, JNK, p38, and c-Jun protein were detected by western blotting. RW0117 inhibited LPS-induced NO and IL-6 production. The mRNA levels of iNOS and IL-6 were strongly suppressed. The phosphorylation of ERK, JNK, and c-Jun decreased by treatment with RW0117. Oral administration of RW0117 recovered the amount of mucin mRNA and protein level that was decreased due to gastric ulcers by HCl-EtOH. A. argyi exhibited strong anti-inflammatory effects and contributed to the modulation of HCl-EtOH-induced gastric ulcer in rats.

ALDH1A2 Is a Candidate Tumor Suppressor Gene in Ovarian Cancer.

Aldehyde dehydrogenase 1 family member A2 (ALDH1A2) is a rate-limiting enzyme involved in cellular retinoic acid synthesis. However, its functional role in ovarian cancer remains elusive. Here, we found that ALDH1A2 was the most prominently downregulated gene among ALDH family members in ovarian cancer cells, according to complementary DNA microarray data. Low ALDH1A2 expression was associated with unfavorable prognosis and shorter disease-free and overall survival for ovarian cancer patients. Notably, hypermethylation of ALDH1A2 was significantly higher in ovarian cancer cell lines when compared to that in immortalized human ovarian surface epithelial cell lines. ALDH1A2 expression was restored in various ovarian cancer cell lines after treatment with the DNA methylation inhibitor 5-aza-2'-deoxycytidine. Furthermore, silencing DNA methyltransferase 1 (DNMT1) or 3B (DNMT3B) restored ALDH1A2 expression in ovarian cancer cell lines. Functional studies revealed that forced ALDH1A2 expression significantly impaired the proliferation of ovarian cancer cells and their invasive activity. To the best of our knowledge, this is the first study to show that ALDH1A2 expression is regulated by the epigenetic regulation of DNMTs, and subsequently that it might act as a tumor suppressor in ovarian cancer, further suggesting that enhancing ALDH1A2-linked signaling might provide new opportunities for therapeutic intervention in ovarian cancer.

MicroRNA-mediated disruption of dendritogenesis during a critical period of development influences cognitive capacity later in life.

The prenatal period of cortical development is important for the establishment of neural circuitry and functional connectivity of the brain; however, the molecular mechanisms underlying this process remain unclear. Here we report that disruption of the actin-cytoskeletal network in the developing mouse prefrontal cortex alters dendritic morphogenesis and synapse formation, leading to enhanced formation of fear-related memory in adulthood. These effects are mediated by a brain-enriched microRNA, miR-9, through its negative regulation of diaphanous homologous protein 1 (Diap1), a key organizer of the actin cytoskeletal assembly. Our findings not only revealed important regulation of dendritogenesis and synaptogenesis during early brain development but also demonstrated a tight link between these early developmental events and cognitive functions later in life.

Influence of Leisure Competence and Level of Leisure Activity on Life Satisfaction in Low-Income Older Adults in Rural South Korea.

The purpose of the current study was to investigate the relationships among leisure competence, level of leisure activity, and life satisfaction in low-income older adults in rural South Korea. A sample of 137 older adults answered the study questionnaire, and significant differences in leisure competence were noted depending on age, religion, and perceived health status as well as level of leisure activity based on perceived health status and type of leisure activities. There were also notable differences in life satisfaction regarding religion and perceived health status, and a correlation among leisure competence, level of leisure activity, and life satisfaction; the influencing power of leisure competence and level of leisure activity on life satisfaction was 47%. The findings suggest that enhancement of older adults' leisure competence may increase participation in leisure activities. [Res Gerontol Nurs. 2017; 10(2):67-75.].

TIS21/BTG2 inhibits doxorubicin-induced stress fiber-vimentin networks via Nox4-ROS-ABI2-DRF-linked signal cascade.

Activities of TIS21/BTG2 gene regulating cancer cell senescence were investigated in hepatoma cells by using low dose doxorubicin (Doxo, 100ng/mL). Treatment of Huh7 cells with Doxo increased linear actin nucleation e.g., transverse arcs and ventral stress fibers, as opposed to loss of filopodia. The linear actin nucleation was accompanied with thick vimentin networks at periphery of the cells, when examined by super-resolution STED microscope. However, expression of TIS21 inhibited ABI2-DRF pathway by inhibiting DRF expression and reducing ABI2 protein stability. The change lead to downregulation of stress fiber formations and thick vimentin networks at the periphery of Huh7 cells. In addition, TIS21 inhibited NADPH oxidase 4 (Nox4)-derived reactive oxygen species (ROS) generation that regulates actin nucleator, DRF family gene expression. Taken together, TIS21 attenuated Doxo-induced cancer cell senescence by inhibiting linear actin nucleation via Nox4-ROS-ABI2-DRF signal cascade, implying that expression of TIS21 overcomes resistance of senescent cells to cancer chemotherapy via inhibiting linear actin nucleation.

Interaction of the diabetes mellitus and cardiac diseases on survival outcomes in out-of-hospital cardiac arrest.

BACKGROUND: Diabetes mellitus (DM) and cardiac disease (CD) both likely effect out-of-hospital cardiac arrest (OHCA) survival, but the effect of their relationship on survival outcomes is unclear. This study aims to investigate whether the association of DM and OHCA outcomes differ in patients with and without CD. METHODS: The study was conducted from the national cardiac arrest registry among OHCA patients who survived to hospital admission from 2009 to 2013. Clinical histories of DM and CD were abstracted from patient medical records. Multivariable logistic regression analysis with an interaction term (DM and CD) was performed to calculate adjusted odds ratios (AORs) for survival to discharge and good cerebral performance category 1 or 2 (good CPC). RESULTS: Among 7583 study-eligible patients, 2651 (34.96%) patients had been previously diagnosed as having DM where 639 (24.1%) diabetic and 753 (15.3%) nondiabetic patients had CD (P<.01). Diabetes mellitus was observed to have harmful effect on survival and good CPC (AORs, 0.84 [0.75-0.95] and 0.81 [0.67-0.97]), whereas CD had nonsignificant effect (AORs, 1.34 [1.17-1.54] and 1.14 [0.94-1.38]). Diabetes mellitus had a significant negative association with survival outcomes in patients with CD (AORs, 0.58 [0.45-0.74] for survival and 0.52 [0.36-0.75] for good CPC), whereas the association was nonsignificant in patients without CD (AORs, 0.93 [0.82-1.06] for survival and [0.76-1.14] for good CPC). CONCLUSION: Diabetes mellitus had a significant negative association with survival to discharge and neurologic recovery among patients with CD, but the association was not significant in patients without CD.

Ras promotes transforming growth factor-ß (TGF-ß)-induced epithelial-mesenchymal transition via a leukotriene B4 receptor-2-linked cascade in mammary epithelial cells.

Inflammation and inflammatory mediators are inextricably linked with epithelial-mesenchymal transition (EMT) through complex pathways in the tumor microenvironment. However, the mechanism by which inflammatory mediators, such as the lipid inflammatory mediators, eicosanoids, contribute to EMT is largely unknown. In the present study we observed that BLT2, leukotriene B4 receptor-2, is markedly up-regulated by oncogenic Ras and promotes EMT in response to transforming growth factor-ß (TGF-ß) in mammary epithelial cells. Blockade of BLT2 by the BLT2 inhibitor LY255283 or by siRNA reduced EMT induced by Ras in the presence of TGF-ß. In addition, stimulation of BLT2 by the addition of a BLT2 ligand, such as leukotriene B4, restored EMT in the presence of TGF-ß in human immortalized mammary epithelial MCF-10A cells. We further searched BLT2 downstream components and identified reactive oxygen species and nuclear factor κB as critical components that contribute to EMT. Taken together, these results demonstrate for the first time that a BLT2-linked inflammatory pathway contributes to EMT. This provides valuable insight into the mechanism of EMT in mammary epithelial cells. In addition, considering the implications of EMT with the stemness of cancer cells, our finding may contribute to a better understanding of tumor progression.

TIS21/BTG2 inhibits invadopodia formation by downregulating reactive oxygen species level in MDA-MB-231 cells.

PURPOSE: Invasion of cancer cells depends on the proteolytic degradation of extracellular matrix regulated by actin-driven membrane protrusions, called invadopodia. However, the mechanisms underlying invadopodia formation in cancer cells remain largely unknown. METHODS: By employing adenoviral transduction of breast cancer cells with either ß-galactosidase (Ad-LacZ) or TIS21(/BTG2/Pc3) (Ad-TIS21) gene, the regulation of invadopodia formation was investigated. Invasion activity was examined by invadopodia assay and Matrigel assay. Intracellular reactive oxygen species (ROS) was monitored by FACS-based analysis. RESULTS: Here, we observed that TIS21 suppressed invadopodia formation as well as invasion activity along with F-actin remodeling. The inhibition of TIS21-mediated invadopodia formation was accompanied with attenuation of ROS generation in the TIS21 expressers, indicating that TIS21-mediated inhibition of ROS plays a critical role for invadopodia formation by regulating actin-associated protein remodeling. This was further confirmed in the TIS21(-/-)MEF cells. CONCLUSIONS: This is the first report to provide insight into invasion signals regulated by tumor suppressor, TIS21(/BTG2/Pc3) gene, in the intractable breast cancer cells.

BLT2 up-regulates interleukin-8 production and promotes the invasiveness of breast cancer cells.

BACKGROUND: The elevated production of interleukin (IL)-8 is critically associated with invasiveness and metastatic potential in breast cancer cells. However, the intracellular signaling pathway responsible for up-regulation of IL-8 production in breast cancer cells has remained unclear. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we report that the expression of BLT2 is markedly up-regulated in the highly aggressive human breast cancer cell lines MDA-MB-231 and MDA-MB-435 compared with MCF-10A immortalized human mammary epithelial cells, as determined by RT-PCR, real-time PCR and FACS analysis. Blockade of BLT2 with BLT2 siRNA knockdown or BLT2 inhibitor treatment downregulated IL-8 production and thereby diminished the invasiveness of aggressive breast cancer cells, analyzed by Matrigel invasion chamber assays. We further characterized the downstream signaling mechanism by which BLT2 stimulates IL-8 production and identified critical mediatory roles for the generation of reactive oxygen species (ROS) and the consequent activation of the transcription factor NF-κB. Moreover, blockade of BLT2 suppressed the formation of metastatic lung nodules by MDA-MB-231 cells in both experimental and orthotopic metastasis models. CONCLUSIONS/SIGNIFICANCE: Taken together, our study demonstrates that a BLT2-ROS-NF-κB pathway up-regulates IL-8 production in MDA-MB-231 and MDA-MB-435 cells, thereby contributing to the invasiveness of these aggressive breast cancer cells. Our findings provide insight into the molecular mechanism of invasiveness in breast cancer.

Pro-survival of estrogen receptor-negative breast cancer cells is regulated by a BLT2-reactive oxygen species-linked signaling pathway.

Leukotriene B4 (LTB4) is an inflammatory mediator with potent biological activities in the pathogenesis of many inflammatory diseases. In the present study, we found that expression of BLT2, a low-affinity LTB4 receptor, is significantly upregulated in breast cancer cells. In addition, we observed that inhibition of BLT2 by a specific antagonist, LY255283, or by siBLT2 RNA interference caused dramatic apoptotic cell death in breast cancer cells, especially in the estrogen receptor (ER)-negative MDA-MB-468 and MDA-MB-453 cells, suggesting a role for BLT2 in survival of these breast cancer cells. In an approach to understand the downstream mechanism by which BLT2 mediates the potential pro-survival signaling, we found that the elevated reactive oxygen species (ROS) generation is associated with BLT2-mediated survival. Expression of Nox1, a member of the NADPH oxidase family, is also highly upregulated in a BLT2-dependent manner in these breast cancer cells, suggesting that 'Nox1-derived ROS' lie downstream of BLT2. Consistent with the proposed role of 'Nox1-ROS' in pro-survival signaling, knockdown of Nox1 with siNox1 or treatment with a ROS scavenging agent caused dramatic apoptotic death in these breast cancer cells. Taken together, our results demonstrate, for the first time, that the 'BLT2-Nox1-ROS'-linked cascade is involved in the pro-survival signaling, especially in ER-negative breast cancer cells.

Reactive oxygen species are generated through a BLT2-linked cascade in Ras-transformed cells.

Although production of reactive oxygen species (ROS) by oncogenic Ras is thought to be crucial for Ras transformation, very little is known about the signaling mechanism involved. In the present study, we investigated whether BLT2, a low-affinity leukotriene B(4) receptor, is involved in the generation of ROS in H-Ras(V12)-transformed fibroblasts. We show that downregulation of BLT2 using RNA interference or antisense oligonucleotides inhibits ROS generation, and that Nox1 acts downstream of BLT2. Moreover, BLT2 overexpression caused increased ROS production and partial transformation. Taken together, our results suggest that a BLT2-Nox1-linked cascade is responsible for the elevated ROS generation in Ras-transformed cells. Our finding may contribute to clarifying the signaling events underlying the enhanced levels of ROS frequently observed in various transformed cells and possibly serve as a basis for developing new therapeutic strategies for human cancers.

Cellular metabolic responses of PET radiotracers to (188)Re radiation in an MCF7 cell line containing dominant-negative mutant p53.

UNLABELLED: We investigated the relations between the cell uptakes of metabolic radiotracers and beta-radiation pretreatment using a dominant mutant p53 (p53mt) cell line to evaluate the effects of p53 genes on (18)F labeled positron emission tomography (PET) radiotracer uptakes. METHODS: pCMV-Neo-Bam (control), which contains a neo-resistance marker, and p53 dominant-negative mutant expression constructs were stably transfected into MCF7 cell line. Cells were plated in 24-well plates at 1.0x10(5) cells for 18 h. Rhenium-188 ((188)Re) (a beta emitter) was added to the medium (3.7, 18.5, 37 MBq) and incubated for 24 h. We performed gamma-counting to determine the cellular uptakes of 2-[(18)F]fluoro-2-deoxy-d-glucose (FDG), o-(2-[(18)F]fluoroethyl)-l-tyrosine (FET) and 2'-[(18)F]fluoro-2'-deoxythymidine (FLT) (370 kBq, 60 min). Cell viabilities were determined by trypan blue staining and flow cytometry. RESULTS: p53mt cells showed 1.5-2-fold higher FDG uptake than wild-type p53 cells in basal condition, and the difference of FDG uptake was greater after (188)Re treatment (P<.01). FET uptake increased with (188)Re dose without a significant difference between p53 statuses. p53mt cells showed lower FLT uptake than wild-type p53 cells in basal condition, and the difference of FLT uptake was greater after (188)Re treatment. By cell viability testing and FACS analysis, p53mt cells showed lower viability and a larger apoptotic fraction (sub-G1) than wild-type p53 cells after (188)Re treatment. CONCLUSION: We speculate that p53 dysfunction increases glucose and decreases thymidine metabolism in cancer cells and that this may be exaggerated by (188)Re beta-radiation. Our findings suggest that FDG could reflect tumor viability and malignant potential after (188)Re beta-radiation treatment, whereas FLT could be a more useful PET radiotracer for assessing therapeutic response to beta-radiation, especially in cancer cells with an altered function of p53.

Inhibition of receptor internalization attenuates the TNFalpha-induced ROS generation in non-phagocytic cells.

Reactive oxygen species (ROS) are important regulatory molecules implicated in the signaling cascade triggered by tumor necrosis factor (TNF)alpha, although the events through which TNFalpha induces ROS generation are not well characterized. Here, we report that TNFalpha-induced ROS production was blocked by pretreatment with internalization inhibitor monodansyl cadaverine (MDC). Similarly, a transient expression of a GTP-binding and hydrolysis-defective dynamin mutant (dynamin(K44A)) that had been shown to be defective in internalization significantly attenuated the TNFalpha-induced intracellular ROS production. Importantly, the inhibition of receptor internalization suppressed TNFalpha signaling to mitogen-activated protein kinases (MAPKs) stimulation. Together, our results suggest that receptor internalization is somehow necessary for the TNFalpha-induced ROS generation and subsequent intracellular downstream signaling in non-phagocytes.