Curcumin Enhances the Anticancer Effects of Binimetinib on Melanoma Cells by Inducing Mitochondrial Dysfunction and Cell Apoptosis with Necroptosis

Background@#Recent studies suggest that MEK1/2 inhibitors, including binimetinib, significantly improve malignant melanoma (MM) patient survival. Growing evidence suggests that phytochemicals, especially curcumin, can overcome drug resistance in cancer cells through a variety of mechanisms. @*Objective@#This study aims to examine curcumin’s efficacy in vitro combined with binimetinib in human MM cells. @*Methods@#We used 2D monolayer and 3D spheroid human epidermal melanocyte culture models, HEMn-MP (human epidermal melanocytes, neonatal, moderately pigmented), and two human MM cell lines, G361 and SK-MEL-2, to evaluate cell viability, proliferation, migration, death, and reactive oxygen species (ROS) production following single therapy treatment, with either curcumin or binimetinib, or a combination of both. @*Results@#Compared to MM cells treated with single therapy, those with combination therapy showed significantly decreased cell viability and increased ROS production. We observed apoptosis following both single and combination therapies. However only those who had had combination therapy had necroptosis. @*Conclusion@#Collectively, our data demonstrates that curcumin exerts significant synergistic anticancer effects on MM cells by inducing ROS and necroptosis when combined with binimetinib. Therefore, a strategy of adding curcumin to conventional anticancer agents holds promise for treating MM.

Overexpression of Nrf2 promotes colon cancer progression via ERK and AKT signaling pathways

Purpose@#We investigated the expression of Nrf2 in colorectal cancer and its correlation with clinicopathological characteristics as well as mechanisms and roles of Nrf2 expression including cell signaling pathway, survival, proliferation, and migration. @*Methods@#Nrf2 expression was measured in 12 and 30 different colorectal cancer (CRC) tissues by western blot (WB) and immunohistochemistry (IHC), respectively. SW480 cells were used for cell proliferation and cell migration tests. The correlation between the expression of Nrf2 and clinicopathologic parameters were evaluated using the chi-square or Fisher exact test. Data are expressed as the mean ± standard deviation for 3 independent experiments. P < 0.05 was considered statistically significant. @*Results@#Analysis of WB demonstrated that Nrf2 proteins were increased in CRC tissues, and decreased in normal tissues. IHC staining showed that the Nrf2 expression was elevated in CRC tissues, compared to matched normal tissues. When SW480 cells were suppressed with small interfering RNA of Nrf2, cell viability was inhibited, and cell apoptosis was increased. These results were found along with suppression of the phosphorylated form of extracellular signal-regulated kinase 1/2 and AKT. @*Conclusion@#This study suggests that overexpression of Nrf2 may be related to carcinogenesis and progression of CRC.

Apigenin causes necroptosis by inducing ROS accumulation, mitochondrial dysfunction, and ATP depletion in malignant mesothelioma cells

Apigenin, a naturally occurring flavonoid, is known to exhibit significant anticancer activity. This study was designed to determine the effects of apigenin on two malignant mesothelioma cell lines, MSTO-211H and H2452, and to explore the underlying mechanism(s). Apigenin significantly inhibited cell viability with a concomitant increase in intracellular reactive oxygen species (ROS) and caused the loss of mitochondrial membrane potential (ΔΨm), and ATP depletion, resulting in apoptosis and necroptosis in monolayer cell culture. Apigenin upregulated DNA damage response proteins, including the DNA double strand break marker phospho (p)-histone H2A.X. and caused a transition delay at the G2 /M phase of cell cycle. Western blot analysis showed that apigenin treatment upregulated protein levels of cleaved caspase-3, cleaved PARP, p-MLKL, and p-RIP3 along with an increased Bax/Bcl-2 ratio.ATP supplementation restored cell viability and levels of DNA damage-, apoptosisand necroptosis-related proteins that apigenin caused. In addition, N-acetylcysteine reduced ROS production and improved ΔΨm loss and cell death that were caused by apigenin. In a 3D spheroid culture model, ROS-dependent necroptosis was found to be a mechanism involved in the anti-cancer activity of apigenin against malignant mesothelioma cells. Taken together, our findings suggest that apigenin can induce ROS-dependent necroptotic cell death due to ATP depletion through mitochondrial dysfunction. This study provides us a possible mechanism underlying why apigenin could be used as a therapeutic candidate for treating malignant mesothelioma.

Apigenin causes necroptosis by inducing ROS accumulation, mitochondrial dysfunction, and ATP depletion in malignant mesothelioma cells

Apigenin, a naturally occurring flavonoid, is known to exhibit significant anticancer activity. This study was designed to determine the effects of apigenin on two malignant mesothelioma cell lines, MSTO-211H and H2452, and to explore the underlying mechanism(s). Apigenin significantly inhibited cell viability with a concomitant increase in intracellular reactive oxygen species (ROS) and caused the loss of mitochondrial membrane potential (ΔΨm), and ATP depletion, resulting in apoptosis and necroptosis in monolayer cell culture. Apigenin upregulated DNA damage response proteins, including the DNA double strand break marker phospho (p)-histone H2A.X. and caused a transition delay at the G2 /M phase of cell cycle. Western blot analysis showed that apigenin treatment upregulated protein levels of cleaved caspase-3, cleaved PARP, p-MLKL, and p-RIP3 along with an increased Bax/Bcl-2 ratio.ATP supplementation restored cell viability and levels of DNA damage-, apoptosisand necroptosis-related proteins that apigenin caused. In addition, N-acetylcysteine reduced ROS production and improved ΔΨm loss and cell death that were caused by apigenin. In a 3D spheroid culture model, ROS-dependent necroptosis was found to be a mechanism involved in the anti-cancer activity of apigenin against malignant mesothelioma cells. Taken together, our findings suggest that apigenin can induce ROS-dependent necroptotic cell death due to ATP depletion through mitochondrial dysfunction. This study provides us a possible mechanism underlying why apigenin could be used as a therapeutic candidate for treating malignant mesothelioma.

Cytohesin-2 Is Upregulated in Malignant Melanoma and Contributes to Tumor Growth

No abstract available.

Infection Status of Endoparasites in Foreigner Workers Living in Cheonan City, Chungnam Province, Korea

At present, more than 500,000 foreigner workers, most of them from Asian countries with high parasitic infection rates, are working in Korea. Since investigation into the prevalence of parasitic infections in foreigner workers has not yet been conducted in Korea, the present study was performed to determine the parasitic infection status of foreigner workers living in Cheonan City, Chungcheongnam-do (Chungnam Province) and to plan, on that basis, effective control measures. From October to December 2013, the parasitic infection status of 231 foreigner workers employed at selected Cheonan-si small businesses was investigated by both stool examination and ELISA. A total of 60 individuals (26.0%) were found to be infected with parasites. The stool examination detected 14 positive cases (6.1%), and ELISA revealed 50 positive people (21.6%), for at least a kind of parasitic disease. The most common infection was cysticercosis (8.7%), followed by toxocariasis (7.8%) and clonorchiasis (7.4%). Since it was proved that parasitic infections were prevalent among foreigner workers living in Cheonan City, more comprehensive study is urgently needed in order to understand the nationwide status of parasitic infections in foreigner workers.

Oxidative Damage and Nuclear Factor Erythroid 2-Related Factor 2 Protein Expression in Normal Skin and Keloid Tissue

BACKGROUND: Reactive oxygen species (ROS) play an important role in the induction of apoptosis under pathological conditions. Recently, a significant increase in ROS production and disrupted apoptosis mechanisms in keloids have been reported. Nuclear factor erythroid 2-related factor 2 (Nrf2) represents one of the most important cellular defense mechanisms against oxidative stress and is implicated in the regulation of apoptosis. Recently, it has been reported that Nrf2 upregulates Bcl-2, an anti-apoptotic protein. OBJECTIVE: To compare Nrf2 protein expression in normal skin tissues to keloid tissues. METHODS: ROS generation in keloid tissues was evaluated with OxyBlot analysis. Western blotting and/or immunohistochemical staining approaches were used to study expression of Nrf2 or Bcl-2 in keloid and normal skin tissues. Cellular fractionation was performed to examine subcellular distribution of Nrf2. Transfection of fibroblasts with Nrf2-specific small interfering RNA (siRNA) was conducted to understand the relationship between Nrf2 expression and apoptosis induction. RESULTS: Protein oxidation, a marker of oxidative stress, is increased in keloid tissues. Western blot analysis clearly showed that Nrf2 and Bcl-2 are downregulated in keloid tissues. Immunohistochemical staining of Nrf2 confirmed the results of the western blot analysis. Transfection of fibroblasts with the Nrf2-specific siRNA results in increased apoptosis and decreased cell viability. CONCLUSION: Collectively, our data indicate that Nrf2 expression is downregulated in keloid tissues, and that Nrf2 is involved in the development of apoptosis in Nrf2 siRNA-transfected fibroblasts. We propose that a defective antioxidant system and apoptotic dysregulation may participate in keloid pathogenesis.

Oxidative Damage and Nuclear Factor Erythroid 2-Related Factor 2 Protein Expression in Normal Skin and Keloid Tissue

BACKGROUND: Reactive oxygen species (ROS) play an important role in the induction of apoptosis under pathological conditions. Recently, a significant increase in ROS production and disrupted apoptosis mechanisms in keloids have been reported. Nuclear factor erythroid 2-related factor 2 (Nrf2) represents one of the most important cellular defense mechanisms against oxidative stress and is implicated in the regulation of apoptosis. Recently, it has been reported that Nrf2 upregulates Bcl-2, an anti-apoptotic protein. OBJECTIVE: To compare Nrf2 protein expression in normal skin tissues to keloid tissues. METHODS: ROS generation in keloid tissues was evaluated with OxyBlot analysis. Western blotting and/or immunohistochemical staining approaches were used to study expression of Nrf2 or Bcl-2 in keloid and normal skin tissues. Cellular fractionation was performed to examine subcellular distribution of Nrf2. Transfection of fibroblasts with Nrf2-specific small interfering RNA (siRNA) was conducted to understand the relationship between Nrf2 expression and apoptosis induction. RESULTS: Protein oxidation, a marker of oxidative stress, is increased in keloid tissues. Western blot analysis clearly showed that Nrf2 and Bcl-2 are downregulated in keloid tissues. Immunohistochemical staining of Nrf2 confirmed the results of the western blot analysis. Transfection of fibroblasts with the Nrf2-specific siRNA results in increased apoptosis and decreased cell viability. CONCLUSION: Collectively, our data indicate that Nrf2 expression is downregulated in keloid tissues, and that Nrf2 is involved in the development of apoptosis in Nrf2 siRNA-transfected fibroblasts. We propose that a defective antioxidant system and apoptotic dysregulation may participate in keloid pathogenesis.

Expression of Nuclear Factor Erythroid 2 Protein in Malignant Cutaneous Tumors

BACKGROUND: Reactive oxygen species (ROS) damages cell molecules, and modifies cell signaling. The nuclear factor E2-related factor (Nrf2) is a critical transcription regulator, which protects cells against oxidative damage. Nrf2 expression is increased in a large number of cancers. However, little information has been reported regarding the expression of Nrf2 in skin cancers. Hence, we explored the expression of Nrf2 protein in skin cancers. METHODS: The Nrf2 protein expression in 24 specimens, including 6 malignant melanomas (MM), 6 squamous cell carcinomas (SCC), 6 basal cell carcinomas (BCC), and 6 normal skin tissues, was evaluated by western blotting. Immunohistochemical staining was performed. The expression of Kelch-like ECH-associated protein 1 (Keap1), the key regulator of Nrf2, was also analyzed by western blotting. RESULTS: Small interfering RNA transfection to the melanoma cell line G361 confirmed that an approximately 66 kDa band was the true Nrf2 band. The western blot revealed that the Nrf2 protein was definitely expressed in normal skin tissues, but the Nrf2 expression was decreased in MM, SCC, and BCC. Immunohistochemical examination showed that expression of Nrf2 was decreased in all skin cancer tissues compared to the normal skin tissues. Keap1 was not expressed in all malignant skin tumors and normal skin tissues by western blot. CONCLUSIONS: ROS was increased in various types of cancers which proteins were highly expressed or underexpressed. This study demonstrated that the expression of Nrf2 protein was down-regulated in human malignant skin tumors. We suggest that decreased expression of Nrf2 is related to skin cancers.

Overexpression of KAI1 Protein in Diabetic Skin Tissues

BACKGROUND: Patients with diabetes mellitus often have a difficult life, suffering from foot ulceration or amputation. Diabetes is characterized by chronic inflammation, and one of the features of inflammation is hypoxia. Recently, it has been reported that KAI1 is a hypoxia target gene. There is no published research on hypoxia-related KAI1 protein levels in human diabetic skin. Therefore, we have investigated the expression of KAI1 protein in diabetic skin tissue in vivo. METHODS: The expression of KAI1 protein was evaluated by western blotting in 6 diabetic skin tissue samples and 6 normal skin samples. Immunohistochemical staining was carried out to identify KAI1 expression. RESULTS: The western blotting revealed significantly increased expression of the KAI1 protein in diabetic skin tissues as compared to normal skin tissues. Immunohistochemical examination demonstrated that KAI1 was expressed in all diabetic skin tissues with moderate-to-strong positivity and weakly expressed in normal skin tissues. CONCLUSIONS: Our data suggest that a high expression of the KAI1 protein can be observed in diabetic skin tissue. To the best of our knowledge, this is the first report suggesting that KAI1 protein expression in diabetic skin tissues may be associated with chronic inflammatory states and hypoxia.

Evaluation of a New Immunochromatographic Assay Kit for the Rapid Detection of Norovirus in Fecal Specimens

Rapid and accurate detection of norovirus is essential for the prevention and control of norovirus outbreaks. This study compared the effectiveness of a new immunochromatographic assay kit (SD BIOLINE Norovirus; Standard Diagnostics, Korea) and real-time reverse transcription-PCR (RT-PCR) for detecting norovirus in fecal specimens. Compared with real-time RT-PCR, the new assay had sensitivity, specificity, positive predictive value, and negative predictive value of 76.5% (52/68), 99.7% (342/343), 98.1% (52/53), and 95.5% (342/358), respectively. The sensitivity of the assay was 81.8% (18/22) for GII.3 and 75.7% (28/37) for GII.4. None of the 38 enteric virus-positive specimens (3 for astrovirus, 5 for enteric adenovirus, and 30 for rotavirus) tested positive in the cross-reactivity test performed by using this assay. The new immunochromatographic assay may be a useful screening tool for the rapid detection of norovirus in sporadic and outbreak cases; however, negative results may require confirmatory assays of greater sensitivity.

Efficacy of Intravenous Immunoglobulin Therapy in Childhood Atopic Dermatitis

OBJECTIVE: Atopic dermatitis (AD) is a chronic inflammatory skin disease with significant morbidity, and for which there is a need for safe and effective alternative therapies. Although a few observations on the efficacy of intravenous immunoglobulin (IVIG) in AD have been reported, clinical evidence of effectiveness from controlled trials is lacking. Therefore, the purpose of this study was to clarify whether IVIG therapy (1.0 g/kg body weight at each monthly visit for 6 months) is effective in childhood atopic dermatitis and to analyze the clinical characteristics of IVIG responses in this disease. METHODS: Forty three atopic dermatitis patients who had characteristic clinical features of atopic dermatitis were included in this study. The patients received an injection of IVIG at 1.0 g/kg body weight at each monthly visit for 6 months. Laboratory tests were performed for blood chemistry, total immunoglobulin E, immunoglobulin G/immunoglobulin A/immunoglobulin M, blood eosinophil count, and C-reactive protein. RESULTS: In total forty three atopic dermatitis patients, only 14 patients completely underwent 6 cycles, but other 29 patients incompletely (1-5 cycles). In the 14 patients, there were just 13 records of scoring atopic dermatitis (SCORAD) index. The mean SCORAD score in the 13 patients was 39.6+/-24.4. SCORAD score decreased significantly (initial SCORAD, 39.6+/-24.4; final SCORAD, 21.3+/-15.6; P=0.016). CONCLUSION: IVIG therapy may be recommended in the treatment of recalcitrant atopic dermatitis. In addition, further investigation on predictive markers for responses of IVIG therapy in atopic dermatitis may be needed.

Evaluation of Peptide Nucleic Acid Probe-based Real-time PCR for Detection of Mycobacterium tuberculosis Complex and Nontuberculous Mycobacteria in Respiratory Specimens

BACKGROUND: A peptide nucleic acid (PNA) probe-based real-time PCR (PNAqPCR(TM) TB/NTM detection kit; PANAGENE, Korea) assay has been recently developed for the simultaneous detection of Mycobacterium tuberculosis complex (MTBC) and nontuberculous mycobacteria (NTM) in clinical specimens. The study was aimed at evaluation of the performance of PNA probe-based real-time PCR in respiratory specimens. METHODS: To evaluate potential cross-reactivity, the extracted DNA specimens from Mycobacterium species and non-mycobacterial species were tested using PNA probe-based real-time PCR assay. A total of 531 respiratory specimens (482 sputum specimens and 49 bronchoalveolar washing fluid specimens) were collected from 230 patients in July and August, 2011. All specimens were analyzed for the detection of mycobacteria by direct smear examination, mycobacterial culture, and PNA probe-based real-time PCR assay. RESULTS: In cross-reactivity tests, no false-positive or false-negative results were evident. When the culture method was used as the gold standard test for comparison, PNA probe-based real-time PCR assay for detection of MTBC had a sensitivity and specificity of 96.7% (58/60) and 99.6% (469/471), respectively. Assuming the combination of culture and clinical diagnosis as the standard, the sensitivity and specificity of the new real-time PCR assay for detection of MTBC were 90.6% (58/64) and 99.6% (465/467), respectively. The new real-time PCR for the detection of NTM had a sensitivity and specificity of 69.0% (29/42) and 100% (489/489), respectively. CONCLUSIONS: The new real-time PCR assay may be useful for the detection of MTBC in respiratory specimens and for discrimination of NTM from MTBC.

Expression of the c-Met Proteins in Malignant Skin Cancers

BACKGROUND: The expression of c-Met is substantially elevated in most malignant human cancers. We therefore searched for c-Met expression and compared the expression level among malignant skin cancers. OBJECTIVE: The aim of this study was to determine the c-Met expression pattern and the protein expression level in selected malignant cutaneous tumors. METHODS: G361 cells (malignant melanoma cell line) and A431 cells (squamous cell carcinoma cell line) were cultured and analyzed, using immunoprecipitation and Western blot analysis, for expression of c-Met. Additionally, 16 separate specimens of malignant melanomas (MMs), 16 squamous cell carcinomas (SCCs), 16 basal cell carcinomas (BCCs) and 16 normal tissues were analyzed for the expression of c-Met using immunohistochemical studies. RESULTS: Based on cultured cell immunoprecipitation and Western blot analysis, both A431 cells and G361 cells expressed c-Met, however, c-Met was expressed substantially more in G361 cells. Immunohistochemical examination of c-Met showed that it was over-expressed in all malignant skin cancers. In addition, c-Met expression was more increased in MM compared to other cancers. CONCLUSION: In our study, c-Met is involved in malignant skin cancer development and the level of its expression is thought to be related to the degree of malignancy in melanoma cancers.

Vulva sparganosis misdiagnosed as a Bartholin's gland abscess / 대한산부인과학회지

Sparganosis is a parasitic infection caused by the plerocercoid larvae of diphyllobothroid tapeworms belonging to the genus Spirometra, as first described by Manson in 1882. The infection is transmitted by ingestion of contaminated water, frogs, and snakes, and contact between a second intermediate host and an open wound or mucus membranes. Humans are accidental hosts in the life cycle, but dogs, cats, and other mammals are definitive hosts. Once a human becomes infected, the plerocercoid larvae migrate to a subcutaneous location, where they typically develop into a painful nodule. We misdiagnosed vulva sparganosis as a Bartholin's gland abscess. The patient was a green consumer, so she may have been infected by consuming health foods. Sparganosis should be considered as a cause of soft tissue masses especially among patients who have ingested health foods.

Comparison of Clinical Features of Norovirus and Rotavirus Gastroenteritis in Hospitalized Children and Norovirus Genotype Analysis

BACKGROUND: Norovirus is one of the most prevalent pathogens causing acute gastroenteritis in children. We compared the clinical features of noroviral gastroenteritis to those of rotaviral gastroenteritis and analyzed the noroviruses' genotype frequencies. MATERIALS AND METHODS: Stool samples were obtained form 433 children hospitalized with acute gastroenteritis from May 2008 through February 2009 at Soonchunhyang University Cheonan Hospital and examined for the presence of norovirus or rotavirus. We then analyzed the clinical features of noroviral gastroenteritis in comparison with rotaviral gastroenteritis and observed the capsid protein gene sequences from the isolated norovirus for genotyping. RESULTS: Norovirus was isolated from 69 patients (16.4%) and rotavirus from 49 patients (11.6%). The noroviral gastroenteritis patients experienced vomiting (77.4%), diarrhea (73.2%), and respiratory symptoms (53.6%); the rotaviral gastroenteritis patients experienced diarrhea (71.4%), dehydration (69.3%), and vomiting (65.3%). Dehydration in patients with noroviral gastroenteritis (43.4%) was rare compared with rotavirus (69.3%) (P=0.008). The isolated norovirus belonged primarily to the GII.4 genogroup (85.5%). Our phylogenetic analysis of the GII.4 isolates revealed 3 clusters, including novel cluster C. CONCLUSIONS: Vomiting was the most common symptom in noroviral gastroenteritis patients. Dehydration in noroviral gastroenteritis patients was less common compared with rotavirus gastroenteritis patients. The majority of the norovirus strains isolated from children with acute gastroenteritis belonged to the GII.4 genogroup.

Chemokine Receptor CCR3 Expression in Malignant Cutaneous Tumors

BACKGROUND: Chemokines and their receptors are important players in tumorigenesis by facilitating tumor proliferation and metastasis. Little is known about the possible function of chemokine receptors in relation to the development and progression of malignant cutaneous tumors. OBJECTIVE: The aim of this study was to determine the chemokine receptor CCR3 expression pattern and the protein expression level in selected malignant cutaneous tumors. METHODS: Four types of cell lines (G361, A431, SK-MEL-2, SK-MEL-24) were analyzed, using Western blotting, for the expression of CCR3 protein. Immunohistochemical staining for CCR3 was done on 36 skin cancer tissue samples that included 16 squamous cell carcinomas (SCCs), 16 basal cell carcinomas (BCCs), 16 malignant melanomas (MMs) and 6 normal tissue samples. RESULTS: Western blot analysis showed that CCR3 protein was more expressed in the MM cell lines (G361, SK-MEL-2,SK-MEL-24) than that in the SCC cell line (A431), and the immunohistochemical analysis showed that CCR3 protein was overexpressed in MM and SCC, it was mildly expressed in BCC and it was hardly expressed in normal tissue. CONCLUSION: This study demonstrated via immunochemistry that CCR3 was more expressed in MM, followed by SCC and BCC. The existence of CCR3 protein may enhance the tumorigenic potential of malignant cutaneous tumors.

The Expression of HSP105 in Spitz Nevus and Malignant Melanoma / 대한피부과학회지

BACKGROUND: Spitz nevus and malignant melanoma have common features clinically and histologically, and in some cases it is impossible to distinguish between the two. Heat shock proteins (HSPs) serve to protect cells, and are activated by cell injury. Some HSPs are shown to be elevated in many types of cancers. Previous studies have reported the expression of heat shock protein in association with melanoma; however, a similar relationship with Spitz nevi has never been investigated. OBJECTIVE: This study was designed to measure the expression pattern of HSP 105 in both Spitz nevi and melanomas. METHODS: The specimens of 4 of Spitz nevi and 10 of malignant melanomas were analyzed for heat shock protein 105 expression through immunohistochemical staining. RESULTS: Immunohistochemical examination of HSP 105 showed strong expression in malignant melanoma specimens. On the other hand, weak expression was observed in Spitz nevus specimens. The degree of expression of HSP 105 showed a statistically significant difference (p<0.05). CONCLUSION: These findings provide the possibility of using HSP 105 as a effective marker for differentiating between Spitz nevi and malignant melanomas. In support of this, HSP 105 is considered to be a tumor-associated antigen of malignant melanoma.

Reactive Oxygen Species Generated by 17beta-estradiol Play a Role in the Up-regulation of GPX4 Protein in MCF-7 Breast Cancer Cells / 한국유방암학회지

PURPOSE: Estrogen is known to act as both a growth factor and a survival factor for breast cancer. The responsible molecular mechanisms remain, however, to be fully elucidated. We hypothesize that the effect of estrogen relates to its ability to induce the cellular antioxidant defense enzymes. METHODS: In the presence study, we examined the ability of 17beta-estradiol (E2) to regulate the level of phospholipid hydroperoxide glutathione peroxidase (GPX4) protein, which is an anti-oxidative enzyme that can directly reduce both phospholipids and cholesterol-hydroperoxides located in the cell membranes and lipoproteins. RESULTS: E2 elicited a dose- and time-dependent increase in the GPX4 expression in the MCF-7 breast cancer cells, and this up-regulation was blocked by the free radical scavenger N-acetylcysteine (NAC). Additionally, we confirmed that E2 triggered a rapid and transient increase in the intracellular reactive oxygen species (ROS) levels, and this E2-induced increase in the ROS levels was inhibited by pretreatment with NAC. Moreover, such ROS inducers as TGF-beta, TNF-alpha and insulin induced an increase in the level of GPX4 protein. However, estrogen receptor (ER)alpha knockdown by transfection with ERalpha-siRNA did not significantly change the GPX4 protein level that was induced by E2. Furthermore, pre-incubation with the ER antagonist ICI 182,780 did not inhibit E2-mediated GPX4 induction. Conversely, pretreatment of cells with LY294002, a pharmacological inhibitor of phosphatidylinositol 3-kinase inhibitor, suppressed the E2-augmented GPX4 expression. CONCLUSION: Collectively, our data show that E2 may partly provide a survival advantage through the regulation of cellular oxidative homeostasis in MCF-7 breast cancer cells.

Validity of 38 mg Low Dose 13C-Urea Breath Test for the Diagnosis of Helicobacter pylori Infection

BACKGROUND: To assess the diagnostic value of 13C-UBT using capsulated 38 mg low dose for H. pylori infection, we investigated the sensitivity and specificity of 13C-UBT and to suggest the optimal positive cut-off value of DOB20 in 13C-UBT using ROC analysis. METHODS: The study subjects were 76 healthy individuals (males; 52, females; 24) who visited a health promotion center at a university hospital between July 2005 and June 2007. We tested for H. pylori infection by 38 mg low dose 13C-UBT and histology. We measured the expiratory 13C-urea concentration of basal and 20 minutes value after oral ingestion of 38 mg 13C- labelled urea with capsulated. The breath samples were analysed by gas chromatograph isotope ratio mass spectrometer and expressed as units of delta. RESULTS: Fifty subjects (65.8%) were H. pylori positive as judged from histology. ROC analysis showed an area under the curve (AUC) of 0.943 (95% confidence interval: 0.891~0.995), indicating an excellent classification performance of the model. The sensitivity of 96%, specificity of 85% were achieved at the optimal cut-off value of DOB20 which was 1.39. The 38 mg low dose 13C-UBT was a non-invasive, simple, short-time required and highly accurate method. CONCLUSION: The results suggested that capsulated 38 mg low dose 13C-UBT is considered more in term of accuracy, costeffectiveness and convenient method for the diagnosis of H. pylori infection. Further long-term research and meta analysis based on large-scale investigations is needed to establish a standardized testing method in creating protocol of 13C-UBT.