Megakaryocyte-Derived IL-8 Acts as a Paracrine Factor for Prostate Cancer Aggressiveness through CXCR2 Activation and Antagonistic AR Downregulation

Prostate cancer is the fifth leading cause of cancer-related mortality in men, primarily because of treatment resistance, recurrence, and metastasis. In the present study, we investigated the role of paracrine interleukin-8 (IL-8) in the antagonistic expression of IL-8 and androgen receptor (AR), and the contribution of IL-8 to prostate cancer aggressiveness. In hormone-responsive LNCaP cells that do not express IL-8, recombinant IL-8 treatment significantly increased expressions of IL-8, CXC chemokine receptor 2 (CXCR2), matrix metalloproteinase (MMP)-2/9, Snail, and vimentin. IL-8 treatment significantly decreased AR and E-cadherin expression. IL-8-induced gene expression changes were suppressed by navarixin, a CXCR1/2 inhibitor, and gallein, a Gβγ inhibitor. In PC-3 androgen-refractory prostate cancer cells, IL-8 knockdown reduced expressions of CXCR2, MMP-2/9, Snail, and vimentin, and increased AR and E-cadherin expressions at the mRNA and protein levels. Co-culture with MEG-01 human megakaryocytic cells secreting high levels of IL-8 induced gene expression changes in both LNCaP and PC-3 cells, similar to those induced by IL-8 treatment. The altered gene expressions were accompanied by significant activation of transcription factor Snail in LNCaP and PC-3 cells. Treatment with the CXCR blocker navarixin inhibited the invasion of PC-3 cells but not LNCaP cells. However, invasion induced by MEG-01 was inhibited by navarixin in both LNCaP and PC-3 cells. The collective findings demonstrate that IL-8 enhances CXCR2 expression, which antagonistically regulates AR expression. More importantly, through changes in IL-8/CXCR2-regulated gene expression, IL-8 induces antiandrogen therapy resistance and epithelial-mesenchymal transition in prostate cancer.

Association Between Oral Health and Airflow Limitation: Analysis Using a Nationwide Survey in Korea

Background@#Although poor oral health is a common comorbidity in individuals with airflow limitation (AFL), few studies have comprehensively evaluated this association. Furthermore, the association between oral health and the severity of AFL has not been well elucidated. @*Methods@#Using a population-based nationwide survey, we classified individuals according to the presence or absence of AFL defined as pre-bronchodilator forced expiratory volume in 1 second/forced vital capacity < 0.7. Using multivariable logistic regression analyses, we evaluated the association between AFL severity and the number of remaining teeth; the presence of periodontitis; the Decayed, Missing, and Filled Teeth (DMFT) index; and denture wearing. @*Results@#Among the 31,839 participants, 14% had AFL. Compared with the control group, the AFL group had a higher proportion of periodontitis (88.8% vs. 79.4%), complete denture (6.2% vs. 1.6%), and high DMFT index (37.3% vs. 27.8%) (P < 0.001 for all). In multivariable analyses, denture status: removable partial denture (adjusted odds ratio [aOR], 1.12; 95% confidence interval [95% CI], 1.04–1.20) and complete denture (aOR, 1.52; 95% CI, 1.01– 2.05), high DMFT index (aOR, 1.13; 95% CI, 1.02–1.24), and fewer permanent teeth (0–19;aOR, 1.32; 95% CI, 1.12–1.52) were significantly associated with AFL. Furthermore, those with severe to very severe AFL had a significantly higher proportion of complete denture (aOR, 2.41; 95% CI, 1.11–3.71) and fewer remaining teeth (0–19; aOR, 2.29; 95% CI, 1.57–3.01). @*Conclusion@#Denture wearing, high DMFT index, and fewer permanent teeth are significantly associated with AFL. Furthermore, a reduced number of permanent teeth (0–19) was significantly related to the severity of AFL. Therefore, physicians should pay attention to oral health in managing patients with AFL, such as chronic obstructive pulmonary disease.

Nationwide Comparison of Surgical and Oncologic Outcomes in Endometrial Cancer Patients Undergoing Robotic, Laparoscopic, and Open Surgery: A Population-Based Cohort Study / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Population-based comparisons between minimally invasive surgery (MIS) (robotic surgery [RS] and laparoscopic surgery [LS]) and open surgery (OS) for managing endometrial cancer are lacking. This study aimed to compare surgical and oncologic outcomes between endometrial cancer patients who underwent surgical staging via MIS or OS. @*Materials and Methods@#A population-based retrospective cohort study was performed using claims data from the Korean National Health Insurance database from January 2012 to December 2016. All patients who underwent hysterectomy under diagnosis of endometrial cancer were identified. Patients were classified into RS, LS, and OS groups. Operative and oncologic outcomes were compared among the three groups after adjustments for age group, risk group (adjuvant therapy status), modified Charlson comorbidity index, income level, insurance type, and index year using propensity scores obtained via the inverse probability of treatment weighted method. @*Results@#After adjustment, 5,065 patients (RS, n=315; LS, n=3,248; OS, n=1,503) were analyzed. Patient demographics were comparable. Hospital stay, postoperative complications, and cost were more favorable in the RS and LS groups than in the OS group (all p < 0.001). Five-year overall survival was significantly longer in the RS and LS groups than in the OS group (94.8%, 91.9%, and 86.9%, respectively; p < 0.001). Moreover, the survival benefit of RS was shown in the subgroup analysis of low-risk endometrial cancer patients. @*Conclusion@#Our study provides further evidence for the RS being a safe surgical alternative to the LS and OS, especially in low-risk endometrial cancer patients, offering surgical and oncologic outcomes equivalent to other surgical approaches.

Nationwide Comparison of Surgical and Oncologic Outcomes in Endometrial Cancer Patients Undergoing Robotic, Laparoscopic, and Open Surgery: A Population-Based Cohort Study / Journal of the Korean Cancer Association, 대한암학회지

Purpose@#Population-based comparisons between minimally invasive surgery (MIS) (robotic surgery [RS] and laparoscopic surgery [LS]) and open surgery (OS) for managing endometrial cancer are lacking. This study aimed to compare surgical and oncologic outcomes between endometrial cancer patients who underwent surgical staging via MIS or OS. @*Materials and Methods@#A population-based retrospective cohort study was performed using claims data from the Korean National Health Insurance database from January 2012 to December 2016. All patients who underwent hysterectomy under diagnosis of endometrial cancer were identified. Patients were classified into RS, LS, and OS groups. Operative and oncologic outcomes were compared among the three groups after adjustments for age group, risk group (adjuvant therapy status), modified Charlson comorbidity index, income level, insurance type, and index year using propensity scores obtained via the inverse probability of treatment weighted method. @*Results@#After adjustment, 5,065 patients (RS, n=315; LS, n=3,248; OS, n=1,503) were analyzed. Patient demographics were comparable. Hospital stay, postoperative complications, and cost were more favorable in the RS and LS groups than in the OS group (all p < 0.001). Five-year overall survival was significantly longer in the RS and LS groups than in the OS group (94.8%, 91.9%, and 86.9%, respectively; p < 0.001). Moreover, the survival benefit of RS was shown in the subgroup analysis of low-risk endometrial cancer patients. @*Conclusion@#Our study provides further evidence for the RS being a safe surgical alternative to the LS and OS, especially in low-risk endometrial cancer patients, offering surgical and oncologic outcomes equivalent to other surgical approaches.

Metabolic Signaling to Epigenetic Alterations in Cancer

Cancer cells reprogram cellular metabolism to support the malignant features of tumors, such as rapid growth and proliferation. The cancer promoting effects of metabolic reprogramming are found in many aspects: generating additional energy, providing more anabolic molecules for biosynthesis, and rebalancing cellular redox states in cancer cells. Metabolic pathways are considered the pipelines to supply metabolic cofactors of epigenetic modifiers. In this regard, cancer metabolism, whereby cellular metabolite levels are greatly altered compared to normal levels, is closely associated with cancer epigenetics, which is implicated in many stages of tumorigenesis. In this review, we provide an overview of cancer metabolism and its involvement in epigenetic modifications and suggest that the metabolic adaptation leading to epigenetic changes in cancer cells is an important non-genetic factor for tumor progression, which cooperates with genetic causes. Understanding the interaction of metabolic reprogramming with epigenetics in cancers may help to develop novel or highly improved therapeutic strategies that target cancer metabolism.

Gut Microbiome, a Potent Modulator of Epigenetics in Human Diseases

Human physiology and pathology can be affected by different nutritional conditions. At cellular level, the availability of a nutritional component not only mediates metabolic reactions but also transmits signals for diverse biological activities. Epigenetic regulation such as DNA methylation and histone post-translational modifications is considered as one of the nutrient-mediated signaling receivers as almost all of the epigenetic enzyme activities require intermediary metabolites as cofactors. The gut microbiome as “forgotten organ” has been suggested as a metabolite generator as well as a nutrient sensor for its host organism, affecting human health and diseases. Given the metabolite-dependent activities of epigenetic regulators, the gut microbiome has a high potential to influence the epigenetics in human physiology. Here, I review the involvement of gut microbiome in diverse human diseases and the mechanisms of epigenetic regulation by different metabolites. Thereafter, I discuss how the gut microbiome-generated metabolites affect host epigenetics, raising a possibility to develop a therapeutic intervention based on the interaction between the microbiome and epigenetics for human health.

Corrigendum: Necessity for a National Carcinogen List in Korea, Based on International Harmonization

This article was initially published on the Environmental Health and Toxicology 2013;28:e2013008, with a misspelled name of the 7th coauthor.

Necessity for a National Carcinogen List in Korea, Based on International Harmonization

Cancer has been the leading cause of death in Korea for the last 30 years. Cancer patients' 5-year survival rate between 2005 and 2009 was 62.0%, representing a highly advanced standard of care, as much as developed countries in the EU and the US. The Korean government formulated its first 10-year plan for cancer control in 1996 and has been carrying out a second 10-year plan for cancer control since 2006. But despite the Korean government's efforts, the cancer burden in Korea continues to increase. Many separate laws have gone into effect concerning the management of carcinogen exposure. However, there are no integrated regulatory laws or management systems against carcinogen exposure in Korea. Dead zones remain where carcinogen exposure cannot be controlled properly in Korea. In this paper, we suggest the need to establish a national carcinogen list based on international harmonization as a prerequisite for a paradigm shift in cancer control policy from treatment to primary prevention.

Comparison of Preventive Health Behaviors in Adults Aged 50~64 in Korea and the United States

PURPOSE: The purpose of this study was to compare Preventive Health Behaviors (PHBs) in adults in Korea and the United States and identify factors influencing PHBs. METHODS: This was a secondary data analysis study using data from the 2008 Korean National Health and Nutrition Examination Survey and the 2008 USA Behavioral Risk Factor Surveillance System. The PHBs were predicted using multiple linear regression analysis. RESULTS: 1) The total score of PHBs was significantly higher in American males (5.11) than in Korean males (4.78). There was also a significant difference between Korean females' total score (6.57) and American females'(6.75). 2) Age, marriage, monthly income, subjective health status, and cardiovascular disease were significant factors of PHBs in Korean males (p<.001). However, age, marriage, education, monthly income, health insurance, subjective health status, and cardiovascular disease were significant factors in American males (p<.001). In Korean females, only age and education were significant predictors (p<.001). However, six variables(age, marriage, education, monthly income, health insurance, and subjective health status) were significant predictors in American females (p<.001). CONCLUSION: There were different variables in predicting PHBs between Koreans and Americans. Each country should focus on those significant predictors to promote the PHBs for adults.

Grifola frondosa water extract alleviates intestinal inflammation by suppressing TNF-alpha production and its signaling

TNF-alpha is a major cytokine involved in inflammatory bowel disease (IBD). In this study, water extract of Grifola frondosa (GFW) was evaluated for its protective effects against colon inflammation through the modulation of TNF-alpha action. In coculture of HT-29 human colon cancer cells with U937 human monocytic cells, TNF-alpha-induced monocyte adhesion to HT-29 cells was significantly suppressed by GFW (10, 50, 100 microg/ml). The reduced adhesion by GFW correlated with the suppressed expression of MCP-1 and IL-8, the major IBD-associated chemokines. In addition, treatment with GFW significantly suppressed TNF-alpha-induced reactive oxygen species production and NF-kappaB transcriptional activity in HT-29 cells. In differentiated U937 monocytic cells, LPS-induced TNF-alpha production, which is known to be mediated through NF-kappaB activation, was significantly suppressed by GFW. In an in vivo rat model of IBD, oral administration of GFW for 5 days (1 g/kg per day) significantly inhibited the trinitrobenzene sulfonic acid (TNBS)-induced weight loss, colon ulceration, myeloperoxidase activity, and TNF-alpha expression in the colon tissue. Moreover, the effect of GFW was similar to that of intra-peritoneal injection of 5-aminosalicylic acid (5-ASA), an active metabolite of sulfasalazine, commonly used drug for the treatment of IBD. The results suggest that GFW ameliorates colon inflammation by suppressing production of TNF-alpha as well as its signaling through NF-kappaB leading to the expression of inflammatory chemokines, MCP-1 and IL-8. Taken together, the results strongly suggest GFW is a valuable medicinal food for IBD treatment, and thus may be used as an alternative medicine for IBD.

The Relationship of Sexual Satisfaction and Daily Stress in the Breast Cancer Patients / 성인간호학회지

PURPOSE: The purpose of this study was to investigate the correlation of sexual satisfaction and daily stress in breast cancer patients. METHODS: Data was collected through self-administered questionnaires and analyzed by descriptive statistics, t-test, ANOVA and Pearson's correlation. Data survey was conducted with 500 conveniently selected breast cancer patients who visited the out patient department in 5 university hospitals in Seoul, Gyung-gi and Gang-won province. RESULTS: The sexual satisfaction of breast cancer patients score was 31.34 and there were significant sexual satisfaction differences by age, education level, menopause and sexual activity frequency. Sexual satisfaction was negatively related with daily stress (r = -.177) especially personal stress (r = -.155), economic stress (r = -.138), stress of self (r = -.181), family stress (r = -.154) and stress about leisure (r = -.139). CONCLUSION: These findings are expected to make a contribution to creation of ideal sexual rehabilitation nursing interventions for breast cancer patients care nurse. Furthermore continuous and customized education and counseling programs can contribute to promote healthy sexual life for breast cancer patients.

Protective effects of fustin, a flavonoid from Rhus verniciflua tokes, on 6-hydroxydopamine-induced neuronal cell death

6-Hydroxydopamine (6-OHDA) is a neurotoxin and is commonly used to generate experimental models of Parkinson's disease (PD). In this study, we investigated the signaling molecules involved in the 6-OHDA-induced cell death using a neuronal catecholaminergic cell line (SK-N-SH cells), and the protective effect of fustin, a flavonoid from Rhus verniciflua Stokes, on 6-OHDA-induced neuronal death. 6-OHDA significantly increased levels of reactive oxygen species (ROS), intracellular Ca2+ ([Ca2+](i)), and p38 phosphorylation. In addition, this ROS increase by 6-OHDA was reduced by pretreatment with N-acetylcysteine (NAC), a free radical scavenger, but not by bis-(o-aminophenoxy)-ethane-N,N,N,N-tetraacetic acid (BAPTA), a Ca2+ chelator. However, the [Ca2+](i) increase induced by 6-OHDA was suppressed by NAC. Moreover, pretreatment with NAC or BAPTA significantly prevented the 6-OHDA-induced increases in p38 phosphorylation, Bax/Bcl-2 ratio, and caspase-3 activity. Although 6-OHDA-increased phosphorylation of p38 was prevented by NAC or BAPTA, inhibition of p38 by SB203580 did not suppress ROS, Bax/Bcl-2 ratio, or caspase-3 activity increases, and only partially prevented 6-OHDA-induced cell death, thus demonstrating that p38 activation is a component of a signaling pathway leading to the initiation of 6-OHDA-induced cell death, which acts in parallel with an ROS-Ca2+ -Bcl-2-caspase-3 pathway. Moreover, fustin not only suppressed 6-OHDA-induced cell death in a concentration-dependent manner but also blocked 6-OHDA-induced increases in ROS, [Ca2+](i), Bax/Bcl-2 ratio, caspase-3 activity, and p38 phosphorylation. These results suggest that fustin exerts neuroprotection against 6-OHDA-induced cell death.

A Study of Correlation between Self Concept and Climacteric Symptoms in Middle-Aged Women / 기본간호학회지

PURPOSE: The purpose of this study was to investigate the relationship between self concept and the climacteric symptoms in middle-aged women. METHOD: From a convenience sample of 123 women between 40 and 59 years of age living in P-city data were collected using a structured questioanaire. It included a self concept scale and climacteric symptom scale. With spss/pc(+), data were analyzed using descriptive statistics, t-test, ANOVA and Pearson's correlation coefficients. RESULT: 1. The mean score for self concept was 108.73+/-16.24. 2. The variables that influenced the self concept of middle-aged women most were 'health state' and 'marriage satisfaction'. They were statistically significant at the .01 level. 3. The mean score for climacteric symptoms was 3.13. Of psychophysical, physical and psychological symptoms the scores for psychophysical symptoms were the highest. 4. There were significant negative correlations between self concept and climacteric symptoms (r=-0.333, p=0.000). CONCLUSION: This study suggests that positive self concept can reduce climacteric symptoms in middle-aged women.

The mechanism of t-butylhydroperoxide-induced apoptosis in IMR-32 human neuroblastoma cells

Apoptosis has been implicated in the pathophysiological mechanisms of various neurodegenerative diseases. In a variety of cell types, oxidative stress has been demonstrated to play an important role in the apoptotic cell death. However, the exact mechanism of oxidative stress-induced apoptosis in neuronal cells is not known. In this study, we induced oxidative stress in IMR-32 human neuroblastoma cells with tert-butylhydroperoxide (TBHP), which was confirmed by significantly reduced glutathione content and glutathione reductase activity, and increased glutathione peroxidase activity. TBHP induced decrease in cell viability and increase in DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. TBHP also induced a sustained increase in intracellular Ca2+ concentration, which was completely prevented either by EGTA, an extracellular Ca2+ chelator or by flufenamic acid (FA), a non-selective cation channel (NSCC) blocker. These results indicate that the TBHP-induced intracellular Ca2+ increase may be due to Ca2+ influx through the activation of NSCCs. In addition, treatment with either an intracellular Ca2+ chelator (BAPTA/AM) or FA significantly suppressed the TBHP-induced apoptosis. Moreover, TBHP increased the expression of p53 gene but decreased c-myc gene expression. Taken together, these results suggest that the oxidative stress-induced apoptosis in neuronal cells may be mediated through the activation of intracellular Ca2+ signals and altered expression of p53 and c-myc.

Development of Nursing Diagnosis Program Using Back-propagating Neural Network Model for Self-learning / 대한의료정보학회지

With the rapid growth of research and recognition about usefulness and importnace of the Nursing Diagnosis, the demand for application of Nursing Diagnosis has never been stronger. But in clinical field, not many nurses has used Nursing Diagnosis. Especially, nursing student have a difficulty to use Nursing Diagnosis because it demands for high level of capability of analyzing collected data and combining with relevant references. Therefore. this research has developed Nursing Diagnosis Self-learning Program using Back-propagating Neutral Network Model which is based on 98 surgery patients' data for nursing student. The twenty-six nursing diagnoses based on NANDA Taxonomy with 189 cases' reports and aid of 8 nursing experts wee determined to develop the program. To verify the usefulness of Nursing Diagnosis Self-learning Program constructed with the fully trained neural nets, the Program was tested with 70 real patients' data. The simulated output of program was compared with the judgement of the researcher and of two experts of nursing. The misdiagnosis rate of this program was eleven percent. This Program needs input of Signs and Symptoms, risk factors and 'related to' factors and also input the nursing diagnoses which a student selects. And than prints out two types of diagnoses. One is from the system and the other is what the student inputed. And the student makes the final diagnosis by refering the two types of diagnoses. Finally, the program prints out the completed diagnosis which problem combines with etiology in the diagnosis producing module. The program helps students to improve her capacity related to use Nursing Diagnosis.

Mediation of intracellular Ca2+ in the phospholipase A2-induced cell proliferation in human neuroblastoma cells

The role of phospholipase A2 (PLA2) in tumor cell growth was investigated using SK-N-MC human neuroblastoma cells. 4-Bromophenacyl bromide (BPB) and mepacrine (Mep), known PLA2 inhibitors, suppressed growth of the tumor cells in a dose-dependent manner without a significant cytotoxicity. Melittin (Mel), a PLA2 activator, enhanced the cell growth in a concentration-dependent fashion. The growth-enhancing effects of Mel were significantly reversed by the co-treatment with PLA2 inhibitors. In addition, Mel induced intracellular Ca2+ release from internal stores like as did serum, a known intracellular Ca2+ agonist in the tumor cells. Intracellular Ca2+ release induced by these agonists was significantly blocked by PLA2 inhibitors at growth-inhibitory concentrations. Arachidonic acid (AA), a product of the PLA2-catalyzed reaction, induced cell growth enhancement and intracellular Ca2+ release. These effects of AA were significantly blocked by BAPTA/AM, an intracellular Ca2+ chelator. Taken together, these results suggest that the modulation of PLA2 activity may be one of the regulatory mechanisms of cell growth in human neuroblastoma cells. Intracellular Ca2+ may act as a key mediator in the PLA2-induced growth regulation.

Role of Ca2+ influx in the tert-butyl hydroperoxide-induced apoptosis of HepG2 human hepatoblastoma cellse

Oxidative stress appears to be implicated in the pathogenesis of various diseases including alcoholic liver injury. In this study we investigated the mechanism of apoptosis induced by tert-butyl hydroperoxide (TBHP) in HepG2 human hepatoblastoma cells. Treatment with TBHP significantly reduced glutathione content and glutathione reductase activity, and increased glutathione peroxidase activity, indicating that TBHP induced oxidative stress in the HepG2 cells. TBHP also induced reduction of cell viability and DNA fragmentation, a hallmark of apoptosis, in a dose-dependent manner. In addition, TBHP induced a sustained increase in intracellular Ca2+ concentration, which was completely prevented by the extracellular Ca2+ chelation with EGTA. TBHP also induced Mn2+ influx. These results indicate that the intracellular Ca2+ increase by TBHP is exclusively due to Ca2+ influx from the extracellular site. Treatment with either an extracellular (EGTA) or an intracellular Ca2+ chelator (BAPTA/AM) significantly suppressed the TBHP-induced apoptosis. Taken together, these results suggest that TBHP induced the apoptotic cell death in the HepG2 cells and that Ca2+ influx may play an important role in the apoptosis induced by TBHP.

A Comparative Study on the Effects of the Nursing Diagnosis Systems Using Neural Network and Expert System / 대한의료정보학회지

With growing need in the field, the application of computers in nursing has been frequently studied to improve the quality of nursing care in Korea. But the development of useful clinical programs has not received adequate alternatives. The aim of this study is to compare of two Nursing Diagnosis Systems - Neutral Network and Expert System. The simulated output of each Nursing Diagnosis System and the Judgment from the researcher and two professors of nursing were comparatively examined. The misdiagnosis rate of Nursing Diagnosis System using the Neural Network was nine percent, while the Nursing Diagnosis System using the Expert System showed consistency with those three experts in every aspect. Accordingly, the result of this study demonstrated the possibility of application of a nursing diagnosis system as another nursing tool.

Induction of apoptosis by bile acids in HepG2 human hepatocellular carcinoma cells

We studied the effects of bile acids on the induction of apoptosis in HepG2 human hepatocellular carcinoma cells. Treatment with either ursodeoxycholic acid (UDCA) or lithocholic acid (LCA) resulted in a dose- and time-dependent decrease in cell viability assessed by MTT assay. Both UDCA and LCA also induced genomic DNA fragmentation, a hallmark of apoptosis, indicating that the mechanism by which these bile acids induce cell death was through apoptosis. Cycloheximide, a protein synthesis inhibitor, blocked the apoptosis induced by these bile acids, implying that new protein synthesis may be required for the apoptosis. Intracellular Ca2+ release blockers (dantrolene and 3,4,5-trimethoxybenzoic acid-8-(diethylamino)octyl ester) inhibited decreased cell viability and DNA fragmentation induced by these bile acids. Treatment of HepG2 cells with calcium ionophore A23187 induced DNA fragmentation. These results suggest that UDCA and LCA induce apoptosis in the HepG2 cells and that the activation of intracellular Ca2+ signals may play an important role in the apoptosis induced by these bile acids.

Studies on the Mechanism of Hypoxic Increase of VEGF Expression in the Hep3B Human Hepatoma Cells / 대한암학회지

PURPOSE: Hepatocellular carcinoma (HCC), a typical hypervasculized tumor is very sensitive to hypoxia and vascular endothelial growth factor (VEGF) has previously been identified to be up-regulated in response to hypoxia in several cell types. However, the molecular mechanisms by which hypoxia is sensed by the cells remain enigmatic. To investigate whether calcium and AP-1 are involved in hypoxia-sensing mechanism, we performed following experiments. MATERIALS AND METHODS: Hep3B cells were grown in hypoxic condition. To assess cell viability, MTT assay was performed. To investigate the effect of calcium and AP-1, northern blot analysis was performed after treatment with BAPTA/AM. RESULTS: The expression of VEGF was significantly up-regulated by hypoxia in Hep3B, hepatocellular carcinoma cell line. The increased expression of VEGF induced by hypoxia was blocked by the addition of BAPTA/AM, a cytosolic calcium chelator to the media. In addition, we found that the expression of c-jun protooncogene was also up-regulated by hypoxia. Hypoxic increase of c-jun expression was also normalized by the treatment with BAPTA/AM. CONCLUSION: These results suggest that the increased expression of VEGF by hypoxia is mediated through the calcium and c-jun signalling pathway in the Hep3B human hepatoma cell lines.