Bisphenol A regulates bladder cells responses via control of G2/M-phase cell cycle, apoptotic signaling, MAPK pathway, and transcription factor-associated MMP modulation.

Bisphenol A (BPA), an exogenous endocrine-disrupting chemical, is widely used to produce polycarbonate plastics. The widely used BPA has been detected in human urine samples, raising public anxiety about the detrimental effects of BPA on the bladder. In this study, we explored regulatory mechanisms for the adverse effects of BPA in human bladder BdFC and T24 cells. BPA induced extrinsic and intrinsic apoptosis and G2/M cell cycle arrest caused by the ATM-CHK1/CHK2-CDC25c-CDC2 signaling, which ultimately inhibited the growth of human bladder cells. We also found that BPA decreased the binding activity of AP-1 and NF-κB transcription factors in human bladder cells, which inhibited migration and invasion through matrix metallopeptidase-2 and -9 inactivation. Phosphorylation of MAPKs was implicated with BPA-mediated detrimental effects in human bladder cells. Collectively, our results provide a novel explanation for the underlying molecular mechanisms that BPA induces cytotoxicity in human bladder cells.

Bisphenol A modulates proliferation, apoptosis, and wound healing process of normal prostate cells: Involvement of G2/M-phase cell cycle arrest, MAPK signaling, and transcription factor-mediated MMP regulation.

Bisphenol A (BPA) is commonly used to produce epoxy resins and polycarbonate plastics. BPA is an endocrine-disrupting chemical that is leaked from the polymer and absorbed into the body to disrupt the endocrine system. Although BPA may cause cytotoxicity in the prostate, a hormone-dependent reproductive organ, its underlying mechanism has not yet been elucidated. Here, we investigated the effects of BPA on cell proliferation, apoptosis, and the wound healing process using prostate epithelial cells (RWPE-1) and stromal cells (WPMY-1). Observations revealed that BPA induced G2/M cell cycle arrest in both cell types through the ATM-CHK1/CHK2-CDC25c-CDC2 signaling pathway, and the IC50 values were estimated to be 150 µM. Furthermore, BPA was found to induce caspase-dependent apoptosis through initiator (caspase-8 and -9) and executioner (caspase-3 and -7) caspase cascades. In addition, BPA interfered with the wound healing process through inhibition of MMP-2 and - 9 expression, accompanied by reductions in the binding activities of AP-1 as well as NF-κB motifs. Phosphorylation of MAPKs was associated with the BPA-mediated toxicity of prostate cells. These results suggest that BPA exhibits prostate toxicity by inhibiting cell proliferation, inducing apoptosis, and interfering with the wound healing process. Our study provided new insights into the precise molecular mechanisms of BPA-induced toxicity in human prostate cells.

Utility of a Molecular Signature for Predicting Recurrence and Progression in Non-Muscle-Invasive Bladder Cancer Patients: Comparison with the EORTC, CUETO and 2021 EAU Risk Groups.

To evaluate the utility of different risk assessments in non-muscle-invasive bladder cancer (NMIBC) patients, a total of 178 NMIBC patients from Chungbuk National University Hospital (CBNUH) were enrolled, and the predictive value of the molecular signature-based subtype predictor (MSP888) and risk calculators based on clinicopathological factors (EORTC, CUETO and 2021 EAU risk scores) was compared. Of the 178 patients, 49 were newly analyzed by the RNA-sequencing, and their MSP888 subtype was evaluated. The ability of the EORTC, MSP888 and two molecular subtyping systems of bladder cancer (Lund and UROMOL subtypes) to predict progression of 460 NMIBC patients from the UROMOL project was assessed. Cox regression analyses showed that the MSP888 was an independent predictor of NMIBC progression in the CBNUH cohort (p = 0.043). Particularly in patients without an intravesical BCG immunotherapy, MSP888 significantly linked with risk of disease recurrence and progression (both p < 0.05). However, the EORTC, CUETO and 2021 EAU risk scores showed disappointing results with respect to estimating the NMIBC prognosis. In the UROMOL cohort, the MSP888, Lund and UROMOL subtypes demonstrated a similar capacity to predict NMIBC progression (all p < 0.05). Conclusively, the MSP888 is favorable for stratifying patients to facilitate optimal treatment.

Anti-Metastatic Effect of Pyruvate Dehydrogenase Kinase 4 Inhibition in Bladder Cancer via the ERK, SRC, and JNK Pathways.

Bladder cancer is a common global cancer with a high percentage of metastases and high mortality rate. Thus, it is necessary to identify new biomarkers that can be helpful in diagnosis. Pyruvate dehydrogenase kinase 4 (PDK4) belongs to the PDK family and plays an important role in glucose utilization in living organisms. In the present study, we evaluated the role of PDK4 in bladder cancer and its related protein changes. First, we observed elevated PDK4 expression in high-grade bladder cancers. To screen for changes in PDK4-related proteins in bladder cancer, we performed a comparative proteomic analysis using PDK4 knockdown cells. In bladder cancer cell lines, PDK4 silencing resulted in a lower rate of cell migration and invasion. In addition, a PDK4 knockdown xenograft model showed reduced bladder cancer growth in nude mice. Based on our results, PDK4 plays a critical role in the metastasis and growth of bladder cancer cells through changes in ERK, SRC, and JNK.

Effect of pre-operative internal obturator muscle mass index in MRI on biochemical recurrence of prostate cancer patients after radical prostatectomy: a multi-center study.

BACKGROUND: Recent reports show that the pre-operative or post-operative skeletal mass index (sarcopenia) affects survival rates for various cancers; however, the link between prostate cancer survival and sarcopenia is unclear. Therefore, this study examined the effect of the pre-operative internal obturator muscle (IOM) mass index on biochemical recurrence (BCR) of prostate cancer (PCa) patients who underwent radical prostatectomy. METHODS: In total, 222 patients, who underwent open, laparoscopic, or robot-assisted radical prostatectomy at seven centers in 2011 and were followed up for 5 years, were enrolled. BCR was examined in the context of pre-operative IOM mass index and BMI. RESULTS: The mean age of the patients was 67.82 ± 6.23 years, and the mean pre-operative prostate-specific antigen (PSA) level was 11.61 ± 13.22 ng/ml. There was no significant difference in baseline characteristics between the low and high IOM mass index groups (p > 0.05). Age, pre-op PSA level, ECE, and T-stage were associated with BCR (p = 0.049, p < 0.001, p = 0.001, p = 0.004, respectively). BMI, prostate volume, Gleason score, resection margin, N-stage, M-stage and IOM mass index was not associated with BCR (p > 0.05). CONCLUSIONS: Pre-operative IOM mass index was not associated with BCR; however, long-term follow-up is necessary to evaluate cancer-specific and overall survival of PCa patients.

Role of Exosomal miRNA in Bladder Cancer: A Promising Liquid Biopsy Biomarker.

Bladder cancer (BCa) is the most prevalent neoplasia of the urinary tract. Unfortunately, limited improvements in effective BCa management have meant that it remains a challenging disease. Cystoscopy has been the gold standard for BCa diagnosis and surveillance for over two centuries but is an invasive and expensive approach. Recently, liquid biopsy has been identified as a promising field of cancer research, due to its noninvasiveness and ease of sampling. Liquid biopsy samples could provide comprehensive information regarding the genetic landscape of cancer and could track genomic evolution of the disease over time. Exosomes, which contain RNAs, DNAs, and proteins, are a potential source of tumor biomarkers in liquid biopsy samples. In particular, exosomal miRNAs (exomiRs) hold great promise as biomarkers for tumor development and progression. In this review, we provide an overview of liquid biopsy biomarkers, with a particular focus on the use of exomiRs as biomarkers of cancer, and summarize their clinical implications for BCa. Finally, we discuss the future perspectives of these biomarkers in cancer research.

A Molecular Signature Determines the Prognostic and Therapeutic Subtype of Non-Muscle-Invasive Bladder Cancer Responsive to Intravesical Bacillus Calmette-Guérin Therapy.

Non-muscle-invasive bladder cancer (NMIBC) is clinically heterogeneous; thus, many patients fail to respond to treatment and relapse. Here, we identified a molecular signature that is both prognostic and predictive for NMIBC heterogeneity and responses to Bacillus Calmette-Guérin (BCG) therapy. Transcriptomic profiling of 948 NMIBC patients identified a signature-based subtype predictor, MSP888, along with three distinct molecular subtypes: DP.BCG+ (related to progression and response to BCG treatment), REC.BCG+ (related to recurrence and response to BCG treatment), and EP (equivocal prognosis). Patients with the DP.BCG+ subtype showed worse progression-free survival but responded to BCG treatment, whereas those with the REC.BCG+ subtype showed worse recurrence-free survival but responded to BCG treatment. Multivariate analyses revealed that MSP888 showed independent clinical utility for predicting NMIBC prognosis (each p = 0.001 for progression and recurrence, respectively). Comparative analysis of this classifier and previously established molecular subtypes (i.e., Lund taxonomy and UROMOL class) revealed that a great proportion of patients were similar between subtypes; however, the MSP888 predictor better differentiated biological activity or responsiveness to BCG treatment. Our data increase our understanding of the mechanisms underlying the poor prognosis of NMIBC and the effectiveness of BCG therapy, which should improve clinical practice and complement other diagnostic tools.

Betulinic Acid Restricts Human Bladder Cancer Cell Proliferation In Vitro by Inducing Caspase-Dependent Cell Death and Cell Cycle Arrest, and Decreasing Metastatic Potential.

Betulinic acid (BA) is a naturally occurring pentacyclic triterpenoid and generally found in the bark of birch trees (Betula sp.). Although several studies have been reported that BA has diverse biological activities, including anti-tumor effects, the underlying anti-cancer mechanism in bladder cancer cells is still lacking. Therefore, this study aims to investigate the anti-proliferative effect of BA in human bladder cancer cell lines T-24, UMUC-3, and 5637, and identify the underlying mechanism. Our results showed that BA induced cell death in bladder cancer cells and that are accompanied by apoptosis, necrosis, and cell cycle arrest. Furthermore, BA decreased the expression of cell cycle regulators, such as cyclin B1, cyclin A, cyclin-dependent kinase (Cdk) 2, cell division cycle (Cdc) 2, and Cdc25c. In addition, BA-induced apoptosis was associated with mitochondrial dysfunction that is caused by loss of mitochondrial membrane potential, which led to the activation of mitochondrial-mediated intrinsic pathway. BA up-regulated the expression of Bcl-2-accociated X protein (Bax) and cleaved poly-ADP ribose polymerase (PARP), and subsequently activated caspase-3, -8, and -9. However, pre-treatment of pan-caspase inhibitor markedly suppressed BA-induced apoptosis. Meanwhile, BA did not affect the levels of intracellular reactive oxygen species (ROS), indicating BA-mediated apoptosis was ROS-independent. Furthermore, we found that BA suppressed the wound healing and invasion ability, and decreased the expression of Snail and Slug in T24 and 5637 cells, and matrix metalloproteinase (MMP)-9 in UMUC-3 cells. Taken together, this is the first study showing that BA suppresses the proliferation of human bladder cancer cells, which is due to induction of apoptosis, necrosis, and cell cycle arrest, and decrease of migration and invasion. Furthermore, BA-induced apoptosis is regulated by caspase-dependent and ROS-independent pathways, and these results provide the underlying anti-proliferative molecular mechanism of BA in human bladder cancer cells.

A Low Geriatric Nutritional Risk Index is Associated with Aggressive Pathologic Characteristics and Poor Survival after Nephrectomy in Clear Renal Cell Carcinoma: A Multicenter Retrospective Study.

Purpose: To investigated the prognostic significance of the geriatric nutritional risk index (GNRI) in patients with surgically treated clear cell renal cell carcinoma (ccRCC).Patients and methods: We retrospectively selected 4,591 consecutive patients with surgically treated ccRCC from a multi-institutional Korean collaboration between 1988 and 2015. The clinical significance of the GNRI as a continuous and categorical variable was determined.Results: Preoperative low GNRI was significantly associated with older age, low body mass index, presence of diabetes, poor performance status, and presence of symptoms at diagnosis, as well as pathologic features such as aggressive tumor characteristics including large tumor size, advanced stage, high nuclear grade, lymphovascular invasion, sarcomatous differentiation, and tumor necrosis. A low GNRI was significantly associated with a short recurrence-free survival (RFS) in localized (pT1-2N0M0) ccRCC and cancer-specific survival (CSS) in the entire cohort, and with short RFS and CSS in the subgroup analysis according to age categories (≤65 and >65 years). Multivariate Cox regression analysis showed that preoperative GNRI, as a continuous or categorical variable, was an independent predictor of RFS and CSS.Conclusion: Malnutrition as assessed by the preoperative GNRI is associated with aggressive tumor characteristics and poor survival in patients with surgically treated ccRCC.

Intraoperative allogeneic blood transfusion is associated with adverse oncological outcomes in patients with surgically treated non-metastatic clear cell renal cell carcinoma.

BACKGROUND: The objective of this study was to provide more definitive information about the prognostic impact of perioperative blood transfusion (PBT) on patients with surgically treated renal cell carcinoma (RCC). METHODS: A database of 4019 patients with clear cell RCC, all of whom underwent radical or partial nephrectomy as primary therapy as part of a multi-institutional Korean collaboration between 1988 and 2015, was analyzed retrospectively. PBT was defined as transfusion of allogeneic red blood cells during surgery or postsurgical period. Receipt of a PBT, as well as the amount and time of blood transfusion (BT), was compared. RESULTS: Overall, 335 (8.3%) patients received a PBT: 84 received postoperative BT, 202 received intraoperative BT, and 49 received both intraoperative and postoperative BT. Patients receiving a PBT had a poor preoperative immuno-nutritional status, and aggressive tumor characteristics. Multivariate analyses identified PBT as an independent predictor of recurrence-free survival and cancer-specific survival. Prognostic impact of PBT was restricted to those with locally advanced stage (pT3-4), and who underwent radical nephrectomy. Among patients who received a PBT, intraoperative (but not postoperative) BT was a prognostic factor for survival. Among patients who received intraoperative BT, those receiving three or more transfusion units had a significantly worse survival. CONCLUSION: Receipt of a PBT was an independent predictor of RFS and CSS in patients with surgically treated RCC, specifically locally advanced disease. Regarding the prognostic impact of timing or dose of PBT on survival, intraoperative BT and ≥ 3 pRBC units were associated with adverse oncological outcomes.

Induction of Apoptosis by Coptisine in Hep3B Hepatocellular Carcinoma Cells through Activation of the ROS-Mediated JNK Signaling Pathway.

Hepatocellular carcinoma (HCC) has a high mortality rate worldwide, and treatment is very limited due to its high recurrence and low diagnosis rate, and therefore there is an increasing need to develop more effective drugs to treat HCC. Coptisine is one of the isoquinoline alkaloids, and it has various pharmacological effects. However, the evidence for the molecular mechanism of the anticancer efficacy is still insufficient. Therefore, this study investigated the antiproliferative effect of coptisine on human HCC Hep3B cells and identified the action mechanism. Our results showed that coptisine markedly increased DNA damage and apoptotic cell death, which was associated with induction of death receptor proteins. Coptisine also significantly upregulated expression of proapoptotic Bax protein, downregulated expression of anti-apoptotic Bcl-2 protein, and activated caspase-3, -8, and -9. In addition, coptisine remarkably increased the generation of reactive oxygen species (ROS), loss of mitochondrial membrane potential (MMP), and release of cytochrome c into the cytoplasm. However, N-acetylcysteine (NAC), a ROS scavenger, significantly attenuated the apoptosis-inducing effect of coptisine. It is worth noting that coptisine significantly upregulated phosphorylation of ROS-dependent c-Jun N-terminal kinase (JNK), whereas treatment with JNK inhibitor could suppress an apoptosis-related series event. Taken together, our results suggest that coptisine has an anticancer effect in Hep3B cells through ROS-mediated activation of the JNK signaling pathway.

Urinary cell-free microRNA biomarker could discriminate bladder cancer from benign hematuria.

The most common symptom of bladder cancer (BC) is hematuria. However, not all patients with hematuria are diagnosed with BC. Here, we explored a novel method to discriminate BC from hematuria under nonmalignant conditions by measuring differences in urinary cell-free microRNA (miRNA) expression between patients with BC and those with hematuria. A multicenter study was performed using 543 urine samples obtained from the National Biobank of Korea, including 326 BC, 174 hematuria and 43 pyuria without cancer. The urinary miR-6124 to miR-4511 ratio was considerably higher in BC than in hematuria or pyuria, and enabled the discrimination of BC from patients with hematuria at a sensitivity of >90% (p < 0.001). Conclusively, the proposed noninvasive diagnostic tool based on the expression ratio of urinary cell-free miR-6124 to miR-4511 can reduce unnecessary cystoscopies in patients with hematuria undergoing evaluation for BC, with a minimal loss in sensitivity for detecting cancer.

Report of the forth Asian Prostate Cancer (A-CaP) study meeting.

The Asian Prostate Cancer (A-CaP) Study is an Asia-wide prospective registry study for surveying the treatment outcome of prostate cancer patients who have received a histopathological diagnosis. The study aims to clarify the clinical situation for prostate cancer in Asia and use the outcomes for the purposes of international comparison. Following the first meeting in Tokyo on December 2015, the second meeting in Seoul, Korea 2016, the third meeting in Chiang Mai, Thailand, on October 2017, the fourth meeting was held in Seoul, again on August 2018 with the participation of members and collaborators from 13 countries and regions. In the meeting, participating countries and regions presented the current status of data collection and the A-CaP office presented a preliminary analysis of the registered cases received from each country and region. Participants discussed ongoing challenges relating to data cleaning and data up-dating which is the next step of the A-CaP study following the data collection phase between 2016 and 2018. There was specific difference in term of the patient characteristics, and initial treatment pattern among East Asia, Southeast Asia and Turkey, and Jordan. Finally, a close relationship between prevalence of PSA test and disease stage of the patients at diagnosis in Japan and Malaysia was discussed.

Similar incidence of DNA damage response pathway alterations between clinically localized and metastatic prostate cancer.

BACKGROUND: In this era of precision medicine, the DNA damage response (DDR) pathway has been shown to be a viable target of intervention in metastatic castration-resistant prostate cancer (CRPC) as approximately one-third of CRPC patients harbor DDR pathway mutations. To determine whether DDR pathway is a potential therapeutic target in localized disease, we analyzed The Cancer Genome Atlas (TCGA) in the present study. METHODS: TCGA is a publically available cancer genome database that is sponsored by the United States National Cancer Institute. Total of 455 cases were available in the database at the time of this analysis. RESULTS: DDR pathway gene mutations or copy number alterations were present in 136 (29.9%) of the 455 cases. On a univariate analysis, DDR pathway status did not correlate with serum prostate specific antigen, tumor stage or grade. However, among patients with high-risk features post-operatively (pathologic stage ≥ T3, Gleason score ≥ 8, or PSA > 20 ng/ml), DDR pathway alteration was associated with a lower overall survival (p = 0.0291). CONCLUSIONS: Collectively these results suggest that DDR pathway alterations may also be significant in localized prostate cancer and agents such as PARP inhibitors should be considered in patients with a high-risk disease.

Association between De Ritis ratio (aspartate aminotransferase/alanine aminotransferase) and oncological outcomes in bladder cancer patients after radical cystectomy.

BACKGROUND: New biological prognostic predictors have been studied; however, some factors have limited clinical application due to tissue-specific expression and high cost. There is the need for a promising predictive factor that is simple to detect and that is closely linked to oncological outcomes in patients with urothelial bladder cancer (BC) who have undergone radical cystectomy (RC). Therefore, we investigated the clinical prognostic value of the preoperative De Ritis ratio (aspartate aminotransferase/alanine aminotransferase) on oncological outcomes in patients with urothelial BC after RC. METHODS: We retrospectively evaluated clinicopathological data of 118 patients with non-metastatic urothelial BC after RC between 2008 and 2013 at a single center. The association between the De Ritis ratio and clinicopathological findings was assessed. The potential prognostic value of the De Ritis ratio was analyzed using the Kaplan-Meier method, and multivariate Cox analyses were performed to identify the independent predictors of metastasis-free survival, cancer-specific survival, and overall survival. RESULTS: According to the receiver operating curve of the De Ritis ratio for metastasis, we stratified the patients into 2 groups using a threshold of 1.3. A high De Ritis ratio was more likely to be associated with old age and the female sex. Kaplan-Meier estimates revealed that patients with a high De Ritis ratio had inferior metastasis-free survival, cancer-specific survival, and overall survival outcomes (P = 0.012, 0.024, and 0.022, respectively). Multivariate analysis revealed that a high De Ritis ratio was an independent prognostic factor for metastasis (hazard ratio [HR], 2.389; 95% confidence interval [CI], 1.161-4.914; P = 0.018), cancer-related death (HR, 2.755; 95% CI, 1.214-6.249; P = 0.015), and overall death (HR, 2.761; 95% CI, 1.257-6.067; P = 0.011). CONCLUSIONS: An elevated De Ritis ratio was significantly associated with worse prognosis in patients who underwent RC for urothelial BC. This ratio might further improve the predictive accuracy for prognosis in BC.

National practice patterns and direct medical costs for prostate cancer in Korea across a 10 year period: a nationwide population-based study using a national health insurance database.

BACKGROUND: A complete enumeration study was conducted to evaluate trends in national practice patterns and direct medical costs for prostate cancer (PCa) in Korea over a 10-year retrospective period using data from the Korean National Health Insurance Service. METHODS: Reimbursement records for 874,924 patients diagnosed between 2002 and 2014 with primary PCa according to the International Classification of Disease (ICD) 10th revision code C61 were accessed. To assess direct medical costs for patients newly diagnosed after 2005, data from 68,596 patients managed between January 2005 and 31 December 2014 were evaluated. RESULTS: From 2005 to 2014, the total number of PCa patients showed a 2.6-fold increase. Surgery and androgen deprivation therapy were the most common first-line treatment, alone or within the context of combined therapy. Surgery as a monotherapy was performed in 23.5% of patients in 2005, and in 39.4% of patients in 2014. From 2008, the rate of robot-assisted RP rose sharply, showing a similar rate to open RP in 2014. Average total treatment costs in the 12 months post-diagnosis were around 10 million Korean won. Average annual treatment costs thereafter were around 5 million Korean won. Out-of-pocket expenditure was highest in the first year post-diagnosis, and ranged from 12 to 17% thereafter. CONCLUSIONS: Between 2005 and 2014, a substantial change was observed in the national practice pattern for PCa in Korea. The present data provide a reliable overview of treatment patterns and medical costs for PCa in Korea.

Methylation Signature for Prediction of Progression Free Survival in Surgically Treated Clear Cell Renal Cell Carcinoma.

BACKGROUND: Little is known about epigenetic silencing of genes by promoter hypermethylation in renal cell carcinoma (RCC). The aim of this study was to identify prognostic methylation markers in surgically treated clear cell RCC (ccRCC). METHODS: Methylation patterns were assayed using the Infinium HumanMethylation450 BeadChip array on pairs of ccRCC and normal tissue from 12 patients. Using quantitative PSQ analysis, tumor-specific hypermethylated genes were validated in 25 independent cohorts and their clinical relevance was also verified in 152 independent cohorts. RESULTS: Using genome-wide methylation array, Zinc finger protein 278 (ZNF278), Family with sequence similarity 155 member A (FAM155A) and Dipeptidyl peptidase 6 (DPP6) were selected for tumor-specific hypermethylated genes in primary ccRCC. The promoter methylation of these genes occurred more frequently in ccRCC than normal kidney in independent validation cohort. The hypermethylation of three genes were associated with advanced tumor stage and high grade tumor in ccRCC. During median follow-up of 39.2 (interquartile range, 15.4-79.1) months, 22 (14.5%) patients experienced distant metastasis. Multivariate analysis identified the methylation status of these three genes, either alone, or in a combined risk score as an independent predictor of distant metastasis. CONCLUSION: The promoter methylation of ZNF278, FAM155A and DPP6 genes are associated with aggressive tumor phenotype and early development of distant metastasis in patients with surgically treated ccRCC. These potential methylation markers, either alone, or in combination, could provide novel targets for development of individualized therapeutic and prevention regimens.

Citrus unshiu peel suppress the metastatic potential of murine melanoma B16F10 cells in vitro and in vivo.

The peel of Citrus unshiu Marcow. fruits (CU) has long been used as a traditional medicine that has therapeutic effects against pathogenic diseases, including asthma, vomiting, dyspepsia, blood circulation disorders, and various types of cancer. In this study, we investigated the effect of CU peel on metastatic melanoma, a highly aggressive skin cancer, in B16F10 melanoma cells, and in B16F10 cells inoculated-C57BL/6 mice. Our results show that ethanol extracts of CU (EECU) inhibited cell growth and increased the apoptotic cells in B16F10 cells. EECU also stimulated the induction of mitochondria-mediated intrinsic pathway, with reduced mitochondrial membrane potential and increased generation of intracellular reactive oxygen species. Furthermore, EECU suppressed the migration, invasion, and colony formation of B16F10 cells. In addition, the oral administration of EECU reduced serum lactate dehydrogenase activity without weight loss, hepatotoxicity, nor nephrotoxicity in B16F10 cell-inoculated mice. Moreover, EECU markedly suppressed lung hypertrophy, the number and expression of metastatic tumor nodules, and the expression of inflammatory tumor necrosis factor-alpha in lung tissue. In conclusion, our findings suggest that the inhibitory effect of EECU on the metastasis of melanoma indicates that it may be regarded as a potential therapeutic herbal drug for melanoma.

Anti-Proliferative and Pro-Apoptotic Effects of Licochalcone A through ROS-Mediated Cell Cycle Arrest and Apoptosis in Human Bladder Cancer Cells.

Licochalcone A (LCA) is a chalcone that is predominantly found in the root of Glycyrrhiza species, which is widely used as an herbal medicine. Although previous studies have reported that LCA has a wide range of pharmacological effects, evidence for the underlying molecular mechanism of its anti-cancer efficacy is still lacking. In this study, we investigated the anti-proliferative effect of LCA on human bladder cancer cells, and found that LCA induced cell cycle arrest at G2/M phase and apoptotic cell death. Our data showed that LCA inhibited the expression of cyclin A, cyclin B1, and Wee1, but increased the expression of cyclin-dependent kinase (Cdk) inhibitor p21WAF1/CIP1, and increased p21 was bound to Cdc2 and Cdk2. LCA activated caspase-8 and -9, which are involved in the initiation of extrinsic and intrinsic apoptosis pathways, respectively, and also increased caspase-3 activity, a typical effect caspase, subsequently leading to poly (ADP-ribose) polymerase cleavage. Additionally, LCA increased the Bax/Bcl-2 ratio, and reduced the integrity of mitochondria, which contributed to the discharge of cytochrome c from the mitochondria to the cytoplasm. Moreover, LCA enhanced the intracellular levels of reactive oxygen species (ROS); however, the interruption of ROS generation using ROS scavenger led to escape from LCA-mediated G2/M arrest and apoptosis. Collectively, the present data indicate that LCA can inhibit the proliferation of human bladder cancer cells by inducing ROS-dependent G2/M phase arrest and apoptosis.

Protective effect of diphlorethohydroxycarmalol against oxidative stress-induced DNA damage and apoptosis in retinal pigment epithelial cells.

Purpose: Reactive oxygen species (ROS) contribute to the onset and progression of disease pathogenesis in a variety of organs, including age-related macular degeneration (AMD). Diphlorethohydroxycarmalol (DPHC), a phlorotannin compound, is one of the major components of the brown alga Ishige okamurae Yendo, and has been shown to have strong antioxidant capacity. The purpose of this study was to evaluate the protective effects of DPHC against oxidative stress (hydrogen peroxide, H2O2)-induced DNA damage and apoptosis in cultured ARPE19 retinal pigment epithelial (RPE) cells. Materials and methods: Cell viability was assessed by 3-(4,5-dimethyl-2-thiazolyl)-2,5-diphenyltetrazolium bromide assay. Intracellular ROS generation was measured by flow cytometer using 2',7'-dichlorofluorescin diacetate. The magnitude of apoptosis was measured by flow cytometry using the annexin V/propidium iodide double staining. DNA damage was evaluated by DNA fragmentation assay, comet assay and 8-hydroxy-2'-deoxyguanosine (8-OHdG) analysis. To observe the mitochondrial membrane potential, 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethyl-imidacarbocyanine iodide staining was performed. In order to identify the underling mechanism of DPHC against H2O2-induced cellular alteration, we performed immune blotting. Results: The results of this study showed that the decreased survival rate brought about by H2O2 could be attributed to the induction of DNA damage and apoptosis accompanied by the increased production of ROS, which was remarkably reversed by DPHC. In addition, the loss of H2O2-induced mitochondrial membrane potential was significantly attenuated in the presence of DPHC. The inhibitory effect of DPHC on H2O2-induced apoptosis was associated with a reduced Bax/Bcl-2 ratio, the protection of the activation of caspase-9 and -3 and the inhibition of poly (ADP-ribose) polymerase cleavage, which was associated with the blockage of cytochrome c release to the cytoplasm. Conclusions: Our data proved that DPHC protects ARPE19 cells against H2O2-induced DNA damage and apoptosis by scavenging ROS and thus suppressing the mitochondrial-dependent apoptosis pathway. Therefore, this study suggests that DPHC has the therapeutic potential to prevent AMD by inhibiting oxidative stress-induced injury in RPE cells.