Isolinderalactone Induces Apoptosis, Autophagy, Cell Cycle Arrest and MAPK Activation through ROS-Mediated Signaling in Colorectal Cancer Cell Lines.

Colorectal cancer (CRC) is one of the most common malignancies worldwide. Isolinderalactone (ILL), a sesquiterpene isolated from the root extract of Lindera aggregata, has been reported to exhibit anti-proliferative and anti-metastatic activities in various cancer cell lines. However, the mechanisms associated with its antitumor effects on CRC cells remain unclear. ILL treatment significantly suppressed proliferation and induced cell cycle G2/M arrest in CRC cells by inhibiting the expression of cyclin B, p-cdc2, and p-cdc25c and up-regulating the expression of p21. In addition, ILL induced mitochondria-associated apoptosis through the up-regulation of cleaved -caspase-9 and -3 expression. ILL induced autophagy by increasing the levels of LC3B in CRC cells, which was partially rescued by treatment with an autophagy inhibitor (chloroquine). Furthermore, ILL increases the accumulation of reactive oxygen species (ROS) and activates the MAPK pathway. Application of the ROS scavenger, N-acetyl cysteine (NAC), effectively inhibited ILL toxicity and reversed ILL-induced apoptosis, cell cycle arrest, autophagy, and ERK activation. Taken together, these results suggest that ILL induces G2/M phase arrest, apoptosis, and autophagy and activates the MAPK pathway via ROS-mediated signaling in human CRC cells.

Hispolon Induces Apoptosis, Suppresses Migration and Invasion of Glioblastoma Cells and Inhibits GBM Xenograft Tumor Growth In Vivo.

Hispolon, a polyphenol compound isolated from Phellinus linteus, has been reported to exhibit antioxidant, antiproliferative, and antitumor activities. This study aimed to explore the antitumor effects of hispolon on glioblastoma multiforme (GBM) cells in vitro and in vivo. The results revealed that hispolon significantly inhibited GBM cell proliferation and induced apoptosis through caspase-9 and caspase-3 activation and PARP cleavage. Hispolon also induced cell cycle G2/M phase arrest in GBM cells, as supported by flow cytometry analysis and confirmed by a decrease in cyclin B1, cdc2, and cdc25c protein expressions in a dose- and time-dependent manner. Furthermore, hispolon suppressed the migration and invasion of GBM cells by modulating epithelial-mesenchymal transition (EMT) markers via wound healing, transwell assays, and real-time PCR. Moreover, hispolon significantly reduced tumor growth in DBTRG xenograft mice and activated caspase-3 in hispolon-treated tumors. Thus, our findings revealed that hispolon is a potential candidate for the treatment of GBM.

Gastrodin alleviates seizure severity and neuronal excitotoxicities in the rat lithium-pilocarpine model of temporal lobe epilepsy via enhancing GABAergic transmission.

ETHNOPHARMACOLOGICAL RELEVANCE: Temporal lobe epilepsy remains one of the most drug-resistant focal epilepsy, leading to enormous healthcare burden. Among traditional herb medicine, some ingredients have the potential to treat seizure and alleviate the neuronal excitoxicity. The dried rhizome of Gastrodia elata Blume has been used to treat convulsive disorder, dizziness, dementia and migraine in eastern Asia. AIM OF THE STUDY: To determine whether gastrodin, an active ingredient of Gastrodia elata Blume, can reduce lithium-pilocarpine induced seizure severity and neuronal excitotoxicity and explore the underlying mechanism. MATERIALS AND METHODS: We divided the Sprague-Dawley rats into an experimental group (gastrodin group) and a control group (Dimethyl sulfoxide, vehicle group) and performed the behavioral analysis and electroencephalography to determine the effect of gastrodin on the seizure severity induced by lithium-pilocarpine injection. Nissl-stained histopathology elucidated the degree of rat hippocampal neuronal damage as markers of acute and subacute neuronal excitotoxicity. Besides, the Western blotting of dissected hippocampus was carried out to demonstrate the protein expression involving GABAergic transmission and metabolic pathway. RESULTS: Gastrodin reduced the acute seizure severity in lithium-pilocarpine-induced seizure model. In electroencephalography recording, gastrodin exerted inhibitory action on epileptiform discharge. Compared with control group, gastrodin exhibited neuroprotective effect against seizure related hippocampal neuronal damage at acute and subacute stages. The Western blotting showed that gastrodin reversed the degradation of GABAA receptor after pilocarpine-induced seizures. CONCLUSIONS: In the experimental seizure model, gastrodin showed anti-seizure and neuroprotective abilities. Enhancing the expression of GABAA receptor plays an important role in its antiepileptic mechanism. The results offer a new insight of developing new antiepileptic drugs from traditional Chinese medicine.

The Synergistic Anti-Cancer Effects of NVP-BEZ235 and Regorafenib in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the most common type of liver cancer worldwide. Regorafenib is a multi-kinase inhibitor and the second-line treatment for HCC. Since the PI3K/Akt/mTOR signaling pathway is dysregulated in HCC, we evaluated the therapeutic effects of regorafenib combined with a dual PI3K/mTOR inhibitor BEZ235 in the human HCC cell lines (n = 3). The combined treatment with BEZ235 and regorafenib enhanced the inhibition of cell proliferation and increased the expression of cleaved caspase-3 and cleaved PARP in HCC cells. Moreover, the combined treatment suppressed HCC cell migration and invasion in the transwell assay. Further, the Western blot analyses confirmed the involvement of epithelial-mesenchymal transition (EMT)-related genes such as slug, vimentin, and matrix metalloproteinase (MMP)-9/-2. Additionally, the proteinase activity of MMP-9/-2 was analyzed using gelatin zymography. Furthermore, the inhibition of phosphorylation of the Akt, mTOR, p70S6K, and 4EBP1 after combined treatment was validated using Western blot analysis. Therefore, these results suggest that the combined treatment with BEZ235 and regorafenib benefits patients with HCC.

The Protective Effect of Hispidin against Hydrogen Peroxide-Induced Oxidative Stress in ARPE-19 Cells via Nrf2 Signaling Pathway.

Hispidin, a polyphenol compound isolated from Phellinuslinteus, has been reported to possess antioxidant activities. In this study, we aimed to investigate the mechanisms underlying the protective effect of hispidin against hydrogen peroxide (H2O2)-induced oxidative stress on Adult Retinal Pigment Epithelial cell line-19 (ARPE-19) cells. Hispidin was not cytotoxic to ARPE-19 cells at concentrations of less than 50 µM. The levels of intracellular reactive oxygen species (ROS) were analyzed by dichlorofluorescin diacetate (DCFDA) staining. Hispidin significantly restored H2O2-induced cell death and reduced the levels of intracellular ROS. The expression levels of antioxidant enzymes, such as NAD(P)H:Quinine oxidoreductase-1 (NQO-1), heme oxygenase-1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and glutamate-cysteine ligase modifier subunit (GCLM) were examined using real-time PCR and Western blotting. Our results showed that hispidin markedly enhanced the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), HO-1, NQO-1, GCLM, and GCLC in a dose-dependent manner. Furthermore, knockdown experiments revealed that transfection with Nrf2 siRNA successfully suppresses the hispidin activated Nrf2 signaling in ARPE-19 cells. Moreover, activation of the c-Jun N-terminal kinase (JNK) pathway is involved in mediating the protective effects of hispidin on the ARPE-19 cells. Thus, the present study demonstrated that hispidin provides protection against H2O2-induced damage in ARPE-19 cells via activation of Nrf2 signaling and up-regulation of its downstream targets, including Phase II enzymes, which might be associated with the activation of the JNK pathway.

Anti-Cancer Effects of Radix Angelica Sinensis (Danggui) and N-Butylidenephthalide on Gastric Cancer: Implications for REDD1 Activation and mTOR Inhibition.

BACKGROUND/AIMS: Radix Angelica Sinensis (danggui in Chinese) is widely used in traditional chinese medicine (TCM). N-butylidenephthalide (BP), a bioactive compound in danggui, is a potential antitumor agent for various cancer types. However, its clinical effect and mechanism in the treatment of gastric cancer remain undetermined. METHODS: The in vivo protective effect of danggui in patients with gastric cancer were validated using data from Taiwan's National Health Insurance Research Database (NHIRD). The genes induced by BP-treatment were analyzed by whole transcriptome RNA sequencing (RNA-seq) and validated by real-time PCR, western blot and siRNA transfection. The effect of BP on AGS cell migration and invasion was evaluated in transwell assays. The antitumor effects of BP were evaluated in vivo in an AGS xenograft animal model. RESULTS: Danggui users were found to have an increased survival rate when compared with danggui nonusers (log-rank test p = 0.002) . The use of danggui highly associated with decreased mortality (the adjusted hazard ratio (HR) of danggui user was 0.72 [95 % CI, 0.57-0.92] (p = 0.009). The in vitro results showed that BP inhibited gastric cancer cell proliferation, and triggered cellular apoptosis depending on the activation of mitochondrial apoptotic pathway. Using RNA-seq analysis we found that REDD1 was the highest transcript induced by BP in gastric cancer cells. BP induce an increase of REDD1 expression that inhibits mTOR signaling, thus inhibiting gastric cancer growth. We used RNA interference to demonstrate that the knock-down of REDD1 attenuated the BP-induced mTORC1 activation and growth inhibition. BP suppressed the growth of AGS xenografts tumor in vivo. CONCLUSION: Danggui can prolong the survival rate of gastric cancer patients in Taiwan. BP caused gastric cancer cell death through the activation of mitochondria-intrinsic pathway and induced the REDD1 expression leading to mTOR signal pathway inhibition in gastric cancer cells. BP inhibited the in vivo growth of AGS xenograft tumors. These results may provide the basis for a new therapeutic approach toward the treatment of gastric cancer progression.

Synergistic antitumor effects of tanshinone IIA and sorafenib or its derivative SC-1 in hepatocellular carcinoma cells.

INTRODUCTION: Hepatocellular carcinoma (HCC) is the most common form of hepatic malignancy in the world. We aimed to determine the effect of tanshinone IIA (Tan-IIA) in combination with sorafenib or its derivative SC-1 on cytotoxicity, apoptosis, and metastasis in human HCC cells. MATERIALS AND METHODS: Cytotoxicity was detected by MTT assay. Apoptosis and sub-G1 populations were analyzed by flow cytometry. Cell migration and invasion were evaluated by Transwell assay. Protein expression was detected by Western blot. RESULTS: Tan-IIA combined with sorafenib or SC-1 exerted synergistic cytotoxicity in HCC cells. Elevated proportions of sub-G1 and caspase activation were observed in the combinative treatments; in addition, marked inhibition of cell migration and invasion, which could be mediated by the modulation of epithelial-mesenchymal transition was observed. pSTAT3 levels were significantly reduced as well. CONCLUSION: A combination therapy using Tan-IIA and sorafenib or SC-1 could be a promising approach to target HCC, and further preclinical investigations are warranted to establish their synergetic advantage.

Anti-Tumor and Radiosensitization Effects of N-Butylidenephthalide on Human Breast Cancer Cells.

N-Butylidenephthalide (BP), which is extracted from a traditional Chinese medicine, Radix Angelica Sinensis (danggui), displays antitumor activity against various cancer cell lines. The purpose of this study was to investigate the cytotoxic and radiosensitizing effect of BP and the underlying mechanism of action in human breast cancer cells. BP induces apoptosis in breast cancer cells, which was revealed by the TUNEL assay; the activation of caspase-9 and PARP was detected by western blot. In addition, BP-induced G2/M arrest was examined by flow cytometry and the expression levels of the G2/M regulatory protein were detected by western blot. BP also suppresses the migration and invasion of breast cancer cells, which was tested by wound healing and the matrigel invasion assay; the involvement of EMT-related gene expressions was detected by real-time PCR. Furthermore, BP enhanced the radiosensitivity of breast cancer cells, which was measured by the colony formation assay and comet assay, where the foci of γ-H2AX after radiation significantly increased in BP pretreated cells and was evidenced by immunocytochemistry staining and western blot. The homologous recombination (HR) repair protein Rad51 was down-regulated after BP pretreatment. These results indicate that BP might be a potential chemotherapeutic and radiosensitizing agent for breast cancer therapy.

Potential therapeutic effects of N-butylidenephthalide from Radix Angelica Sinensis (Danggui) in human bladder cancer cells.

BACKGROUND: N-butylidenephthalide (BP) isolated from Radix Angelica Sinensis (Danggui) exhibits anti-tumorigenic effect in various cancer cells both in vivo and in vitro. The effect of BP in bladder cancer treatment is still unclear and worth for further investigate. METHODS: Changes of patients with bladder cancer after Angelica Sinensis exposure were evaluated by analysis of Taiwan's National Health Insurance Research Database (NHIRD) database. The anti-proliferative effect of BP on human bladder cancer cells was investigated and their cell cycle profiles after BP treatment were determined by flow cytometry. BP-induced apoptosis was demonstrated by Annexin V-FITC staining and TUNEL assay, while the expressions of apoptosis-related proteins were determined by western blot. The migration inhibitory effect of BP on human bladder cancer cells were shown by trans-well and wound healing assays. Tumor model in NOD-SCID mice were induced by injection of BFTC human bladder cancer cells. RESULTS: The correlation of taking Angelica sinensis and the incidence of bladder cancer in NHIRD imply that this herbal product is worth for further investigation. BP caused bladder cancer cell death in a time- and dose- dependent manner and induced apoptosis via the activation of caspase-9 and caspase-3. BP also suppressed the migration of bladder cancer cells as revealed by the trans-well and wound healing assays. Up-regulation of E-cadherin and down-regulation of N-cadherin were evidenced by real-time RT-PCR analysis after BP treatment in vitro. Besides, in combination with BP, the sensitivity of these bladder cancer cells to cisplatin increased significantly. BP also suppressed BFTC xenograft tumor growth, and caused 44.2% reduction of tumor volume after treatment for 26 days. CONCLUSIONS: BP caused bladder cancer cell death through activation of mitochondria-intrinsic pathway. BP also suppressed the migration and invasion of these cells, probably by modulating EMT-related genes. Furthermore, combination therapy of BP with a lower dose of cisplatin significantly inhibited the growth of these bladder cancer cell lines. The incidence of bladder cancer decreased in patients who were exposed to Angelica sinensis, suggesting that BP could serve as a potential adjuvant in bladder cancer therapy regimen.

Tanshinone IIA Inhibits Epithelial-Mesenchymal Transition in Bladder Cancer Cells via Modulation of STAT3-CCL2 Signaling.

Tanshinone IIA (Tan-IIA) is an extract from the widely used traditional Chinese medicine (TCM) Danshen (Salvia miltiorrhiza), and has been found to attenuate the proliferation of bladder cancer (BCa) cells (The IC50 were: 5637, 2.6 µg/mL; BFTC, 2 µg/mL; T24, 2.7 µg/mL, respectively.). However, the mechanism of the effect of Tan-IIA on migration inhibition of BCa cells remains unclear. This study investigates the anti-metastatic effect of Tan-IIA in human BCa cells and clarifies its molecular mechanism. Three human BCa cell lines, 5637, BFTC and T24, were used for subsequent experiments. Cell migration and invasion were evaluated by transwell assays. Real-time RT-PCR and western blotting were performed to detect epithelial-mesenchymal transition (EMT)-related gene expression. The enzymatic activity of matrix metalloproteinases (MMP) was evaluated by zymography assay. Tan-IIA inhibited the migration and invasion of human BCa cells. Tan-IIA suppressed both the protein expression and enzymatic activity of MMP-9/-2 in human BCa cells. Tan-IIA up-regulated the epithelial marker E-cadherin and down-regulated mesenchymal markers such as N-cadherin and Vimentin, along with transcription regulators such as Snail and Slug in BCa cells in a time- and dose-dependent manner. Mechanism dissection revealed that Tan-IIA-inhibited BCa cell invasion could function via suppressed chemokine (C-C motif) ligand 2 (CCL2) expression, which could be reversed by the addition of CCL2 recombinant protein. Furthermore, Tan-IIA could inhibit the phosphorylation of the signal transducer and activator of transcription 3 (STAT3) (Tyr705), which cannot be restored by the CCL2 recombinant protein addition. These data implicated that Tan-IIA might suppress EMT on BCa cells through STAT3-CCL2 signaling inhibition. Tan-IIA inhibits EMT of BCa cells via modulation of STAT3-CCL2 signaling. Our findings suggest that Tan-IIA can serve as a potential anti-metastatic agent in BCa therapy.

A 7-year-old female child of incontinentia pigmenti presenting with vitreous hemorrhage.

Incontinentia pigmenti (IP) is a rare disease with multisystemic anomalies, which commonly presents just after birth. Here, we report a rare case of IP patient with vitreous hemorrhage in school-age children. Therefore, physicians have to be alert and evaluate IP patients at all ages. Regular ophthalmic follow-up is necessary, and fluorescein angiography should be performed if peripheral ischemia or neovascularization is suspected. The effect of peripheral laser ablation on peripheral retinal nonperfusion is not clear and merits further study.

The Role of Intermittent Hypoxia on the Proliferative Inhibition of Rat Cerebellar Astrocytes.

Sleep apnea syndrome, characterized by intermittent hypoxia (IH), is linked with increased oxidative stress. This study investigates the mechanisms underlying IH and the effects of IH-induced oxidative stress on cerebellar astrocytes. Rat primary cerebellar astrocytes were kept in an incubator with an oscillating O2 concentration between 20% and 5% every 30 min for 1-4 days. Although the cell loss increased with the duration, the IH incubation didn't induce apoptosis or necrosis, but rather a G0/G1 cell cycle arrest of cerebellar astrocytes was noted. ROS accumulation was associated with cell loss during IH. PARP activation, resulting in p21 activation and cyclin D1 degradation was associated with cell cycle G0/G1 arrest of IH-treated cerebellar astrocytes. Our results suggest that IH induces cell loss by enhancing oxidative stress, PARP activation and cell cycle G0/G1 arrest in rat primary cerebellar astrocytes.

Potential therapeutic roles of tanshinone IIA in human bladder cancer cells.

Tanshinone IIA (Tan-IIA), one of the major lipophilic components isolated from the root of Salviae Miltiorrhizae, has been found to exhibit anticancer activity in various cancer cells. We have demonstrated that Tan-IIA induces apoptosis in several human cancer cells through caspase- and mitochondria-dependent pathways. Here we explored the anticancer effect of Tan-IIA in human bladder cancer cell lines. Our results showed that Tan-IIA caused bladder cancer cell death in a time- and dose-dependent manner. Tan-IIA induced apoptosis through the mitochondria-dependent pathway in these bladder cancer cells. Tan-IIA also suppressed the migration of bladder cancer cells as revealed by the wound healing and transwell assays. Finally, combination therapy of Tan-IIA with a lower dose of cisplatin successfully killed bladder cancer cells, suggesting that Tan-IIA can serve as a potential anti-cancer agent in bladder cancer.

Proteomic-based identification of multiple pathways underlying n-butylidenephthalide-induced apoptosis in LNCaP human prostate cancer cells.

Although numerous studies have shown the cancer-preventive properties of butylidenephthalide (BP), there is little report of BP affecting human prostate cancer cells. In the present study, proteomic-based approaches were used to elucidate the anticancer mechanism of BP in LNCaP human prostate cancer cells. BP treatment decreased the viability of LNCaP human prostate cancer cells in a concentration- and time-dependent manner, which was correlated with G0/G1 phase cell cycle arrest. Increased cell cycle arrest was associated with a decrease in the level of CCND1, CDK2, and PCNA proteins and an increase in the level of CDKN2A, CDKN1A, and SFN proteins. Proteomic studies revealed that among 48 differentially expressed proteins, 25 proteins were down-regulated and 23 proteins were up-regulated and these proteins fall into one large protein protein interaction network. Among these proteins, FAS, AIFM1, BIK, CYCS, SFN, PPP2R1A, CALR, HSPA5, DDIT3, and ERN1 are apoptosis and endoplasmic reticulum (ER) stress associated proteins. Proteomic data suggested that multiple signaling pathways including FAS-dependent pathway, mitochondrial pathway, and ER stress pathway are involved in the apoptosis induced by BP.

Renoprotective effect of human umbilical cord-derived mesenchymal stem cells in immunodeficient mice suffering from acute kidney injury.

It is unknown whether human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) can improve the renal function of patients suffering from acute kidney injury. Moreover, before beginning clinical trials, it is necessary to investigate this renoprotective effect of hUC-MSCs in a xenogeneic model of acute kidney injury. However, no previous studies have examined the application of hUC-MSCs to immunodeficient mice suffering from acute kidney injury. The objectives of this study were to examine whether hUC-MSCs could improve renal function in nonobese diabetic-severe combined immune deficiency (NOD-SCID) mice suffering from acute kidney injury, and to investigate the mechanism(s) for hUC-MSCs to improve renal function in this xenogeneic model. Early (3 hr) and late (12 hr) administrations of hUC-MSCs (10(6) cells) were performed via the external jugular vein into NOD-SCID mice suffering from either folic acid (FA) (250 mg/kg body weight) or vehicle. The results showed that early administration of hUC-MSCs improved the renal function of NOD-SCID mice suffering from FA-induced acute kidney injury, as evidenced by decreased serum urea nitrogen and serum creatinine levels, as well as a reduced tubular injury score. The beneficial effects of hUC-MSCs were through reducing apoptosis and promoting proliferation of renal tubular cells. These benefits were independent of inflammatory cytokine effects and transdifferentiation. Furthermore, this study is the first one to show that the reduced apoptosis of renal tubular cells by hUC-MSCs in this xenogeneic model is mediated through the mitochondrial pathway, and through the increase of Akt phosphorylation.

ß-catenin and K-ras mutations and RASSF1A promoter methylation in Taiwanese colorectal cancer patients.

AIMS: The purpose of this study was to investigate the associations of ß-catenin mutations, K-ras mutations, methylations of the RASSF1A promoter, and the survival of Taiwanese colorectal cancer (CRC) subjects who received 5-fluorouracil (5-FU) adjuvant chemotherapy. RESULTS: The complete coding region of the K-ras gene and exon 3 and exon 4 of the ß-catenin gene isolated from tumor tissues and adjacent normal colon tissues from 117 CRC subjects were sequenced, respectively. Methylations in the RASSF1A promoter region were also investigated. Various characteristics of the 117 subjects were recorded and used in the Cox proportional-hazard model analyses. Three missense mutations, one nonsense mutation, and one deletion were identified in the ß-catenin gene. A 2 bp deletion was identified in the K-ras gene. We found that the frequencies of mutations in the ß-catenin and K-ras genes were less pronounced in Taiwanese CRC subjects as compared with other populations. Methylations in the RASSF1A promoter region were detected in 73.5% (n=86/117) of the subjects, which was higher than in other studies. Methylations in the RASSF1A promoter have no significant effect on hazards for all CRC deaths caused in Taiwanese CRC patients. No interaction between 5-FU adjuvant chemotherapy and methylations of the RASSF1A promoter was observed. CONCLUSIONS: The mutation frequencies of ß-catenin and K-ras genes in Taiwanese CRC patients are very low, which may suggest that they are not the dominant factors for CRC occurrence and prognosis in Taiwanese CRC patients. Methylation of RASSF1A promoter is independent of the prognosis for Taiwanese CRC patients. Taiwanese subjects differ from subjects of other populations with regard to ß-catenin, K-ras, and RASSF1A presentations for CRC.

Induction of apoptosis coupled to endoplasmic reticulum stress in human prostate cancer cells by n-butylidenephthalide.

BACKGROUND: N-butylidenephthalide (BP) exhibits antitumor effect in a variety of cancer cell lines. The objective of this study was to obtain additional insights into the mechanisms involved in BP induced cell death in human prostate cancer cells. METHODS/PRINCIPAL FINDINGS: Two human prostate cancer cell lines, PC-3 and LNCaP, were treated with BP, and subsequently evaluated for their viability and cell cycle profiles. BP caused cell cycle arrest and cell death in both cell lines. The G0/G1 phase arrest was correlated with increase levels of CDK inhibitors (p16, p21 and p27) and decrease of the checkpoint proteins. To determine the mechanisms of BP-induced growth arrest and cell death in prostate cancer cell lines, we performed a microarray study to identify alterations in gene expression induced by BP in the LNCaP cells. Several BP-induced genes, including the GADD153/CHOP, an endoplasmic reticulum stress (ER stress)-regulated gene, were identified. BP-induced ER stress was evidenced by increased expression of the downstream molecules GRP78/BiP, IRE1-α and GADD153/CHOP in both cell lines. Blockage of IRE1-α or GADD153/CHOP expression by siRNA significantly reduced BP-induced cell death in LNCaP cells. Furthermore, blockage of JNK1/2 signaling by JNK siRNA resulted in decreased expression of IRE1-α and GADD153/CHOP genes, implicating that BP-induced ER stress may be elicited via JNK1/2 signaling in prostate cancer cells. BP also suppressed LNCaP xenograft tumor growth in NOD-SCID mice. It caused 68% reduction in tumor volume after 18 days of treatment. CONCLUSIONS: Our results suggest that BP can cause G0/G1 phase arrest in prostate cancer cells and its cytotoxicity is mediated by ER stress induction. Thus, BP may serve as an anticancer agent by inducing ER stress in prostate cancer.

Poly (ADP-ribose) polymerase plays an important role in intermittent hypoxia-induced cell death in rat cerebellar granule cells.

BACKGROUND: Episodic cessation of airflow during sleep in patients with sleep apnea syndrome results in intermittent hypoxia (IH). Our aim was to investigate the effects of IH on cerebellar granule cells and to identify the mechanism of IH-induced cell death. METHODS: Cerebellar granule cells were freshly prepared from neonatal Sprague-Dawley rats. IH was created by culturing the cerebellar granule cells in the incubators with oscillating O2 concentration at 20% and 5% every 30 min for 1-4 days. The results of this study are based on image analysis using a confocal microscope and associated software. Cellular oxidative stress increased with increase in IH. In addition, the occurrence of cell death (apoptosis and necrosis) increased as the duration of IH increased, but decreased in the presence of an iron chelator (phenanthroline) or poly (ADP-ribose) polymerase (PARP) inhibitors [3-aminobenzamide (3-AB) and DPQ]. The fluorescence of caspase-3 remained the same regardless of the duration of IH, and Western blots did not detect activation of caspase-3. However, IH increased the ratio of apoptosis-inducing factor (AIF) translocation to the nucleus, while PARP inhibitors (3-AB) reduced this ratio. RESULTS: According to our findings, IH increased oxidative stress and subsequently leading to cell death. This effect was at least partially mediated by PARP activation, resulting in ATP depletion, calpain activation leading to AIF translocation to the nucleus. CONCLUSIONS: We suggest that IH induces cell death in rat primary cerebellar granule cells by stimulating oxidative stress PARP-mediated calpain and AIF activation.

Activation of NAG-1 via JNK signaling revealed an isochaihulactone-triggered cell death in human LNCaP prostate cancer cells.

BACKGROUND: We explored the mechanisms of cell death induced by isochaihulactone treatment in LNCaP cells. METHODS: LNCaP cells were treated with isochaihulactone and growth inhibition was assessed. Cell cycle profiles after isochaihulactone treatment were determined by flow cytometry. Expression levels of cell cycle regulatory proteins, caspase 9, caspase 3, and PARP were determined after isochaihulactone treatment. Signaling pathway was verified by inhibitors pre-treatment. Expression levels of early growth response gene 1 (EGR-1) and nonsteroidal anti-inflammatory drug-activated gene 1 (NAG-1) were determined to investigate their role in LNCaP cell death. NAG-1 expression was knocked down by si-NAG-1 siRNA transfection. Rate of cell death and proliferation were obtained by MTT assay. RESULTS: Isochaihulactone caused cell cycle arrest at G2/M phase in LNCaP cells, which was correlated with an increase of p53 and p21 levels and downregulation of the checkpoint proteins cdc25c, cyclin B1, and cdc2. Bcl-2 phosphorylation and caspase activation were also observed. Isochaihulactone induced phosphorylation of c-Jun-N-terminal kinase (JNK), and JNK inhibitor partially reduced isochaihulactone-induced cell death. Isochaihulactone also induced the expressions of EGR-1 and NAG-1. Expression of NAG-1 was reduced by JNK inhibitor, and knocking down of NAG-1 inhibited isochaihulactone-induced cell death. CONCLUSIONS: Isochaihulactone apparently induces G2/M cell cycle arrest via downregulation of cyclin B1 and cdc2, and induces cellular death by upregulation of NAG-1 via JNK activation in LNCaP cells.

The association of methylation in the promoter of APC and MGMT and the prognosis of Taiwanese CRC patients.

AIMS: The purpose of this study was to investigate the association of methylation in the promoter regions of adenomatous polyposis coli (APC) and O(6)-methylguanine-DNA methyltransferase (MGMT) and the survival of Taiwanese colorectal cancer (CRC) subjects who received 5-fluorouracil (5-FU) adjuvant chemotherapy. RESULTS: DNA isolated from tumor tissue of 117 CRC subjects was analyzed for the existence of methylation in the promoter regions of APC and MGMT by methylation-specific PCR. Various characteristics of the 117 subjects were recorded and used in the Cox proportional-hazard model analyses. Methylation in the promoter region is 62.4% (73/117) for APC and 60.7% (71/117) for MGMT in our CRC patients. Subjects presenting methylation in the APC promoter demonstrate significantly lower hazards for all causes of death (hazard ratios=0.378, p=0.011) or CRC deaths (hazard ratios=0.426, p=0.039). However, no significant correlation is found between the methylation of MGMT promoter and the prognosis of CRC subjects. In addition, no interaction between 5-FU adjuvant chemotherapy and methylation of the two genes are observed. CONCLUSIONS: Methylation in the APC promoter may serve as a predictor for the prognosis of Taiwanese CRC patients.