WT1 and TP53 as valuable diagnostic biomarkers for relapse after hematopoietic stem cell transplantation in acute myeloid leukemia.

BACKGROUND: Relapse following hematopoietic stem cell transplantation (HSCT) occurs relatively frequently and is a significant risk factor for mortality in patients with acute myeloid leukemia (AML). Early diagnosis is, therefore, of utmost importance and can provide valuable guidance for appropriate and timely intervention. Here, the diagnostic value of two molecular markers, Wilms tumor 1 (WT1) and tumor suppressor protein p53 (TP53), were studied. METHODS AND RESULTS: Twenty AML patients undergoing HSCT participated in this investigation. Some had relapsed following HSCT, while others were in remission. Peripheral blood (PB) and bone marrow (BM) samples were collected following relapse and remission. WT1 and TP53 messenger RNA (mRNA) expression was evaluated using reverse transcription-quantitative polymerase chain reaction (RT‒qPCR). The diagnostic value of genes was evaluated by utilizing receiver-operating characteristic (ROC) curve analysis. ROC analysis showed WT1 and TP53 as diagnostic markers for relapse after HSCT in AML patients. The mRNA expression level of WT1 was elevated in individuals who experienced relapse compared to those in a state of remission (p value < 0.01). Conversely, the expression level of TP53 mRNA was lower in individuals who had relapsed compared to those in remission (p value < 0.01). CONCLUSIONS: WT1 and TP53 possess the potential to serve as invaluable biomarkers in the identification of molecular relapse after HSCT in patients with AML. Further studies for a definitive conclusion are recommended.

Targeting PPARγ/ NF-κB Signaling Pathway by Britannin, a Sesquiterpene Lactone from Inula aucheriana DC., in Gastric Cancer.

BACKGROUND: Gastric cancer is one of the most common and deadliest malignancies in the world. Therefore, there is an urgent need to develop new and effective agents to reduce mortality. The plants of genus Inula have gained the attention of researchers worldwide as a rich source of potent medicinal compounds. OBJECTIVE: This study explores the anti-cancer activity of Britannin, a sesquiterpene lactone isolated from Inula aucheriana DC., and its molecular mechanism in gastric cancer cells, AGS and MKN45. METHODS: Cytotoxicity was evaluated through the MTT assay following 24 h, 48 h, and 72 h treatment with different concentrations of Britannin. Apoptosis rate and caspase-3 activity were measured 24 h after treatment by Britannin. . Western blotting was performed to determine the expression of the NF-κB, IκBα, and PPARγ proteins. Moreover, quantitative RT-PCR was applied to measure the expression of NF-κB target genes. RESULTS: We showed that Britannin induced cell growth inhibition and apoptosis in gastric cancer cells. Britannin caused an elevation in mRNA and protein levels of PPARγ. The involvement of PPARγ was more confirmed using GW9662, a PPARγ inhibitor. Suppression of NF-κB was demonstrated by western blot analysis. Down-regulation of MMP-9, TWIST-1, COX-2, and Bcl-2 and up-regulation of Bax were also observed in gastric cancer cells. CONCLUSION: These results imply that activation of the PPARγ signaling pathway through suppression of NF-κB underlies the anti-cancer properties of Britannin in gastric cancer. Therefore, Britannin could be considered as a promising anti-cancer candidate for further evaluation.

Gaillardin, a potent sesquiterpene lactone induces apoptosis via down-regulation of NF-κß in gastric cancer cells, AGS and MKN45.

ETHNOPHARMACOLOGICAL RELEVANCE: The genus Inula has been traditionally used as folk medicine in treating different illnesses such as kidney stones, urethra infection, jaundice, bronchitis, respiratory diseases and cancer. AIM OF THE STUDY: Gaillardin, a sesquiterpene lactone isolated from Inula oculus-christi, seems to have great potential as an anti-cancer agent. This study was carried out to evaluate the anti-cancer properties of Gaillardin in gastric cancer cells and also its possible underlying mechanism. METHODS: The colorimetric MTT assay was used to assess metabolic activity of cells as an indicator of viability and cytotoxicity. Flow cytometry using Annexin V-FITC/PI was applied to detect and quantify the level of apoptosis. Detection of activated caspase-3, as a biochemical marker of apoptosis, was done using caspase-3 assay kit. Activation of NF-κB pathway was determined by western blotting. The mRNA expression levels of NF-κB target genes were measured using quantitative RT-PCR. Moreover, intracellular reactive oxygen species (ROS) production was evaluated. RESULTS: Gaillardin significantly reduced cell viability in a time and dose-dependent manner. The inhibitory effect of Gaillardin was attributed to induction of apoptosis. Investigation about the underlying mechanism revealed that Gaillardin exerts its action through inhibition of NF-κB activation and subsequently down-regulation of genes (COX-2, MMP-9, TWIST-1, and BCl-2) regulated by NF-κB. Moreover, Gaillardin caused remarkable elevation in ROS production in AGS and MKN45 cells. CONCLUSION: We provided evidences about the role of NF-κB pathway in the induction of apoptosis by the sesquiterpene lactone Gaillardin in AGS and MKN45 cells for the first time, which suggest Gaillardin could be considered as a promising natural agent for further investigations to identify new potent anticancer drugs in the future.

New Diterpene Compound from Euphorbia connate Boiss., 3,7,14,15-Tetraacetyl-5-Propanoyl-13(17)-Epoxy-8,10(18)-Myrsinadiene, Inhibits the Growth of Ovarian Cancer Cells by Promoting Mitochondrial-Mediated Apoptosis.

Ovarian cancer due to the difficulties in early clinical diagnosis and absence of successfull treatment has poor prognosis and high mortality among all gynecological malignancies. Many evidence has revealed that plants of the Euphorbiaceae family are precious sources of novel bioactive compounds with anti-tumor activities. 3,7,14,15-tetraacetyl-5-propanoyl-13(17)-epoxy-8,10(18)-myrsinadiene (TPEM) is a new myrsinane-type diterpene isolated recently by our group from aerial parts of Euphorbia Connata and the present study was aimed to explore its inhibitory effects on growth of two human ovarian cancer cells, OVCAR-3, and Caov-4. The obtained results indicated that growth of OVCAR-3 and Caov-4 cells was significantly inhibited by TPEM in a dose-dependent manner, with the IC50 values of 41.27 ± 1.52 and 36.44 ± 2.41 µM, respectively. Furthermore, using Annexin V-FITC and PI staining it was confirmed that the induced cell death was mainly mediated through apoptotic pathway. Further observations such as decrease in the mitochondrial membrane potential (ΔΨm), increase in the activity of caspase-3 and elevation of the Bax/Bcl-2 ratio suggested the role of mitochondria in the induction of apoptosis by TPEM. ROS level was also remarkably increased in OVCAR-3 and Caov-4 cells in response to TPEM treatment. In conclusion, these findings provide first evidences about potential anticancer properties of TPEM.

Integrin α2ß1 inhibition attenuates prostate cancer cell proliferation by cell cycle arrest, promoting apoptosis and reducing epithelial-mesenchymal transition.

Integrin α2ß1 plays an important role in cellular migration and metastasis processes associated with prostate cancer. The aim of this study was to assess whether selective inhibition of integrin α2ß1 is an effective strategy to target metastatic prostate cancer cells. In this regard, we examined the effects of the inhibitor BTT-3033, which selectively interferes with the connection between integrin a2b1 and its ligand, on migration, epithelial-mesenchymal transition (EMT), cell cycle arrest, apoptosis, and specific intracellular signaling pathways using LNcap-FGC and DU-145 prostate cancer cell lines. Western blot analysis and immunocytochemistry assays showed that inhibition of integrin a2b1 inhibits EMT, through the increased expression of E-cadherin and decreased expression of N-cadherin and vimentin. Scratch wound healing assays revealed a direct effect on integrin α2ß1 in the migration capacity of cells. In addition, treatment with BTT-3033 induced a reduction in cell viability and proliferation, as assessed by MTT and BrdU assays. In addition, the results show that BTT-3033 inhibits cell proliferation by inducing G1 cell cycle arrest. Moreover, inhibition of integrin α2ß1 induces apoptosis through the activation of ROS, Bax protein upregulation, caspase-3 activation, and depletion of ΔΨm.  Molecular signaling studies showed that integrin α2ß1 was a positive regulator of MKK7 phosphorylation. In conclusion, our results reveal a critical role for integrin a2b1 in the proliferation of prostate cancer cells, as demonstrated by EMT inhibition, cell cycle arrest, and apoptosis induction in response to treatment with its specific inhibitor BT-3033.

Down-Regulation of DDR1 Induces Apoptosis and Inhibits EMT through Phosphorylation of Pyk2/MKK7 in DU-145 and Lncap-FGC Prostate Cancer Cell Lines.

BACKGROUND: In cancer cells, re-activation of Epithelial-Mesenchymal Transition (EMT) program through Discoidin Domain Receptor1 (DDR1) leads to metastasis. DDR1-targeted therapy with siRNA might be a promising strategy for EMT inhibition. Therefore, the aim of this study was to investigate the effect of DDR1 knockdown in the EMT, migration, and apoptosis of prostate cancer cells. For this purpose, the expression of DDR1 was down regulated by the siRNA approach in LNcap-FGC and DU-145 prostate cancer cells. METHODS: Immunocytochemistry was carried out for the assessment of EMT. E-cadherin, N-cadherin, Bax, Bcl2, and the phosphorylation level of Proline-rich tyrosine kinase 2 (Pyk2) and Map Kinase Kinase 7 (MKK7) was determined using the western blot. Wound healing assay was used to evaluate cell migration. Flow cytometry was employed to determine the apoptosis rate in siRNA-transfected cancer cells. RESULTS: Our findings showed that the stimulation of DDR1 with collagen-I caused increased phosphorylation of Pyk2 and MKK7 signaling molecules that led to the induction of EMT and migration in DU-145 and LNcap- FGC cells. In contrast, DDR1 knockdown led to significant attenuation of EMT, migration, and phosphorylation levels of Pyk2 and MKK7. Moreover, DDR1 knockdown via induction of Bax expression and suppression of Bcl-2 expression induces apoptosis. CONCLUSION: Collectively, our results indicate that the DDR1 targeting with siRNA may be beneficial for the inhibition of EMT and the induction of apoptosis in prostate cancer.

Anticancer activity of britannin through the downregulation of cyclin D1 and CDK4 in human breast cancer cells.

AIM OF THE STUDY: Both apoptotic induction and cell cycle blockade in cancer cells are effective strategies to eliminate cancer cells. Many conventional cancer drugs that induce apoptosis and inhibit cell cycle progression have been reported as potential therapeutics for various types of cancer. Britannin is a natural sesquiterpene lactone that its profound anticancer properties were revealed in our previous study. In this study, we evaluated the effects of britannin on the cell cycle distribution and also cell cycle-related proteins. MATERIALS AND METHODS: Analysis of cell cycle distribution was carried out using flow cytometer. The effects of britannin on cyclin D1 and CDK4 expression were evaluated using the Western blot. RESULTS: The obtained results show that britannin at the low concentrations induces cell growth inhibition mainly through G1-phase arrest while it seems that apoptosis contributes to cell growth inhibitory effect of high doses of britannin. Reduction of cyclin D1 and CDK4 protein levels were also observed after treating cancer cells with britannin. CONCLUSION: The obtained results reveal that britannin can inhibit MCF-7 and MDA-MB-468 breast cancer cells proliferation through arresting cell cycle progression through cyclin D1/CDK4-mediated pathway.

Inhibition of didscoidin domain receptor 1 reduces epithelial-mesenchymal transition and induce cell-cycle arrest and apoptosis in prostate cancer cell lines.

Didscoidin domain receptor 1 (DDR1) is involved in the progression of prostate cancer metastasis through stimulation of epithelial-mesenchymal transition (EMT). So DDR1 inhibition can be a helpful target for cancer metastasis prevention. So, we studied the effects of DDR1 inhibition on EMT as well as induction of cell-cycle arrest and apoptosis in prostate cancer cell lines. DDR1 expression was evaluated using reverse-transcription polymerase chain reaction and western blot analysis. The EMT-associated protein expression was determined using the western blot analysis and immunocytochemistry following treatment with various concentrations of DDR1 inhibitor. The activation of DDR1 and also downstream-signaling molecules Pyk2 and MKK7 were determined using western blot analysis. Cell survival and proliferation after DDR1 inhibition were evaluated using 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide, bromodeoxyuridine, and colony formation assays. Flow cytometry analysis was used to determine the effects of DDR1 inhibition on cell-cycle arrest and apoptosis using annexin V/propidium iodide-based flow cytometry. Results showed that the protein expression of N-cadherin and vimentin were decreased whereas protein expression of E-cadherin was increased after DDR1 inhibition. Results of our western blot analysis indicated that DDR1 inhibitor effectively downregulated P-DDR1, P-Pyk2, and P-MKK7 levels. This result also showed that DDR1 inhibition decreased cell survival and proliferation, induced G1 cell-cycle arrest, induced apoptosis by an increase in the Bax/Bcl-2 ratio and depletion of the mitochondrial membrane potential, and also by reactive oxygen species creation in prostate cancer cells. These data show that DDR1 inhibition can result in the EMT prevention via inhibition of Pyk2 and MKK7 signaling pathway and induces cell-cycle arrest and apoptosis in prostate cancer cell lines. Thus, this study identifies DDR1 as an important target for modulating EMT and induction of apoptosis in prostate cancer cells.

Cytotoxic effect of Drimia maritima bulb extract and induction of mitochondrial apoptotic signaling in human breast cancer cells, MCF-7 and MDA-MB-468.

BACKGROUND: Drimia maritima (D. maritima) is a plant belonging to the family Asparagaceae, which has been used for the treatment of several ailments including cancer around the world. To our knowledge, there is no comprehensive study about the molecular mechanisms of anticancer activity of this plant, yet. MATERIALS AND METHODS: In the current study, cell viability, apoptosis induction, ROS production, mitochondrial apoptotic pathway, and ER stress mediators have been evaluated in breast cancer cells, MCF7, and MDA-MB-468 treated with D. maritima. RESULTS: Significant cytotoxic effects were observed in MCF-7 and MDA-MB-468 cells after exposure to D. maritima. Apoptosis induction was determined using Annexin-V-FITC and propidium iodide staining. Furthermore, an increase of ROS, loss of mitochondrial membrane potential, the release of cytochrome c, activation of caspases, and elevation in the Bax/Bcl-2 ratio was determined. D. maritima dose-dependently increased the mRNA expression of ER stress markers such as CHOP, ATF-4, GADD34, and TRIB3 in MCF-7, and MDA-MB-468 cells. CONCLUSION: These data suggest that D. maritima induces apoptosis in human breast cancer cells via the mitochondrial-mediated pathway. In addition, endoplasmic reticulum stress seems to be involved in D. maritima-induced cell death.

Britannin induces apoptosis through AKT-FOXO1 pathway in human pancreatic cancer cells.

Induction of apoptosis in cancerous cells is considered as a promising treatment option for cancer therapy. The present study was designed to evaluate the anticancer properties of Britannin and its possible mechanisms of action in human pancreatic cancer cells. Apoptosis induction by Britannin was confirmed by annexin V-FITC/PI staining, Hoechst 33258 staining and caspase-3 activity assay in both AsPC-1 and Panc-1 cells. Additionally, by using western blot and Real-time PCR, we observed that Britannin induced apoptosis by decreasing the expression of BCL-2 and increasing the expression of BAX. Moreover, Britannin increased reactive oxygen species (ROS) generation in different intracellular sites of pancreatic cancer cells. Using western blot analysis, we observed that Britannin decreased the phosphorylated AKT and induced the nuclear accumulation of FOXO1 and also up regulation of FOXO-responsive target BIM in both pancreatic cancer cell lines. Taken together, we found that Britannin is able to induce mitochondrial apoptotic pathway through ROS production and modulation of the AKT-FOXO1 signaling axis in AsPC-1 and Panc-1 human pancreatic cancer cells. Our results can help to illuminate the molecular mechanisms underlying Britannin-induced cell death in pancreatic cancer cell lines and may potentially serve as an anticancer agent for the treatment of pancreatic cancer.

Application of new ZnO nanoformulation and Ag/Fe/ZnO nanocomposites as water-based nanofluids to consider in vitro cytotoxic effects against MCF-7 breast cancer cells.

Novel formulations of nanocomposites derived from ZnO nanoparticles have provided potential biomedical applications as a new strategy for treatment of breast cancer. In this research, two types of ZnO nanomaterials were synthesized by sol-gel hydrothermal process and co-precipitation containing fast quenching and also surface modification methods. The cytotoxic effects on growth of the breast cancer cell lines MCF-7 were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cell viability of the breast cancer cell line MCF-7 was reduced with increasing ZnO nanofluid concentrations at 48 and 72 h of treatment. The IC50 value of MCF-7 cells after 72 h of treatment with the first product ZnO (a) and second one ZnO

Analysis of killer cell immunoglobulin-like receptors (KIRs) and their HLA ligand genes polymorphisms in Iranian patients with systemic sclerosis.

Genetic factors have a great role in the pathogenesis of autoimmune diseases by cooperating with environmental stimuli. Killer immunoglobulin-like receptors (KIRs) are cell surface proteins on NK cells whose association with major histocompatibility complex-I regulates their killing function. The aim of this study was to provide information on the possible association between KIR and human leukocyte antigen (HLA) genes with systemic sclerosis disease in Iranian population. A total of 279 systemic sclerosis patients and 451 healthy controls were enrolled in this case-control study in order to determine the presence or absence of 19 KIR genes and 6 specific HLA class I ligands. DNA was analyzed by polymerase chain reaction using the specific sequence primer method (PCR-SSP). Among 11 discovered KIR genotypes, 6 genotypes showed a considerable role and 4 genotypes could preclude the risk of systemic sclerosis (SSc) disease. The gene-gene interactions were also analyzed, and significant confounding effects were seen between involved genes in these two combinations: "KIR3DL1; HLA-BW4-Thr80" and "KIR3DL1 -HLA-BW4-A1." None of single KIR genes showed significant effect on the risk of SSc. We conclude that there is an important relationship between KIR genes and their HLA ligands with incidence rate of systemic sclerosis in Iranian population. The powerful role of a number of discovered KIR/HLA compounds such as activating KIR genotype 3 and HLA-BW4-A1 confirmed the provocative hypothesis of the interplay between activating or inhibitory KIR genes with HLA ligands as a critical index of systemic sclerosis predisposition.

Induction of G2/M phase arrest and apoptosis by a new tetrahydroingenol diterpenoid from Euphorbia erythradenia Bioss. in melanoma cancer cells.

In the current study, a new tetrahydroingenol diterpene isolated from Euphorbia erythradenia, 7,13-diacetyl-5-angeloyl-20-nicotinyl-3-propionyl-1,2,6,7-tetrahydroingenol (DANPT), were tested for the molecular mechanism of its anti-cancer activity in two human melanoma cancer cell lines, A375 and HMCB. DANPT was found cytotoxic against A375 and HMCB cells with IC50 value of 15.37±2.6µM and 15.62±1.89µM, respectively. Flow cytometric analysis showed that DANPT halted the A375 and HMCB cells in G2/M phase and induced apoptosis in a dose-dependent manner. Cell cycle arrest was associated with down-regulation of cyclin B and Cdk-1 and subsequent up-regulation of p53 and p21. Moreover, DANPT induced Bax and inhibited Bcl-2 expression, which results in increasing Bax/Bcl-2 ratio and activation of caspase-3. Furthermore, the apoptotic effect of DANPT was also related to ROS production and loss of mitochondrial membrane potential (ΔYm). Overall, our results suggest that DANPT can inhibit proliferation of human melanoma cancer cells by promoting apoptosis and inducing cell cycle arrest and therefore, it can be a promising natural agent for the treatment of melanoma cancer.

Molecular mechanism of apoptosis induction by Gaillardin, a sesquiterpene lactone, in breast cancer cell lines : Gaillardin-induced apoptosis in breast cancer cell lines.

Medicinal plant extracts have been widely used for cancer treatment. Gaillardin is a natural sesquiterpene lactone that has recently been reported to have anticancer properties. The ability to induce apoptosis is an important property of a candidate anticancer drug, which discriminates between anticancer drugs and toxic compounds. The current study was therefore carried out to address the issue if Gaillardin is able to induce apoptosis in the breast cancer cell lines MCF-7 and MDA-MB-468 and to determine the underlying mechanism of its anticancer effects. Apoptosis induction by Gaillardin treatment was confirmed by annexin V-FITC/PI staining, and caspase-3,-6, and-9 activation. Using Western blot analysis, we found that Gaillardin upregulated the pro-apoptotic protein Bax and p53 and downregulated the anti-apoptotic protein Bcl-2. Moreover, the apoptotic effect of Gaillardin was also related to ROS production and loss of mitochondrial membrane potential (ΔΨm). Taken together, these results demonstrate that Gaillardin can inhibit proliferation of breast cancer cells via inducing mitochondrial apoptotic pathway and therefore, might be a promising molecule in cancer chemoprevention or chemotherapy.

Britannin, a sesquiterpene lactone, inhibits proliferation and induces apoptosis through the mitochondrial signaling pathway in human breast cancer cells.

Induction of apoptosis in cancer cells can be a promising treatment method in cancer therapy. Naturally derived products had drawn growing attention as agent in cancer therapy. The main target of anticancer drugs may be distinct, but eventually, they lead to identical cell death pathway, which is apoptosis. Here, we indicated that britannin, a sesquiterpene lactone isolated from Asteraceae family, has antiproliferative activity on the MCF-7 and MDA-MB-468 human breast cancer cells. Annexin V/propidium iodide (PI) staining, Hoechst 33258 staining, and caspase-3/9 activity assay confirmed that britannin is able to induce apoptosis in MCF-7 and MDA-MB-468 cells. The Western blot analysis showed that the expression of Bcl-2 was noticeably decreased in response to britannin treatment, while the expression of Bax protein was increased, which were positively correlated with elevated expression of p53. Moreover, britannin also increased reactive oxygen species (ROS) generation which in turn triggered the loss of mitochondrial transmembrane potential (ΔΨm) and the subsequent release of cytochrome c from mitochondria into cytosol. Taken together, these results suggest that britannin inhibits growth of MCF-7 and MDA-MB-468 breast cancer cells through the activation of the mitochondrial apoptotic pathway and may potentially serve as an agent for breast cancer therapy.

Unusual ingenoids from Euphorbia erythradenia Bioss. with pro-apoptotic effects.

Dichloromethane-acetone extract of Euphorbia erythradenia Bioss., a spurge endemic to the Iran, afforded four novel tetrahydroingenol diterpenes, one new myrsinane type diterpene, and two known triterpenes. Tetrahydroingenoids are novel compounds not only for the double bond reduction but also for their unique hydroxylation pattern at C-11 and C-13. The structures of these compounds were elucidated by spectroscopic methods, and especially 2D NMR measurements. The biological effects of the compounds were done by the MTT and Annexin V-FITC & PI staining assays on different cancer cell lines. The results obtained on EJ-138, CAOV-4, and OVCAR-3 cell lines suggested that tetrahydroingenanes inhibit cell proliferation through apoptosis in cancer cell lines. In conclusion, the new pattern of hydrogenation and hydroxylation of these compounds compared to other ingenoids, along with their apoptosis inducing properties on cancer cells, makes them of great interest for more investigation.

Expression of cGMP-dependent protein kinase, PKGIα, PKGIß, and PKGII in malignant and benign breast tumors.

Cyclic GMP-dependent protein kinases (PKG) constitute a small family of enzymes that are encoded by two genes. Two major forms of PKG have been identified in mammalian cells, PKG I and PKG II. In addition, there are two splice variants of PKG I, which are designated as Iα and Iß. There are increasing evidences that PKG can play an important role in the inhibition of cell proliferation and induction of apoptosis. In our previous studies, the inhibitory effects of cGMP/PKG on the cell growth were indicated using breast cancer cell lines. Accordingly, the present study was designed to compare the expression levels of three PKG isoforms in normal, benign, and malignant breast tissues. The expression level of PKG isoforms was assayed using quantitative real-time RT-PCR. The correlation between relative expression of PKG isoforms and clinicopathological characteristics were also analyzed. Downregulation of PKG isoforms was observed in the malignant and benign tumors when compared to those of respective normal tissues. No significant correlation was found between PKGIα, PKGIß, and PKGII expression and clinicopathological features. The present study is the first to evaluate the expression level of PKG isoforms PKGIα, PKGIß, and PKGII in the malignant and benign breast tumors. Reduction in the PKG expression is an important evidence to support the antitumor activity of this enzyme in vivo.

Adenosine induces cell-cycle arrest and apoptosis in androgen-dependent and -independent prostate cancer cell lines, LNcap-FGC-10, DU-145, and PC3.

BACKGROUND: Adenosine has been shown to inhibit cell growth and induce apoptosis in the several cancer cells via intrinsic and extrinsic pathway. The present study was designed to understand the mechanism underlying adenosine-induced apoptosis in the DU-145, PC3, and LNcap-FGC10 human prostate cancer cells. METHODS: To observe cell viability and proliferation, MTT assay, cell counting, and BrdU assay were carried out in DU-145, PC3, and LNcap-FGC10 cells. Apoptosis was assessed with the analysis of cell cycle, Hoechst 33258 staining, propidium iodide and annexin-V staining, reactive oxygen species (ROS) formation, mitochondrial membrane potential (ΔΨM) measurement, caspase-3 activity assay, Bcl-2 and Bax protein expression. Moreover, the expression of adenosine receptors and the effects of adenosine receptor (A(1) , A(2a) , and A(3) ) antagonists were examined. RESULT: Adenosine significantly reduced cell proliferation in a dose-dependent manner in DU-145, PC3, and LNcap-FGC10 cell lines. Adenosine induced arrest in the cell-cycle progression in G0/G1 phase through Cdk4/cyclinD1-mediated pathway. Adenosine induced apoptosis, which was determined by morphological changes and increased sub-G1 population. Furthermore, increase of ROS, loss of MMP, activation of caspase-3, and down-regulation of Bcl-2 expression was observed. A(1) , A(2a) , A(2b) , and A(3) adenosine receptors mRNA are expressed in the cell lines. Moreover, adenosine-induced apoptosis was inhibited by MRS1220, A(3) adenosine receptor antagonist. CONCLUSION: Our results suggest that adenosine induced apoptosis in prostate cancer cells via the mitochondrial pathway and is related to the adenosine receptors. These data might suggest that adenosine could be used as an agent for the treatment of prostate cancer.

Induction of apoptosis by type Iß protein kinase G in the human breast cancer cell lines MCF-7 and MDA-MB-468.

Activation of protein kinase G (PKG) by cyclic guanosine 3,5-monophosphate (cGMP) has become of considerable interest as a novel molecular approach for the induction of apoptosis in cancer cells. This study was conducted to investigate the role of PKG isoforms in the regulation of cell growth in human breast cancer cell lines MCF-7 and MDA-MB468. The expression levels of PKG isoforms were also examined using real-time reverse transcriptase polymerase chain reaction. No differences in the gene expression of PKG isoforms were observed between MCF-7 and MDA-MB-468 cells. To investigate the effects of PKG isoforms on the regulation of cell growth, the cGMP analogues 8-APT-cGMP (PKGIα activator), 8-Br-PET-cGMP (PKGIß activator) and 8-pCPT-cGMP (PKGII activator) were employed. Apoptosis was assessed with the Annexin-V-propidium iodide (PI) staining, cell cycle analysis and caspase-3/9 activity assay. Treatment of MCF-7 and MDA-MB-468 cells with 8-Br-PET-cGMP resulted in a concentration-dependent cell growth inhibition and apoptosis, whereas neither PKGIα nor PKGII activators had any effect on the cell growth. The role of PKGIß in the inhibition of cell growth was confirmed using PKGI and PKGII inhibitors. The present study is the first to demonstrate the involvement of PKGIß in the inhibition of cell growth and induction of apoptosis in breast cancer cells.

Cyclic GMP induced apoptosis via protein kinase G in oestrogen receptor-positive and -negative breast cancer cell lines.

The activation of protein kinase G (PKG) by cyclic guanosine 3,5-monophosphate (cGMP) has become of considerable interest as a novel molecular approach for the induction of apoptosis in cancer cells. The present study was designed to examine the effects of cGMP and PKG on cell growth and apoptosis in the human breast cancer cell lines, MCF-7 and MDA-MB-468. To achieve this, 1-benzyl-3-(5P-hydroxymethyl-2P-furyl) indazole (YC-1), a soluble guanylyl cyclase activator, and 8-bromo-cGMP (8-br-cGMP), a membrane-permeant and phosphodiesterase-resistant analogue of cGMP, were employed in MCF-7 and MDA-MB-468 cells. Then, the role of PKG in the induction of apoptosis was evaluated using KT5823 and Rp-8-pCPT-cGMP as specific inhibitors of PKG. The expression of PKG isoforms in these cell lines was also investigated. KT5823 and Rp-8-pCPT-cGMP significantly attenuated the loss of cell viability caused by YC-1 and 8-br-cGMP in these cells. This study provides direct evidence that the activation of PKG by cGMP induces growth inhibition and apoptosis in MCF-7 and MDA-MB-468 breast cancer cell lines.