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

BACKGROUND: Granulocyte colony-stimulating factor (G-CSF) is commonly used to reduce leukopenic period during treatment of malignancy including acute leukemia. Leukemic blasts expressing granulocyte colony-stimulating factor receptor (G-CSFR) were reported and also may proliferate in response to therapeutic administration of G-CSF. However, it is not clear whether G-CSFR expression on leukemic blasts is related to clinical outcome such as leukocyte recovery or leukemia relapse. Current study evaluated expression of G-CSFR in acute leukemia and correlated with hematologic and clinical parameters. METHODS: Peripheral blood or bone marrow aspirate was evaluated from 20 patients with acute myelogenous leukemia (AML) and 10 with acute lymphoblastic leukemia (ALL), 2 with acute undifferentiated leukemia (AUL), 1 with acute biphenotypic leukemia (ABL), 1 with acute mixed-lineage leukemia (AMLL). G-CSFR expression was analyzed using flow cytometry and was correlated with immunophenotype and response for chemotherapy. RESULTS: More than 20% of blasts were positive for G-CSFR in 65% (13/20) of AML, 40% (4/10) of ALL, and all negative in ABL, AMLL, and AUL. Except that all 6 monocytic lineage leukemias (M4, M5) and all three cases of ALL with CD33 expression were positive, no consistent correlation was observed among G-CSFR expression pattern, type of acute leukemia, response to induction therapy and relapse (P>0.05). CONCLUSION: Current study revealed G-CSFR was expressed on not only myelogenous leukemic cells but also lymphoid ones. Although our data suggest G-CSFR expression does not affect therapeutic outcome, it remains to be determined whether G-CSF therapy is safe in G-CSFR-positive acute leukemia.
Bone Marrow ; Drug Therapy ; Flow Cytometry ; Granulocyte Colony-Stimulating Factor* ; Granulocytes* ; Humans ; Leukemia* ; Leukemia, Biphenotypic, Acute ; Leukemia, Myeloid, Acute ; Leukocytes ; Precursor Cell Lymphoblastic Leukemia-Lymphoma ; Recurrence

An F-box protein, beta-TrCP recognizes substrate proteins and destabilizes them through ubiquitin-dependent proteolysis. It regulates the stability of diverse proteins and functions as either a tumor suppressor or an oncogene. Although the regulation by beta-TrCP has been widely studied, the regulation of beta-TrCP itself is not well understood yet. In this study, we found that the level of beta-TrCP1 is downregulated by various protein kinase inhibitors in triple-negative breast cancer (TNBC) cells. A PI3K/mTOR inhibitor PI-103 reduced the level of beta-TrCP1 in a wide range of TNBC cells in a proteasome-dependent manner. Concomitantly, the levels of c-Myc and cyclin E were also downregulated by PI-103. PI-103 reduced the phosphorylation of beta-TrCP1 prior to its degradation. In addition, knockdown of beta-TrCP1 inhibited the proliferation of TNBC cells. We further identified that pharmacological inhibition of mTORC2 was sufficient to reduce the beta-TrCP1 and c-Myc levels. These results suggest that mTORC2 regulates the stability of beta-TrCP1 in TNBC cells and targeting beta-TrCP1 is a potential approach to treat human TNBC.
Cell Line, Tumor ; Cell Proliferation ; Cell Survival/drug effects ; Cyclin E/genetics/metabolism ; Dose-Response Relationship, Drug ; Female ; Furans/pharmacology ; Gene Knockdown Techniques ; Humans ; Models, Biological ; Multiprotein Complexes/antagonists & inhibitors ; Phosphatidylinositol 3-Kinases/*antagonists & inhibitors ; Phosphorylation/drug effects ; Protein Kinase Inhibitors/*pharmacology ; Proteolysis/drug effects ; Proto-Oncogene Proteins c-myc/genetics/metabolism ; Pyridines/pharmacology ; Pyrimidines/pharmacology ; TOR Serine-Threonine Kinases/*antagonists & inhibitors ; Triple Negative Breast Neoplasms/genetics/*metabolism ; beta-Transducin Repeat-Containing Proteins/genetics/*metabolism

Resveratrol has been reported to possess cancer preventive properties. In this study, we analyzed anti-tumor activity of a newly synthesized resveratrol analog, cis-3,4',5-trimethoxy-3'-hydroxystilbene (hereafter called 11b) towards breast and pancreatic cancer cell lines. 11b treatments reduced the proliferation of human pancreatic and breast cancer cells, arrested cells in the G2/M phase, and increased the percentage of cells in the subG1/G0 fraction. The 11b treatments also increased the total levels of mitotic checkpoint proteins such as BubR1, Aurora B, Cyclin B, and phosphorylated histone H3. Mechanistically, 11b blocks microtubule polymerization in vitro and it disturbed microtubule networks in both pancreatic and breast cancer cell lines. Computational modeling of the 11b-tubulin interaction indicates that the dimethoxyphenyl group of 11b can bind to the colchicine binding site of tubulin. Our studies show that the 11b treatment effects occur at lower concentrations than similar effects associated with resveratrol treatments and that microtubules may be the primary target for the observed effects of 11b. These studies suggest that 11b should be further examined as a potentially potent clinical chemotherapeutic agent for treating pancreatic and breast cancer patients.
Antineoplastic Agents/*pharmacology ; Binding Sites ; Breast Neoplasms ; Cell Cycle/drug effects ; Cell Line, Tumor ; Cell Proliferation/*drug effects ; Colchicine/chemistry/pharmacology ; Cyclin B/metabolism ; G2 Phase/drug effects ; Humans ; Microtubules/drug effects/metabolism ; Models, Molecular ; Pancreatic Neoplasms ; Protein-Serine-Threonine Kinases/metabolism ; Stilbenes/*pharmacology ; Tubulin/metabolism

Induction of apoptosis in target cells is a key mechanism by which chemotherapy promotes cell killing. The purpose of this study was to determine whether Indole-3-Carbinol (I3C) and Genistein in combination with tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) induce apoptosis in endometrial cancer cell (Ishikawa) and to assess apoptotic mechanism. The MTT assay and flow cytometry were performed to determine cell viability and cell cycle. The induction of apoptosis was measured by caspase-3 activity test, DNA fragmentation assay, annexin V binding assay and western blot analysis. There was no effect in cell growth inhibition and cell cycle progression alone or in two-combination. However, the treatment of I3C and Genistein followed by TRAIL showed significant cell death and marked increase in sub-G1 arrest. Three-combination treatment revealed elevated expression of DR4, DR5 and cleaved forms of caspase-3, caspase-8, PARP. The Flip was found down regulated. Moreover, increase in caspase-3 activity and DNA fragmentation indicated the induction of apoptosis. The results indicate that I3C and Genistein with TRAIL synergistically induced apoptosis via death receptor dependent pathway. Our findings might provide a new insight into the development of novel combination therapies against endometrial cancer.
Anticarcinogenic Agents/*pharmacology ; Apoptosis/*drug effects ; Caspase 3/metabolism ; Caspase 8/metabolism ; Cell Line, Tumor ; Drug Synergism ; Endometrial Neoplasms/metabolism/pathology ; Female ; G1 Phase Cell Cycle Checkpoints/drug effects ; Genistein/*pharmacology ; Humans ; Indoles/*pharmacology ; Poly(ADP-ribose) Polymerases/metabolism ; Receptors, TNF-Related Apoptosis-Inducing Ligand/metabolism ; TNF-Related Apoptosis-Inducing Ligand/*pharmacology

The molecular mechanism of the cell-cycle machinery in uterine leiomyoma has not yet been fully elucidated. Among the various types of cell-cycle regulators, p27(Kip1)(p27) is considered to be a potent tumor suppressor. To provide further molecular basis for understanding the progression of uterine leiomyoma, our objective was to evaluate the expression level of p27 in normal myometrium and uterine leiomyoma tissue and its effect on cytogenic growth. Western blot analysis, real-time polymerase chain reaction (PCR) and immunohistochemical staining revealed that p27 protein and messenger RNA were down-regulated in uterine leiomyoma tissue and cultured cells compared to normal myometerium. Full-length human p27 cDNA was transferred using a replication-deficient recombinant adenoviral vector (Ad.p27) into uterine leiomyoma cells and evaluated the effect on cell proliferation. Transfection of Ad.p27 into uterine leiomyoma cells resulted in the induction of apoptosis, reduction in viability and proliferation of uterine leiomyoma cells. Our results suggest a new paradigm that down-regulated p27 protein expression is the possible underlying mechanism for the growth of uterine leiomyoma and over-expression of p27 induces cell death. This study provides better understanding of the control exerted by p27 in regulating growth and disease progression of uterine leiomyoma.
Adult ; Cell Cycle ; Cell Proliferation ; Female ; Humans ; Intracellular Signaling Peptides and Proteins/antagonists & inhibitors/genetics/*physiology ; Leiomyoma/*pathology ; Middle Aged ; RNA, Messenger/analysis ; Uterine Neoplasms/*pathology

PURPOSE: A number of countries have experienced an increase in pertussis during the past decade. In particular, there has been an increase in the incidence rate among adolescents and adults. To learn more about the current epidemiology of pertussis, we studied the prevalence and clinical characteristics of pertussis in children in Cheonan, South Korea. METHODS: We collected nasopharyngeal aspirates of 118 patients who were treated for respiratory symptoms at Dankook Univeristy Hospital between March 2008 and September 2009. We performed multiplex PCR for detection of Bordetella pertussis in those aspirates. RESULTS: Of the 118 patients, 10 (8%) were positive by PCR for B. pertussis. Six episodes occurred during the period July to September 2009. Nine of the 10 patients were less than 3 months old. Seven of them had not received DTaP vaccine. The mean duration of coughing before diagnosis was 10.9+/-5.2 days. Ten patients (100%) had paroxysmal cough and 8 (80%) had post-tussive vomiting. Only one patient had fever. One who had complications that include pneumonia, atelectasis and pneumomediastinum developed an absolute increase in leukocyte count (84,400/mm3). There was a statistically significant relation between vaccine being received and development of complications (P=0.033). CONCLUSION: We suspect that there was an epidemic of pertussis between July and September 2009. Further investigation by a pediatric or nationwide surveillance system is needed to monitor the changing epidemiology for pertussis.
Adolescent ; Adult ; Bordetella pertussis ; Child ; Cough ; Diphtheria-Tetanus-acellular Pertussis Vaccines ; Fever ; Humans ; Incidence ; Korea ; Leukocyte Count ; Mediastinal Emphysema ; Multiplex Polymerase Chain Reaction ; Organothiophosphorus Compounds ; Pneumonia ; Polymerase Chain Reaction ; Prevalence ; Pulmonary Atelectasis ; Republic of Korea ; Vomiting ; Whooping Cough