The role of sphingomyelinase (SMase) activation and mitogen activated protein kinases (MAPKs) activation in cellular apoptosis was investigated during the hyperthermic treatment of HL-60 human leukemia cells. Treating the cells for 1 h at 43oC caused more than 50% of cellular apoptosis within several hours. The neutral-SMase activity in the cells treated for 1 h at 42degrees C was slightly increased but decreased in the cells treated at 43degrees C or 44degrees C for the same period whereas the acid SMase activity was slightly increased after heating the cells at 42degrees C and 43degrees C and markedly increased at 44degrees C for 1 h. Treatment of cells with inhibitors of SMase activation and ceramide formation significantly reduced the heat-induced apoptosis. Three major families of mitogen-activated protein kinases (MAPKs) i.e. ERK1/2, p38 and JNK, were activated by the hyperthermic treatment of cells. Inhibition of ERK1/2 with PD98059 exerted little effect on the heat-induced apoptosis and p38 inhibition with SB203580 slightly lessened apoptosis whereas, inhibition of JNK with SP600125 markedly suppressed the heat-induced apoptosis. These results indicate that heat-shock induced the activation of SMase, particularly acid-SMase, thereby causing apoptosis and that JNK played a pivotal role in heat-induced apoptosis in HL-60 leukemia cells.
Apoptosis/*physiology ; Enzyme Activation ; HL-60 Cells ; Heat ; Human ; Mitogen-Activated Protein Kinase Kinases/*metabolism ; Sphingomyelin Phosphodiesterase/*metabolism

In the present study, a perfluorochemical emulsion (Fluosol-DA 20%) did not alter Do and and Dq values on cell survival curve, indicating that the lack of a direct effect of Fluosol-DA 20% on cellular radiosensitivity in vitro. The effect of Fluosol-DA 20% injection in combination with carbogen breathing was determined on the hupoxic cell fraction in SCK tumors. The hypoxic cell fraction in control SCK tumors was 0.39. This value decreased to 0.05 when the mice were i.v. injected with 12 ml/kg of Fluosol-DA 20% in a carbogen atomosphere. The measured mean and median PO2 values with a microelectorde in the control tumors was 9 mmHg and 4 mmHg, respectively. The treatment of the SCK tumors in the host mice with injected Fluosol-DA 20% in combination with carbogen breathing increased the mean and median PO2 values to 67 mmHg and 62 mmHg, respectively. Using carbogen breathing alone caused a moderate increase of tumor PO2. But Fluosol-DA 20% injection alone caused little change PO2 in the tumor. It was concluded that the combination of Fluosol-DA injection and carbogen breathing is an effective means to improve oxygenation of tumors.
Animals ; Cell Survival ; Mice ; Oxygen* ; Radiation Tolerance ; Respiration

OBJECTIVESTo examine the anti-oncogenic effects of promyelocytic leukemia (PML) on bladder cancer and to explore its molecular mechanisms of growth suppression.

METHODSWild-type PML was transfected into bladder cancer cells (5637 cell) and expressed in a replication-deficient adenovirus-mediated gene delivery system and introduced into human bladder cancer cells (5637 cell) in vitro and in vivo. The effect and mechanisms of the PML gene in cell growth, clonogenicity, and tumorigenicity of bladder cancer cells were studied using in vitro and in vivo growth assays, soft agar colony-forming assay, cell cycle analysis, apoptosis assay and in vivo tumorigenicity assay.

RESULTSOverexpression of PML in 5637 cells significantly reduced their growth rate and clonogenicity on soft agar. PML suppressed bladder cancer cell growth by inducing G1 cell cycle arrest and apoptosis. Adenovirus-mediated PML (Ad-PML) significantly suppressed the tumorigenicity and growth of bladder cancer cells. Intratumoral injection of Ad-PML into tumors induced by 5637 cells dramatically suppressed their growth.

CONCLUSIONSThe results indicated that overexpression of PML protein may promote efficient growth inhibition of human bladder cancer cells by inducing G1 cell cycle arrest and apoptosis, and adenovirus-mediated PML (Ad-PML) expression efficiently suppresses human bladder cancer growth.

Adenoviridae ; Animals ; Apoptosis ; physiology ; Cell Division ; physiology ; Cells, Cultured ; Humans ; Male ; Mice ; Mice, Nude ; Neoplasm Proteins ; analysis ; Nuclear Proteins ; Promyelocytic Leukemia Protein ; Transcription Factors ; analysis ; Transfection ; Tumor Cells, Cultured ; Tumor Suppressor Proteins ; Urinary Bladder Neoplasms ; pathology

Despite the increasing use of stereotactic body radiation therapy (SBRT) and stereotactic radiation surgery (SRS) in recent years, the biological base of these high-dose hypo-fractionated radiotherapy modalities has been elusive. Given that most human tumors contain radioresistant hypoxic tumor cells, the radiobiological principles for the conventional multiple-fractionated radiotherapy cannot account for the high efficacy of SBRT and SRS. Recent emerging evidence strongly indicates that SBRT and SRS not only directly kill tumor cells, but also destroy the tumor vascular beds, thereby deteriorating intratumor microenvironment leading to indirect tumor cell death. Furthermore, indications are that the massive release of tumor antigens from the tumor cells directly and indirectly killed by SBRT and SRS stimulate anti-tumor immunity, thereby suppressing recurrence and metastatic tumor growth. The reoxygenation, repair, repopulation, and redistribution, which are important components in the response of tumors to conventional fractionated radiotherapy, play relatively little role in SBRT and SRS. The linear-quadratic model, which accounts for only direct cell death has been suggested to overestimate the cell death by high dose per fraction irradiation. However, the model may in some clinical cases incidentally do not overestimate total cell death because high-dose irradiation causes additional cell death through indirect mechanisms. For the improvement of the efficacy of SBRT and SRS, further investigation is warranted to gain detailed insights into the mechanisms underlying the SBRT and SRS.
Antigens, Neoplasm ; Cell Death ; Humans ; Radiobiology ; Radiotherapy ; Recurrence

PURPOSE: To reveal the interaction between beta-Lapachone (beta-lap) and ionizing radiation in causing cell death in RKO human colon adenocarcinoma cells, and to elucidate the potential usefulness of combined beta-lap treatment and radiotherapy for cancer treatment. MATERIALS AND METHODS: The cytotoxicities of various treatments were determined in vitro using clonogenic and apoptotic cell death. The changes in cell cycle distribution were studied using flow cytometry and an in vitro kinase assay. The tumor growth was studied using RKO tumors grown s.c. in the hind leg BALB/c- nuslc nude mice. RESULTS: beta-lap caused clonogenic cell death and rapid apoptosis in RKO cells in vitro, in a dose dependent manner. The repair of sublethal radiation damage was almost completely inhibited when cells were maintained in beta-lap during the interval between the two-dose irradiation. Flow cytometry study demonstrated that beta-lap induced apoptosis, independent of the cell cycle phase, and completely prohibited the induction of radiation- induced G2 arrest in irradiated cells. The prohibition of radiation-induced G2 arrest is unclear, but may be related to the profound suppression of the p53, p21 and cyclin B1-Cdc2 kinase activities observed in cells treated with beta-lap. The combination of beta-lap and radiation markedly enhanced the radiation-induced growth suppression of tumors. CONCLUSION: beta-lap is cytotoxic against RKO cells, both in vitro and in vivo, and also sensitized cells to ionizing radiation by inhibiting sublethal radiation damage repair. beta-lap is potentially useful as a potent anti-cancer chemotherapy drug and potent radiosensitizer against caner cells.
Adenocarcinoma* ; Animals ; Apoptosis ; Cell Cycle ; Cell Death ; Colon* ; Cyclins ; Drug Therapy ; Flow Cytometry ; Humans* ; Leg ; Mice ; Mice, Nude ; Phosphotransferases ; Radiation, Ionizing* ; Radiotherapy

Successful recovery from brain ischemia is limited due to poor vascularization surrounding the ischemic zone. Cell therapy with strong angiogenic factors could be an effective strategy to rescue the ischemic brain. We investigated whether cartilage oligomeric matrix protein (COMP)-Ang1, a soluble, stable and potent Ang1 variant, enhances the angiogenesis of human cord blood derived endothelial progenitor cells (hCB-EPCs) for rescuing brain from ischemic injury. COMP-Ang1 markedly improved the tube formation of capillaries by EPCs and incorporation of EPCs into tube formation with human umbilical vein endothelial cells (HUVECs) upon incubation on matrigel in vitro. COMP-Ang1 stimulated the migration of EPCs more than HUVECs in a scratch wound migration assay. The transplanted EPCs and COMP-Ang1 were incorporated into the blood vessels and decreased the infarct volume in the rat ischemic brain. Molecular studies revealed that COMP-Ang1 induced an interaction between Tie2 and FAK, but AKT was separated from the Tie2-FAK-AKT complex in the EPC plasma membrane. Tie2-FAK increased pp38, pSAPK/JNK, and pERK-mediated MAPK activation and interacted with integrins alphanubeta3, alpha4, beta1, finally leading to migration of EPCs. AKT recruited mTOR, SDF-1, and HIF-1alpha to induce angiogenesis. Taken together, it is concluded that COMP-Ang1 potentiates the angiogenesis of EPCs and enhances the vascular morphogenesis indicating that combination of EPCs with COMP-Ang1 may be a potentially effective regimen for ischemic brain injury salvage therapy.
Angiogenesis Inducing Agents ; Animals ; Blood Vessels ; Brain ; Brain Injuries* ; Brain Ischemia ; Capillaries ; Cartilage Oligomeric Matrix Protein ; Cell Membrane ; Cell- and Tissue-Based Therapy ; Fetal Blood ; Human Umbilical Vein Endothelial Cells ; Humans ; Integrins ; Ischemia ; Morphogenesis ; Rats ; Salvage Therapy ; Stem Cells ; Wounds and Injuries

Background: and Purpose Nelonemdaz (Neu2000) has both selective antagonism against 2B subunit of N-methyl-D-aspartate receptor and antioxidant activity. This drug provides sufficient evidence of neuroprotection in acute cerebral ischemia/reperfusion models. This phase III trial aims to determine this effect in patients.Design The Rescue on Reperfusion Damage in Cerebral Infarction by Nelonemdaz is a multicenter, double-blinded clinical trial. A total of 496 patients will be randomly assigned into the nelonemdaz (a total of 5,250 mg divided by 10 times for 5 days) and placebo groups. Patients will be included if they have an acute ischemic stroke (National Institutes of Health Stroke Scale score ≥8) caused by intracranial large vessel occlusion in the anterior circulation (Alberta Stroke Program Early CT Score ≥4), and if they are expected to undergo endovascular thrombectomy within 12 hours after stroke onset.Endpoints The primary endpoint is a favorable shift in the modified Rankin Scale (mRS) score at 90 days after the first dose of drug. The data will be analyzed by the Cochran–Mantel–Haenszel shift test. The secondary endpoints include functional independence (mRS 0–2) at 35 and 90 days, the favorable shift of mRS at 35 days, the proportion of mRS 0 at 35 and 90 days, and the occurrence rates of symptomatic intracranial hemorrhage within 7 days. Conclusion This trial will clarify the efficacy and safety of nelonemdaz in patients with acute ischemic stroke and endovascular thrombectomy. This study has been registered at ClinicalTrials. gov (NCT05041010).

Background: There has been no comparison of the determinants of admission route between acute ischemic stroke (AIS) and acute myocardial infarction (AMI). We examined whether factors associated with direct versus transferred-in admission to regional cardiocerebrovascular centers (RCVCs) differed between AIS and AMI. Methods: Using a nationwide RCVC registry, we identified consecutive patients presenting with AMI and AIS between July 2016 and December 2018. We explored factors associated with direct admission to RCVCs in patients with AIS and AMI and examined whether those associations differed between AIS and AMI, including interaction terms between each factor and disease type in multivariable models. To explore the influence of emergency medical service (EMS) paramedics on hospital selection, stratified analyses according to use of EMS were also performed. Results: Among the 17,897 and 8,927 AIS and AMI patients, 66.6% and 48.2% were directly admitted to RCVCs, respectively. Multivariable analysis showed that previous coronary heart disease, prehospital awareness, higher education level, and EMS use increased the odds of direct admission to RCVCs, but the odds ratio (OR) was different between AIS and AMI (for the first 3 factors, AMI > AIS; for EMS use, AMI < AIS). EMS use was the single most important factor for both AIS and AMI (OR, 4.72 vs. 3.90). Hypertension and hyperlipidemia increased, while living alone decreased the odds of direct admission only in AMI;additionally, age (65–74 years), previous stroke, and presentation during non-working hours increased the odds only in AIS. EMS use weakened the associations between direct admission and most factors in both AIS and AMI. Conclusions Various patient factors were differentially associated with direct admission to RCVCs between AIS and AMI. Public education for symptom awareness and use of EMS is essential in optimizing the transportation and hospitalization of patients with AMI and AIS.