Correlation between endothelial CXCR7 expression and clinicopathological factors in oral squamous cell carcinoma.

Oral squamous cell carcinoma (OSCC) impairs functionality and sensuousness resulting in poor quality of life. Biomarkers can predict disease trajectory and lead to effective treatments. Transcriptomics have identified genes that are upregulated in tumor endothelial cells (TECs) compared with normal endothelial cells (NECs). Among them, chemokine receptor 7 (CXCR7) is highly expressed in TECs of several cancers and involved in angiogenesis of TECs. However, levels of CXCR7 in OSCC blood vessels have not been fully investigated. In this study, we analyzed the correlation between CXCR7 expression in TECs and clinicopathological factors in OSCC. Immunohistochemistry for CXCR7 and CD34 was performed on 59 OSCC tissue specimens resected between 1996 and 2008 at Hokkaido University Hospital. CXCR7 expression in blood vessels was evaluated by the ratio of CXCR7+/CD34+ blood vessels. CXCR7 expression was 42% and 19% in tumor and non-tumor parts, respectively, suggesting that CXCR7 expression is higher in TECs than in NECs. CXCR7 expression in TECs correlated with advanced T-stage and cancer stage. Overall survival and disease-free survival rates were higher in low-expressing CXCR7 patients than in high-expressing. These results suggest that CXCR7 expression in blood vessels may be a useful diagnostic and prognostic marker for OSCC patients.

Histological evaluation of a novel phosphorylated pullulan-based pulp capping material: An in vivo study on rat molars.

AIM: To evaluate the dental pulp response to a novel mineral trioxide aggregate containing phosphorylated pullulan (MTAPPL) in rats after direct pulp capping. METHODS: Ninety-six cavities were prepared in the maxillary first molars of 56 male Wistar rats. The dental pulps were intentionally exposed and randomly divided into four groups according to the application of pulp capping materials: MTAPPL; phosphorylated pullulan (PPL); a conventional MTA (Nex-Cem MTA, NCMTA; positive control); and Super-Bond (SB; negative control). All cavities were restored with SB and observed for pulpal responses at 1-, 3-, 7- and 28-day intervals using a histological scoring system. Statistical analysis was performed using Kruskal-Wallis and Mann-Whitney U-test with Bonferroni's correction, and the level of significance was set at 0.05. DMP1 and CD34 antigen were used to evaluate odontoblast differentiation and pulpal vascularization, respectively. RESULTS: On day 1, mild inflammatory cells were present in MTAPPL and NCMTA groups; fewer inflammatory cells were present in the PPL, whereas SB was associated with a mild-to-moderate inflammatory response. A significant difference was observed between PPL and SB (p < .05). No mineralized tissue deposition was observed. On day 3, moderate-to-severe inflammatory cells were present in PPL and SB, whereas MTAPPL and NCMTA had a mild inflammatory response. Initial mineralized tissue deposition was observed in the NCMTA, MTAPPL and SB. A significant difference was observed between MTAPPL and PPL (p < .05). On day 7, a thin layer of mineralized tissue was observed in all tested groups with no or mild inflammatory response. On day 28, no inflammatory response was observed in MTAPPL, whereas NCMTA, PPL and SB had mild inflammatory responses. A significant difference was observed between MTAPPL and SB (p < .05). Complete mineralized tissue barrier formation was observed in MTAPPL, NCMTA and PPL with no significant difference (p > .05). SB exhibited incomplete mineralized tissue barriers, significantly different from NCMTA, MTAPPL and PPL (p < .05). The staining with CD34 was positive in all the groups on all observation days. CONCLUSION: The favourable pulpal responses and induction of mineralized tissue formation associated with MTAPPL indicate its potential application as a direct pulp capping material.

Enhanced oncolytic activity of E4orf6-deficient adenovirus by facilitating nuclear export of HuR.

An AU-rich element (ARE) is RNA element that enhances the rapid decay of mRNA. The RNA binding protein HuR stabilizes ARE-mRNA by exporting it to the cytoplasm. In most of cancer cells, HuR is exported to the cytoplasm and ARE-mRNA is stabilized. In addition, the viral gene product E4orf6 exports HuR to stabilize ARE-mRNA in adenovirus-infected cells and the stabilization is required for full virus replication. Previously we showed the oncolytic activity of E4orf6-deleted adenovirus dl355, which can replicate in cancer cells where ARE-mRNA is stabilized. In this study, we examined whether the further enhancement of HuR export can stimulate the replication and the oncolytic activity of dl355. We found that ethanol treatment promoted the cytoplasmic relocalization of HuR in cancer cells. In addition, the replication efficiency of dl355 increased in ethanol-treated cells, and in response, the cytolytic activity of the virus also increased in vitro and in vivo. Upregulation of a cleaved-PARP level in infected cells mediated by ethanol is suggesting that ethanol activated the apoptosis induced by dl355. IVa2 mRNA, the only ARE-mRNA among transcripts of adenovirus was augmented by ethanol treatment. These data indicate that the enhancement of ARE-mRNA stabilization as a result of ethanol treatment upregulates the oncolytic activity of dl355 and suggests that the combined use of an oncolytic adenovirus and ethanol treatment may be a good strategy for cancer therapy.

Prevalence and Prognosis of Familial Hypercholesterolemia in Patients With Acute Coronary Syndrome in Mie Prefecture, Japan　- Report From Mie ACS Registry.

BACKGROUND: Familial hypercholesterolemia (FH) is an autosomal dominant disorder characterized by elevated low-density lipoprotein cholesterol concentration and premature acute coronary syndrome (ACS). However, hereditary diseases may have regional characteristics, and few data are available regarding the prevalence of FH throughout particular regions in Japan. This study investigated the prevalence and prognosis of FH in patients with ACS in Mie Prefecture, Japan.Methods and Results:This study investigated 738 ACS patients from the Mie ACS Registry in Mie Prefecture, and 706 (95.7%) with sufficient data to diagnose FH were enrolled for analysis. Eighteen patients (2.5%) were diagnosed with FH, which was similar to findings of another multidistrict registry conducted in Japan. Patients with FH were significantly younger and had a higher prevalence of premature onset of ACS than patients with non-FH (P<0.01). Incidence of major adverse cardiac and cerebrovascular events (MACCE) was not statistically different between patients with FH and non-FH in this study population, even in the propensity score-matched analysis. CONCLUSIONS: Prevalence of FH in ACS patients from the Mie Prefecture was similar to that found in another Japanese multidistrict registry. Among ACS patients, short-term incidence of MACCE was not statistically different between patients with FH and non-FH in this study population.

Carbonic anhydrase 2 (CAII) supports tumor blood endothelial cell survival under lactic acidosis in the tumor microenvironment.

BACKGROUND: Tumor endothelial cells (TECs) perform tumor angiogenesis, which is essential for tumor growth and metastasis. Tumor cells produce large amounts of lactic acid from glycolysis; however, the mechanism underlying the survival of TECs to enable tumor angiogenesis under high lactic acid conditions in tumors remains poorly understood. METHODOLOGY: The metabolomes of TECs and normal endothelial cells (NECs) were analyzed by capillary electrophoresis time-of-flight mass spectrometry. The expressions of pH regulators in TECs and NECs were determined by quantitative reverse transcription-PCR. Cell proliferation was measured by the MTS assay. Western blotting and ELISA were used to validate monocarboxylate transporter 1 and carbonic anhydrase 2 (CAII) protein expression within the cells, respectively. Human tumor xenograft models were used to access the effect of CA inhibition on tumor angiogenesis. Immunohistochemical staining was used to observe CAII expression, quantify tumor microvasculature, microvessel pericyte coverage, and hypoxia. RESULTS: The present study shows that, unlike NECs, TECs proliferate in lactic acidic. TECs showed an upregulated CAII expression both in vitro and in vivo. CAII knockdown decreased TEC survival under lactic acidosis and nutrient-replete conditions. Vascular endothelial growth factor A and vascular endothelial growth factor receptor signaling induced CAII expression in NECs. CAII inhibition with acetazolamide minimally reduced tumor angiogenesis in vivo. However, matured blood vessel number increased after acetazolamide treatment, similar to bevacizumab treatment. Additionally, acetazolamide-treated mice showed decreased lung metastasis. CONCLUSION: These findings suggest that due to their effect on blood vessel maturity, pH regulators like CAII are promising targets of antiangiogenic therapy. Video Abstract.

HuR translocation to the cytoplasm of cancer cells in actin-independent manner.

Human antigen R (HuR) is a RNA-binding protein, which binds to the AU-rich element (ARE) in the 3'-untranslated region (3'-UTR) of certain mRNA and is involved in the export and stabilization of ARE-mRNA. HuR constitutively relocates to the cytoplasm in many cancer cells, however the mechanism of intracellular HuR trafficking is poorly understood. To address this question, we examined the functional role of the cytoskeleton in HuR relocalization. We tested the effect of actin depolymerizing macrolide latrunculin A or myosin II ATPase activity inhibitor blebbistatin for HuR relocalization induced by the vasoactive hormone Angiotensin II in cancer and control normal cells. Western blot and confocal imaging data revealed that both inhibitors attenuated the cytoplasmic HuR in normal cells but no such alteration was observed in cancer cells. Concomitant with changes in intracellular HuR localization, both inhibitors markedly decreased the accumulation and half-lives of HuR target ARE-mRNAs in normal cells, whereas no change was observed in cancer cells. Furthermore, co-immunoprecipitation experiments with HuR proteins revealed clear physical interaction with ß-actin only in normal cells. The current study is the first to verify that cancer cells can implicate a microfilament independent HuR transport. We hypothesized that when cytoskeleton structure is impaired, cancer cells can acquire an alternative HuR trafficking strategy.

Adenovirus infection induces HuR relocalization to facilitate virus replication.

HuR is an RNA-binding protein of the embryonic lethal abnormal vision (ELAV) family, which binds to the AU-rich element (ARE) in the 3'-untranslated region (UTR) of certain mRNAs and is involved in the nucleo-cytoplasmic export and stabilization of ARE-mRNAs. The cytoplasmic relocalization of ARE-mRNAs with several proteins such as HuR and pp32 increases in cells transformed by the adenovirus oncogene product E4orf6. Additionally, these ARE-mRNAs were stabilized and acquired the potential to transform cells. Although, the relocalization of HuR and the stabilization of ARE-mRNAs are crucial for cell transformation, evidence regarding the relationship of HuR and ARE-mRNAs with adenovirus replication is lacking. In this report, we demonstrate that adenovirus infection induces the relocation of HuR to the cytoplasm of host cells. Analysis using the luciferase-ARE fusion gene and the tetracycline (tet)-off system revealed that the process of stabilizing ARE-mRNAs is activated in adenovirus-infected cells. Heat shock treatment or knockdown-mediated depletion of HuR reduced adenovirus production. Furthermore, expression of ARE-including viral IVa2 mRNA, decreased in HuR-depleted infected cells. These results indicate that HuR plays an important role in adenovirus replication, at least in part, by up-regulating IVa2 mRNA expression and that ARE-mRNA stabilization is required for both transformation and virus replication.

Progression level of extracapsular spread and tumor budding for cervical lymph node metastasis of OSCC.

OBJECTIVES: The progression level of extracapsular spread (ECS) for cervical lymph node metastasis of oral squamous cell carcinoma (OSCC) was previously divided into three types, and their relationships with the prognosis of patients were re-examined. PATIENTS AND METHODS: The Kaplan-Meier method was used to examine overall survival (OS) and relapse-free survival (RFS) curves. Prognosis factor for recurrence was analyzed with univariate and multivariate analysis. RESULTS: ECS was detected in 216 cases of OSCC and analyzed. The 5-year overall survival and RFS rates of patients with type C, which was microscopically defined as tumor invasion to perinodal fat or muscle tissue, were significantly poor at 40.6 and 37.8%, respectively. The results of a univariate analysis suggested that the prognosis of ECS in OSCC patients is associated with its progression level, particularly type C. The 5-year RFS rate of type C with tumor budding was significantly poor at 31.5%. Type C with tumor budding correlated with local and regional recurrence as well as distant metastasis. In a multivariate analysis, tumor budding was identified as an independent prognostic factor. CONCLUSIONS: These results suggest that the progression level of ECS and tumor budding are useful prognostic factors in OSCC patients. CLINICAL RELEVANCE: This study indicated that the progression level and tumor budding of ECS for cervical lymph node metastasis were useful prognostic factors in OSCC patients.

Human antigen R knockdown attenuates the invasive activity of oral cancer cells through inactivation of matrix metalloproteinase-1 gene expression.

Background/purpose: The RNA-binding protein human antigen R (HuR) recognizes AU-rich elements in the 3'-untranslated regions of mRNA. The expression of cytoplasmic HuR is related to the malignancy of many carcinomas. The aim of this study is investigation of effect of HuR knockdown for invasive activity of oral carcinoma. Materials and methods: Proliferation, invasion, real-time PCR, and reporter gene assays were performed to confirm that the knockdown of HuR downregulates the invasive activity of cancer cells. Immunohistochemical staining was performed for high invasive carcinoma, squamous cell carcinoma (SCC) and low invasive carcinoma, verrucous carcinoma (VC), to determine if the localization of cytoplasmic HuR is related to matrix metalloproteinase-1 (MMP-1) expression. Results: Invasive activity was significantly lower in HuR knockdown cancer cells than in control cells. A luciferase assay revealed that HuR knockdown inactivated the promoter activity of the MMP-1 gene. The mRNA levels of the transcription factors required for MMP-1 expression, including c-fos and c-jun, were decreased in HuR knockdown cancer cells. Immunohistochemical analysis revealed the level of cytoplasmic HuR and MMP-1 in invasive carcinoma to be higher than in low invasive cancer. HuR induced MMP-1 expression in the invasive front of most SCC cases. Conclusion: HuR knockdown attenuated the invasive activity of cancer cells by decreasing the expression of the MMP-1, at least partially. HuR localization may help determine the invasive phenotype of cancer cells and inhibit cancer cell invasion. Furthermore, in oral SCC, HuR may be related to invasive activity through the expression of MMP-1.

Cardiac angiosarcoma with pulmonary and adrenal metastases diagnosed by FDG-PET/CT-guided adrenal biopsy.

Primary cardiac angiosarcoma is a high-grade aggressive tumor with a poor prognosis and low incidence. We describe a case of cardiac angiosarcoma, with pulmonary and adrenal metastases, diagnosed via fluorodeoxyglucose-positron emission tomography/computed tomography-guided adrenal biopsy. Learning objective: Cardiac angiosarcoma should be considered in a patient with a cardiac mass with no tumor cells in the pericardial fluid. Fluorodeoxyglucose-positron emission tomography/computed tomography could be useful in determining the biopsy site.

Modeling Low Muscle Mass Screening in Hemodialysis Patients.

INTRODUCTION: Computed tomography (CT) can accurately measure muscle mass, which is necessary for diagnosing sarcopenia, even in dialysis patients. However, CT-based screening for such patients is challenging, especially considering the availability of equipment within dialysis facilities. We therefore aimed to develop a bedside prediction model for low muscle mass, defined by the psoas muscle mass index (PMI) from CT measurement. METHODS: Hemodialysis patients (n = 619) who had undergone abdominal CT screening were divided into the development (n = 441) and validation (n = 178) groups. PMI was manually measured using abdominal CT images to diagnose low muscle mass by two independent investigators. The development group's data were used to create a logistic regression model using 42 items extracted from clinical information as predictive variables; variables were selected using the stepwise method. External validity was examined using the validation group's data, and the area under the curve (AUC), sensitivity, and specificity were calculated. RESULTS: Of all subjects, 226 (37%) were diagnosed with low muscle mass using PMI. A predictive model for low muscle mass was calculated using ten variables: each grip strength, sex, height, dry weight, primary cause of end-stage renal disease, diastolic blood pressure at start of session, pre-dialysis potassium and albumin level, and dialysis water removal in a session. The development group's adjusted AUC, sensitivity, and specificity were 0.81, 60%, and 87%, respectively. The validation group's adjusted AUC, sensitivity, and specificity were 0.73, 64%, and 82%, respectively. DISCUSSION/CONCLUSION: Our results facilitate skeletal muscle screening in hemodialysis patients, assisting in sarcopenia prophylaxis and intervention decisions.

Rapidly Growing Superficial Angiomyxoma in Mandibular Gingiva: A Case Report and Literature Review.

Superficial angiomyxoma (SA) is a benign tumor characterized by extensive myxoid stroma, numerous small blood vessels, sparse spindle-shaped fibroblastic cells, and inflammatory cell infiltrate. Oral cavity SA is extremely rare and typically presents as a painless, slow growth. We experienced SA in the mandibular gingiva that is rapidly growing. The patient was a 15-year-old female whose chief complaint was a painless mass in the lingual gingiva of the mandible that increased in size over 1 month. An excisional biopsy was performed under local anesthesia. According to histopathological examination, the mass was diagnosed as SA. The patient experienced recurrence twice because of positive margins. The second recurrent lesion, including periosteum, was resected, and no recurrence has been observed for 1 year. The cause of rapid growth was attributed to edematous changes due to tongue habit or traumatic stimuli. As this case exhibited repeated local recurrence, careful follow-up is required.

Endovascular therapy for cardiocerebral infarction associated with atrial fibrillation: A case report and literature review.

Background: Cardiocerebral infarction (CCI) is a rare entity that refers to the simultaneous occurrence of acute myocardial infarction and acute ischemic stroke. The management of CCI patients remains unclear. Case Description: An 86-year-old woman with a medical history of paroxysmal atrial fibrillation presented with a sudden onset of consciousness disturbance and right hemiplegia. Computed tomography of the head revealed no intracranial hemorrhage but the left hyperdense middle cerebral artery sign, associated with ST-segment elevation in II, III, and aVF noted on a routine 12-lead electrocardiogram at admission. The patient was immediately brought to the catheterization laboratory and percutaneous coronary intervention (PCI) was performed first, followed by mechanical thrombectomy, resulting in successful revascularization of the both diseases. Conclusion: Although the treatment strategy of CCI may depend on the condition of coronary and cerebral ischemia, it may be appropriate to prioritize coronary angiography and PCI if not acute ischemic stroke is critical.

Adenovirus infection controls processing bodies to stabilize AU-rich element-containing mRNA.

In the adenovirus-infected cells, virus mRNAs are selectively exported to the cytoplasm by virus early gene products to facilitate virus replication. We previously showed AU-rich elements (AREs) containing mRNAs are exported to the cytoplasm and stabilized in infected cells. Here, we analyzed ribonucleoprotein (RNP) granules in the cytoplasm that are involved in mRNA degradation to elucidate the mechanism of ARE-mRNA stabilization in adenovirus infected cells. Our findings showed that processing bodies (PBs) aggregate, then almost all PBs are translocated to aggresomes formed by adenoviral gene products during the late phase of infection. Furthermore, E4orf3 was required for the PBs translocation, and the same domains of E4orf3-mutants required to change the form of promyelocytic leukemia bodies were also needed for PBs translocation. Luciferase activity showed that these domains were critical for miRNA- and ARE-mediated mRNA decay. These findings suggest that adenovirus changes the behavior of PBs to prevent ARE-mRNA downregulation.

Transfusion-dependent anaemia treatment using continuous erythropoietin receptor activator (epoetin ß pegol) and roxadustat after darbepoetin treatment failure in low-risk myelodysplastic syndrome: a case report.

Treatment of anaemia and reduction of transfusion are major therapeutic goals in patients with low-risk myelodysplastic syndrome (MDS). Although erythropoiesis-stimulating agents (ESAs) are widely used to reduce transfusion requirement, ESAs lose effectiveness within 12 months. We report a 65-year-old Japanese woman diagnosed with low-risk MDS who underwent long-term use of continuous epoetin ß pegol, an erythropoietin receptor activator (CERA), and her treatment after CERA failure. She received darbepoetin alpha (DPO) for transfusion-dependent anaemia and was free from transfusion. However, after 8 months, DPO lost effectiveness. She then received CERA and recovered from anaemia. Her haemoglobin level remained >10 g/dl for 3 years and 4 months. However, even CERA lost effectiveness, and she received roxadustat treatment with CERA, leading to recovery from anaemia again. Although further evidence is required, the extension of the no-transfusion period provided by ESAs and roxadustat is important and is awaited among low-risk MDS patients.

Regional myocardial perfusion reserve determined using myocardial perfusion magnetic resonance imaging showed a direct correlation with coronary flow velocity reserve by Doppler flow wire.

AIMS: Quantitative analysis of rest-stress myocardial perfusion magnetic resonance imaging (MRI) can provide assessments of regional myocardial perfusion reserve (MPR). The purpose of this study was to compare regional MPR determined by myocardial perfusion MRI with coronary flow reserve (CFR) by intracoronary Doppler flow wire. METHODS AND RESULTS: Twenty patients with suspected coronary artery disease (CAD) were studied. Average peak velocity was measured by Doppler flow wire in the resting state and during adenosine triphosphate (ATP) stress in 36 coronary arteries. CFR measurements for each patient were performed in the culprit and one non-culprit non-stenotic artery. First-pass, contrast-enhanced myocardial perfusion MR images were obtained in the resting state and during ATP stress within the week before the Doppler wire procedure. Regional myocardial blood flow (MBF) was quantified in 16 myocardial segments by analysing arterial input and myocardial output using a Patlak plot method. MPR was calculated as stress MBF divided by rest MBF. CFR measured by Doppler flow wire was compared with MPR in the myocardial segments corresponding to vessel territories. The average MPR measured by perfusion MRI was 1.77 +/- 0.62 for the culprit arteries and 3.45 +/- 0.78 for the non-culprit arteries, respectively (P < 0.001). The averaged CFR by Doppler flow wire was 1.72 +/- 0.44 in the culprit arteries and 3.14 +/- 0.74 in the non-culprit arteries, respectively (P < 0.001). For both culprit and non-culprit vessel groups, significant direct correlations were observed between MR assessments of MPR and Doppler assessments of CFR (culprit artery: R = 0.87, Non-culprit artery: R = 0.86) On Bland-Altman analysis, the mean differences between MPR determined by myocardial perfusion MRI and CFR measured by Doppler wire were 0.05 in culprit arteries (95% limit of agreement; -0.65 to 0.56) and 0.36 in non-culprit arteries (95% limit of agreement; -1.24 to 0.44). The sensitivity and specificity of MR measurement of MPR for predicting physiologically significant reduction of Doppler CFR (<2) was 88% (95% CI 61.7-98.5) and 90% (95% CI 68.3-98.8), respectively. CONCLUSION: The current results using Doppler flow wire as a reference method demonstrated that quantitative analysis of stress-rest myocardial perfusion MRI can provide a non-invasive assessment of reduced MPR in patients with CAD.

Amyloid Variant of Central Odontogenic Fibroma in the Mandible: A Case Report and Literature Review.

BACKGROUND Odontogenic fibroma is a rare mesenchymal odontogenic tumor. It can be classified as central odontogenic fibroma (COF) or peripheral odontogenic fibroma (POF) based on clinical features. There are several variants of COF, including amyloid, ossifying, and giant cell. It grows slowly and exhibits painless cortical expansion of the jawbone. Radiographically, COF appears as a radiolucent unilocular or multilocular lesion with well-defined borders. COF may be associated with unerupted or displaced teeth and root resorption. CASE REPORT A 35-year-old man was referred to our hospital for submandibular swelling. Panoramic radiography and contrast-enhanced computed tomography revealed a unilocular area of bone resorption with a well-defined border and equal enhancement from the canine to first molar on the right side of the mandible. Root resorption of the first premolar and root separation of the first and second premolars were also evident. The lesion was asymptomatic. Histopathological examination of a biopsy of the lesion was suggestive of OF. Enucleation of the tumor, curettage of the bone around the tumor, and extraction of the premolar were then performed. Histopathological examination of the tumor showed fibrous connective tissue with inactive-looking odontogenic epithelial islands and strands, amyloid deposit, intercalation of Langerhans cells into the tumor epithelium, and no calcification. The final diagnosis of amyloid variant of COF was made. The postoperative course is going well. CONCLUSIONS Herein we describe and discuss the clinical, radiological, and pathological features of the amyloid variant of COF. This report will enhance understanding of this extremely rare variant.

Conditionally Replicative Adenovirus Controlled by the Stabilization System of AU-Rich Elements Containing mRNA.

AU-rich elements (AREs) are RNA elements that enhance the rapid decay of mRNAs, including those of genes required for cell growth and proliferation. HuR, a member of the embryonic lethal abnormal vision (ELAV) family of RNA-binding proteins, is involved in the stabilization of ARE-mRNA. The level of HuR in the cytoplasm is up-regulated in most cancer cells, resulting in the stabilization of ARE-mRNA. We developed the adenoviruses AdARET and AdAREF, which include the ARE of TNF-α and c-fos genes in the 3'-untranslated regions of the E1A gene, respectively. The expression of the E1A protein was higher in cancer cells than in normal cells, and virus production and cytolytic activities were also higher in many types of cancer cells. The inhibition of ARE-mRNA stabilization resulted in a reduction in viral replication, demonstrating that the stabilization system was required for production of the virus. The growth of human tumors that formed in nude mice was inhibited by an intratumoral injection of AdARET and AdAREF. These results indicate that these viruses have potential as oncolytic adenoviruses in the vast majority of cancers in which ARE-mRNA is stabilized.

Hyperthermia activates a subset of ataxia-telangiectasia mutated effectors independent of DNA strand breaks and heat shock protein 70 status.

All cells have intricately coupled sensing and signaling mechanisms that regulate the cellular outcome following exposure to genotoxic agents such as ionizing radiation (IR). In the IR-induced signaling pathway, specific protein events, such as ataxia-telangiectasia mutated protein (ATM) activation and histone H2AX phosphorylation (gamma-H2AX), are mechanistically well characterized. How these mechanisms can be altered, especially by clinically relevant agents, is not clear. Here we show that hyperthermia, an effective radiosensitizer, can induce several steps associated with IR signaling in cells. Hyperthermia induces gamma-H2AX foci formation similar to foci formed in response to IR exposure, and heat-induced gamma-H2AX foci formation is dependent on ATM but independent of heat shock protein 70 expression. Hyperthermia also enhanced ATM kinase activity and increased cellular ATM autophosphorylation. The hyperthermia-induced increase in ATM phosphorylation was independent of Mre11 function. Similar to IR, hyperthermia also induced MDC1 foci formation; however, it did not induce all of the characteristic signals associated with irradiation because formation of 53BP1 and SMC1 foci was not observed in heated cells but occurred in irradiated cells. Additionally, induction of chromosomal DNA strand breaks was observed in IR-exposed but not in heated cells. These results indicate that hyperthermia activates signaling pathways that overlap with those activated by IR-induced DNA damage. Moreover, prior activation of ATM or other components of the IR-induced signaling pathway by heat may interfere with the normal IR-induced signaling required for chromosomal DNA double-strand break repair, thus resulting in increased cellular radiosensitivity.