Predictors of Long-Term Survival in Patients Treated for Oligometastases

PURPOSE/OBJECTIVE(S)

The purpose of this work is to report the long-term outcomes of patients with oligometastases treated with curative intent radiotherapy in the context of the recently developed ESTRO EORTC classification schema.

MATERIALS/METHODS

This retrospective, single institution study consists of consecutive adult patients with oligometastases from solid tumor malignancy referred to a single high volume radiation oncologist. Oligometastases were defined as 5 or fewer extracranial or intracranial metastatic lesions where all sites of active disease are amenable to treatment. Patients with a history of distant metastases requiring treatment of the primary tumor ± regional lymph nodes were included. Radical local therapies utilized included stereotactic radiotherapy (53% of patients, median dose 27 Gy in 3 fractions), intensity modulated radiotherapy (64% of patients; median dose 50 Gy in 15 fractions), surgery and/or ablation. Overall survival and progression-free survival were estimated using the Kaplan-Meier method. Predictors of survival were assessed using log-rank test for categorical variables and Cox regression for continuous variables for univariable analysis and Cox multivariable analyses.

RESULTS

The study population consists of 130 patients with 207 treated distant metastases referred to radiation oncology between 1/2014 and 12/2021. Key patient characteristics include median age 71, median pre-radiation albumin 3.7 g/dl, 72% ECOG 0-1 performance status, 35% lung primary, 12% prostate primary, median of 1 distant metastasis treated, 31% bone metastases, 30% brain metastases, 47% required treatment to primary tumor ± regional lymph nodes and 71% received systemic therapy after radiation. The most frequent ESTRO EORTC oligometastatic groups were synchronous oligometastases (40%) and metachronous oligorecurrence (29%). At a median follow-up of 28.8 months (IQR 16.0 to 56.3 months), the median overall survival is 37.9 months with a 4-year overall survival of 41.1%. The median progression-free survival was 12.3 months with a 4-year progression-free survival of 22.6%. On multivariable analysis, the strongest predictors of overall survival are age (HR 1.05 [1.02-1.08]; CI: 95%; p<0.001), ECOG performance status (HR 1.69 [1.15-2.47]; CI: 95%; p = 0.007), primary prostate, breast or kidney tumor (HR 2.79 [1.29-6.03]; CI: 95%; p = 0.009) and pre-radiation serum albumin (HR 0.55 [0.35-0.87]; CI: 95%; p = 0.01). The strongest predictors of progression free survival on multivariable analysis are albumin (HR 0.59 [0.39-0.88]; CI: 95%; p = 0.009) and primary prostate, breast or kidney tumor (HR 1.90 [1.06-3.38]; CI: 95%; p = 0.03).

CONCLUSION

Long-term overall survival is not uncommon after radical treatment for oligometastases. The ESTRO EORTC classification provides an enriched nomenclature for oligometastases but is not independently predictive of survival.

Clinical experience with non-invasive prenatal screening for single-gene disorders

OBJECTIVE

To assess the performance of a non-invasive prenatal screening test (NIPT) for a panel of dominant single-gene disorders (SGD) with a combined population incidence of 1 in 600.

METHODS

Cell-free fetal DNA isolated from maternal plasma samples accessioned from 14 April 2017 to 27 November 2019 was analyzed by next-generation sequencing, targeting 30 genes, to look for pathogenic or likely pathogenic variants implicated in 25 dominant conditions. The conditions included Noonan spectrum disorders, skeletal disorders, craniosynostosis syndromes, Cornelia de Lange syndrome, Alagille syndrome, tuberous sclerosis, epileptic encephalopathy, SYNGAP1-related intellectual disability, CHARGE syndrome, Sotos syndrome and Rett syndrome. NIPT-SGD was made available as a clinical service to women with a singleton pregnancy at ≥ 9 weeks' gestation, with testing on maternal and paternal genomic DNA to assist in interpretation. A minimum of 4.5% fetal fraction was required for test interpretation. Variants identified in the mother were deemed inconclusive with respect to fetal carrier status. Confirmatory prenatal or postnatal diagnostic testing was recommended for all screen-positive patients and follow-up information was requested. The screen-positive rates with respect to the clinical indication for testing were evaluated.

RESULTS

A NIPT-SGD result was available for 2208 women, of which 125 (5.7%) were positive. Elevated test-positive rates were observed for referrals with a family history of a disorder on the panel (20/132 (15.2%)) or a primary indication of fetal long-bone abnormality (60/178 (33.7%)), fetal craniofacial abnormality (6/21 (28.6%)), fetal lymphatic abnormality (20/150 (13.3%)) or major fetal cardiac defect (4/31 (12.9%)). For paternal age ≥ 40 years as a sole risk factor, the test-positive rate was 2/912 (0.2%). Of the 125 positive cases, follow-up information was available for 67 (53.6%), with none classified as false-positive. No false-negative cases were identified.

CONCLUSIONS

NIPT can assist in the early detection of a set of SGD, particularly when either abnormal ultrasound findings or a family history is present. Additional clinical studies are needed to evaluate the optimal design of the gene panel, define target populations and assess patient acceptability. NIPT-SGD offers a safe and early prenatal screening option. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

0669 The Effects Of Continuous Positive Airway Pressure Therapy In Moderate To Severe Obstructive Sleep Apnea: A High-density EEG Study

Introduction

A previous high-density electroencephalography (EEG) investigation in asymptomatic OSA showed regional deficits in sleep EEG power particularly slow wave activity (SWA) during NREM sleep in the parietal region. It is unclear whether treatment with CPAP can reverse local sleep EEG abnormalities in OSA, and whether any recovery is related to improvement in sleep-dependent memory consolidation.

Methods

Fifteen male participants (age 50.4±6.5yrs, AHI 51.7±23.5/h) with moderate-severe OSA (AHI&gt;15/h) underwent overnight polysomnography with 256-channel high-density EEG at baseline and following 3 months of CPAP therapy. A word paired associates declarative memory task was administered before and after sleep. After artefact removal, spectral analysis was performed for all channels. Topographical power maps were calculated for standard frequency ranges for NREM sleep (164 channels within a 0.57 radius from the vertex). Maps were compared using both absolute and normalized power (z-scores computed for each subject) and differences between baseline and treatment were determined by statistical nonparametric mapping.

Results

In 11 CPAP compliant patients (intolerant of CPAP [n=3]/high-density EEG [n=1]), analysis of polysomnographic variables showed that total sleep time did not differ but N1 (baseline vs. treatment: 66.9 vs. 39.5 mins,p=0.008) and N2 (195.0 vs. 150.6 mins,p=0.002) sleep was lower and N3 (89.8 vs. 128.7 mins,p=0.003) was higher after CPAP. Topographic analysis of high-density EEG data revealed a regional increase in SWA (1-4.5Hz) EEG power during N3 sleep in a cluster of electrodes overlying the centro-parietal cortex (cluster mean t-value=2.87,p=0.02). The change in overnight declarative memory consolidation (% recognition) after CPAP was significantly correlated with the change in slow spindle frequency activity in frontal regions (cluster mean r=0.875,p=0.003).

Conclusion

CPAP treatment may enhance localised deficits in sleep EEG activity in OSA, and specific regional recovery may translate to memory improvements in the short-term. These data also highlight the potential for long-term therapeutic effects on cognitive outcomes in OSA.

Support

 

Bortezomib enhances cancer cell death by blocking the autophagic flux through stimulating ERK phosphorylation

The antitumor activity of an inhibitor of 26S proteasome bortezomib (Velcade) has been observed in various malignancies, including colon cancer, prostate cancer, breast cancer, and ovarian cancer. Bortezomib has been proposed to stimulate autophagy, but scientific observations did not always support this. Interactions between ERK activity and autophagy are complex and not completely clear. Autophagy proteins have recently been shown to regulate the functions of ERK, and ERK activation has been found to induce autophagy. On the other hand, sustained activation of ERK has also been shown to inhibit the maturation step of the autophagy process. In this study, we sought to identify the mechanism of autophagy regulation in cancer cells treated with bortezomib. Our results indicate that bortezomib blocked the autophagic flux without inhibiting the fusion of the autophagosome and lysosome. In ovarian cancer, as well as endometrial cancer and hepatocellular carcinoma cells, bortezomib inhibited protein degradation in lysosomes by suppressing cathepsins, which requires the participation of ERK phosphorylation, but not JNK or p38. Our findings that ERK phosphorylation reduced cathepsins further explain how ERK phosphorylation inhibits the autophagic flux. In conclusion, bortezomib may induce ERK phosphorylation to suppress cathepsin B and inhibit the catalytic process of autophagy in ovarian cancer and other solid tumors. The inhibition of cisplatin-induced autophagy by bortezomib can enhance chemotherapy efficacy in ovarian cancer. As we also found that bortezomib blocks the autophagic flux in other cancers, the synergistic cytotoxic effect of bortezomib by abolishing chemotherapy-related autophagy may help us develop strategies of combination therapies for multiple cancers.

Curative vs. preventive management of nitrogen transfers in rural areas: lessons from the case of the Orgeval watershed (Seine River basin, France)

The Orgeval watershed (104 km(2)) is a long-term experimental observatory and research site, representative of rural areas with intensive cereal farming of the temperate world. Since the past few years, we have been carrying out several studies on nitrate source, transformation and transfer of both surface and groundwaters in relation with land use and agriculture practices in order to assess nitrate (NO3(-)) leaching, contamination of aquifers, denitrification processes and associated nitrous oxide (N2O) emissions. A synthesis of these studies is presented to establish a quantitative diagnosis of nitrate contamination and N2O emissions at the watershed scale. Taking this watershed as a practical example, we compare curative management measures, such as pond introduction, and preventive measures, namely conversion to organic farming practices, using model simulations. It is concluded that only preventive measures are able to reduce the NO3(-) contamination level without further increasing N2O emissions, a result providing new insights for future management bringing together water-agro-ecosystems.

Smoking cessation in Taiwanese male smokers with coronary artery disease: influencing factors and policy implications

AIM

To investigate factors affecting smoking cessation in male smokers with coronary artery disease.

DESIGN

A descriptive, correlation, cross-sectional study was conducted.

METHODS

Data were collected using a questionnaire constructed by a literature review of research on smoking cessation in male smokers including demographics and smoking background, as well as psychological, interpersonal and environmental factors. A total of 130 male patients with coronary artery disease were recruited from the cardiac clinic at a regional hospital in Taiwan from August to December 2008. The response rate was 93% (n = 121). Descriptive statistics, chi-square, t-tests and logistic regression analysis were conducted.

RESULTS

During the survey, 64.5% of the respondents reported that they had stopped smoking after a coronary event. Five factors were significantly associated with smoking cessation after diagnosis of coronary artery disease: age, the severity of heart diagnoses, antismoking norms (perceived that smoking was against the social norms), nicotine dependence level, and contrary views of smoking (perceived negative expectancy of smoking). Multivariate analysis revealed antismoking norms to be the most important predictor (AOR = 4.27; P < .05) after adjusting age.

CONCLUSION

The study highlights the need to develop smoking cessation interventions that specifically counsel patients with coronary artery disease about these information, such as the disease risk and development, health consequences of smoking, and dependence therapy. Additionally, government support for tobacco control programmes in hospitals and elsewhere is designed to have a beneficial effect on patients' smoking behaviours primarily by increasing antismoking norms.

Antitumor activity of Ad-IU2, a prostate-specific replication-competent adenovirus encoding the apoptosis inducer, TRAIL

In this study, we investigated the preclinical utility and antitumor efficacy of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) delivered by Ad-IU2, a prostate-specific replication-competent adenovirus (PSRCA), against androgen-independent prostate cancer. Through transcriptional control of adenoviral early genes E1a, E1b and E4, as well as TRAIL by two bidirectional prostate-specific enhancing sequences (PSES), expression of TRAIL as well adenoviral replication was limited to prostate-specific antigen (PSA) and prostate-specific membrane antigen (PSMA)-positive cells. Ad-IU2 induced 5-fold greater apoptosis selectively in PSA/PSMA-positive CWR22rv and C4-2 cells than an oncolytic adenoviral control. Furthermore, prolonged infection with Ad-IU2 reversed TRAIL resistance in LNCaP cells. Ad-IU2 exhibited superior killing efficiency in PSA/PSMA-positive prostate cancer cells at doses 5- to 8-fold lower than required by a PSRCA to produce a similar effect. This cytotoxic effect was not observed in non-prostatic cells, however. As an enhancement of its therapeutic efficacy, Ad-IU2 exerted a TRAIL-mediated bystander effect through direct cell-to-cell contact and soluble factors such as apoptotic bodies. In vivo, Ad-IU2 markedly suppressed the growth of subcutaneous androgen-independent CWR22rv xenografts compared to a PSRCA at six weeks post-treatment (3.1- vs. 17.1-fold growth of tumor). This study demonstrates the potential clinical utility of a PSRCA armed with an apoptosis-inducing ligand.

In vivo arginine production and nitric oxide synthesis in pregnant Indian women with normal and low body mass indices

BACKGROUND/OBJECTIVES

Nitric oxide (NO) has been proposed as a mediator of vascular expansion during pregnancy. Inability to increase NO synthesis and/or production of its precursor, arginine, may be a contributor to pregnancy-induced hypertension or preeclampsia. Because maternal weight is associated with blood pressure and risk of preeclampsia during pregnancy, it may also influence arginine and/or NO production. The purpose of this study was to determine the in vivo arginine production and NO synthesis rate in pregnant women with normal (n=10) and low (n=10) body mass indices (BMIs).

SUBJECTS/METHODS

Arginine flux and NO synthesis rate were measured in the postabsorptive state with constant infusions of 15N2-arginine and 13C,2H4-citrulline. Plasma concentrations of arginine and NO metabolites were also measured. Kinetic parameters were correlated to maternal variables, gestational age, birth weight and blood pressure.

RESULTS

Endogenous arginine flux was significantly faster in the low-BMI compared with normal-BMI women in the first trimester (63.1+/-3.4 vs 50.2+/-2.0 micromol/kg per h, P<0.01), but not in the second. Plasma NO concentration was higher (44.7+/-5.3 vs 30.4+/-1.9 micromol/l, P=0.03) and its rate of synthesis trended faster in the low-BMI compared with normal-BMI group in the second trimester. Maternal weight and BMI were negatively correlated with arginine flux in both trimesters and NO synthesis in the second trimester.

CONCLUSIONS

These findings suggest, but do not prove, that maternal BMI may be a factor in the ability to produce NO during pregnancy and may be one way by which BMI influences blood pressure during pregnancy.

A conditionally replicative, Wnt/beta-catenin pathway-based adenovirus therapy for anaplastic thyroid cancer

Thyroid cancer affects between 10,000 and 15,000 people per year in the US. Typically, this disease can be controlled with surgical resection and radioiodide treatment. However, resistance to these conventional therapies is observed in some patients, who develop intractable anaplastic thyroid cancer (ATC), for which no effective therapies exist. Recently, a sizable fraction of undifferentiated or poorly differentiated thyroid cancers were shown to contain mutations in beta-catenin, an oncogenic protein involved in the etiology of cancers of many tissues. We developed a conditionally replicative adenovirus (named 'HILMI') which, by virtue of TCF response elements drives E1A and E1B expression, replicates specifically in cells with an active Wnt/beta-catenin pathway. We show that several thyroid cancer cell lines, derived from undifferentiated or anaplastic tissues and possessing an active Wnt/beta-catenin pathway, are susceptible to cell killing by HILMI. Furthermore, viral replication in ATC cells as xenograft tumors in nude mice was observed, and prolonged survival of mice with ATC tumors was observed following administration of the HILMI therapeutic vector. The results warrant further development of this therapeutic approach for ATC patients.

Interaction between Brome mosaic virus proteins and RNAs: effects on RNA replication, protein expression, and RNA stability

Brome mosaic virus (BMV) RNA replication has been examined in a number of systems, including Saccharomyces cerevisiae. We developed an efficient T-DNA-based gene delivery system using Agrobacterium tumefaciens to transiently express BMV RNAs in Nicotiana benthamiana. The expressed RNAs can systemically infect plants and provide material to extract BMV replicase that can perform template-dependent RNA-dependent RNA synthesis in vitro. We also expressed the four BMV-encoded proteins from nonreplicating RNAs and analyzed their effects on BMV RNA accumulation. The capsid protein that coinfiltrated with constructs expressing RNA1 and RNA2 suppressed minus-strand levels but increased plus-strand RNA accumulation. The replication proteins 1a and 2a could function in trans to replicate and transcribe the BMV RNAs. None of the BMV proteins or RNA could efficiently suppress posttranscriptional silencing. However, 1a expressed in trans will suppress the production of a recombinant green fluorescent protein expressed from the nontranslated portions of BMV RNA1 and RNA2, suggesting that 1a may regulate translation from BMV RNAs. BMV replicase proteins 1a did not affect the accumulation of the BMV RNAs in the absence of RNA replication, unlike the situation reported for S. cerevisiae. This work demonstrates that the Agrobacterium-mediated gene delivery system can be used to study the cis- and trans-acting requirements for BMV RNA replication in plants and that significant differences can exist for BMV RNA replication in different hosts.

HOXB13 is downregulated in colorectal cancer to confer TCF4-mediated transactivation

Mutations in the Wnt signalling cascade are believed to cause aberrant proliferation of colorectal cells through T-cell factor-4 (TCF4) and its downstream growth-modulating factors. HOXB13 is exclusively expressed in prostate and colorectum. In prostate cancers, HOXB13 negatively regulates β-catenin/TCF4-mediated transactivation and subsequently inhibits cell growth. To study the role of HOXB13 in colorectal tumorigenesis, we evaluated the expression of HOXB13 in 53 colorectal tumours originated from the distal left colon to rectum with their matching normal tissues using quantitative RT–PCR analysis. Expression of HOXB13 is either lost or diminished in 26 out of 42 valid tumours (62%), while expression of TCF4 RNA is not correlated with HOXB13 expression. TCF4 promoter analysis showed that HOXB13 does not regulate TCF4 at the transcriptional level. However, HOXB13 downregulated the expression of TCF4 and its target gene, c-myc, at the protein level and consequently inhibited β-catenin/TCF-mediated signalling. Functionally, forced expression of HOXB13 drove colorectal cancer (CRC) cells into growth suppression. This is the first description of the downregulation of HOXB13 in CRC and its mechanism of action is mediated through the regulation of TCF4 protein stability. Our results suggest that loss of HOXB13 may be an important event for colorectal cell transformation, considering that over 90% of colorectal tumours retain mutations in the APC/β-catenin pathway.

Repair of the tRNA-like CCA sequence in a multipartite positive-strand RNA virus

The 3' portions of plus-strand brome mosaic virus (BMV) RNAs mimic cellular tRNAs. Nucleotide substitutions or deletions in the 3'CCA of the tRNA-like sequence (TLS) affect minus-strand initiation unless repaired. We observed that 2-nucleotide deletions involving the CCA 3' sequence in one or all BMV RNAs still allowed RNA accumulation in barley protoplasts at significant levels. Alterations of CCA to GGA in only BMV RNA3 also allowed RNA accumulation at wild-type levels. However, substitutions in all three BMV RNAs severely reduced RNA accumulation, demonstrating that substitutions have different repair requirements than do small deletions. Furthermore, wild-type BMV RNA1 was required for the repair and replication of RNAs with nucleotide substitutions. Results from sequencing of progeny viral RNA from mutant input RNAs demonstrated that RNA1 did not contribute its sequence to the mutant RNAs. Instead, the repaired ends were heterogeneous, with one-third having a restored CCA and others having sequences with the only commonality being the restoration of one cytidylate. The role of BMV RNA1 in increased repair was examined.

Replicase-binding sites on plus- and minus-strand brome mosaic virus RNAs and their roles in RNA replication in plant cells

The cis-acting elements for Brome mosaic virus (BMV) RNA synthesis have been characterized primarily for RNA3. To identify additional replicase-binding elements, nested fragments of all three of the BMV RNAs, both plus- and minus-sense fragments, were constructed and tested for binding enriched BMV replicase in a template competition assay. Ten RNA fragments containing replicase-binding sites were identified; eight were characterized further because they were more effective competitors. All eight mapped to noncoding regions of BMV RNAs, and the positions of seven localized to sequences containing previously characterized core promoter elements (C. C. Kao, Mol. Plant Pathol. 3:55-62, 2001), thus suggesting the identities of the replicase-binding sites. Three contained the tRNA-like structures that direct minus-strand RNA synthesis, three were within the 3' region of each minus-strand RNA that contained the core promoter for genomic plus-strand initiation, and one was in the core subgenomic promoter. Single-nucleotide mutations known previously to abolish RNA synthesis in vitro prevented replicase binding. When tested in the context of the respective full-length RNAs, the same mutations abolished BMV RNA synthesis in transfected barley protoplasts. The eighth site was within the intercistronic region (ICR) of plus-strand RNA3. Further mapping showed that a sequence of 22 consecutive adenylates was responsible for binding the replicase, with 16 being the minimal required length. Deletion of the poly(A) sequence was previously shown to severely debilitate BMV RNA replication in plants (E. Smirnyagina, Y. H. Hsu, N. Chua, and P. Ahlquist, Virology 198:427-436, 1994). Interestingly, the B box motif in the ICR of RNA3, which has previously been determined to bind the 1a protein, does not bind the replicase. These results identify the replicase-binding sites in all of the BMV RNAs and suggest that the recognition of RNA3 is different from that of RNA1 and RNA2.

Tissue-specific promoters in gene therapy for the treatment of prostate cancer

Delivery of therapeutic toxic genes to and their expression in tumor cells through the use of tissue-specific promoters could decrease their toxic effect on neighboring normal cells when virus-mediated gene delivery results in their infection. We have demonstrated the utility of two prostate cancer-specific promoters, long PSA and osteocalcin, for tissue-specific toxic gene therapy for prostate cancer. The two promoters were highly active in both androgen-dependent and androgen-independent prostate cancer cells. We also introduce the Phase I trial of osteocalcin promoter-based toxic gene therapy for bone metastases of prostate cancer, which is in progress at the University of Virginia.

The burden of osteoporosis in California, 1998

This study estimates the cost of osteoporosis in California, including health care services and the value of lives lost prematurely to the disease. Costs are estimated for diagnoses of "osteoporosis" and for the proportion of spine, forearm, hip and other fractures that are caused by the disease. The additional costs resulting from a secondary diagnosis of osteoporosis are also included. Osteoporosis accounted for over $2.4 billion in direct health care costs in 1998, and over $4 million in lost productivity resulting from premature death. Most of the cost results from hip fractures and other fractures. In fact, only 15% of costs are for people with a diagnosis of "osteoporosis" per se, and, of this group, most of the costs are associated with a secondary, not a primary diagnosis. The disease is largely a diagnosis of older white women: three-quarters of the hospitalization costs are incurred by women, 80% of those hospitalized are white, and three-quarters are over age 65 years. As would be expected, Medicare pays for most of the hospital care -- almost three-fourths of the total. Nursing home care represents the largest cost for people with osteoporosis, accounting for 59% of the money spent treating the disease.

Drug-resistant human bladder-cancer cells are more sensitive to adenovirus-mediated wild-type p53 gene therapy compared to drug-sensitive cells

We investigated the therapeutic potential and molecular mechanism of adenovirus-mediated wt p53 gene therapy for drug-resistant human bladder cancers. KK47, a human bladder-cancer cell line, along with the drug-resistant sublines KK47/DDP10, KK47/DDP20 (cisplatin-resistant) and KK47/ADM (doxorubicin-resistant) were used for the experiments. All 4 KK47 cell lines had genetically normal p53 genes. Using an in vitro cytotoxicity assay, the drug-resistant cell lines were more sensitive to Ad-CMV-p53 cell killing than the KK47 parental cell line. Ad-CMV-p53 induced higher levels of p53 protein and mRNA in the drug-resistant cell lines than in the parental cell line and, consequently, higher levels of p21 and Bax mRNA, which resulted in higher percentages of G(1) cell-cycle arrest and apoptosis. The higher efficiencies of adenoviral gene transfer in the drug-resistant cell lines were confirmed by X-gal staining after infection with Ad-CMV-beta-gal. In conclusion, adenovirus-mediated wt p53 gene therapy was more effective in the drug-resistant bladder-cancer cell lines than in the drug-sensitive bladder-cancer cell line.

Adhesion of monocytes to arterial endothelium and initiation of atherosclerosis are critically dependent on vascular cell adhesion molecule-1 gene dosage

- Vascular cell adhesion molecule-1 (VCAM-1/Vcam1) is a cytokine-inducible member of the immunoglobulin gene superfamily that is expressed by arterial endothelial cells in regions predisposed to atherosclerosis and at borders of atherosclerotic plaques. To determine whether VCAM-1 expression regulates atherosclerotic lesion formation, we crossed Vcam1 domain 4-deficient (D4D) mice, which partially circumvent the embryonic lethality of Vcam1 null mice, with apolipoprotein E null (Apoe(-/-)) mice, which spontaneously develop hypercholesterolemia and atherosclerosis. In the Apoe(-/-) background, mice homozygous for the Vcam1 D4D allele had markedly reduced arterial VCAM-1 expression, monocyte adherence in the aortic root, and fatty streak formation. Heterozygous Vcam1 D4D mice revealed a Vcam1 gene-dosage effect and had intermediate, yet significant, reductions in these parameters. Our data demonstrate that VCAM-1 plays a pivotal role in the initiation of atherosclerosis in Apoe(-/-) mice.

A conditional replication-competent adenoviral vector, Ad-OC-E1a, to cotarget prostate cancer and bone stroma in an experimental model of androgen-independent prostate cancer bone metastasis

Prostate cancer has a high propensity to metastasize to bone, which often resists hormone, radiation, and chemotherapies. Because of the reciprocal nature of the prostate cancer and bone stroma interaction, we designed a cotargeting strategy using a conditional replication-competent adenovirus to target the growth of tumor cells and their associated osteoblasts. The recombinant Ad-OC-E1a was constructed using a noncollagenous bone matrix protein osteocalcin (OC) promoter to drive the viral early E1a gene with restricted replication in cells that express OC transcriptional activity. Unlike Ad-PSE-E1a, Ad-OC-E1a was highly efficient in inhibiting the growth of PSA-producing (LNCaP, C4-2, and ARCaP) and nonproducing (PC-3 and DU145) human prostate cancer cell lines. This virus was also found to effectively inhibit the growth of human osteoblasts and human prostate stromal cells in vitro. Athymic mice bearing s.c. androgen receptor-negative and PSA-negative PC-3 xenografts responded to a single intratumoral administration of 2 x 10(9) plaque-forming unit(s) of Ad-OC-E1a. In SCID/bg mice, intraosseous growth of androgen receptor-positive and PSA-producing C4-2 xenografts responded markedly to i.v. administrations of a single dose of Ad-OC-E1a. One hundred percent of the treated mice responded to this systemic Ad-OC-E1a therapy with a decline of serum PSA to an undetectable level, and 80% of the mice with PSA rebound responded to the second dose of systemic Ad-OC-E1a. Forty percent of the mice were found to be cured by systemic Ad-OC-E1a without subsequent PSA rebound or tumor cells found in the skeleton. This cotargeting strategy shows a broader spectrum and appears to be more effective than systemic Ad-PSE-E1a in preclinical models of human prostate cancer skeletal metastasis.

Osteocalcin is incompletely spliced in non-osseous tissues

Osteocalcin (OC) is known to be a bone tissue-specific protein, expression of which is believed to be controlled by the OC promoter. In this communication, we provided evidence to demonstrate that tissue-specific expression of OC was also regulated at the RNA splicing level. We identified incompletely spliced variants of human OC mRNA, which retain one or more introns during RNA splicing, existing dominantly in non-osseous organs. Northern blot analysis identified two OC RNA transcripts expressed in normal human tissues, but the expression level of the transcripts varied between the tissues. Most non-osseous tissues expressed transcripts with higher molecular weight, prominent in ovary, kidney, pancreas, spleen, thymus, prostate, and testis, than the expected size of OC mRNA as seen in bone marrow. RT-PCR analysis identified up to six OC transcripts in most tissues tested except bone marrow. Sequence analysis showed that four of five RNA variants contained intron 1 in common and the dominant one contained all three introns. MG63, an osteoblastic osteosarcoma cell, expressed only the completely-spliced form of OC, whereas incompletely spliced RNA was dominant in most prostate tumor cells. Combined study of in situ hybridization and immunohistochemistry revealed that OC RNA was highly expressed in prostate tumor epithelial cells while only very low levels of protein were detected, which confirms that there are OC RNA variants in non-osseous tissues. In conclusion, we demonstrated that OC mRNA is also expressed in several non-osseous tissues. However, only bone preferentially underwent the complete splicing event of all three introns. The function of other splicing variants of OC mRNA needs to be further investigated.

Factors regulating template switch in vitro by viral RNA-dependent RNA polymerases: implications for RNA-RNA recombination

Copy-choice RNA recombination occurs during viral RNA synthesis when the viral transcription complex switches templates. We demonstrate that RNA-dependent RNA polymerase from bovine viral diarrhea virus and the replicases from three plant-infecting RNA viruses can produce easily detectable recombination products in vitro by switching templates during elongative RNA synthesis. Template sequence and/or structure, and NTP availability affected the frequency of template switch by the transcription complex. Our results provide biochemical support for copy-choice recombination and establish assays for mechanistic analyses of intermolecular RNA recombination in vitro.

Apolipoprotein E deficiency effects on learning in mice are dependent upon the background strain

Apolipoprotein E (apoE) deficient mice were bred onto the C57BL/6 and FVB/N strain backgrounds. The cognitive behavior of food-restricted apoE-deficient and wildtype male mice from these strains was assessed in an olfactory cued 8-arm radial maze. At 6 weeks of age, all four types of mice improved in maze performance over the course of 5 days. However, at 6 months of age, only the apoE-deficient mice on the C57BL/6 background failed to improve their maze performance over the 5 day course, as gauged by the number of incorrect choices made before retrieving both food rewards. Thus, an age-dependent and strain-specific effect of apoE deficiency on cognitive behavior was observed in these mice. The background strain affected activity levels in the maze, as well as in an open field assay. Plasma corticosterone levels were assessed in control, fasted, and post-restraint stress states. Fasting and restraint stress led to increases in plasma corticosterone levels. Although there were strain specific effects on fasting corticosterone levels, and the effect of apoE deficiency on post-stress corticosterone levels, there was no association between fasted corticosterone levels and impaired cognitive behavior in the 8-arm radial maze assay.

A simple and efficient method to transcribe RNAs with reduced 3' heterogeneity

Ribose C2' methoxy groups (-OCH3) on the penultimate nucleotide or the last two nucleotides of DNA templates can dramatically improve the quality of transcripts produced by T7 RNA polymerase. This strategy can be adapted to generate transcripts of varying lengths and will allow greater ease in purification of the products.

Serum-free recombinant production of adenovirus using a hollow fiber capillary system

A novel method for the production of adenoviral vectors on a scale sufficient to support most research applications and early phase clinical trials is presented. This method utilizes serum-free cell culture medium and a hollow fiber cell culture apparatus. Significantly less time and space are required than in conventional methods, and the resulting adenovirus is collected in a much smaller volume, simplifying the purification steps. The protocol described is a reproducible, convenient, biologically safe, and environmentally sound method for the production of adenoviral vectors for laboratory use and has the potential to scale-up the adenovirus production for clinical use.