Characterization of the Response of 9L and U-251N Orthotopic Brain Tumors to 3D Conformal Radiation Therapy.

In a study employing MRI-guided stereotactic radiotherapy (SRS) in two orthotopic rodent brain tumor models, the radiation dose yielding 50% survival (the TCD50) was sought. Syngeneic 9L cells, or human U-251N cells, were implanted stereotactically in 136 Fischer 344 rats or 98 RNU athymic rats, respectively. At approximately 7 days after implantation for 9L, and 18 days for U-251N, rats were imaged with contrast-enhanced MRI (CE-MRI) and then irradiated using a Small Animal Radiation Research Platform (SARRP) operating at 220 kV and 13 mA with an effective energy of ∼70 keV and dose rate of ∼2.5 Gy per min. Radiation doses were delivered as single fractions. Cone-beam CT images were acquired before irradiation, and tumor volumes were defined using co-registered CE-MRI images. Treatment planning using MuriPlan software defined four non-coplanar arcs with an identical isocenter, subsequently accomplished by the SARRP. Thus, the treatment workflow emulated that of current clinical practice. The study endpoint was animal survival to 200 days. The TCD50 inferred from Kaplan-Meier survival estimation was approximately 25 Gy for 9L tumors and below 20 Gy, but within the 95% confidence interval in U-251N tumors. Cox proportional-hazards modeling did not suggest an effect of sex, with the caveat of wide confidence intervals. Having identified the radiation dose at which approximately half of a group of animals was cured, the biological parameters that accompany radiation response can be examined.

The impact of initial tumor microenvironment on imaging phenotype.

Models of human cancer, to be useful, must replicate human disease with high fidelity. Our focus in this study is rat xenograft brain tumors as a model of human embedded cerebral tumors. A distinguishing signature of such tumors in humans, that of contrast-enhancement on imaging, is often not present when the human cells grow in rodents, despite the xenografts having nearly identical DNA signatures to the original tumor specimen. Although contrast enhancement was uniformly evident in all the human tumors from which the xenografts' cells were derived, we show that long-term contrast enhancement in the model tumors may be determined conditionally by the tumor microenvironment at the time of cell implantation. We demonstrate this phenomenon in one of two patient-derived orthotopic xenograft (PDOX) models using cancer stem-like cell (CSC)-enriched neurospheres from human tumor resection specimens, transplanted to groups of immune-compromised rats in the presence or absence of a collagen/fibrin scaffolding matrix, Matrigel. The rats were imaged by dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and their brains were examined by histopathology. Targeted proteomics of the PDOX tumor specimens grown from CSC implanted with and without Matrigel showed that while the levels of the majority of proteins and post-translational modifications were comparable between contrast-enhancing and non-enhancing tumors, phosphorylation of Fox038 showed a differential expression. The results suggest key proteins determine contrast enhancement and suggest a path toward the development of better animal models of human glioma. Future work is needed to elucidate fully the molecular determinants of contrast-enhancement.

Effect of vitamin D nutrition on disease indices in patients with primary hyperparathyroidism.

In patients with primary hyperparathyroidism, the size of the adenoma is a major determinant of biochemical indices, disease severity, and manner of presentation. However, the large variation in adenoma weight, both within and between populations and a steady decline in parathyroid adenoma weights over time remain largely unexplained. Based on the results in a small number of patients almost two decades ago we proposed that vitamin D nutritional status of the patient explains both the disease manifestations and much of the variation in adenoma size. Accordingly, we examined the relationship between vitamin D nutrition, as assessed by serum levels of 25-hydroxyvitamin D, and parathyroid gland weight, the best available index of disease severity, in a large number of patients (n = 440) with primary hyperparathyroidism. A significant inverse relationship was found between serum 25-hydroxyvitamin D level and log adenoma weight (r = -0.361; p < 0.001). Also, the adenoma weight was significantly related directly to serum PTH, calcium, and alkaline phosphatase as dependent variables. In patients with vitamin D deficiency (defined as serum 25-hydroxyvitamin D levels 15 ng/mL or lower), gland weight, PTH, AP, and adjusted calcium were each significantly higher than in patients with 25-hydroxyvitamin D levels of 16 ng/mL or higher, but serum 1,25-dihydroxyvitamin D levels were similar in both groups. We interpret this to mean that suboptimal vitamin D nutrition stimulates parathyroid adenoma growth by a mechanism unrelated to 1,25-dihydroxyvitamin D deficiency. We conclude that variable vitamin D nutritional status in the population may partly explain the differences in disease presentation.

Toward a noninvasive estimate of interstitial fluid pressure by dynamic contrast-enhanced MRI in a rat model of cerebral tumor.

PURPOSE: This study demonstrates a DCE-MRI estimate of tumor interstitial fluid pressure (TIFP) and hydraulic conductivity in a rat model of glioblastoma, with validation against an invasive wick-in-needle (WIN) technique. An elevated TIFP is considered a mark of aggressiveness, and a decreased TIFP a predictor of response to therapy. METHODS: The DCE-MRI studies were conducted in 36 athymic rats (controls and posttreatment animals) with implanted U251 cerebral tumors, and with TIFP measured using a WIN method. Using a model selection paradigm and a novel application of Patlak and Logan plots to DCE-MRI data, the MRI parameters required for estimating TIFP noninvasively were estimated. Two models, a fluid-mechanical model and a multivariate empirical model, were used for estimating TIFP, as verified against WIN-TIFP. RESULTS: Using DCE-MRI, the mean estimated hydraulic conductivity (MRI-K) in U251 tumors was (2.3 ± 3.1) × 10-5 (mm2 /mmHg-s) in control studies. Significant positive correlations were found between WIN-TIFP and MRI-TIFP in both mechanical and empirical models. For instance, in the control group of the fluid-mechanical model, MRI-TIFP was a strong predictor of WIN-TIFP (R2 = 0.76, p < .0001). A similar result was found in the bevacizumab-treated group of the empirical model (R2 = 0.93, p = .014). CONCLUSION: This research suggests that MRI dynamic studies contain enough information to noninvasively estimate TIFP in this, and possibly other, tumor models, and thus might be used to assess tumor aggressiveness and response to therapy.

Bone Structure and Turnover Status in Postmenopausal Women with Atypical Femur Fracture After Prolonged Bisphosphonate Therapy.

Atypical femur fracture (AFF), a serious complication of long-term bisphosphonate therapy, is usually preceded by an incomplete fracture appearing on the lateral femur. AFF is most likely the result of severely suppressed bone turnover (SSBT). However, the differences in bone structure and turnover between patients with incomplete and complete AFF remain unknown. We examined trans-iliac bone biopsies from 12 white postmenopausal women with AFF (incomplete = 5; complete = 7) on BP therapy of >5 years and 43 healthy white premenopausal women. Histomorphometric measurements were performed separately in cancellous, intracortical and endosteal envelopes. Of the 43 histomorphometric measurements on 3 difference bone surfaces (cancellous, intracortical and endosteal), only 2 bone resorption variables (Oc.S/BS and Oc.S/NOS) on the endosteal surface were significantly lower in patients with complete AFF than those with incomplete AFF. Compared to healthy premenopausal women, the trabecular bone volume, thickness and number were all significantly lower in patients with AFF. The dynamic bone formation variables in patients with AFF were significantly reduced on all bone surfaces. The likelihood of a biopsy with no tetracycline labeling was significantly higher in AFF patients than in healthy premenopausal women. Based on these results, we conclude that there are no significant differences in bone turnover between patients with incomplete and complete AFF, suggesting that the suppression of bone turnover had already existed in the femur with incomplete AFF. Compared to healthy premenopausal women, bone turnover is similarly suppressed in patients with either type of AFF.

The Effect of Time to Castration Resistance on Outcomes With Abiraterone and Enzalutamide in Metastatic Prostate Cancer.

BACKGROUND: Abiraterone and enzalutamide are 2 novel androgen receptor (AR)-targeting therapies that improve survival in patients with metastatic castration-resistant prostate cancer. The factors that predict abiraterone and enzalutamide response are lacking. The objective of the present study was to determine whether the outcomes from primary androgen deprivation therapy (ADT) could predict the outcomes with subsequent novel AR-targeting therapies. MATERIALS AND METHODS: We identified 80 consecutive patients with metastatic castration-resistant prostate cancer treated with abiraterone or enzalutamide. Cox regression models were used to analyze the relationships between the primary ADT response and the primary outcome of progression-free survival (PFS) after initiating novel hormonal therapy. The secondary outcomes included prostate-specific antigen decline and overall survival. The survival probabilities were plotted using the Kaplan-Meier method, and the differences assessed with the log-rank test. RESULTS: The time to castration resistance with primary ADT showed a significant association with both PFS and overall survival after initiating novel hormone therapy (P = .032 and P = .028, respectively). Patients with progression during primary ADT before 1 year had a median PFS of 3.4 months compared with a median PFS of 7.6 and 8.1 months for patients whose time to castration resistance was ≥ 1 and ≤ 5 years (P = .008) and > 5 years (P = .026), respectively. However, the time to castration resistance was not an independent predictor of survival or the PSA response with novel AR-targeting therapy on multivariate analysis. CONCLUSION: A rapid time to progression during primary ADT was associated with poor outcomes but was not an independent predictor of the response to enzalutamide or abiraterone.

Computer-Delivered Screening and Brief Intervention for Alcohol Use in Pregnancy: A Pilot Randomized Trial.

BACKGROUND: Although screening and brief intervention (SBI) for unhealthy alcohol use has demonstrated efficacy in some trials, its implementation has been limited. Technology-delivered approaches are a promising alternative, particularly during pregnancy when the importance of alcohol use is amplified. The present trial evaluated the feasibility and acceptability of an interactive, empathic, video-enhanced, and computer-delivered SBI (e-SBI) plus 3 tailored mailings, and estimated intervention effects. METHODS: We recruited 48 pregnant women who screened positive for alcohol risk at an urban prenatal care clinic. Participants were randomly assigned to the e-SBI plus mailings or to a control session on infant nutrition, and were re-evaluated during their postpartum hospitalization. The primary outcome was 90-day period prevalence abstinence as measured by timeline follow-back interview. RESULTS: Participants rated the intervention as easy to use and helpful (4.7 to 5.0 on a 5-point scale). Blinded follow-up evaluation at childbirth revealed medium-size intervention effects on 90-day period prevalence abstinence (OR = 3.4); similarly, intervention effects on a combined healthy pregnancy outcome variable (live birth, normal birthweight, and no neonatal intensive care unit stay) were also of moderate magnitude in favor of e-SBI participants (OR = 3.3). As expected in this intentionally underpowered pilot trial, these effects were nonsignificant (p = 0.19 and 0.09, respectively). CONCLUSIONS: This pilot trial demonstrated the acceptability and preliminary efficacy of e-SBI plus tailored mailings for alcohol use in pregnancy. These findings mirror the promising results of other trials using a similar approach and should be confirmed in a fully powered trial.

Ceramide synthase inhibitor fumonisin B1 inhibits apoptotic cell death in SCC17B human head and neck squamous carcinoma cells after Pc4 photosensitization.

The sphingolipid ceramide modulates stress-induced cell death and apoptosis. We have shown that ceramide generated via de novo sphingolipid biosynthesis is required to initiate apoptosis after photodynamic therapy (PDT). The objective of this study was to define the role of ceramide synthase (CERS) in PDT-induced cell death and apoptosis using fumonisin B1 (FB), a CERS inhibitor. We used the silicon phthalocyanine Pc4 for PDT, and SCC17B cells, as a clinically-relevant model of human head and neck squamous carcinoma. zVAD-fmk, a pan-caspase inhibitor, as well as FB, protected cells from death after PDT. In contrast, ABT199, an inhibitor of the anti-apoptotic protein Bcl2, enhanced cell killing after PDT. PDT-induced accumulation of ceramide in the endoplasmic reticulum and mitochondria was inhibited by FB. PDT-induced Bax translocation to the mitochondria and cytochrome c release were also inhibited by FB. These novel data suggest that PDT-induced cell death via apoptosis is CERS/ceramide-dependent.

Statin use and risk of hepatocellular carcinoma in a U.S. population.

PURPOSE: Statins (3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors) are medications widely prescribed to reduce cholesterol levels. Observational studies in high-risk populations, mostly in Asia, have suggested that statins are associated with a reduced risk of hepatocellular carcinoma (HCC). The current study sought to evaluate the association of statin use and HCC in a U.S.-based, low-risk, general population. METHODS: A nested case-control study was conducted among members of the Health Alliance Plan HMO of the Henry Ford Health System enrolled between 1999 and 2010. Electronic pharmacy records of statin use were compared among tumor registry-confirmed cases of HCC (n=94) and controls (n=468) matched on age, sex, diagnosis date, and length of HMO enrolment. RESULTS: In multivariate analyses, ever-use of statins was significantly inversely associated with development of HCC (Odds ratio (OR): 0.32, 95%CI: 0.15-0.67). No clear dose-response relationship was evident as statin use for <2 years (OR=0.32, 95%CI=0.13-0.83) and >2 years (OR=0.31, 95CI%=0.12-9.81) resulted in very similar ORs. CONCLUSIONS: The use of statins among populations in low-risk HCC areas may be associated with decreased risk of HCC.

Accurate gene expression-based biodosimetry using a minimal set of human gene transcripts.

PURPOSE: Rapid and reliable methods for conducting biological dosimetry are a necessity in the event of a large-scale nuclear event. Conventional biodosimetry methods lack the speed, portability, ease of use, and low cost required for triaging numerous victims. Here we address this need by showing that polymerase chain reaction (PCR) on a small number of gene transcripts can provide accurate and rapid dosimetry. The low cost and relative ease of PCR compared with existing dosimetry methods suggest that this approach may be useful in mass-casualty triage situations. METHODS AND MATERIALS: Human peripheral blood from 60 adult donors was acutely exposed to cobalt-60 gamma rays at doses of 0 (control) to 10 Gy. mRNA expression levels of 121 selected genes were obtained 0.5, 1, and 2 days after exposure by reverse-transcriptase real-time PCR. Optimal dosimetry at each time point was obtained by stepwise regression of dose received against individual gene transcript expression levels. RESULTS: Only 3 to 4 different gene transcripts, ASTN2, CDKN1A, GDF15, and ATM, are needed to explain ≥ 0.87 of the variance (R(2)). Receiver-operator characteristics, a measure of sensitivity and specificity, of 0.98 for these statistical models were achieved at each time point. CONCLUSIONS: The actual and predicted radiation doses agree very closely up to 6 Gy. Dosimetry at 8 and 10 Gy shows some effect of saturation, thereby slightly diminishing the ability to quantify higher exposures. Analyses of these gene transcripts may be advantageous for use in a field-portable device designed to assess exposures in mass casualty situations or in clinical radiation emergencies.

Gene expression-based dosimetry by dose and time in mice following acute radiation exposure.

Rapid and reliable methods for performing biological dosimetry are of paramount importance in the event of a large-scale nuclear event. Traditional dosimetry approaches lack the requisite rapid assessment capability, ease of use, portability and low cost, which are factors needed for triaging a large number of victims. Here we describe the results of experiments in which mice were acutely exposed to (60)Co gamma rays at doses of 0 (control) to 10 Gy. Blood was obtained from irradiated mice 0.5, 1, 2, 3, 5, and 7 days after exposure. mRNA expression levels of 106 selected genes were obtained by reverse-transcription real time PCR. Stepwise regression of dose received against individual gene transcript expression levels provided optimal dosimetry at each time point. The results indicate that only 4-7 different gene transcripts are needed to explain ≥ 0.69 of the variance (R(2)), and that receiver-operator characteristics, a measure of sensitivity and specificity, of ≥ 0.93 for these statistical models were achieved at each time point. These models provide an excellent description of the relationship between the actual and predicted doses up to 6 Gy. At doses of 8 and 10 Gy there appears to be saturation of the radiation-response signals with a corresponding diminution of accuracy. These results suggest that similar analyses in humans may be advantageous for use in a field-portable device designed to assess exposures in mass casualty situations.

Averaged differential expression for the discovery of biomarkers in the blood of patients with prostate cancer.

BACKGROUND: The identification of a blood-based diagnostic marker is a goal in many areas of medicine, including the early diagnosis of prostate cancer. We describe the use of averaged differential display as an efficient mechanism for biomarker discovery in whole blood RNA. The process of averaging reduces the problem of clinical heterogeneity while simultaneously minimizing sample handling. METHODOLOGY/PRINCIPAL FINDINGS: RNA was isolated from the blood of prostate cancer patients and healthy controls. Samples were pooled and subjected to the averaged differential display process. Transcripts present at different levels between patients and controls were purified and sequenced for identification. Transcript levels in the blood of prostate cancer patients and controls were verified by quantitative RT-PCR. Means were compared using a t-test and a receiver-operating curve was generated. The Ring finger protein 19A (RNF19A) transcript was identified as having higher levels in prostate cancer patients compared to healthy men through the averaged differential display process. Quantitative RT-PCR analysis confirmed a more than 2-fold higher level of RNF19A mRNA levels in the blood of patients with prostate cancer than in healthy controls (p = 0.0066). The accuracy of distinguishing cancer patients from healthy men using RNF19A mRNA levels in blood as determined by the area under the receiving operator curve was 0.727. CONCLUSIONS/SIGNIFICANCE: Averaged differential display offers a simplified approach for the comprehensive screening of body fluids, such as blood, to identify biomarkers in patients with prostate cancer. Furthermore, this proof-of-concept study warrants further analysis of RNF19A as a clinically relevant biomarker for prostate cancer detection.

Gene expression-based detection of radiation exposure in mice after treatment with granulocyte colony-stimulating factor and lipopolysaccharide.

In a large-scale nuclear incident, many thousands of people may be exposed to a wide range of radiation doses. Rapid biological dosimetry will be required on an individualized basis to estimate the exposures and to make treatment decisions. To ameliorate the adverse effects of exposure, victims may be treated with one or more cytokine growth factors, including granulocyte colony-stimulating factor (G-CSF), which has therapeutic efficacy for treating radiation-induced bone marrow ablation by stimulating granulopoiesis. The existence of infections and the administration of G-CSF each may confound the ability to achieve reliable dosimetry by gene expression analysis. In this study, C57BL/6 mice were used to determine the extent to which G-CSF and lipopolysaccharide (LPS, which simulates infection by gram-negative bacteria) alter the expression of genes that are either radiation-responsive or non-responsive, i.e., show potential for use as endogenous controls. Mice were acutely exposed to (60)Co γ rays at either 0 Gy or 6 Gy. Two hours later the animals were injected with either 0.1 mg/kg of G-CSF or 0.3 mg/kg of LPS. Expression levels of 96 different gene targets were evaluated in peripheral blood after an additional 4 or 24 h using real-time quantitative PCR. The results indicate that the expression levels of some genes are altered by LPS, but altered expression after G-CSF treatment was generally not observed. The expression levels of many genes therefore retain utility for biological dosimetry or as endogenous controls. These data suggest that PCR-based quantitative gene expression analyses may have utility in radiation biodosimetry in humans even in the presence of an infection or after treatment with G-CSF.

Prevention of Prostate Cancer with Oleanane Synthetic Triterpenoid CDDO-Me in the TRAMP Mouse Model of Prostate Cancer.

2-Cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO), a synthetic analog of oleanolic acid, and its C28 methyl ester derivative (CDDO-Me), have shown potent antitumorigenic activity against a wide range of cancer cell lines, including prostate cancer cells in vitro, and inhibited the development of liver and lung cancer in vivo. In the present study, we examined the efficacy of CDDO-Me in preventing the development and progression of prostate cancer in the transgenic adenocarinoma of the mouse prostate (TRAMP) model. CDDO-Me inhibited the growth of murine TRAMPC-1 prostate cancer cells by inducing apoptosis through the inhibition of antiapoptotic p-Akt, p-mTOR and NF-κB. Early intervention with CDDO-Me (7.5 mg/kg) initiated at five weeks of age for 20 wk inhibited the progression of the preneoplastic lesions (low-grade PIN and high-grade-PIN) to adenocarcinoma in the dorsolateral prostate (DLP) and ventral prostate (VP) lobes of TRAMP mice. Even delayed administration of CDDO-Me started at 12 wk of age for 12 wk inhibited the development of adenocarcimona of the prostate. Both early and late treatment with CDDO-Me inhibited the metastasis of tumor to the distant organs. Treatment with CDDO-Me inhibited the expression of prosurvival p-Akt and NF-κB in the prostate and knocking-down Akt in TRAMPC-1 tumor cells sensitized them to CDDO-Me. These findings indicated that Akt is a target for apoptoxicity in TRAMPC-1 cells in vitro and potentially a target of CDDO-Me for inhibition of prostate cancer in vivo.

In vivo shoulder function after surgical repair of a torn rotator cuff: glenohumeral joint mechanics, shoulder strength, clinical outcomes, and their interaction.

BACKGROUND: Surgical repair of a torn rotator cuff is based on the belief that repairing the tear is necessary to restore normal glenohumeral joint (GHJ) mechanics and achieve a satisfactory clinical outcome. HYPOTHESIS: Dynamic joint function is not completely restored by rotator cuff repair, thus compromising shoulder function and potentially leading to long-term disability. STUDY DESIGN: Controlled laboratory study and Case series; Level of evidence, 4. METHODS: Twenty-one rotator cuff patients and 35 control participants enrolled in the study. Biplane radiographic images were acquired bilaterally from each patient during coronal-plane abduction. Rotator cuff patients were tested at 3, 12, and 24 months after repair of a supraspinatus tendon tear. Control participants were tested once. Glenohumeral joint kinematics and joint contact patterns were accurately determined from the biplane radiographic images. Isometric shoulder strength and patient-reported outcomes were measured at each time point. Ultrasound imaging assessed rotator cuff integrity at 24 months after surgery. RESULTS: Twenty of 21 rotator cuff repairs appeared intact at 24 months after surgery. The humerus of the patients' repaired shoulder was positioned more superiorly on the glenoid than both the patients' contralateral shoulder and the dominant shoulder of control participants. Patient-reported outcomes improved significantly over time. Shoulder strength also increased over time, although strength deficits persisted at 24 months for most patients. Changes over time in GHJ mechanics were not detected for either the rotator cuff patients' repaired or contralateral shoulders. Clinical outcome was associated with shoulder strength but not GHJ mechanics. CONCLUSION: Surgical repair of an isolated supraspinatus tear may be sufficient to keep the torn rotator cuff intact and achieve satisfactory patient-reported outcomes, but GHJ mechanics and shoulder strength are not fully restored with current repair techniques. CLINICAL RELEVANCE: The study suggests that current surgical repair techniques may be effective for reducing pain but have not yet been optimized for restoring long-term shoulder function.

Developing point of care and high-throughput biological assays for determining absorbed radiation dose.

BACKGROUND AND PURPOSE: Systems are being developed to assess radiation exposure based on leukocyte mRNA levels obtained by finger-stick sampling. The goal is to provide accurate detection of dose exposures up to 10 Gy for up to 1 week following exposure. We previously showed that specific mRNA sequences increase expression within an hour of exposure, and some genes continue to show elevated expression for at least 24 h. Full duration and dose-dependence of this persistence remain to be determined. In the present study, real-time quantitative PCR (qPCR) was used to determine changes in gene expression. qPCR can rapidly analyze small blood samples and could be adopted into a field-portable instrument that provides a radiation dose readout within 30 min. MATERIALS AND METHODS: From previous microarray analysis of 21,000 genes expressed in human lymphoblastoid cells 4 h post-irradiation (0-4 Gy), 118 genes were selected for evaluation by qPCR of gene expression in the leukocytes of human blood irradiated in vitro with doses of 0-10 Gy from a Co-60 gamma source at a dose rate of 30 cGy/min. RESULTS: Blood from 20 normal healthy human donors yielded many mRNA sequences that could be used for radiation dosimetry. We observed four genes with large and persistent responses following exposure: ASTN2, CDKN1A, GADD45A, and GDF15. Five genes were identified as reliably non-responsive and were suitable for use as endogenous controls: DPM1, ITFG1, MAP4, PGK1, and SLC25A36; of these, ITFG1 was used for the analyses presented here. A significant dose-responsive increase in expression occurred for CDKN1A that was >16-fold at 10 Gy and 3-fold at 0.5 Gy compared to pre-irradiation values. CONCLUSIONS: These data show large, selective increases in mRNA transcript levels that persist for at least 48 h after single exposures between 0.5 and 10 Gy. Stable, non-responsive mRNA sequences for use as endogenous controls were also identified. These results indicate that following further study to establish the most reproducible gene and dose-response models under a wide range of conditions in vivo, rapid real-time qPCR on blood samples could potentially be used to establish biologically-effective dosimetry from either accidental irradiation or clinical radiotherapy.

Synthetic triterpenoid CDDO prevents the progression and metastasis of prostate cancer in TRAMP mice by inhibiting survival signaling.

In an extension of our previous studies showing potent antitumorigenic activity of synthetic triterpenoids of oleanolic acid against prostate cancer cell lines, we examined the efficacy of 2-cyano-3,12-dioxooleana-1,9(11)-dien-28-oic acid (CDDO) in preventing the development and/or progression of prostate cancer in the transgenic adenocarcinoma of the mouse prostate (TRAMP) model. Data show that oral gavage with CDDO (10 µmol/kg) for 20 weeks resulted in inhibition of the progression of preneoplastic lesions in the dorsolateral prostate and ventral prostate to adenocarcinoma without toxicity. CDDO also inhibited metastasis of tumor to the distant organs. Treatment with CDDO significantly inhibited cell proliferation, reduced the density of blood vessels and promoted apoptosis in the prostatic tissue. Further, Akt, NF-κB and NF-κB regulated Bcl-2, Bcl-xL, survivin and cIAP1 appear to be the molecular targets of CDDO for inhibiting the progression of prostate cancer in TRAMP mice. Thus, these studies show for the first time the potential of CDDO for chemoprevention of human prostate cancer.

Recruitment to a randomized web-based nutritional intervention trial: characteristics of participants compared to non-participants.

BACKGROUND: Web-based behavioral programs efficiently disseminate health information to a broad population, and online tailoring may increase their effectiveness. While the number of Internet-based behavioral interventions has grown in the last several years, additional information is needed to understand the characteristics of subjects who enroll in these interventions, relative to those subjects who are invited to enroll. OBJECTIVE: The aim of the study was to compare the characteristics of participants who enrolled in an online dietary intervention trial (MENU) with those who were invited but chose not to participate, in order to better understand how these groups differ. METHODS: The MENU trial was conducted among five health plans participating in the HMO Cancer Research Network in collaboration with the University of Michigan Center for Health Communication Research. Approximately 6000 health plan members per site, between the ages of 21 and 65, and stratified by gender with oversampling of minority populations, were randomly selected for recruitment and were mailed an invitation letter containing website information and a US$2 bill with the promise of US$20 for completing follow-up surveys. Administrative and area-based data using geocoding along with baseline survey data were used to compare invitees (HMO members sent the introductory letter), responders (those who entered a study ID on the website), and enrollees (those who completed the enrollment process). Generalized estimating equation multivariate and logistic regression models were used to assess predictors of response and enrollment. RESULTS: Of 28,460 members invited to participate, 4270 (15.0%) accessed the website. Of the eligible responders, 2540 (8.9%) completed the consent form and baseline survey and were enrolled and randomized. The odds of responding were 10% lower for every decade of increased age (P < .001), while the likelihood of enrolling was 10% higher for every decade increase in age (P < .001). Women were more likely to respond and to enroll (P < .001). Those living in a census tract associated with higher education levels were more likely to respond and enroll, as well as those residing in tracts with higher income (P < .001). With a 22% (n = 566) enrollment rate for African Americans and 8% (n = 192) for Hispanics, the enrolled sample was more racially and ethnically diverse than the background sampling frame. CONCLUSIONS: Relative to members invited to participate in the Internet-based intervention, those who enrolled were more likely to be older and live in census tracts associated with higher socioeconomic status. While oversampling of minority health plan members generated an enrolled sample that was more racially and ethnically diverse than the overall health plan population, additional research is needed to better understand methods that will expand the penetration of Internet interventions into more socioeconomically diverse populations. TRIAL REGISTRATION: Clinicaltrials.gov NCT00169312; http://clinicaltrials.gov/ct2/show/NCT00169312 (Archived by WebCite at http://www.webcitation.org/5jB50xSfU).

Identification of prostate cancer mRNA markers by averaged differential expression and their detection in biopsies, blood, and urine.

The advent of serum prostate-specific antigen (PSA) as a biomarker has enabled early detection of prostate cancer and, hence, improved clinical outcome. However, a low PSA is not a guarantee of disease-free status, and an elevated PSA is frequently associated with a negative biopsy. Therefore, our goal is to identify molecular markers that can detect prostate cancer with greater specificity in body fluids such as urine or blood. We used the RT-PCR differential display method to first identify mRNA transcripts differentially expressed in tumor vs. patient-matched nontumor prostate tissue. This analysis led to the identification of 44 mRNA transcripts that were expressed differentially in some but not all tumor specimens examined. To identify mRNA transcripts that are differentially expressed in most tumor specimens, we turned to differential display of pooled tissue samples, a technique we name averaged differential expression (ADE). We performed differential display of mRNA from patient-matched nontumor vs. tumor tissue, each pooled from 10 patients with various Gleason scores. Differentially expressed mRNA transcripts identified by ADE were fewer in number, but were expressed in a greater percentage of tumors (>75%) than those identified by differential display of mRNA from individual patient samples. Differential expression of these mRNA transcripts was also detected by RT-PCR in mRNA isolated from urine and blood samples of prostate cancer patients. Our findings demonstrate the principle that specific cDNA probes of frequently differentially expressed mRNA transcripts identified by ADE can be used for the detection of prostate cancer in urine and blood samples.