Preclinical evaluation of (111)In-DTPA-INCA-X anti-Ku70/Ku80 monoclonal antibody in prostate cancer.

The aim of this investigation was to assess the Ku70/Ku80 complex as a potential target for antibody imaging of prostate cancer. We evaluated the in vivo and ex vivo tumor targeting and biodistribution of the (111)In-labeled human internalizing antibody, INCA-X ((111)In-DTPA-INCA-X antibody), in NMRI-nude mice bearing human PC-3, PC-3M-Lu2 or DU145 xenografts. DTPA-conjugated, non-labeled antibody was pre-administered at different time-points followed by a single intravenous injection of (111)In-DTPA-INCA-X. At 48, 72 and 96 h post-injection, tissues were harvested, and the antibody distribution was determined by measuring radioactivity. Preclinical SPECT/CT imaging of mice with and without the predose was performed at 48 hours post-injection of labeled DTPA-INCA-X. Biodistribution of the labeled antibody showed enriched activity in tumor, spleen and liver. Animals pre-administered with DTPA-INCA-X showed increased tumor uptake and blood content of (111)In-DTPA-INCA-X with reduced splenic and liver uptake. The in vitro and in vivo data presented show that the (111)In-labeled INCA-X antibody is internalized into prostate cancer cells and by pre-administering non-labeled DTPA-INCA-X, we were able to significantly reduce the off target binding and increase the (111)In-DTPA-INCA-X mAb uptake in PC-3, PC-3M-Lu2 and DU145 xenografts. The results are encouraging and identifying the Ku70/Ku80 antigen as a target is worth further investigation for functional imaging of prostate cancer

Unanswered questions in prostate cancer : Findings of an international multi-stakeholder consensus by the PIONEER Consortium

Acknowledgements PIONEER is funded through the IMI2 Joint Undertaking and is listed under grant agreement No. 777492. This joint under- taking receives support from the European Union’s Horizon 2020 research and innovation programme and EFPIA.Peer reviewedPostprin

How Well do Polygenic Risk Scores Identify Men at High Risk for Prostate Cancer? : Systematic Review and Meta-Analysis

OBJECTIVES: Genome-wide association studies have revealed over 200 genetic susceptibility loci for prostate cancer (PCa). By combining them, polygenic risk scores (PRS) can be generated to predict risk of PCa. We summarize the published evidence and conduct meta-analyses of PRS as a predictor of PCa risk in Caucasian men. PATIENTS AND METHODS: Data were extracted from 59 studies, with 16 studies including 17 separate analyses used in the main meta-analysis with a total of 20,786 cases and 69,106 controls identified through a systematic search of ten databases. Random effects meta-analysis was used to obtain pooled estimates of area under the receiver-operating characteristic curve (AUC). Meta-regression was used to assess the impact of number of single-nucleotide polymorphisms (SNPs) incorporated in PRS on AUC. Heterogeneity is expressed as I2 scores. Publication bias was evaluated using funnel plots and Egger tests. RESULTS: The ability of PRS to identify men with PCa was modest (pooled AUC 0.63, 95% CI 0.62-0.64) with moderate consistency (I2 64%). Combining PRS with clinical variables increased the pooled AUC to 0.74 (0.68-0.81). Meta-regression showed only negligible increase in AUC for adding incremental SNPs. Despite moderate heterogeneity, publication bias was not evident. CONCLUSION: Typically, PRS accuracy is comparable to PSA or family history with a pooled AUC value 0.63 indicating mediocre performance for PRS alone.publishedVersionPeer reviewe

Clinical Characterization of Patients Diagnosed with Prostate Cancer and Undergoing Conservative Management:A PIONEER Analysis Based on Big Data

Background: Conservative management is an option for prostate cancer (PCa) patients either with the objective of delaying or even avoiding curative therapy, or to wait until palliative treatment is needed. PIONEER, funded by the European Commission Innovative Medicines Initiative, aims at improving PCa care across Europe through the application of big data analytics. Objective: To describe the clinical characteristics and long-term outcomes of PCa patients on conservative management by using an international large network of real-world data. Design, setting, and participants: From an initial cohort of &gt;100 000 000 adult individuals included in eight databases evaluated during a virtual study-a-thon hosted by PIONEER, we identified newly diagnosed PCa cases (n = 527 311). Among those, we selected patients who did not receive curative or palliative treatment within 6 mo from diagnosis (n = 123 146). Outcome measurements and statistical analysis: Patient and disease characteristics were reported. The number of patients who experienced the main study outcomes was quantified for each stratum and the overall cohort. Kaplan-Meier analyses were used to estimate the distribution of time to event data. Results and limitations: The most common comorbidities were hypertension (35–73%), obesity (9.2–54%), and type 2 diabetes (11–28%). The rate of PCa-related symptomatic progression ranged between 2.6% and 6.2%. Hospitalization (12–25%) and emergency department visits (10–14%) were common events during the 1st year of follow-up. The probability of being free from both palliative and curative treatments decreased during follow-up. Limitations include a lack of information on patients and disease characteristics and on treatment intent. Conclusions: Our results allow us to better understand the current landscape of patients with PCa managed with conservative treatment. PIONEER offers a unique opportunity to characterize the baseline features and outcomes of PCa patients managed conservatively using real-world data. Patient summary: Up to 25% of men with prostate cancer (PCa) managed conservatively experienced hospitalization and emergency department visits within the 1st year after diagnosis; 6% experienced PCa-related symptoms. The probability of receiving therapies for PCa decreased according to time elapsed after the diagnosis.</p

Novel genetic loci underlying human intracranial volume identified through genome-wide association

Intracranial volume reflects the maximally attained brain size during development, and remains stable with loss of tissue in late life. It is highly heritable, but the underlying genes remain largely undetermined. In a genome-wide association study of 32,438 adults, we discovered five novel loci for intracranial volume and confirmed two known signals. Four of the loci are also associated with adult human stature, but these remained associated with intracranial volume after adjusting for height. We found a high genetic correlation with child head circumference (ρgenetic=0.748), which indicated a similar genetic background and allowed for the identification of four additional loci through meta-analysis (Ncombined = 37,345). Variants for intracranial volume were also related to childhood and adult cognitive function, Parkinson’s disease, and enriched near genes involved in growth pathways including PI3K–AKT signaling. These findings identify biological underpinnings of intracranial volume and provide genetic support for theories on brain reserve and brain overgrowth

Preclinical imaging of prostate cancer using radiolabeled antibodies

Target-specific molecular imaging with radiolabeled antibodies has experienced a rapid growth over the past 20 years, and is now an essential tool to provide information on disease presence and extent. Despite all efforts to detect and control prostate cancer at an early stage, a number of men are still progressing to develop incurable metastatic disease. Because of this, development of new methods based on target-specific imaging is becoming increasingly important in the assessment and management of prostate cancer. The main purpose of this work was to investigate three target antigens: Ku70/Ku80, free prostate specific antigen (fPSA) and ICAM-1, as potential candidates for imaging of prostate cancer using radiolabeled antibodies. The studies were designed to assess the in vivo and ex vivo tumor targeting potential using animal models of prostate cancer. Preclinical SPECT/CT and PET/CT in vivo imaging modalities, ex vivo multi-radionuclide digital autoradiography, ex vivo activity measurements and immunohistochemistry were used to obtain biokinetics and specific activity uptake. In these studies, we found that radiolabeled INCA-X mAb could efficiently target the Ku70/Ku80 antigen in prostate cancer xenografts in mice that first receive a predose of non-labeled antibody. We also demonstrate that two antibodies specific for fPSA (PSA30 and 5A10) can efficiently target PSA positive prostate cancer xenografts. In that study, we also show that the animal models immune deficiency status can affect the antibody performance. Lastly, we show that 111In-R6.5 mAb outperformed the 177Lu-R6.5 or control IgG mAb and can be used as a complement to clinically used metabolic and proliferative probes. Our ex vivo and in vivo investigations presented in this dissertation should act as support for further studies of the Ku70/Ku80, fPSA and ICAM-1 antigens. Future studies should include therapeutic applications based on dosimetry calculation to evaluate possible therapeutic efficacy

An attenuation method for reducing count rate losses in preclinical PET during intratherapeutic imaging

In pre-clinical imaging, tumor response to radionuclide therapy can be monitored with PET imaging. Radionuclides used for therapy such as 177Lu emit a significant amount of low energy photons. These photons may have an energy high enough to penetrate the imaged object and are the prone to be detected. Although these phtons are likely to be rejected electronically, they add dead-time to the system since they need to be processed by the electronics. This is a problem in high-sensitivity pre-clinical PET system with a low number of readout channels, such as the Genisys G8 investigated in this work. The low energy gammas may also affect image quality due to increased probability of pulse pile-up. The use of high-attenuating shields designed to absorb most of the low energy photons emitted from the therapeutic radionuclide were investigated. Cylindrical led shields were constructed with thicknesses between 1 and 3 mm. A 3mm thick cylindrical shield was also constructed out of Rose metal (50% Bi, 28% Pb, and 22% Sn). The diameter of the shield was wide enough to accommodate a NEMA IQ phantom and a mouse. The attenuation of the shields for annihilation radiation was measured with a 22Na point source placed at the center of the FOV. Measurements of the coincidence rate were performed with the lead shields in place. At a of thicknesses of 1 and 3mm, the coincidence rate was reduced by a factor or 0.70 and 0.40, respectively. To study the effect of the presence of a background of low energy gammas on the coincidence count rate and the efficacy of the lead shields, 177Lu was added to a 1 cm diameter hollow sphere. In the presence of 100 MBq of 177Lu, the coincidence count rate was reduced by a factor 0.20 due to the detector dead-time. Although the count rate was reduced by a factor of 0.40 with the 3mm shield around the source, the dead-time effects due to the 177Lu background were less than 7%. 18F imaging of a NEMA phantom and a tumor bearing mouse showed dramatic image distortions in the presence of the 177Lu background. When imaging of with the 3mm shield in place, the image distortions were eliminated and were comparable in to the images acquired without the background activity

Preserving Preclinical PET Quality During Intratherapeutic Imaging in Radionuclide Therapy with Rose Metal Shielding Reducing Photon Flux

Performing PET imaging during ongoing radionuclide therapy can be a promising method to follow tumor response in vivo. However, the high therapeutic activity can interfere with the PET camera performance and degrade both image quality and quantitative capabilities. As a solution, low-energy photon emissions from the therapeutic radionuclide can be highly attenuated, still allowing sufficient detection of annihilation photons in coincidence. Methods: Hollow Rose metal cylinders with walls 2-4 mm thick were used to shield a 22Na point source and a uniform phantom filled with 18F as they were imaged on a preclinical PET camera with increasing activities of 177Lu. A mouse with a subcutaneous tumor was injected with 18F-FDG and imaged with an additional 120 MBq of 177Lu and repeated with shields surrounding the animal. Results: The addition of 177Lu to the volume imaged continuously degraded the image quality with increasing activity. The image quality was improved when shielding was introduced. The shields showed a high ability to produce stable and reproducible results for both spatial resolution and quantification of up to 120 MBq of 177Lu activity (maximum activity tested). Conclusion: Without shielding, the activity quantification will be inaccurate for time points at which therapeutic activities are high. The suggested method shows that the shields reduce the noise induced by the 177Lu and therefore enable longitudinal quantitative intratherapeutic imaging studies

The effect of a novel botanical agent TBS-101 on invasive prostate cancer in animal models.

BACKGROUND: Traditional Botanical Supplement-101 (TBS-101) is a newly developed proprietary botanical agent containing seven standardized botanical extracts, including: Panax ginseng, cranberry, green tea, grape skin, grape seed, Ganoderma lucidum and chamomile. Each of the components has been consumed either in the regular diet or as natural supplement. When used as a single agent, each of these seven botanicals has been implicated in chemoprevention and therapy in various types of cancer. The anticancer effect of TBS-101, with the specific combination of these anti-cancer botanicals for the treatment of prostate cancer (PCa), has not been tested. MATERIALS AND METHODS: The IC(50) and the effect of TBS-101 on the proliferation and apoptosis of PC-3 cells were determined. Tumor xenograft mice were generated by subcutaneously implanting PC-3 cells into mice and tumors were allowed to grow to different sizes before starting the treatment. The effects of TBS-101 on tumor growth were assessed by measuring tumor size and by histological, pathological and immunohistochemical analyses. A basic toxicity study was performed to test the tolerance of the mice to high doses of TBS-101. RESULTS: Treatment of the PC-3 cells with TBS-101 resulted in a dose-dependent inhibition of cell growth, with an IC(50) of 1.4 microg/ml. A concomitant induction of apoptosis in PC-3 cells treated with TBS-101 was also observed. Upon the treatment with TBS-101, all three groups of mice bearing moderate or large tumors showed significant inhibition of tumor growth and invasion. In contrast, control mice treated with vehicle alone had significant tumor growth and lymph node metastasis. In the basic toxicity studies, high doses of TBS-101 exerted no toxicity in healthy or tumor-bearing mice. CONCLUSION: The natural botanical agent TBS-101 has a good safety profile and significant anticancer activities in hormone-refractory PC-3 cells and large aggressive PC-3 tumors in a xenograft mouse model and has great potential for the treatment of aggressive prostate cancer