MR Molecular Imaging of Prostate Cancer with a Small Molecular CLT1 Peptide Targeted Contrast Agent

Tumor extracellular matrix has abundance of cancer related proteins that can be used as biomarkers for cancer molecular imaging. In this work, we demonstrated effective MR cancer molecular imaging with a small molecular peptide targeted Gd-DOTA monoamide complex as a targeted MRI contrast agent specific to clotted plasma proteins in tumor stroma. We performed the experiment of evaluating the effectiveness of the agent for non-invasive detection of prostate tumor with MRI in a mouse orthotopic PC-3 prostate cancer model. The targeted contrast agent was effective to produce significant tumor contrast enhancement at a low dose of 0.03 mmol Gd/kg. The peptide targeted MRI contrast agent is promising for MR molecular imaging of prostate tumor.     

Targeted Drug Delivery Systems Mediated by a Novel Peptide in Breast Cancer Therapy and Imaging

Targeted delivery of drugs to tumors represents a significant advance in cancer diagnosis and therapy. Therefore, development of novel tumor-specific ligands or pharmaceutical nanocarriers is highly desirable. In this study, we utilized phage display to identify a new targeting peptide, SP90, which specifically binds to breast cancer cells, and recognizes tumor tissues from breast cancer patients. We used confocal and electron microscopy to reveal that conjugation of SP90 with liposomes enables efficient delivery of drugs into cancer cells through endocytosis. Furthermore, in vivo fluorescent imaging demonstrated that SP90-conjugated quantum dots possess tumor-targeting properties. In tumor xenograft and orthotopic models, SP90-conjugated liposomal doxorubicin was found to improve the therapeutic index of the chemotherapeutic drug by selectively increasing its accumulation in tumors. We conclude that the targeting peptide SP90 has significant potential in improving the clinical benefits of chemotherapy in the treatment and the diagnosis of breast cancer.     

In vivo Macrophage Imaging Using MR Targeted Contrast Agent for Longitudinal Evaluation of Septic Arthritis

Macrophages are key-cells in the initiation, the development and the regulation of the inflammatory response to bacterial infection. Macrophages are intensively and increasingly recruited in septic joints from the early phases of infection and the infiltration is supposed to regress once efficient removal of the pathogens is obtained. The ability to identify in vivo macrophage activity in an infected joint can therefore provide two main applications: early detection of acute synovitis and monitoring of therapy.In vivo noninvasive detection of macrophages can be performed with magnetic resonance imaging using iron nanoparticles such as ultrasmall superparamagnetic iron oxide (USPIO). After intravascular or intraarticular administration, USPIO are specifically phagocytized by activated macrophages, and, due to their magnetic properties, induce signal changes in tissues presenting macrophage infiltration. A quantitative evaluation of the infiltrate is feasible, as the area with signal loss (number of dark pixels) observed on gradient echo MR images after particles injection is correlated with the amount of iron within the tissue and therefore reflects the number of USPIO-loaded cells.We present here a protocol to perform macrophage imaging using USPIO-enhanced MR imaging in an animal model of septic arthritis, allowing an initial and longitudinal in vivo noninvasive evaluation of macrophages infiltration and an assessment of therapy action.     

Ultrasound Molecular Imaging with Targeted Microbubbles for Cancer Diagnostics: From Bench to Bedside

Background

Ultrasound plays an important role in cancer diagnosis. B-mode imaging and contrast-enhanced ultrasound are routinely used to detect cancerous lesions in breast and liver. The use of ultrasound contrast agents (UCAs) such as microbubbles (MBs), which can be functionalized with targeting ligands, has further enabled ultrasound molecular imaging (USMI) of specific molecular markers in pre-clinical and the first clinical studies. As targeted MBs have a diameter of 1–4 μm, they are limited to the blood vasculature upon intravenous injection, and can bind to markers of the vascular endothelium. USMI with targeted MBs was applied for imaging of markers of inflammation, angiogenesis, and the tumor endothelium.

Evaluation of Multiparametric Magnetic Resonance Imaging in Detection and Prediction of Prostate Cancer

Background

Although European Society of Urogenital Radiology proposed the potential of multiparametric magnetic resonance imaging (MP-MRI) as a tool in the diagnostic pathway for prostate cancer (PCa) and published a unified scoring system named Prostate Imaging Reporting and Data System (PI-RADS version 1), these still need to be validated by real-life studies.

Objective

To evaluate the role of MP-MRI in detection and prediction of PCa.

Methods

Patients with clinical suspicion of PCa who underwent prebiopsy MP-MRI from 2002 to 2009 were recruited. MP-MRI results were retrospectively assigned as overall scores using PI-RADS by two radiologists. Patients were followed and the end point was the diagnosis of PCa. Receiver operating characteristics (ROC) curve was performed to test diagnostic efficacy of MP-MRI, under results of biopsy within three months. The cox proportional hazards model was used to identify independent variables for the detection of PCa.

Results

Finally, 1113 of the 1806 enrolled patients were included for analysis. The median follow-up was 56.0 months (1–137 mo). For 582 patients biopsied within three months, area under the curve for the detection of PCa with MP-MRI was 0.88 (95% confidence interval [CI], 0.75–1.00) in group of baseline prostate specific antigen (PSA) 0.01–4.00 ng/ml (n = 31), 0.90 (95% CI, 0.84–0.95) in PSA 4.01–10.00 ng/ml (n = 142), and 0.91 (95% CI, 0.87–0.94) in PSA >10.00 ng/ml (n = 409), respectively. In the cox model adjusted for age and baseline PSA level, for the detection rate of PCa, compared with PI-RADS 1–2 (reference), the hazard ratio was 6.43 (95% CI, 4.29–9.65) for PI-RADS 3, 18.58 (95% CI, 13.36–25.84) for PI-RADS 4–5 (p < 0.001).

Conclusions

Prebiopsy MP-MRI with PI-RADS is demonstrated as a valuable diagnostic and predictive tool for PCa.     

Synthesis and Biological Evaluation of a Carbocyclic Azanoraristeromycin Siderophore Conjugate

Abstract

Synthesis and biological evaluation of a carbocyclic azanoraristeromycin siderophore conjugate 22 is reported. Coupling of previously prepared L-alanyl-4′-azanoraristeromycin 19 with protected tripeptide trihydroxamate 20, followed by hydrogenolytic removal of all protecting groups, provided the first carbocylic azanoraristeromycin siderophore conjugate (22, 8 with iron). Compounds 19 and 22 showed inhibitory activity against tumor cells, and conjugate 22, in particular, displayed significant activity against those viruses (i.e. reo, parainfluenza, vaccinia, cytomegalo) that are known to be inhibited by S-adenosylhomocysteine hydrolase inhibitors.     

新型小分子酪氨酸激酶抑制剂NXGH/NXGF对不同肺癌细胞的敏感性研究

目的:研究新型小分子酪氨酸激酶抑制剂NXGH和NXGF对不同EGFR表达水平及突变状态肺癌细胞的敏感性,为构建EGFR分子分型成像探针提供参考依据。方法:构建基于NXG结构的新型小分子酪氨酸激酶抑制剂NXGH和NXGF,选择4种不同EGFR表达水平及突变状态肺癌细胞:PC9(EGFR 19外显子缺失突变)、H1975(EGFR L858R突变合并T790M二次突变)、H358(EGFR野生型表达)及H520(EGFR阴性表达),应用MTT方法分析梯度浓度NXGH及NXGF 48 h时间点对4种肺癌细胞的抑制作用,分别计算IC_(50)及细胞存活率,比较NXGH及NXGF对不同肺癌细胞的敏感性。结果:NXGH作用下,PC9、H358、H520、H1975肺癌细胞IC_(50)分别是0.675μmo L·L~(-1)、12.097μmo L·L~(-1)、11.368μmo L·L~(-1)和0.981μmo L·L~(-1),NXGH浓度为1.25、2.5和5μmo L·L~(-1)时,PC9和H1975细胞的IC_(50)低于H358和H520(P0.05)。NXGF作用下,PC9、H358、H520、H1975肿瘤细胞IC_(50)分别是0.685μmo L·L~(-1)、4.265μmo L·L~(-1)、3.097μmo L·L~(-1)和0.331μmo L·L~(-1),NXGF浓度为1.25、2.5μmo L·L~(-1)时,PC9和H1975的IC_(50)低于H358和H520(P0.05)。结论:本实验室设计构建的新型小分子酪氨酸激酶抑制剂NXGH和NXGF对不同EGFR表达水平和突变状态的肺癌细胞均有较高亲和性,且低浓度时对EGFR突变型更敏感。     

Evaluation of NUF2 and GMNN Expression in Prostate Cancer: Potential Biomarkers for Prostate Cancer Screening

Background:Prostate cancer (PC) is one of the most abundant cancers among men, and In Iran, has been responsible for 6% of all deaths from cancer in men. NUF2 and GMNN genes are considered as loci of susceptibility to tumorigenesis in humans. Alterations in expression of these genes have been reported in various malignancies. The aim of our study was to test whether different NUF2 and GMNN expression levels are associated with PC incidence and hence, might be considered as new molecular tools for PC screening.Methods:Biopsy samples from 40 PC patients and 41 healthy Iranian men were used to determine the relative gene expression. After RNA extraction and cDNA synthesis, samples were analyzed using TaqMan Quantitative Real time PCR. Patients’ background information, included smoking habits and family histories of PC, were recorded. Stages and grades of their PC were classified by the TNM tumor, node, metastasis (TMN) staging system based on standard guidelines.Results:NUF2 expression did not significantly differ between the groups, while GMNN expression was significantly greater in the PC specimens than in the controls.Conclusion:Regarding the significant role of GMNN in various tumor phenotypes, and its importance in PC progression, the alteration in GMNN expression in PC samples vs. controls indicate that the genetic profiling of this cancer might be considered to personalize therapy for each patient in the future.Key Words: Family history, Geminin (GMNN), Tumor staging, NUF2, Prostate cancer     

RGD肽介导的MR分子探针在体外结直肠癌细胞的显像及对其生物学行为的影响

目的:探讨RGD肽介导的MR分子探针在体外结直肠癌细胞的MRI显像及对其生物学行为的影响方法:利用纳米技术构建靶向RGD荧光纳米MR探针,利用荧光倒置相差显微镜观察该探针与LOVO细胞结合情况;体外磁共振成像（MRI）显像;利用细胞克隆实验测其增殖活性;流式细胞术检测其细胞周期、凋亡。结果:荧光相差显微镜示该RGD肽介导的MR分子探针能特异性与LOVO细胞结合;体外MRI成像示靶向RGD组T₁信号强度高于非靶向组及对照组（P<0.05）;该探针作用24h后的LOVO细胞增殖活性降低,细胞分裂周期发生变化,阻滞在S+G₂M期的细胞比例上升,细胞凋亡率与其他两组相比有显著增加（P<0.05）结论:该RGD肽介导的MR分子探针能与结直肠癌LOVO细胞靶向结合,能增强MRI的显像效果,并对肿瘤细胞具有一定的抑制作用     

RGD肽介导的MR分子探针在体外结直肠癌细胞的显像及对其生物学行为的影响

目的：探讨RGD肽介导的MR分子探针在体外结直肠癌细胞的MRJ显像及对其生物学行为的影响。方法：利用纳米技术构建靶向RGD荧光纳米MR、探针,利用荧光倒置相、差显微镜观察该探针与LOVO细胞结合情况;体外磁共振成像（MRI）显像;利用细胞克隆实验测其增殖活性;流式细胞术检测其细胞周期、凋亡。结果：荧光相差显微镜示该RGD肽介导的MR分子探针能特异性与LOVO细胞结合;体外MRI成像示靶向RGD组T1信号强度高于非靶向组及对照组（P〈0．05）;该探针作用24h后的LOVO细胞增殖活性降低,细胞分裂周期发生变化,阻滞在S＋G2M期的细胞比例上升,细胞凋亡率与其他两组相比有显著增加（P〈0．05）。结论：该RGD肽介导的MR分子探针能与结直肠癌LOVO细胞靶向结合,能增强MR1的显像效果,并对肿瘤细胞具有一定的抑制作用．     

Molecular Validation of PACE4 as a Target in Prostate Cancer

Prostate cancer remains the single most prevalent cancer in men. Standard therapies are still limited and include androgen ablation that initially causes tumor regression. However, tumor cells eventually relapse and develop into a hormone-refractory prostate cancer. One of the current challenges in this disease is to define new therapeutic targets, which have been virtually unchanged in the past 30 years. Recent studies have suggested that the family of enzymes known as the proprotein convertases (PCs) is involved in various types of cancers and their progression. The present study examined PC expression in prostate cancer and validates one PC, namely PACE4, as a target. The evidence includes the observed high expression of PACE4 in all different clinical stages of human prostate tumor tissues. Gene silencing studies targeting PACE4 in the DU145 prostate cancer cell line produced cells (cell line 4-2) with slower proliferation rates, reduced clonogenic activity, and inability to grow as xenografts in nude mice. Gene expression and proteomic profiling of the 4-2 cell line reveals an increased expression of known cancer-related genes (e.g., GJA1, CD44, IGFBP6) that are downregulated in prostate cancer. Similarly, cancer genes whose expression is decreased in the 4-2 cell line were upregulated in prostate cancer (e.g., MUC1, IL6). The direct role of PACE4 in prostate cancer is most likely through the upregulated processing of growth factors or through the aberrant processing of growth factors leading to sustained cancer progression, suggesting that PACE4 holds a central role in prostate cancer.     

Seminal Plasma as a Source of Prostate Cancer Peptide Biomarker Candidates for Detection of Indolent and Advanced Disease

Background

Extensive prostate specific antigen screening for prostate cancer generates a high number of unnecessary biopsies and over-treatment due to insufficient differentiation between indolent and aggressive tumours. We hypothesized that seminal plasma is a robust source of novel prostate cancer (PCa) biomarkers with the potential to improve primary diagnosis of and to distinguish advanced from indolent disease.

Methodology/Principal Findings

In an open-label case/control study 125 patients (70 PCa, 21 benign prostate hyperplasia, 25 chronic prostatitis, 9 healthy controls) were enrolled in 3 centres. Biomarker panels a) for PCa diagnosis (comparison of PCa patients versus benign controls) and b) for advanced disease (comparison of patients with post surgery Gleason score <7 versus Gleason score >7) were sought. Independent cohorts were used for proteomic biomarker discovery and testing the performance of the identified biomarker profiles. Seminal plasma was profiled using capillary electrophoresis mass spectrometry. Pre-analytical stability and analytical precision of the proteome analysis were determined. Support vector machine learning was used for classification. Stepwise application of two biomarker signatures with 21 and 5 biomarkers provided 83% sensitivity and 67% specificity for PCa detection in a test set of samples. A panel of 11 biomarkers for advanced disease discriminated between patients with Gleason score 7 and organ-confined (<pT3a) or advanced (≥pT3a) disease with 80% sensitivity and 82% specificity in a preliminary validation setting. Seminal profiles showed excellent pre-analytical stability. Eight biomarkers were identified as fragments of N-acetyllactosaminide beta-1,3-N-acetylglucosaminyltransferase, prostatic acid phosphatase, stabilin-2, GTPase IMAP family member 6, semenogelin-1 and -2. Restricted sample size was the major limitation of the study.

Conclusions/Significance

Seminal plasma represents a robust source of potential peptide makers for primary PCa diagnosis. Our findings warrant further prospective validation to confirm the diagnostic potential of identified seminal biomarker candidates.     

Synthesis and Antiproliferative Activity of Hybrid Peptides for Ovarian and Prostate Cancer

International Journal of Peptide Research and Therapeutics - Ovarian carcinoma is the leading malignancy of the female congenital system with a high mortality rate. In ovarian carcinoma,...     

Quantitative Ultrasound Spectroscopic Imaging for Characterization of Disease Extent in Prostate Cancer Patients

Three-dimensional quantitative ultrasound spectroscopic imaging of prostate was investigated clinically for the noninvasive detection and extent characterization of disease in cancer patients and compared to whole-mount, whole-gland histopathology of radical prostatectomy specimens. Fifteen patients with prostate cancer underwent a volumetric transrectal ultrasound scan before radical prostatectomy. Conventional-frequency (~ 5 MHz) ultrasound images and radiofrequency data were collected from patients. Normalized power spectra were used as the basis of quantitative ultrasound spectroscopy. Specifically, color-coded parametric maps of 0-MHz intercept, midband fit, and spectral slope were computed and used to characterize prostate tissue in ultrasound images. Areas of cancer were identified in whole-mount histopathology specimens, and disease extent was correlated to that estimated from quantitative ultrasound parametric images. Midband fit and 0-MHz intercept parameters were found to be best associated with the presence of disease as located on histopathology whole-mount sections. Obtained results indicated a correlation between disease extent estimated noninvasively based on midband fit parametric images and that identified histopathologically on prostatectomy specimens, with an r² value of 0.71 (P < .0001). The 0-MHz intercept parameter demonstrated a lower level of correlation with histopathology. Spectral slope parametric maps offered no discrimination of disease. Multiple regression analysis produced a hybrid disease characterization model (r² = 0.764, P < .05), implying that the midband fit biomarker had the greatest correlation with the histopathologic extent of disease. This work demonstrates that quantitative ultrasound spectroscopic imaging can be used for detecting prostate cancer and characterizing disease extent noninvasively, with corresponding gross three-dimensional histopathologic correlation.     

超声弹性成像技术在前列腺癌诊断中的应用

超声弹性成像技术是一项新兴的超声成像方法,可通过分析不同组织间机械组织差异区分组织软硬度,早期主要应用于乳腺、甲状腺结节的区分和定性。随着科技的进步和医疗水平的提高,目前弹性成像技术可在二维声像图的基础上,对感兴趣区域进行定性诊断和定量分析,已逐步应用于医学各领域相关研究和临床疾病的鉴别诊断。本文介绍了弹性成像的基本原理和目前弹性成像技术在医学领域中的相关应用,叙述了前列腺癌的发展趋势和目前常用的筛查、诊断方法,详细阐述了弹性成像技术在前列腺癌诊断中的应用方法和现状,分析总结了弹性成像技术在前列腺癌诊断中的应用价值。运用弹性成像技术无创、经济便捷、实时动态、可重复性好等优点,联合前列腺癌相关筛查、诊断检查,可有效帮助早期诊断前列腺癌,减少前列腺穿刺术的针数,提高前列腺癌的检出率。     

Haptoglobin Proved a Prognostic Biomarker in Peripheral Blood of Patients with Personalized Peptide Vaccinations for Advanced Castration-Resistant Prostate Cancer

The fopA gene encoding a fructooligosaccharide-producing β-fructofuranosidase was isolated from Aspergillus niger ATCC 20611. The primary structure deduced from the nucleotide sequence showed considerable similarity to those of two other β-fructofuranosidases from A. niger, but the fopA gene product had several amino acid insertions and an extra C-terminal polypeptide consisting of 38 amino acids that could not be found in the two others. We could successfully express the fopA gene in S. cerevisiae and the fopA gene product obtained from the culture supernatant of the S. cerevisiae transformant had similar characteristics to the β-fructofuranosidase purified from A. niger ATCC 20611. However, we could not detect any β-fructofuranosidase activity in either the culture supernatant or cell lysate when the C-terminal truncated fopA gene product by 38 amino acids was used to transform S. cerevisiae. In western analysis of those samples, there was no protein product that is cross-reacted with anti-β-fructofuranosidase antibody. These results suggested that the C-terminal region of the fopA gene product consisting of 38 amino acids was essential for the enzyme production.     

胃癌血管靶向肽GX1修饰的人血清白蛋白用于胃癌近红外活体成像

目的:以肿瘤血管靶向肽GX1修饰的人血清白蛋白(HSA)作为吲哚菁绿(ICG)的载体,合成近红外荧光探针GX1-HSA-ICG,研究其作为近红外荧光探针在荷人胃癌裸鼠活体中的靶向成像能力。方法:以HSA作为ICG的载体,通过化学修饰与GX1共价连接,合成GX1-HSA-ICG纳米颗粒探针;使用SDS-PAGE对探针合成进行鉴定;采用探针与脐静脉内皮细胞HUVEC以及与肿瘤细胞共培养的脐静脉内皮细胞Co-HUVEC进行结合和竞争抑制试验,验证探针和Co-HUVEC细胞结合的特异性;利用小动物活体成像系统对皮下荷胃癌小鼠进行近红外荧光活体成像,验证探针在体内的胃癌靶向性。结果:成功合成GX1-HSA-ICG。细胞结合与竞争抑制实验显示GX1-HSA-ICG可与Co-HUVEC细胞特异性结合;荷瘤小鼠活体成像也显示出GX1-HSA-ICG较ICG有更长体内的循环时间,并且胃癌组织局部较HSA-ICG有更强的聚集。结论:本研究成功合成了胃癌血管靶向肽GX1修饰的HSA为荧光染料载体的胃癌血管靶向探针,成功对荷胃癌裸鼠进行了活体成像。使用HSA为载体的探针较单纯使用ICG的肿瘤局部滞留能力显著提高,GX1增加了探针的胃癌靶向特异性。该探针在胃癌的早期诊断和抗肿瘤血管生成治疗评估中具有潜在的应用价值。