Draft genome sequences of Chryseobacterium sp. MHB01, Rhodococcus qingshengii MHB02, and Agrobacterium tumefaciens MHB03 isolated from superabsorbent polymer granules inoculated with an arbuscular mycorrhizal fungus.

Chryseobacterium sp. MHB01, Rhodococcus qingshengii MHB02, and Agrobacterium tumefaciens MHB03 were isolated from superabsorbent polymer granules cultured with an arbuscular mycorrhizal fungus. Whole-genome sequencing of these three strains revealed genome sizes of 4.57 Mb, 7.13 Mb, and 5.49 Mb with G + C contents of 36.9%, 62.5%, and 58.2%, respectively.

When Pregnancy Becomes an Inclusion Criterion in Neuroscience Research.

This Viewpoint discusses the inclusion of pregnant patients in clinical trials for antiseizure medication.

Targeting Ligand Specificity Linked to Tumor Tissue Topological Heterogeneity via Single-Cell Micro-Pharmacological Modeling.

Targeted therapy has held promise to be a successful anticancer treatment due to its specificity towards tumor cells that express the target receptors. However, not all targeting drugs used in the clinic are equally effective in tumor eradication. To examine which biochemical and biophysical properties of targeted agents are pivotal for their effective distribution inside the tumor and their efficient cellular uptake, we combine mathematical micro-pharmacological modeling with in vivo imaging of targeted human xenograft tumors in SCID mice. The mathematical model calibrated to experimental data was used to explore properties of the targeting ligand (diffusion and affinity) and ligand release schemes (rates and concentrations) with a goal to identify the properties of cells and ligands that enable high receptor saturation. By accounting for heterogeneities typical of in vivo tumors, our model was able to identify cell- and tissue-level barriers to efficient drug uptake. This work provides a base for utilizing experimentally measurable properties of a ligand-targeted agent and patient-specific attributes of the tumor tissue to support the development of novel targeted imaging agents and for improvement in their delivery to individual tumor cells.

Tumor Targeting and Pharmacokinetics of a Near-Infrared Fluorescent-Labeled δ-Opioid Receptor Antagonist Agent, Dmt-Tic-Cy5.

Fluorescence molecular imaging can be employed for the development of novel cancer targeting agents. Herein, we investigated the pharmacokinetics (PK) and cellular uptake of Dmt-Tic-Cy5, a delta-opioid receptor (δOR) antagonist-fluorescent dye conjugate, as a tumor-targeting molecular imaging agent. δOR expression is observed normally in the CNS, and pathologically in some tumors, including lung liver and breast cancers. In vitro, in vivo, and ex vivo experiments were conducted to image and quantify the fluorescence signal associated with Dmt-Tic-Cy5 over time using in vitro and intravital fluorescence microscopy and small animal fluorescence imaging of tumor-bearing mice. We observed specific retention of Dmt-Tic-Cy5 in tumors with maximum uptake in δOR-expressing positive tumors at 3 h and observable persistence for >96 h; clearance from δOR nonexpressing negative tumors by 6 h; and systemic clearance from normal organs by 24 h. Live-cell and intravital fluorescence microscopy demonstrated that Dmt-Tic-Cy5 had sustained cell-surface binding lasting at least 24 h with gradual internalization over the initial 6 h following administration. Dmt-Tic-Cy5 is a δOR-targeted agent that exhibits long-lasting and specific signal in δOR-expressing tumors, is rapidly cleared from systemic circulation, and is not retained in non-δOR-expressing tissues. Hence, Dmt-Tic-Cy5 has potential as a fluorescent tumor imaging agent.

Novel toll-like receptor 2 ligands for targeted pancreatic cancer imaging and immunotherapy.

Toll-like receptor 2 (TLR2) is a target for immune system stimulation during cancer immunotherapy and a cell-surface marker for pancreatic cancer. To develop targeted agents for cancer imaging and therapy, we designed, synthesized, and characterized 13 novel, fully synthetic high affinity TLR2 agonists. Analogue 10 had the highest agonist activity (NF-κB functional assay, EC(50) = 20 nM) and binding affinity (competitive binding assay, K(i) = 25 nM). As an immune adjuvant, compound 10 stimulated the immune system in vivo by generation and persistence of antigen-specific CD8+ T cells indicating its potential use in cancer immunotherapy. After conjugation of near-infrared dye to 10, agonist activity (EC(50) = 34 nM) and binding affinity (K(i) = 11 nM) were retained in 13. Fluorescence signal was present in TLR2 expressing pancreatic tumor xenografts 24 h after injection of 13, while an excess of unlabeled ligand blocked 13 from binding to the tumor, resulting in significantly decreased signal (p < 0.001) demonstrating in vivo selectivity.

Development of an orthotopic human pancreatic cancer xenograft model using ultrasound guided injection of cells.

Mice have been employed as models of cancer for over a century, providing significant advances in our understanding of this multifaceted family of diseases. In particular, orthotopic tumor xenograft mouse models are emerging as the preference for cancer research due to increased clinical relevance over subcutaneous mouse models. In the current study, we developed orthotopic pancreatic cancer xenograft models in mice by a minimally invasive method, ultrasound guided injection (USGI) comparable to highly invasive surgical orthotopic injection (SOI) methods. This optimized method prevented injection complications such as recoil of cells through the injection canal or leakage of cells out of the pancreas into the peritoneal cavity. Tumor growth was monitored in vivo and quantified by ultrasound imaging weekly, tumors were also detected by in vivo fluorescence imaging using a tumor targeted molecular probe. The mean tumor volumes for the USGI and SOI models after 2 weeks of tumor growth were 205 mm(3) and 178 mm(3) respectively. By USGI of human pancreatic cancer cell lines, human orthotopic pancreatic cancer xenografts were established. Based on ultrasound imaging, the orthotopic human pancreatic cancer xenograft take rate was 100% for both human pancreatic cancer cell lines used, MiaPaCa-2 and Su86.86, with mean tumor volumes of 28 mm(3)and 30 mm(3). We demonstrated that this USGI method is feasible, reproducible, facile, minimally invasive and improved compared to the highly-invasive SOI method for establishing orthotopic pancreatic tumor xenograft models suitable for molecular imaging.

A mammaglobin-A targeting agent for noninvasive detection of breast cancer metastasis in lymph nodes.

Pathologic axillary lymph node (ALN) status is an important prognostic factor for staging breast cancer. Currently, status is determined by histopathology following surgical excision of sentinel lymph node(s), which is an invasive, time consuming, and costly procedure with potential morbidity to the patient. Here, we describe an imaging platform for noninvasive assessment of ALN status, eliminating the need for surgical examination of patients to rule out nodal involvement. A targeted imaging probe (MamAb-680) was developed by conjugation of a mammaglobin-A-specific monoclonal antibody to a near-infrared fluorescent dye. Using DNA and tissue microarray, mammaglobin-A was validated as a cell-surface target that is expressed in ALN-positive patient samples but is not expressed in normal lymph nodes. In vivo selectivity was determined by i.v. injection of MamAb-680 into mice with mammaglobin-A-positive and -negative mammary fat pad (MFP) tumors; and by peritumoral MFP injection of the targeted imaging probe in mice with spontaneous ALN metastases. Fluorescence imaging showed that probe was only retained in positive tumors and metastases. As few as 1,000 cells that endogenously express mammaglobin-A were detected in ALN, indicating high sensitivity of this method. Translation of this approach offers considerable potential as a noninvasive clinical strategy to stage breast cancer.