Peptide phage display: opportunities for development of personalized anti-cancer strategies.

Personalized medicine is critical for cancer patients, because (1) cancer is a highly heterogeneous disease with major molecular differences in the expression and distribution of tumor cell surface markers among patients with the same type and grade of cancer, (2) cellular mutations tend to accumulate as cancer progresses, further increasing tumor heterogeneity, and (3) currently used cancer therapies often are toxic to normal cells, causing severe side effects rarely seen in other diseases. To prevent side effects and to improve effectiveness, cytotoxic therapies should be targeted and each patient should be profiled for the presence of cancer targets before the therapy is administered. Phage display technology utilizes combinatorial libraries of proteins expressed on phage particles that can be selected for specific binding to cancer cells. Such cancer-specific molecules can be used in a variety of applications, including identification of cell-specific targeting molecules; identification of cell surface biomarkers; profiling of specimens obtained from individual cancer patients, and the design of peptide-based anti-cancer therapeutics for personalized treatments. This review is focused on peptide phage display strategies that target cell surfaces because many biomarkers important in cancer are differentially expressed molecules located on the outside of the cell membranes.

Molecular markers of glial tumors: current targeting strategies.

Diagnosis and therapy for malignant gliomas represents one of the most challenging problems in clinical oncology. Current treatment of malignant glioma is multimodal, involving surgical resection, radiotherapy and chemotherapy. Even with these combined therapies, patients usually die within 1 to 2 years after onset of symptoms. Clearly, improved strategies for selective delivery of therapeutic agents to gliomas are needed to combat these devastating and usually fatal cancers. This review summarizes current knowledge concerning targetable molecular markers on the surface of glial tumor cells and tumor vasculature. Such markers are altered or up-regulated in gliomas compared to normal tissues, or they might be glioma-restricted. These markers include growth factor receptors, cell-surface adhesion molecules, and membrane-type matrix metalloproteinases. Current approaches that utilize growth factor peptides and peptide/antibodies identified via phage display technology as carrier ligands for targeting malignant gliomas are discussed.

Flow microsphere immunoassay-based method of virus quantitation.

A sensitive assay for adenovirus quantitation in vitro was developed using the flow microsphere immunoassay (FMIA) approach. Polystyrene microspheres were covalently coated with purified anti-adenoviral antibodies and incubated with virus-containing samples. After incubation, the samples were stained with DNA-specific fluorescent dyes, and microsphere-associated fluorescence was quantitated with a flow cytometer. The adsorption of virus to microspheres was examined under different experimental conditions. The flow cytometric assay was determined to be as accurate in detecting adenovirus as titering on 293 cells. The proposed method can be used to quantify virus in viral stocks and in biological samples.

Elucidation of muscle-binding peptides by phage display screening.

Muscle makes up the largest tissue volume of the body, yet its size makes muscle-specific therapy difficult. This becomes particularly relevant when approaches to gene therapy for inherited myopathies are evaluated. Thus, a mechanism to target constructs or pharmaceuticals to muscle following intravenous injection would be advantageous. By screening a random phage display library we have identified a heptapeptide sequence, ASSLNIA, with enhanced in vivo skeletal and cardiac muscle binding. Phage carrying this peptide showed a 9- to 20-fold (depending on control tissue) increase in muscle selectivity compared with phage with no insert. When the injected individual phage clone was localized by immunohistochemistry, it was found within focal areas of the membrane of myofibers. Thus, the peptide identified represents a ligand that is capable of accessing skeletal and cardiac muscle from the lumen of blood vessels and could therefore readily be exploited for targeted delivery to muscle cells.

The flow karyotype of Arabidopsis thaliana interphase chromosomes.

The DNA contents of various aneuploid lines of Arabidopsis thaliana were measured by flow cytometry of 4',6-diamidino-2-phenylindole-stained interphase nuclei in suspensions and compared with each other as well as with the wild-type. The fluorescence intensifies for all lines were highly reproducible as were the deviations from the wild-type. The results allowed the estimation of the relative DNA contents of each Arabidopsis chromosome and of chromosomes arms. The sum of the surplus values for all trisomics was close to the value expected for the haploid (2C) DNA content. Only the line with the smallest telotrisome (Tr 3A) did not significantly differ in DNA content from that of the wild-type. It is concluded that approximately 3% of the genome represents the limit for resolution of differences in DNA content in this system. Thus, the approach allows a fast and reliable screening for duplications and deficiencies extending to 3% of the Arabidopsis genome. Regarding chromosomes sizes a comparison of the flow karyotype with existing karyotypes revealed differences which are discussed.

Tick-borne encephalitis (TBE) epidemiology in the Brest Province of the Republic of Belarus.

Prevalence of tick-borne encephalitis (TBE) and number of TBE infected ticks was analysed in the Brest Province since 1955. They revealed increasing tendency, which reached the highest values in the last years. TBE incidence was the highest in June and it was observed predominantly in people between 30 and 39 of age. The studies of TBE incidence rate regularities have disclosed its cyclical nature.