Quantitative biology: where modern biology meets physical sciences

Quantitative methods and approaches have been playing an increasingly important role in cell biology in recent years. They involve making accurate measurements to test a predefined hypothesis in order to compare experimental data with predictions generated by theoretical models, an approach that has benefited physicists for decades. Building quantitative models in experimental biology not only has led to discoveries of counterintuitive phenomena but has also opened up novel research directions. To make the biological sciences more quantitative, we believe a two-pronged approach needs to be taken. First, graduate training needs to be revamped to ensure biology students are adequately trained in physical and mathematical sciences and vice versa. Second, students of both the biological and the physical sciences need to be provided adequate opportunities for hands-on engagement with the methods and approaches necessary to be able to work at the intersection of the biological and physical sciences. We present the annual Physiology Course organized at the Marine Biological Laboratory (Woods Hole, MA) as a case study for a hands-on training program that gives young scientists the opportunity not only to acquire the tools of quantitative biology but also to develop the necessary thought processes that will enable them to bridge the gap between these disciplines

Src Inhibitors Pyrazolo[3,4-d]pyrimidines, Si306 and Pro-Si306, Inhibit Focal Adhesion Kinase and Suppress Human Glioblastoma Invasion In Vitro and In Vivo

Glioblastoma (GBM), as the most aggressive brain tumor, displays a high expression of Src tyrosine kinase, which is involved in the survival, migration, and invasiveness of tumor cells. Thus, Src emerged as a potential target for GBM therapy. The effects of Src inhibitors pyrazolo[3,4-d]pyrimidines, Si306 and its prodrug pro-Si306 were investigated in human GBM cell lines (U87 and U87-TxR) and three primary GBM cell cultures. Primary GBM cells were more resistant to Si306 and pro-Si306 according to the 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. However, the ability of all GBM cells to degrade the extracellular matrix was considerably compromised after Si306 and pro-Si306 applications. Besides reducing the phosphorylation of Src and its downstream signaling pathway components, both compounds decreased the phosphorylated form of focal adhesion kinase (FAK) and epidermal growth factor receptor (EGFR) expression, showing the potential to suppress the aggressiveness of GBM. In vivo, Si306 and pro-Si306 displayed an anti-invasive effect against U87 xenografts in the zebrafish embryo model. Considering that Si306 and pro-Si306 are able to cross the blood-brain barrier and suppress the spread of GBM cells, we anticipate their clinical testing in the near future. Moreover, the prodrug showed similar efficacy to the drug, implying the rationality of its use in clinical settings

CLINICAL GUIDELINES FOR DIAGNOSIS, TREATMENT AND MONITORING OF PATIENTS WITH INVASIVE BREAST CANCER – CROATIAN ONCOLOGY SOCIETY

Rak dojke najčešći je zloćudni tumor u žena koji se može probirom, redovitim kontrolama i zdravstvenim odgojem otkriti u ranim stadijima bolesti i uspješno liječiti. Metode liječenja uključuju kirurgiju, kemoterapiju, radioterapiju, hormonsku terapiju i ciljanu biološku terapiju ovisno o stadiju bolesti, biološkim obilježjima tumora i općem stanju bolesnice. Odluku o liječenju donosi multidisciplinarni tim. S obzirom na važnost ove bolesti, potrebno je definirati i provoditi standardizirani pristup u dijagnostici, liječenju i praćenju ovih bolesnica. U tekstu koji slijedi iznesene su kliničke smjernice s ciljem implementacije standardiziranih postupaka u radu s bolesnicama s rakom dojke u Republici Hrvatskoj.Breast cancer is the most common cancer in women. It can be diagnosed in early stage through screening, early detection and educational programs, and when diagnosed early it can be efficiently treated. Treatment modalities include surgery, chemotherapy, radiotherapy, hormonal therapy and targeted biologic therapy, according to the stage of the disease and patient condition. Treatment decisions should be made after multidisciplinary team discussion. Due to the significance of this disease it is important to define and implement standardized approach for diagnostic, treatment and monitoring algorithm as well. The following text presents the clinical guidelines in order to standardize the procedures and criteria for diagnosis, management, treatment and monitoring of patients with breast cancer in the Republic of Croatia

CLINICAL GUIDELINES FOR DIAGNOSIS, TREATMENT AND MONITORING OF PATIENTS WITH INVASIVE BREAST CANCER – CROATIAN ONCOLOGY SOCIETY

Rak dojke najčešći je zloćudni tumor u žena koji se može probirom, redovitim kontrolama i zdravstvenim odgojem otkriti u ranim stadijima bolesti i uspješno liječiti. Metode liječenja uključuju kirurgiju, kemoterapiju, radioterapiju, hormonsku terapiju i ciljanu biološku terapiju ovisno o stadiju bolesti, biološkim obilježjima tumora i općem stanju bolesnice. Odluku o liječenju donosi multidisciplinarni tim. S obzirom na važnost ove bolesti, potrebno je definirati i provoditi standardizirani pristup u dijagnostici, liječenju i praćenju ovih bolesnica. U tekstu koji slijedi iznesene su kliničke smjernice s ciljem implementacije standardiziranih postupaka u radu s bolesnicama s rakom dojke u Republici Hrvatskoj.Breast cancer is the most common cancer in women. It can be diagnosed in early stage through screening, early detection and educational programs, and when diagnosed early it can be efficiently treated. Treatment modalities include surgery, chemotherapy, radiotherapy, hormonal therapy and targeted biologic therapy, according to the stage of the disease and patient condition. Treatment decisions should be made after multidisciplinary team discussion. Due to the significance of this disease it is important to define and implement standardized approach for diagnostic, treatment and monitoring algorithm as well. The following text presents the clinical guidelines in order to standardize the procedures and criteria for diagnosis, management, treatment and monitoring of patients with breast cancer in the Republic of Croatia

Information from the Norwegian R&D statistics 2009: Main results

Newsletter presenting main results from the R&D statistics of Norway.Newsletter presenting main results from the R&D statistics of Norway

Molecular height measurement by cell surface optical profilometry (CSOP)

The physical dimensions of proteins and glycans on cell surfaces can critically affect cell function, for example, by preventing close contact between cells and limiting receptor accessibility. However, high-resolution measurements of molecular heights on native cell membranes have been difficult to obtain. Here we present a simple and rapid method that achieves nanometer height resolution by localizing fluorophores at the tip and base of cell surface molecules and determining their separation by radially averaging across many molecules. We use this method, which we call cell surface optical profilometry (CSOP), to quantify the height of key multidomain proteins on a model cell, as well as to capture average protein and glycan heights on native cell membranes. We show that average height of a protein is significantly smaller than its contour length, due to thermally driven bending and rotation on the membrane, and that height strongly depends on local surface and solution conditions. We find that average height increases with cell surface molecular crowding but decreases with solution crowding by solutes, both of which we confirm with molecular dynamics simulations. We also use experiments and simulations to determine the height of an epitope, based on the location of an antibody, which allows CSOP to profile various proteins and glycans on a native cell surface using antibodies and lectins. This versatile method for profiling cell surfaces has the potential to advance understanding of the molecular landscape of cells and the role of the molecular landscape in cell function

Size-Dependent Segregation Controls Macrophage Phagocytosis of Antibody-Opsonized Targets

Macrophages protect the body from damage and disease by targeting antibody-opsonized cells for phagocytosis. Though antibodies can be raised against antigens with diverse structures, shapes, and sizes, it is unclear why some are more effective at triggering immune responses than others. Here, we define an antigen height threshold that regulates phagocytosis of both engineered and cancer-specific antigens by macrophages. Using a reconstituted model of antibody-opsonized target cells, we find that phagocytosis is dramatically impaired for antigens that position antibodies >10 nm from the target surface. Decreasing antigen height drives segregation of antibody-bound Fc receptors from the inhibitory phosphatase CD45 in an integrin-independent manner, triggering Fc receptor phosphorylation and promoting phagocytosis. Our work shows that close contact between macrophage and target is a requirement for efficient phagocytosis, suggesting that therapeutic antibodies should target short antigens in order to trigger Fc receptor activation through size-dependent physical segregation

Src Inhibitors Pyrazolo[3,4-d]pyrimidines, Si306 and Pro-Si306, Inhibit Focal Adhesion Kinase and Suppress Human Glioblastoma Invasion In Vitro and In Vivo

Glioblastoma (GBM), as the most aggressive brain tumor, displays a high expression of Src tyrosine kinase, which is involved in the survival, migration, and invasiveness of tumor cells. Thus, Src emerged as a potential target for GBM therapy. The effects of Src inhibitors pyrazolo[3,4-d]pyrimidines, Si306 and its prodrug pro-Si306 were investigated in human GBM cell lines (U87 and U87-TxR) and three primary GBM cell cultures. Primary GBM cells were more resistant to Si306 and pro-Si306 according to the 3-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay. However, the ability of all GBM cells to degrade the extracellular matrix was considerably compromised after Si306 and pro-Si306 applications. Besides reducing the phosphorylation of Src and its downstream signaling pathway components, both compounds decreased the phosphorylated form of focal adhesion kinase (FAK) and epidermal growth factor receptor (EGFR) expression, showing the potential to suppress the aggressiveness of GBM. In vivo, Si306 and pro-Si306 displayed an anti-invasive effect against U87 xenografts in the zebrafish embryo model. Considering that Si306 and pro-Si306 are able to cross the blood–brain barrier and suppress the spread of GBM cells, we anticipate their clinical testing in the near future. Moreover, the prodrug showed similar efficacy to the drug, implying the rationality of its use in clinical settings