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New synthetic chemical inducers of dimerization, comprising homodimeric FKBP ligands with engineered specificity for the designed point mutant F36V, have been evaluated for inducing targeted gene expression in mammalian cells. Structure-activity studies indicated that high-affinity dimerizers such as AP1903 are ineffective, perhaps due to kinetic trapping of non-productive dimers, whereas lower-affinity molecules, exemplified by AP1889 and AP1966, potently activate transcription.

Src tyrosine kinase is a therapeutic target for bone diseases that has been validated by gene knockout studies. Furthermore, in vitro cellular studies implicate that Src has a positive regulatory role in osteoclasts and a negative regulatory role in osteoblasts. The potential use of Src inhibitors for osteoporosis therapy has been previously shown by novel bone-targeted ligands of the Src SH2 (e.g., AP22408) and non-bone-targeted, ATP-based inhibitors of Src kinase. Significant to this study, compounds 2-12 exemplify novel analogues of known pyrrolopyrimidine and pyrazolopyrimidine template-based Src kinase inhibitors that incorporate bone-targeting group modifications designed to provide tissue (bone) selectivity and diminished side effects. Accordingly, we report here the structure-based design, synthetic chemistry and biological testing of these compounds and proof-of-concept studies thereof.

Novel bone-targeted 2,6,9-trisubstituted purine template-based inhibitors of Src tyrosine kinase are described. Drug design studies of known purine compounds revealed that both positions-2 and -6 were suitable for incorporating bone-seeking moieties. A variety of bone-targeting groups with different affinity to hydroxyapatite were utilized in the study. Compound 3d was determined to be a potent Src inhibitor and was quite selective against a panel of other protein kinases.

The design of bone-targeted pyrido[2,3-d]pyrimidin-7-ones as Src tyrosine kinase inhibitors is described. Leveraging SAR from known compounds and using structure-based methods, we were able to rapidly incorporate bone binding components, which maintained, and even increased potency against the target enzyme. Compound 4 displayed a high affinity for hydroxyapatite, a major constituent of bone, and demonstrated antiresoprtive activity in our cell-based assay.

The desire to replace the amide backbone of renin inhibitors with a new scaffold led us to explore vinylogous amides (enaminones). An initial attempt proved unsuccessful, a result explained after the fact via docking experiments. Based on this lesson, we designed a different vinylogous amide scaffold which incorporated one or more pyrrolinone rings into the backbone. Three of the four compounds gave IC50S in the 0.6 to 18 microM range. These compounds did not inhibit HIV-1 protease. Taken together, the results reported herein provide insights into the role of hydrogen bonding and steric interactions for binding to renin.

The BIAS (Biological Image Analysis System) was developed to: (i) permit accurate entry and image processing of biological data; (ii) minimize the need for specialized hardware; and (iii) aid in the human genome mapping and other projects. The first mouse/cursor key-driven module was designed to be user interactive and readily accessible to many laboratories. It contains the DRSNDS programs which automate the entering of data in a systematic format. The types of data that can be entered utilizing this module are DNA-RNA gels from either a positive or negative Polaroid image, autoradiograms or biotinylated images from Southern, Northern and dot or slot blot hybridization analyses. The image is acquired using a video camera and then digitized for subsequent analysis. During the analysis graphical representations of the intermediate results are provided to assure user confidence. At any point within the program the user may obtain on-line help with the current task. The output displays the mol. wt of each individual component in the appropriate context. The present version of the program produces results comparable with a human interpreter for some data. Band shifting and optical density calculations are in a prototype form to permit evaluation of various techniques. Future work is directed at expanding the system's capabilities to interpret data from other biological analyses including DNA sequencing gels.

Cavernous hemangiomas of the orbit produce echographic A-scan patterns which allow their detection, localization, measurement, and differentiation from all other orbital lesions with a high degree of accuracy. Specific echograms, however, of these tumors can only be obtained with optimized and standardized A-scan instruments providing specific settings of the sensitivity, amplifier characteristics, dynamic range, expansion of the screen display, filtering, etc. When instruments other than these are used, both differentiation and detection of this tumor become difficult or impossible. The more an A-scan instrument differs from the optimized and standardized type, the less successful the diagnosis of cavernous hemangiomas becomes, B-scan techniques add to the A-scan examination by better demonstrating the round shape and the topographic relationship to the globe, the optic nerve and the orbital wall.