OBOC Combinatorial Chemistry:
Dr. Lam invented the “one-bead-one-compound” (OBOC) combinatorial library methods in 1990. This is a very powerful combinatorial technology for basic research, the development of cancer targeting ligands, and more recently the development of affinity element for efficient site-specific ligation of immunoglobulins. Many new advances in the chemical synthesis, encoding, screening and polymer support of the OBOC technology were developed in our laboratory. We have also developed solution phase OBOC method and OB2C method and use them for ultrahigh-throughput cell-based assay. Currently we are using OBOC and OB2C methods to develop affinity elements for site-specific ligation of immunoglobulins, membrane active peptides, cell-penetrating peptides, galectin-1 inhibitors and PD-1 inhibitors.
- Lam KS, Salmon SE, Hersh EM, Hruby V, Kazmierski WM, Knapp RJ: A new type of synthetic peptide library for identifying ligand-binding activity. Nature 354(7):82-84, 1991.
- Liu R, Marik J, Lam KS: A novel peptide-based encoding system for:one-bead one-compound” peptidomimetic and small molecule combinatorial libraries. J. Am. Chem. Soc., 124: 7678-7680, 2002.
- Kumaresan PR, Arutselvan N, Song A, DeNardo G, DeNardo S, and Lam KS. The development of tissue plasminogen activator specific “On Demand Cleavable” (ODC) linkers for radioimmunotherapy by screening one-bead-one-compound combinatorial peptide libraries. Bioconjugate Chemistry, 18:175-82, 2006.
- Townsend JB, Shaheen F, Liu R, Lam KS. Jeffamine Derivatized TentaGel Beads and Poly(dimethylsiloxane) Microbead Cassettes for Ultrahigh-Throughput in Situ Releasable Solution-Phase Cell-Based Screening of One-Bead-One-Compound Combinatorial Small Molecule Libraries. J Comb Chem. 2010; 12(5):700-712. PMCID: PMC3045263.
- Wu C, Wang DH, Wang X, Dixon S, Meng L, Ahadi S, Enter D, Chen CY, Kato J, Leon L, Ramirez L, Maeda Y, Reis C, Ribeiro B, Weems B, Kung HJ, Lam, KS. Rapid Discovery of Functional Small Molecule Ligands against Proteomic Targets through Library-Against-Library Screening" ACS Combinatorial Sciences. 2016 Apr 6. [Epub ahead of print] PMID:27053324. PMCID: PMC4908505.
- Lac D, Feng C, Bhardwah G, Le H, Tran J, Xing L, Fung G, Liu R, Cheng H, Lam KS. Covalent chemical ligation strategy for mono- and polyclonal immunoglobulins at their nucleotide binding sites. Bioconjugate chemistry 2015. PMID 26630124.
- Carney RP, Thillier Y, Kiss Z, Sahabi A, Heleno Campos JC, Knudson A, Liu R, Olivos D, Saunders M, Tian L, Lam KS. Combinatorial library screening with liposomes for discovery of membrane active peptides. ACS Comb Sci. 19(5): 299-307, 2017.
- Shih TC, Liu R., Fung G, Bhardwaj G, Ghosh PM, Lam KS. A novel galectin-1 inhibitor discovered through one-bead-two-compounds library potentiates the anti-tumor effects of paclitaxel in vivo. Mol Cancer Ther. 2017 Jul;16(7):1212-1223.
- Liu R, Li X, Lam KS. Combinatorial chemistry in drug discovery. Curr Opin Chem Biol 38:117-126, 2017.
- Shih TC, Liu R, Wu CT, Li X, Xiao W, Deng X, Kiss S, Wang T, Chen XJ, Carney R, Kung HJ, Duan Y, Ghosh PM, Lam KS. Targeting Galectin-1 Impairs Castration-Resistant Prostate Cancer Progression and Invasion. Clin Cancer Res. 2018 Sep 1;24(17):4319-4331
Cell Surface Targeting Ligand Discovery:
We were the first to use live intact cells as probes to screen OBOC libraries for cell surface targeting ligands, and we were able to demonstrate that these ligands can target tumors in vivo with high specificity and efficiency. We have been using these ligands as vehicles for tumor imaging and drug delivery. One ligand LLP2A, binds to activated α4b1 integrin of mesenchymal stem cells and when tethered to bisphosphonate can be use as stem cell mobilization agent for the treatment of osteoporosis and bone fracture. Phase I clinical trial on this novel agent has begun early 2017.
- Peng L, Liu R, Marik J, Wang X, Takada Y, Lam KS. Combinatorial Chemistry Identifies High-Affinity Peptidomimetics against a4b1 Integrin. Nature Chemical Biology, 2(7). 381-389, 2006.
- Yao N, Xiao W, Wang X, Marik J, Park SH, Takada Y, Lam KS Discovery of targeting ligands for breast cancer cells using the one-bead one-compound combinatorial method. J Med Chem. 2009 Jan 8;52(1):126-33, PMCID: PMC2836207.
- Carpenter RD, Andrei M, Aina OH, Liu R, Lam KS, Kurth MJ. Selectively targeting T- and B-cell Lymphomas: A Benzimidazole antagonist of alpha4beta1 Integrin. J Med Chem 52: 14-19, 2009. PMC3164867
- Guan M, Yao W, Liu R, Lam KS, Nolta J, Jia J, Ranganiban B, Meng L, Zhou P, Shahnazari M, Ritchie RO, and Lane NE. Directing mesenchymal stem cells to bone to augment bone formation and increase bone mass. Nature Medicine. 18: 456-462, 2012. PMC3755884
- Liu R, Li X, Xiao W and Lam KS. Tumor-targeting peptides from combinatorial libraries. Adv Drug Deliv Rev. 2016 PMID: 27210583
- Wang Y, Xiao W, Zhang Y, Meza L, Tseng H, Takada Y, Ames JB and Lam KS. Optimization of RGD containing cyclic peptides against αvβ3 integrin. Mol Cancer Therapeutics, 15:232-240, 2016.
- Xiao W, Li T, Bononi FC, Lac D, Kekessie IA, Liu Y, Sanchez E, Mazloom A, Ma AH, Lin J, Tran J, Yang K, Lam KS, Liu R. Discovery and characterization of a high-affinity and high-specificity peptide ligand LXY30 for in vivo targeting of α3 integrin-expressing human tumors. EJNMMI Res. 6: 18, 2016.
Peptide & Chemical Microarrays, and Microfluidics for Cancer Research:
Reference: Li J, Carney RP, Liu R, Fan J, Zhao S, Chen Y, Lam KS, Pan T. Microfluidic Print-to-Synthesis Platform for Efficient Preparation and Screening of Combinatorial Peptide Microarrays. Anal. Chem., 2018, 90 (9), pp 5833–5840
We are among the few groups that first reported the “printing” of chemical microarrays on planar surfaces. We have also applied the multiple different biochemical and cell-based assays to evaluate these chemical microarrays. Later, we teamed up with Dr. Xandong Zhu of UC Davis to develop and apply oblique-incidence reflectivity difference microscope for label-free detection of huge planar chemical microarrays, and use it to determine concurrently the binding affinity of thousands of immobilized peptides and small molecules to protein analytes. In the last few years, we teamed up with Dr. Tingrui pan of UC Davis to apply microfluidics to combinatorial synthesis, screening, and optical encoding. We recently reported on the development of a microfluidic print-to-synthesis platform for efficient preparation and screening of combinatorial peptide microarrays. We have also applied the microfluidic printer to dispense drug combinations for the discovery of synergistic drug combination and precision medicine.
- Falsey JR, Renil M, Park S, Li S, and Lam KS: Peptide and small molecule microarray for high-throughput cell adhesion and functional assays. Bioconjugate Chemistry, 12: 346-353, 2001.
- Lam KS, and Renil M: From combinatorial chemistry to chemical microarray. Current Opinion in Chemical Biology 6:353-358, 2002.
- Zhu X, Landry JP, Sun YS, Gregg JP, Lam KS, Guo X. Oblique-incidence reflectivity difference microscope for label-free high-throughput detection of biochemical reactions in a microarray format. Applied Optics. 48: 1890-1895, 2007.
- Sun YS, Landry JP, Fei YY, Zhu XD, Luo JT, Wang XB, Lam KS. Macromolecular scaffolds for immobilizing small molecule microarrays in label-free detection of protein-ligand interactions on solid support. Anal Chem, 81: 5373-5380, 2009. PMCID: PMC2751602
- Li J, Carney RP, Liu R, Fan J, Zhao S, Chen Y, Lam KS, Pan T. Microfluidic Print-to-Synthesis Platform for Efficient Preparation and Screening of Combinatorial Peptide Microarrays. Anal. Chem., 2018, 90 (9), pp 5833–5840
We have developed a novel class of oligocholate-PEG amphiphilic telodendrimers that can self-assemble to form nanomicelles or nanodiscs. These nanoparticles can serve as efficient carriers for drug delivery. We have introduced the on-demand reversible cross-linking concept to micellar-based nanoplatform, such that the micelle can dissociate, upon administration of a cleaving agent to the patient. We have recently reported a novel and highly versatile multifunctional nanoporphyrin nanoplatform and PVA-based micellar nanoplatform suitable for drug delivery, MR and PET imaging, as well as photo-thermal and photo-dynamic therapy. Very recently, we reported a novel cyanine and cholic acid based micellar nanoplatform (abs 800nm), not only can afford drug delivery and phototherapy, but can also deliver immune stimulants to tumor sites to elicit strong systemic anti-tumor response and anti-tumor immune memory.
- Li Y, Xiao W, Xiao K, Berti L, Luo J, Tseng HP, Gung G, and Lam KS. Well-Defined, Reversible Boronate Crosslinked Nanocarriers for Targeted Drug Delivery in Response to acidic pH and cis-Diols. Angewandte Chemie. 2012;51(12):2864-9. Epub 2012/01/19. PMC3545653
- Kenyon NJ, Bratt JM, Lee J, Luo J, Franzi LM, Zeki AA, and Lam KS. Self-ssembling nanoparticles containing dexamethasone as a novel therapy in allergic airway inflammation. PLOS ONE, 2013; Oct 5;8(10): PMC3808398
- Xiao K, Li Y, Lee JS, Gonik AM, Dong T, Fung G, et al. "OA02" peptide facilitates the precise targeting of paclitaxel-loaded micellar nanoparticles to ovarian cancer in vivo. Cancer Res. 2012;72(8):2100-10. Epub 2012/03/08. PMC3343697
- Li Y, Lin TY, Luo Y, Liu Q, Xiao W, Guo W, Lac D, Zhang H, Feng C, Wachsmann-Hogiu S, Walton JH, Cherry SR, Rowland DJ, Kukis D, Pan C, Lam KS. A smart and versatile theranostic nanomedicine platform based on nanoporphyrin. Nat Commun. 2014 Aug 26;5:4712. PMC4145614
- Xiao K, Li YP, Wang C, Ahmad S, Vu M, Kuma K, Cheng YQ, Lam KS. Disulfide cross-linked micelles of novel HDAC inhibitor thailandepsin A for the treatment of breast cancer. Biomaterials. 67:183-93, 2015. PMID:26218744. PMCID: PMC4550558
- Chen CC, Xing L, Stark M, Ou T, Holla P, Xiao K, Kamita SG, Hammock BD, Lam K, Cheng RH. Chemically activatable viral capsid functionalized for cancer targeting. Nanomedicine (London) 11:377-390 (2016).
Left: Unique Photochemo-Immuno-Nanoplatform against Orthotopic Xenograft Oral Cancer and Metastatic Syngeneic Breast Cancer. Right: Design and characterizations of PCI-NP and CPCI-NP
Reference: Lu Zhang,Di Jing,Lei Wang,Yuan Sun,Jian Jian Li,Brianna Hill,Fan Yang,Yuanpei Li,Kit S. Lam. Unique Photochemo-Immuno-Nanoplatform against Orthotopic Xenograft Oral Cancer and Metastatic Syngeneic Breast Cancer. Nano Letters 2018, 18 (11), 7092-7103.
Biophysical Approaches to Study Protein-nanoparticle Interactions:
Biophysical approaches such as electron paramagnetic resonance (EPR) spectroscopy and fluorescence resonance energy transfer (FRET) could provide great inside of the nanoparticles. We combined site-specific nitroxide spin labeling and fluorescence labeling techniques with EPR spectroscopy and FRET technique to probe the multiple dynamic processes occurring within a nanoparticle during interaction with blood proteins. These techniques enable us quantitatively analyze the dynamic changes in assembly structure, local stability and cargo diffusion of a class of novel telodendrimer-based micellar nanoparticles in human plasma and individual plasma components. We demonstrated we could gain much greater insight into nanoparticle-protein and nanoparticle-lipoprotein interactions by using site specific labeling technique and two highly sensitive and complementary analytical techniques, which is of utmost importance in the better design of nanomedicines. We are currently exploring novel techniques to probing the nanoparticles in single nanoparticle level and apply these techniques to study the nanoparticles in cells and animals.
Reference: Y. Li, M. S. Budamagunta, J. Luo, W. Xiao, J. C. Voss, K. S. Kim. Probing of the Assembly Structure and Dynamics within Nanoparticles during Interaction with Blood Proteins. ACS nano 2012, 6 (11), 9485-9495
In the past few years, we are developing methods for exosome isolation, characterization and detection. We identified ligands against exosome-associated integrins and developed Raman-based techniques for single exosome analysis.
Carney R, Hazari S, Colquhoun M, Tran D, Hwang B, Mulligan M, Bryers J, Girda E, Leiserowitz G, Smith Z, Lam KS. Multispectral optical tweezers for biochemical fingerprinting of CD9-positive exosome subpopulations. Analytical Chemistry, 89:5357-5363, 2017.
Left: Electron micrograph of exosomes by negative-stained conventional EM showing the typical cup shape morphology. Right: AFM amplitude image of isolated exosomes deposited on mica.
Reference: Carney R, Hazari H, Rojalin T, Knudson A, Gao T, Tang Y, Liu R, Viitala T, Yliperttula M, and Lam K S. Targeting Tumor-Associated Exosomes with Integrin-Binding Peptides. Advanced Biosystems, 2017 May; 1(5): 1600038.
Genetically-encoded Small Illuminants for 4D Functional Imaging of Living Cells:
In the last two decades, application of fluorescent probes and sensors in molecular imaging has greatly improved our understanding about how specific molecules orchestrate cellular functions and how errant cells cause diseases. To expand the toolbox of fluorescent probes, we have developed a novel class of genetically encoded illuminants to probe the cellular function. Using highly efficient one-bead-one-compound (OBOC) combinatorial library technique, we have identified 10 to 20-mer peptides that can specifically bind and activate the fluorescence of a variety of organic dyes, such as malachite green (MG) and bromo cresol purple (BCP). These peptides may serve as genetically encoded small illuminants (GESIs), which allows visualization of fusion protein localization in living cell. The interplay between the peptide and organic dyes provides a general platform for the design of genetically encoded biosensors to probe many biochemical events in living cells.
Expression and characterization of BCP-activating GESI peptide in living cells
Intraocular Xenograft Model & Use of EyePod for Real-time Imaging of Tumor Microenvironment
Dr. Lam together with Prof. Edward Pugh co-developed the intraocular model of xenografts so that the tumor and tumor microenvironment can be visualized in real-time at cellular level, longitudinally over weeks and months.