Phoenix’s Tumor-Targeting Peptide library lists many endogenous peptides that can have a major impact on the study of tumors which includes:
(1) Tumor Microenvironment-Associated Peptides (promotors or anticancer) : Many signature peptides present in the microenviroment of cancer cells has been identified by the Mass Spectrometry methods, some of these peptides has been found to influence the cell behavior such as cancer proliferation and metastasis. Especially, the peptides that derived from growth factors or their receptors or surround extracellular-matrix has strong influence on the cell behaviors such as proliferation and metastasis. Based on the evidence to indicate an important roles either in the cancer promoting or anticancer activity, we have assembled these peptides as a tumor-associated Peptide Library. The important feature of this tumor-associated Peptide library is that it also provides information that can have a various chemical modifications like non-natural, D-amino acids, modified-amino acid like ornithine to prevent degradation. Accumulated data has been curated manually into our library from both published articles, patents as well as from other repositories. The database is cross-linked with various other related resources in order to provide comprehensive information related to the previous studies that are associated with the current Cancer-Targeted peptide.
(2) Tumor Penetrating Peptides : These peptides has been used for targeted delivery of oligonucleotides, drugs, imaging agents, inorgannic nanoparticles, liposomes, and viruses to the tumor cells. In addition to the specifically internalizing peptides with your targeted molecules (e.g. siRNA, protein.. etc.) delivery into human cancer cells, many of these peptides also has been found to have a powerful anti-cancer properties. (Note: Special biotinylated or fluorescent peptides can be included upon requested)
(3) Homing Peptides : A list of peptides which are capable of binding tumor cells with exquisite specificity. Peptides containing RGD binds to integrins and facilitate cancer cell migration. In contrast, peptides containing GSL exhibit an inhibition of tumor homing. Some of these peptides also have ability to identify and antagonize or enhance the signal transduction pathways in tumor cells or tissues. These peptides also can be used to deliver target specific drugs and as imaging agents for therapeutics and diagnostics. Thus screening of tumor homing peptide has become an important tool for managing cancer treatment effectively. (Note: Special biotinylated or fluorescent peptides can be included upon requested)
Targeting the microenvironment for treating advanced ovarian cancer has been promise in mice. For example, the researchers identified the segment of prosaposin that stimulates thrombospondin-1 and created a modified version of the peptide for use as a potential drug. “We found that the peptide could not only stop the progression of the tumors but could also shrink tumors to an undetectable state, which was very exciting,” said Dr. Watnick. They tested the peptide in mice with tumors formed by transplanted human ovarian cancer cells.
The below is an example to explore the (A). Biological (e.g. Integrin binding sites, cell-cell interaction), (B) Biophysical (e.g. matrix stiffness properties), and (C) Biochemical (e.g. cell-mediated enzymatic degradation) effects using Corning® HTS Transwell®-96 well permeable support.
Example of discovery of anti-angiogenic TSP-1 using peptides/peptidomimetics
Angiogenesis has to be tightly regulated by a balance between the production and release of pro- and antiangiogenic molecules regulates neovascularization. A balance in this process contributes to numerous malignant, inflammatory, ischemic, infectious, and immune disorders.
a, Immune cells called T cells that express the proteins CD4 or CD8 on their surface can target and kill tumour cells if they recognize peptides known as antigens (not shown) expressed by the tumour cells. However, this immune response is often suppressed in the microenvironment of a tumour. b, Such immunosuppression can be blocked through treatment that blocks the PD-1-receptor pathway in T cells, enabling them to cause tumour destruction or regression. c, Ott et al. and Sahin et al. report phase I clinical studies that investigated a vaccine-based approach to treat skin cancer. They identified antigens that were expressed on the tumours of individual patients, and generated a personalized vaccine to initiate or strengthen immune responses against these antigens. The authors observed a broadened and boosted immune response against the tumour, with both CD8+ and CD4+ T cells responding to the antigens presented in the vaccine. d, The vaccinations resulted in the destruction or regression of tumours. In some patients, residual tumours could be destroyed by the subsequent use of a treatment to block the PD-1-receptor pathway. It seems probable that vaccination can lead to the destruction of small tumours that have recurred or migrated to other locations in the body (metastases), whereas larger recurrences or metastases might need PD-1-receptor pathway blockade to be completely destroyed.
Tumor-targeting peptide ligands can be conjugated directly or indirectly to functional groups on the outer leaflet of the protocell lipid bilayer. Functionalized protocells can be loaded with a wide variety of cargos such as chemotoxins, genes, siRNA, aptamers or imaging agents. The composition of the lipid bilayer can be modified to regulate the concentration of bound peptide ligands to minimize binding site inhibition and optimize therapeutic indices, and may also incorporate different polymer coatings (purple dots) to improve circulation retention times.
Self-assembling peptides improve the stability of glucagon-like peptide-1 by forming a stable and sustained complex. An complex of Pep-1 and GLP-1 exhibited a remarkable extension in the half-life of GLP-1. In addition, the experimental animals treated with a GLP-1/Pep-1 complex exhibited better blood glucose clearance activity over a greater duration of time than the animals treated with GLP-1 alone. Based on these results, an adjustment of the Pep-1 and GLP-1 ratios is presumed to be able to control the half-life of GLP-1 (e.g., medium-acting and long-acting). The findings in this study also suggest that the self-assembling peptide Pep-1 could serve as a powerful drug preparation tool to extend the short half-life of therapeutic peptides.