Identification, design and synthesis of tubulin-derived peptides as novel hyaluronan mimetic ligands for the receptor for hyaluronan-mediated motility (RHAMM/HMMR)

Abstract

Fragments of the extracellular matrix component hyaluronan (HA) promote tissue inflammation, fibrosis and tumor progression. HA fragments act through HA receptors including CD44, LYVE1, TLR2,4 and the receptor for hyaluronan mediated motility (RHAMM/HMMR). RHAMM is a multifunctional protein with both intracellular and extracellular roles in cell motility and proliferation. Extracellular RHAMM binds directly to HA fragments while intracellular RHAMM binds directly to ERK1 and tubulin. Both HA and regions of tubulin (s-tubulin) are anionic and bind to basic amino acid-rich regions in partner proteins, such as in HA and tubulin binding regions of RHAMM. We used this as a rationale for developing bioinformatics and SPR (surface plasmon resonance) based screening to identify high affinity anionic RHAMM peptide ligands. A library of 12-mer peptides was prepared based on the carboxyl terminal tail sequence of s-tubulin isoforms and assayed for their ability to bind to the HA/tubulin binding region of recombinant RHAMM using SPR. This approach resulted in the isolation of three 12-mer peptides with nanomolar affinity for RHAMM. These peptides bound selectively to RHAMM but not to CD44 or TLR2,4 and blocked RHAMM:HA interactions. Furthermore, fluorescein-peptide uptake by PC3MLN4 prostate cancer cells was blocked by RHAMM mAb but not by CD44 mAb. These peptides also reduced the ability of prostate cancer cells to degrade collagen type I. The selectivity † These might include comments relevant to but not central to the matter under discussion, limited experimental and spectral data, and crystallographic data.

Receptor for hyaluronan mediated motility (RHAMM/HMMR) is a novel target for promoting subcutaneous adipogenesis

“…We have previously reported the isolation of tubulin derived peptides that bind with nM affinity to RHAMM and that mimic HA fragments that are ligands for extracellular RHAMM [53]. We therefore next compared the adipogenic dose response of mouse pre-adipocytes (3T3-L1) to one of these peptides (NPI-0109) with the response to NPI-201 and NPI-104 using promotion of adiponectin protein expression as a marker for adipogenesis (Figure 6).…”

Carcinoma Cell Hyaluronan as a “Portable” Cancerized Prometastatic Microenvironment

“…These are structurally distinct from HA binding CD44 link domain [4, 14]. Peptides mimicking the RHAMM BX 7 B motif and peptides mimicking the size of HA fragments, which specifically block cell surface RHAMM functions [56, 57] along with anti-RHAMM antibodies, inhibit early responses relevant to both wound repair and tumorigenesis. These responses include RHAMM stimulated mesenchymal cell motility, tumor cell invasion and angiogenesis [57, 58].…”

RHAMM-target peptides inhibit invasion of breast cancer cells

“…Previously, we demonstrated that RHAMM-target peptides interact with HA binding domain of RHAMM with high selectivity and specificity (12,13). These RHAMM-target peptides have a small size (M.w.…”

“…Another category of anti-peptides act as a peptide antagonists which preferentially bind to a known receptor. It was shown, that RHAMM-binding peptides specifically bind to RHAMM receptor, block the signal pathway, induce the apoptosis, necrosis of cancer cells (12,13). Such selective peptides have great prospects, because their main mechanism of action targeted to a specific molecular target cancer cells that may lead to cell death (14,15).…”