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Biology subjects

Ruoslahti, E.

Publications and source records attributed to Ruoslahti, E..

5 recordsLinked to original sources

A neuroprotective tetrapeptide for treatment of acute traumatic brain injury

Traumatic brain injury (TBI) is a major clinical problem because of the high incidence and the severity of the subsequent sequelae. Despite extensive efforts, there are no therapeutic drugs clinically approved for treating acute TBI patients. To address this unmet need, we assessed the activity of the tetrapeptide, CAQK, in mice. When administered intravenously shortly after moderate or severe TBI, CAQK accumulates in the injured brain in mice and pigs. CAQK binds to an extracellular matrix glycoprotein complex that is upregulated in injured brain. Treatment of TBI mice with CAQK resulted in reduction in the size of the injury compared to control mice. There was reduced upregulation of the glycoprotein complex, less apoptosis, and lower expression of inflammatory markers in the injured area, indicating that CAQK alleviates neuroinflammation and the ensuing secondary injury. CAQK treatment also improved functional deficit in TBI mice, with no overt toxicity. Our findings suggest that CAQK may have therapeutic applications in TBI.

neuroscience↗

A CYCLIC PEPTIDE TARGETS GLIOBLASTOMA BY BINDING TO ABERRANTLY EXPOSED SNAP25

Disease-specific changes in tumors and other diseased tissues are an important target of research because they provide clues on the pathophysiology of the disease as well as uncovering potentially useful markers for diagnosis and treatment. Here, we report a new cyclic peptide, CESPLLSEC (CES), that specifically accumulated (homed) in intracranial U87MG and the WT-GBM model of glioblastoma from intravenous (IV) injection, associating with the vasculature. Affinity chromatography of U87MG tumor extracts on insolubilized CES peptide identified Synaptosomal Associated Protein 25 (SNAP25) as a candidate target molecule (receptor) for CES. Several results supported the identification of SNAP25 as the CES receptor. IV-injected FAM-CES colocalized with SNAP25 in the tumors, and direct binding studies showed specific CES peptide binding to recombinant human SNAP25. A CES peptide-drug conjugate designed for photodynamic therapy showed selective cytotoxicity to SNAP25+ glioblastoma cell lines. Specific accumulation of systemically injected anti-SNAP25 antibody in U87MG glioblastoma, and labeling of intact U87MG cells with anti-SNAP in flow cytometry showed that SNAP25 is available from the circulation but not in normal tissues and that it is present at the cell surface. Using an array of ECM proteins and surface plasmon resonance revealed that SNAP25 binds moderately to collagen V and strongly to collagen VI. Modeling studies suggested that CES and collagen VI compete for the same binding site on SNAP25. Our results introduce CES as a valuable targeting peptide for drug delivery, and its receptor SNAP25 as a possible molecular marker of interest for glioblastoma.

cancer biology↗

Tumor-resident regulatory T cells in pancreatic cancer express the αvβ5 integrin as a targetable activation marker

Pancreatic ductal adenocarcinoma (PDAC) has abundant immunosuppressive regulatory T cells (Tregs), which contribute to a microenvironment resistant to immunotherapy. Here, we report that Tregs in the PDAC tissue, but not those in the spleen, express the v{beta}5 integrin in addition to neuropilin-1 (NRP-1), which makes them susceptible to the iRGD tumor-penetrating peptide, which targets cells positive for v integrin- and NRP-1. As a result, long-term treatment of PDAC mice with iRGD leads to tumor-specific depletion of Tregs and improved efficacy of immune checkpoint blockade. v{beta}5 integrin+ Tregs are induced from both naive CD4+ T cells and natural Tregs upon T cell receptor stimulation, and represent a highly immunosuppressive subpopulation of CCR8+ Tregs. This study identifies the v{beta}5 integrin as a marker for activated tumor-resident Tregs, which can be targeted to achieve tumor-specific Treg depletion and thereby augment anti-tumor immunity for PDAC therapy.

cancer biology↗

iRGD-liposomes enhance tumor delivery and therapeutic efficacy of antisense oligonucleotide drugs against primary prostate cancer and bone metastasis

Nucleotide-based drugs, such as antisense oligonucleotides (ASOs), have unique advantages in treating human diseases as they provide virtually unlimited ability to target any gene. However, their clinical translation faces many challenges, one of which is poor delivery to the target tissue in vivo. This problem is particularly evident in solid tumors. Here, we functionalized liposomes with a tumor-homing and -penetrating peptide, iRGD, as a carrier of an ASO against androgen receptor (AR) for prostate cancer treatment. The iRGD-liposomes exhibited a high loading efficiency of AR-ASO, and an efficient knockdown of AR gene products was achieved in vitro, including AR splice variants. In vivo, iRGD-liposomes significantly increased AR-ASO accumulation in the tumor tissue and decreased AR expression relative to free ASOs in prostate tumors established as subcutaneous xenografts. Similar results were obtained with intra-tibial xenografts modeling metastasis to bones, the predominant site of metastasis for prostate cancer. In treatment studies, iRGD-liposomes markedly improved the AR-ASO efficacy in suppressing the growth of both subcutaneous xenografts and intra-tibial xenografts. The inhibitory effect on tumor growth was also significantly prolonged by the delivery of the AR-ASO in the iRGD-liposomes. Meanwhile, iRGD-liposomes did not increase ASO accumulation or toxicity in healthy organs. Overall, we provide here a delivery system that can significantly increase ASO accumulation and efficacy in solid tumors. These benefits are achieved without significant side effects, providing a way to increase the antitumor efficacy of ASOs.

cancer biology↗

Systemic Brain Tumor Delivery of Synthetic Protein Nanoparticles for Glioblastoma Therapy

Glioblastoma multiforme (GBM), the most aggressive form of brain cancer, has witnessed very little clinical progress over the last decades, in parts, due to the absence of effective drug delivery strategies. Intravenous injection is the least invasive delivery route to the brain, but has been severely limited by the blood-brain barrier (BBB). Inspired by the capacity of natural proteins and viral particulates to cross the BBB, we engineered a synthetic protein nanoparticle (SPNP) based on polymerized human serum albumin (HSA) equipped with the cell-penetrating peptide iRGD. SPNPs containing siRNA against Signal Transducer and Activation of Transcription 3 factor (STAT3i) result in in vitro and in vivo downregulation of STAT3, a central hub associated with GBM progression. When combined with the standard of care, ionized radiation, STAT3i SPNPs result in tumor regression and long-term survival in 87.5% of GBM bearing mice and primes the immune system to develop anti-GBM immunological memory.

bioengineering↗