Tuning a Polar Molecule for Selective Cytoplasmic Delivery by a pH (Low) Insertion Peptide

Wijesinghe, Dayanjali; Engelman, Donald M.; Andreev, Oleg A.; Reshetnyak, Yana K.

doi:10.1021/bi2009773

Cited by 47 publications

(61 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This process has been used for the translocation and release of various payloads, including cell-impermeable model peptides, imaging agents and toxins into cancer cells. 19–21 Importantly, pHLIP-mediated translocation of cargo molecules across the cell membrane is not mediated either by interactions with cell surface receptors or through formation of pores in cell membranes. Thus, pHLIP releases cargo molecules directly into the cytoplasm without the need to escape endosomes or lysosomes.…”

Section: Introductionmentioning

confidence: 99%

Inhibition of Cancer Cell Proliferation and Breast Tumor Targeting of pHLIP–Monomethyl Auristatin E Conjugates

2015

View full text Add to dashboard Cite

Localized delivery is vital for the successful development of novel and effective therapeutics for the treatment of cancer. The targeting and delivery described herein is based on the pH(Low) Insertion Peptide (pHLIP), a unique delivery peptide that can selectively target tumors in mice and translocate and release cargo molecules intra-cellularly based solely on the low extracellular pH intrinsic to cancer cells. In this study, we investigate the efficacy of pHLIP to target and deliver the highly potent and clinically validated microtubule inhibitor monomethyl auristatin E (MMAE) to cancer cells and breast tumors. We show that pHLIP-MMAE conjugates induce a potent cytotoxic effect (> 90% inhibition of cell growth) in a concentration- and pH-dependent manner after only 2-hour incubation without any apparent disruption of the plasma membrane. pHLIP-MMAE conjugates exhibit between an 11 and 144-fold higher anti-proliferative effect at low pH than at physiological pH, and a pronounced pH-dependent cytotoxicity as compared to free drug. Furthermore, we demonstrate that a pHLIP-MMAE drug conjugate effectively targets triple negative breast tumor xenografts in mice. These results indicate pHLIP-based auristatin conjugates may have an enhanced therapeutic window as compared to free drug, providing a targeting mechanism to attenuate systemic toxicity.

show abstract

Section: Introductionmentioning

confidence: 99%

Inhibition of Cancer Cell Proliferation and Breast Tumor Targeting of pHLIP–Monomethyl Auristatin E Conjugates

2015

View full text Add to dashboard Cite

show abstract

“…While studying membrane protein folding, we discovered a peptide called pH (low) insertion peptide (pHLIP) that reversibly folds and inserts across membranes in response to pH changes, and this discovery has led to a unique way to target acidic tissue. Our biophysical studies have revealed the molecular mechanism of pHLIP action (1-3), and we have shown that pHLIP can target acidic tissue and selectively translocate polar, cell-impermeable molecules across cell membranes in response to low extracellular pH (1,(4)(5)(6)(7)(8)(9). pHLIP conjugated with fluorescent dyes, PET [ 64 Cu-DOTA (1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid) and 18 F], single photon emission computed tomography (SPECT; 99 Tc) probes, and gold nanoparticles targets acidic tumors (1,4,5,10,11).…”

mentioning

confidence: 99%

Family of pH (low) insertion peptides for tumor targeting

Weerakkody

Moshnikova

Thakur

et al. 2013

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

181

275

View full text Add to dashboard Cite

Cancer is a complex disease with a range of genetic and biochemical markers within and among tumors, but a general tumor characteristic is extracellular acidity, which is associated with tumor growth and development. Acidosis could be a universal marker for cancer imaging and the delivery of therapeutic molecules, but its promise as a cancer biomarker has not been fully realized in the clinic. We have discovered a unique approach for the targeting of acidic tissue using the pH-sensitive folding and transmembrane insertion of pH (low) insertion peptide (pHLIP). The essence of the molecular mechanism has been elucidated, but the principles of design need to be understood for optimal clinical applications. Here, we report on a library of 16 rationally designed pHLIP variants. We show how the tuning of the biophysical properties of peptide-lipid bilayer interactions alters tumor targeting, distribution in organs, and blood clearance. Lead compounds for PET/single photon emission computed tomography and fluorescence imaging/MRI were identified, and targeting specificity was shown by use of noninserting variants. Finally, we present our current understanding of the main principles of pHLIP design.membrane-associated folding | tumor acidity | thermodynamics | kinetics | diagnostics

show abstract

“…This coil inserts into cell membranes and thus allows selective targeting of cancerous tissue of low extracellular pH (pH 6.0-6.8) while avoiding retention in healthy tissue (pH 7.2-7.4). WT-pHLIP has been successfully tested in vitro as an agent for intracellular delivery of large polar cargo molecules (26)(27)(28)(29). In addition, WT-pHLIP promotes pHdependent fusion of pHLIP-coated liposomes containing gramicidin channels with cellular membranes, thus destroying the balance of monovalent ions (30).…”

mentioning

confidence: 99%

The pH low insertion peptide pHLIP Variant 3 as a novel marker of acidic malignant lesions

Tapmeier

Moshnikova

Beech

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

View full text Add to dashboard Cite

Current strategies for early detection of breast and other cancers are limited in part because some lesions identified as potentially malignant do not develop into aggressive tumors. Acid pH has been suggested as a key characteristic of aggressive tumors that might distinguish aggressive lesions from more indolent pathology. We therefore investigated the novel class of molecules, pH low insertion peptides (pHLIPs), as markers of low pH in tumor allografts and of malignant lesions in a mouse model of spontaneous breast cancer, BALB/neu-T. pHLIP Variant 3 (Var3) conjugated with fluorescent Alexa546 was shown to insert into tumor spheroids in a sequence-specific manner. Its signal reflected pH in murine tumors. It was induced by carbonic anhydrase IX (CAIX) overexpression and inhibited by acetazolamide (AZA) administration. By using 31 P magnetic resonance spectroscopy (MRS), we demonstrated that pHLIP Var3 was retained in tumors of pH equal to or less than 6.7 but not in tissues of higher pH. In BALB/neu-T mice at different stages of the disease, the fluorescent signal from pHLIP Var3 marked cancerous lesions with a very low false-positive rate. However, only ∼60% of the smallest lesions retained a pHLIP Var3 signal, suggesting heterogeneity in pH. Taken together, these results show that pHLIP can identify regions of lower pH, allowing for its development as a theranostic tool for clinical applications.

show abstract

Tuning a Polar Molecule for Selective Cytoplasmic Delivery by a pH (Low) Insertion Peptide

Cited by 47 publications

References 26 publications

Inhibition of Cancer Cell Proliferation and Breast Tumor Targeting of pHLIP–Monomethyl Auristatin E Conjugates

Inhibition of Cancer Cell Proliferation and Breast Tumor Targeting of pHLIP–Monomethyl Auristatin E Conjugates

Family of pH (low) insertion peptides for tumor targeting

The pH low insertion peptide pHLIP Variant 3 as a novel marker of acidic malignant lesions

Contact Info

Product

Resources

About