Cell-penetrating ATF5 polypeptides and uses thereof
Inventors
Kappel, Barry Jay • Rotolo, Jimmy Andrew • Merutka, Gene
Assignees
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Publication Number
US-10316077-B2
Publication Date
2019-06-11
Expiration Date
Abstract
Provided are cell-penetrating ATF5 polypeptides having a cell-penetrating region and an ATF5 leucine zipper region, compositions comprising the ATF5 polypeptides, and methods of treating a tumor and promoting cytotoxicity in a neoplastic cell using the ATF5 polypeptides.
Core Innovation
The invention provides cell-penetrating ATF5 polypeptides that include a cell-penetrating region and an ATF5 leucine zipper region. The ATF5 leucine zipper region is defined by amino acid sequences selected from LEGECQGLEARNRELKERAESV (SEQ ID NO: 7) and LEGECQGLEARNRELRERAESV (SEQ ID NO: 8), and the polypeptide lacks an extended leucine zipper region. The polypeptides are described as capable of crossing the blood-brain barrier.
The polypeptides can include an optional lactam-bridge at defined position pairs, and can include optional N-terminal acetyl and/or C-terminal amide modifications. Different cell-penetrating region choices are described, including peptide sequences associated with SEQ ID NO: 20, SEQ ID NO: 21, SEQ ID NO: 35, and SEQ ID NO: 36.
The invention is directed to functional outcomes including inhibition of ATF5 activity and apoptosis/cytotoxicity in neoplastic cells. Documented examples compare a shorter-leucine-zipper variant ST-3 to a prior longer-leucine-zipper inhibitor ST-2, including penetration into glioblastoma cells, enhanced in vitro potency across multiple cancer cell lines, and enhanced caspase activation with ABT-263 (Navitoclax). In vivo tumor growth repression and delay are described in xenograft models.
Claims Coverage
The independent claims cover cell-penetrating ATF5 polypeptides with restricted leucine zipper sequences lacking an extended leucine zipper region, and in vitro or ex vivo methods of promoting cytotoxicity using either the polypeptide or a nucleic acid encoding it. Overall, the inventive coverage centers on structural restriction of the ATF5 leucine zipper region to SEQ ID NO: 7 or SEQ ID NO: 8, exclusion of an extended leucine zipper region, and method use in the independent method claims.
Cell-penetrating ATF5 polypeptide lacking extended leucine zipper region
A cell-penetrating ATF5 polypeptide consisting essentially of a cell-penetrating region and an ATF5 leucine zipper region, wherein the ATF5 leucine zipper region has an amino acid sequence selected from the group consisting of LEGECQGLEARNRELKERAESV (SEQ ID NO: 7) and LEGECQGLEARNRELRERAESV (SEQ ID NO: 8), and wherein the polypeptide lacks an extended leucine zipper region.
Specified cell-penetrating ATF5 amino acid sequences lacking extended leucine zipper region
A cell-penetrating ATF5 polypeptide comprising an amino acid sequence selected from the group consisting of RQIKIWFQNRRMKWKKLEGECQGLEARNRELKERAESV (SEQ ID NO: 3), RQIKIWFQNRRMKWKKLEGECQGLEARNRELRERAESV (SEQ ID NO: 4), YGRKKRRQRRRLEGECQGLEARNRELKERAESV (SEQ ID NO: 5), and YGRKKRRQRRRLEGECQGLEARNRELRERAESV (SEQ ID NO: 6), wherein the polypeptide lacks an extended leucine zipper region.
In vitro or ex vivo cytotoxicity promotion using ATF5 polypeptide lacking extended leucine zipper region
An in vitro or ex vivo method of promoting cytotoxicity in a neoplastic cell, the method comprising introducing into the neoplastic cell an ATF5 polypeptide consisting essentially of an amino acid sequence selected from the group consisting of LEGECQGLEARNRELKERAESV (SEQ ID NO: 7) and LEGECQGLEARNRELRERAESV (SEQ ID NO: 8), wherein the polypeptide lacks an extended leucine zipper region.
In vitro or ex vivo cytotoxicity promotion using nucleic acid encoding ATF5 polypeptide lacking extended leucine zipper region
An in vitro or ex vivo method of promoting cytotoxicity in a neoplastic cell, the method comprising introducing into the neoplastic cell a nucleic acid molecule encoding an ATF5 polypeptide consisting essentially of an amino acid sequence selected from the group consisting of LEGECQGLEARNRELKERAESV (SEQ ID NO: 7) and LEGECQGLEARNRELRERAESV (SEQ ID NO: 8), wherein the polypeptide lacks an extended leucine zipper region.
Across the independent claims, the core inventive concept is centered on ATF5 polypeptides or nucleic acids encoding them that are cell-penetrating and include an ATF5 leucine zipper limited to SEQ ID NO: 7 or SEQ ID NO: 8, while lacking an extended leucine zipper region. The independent method claims then use these restricted polypeptides or their encoding nucleic acids to promote cytotoxicity in a neoplastic cell in vitro or ex vivo.
Stated Advantages
Improved in vitro potency compared to a prior longer-leucine-zipper inhibitor ST-2, including penetration into glioblastoma cells and enhanced potency across multiple cancer cell lines.
Enhanced caspase activation when combined with ABT-263 (Navitoclax).
Improved tumor growth repression and delay in xenograft models.
Documented Applications
Crossing the blood-brain barrier with the described cell-penetrating ATF5 polypeptides.
Treatment of tumors, including tumor growth repression and delay in xenograft models.
In vitro or ex vivo promotion of cytotoxicity in neoplastic cells by contacting neoplastic cells with the described cell-penetrating ATF5 polypeptides.
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