Amino terminal hydrophobic import signals target the p14ARF tumor suppressor to the mitochondria

Irvine, Mal; Philipsz, Suzanah; Frausto, Monika; Mijatov, Branka; Gallagher, Stuart J.; Fung, Carina; Becker, Therese M.; Kefford, Richard; Rizos, Helen

doi:10.4161/cc.9.4.10785

Cited by 14 publications

(21 citation statements)

References 36 publications

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“…We next attempted to shorten the sequence of the prototype peptide to the minimal functional amino acid sequence within the p14 derived segment. Because “AVAL,” at the 41st through 44th amino acid positions of the p14 protein, is known to be the mitochondrial localization motif, we constructed the truncated peptides with or without this motif, and compared the efficiency of growth suppression among the four peptides; namely, prototype r9‐p14 38‐65 with the original “GPG” spacer , r9‐CatB‐p14 38‐65 with the “GFLG” spacer, truncated r9‐CatB‐p14 41‐57 retaining “AVAL,” and the most truncated form, r9‐CatB‐p14 MIS (see and Fig. S1a).…”

Section: Resultsmentioning

confidence: 99%

“…It interacts with the mitochondrial protein p32/C1QBP, which is essential to ARF's pro‐apoptotic function . The hydrophobic domain within the amino‐terminal half of p14 ARF serves as a mitochondrial import sequence, and it interacts with Bcl‐XL and p32 in a p53‐independent manner after mitochondrial entry . Moreover, a heat shock protein, HSP70, is reported to mediate mitochondrial localization of p14 ARF , which triggers autophagy in response to cellular stress .…”

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confidence: 82%

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Peptide‐based tumor inhibitor encoding mitochondrial p14^ARF is highly efficacious to diverse tumors

et al. 2016

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p14 ARF is one of the major tumor suppressors conventionally identified both as the mdm2‐binding molecule restoring p53 function in the nucleus, and as a nucleophosmin‐binding partner inside the nucleolous to stabilize ribosomal RNA. However, its recently reported mitochondrial localization has pointed to novel properties as a tumor suppressor. At the same time, functional peptides are gaining much attention in nanomedicine for their in vivo utility as non‐invasive biologics. We previously reported the p14ARF‐specific peptide that restored the sensitivity to gefitinib on the gefitinib‐resistant lung cancer cells. Based on the information of this prototype peptide, here we generated the more powerful anti‐tumor peptide “r9‐CatB‐p14 MIS,” which comprises the minimal inhibitory sequence of the mitochondrial targeting p14ARF protein in combination with the proteolytic cleavage site for cathepsin B, which is activated in various tumor cells, fused with the nine‐polyarginine‐domain for cell penetration, and demonstrated its novel action of regulating mitochondrial function in accordance with localization of endogenous p14ARF. The p14 MIS peptide showed a potent tumor inhibiton in vitro and in vivo against not only lung cancer cells but also tumor cells of diverse lineages, via modulating mitochondrial membrane potential, with minimal cytotoxicity to non‐neoplastic cells and tissues. Hence, this mitochondrially targeted p14 peptide agent provides a novel basis for non‐invasive peptide‐based antitumor therapeutics.

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Section: Resultsmentioning

confidence: 99%

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confidence: 82%

Peptide‐based tumor inhibitor encoding mitochondrial p14^ARF is highly efficacious to diverse tumors

et al. 2016

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“…The ratio of viable cells to the untreated cells (without peptides and gefitinib) is shown. Shown as means AE SD (n ¼ 3,mitochondrial localization, although it lacks a mdm2/B23 binding site (34). This newly designed peptide is powerful for antitumor potency because its antiproliferative effect was much stronger than that of the p14 38-50 peptide (fourfold more; Supplementary Fig.…”

Section: Discussionmentioning

confidence: 99%

Antitumor Impact ofp14ARFon Gefitinib-Resistant Non–Small Cell Lung Cancers

Saito

Takigawa

Ohtani

et al. 2013

Molecular Cancer Therapeutics

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Activation of the epidermal growth factor receptor (EGFR) has been observed in many malignant tumors and its constitutive signal transduction facilitates the proliferation of tumors. EGFR-tyrosine kinase inhibitors, such as gefitinib, are widely used as a molecular-targeting agent for the inactivation of EGFR signaling and show considerable therapeutic effect in non-small cell lung cancers harboring activating EGFR mutations. However, prolonged treatment inevitably produces tumors with additional gefitinibresistant mutations in EGFR, which is a critical issue for current therapeutics. We aimed to characterize the distinct molecular response to gefitinib between the drug-resistant and drug-sensitive lung adenocarcinoma cells in order to learn about therapeutics based on the molecular information. From the quantitative PCR analysis, we found a specific increase in p14 ARF expression in gefitinib-sensitive lung adenocarcinoma clones, which was absent in gefitinib-resistant clones. Moreover, mitochondria-targeted p14 ARF triggered the most augmented apoptosis in both clones. We identified the amino acid residues spanning from 38 to 65 as a functional core of mitochondrial p14 ARF (p14 38-65 a.a.), which reduced the mitochondrial membrane potential and caused caspase-9 activation. The synthesized peptide covering the p14 38-65 a.a. induced growth suppression of the gefitinib-resistant clones without affecting nonneoplastic cells. Notably, transduction of the minimized dose of the p14 38-65 peptide restored the response to gefitinib like that in the sensitive clones. These findings suggest that the region of p14 ARF 38-65 a.a. is critical in the pharmacologic action of gefitinib against EGFR-mutated lung adenocarcinoma cells and has potential utility in the therapeutics of gefitinib-resistant cancers.

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“…Keywords: ARF, mitochondria, autophagy, HSP70, phenylethynesulfonamide localization, and presumably also autophagy induction, are distinct on human and murine ARF, probably reflecting the poor degree of homology of these two proteins. Specifically, highly hydrophobic residues in the N-terminus of human ARF act as a mitochondrial import sequence, 9 while a version of murine ARF that lacks the N-terminal domain shows enhanced trafficking to mitochondria. 10 Presently unknown are the proteins or controls that regulate mitochondrial trafficking and/or autophagy by ARF.…”

Section: Introductionmentioning

confidence: 99%

Interaction of the ARF tumor suppressor with cytosolic HSP70 contributes to its autophagy function

Pimkina¹,

Murphy

2011

Cancer Biology & Therapy

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Amino terminal hydrophobic import signals target the p14ARF tumor suppressor to the mitochondria

Cited by 14 publications

References 36 publications

Peptide‐based tumor inhibitor encoding mitochondrial p14^ARF is highly efficacious to diverse tumors

Peptide‐based tumor inhibitor encoding mitochondrial p14^ARF is highly efficacious to diverse tumors

Antitumor Impact ofp14ARFon Gefitinib-Resistant Non–Small Cell Lung Cancers

Interaction of the ARF tumor suppressor with cytosolic HSP70 contributes to its autophagy function

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Amino terminal hydrophobic import signals target the p14ARF tumor suppressor to the mitochondria

Cited by 14 publications

References 36 publications

Peptide‐based tumor inhibitor encoding mitochondrial p14ARF is highly efficacious to diverse tumors

Peptide‐based tumor inhibitor encoding mitochondrial p14ARF is highly efficacious to diverse tumors

Antitumor Impact ofp14ARFon Gefitinib-Resistant Non–Small Cell Lung Cancers

Interaction of the ARF tumor suppressor with cytosolic HSP70 contributes to its autophagy function

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Peptide‐based tumor inhibitor encoding mitochondrial p14^ARF is highly efficacious to diverse tumors

Peptide‐based tumor inhibitor encoding mitochondrial p14^ARF is highly efficacious to diverse tumors