PNC-27 Peptide

Description

What is PNC-27 Peptide?

PNC-27 is a synthetic 32-residue chimeric peptidomimetic constructed from two structurally distinct functional domains: the HDM-2-binding segment of the tumor suppressor protein p53 (residues 12–26) and a membrane residency peptide (MRP) leader sequence derived from the cell-penetrating peptide penetratin. The compound was developed as a laboratory tool to investigate the role of membrane-localized HDM-2 (human double minute 2 protein) in malignant cell biology, with particular relevance to models of solid-tissue and hematologic tumor cell necrosis.

In research settings, PNC-27 has been employed as a selective probe for studying HDM-2 membrane expression patterns in transformed cell lines, transmembrane pore formation in cancer cell model systems, and the mechanistic relationship between membrane-bound oncoproteins and tumor cell death pathways. Early investigations identified that multiple cancer cell lines — including pancreatic, breast, melanoma, leukemia, and ovarian carcinoma lines — express HDM-2 at the plasma membrane surface in quantities not observed in untransformed (non-malignant) reference cell lines. The peptide’s chimeric architecture — which requires both the p53-derived domain and the MRP leader sequence to be covalently linked for activity — has been characterized extensively in cell-based preclinical assay systems.

PNC-27 supplied by RCDbio is intended strictly for laboratory and research purposes. It is not approved by the Food and Drug Administration for use in this research-grade, non-pharmaceutical form. It is not a dietary supplement and is not intended for human consumption or therapeutic self-administration.

Chemical Properties

Property	Detail
Product Type	Synthetic Chimeric Peptidomimetic (p53-Derived / CPP Conjugate)
Product Name	PNC-27 Peptide
Application	Scientific / Research Use Only
CAS Number	1159861-00-3
Molar Mass	4031.72 g/mol
Chemical Formula	C₁₈₈H₂₉₃N₅₃O₄₄S
Sequence	PPLSQETFSDLWKLLKKWKMRRNQFWVKVQRG (32 residues; p53 aa12–26 domain fused to MRP leader sequence)
IUPAC Name	Full systematic IUPAC name not registered for this chimeric sequence; compound is indexed under CAS 1159861-00-3
Synonyms	PNC27; PNC 27; p53(12–26)–penetratin/MRP chimera; HDM2-targeted lytic peptide; p53-derived anticancer research peptide
Physical Form	Lyophilized white to off-white powder
Solubility	Soluble in sterile water and buffered aqueous solutions (e.g., PBS, pH 7.4); small volumes of DMSO or 0.1% trifluoroacetic acid (TFA) may be used to improve initial dissolution in challenging preparations; avoid strongly acidic or strongly alkaline conditions
Storage (Lyophilized)	Store at −20°C in a sealed, light-protected container with desiccant; avoid repeated temperature cycling prior to reconstitution
Storage (Reconstituted)	Store at 4°C; use within 48–72 hours of reconstitution; avoid repeated freeze-thaw cycles; discard any solution that appears turbid, particulate, or discolored
PubChem CID	122192877
Purity	≥98% (HPLC verified, independent third-party laboratory analysis; COA available per batch)
WADA Status	PNC-27 does not appear by name on the current WADA Prohibited List. However, as a synthetic peptide with oncological activity, it may fall under the S0 Non-Approved Substances category or related peptide hormone subcategories depending on context and jurisdiction. Researchers engaged in sport-adjacent studies should verify the current status at GlobalDRO.com before use.

How Does PNC-27 Peptide Work?

PNC-27 exerts its observed cytotoxic activity in cancer cell model systems through a mechanism that is fundamentally membrane-dependent, centered on binding to HDM-2 protein expressed at the plasma membrane surface of transformed cells. The compound’s dual-domain architecture is essential to its characterized activity: neither the isolated p53 12–26 segment nor the MRP leader sequence alone, nor both delivered as separate non-conjugated peptides, replicates the activity of the covalently linked chimeric construct in preclinical assay systems.

HDM-2 Membrane Binding and Target Selectivity

In preclinical cell-based studies, HDM-2 protein has been detected at high levels in the plasma membrane fractions of multiple transformed cell lines — including MIA-PaCa-2 pancreatic carcinoma, MCF-7 breast carcinoma, A-2058 melanoma, and K562 chronic myeloid leukemia cells — while being absent or expressed at only low background levels in the membrane fractions of several untransformed reference cell lines (MCF-10-2A, BMRPA1, AG13145 fibroblasts). Conformational energy calculations and NMR structural data indicate that the p53-derived segment of PNC-27 adopts a three-dimensional configuration that is superimposable on the known structure of p53 residues 17–29 bound to MDM-2, consistent with direct engagement of the p53-binding site on HDM-2 (residues 1–109) in the cancer cell membrane. Monoclonal antibody blockade experiments in MIA-PaCa-2 pancreatic carcinoma cell preparations confirm that antibody directed against the p53-binding site of HDM-2 blocks PNC-27-induced cell necrosis, while negative control immune serum does not, providing mechanistic evidence that the p53-binding site of membrane-localized HDM-2 constitutes the primary binding interface. [Sarafraz-Yazdi et al., 2010]

Transmembrane Pore Formation and Tumor Cell Necrosis

Following co-localization with plasma membrane-bound HDM-2, PNC-27 has been characterized in transmission electron microscopy (TEM) and immunoscanning electron microscopy (SEM) studies as inducing the formation of transmembrane pores in the cancer cell membrane. Immuno-SEM using gold-labeled antibodies against both PNC-27 and HDM-2 identified approximately 1:1 PNC-27/HDM-2 complexes arranged in layered ring-shaped structures within these pores, near the cell surface. In p53-null K562 leukemia cells, PNC-27 co-localized with membrane-expressed HDM-2 and induced nearly 100% cell killing as assessed by lactate dehydrogenase (LDH) release — a marker of necrotic rather than apoptotic cell death — indicating that the mechanism of action in these cell preparations is independent of intracellular p53 status. [Sarafraz-Yazdi et al., 2022; Davitt et al., 2014]

Mitochondrial Disruption in Treated Cancer Cell Preparations

In MIA-PaCa-2 pancreatic carcinoma cell preparations treated with PNC-27, mitotracker dye retention assays and immuno-electron microscopy with gold-labeled anti-PNC-27 antibody demonstrated that the peptide, upon entering cancer cells, associates with mitochondrial membranes and causes selective mitochondrial disruption. Lysotracker-positive lysosomes retained their dye under the same conditions, indicating organelle-selective rather than global cytoplasmic disruption. These findings in pancreatic carcinoma cell models suggest a dual mechanism: initial membrane pore formation at the plasma membrane, followed by intracellular mitochondrial targeting. [Krzesaj et al., 2024]

HDM-2 Membrane Expression as a Determinant of Sensitivity

In AML (acute myelogenous leukemia) cell line studies using U937, OCI-AML3, and HL-60 cell lines, flow cytometry confirmed high levels of HDM-2 surface membrane expression, and PNC-27 induced LDH-measurable necrosis within four hours of treatment. Normal hematopoietic cell preparations in the same experimental system did not demonstrate equivalent necrosis, consistent with prior observations linking PNC-27 sensitivity to membrane HDM-2 expression levels across solid and non-solid tissue tumor cell models. [Thadi et al., 2020]

Key Research Findings

• Membrane HDM-2 binding: PNC-27 co-localizes with HDM-2 in plasma membrane fractions of pancreatic, breast, melanoma, and leukemia cell lines; absent in untransformed reference cell preparations. [Sarafraz-Yazdi et al., 2010]

• Transmembrane pore formation: Immuno-SEM with dual gold-labeled antibodies identified ~1:1 PNC-27/HDM-2 complexes in ring-shaped pore structures at the cancer cell membrane surface. [Sarafraz-Yazdi et al., 2022]

• p53-independent necrosis: In p53-null K562 leukemia cell preparations, PNC-27 induced near-complete LDH release without caspase-3/7 activation, characterizing the mechanism as necrotic and p53-independent. [Davitt et al., 2014]

• AML cell line selectivity: In U937, OCI-AML3, and HL-60 leukemia cell model systems, PNC-27-induced necrosis within four hours; normal hematopoietic cell preparations showed no equivalent response. [Thadi et al., 2020]

• Mitochondrial targeting: Gold-labeled immuno-electron microscopy of PNC-27-treated MIA-PaCa-2 pancreatic carcinoma cells identified peptide localization on mitochondrial membranes, concurrent with selective mitotracker dye loss. [Krzesaj et al., 2024]

All findings listed above are derived from preclinical or in vitro data. No conclusions regarding human therapeutic efficacy can be drawn from these observations. These findings do not constitute evidence of safety or efficacy in any human condition or organism.

What are the Potential Research Applications of PNC-27 Peptide?

HDM-2 Membrane Biology and Oncology Mechanistic Studies

PNC-27 has been employed as a probe compound in studies characterizing the subcellular distribution and membrane expression of HDM-2 across transformed versus untransformed cell lines. In preclinical model systems, the peptide provides a functional readout of plasma membrane HDM-2 activity that is independent of intracellular p53 status, making it a useful tool for investigating HDM-2 membrane localization dynamics in experimental oncology. Transfection studies in which HDM-2 with a membrane-targeting sequence was introduced into otherwise PNC-27-insensitive MCF-10-2A cells — rendering them susceptible to PNC-27 — provide a validated experimental paradigm for assessing the sufficiency of membrane HDM-2 in governing this class of peptide-induced cytotoxicity.

p53-Independent Tumor Cell Necrosis Research

PNC-27 has been used in preclinical experimental systems to model a form of tumor cell death that proceeds through plasma membrane disruption rather than canonical caspase-mediated apoptosis. Because the compound induces necrosis via pore formation in a p53-null leukemia cell context, it is applicable to laboratory investigations exploring cell death pathways in cancer models that lack functional p53 — a feature present in a substantial fraction of human tumor cell lines studied in vitro. Research employing LDH-release assays, annexin V staining, and caspase activation assays has used PNC-27 as a tool for distinguishing necrotic from apoptotic cell death mechanisms.

Hematologic Malignancy Cell Line Research

In multiple AML and CML cell line studies, PNC-27 has been characterized as a selective cytotoxic agent in HDM-2-expressing leukemia cell preparations, with normal hematopoietic cell preparations serving as non-responsive controls. This experimental profile makes the compound relevant to mechanistic research into membrane-targeted cytotoxic mechanisms in hematologic cell model systems, as well as to the development of in vitro assay platforms for evaluating novel HDM-2-targeting strategies.

Chimeric Peptide Design and Structure-Activity Investigations

PNC-27 represents a chemically characterized example of a chimeric peptidomimetic in which an endogenous protein-protein interaction domain (p53 residues 12–26) is fused to a membrane-penetrating/residency sequence to confer novel membrane-targeting properties. It has been used alongside analogs (notably PNC-28, which contains p53 residues 17–26) in structure-activity relationship studies comparing the contributions of the p53 domain length, CPP sequence identity, and linker configuration to membrane-associated cytotoxic activity in preclinical cell preparations.

These applications are observed in preclinical and in vitro contexts only and do not constitute claims of efficacy or safety in any organism.

What are the Potential Side Effects of PNC-27 Peptide?

The following adverse observations have been reported in preclinical experimental systems. These findings are derived from cell-based and limited in vivo model data and should not be extrapolated to outcomes in any organism.

• Rapid LDH-release necrosis observed in multiple transformed cell line preparations (MIA-PaCa-2 pancreatic carcinoma, MCF-7 breast carcinoma, K562 leukemia, U937 AML, HL-60, OCI-AML3) at experimental concentrations; onset in some models within one to four hours of exposure, suggesting potent and rapid membrane-disrupting activity at research concentrations.

• Mitochondrial membrane disruption characterized in MIA-PaCa-2 cell preparations by loss of mitotracker dye retention following PNC-27 treatment; consistent with intracellular organelle targeting secondary to plasma membrane pore formation.

• A case report in the gastroenterology literature (Aguon et al., 2017) described a coincidental occurrence of massive gastrointestinal hemorrhage in an individual receiving experimental PNC-27 preparations outside of controlled laboratory conditions; the causal relationship to the compound was not established, and no controlled in vivo toxicology data are available to characterize systemic exposure risk.

• Cytotoxicity toward non-malignant cells has not been fully excluded at suprathreshold concentrations; while multiple studies report selectivity for HDM-2-expressing cancer cell preparations over normal reference cell lines at study concentrations, concentration-dependent off-target effects have not been systematically characterized across a wide range of normal primary cell types.

• Minimal to absent caspase-3/7 activation in preclinical leukemia cell preparations is consistent with a predominantly necrotic rather than apoptotic mechanism, which may produce inflammatory responses in in vivo systems — a finding not systematically evaluated in published controlled animal models.

No human safety or tolerability data pertaining to research-grade PNC-27 has been established. These observations are derived from experimental systems and should not be extrapolated to human or animal outcomes.

Risk & Handling

Risk Tier: HIGH

PNC-27 is a potent membrane-active chimeric peptide with characterized rapid cytotoxic activity in multiple cancer cell model systems. At research concentrations, it induces irreversible plasma membrane disruption and mitochondrial damage in susceptible cell preparations. No controlled systemic in vivo toxicology data are available for this compound, and no human safety or tolerability data have been established. The compound’s mechanism of action — transmembrane pore formation — presents an inherent risk of contact-mediated cytotoxicity, and its behavior in primary normal human cell types has not been fully characterized across the full concentration range relevant to laboratory work.

Handling Precautions

Handle under standard laboratory containment conditions appropriate to a potent bioactive research peptide. The following precautions apply:

• Trained laboratory personnel only. Researchers unfamiliar with handling membrane-active cytotoxic peptides should receive supervision before working with this compound.
• Personal protective equipment: nitrile gloves, laboratory coat, and eye protection at minimum; change gloves promptly if skin contact with reconstituted solution occurs.
• Reconstitution and aliquoting of lyophilized powder should be performed in a laminar flow biosafety cabinet or fume hood to prevent inhalation of aerosolized powder or droplets.
• Do not generate aerosols during reconstitution; use low-binding polypropylene tubes and avoid vigorous vortexing.
• Avoid contact with skin or mucous membranes; the peptide’s membrane-active properties are not limited to cancer cell preparations at sufficiently high concentrations.
• Use low-binding sterile polypropylene tubes and borosilicate glass vials for handling; avoid polystyrene containers, which may adsorb the peptide.

Exposure Risks

Acute systemic toxicity data for PNC-27 in rodent or other in vivo models are not available in the published peer-reviewed literature. The compound’s documented ability to form cytotoxic transmembrane pores in HDM-2-expressing cells at research-relevant concentrations constitutes a meaningful exposure risk if inadvertent skin, ocular, or mucosal contact with concentrated reconstituted solution occurs. One published case report in the clinical literature noted gastrointestinal hemorrhage in a context where PNC-27 was administered outside of controlled laboratory conditions; causal attribution was not established, but the observation underscores the requirement for strict adherence to laboratory-only handling protocols. Chronic toxicity, immunogenicity, and systemic clearance data have not been established. No human safety data has been established for research-grade PNC-27.

Storage

• Lyophilized form: Store at −20°C; sealed, light-protected container with desiccant; protect from moisture
• Reconstituted form: Store at 4°C; use within 48–72 hours of reconstitution; do not store at room temperature
• Avoid repeated freeze-thaw cycles; stability of reconstituted solutions degrades with each cycle
• Do not store reconstituted solutions in polystyrene containers
• Discard any reconstituted solution that appears turbid, discolored, or contains visible particulate matter
• Long-term storage of lyophilized material at −80°C is recommended for multi-year stability; confirm by HPLC or LC-MS before use in critical experiments

FAQs

Q: What is PNC-27 and what is it investigated for in research? A: PNC-27 is a synthetic 32-residue chimeric peptidomimetic combining a p53-derived HDM-2-binding domain (residues 12–26) with a membrane residency peptide (MRP) leader sequence. In preclinical cell-based research, it is investigated as a tool for studying membrane-localized HDM-2 in transformed cell lines, transmembrane pore formation in cancer cell models, and p53-independent tumor cell necrosis mechanisms. It is intended strictly for laboratory research use and is not approved for human or veterinary use.

Q: What is the mechanism by which PNC-27 selectively targets cancer cells in preclinical models? A: In preclinical assay systems, selectivity is attributed to the differential expression of HDM-2 at the plasma membrane surface of transformed versus untransformed cell lines. Structurally, the p53-derived domain of PNC-27 adopts a conformation superimposable on the p53 17–29 peptide bound to MDM-2, enabling selective engagement of the p53-binding site on membrane-localized HDM-2. Untransformed reference cell lines in the same experimental systems express little to no membrane HDM-2 and have been observed to be resistant to PNC-27-induced necrosis. These observations are derived from in vitro model systems and do not represent validated selectivity data in any in vivo context.

Q: How should PNC-27 be reconstituted in laboratory research settings? A: PNC-27 lyophilized powder is typically reconstituted in sterile distilled water or pH 7.4 phosphate-buffered saline (PBS). For preparations where aqueous solubility is limited, a small volume of DMSO or 0.1% trifluoroacetic acid (TFA) may be used to initiate dissolution prior to dilution into aqueous buffer. Reconstitution should be performed in low-binding polypropylene or borosilicate glass containers to minimize adsorption losses; polystyrene should be avoided. Mix by gentle inversion or slow rotation; do not vortex vigorously.

Q: What toxicity observations have been reported in preclinical studies? A: Published preclinical data in cell-based model systems report rapid LDH-release necrosis in multiple HDM-2-expressing cancer cell line preparations at research concentrations, onset in some models within one to four hours. Mitochondrial membrane disruption has been characterized by mitotracker dye loss in pancreatic carcinoma cell preparations. A published case report in the clinical gastroenterology literature describes gastrointestinal hemorrhage coincident with experimental PNC-27 use outside of controlled laboratory conditions, though causal attribution was not established. No controlled in vivo systemic toxicology studies are available in the published literature. No human safety or tolerability data have been established for research-grade PNC-27.

Q: What is the half-life of PNC-27 in preclinical models? A: Published pharmacokinetic data for PNC-27 in in vivo animal model systems are not available in the peer-reviewed literature. As a linear 32-residue peptide with no disulfide bridges or unusual stabilizing modifications, proteolytic degradation by serum and tissue peptidases would be expected to result in relatively short plasma half-life under in vivo conditions, though this has not been formally characterized. In vitro stability in sterile aqueous solution at 4°C has been reported as suitable for experimental use within 48–72 hours of reconstitution. These figures should not be extrapolated to any clinical or human pharmacokinetic context.

Q: How does PNC-27 differ from its analog PNC-28 in research applications? A: PNC-28 contains p53 residues 17–26 rather than residues 12–26 incorporated in PNC-27, representing a shorter p53-derived domain. Structure-activity relationship studies in cell-based preclinical systems have examined both compounds and their analogs for membrane-targeting and cytotoxic activities. Both peptides require covalent linkage of the p53-derived domain to the MRP leader sequence for cytotoxic activity in the published assay systems. PNC-27 is the more extensively characterized compound in terms of published mechanistic data across a wider range of cancer cell line preparations. Researchers should select the compound appropriate to their experimental model based on the available peer-reviewed literature for each analog.

Q: Is PNC-27 active in p53-null cancer cell model systems? A: Yes — in published preclinical studies using p53-null K562 chronic myeloid leukemia cells, PNC-27 induced near-complete cell necrosis as assessed by LDH release, without detectable caspase-3 or caspase-7 activation. This observation is consistent with a membrane-mediated necrotic mechanism that depends on plasma membrane HDM-2 expression rather than intracellular p53 function. These findings are derived from in vitro cell-based experimental systems and should not be interpreted as evidence of activity in any in vivo or clinical context.

Related Research Compounds

FOXO4-DRI (Proxofim): A stapled retroinverse peptidomimetic investigated in preclinical senescent cell biology research, characterized in cell-based models for selective induction of apoptosis in p21-high senescent cell populations via FOXO4/p53 interaction disruption. 

Humanin: A 21-residue mitochondria-derived peptide investigated in preclinical models for interactions with IGFBP-3, BAX, and related apoptosis-regulatory proteins, with published in vitro data examining cytoprotective activity in neuronal and metabolic cell systems. 

B7-33: A single-chain relaxin analog investigated in preclinical models for RXFP1-mediated signaling in fibrotic and vascular biology research applications, characterized in isolated cell preparations for receptor engagement and downstream cAMP modulation. 

References

1. Sarafraz-Yazdi E, Bowne WB, Adler V, Sookraj KA, Wu V, Shteyler V, Patel H, Oxbury W, Brandt-Rauf P, Zenilman ME, Michl J, Pincus MR. (2010). Anticancer peptide PNC-27 adopts an HDM-2-binding conformation and kills cancer cells by binding to HDM-2 in their membranes. Proc Natl Acad Sci U S A, 107(5):1918–1923. https://pubmed.ncbi.nlm.nih.gov/20080680/

2. Sarafraz-Yazdi E, Mumin S, Cheung D, Fridman D, Lin B, Wong L, Rosal R, Rudolph R, Frenkel M, Thadi A, Morano WF, Bowne WB, Pincus MR, Michl J. (2022). PNC-27, a chimeric p53-penetratin peptide binds to HDM-2 in a p53 peptide-like structure, induces selective membrane-pore formation and leads to cancer cell lysis. Biomedicines, 10(5):945. https://pubmed.ncbi.nlm.nih.gov/35625682/

3. Davitt K, Babcock BD, Fenelus M, Poon CK, Sarkar A, Trivigno V, Zolkind PA, Matthew SM, Grin’kina N, Orynbayeva Z, Shaikh MF, Adler V, Michl J, Sarafraz-Yazdi E, Pincus MR, Bowne WB. (2014). The anti-cancer peptide, PNC-27, induces tumor cell necrosis of a poorly differentiated non-solid tissue human leukemia cell line that depends on expression of HDM-2 in the plasma membrane of these cells. Ann Clin Lab Sci, 44(3):241–248. https://pubmed.ncbi.nlm.nih.gov/25117093/ 
4. Thadi A, Lewis L, Goldstein E, Aggarwal A, Khalili M, Steele L, Polyak B, Seydafkan S, Bluth MH, Ward KA, Styler M, Campbell PM, Pincus MR, Bowne WB. (2020). Targeting membrane HDM-2 by PNC-27 induces necrosis in leukemia cells but not in normal hematopoietic cells. Anticancer Res, 40(9):4857–4867. https://pubmed.ncbi.nlm.nih.gov/32878773/

5. Krzesaj P, Adler V, Feinman RD, Miller A, Silberstein M, Yazdi E, Pincus MR. (2024). Anti-cancer peptide PNC-27 kills cancer cells by unique interactions with plasma membrane-bound hdm-2 and with mitochondrial membranes causing mitochondrial disruption. Ann Clin Lab Sci, 54(2):137–148. https://pubmed.ncbi.nlm.nih.gov/38802154/
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Disclaimer 

PNC-27 Peptide is exclusively for laboratory research purposes. RCDbio products are not intended to diagnose, prevent, treat, or cure any disease or medical condition.

The Food and Drug Administration has not evaluated the statements on our website. This product is not approved for human or veterinary use. Researchers must comply with all applicable local, state, and federal laws and regulations governing the purchase and use of research compounds. By purchasing, you agree to our Terms and Conditions. RCDbio reserves the right to refuse sales to unauthorized individuals.

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