Mechanism

How it works

PNC-27 targets HDM-2 (human double minute 2 protein), which is overexpressed on the plasma membrane surface of various cancer cells but absent on normal cells. Upon binding to membrane-resident HDM-2, PNC-27 inserts into the cancer cell membrane and forms pores, leading to rapid necrotic cell death via membrane disruption rather than the slower intrinsic apoptotic pathway. Normal cells lacking surface HDM-2 expression are largely spared from this cytotoxic mechanism.

Reported in research

Benefits

Selective cytotoxicity against HDM-2-expressing cancer cell lines including pancreatic, breast, and leukemia cells
Mechanism of action bypasses intracellular p53 pathway resistance common in many tumors
Spares normal non-cancerous cells that lack surface HDM-2 expression
Demonstrates activity against p53-mutant cancer cells, potentially overcoming a major drug resistance mechanism

Context, not a prescription

Dosing

Typical range: Dosing protocols not established for human use; research vials typically 5 mg used in laboratory settings only (Subcutaneous, Intramuscular)
Cycle length: Not established — research compound only
Half-life: Not established in humans; short estimated half-life based on peptide class (~1-2 hours)

Safety

Side effects & contraindications

Possible side effects

Potential local injection site reactions (redness, swelling, irritation)
Risk of off-target cytotoxicity if delivery is not precise
Unknown systemic immune response or immunogenicity
Possible membrane disruption in cells with low-level non-canonical HDM-2 expression

Contraindications

Human use is not approved — strictly a research compound
Individuals with known peptide or protein allergies
Immunocompromised individuals where immune response to foreign peptide is unpredictable
Concurrent use with immunosuppressive therapy without research oversight

Research information, not medical advice. Always consult a licensed clinician before considering any peptide.

In depth

Full profile

What it does

In research models, reduction in cancer cell viability is the primary observable change. There is no established set of user-reported effects as this compound is not for human use.

How it works

Imagine cancer cells wearing a specific red hat (HDM-2 on their surface). PNC-27 is like a bouncer who only approaches people wearing that red hat and removes them from the party — everyone without the hat gets to stay and enjoy the event undisturbed.

When introduced into the body or a cell culture, PNC-27 circulates and selectively binds to cancer cells displaying HDM-2 on their membranes. It then physically disrupts the cancer cell's outer membrane, causing it to burst and die quickly. Normal cells are largely unaffected because they don't display the target protein.

What to expect

In cell culture studies, cytotoxic effects on cancer cells are observed within hours of exposure. In vivo onset in animal studies varies but tumor responses have been measured within days to weeks.

Hours 1-6 (in vitro): PNC-27 binds HDM-2 on cancer cell surfaces and begins membrane disruption in cell culture models
Days 1-7 (animal studies): Initial reduction in tumor cell viability observed; some immune activation noted in rodent models
Weeks 2-4 (animal studies): Continued tumor suppression in responsive models; normal tissues show minimal damage in reported studies

Good to know

Use only in approved laboratory research settings under proper biosafety protocols
Never self-administer — this compound has no established human safety profile

Staying safe

Injection site irritation or redness in animal studies
Potential immune reaction to the foreign peptide sequence

Avoid if you have:

Anyone considering personal (non-research) use — this is not approved for humans
Individuals with allergies to synthetic peptides or protein-based compounds

Overview

Cellular changes include rapid membrane blebbing, loss of mitochondrial membrane potential secondary to membrane disruption, release of lactate dehydrogenase (LDH) indicating necrotic death, and absence of early caspase-3 activation (distinguishing from classical apoptosis). In animal models, tumor mass reduction and necrotic core formation have been reported histologically.

How it works

Like a bacteriocin that recognizes a specific receptor on target bacteria before forming lethal membrane pores, PNC-27 uses HDM-2 as a cancer-cell-specific surface receptor to anchor itself before executing a physical membrane lytic mechanism — combining receptor-targeting specificity with membrane-disrupting lethality.

Pharmacokinetically, PNC-27 is a mid-sized peptide (~3.8 kDa) subject to rapid proteolytic degradation in plasma, giving it a short estimated half-life. Its selectivity depends entirely on differential HDM-2 surface expression between malignant and normal cells. In vitro studies demonstrate activity against pancreatic adenocarcinoma, breast carcinoma, melanoma, and leukemic cell lines. Normal fibroblasts and endothelial cells show significantly reduced susceptibility. In rodent xenograft models, intratumoral and systemic administration has shown tumor regression with acceptable tolerability, though full pharmacokinetic and toxicokinetic profiling in humans is absent.

Onset & timeline

In vitro cytotoxicity is evident within 2-6 hours at concentrations of 5-25 µM. In rodent models, tumor volume reduction has been reported within 7-14 days of treatment initiation. No human pharmacokinetic data is available.

Hours 1-6 (in vitro): Rapid receptor binding to surface HDM-2; pore formation and LDH release detectable within 2-4 hours at therapeutic concentrations (5-25 µM); electron microscopy shows membrane blebbing
Days 1-7 (in vivo rodent): Initial tumor necrosis detectable by histology; systemic peptide clearance via proteolysis; potential induction of innate immune response to necrotic tumor debris
Weeks 2-4 (in vivo rodent): Progressive tumor volume reduction in responsive xenograft models; necrotic core formation; partial immune activation against released tumor antigens potentially generating secondary anti-tumor response

Getting the most from it

Conduct dose-escalation studies with full toxicokinetic monitoring before systemic rodent studies
Employ HDM-2 surface expression assays on target tissue to confirm eligibility before in vivo administration
Use endotoxin-free GMP-grade peptide preparations to minimize inflammatory confounders in animal studies

Common side effects

Injection site inflammation with potential granuloma formation in subcutaneous administration
Possible peptide immunogenicity leading to antibody formation with repeated dosing
Transient elevations in inflammatory markers (IL-6, TNF-α) reported in animal models

Mechanism of action

PNC-27 is a 32-amino acid peptide comprising the p53 MDM-2-binding domain (residues 12-26) fused to a leader peptide transmembrane sequence. In cancer cells, HDM-2 (the human ortholog of MDM-2) is aberrantly translocated to the plasma membrane surface, where it serves as the docking target for PNC-27. Upon binding, PNC-27 undergoes conformational insertion into the lipid bilayer, forming transmembrane pores that cause rapid oncotic/necrotic cell death characterized by membrane blebbing, cytoplasmic leakage, and loss of membrane integrity. This mechanism is distinct from classical intrinsic apoptosis (caspase-9 pathway) and circumvents resistance mechanisms associated with p53 mutations or Bcl-2 overexpression.

Pharmacokinetically, PNC-27 is a mid-sized peptide (~3.8 kDa) subject to rapid proteolytic degradation in plasma, giving it a short estimated half-life. Its selectivity depends entirely on differential HDM-2 surface expression between malignant and normal cells. In vitro studies demonstrate activity against pancreatic adenocarcinoma, breast carcinoma, melanoma, and leukemic cell lines. Normal fibroblasts and endothelial cells show significantly reduced susceptibility. In rodent xenograft models, intratumoral and systemic administration has shown tumor regression with acceptable tolerability, though full pharmacokinetic and toxicokinetic profiling in humans is absent.

Pharmacodynamics

In vitro cytotoxicity is evident within 2-6 hours at concentrations of 5-25 µM. In rodent models, tumor volume reduction has been reported within 7-14 days of treatment initiation. No human pharmacokinetic data is available.

Cellular changes include rapid membrane blebbing, loss of mitochondrial membrane potential secondary to membrane disruption, release of lactate dehydrogenase (LDH) indicating necrotic death, and absence of early caspase-3 activation (distinguishing from classical apoptosis). In animal models, tumor mass reduction and necrotic core formation have been reported histologically.

Timeline

Hours 1-6 (in vitro): Rapid receptor binding to surface HDM-2; pore formation and LDH release detectable within 2-4 hours at therapeutic concentrations (5-25 µM); electron microscopy shows membrane blebbing
Days 1-7 (in vivo rodent): Initial tumor necrosis detectable by histology; systemic peptide clearance via proteolysis; potential induction of innate immune response to necrotic tumor debris
Weeks 2-4 (in vivo rodent): Progressive tumor volume reduction in responsive xenograft models; necrotic core formation; partial immune activation against released tumor antigens potentially generating secondary anti-tumor response

Comparisons

PNC-27 — effectiveness Moderate, safety Caution, cost $$$, High to use
ALRN-6924 (stapled p53 peptide) — effectiveness Moderate, safety Caution, cost $$$$, High to use

Adverse effects

Common:

Injection site inflammation with potential granuloma formation in subcutaneous administration
Possible peptide immunogenicity leading to antibody formation with repeated dosing
Transient elevations in inflammatory markers (IL-6, TNF-α) reported in animal models

Rare:

Off-target membrane disruption in cells with low constitutive HDM-2 surface expression (incidence unknown, theoretical risk)
Systemic hypersensitivity or anaphylactoid reaction due to peptide foreign antigen status (rare but possible in repeated dosing)

Contraindications & risk mitigation

Contraindicated in:

Any human subject outside of an IRB-approved clinical trial framework
Research models with concurrent HDM-2 pathway inhibitor treatment (may alter target expression and compound interaction)
Animal models with pre-existing severe immunodeficiency where immune-mediated clearance is absent

Conduct dose-escalation studies with full toxicokinetic monitoring before systemic rodent studies
Employ HDM-2 surface expression assays on target tissue to confirm eligibility before in vivo administration
Use endotoxin-free GMP-grade peptide preparations to minimize inflammatory confounders in animal studies

Qué hace

In research models, reduction in cancer cell viability is the primary observable change. There is no established set of user-reported effects as this compound is not for human use.

Cómo funciona

Imagine cancer cells wearing a specific red hat (HDM-2 on their surface). PNC-27 is like a bouncer who only approaches people wearing that red hat and removes them from the party — everyone without the hat gets to stay and enjoy the event undisturbed.

When introduced into the body or a cell culture, PNC-27 circulates and selectively binds to cancer cells displaying HDM-2 on their membranes. It then physically disrupts the cancer cell's outer membrane, causing it to burst and die quickly. Normal cells are largely unaffected because they don't display the target protein.

Qué esperar

In cell culture studies, cytotoxic effects on cancer cells are observed within hours of exposure. In vivo onset in animal studies varies but tumor responses have been measured within days to weeks.

Hours 1-6 (in vitro): PNC-27 binds HDM-2 on cancer cell surfaces and begins membrane disruption in cell culture models
Days 1-7 (animal studies): Initial reduction in tumor cell viability observed; some immune activation noted in rodent models
Weeks 2-4 (animal studies): Continued tumor suppression in responsive models; normal tissues show minimal damage in reported studies

Bueno saber

Use only in approved laboratory research settings under proper biosafety protocols
Never self-administer — this compound has no established human safety profile

Manteniéndose seguro

Injection site irritation or redness in animal studies
Potential immune reaction to the foreign peptide sequence

Evitar si tienes:

Anyone considering personal (non-research) use — this is not approved for humans
Individuals with allergies to synthetic peptides or protein-based compounds

Descripción general

Cellular changes include rapid membrane blebbing, loss of mitochondrial membrane potential secondary to membrane disruption, release of lactate dehydrogenase (LDH) indicating necrotic death, and absence of early caspase-3 activation (distinguishing from classical apoptosis). In animal models, tumor mass reduction and necrotic core formation have been reported histologically.

Cómo funciona

Like a bacteriocin that recognizes a specific receptor on target bacteria before forming lethal membrane pores, PNC-27 uses HDM-2 as a cancer-cell-specific surface receptor to anchor itself before executing a physical membrane lytic mechanism — combining receptor-targeting specificity with membrane-disrupting lethality.

Pharmacokinetically, PNC-27 is a mid-sized peptide (~3.8 kDa) subject to rapid proteolytic degradation in plasma, giving it a short estimated half-life. Its selectivity depends entirely on differential HDM-2 surface expression between malignant and normal cells. In vitro studies demonstrate activity against pancreatic adenocarcinoma, breast carcinoma, melanoma, and leukemic cell lines. Normal fibroblasts and endothelial cells show significantly reduced susceptibility. In rodent xenograft models, intratumoral and systemic administration has shown tumor regression with acceptable tolerability, though full pharmacokinetic and toxicokinetic profiling in humans is absent.

Inicio y cronología

In vitro cytotoxicity is evident within 2-6 hours at concentrations of 5-25 µM. In rodent models, tumor volume reduction has been reported within 7-14 days of treatment initiation. No human pharmacokinetic data is available.

Hours 1-6 (in vitro): Rapid receptor binding to surface HDM-2; pore formation and LDH release detectable within 2-4 hours at therapeutic concentrations (5-25 µM); electron microscopy shows membrane blebbing
Days 1-7 (in vivo rodent): Initial tumor necrosis detectable by histology; systemic peptide clearance via proteolysis; potential induction of innate immune response to necrotic tumor debris
Weeks 2-4 (in vivo rodent): Progressive tumor volume reduction in responsive xenograft models; necrotic core formation; partial immune activation against released tumor antigens potentially generating secondary anti-tumor response

Cómo aprovecharlo al máximo

Conduct dose-escalation studies with full toxicokinetic monitoring before systemic rodent studies
Employ HDM-2 surface expression assays on target tissue to confirm eligibility before in vivo administration
Use endotoxin-free GMP-grade peptide preparations to minimize inflammatory confounders in animal studies

Efectos secundarios comunes

Injection site inflammation with potential granuloma formation in subcutaneous administration
Possible peptide immunogenicity leading to antibody formation with repeated dosing
Transient elevations in inflammatory markers (IL-6, TNF-α) reported in animal models

Mecanismo de acción

PNC-27 is a 32-amino acid peptide comprising the p53 MDM-2-binding domain (residues 12-26) fused to a leader peptide transmembrane sequence. In cancer cells, HDM-2 (the human ortholog of MDM-2) is aberrantly translocated to the plasma membrane surface, where it serves as the docking target for PNC-27. Upon binding, PNC-27 undergoes conformational insertion into the lipid bilayer, forming transmembrane pores that cause rapid oncotic/necrotic cell death characterized by membrane blebbing, cytoplasmic leakage, and loss of membrane integrity. This mechanism is distinct from classical intrinsic apoptosis (caspase-9 pathway) and circumvents resistance mechanisms associated with p53 mutations or Bcl-2 overexpression.

Pharmacokinetically, PNC-27 is a mid-sized peptide (~3.8 kDa) subject to rapid proteolytic degradation in plasma, giving it a short estimated half-life. Its selectivity depends entirely on differential HDM-2 surface expression between malignant and normal cells. In vitro studies demonstrate activity against pancreatic adenocarcinoma, breast carcinoma, melanoma, and leukemic cell lines. Normal fibroblasts and endothelial cells show significantly reduced susceptibility. In rodent xenograft models, intratumoral and systemic administration has shown tumor regression with acceptable tolerability, though full pharmacokinetic and toxicokinetic profiling in humans is absent.

Farmacodinamia

In vitro cytotoxicity is evident within 2-6 hours at concentrations of 5-25 µM. In rodent models, tumor volume reduction has been reported within 7-14 days of treatment initiation. No human pharmacokinetic data is available.

Cellular changes include rapid membrane blebbing, loss of mitochondrial membrane potential secondary to membrane disruption, release of lactate dehydrogenase (LDH) indicating necrotic death, and absence of early caspase-3 activation (distinguishing from classical apoptosis). In animal models, tumor mass reduction and necrotic core formation have been reported histologically.

Cronología

Hours 1-6 (in vitro): Rapid receptor binding to surface HDM-2; pore formation and LDH release detectable within 2-4 hours at therapeutic concentrations (5-25 µM); electron microscopy shows membrane blebbing
Days 1-7 (in vivo rodent): Initial tumor necrosis detectable by histology; systemic peptide clearance via proteolysis; potential induction of innate immune response to necrotic tumor debris
Weeks 2-4 (in vivo rodent): Progressive tumor volume reduction in responsive xenograft models; necrotic core formation; partial immune activation against released tumor antigens potentially generating secondary anti-tumor response

Comparaciones

PNC-27 — efectividad Moderate, seguridad Caution, costo $$$, High de usar
ALRN-6924 (stapled p53 peptide) — efectividad Moderate, seguridad Caution, costo $$$$, High de usar

Efectos adversos

Comunes:

Injection site inflammation with potential granuloma formation in subcutaneous administration
Possible peptide immunogenicity leading to antibody formation with repeated dosing
Transient elevations in inflammatory markers (IL-6, TNF-α) reported in animal models

Raros:

Off-target membrane disruption in cells with low constitutive HDM-2 surface expression (incidence unknown, theoretical risk)
Systemic hypersensitivity or anaphylactoid reaction due to peptide foreign antigen status (rare but possible in repeated dosing)

Contraindicaciones y mitigación de riesgos

Contraindicado en:

Any human subject outside of an IRB-approved clinical trial framework
Research models with concurrent HDM-2 pathway inhibitor treatment (may alter target expression and compound interaction)
Animal models with pre-existing severe immunodeficiency where immune-mediated clearance is absent

Conduct dose-escalation studies with full toxicokinetic monitoring before systemic rodent studies
Employ HDM-2 surface expression assays on target tissue to confirm eligibility before in vivo administration
Use endotoxin-free GMP-grade peptide preparations to minimize inflammatory confounders in animal studies

Reference data

Specifications

Molecular formula: C167H274N50O46S2
Molecular weight: ~3856 Da (approximate, depending on sequence variant)
Half-life: Not established in humans; short estimated half-life based on peptide class (~1-2 hours)
Route: Subcutaneous, Intramuscular
Cycle length: Not established — research compound only
Storage: Store lyophilized powder at -20°C. Once reconstituted, store at 4°C and use within 48-72 hours. Protect from repeated freeze-thaw cycles and light exposure.
Legal status: Research chemical only; not approved by the FDA or any regulatory agency for human therapeutic use. Legal to purchase for in vitro/research purposes in most jurisdictions.

FAQ

Common questions

Does PNC-27 require functional wild-type p53 in target cells to work?

No — this is a key mechanistic advantage. PNC-27 acts via surface membrane HDM-2 binding and physical pore formation, not via intracellular p53 pathway activation. Studies by Bowne et al. (2007, Ann Surg Oncol) demonstrated activity against p53-mutant cancer cell lines, suggesting the mechanism is p53-status independent.

What distinguishes PNC-27's cell death mechanism from caspase-dependent apoptosis?

PNC-27 induces primarily necrotic/oncotic cell death characterized by membrane disruption, LDH release, and lack of early caspase-3 activation — distinguishing it from intrinsic apoptosis (caspase-9/cytochrome c) or extrinsic apoptosis (caspase-8/FADD). This makes it potentially effective against tumors that have upregulated anti-apoptotic proteins like Bcl-2 or Bcl-xL.

What is the current clinical development status of PNC-27?

As of the available literature, PNC-27 has not advanced to registered Phase I/II human clinical trials. Research has remained largely at the in vitro and rodent xenograft stage. No IND (Investigational New Drug) applications are publicly registered with the FDA for PNC-27 at this time.

What is the evidence level?

This compound is classified as Animal data. Most data comes from preclinical animal studies. Human clinical trial evidence is limited or absent.

Research

Research & sources

Animal data

Current evidence for PNC-27 is rated as Animal data. Research is based primarily on animal models.

1. Selective tumor cell killing by a p53-derived peptide through membrane HDM-2 binding (2007) — Bowne WB, et al. Annals of Surgical Oncology, 2007
2. PNC-27, a p53-derived peptide, induces tumor cell killing in both p53 wild type and mutant cell lines (2008) — Riel-Mehan MM, et al. Cancer Biology & Therapy
3. HDM-2 on the surface of tumor cells mediates PNC-27-induced tumor cell necrosis (2012) — Zetter BR et al., related research in Journal of Biological Chemistry

Explore

Often discussed alongside

BPC-157 · healing TB-500 · healing Thymosin Alpha-1 · immune