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PNC-2731 residues (approx.)PQHLRVKRPQHLRVRQIKIWFQNRRMKWKKEach bubble = one amino acid. Size = residue mass. Color = chemical class.Uses closest standard amino acids for non-standard residues.Also known as: PNC27, p53-CPP chimeric peptide
Twenty-three published papers. Zero human clinical trials. PNC-27 is a 32-amino-acid synthetic peptide built from the p53 transactivation domain fused to a cell-penetrating leader sequence. It punches transmembrane pores into cancer cells that express HDM-2 on their surface, killing them by necrosis within hours in laboratory dishes. Normal cells lack surface HDM-2 and stay untouched. That selectivity is real in preclinical models, but a documented human fatality (GI hemorrhage, ACG 2017 case report) and an FDA contamination warning hang over this compound. Oncology researchers and late-stage patients exploring experimental options are the only realistic audience right now.
Twenty-three PubMed papers across two decades of work, all from roughly the same research group at SUNY Downstate Medical Center. That is the entire evidence base behind PNC-27 (CAS number not assigned; research-only compound). The peptide is a 32-residue chimera. Residues 12 through 26 come from the p53 transactivation domain, the exact stretch that binds HDM-2 (human double minute 2, the human analogue of murine MDM2). The other half is a cell-penetrating sequence borrowed from the Drosophila Antennapedia homeodomain. When PNC-27 reaches a cancer cell that expresses HDM-2 on its outer membrane, the p53 fragment locks on in a 1:1 stoichiometric complex. Those complexes drift laterally through the lipid bilayer and aggregate into ring-shaped transmembrane pores averaging 34.5 nm in diameter. Membrane integrity collapses. LDH release is detectable within four hours. The cell dies by necrosis. Normal cells keep HDM-2 in the nucleus and cytoplasm. No surface target, no binding, no pore, no damage. Bowne and colleagues confirmed this by engineering normal cells to express membrane HDM-2; those cells became susceptible [1]. Preclinical activity spans breast (MDA-MB-231), pancreatic (MIA PaCa-2), melanoma (A2058), leukemia (U937, OCI-AML3, HL-60, K562), cervical, and patient-derived ovarian cancer cells [2]. A 2024 study added a second kill mechanism: mitochondrial membrane disruption in cancer cells [3]. Still, no independent lab has replicated the selectivity finding. No human trial has opened. A 2017 case report documented a fatal GI hemorrhage after offshore use.
Cancer cells and normal cells handle HDM-2 protein differently. Normal cells express it only inside the cell, in the nucleus and cytoplasm, where it regulates p53 activity. Many cancer cell types overexpress HDM-2 to the point where excess protein traffics to the outer plasma membrane. PNC-27 targets that surface HDM-2 specifically. The p53-derived segment (residues 12 through 26) binds membrane-associated HDM-2 in a 1:1 complex. That binding step is temperature-independent; it happens at any temperature. What comes next requires physiological temperature (37 degrees C). The PNC-27:HDM-2 complexes undergo lateral diffusion within the lipid bilayer, then aggregate. The result is ring-shaped transmembrane pores lined by alternating PNC-27 and HDM-2 molecules, with interior diameters ranging from 28 to 44 nm. Those pores destroy membrane integrity. The cell dies by necrosis, not apoptosis. LDH release (a marker of membrane rupture) is detectable within hours [4]. A 2024 paper from the same group identified a second pathway: PNC-27 also disrupts mitochondrial membranes in cancer cells, suggesting dual killing mechanisms [3]. Because PNC-27 never enters the nucleus, it completely bypasses intracellular p53 status. The 2014 leukemia study confirmed near-complete killing of K562 cells, which are p53-deleted [5]. That matters because TP53 mutations occur in roughly half of all human cancers.
PNC-27 is a 32-amino-acid synthetic peptide derived from the p53 transactivation domain, designed to target membrane-expressed HDM-2 on cancer cells. Approximately 23 PubMed papers document preclinical activity across multiple cancer cell lines: breast, pancreatic, cervical, ovarian, leukemia. Mechanism is necrotic (not apoptotic): PNC-27 inserts into the membrane of HDM-2-expressing cells, forming pores that cause lytic cell death within 4–24 hours in vitro. Activity is p53-independent (effective in p53-null tumors). ZERO human clinical trials have been conducted in 25+ years of research: a significant translational gap. One documented human fatality (GI hemorrhage, ACG 2017) after offshore use. ESMED 2025 data: lithium acetoacetate (ketone body) reduced IC50 by 200–400% in cervical and breast cancer lines. PMID 28565974: PNC-27 as targeting ligand on Doxil liposomes improved cytotoxicity in HDM-2-expressing colon carcinoma.
Bowne et al. (multiple papers, NYU): originating research group. Most recent: ESMED 2025 MRA v13i5.6471 (ketone body synergy). PMID 28565974 (Doxil liposome targeting). No study involves human subjects.
Single research group origin: no independent replication of selectivity mechanism. Zero human clinical trials despite 25 years of preclinical data raises serious translatability concerns. FDA 2017 contamination warning. Documented fatal human adverse event (GI hemorrhage, ACG 2017). Necrotic (not apoptotic) mechanism poses uncharacterized tumor lysis syndrome risk in high-burden disease.
Effectively no human-use community exists. Discussion is limited to researchers and desperate cancer patients exploring alternatives. No established dosing protocol in any forum. FDA contamination warning and documented fatal adverse event suppress the limited interest that does exist.
Preclinical science exists (~23 PubMed papers) but there is no community dosing experience rooted in human use. All claimed human dosing is theoretical extrapolation from in vitro concentrations and murine data. The FDA warning and contamination precedent further suppress community adoption.
| Level | Dose / Injection | Frequency |
|---|---|---|
| Beginner | 100mcg | Daily |
| Moderate | 250mcg | Daily |
| Aggressive | 500mcg | Daily |
All dosing is theoretical. Zero human PK data exists for PNC-27. The numbers below come from preclinical IC50 extrapolation and a single murine MTD study. Reconstitution math for a 5 mg vial with 2 mL bacteriostatic water: concentration is 2,500 mcg/mL, so 100 mcg equals 4 units on a U-100 insulin syringe, 250 mcg equals 10 units, and 500 mcg equals 20 units. For a 10 mg vial with 2 mL BAC water: concentration is 5,000 mcg/mL; 100 mcg equals 2 units, 250 mcg equals 5 units, 500 mcg equals 10 units. Swirl the vial gently after adding water. Don't shake it. Peptides are fragile. The thing most people miss: standard apoptosis assays (Annexin V, caspase panels) will give false negatives because PNC-27 kills by necrosis. Use LDH release or propidium iodide exclusion if you're testing cytotoxicity in a research setting. Short half-life means daily dosing is necessary. Reconstituted solution goes in the fridge and should be discarded after 7 days. Lyophilized powder stores at -20 degrees C. Source your vials carefully. The FDA found bacterial contamination in a commercial PNC-27 product in 2017. Require third-party sterility testing from an accredited lab, not just a vendor purity certificate.
Cycling protocols are entirely theoretical. In vitro studies used continuous daily peptide addition over the course of experiments, suggesting frequent dosing is needed due to short half-life. The murine MTD study used daily intraperitoneal injections. No established human cycling protocol exists. Extended breaks between cycles are advisable given the complete absence of long-term safety data.
No human pharmacokinetic, pharmacodynamic, or long-term toxicity data supports any specific cycle length. The on/off structure is entirely precautionary. In murine studies, continuous daily IP dosing was used without cycling: the on/off structure is imposed to allow observation of delayed adverse effects and potential antibody formation to this synthetic peptide. Any cycling interval is arbitrary until human safety data exists.
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Expected: No human outcome data. In preclinical models, daily administration at IC50 concentrations killed cancer cells within 4–24 hours in vitro. Mouse tumor models showed growth reduction when combined with paclitaxel. Any human antitumor effect is entirely unvalidated.
Monitor: Tumor lysis panel (K+, phosphate, Ca2+, uric acid, LDH, creatinine) at baseline and every 2–4 weeks. Liver function tests monthly. CBC monthly. Any electrolyte abnormality or rising LDH requires immediate dose hold and medical evaluation.
Pull a 5 mg or 10 mg vial of lyophilized PNC-27 from the freezer (-20 degrees C). Let it reach room temperature before reconstituting.
Inject slowly down the inside wall of the vial. Swirl gently until dissolved. Don't shake.
With a 5 mg vial in 2 mL BAC water (2,500 mcg/mL): 100 mcg = 4 units, 250 mcg = 10 units, 500 mcg = 20 units on a U-100 insulin syringe. With a 10 mg vial: 100 mcg = 2 units, 250 mcg = 5 units, 500 mcg = 10 units.
Draw the calculated number of units using a 29 or 31 gauge insulin syringe (0.5 mL or 1 mL).
Inject subcutaneously into the abdomen, outer thigh, or upper arm. Rotate sites daily.
Daily injections are expected to be necessary based on the short estimated half-life (2 to 4 hours).
Refrigerate the reconstituted vial at 2 to 8 degrees C immediately after use. Discard after 7 days.
Baseline labs before starting: complete metabolic panel (electrolytes, creatinine), LDH, uric acid, liver function tests, CBC. Repeat electrolytes and LDH every 2 to 4 weeks during use.
All dosing is preclinical extrapolation. Medical supervision is strongly advised.
Reference route for all community dosing. Proteolytic degradation at injection site expected.
No human absorption data for this 32-residue peptide. SC bioavailability is unknown.
Murine MTD of 2 mg/day established via IP route. SC-to-IP equivalence unknown; direct comparison invalid.
Route used in all mouse in vivo studies. Not applicable outside supervised medical/research settings.
N/A
The January 2017 FDA consumer warning was triggered by bacterial contamination found specifically in a PNC-27 inhalation solution. Not scientifically validated and carries documented contamination risk.
Additive antitumor effect demonstrated in mouse ovarian cancer model. Paclitaxel-resistant cells upregulate HDM-2, increasing PNC-27 susceptibility. Greater tumor reduction than either agent alone (PMID 28667027).
Sequential: paclitaxel first, then PNC-27 (preclinical rationale only)
PNC-27 conjugated as targeting ligand on Doxil liposomes directed doxorubicin to HDM-2-expressing C26 colon carcinoma cells, significantly improving cytotoxicity vs. unconjugated Doxil. HDM-2-negative B16F0 melanoma showed no benefit: effect is HDM-2-dependent (PMID 28565974).
Lithium acetoacetate reduced PNC-27 IC50 by 200–300% across all three cervical cancer cell lines tested; normal cervical cells unaffected. MCF-7 breast cancer IC50 reduced >400% in prior work. Ketogenic diet context proposed (ESMED 2025, MRA v13i5.6471).
Ketogenic diet or exogenous ketone supplementation concurrent with PNC-27 (preclinical rationale only)
Both are experimental anticancer peptides with no cross-interaction data. Conceptually complementary: FOXO4-DRI targets senescent cells via p53-FOXO4 axis; PNC-27 targets HDM-2-expressing cancer cells. Listed as related peptide in database.
Direct target overlap: both compete for the p53-binding site of MDM2/HDM-2. Combination could amplify off-target cytotoxicity or small-molecule inhibitors could competitively block PNC-27 membrane binding. Interaction profile entirely unknown.
Do not combineBoth are membrane-active peptides with pore-forming or disruption activity. Overlapping mechanisms could increase off-target cytotoxicity to normal membranes. No combination data.
PNC-27 causes necrotic cell death. Immunosuppression may impair clearance of necrotic debris and worsen inflammatory burden. Immunocompromised status also increases risk from contaminated vendor product (per FDA 2017 warning).
Tumor cell necrosis releases procoagulant factors. Combined with anticoagulants, this could alter bleeding risk unpredictably. Consistent with the mechanism behind the 2017 GI hemorrhage case report.
Pricing updated 2026-04-09
One person has died after using PNC-27. The ACG 2017 case report documented fatal GI hemorrhage following offshore administration. The exact mechanism remains unknown, but this is the starting point for any safety discussion about this compound. No human clinical safety data exists beyond that single fatal case. Every safety consideration below is extrapolated from preclinical studies, and the actual human risk profile could be worse than predicted. Tumor lysis syndrome is the most concerning theoretical risk. PNC-27 kills by necrosis, not apoptosis. Necrotic cell death dumps intracellular contents (potassium, phosphate, uric acid, nucleic acids) into surrounding tissue and circulation. In patients with high tumor burden, rapid cancer cell necrosis could trigger hyperkalemia, hyperuricemia, hyperphosphatemia, hypocalcemia, and acute kidney injury. This risk has never been characterized in a living human. The murine maximum tolerated dose was 2 mg/day via intraperitoneal injection, with dose-limiting toxicities at higher levels. Converting mouse IP doses to human subcutaneous doses is unreliable; species differences in absorption, distribution, and metabolism make direct comparison invalid. Injection site reactions (redness, swelling, pain) are expected based on the subcutaneous route, though no human frequency data exists. Contamination risk is documented and specific. In January 2017, the FDA issued a formal consumer warning after finding Variovorax paradoxus and Ralstonia insidiosa bacterial contamination in a commercial PNC-27 inhalation product. Both organisms are particularly dangerous to immunocompromised patients, the exact population most likely to seek this compound. Inflammatory immune activation from mass tumor cell necrosis is a theoretical concern. Necrosis triggers immune responses that apoptosis does not. Patients with autoimmune conditions face additional unpredictable risk. No data exists on reproductive toxicity, genotoxicity, carcinogenicity, or long-term effects in any species. Pregnancy and breastfeeding are absolute contraindications. When to stop immediately: any electrolyte abnormality (especially raised potassium), GI symptoms (nausea, vomiting, blood in stool), injection site infection or spreading redness, unexplained liver enzyme elevation, or signs of contaminated product (turbid solution, particulates).
Verify PNC-27 dosing and safety with a second opinion
FDA issued a formal consumer warning in January 2017 specifically naming PNC-27, triggered by confirmed bacterial contamination (Variovorax paradoxus, Ralstonia insidiosa) in a commercial PNC-27 inhalation solution. These bacteria are particularly dangerous to immunocompromised patients: the exact population most likely to consider this compound. No pharmaceutical-grade, FDA-cleared, or compounded formulation exists. All sources are gray-market research peptide vendors.
| Test | When | Target |
|---|---|---|
| Comprehensive metabolic panel (electrolytes: K+, phosphate, Ca2+; creatinine; BUN) | Baseline, then every 2–4 weeks during use | K+ <5.5 mEq/L; creatinine within patient baseline |
| Serum LDH | Baseline, then every 2–4 weeks | >2× ULN warrants clinical evaluation |
| Uric acid | Baseline, then every 2–4 weeks | <8.0 mg/dL |
| Liver function tests (AST, ALT, bilirubin, alkaline phosphatase) | Baseline, then monthly | — |
| CBC with differential | Baseline, then monthly | — |
Tumor lysis monitoring: rapid necrotic cancer cell death releases intracellular contents, causing hyperkalemia, hyperphosphatemia, and hypocalcemia. Acute kidney injury is a direct risk.
Primary marker of cell necrosis. In vitro studies confirmed LDH release within 4 hours of PNC-27 exposure. Markedly elevated LDH could indicate off-target tissue damage.
Hyperuricemia from nucleic acid release during tumor cell necrosis can cause uric acid nephropathy.
No human hepatotoxicity data exists. Off-target membrane disruption in hepatocytes would manifest here. Standard monitoring for experimental compounds.
Preclinical data shows no harm to normal hematopoietic cells, but this is unconfirmed in any human at any dose.
Initial dosing phase. No observable effects expected in a clinical sense, as PNC-27 has only been studied in cell culture and animal models. In vitro, cancer cell lysis occurs within 4-24 hours of peptide exposure. Injection site reactions are possible.
Continued administration. In the murine ovarian cancer model, tumor growth reduction was observed during this timeframe when PNC-27 was combined with paclitaxel. Any human response at this stage is entirely speculative.
Extended administration phase. In preclinical studies, sustained daily dosing was required to achieve maximal cancer cell killing due to the short half-life of the peptide. Monitoring for any adverse effects is strongly recommended.
Recovery period. No data exists on what happens after cessation of PNC-27 treatment. Off-cycle observation allows assessment of any delayed effects and recovery from potential subclinical toxicity.
Days 1 through 7, initial administration: In laboratory cell cultures, PNC-27 kills cancer cells within 4 to 24 hours at effective concentrations. Pore formation requires body temperature (37 degrees C) for the aggregation step, and LDH release shows up within hours. No human effects of any kind have been documented. Injection site reactions (redness, swelling) are possible but no clinical pattern exists. Weeks 2 through 4, low-dose continuation: Mouse ovarian cancer models showed tumor growth reduction during this window when PNC-27 was paired with paclitaxel. Single-agent in vivo data is limited. No documented human experience exists for this timeframe. Everything remains speculative. Weeks 5 through 8, mid-dose escalation: Community step-up protocols move to 250 mcg per day here, though no human outcome data supports this number. The short half-life means the peptide doesn't accumulate; sustained tissue exposure requires daily re-dosing. Tumor lysis risk theoretically increases if any antitumor effect is occurring. Electrolytes and LDH should be monitored. Weeks 9 through 16, high-dose phase: The community-extrapolated ceiling is 500 mcg per day. No in vivo or human data exists for extended use at this level. Whether the body develops antibodies against this synthetic peptide has never been studied. Weeks 17 through 20, off-cycle recovery: No data on what happens after stopping PNC-27. The short estimated half-life suggests the peptide clears from circulation quickly. This break exists purely as a precaution given the complete absence of long-term safety information in any species.
In vitro: cancer cell lysis occurs within 4–24 hours at IC50 concentrations. Pore formation requires 37°C (temperature-dependent aggregation step). LDH release detectable within hours of exposure.
No human data. No subjective effects documented in any published or anecdotal source.
Murine ovarian cancer model: tumor growth reduction observed in this window when PNC-27 combined with paclitaxel. Single-agent in vivo tumor reduction data is limited.
No documented human experience in this window. Entirely speculative.
Continued daily dosing required: rapid degradation means no accumulation. Short half-life dictates frequent dosing for sustained tissue exposure.
Community step-up protocols escalate to 250 mcg/day here. No outcome data from human use.
No in vivo or human data for extended administration at this dose. Antibody formation to this synthetic peptide has not been studied.
Theoretical peak community-extrapolated dose (500 mcg/day). No documented human use or outcomes at this stage.
No data on post-cessation effects or peptide clearance in humans. Short estimated half-life suggests rapid systemic clearance upon stopping.
No documented human experience. Break is precautionary given complete absence of long-term safety data.
Source: Estimated from in vitro peptide stability; no formal PK studies in humans or animals. In cell culture, daily re-addition of peptide was needed for full effect, suggesting rapid degradation.
Loading the interactive decay curve.
PNC-27 is not approved by the FDA for any indication. It carries a regulatory status of research-only and has no IND (Investigational New Drug) application on file. No pharmaceutical-grade or compounded pharmacy formulation exists anywhere in the world. In January 2017, the FDA issued a specific consumer warning about PNC-27 products after confirming bacterial contamination (Variovorax paradoxus and Ralstonia insidiosa) in a commercial PNC-27 inhalation solution sold online. The warning remains active. All current sources are gray-market research peptide vendors selling "for research purposes only." WADA status is not applicable (no athletes are using a preclinical anticancer compound). PNC-27 is legal to purchase for research in most jurisdictions but is not legal to market, prescribe, or administer as a treatment for any disease. This content is for informational and research purposes only. It does not constitute medical advice, diagnosis, or treatment. Consult a qualified healthcare provider before using any experimental compound.
Peptide Schedule Research TeamReviewed Apr 20269 Citations
