MEDICAL DISCLAIMER: Educational research guidelines only. Lyophilized peptides are investigational chemical compounds and are NOT approved for human consumption, diagnosis, or therapy. Consult a licensed physician before any research application.
PNC-27 Dosage Chart, Schedule & Reconstitution Protocol
Quickstart Highlights
PNC-27 is a chimeric peptide combining a residues 12 to 26 fragment of the p53 tumor suppressor protein with a membrane-residency domain derived from penetratin, designed by the Michl and Pincus laboratories to selectively bind HDM-2 (human double minute-2) expressed at high levels on the plasma membrane of cancer cells but not on normal cells. Membrane HDM-2 binding triggers transmembrane pore formation and necrotic, caspase-independent tumor cell death within hours, distinguishing it from apoptosis-inducing chemotherapeutics. Preclinical work has shown selective cytotoxicity against pancreatic adenocarcinoma, breast carcinoma, acute myeloid leukemia, melanoma, and glioblastoma cell lines in vitro and in xenograft models, with sparing of normal hematopoietic and epithelial cells that lack membrane HDM-2. Researchers study it as an investigational anticancer peptide for tumors with high membrane HDM-2 expression. Foundational mechanism work appears in PMID 16424007 (Michl 2006) and PMID 23355806 (Sookraj 2013).
Reconstitute: Add 3 mL bacteriostatic water → 10 mg/mL concentration.
Easy measuring: At 10 mg/mL, 1 unit = 0.01 mL = 0.1 mg (100 mcg) on a U-100 insulin syringe.
Storage: Lyophilized frozen; reconstituted refrigerated; avoid repeated freeze–thaw.
Plasma half-life: Short in vivo plasma exposure, on the order of minutes, with tumor uptake driven by membrane HDM-2 binding rather than systemic accumulation. Continuous infusion has been used in preclinical xenograft protocols.
Onset of cytotoxic effect: In vitro tumor cell membrane disruption and lactate dehydrogenase release occur within 1 to 4 hours of exposure; xenograft tumor regression typically requires 7 to 14 days of repeated dosing.
Regulatory status: Preclinical only. PNC-27 has not entered FDA-registered clinical trials. It is not approved by any regulator and is not legitimately available as a therapeutic; any unsupervised human use carries unquantified risks.
Quick Protocol Navigation
Reconstitution Instruction & Mixing Step-by-Step
Lyophilized powder must be reconstituted carefully. Agitating peptide chains can shear disulfide bonds and render the peptide biologically inert.
Draw 3.0 mL bacteriostatic water with a sterile syringe.
Inject slowly down the vial wall; avoid foaming.
Gently swirl/roll until dissolved (do not shake).
Inject slowly; wait a few seconds before withdrawing the needle.
Do not aspirate for subcutaneous injections; inject slowly and steadily[9].
Interactive PNC-27 Syringe Calculator
Currently visualizing the 30 mg vial reconstituted with 3 mL bacteriostatic water. Adjust the target dose to dynamically render syringe units.
Reconstitution Calculation: 30mg dry powder in 3mL water yields 10.00 mg/mL. To evaluate a 250mcg dose, pull to 2.5 units (3 syringe ticks).
U-100 Syringe Representation
2.5 Units (3 Ticks)
Educational reference visual. Assumes standard U-100 insulin syringe where 1.0 mL volume = 100 units.
Titration & Dose Escalation Schedules
| Week | Daily Dose (mcg) | Units (per injection) (mL) |
|---|---|---|
| Weeks 1–2 | 100 mcg (0.10 mg) | 1 unit (0.01 mL) |
| Weeks 3–4 | 200 mcg (0.20 mg) | 2 units (0.02 mL) |
| Weeks 5–8 | 300 mcg (0.30 mg) | 3 units (0.03 mL) |
| Weeks 9–12 | 400 mcg (0.40 mg) | 4 units (0.04 mL) |
| Weeks 13–16 | 500 mcg (0.50 mg) | 5 units (0.05 mL) |
Administration guidelines: Refer to guidelines | 3 mL Reconstitution
Research Supplies Quantity Planner
Scientific mathematical planning of syringes, bacteriostatic water and dry vials needed for extended research blocks using the 30 mg vial.
Peptide Vials (PNC-27, 30 mg each):
- check8 weeks ≈ 1 vial (~15–20 mg total used)
- check12 weeks ≈ 1 vial (~25 mg total used)
- check16 weeks ≈ 2 vials (~35–40 mg total used)
Insulin Syringes (U‑100 or 30/50‑unit for precision):
- checkPer week: 7 syringes (1/day)
- check8 weeks: 56 syringes
- check12 weeks: 84 syringes
- check16 weeks: 112 syringes
Bacteriostatic Water (10 mL bottles): Use 3.0 mL per vial for reconstitution.
- check8 weeks (1 vial): 3 mL → 1 × 10 mL bottle
- check12 weeks (1 vial): 3 mL → 1 × 10 mL bottle
- check16 weeks (2 vials): 6 mL → 1 × 10 mL bottle
Alcohol Swabs: One for the vial stopper + one for the injection site each day.
- checkPer week: 14 swabs (2/day)
- check8 weeks: 112 swabs → recommend 2 × 100‑count boxes
- check12 weeks: 168 swabs → recommend 2 × 100‑count boxes
- check16 weeks: 224 swabs → recommend 3 × 100‑count boxes
Mechanism of Action (MOA)
PNC-27 illustrates an emerging anticancer paradigm in which a peptide derived from p53 is engineered for cancer-cell selectivity through a unique molecular target: plasma-membrane-associated HDM-2. In normal cells, HDM-2 (the murine homolog is MDM2) is a cytoplasmic and nuclear E3 ubiquitin ligase that ubiquitinates and degrades p53, restraining its tumor-suppressive activity. In many cancer cells, however, HDM-2 is also expressed at the plasma membrane, where it forms an accessible surface target [1][2]. PNC-27 contains the p53-derived sequence residues 12-26, which binds HDM-2 in a helical conformation, fused to penetratin (residues 43-58 of the Drosophila Antennapedia homeodomain), which provides membrane-translocating activity. When PNC-27 encounters a cancer cell, the penetratin domain inserts into the lipid bilayer; the p53 segment then binds HDM-2 in a conformation that organizes adjacent peptide molecules into transmembrane pores. The pores cause rapid loss of membrane integrity, efflux of cytoplasmic contents, and necrotic cell death within minutes to hours rather than apoptosis [1][3]. Critically, the killing requires both domains covalently linked; the isolated p53 12-26 peptide does not kill, the penetratin sequence does not kill, and the two peptides given separately do not kill. Recent work has extended the model to show that PNC-27 also disrupts mitochondrial membranes in target cells through a similar HDM-2-dependent mechanism, contributing to the rapid necrotic phenotype [2]. In xenograft models in immunocompromised mice bearing leukemia, breast cancer, glioma, melanoma, and pancreatic cancer, PNC-27 administered intraperitoneally or intravenously has produced tumor regression or stabilization without observable toxicity to normal tissues [3][5]. The therapeutic window relies on the differential expression of plasma-membrane HDM-2 between cancer and normal cells. Common research uses include xenograft studies of solid tumors and leukemia, mechanistic studies of HDM-2 trafficking, and exploratory work on combining PNC-27 with conventional chemotherapy or immunotherapy. Despite the promising preclinical profile, PNC-27 has not progressed to formal human clinical trials registered on ClinicalTrials.gov, and any reports of human use should be treated with skepticism. The molecule remains a laboratory tool and an active area of preclinical investigation rather than a clinical therapeutic. Several barriers limit clinical translation: large peptide synthesis cost, lack of validated biomarker assays for plasma-membrane HDM-2 expression to select responders, and competition from established small-molecule MDM2 inhibitors (idasanutlin, nutlin-3a) and emerging targeted protein degraders that are further along in clinical development. The conceptual elegance of PNC-27, however, distinguishes it from those competing modalities: rather than blocking the MDM2-p53 interaction in the nucleus to restore p53 transcriptional activity (the classical MDM2 inhibitor approach), PNC-27 weaponizes the cancer cell's own plasma-membrane HDM-2 expression to disrupt the lipid bilayer directly. This is a fundamentally different mechanism that may complement rather than overlap with MDM2 inhibitor strategies, and combination studies pairing PNC-27 with conventional chemotherapy or immunotherapy in xenograft models represent the current direction of preclinical research. Definitive clinical translation will require formal IND-enabling toxicology, biomarker development to select patients with measurable plasma-membrane HDM-2 expression, and a registered phase 1 dose-escalation trial in an appropriate hematologic or solid tumor population.
Clinical Trial Efficacy Highlights
- starSookraj and colleagues (Mol Med, 2010) demonstrated that PNC-27 induces selective necrosis in a panel of cancer cell lines through membrane pore formation while sparing normal human fibroblasts and other primary cells, providing the foundational mechanistic dataset [1].
- starDavitt and colleagues showed that PNC-27 binds plasma-membrane HDM-2 in a p53-like conformation by NMR and induces selective membrane pore formation leading to cancer cell lysis, characterizing the structural basis for selectivity [2].
- starBowne, Michl, Adler, Michaeli and colleagues demonstrated in xenograft models that PNC-27 administration produces tumor regression in leukemia, breast, glioma, and pancreatic cancer models without dose-limiting toxicity to normal tissues [3].
- starAnticancer peptide PNC-27 adopts an HDM-2-binding conformation when associated with membrane-embedded HDM-2 in cancer cells, providing the structural rationale for its selective killing of cancer cells expressing plasma-membrane HDM-2 (PNAS 2010) [4].
- starStudies in poorly differentiated non-solid tissue human leukemia cell lines showed that the cytotoxic effect of PNC-27 depends specifically on plasma-membrane HDM-2 expression, with HDM-2 knockdown experiments confirming the molecular target [5].
- starSubsequent work demonstrated that PNC-27 also disrupts mitochondrial membranes in cancer cells through HDM-2-dependent membrane translocation, contributing to the rapid necrotic phenotype and providing a second cellular target beyond plasma membrane pore formation [2].
Side Effects & Tolerability Profile
Clinical subjects transiently report mild side effects. Slowly escalating the titration dose represents the single most effective intervention to limit side effects.
- warningBecause PNC-27 has not been administered to humans in formal clinical trials, no controlled human side effect data exist; any use outside of regulated preclinical research is hazardous and not supported by published safety data.
- warningIn animal xenograft studies, PNC-27 has been described as well tolerated at the doses producing tumor regression, with no observed weight loss, organ toxicity, or hematologic adverse effects, but these observations are limited to small experimental cohorts.
- warningTheoretical risks of off-target membrane permeabilization in cells that transiently express plasma-membrane HDM-2 (proliferating endothelium, regenerating epithelia, certain immune cell populations) have not been systematically characterized.
- warningCytokine release and tumor lysis syndrome would be plausible concerns in any clinical application against high-tumor-burden malignancies, given the rapid necrotic mechanism that releases large quantities of intracellular contents into the circulation.
- warningImmunogenicity of a synthetic chimeric peptide is a standard risk; antibody development against the penetratin or p53 segment could limit repeated dosing efficacy.
- warningBecause PNC-27 is not a commercial pharmaceutical, contamination, misidentification, and dose miscalculation are significant additional risks in any non-regulated use.
- warningNo teratogenicity, reproductive toxicity, or carcinogenicity studies meeting modern regulatory standards have been published; use in any human context outside controlled clinical trials is not supported.
Subcutaneous Injection Technique
Most research peptides require subcutaneous injection into fatty tissue. Never inject directly into a blood vessel or deep muscle tissue unless clinically detailed.
1. Site Selection
Common locations include the abdomen (2 inches from navel), outer upper arms, or thighs.
2. Sanitization
Thoroughly clean the selected site, stopper and vial top using 70% isopropyl alcohol prep swabs.
3. Angle & Push
Pinch the skin and insert the needle at a 45 to 90-degree angle. Depress plunger smoothly.
4. Site Rotation
Rotate injection sites continuously to avoid lipodystrophy or tissue scarring.
Frequently Asked Questions
What is the typical PNC-27 dosage?expand_more
There is no validated human dose. Preclinical xenograft studies have used intraperitoneal or intravenous PNC-27 at 10 to 200 mg/kg in mice. No human dose-finding study has been published, and any extrapolation to human dosing is speculative and not supported by clinical evidence.
How is PNC-27 used in research protocols?expand_more
PNC-27 is used in preclinical cancer biology research, including in vitro studies of HDM-2-dependent cancer cell killing, xenograft models of leukemia and solid tumors, and mechanistic studies of plasma-membrane HDM-2 trafficking. It is not a clinically validated therapeutic.
Can PNC-27 be combined with other peptides?expand_more
In preclinical research PNC-27 has been combined with conventional chemotherapy agents, small-molecule MDM2 inhibitors, and immunotherapy in proof-of-concept studies. Clinical combination protocols have not been validated, and any combination use is purely investigational.
What are the side effects of PNC-27?expand_more
Human side effect data are absent. Animal studies report no observable toxicity in normal tissues at therapeutic doses, but theoretical risks include tumor lysis syndrome, cytokine release, off-target permeabilization of HDM-2-expressing non-cancer cells, and immunogenicity with repeated dosing.
Is PNC-27 FDA approved?expand_more
No. PNC-27 is not approved by the FDA, EMA, or any other regulator for any indication, and is not currently registered in any human clinical trial on ClinicalTrials.gov. It remains a preclinical research peptide; use outside regulated research is not supported by safety or efficacy evidence.
Academic References & Study Citations
Sookraj KA, Bowne WB, Adler V, Sarafraz-Yazdi E, Michl J, Pincus MR. The anti-cancer peptide, PNC-27, induces tumor cell lysis as the intact peptide. Cancer Chemother Pharmacol. 2010;66(2):325-331. View Scientific Paper →
Davitt K, Babcock BD, Fenelus M, et al. 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. 2014;44(3):241-248. View Scientific Paper →
Michl J, Scharf B, Schmidt A, et al. 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. 2022;10(4):945. View Scientific Paper →
Sarafraz-Yazdi E, Bowne WB, Adler V, et al. 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. 2010;107(5):1918-1923. View Scientific Paper →
Bowne WB, Sookraj KA, Vishnevetsky M, et al. The penetratin sequence in the anticancer PNC-27 peptide causes tumor cell necrosis rather than apoptosis of human pancreatic cancer cells. Ann Surg Oncol. 2008;15(12):3588-3600. View Scientific Paper →
Kanovsky M, Raffo A, Drew L, et al. Peptides from the amino terminal mdm-2-binding domain of p53, designed from conformational analysis, are selectively cytotoxic to transformed cells. Proc Natl Acad Sci U S A. 2001;98(22):12438-12443. View Scientific Paper →
Do TN, Rosal RV, Drew L, et al. Preferential induction of necrosis in human breast cancer cells by a p53 peptide derived from the MDM2 binding site. Oncogene. 2003;22(10):1431-1444. View Scientific Paper →
Michl J, Scharf B, Schmidt A, et al. Anti-cancer peptide PNC-27 kills cancer cells by unique interactions with plasma membrane-bound HDM-2 and with mitochondrial membranes causing mitochondrial disruption. Biomedicines. 2024;12(5):1110. View Scientific Paper →