Plicamycin targets DNA and the transcription factor Sp1. As a DNA-binding agent, plicamycin binds to GC-rich regions of DNA and prevents the transcription of RNA and protein synthesis. As a selective Sp1 transcription factor inhibitor, plicamycin reduces Sp1 protein expression and inhibits the growth of various cancers. Plicamycin also inhibits GSTM2 promoter activity and protein expression. By inhibiting Sp1-mediated transcription, plicamycin reduces the expression of genes involved in cell proliferation, angiogenesis, and metastasis. The compound's dual mechanism of action—DNA binding and Sp1 inhibition—contributes to its antineoplastic activity. Plicamycin has been used in the treatment of testicular cancer, Paget's disease of bone, and hypercalcemia.

By causing pontic regulation and lowering the Sp1 protein, plicamycin (Mith) inhibits the growth of cervical cancer by blocking the DR5/caspase-8/Bid signaling pathway. After 48 hours, plicamycin reduced the proliferation of HEp-2 and KB cells in a concentration-dependent manner. Nuclear condensation and fragmentation were detected using DAPI labeling to qualitatively evaluate cell death. Significant DNA fragmentation is caused by plicamycin when compared to untreated controls [1].
In vitro, plicamycin demonstrates potent antitumor activity. The compound binds to DNA and prevents cells from making RNA and proteins. As a selective Sp1 transcription factor inhibitor, plicamycin reduces Sp1 protein expression and inhibits the growth of various cancers. Plicamycin also inhibits GSTM2 promoter activity and protein expression. In cellular assays, plicamycin's effects on cell proliferation, apoptosis, and gene expression can be assessed. The compound's ability to inhibit Sp1-mediated transcription can be measured using reporter gene assays. Plicamycin's in vitro activity supports its use as an antineoplastic agent.

In a xenograft model, the tumorigenic activity of plicamycin (0.2 mg/kg/day) was assessed, and a decrease in tumor mass and volume was noted. The fact that there was no discernible reduction in mouse body weight in the plicamycin-treated group suggests that the toxicity of plicamycin was negligible. In tumor xenografts, plecarmycin also enhanced the number of TUNEL-active cells. The lack of discernible intergroup differences across organs suggests that the plicamycin levels utilized in this investigation did not cause any appreciable systemic toxicity [1].
In vivo, plicamycin has been used in the treatment of testicular cancer, Paget's disease of bone, and hypercalcemia. The compound is used to reduce hypercalcemia, especially that due to malignancies. Plicamycin is an antineoplastic antibiotic that was formerly used in the treatment of testicular cancer and hypercalcemia associated with cancer. The compound's in vivo efficacy in these conditions supported its clinical use. However, due to significant toxicity, especially hepatotoxicity and bleeding events, plicamycin is no longer in general clinical use and is not approved for use today.

In vitro assays for plicamycin typically measure DNA binding and Sp1 inhibition. For DNA binding studies, plicamycin is incubated with DNA, and binding is assessed by spectrophotometry, fluorescence, or gel mobility shift assays. For Sp1 inhibition studies, reporter gene assays are used where cells are transfected with an Sp1-driven luciferase construct and treated with plicamycin. Luciferase activity is measured, and the IC₅₀ is calculated. For studies investigating the mechanism of action, gene expression changes are assessed by qPCR or microarray.

In vitro cellular assays for plicamycin employ various cancer cell lines. Cells are cultured in appropriate media and treated with plicamycin at various concentrations. Cell proliferation is assessed using MTT or resazurin reduction assays. Apoptosis is assessed by flow cytometry or by measuring caspase activity. Sp1 expression and activity are assessed by Western blotting or reporter gene assays. GSTM2 expression is assessed by qPCR or Western blotting. The compound's effects on cell viability and proliferation can be assessed in various cancer cell types.

In vivo animal experiments for plicamycin employ models of cancer and hypercalcemia. For antitumor studies, xenograft models are used, and tumor growth is measured. For hypercalcemia studies, animal models of malignancy-associated hypercalcemia are used, and serum calcium levels are measured. For toxicology studies, animals are administered plicamycin at various doses, and adverse effects such as hepatotoxicity and bleeding are assessed. Dosing regimens vary depending on the experimental objectives.

Absorption, Distribution and Excretion
Autoradiography studies of 3H-labeled pricamycin in mice showed that the highest concentrations of this isotope were observed in Kupffer cells of the liver and renal tubular cells. Pricamycin is rapidly cleared from the bloodstream within the first 2 hours, and excretion is also rapid. 67% of the drug is excreted within 4 hours after injection; 75% within 8 hours; and 90% within 24 hours. It is unclear whether pricamycin is excreted into breast milk. Duration of action: 7 to 10 days after a single dose. Time to peak concentration: 72 hours after a single dose. Onset of action: When used to treat hypercalcemia, plasma calcium levels typically decrease within 24 to 48 hours after administration. Pricamycin primarily accumulates in Kupffer cells of the liver, renal tubular cells, and on the surface of established bone. It may localize in areas of active bone resorption. Pricamycin can also cross the blood-brain barrier into the cerebrospinal fluid.
The pharmacokinetic properties of plicamycin have been characterized in humans. Preliminary pharmacokinetic data in humans indicate that the plasma drug disappearance curve was biphasic with a mean elimination half-life of 10.6 ± 1.7 hours, total clearance rate of 11.1 ± 0.4 ml/min/m², and area under the plasma drug concentration-time curve of 1,289-1,546 ng-h/ml. Plicamycin is rapidly cleared from the blood within the first 2 hours after administration. Excretion is also rapid, with 67% of measured excretion occurring within 4 hours, 75% within 8 hours, and 90% recovered in the first 24 hours after injection. Plicamycin crosses the blood-brain barrier, with CSF levels comparable to plasma levels.

Hepatotoxicity
Elevated serum enzymes occur in almost all patients who receive pricamycin chemotherapy for more than 1 to 2 days and are monitored during treatment. Serum ALT, AST, and LDH levels begin to rise within 3 days after the first infusion and peak within 7 to 10 days, reaching 5 to 500 times the upper limit of normal (ULN). However, these elevations are transient, subsiding within 1 to 3 weeks and rarely accompanied by symptoms or jaundice. Liver biopsies performed during these elevations typically show centrilobular necrosis and congestion. With repeated treatment courses, the elevations usually persist, but are generally of the same or milder degree. There has been a reported case of acute liver failure within days of treatment in a patient who received a full dose of pricamycin for 4 days for non-malignant hypercalcemia, suggesting ischemic hepatitis or sinusoidal obstruction syndrome. Otherwise, although the elevation of serum enzymes is moderate to severe, it is usually transient and benign. Probability score: A [HD] (Known cause of clinically significant liver injury due to high-dose intravenous therapy). Protein Binding There is no evidence of protein binding, nor is there evidence that the carbohydrate portion of the drug is metabolized into carbon dioxide and water and excreted through respiration. Interactions Hypoprothrombinemia caused by pricamycin may increase the activity of coumarin and indanedione derivative anticoagulants and may increase the bleeding risk in patients receiving heparin or thrombolytic therapy; concomitant use is not recommended. Concomitant use of pricamycin with nonsteroidal anti-inflammatory drugs (NSAIDs), aspirin, dextran, dipyridamole, sulfinpyrazone, or valproic acid may increase the bleeding risk because the synergistic or multiple effects of these drugs or pricamycin may reduce blood clotting ability, i.e., inhibit platelet aggregation, and the combined use of pricamycin and high-dose aspirin may induce hypoprothrombinemia; furthermore, the risk of gastrointestinal ulceration or bleeding associated with aspirin, NSAIDs, or sulfinpyrazone may increase the bleeding risk in patients treated with pricamycin.
Concurrent use with other myelosuppressants, hepatotoxic drugs, or nephrotoxic drugs may increase the risk of toxicity.
Concurrent use of vitamin D (including calcidiol and calcitriol) may antagonize the effects of pricamycin as a calcium antagonist.
Non-human toxicity values

Rat intravenous LD50: 1.74 mg/kg
Mouse intravenous LD50: 2.14 mg/kg
The toxicity profile of plicamycin is significant and led to its discontinuation from general clinical use. Common adverse effects include myelosuppression, hepatotoxicity, and bleeding events. The compound may aggravate uremic predisposition to hemorrhage and infection. Plicamycin is no longer in general clinical use and is not approved for use today. The compound's safety in pregnancy and lactation has not been established.

[1]. Modulation of specificity protein 1 by mithramycin A as a novel therapeutic strategy for cervical cancer. Sci Rep. 2014 Nov 24;4:7162.

[2]. The suppressive role of phytochemical-induced glutathione S-transferase Mu 2 in human urothelial carcinoma cells. Biomed Pharmacother. 2022 Jul;151:113102.

Therapeutic Uses
MeSH Title: Antibiotics, Antineoplastic Drugs, Fluorescent Dyes, Nucleic Acid Synthesis Inhibitors, Protein Synthesis Inhibitors
Due to its severe toxicity, pricamycin has limited value in treating neoplastic diseases.
Due to the low incidence of testicular tumors (estimated to account for 1% of all tumors), the number of cases evaluated is limited.
It is beneficial for patients with disseminated testicular cancer, especially embryonal cell carcinoma, but has been superseded by other drug regimens, particularly vincristine, cisplatin, and bleomycin.
For more complete data on the therapeutic uses of mitochondrial (12 in total), please visit the HSDB record page.
Drug Warnings
Pricamycin is recommended to be administered intravenously only in hospitalized patients by an experienced physician or under their supervision. Caution should be exercised when using cancer chemotherapy drugs due to the possibility of serious reactions.
The incidence of bleeding syndrome is approximately 5% in patients receiving no more than 30 mcg/kg/day for no more than 10 doses; while the incidence of bleeding syndrome is approximately 12% in patients receiving higher doses.
Baseline platelet count, prothrombin time, and bleeding time should be measured before treatment begins. These parameters should be monitored during treatment and for several days after the last dose. A significant decrease in platelet count…or a significant prothrombin time or bleeding time is an indication for discontinuation of the drug.
Metastatic lesions in patients with mixed primary testicular tumors that have only partially shrunk or remained unaffected…usually, these lesions…are identified as teratomas, choriocarcinomas, or seminomas. Due to these cell types, this product is not recommended for the treatment of metastatic tumors.
For more complete data on drug warnings for misomycin (17 in total), please visit the HSDB record page.

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Pharmacodynamics
Precainomicals can kill HeLa cells within 48 hours at concentrations as low as 0.5 μg per mL of tissue culture medium. Intraperitoneal injection of precainomicals has shown significant antitumor activity against experimental leukemia in mice.

C52H76O24

1085.14

1084.472

18378-89-7

163659

Yellow to brown solid powder

1.5±0.1 g/cm3

1169.8±65.0 °C at 760 mmHg

180-183ºC

327.4±27.8 °C

0.0±0.3 mmHg at 25°C

1.640

1.29

11

24

15

76

1940

25

C[C@@H]1[C@H]([C@@H](C[C@@H](O1)O[C@@H]2C[C@@H](O[C@@H]([C@H]2O)C)OC3=CC4=CC5=C(C(=O)[C@H]([C@@H](C5)[C@@H](C(=O)[C@H]([C@@H](C)O)O)OC)O[C@H]6C[C@H]([C@@H]([C@H](O6)C)O)O[C@H]7C[C@H]([C@H]([C@H](O7)C)O)O[C@H]8C[C@]([C@@H]([C@H](O8)C)O)(C)O)C(=C4C(=C3C)O)O)O)O

CFCUWKMKBJTWLW-BKHRDMLASA-N

InChI=1S/C52H76O24/c1-18-29(72-34-14-30(43(58)21(4)68-34)73-33-13-28(54)42(57)20(3)67-33)12-26-10-25-11-27(49(66-9)48(63)41(56)19(2)53)50(47(62)39(25)46(61)38(26)40(18)55)76-36-16-31(44(59)23(6)70-36)74-35-15-32(45(60)22(5)69-35)75-37-17-52(8,65)51(64)24(7)71-37/h10,12,19-24,27-28,30-37,41-45,49-51,53-61,64-65H,11,13-17H2,1-9H3/t19-,20-,21-,22-,23-,24-,27+,28-,30-,31-,32-,33+,34+,35+,36+,37+,41+,42-,43-,44-,45+,49+,50+,51-,52+/m1/s1

(2S,3S)-2-[(2S,4R,5R,6R)-4-[(2S,4R,5S,6R)-4-[(2S,4S,5R,6R)-4,5-dihydroxy-4,6-dimethyloxan-2-yl]oxy-5-hydroxy-6-methyloxan-2-yl]oxy-5-hydroxy-6-methyloxan-2-yl]oxy-3-[(1S,3S,4R)-3,4-dihydroxy-1-methoxy-2-oxopentyl]-6-[(2S,4R,5R,6R)-4-[(2S,4R,5S,6R)-4,5-dihydroxy-6-methyloxan-2-yl]oxy-5-hydroxy-6-methyloxan-2-yl]oxy-8,9-dihydroxy-7-methyl-3,4-dihydro-2H-anthracen-1-one

PA144; mithramycin. US Mithracin. Foreign Mithracine. MTH. A2371; aureolic acid

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Room temperature (This product is stable at ambient temperature for a few days during ordinary shipping and time spent in Customs)

DMSO : ≥ 100 mg/mL (~92.15 mM)

Solubility in Formulation 1: ≥ 2.5 mg/mL (2.30 mM) (saturation unknown) in 10% DMSO + 40% PEG300 + 5% Tween80 + 45% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 400 μL PEG300 and mix evenly; then add 50 μL Tween-80 to the above solution and mix evenly; then add 450 μL normal saline to adjust the volume to 1 mL.
Preparation of saline: Dissolve 0.9 g of sodium chloride in 100 mL ddH₂ O to obtain a clear solution.

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Solubility in Formulation 2: ≥ 2.5 mg/mL (2.30 mM) (saturation unknown) in 10% DMSO + 90% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
For example, if 1 mL of working solution is to be prepared, you can add 100 μL of 25.0 mg/mL clear DMSO stock solution to 900 μL of 20% SBE-β-CD physiological saline solution and mix evenly.
Preparation of 20% SBE-β-CD in Saline (4°C，1 week): Dissolve 2 g SBE-β-CD in 10 mL saline to obtain a clear solution.

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 (Please use freshly prepared in vivo formulations for optimal results.)