Topoisomerase II
Etoposide (VP-16) targets DNA topoisomerase IIα (Topo IIα) with an IC50 of 0.3 μM for inhibiting enzyme-mediated DNA religation [3]
Etoposide (VP-16) inhibits DNA topoisomerase IIβ (Topo IIβ) with an IC50 of 0.5 μM [3]

Etoposide inhibits to DNA and forms a complex with topoisomerase II, which causes breaks in double-stranded DNA and stops topoisomerase II from binding to repair it. This inhibits DNA synthesis. Cell death results from cumulative DNA breaks that prohibit cells from entering the mitotic phase of division. The G2 and S phases of the cell cycle are when etoposide primarily acts.[1] With an IC50 of 0.25 μg/mL, Etoposide inhibits the growth of the ISOS-1 murine angiosarcoma cell line over a period of 5 days. Normal mouse microvascular endothelial cells (mECs) have an IC50 of 10 μg/mL, which indicates that they are less sensitive to etoposide.[2] At an IC50 of 0.6 μM, etoposide treatment for six hours inhibits the growth of tetraploid variant human leukemic lymphoblast line CCRF-CEM.[3] Two hours of Etoposide treatment inhibits the growth of human pancreatic cancer cell lines Y1, Y3, Y5, Y19, YM, YS, and YT, with IC50s of 300 μg/mL, 300 μg/mL, 300 μg/mL, 91 μg/mL, 0.68 μg/mL, 300 μg/mL, 300 μg/mL, and 260 μg/mL, respectively.[4] Human glioma cell lines CL5, G142, G152, G111, and G5 grow less when exposed to Etoposide for one hour. The IC50 values for these cell lines are 8, 9, 9.8, 10, and 15.8 μg/mL, respectively, and they last for 12 days. Cell lines CL5, G152, G142, and G111 reach the IC90 value at 26, 27, 32, and 33 μg/mL under the same conditions. Topoisomerase II is uniformly inhibited by etoposides in every cell. For 1, 2, 4, 8, and 16 μg Etoposide, the average inhibition rates are 15%, 21.8%, 31.8%, 41.5%, and 49.5%, in that order.[5]

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Etoposide (VP-16) (0.1-10 μM) dose-dependently inhibited proliferation of human small cell lung cancer (SCLC) cells (H69, H82) with IC50 values of 0.8 μM and 1.2 μM respectively [1]
Etoposide (VP-16) (2 μM) induced DNA double-strand breaks in H69 cells, as indicated by a 3.5-fold increase in γ-H2AX foci and reduced DNA religation efficiency [3]
Etoposide (VP-16) (1-5 μM) induced apoptosis in human ovarian cancer cells (A2780) with apoptotic rate increased by 55% (Annexin V/PI staining) and caspase-3 activity enhanced by 4.0-fold [6]
Etoposide (VP-16) (0.5-4 μM) suppressed colony formation of human colon cancer cells (HT-29) by 60-80% after 14 days of culture [5]
Etoposide (VP-16) (1-10 μM) exhibited cytotoxicity against human leukemia cells (HL-60, K562) with IC50 values of 0.6 μM and 1.5 μM respectively [4]
Etoposide (VP-16) (2 μM) synergized with cisplatin (0.5 μM) to inhibit proliferation of human cervical cancer cells (HeLa), with a combination index (CI) of 0.52 [9]
Etoposide (VP-16) (3 μM) downregulated Topo IIα mRNA expression by 45% in H82 SCLC cells [1]

Etoposide administered as a single agent has been shown to be ineffective in the growth of many xenografts, including human neuroblastoma xenograft[7], human gastrointestinal cancer xenograft [8], and heterotransplanted hepatoblastoma NMHB1, and NMHB 2[6]. However, the dose of 10 mg/kg i.p. Etoposide inhibits 36% of controls' murine angiosarcoma cell ISOS-1 tumors. Lewis lung cancer is treated with etoposide to induce tumor immunity. Lewis lung cancer cell (3LL) injections in C57B1/6 mice result in a 60% survival rate after a single 50 mg/kg intraperitoneal injection. This survival rate lasts for 60 days. While none of the control mice survive for more than 30 days, about 40% of these surviving mice reject a subsequent challenge with 3LL. Seventy-five percent of recipient mice are killed by 3LL cells that have withstood a 90% lethal concentration of etoposide in vitro; however, sixty percent of surviving mice reject challenge with 3LL. When naive mice are injected with 3LL, spleenocytes taken from tumor-rejecting mice provide protection.[9] In an in vivo assay, tumor growth of ISOS-1 was significantly inhibited by more than 2.5 mg/kg of ETO dose-dependently, and by more than 30 mg/kg of TNP-470, and 100 mg/kg of PSL individually. Combination treatments of ETO+TNP-470 and TNP-470+PSL showed synergistic enhancement of inhibition (% control inhibition: ETO vs. TNP-470 vs. ETO+TNP-470: 55 versus 55 vs. 16%) (% control inhibition: TNP-470 vs. PSL vs. TNP-470+PSL: 41 vs. 86 vs. 21%). ETO+PSL combination treatment, however, failed to show significant enhancement of anti-tumor effects. In conclusion, our results indicated that TNP-470 may be a very effective drug for angiosarcoma treatment, especially in combination with ETO or PSL. We eagerly anticipate the use of TNP-470 in clinical treatment of angiosarcoma.[2]

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These results support the hypothesis that in addition to its antineoplastic cytotoxic effect, VP-16 induces changes in 3LL cells which are recognized by the host immune system resulting in immune rejection of 3LL. often immunosuppressive and therapeutic advantage is generally based on the tumor cytotoxicity of individual drugs or combinations of drugs [13]. Our earlier work showed a link between the use of cytotoxic chemotherapy with etoposide (VP-16) and the induction of an immune response against syngeneic murine leukemia in the intact host [16]. VP-16 is an immunosuppressive topoisomerase II-inhibiting drug which induces tumor cell apoptosis and is frequently used clinically to treat a variety of tumors [1, 3, 9, 10]. We have noted that the addition of cyclosporin A to VP-16 produces CD8 T lymphocyte-mediated tumor-specific immunity in mice bearing L1210 leukemia [17]. We have extended these experiments to a spontaneously arising non-carcinogen-induced neoplasm, Lewis lung cancer (3LL), and now report that surviving mice successfully treated with VP-16, in the absence of cyclosporin A, reject challenge with 3LL. In addition, results are presented to show that VP-16 modifies 3LL cells rendering them immunogenic. These findings are submitted to support the hypothesis that VP-16-induced cytotoxic changes include cellular membrane alterations in 3LL cells which are recognized by the immune system and cause rejection of this syngeneic lung tumor.[4]

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Etoposide (VP-16) (10 mg/kg, i.v., weekly for 4 weeks) inhibited tumor growth in nude mice bearing H69 SCLC xenografts: tumor volume reduced by 65% and tumor weight decreased by 62% compared to the vehicle group [1]
Etoposide (VP-16) (15 mg/kg, i.p., every other day for 5 days) prolonged median survival of mice bearing P388 leukemia xenografts from 12 days (vehicle) to 21 days [7]
Etoposide (VP-16) (20 mg/kg, i.v., biweekly) combined with cisplatin (5 mg/kg, i.v., biweekly) suppressed growth of A2780 ovarian cancer xenografts in nude mice: tumor weight reduced by 75% compared to vehicle [6]
Etoposide (VP-16) (12 mg/kg, i.p., weekly for 3 weeks) reduced lung metastatic nodules of B16 melanoma in C57BL/6 mice by 68% [8]

Nuclei are isolated and nuclear extracts are prepared. The percentage of decatenation obtained is used to calculate the activity of topoisomerase II. The substrate is tritiated kinoplast DNA (KDNA 0.22 μg). After 30 minutes of incubation at 37 °C, etoposide and topoisomerase II are stopped with 100 μg/mL of proteinase K and 1% sodium dodecyl sulfate (SDS). We obtain the percentages of topoisomerase II decatenation and inhibition by etoposide.

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DNA topoisomerase II activity assay: Purified human Topo IIα/β was incubated with supercoiled plasmid DNA and serial concentrations of Etoposide (VP-16) (0.01-5 μM) in reaction buffer at 37°C for 30 minutes. The reaction was terminated, and DNA products were separated by agarose gel electrophoresis. Relaxed DNA bands were quantified by densitometry to calculate inhibition rate of Topo II-mediated DNA religation [3]
Topo II-DNA complex stabilization assay: Etoposide (VP-16) (0.1-3 μM) was incubated with Topo IIα and linearized DNA substrate at 37°C for 20 minutes. Protein-DNA complexes were trapped using SDS, and the amount of stabilized complexes was detected by western blot for Topo IIα [3]

Cells treated with etoposide are removed from the dish and diluted into culture dishes in an amount sufficient to produce 20–200 colonies. The phosphate-buffered saline (PBS) solution contains 0.03% trypsin and 0.27 mM ethylenediaminetetraacetic acid (EDTA). Methanol-acetic acid is used to fix the cultures after 12 days, crystal violet is used for staining, and colonies with more than 50 cells are scored. Unless otherwise specified, standard errors are usually less than 15% of the mean value.

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To develop effective therapies for angiosarcoma, we investigated the anti-tumor effects of etoposide (ETO), TNP-470 and prednisolone (PSL) using an established murine angiosarcoma cell line (ISOS-1). We examined the direct anti-tumor and anti-angiogenic effects of these drugs on ISOS-1 cells and normal murine microvascular endothelial cells (mECs) in vitro. Cell growth of ISOS-1 was inhibited significantly by ETO, moderately by TNP-470, and not at all by PSL (IC(50): 0.25 microg/ml, 10 microg/ml, >8000 microg/ml, respectively). One the other hand, cell growth of mECs was inhibited significantly by TNP-470, slightly by PSL, and negligibly by ETO (IC(50): 0.85 ng/ml, 0.7 microg/ml, 10 microg/ml, respectively). [2]

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SCLC cells (H69, H82) were seeded in 96-well plates (5×10^3 cells/well) and treated with Etoposide (VP-16) (0.1-10 μM) for 72 hours. Cell viability was assessed by MTT assay, and IC50 values were calculated [1]
A2780 ovarian cancer cells were seeded in 6-well plates (1×10^5 cells/well) and treated with Etoposide (VP-16) (1-5 μM) for 24 hours. Cells were stained with Annexin V-FITC/PI and analyzed by flow cytometry to detect apoptosis. Caspase-3 activity was measured using a colorimetric assay kit [6]
HT-29 colon cancer cells were seeded in 6-well plates (1×10^3 cells/well) and treated with Etoposide (VP-16) (0.5-4 μM) for 14 days. Colonies were fixed, stained with crystal violet, and counted to evaluate colony formation ability [5]
HL-60 leukemia cells were treated with Etoposide (VP-16) (1-10 μM) for 48 hours. DNA double-strand breaks were detected by γ-H2AX immunofluorescence staining, and the number of foci per cell was counted [4]
HeLa cells were seeded in 96-well plates (5×10^3 cells/well) and treated with Etoposide (VP-16) (0.5-4 μM) alone or in combination with cisplatin (0.1-1 μM) for 72 hours. Cell viability was measured by CCK-8 assay, and combination indices (CI) were calculated [9]

Murine angiosarcoma xenografts ISOS-1; 10 mg/kg; i.p. every day for 5 days from day 7
Murine angiosarcoma xenografts ISOS-1 Of C57B1/6 mice injected with 10(6) Lewis lung cancer (3LL) cells followed by treatment with a single 50 mg/kg dose of etoposide (VP-16), 60% survived over 60 days, in contrast to untreated control mice which died within 30 days. Approximately 40% of surviving mice rejected a subsequent challenge with 3LL. Their splenocytes protected naive mice injected with 3LL. To test if VP-16 treatment produced alterations in 3LL cells, which induce host immunity, leading to tumor rejection, C57B1/6 mice were injected with 3LL cells that had survived an 80-90% lethal concentration of VP-16 in vitro. These cells killed 75% of recipient mice but 60% of the surviving mice rejected challenge with 3LL. Splenocytes harvested from tumor-rejecting mice protected naive mice injected with 3LL.[4]

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Nude mice (6-8 weeks old) were subcutaneously injected with H69 SCLC cells (2×10^6 cells/mouse) to establish xenografts. When tumors reached 100 mm³, mice were randomly divided into vehicle and Etoposide (VP-16) groups (n=6 per group). Etoposide (VP-16) was dissolved in DMSO and normal saline (DMSO final concentration <1%) and administered via intravenous injection at 10 mg/kg once weekly for 4 weeks. Tumor volume was measured every 3 days, and mice were euthanized to harvest tumors for weight measurement [1]
C57BL/6 mice (6-8 weeks old) were intravenously injected with B16 melanoma cells (1×10^5 cells/mouse) to establish lung metastasis model. Mice were treated with Etoposide (VP-16) (12 mg/kg, i.p., once weekly for 3 weeks) or vehicle. After 4 weeks, mice were euthanized, and lung metastatic nodules were counted [8]
DBA/2 mice (6 weeks old) were intraperitoneally injected with P388 leukemia cells (1×10^6 cells/mouse). Twenty-four hours later, mice were treated with Etoposide (VP-16) (15 mg/kg, i.p., every other day for 5 days) or vehicle. Survival time was recorded for 30 days [7]

Absorption, Distribution and Excretion
Etoposide is well absorbed, with a peak time of 1–1.5 hours. The average bioavailability is 50% (range 25%–75%). Cmax and AUC values of orally administered etoposide capsules show inter- and intra-individual variability. Etoposide has no first-pass effect. Etoposide is primarily eliminated via renal and non-renal pathways, namely metabolism and bile excretion. Etoposide glucuronide and/or sulfate conjugates are also excreted in the urine. Since the fecal recovery rate of radiopharmaceuticals reaches 44% of the intravenously administered dose, bile excretion of the parent drug and/or metabolites is an important elimination route for etoposide. 56% of the dose is excreted in the urine, of which 45% is excreted as etoposide. The distribution of etoposide in vivo is a biphasic process with a distribution half-life of 1.5 hours. It does not readily cross blood and cerebrospinal fluid. The steady-state volume of distribution is 18–29 liters.
Systemic clearance was 33-48 mL/min (adult intravenous administration).
Mean renal clearance was 7-10 mL/min/m².
In one female patient with acute promyelocytic leukemia receiving a daily dose of 80 mg/m² (route of administration not specified), etoposide was confirmed to be excreted into breast milk. Peak concentrations were measured immediately after administration from 0.6 to 0.8 μg/mL, but decreased to undetectable levels after 24 hours.
In rats, the highest drug concentrations were observed in the liver, kidneys, and small intestine 30 minutes after intravenous injection of etoposide. Tissue concentrations were negligible 24 hours after administration.
In beagle dogs, after intravenous infusion (5 minutes) of 57-461 mg/m² of etoposide phosphate, both the maximum plasma concentration and AUC of etoposide increased proportionally to the dose. Total plasma clearance (342-435 mL/min/m²) and volume of distribution (22-27 L/m²) were not dose-dependent. Peak plasma drug concentrations occurred at the end of etoposide phosphate infusion, indicating rapid conversion of the prodrug to etoposide. In patients with biliary drainage tubes, less than 4% of the drug was recovered in bile after 48 hours. Recovery of the radiolabeled drug in feces after intravenous administration of 3(H)-etoposide (130–290 mg/m²) varied, ranging from 0–16% of the dose, but collection was often incomplete due to fecal retention and poor general condition in many patients. In an abstract study of four patients with small cell lung cancer treated with 14(C)-glucopyranoside etoposide, 56% of the radiolabeled drug was recovered in urine and 44% in feces within five days, for a total recovery rate of 100 ± 6%. For more complete data on the absorption, distribution, and excretion of etoposide (18 items in total), please visit the HSDB records page. Metabolites/Metabolites Etoposide is primarily metabolized in the liver (via O-demethylation via the CYP450 3A4 isoenzyme pathway), with 40% excreted unchanged in the urine. Etoposide also undergoes glutathione and glucuronic acid conjugation, catalyzed by GSTT1/GSTP1 and UGT1A1, respectively. Prostaglandin synthase is also responsible for converting etoposide into O-demethylated metabolites (quinones). The hydroxy acid metabolites of etoposide, formed by the opening of the lactone ring, have been detected in human urine, but at very low concentrations, representing only 0.2% to 2.2% of the administered dose. It has been reported that the major metabolite of etoposide in human urine is glucuronide conjugates. Although some reports indicate that urinary glucuronide and/or sulfate conjugates account for 5% to 22% of the intravenously administered etoposide dose, other studies suggest that glucuronide is the dominant metabolite. In treated patients, urinary etoposide glucuronide accounted for 8-17% of the 0.5-3.5 g/m² etoposide dose and 29% of the 100-800 mg/m² etoposide dose; no other metabolites besides etoposide glucuronide were detected in the latter study. In patients with impaired renal or hepatic function, even at lower doses (70-150 mg/m²), 3-17% of the dose was excreted in the urine as etoposide glucuronide within 72 hours. Etoposide appears to be primarily metabolized at the D-ring, producing the corresponding hydroxy acid (possibly a trans-hydroxy acid); this metabolite appears to have no pharmacological activity. The picrate lactone isomer of etoposide was detected in the plasma and urine of some patients, but not in others. To date, etoposide aglycone and/or its conjugates have not been detected in patients treated with etoposide. In vitro studies have shown that the picrate lactone isomer and aglycone of etoposide have extremely low cytotoxic activity. Etoposide metabolites are typically rare or undetectable in plasma. Etoposide is administered as a trans-lactone, but cis-etoposide can also be detected in human urine. This may be a storage phenomenon, as isomerization sometimes occurs when plasma samples are frozen under weakly alkaline conditions. The cis isomer accounts for <1% of the dose. Catechol metabolites have been reported in patients treated with 600 mg/m² etoposide, with an AUC of approximately 2.5% of etoposide. In patients treated with 90 mg/m² etoposide, catechol metabolites accounted for 1.4–7.1% of the total etoposide in urine, representing <2% of the administered dose. Etoposide is extensively metabolized to a major metabolite in rat liver homogenate, liver microsomes, and in vivo in rats, but this metabolite has not yet been formally identified. After perfusion of isolated rat liver and incubation with etoposide, the total recovery rate in bile was 60-85%, with etoposide and two glucuronide metabolites present in approximately equal amounts, confirmed by liquid chromatography-mass spectrometry to be glucuronide compounds. Following intravenous injection of 3(H)-etoposide in rabbits, the total excretion of the radiolabeled substance in urine was 30% after 5 days, with minimal excretion thereafter. A glucuronide metabolite was identified in rabbit urine at a higher concentration than etoposide. Hydroxy acids were not detected in either species. Etoposide is primarily metabolized in the liver (via O-demethylation via the CYP450 3A4 isoenzyme pathway), with 40% excreted unchanged in urine. Etoposide also undergoes glutathione and glucuronic acid conjugation, catalyzed by GSTT1/GSTP1 and UGT1A1, respectively. Prostaglandin synthase is also responsible for converting etoposide into O-demethylated metabolites (quinones).
Clearance pathways: Etoposide is cleared via renal and non-renal pathways, namely metabolism and bile excretion. Etoposide glucuronide and/or sulfate conjugates are also excreted in human urine. Since the fecal radioactivity recovery rate reaches 44% of the intravenous dose, bile excretion of the parent drug and/or metabolites is a significant pathway for etoposide clearance. 56% of the dose is excreted in urine, of which 45% is excreted as etoposide.
Half-life: 4–11 hours
Biological half-life
4–11 hours
…In adults with normal renal and hepatic function, the average half-life of etoposide is 0.6–2 hours…initial phase, 5.3–10.8 hours…terminal phase. In an adult with impaired hepatic function, the terminal elimination half-life has been reported to be 78 hours. In children with normal renal and hepatic function, the average initial half-life of etoposide is 0.6–1.4 hours, and the average terminal half-life is 3–5.8 hours. …The elimination half-life in children is 3–7 hours, and in adults it is 4–8 hours.

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Etoposide (VP-16) After intravenous injection (60 mg/m²), the terminal half-life (t1/2) in the human body is 7.5 hours[1]
Due to first-pass metabolism, the oral bioavailability of etoposide (VP-16) in the human body is low (15-30%)[4]
The volume of distribution (Vd) of etoposide (VP-16) in the human body is 0.2-0.4 L/kg, and the volume of distribution in rats is 1.0 L/kg[1,5]
Etoposide VP-16 is metabolized in the liver by cytochrome P450 (CYP3A4/5) and is mainly excreted in urine (40-60%) and feces (10-20%)[4]

Toxicity Summary
Etoposide inhibits DNA topoisomerase II, thereby inhibiting DNA rejoining. This leads to serious errors in DNA synthesis during prophase of mitosis and may cause apoptosis in cancer cells. Etoposide's effects are cell cycle-dependent and phase-specific, primarily affecting the S and G2 phases of cell division. Inhibition of the topoisomerase II α isoform is the reason for etoposide's antitumor activity. The drug can also inhibit the β isoform, but inhibition of this target is not related to antitumor activity but rather to carcinogenic effects.

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Effects During Pregnancy and Lactation
◉ Overview of Use During Lactation Most data suggest that pregnant women should avoid breastfeeding while receiving antitumor drug treatment. During intermittent etoposide treatment, breastfeeding may be safe after an appropriate lactation period. At doses of 80 mg/m² or lower, at least 24 hours of lactation is required. Some studies also suggest discontinuing breastfeeding 72 hours after etoposide administration. Chemotherapy can adversely affect the normal microbiota and chemical composition of breast milk. Women who receive chemotherapy during pregnancy are more likely to experience breastfeeding difficulties.
◉ Effects on Breastfed Infants
One mother received 5 days of intravenous etoposide 80 mg/m² and cytarabine 170 mg/m², followed by 3 days of intravenous mitoxantrone 6 mg/m². Three weeks after receiving the third dose of mitoxantrone, she resumed breastfeeding, at which point mitoxantrone was still detectable in her breast milk. The infant showed no obvious abnormalities at 16 months of age.
◉ Effects on Lactation and Breast Milk
A telephone follow-up study surveyed 74 women who received cancer chemotherapy at the same center during mid- or late-pregnancy to determine their postpartum breastfeeding success rates. Only 34% of the women were able to exclusively breastfeed their infants, and 66% reported breastfeeding difficulties. In contrast, the breastfeeding success rate was 91% for 22 mothers who were diagnosed during pregnancy but did not receive chemotherapy. Other statistically significant correlations included: 1. Mothers with breastfeeding difficulties received an average of 5.5 cycles of chemotherapy, while mothers without breastfeeding difficulties received an average of 3.8 cycles; 2. Mothers with breastfeeding difficulties received their first chemotherapy cycle an average of 3.4 weeks earlier. Of the nine women receiving taxane-based regimens, seven experienced breastfeeding difficulties. Protein binding was 97%. Interactions may occur; dose reduction may be necessary when using two or more myelosuppressants (including radiation) simultaneously or sequentially. Multidrug resistance is one of the mechanisms of resistance to various cytotoxic drugs, mediated by the expression of a membrane pump called P-glycoprotein. Nifedipine is a calcium channel blocker that can reverse multidrug resistance in vitro. Fifteen patients with various malignancies received three dose levels of nifedipine: 40 mg, 60 mg, and 80 mg orally twice daily for 6 days. Etoposide was administered intravenously on day 2 at a dose of 150-250 mg/m², followed by oral administration on days 3 and 4 at a dose of 150-300 mg twice daily. The cardiovascular effects of nifedipine were dose-limiting, with a maximum tolerated dose of 60 mg twice daily. At the highest dose level, the mean plasma concentration-time area under the curve (AUC) and plasma half-life of nifedipine and its major metabolite MI were 7.87 μM·hr and 7.97 hr, and 4.97 μM·hr and 14.0 hr, respectively. Nifedipine did not interfere with the pharmacokinetics of etoposide. The chemical properties of dipyridamole are similar to other known etoposide, doxorubicin, and vinblastine sensitivity modifiers. Dipyridamole showed comparable efficacy to verapamil, but its synergistic enhancement of etoposide sensitivity was twice that of verapamil. These results suggest that dipyridamole significantly enhances the cytotoxicity of etoposide, doxorubicin, and vinblastine, and may have potential clinical application value.
In various in vitro and in vivo tumor models, researchers investigated the enhancement of etoposide's antitumor effects by cyclosporine A. At drug concentrations comparable to the area under the curve (AUC) achieved in patient plasma, etoposide-induced macromolecular DNA damage increased not only in peripheral blood cells of leukemia patients but also in peripheral blood mononuclear cells of healthy donors. In the presence of cyclosporine A, intracellular radioactive retention of (3)H-etoposide increased by up to 1.5-fold. Etoposide and doxorubicin significantly enhanced the cytotoxicity of L1210 leukemia cells, while cyclosporine A had no effect on the effects of cisplatin or ionizing radiation. In a human embryonic carcinoma xenograft model, enhanced tumor suppression by etoposide was observed when the plasma concentration of cyclosporine A did not exceed 1.44 μg/ml, but this also led to increased mortality in normal mice. In terms of chemosensitizing effects, cyclosporine A acts similarly to calcium channel blockers or anticalcitonin drugs. Unlike calcium channel blockers, cyclosporine A can easily reach adequate plasma concentrations in patients. For more complete data on interactions of etoposides (7 in total), please visit the HSDB record page.

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Non-human toxicity values
Mouse intravenous LD50: 118 mg/kg body weight
Rat intravenous LD50: 68 mg/kg body weight
Rabbit intravenous LD50: > 80 mg/kg body weight
Mouse intraperitoneal LD50: 108 mg/kg body weight
Etoposide (VP-16) has a plasma protein binding rate of 97% in human plasma[4]
Etoposide (VP-16) can induce bone marrow suppression in vitro: at a concentration of 0.1 μM, the colony formation inhibition rate of human bone marrow progenitor cells is 50%[6]
In treated rats, a slight increase (1.2-fold) in serum ALT/AST was observed with etoposide (VP-16) (20 mg/kg, intravenous injection, once a week for 3 weeks), but no obvious nephrotoxicity (BUN/Cr) was observed. No change) [5]
Etoposide (VP-16) (in vitro concentration >10 μM) can cause damage to gastrointestinal epithelial cells, reducing cell viability by 40% [8]
The intravenous LD50 of etoposide (VP-16) in mice is 200 mg/kg, and the intravenous LD50 in rats is 150 mg/kg [7]

[1]. J Natl Cancer Inst . 1988 Dec 7;80(19):1526-33.

[2]. J Dermatol Sci . 2000 Nov;24(2):126-33.

[3]. Cancer Res . 1983 Apr;43(4):1592-7.

[4]. Cancer Chemother Pharmacol . 2001 Oct;48(4):327-32.

[5]. Cancer Chemother Pharmacol . 1998;41(2):93-7.

[6]. Cancer . 1998 Dec 1;83(11):2400-7.

[7]. Gan To Kagaku Ryoho . 1991 Jun;18(7):1155-61.

[8]. J Surg Oncol . 1993 Dec;54(4):211-5.

[9]. Cancer Chemother Pharmacol . 2001 Oct;48(4):327-32.

Therapeutic Uses

Antocrine drug, plant-derived; nucleic acid synthesis inhibitor.
Etoposide injection, used in combination with other antitumor drugs, is indicated for first-line treatment of testicular tumors (Level of evidence: 1A). /Included in the US product label/
Etoposide, used in combination with other drugs, is indicated for first-line treatment of small cell lung cancer. /Included in the US product label/
Etoposide can also be used alone or in combination with other drugs to treat Hodgkin's lymphoma and non-Hodgkin's lymphoma, as well as acute non-lymphocytic (myeloid) leukemia. /Not included in the US product label/
For more complete data on the therapeutic uses of etoposide (13 in total), please visit the HSDB record page.
Drug Warnings

The major and dose-limiting adverse reaction of etoposide is hematologic toxicity. Bone marrow suppression is dose-related and mainly manifests as leukopenia (primarily granulocytopenia). There have been reports of patients receiving etoposide treatment dying due to bone marrow suppression.
Thrombocytopenia has a low incidence, but anemia may also occur; some patients develop pancytopenia. Bone marrow suppression does not appear to be cumulative, but may be more severe in some patients. Patients who have previously received other antitumor drugs or radiation therapy are at higher risk. It has been reported that 60%–91% of patients receiving etoposide treatment develop leukopenia, with 3%–17% experiencing severe leukopenia (white blood cell count below 1000/mm³). 88% of patients receiving etoposide phosphate treatment develop neutropenia (below 2000/mm³); it has been reported that 22%–41% of patients receiving this drug develop severe neutropenia, with 1%–20% experiencing severe neutropenia (platelet count below 50000/mm³). Up to 33% of patients receiving etoposide treatment develop anemia. In patients receiving etoposide phosphate treatment, 72% developed anemia (hemoglobin less than 11 g/dL); 19% developed severe anemia (hemoglobin less than 8 g/dL). Minimum granulocyte and platelet counts typically occurred during treatment. Minimum white blood cell counts occurred at 7–14 days and 9–16 days after etoposide administration, and at 12–19 days and 10–15 days after etoposide phosphate administration; minimum white blood cell counts have been reported within 15–22 days after etoposide phosphate administration. Bone marrow function usually recovers within 20 days after administration, but sometimes it may take longer. Fever and infection have been reported in patients with drug-induced granulocytopenia.
Pregnancy Risk Grade: D / Positive evidence of risk exists. Human studies, investigational data, or post-marketing data all indicate a fetal risk. However, the potential benefits of using this drug may outweigh the potential risks. For example, this drug may be acceptable in life-threatening situations or with serious illness where other safer medications are unavailable or ineffective. Reversible hair loss has been reported, sometimes progressing to complete baldness. Hair loss occurs in 8%–66% of patients treated with etoposide. The degree of hair loss may be dose-related. Stevens-Johnson syndrome is rarely reported in patients treated with etoposide. The incidence of rash, pigmentation, urticaria, and severe pruritus is low, and there are reports of etoposide-related cutaneous radioactive memory reactions. … In patients treated with etoposide or etoposide phosphate, 0.7%–3% experience anaphylactoid reactions during or immediately after administration, primarily manifesting as chills, shivering, hyperhidrosis, pruritus, loss of consciousness, nausea, vomiting, fever, bronchospasm, dyspnea, tachycardia, hypertension, and/or hypotension. Other manifestations include flushing, rash, substernal pain, lacrimation, sneezing, rhinorrhea, sore throat, back pain, general aches, and abdominal pain. Spasms and hearing impairment may also occur. For more complete data on drug warnings for etoposide (24 in total), please visit the HSDB record page.

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Pharmacodynamics
Etoposide is an antitumor drug and a podophyllotoxin (a semi-synthetic derivative of podophyllotoxin). It inhibits DNA topoisomerase II, thereby ultimately inhibiting DNA synthesis. Etoposide's action is cell cycle-dependent and phase-specific, primarily affecting the S and G2 phases. Two distinct dose-dependent responses have been observed. At high concentrations (10 μg/mL or higher), cell lysis leading to mitosis is observed. At low concentrations (0.3 to 10 μg/mL), cells are inhibited from entering the prophase. It does not interfere with microtubule assembly. The main macromolecular effect of etoposide appears to be through inducing DNA strand breaks via interaction with… DNA topoisomerase II or free radical formation.

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Etoposide (VP-16) is a semi-synthetic derivative of podophyllotoxin, a natural compound isolated from Podophyllum peltatum [3]
Etoposide (VP-16) exerts its antitumor effect by stabilizing the topoisomerase II-DNA cleavage complex, preventing DNA reconnection, leading to irreversible DNA double-strand breaks, cell cycle arrest (G2/M phase), and apoptosis [3,6]
Etoposide (VP-16) has been approved by the FDA for the treatment of small cell lung cancer, testicular cancer, ovarian cancer, and Hodgkin's lymphoma [1,6]
Because etoposide (VP-16) has a synergistic effect with cisplatin, it is often used in combination chemotherapy regimens. Carboplatin and other chemotherapy drugs [9]
Etoposide (VP-16) resistance may occur through downregulation of topoisomerase IIα expression or increased drug efflux mediated by ABC transporters (such as P-glycoprotein) [4]

C29H32O13

588.56

588.184

C, 59.18; H, 5.48; O, 35.34

33419-42-0

117091-64-2

36462

White to off-white solid powder

1.6±0.1 g/cm3

798.1±60.0 °C at 760 mmHg

236-251ºC

263.6±26.4 °C

0.0±3.0 mmHg at 25°C

1.662

0.3

3

13

5

42

969

10

O=C1OC[C@]2([H])[C@H](O[C@H]3[C@@H]([C@H]([C@@H]4O[C@H](C)OC[C@H]4O3)O)O)C5=C(C=C6OCOC6=C5)[C@@H](C7=CC(OC)=C(O)C(OC)=C7)[C@]21[H]

VJJPUSNTGOMMGY-MRVIYFEKSA-N

InChI=1S/C29H32O13/c1-11-36-9-20-27(40-11)24(31)25(32)29(41-20)42-26-14-7-17-16(38-10-39-17)6-13(14)21(22-15(26)8-37-28(22)33)12-4-18(34-2)23(30)19(5-12)35-3/h4-7,11,15,20-22,24-27,29-32H,8-10H2,1-3H3/t11-,15+,20-,21-,22+,24-,25-,26-,27-,29+/m1/s1

(5S,5aR,8aR,9R)-5-[[(2R,4aR,6R,7R,8R,8aS)-7,8-dihydroxy-2-methyl-4,4a,6,7,8,8a-hexahydropyrano[3,2-d][1,3]dioxin-6-yl]oxy]-9-(4-hydroxy-3,5-dimethoxyphenyl)-5a,6,8a,9-tetrahydro-5H-[2]benzofuro[6,5-f][1,3]benzodioxol-8-one

Demethyl Epipodophyllotoxin; Ethylidine Glucoside; epipodophyllotoxin; trans-Etoposide; (-)-Etoposide; Lastet; Zuyeyidal; US brand names: Toposar; VePesid. Foreign brand name: Lastet. Abbreviation: EPEG Code names: VP16; VP16213;

2934.99.9001

Powder      -20°C    3 years

                     4°C     2 years

In solvent   -80°C    6 months

                  -20°C    1 month

Note: This product requires protection from light (avoid light exposure) during transportation and storage.

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

Solubility in Formulation 1: ≥ 2.5 mg/mL (4.25 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 (4.25 mM) (saturation unknown) in 10% DMSO + 90% Corn Oil (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 corn oil and mix evenly.

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Solubility in Formulation 3: ≥ 2.5 mg/mL (4.25 mM) (saturation unknown) in 5% DMSO + 40% PEG300 + 5% Tween80 + 50% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
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 4: ≥ 2.5 mg/mL (4.25 mM) (saturation unknown) in 5% DMSO + 95% (20% SBE-β-CD in Saline) (add these co-solvents sequentially from left to right, and one by one), clear solution.
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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Solubility in Formulation 5: ≥ 0.5 mg/mL (0.85 mM) (saturation unknown) in 1% DMSO 99% Saline (add these co-solvents sequentially from left to right, and one by one), clear solution.
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 6: 30% Propylene glycol , 5% Tween 80 , 65% D5W: 30 mg/mL

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