In vivo efficacy and toxicity of intratumorally delivered mitomycin C and its combination with doxorubicin using microsphere formulations

The efficacy and toxicity of intratumorally (i.t.) administered anticancer drugs mitomycin C (MMC) and doxorubicin (Dox) incorporated in polymeric microspheres were investigated. Biodegradable sulfopropyl dextran microspheres and their oxidized products were used to load Dox and MMC, respectively. EMT6 mouse mammary cancer cells were injected into the hind leg of BALB/c mice. MMC microspheres, alone or combined with Dox microspheres, were injected i.t. once tumors had reached around 0.3 g. The tumor-plus-leg diameter was measured daily and the delay in time for the tumor to grow to 1.13 g relative to control (TGD) was employed as an indication of therapeutic effect. General toxicity was determined by monitoring weight, appearance and behavior of the mice. Morphology and histology of tumor and heart tissues were also examined. An average 79% TGD was observed after i.t. injection of MMC microspheres. The i.t. co-administration of MMC and Dox microspheres resulted in a 185% TGD. The i.t. injections of the microsphere formulations did not result in visible signs of toxicity in animals. In contrast, systemic (i.e. i.p.) injections of MMC solutions caused considerable general toxicity. This study suggests that i.t. delivery of anticancer drugs by polymeric microspheres is an effective way of improving the therapeutic index for cancer chemotherapy of selected solid tumors under special conditions.     

On the synergistic effect of doxorubicin and mitomycin C against breast cancer cells

The combination of doxorubicin and mitomycin C has been shown previously to result in supra-additive tumor cell killing in vitro in both murine and human breast cancer cells and in vivo against murine breast cancer cells. Median effect analysis was used to determine the significance and degree of interaction. The origin of this synergy was sought by evaluating the contribution of membrane efflux pump modulation, formaldehyde production, reactive oxygen species, DNA cross-linking, and DNA double-strand breaks to this effect. The interaction of mitomycin C and doxorubicin in vitro was found to be a true synergy whose mechanism was efflux pump-independent. DNA cross-links were only found to increase additively with co-administration of the drugs; however, a supra-additive increase in DNA double-strand breaks was observed. The results suggest that poisoning of topoisomerase IIalpha by doxorubicin may interact with drug-induced DNA cross-links to enhance the formation of DNA double-strand breaks. This interaction, together with glutathione depletion and mitomycin C-derived formaldehyde, may be the underlying mechanism(s) of the synergy observed between mitomycin C and doxorubicin.     

Synergistic suppression of human breast cancer cells by combination of plumbagin and zoledronic acid In vitro

Aim:

Zoledronic acid (ZA), a bisphosphonate, is currently used in combination with chemotherapeutic agents to suppress breast cancer cell proliferation or breast cancer-induced osteolysis. The aim of this study was to investigate the effects of ZA combined with a natural anticancer compound plumbagin (PL) against human breast cancer cells in vitro.

Methods:

Human breast cancer MDA-MB-231SArfp cells were treated with ZA, PL or a combination of ZA and PL. The cell growth, apoptosis and migration were evaluated using CCK-8 assay, flow cytometry and transwell assay, respectively. The expression of apoptosis-related proteins was measured using real-time PCR and Western blotting. Synergism was evaluated using Compusyn software, and the combination index (CI) and drug reduction index (DRI) values were determined.

Results:

PL or ZA alone caused mild cytotoxicity (the IC50 value at 24 h was 12.18 and above 100 μmol/L, respectively). However, the combination of ZA and PL caused a synergistic cytotoxicity (CI=0.26). The DRI values also showed a synergistic effect between PL and ZA, with actual values of 5.52 and 3.59, respectively. Furthermore, PL and ZA synergistically induced apoptosis and inhibited migration of the breast cancer cells. Moreover, the combination of ZA and PL decreased the expression of Notch-1, cleaved PARP, Bcl-2 and Bcl-xl, and increased the expression of cleaved caspase-3, CDKN1A and ID1. When the breast cancer cells were transfected with specific siRNA against Notch-1, the combination of ZA and PL markedly increased the expression of Bcl-2.

Conclusion:

Combination of ZA and PL synergistically suppresses human breast cancer MDA-MB-231SArfp cells in vitro. PL can inhibit ZA-induced activation of the Notch-1 signaling pathway and subsequently reduce the expression of Bcl-2, thus potentiating cancer cell apoptosis.     

Synergistic anti-cancer activity of the combination of dihydroartemisinin and doxorubicin in breast cancer cells

BackgroundDihydroartemisinin (DHA) exhibits potent anti-malarial and anti-cancer activities. This study aimed to investigate the anti-proliferative effects of a combination of DHA and doxorubicin (DOX) on human breast cancer cells.MethodsMTT assay and the combination index (CI) were used to show the anti-proliferative effects and calculate the synergism potential, respectively. Flow cytometry assay was used to detect apoptosis and the intracellular accumulation of DOX. JC-1 staining was used to determine the mitochondrial membrane potential. Western blot analysis was used to detect the protein expression of some apoptosis-related molecules.ResultsAsynergistic anti-proliferative effect was found, and the enhanced anti-cancer activity was observed to be accompanied by the prompt onset of apoptosis in MCF-7 cells. The combinative treatment remarkably decreased the mitochondrial membrane potential and activated caspase cascades more than the mono-treatment. Pretreatment with DHAalso did not influence the accumulation of DOX in MCF-7 cells.ConclusionThis study presented a new opportunity to enhance the effectiveness of future treatment regimens of breast cancer using DOX.     

吉西他滨和丝裂霉素联合应用对人肺癌细胞A549的作用

目的 观察吉西他滨和丝裂霉素联合应用对人肺癌细胞A549的抑制效应,并探讨其作用机制.方法 用MTT法检测化疗药物对人肺癌细胞A549生长的抑制作用;流式细胞术(FCM)检测细胞周期分布和凋亡率.结果 (1)丝裂霉素和吉西他滨单独和联合用药可浓度依赖性抑制A549细胞的生长.(2)丝裂霉素和吉西他滨在合用72 h后,当Fa >0.18时,丝裂霉素和吉西他滨合用指数CI均<1,两种药物之间是协同作用,当Fa<0.18时,合用指数CI大于1,两种药物之间为拮抗作用.(3)丝裂霉素和吉西他滨同时用药时抑制率最高,其次是先用丝裂霉素后用吉西他滨,抑制率最低是先用吉西他滨后用丝裂霉素.(4)丝裂霉素和不同浓度的吉西他滨合用,除与2.5 μg/ml吉西他滨合用时CI>1外,其余均<1.10 μg/ml吉西他滨和不同浓度的丝裂霉素合用,除与0.0625 μg/ml合用时CI >1外,其余均<1.(5)丝裂霉素和吉西他滨单用和合用时对细胞周期和凋亡均有影响.结论 丝裂霉素和吉西他滨单独和联合用药可浓度依赖性抑制A549细胞的生长.不同用药次序和药物浓度比例也影响药物联合作用.     

Curcumin enhanced antiproliferative effect of mitomycin C in human breast cancer MCF-7 cells in vitro and in vivo

Aim:

To investigate the efficacy of mitomycin C (MMC) in combination with curcumin in suppressing human breast cancer in vitro and in vivo.

Methods:

Human breast cancer MCF-7 cells were used. Cell viability was measured using MTT assay. The cell cycle phase was detected with flow cytometric analysis. Cell cycle-associated proteins were examined using Western blot analysis. MCF-7 breast cancer xenografts were established to monitor tumor growth and cell cycle-associated protein expression.

Results:

Curcumin inhibited MCF-7 breast cancer cell viability in a concentration-dependent manner (IC₅₀ value=40 μmol/L). Similarly, MMC inhibited the cell viability with an IC₅₀ value of 5 μmol/L. Combined treatment of MMC and curcumin showed a synergistic antiproliferative effect. In the presence of curcumin (40 μmol/L), the IC₅₀ value of MMC was reduced to 5 μmol/L. In MCF-7 xenografts, combined administration of curcumin (100 mg/kg) and MMC (1-2 mg/kg) for 4 weeks produced significantly greater inhibition on tumor growth than either treatment alone. The combined treatment resulted in significantly greater G₁ arrest than MMC or curcumin alone. Moreover, the cell cycle arrest was associated with inhibition of cyclin D1, cyclin E, cyclin A, cyclin-dependent kinase 2 (CDK2) and CDK4, along with the induction of the cell cycle inhibitor p21 and p27 both in MCF-7 cells and in MCF-7 xenografts. These proteins were regulated through p38 MAPK pathway.

Conclusion:

The results suggest that the combination of MMC and curcumin inhibits MCF-7 cell proliferation and cell cycle progression in vitro and in vivo via the p38 MAPK pathway.     

In vitro toxicity of camalexin derivatives in human cancer and non-cancer cells

The aim of the study was to investigate the cytotoxic activity of camalexin and its five synthetic derivatives in cancer and non-cancer cells.In cancer cells the benzocamalexin (BC) displayed the most potent activity with an IC₅₀ value of 23.3–30.1 μmol/L. On the other hand, minimal toxicity (IC₅₀ > 100.0 μmol/L) in non-cancer cells was observed. Based on these results, BC was selected for further studies.Flow cytometric analysis revealed a BC-induced arrest of the cell cycle in the G2 phase associated with downregulation of α-tubulin, α1-tubulin, β5-tubulin expression. These findings suggest that the inhibitory effect of BC is mediated via inhibition of microtubule formation. Moreover, BC downregulated the expression of microtubule-related protein indicating the effect of this compound on microtubule assembly. After treatment with BC increase of the sub-G₁ DNA content fraction was noted which is considered to be a marker of apoptotic cell death. Apoptosis was also confirmed by DNA fragmentation assay. Moreover, quantitative real-time PCR showed that BC downregulated the expression of antiapoptotic genes Bcl-2 and Bcl-xL and upregulated the expression of proapoptotic Bax.Taken together, our study suggests that the blockade of cell cycle progression and initiation of apoptosis may play an important role in the antiproliferative activity of BC in human cancer cells.     

In vitro toxicity of silica nanoparticles in human lung cancer cells

The cytotoxicity of 15-nm and 46-nm silica nanoparticles was investigated by using crystalline silica (Min-U-Sil 5) as a positive control in cultured human bronchoalveolar carcinoma-derived cells. Exposure to 15-nm or 46-nm SiO(2) nanoparticles for 48 h at dosage levels between 10 and 100 microg/ml decreased cell viability in a dose-dependent manner. Both SiO(2) nanoparticles were more cytotoxic than Min-U-Sil 5; however, the cytotoxicities of 15-nm and 46-nm silica nanoparticles were not significantly different. The 15-nm SiO(2) nanoparticles were used to determine time-dependent cytotoxicity and oxidative stress responses. Cell viability decreased significantly as a function of both nanoparticle dosage (10-100 microg/ml) and exposure time (24 h, 48 h, and 72 h). Indicators of oxidative stress and cytotoxicity, including total reactive oxygen species (ROS), glutathione, malondialdehyde, and lactate dehydrogenase, were quantitatively assessed. Exposure to SiO(2) nanoparticles increased ROS levels and reduced glutathione levels. The increased production of malondialdehyde and lactate dehydrogenase release from the cells indicated lipid peroxidation and membrane damage. In summary, exposure to SiO(2) nanoparticles results in a dose-dependent cytotoxicity in cultural human bronchoalveolar carcinoma-derived cells that is closely correlated to increased oxidative stress.     

Antitumor activity of doxorubicin in combination with docetaxel against human breast cancer xenografts

In this study we assessed the in vivo antitumor activity of combined docetaxel (DOCE) and doxorubicin (DXR) treatment using 2 human breast carcinoma cell xenografts (R-27 and MX-1) in the nude mouse model. The transplanted tumors were allowed to reach exponential growth, whereupon 10 or 40 mg DOCE per kg alone (i.p.), 8 mg DXR per kg alone (i.v.), or 10 mg/kg DOCE (i.p.) and 8 mg/kg of DXR (i.v.), in the sequence of DOCE followed by DXR, were administered. The in vivo antitumor activity of combined DOCE and DXR was synergistic against R-27 and additive against MX-1. P-glycoprotein (P-gp) was detected immunohistochemically, and was highly expressed in R-27, but not in MX-1. In conclusion, DOCE may increase the antitumor activity of DXR against P-gp-positive breast cancer xenografts, such that the DOCE and DXR combination may be a useful treatment in clinical breast cancer.     

Phase I clinical trial of doxorubicin and iproplatin combination chemotherapy in patients with breast cancer

Summary Forty-eight patients with advanced breast cancer were treated in a disease-specific phase I trial of doxorubicin and iproplatin combination chemotherapy. The doses of doxorubicin ranged between 30 and 50 mg/m₂, and the doses of iproplatin ranged between 150 and 250 mg/m₂. Myelosuppression was observed at all levels, but was dose-limiting at the highest level. In addition, nausea, diarrhea and malaise were prominent toxicities. Neither cardiac nor renal toxicity was encountered. Nine of 26 (35%) of previously untreated patients, and 5 of 22 (23%) previously treated patients demonstrated partial or complete responses. Although this combination possesses therapeutic activity, given its toxicities, further evaluation of doxorubicin in combination with iproplatin is not recommended.     

In vitro interaction of mezlocillin with fluorouracil and mitomycin

The interaction of mezlocillin (Baypen) with either fluorouracil (5-fluorouracil, 5-FU) or mitomycin was tested in vitro by incubating colorectal carcinoma cell line HT 29 with varying concentrations of mezlocillin, 5-FU, mitomycin and the combinations of mezlocillin + 5-FU and mezlocillin + mitomycin. Inhibition of colony growth in soft agar of treated compared with untreated cells was used as an in vitro response parameter. Concentration ranges were representative for regional chemotherapy with mitomycin or 5-FU and perioperative antibiotic therapy with mezlocillin. Mezlocillin, 5-FU and mitomycin showed dose-dependent inhibition of colony growth. Mezlocillin produced a maximal toxicity of 16% at 1000 micrograms/ml. Toxicity of 5-FU was reduced by addition of mezlocillin. The increase of colony growth after coincubation of mezlocillin with 5-FU (compared to cells treated with 5-FU alone) at a mezlocillin concentration of 10 micrograms/ml was 47% to 116%, at 100 micrograms/ml 44% to 132%, depending on the 5-FU test concentrations. The 5-FU toxicity in some instances was nearly abolished. There was no interaction between mezlocillin and mitomycin. The interference of mezlocillin with 5-FU-toxicity should be respected in case of combined perioperative antitumor and antibiotic therapy with 5-FU mezlocillin. Similar interactions with related antibiotics cannot be excluded.     

In vitro antimetastatic activity of koetjapic acid against breast cancer cells

Breast cancer is the most common cancer in women, and it can metastasize very rapidly. Tumor metastasis is the primary cause of cancer deaths. In the present study, we investigated the capability of koetjapic acid, a natural triterpene, in the induction of apoptosis and the inhibition of metastasis in the breast cancer cell line (MCF 7). The effects of koetjapic acid against 4 steps of metastasis have been assessed, including cell survival, clonogenicity, migration and invasion. Koetjapic acid exhibited cytotoxic activity against MCF 7 cells with an IC(50) of 68.88±6.075 μg/mL. The mechanism of cell death was confirmed due to the induction of apoptosis machineries; early and late apoptosis-related changes were detected, including the stimulation of caspase 3/7 activities, apoptosis-related morphological changes such as membrane blebbing, chromatin condensation and DNA fragmentation. A mitochondrial apoptosis pathway was found to be involved in koetjapic acid-induced cell death induction. Moreover, at a sub-toxic dose (15 μg/mL), Koetjapic acid inhibited cell migration and invasion significantly. Finally, koetjapic acid inhibited the colony formation properties of MCF 7 significantly. These results indicate that koetjapic acid possesses significant antitumor and antimetastatic effects, and warrants further investigation.     

Vinblastine-associated pulmonary toxicity in patients receiving combination therapy with mitomycin and cisplatin

Two of 33 patients entered in a local pilot study of mitomycin, vinblastine, and cisplatin for non-small cell lung cancer developed vinblastine-associated pulmonary toxicity. As with other reports of vinca alkaloid-related pulmonary toxicity, the regimen included mitomycin. Based on these cases and others previously reported, the incidence of abrupt pulmonary toxicity following vinca alkaloid administration as part of mitomycin/vinca alkaloid combination appears to be three to six percent. Suggestions for management are given.     

In vivo and in vitro toxicity of phospholipase C from Pseudomonas aeruginosa.

Pseudomonas aeruginosa produces phospholipase C (PLC), a heat-labile hemolysin. Histopathological analysis of PLC-treated mice revealed that the primary target organs involved in PLC-induced toxicity were the liver and kidney. Mice treated i.v. with PLC demonstrated significant tubular epithelial necrosis of the kidney with hematuria, while when given i.p. they exhibited hepatonecrosis with cellular infiltration. Splenomegaly was also a consistent finding. Results from in vitro studies indicate that PLC is toxic for mouse peritoneal cells and human leukocytes.     

消癌平辅助丝裂霉素对肺癌细胞化疗增效的研究

目的：通过消癌平联合丝裂霉素对肺癌 A549细胞增殖,细胞周期、凋亡及相关基因表达的影响,探讨化疗增效机制。方法MTT 检测消癌平（2、8、21μl／ml）联合丝裂霉素（2μg／nl）对肺癌 A549细胞生长抑制（联合用药 A、B、C 组）,并设立对照组、丝裂霉素组和消癌平组;流式细胞术检测细胞周期及凋亡;RT－PCR 检测 P53、CyclinD1基因表达。结果MTT 检测显示在24、48、72 h 联合用药 A、B、C 组 OD（光密度）均比丝裂霉素低（ P ＜0．05）;流式细胞术检测表明消癌平、丝裂霉素与对照组相比,肺癌细胞均阻滞于 G0／G1期,差异有统计学意义（ P ＜0．05）。联合用药组 G0／G1期细胞比率、细胞凋亡率与丝裂霉素组比较,差异有统计学意义（ P ＜0．05）。消癌平组、丝裂霉素组与对照组比较,均能提高 P53 mRNA 表达（ P ＜0．05）,联合治疗组 P53 mRNA 表达高于丝裂霉素组（ P ＜0．05）。消癌平组、丝裂霉素组与对照组比较均能降低 Cyclin D1基因的表达（ P ＜0．05）。与丝裂霉素组比较,联合用药可显著减低CyclinD1基因的表达（ P ＜0．05）。结论消癌平辅助丝裂霉素对肺癌细胞化疗增效可能与上调 P53 mRNA 表达,增强细胞凋亡作用,以及下调 CyclinD1 mRNA 表达,阻滞细胞周期于 G0／G1期有关。     

优降宁与多柔比星协同抑制小鼠三阴性乳腺癌4T-1细胞的增殖和迁移

目的研究赖氨酸特异性去甲基化酶1(lysine-specifc demethylase 1,LSD1)抑制剂优降宁(Pargyline)与化疗药物多柔比星(Doxorubicin)联合应用对小鼠三阴性乳腺癌4T-1细胞增殖、迁移和侵袭的影响。方法体外实验以小鼠三阴性乳腺癌4T-1细胞为模型,以CCK-8法、乳酸脱氢酶释放实验、Chou-Talay法、划痕实验、Transwell实验、Western blot等试验方法检测两药联合对4T-1细胞增殖、侵袭、迁移的影响;构建荷瘤小鼠模型研究两药联用对4T-1细胞体内增殖的影响。结果优降宁和多柔比星可有效抑制4T-1细胞增殖、迁移和侵袭,两药联用具有协同效应,且无明显细胞毒性。体内实验证明,与单用药组相比,两药联用可明显抑制乳腺癌的体内增殖并延长三阴性乳腺癌4T-1细胞荷瘤小鼠的生存期。结论优降宁与多柔比星联合应用对小鼠乳腺癌4T-1细胞的增殖、迁移和侵袭具有协同抑制效应,具有用于临床三阴性乳腺癌治疗的潜在价值。     

In vitro fertilization and development of ova obtained from female mice treated with aminopterin and mitomycin C

We examined the effects of mitomycin C and aminopterin on ovulation in vivo and, fertilization, subsequent cleavage and implantation in slc-ICR female mice using methods of fertilization and culture in vitro. Chemicals were injected into mice at the MI (meiosis I) stage or 3 hours before the MI stage in order to examine their toxicity. Mitomycin C did not affect ovulation, but decreased the rate of fertilization. A high dose of mitomycin C (4 mg/kg) inhibited fertilization and the development of ova to the 2-cell stage. Aminopterin affected neither ovulation nor fertilization. At either the MII (meiosis II) stage or 3 hours before the MII stage, high doses (4 and 2 mg/kg) of mitomycin C arrested cleavage and implantation. The cleavage was blocked frequently between the 3-4 cell stage and the 5-8 cell stage. Aminopterin affected neither cleavage nor implantation.     

In vitro toxicity of aflatoxin B1 and its photodegradation products in HepG2 cells

The effects of aflatoxin B₁ (AFB₁) were studied using the HepG2 cell line. Cytotoxicity, apoptosis and p53 expression were assessed after exposure to different concentrations of AFB₁ (0–100 μm ) and its two types of degradation products, namely the mixtures of photodegradation products in water (Pw) and the mixtures of photodegradation products in peanut oil (Po) for different time periods (0, 24, and 48 h). After exposure of the HepG2 cells to these compounds for different times and concentrations, the cytotoxicity of Pw and Po decreased approximately 40 and 100% compared with AFB₁, respectively. The expression of p53 protein decreased significantly in AFB₁‐exposed cells, decreased slightly in Pw‐treated cells and did not decrease compared to the untreated cells. The results of the in vitro cytotoxicity assay indicate that Pw is less toxic than AFB₁, and Po has almost no toxicity, which can be explained by the differences in the chemical nature of the various kinds of the test compounds. Copyright © 2011 John Wiley & Sons, Ltd.     

Chronopharmacokinetics of doxorubicin in patients with breast cancer

Summary The chronopharmacokinetics of doxorubicin (DOX) has been studied in 18 patients suffering from breast cancer. They received combined chemotherapy, including DOX (50 mg/m² as an iv bolus), given at two different times (09.00 h or 21.00 h). The two randomized courses of the protocol were given to each patient at a four week interval.The total body clearance (CL) of DOX was significantly decreased when the drug was administered at 21.00 h, resulting in a longer elimination half-life and an increase in AUC. The renal clearance of DOX did not differ at the different times of administration, and it appears that the decrease in CL was related to a change in hepatic blood flow. The volume of distribution of the drug was not changed.     

In vitro cytotoxicity assay with selected chemicals using human cells to predict target-organ toxicity of liver and kidney.

In order to elucidate the feasibility of predicting liver and kidney target-organ toxicity using in vitro cytotoxicity assay, cytotoxicity of selected chemicals, acetaminophen (AAP), mitomycin (MMC), cupric chloride (CuCl2), phenacetin, cadmium chloride (CdCl2) and aristolochic acid (AA), was studied using human hepatoma (Bel-7402) cells and human renal tubular epithelial (HK-2) cells. Cell viability and mitochondrial permeability transition (MPT) were assessed by the neutral red (NR) assay and laser scanning confocal microscope, respectively. The results of the NR assay indicated that cytotoxicity of hepatoxicants, AAP, MMC and CuCl2 in liver cells was higher than that in kidney cells. Cytotoxicitiy of nephrotoxicant, CdCl2 was lower in liver cells than that in kidney cells, but nephrotoxicant phenacetin and AA was higher cytotoxicity in liver cells than that in kidney cells. The cytotoxicity of AAP and phenacetin was strengthened in the presence of S9 mixture, indicating that they are metabolism-mediated cytotoxicants. All selected chemicals disrupted MPT in dose-dependent manner. Linear regression analysis revealed a good correlation between the IC50 values of cytotoxicity and the EC50 values of MPT in Bel-7402 cells and HK-2 cells (R2 = 0.987 and 0.823, respectively). Cytotoxicity assay in vitro using specific cells show good compatibility with target-organ toxicity in vivo. However, limitations of in vitro cytotoxicity assay are due to its incomplete process of ADME and the defect of predicting chronic toxicity effect after long-term exposure to a chemical.