NC381, a Novel Anticancer Agent, Arrests the Cell Cycle in G0-G1 and Inhibits Lung Tumor Cell Growth in Vitro and in Vivo

Cross-linkable star-hyperbranched unimolecular micelles for the enhancement of the anticancer activity of clotrimazole

Clotrimazole, a hydrophobic drug routinely used in the treatment of vaginal candidiasis, also shows antitumor activity. However, its use in chemotherapy has been unsuccessful to date due to its low solubility in aqueous media. In this work, new unimolecular micelles based on polyether star-hyperbranched carriers of clotrimazole are presented that can enhance solubility, and consequently the bioavailability, of clotrimazole in water. The amphiphilic constructs consisting of a hydrophobic poly(n-alkyl epoxide) core and hydrophilic corona of hyperbranched polyglycidol were synthesized in a three-step anionic ring-opening polymerization of epoxy monomers. The synthesis of such copolymers, however, was only possible by incorporating a linker to facilitate the elongation of the hydrophobic core with glycidol. Unimolecular micelles-clotrimazole formulations displayed significantly increased activity against human cervical cancer HeLa cells compared to the free drug, along with a weak effect on the viability of the normal dermal microvascular endothelium cells HMEC1. This selective activity of clotrimazole on cancer cells with little effect on normal cells was a result of the fact that clotrimazole targets the Warburg effect in cancer cells. Flow cytometric analysis revealed that the encapsulated clotrimazole significantly blocks the progression of the HeLa cycle in the G0/G1 phase and induces apoptosis. In addition, the ability of the synthesized amphiphilic constructs to form a dynamic hydrogel was demonstrated. Such a gel facilitates the delivery of drug-loaded single-molecule micelles to the affected area, where they can form a continuous, self-healing layer.

Anticancer Agents as Design Archetypes: Insights into the Structure-Property Relationships of Ionic Liquids with a Triarylmethyl Moiety

A fundamental challenge underlying the design principles of ionic liquids (ILs) entails a lack of understanding into how tailored properties arise from the molecular framework of the constituent ions. Herein, we present detailed analyses of novel functional ILs containing a triarylmethyl (trityl) motif. Combining an empirically driven molecular design, thermophysical analysis, X-ray crystallography, and computational modeling, we achieved an in-depth understanding of structure-property relationships, establishing a coherent correlation with distinct trends between the thermophysical properties and functional diversity of the compound library. We observe a coherent relationship between melting (T _m) and glass transition (T _g) temperatures and the location and type of chemical modification of the cation. Furthermore, there is an inverse correlation between the simulated dipole moment and the T _m/T _g of the salts. Specifically, chlorination of the ILs both reduces and reorients the dipole moment, a key property controlling intermolecular interactions, thus allowing for control over T _m/T _g values. The observed trends are particularly apparent when comparing the phase transitions and dipole moments, allowing for the development of predictive models. Ultimately, trends in structural features and characterized properties align with established studies in physicochemical relationships for ILs, underpinning the formation and stability of these new lipophilic, low-melting salts.

The in vitro and in vivo antitumor effects of clotrimazole on oral squamous cell carcinoma

Background

Clotrimazole is an antifungal imidazole derivative showing anti- neoplastic effect in some tumors, but its anticancer potential is still unclear in oral squamous cell carcinoma (OSCC). The aim of this study was to evaluate the antitumor effect of clotrimazole, and to investigate the possible mechanism of clotrimazole-mediated antitumor activity in OSCC.

Methodology

In vitro experiments, the cell viability and clonogenic ability of three human OSCC cell lines CAL27, SCC25 and UM1 were detected after clotrimazole treatment by CCK8 assay and colony formation assay. Cell cycle progression and apoptosis were assessed by flow cytometry, and the involvement of several mediators of apoptosis was examined by western blot analysis. Then, the in vivo antitumor effect of clotrimazole was investigated in CAL27 xenograft model. Immunohistochemistry and western blot analysis were performed to determine the presence of apoptotic cells and the expression of Bcl-2 and Bax in tumors from mice treated with or without clotrimazole.

Results

Clotrimazole inhibited proliferation in all three OSCC cell lines in a dose-and time-dependent manner, and significantly reduced the colony formation of OSCC cells in vitro. Clotrimazole caused cell cycle arrest at the G₀/G₁ phase. In addition, clotrimazole induced apoptosis in OSCC cells, and significantly down-regulated the anti-apoptotic protein Bcl-2 and up-regulated the pro-apoptotic protein Bax. Notably, clotrimazole treatment inhibited OSCC tumor growth and cell proliferation in CAL27 xenograft model. Clotrimazole also markedly reduced Bcl-2 expression and increased the protein level of Bax in tumor tissues of xenograft model.

Conclusion

Our findings demonstrated a potent anticancer effect of clotrimazole by inducing cell cycle arrest and cellular apoptosis in OSCC.

Analysis of the cytotoxic effects of ruthenium-ketoconazole and ruthenium-clotrimazole complexes on cancer cells

Ruthenium-based compounds have intriguing anti-cancer properties, and some of these novel compounds are currently in clinical trials. To continue the development of new metal-based drug combinations, we coupled ruthenium (Ru) with the azole compounds ketoconazole (KTZ) and clotrimazole (CTZ), which are well-known antifungal agents that also display anticancer properties. We report the activity of a series of 12 Ru-KTZ and Ru-CTZ compounds against three prostate tumor cell lines with different androgen sensitivity, as well as cervical cancer and lymphoblastic lymphoma cell lines. In addition, human cell lines were used to evaluate the toxicity against non-transformed cells and to establish selectivity indexes. Our results indicate that the combination of ruthenium and KTZ/CTZ in a single molecule results in complexes that are more cytotoxic than the individual components alone, displaying in some cases low micromolar CC50 values and high selectivity indexes. Additionally, all compounds are more cytotoxic against prostate cell lines with lower cytotoxicity against non-transformed epidermal cell lines. Some of the compounds were found to primarily induce cell death via apoptosis yet weakly interact with DNA. Our studies also demonstrate that the cytotoxicity induced by our Ru-based compounds is not directly related to their ability to interact with DNA.

Gene expression profiling analysis of deoxynivalenol-induced inhibition of mouse thymic epithelial cell proliferation

Deoxynivalenol (DON) is a mycotoxin produced as a secondary metabolite by fungal species. It has been shown that DON has serious toxic effects on many kinds of immune cells. However, the toxic effects on thymic epithelial cells were poorly understood. The purpose of this study is to investigate the gene expression differences for the DON-induced inhibition on the proliferation of mouse thymic epithelial cell line 1 (MTEC1). After the experiments of cell viability, morphological investigation and cell cycle analysis, microarray analysis was carried out. The differentially expressed genes belong to a variety of functional categories, including genes involved in metabolic process, cell cycle, oxidation-reduction process and apoptosis. Our results provide molecular insights into the gene expression differences of DON-induced toxic effects and suggest that p53 signaling pathway may play an important role in the inhibition of MTEC1 cell proliferation.

Clotrimazole induces a late G1 cell cycle arrest and sensitizes glioblastoma cells to radiation in vitro

Tumor cells are characterized by their high rate of glycolysis and clotrimazole has been shown to disrupt the glycolysis pathway thereby arresting the cells in the G1 cell cycle phase. Herein, we present data to support our hypothesis that clotrimazole arrests tumor cells in a radiosensitizing, late G1 phase. The effects of clotrimazole were studied using the glioblastoma cell line, U-87 MG. Flow cytometry was used to analyze cell cycle redistribution and induction of apoptosis. Immunoblots were probed to characterize a late G1 cell cycle arrest. Nuclear and cytoplasmic fractions were collected to follow the clotrimazole-induced translocation of hexokinase II. Clonogenic assays were designed to determine the radiosensitizing effect by clotrimazole. Our studies have shown a dose-dependent and time-dependent clotrimazole arrest in a late G1 cell cycle phase. Concurrent with the late G1 arrest, we observed an overexpression of p27 along with a decreased expression of p21, cyclin-dependent kinase 1, cyclin-dependent kinase 4, and cyclin D. Clotrimazole induced the translocation of mitochondrial-bound hexokinase II to the cytoplasm and the release of cytochrome c into the cytoplasm. Clotrimazole-induced apoptosis was enhanced when combined with radiation. Clotrimazole was shown to sensitize tumor cells to radiation when the cells were irradiated for 18 h post-clotrimazole treatment. The disruption of the glycolysis pathway by clotrimazole leads to cell cycle arrest of U-87 MG cells in the radiosensitizing late G1 phase. The use of clotrimazole as a radiosensitizing agent for cancer treatment is novel and may have broad therapeutic applications.

IL-17E, a proinflammatory cytokine, has antitumor efficacy against several tumor types in vivo

Interleukin-17E (IL-17E) belongs to a novel family of cytokines that possess significant homology to IL-17. IL-17E has potent inflammatory effects in vitro and in vivo. Overexpression of IL-17E in mice results in a T helper-2 (Th2)-type immune response, which includes the expansion of eosinophils through the production of IL-5, and elevated gene expression of IL-4 and IL-13 in multiple tissues. In this study, we show that IL-17E has antitumor activity in vivo, a previously unrecognized function of IL-17E. Antitumor efficacy of IL-17E was examined in a variety of human tumor xenograft models, including melanoma, breast, lung, colon, and pancreatic cancers. Injection of recombinant IL-17E every other day resulted in significant antitumor activity in these tumor models. In addition, the combination of IL-17E with chemotherapy or immunotherapy agents showed an enhanced antitumor efficacy in human tumor xenograft models in mice as compared to either agent alone. Antitumor activity was demonstrated using different routes of administration, including intraperitoneal, intravenous, and subcutaneous injection. Anticancer activity was shown for both mouse and human forms of IL-17E, which have a high degree of sequence identity. Tumor-bearing mice treated with IL-17E showed a significant increase in serum levels of IL-5 and increased numbers of eosinophils in peripheral blood compared to the control group. Spleens isolated from IL-17E-treated mice showed a significant increase in eosinophils that correlated with antitumor activity of IL-17E in a dose-response manner. Finally, we demonstrate that B cells are necessary for IL-17E-mediated antitumor activity and that IL-17E was found to activate signaling pathways in B cells in vitro. Taken together, these data demonstrate that IL-17E has antitumor activity in vivo, and support further investigation of the potential clinical use of IL-17E as an anticancer agent.

Virulizin induces production of IL-17E to enhance antitumor activity by recruitment of eosinophils into tumors

Virulizin has demonstrated strong antitumor efficacy in a variety of human tumor xenograft models including melanoma, pancreatic cancer, breast cancer, ovarian cancer and prostate cancer. Our previous studies have demonstrated that macrophages, NK cells, and cytokines are important in the antitumor mechanism of Virulizin. Virulizin treatment of tumor bearing mice results in the expansion as well as increased activity of monocytes/macrophages and production of cytokines IL-12 and TNFalpha and activation of NK cells. In this study we show that the inflammatory cytokine IL-17E (IL-25) is induced by Virulizin treatment and is part of its antitumor mechanism. IL-17E is a proinflammatory cytokine, which induces a T(H)2 type immune response, associated with eosinophil expansion and infiltration into mucosal tissues. IL-17E was increased in sera of Virulizin-treated mice bearing human melanoma xenografts, compared to saline-treated controls, as shown by 2D gel electrophoresis and ELISA. Treatment of splenocytes in vitro with Virulizin resulted in increased IL-17E mRNA expression, which peaked between 24 and 32 h post-stimulation. Both in vitro and in vivo experiments demonstrated that B cells produced IL-17E in response to Virulizin treatment. Furthermore, Virulizin treatment in vivo resulted in increased blood eosinophilia and eosinophil infiltration into tumors. Finally, injection of recombinant IL-17E showed antitumor activity towards xenografted tumors, which correlated with increased eosinophilia in blood and tumors. Taken together, these results support another antitumor mechanism mediated by Virulizin, through induction of IL-17E by B cells, leading to recruitment of eosinophils into tumors, which may function in parallel with macrophages and NK cells in mediating tumor destruction.

11-Phenyl-[b,e]-dibenzazepine compounds: novel antitumor agents

A series of 11-phenyl-[b,e]-dibenzazepine compounds were synthesized and shown to be inhibitors of tumor cell proliferation with IC(50) values ranging from submicromolar to micromolar concentrations. Flow cytometric analyses of several active compounds demonstrated inhibition of cell cycle progression at the G(0)-G(1) phase transition resulting in G(0)-G(1) arrest.

Triphenylmethylamides (TPMAs): Structure-activity relationship of compounds that induce apoptosis in melanoma cells

Triphenylmethylamides (TPMAs) have been previously identified as compounds that arrest cells in the G1-phase of the cell cycle and induce apoptotic death in melanoma cell lines in culture. Here we report the synthesis of a series of TPMA derivatives, allowing the structure-activity relationship of this class of molecules to be established. Several new compounds have been identified that induce death in UACC-62 and SK-MEL-5 human melanoma cell lines, including a compound with enhanced aqueous solubility.

Isokotomolide A, a new butanolide extracted from the leaves of Cinnamomum kotoense, arrests cell cycle progression and induces apoptosis through the induction of p53/p21 and the initiation of mitochondrial system in human non-small cell lung cancer A549 cells

This study is the first to investigate isokotomolide A (IKA), a butanolide compound isolated from the leaves of Cinnamomum kotoense Kanehira & Sasaki (Lauraceaee), which exhibits an anti-proliferative activity in human non-small cell lung cancer A549 cells. The results show that IKA inhibits the proliferation of A549 by blocking cell cycle progression in the G0/G1 phase and inducing apoptosis. Blockade of cell cycle was associated with increased p21/WAF1 levels and reduced amounts of cyclin D1, cyclin E, Cdk2, Cdk4, and Cdk6 in a p53-mediated manner. IKA treatment also increased p53 phosphorylation (Ser15) and decreased the interaction of p53-MDM2. IKA treatment triggered the mitochondrial apoptotic pathway, indicated by changing Bax/Bcl-2 ratios, cytochrome c release and caspase-9 activation. In addition, pre-treatment of cells with caspase-9 inhibitor inhibited IKA-induced apoptosis, indicating that caspase-9 activation was involved in A549 cells' apoptosis induced by IKA. Our study reports here for the first time that the induction of p53/p21 and the initiation of the mitochondrial apoptotic system may participate in the anti-proliferative activity of IKA in human non-small cell lung cancer cells.

Virulizin, a novel immunotherapy agent, stimulates TNFalpha expression in monocytes/macrophages in vitro and in vivo

Virulizin, a novel biological response modifier, has demonstrated broad antitumor efficacy in a variety of human tumor xenograft models including melanoma, pancreatic cancer, breast cancer, ovarian cancer and prostate cancer. Previous studies have demonstrated a significant role of macrophages and NK cells in the antitumor mechanism of Virulizin. Increased activity and expansion of macrophages and NK cells has been observed in mice treated with Virulizin. In the present study, the effects of Virulizin on TNFalpha expression were investigated in vitro and in vivo. CD-1 nude mice were treated with Virulizin daily for 5 days. Quantitative RT-PCR demonstrated that the level of TNFalpha mRNA increased in peritoneal macrophages isolated from Virulizin-treated mice as compared to the control group. An increase in TNFalpha protein expression was also observed, as assessed by flow cytometric analysis. Increased levels of TNFalpha mRNA were seen in human tumor xenografts following treatment of tumor-bearing mice with Virulizin. In the presence of LPS, Virulizin also stimulated TNFalpha protein secretion and mRNA expression in human monocytic U937 cells and mouse macrophage RAW264.7 cells in vitro in a time- and dose-dependent manner. U937 cells treated with Virulizin showed a significantly enhanced cytotoxicity that was eliminated upon neutralization of TNFalpha. Virulizin also induced the phosphorylation of IkappaB, suggesting that induction of TNFalpha expression by Virulizin is mediated by activation of NFkappaB. The results indicate that Virulizin-induced TNFalpha expression contributes to modulation of immune responses and antitumor activities.

Enhanced anti-tumor activity and alleviated hepatotoxicity of clotrimazole-loaded suppository using poloxamer-propylene glycol gel

To develop a novel clotrimazole-loaded poloxamer-based suppository with enhanced anti-tumor activity and alleviated hepatotoxicity, the melting point of various formulations composed of P 188 and propylene glycol were investigated. The dissolution and anti-tumor activity of clotrimazole delivered by the poloxamer-based suppository was performed. Furthermore, the hepatotoxicity of clotrimazole was carried out after its rectal administration compared to oral administration in mice. The poloxamer mixtures composed of P 188 and propylene glycol were homogeneous phases. P 188 greatly affected the melting point of poloxamer mixtures. In particular, the poloxamer mixture [P 188/propylene glycol (70%/30%)] with the melting point of about 32 degrees C was a solid form at room temperature and instantly melted at physiological temperature. The ratio of P 188/propylene glycol greatly affected the dissolution rates of clotrimazole from poloxamer-based suppository. Dissolution mechanism analysis showed the dissolution rate of clotrimazole from poloxamer-based suppositories was independent of the time. The clotrimazole-loaded suppository with P 188 and propylene glycol could not irritate or damage the rectal tissues of rats and gave the improved anti-tumor activity in a dose-dependent manner at mouse. Furthermore, its rectal administration decreased the hepatotoxicity compared to oral administration. Thus, the poloxamer-based solid suppository system with clotrimazole/P 188/propylene glycol was an effective rectal dosage form for the treatment of tumors with alleviated adverse effects.

Contragestazol (DL111-IT) inhibits proliferation of human an-drogen-independent prostate cancer cell line PC3 in vitro and in vivo

AIM

To evaluate the antiproliferative activity of contragestazol (DL111-IT) on the human prostate cancer cell line PC3 in vitro and in vivo and to elucidate its potential molecular mechanisms.

METHODS

The cell killing ability of DL111-IT was measured by the 3-(4,5-dimethylthia-zol,2-yl)-2,5-diphenyltetrazolium bromide (MTT) reagent assay method and the tumor xenograft model. The cell cycle was analyzed by flow cytometry and protein expression, including retinoblastoma (pRb), cyclin-dependent kinase 4 (CDK4) and cyclin D1, was detected by Western blotting.

RESULTS

DL111-IT exhibited high efficiency on cell growth inhibition of the human androgen-independent prostate cancer cell line PC3. The drug concentration that yielded 50% cell inhibition (IC50 value) was 9.9 mg/mL. In the PC3 tumor xenograft study, DL111-IT (1.25 mg/kg-20.0 mg/kg) given once a day for 10 days significantly inhibited tumor growth, with the inhibition rate ranging from 21% to 50%. Flow cytometric analysis indicated that DL111-IT could cause G1 arrest in the PC3 cell line, but not apoptosis. DL111-IT enhanced pRb expression and down-regulated CDK4 and cyclin D1 expression, suggesting that cell cycle regulation might contribute to the anticancer property of DL111-IT.

CONCLUSION

DL111-IT inhibits the proliferation of human androgen-independent prostate cancer cell line PC3 in vitro and in vivo by a cell cycle regulation pathway.

Antiproliferative activity of contragestazol (DL111-IT) in murine and human tumor models in vitro and in vivo

PURPOSES

To evaluate the antiproliferative activity of contragestazol (DL111-IT) in vitro and in vivo and to elucidate potential molecular mechanisms.

METHODS

Cell killing ability of DL111-IT was measured by MTT/Trypan blue exclusion method and murine and human tumor models; cell cycle was analyzed by flow cytometry; pRb, CDK4 and Cyclin D1 expressions were detected by western blotting.

RESULTS

DL111-IT exhibited high efficiency on cell growth inhibition of 12 cancer cell lines, the IC50 values were 4.1-19.7 microg/ml. In Sarcoma-180 (S180) and Hepatoma-22 (H22) tumor bearing mice models, the inhibition rates were 55.9 and 55.6%, respectively, at the doses of DL111-IT 12.5-50.0 mg/kg for 9 days consecutive administration. Human ovarian carcinoma (HO-8910) xenograft study showed that, nine administrations (within 15 days) of DL111-IT (12.5-50.0 mg/kg) significantly inhibited tumor growth with the inhibition rates ranging from 17.0 to 64.3%. DL111-IT induced G1 arrest and overexpression of pRb, CDK4 and Cyclin D1 were observed in HO-8910 cell line, suggesting that cell cycle regulation might contribute to the anticancer property of DL111-IT.

CONCLUSIONS

DL111-IT could inhibit the proliferation of cancer cells both in vitro and in vivo via a cell cycle regulation pathway.