Apoptosis-inducing, anti-angiogenic and anti-migratory effects of a dinuclear Pd(II) complex on breast cancer: A promising novel compound.

Because of the high mortality and morbidity rate of breast cancer, successful management of the disease requires synthesis of novel compounds. To this end, ongoing attempts to create new candidates include synthesis of multinuclear metal complexes. The high DNA binding affinity and cytotoxic activity of these complexes makes them promising as breast cancer treatments. This study investigated anti-growth/cytotoxic effect of the dinuclear Pd(II) complex on breast cancer cell lines (MCF-7, MDA-MB-231) using various methods of staining, flow cytometry, and immunoblotting. The study conducted colony formation, invasion, and migration assays were to assess the effect of the complex on metastasis. Increased caspase-3/7 levels and positive annexin V staining were observed in both cell lines, proving apoptosis. Altered TNFR1 and TRADD expression with caspase-8 cleavage followed by BCL-2 inactivation with loss of mitochondrial membrane potential confirmed the presence of apoptosis in MCF-7 and MDA-MB-231, regardless of p53 expression status. The results implied anti-migration properties. Finally, the study used the CAM assay to assess antiangiogenic properties and showed that the complex inhibited angiogenesis. The study concluded the dinuclear Pd(II) complex warrants further in vivo experiments to show its potential in the treatment of breast cancer.

Development of a cysteine responsive chlorinated hemicyanine for image-guided dual phototherapy.

A cysteine (Cys) activatable chlorinated hemicyanine (Cl-Cys) was introduced as a tumour selective image-guided dual phototherapy agent. Cl-Cys exhibited a significant turn on response in its near-IR emission signal and activated its singlet oxygen generation as well as photothermal conversion potentials upon reacting with Cys. The laser irradiation of Cl-Cys induced significant cell death in cancer cells with high Cys level, while it stayed deactivated and non-emissive in a healthy cell line. A profound synergistic PDT/PTT effect was observed at high doses. Remarkably, Cl-Cys marks the first ever example of Cys-responsive small organic-based therapeutic agent and holds a great promise to develop new activity-based photosensitizers for dual phototherapy action.

Palladium (II) complex and thalidomide intercept angiogenic signaling via targeting FAK/Src and Erk/Akt/PLCγ dependent autophagy pathways in human umbilical vein endothelial cells.

The current study assessed the effects of the thalidomide and palladium (II) saccharinate complex of terpyridine on the suppression of angiogenesis-mediated cell proliferation. The viability was assessed after treatment with palladium (II) complex (1.56-100 µM) and thalidomide (0.1-400 µM) alone by using ATP assay for 48 h. Palladium (II) complex was found to inhibit growth statistically significant in a dose-dependent manner in HUVECs and promoted PARP-1 cleavage through the production of ROS. On the other hand, thalidomide did not cause any significant change in cell viability. Moreover, cell death was observed to be manifested as late apoptosis due to Annexin V/SYTOX staining after palladium (II) complex treatment however, thalidomide did not demonstrate similar results. Thalidomide and palladium (II) complex also suppressed HUVEC migration and capillary-like structure tube formation in vitro in a time-dependent manner. Palladium (II) complex (5 mg/ml) treatment showed a strong antiangiogenic effect similar to positive control thalidomide (5 mg/ml) and successfully disrupted the vasculature and reduced the thickness of the vessels compared to control (agar). Furthermore, suppression of autophagy enhanced the cell death and anti-angiogenic effect of thalidomide and palladium (II) complex. We also showed that being treated with thalidomide and palladium (II) complex inhibited phosphorylation of the signaling regulators downstream of the VEGFR2. These results provide evidence for the regulation of endothelial cell functions that are relevant to angiogenesis through the suppression of the FAK/Src/Akt/ERK1/2 signaling pathway. Our results also indicate that PLC-γ1 phosphorylation leads to activation of p-Akt and p-Erk1/2 which cause stimulation on cell proliferation at lower doses. Hence, we demonstrated that palladium (II) and thalidomide can induce cell death via the Erk/Akt/PLCγ signaling pathway and that this pathway might be a novel mechanism.

Soloxolone methyl, as a 18ßH-glycyrrhetinic acid derivate, may result in endoplasmic reticulum stress to induce apoptosis in breast cancer cells.

Being one of the leading causes of cancer death among women, various chemotherapeutic agents isolated from natural compounds are used in breast cancer treatment and consequently studies to develop new drugs still continue. There are several studies on 18ßH-glycyrrhetinic acid, a secondary metabolite which is found in Glycyrrhiza glabra (liquorice roots), as a potential anticancer agent. In this study, the cytotoxic and apoptotic effects of Soloxolone methyl compound, a semisynthetic derivative of 18ßH-glycyrrhetinic acid were investigated on breast cancer cells (MCF-7, MDA-MBA-231). Soloxolone methyl is found to be cytotoxic on both MCF-7 and MDA-MBA-231 breast cancer cells by inducing apoptosis. Especially in MDA-MB-231 cells apoptosis is detected to be triggered by ER stress. The antigrowth effects of Soloxolone methyl were determined using MTT and ATP assays. To identify the mode of cell death (apoptosis/necrosis), fluorescent staining (Hoechst 33342 and Propidium iodide) and caspase-cleaved cytokeratin 18 (M30-antigen) analyses were used. In addition, apoptosis was investigated on gene and protein levels by PCR and Western Blotting. Soloxolone methyl decreased cell viability on cells in a dose and time-dependent manner and induced apoptosis markers. An increase on apoptotic proteins related to endoplasmic reticulum stress (IRE1-α, Bip, CHOP) was also determined in MDA-MB-231 cells. Moreover, an increase of apoptotic gene expressions was determined in both cells treated with Soloxolone methyl. Advance analyses should be performed to elucidate the potential of Soloxolone methyl as an anticancer agent in breast cancer treatment.

Epigenetic modulators combination with chemotherapy in breast cancer cells.

Despite the concerning adverse effects on tumour development, epigenetic drugs are very promising in cancer treatment. The aim of this study was to compare the differential effects of standard chemotherapy regimens (FEC: 5-fluorouracil plus epirubicine plus cyclophosphamide) in combination with epigenetic modulators (decitabine, valproic acid): (a) on gene methylation levels of selected tumour biomarkers (LINE-1, uPA, PAI-1, DAPK); (b) their expression status (uPA and PAI-1); (c) differentiation status (5meC and H3K27me3). Furthermore, cell survival as well as changes concerning the invasion capacity were monitored in cell culture models of breast cancer (MCF-7, MDA-MB-231). A significant overall decrease of cell survival was observed in the FEC-containing combination therapies for both cell lines. Methylation results showed a general tendency towards increased demethylation of the uPA and PAI-1 gene promoters for the MCF-7 cells, as well as the proapoptotic DAPK gene in the treatment regimens for both cell lines. The uPA and PAI-1 antigen levels were mainly increased in the supernatant of FEC-only treated MDA-MB-231 cells. DAC-only treatment induced an increase of secreted uPA protein in MCF-7 cell culture, while most of the VPA-containing regimens also induced uPA and PAI-1 expression in MCF-7 cell fractions. Epigenetically active substances can also induce a re-differentiation in tumour cells, as shown by 5meC, H3K27me3 applying ICC. SIGNIFICANCE OF THE STUDY: Epigenetic modulators especially in the highly undifferentiated and highly malignant MDA-MB-231 tumour cells significantly reduced tumour malignancy thus; further clinical studies applying specific combination therapies with epigenetic modulators may be warranted.

Lichens exerts an anti-proliferative effect on human breast and lung cancer cells through induction of apoptosis.

Successful cancer treatment still requires new complexes or compounds from natural sources. Therefore, we investigated anti-growth/apoptotic effects of methanol extracts of the lichen species (Xanthoparmelia somloensis (Gleyn.) Hale, Usnea intermedia (A. Massal.) Jatta, Bryoria capillaris (Ach.) Brodo & D. Hawksw and Lobaria pulmonaria (L.) Hoffm.) on human lung (A549, H1299) and breast (MCF-7, MDA-MB-231) cancer cell lines. Anti-growth effects were monitored by the MTT and ATP viability assays. Cell death mode was evaluated by employing the fluorescence staining of nucleus, caspase-cleaved cytokeratin 18 detection, caspase 3/7 activity assay, Anneksin V cytofluorimetric assay and mitochondria membrane potential assay. Among the lichen extracts, Usnea intermedia exhibited strong anti-growth activity in a dose-dependent manner (1.56-100 µg/ml) compared to the others. Usnea intermedia was especially cytotoxic against MDA-MB-231 and H1299 cells (IC50 value for was found 3.0 and 10.2 µg/ml respectively). The cytotoxicity was resulted from apoptosis as proved by the presence of pyknotic nuclei, caspase 3/7 activity, phosphatidylserine translocation and loss of mitochondria membrane potential. In conclusion, Usnea intermedia warrants for further in vivo evaluation as a new alternative in cancer treatment.

Preparation and Characterization of Palladium Derivate-Loaded Micelle Formulation in Vitro as an Innovative Therapy Option against Non-Small Cell Lung Cancer Cells.

Nanoparticles have been used in cancer treatments to target tumor and reduce side effects. In this study, we aimed to increase the effectiveness of palladium(II) complex [PdCl(terpy)](sac) ⋅ 2H2 O, which previously showed anticancer potential, by preparing the nanoparticle formulation. An inhalable micellar dispersion containing a palladium(II) complex (PdNP) was prepared and its physicochemical characteristics were evaluated using in vitro tests. Morphology, size and surface charges of particle and loading/encapsulation efficiency of PdNP were analyzed by scanning electron microscopy, zeta sizer and inductively coupled plasma mass spectrometry while aerosol properties of PdNP were measured by the next generation impactor. A549 and H1299 non-small lung cancer cell types were used for cytotoxicity using SRB and ATP assays. Fluorescent staining and M30 antigen assay were carried out for cell death evaluation. Apoptosis was confirmed by flow cytometry analyses. SEM, particle size, and zeta potential results showed the particles have inhalable properties. The amount of the palladium(II) complex loaded into the particles was quantified which indicated high encapsulation efficiencies (97 %). The micellar dispersion expected to reach the alveolar region and the brachial region was determined 35 % and 47 %, respectively. PdNP showed an anti-growth effect by increasing reactive oxygen species that is followed by the induction of mitochondria-dependent apoptosis that is evidenced by pyknotic nuclei and M30 antigen level increments and disruption of polarization of membrane in mitochondria (Δψm). The results show that PdNP might be a promising inhalable novel complex to be used in non-small cell lung cancer, which warrants animal studies in further.

Tumor Chemosensitivity Assays Are Helpful for Personalized Cytotoxic Treatments in Cancer Patients.

Tumor chemosensitivity assays (TCAs), also known as drug response assays or individualized tumor response tests, have been gaining attention over the past few decades. Although there have been strong positive correlations between the results of these assays and clinical outcomes, they are still not considered routine tests in the care of cancer patients. The correlations between the assays' results (drug sensitivity or resistance) and the clinical evaluations (e.g., response to treatment, progression-free survival) are highly promising. However, there is still a need to design randomized controlled prospective studies to secure the place of these assays in routine use. One of the best ideas to increase the value of these assays could be the combination of the assay results with the omics technologies (e.g., pharmacogenetics that gives an idea of the possible side effects of the drugs). In the near future, the importance of personalized chemotherapy is expected to dictate the use of these omics technologies. The omics relies on the macromolecules (Deoxyribonucleic acid -DNA-, ribonucleic acid -RNA-) and proteins (meaning the structure) while TCAs operate on living cell populations (meaning the function). Therefore, wise combinations of TCAs and omics could be a highly promising novel landscape in the modern care of cancer patients.

Cytotoxic platinum(II) complexes derived from saccharinate and phosphine ligands: synthesis, structures, DNA cleavage, and oxidative stress-induced apoptosis.

A series of the structurally related platinum(II) saccharinate (sac) complexes with alkylphenylphosphines, namely cis-[Pt(sac)2(PPh2Me)2]·DMSO (1), cis-[Pt(sac)2(PPhMe2)2] (2), cis-[Pt(sac)2(PPh2Et)2] (3), and cis-[Pt(sac)2(PPhEt2)2]·2DMSO (4), were synthesized and fully characterized; their structures were determined by X-ray crystallography. All the complexes were investigated for their anticancer potentials on three human cancer cells including A549 (lung), MCF-7 (breast), and HCT116 (colon) in addition to a noncancerous human bronchial epithelial cells (BEAS-2B). Specifically, 1 and 3 showed significant cytotoxic effects against MCF-7 and HCT116 cell lines in comparison to cisplatin, and were considered as the most potent ones in the series. The cytotoxic complexes were found to cleave DNA efficiently. In addition, the binding interactions of the complexes with DNA were confirmed by enzyme inhibition and molecular docking studies. Complexes 1 and 3 were capable of inducing apoptosis and arrested the cell cycle at the DNA synthesis (S) phase in MCF-7 cells. Furthermore, 1 and 3 caused the excessive generation of reactive oxygen species (ROS), leading to mitochondrial dysfunction and double-strand DNA breaks.

Mixed ligand complexes of Co(II), Ni(II) and Cu(II) with quercetin and diimine ligands: synthesis, characterization, anti-cancer and anti-oxidant activity.

In this work, mixed ligand complexes of Co(II) Ni(II) and Cu(II) were synthesized using quercetin and diimine (1,10-phenanthroline or 2,2'-bipyiridine) ligands. The obtained Ni(II) and Co(II) complexes are new and the Cu(II) complexes are synthesized by different method from the literature. The characterization of complexes was performed by elemental analysis, thermogravimetric analysis, ESI-MS, UV-visible and infrared spectral analyses, magnetic susceptibility and molar conductivity measurements. It was found that quercetin, diimine and metal(II) ion form 1:1:1 complexes. Resulting data supported octahedral geometry for Ni(II) and Co(II) complexes and square pyramidal geometry for Cu(II) complexes. The proposed compositions are [Co(queH-1)Cl(phen)(H2O)]∙2H2O (1, queH = quercetin, phen = 1,10-phenanthroline), [Ni(queH-1)Cl(phen)(H2O)]∙2H2O (2), [Cu(queH-1)Cl(phen)]∙2.5H2O (3) and [Cu(queH-1)Cl(bpy)]∙2H2O (4, bpy = 2,2'-bipyiridine). Antioxidant capacity and total phenolic content of complexes measured by Folin-Ciocalteu and ABTS methods. Anti-cancer effect of these compounds were tested against different cancer cells (A549, PC-3, HeLa and MCF-7). Apoptosis identified by the fluorescence imaging, caspase cleaved cytokeratin-18 and flow cytometry analysis (annexin V, caspase 3/7, mitochondria membrane potential and oxidative stress). As a result, Cu(II) complexes are more effective than the other compounds and Complex 3 is a promising anti-cancer compound against breast cancer MCF-7 and MDA-MB-231 cells (IC50 values are 2.4 and 5.4 µM for 48 h, respectively). Flow cytometry analysis exhibited that Complex 3 caused apoptosis in MCF-7 cells. These results support that Complex 3 has anticancer activity and can be a potential anticancer agent especially in breast cancer.

Trans-Pd/Pt(II) saccharinate complexes with a phosphine ligand: Synthesis, cytotoxicity and structure-activity relationship.

New trans-[Pd(sac)2(PPhMe2)(DMSO)]·H2O (Pd) and trans-[Pt(sac)2(PPhMe2)2]·H2O (Pt) complexes (sac = saccharinate and PPhMe2 = dimethylphenylphosphine) were synthesized and characterized by elemental analysis, IR, NMR, ESI-MS spectral analyses and X-ray diffraction. The complexes were evaluated for their in vitro cytotoxicity against breast (MCF-7), colon (HCT116) and lung (A549) human cancer cell lines. The ATP viability assay displayed that Pd was biologically inactive, but Pt showed significant anticancer potency on MCF-7 cancer cells, similar to cisplatin. The results suggested that Pt targeted DNA, whereas Pd displayed higher binding affinity towards human serum albumin (HSA). Mechanism of action studies of Pt suggested apoptotic cell death due to significant increase in intracellular ROS (reactive oxygen species) levels, mitochondrial damage and formation of DNA double-strand breaks. Finally, this work represents a new example of potent transplatin anticancer complexes.

Etoposide Loaded SPION-PNIPAM Nanoparticles Improve the in vitro Therapeutic Outcome on Metastatic Prostate Cancer Cells via Enhanced Apoptosis.

Prostate cancer is among the leading causes of death worldwide because its metastatic form is a deadly disease. Therefore, the development of new chemotherapeutics is of immense importance. Nanoparticle technology seems to provide diverse options in this regard. Therefore, poly(N-isopropylacrylamide) (PNIPAM) coated superparamagnetic iron oxide nanoparticles (SPION) loaded with Etoposide were prepared in small sizes (57 nm) and with 3.5 % drug content to improve the efficiency of Etoposide in prostate cancer therapy. Sustained release of the drug was achieved, which found to be sensitive to low pH and high temperature. The anti-growth activity of SPION-PNIPAM-Etoposide formulation against metastatic prostate cancer cells (PC-3, LNCaP) were investigated by SRB assay, then, confirmed by ATP assay. Mode of cell death was evaluated by using flow cytometry analyses. A significant improvement of nanoformulated drug was observed at 5-10 µg/ml doses of the drug in both cell lines. More importantly, this formulation enhanced the cytotoxic effect of Etoposide on PC-3 cells, which is considered more resistant to Etoposide than LNCaP and reduced the IC50 value by 55 % reaching to 4.5 µg drug/ml, which is a very significant improvement in the literature. It was clearly shown that nanoformulated drug provided about 3-fold increases in caspase-dependent early apoptotic cells in PC-3 cells. The novel formulation seems to successfully cause cell death of especially PC-3 metastatic prostate cancer cells. It should therefore be taken into consideration for further animal studies as a novel potent anticancer agent.

Toxicity assessment of Hypericum olympicum subsp. olympicum L. on human lymphocytes and breast cancer cell lines.

There is a limited number of studies about the constituents of Hypericum olympicum subsp. olympicum and its genotoxic and cytotoxic potency. We examined the possible antigenotoxic/genotoxic properties of methanolic extract of H. olympicum subsp. olympicum (HOE) on human lymphocytes by employing sister chromatid exchange, micronucleus and comet assay and analyzed its chemical composition by GCxGC-TOF/MS. The anti-growth activity against MCF-7 and MDA-MB-231 cell lines was assessed by using the ATP viability assay. Cell death mode was investigated with fluorescence staining and ELISA assays. The major components of the flower and trunk were determined as eicosane, heptacosane, 2-propen-1-ol, hexahydrofarnesyl acetone and α-muurolene. HOE caused significant DNA damage at selected doses (250-750 µg/ml) while chromosomal damage was observed at higher concentrations (500 and 750 µg/ml). HOE demonstrated anti-growth activity in a dose-dependent manner between 3.13-100 µg/ml. Pyknotic nuclei were observed at 100 µg/ml concentration of HOE in both cell lines. In conclusion, HOE demonstrated cytotoxic effects in a cell type-dependent manner, however its genotoxic effects were observed at relatively higher doses.

The roles of M30 and M65 in the assessment of treatment response and prognosis in patients with non-small cell lung cancer, who receive neoadjuvant treatment.

AIM OF THE STUDY: To investigate the efficacy of evaluating prognosis and response to lung cancer treatment using M30 and M65 antigens, which are indicators of necrosis. MATERIAL AND METHODS: Forty-eightpatients with lung cancer, who were planned to receive neoadjuvant chemotherapy, and 38 healthy volunteers were enrolled in the study. Using M30 and M65 levels, cytokeratin 18 levels were measured twice: before and 48 hours after the first chemotherapy treatment. Apoptotic and total necrosis levels were determined by measuring the M65 and M30 levels. RESULTS: The M30 and M65 antigen levels in the patient group were significantly higher than in the control group (p< 0.001). The M30 and M65 antigen levels were significantly higher 48 hours after the chemotherapy compared with before the chemotherapy (p< 0.001). There were no significant differences in M65 levels between patients who responded to treatment and patients who progressed. The M30 levels increased significantly in patients with disease progression (p= 0.694 and p = 0.024, respectively). No significant differences in serum M30 and M65 antigen levels were found when compared between the surviving and deceased patients (p = 0.126 and p = 0.340, respectively). CONCLUSIONS: A significant increase was detected in serum M30 and M65 levels in patients with lung cancer. There was a greater increase in serum M30 levels in patients who did not respond to the chemotherapy. This result gives rise to the thought that evaluating apoptosis and total necrosis through M30 and M65 measurements alone only in patients receiving neoadjuvant chemotherapy would be insufficient for specifying the effectiveness of the treatment.

A promising natural product, pristimerin, results in cytotoxicity against breast cancer stem cells in vitro and xenografts in vivo through apoptosis and an incomplete autopaghy in breast cancer.

Several natural products have been suggested as effective agents for the treatment of cancer. Given the important role of CSCs (Cancer Stem Cells) in cancer, which is a trendy hypothesis, it is worth investigating the effects of pristimerin on CSCs as well as on the other malignant cells (MCF-7 and MDA-MB-231) of breast cancer. The anti-growth activity of pristimerin against MCF-7 and MCF-7s (cancer stem cell enriched population) cells was investigated by real time viability monitorization (xCELLigence System®) and ATP assay, respectively. Mode of cell death was evaluated using electron and fluorescence microscopies, western blotting (autophagy, apoptosis and ER-stress related markers) and flow cytometry (annexin-V staining, caspase 3/7 activity, BCL-2 and PI3K expressions). Pristimerin showed an anti-growth effect on cancer cells and cancer stem cells with IC50 values ranging at 0.38-1.75µM. It inhibited sphere formation at relatively lower doses (<1.56µM). Apoptosis was induced in MCF-7 and MCF-7s cells. In addition, extensive cytoplasmic vacuolation was observed, implying an incompleted autophagy as evidenced by the increase of autophagy-related proteins (p62 and LC3-II) with an unfolded protein response (UPR). Pristimerin inhibited the growth of MCF-7 and MDA-MB-231-originated xenografts in NOD.CB17-Prkdcscid/J mice. In mice, apoptosis was further confirmed by cleavage of PARP, activation of caspase 3 and/or 7 and TUNEL staining. Taken together, pristimerin shows cytotoxic activity on breast cancer both in vitro and in vivo. It seems to represent a robust promising agent for the treatment of breast cancer. Pristimerin's itself or synthetic novel derivatives should be taken into consideration for novel potent anticancer agent(s).

Anti-angiogenic effect of a Palladium(II)-Saccharinate Complex of Terpyridine in vitro and in vivo.

Anti-angiogenic activity of palladium (Pd)(II)-based complexes is unknown despite their quite powerful anticancer activity. This study was therefore carried out to evaluate both in vivo anti-angiogenic effect and in vitro cytotoxic activity of a Pd(II)-based complex. ([Pd(sac)(terpy)](sac)·4H2O(sac=saccharinate and terpy=2,2':6',2″-terpyridine)) on HUVEC cells. The anti-angiogenic activity of the complex was evaluated in vivo using the chick embryo chorioallantoic membrane (CAM) assay, tube formation assay and the cytotoxicity was screened using the MTT viability assays. The CAM treated with the complex (50µg/pellet) showed a strikingly high anti-angiogenic effect (score 1.1±0.2) compared to the positive controls cortisone, prednisone and (±)-thalidomide (e.g. (±)-thalidomide score 0.9±0.2) tested at the same concentration. Furthermore, the complex showed neither membrane toxicity nor irritation at the tested concentration. According to the MTT assays, the human umbilical vein endothelial cell (HUVEC) viability was inhibited in a dose-dependent manner at tested concentrations (1.56-100µM). Pd(II) complex also reduced the tube network at the lower dose than the compared with thalidomide. These results suggest that the Pd(II)-complex has strong anti-angiogenic activity, which adds an important feature to the previously-described anticancer activity of the complex.

A palladium(II)-saccharinate complex of terpyridine exerts higher anticancer potency and less toxicity than cisplatin in a mouse allograft model.

The main aim of this study is to assess the safety and antitumor efficacy of a palladium(II) (Pd)-saccharinate complex with terpyridine. To characterize the Pd(II) complex in vitro, its cytotoxicity was evaluated using a water-soluble tetrazolium salt cell viability assay and the mechanism of cell death was assessed by DNA fragmentation/condensation and live cell imaging analyses. The antitumor efficacy and safety of the Pd(II) complex in-vivo were examined by analyzing reduction in tumor size, changes in body and organ weight, histopathological analysis of liver, kidney, and tumor sections, and biochemical analysis of serum in C57BL/6 mice. Our results showed that the Pd(II) complex was more cytotoxic to cancer cells than noncancer cell lines and caused cell death through apoptotic pathways. The treatment of the Pd(II) complex in tumor-bearing mice effectively reduced the tumor size at half the dose used for cisplatin. The Pd(II) complex appeared to exert less liver damage than the cisplatin-based complex on changes in the hepatic enzymes levels in the serum. Hence, the complex appears to be a potential chemotherapeutic drug with high antitumor efficacy and fewer hepatotoxic complications, providing an avenue for further studies.

Enhanced cytotoxic activity of doxorubicin through the inhibition of autophagy in triple negative breast cancer cell line.

BACKGROUND: The outcome of triple negative breast cancer is still poor and requires improvement with better therapy options. Autophagy has recently been shown to play a role in anticancer drug resistance. Therefore, we investigated if the effectiveness of doxorubicin was augmented by the inhibition of autophagy. METHODS: MDA-MB-231 was used as a model cell line for triple negative breast cancer and 3-methyladenine was used as an inhibitor of autophagy. Cells were treated with 0.46-1.84µM doxorubicin and 2.5-10µM 3-methyladenine for 48h. Cell death mode was examined with M30 and M65 ELISA assays. ROS level and LDH activity was examined and the cellular acidic compartment of cells was monitored by acridine orange staining. The expression of various autophagy and apoptosis related proteins/genes were evaluated with Western blotting and RT-qPCR respectively. RESULTS: Synergism was observed between the compounds (CI value<1.0). RT-qPCR analysis revealed that the combination resulted in a down-regulation of autophagy-related genes. Moreover, the combination resulted in a different cell death modality, upregulating necroptosis-related genes. This suggests that the mode of cell death may switch from apoptosis to necroptosis, which is a more severe form of cell death, when autophagy is inhibited. These results were further confirmed at protein level by Western blotting. CONCLUSION: Inhibition of autophagy seems to sensitize triple negative breast cancer cells to doxorubicin, warranting further in vivo studies for the proof of this concept. GENERAL SIGNIFICANCE: Autophagy has a key role in drug resistance in MDA-MB-231 cells. Therefore combinatorial approaches may effectively overcome resistance.

Synthesis, biological characterization and evaluation of molecular mechanisms of novel copper complexes as anticancer agents.

BACKGROUND: To overcome the hurdles of cisplatin, majorly its toxicity and resistance, there has been extensive search for alternative anti-cancer metal-based compounds. Here, three Cu(II)-complexes, Cu(Sal-Gly)(phen), Cu(Sal-Gly)(pheamine), Cu(Sal-Gly)(phepoxy) are characterized for their interaction with DNA, cytotoxicity and mechanism of action. METHODS: The binding ability of the complexes to Calf-Thymus DNA was evaluated by competition fluorescence studies with thiazole-orange, UV-Vis and circular dichroism spectroscopic titrations. Cytotoxicity was evaluated by MTT analysis. The DNA damage was analyzed through cleavage of supercoiled DNA via agarose gel-electrophoresis, and 8-oxo-guanidine and É£H2AX staining in cells. Apoptosis was detected via DNA condensation/fragmentation, mitochondrial membrane potential, Annexin V staining and caspase 3/7 activity. Formation of reactive oxygen species was determined by DCFDA- and GSSG/GSH-analysis. RESULTS: Binding constants to DNA were evaluated as 1.7×106 (Cu(Sal-Gly)(phen)), 2.5×106 (Cu(Sal-Gly)(pheamine)) and 3.2×105 (Cu(Sal-Gly)(phepoxy)). All compounds induced DNA damage. Apoptosis was the main form of cell death. There was an increase in ROS, which is most likely responsible for the observed DNA-damage. Although the compounds were cytotoxic to all tested cancer cell lines, only Cu(Sal-Gly)(pheamine) displayed significantly lower toxicity towards non-cancer cells, its associated phenotypes differing from the other two Cu-complexes. Thus, Cu(Sal-Gly)(pheamine) was further assayed for molecular changes in response to drug treatment using a custom designed RT-qPCR array. Results showed that Harakiri was significantly upregulated. Presence of p53 was not required for apoptosis in response to Cu-complexes. CONCLUSIONS AND GENERAL SIGNIFICANCE: These Cu-complexes, namely Cu(Sal-Gly)(pheamine), may be considered promising anticancer agents with activity in cancer cells even with deficient p53 status.

Cytotoxic and apoptotic effects of the combination of palladium (II) 5,5-diethylbarbiturate complex with bis(2-pyridylmethyl)amine and curcumin on non small lung cancer cell lines.

Metal-based chemotherapeutics such as cisplatin are widely used treatment of lung cancer which is the major cause of cancer-related mortality worldwide. Recent studies demonstrated that novel metal-based compounds have strong cytotoxic activity in a similar way as cisplatin. Therefore, metal-based compounds have been synthesized and investigated in order to determine their cytotoxic activities. It has been also reported curcumin, which has been derived from turmeric plant, has powerful cytotoxic effect on various cancer cell lines. In the light of these data, it has been investigated the cytotoxic effects of combination of curcumin (0.78-100µM) and palladium (II) 5,5-diethylbarbiturate complex with bis(2-pyridylmethyl)amine [Pd(II) complex] (0.39-50µM) against non small lung cancer cell lines, A549 and H1299. It has been found that combination of Pd(II) complex and curcumin enhanced the cytotoxic activity and apoptotic cell death at 48h, compared to single use of each agent, only in H1299 cell line (combination index <1). Apoptosis was evident by annexin v staining positivity, increased caspase 3/7 activity and the presence of pyknotic nuclei. Pro-apoptotic genes of TNFRSF10A and HRK were found to be involved in apoptotic cell death. In conclusion, the application of this combination may be regarded as a novel and effective approach for the treatment of lung cancer due to its promising cytotoxic and apoptotic effect.