Morpholine or methylpiperazine and salicylaldimine based heteroleptic square planner platinum (II) complexes: In vitro anticancer study and growth retardation effect on E. coli

A Morpholine Derivative N-(4-Morpholinomethylene)ethanesulfonamide Induces Ferroptosis in Tumor Cells by Targeting NRF2

Small molecule drugs containing morpholine-based moieties have become crucial candidates in the tumor targeted therapy strategies, but the specific molecular mechanisms of these drugs causing tumor cell death require further investigation. The morpholine derivative N-(4-morpholinomethylene)ethanesulfonamide (MESA) was used to stimulate prostate and ovarian cancer cells and we focused on the ferroptosis effects, including the target molecule and signal pathways mediated by MESA. The results showed that MESA could induce ferroptosis to cause the proliferation inhibition and apoptosis effects of tumor cells according to the identification of ferroptosis inhibitor fer-1 and other cell death inhibitors. Further MESA could significantly increase the intracellular malondialdehyde (MDA), reactive oxygen species (ROS) and Fe2+ levels in tumor cells and mediate the dynamic changes of ferroptosis-relative molecules GPX4, nuclear factor erythroid2-related factor 2 (NRF2), ACSL4, SLC7A11 and P62-Kelch-like ECH-associated protein 1 (KEAP1)-NRF2-antioxidant response element (ARE) signal pathways. Further, NRF2 overexpression could reduce the tumor cell death and ROS levels exposure to MESA. Most importantly, it was confirmed that MESA could bind to NRF2 protein through molecular docking and thermal stability assays and NRF2 was a target molecule of MESA for inducing ferroptosis effects in tumor cells. Collectively, our findings indicated the ferroptosis effects of the morpholine derivative MESA in prostate and ovarian cancer cells and its function mechanism including targeted molecule and signal pathways, which would be helpful for developing MESA as a prospective small molecule drug for cancer therapy based on cell ferroptosis.

Vitamin B6 based Pt(II) complexes: Biomolecule derived potential cytotoxic agents for thyroid cancer

Vitamin B6 is an essential vitamin that serves as a co-enzyme in a number of enzymatic reactions in metabolism of lipids, amino acids and glucose. In the current study, we synthesized vitamin B6 derived ligand (L) and its complex Pt(L)Cl (C1). The ancillary chloride ligand of C1 was exchanged with pyridine co-ligand and another complex Pt(L)(py).BF4 (C2) was obtained. Both these complexes were obtained in excellent isolated yields and characterized thoroughly by different analytical methods. Thyroid cancer is one of the most common malignancies of the endocrine system, we studied the in vitro anticancer activity and mechanism of these vitamin B6 derived L and Pt(II) complexes in thyroid cancer cell line (FTC). Based on MTT assay, cell proliferation rate was reduced in a dose-dependent manner. According to apoptosis analysis, vitamin B6 based Pt(II) complexes treated cells depicted necrotic effect and TUNEL based apoptosis was observed in cancer cells. Furthermore, qRT-PCR analyses of cancer cells treated with C1 and/or C2 showed regulated expression of anti-apoptotic, pro-apoptosis and autophagy related genes. Western blot results demonstrated that C1 and C2 induced the activation of p53 and the cleavage of Poly (ADP-ribose) polymerase (PARP). These results suggest that these complexes inhibit the growth of FTC cells and induce apoptosis through p53 signaling. Thus, vitamin B6 derived Pt(II) complexes C1 and C2 may be potential cytotoxic agents for the treatment of thyroid cancer.

Inhibition of SREBP-mediated lipid biosynthesis and activation of multiple anticancer mechanisms by platinum complexes: Ascribe possibilities of new antitumor strategies

Cancer is one of the most aggressive diseases with poor prognosis and survival rates. Lipids biogenesis play key role in cancer progression, metastasis and tumor development. Suppression of SREBP-mediated lipid biogenesis pathway has been linked with cancer inhibition. Platinum complexes bearing good anticancer effect and multiple genes activation properties are considered important and increase the chances for development of new platinum-based drugs. In this study, we synthesized pyridine co-ligand functionalized cationic complexes and characterized them using multiple spectroscopic and spectrophotometric methods. Two of these complexes were studied in solid state by single crystal X-ray analysis. The stability of these complexes were measured in solution state using ¹H NMR methods. These complexes were further investigated for their anticancer activity against human breast, lung and liver cancer cells. MTT assay showed potential cytotoxic activity in dose-dependent manner and decrease survival rates of cancer cells was observed upon treatment with these complexes. Biological assays results revealed higher cytotoxicity as compared to cisplatin and oxaliplatin. Further we studied C2, C6 and C8 in detailed mechanistic anticancer analyses. Clonogenic assay showed decrease survival of MCF-7, HepG2 and A549 cancer cells treated with C2, C6 and C8 as compared to control cells treated with DMSO. TUNEL assay showed more cell death, these complexes suppressed invasion and migration ability of cancer cells and decreased tumor spheroids formation, thus suggesting a potential role in inhibition of cancer metastasis and cancer stem cells formation. Mechanistically, these complexes inhibited sterol regulatory element-binding protein 1 (SREBP-1) expression in cancer cells in dose-dependent manner and thereby reduced lipid biogenesis to suppress cancer progression. Furthermore, expression level was decreased for the key genes LDLR, FASN and HMGCR, those required for sterol biosynthesis. Taken together, these complexes suppressed cancer cell growth, migration, invasion and spheroids formation by inhibiting SREBP-1 mediated lipid biogenesis pathway.

Crystal structure of chlorido-(4-methyl-2-((phenylimino)methyl)phenolato-κ2 N,O)-(pyridine-κ1 N)platinum(II), C19H17ClN2OPt

C10H8BrN3, orthorhombic, P 1 ‾ $P‾{1}$ (no. 2), a = 12.114(7) Å, b = 12.254(8) Å, c = 13.186(8) Å, α = 71.659(10)°, β = 84.744(10)°, γ = 89.725(10)°, V = 1850(2) Å3, Z = 4, R gt (F) = 0.0511, wR ref (F 2) = 0.1644, T = 293 K.

Preparation and antitumor application of N-phenylcarbazole/triphenylamine-modified fluorescent half-sandwich iridium(III) Schiff base complexes

Four N-phenylcarbazole/triphenylamine-appended half-sandwich iridium(III) salicylaldehyde Schiff base complexes ([(η⁵-Cp^x)Ir(O^N)Cl]) were prepared and characterized. The complexes exhibited similar antitumor activity to cisplatin and effectively inhibited the migration of tumor cells. Furthermore, the complexes showed favourable hydrolytic activity, while remaining relatively stable in the plasma environment, which facilitated the binding of serum proteins and transport through them. These complexes could decrease the mitochondrial membrane potential, catalyze the oxidation of nicotinamide adenine dinucleotide, induce an increase in intracellular reactive oxygen species (ROS), and eventually result in apoptosis. Aided by their suitable fluorescence property, laser confocal detection showed that the complexes followed an energy-dependent mechanism for their cellular uptake, effectively accumulating in the lysosome and leading to lysosomal damage. In summary, the half-sandwich iridium(III) salicylaldehyde Schiff base complexes could induce lysosomal damage, increase intracellular ROS, and lead to apoptosis, which contributed to their antitumor mechanism of oxidation.

High anticancer activity and apoptosis- and autophagy-inducing properties of novel lanthanide(III) complexes bearing 8-hydroxyquinoline-N-oxide and 1,10-phenanthroline

In the quest for rare earth metal complexes with enhanced cancer chemotherapeutic properties, the discovery of seven lanthanide(iii) complexes bearing 8-hydroxyquinoline-N-oxide (NQ) and 1,10-phenanthroline (phen) ligands, i.e., [SmIII(NQ)(phen)(H2O)Cl2] (Ln1), [EuII(NQ)(phen)(H2O)Cl2] (Ln2), [GdIII(NQ)(phen)(H2O)Cl2] (Ln3), [DyIII(NQ)(phen)(H2O)Cl2] (Ln4), [HoIII(NQ)(phen)(H2O)Cl2] (Ln5), [ErIII(NQ)(phen)(H2O)Cl2] (Ln6), and [YbIII(NQ)(phen)(H2O)Cl2] (Ln7), as potential anticancer drugs is described. Complexes Ln1-Ln7 exhibit high antiproliferative activity against cisplatin-resistant A549/DDP cells (IC50 = 0.025-0.097 μM) and low toxicity to normal HL-7702 cells. Moreover, complex Ln1, and to a lesser extent Ln7, can upregulate the expression of LC3 and Beclin1 and downregulate p62 to induce apoptosis in cisplatin-resistant A549/DDP cell lines, which is related to the cell autophagy-inducing properties of Ln1 and Ln7. Furthermore, in vivo assays suggest that Ln1 significantly inhibits A549/DDP xenograft tumor growth (56.5%). These results indicate that lanthanide(iii) complex Ln1 is a promising candidate as an anticancer drug against cisplatin-resistant A549/DDP cells.

Design, synthesis, and validation of novel nitrogen-based chalcone analogs against triple negative breast cancer

Great strides have been made in triple negative breast cancer (TNBC) treatment, which represents 20% of total predicted annual US breast cancer (BC) cases. Despite the development of several therapeutics, TNBC patients have poor overall survival rate, compared to other BC patients, justifying the urgent need to discover new entities for use to control TNBC. Chalcones are important natural products with diverse bioactivities including anticancer effects. This study aimed to design, synthesize and validate novel chalcone leads as potential therapies for TNBC. Fourteen novel chalcone analogs were designed and synthesized comprising alicyclic amines (pyrrolidine, morpholine and piperidine) or nitrogen mustard (Bis-(2-chloroethyl) amine) substituents. Among them, compound 14((E)-3-(4-(Bis(2-chloroethyl) amino) phenyl)-1-(3-methoxyphenyl) prop-2-en-1-one) was identified as the most effective against TNBC and other BC phenotypes, with anti-proliferative IC₅₀ values ranging between 3.94 and 9.22 μM against the TNBC cell lines MDA-MB-231 and MDA-MB-468, as well as against the estrogen positive MCF-7 cell line. Chalcone 14 effectively suppressed the colony formation capacity of MDA-MB-231, MDA-MB-468, and MCF-7 cell lines at 5 and 10 μM treatment concentrations. Furthermore, compound 14 has significantly inhibited cell invasion and migration of MDA-MB-231 and MCF-7 BC cell lines. Additionally, compound 14 had significantly promoted apoptosis by upregulating BAX and downregulating Bcl-2 proteins. Compound 14 induced significant cell cycle arrest of TNBC cells at the G2/M phase. It also induced a reversal of Epithelial Mesenchymal Transition (EMT) by upregulating the epithelial markers E-cadherin and Pan-cadherin and downregulating FAK. Furthermore, it had dramatically diminished new vessel formation (vasculogenesis) in chick chorioallantoic membrane (CAM) model by 60.20 ± 8.47%. Chalcone 14 inhibited 46.41 ± 0.71% of the TNBC MAD-MB-231 cells growth in a nude mouse orthotopic xenograft model in comparison with vehicle control treated animals. Collectively, this study results propose chalcone 14 as a promising lead molecule for the control of TNBC as well as other breast cancer phenotypes.

Anticancer activity and mechanism of bis-pyrimidine based dimetallic Ru(II)(η6-p-cymene) complex in human non-small cell lung cancer via p53-dependent pathway

Non-small cell lung cancer (NSCLC) is the most common cancer worldwide, which is related with poor prognosis and resistance to chemotherapy. Notably, ruthenium-based complexes have emerged as good alternative to the currently used platinum-based drugs for cancer therapy. In the present study, we synthesized a novel bis-pyrimidine based ligand 1,3-bis(2-methyl-6-(pyridin-2-yl)pyrimidin-4-yl)benzene (L) and used it in the synthesis of a dimetallic Ru(II) cymene complex [(Ru(η⁶-p-cymene)Cl)₂(1,3-bis(2-methyl-6-(pyridin-2-yl)pyrimidin-4-yl)benzene)] (L-Ru). We checked the stability of this complex in solution state in D₂O/DMSO‑d₆ mixture and found it to be highly stable under these conditions. We determined the anticancer activity and mechanism of action of L-Ru in human NSCLC A549 and A427 by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and related biological analyses. These results revealed that L-Ru exerted a strong inhibitory effect on the cells proliferation,G0/G1-arrest, accompanied with upregulation of p53, p21, p15, cleaved Poly (ADP-ribose) polymerase (PARP) protein and downregulation of cell cycle markers. L-Ru inhibited cell migration and invasion. The mitochondria-mediated apoptosis of NSCLC induced by L-Ru was also observed followed by the increase of apoptosis regulator B-cell lymphoma 2 associated X (BAX), and activation of caspase-3/-9. The effects of L-Ru on the cell viability, Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) positive cells and Annexin V-positive cells apoptosis induction were remarkably attenuated. This complex induced DNA damage, cell cycle arrest and cell death via caspase-dependent apoptosis involving PARP activation and induction of p53-dependent pathway. These findings suggested that this ruthenium complex might be a potential effective chemotherapeutic agent in NSCLC therapy.

Synthesis and biological evaluation of substituted 3-(2'-benzimidazolyl)coumarin platinum(II) complexes as new telomerase inhibitors

Eight new platinum(II) complexes Pt1-Pt8 with substituted 3‑(2'‑benzimidazolyl) coumarins were successfully synthesized and characterized by single crystal X-ray diffraction analysis, nuclear magnetic resonance spectroscopy (NMR), electrospray ionization-mass spectrometry (ESI-MS), infrared spectrophotometry (IR) and elemental analysis. Crystallographic data of these Pt1-Pt8 complexes showed that the Pt(II) has distorted four-coordinated square planar geometry. Pt1-Pt8 were found to display high cytotoxic activity in vitro against the cisplatin-resistant SK-OV-3/DDP cancer cells with a low IC₅₀ from 1.01-10.32 μM, but low cytotoxicity on the normal HL-7702 cells. Further studies revealed that Pt1-Pt3 induced apoptosis in SK-OV-3/DDP cancer cells via mitochondria dysfunction signaling pathways. Our findings also indicated that Pt1 was a telomerase inhibitor targeting c-myc promoter elements.

In Vitro Antitumor Activity of Alkylaminoguaiazulenes

BACKGROUND/AIM

Guaiazulene (1,4-dimethyl-7-isopropylazulene) is present in several essential oils of medicinal and aromatic plants. There exist few studies that investigated the anticancer activity of guaiazulenes. We investigated the relative cytotoxicity of 10 alkylaminoguaiazulene derivatives towards both cancer and normal cells.

MATERIALS AND METHODS

Cytotoxicity towards four human oral squamous cell carcinoma (OSCC) cell lines and five types of human normal oral cells (gingival fibroblasts, periodontal ligament fibroblasts, pulp cells and keratinocytes, gingival epithelial progenitors) was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) method. Tumor specificity (TS) was evaluated as the ratio of the mean 50% cytotoxic concentration against normal oral cells to that against OSCC cell lines. Apoptosis-inducing activity was evaluated by cleavage of poly ADP-ribose polymerase and caspsase-3 with western blot analysis.

RESULTS

Validity of the present TS measurement method was confirmed using methotrexate. With increasing length of the alkyl group of alkylaminoguaiazulene derivatives, cytotoxicity increased. Introduction of oxygen, nitrogen or sulfur atom into the alkyl group slightly reduced cytotoxicity. Most compounds had very low TS, no synergistic action with methotrexate and doxorubicin, nor did they induce apoptosis of OSCC cells. On the other hand, compound [10], containing a morpholino group, induced apoptosis of OSCC cells.

CONCLUSION

The cytotoxicity of alkylaminoguaiazulenes is not always coupled with TS and apoptosis-inducing activity.