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Breast cancer is a major malignancy among women, characterized by a high mortality rate. The available literature evidence indicates that selenium, as a trace element, has chemopreventive properties against many types of cancer; as such, compounds containing it in their structure may potentially exhibit anticancer activity. Accordingly, we have undertaken a study to evaluate the effects of novel selenoesters (EDAG-1, -7, -8, -10) on MCF-7 and MDA-MB-231 breast cancer cells. Our analysis included investigations of cell proliferation and viability as well as cytometric determinations of apoptosis/autophagy induction, changes in mitochondrial membrane polarity (ΔΨ m ), caspase 3/7, 8, and 9 activities, and Bax, Bcl-2, p53, Akt, AMPK, and LC3A/B proteins. The obtained data revealed that the tested derivatives are highly cytotoxic and inhibit cell proliferation even at nanomolar doses (0.41-0.79 µM). Importantly, their strong proapoptotic properties (↑ caspase 3/7) are attributable to the effects on both the extrinsic (↑ caspase 8) and intrinsic (↓ ΔΨ m and Bcl-2, ↑ Bax, p53, and caspase 9) pathways of apoptosis. Moreover, the tested compounds are autophagy activators (↓ Akt, ↑ autophagosomes and autolysosomes, AMPK, LC3A/B). In summary, the potent anticancer activity suggests that the tested compounds may be promising drug candidates for future breast cancer therapy.

In the last decade, an increasing interest in compounds containing pyrazolo[4,3- e ][1,2,4]triazine moiety is observed. Therefore, the aim of the research was to synthesise a novel sulphonyl pyrazolo[4,3- e ][1,2,4]triazines ( 2a , 2b ) and pyrazolo[4,3- e ]tetrazolo[1,5- b ][1,2,4]triazine sulphonamide derivatives ( 3a , 3b ) to assess their anticancer activity. The MTT assay showed that 2a , 2b , 3a , 3b have stronger cytotoxic activity than cisplatin in both breast cancer cells (MCF-7 and MDA-MB-231) and exhibited weaker effect on normal breast cells (MCF-10A). The obtained results showed that the most active compound 3b increased apoptosis via caspase 9, caspase 8, and caspase 3/7. It is worth to note that compound 3b suppressed NF-κB expression and promoted p53, Bax, and ROS which play important role in activation of apoptosis. Moreover, our results confirmed that compound 3b triggers autophagy through increased formation of autophagosomes, expression of beclin-1 and mTOR inhibition. Thus, our study defines a possible mechanism underlying 3b -induced anti-cancer activity against breast cancer cell lines.

Design of tubulin inhibitors as anticancer drugs dynamically developed over the past 20 years. The modern arsenal of potential tubulin-targeting anticancer agents is represented by small molecules, monoclonal antibodies, and antibody-drug conjugates. Moreover, targeting tubulin has been a successful strategy in the development of antiparasitic drugs. In the present review, an overall picture of the research and development of potential tubulin-targeting agents using small molecules between 2018 and 2023 is provided. The data about some most often used and prospective chemotypes of small molecules (privileged heterocycles, moieties of natural molecules) and synthetic methodologies (analogue-based, fragment-based drug design, molecular hybridization) applied for the design of novel agents with an impact on the tubulin system are summarized. The design and prospects of multi-target agents with an impact on the tubulin system were also highlighted. Reported in the review data contribute to the "structure-activity" profile of tubulin-targeting small molecules as anticancer and antiparasitic agents and will be useful for the application by medicinal chemists in further exploration, design, improvement, and optimization of this class of molecules., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

A series of new ursolic acid (UA) derivatives substituted with various amino acids (AAs) or dipeptides (DP) at the C-3 position of the steroid skeleton was designed and synthesized. The compounds were obtained by the esterification of UA with the corresponding AAs. The cytotoxic activity of the synthesized conjugates was determined using the hormone-dependent breast cancer cell line MCF-7 and the triple-negative breast cancer cell line MDA. Three derivatives ( l -seryloxy-, l -prolyloxy- and l -alanyl- l -isoleucyloxy-) showed micromolar IC 50 values and reduced the concentrations of matrix metalloproteinases 2 and 9. Further studies revealed that for two compounds ( l -seryloxy- and l -alanyl- l -isoleucyloxy-), a possible mechanism of their antiproliferative action is the activation of caspase-7 and the proapoptotic Bax protein in the apoptotic pathway. The third compound ( l -prolyloxy- derivative) showed a different mechanism of action as it induced autophagy as measured by an increase in the concentrations of three autophagy markers: LC3A, LC3B, and beclin-1. This derivative also showed statistically significant inhibition of the proinflammatory cytokines TNF-α and IL-6. Finally, for all synthesized compounds, we computationally predicted their ADME properties as well as performed molecular docking to the estrogen receptor to assess their potential for further development as anticancer agents.

A series of 11-substituted 9-hydroxy-3,5,10,11-tetrahydro-2H-benzo[6,7]thiochromeno[2,3-d][1,3]thiazole-2,5,10-triones 3.1-3.13 were synthesized via hetero-Diels-Alder reaction of 5-ene-4-thioxo-2-thiazolidinones and 5-hydroxy-1,4-naphthoquinone (juglone). The structure of newly synthesized compounds was established by means of spectral data and a single-crystal X-ray diffraction analysis. The synthesized compounds were tested on a panel of cell lines representing different types of cancer as well as normal and pseudonormal cells and peripheral human blood lymphocytes. Compound 3.10 was found to be the most active derivative, exhibiting a cytotoxic effect similar to doxorubicin's one (IC 50 ranged from 0.6 to 5.98 μM), but less toxic to normal and pseudonormal cells. All synthesized compounds were able to interact with DNA, although their anticancer activity did not correlate with the potency of interaction with DNA. The status of p53 in colorectal cancer cells correlated with the activity of the synthesized derivatives 3.1, 3.7, and 3.10. Compound 3.10 did not have an acute toxic effect on the body of С57BL/6 mice, unlike the well-known anticancer drug doxorubicin, which was used as a positive control. The injection of 3.10 (20 mg/kg) to mice had no effect on the counts of leukocytes, erythrocytes, platelets and hemoglobin level in their blood, in contrast to doxorubicin, which caused anemia and leukopenia, indicating bio-tolerance of 3.10in vivo., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Oncological diseases have currently reached an epidemic scale, especially in industrialized countries. Such a situation has prompted complex studies in medicinal chemistry focused on the research and development of novel effective anticancer drugs. In this review, the data concerning new 4-thiazolidinone-bearing hybrid molecules with potential anticancer activity reported during the period from the years 2017-2022 are summarized. The main emphasis is on the application of molecular hybridization methodologies and strategies in the design of small molecules as anticancer agents. Based on the analyzed data, it was observed that the main directions in this field are the hybridization of scaffolds, the hybrid-pharmacophore approach, and the analogue-based drug design of 4-thiazolidinone cores with early approved drugs, natural compounds, and privileged heterocyclic scaffolds. The mentioned design approaches are effective tools/sources for the generation of hit/lead compounds with anticancer activity and will be relevant to future studies.

Based on the results of previous work, we designed and synthesized 1,3,4-thiadiazole derivatives. The cytotoxic activity of the obtained compounds was then determined in biological studies using MCF-7 and MDA-MB-231 breast cancer cells and a normal cell line (fibroblasts). The results showed that all compounds displayed weak anticancer activity towards two breast cancer lines: an estrogen-dependent cell line (MCF-7) and an estrogen-independent cell line (MDA-MB-231). The compound most active towards MCF-7 breast cancer cells was SCT-4, which decreased DNA biosynthesis to 70% ± 3 at 100 µM. The mechanism of the anticancer action of 1,3,4-thiadiazole was also investigated. We choose a set of the most investigated proteins, which are attractive anticancer targets. In silico studies demonstrated a possible multitarget mode of action for the synthesized compounds but the most likely mechanism of action for the new compounds is connected with the activity of caspase 8.

Novel pyridine-thiazole hybrid molecules were synthesized and subjected to physico-chemical characterization and screening of their cytotoxic action towards a panel of cell lines derived from different types of tumors (carcinomas of colon, breast, and lung, glioblastoma and leukemia), and normal human keratinocytes, for comparison. High antiproliferative activity of the 3-(2-fluorophenyl)-1-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-propenone 3 and 4-(2-{1-(2-fluorophenyl)-3-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-3-oxopropylsulfanyl}-acetylamino)-benzoic acid ethyl ester 4 was revealed. The IC50 of the compound 3 in HL-60 cells of the acute human promyelocytic leukemia was 0.57 µM, while in the pseudo-normal human cell lines, the IC50 of this compound was >50 µM, which suggests that the compounds 3 and 4 might be perspective anticancer agents. The detected selectivity of the derivatives 3 and 4 for cancer cell lines inspired us to study the mechanisms of their cytotoxic action. It was shown that preincubation of tumor cells with Fluzaparib (inhibitor of PARP1) reduced the cytotoxic activity of the derivatives 3 and 4 by more than twice. The ability of these compounds to affect DNA nativity and cause changes in nucleus morphology allows for the suggestion that the mechanism of action of the novel pyridine-thiazole derivatives might be related to inducing the genetic instability in tumor cells.

It was established that the synthesis of hybrid molecules containing a thiazolidinone and a (2 Z )-2-chloro-3-(4-nitrophenyl)prop-2-ene structural fragments is an effective approach for the design of potential anticancer agents. Given the results of the previous SAR-analysis, the aim of the study was to synthesize a novel 4-thiazolidinone derivative Les-3331 and investigate its molecular mechanism of action in MCF-7 and MDA-MB-231 breast cancer cells. The cytotoxic properties and antiproliferative potential of Les-3331 were determined. The effect of the tested compound on apoptosis induction and mitochondrial membrane potential was checked by flow cytometry. ELISA was used to determine caspase-8 and caspase-9, LC3A, LC3B, Beclin-1, and topoisomerase II concentration. Additionally, PAMPA, in silico or in vitro prediction of metabolism, CYP3A4/2D6 inhibition, and an Ames test were performed. Les-3331 possesses high cytotoxic and antiproliferative activity in MCF-7 and MDA-MB-231 breast cancer cells. Its molecular mechanism of action is associated with apoptosis induction, decreased mitochondrial membrane potential, and increased caspase-9 and caspase-8 concentrations. Les-3331 decreased LC3A, LC3B, and Beclin-1 concentration in tested cell lines. Topoisomerase II concentration was also lowered. The most probable metabolic pathways and no DDIs risk of Les-3331 were confirmed in in vitro assays. Our studies confirmed that a novel 4-thiazolidinone derivative represents promising anti-breast cancer activity.

Colorectal cancer (CRC) is the third leading cause of cancer-related deaths in men and in women. The impact of the new pyrazolo[4,3- e ]tetrazolo[1,5- b ][1,2,4]triazine sulphonamide ( MM-129 ) was evaluated against human colon cancer in vitro and in zebrafish xenografts. Our results show that this new synthesised compound effectively inhibits cell survival in BTK-dependent mechanism. Its effectiveness is much higher at a relatively low concentration as compared with the standard chemotherapy used for CRC, i.e. 5-fluorouracil (5-FU). Flow cytometry analysis after annexin V-FITC and propidium iodide staining revealed that apoptosis was the main response of CRC cells to MM-129 treatment. We also found that MM-129 effectively inhibits tumour development in zebrafish embryo xenograft model, where it showed a markedly synergistic anticancer effect when used in combination with 5-FU. The above results suggest that this novel heterofused 1,2,4-triazine derivative may be a promising candidate for further evaluation as chemotherapeutic agent against CRC.

MUC1 seems to be promising target in cancer cells due to its abundant and specifically altered expression as well as differential distribution pattern relative to normal tissues. Rosmarinic acid (RA) is a natural, polyphenolic compound with pharmacological activities, including anti-cancer. Herein, we aim to explore the effect of combined action of anti-MUC1 and RA on selected cancer-related factors in AGS gastric cancer cells. Cancer cells were treated with 100, 200 μM rosmarinic acid, 5 μg/ml anti-MUC1 and acid together with antibody. Western blotting, ELISA and RT-PCR were used to assess the expression of MUC1, selected sugar antigens, enzymes participating in protein glycosylation, Gal-3, p53, pro- and anti-apoptotic factors, and caspases-3,-8,-9 in cancer cells. MUC1 mRNA was significantly suppressed by combined action of anti-MUC1 and RA. Such treatment markedly inhibited expression of cancer-related Tn, T, sialyl Tn, sialyl T, and fucosylated sugar antigens as well as mRNA expression of enzymes participating in their formation: ppGalNAcT2, C1GalT1, ST6GalNAcT2, ST3GalT1 and FUT4. C1GalT1 was suppressed also on protein level. Gal-3, factor likely participating in metastasis, was significantly suppressed on mRNA level by RA administrated with anti-MUC1. Pro-apoptotic Bax protein and Bad mRNA were significantly induced, and anti-apoptotic Bcl-2 mRNA expression was inhibited by such treatment. Combined action of mAb and RA markedly increased caspase-9 mRNA expression. Results of the study indicate that combined action of anti-MUC1 and RA is more effective than monotherapy in relation to examined cancer related factors. Such treatment can be considered as new, promising strategy in gastric cancer therapy., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)

Autophagy is a process of self-degradation that plays an important role in removing damaged proteins, organelles or cellular fragments from the cell. Under stressful conditions such as hypoxia, nutrient deficiency or chemotherapy, this process can also become the strategy for cell survival. Autophagy can be nonselective or selective in removing specific organelles, ribosomes, and protein aggregates, although the complete mechanisms that regulate aspects of selective autophagy are not fully understood. This review summarizes the most recent research into understanding the different types and mechanisms of autophagy. The relationship between apoptosis and autophagy on the level of molecular regulation of the expression of selected proteins such as p53, Bcl-2/Beclin 1, p62, Atg proteins, and caspases was discussed. Intensive studies have revealed a whole range of novel compounds with an anticancer activity that inhibit or activate regulatory pathways involved in autophagy. We focused on the presentation of compounds strongly affecting the autophagy process, with particular emphasis on those that are undergoing clinical and preclinical cancer research. Moreover, the target points, adverse effects and therapeutic schemes of autophagy inhibitors and activators are presented.

A series of novel 5-[( Z ,2 Z )-2-chloro-3-(4-nitrophenyl)-2-propenylidene]-thiazolidinones (Ciminalum-thiazolidinone hybrid molecules) have been synthesized. Anticancer activity screening toward the NCI60 cell lines panel, gastric cancer (AGS), human colon cancer (DLD-1), and breast cancer (MCF-7 and MDA-MB-231) cell lines allowed the identification of 3-{5-[( Z ,2 Z )-2-chloro-3-(4-nitrophenyl)-2-propenylidene]-4-oxo-2-thioxothiazolidin-3-yl}propanoic acid ( 2h ) with the highest level of antimitotic activity with mean GI 50 /TGI values of 1.57/13.3 μM and a certain sensitivity profile against leukemia (MOLT-4, SR), colon cancer (SW-620), CNS cancer (SF-539), melanoma (SK-MEL-5), gastric cancer (AGS), human colon cancer (DLD-1), and breast cancers (MCF-7 and MDA-MB-231) cell lines. The hit compounds 2f , 2i , 2j , and 2h have been found to have low toxicity toward normal human blood lymphocytes and a fairly wide therapeutic range. The significant role of the 2-chloro-3-(4-nitrophenyl)prop-2-enylidene ( Ciminalum ) substituent in the 5 position and the substituent's nature in the position 3 of core heterocycle in the anticancer cytotoxicity levels of 4-thiazolidinone derivatives have been established.

Cancer therapy is one of the most important challenges of modern medical and chemical sciences. Among the many methods of combating cancer, chemotherapy plays a special role. Imperfect modern chemotherapy justifies continuing the search for new, more effective, and safe drugs. Sulfonamides are the classic group of chemotherapeutic drugs with a broad spectrum of pharmacological activity. Recent literature reports show that sulfonamide derivatives have anti-tumor activity in vitro and in vivo. The aim of the study was to synthesize a novel 1,2,4-triazine sulfonamide derivative and check its anticancer potential in DLD-1 and HT-29 colon cancer cells. The biological studies included MTT assay, DNA biosynthesis, cell cycle analysis, Annexin V binding assay, ethidium bromide/acridine orange staining, and caspase-8, -9, and -3/7 activity. The concentrations of important molecules (sICAM-1, mTOR, Beclin-1, cathepsin B) involved in the pathogenesis and poor prognosis of colorectal cancer were also evaluated by ELISA. We demonstrated that the novel compound was able to induce apoptosis through intrinsic and extrinsic pathways and was capable of decreasing sICAM-1, mTOR, cathepsin B concentrations, whereas increased Beclin-1 concentration was detected in both colon cancer cell lines. The novel compound represents promising multi-targeted potential in colorectal cancer, but further in vivo examinations are needed to confirm the claim.

The significant role of topoisomerases in the control of DNA chain topology has been confirmed in numerous research conducted worldwide. The prevalence of these enzymes, as well as the key importance of topoisomerase in the proper functioning of cells, have made them the target of many scientific studies conducted all over the world. This article is a comprehensive review of knowledge about topoisomerases and their inhibitors collected over the years. Studies on the structure-activity relationship and molecular docking are one of the key elements driving drug development. In addition to information on molecular targets, this article contains details on the structure-activity relationship of described classes of compounds. Moreover, the work also includes details about the structure of the compounds that drive the mode of action of topoisomerase inhibitors. Finally, selected topoisomerases inhibitors at the stage of clinical trials and their potential application in the chemotherapy of various cancers are described.

The discovery of cytotoxic drugs is focused on designing a compound structure that directly affects cancer cells without an impact on normal cells. The mechanism of anticancer activity is mainly related with activation of apoptosis. However, recent scientific reports show that autophagy also plays a crucial role in cancer cell progression. Thus, the objective of this study was to synthesize 7-methyl-5-phenyl-pyrazolo[4,3- e ]tetrazolo[4,5- b ][1,2,4]triazine utilizing nucleophilic substitution reaction at the position N1. The biological activity of tested compounds was assessed in DLD-1 and HT-29 cell lines. The induction of apoptosis was confirmed by Annexin V binding assay and acridine orange/ethidium bromide staining. The loss of mitochondrial membrane potential and caspase-8 activity was estimated using cytometer flow analysis. The concentration of p53, LC3A, LC3B and beclin-1 was measured using the ELISA technique. Our study revealed that anticancer activity of 7-methyl-5-phenyl-pyrazolo[4,3- e ]tetrazolo[4,5- b ][1,2,4]triazine derivatives is related with initiation of apoptosis occur on the intrinsic pathway with mitochondrial membrane decrease and extrinsic with increase of activity of caspase-8. Moreover, a decrease in beclin-1, LC3A, and LC3B were observed in two cell lines after treatment with novel compounds. This study showed that novel 7-methyl-5-phenyl-pyrazolo[4,3- e ]tetrazolo[4,5- b ][1,2,4]triazine derivatives might be a potential strategy in colon cancer treatment.

Novel transition metal complexes (Au, Pd, Pt) with berenil and 2-(1-methyl-5-nitroimidazol-2-yl)ethanol were obtained through two-step synthesis. The cytotoxicity assay against MCF-7 and MDA-MB-231 breast cancer cells revealed that novel platinum and palladium complexes cause a reduction on the viability of MCF-7 and MDA-MB-231 breast cancer cells to a greater extent than cisplatin. The complexes showed lower cytotoxicity on normal MCF-10A human breast epithelial cells than on tumor cells. Furthermore, we observed that these complexes selectively concentrate in tumor cell mitochondria due to the characteristic for these cells increased membrane potential that may explain their increased proapoptotic activity. The activity of the synthesized compounds against topoisomerase type IIα and their increased impact on DNA defragmentation also were documented. The novel complexes also induced autophagosome changes and inhibited tumor growth in xenograft models (established using breast cancer cells).

In this study, we synthesized novel sulfonamides with a 1,2,4-triazine moiety according to pharmacophore requirements for biological activity. All the synthesized compounds were tested in vitro to verify whether they exhibited anticancer activity against the human breast cancer cell lines MCF-7 and MDA-MB-231. Among them, two most active ones, having IC 50 values of 50 and 42 µM, respectively, were found to show higher anticancer activity than chlorambucil used as the reference in the in vitro tests. In addition, two other compounds, which had IC 50 values of 78 and 91 µM, respectively, exhibited a similar level of activity as chlorambucil. X-ray analysis carried out for two of the compounds confirmed their synthesis pathway as well as their assumed molecular structures. Furthermore, a conformational analysis was performed, and electronic parameters of molecules were characterized using theoretical calculations at AM1 and DFT level. Moreover, molecular docking revealed the mode of binding of the investigated 1,2,4-triazine sulfonamides with the human estrogen receptor alpha (ER α ).

Six novel compounds of platinum(II) with pyrazole derivatives PtPz1-PtPz6 were synthesised and characterised (PtPz1 - [Pt 2 N-hydroksymethyl-3,5-dimethylpyrazole 4 (berenil) 2 ]Cl 4 ; PtPz2 - [Pt 2 3,5-dimethylpyrazole 4 (berenil) 2 ]Cl 4 ; PtPz3 - [Pt 2 3,4-dimethylpyrazole 4 (berenil) 2 ]Cl 4 ; PtPz4 - [Pt 2 pyrazole 4 (berenil) 2 ]Cl 4 ; PtPz5- [Pt 2 5-methylpyrazole 4 (berenil) 2 ]Cl 4 ; PtPz6 - [Pt 2 N-ethylpyrazole 4 (berenil) 2 ]Cl 4 ). The cytotoxic activity of these complexes against MCF-7 and MDA-MB-231 breast cancer cell lines was determined using the MTT assay. Evaluation of apoptosis induction was done with the Annexin V-fluorescein isothiocyanate/propidium iodide assay. In addition, using a flow cytometer, we determined the influence of test compounds on the cell cycle and caspase-3, -8, and -9 activity. The obtained results of caspase activity were confirmed by cell imaging. Moreover, using the flow cytometer, the effects of the test compounds on mitochondrial potential change were assessed. The test results showed that novel pyrazole-platinum(II) complexes exhibited stronger anti-proliferative activity against two breast cancer cell lines than reference cisplatin. Compounds PtPz1, PtPz2, and PtPz3 with methyl substituents at the pyrazole ring showed stronger activity than pyrazole or ethylpyrazole containing complexes. Studies have shown that inhibition of cell survival occurs by arresting the G1 cell cycle and inducing apoptosis. Our analysis associated with the response of MCF-7 and MDA-MB-231 cells to treatment with PtPz1-PtPz6 showed that it leads the cells through the external and intrinsic (mitochondrial) apoptotic pathway via indirect DNA damage.

Objective/method: A group of 4-benzoyl-1-dichlorobenzoylthiosemicarbazides endowed with antibacterial activity was evaluated for its cytotoxic properties against breast cancer cells (MCF-7, MDA-MB-231) and head and neck squamous cell carcinomas (FaDu, SCC-25). Cytotoxicity of the investigated compounds was measured using MTT and [3H]-thymidine incorporation bioassays., Result: 1-(2,3-Dichlorobenzoyl)-4-(2-methylbenzoyl)thiosemicarbazide (TA-4), 1-(2,4-dichlorobenzoyl)- 4-(2-methylbenzoyl)thiosemicarbazide (TA-18), and 1-(2,4-dichlorobenzoyl)-4-(4-nitrolbenzoyl)- thiosemicarbazide (TA-20) were found to possess anticancer activity equipotent or even stronger than that of reference drug - etoposide. In order to clarify the molecular mode of action of the mentioned compounds, the relaxation assay kit for human DNA topoisomerase II was used. It turned out that reduction of viability of cancer cells was a result of inhibition of human DNA topoII. Molecular docking studies proved that 4-benzoyl-1-dichlorobenzoylthiosemicarbazides strongly interact with DNAdependent subunit of that enzyme., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

In this study, we evaluated the cytotoxic activity and antiproliferative potency of novel octahydropyrazin[2,1-a:5,4-a']diisoquinoline derivatives (1-7) in MCF-7 and MDA-MB-231 breast cancer cell lines. Annexin V binding assay and disruption of the mitochondrial potential were performed to determine apoptosis. The activity of caspases 3, 8, 9, and 10 was measured after 24 h of incubation with tested compounds to explain detailed molecular mechanism of induction of apoptosis. The results from experiments were compared with effects obtained after incubation in the presence of camptothecin and etoposide. Our study demonstrated that the most active compounds in both analyzed breast cancer cell lines were compounds 3 and 4. We also observed that all compounds induced apoptosis. We demonstrated the higher activity of caspases 3, 8, 9, and 10, which confirmed that induction of apoptosis is associated with external and internal cell death pathway. Our study revealed that the novel compounds in group of diisoquinoline derivatives are promising candidates in anticancer treatment by activation of both extrinsic and intrinsic apoptotic pathways.

This study investigates the effect of three new platinum complexes: Pt2(2,4-dimethylpyridine)4(berenil)2 (Pt14), Pt2(3,4-dimethylpyridine)4(berenil)2 (Pt15) and Pt2(3,5-dimethylpyridine)4(berenil)2 (Pt16) on growth and viability of breast cancer cells and their putative mechanism(s) of cytotoxicity. Cytotoxicity was measured with MTT assay and inhibition of [3H]thymidine incorporation into DNA in both breast cancer cells. Results revealed that Pt14-Pt16 exhibit substantially greater cytotoxicity than cisplatin against MCF-7 and MDA-MB-231 breast cancer cells. In the case of human skin fibroblast cell, cytotoxicity assays demonstrated that these compounds are less toxic to normal cells than cisplatin. In addition, the effects of Pt14-Pt16 are investigated using the flow cytometry assessment of annexin V binding, analysis of mitochondrial potential, markers of apoptosis such as caspase-3, caspase-8, caspase-9, caspase-10 and defragmentation of DNA by TUNEL assay. These results indicate that Pt14-Pt16 induce apoptosis by the mitochondrial and external pathway.

A series of six 2,5-disubstituted 1,3,4-thiadiazole derivatives was synthesized and examined for cytotoxic activity in MCF-7 and MDA-MB-231 breast cancer cells. MTT assay confirmed that 2-(3-fluorophenylamino)-5-(3-hydroxyphenyl)-1,3,4-thiadiazole (2), 2-(4-bromophenylamino)-5-(2,4-dichlorophenyl)-1,3,4-thiadiazole (3), 2-(4-fluorophenylamino)-5-(2,4-dichlorophenyl)-1,3,4-thiadiazole (4), had ability to inhibit MCF-7 and MDA-MB-231 cells proliferation. The IC50 values for the mentioned compounds ranged between 120 and 160 μM (with respect to MCF-7 cells) and from 70 to 170 μM (with respect to MDA-MB-231 cells). It turned out, moreover, that compound 2 is a human topoisomerase II (topoII) catalytic inhibitor whereas the two other compounds (i.e. 3 and 4) are capable of stabilizing DNA-topoII cleavage complex and thus are topoII poisons.

New sulfonamide derivatives of pyrazolo[4,3-e][1,2,4]triazine were synthesized and investigated as antitumor agents through carbonic anhydrase (CA, EC 4.2.1.1) inhibition. The newly prepared compounds were tested for their anticancer activity against human breast cancer cell lines (MCF-7, MDA-MB-231) using a MTT assay and inhibition of [(3)H]thymidine incorporation into DNA. Preliminary biological studies with several CA isoforms, revealed that the new derivatives were ineffective as CA I and II inhibitors, but they showed activity against tumor-associated enzymes, such as CA IX. The most effective inhibitor against CA IX was compound 8e that exhibited an inhibition constant KI of 13.8nM, and derivatives 8c-8d with moderate activity (8c: KI=25.4nM; 8d: KI=24.5nM). Compounds 8g-8h exhibited acceptable activity (8g: KI=27.7nM; 8d: KI=26.6nM). The detailed synthesis, spectroscopic and biological data are also reported., (Copyright © 2015 Elsevier Ltd. All rights reserved.)

A series of sulfur 1,2,4-triazine derivatives were prepared and evaluated as anticancer compounds for two human breast cancer cell lines (MCF-7, MDA-MB-231) with some of them acting as low micromolar inhibitors. Evaluation of the cytotoxicity using a 3-(4,5-dimethylthiazol-2-yl)-3,5-diphenyltetrazolium bromide (MTT) assay, the inhibition of [(3)H]thymidine incorporation into DNA, and collagen synthesis inhibition demonstrated that these products exhibit cytotoxic effects on these breast cancer cell lines in vitro. The most effective were disulfide and sulfenamide compounds with two valence sulfur atoms. A structure-activity relationship study was performed using X-ray analysis and theoretical calculations at an ab initio density functional theory (DFT) level.

The aim of the present study was to examine the impact of a four platinum complexes of formula [Pt2L4(berenil)2]Cl4 where L is 3-ethylpyridine (Pt10), 3-(n-butyl)pyridine (Pt11), 4- ethylpyridine (Pt12) and 4-(t-butyl)pyridine (Pt13) on viability of Ishikawa endometrial cancer cells using the MTT assay and inhibition of [3H]thymidine incorporation into DNA. Our results confirm that compounds Pt10-Pt13 are more potent antiproliferative agents than cisplatin in endometrial cancer cells. Moreover, it was shown that all examined compounds Pt10-Pt13 inhibit collagen biosynthesis in neoplastic cells stronger than cisplatin. Flow cytometric analysis after annexin V-FITC and propidium iodide staining confirmed also that apoptosis was the main response of Ishikawa endometrial cancer cells to Pt10-Pt13 treatment. Our results suggest that apoptosis of Ishikawa endometrial cancer cell lines in the presence of Pt10-Pt13 follows the mitochondrial pathway, with the decrease in mitochondrial membrane potential and activation of caspase 9, as well as by the external pathway with the significant increase in FADD protein expression and caspase 8.

Evaluation of the cytotoxicity of novel octahydropyrazin[2,1-a:5,4-a']diisoquinoline derivatives (1a-2c) employing a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and inhibition of [(3)H]thymidine incorporation into DNA demonstrated that these compounds were more active than etoposide and camptothecin in both MDA-MB-231 and MCF-7 human breast cancer cells. Flow cytometric analysis after Annexin V-FITC and propidium iodide staining also confirmed that apoptosis was the main response of human breast cancer cells to 1a-2c treatment. Our results suggest that apoptosis of human breast cancer cells in the presence of 1a-2c follows the mitochondrial pathway, with the decrease in mitochondrial membrane potential and activation of caspase 9, as well as by the external pathway with the significant increase in caspase 8 expression. Cytotoxic properties of compounds 1a-2c in cultured human breast cancer cells correlate to their ability to inhibit topoisomerase I/II.

Mucin 1 (MUC1) is overexpressed in various cancer cells especially in breast cancer cells. There are known research works on the use of anti-MUC1 antibody with docetaxel in ovarian cancer, but there are no data about combined therapy platinum compounds with anti-MUC1 in breast cancer. The aim of the study was to evaluate the antiproliferative properties of a new dinuclear platinum(II) complex (Pt12) used with anti-MUC1 in human breast cancer cells. The dinuclear platinum(II) complex (Pt12) has been synthesized, and its cytotoxicity with anti-MUC1 has been tested in both MCF-7 and MDA-MB-231 breast cancer cells. In this study, the effects of Pt12 with anti-MUC1 on collagen and DNA biosynthesis in human breast cancer cells were compared to those evoked by cisplatin and cisplatin with anti-MUC1. The mechanism of action of Pt12 with anti-MUC1 was studied employing flow cytometry assessment of annexin V binding assay. It was found that Pt12 with anti-MUC1 was more active inhibitor of DNA and collagen synthesis as well more cytotoxic agent than Pt12 alone and cisplatin with anti-MUC1. Cytotoxicity of Pt12 with anti-MUC1 against breast cancer cells is due to apoptotic cell death as well as necrotic cell death. These results indicate that the use of Pt12 with anti-MUC1 may constitute a novel strategy in the chemotherapy of breast cancer tumors.

A new series of sulfonamide derivatives of pyrazolo[4,3-e][1,2,4]triazine has been synthesized and characterized. Their anticancer activity was tested in vitro against multiple human cancer cell lines and were found to have dose-dependent antiproliferative effects. Furthermore, some of the new compounds inhibited the Abl protein kinase with low micromolar IC50 values and exhibited selective activity against the Bcr-Abl positive K562 and BV173 cell lines, providing starting points for the further development of this new kinase inhibitor scaffold., (Copyright © 2014 Elsevier Masson SAS. All rights reserved.)

A series of sildenafil analogues and aniline substituted pyrazolo[4,3-e][1,2,4]triazine sulfonamides were prepared and evaluated as carbonic anhydrase (CA, EC 4.2.1.1) inhibitors and for their anticancer activity against two human breast cancer cell lines (MCF-7, MDA-MB-231). The new compounds were ineffective as CA I inhibitors, poorly inhibited CA II, but were more effective against the tumor-associated isoforms CA IX and XII, with some compounds acting as low nanomolar inhibitors. Evaluation of the cytotoxicity by using an MTT assay, the inhibition of [(3)H]thymidine incorporation into DNA as well as collagen synthesis inhibition, demonstrated that these sulfonamides exhibit cytotoxic effects on breast cancer cell lines ex vivo., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

A series of eight thiosemicarbazide derivatives was examined for cytotoxicity in breast cancer cell cultures. Among them, 4-benzoylthiosemicarbazides proved to be only slightly less potent than chlorambucil in both MDA-MB-231 and MCF-7 lines. In contrast, 4-aryl/alkylthiosemicarbazides revealed significantly lower cytotoxicity effect. Subsequently, all titled compounds were tested as potential human topoisomerase I and II (topo I and topo II) inhibitors. Mechanistic studies revealed that tested thiosemicarbazides act as both topoisomerase I and topoisomerase II inhibitors. Among them, the best inhibitory activity was found for 4-benzoylthiosemicarbazides (1 and 2) with IC50 at 50 µM against topo II.

As the alkylating agents metabolism is accompanied by reactive oxygen species (ROS) generation, the aim of this study has been to compare the effect of cisplatin and novel platinum(II) complexes, Pt2(isopropylamine)4(berenil)2, Pt2(piperazine)4(berenil)2, Pt2(2-picoline)4(berenil)2, Pt2(3-picoline)4(berenil)2, Pt2(4-picoline)4(berenil)2, on the redox state of human leukemic T-cells line Molt-4. Treatment of Molt-4 with the novel complexes has shown that all compounds enhance total ROS and superoxide anion generation as well as change the activity of antioxidant enzymes such as superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase. Moreover, all the above-mentioned compounds cause a decrease in the level of non-enzymatic antioxidants such as GSH as well as vitamin C, E and A. Such a situation is conducive to oxidative stress formation and oxidative modifications of cellular macromolecules. DNA damage of MOLT-4 leukemic cells is connected with 8-hydroxy-2'-deoxyguanosine and N7-methyldeoxyguanosine generation. The increased level of protein carbonyl groups and dityrosine indicates enhanced protein oxidative modifications, while an increase in the level of lipid peroxidation products, MDA, 4-HNE and isoprostanes proves the significant lipid peroxidation after treatment of Molt-4 cells with the complexes. Moreover, the complexes enhance expression of Bax and cytochrome c as well as decrease the expression of Bcl-2 and p53 protein. The novel platinum(II) complexes in comparison with cisplatin disturb redox status more intensively and lead to oxidative stress in Molt-4 cells. The enhanced oxidative modifications of macromolecules of human leukemic cancer cells lead to a shift in the proapoptotic-antiapoptotic balance into the proapoptotic direction.

The current work investigates the influence of novel dinuclear platinum(II) compounds of structure: Pt2(3-ethylpyridine)4(berenil)2 (Pt10) and Pt2(3-butylpyridine)4(berenil)2 (Pt11) on growth and viability of MDA-MB-231 and MCF-7 breast cancer cells as well as their putative mechanism of cytotoxicity. Evaluation of the cytotoxicity of Pt10 and Pt11 employing a MTT assay and inhibition of [(3)H]thymidine incorporation into DNA in both MDA-MB-231 and MCF-7 breast cancer cells demonstrated that these compounds were more potent antiproliferative agents than cisplatin. In our study the induction of apoptosis by Pt10 and Pt11 in human breast cancer cells was confirmed by several biochemical markers, such as: phosphatidylserine externalization, loss of mitochondrial membrane potential ΔΨm, caspase-3, -8, -9 activity, and DNA degradation. Pt10 and Pt11 induce apoptosis of breast cancer cells via mechanisms dependent on caspases activation and associated with mitochondrial membrane potential disruption., (Copyright © 2012 Elsevier B.V. All rights reserved.)

Evaluation of the cytotoxicity of a novel G3 PAMAM-NH(2) dendrimer-chlorambucil conjugate employing a MTT assay and inhibition of [(3)H]thymidine incorporation into DNA in both MDA-MB-231 and MCF-7 breast cancer cells demonstrated that the conjugate was more potent antiproliferative agent than chlorambucil. It was found that dendrimer-chlorambucil conjugate was more active inhibitor of collagen biosynthesis than chlorambucil. Our experiments carried out with flow cytometry assessment of annexin V binding and fluorescent microscopy assay revealed that PAMAM-CH conjugate inhibited the proliferation of MCF-7 and MDA-231 malignant cells by increasing the number of apoptotic and necrotic cells. The apoptotic effect of PAMAM-CH conjugate was found to be stronger than that caused by chlorambucil., (Copyright © 2011 Elsevier B.V. All rights reserved.)

Evaluation of the cytotoxicity of a novel dinuclear platinum(II) complex of formula Pt2(2-picoline)4(berenil)2 employing a MTT assay and inhibition of [3H]thymidine incorporation into DNA in both MDA-MB-231 and MCF-7 breast cancer cells demonstrated that the complex was more potent anti-proliferative agent than cisplatin. Data from the ethidium displacement assay indicated that the complex showed specificity for AT base pairs of DNA. Our study showed that Pt2(2-picoline)4(berenil), was a potent catalytic inhibitor of topoisomerase II in opposition to cisplatin.

Evaluation of the cytotoxicity of a novel dinuclear platinum(II) complex of formula Pt(2)(2-picoline)(4)(berenil)(2) employing a MTT assay and inhibition of [(3)H]thymidine incorporation into DNA in both MDA-MB-231 and MCF-7 breast cancer cells demonstrated that the complex was more of a potent antiproliferative agent than cisplatin. The DNA-binding ability of Pt(2)(2-picoline)(4)(berenil)(2) estimated by an ethidium displacement assay indicated that the complex showed strong specificity for AT base pairs in the minor groove of DNA. Our study showed that Pt(2)(2-picoline)(4)(berenil)(2) was a potent catalytic inhibitor of topoisomerase II in opposition to cisplatin. Pt(2)(2-picoline)(4)(berenil)(2) was found to be a more active inhibitor of collagen biosynthesis than cisplatin. The up regulation of beta(1)-integrin and insulin-like growth factor I (IGF-I) receptor expression by the complex was shown to be accompanied by an increase in the expression of mitogen activated protein kinases in breast cell lines. The phenomenon was related to the increased expression of nuclear factor-kappaB (NuF-kappaBeta) by Pt(2)(2-picoline)(4)(berenil)(2) as shown by the Western immunoblot analysis. Flow cytometric analysis and a fluorescent microscopy assay demonstrated that cell death appeared to result from apoptosis, with the possibility of secondary necrosis. The data presented suggested that Pt(2)(2-picoline)(4)(berenil)(2) impaired growth and metabolism of breast cancer cells more efficiently than cisplatin. These results indicated also the different properties of Pt(2)(2-picoline)(4)(berenil)(2) and cisplatin., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)

The objective of this study was to determine the cytotoxicity, antiproliferative activity, and apoptosis induction activity of two modified glycosides - digoxin and proscillaridin A - conjugated to a generation 3 polyamidoamine dendrimer (G3 PAMAM-NH(2)) in human breast cancer cells. The results suggest that conjugation with the G3 PAMAM-NH(2) dendrimer enhances the cytotoxicity of modified digoxin and proscillaridin Aboth in MCF-7 and in MDA-MB-231 breast cancer cells. Additionally, the conjugate-induced apoptosis was significantly greater than apoptosis evoked by free modified digoxin and proscillaridin A.

A series of platinium(II) complexes of formula [Pt2L4(berenil)2]Cl4.4HCl.2H2O where L is piperidine (1), 4-picoline (2), 3-picoline (3) or isopropylamine (4) was prepared and their cytotoxicity have been tested against the growth of human breast cancer cells. Evaluation of the cytotoxicity of these compounds employing a MTT assay and inhibition of [3H]thymidine incorporation into DNA in both MDA-MB-231 and MCF-7 breast cancer cells demonstrated that these compounds were more active than cisplatin. Data from the ethidium displacement assay indicated that these compounds show moderate specificity for AT base pairs of DNA. Compounds 1-4 were also potent topoisomerase II inhibitors, with 50% inhibitory concentrations (IC50) ranging from 5 to 50 microM.

The compounds of formula [Pt2Cl4(berenil)2]Cl4 and [Pt2Cl2(NH3)2(berenil)2]Cl4 were examined for cytotoxicity in breast cancer cell cultures and for inhibition of topoisomerases I and II. Evaluation of the cytotoxicity of these compounds employing a MTT assay and inhibition of [3H]thymidine incorporation into DNA in both MDA-MB-231 and MCF-7 breast cancer cells demonstrated that these compounds were more active than cisplatin. The DNA-binding ability of these compounds was evaluated by an ultrafiltration method using calf thymus DNA, poly(dA-dT)2 and poly(dG-dC)2, indicated that these compounds show strong specificity for AT base pairs. Binding studies indicate that these compounds bind more tightly to double-stranded DNA than cisplatin. The degree to which these compounds inhibited cell growth breast cancer cells was generally consistent with their relative DNA binding affinity. Mechanistic studies revealed that these compounds act as topoisomerase II (topo II) inhibitors in plasmid relaxation assays.

Design, synthesis, and cytotoxic activity of amidine derivatives of melphalan are described and structure-activity relationships are discussed. Evaluation of the cytotoxicity of these compounds employing a MTT assay and inhibition of [(3)H]thymidine incorporation into DNA in both MDA-MB-231 and MCF-7 human breast cancer cells demonstrated that these compounds were more active than melphalan. Data from the ethidium displacement assay showed that these compounds were able to bind in the minor groove-binding mode in AT sequences of DNA. The cytotoxic properties of the amidine analogues of melphalan towards cultured human breast cancer cells correlate with topoisomerase II inhibitory properties but not with DNA-binding properties.

Proline analogue of melphalan (Mel-pro) is one of the pro-drugs activated by prolidase, cytoplasmic imidodipeptidase highly expressed in some neoplastic tissues. In order to limit the action of prolidase on the pro-drug in normal cells, prolidase inhibitor, acetylsalicylic acid (ASA), was tested in fibroblasts (showing average prolidase activity for normal cells) and in MDA-MB 231 breast cancer cells (showing elevated activity of the enzyme). The effect of Mel-pro in the presence and absence of ASA on prolidase activity (colorimetric assay), DNA biosynthesis (3H-thymidine incorporation assay), cytotoxicity (tetrazoline assay) and ability to penetrate cell membrane (thin layer chromatography) in both type of cells was measured. It has been found that 5 mM ASA significantly decreased conversion of Mel-pro to Mel in cultured fibroblasts as well as it decreased cytotoxicity and the effect of this drug on DNA synthesis. In contrast, 5 mM ASA had relatively lower effect on the conversion of Mel-pro into Mel in MDA-MB 231 cells as well it had little effect on Mel-pro-induced inhibition of DNA synthesis and cell death. It suggests that ASA may serve as an inhibitor of prolidase-convertible pro-drugs in normal cells.

Nine carbocyclic analogues of mono- and bis-lexitropsins and two analogues of pentamidine with unsubstituted N-terminal amine group were synthesized. We have investigated the cytotoxic activity of new aromatic analogues of DNA binding ligands in MCF-7 breast cancer cells and assessed their ability to act as inhibitors of topoisomerase I and II. These studies indicate that aromatic analogues of bis-netropsin contain two identical units tethered by alkyloxyl chains are a potent catalytic inhibitor of both topoisomerases and exhibit moderate cytotoxicity in MCF-7 breast cancer cells.

A series of amidine analogues of chlorambucil (9-12), where 5-[4-(N-alkylamidino)phenyl]-2-furancarboxamide and the chlorambucil moiety are linked by a NH(CH(2))(2)NH chain, was synthesized and their cytotoxicity has been tested against the growth of human breast cancer MCF-7 cells. Evaluation of the cytotoxicity of compounds 9-12 employing a MTT assay and inhibition of [(3)H]thymidine incorporation into DNA demonstrated that these conjugates were more active than chlorambucil. Data from the ethidium displacement assay indicated that these compounds bind in the minor groove of DNA and show moderate specificity for AT base pairs. Compounds 9-12 were potent topoisomerase II inhibitors, with 50% inhibitory concentrations (IC(50))ranging from 10 to 40 microM. The cytotoxicity of the compounds 9-12 correlates with their DNA-binding affinities and their relative potency as topoisomerase II inhibitors. Altogether, these data suggest (i) that the cytotoxic activity of compounds 9-12 may be due to the combined effects of alkylation, DNA-minor groove binding, and (ii) that N-(2-aminoethyl)-5-(4-N-alkylamidinophenyl)-2-furancarboxamides (5-8) ligands are suitable linkers that favors DNA targeting by chlorambucil derivatives.

Inhibition of DNA topoisomerase and DNA-binding properties of a series of benzene-containing and C-terminus-modified analogues of distamycin and netropsin are described. These analogues contain two or three benzene units, respectively. Dibenzene analogues did not inhibit the topoisomerases, I and II. In this case, relaxation of DNA was inhibited with tribenzene analogues. Data from the ethidium displacement assay showed that these compounds were able to bind in the minorgroove binding mode in AT sequences of DNA. Molecular modelling experiments were performed to rationalize the lower binding affinity of tribenzene analogues of distamycin and netropsin, 3 and 4, compared to dibenzene analogues, 1 and 2. The superior DNA-binding afforded by 1 and 2 in comparison to 3 and 4 results from their more effective penetration into the minor groove of DNA and smaller perturbation of molecular structure upon complex formation.

A series of carbamate derivatives of Hoechst 33258 was prepared as potential anticancer agents. These new compounds (1-4) were readily prepared in good yields by addition of chloroethyl, bromoethyl, chloropropyl or 4-(chloromethyl)phenyl isocyanates to Hoechst 33258. Their cytotoxic activity was evaluated on human breast cancer MCF-7. Compounds 1-4 were more cytotoxic than Hoechst 33258. In particular derivative 4, the most active of the series, is up to 3 times more potent than Hoechst 33258. The DNA-binding ability of these compounds was evaluated by an ultrafiltration method using calf thymus DNA. These data show that in broad terms the cytotoxic potency of 1-4 in cultured breast cancer MCF-7 cells increases, in accord with their increases in DNA affinity, as shown by the binding constant values.

The effect of the novel aromatic bisamidine 1 on protein synthesis in cell-free translational system isolated from rat livers was studied. The bisamidine 1 caused inhibition of [14C]leucine incorporation into proteins proportionally to its concentration. To establish a precise mechanism of inhibition, we evaluated the effect of the bisamidine 1 on the isolated ribosomes and purified to homogeneity elongation factors. Preincubation of the bisamidine 1 with ribosomes resulted in partial inhibition of their activity in whole elongation system. The eucaryotic elongation factor 1 (eEF-1) was not significantly affected by the bisamidine 1. In contrast to eEF-1, the bisamidine 1 preincubated with the eucaryotic elongation factor 2 (eEF-2) caused total inhibition of its activity in the translocation process. The inhibitory effect of the bisamidine 1 on eEF-2 activity was confirmed in diphtheria toxin-dependent ADP-ribosylation reaction. The results suggest a high action specificity of the bisamidine 1 as potential anticancer drug, since the primary target seems to be highly conserved protein-elongation factor 2.

A series of carbocyclic analogues of netropsin were synthesized and evaluated for their capacity to inhibit human topoisomerases I and II in vitro. The compounds are oligopeptides containing 1,4-di- and 1,2,5-trisubstituted benzene rings and unsubstituted N-terminal NH2 groups. Compounds 4-7 consist of two netropsin-like units linked by aliphatic (tetra- and hexamethylene) chains. In the topoisomerase I and II assay, the relaxation of pBR322 plasmid was inhibited by compounds 4-7 at 100 microM concentration.

Simple Summary: Breast cancer is one of the most frequent tumors worldwide, based on the number of new cases and deaths. Unfortunately, the low selectivity of action and the rapid development of multiple drug resistances remain the main disadvantages of anticancer compounds. The search for new agents with pronounced antitumor activity is an urgent task in modern biology and medicine. We focused on the investigation of the antitumor potential of novel hybrid pyrrolidinedione–thiazolidinone derivatives. The synthesized derivatives are effective and selective agents that exhibit their antitumor effects in breast carcinoma cells via (1) inhibiting viability, proliferation, and the ability to form colonies; (2) inducing extrinsic and intrinsic apoptotic pathways; and (3) decreasing the level of proteins associated with autophagy, invasion, and metastasis. Our results indicate that synthesized derivatives are potential candidates for deeper exploration of their therapeutic efficiency. The development of new, effective agents for the treatment of breast cancer remains a high-priority task in oncology. A strategy of treatment for this pathology depends significantly on the genotype and phenotype of human breast cancer cells. We aimed to investigate the antitumor activity of new pyrrolidinedione–thiazolidinone hybrid molecules Les-6287, Les-6294, and Les-6328 towards different types of human breast cancer cells of MDA-MB-231, MCF-7, T-47D, and HCC1954 lines and murine breast cancer 4T1 cells by using the MTT, clonogenic and [3H]-Thymidine incorporation assays, flow cytometry, ELISA, and qPCR. The studied hybrids possessed toxicity towards the mentioned tumor cells, with the IC50 ranging from 1.37 to 21.85 µM. Simultaneously, these derivatives showed low toxicity towards the pseudonormal human breast epithelial cells of the MCF-10A line (IC50 > 93.01 µM). Les-6287 at 1 µM fully inhibited the formation of colonies of the MCF-7, MDA-MB-231, and HCC1954 cells, while Les-6294 and Les-6328 did that at 2.5 and 5 µM, respectively. Les-6287 suppressed DNA biosynthesis in the MCF-7, MDA-MB-231, and HCC1954 cells. At the same time, such an effect on the MCF-10A cells was significantly lower. Les-6287 induces apoptosis using extrinsic and intrinsic pathways via a decrease in the mitochondrial membrane potential, increasing the activity of caspases 3/7, 8, 9, and 10 in all immunohistochemically different human breast cancer cells. Les-6287 decreased the concentration of the metastasis- and invasion-related proteins MMP-2, MMP-9, and ICAM-1. It did not induce autophagy in treated cells. In conclusion, the results of our study suggest that the synthesized hybrid pyrrolidinedione–thiazolidinones might be promising agents for treating breast tumors of different types. [ABSTRACT FROM AUTHOR]

Combining chemotherapy with immunotherapy still remains a regimen in anticancer therapy. Novel 4-thiazolidinone-bearing hybrid molecules possess well-documented anticancer activity, and together with anti-HER2 antibodies, may represent a promising strategy in treating patients with gastric cancer with confirmed human epidermal growth factor receptor 2 (HER2) expression. The aim of the study was to synthesize a new 4-thiazolidinone derivative (Les-4367) and investigate its molecular mechanism of action in combination with trastuzumab or pertuzumab in human AGS gastric cancer cells. AGS cell viability and antiproliferative potential were examined. The effect of the tested combinations as well as monotherapy on apoptosis and autophagy was also determined. Metalloproteinase-2 (MMP-2), intercellular adhesion molecule 1 (ICAM-1), pro-inflammatory and anti-inflammatory cytokine concentrations were also demonstrated by the ELISA technique. We proved that pertuzumab and trastuzumab were very effective in increasing the sensitivity of AGS gastric cancer cells to novel Les-4367. The molecular mechanism of action of the tested combination is connected with the induction of apoptosis. Additionally, the anticancer activity is not associated with the autophagy process. Decreased concentrations of pro-inflammatory cytokines, MMP-2 and ICAM-1—were observed. The novel combination of drugs based on anti-HER2 antibodies with Les-4367 is a promising strategy against AGS gastric cancer cells. [ABSTRACT FROM AUTHOR]

Simple Summary: Breast cancer ranks at the forefront of all malignancies worldwide, and the numerous incidences and mortality rate associated with it are very burdensome to the health care system. Consequently, there is a constant need for new effective drugs with anticancer activity. There have been reports of highly cytotoxic effects of selenium compounds against cancer cells for some time. Hence, our team decided to evaluate the anticancer activity of novel selenoesters in MCF-7 and MDA-MB-231 breast cancer cells. Our results reveal that these compounds are cytotoxic at very low micromolar concentrations, which is associated with the induction of apoptosis and autophagy and arrest of breast cancer cells in the S or G2/M phase of the cell cycle. The obtained results are promising and show that selenium-containing compounds are worth more attention, as they show considerable potential for future candidates as anticancer agents. Disturbing cancer statistics, especially for breast cancer, are becoming a rationale for the development of new anticancer therapies. For the past several years, studies have been proving a greater role of selenium in the chemoprevention of many cancers than previously considered; hence, a trend to develop compounds containing this element as potential agents with anticancer activity has been set for some time. Therefore, our study aimed to evaluate the anticancer activity of novel selenoesters (EDA-71, E-NS-4) in MCF-7 and MDA-MB-231 human breast cancer cells. The assays evaluating proliferation and cell viability, and flow cytometer analysis of apoptosis/autophagy induction, changes in mitochondrial membrane potential, disruption of cell cycle phases, and protein activity of mTOR, NF-κB, cyclin E1/A2, and caspases 3/7, 8, 9, 10 were performed. The obtained results indicate that the tested selenoesters are highly cytotoxic and exhibit antiproliferative activity at low micromolar doses (<5 µM) compared with cisplatin. The most active compound—EDA-71—highly induces apoptosis, which proceeds via both pathways, as evidenced by the activation of all tested caspases. Furthermore, we observed the occurrence of autophagy (↓ mTOR levels) and cell cycle arrest in the S or G2/M phase (↓ cyclin E1, ↑ cyclin A2). [ABSTRACT FROM AUTHOR]