Design and synthesis of chromone-nitrogen mustard derivatives and evaluation of anti-breast cancer activity

Liposomal Encapsulation of Chlorambucil with a Terpyridine-Based, Glutathione-Targeted Optical Probe Facilitates Cell Entry and Cancer Cell Death

The nitrogen mustard alkylating agent chlorambucil (CBL) is a critical component of chemotherapeutic regimens used in the treatment of chronic lymphocytic leukemia. The cancer cell-killing actions of CBL are limited by glutathione (GSH) conjugation, a process catalyzed by the GSH transferase hGSTA1-1 that triggers CBL efflux from cells. In the cancer cell microenvironment, intracellular GSH levels are elevated to counterbalance oxidative stress generated due to the high glycolytic demand. As many chemotherapeutic drugs trigger cell death through mechanisms that depend on reactive oxygen species (ROS), antioxidant capacity in cancer cells also represents a barrier to anticancer therapies. Here, we demonstrate that a heightened GSH content in cancer cells can also be exploited for cell-selective drug delivery. We successfully synthesized a malononitrile conjugate terpyridine-based derivative L1, which specifically reacts with GSH in the presence of other biologically relevant amino acids including cysteine (Cys) and homocysteine (Hcy). The significant change in the electronic spectra of L1 in the presence of GSH confirmed GSH detection, which was further corroborated by density functional theory calculations. We next encapsulated CBL into L1-containing, anthracene-functionalized, and 10,12-pentacosadiynoic acid (PCDA)- and 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC)-based liposomes (Lip-CBL-L1). We established successful CBL encapsulation and release from L1-containing liposomes in GSH-enriched cancer cells in vitro. Both Lip-CBL-L1 and the L1-lacking Lip-CBL control displayed cell-killing activity. However, human triple-negative breast cancer cells MDAMB231, human lung cancer cells A549, and murine leukemic WEHI cells were more sensitive to the cytotoxic effects of Lip-CBL-L1 compared to the nonmalignant cells (AC16 and HEK293). Indeed, in these cancer cell lines, Lip-CBL-L1 induced greater ROS generation compared to that of Lip-CBL. Together, our results provide initial evidence of the feasibility of exploiting the unique oxidant environment of cancer cells for optimized drug delivery.

Exploring chromone-2-carboxamide derivatives for triple-negative breast cancer targeting EGFR, FGFR3, and VEGF pathways: Design, synthesis, and preclinical insights

Chromone-based compounds have established cytotoxic, antiproliferative, antimetastatic, and antiangiogenic effects on various cancer cell types via modulating different molecular targets. Herein, 17 novel chromone-2-carboxamide derivatives were synthesized and evaluated for their in vitro anticancer activity against 15 human cancer cell lines. Among the tested cell lines, MDA-MB-231, the triple-negative breast cancer cell line, was found to be the most sensitive, where the N-(2-furylmethylene) (15) and the α-methylated N-benzyl (17) derivatives demonstrated the highest growth inhibition with GI50 values of 14.8 and 17.1 μM, respectively. In vitro mechanistic studies confirmed the significant roles of compounds 15 and 17 in the induction of apoptosis and suppression of EGFR, FGFR3, and VEGF protein levels in MDA-MB-231 cancer cells. Moreover, compound 15 exerted cell cycle arrest at both the G0-G1 and G2-M phases. The in vivo efficacy of compound 15 as an antitumor agent was further investigated in female mice bearing Solid Ehrlich Carcinoma. Notably, administration of compound 15 resulted in a marked decrease in both tumor weight and volume, accompanied by improvements in biochemical, hematological, histological, and immunohistochemical parameters that verified the repression of both angiogenesis and inflammation as additional Anticancer mechanisms. Moreover, the binding interactions of compounds 15 and 17 within the binding sites of all three target receptors (EGFR, FGFR3, and VEGF) were clearly illustrated using molecular docking.

Tissue Engineering Scaffolds Loaded With a Variety of Plant Extracts: Novel Model in Breast Cancer Therapy

Despite recent improvements in detecting and managing breast cancer (BC), it continues to be a major worldwide health concern that annually affects millions of people. Exploring the anti-BC potentials of natural compounds has received a lot of scientific attention due to their multi-target mode of action and good safety profiles because of these unmet needs. Drugs made from herbs are secure and have a lot fewer negative effects than those made from synthetic materials. Early stage patients benefit from breast-conserving surgery, but the risk of local recurrence remains, necessitating implanted scaffolds. These scaffolds provide residual cancer cell killing and tailored drug delivery. This review looks at plant extract-infused tissue engineering scaffolds, which provide a novel approach to treating BC. By offering patient individualized, safer treatments, these scaffolds could completely change how BC is treated.

LCN2: Versatile players in breast cancer

Lipocalin 2 (LCN2) is a secreted glycoprotein that is produced by immune cells, including neutrophils and macrophages. It serves various functions such as transporting hydrophobic ligands across the cellular membrane, regulating immune responses, keeping iron balance, and fostering epithelial cell differentiation. LCN2 plays a crucial role in several physiological processes. LCN2 expression is upregulated in a variety of human diseases and cancers. High levels of LCN2 are specifically linked to breast cancer (BC) cell proliferation, apoptosis, invasion, migration, angiogenesis, immune regulation, chemotherapy resistance, and prognosis. As a result, LCN2 has gained attention as a potential therapeutic target for BC. This article offered an in-depth review of the advancement of LCN2 in the context of BC occurrence and development.

Synthesis, biological evaluation, and molecular docking study of chromen-linked hydrazine carbothioamides as potent α-glucosidase inhibitors

Inhibiting α-glucosidase is a reliable method for reducing blood sugar levels in diabetic individuals. Several novel chromen-linked hydrazine carbothioamide (3a-r) were designed and synthesized by condensation of chromone-3-carbaldehyde with a variety of substituted thiosemicarbazides. The structures of these new analogues were elucidated through various advanced spectroscopic techniques (1 H NMR, 13 C NMR, and ESI-MS). The resulted compounds were screened for α-glucosidase inhibitory potential and all the compounds (3a-r) exhibited potent inhibition of α-glucosidase with IC50 values ranging 0.29-53.70 µM. Among them compounds 3c, 3f, 3h, and 3r displayed the highest α-glucosidase inhibitor capability with IC50 values of 1.50, 1.28, 1.08, and 0.29 µM, respectively. Structure-activity relationship showed that different substituted groups are responsible for the variation in the α-glucosidase inhibition. The kinetics studies of the most active inhibitor (3r) were performed, to investigate the mode of inhibition and dissociation constants (Ki), that indicated a competitive inhibitor with Ki value of 1.47 ± 0.31 µM. Furthermore, molecular docking studies was performed to reveal the possible interactions, such as H-bonding, or π-π stacking, with the key residues of α-glucosidase. Docking analysis revealed the importance of hydrazine carbothioamide moiety of compounds in the attachment of ligands with the crucial residues of α-glucosidase. The estimated pharmacokinetic, physicochemical, and drug likeness properties of compounds 3a-r reflects that these molecules have acceptable range of these properties.

Hybrid Molecules of Benzylguanidine and the Alkylating Group of Melphalan: Synthesis and Effects on Neuroblastoma Cells

The therapy of neuroblastoma relies, amongst other things, on administering chemotherapeutics and radioactive compounds, e.g., the (meta-iodobenzyl)guanidine [¹³¹I]mIBG. For special applications (conditioning before stem cell transplantation), busulfan and melphalan (M) proved to be effective. However, both drugs are not used for normal chemotherapy in neuroblastoma because of their side effects. The alkylating drug melphalan contains a (Cl-CH₂-CH₂-)₂N- group in the para-position of the phenyl moiety of the essential amino acid phenylalanine (Phe) and can, therefore, be taken up by virtually all kinds of cells by amino acid transporters. In contrast, mIBG isotopologs are taken up more selectively by neuroblastoma cells via the noradrenaline transporter (NAT). The present study aimed at synthesising and studying hybrid molecules of benzylguanidine (BG) and the alkylating motif of M. Such hybrids should combine the preferential uptake of BGs into neuroblastoma cells with the cytotoxicity of M. Besides the hybrid of BG with the dialkylating group (Cl-CH₂-CH₂-)₂N- bound in the para-position as in M (pMBG), we also synthesised mMBG, which is BG meta-substituted by a (Cl-CH₂-CH₂-)₂N- group. Furthermore, two monoalkylating hybrid molecules were synthesised: the BG para-substituted by a (Cl-CH₂-CH₂-)NH- group (pM*BG) and the BG meta-substituted by a (Cl-CH₂-CH₂-)NH- group (mM*BG). The effects of the four new compounds were studied with human neuroblastoma cell lines (SK-N-SH, Kelly, and LS) with regard to uptake, viability, and proliferation by standard test systems. The dialkylating hybrid molecules pMBG and mMBG were at least as effective as M, whereas the monoalkylating hybrid molecules pM*BG and mM*BG were more effective than M. Considering the preferred uptake via the noradrenaline transporter by neuroblastoma cells, we conclude that they might be well suited for therapy.

Antitumor activity and mechanisms of dual EGFR/DNA-targeting strategy for the treatment of lung cancer with EGFRL858R/T790M mutation

Dual- or multi-targeted EGFR inhibitors as single drugs can overcome EGFR inhibitor resistance and circumvent many disadvantages of combination therapy. In this work, fifteen 4-anilinoquinazoline derivatives bearing nitrogen mustard or hemi mustard moieties were designed and synthesized as dual EGFR-DNA targeting anticancer agents. Structures of target molecules were confirmed by ¹H NMR, ¹³C NMR and HR-MS, and evaluated for their in vitro anti-proliferative activities using MTT assay. Compound 6g emerged as the most potent derivative against mutant-type H1975 cells with IC₅₀ value of 1.45 μM, which exhibited 4-fold stronger potency than Chl/Gef (equimolar combination of chlorambucil and gefitinib). Kinase inhibition studies indicated that 6g showed excellent inhibitory effect on EGFR^L858R/T790M enzyme, which was 8.6 times more effective than gefitinib. Mechanistic studies indicated that 6g induced apoptosis of H1975 cells in a dose-dependent manner and caused DNA damage. Importantly, 6g could significantly inhibit the expression of p-EGFR and its downstream p-AKT and p-ERK in H1975 cells. Molecular docking was also performed to gain insights into the ligand-binding interactions of 6g inside EGFR^WT and EGFR^L858R/T790M binding sites. Moreover, 6g efficiently inhibited tumor growth in the H1975 xenograft model without side effects.

Silver-catalysed three-component reactions of alkynyl aryl ketones, element selenium, and boronic acids leading to 3-organoselenylchromones

An Ag-catalysed three-component reaction of alkynyl aryl ketones bearing an ortho-methoxy group, element selenium, and arylboronic acid, providing a facile route to selenofunctionalized chromone products has been developed. This protocol features high efficiency and high regioselectivity, and the use of selenium powder as the selenium source. Mechanistic experiments indicated that the combined oxidative effect of (bis(trifluoroacetoxy)iodo)benzene and oxygen in the air pushes the catalytic redox cycle of the Ag catalyst and the phenylselenium trifluoroacetate formed in situ is the key intermediate of the PIFA-mediated 6-endo-electrophilic cyclization and selenofunctionalization reaction of alkynyl aryl ketones.

Marine-Derived Stichloroside C2 Inhibits Epithelial–Mesenchymal Transition and Induces Apoptosis through the Mitogen-Activated Protein Kinase Signalling Pathway in Triple-Negative Breast Cancer Cells

Background

Triterpenoid saponins from sea cucumbers exhibit significant antitumour, antifungal, and antibacterial activities. However, the associated molecular mechanisms have yet to be elucidated. In this study, we screened and explored the antitumour activity and underlying mechanisms of triterpenoid saponins isolated from Thelenota ananas.

Methods

We isolated and purified sea cucumber saponins, determined their chemical structures, and confirmed their function in vitro. We also screened and explored the antitumour activity and underlying mechanisms of triterpenoid saponins isolated from Thelenota ananas.

Results

Four saponins were discovered from sea cucumber Thelenota ananas collected from the South China Sea. We found that stichloroside C2 (STC2) inhibited the proliferation and clonogenesis of the human triple-negative breast cancer (TNBC) cell line MDA-MB-231 and mouse TNBC cell line 4 T1 in a dose-dependent manner and induced apoptosis and cycle arrest in these two TNBC cell lines. STC2 induced DNA damage in two TNBC cell lines and significantly increased the protein expression level of the DNA double-strand break marker γ-H2AX. STC2 downregulated the protein expression levels of phosphorylated cyclin-dependent kinase 1 (CDK1), cyclin B1, CDK2, and cyclin A2 in MDA-MB-231 and 4 T1 cells. STC2 upregulated Bax and cleaved PARP protein expression in two types of breast cancer cells. In addition, STC2 promoted E-cadherin expression; inhibited vimentin expression; upregulated the phosphorylation levels of the mitogen-activated protein kinase (MAPK) signalling pathway-related proteins p38, JNK, and ERK1/2; and downregulated Akt phosphorylation.

Conclusions

STC2 exerts anti-TNBC activity, inhibits epithelial–mesenchymal transition (EMT), and induces apoptosis by regulating the cell cycle, EMT-related proteins, and MAPK signalling pathway.