(1) Background: Gastric cancer (GC) remains a major global health challenge due to its high heterogeneity and aggressive progression. The discovery of novel bioactive molecules with anticancer properties has, therefore, become a critical research focus. In this study, we synthesized and characterized 4,4′-(5,8-dioxa-2,11-diazadodecane-1,11-diene-1,12-diyl)diphenol (DODP) and evaluated its anticancer potential using molecular docking, bioinformatics, and experimental analyses. (2) Methods: The chemical structure of DODP was confirmed through ¹H and ¹³C NMR spectroscopy. Molecular docking was conducted to examine the interaction of DODP with apoptosis and cell cycle-related proteins (TP53, MDM2, and MYC) and the immune checkpoint marker CD274 (PD-L1). Cytotoxicity against AGS GC cells was determined using the MTT assay at concentrations ranging from 0.01 to 50 µM, and gene expression alterations were analyzed by quantitative polymerase chain reaction (qPCR) and bioinformatics evaluation. (3) Results: NMR data verified the successful synthesis of DODP. The docking results indicated strong binding affinity, especially with TP53 and CD274. DODP showed notable cytotoxicity after 72 h of exposure and induced upregulation of TP53, MYC, and CD274 and downregulation of MDM2 in AGS cells. Although the patterns were consistent with cell-based and bioinformatic analyses, significant discriminatory ability in blood samples was observed only for MYC (AUC = 0.651; p = 0.044). (4) Conclusions: DODP influenced apoptosis-associated transcriptional responses in GC, offering early mechanistic evidence that should be evaluated in more comprehensive biological models.

We herein report the determination of the cytotoxic activity and expression profiles of some DNA repair genes of newly synthesized azomethines in the gastric cancer cell line (AGS). The studied novel compounds were synthesized by a condensation reaction and received compounds were characterized by ¹H and ¹³C NMR spectroscopy methods. Furthermore, they were applied to the AGS cell line at eight different concentrations (0.1–50 µg/mL). Anticancer activities were determined using the MTT method. Expression levels of ATR, ERCC1, TOP2A, and ABCB1 genes were determined by the RT-PCR method. Biochemical parameters were also examined. The interaction of proteins with other proteins was investigated with the String v11 program. The IC50 values of compounds 1, 2, and 3 obtained after 72 h were 23.10, 8.93, and 1.58 µg/mL, respectively. The results demonstrate that the cytotoxic activity of compound 3 on AGS cancer cells is higher in comparison with other molecules. It was determined that the expression levels of ATR, TOP2A, and ABCB1 genes in compounds 1, 2, and 3 were decreased compared to the control group. In addition, it was determined that ERCC1 gene expression increased in compound 3, decreased in compound 2, and remained unchanged in compound 1 (p < 0.001). In AGS gastric cancer cells, a 64% decrease was detected for GST levels in compound 1, while a 38% decrease in GSH levels in compound 2. In addition, compounds 1–3 were examined at the molecular level with computational techniques and the docking studies revealed 4LN0 as a target protein.

(1) Background: This study evaluates the anticancer potential of a newly synthesized azomethine-based compound, 6,6′,5,8-Dioxa-2,11-diazadodeca-1,11-diene-1,12-diyl)bis(4-bromo-2-methoxyphenol) (B-134-0), against osteosarcoma (SAOS-2) cells, focusing on its effects on apoptosis and DNA-damage-related gene expression. (2) Methods: B-134-0 was synthesized via condensation and tested at eight concentrations (0.5–100 μg/mL) for 24, 48, and 72 h. Cytotoxicity was assessed through MTT assay, and gene expression levels of TP53, RAD51, BRCA2, CASP2, MYC, MDM2, CDKN1A, ERCC1, ATR, and PRKDC were quantified through qPCR using the ΔΔ_Ct method. Molecular docking and DFT analyses were performed to explore structural stability and protein interactions. (3) Results: B-134-0 exhibited strong time-dependent cytotoxicity (IC₅₀: 71.58, 54.36, and 12.59 μg/mL at 24, 48, and 72 h, respectively) and significantly modulated the expression of cell cycle and DNA-repair-associated genes. The compound notably downregulated TP53, RAD51, CASP2, MYC, and MDM2, while CDKN1A and BRCA2 showed relative upregulation, indicating activation of the DNA damage response. Docking results revealed strong binding affinity with BRCA2 and CDKN1A, consistent with experimental findings. (4) Conclusions: These results indicate that B-134-0 exhibits potent anticancer activity by modulating DDR and apoptosis pathways, with strong molecular stability, suggesting its promise as a therapeutic candidate for osteosarcoma.