Breast cancer is one of the leading causes of cancer-related mortality in women worldwide, highlighting the importance of effective therapies. This study evaluates the interaction between camptothecin, a potent anticancer agent, and two key receptors implicated in breast cancer progression: HER2 (human epidermal growth factor receptor 2) and EGFR (epidermal growth factor receptor), using molecular docking. The results reveal a stronger binding affinity between camptothecin and HER2 than EGFR, in contrast to neratinib, which demonstrated affinity exclusively for HER2. Camptothecin exhibits significant hydrophobic and pi-alkyl interactions with HER2, whereas its interactions with EGFR are primarily mediated by hydrogen bonds. Molecular dynamics (MD) simulations of the camptothecin-HER2 complex indicate stable binding, with minimal fluctuations observed over 100 nanoseconds, confirming the stability of the ligand–receptor interaction. Pharmacokinetic evaluations, based on Lipinski’s rule of five, demonstrate that camptothecin adheres to essential drug-likeness parameters, suggesting favorable bioavailability. Furthermore, the analysis comparing the pharmacological properties of camptothecin with other well-known anticancer compounds, such as neratinib, shows that camptothecin exhibited superior compliance with drug-likeness rules. Despite its low solubility, the binding stability and pharmacokinetic profile suggest its potential as an effective therapeutic agent for breast cancer, particularly when combined with drug delivery systems that enhance solubility. This work underscores the importance of receptor-specific ligand interactions in drug design and highlights the need for further studies into camptothecin’s clinical applications, especially in HER2-positive breast cancer treatment.

Protein arginine methyltransferase 5 (PRMT5) is an enzyme that produces monomethyl arginine (MMA) and symmetric dimethyl arginine (sDMA), post-translational modifications that regulate several cellular processes, including stage conversion in parasitic protozoans. Entamoeba histolytica, the etiologic agent of human amebiasis, has two stages in its life cycle, the trophozoite, which is the replicative form, and the cyst, corresponding to the infective phase. The study of the molecular mechanisms that regulate differentiation in this parasite has been overdue because of a lack of efficient protocols for in vitro encystment. For this reason, Entamoeba invadens, a parasite of reptiles, has been used as a differentiation model system for the genus. Here, we demonstrated the presence of sDMA in E. invadens, which increases during encystment, and identified the PRMT5 of this microorganism (EiPRMT5). In addition, we performed 3D modeling of this enzyme, as well as its molecular docking with the PRMT5 inhibitor EPZ015666, which predicted the affinity of the drug for the active site of the enzyme. In agreement with these findings, EPZ015666 reduced trophozoite viability and encystment. Therefore, EiPRMT5 is a potential target for inhibiting the spread of amebiasis.

Breast cancer remains among the leading causes of incidence and mortality worldwide. Consequently, identifying new treatments and strategies is of critical importance. Evidence indicates that camptothecin and its derivatives may exert anticancer effects in various cancer cell lines, including colon, lung, and ovarian cancers. However, their effects in breast cancer are not yet fully understood. Prior theoretical studies employing docking and molecular dynamics suggest that camptothecin could bind to the HER2 and EGFR receptors, which are overexpressed in breast cancer cells. Investigating interactions between novel molecules with affinity for membrane receptors overexpressed in breast cancer is important for developing personalized therapies and for advancing strategies to selectively target nanomaterials to these cells for diagnostic and therapeutic purposes. This study evaluated the in silico and in vitro effects of camptothecin on the MCF-7 and MDA-MB-231 breast cancer cell lines. Our results show significant inhibition of proliferation and reduced migration at 24, 48, and 72 h in both cell lines. The theoretical analysis indicates high affinity of camptothecin for receptors overexpressed in breast cancer compared with current treatments.

PRMT5 methyltranserase is an enzyme that produces monomethyl arginine (MMA) as well as symmetric dimethyl arginine (sDMA), posttranslational modifications that regulate several cellu-lar processes, including stage conversion in parasitic protozoa. Entamoeba histolytica, the etiologic agent of human amebiasis, has two stages in its life cycle, the trophozoite, which is the replicative form, and the cyst, corresponding to the infective phase. The study of the molecular mechanisms that regulate differentiation in this parasite has been overdue by the lack of efficient protocols for in vitro encystment. For this reason, Entamoeba invadens, a reptile parasite, has been used as a dif-ferentiation model system for the genus. Here, we demonstrated the presence of sDMA in E. in-vadens, which increases during encystment, and identified the PRMT5 protein of this microorgan-ism (EiPRMT5). In addition, we performed 3D modeling of this enzyme, as well as its molecular docking with the PRMT5 inhibitor EPZ015666, which predicted the affinity of the drug for the ac-tive site of the enzyme. In agreement, EPZ015666 reduced trophozoite viability and encystment. Therefore, EiPRMT5 is a potential target for the inhibition of amebiasis spread.