The Affinity of Carboplatin to B-Vitamins and Nucleobases

Targeted Therapy with Cisplatin-Loaded Calcium Citrate Nanoparticles Conjugated with Epidermal Growth Factor for Lung Cancer Treatment

Lung cancer is the leading cause of cancer-related deaths worldwide with high incidence rates for new cases. Conventional cisplatin (CDDP) therapy has limitations due to severe side effects from nonspecific targeting. To address this challenge, nanomedicine offers targeted therapies. In this study, cisplatin-loaded calcium citrate nanoparticles conjugated with epidermal growth factor (CaCit@CDDP-EGF NPs) were synthesized. The resulting nanodrug had a size below 350 nm with a cation charge. Based on density functional theory (DFT), the CaCit@CDDP NP model containing two citrates substituted on two chlorides exhibited a favorable binding energy of -5.42 eV, and the calculated spectrum at 261 nm closely matched the experimental data. CaCit@CDDP-EGF NPs showed higher inhibition rates against EGFR-expressed and mutant carcinoma cells compared to those of cisplatin while displaying lower cytotoxicity to lung fibroblast cells. Integrating in vitro experiments with in silico studies, these nanoparticles hold promise as a novel nanomedicine for targeted therapy in clinical applications.

Research progress of small-molecule drugs in targeting telomerase in human cancer and aging

Telomeres are unique structures located at the ends of linear chromosomes, responsible for stabilizing chromosomal structures. They are synthesized by telomerase, a reverse transcriptase ribonucleoprotein complex. Telomerase activity is generally absent in human somatic cells, except in stem cells and germ cells. Every time a cell divides, the telomere sequence is shortened, eventually leading to replicative senescence and cell apoptosis when the telomeres reach a critical limit. However, most human cancer cells exhibit increased telomerase activity, allowing them to divide continuously. The importance of telomerase in cancer and aging has made developing drugs targeting telomerase a focus of research. Such drugs can inhibit cancer cell growth and delay aging by enhancing telomerase activity in telomere-related syndromes or diseases. This review provides an overview of telomeres, telomerase, and their regulation in cancer and aging, and highlights small-molecule drugs targeting telomerase in these fields.

Will the Interactions of Some Platinum (II)-Based Drugs with B-Vitamins Reduce Their Therapeutic Effect in Cancer Patients? Comparison of Chemotherapeutic Agents such as Cisplatin, Carboplatin and Oxaliplatin-A Review

Pt (II) derivatives show anti-cancer activity by interacting with nucleobases of DNA, thus causing some spontaneous and non-spontaneous reactions. As a result, mono- and diaqua products are formed which further undergo complexation with guanine or adenine. Consequently, many processes are triggered, which lead to the death of the cancer cell. The theoretical and experimental studies confirm that such types of interactions can also occur with other chemical compounds. The vitamins from B group have a similar structure to the nucleobases of DNA and have aromatic rings with single-pair orbitals. Theoretical and experimental studies were performed to describe the interactions of B vitamins with Pt (II) derivatives such as cisplatin, oxaliplatin and carboplatin. The obtained results were compared with the values for guanine. Two levels of simulations were implemented at the theoretical level, namely, B3LYP/6-31G(d,p) with LANL2DZ bases set for platinum atoms and MN15/def2-TZVP. The polarizable continuum model (IEF-PCM preparation) and water as a solvent were used. UV-Vis spectroscopy was used to describe the drug-nucleobase and drug-B vitamin interactions. Values of the free energy (ΔG_r) show spontaneous reactions with mono- and diaqua derivatives of cisplatin and oxaliplatin; however, interactions with diaqua derivatives are more preferable. The strength of these interactions was also compared. Carboplatin products have the weakest interaction with the studied structures. The presence of non-covalent interactions was demonstrated in the tested complexes. A good agreement between theory and experiment was also demonstrated.

G-Protein-Coupled Receptors Mediate Modulations of Cell Viability and Drug Sensitivity by Aberrantly Expressed Recoverin 3 within A549 Cells

To elucidate the currently unknown molecular mechanisms responsible for the aberrant expression of recoverin (Rec) within cancerous cells, we examined two-dimensional (2D) and three-dimensional (3D) cultures of Rec-negative lung adenocarcinoma A549 cells which had been transfected with a plasmid containing human recoverin cDNA (A549 Rec) or an empty plasmid as a mock control (A549 MOCK). Using these cells, we measured cytotoxicity by several anti-tumor agents (2D), cellular metabolism including mitochondrial and glycolytic functions by a Seahorse bio-analyzer (2D), the physical properties, size and stiffness of the 3D spheroids, trypsin sensitivities (2D and 3D), and RNA sequencing analysis (2D). Compared with the A549 MOCK, the A549 Rec cells showed (1) more sensitivity toward anti-tumor agents (2D) and a 0.25% solution of trypsin (3D); (2) a metabolic shift from glycolysis to oxidative phosphorylation; and (3) the formation of larger and stiffer 3D spheroids. RNA sequencing analysis and bioinformatic analyses of the differentially expressed genes (DEGs) using Gene Ontology (GO) enrichment analysis suggested that aberrantly expressed Rec is most likely associated with several canonical pathways including G-protein-coupled receptor (GPCR)-mediated signaling and signaling by the cAMP response element binding protein (CREB). The findings reported here indicate that the aberrantly expressed Rec-induced modulation of the cell viability and drug sensitivity may be GPCR mediated.

Carboplatin Niosomal Nanoplatform for Potentiated Chemotherapy

This study aimed to characterize a stable nano-niosome formulation, which could reduce the adverse effects of carboplatin (CB) and improve its therapeutic efficacy in the treatment of breast cancer. For this purpose, CB-loaded polyethylene glycol (PEG)ylated niosome nanoparticles (PEG-NS-CB) were synthesized using the reverse-phase evaporation method. PEG-NS-CB (226.0 ± 10.6 nm) could release CB in a controlled manner and, compared to CB and CB-loaded non-PEGylated niosome (NS-CB), caused higher cytotoxicity effects against mouse breast cancer 4T1 cells (IC₅₀: 83.4, 26.6, and 22.5 µM for CB, NS-CB, and PEG-NS-CB, respectively). Also, PEG-NS-CB demonstrated higher stability, in which its profile of drug release, cytotoxicity, and LE% did not change significantly three months after preparation compared to those at the production time. In addition, the in vivo results demonstrated that PEG-NS-CB caused higher therapeutic (the number of alive mice: 12, 15, and 17 out of 20 in CB, NS-CB, and PEG-NS-CB receiver groups, respectively) and less toxicity effects (weight loss of 17, 12.5, and 10% in CB, NS-CB, and PEG-NS-CB receiver groups, respectively), compared to NS-CB and CB in breast cancer-bearing mice. Overall, the results of this study suggest that PEG-NS-CB could be a promising formulation for the treatment of breast cancer.

Affinities to Oxaliplatin: Vitamins from B Group vs. Nucleobases

Oxaliplatin, similar to Cisplatin, exhibits anticancer activity by interacting with DNA and inducing programmed cell death. It is biotransformed through a number of spontaneous and non-enzymatic processes. In this way, several transient reactive species are formed, including dichloro-, monochloro-, and diaqua-DACH platin, which can complex with DNA and other macromolecules. The molecular level suggests that such interactions can also take place with vitamins containing aromatic rings with lone pair orbitals. Theoretical and experimental studies were performed to investigate interactions of vitamins from the B group with Oxaliplatin, and the results were compared with values characterizing native purines. Quantum-chemical simulations were carried out at the B3LYP/6-31G(d,p) level, with the LANL2DZ basis set representing atomic orbitals of platinum atom, and at the MN15/def2-TZVP levels of theory with the use of Polarizable Continuum Model (IEF-PCM formulation) and water as a solvent. Additionally, time-dependent density functional theory (TD-DFT) was employed to study molecular properties in the electronic excited state. Interactions of vitamins and Oxaliplatin were investigated using UV-Vis spectroscopy. Values of the free energy (ΔG_r) indicate spontaneous reactions with monoaqua [PtH₂OClDACH]⁺ and diaqua [Pt(H₂O)₂DACH]²⁺ derivatives of Oxaliplatin. However, diaqua derivatives were found to be preferable. The free energy (ΔG_r) values obtained for vitamins from the B group indicate lower affinity of Oxaliplatin compared with values characterizing complexes formed by guanine, adenine, and cytosine. The exception is the monoaqua form of vitamin B1 (thiamine) at the MN15/def2-TZVP levels of calculations. An application of atoms in molecules (AIM) theory revealed non-covalent interactions present in the complexes studied. The comparison of computed and experimental spectroscopic properties showed a good agreement.