Cisplatin fastens chromatin irreversibly even at a high chloride concentration

Neuroprotective Effects of Trimetazidine against Cisplatin-Induced Peripheral Neuropathy: Involvement of AMPK-Mediated PI3K/mTOR, Nrf2, and NF-κB Signaling Axes

Cisplatin-induced peripheral neuropathy (CIPN) is a common and debilitating side effect of cisplatin chemotherapy used in cancer treatment. This study explored the neuroprotective effects of Trimetazidine (TRI) against CIPN by preserving nerve integrity, reducing neuro-oxidative stress, and alleviating neuroinflammation. Using a rat model of CIPN, we evaluated TRI's impact on motor coordination, pain sensitivity, and peripheral nerve histopathology. Also, its effects on neuro-oxidative stress and neuroinflammatory markers were assessed. The findings showed that rats with CIPN had worse motor coordination and increased sensitivity to pain but that these symptoms were alleviated by TRI therapy in a dose-dependent way. Nerve conduction velocities were normalized, and expression of genes involved in neuropathy signaling was suppressed after TRI therapy. Antioxidant benefits were also shown in TRI, with oxidative damage being reduced and the cellular energy balance being restored. By inhibiting the production of inflammatory markers, it also demonstrated anti-inflammatory properties. Histopathological examination revealed that TRI, especially when administered at a higher dose, inhibited the degeneration and demyelination of nerve fibers. The anti-inflammatory properties of TRI in the sciatic nerves were further shown by the fact that its administration reduced iNOS expression. In conclusion, AMPK-mediated PI3K/mTOR, Nrf2, and NF-κB signaling pathways may all be involved in the therapeutic benefits of TRI for CIPN. These results indicate that TRI may be useful for reducing the side effects of CIPN and enhancing patient outcomes during cisplatin chemotherapy.

Evidence of direct interaction between cisplatin and the caspase-cleaved prostate apoptosis response-4 tumor suppressor

Prostate apoptosis response-4 (Par-4) tumor suppressor protein has gained attention as a potential therapeutic target owing to its unique ability to selectively induce apoptosis in cancer cells, sensitize them to chemotherapy and radiotherapy, and mitigate drug resistance. It has recently been reported that Par-4 interacts synergistically with cisplatin, a widely used anticancer drug. However, the mechanistic details underlying this relationship remain elusive. In this investigation, we employed an array of biophysical techniques, including circular dichroism spectroscopy, dynamic light scattering, and UV-vis absorption spectroscopy, to characterize the interaction between the active caspase-cleaved Par-4 (cl-Par-4) fragment and cisplatin. Additionally, elemental analysis was conducted to quantitatively assess the binding of cisplatin to the protein, utilizing inductively coupled plasma-optical emission spectroscopy and atomic absorption spectroscopy. Our findings provide evidence of direct interaction between cl-Par-4 and cisplatin, and reveal a binding stoichiometry of 1:1. This result provides insights that could be useful in enhancing the efficacy of cisplatin-based and tumor suppressor-based cancer therapies.

Discovery of cisplatin-binding proteins by competitive cysteinome profiling

Cisplatin is a widely used cancer metallodrug that induces cytotoxicity by targeting DNA and chelating cysteines in proteins. Here we applied a competitive activity-based protein profiling strategy to identify cisplatin-binding cysteines in cancer proteomes. A novel cisplatin target, MetAP1, was identified and functionally validated to contribute to cisplatin's cytotoxicity.

Revisiting the Anti-Cancer Toxicity of Clinically Approved Platinating Derivatives

Cisplatin (CDDP), carboplatin (CP), and oxaliplatin (OXP) are three platinating agents clinically approved worldwide for use against a variety of cancers. They are canonically known as DNA damage inducers; however, that is only one of their mechanisms of cytotoxicity. CDDP mediates its effects through DNA damage-induced transcription inhibition and apoptotic signalling. In addition, CDDP targets the endoplasmic reticulum (ER) to induce ER stress, the mitochondria via mitochondrial DNA damage leading to ROS production, and the plasma membrane and cytoskeletal components. CP acts in a similar fashion to CDDP by inducing DNA damage, mitochondrial damage, and ER stress. Additionally, CP is also able to upregulate micro-RNA activity, enhancing intrinsic apoptosis. OXP, on the other hand, at first induces damage to all the same targets as CDDP and CP, yet it is also capable of inducing immunogenic cell death via ER stress and can decrease ribosome biogenesis through its nucleolar effects. In this comprehensive review, we provide detailed mechanisms of action for the three platinating agents, going beyond their nuclear effects to include their cytoplasmic impact within cancer cells. In addition, we cover their current clinical use and limitations, including side effects and mechanisms of resistance.

Mechanisms supporting aminoadenine-based viral DNA genomes

Bacteriophage genomes are the richest source of modified nucleobases of any life form. Of these, 2,6 diaminopurine, which pairs with thymine by forming three hydrogen bonds violates Watson and Crick's base pairing. 2,6 diaminopurine initially found in the cyanophage S-2L is more widespread than expected and has also been detected in phage infecting Gram-negative and Gram-positive bacteria. The biosynthetic pathway for aminoadenine containing DNA as well as the exclusion of adenine are now elucidated. This example of a natural deviation from the genetic code represents only one of the possibilities explored by nature and provides a proof of concept for the synthetic biology of non-canonical nucleic acids.