In recent yearsjajajj, peptide-based therapeutics have attracted increasing interest as a potential approach to cancer treatment. Peptides are characterized by high specificity and low cytotoxicity, but they cannot be considered universal drugs for all types of cancer. Of the numerous anticancer-reported peptides, both natural and synthetic, only a few have reached clinical applications. However, in most cases, the mechanism behind the anticancer activity of the peptide is not fully understood. For this reason, in this work, we investigated the effect of the novel peptide ∆M4, which has documented anticancer activity, on two human skin cancer cell lines. A novel approach to studying the potential induction of apoptosis by anticancer peptides is the use of protein microarrays. The results of the apoptosis protein study demonstrated that both cell types, skin malignant melanoma (A375) and epidermoid carcinoma (A431), exhibited markers associated with apoptosis and cellular response to oxidative stress. Additionally, ∆M4 induced concentration- and time-dependent moderate ROS production, triggering a defensive response from the cells, which showed decreased activation of cytoplasmic superoxide dismutase. However, the studied cells exhibited a differential response in catalase activity, with A375 cells showing greater resistance to the peptide action, possibly mediated by the Nrf2 pathway. Nevertheless, both cell types showed moderate activity of caspases 3/7, suggesting that they may undergo partial apoptosis, although another pathway of programmed death cannot be excluded. Extended analysis of the mechanisms of action of anticancer peptides may help determine their effectiveness in overcoming chemoresistance in cancerous cells.

Background: Autopolyploids generally exhibit larger phenotypes than their progenitors, suggesting higher biomass and enhanced phytoremediation potential. This study tested this hypothesis using a previously uncharacterized, novel artificial autooctaploid of a Zn- and Cd-tolerant ecotype of Arabidopsis arenosa , derived from a natural tetraploid cytotype. Vegetative development, metal tolerance, and accumulation capacity were compared between the parental tetraploids and the derived autooctaploids under controlled laboratory conditions. Results: During the intermediate growth period (days 56–72), octaploid plants had significantly lower biomass than tetraploids, but this difference was no longer significant by day 84. This transient difference coincided with the earlier entry of octaploids into the generative phase. Despite their autopolyploid origin, the octaploid specimens were fully fertile, enabling sexual reproduction via seeds. They could also be propagated using encapsulated vegetative tissues (artificial seeds). Under extreme heavy metal stress (8 mM Zn and/or 0.2 mM Cd for 9 days), octaploids showed a significantly higher Zn concentration in their roots than tetraploids, while both cytotypes exhibited similar overall resilience to metal toxicity. Conclusions: The autooctaploids demonstrate significant potential for land reclamation due to their ability to tolerate and sequester extreme concentrations of zinc and cadmium without visible signs of toxicity. Under the controlled conditions used here, octaploids showed a > 50% higher Zn concentration in roots than tetraploids, whereas shoot Zn concentrations did not differ, supporting potential for phytostabilisation rather than enhanced phytoextraction. The more rapid life cycle of octaploids may be relevant to future applications, but any advantage under field conditions remains to be tested.