The serine/threonine kinase, GSK-3, is a promising drug discovery target for treating multiple pathological disorders. Most GSK-3 inhibitors that were developed function as ATP competitive inhibitors, with typical limitations in specificity, safety and drug-induced resistance. In contrast, substrate competitive inhibitors (SCIs), are considered highly selective, and more suitable for clinical practice. The development of SCIs has been largely neglected in the past because the ambiguous, undefined nature of the substrate-binding site makes them difficult to design. In this study, we used our previously described structural models of GSK-3 bound to SCI peptides, to design a pharmacophore model and to virtually screen the “drug-like” Zinc database (~6.3 million compounds). We identified leading hits that interact with critical binding elements in the GSK-3 substrate binding site and are chemically distinct from known GSK-3 inhibitors. Accordingly, novel GSK-3 SCI compounds were designed and synthesized with IC₅₀ values of~1–4 μM. Biological activity of the SCI compound was confirmed in cells and in primary neurons that showed increased β-catenin levels and reduced tau phosphorylation in response to compound treatment. We have generated a new type of small molecule GSK-3 inhibitors and propose to use this strategy to further develop SCIs for other protein kinases.

With the increasing incidence and mortality rates, cancer remains a major health challenge in the world. Despite advances in therapies and clinical programs, the efficacy of anti-cancer drugs often fails to translate from pre-clinical models to patient clinical trials. To date, pre-clinical cancer models, including two-dimensional cell cultures and animal models, have limited versatility and accuracy in recapitulating the complexity of human cancer. To address these limitations, a growing focus has fostered the development of three-dimensional (3D) tumor models that closely resemble the in vivo tumor microenvironment and heterogeneity. Recent efforts have leveraged bioengineering technologies, such as biofabrication, to engineer new platforms that mimic healthy and diseased organs, aiming to overcome the shortcomings of conventional models, such as for musculoskeletal tissues. Notably, 3D bioprinting has emerged as a powerful tool in cancer research, offering precise control over cell and biomaterial deposition to fabricate architecturally complex and reproducible functional models. The following review underscores the urgent need for more accurate and relevant 3D tumor models, highlighting the advantages of the use of biofabrication approaches to engineer new biomimetics platforms. We provide an updated discussion on the role of bioengineering technologies in cancer research and modeling with particular focus on 3D bioprinting platforms, as well as a close view on biomaterial inks and 3D bioprinting technologies employed in cancer modeling. Further insights into the 3D bioprinting tissue-specific modeling panorama are presented in this paper, offering a comprehensive overview of the new possibilities for cancer study and drug discovery.

Ras proteins play a role in receptor-mediated signaling pathways and are activated after traumatic brain injury. S-trans-trans-farnesylthiosalicylic acid (FTS), a synthetic Ras inhibitor, acts primarily on the active, GTP-bound form of Ras and was shown to improve neurobehavioral outcome after closed head injury (CHI) in mice. To gain a better understanding of the neuroprotective mechanism of FTS, we used diffusion-weighted imaging (DWI) in a rat model of CHI. Apparent diffusion coefficients (ADC) and transverse relaxation times (T2) were measured in injured rat brains after treatment with vehicle or FTS (5 mg/kg). Neuroprotection by FTS was also assessed in terms of the neurological severity score. One week after injury, significantly better recovery was observed in the FTS-treated rats than in the controls (p = 0.0191). T2 analysis of the magnetic resonance images revealed no differences between the two groups. In contrast, they differed significantly in ADC, particularly at 24 h post-CHI (p < 0.05): in the vehicle-treated rats ADC had decreased to approximately 26% below baseline, whereas it had increased to about 10% above baseline in the FTS-treated rats. As the magnitude of ADC reduction is strongly linked to blood perfusion deficit, these results suggest that the neuroprotective mechanism of FTS might be related to an improvement in cerebral perfusion. We propose that FTS, which is currently being tested in humans for anti-cancer indications, should also be considered as a new strategy for the management of head injury.