Targeting mutant p53 stabilization for cancer therapy

Knockdown of TFAP2E results in rapid G2/M transition in oral squamous cell carcinoma cells

TFAP2E is a member of the activator protein-2 transcription factor family and acts as a tumor suppressor in several types of cancer. Downregulation of TFAP2E expression is significantly associated with a shorter overall survival period in patients with oral squamous cell carcinoma (OSCC). To evaluate the molecular mechanisms by which TFAP2E suppresses the development or progression of OSCC, the present study investigated the effects of TFAP2E downregulation on OSCC-derived Ca9-22 and HSC-4 cells. The present study demonstrated that small interfering RNA mediated-knockdown of TFAP2E accelerated the proliferation of these OSCC cell lines compared with that in the control group, as determined by the standard water-soluble tetrazolium salt-8 assay. To analyze the cell cycle progression rate, the cell cycle distribution patterns of TFAP2E-knockdown and control cells cultured in the presence of nocodazole, which prevents the completion of mitosis, were analyzed by fluorescence-activated cell sorting at different time points. When analyzing cellular DNA contents, no major differences in cell cycle profiles were observed; however, the rate of increase in cells positive for histone H3 Serine 28 phosphorylation, a standard molecular marker of early M phase, was significantly higher in TFAP2E-knockdown cells than in the control cells. Collectively, these results suggested that TFAP2E may attenuate the proliferation of OSCC cells by regulating G2/M transition.

Understanding the prion-like behavior of mutant p53 proteins in triple-negative breast cancer pathogenesis: The current therapeutic strategies and future directions

Breast cancer (BC) is viewed as a significant public health issue and is the primary cause of cancer-related deaths among women worldwide. Triple-negative breast cancer (TNBC) is a particularly aggressive subtype that predominantly affects young premenopausal women. The tumor suppressor p53 playsa vital role in the cellular response to DNA damage, and its loss or mutations are commonly present in many cancers, including BC. Recent evidence suggests that mutant p53 proteins can aggregate and form prion-like structures, which may contribute to the pathogenesis of different types of malignancies, such as BC. This review provides an overview of BC molecular subtypes, the epidemiology of TNBC, and the role of p53 in BC development. We also discuss the potential implications of prion-like aggregation in BC and highlight future research directions. Moreover, a comprehensive analysis of the current therapeutic approaches targeting p53 aggregates in BC treatment is presented. Strategies including small molecules, chaperone inhibitors, immunotherapy, CRISPR-Cas9, and siRNA are discussed, along with their potential benefits and drawbacks. The use of these approaches to inhibit p53 aggregation and degradation represents a promising target for cancer therapy. Future investigations into the efficacy of these approaches against various p53 mutations or binding to non-p53 proteins should be conducted to develop more effective and personalized therapies for BC treatment.

Mechanistic Aspects of Biphenyl Urea-Based Analogues in Triple-Negative Breast Cancer Cell Lines

Triple-negative breast cancer (TNBC) poses significant challenges due to its aggressive nature and limited treatment options. In this study, we investigated the impact of urea-based compounds on TNBC cells to uncover their mechanisms of action and therapeutic potential. Notably, polypharmacology urea analogues were found to work via p53-related pathways, and their cytotoxic effects were amplified by the modulation of oxidative phosphorylation pathways in the mitochondria of cancer cells. Specifically, compound 1 demonstrated an uncoupling effect on adenosine triphosphate (ATP) synthesis, leading to a time- and concentration-dependent shift toward glycolysis-based ATP production in MDA-MB-231 cells. At the same time, no significant changes in ATP synthesis were observed in noncancerous MCF10A cells. Moreover, the unique combination of mitochondrial- and p53-related effects leads to a higher cytotoxicity of urea analogues in cancer cells. Notably, the majority of tested clinical agents, but sorafenib, showed significantly higher toxicity in MCF10A cells. To test our hypothesis of sensitizing cancer cells to the treatment via modulation of mitochondrial health, we explored the combinatorial effects of urea-based analogues with established chemotherapeutic agents commonly used in TNBC treatment. Synergistic effects were evident in most tested combinations in TNBC cell lines, while noncancerous MCF10A cells exhibited higher resistance to these combination treatments. The combination of compound 1 with SN38 displayed nearly 60-fold selectivity toward TNBC cells over MCF10A cells. Encouragingly, combinations involving compound 1 restored the sensitivity of TNBC cells to cisplatin. In conclusion, our study provides valuable insights into the mechanisms of action of urea-based compounds in TNBC cells. The observed induction of mitochondrial membrane depolarization, inhibition of superoxide dismutase activity, disruption of ATP synthesis, and cell-line-specific responses contribute to their cytotoxic effects. Additionally, we demonstrated the synergistic potential of compound 1 to enhance the efficacy of existing TNBC treatments. However, the therapeutic potential and underlying molecular mechanisms of urea-based analogues in TNBC cell lines require further exploration.

Role of m6A modification in regulating the PI3K/AKT signaling pathway in cancer

The phosphoinositide 3-kinase (PI3K)/AKT signaling pathway plays a crucial role in the pathogenesis of cancer. The dysregulation of this pathway has been linked to the development and initiation of various types of cancer. Recently, epigenetic modifications, particularly N6-methyladenosine (m6A), have been recognized as essential contributors to mRNA-related biological processes and translation. The abnormal expression of m6A modification enzymes has been associated with oncogenesis, tumor progression, and drug resistance. Here, we review the role of m6A modification in regulating the PI3K/AKT pathway in cancer and its implications in the development of novel strategies for cancer treatment.