Measuring a cell's response to stress: the p53 pathway

Is autoimmunity associated with the development of premalignant oral conditions and the progression to oral squamous cell carcinoma?: A literature review

OBJECTIVE

Oral potentially malignant disorders (OPMDs) are oral mucosal conditions that may progress to oral squamous cell carcinoma (OSCC). Although autoimmunity has linked to the malignant transformation potential of various precancerous conditions, its role in OPMD remains unclear. This review aimed to identify the role of systemic autoimmunity on OPMD development and their progression to OSCC.

METHODS

A comprehensive literature search was conducted using PubMed, Cochrane CENTRAL, and SCOPUS database for articles published up to January 2024. The key questions addressed by this review were "Is autoimmunity associated with the development of OPMD" and "How does systemic autoimmunity influence the potential for malignant transformation of OPMD?". This review followed the PRISMA guidelines for scoping reviews (PRISMA-ScR).

RESULTS

Of the 1265 articles initially identified, 21 fulfilled the search criteria. Three themes were emerged; 1) the prevalence and prognosis of oral cancers in patients with systemic autoimmune diseases, 2) circulating autoantibodies in OPMD patients, and 3) autoimmune-related markers linked to malignant transformation in OPMD patients. This review indicated that systemic autoimmunity may contribute to chronic inflammatory conditions, disruption of oral mucosal integrity, and interference with the DNA damage repair process, thus influencing malignant transformation in the oral epithelium of patients with OPMD.

CONCLUSION

The co-occurrence of OPMD with circulating autoantibodies or systemic autoimmune diseases underscores the importance of understanding these interactions for improved management of OPMD and early detection of OSCC.

Cellular and molecular effects of non-ionizing electromagnetic fields

The way that living cells respond to non-ionizing electromagnetic fields (EMF), including static/extremely-low frequency and radiofrequency electromagnetic fields, fits the pattern of 'cellular stress response' - a mechanism manifest at the cellular level intended to preserve the entire organism. It is a set pattern of cellular and molecular responses to environmental stressors, such as heat, ionizing radiation, oxidation, etc. It is triggered by cellular macromolecular damage (in proteins, lipids, and DNA) with the goal of repairing and returning cell functions to homeostasis. The pattern is independent of the type of stressor encountered. It involves cell cycle arrest, induction of specific molecular mechanisms for repair, damage removal, cell proliferation, and cell death if damage is too great. This response could be triggered by EMF-induced alternation in oxidative processes in cells. The concept that biological response to EMF is a 'cellular stress response' explains many observed effects of EMF, such as nonlinear dose- and time-dependency, increased and decreased risks of cancer and neurodegenerative diseases, enhanced nerve regeneration, and bone healing. These responses could be either detrimental or beneficial to health, depending on the duration and intensity of the exposure, as well as specific aspects of the living organism being exposed. A corollary to electromagnetic hypersensitivity syndrome (EHS) could be an inappropriate response of the hippocampus/limbic system to EMF, involving glucocorticoids on the hypothalamic-pituitary-adrenal axis.

Role of Apoptotic Proteins in REC-2006 Mediated Radiation Protection in Hepatoma Cell Lines

The present study was carried out to evaluate the role of apoptotic proteins in REC-2006-mediated radiation protection in hepatoma cell lines. REC-2006 treatment 2 h before irradiation strongly inhibited the cleavage of ATM and PARP-1 in HepG2 cells. The expression of nuclear apoptosis inducing factor (AIF) was found to be more inhibited (~17%) in HepG2 cells in REC-2006 + radiation-treated group. More inhibition (~33%) of cytochrome c was observed in HepG2 cells upon REC-2006 treatment 2 h prior irradiation. Similarly, significantly more (P<.05) inhibition of Apaf-1, caspase-9 and caspase-3 was observed in REC-2006 + radition-treated group in HepG2 cells. REC-2006 treatment restored the expression of ICAD in HepG2 cells; however, no restoration was observed in Hep3B cells. Lower nuclear to cytoplasmic CAD ratio was observed in HepG2 cells (~0.6) as compared with Hep3B cells (~1.2) in REC-2006 + radiation-treated group. In conclusion, REC-2006 rendered higher protection in HepG2 cells by inhibiting the expression and translocation of AIF, inhibiting the cleavage of ATM and PARP-1, restoring the expression of ICAD, inhibiting the release of cytochrome c and thus modulating the expression of Apaf-1 caspase-9 and activity of caspase-3.

Evolution of the cellular stress proteome: from monophyletic origin to ubiquitous function

Cells respond to acute environmental change by activating a stress response that is widely studied. However, knowledge of this stress response is fragmentary, and a unifying concept explaining its universality for many different species and types of stress is lacking. The need for a holistic view emphasizing the key aspects of the stress response is addressed by the following hypothesis. The cellular stress response is a reaction to any form of macromolecular damage that exceeds a set threshold, independent of the underlying cause. It is aimed at temporarily increasing tolerance limits towards macromolecular damage by utilizing a phylogenetically conserved set of genes and pathways that mediate global macromolecular stabilization and repair to promote cellular and organismal integrity under suboptimal conditions. This mechanism affords time for a separate set of stressor-specific adaptations, designed to re-establish cellular homeostasis, to take action. Supporting evidence, emerging conclusions, and ways to test this hypothesis are presented.

DNA repair during organogenesis

DNA damage caused by genotoxic agents can impact on virtually any cellular process due to its ability to affect gene expression and subsequent gene products. The importance of repairing damaged DNA is evidenced by the variety of DNA repair pathways that have evolved in all living organisms, and the human syndromes caused by a lack of this repair ability. This review focuses on the expression and activity of DNA repair pathways during mammalian organogenesis, and the role of these pathways in ensuring the stability of the conceptal genome. DNA repair capacity may play a role also in the response of the conceptus to genotoxic agents that may induce malformations; the consequences of exposure to a genotoxic agent during organogenesis depend on the extent of the damage and on the ability of the embryo to respond by repairing DNA or arresting cell division. The four main repair pathways (nucleotide excision repair, base excision repair, mismatch repair, and recombination repair) are expressed to various degrees during organogenesis, as are members of the genotoxic stress-activated cell cycle checkpoint pathways. Developmental-stage-specific alterations in transcript levels, protein levels, as well as activity, indicate that the regulation of DNA repair pathways during development is complex. The importance of DNA repair pathways in endogenous damage control is illustrated by the sensitivity of development to their disruption if some of these genes are mutated. Furthermore, the conceptus has a limited capacity to alter DNA repair responses following exposure to genotoxic agents.