The chaperone system in cancer therapies: Hsp90

: The chaperone system (CS) of an organism is composed of molecular chaperones, chaperone co-factors, co-chaperones, and chaperone receptors and interactors. It is present throughout the body but with distinctive features for each cell and tissue type. Previous studies pertaining to the CS of the salivary glands have determined the quantitative and distribution patterns for several members, the chaperones, in normal and diseased glands, focusing on tumors. Chaperones are cytoprotective, but can also be etiopathogenic agents causing diseases, the chaperonopathies. Some chaperones such as Hsp90 potentiate tumor growth, proliferation, and metastasization. Quantitative data available on this chaperone in salivary gland tissue with inflammation, and benign and malignant tumors suggest that assessing tissue Hsp90 levels and distribution patterns is useful for differential diagnosis-prognostication, and patient follow up. This, in turn, will reveal clues for developing specific treatment centered on the chaperone, for instance by inhibiting its pro-carcinogenic functions (negative chaperonotherapy). Here, we review data on the carcinogenic mechanisms of Hsp90 and their inhibitors. Hsp90 is the master regulator of the PI3K-Akt-NF-kB axis that promotes tumor cell proliferation and metastasization. We discuss pathways and interactions involving these molecular complexes in tumorigenesis and review Hsp90 inhibitors that have been tested in search of an efficacious anti-cancer agent. This targeted therapy deserves extensive investigation in view of its theoretical potential and some positive practical results and considering the need of novel treatments for tumors of the salivary glands as well as other tissues

The Chaperone System in Salivary Glands: Hsp90 Prospects for Differential Diagnosis and Treatment of Malignant Tumors

Salivary gland tumors represent a serious medical problem and new tools for differential diagnosis and patient monitoring are needed. Here, we present data and discuss the potential of molecular chaperones as biomarkers and therapeutic targets, focusing on Hsp10 and Hsp90. The salivary glands are key physiological elements but, unfortunately, the information and the means available for the management of their pathologies, including cancer, are scarce. Progress in the study of carcinogenesis has occurred on various fronts lately, one of which has been the identification of the chaperone system (CS) as a physiological system with presence in all cells and tissues (including the salivary glands) that plays a role in tumor-cell biology. The chief components of the CS are the molecular chaperones, some of which belong to families of evolutionarily related molecules named heat shock protein (Hsp). We are quantifying and mapping these molecular chaperones in salivary glands to determine their possible role in the carcinogenetic mechanisms in these glands and to assess their potential as diagnostic biomarkers and therapeutic targets. Here, we report recent findings on Hsp10 and Hsp90 and show that the quantitative and topographic patterns of tissue Hsp90 are distinctive of malignant tumors and differentiate benign from malignant lesions. The Hsp90 results show a correlation between quantity of chaperone and tumor progression, which in turn calls for negative chaperonotherapy, namely, elimination/inhibition of the chaperone to stop the tumor. We found that in vitro, the Hsp90 inhibitor Ganetespib is cytotoxic for the salivary gland UM-HACC-2A cell line. The drug, by interfering with the pro-survival NF-κB pathway, hampers cellular proliferation and migration, and favors apoptosis, and can, therefore, be considered a suitable candidate for future experimentation to develop a treatment for salivary gland tumors

Molecular Mechanisms Leading from Periodontal Disease to Cancer

Periodontitis is prevalent in half of the adult population and raises critical health concerns as it has been recently associated with an increased risk of cancer. While information about the topic remains somewhat scarce, a deeper understanding of the underlying mechanistic pathways promoting neoplasia in periodontitis patients is of fundamental importance. This manuscript presents the literature as well as a panel of tables and figures on the molecular mechanisms of Porphyromonas gingivalis and Fusobacterium nucleatum, two main oral pathogens in periodontitis pathology, involved in instigating tumorigenesis. We also present evidence for potential links between the RANKL-RANK signaling axis as well as circulating cytokines/leukocytes and carcinogenesis. Due to the nonconclusive data associating periodontitis and cancer reported in the case and cohort studies, we examine clinical trials relevant to the topic and summarize their outcome

Investigation of energy dependance for EBT3 response to irradiation with alpha beams

International audienceThe response of EBT3 radiochromic film to ionizing radiation has been investigated for alpha beams. An experiment has been performed at the ARRONAX cyclotron to measure the net optical density (net OD) of EBT3 films as a function of the deposited doses of an alpha beam at different energies. A stack of 4 films was irradiated, therefore the beam energy is changed as a function of the film position between 45 MeV and 22 MeV. No differences in the film responses were observed in function of the alpha beam energy. The same calibration (Dose vs net OD) can be used for EBT3 film in this range of alpha beam energy. It is necessary to extend this study at lower energy down to the Bragg peak region

THE CHAPERONE SYSTEM IN SALIVARY GLAND DEVELOPMENT

The chaperone system (CS) canonical function is to maintain protein homeostasis. Proper folding of nascent peptides is crucial in developing tissue. The chief components of the CS are 95th National Congress of the Italian Society for Experimental Biology | Trieste, Italy, 12-15 April 2023Non-commercial use only the molecular chaperones, which play key roles in development as indicated by their presence in embryonic tissue as early as at two-cell stage. However, scarce information on the CS in developing tissues is available, especially at advanced stages of embryogenesis and its role is not fully understood. In our previous study, we reported the presence of molecular chaperones in the ducts and acini of human adult salivary glands. Here, we extend our work and report the distribution pattern of the molecular chaperones Hsp10, Hsp27, Hsp60, and Hsp90 in adult mice submandibular glands (SMG) and in human and mice embryos at late stages of development. We also report tissue levels and expression of these molecular chaperones determined by means of immunohistochemistry, Western blot, and RT-PCR. The four molecular chaperones were present in salivary gland tissue with Hsp90 levels being the highest at both stages, embryonic and adult. The data indicate that the CS is active throughout the ontogeny of salivary glands, with time-course changes in levels and distribution that reflect a dynamic functional involvement specific for each developmental step. The implications of these findings for understanding the pathology of salivary glands with roots in abnormal development are worth exploring, and the data presented here should serve as a basis for such studies and, consequently, boost the invention of novel diagnostic and treatment tools