Role of UBE2C in brain cancer invasion and dissemination

© 2023 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).Glioblastoma (GB) and brain metastases (BM) are the most common brain tumors in adults and are invariably associated with a dismal outcome. These highly malignant tumors share common features including increased invasion and migration of the primary or metastatic brain cancer cells, whose triggering mechanisms are largely unknown. Emerging evidence has suggested that the ubiquitin-conjugating enzyme E2C (UBE2C), essential for controlling cell cycle progression, is overexpressed in diverse malignancies, including brain cancer. This review highlights the crucial role of UBE2C in brain tumorigenesis and its association with higher proliferative phenotype and histopathological grade, with autophagy and apoptosis suppression, epithelial-to-mesenchymal transition (EMT), invasion, migration, and dissemination. High expression of UBE2C has been associated with patients' poor prognosis and drug resistance. UBE2C has also been proven as a promising therapeutic target, despite the lack of specific inhibitors. Thus, there is a need to further explore the role of UBE2C in malignant brain cancer and to develop effective targeted therapies for patients with this deadly disease.This work is funded by National Funds through the FCT—Fundação para a Ciência e Tecnologia, I.P., under the scope of the project 2022.08774.PTDC and the fellowship 2023.03882.BD attributed to SD. In addition, the authors are grateful for the funding of Portugal Programa Gilead GÉNESE (Grant ID Number: 17859); Millennium bcp; Associação David Vaz and private donations.info:eu-repo/semantics/publishedVersio

Primary cilia contribute to the aggressiveness of atypical teratoid/rhabdoid tumors

Atypical teratoid/rhabdoid tumor (AT/RT) is a highly malignant brain tumor in infants that is characterized by loss of nuclear expression of SMARCB1 or SMARCA4 proteins. Recent studies show that AT/RTs comprise three molecular subgroups, namely AT/RT-TYR, AT/RT-MYC and AT/RT-SHH. The subgroups show distinct expression patterns of genes involved in ciliogenesis, however, little is known about the functional roles of primary cilia in the biology of AT/RT. Here, we show that primary cilia are present across all AT/RT subgroups with specific enrichment in AT/RT-TYR patient samples. Furthermore, we demonstrate that primary ciliogenesis contributes to AT/RT biology in vitro and in vivo. Specifically, we observed a significant decrease in proliferation and clonogenicity following disruption of primary ciliogenesis in AT/RT cell line models. Additionally, apoptosis was significantly increased via the induction of STAT1 and DR5 signaling, as detected by proteogenomic profiling. In a Drosophila model of SMARCB1 deficiency, concomitant knockdown of several cilia-associated genes resulted in a substantial shift of the lethal phenotype with more than 20% of flies reaching adulthood. We also found significantly extended survival in an orthotopic xenograft mouse model of AT/RT upon disruption of primary ciliogenesis. Taken together, our findings indicate that primary ciliogenesis or its downstream signaling contributes to the aggressiveness of AT/RT and, therefore, may constitute a novel therapeutic target

Decrease of CD68 Synovial Macrophages in Celastrol Treated Arthritic Rats

Rheumatoid arthritis (RA) is a chronic immune-mediated inflammatory disease characterized by cellular infiltration into the joints, hyperproliferation of synovial cells and bone damage. Available treatments for RA only induce remission in around 30% of the patients, have important adverse effects and its use is limited by their high cost. Therefore, compounds that can control arthritis, with an acceptable safety profile and low production costs are still an unmet need. We have shown, in vitro, that celastrol inhibits both IL-1β and TNF, which play an important role in RA, and, in vivo, that celastrol has significant anti-inflammatory properties. Our main goal in this work was to test the effect of celastrol in the number of sublining CD68 macrophages (a biomarker of therapeutic response for novel RA treatments) and on the overall synovial tissue cellularity and joint structure in the adjuvant-induced rat model of arthritis (AIA).FCT fellowship: (SFRH/BPD/92860/2013)

Celastrol reduces the serum levels of IL-6 in arthritic rats.

<p>Notice that celastrol treatment significantly reduces the systemic concentration of the proinflammatory cytokine IL-6 to levels similar to healthy controls. Data are expressed as median with interquartile range. Differences were considered statistically significant for p-values<0.05, according to the Kruskal-Wallis (Dunn´s Multiple Comparison tests) and Mann–Whitney tests. Healthy N = 21, Arthritic N = 23, Celastrol early group N = 15 and Celastrol late group N = 15.</p

Celastrol reduces the number of synovial CD68+ macrophages.

<p>(A) Representation of the immunohistochemical evaluation performed in paw sections at day 22 after celastrol treatment. Magnifications of 200×. Bar: 100 μm. (B) Immunohistochemical analysis was performed using a semi-quantitative score. Notice that both celastrol early and late-treated rats showed a significant reduction in the number of CD68 and CD163 positive cells in comparison with arthritic rats at day 22. Healthy N = 16, Arthritic N = 10, Celastrol early group N = 15 and Celastrol late group N = 15. (C) Immunohistochemical quantification was performed using an image analysis software written in MATLAB to identify and count the number of positive cells for each antibody in representative sections. Notice that both celastrol early and late-treated rats showed a significant reduction in the number of CD68 and CD163 positive cells in comparison with arthritic rats at day 22. Healthy N = 5, Arthritic N = 5, Celastrol early group N = 5 and Celastrol late group N = 5. Data are expressed as median with interquartile range. Differences were considered statistically significant for p-values<0.05, according to the Kruskal-Wallis (Dunn´s Multiple Comparison tests) and Mann–Whitney tests.</p

Histological images of joints after celastrol treatment.

<p>These patterns are merely illustrative of the type of histological features observed. Black arrow indicates the absence/presence of ankle swelling in rat hind paws. C–calcaneus, E–edema or erosion, S–synovia, Tb–tibia, Ts–tarso. Magnification of 50×. Bar: 100 μm.</p

Celastrol reduces the number of T cells and B cells present in the synovial membrane, and suppresses synovial cell proliferation.

<p>(A) Representation of the immunohistochemical evaluation performed in paw sections at day 22 after celastrol treatment. Magnifications of 200×. Bar: 100 μm. (B) Immunohistochemical analysis was performed using a semi-quantitative score. Notice that both celastrol early and late-treated rats showed a significant reduction in the number of CD3 and CD19 positive cells as well as a reduction in the levels of synovial cell proliferation assessed by Ki67 marker in comparison with arthritic rats at day 22. Healthy N = 16, Arthritic N = 10, Celastrol early group N = 15 and Celastrol late group N = 15. (C) Immunohistochemical quantification was performed using an image analysis software written in MATLAB to identify and count the number of positive cells for each antibody in representative sections. Notice that both celastrol early and late-treated rats showed a significant reduction in the number of CD3, CD19 and Ki67 positive cells in comparison with arthritic rats at day 22. Healthy N = 5, Arthritic N = 5, Celastrol early group N = 5 and Celastrol late group N = 5. Data are expressed as median with interquartile range. Differences were considered statistically significant for p-values<0.05, according to the Kruskal-Wallis (Dunn´s Multiple Comparison tests) and Mann–Whitney tests.</p

(A) Celastrol ameliorates inflammation throughout time. Notice that after 7 days of treatment celastrol early-treated rats presented minimal inflammatory activity, whereas arthritic rats started to increase the inflammatory manifestations sharply. Arrows indicate the beginning of treatment after 4 and 11 days of disease induction. (B) Celastrol improves the clinical outcome in adjuvant-induced arthritic rats. Inflammatory score in celastrol-treated AIA rats is maintained significantly diminished in comparison with arthritic rats. (C) Celastrol suppresses the progression of swelling in the left hind paw.

<p>Left paw edema/swelling is markedly present in arthritic rats in contrast to celastrol-treated animals. Data are expressed as median with interquartile range. Differences were considered statistically significant for p-values<0.05, according to the Kruskal-Wallis (Dunn´s Multiple Comparison tests) and Mann–Whitney tests. Healthy N = 19, Arthritic N = 23, Celastrol early group N = 15 and Celastrol late group N = 15.</p

Celastrol suppresses arthritic inflammation and tissue damage locally in the joints of AIA rats.

<p>A semi-quantitative evaluation of histological sections was performed. Notice that celastrol has inhibited cellular infiltration (A), completely reversed the number of lining layer cells to the normal values (B) and prevented bone erosion occurrence (C), allowing for a normal joint structure comparable to healthy rats in both early and late treatment groups (D). Data are expressed as median with interquartile range. Differences were considered statistically significant for p-values<0.05, according to the Kruskal-Wallis (Dunn´s Multiple Comparison tests) and Mann–Whitney tests. Correlation analysis was performed using the Spearman test. Healthy N = 19, Arthritic N = 23, Celastrol early group N = 15 and Celastrol late group N = 15.</p