005 | Targeting the CCT5–AURKA–CEP55 axis in glioblastoma and neuroblastoma cell lines: antitumor effects of SA16

Maria Antonella Augello¹, Giuseppa D’Amico¹, Alessandra Maria Vitale¹, Rosario Barone¹, Simona Rapposelli³, Maciej Wnuk⁴, Francesco Cappello^1|2, Celeste Caruso Bavisotto^1|2, Federica Scalia⁵ | ¹Department of Biomedicine, Neuroscience and Advanced Diagnostics BIND, University of Palermo, Italy; ²Euro-Mediterranean Institute of Science and Technology IEMEST, Palermo, Italy; ³Department of Pharmacy, University of Pisa, Italy; ⁴Faculty of Biotechnology, Collegium Medicum, University of Rzeszow, Poland; ⁵Department of Medicine and Surgery, Kore University of Enna, Italy.

Glioblastoma multiforme (GBM) and neuroblastoma (NB) are currently two tumors of great interest for scientific research, as well as representing a significant clinical challenge. GBM is the most prevalent and aggressive form of primary astrocytoma, accounting for over 60% of adult brain tumors. Its key feature is significant tumor heterogeneity, influenced by epigenetic and metabolic elements. NB, in contrast, is the most frequent extracranial solid tumor in children, arising from neuroblasts and developing in various regions, most commonly in the adrenal medulla and the paravertebral sympathetic ganglia. The role of molecular chaperones in cancer cell biology has emerged as a promising field of investigation. The human chaperonin CCT is essential for preserving cellular homeostasis by facilitating protein folding. Growing evidence suggests that CCT plays a key role in regulating cell division, as it is essential for the correct folding of various cell cycle-related proteins, implying a possible role in cell proliferation. Also, some studies have linked the CCT complex and its subunits to the development and progression of GBM and NB. In this context, we assessed the effects of the antitumor compound SA16, developed at the University of Pisa, which targets, among others, Aurora kinase A (AURKA). Existing literature indicates that AURKA and chaperonin-containing TCP-1 subunit 5 (CCT5) interact with the centrosomal protein CEP55 to control primary cilium disassembly, a pivotal event in tumorigenesis, as cancer cells are reported to lose their cilia to sustain continuous proliferation. MTT assays and IC₅₀ determination revealed that SA16 exhibited strong efficacy across all examined cell lines, with IC₅₀ values below 30 μM. The compound induced a clear proliferation arrest in T98G cells, while exhibiting a more pronounced cytotoxic effect in the LAN5 neuroblastoma cell line. Real-time PCR analyses revealed a statistically significant modulation of genes involved in the investigated pathway, particularly in T98G cells, where SA16 treatment resulted in the upregulation of AURKA, CCT5, and CEP55 transcripts. In HDF cells, AURKA was upregulated, whereas CCT5 was downregulated, while LAN5 cells showed reduced AURKA expression. Western blot analyses confirmed pathway modulation at the protein level, with a marked decrease of AURKA and CEP55 in T98G cells, increased CCT5 and reduced CEP55 in HDF cells, and significant overexpression of CCT5 and CEP55 in LAN5 cells. Immunofluorescence studies demonstrated strong CCT5–AURKA colocalization and highlighted the pronounced efficacy of SA16 in T98G cells. Overall, our results demonstrate that SA16 effectively may inhibit tumor proliferation in two very different tumor cell lines by modulating the AURKA, CCT5 and CEP55 axis, which is currently understudied. These data also confirm the involvement of CCT5 in the tumor progression of GBM and NB and highlight the compound SA16 as a promising candidate for further studies.