Silva, B. L. | bioRxiv Science

bioRxiv2025

Opposite patterns of association of TWIST1 expression with patient survival in SHH and Group 4 medulloblastoma

PurposeTwist1 is a transcription factor that regulates embryonic development, stemness, and differentiation, and can also stimulate initiation of tumorigenesis in peripheral solid cancers. However, its role in central nervous system tumors, including medulloblastoma (MB), the main type of malignant brain cancer that afflicts children, remains poorly understood. Here, we examined expression of Twist1, and its potential significance in prognosis, in different histological variants and molecular subgroups of MB. MethodsGene expression data for TWIST1 and corresponding overall survival (OS) of patients was analyzed in 612 MB samples using a previously described dataset. A cross-sectional analysis of Twist1 protein content in 24 MB tumor samples from patients was carried out by immunohistochemistry. ResultsTWIST1 transcript levels were higher in classic MB compared to desmoplastic tumors. Within samples with classic histology, higher TWIST1 expression was associated with a longer OS. Tumors in the SHH subgroup had lower TWIST1 expression compared to all other subgroups, and Group 4 showed lower expression than WNT tumors. In Group 4 MB, higher TWIST1 levels were associated with shorter OS, whereas patients with SHH tumors and higher TWIST1 levels showed longer OS. Twist1 protein was detectable in part of classic and LCA MB tumors belonging to the SHH, WNT or Group 3/4 subgroups. ConclusionWe found opposite patterns of association between TWST1 and patient survival in Group 4 and SHH MB subgroups. Our results highlight the importance of stratifying tumors by molecular subgroup and histological classification when exploring novel potential biomarkers and therapeutic targets in MB.

cancer biology↗

bioRxiv2024

Neuropsychiatric sequelae in an experimental model of post-COVID syndrome in mice

The global impact of the COVID-19 pandemic has been unprecedented, and presently, the world is facing a new challenge known as Post-COVID syndrome (PCS). Current estimates suggest that more than 65 million people are grappling with PCS, encompassing several manifestations, including pulmonary, musculoskeletal, metabolic, and neuropsychiatric sequelae (cognitive and behavioral). The mechanisms underlying PCS remain unclear. The present study aimed to: (i) comprehensively characterize the acute effects of pulmonary inoculation of the betacoronavirus MHV-A59 in immunocompetent mice at clinical, cellular, and molecular levels; (ii) examine potential acute and long-term pulmonary, musculoskeletal, and neuropsychiatric sequelae induced by the betacoronavirus MHV-A59; and to (iii) assess sex-specific differences. Male and female C57Bl/6 mice were initially inoculated with varying viral titers (3x103 to 3x105 PFU/30 L) of the betacoronavirus MHV-A59 via the intranasal route to define the highest inoculum capable of inducing disease without causing mortality. Further experiments were conducted with the 3x104 PFU inoculum. Mice exhibited an altered neutrophil/lymphocyte ratio in the blood in the 2nd and 5th day post-infection (dpi). Marked lung lesions were characterized by hyperplasia of the alveolar walls, infiltration of polymorphonuclear leukocytes (PMN) and mononuclear leukocytes, hemorrhage, increased concentrations of CCL2, CCL3, CCL5, and CXCL1 chemokines, as well as high viral titers until the 5th dpi. While these lung inflammatory signs resolved, other manifestations were observed up to the 60 dpi, including mild brain lesions with gliosis and hyperemic blood vessels, neuromuscular dysfunctions, anhedonic-like behavior, deficits in spatial working memory, and short-term aversive memory. These musculoskeletal and neuropsychiatric complications were exclusive to female mice and were prevented after ovariectomy. In summary, our study describes for the first time a novel sex-dependent model of PCS focused on neuropsychiatric and musculoskeletal disorders. This model provides a unique platform for future investigations regarding the effects of acute therapeutic interventions on the long-term sequelae unleashed by betacoronavirus infection.

neuroscience↗