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Biology subjects

Arnold, M. R.

Publications and source records attributed to Arnold, M. R..

2 recordsLinked to original sources

Alpha-synuclein knockout impairs melanoma development and alters DNA damage repair in the TG3 mouse model in a sex-dependent manner

Strong evidence suggests links between Parkinsons Disease (PD) and melanoma, as studies have found that people with PD are at an increased risk of developing melanoma and those with melanoma are at increased risk of developing PD. Although these clinical associations are well-established, the cellular and molecular pathways linking these diseases are poorly understood. Recent studies have found a previously unrecognized role for the neurodegeneration-associated protein alpha-synuclein (Syn) in melanoma; the overexpression of Syn promotes melanoma cell proliferation and metastasis. However, to our knowledge, no studies have investigated the role of Syn in in vivo melanoma models outside of a xenograft paradigm. Our study created and characterized Snca knockout in the spontaneously developing melanoma TG3 mouse line, TG3+/+Snca-/-. We show that Syn loss-of-function significantly delays melanoma onset and slows tumor growth in vivo. Furthermore, decreased tumor volume is correlated with a decreased DNA damage signature and increased apoptotic markers, indicating a role for Syn in modulating the DNA damage response (DDR) pathway. Overall, our study provides evidence that targeting Syn and its role in modulating the DDR and melanomagenesis could serve as a promising new therapeutic target.

cancer biology↗

Alpha-synuclein regulates nucleolar DNA double-strand break repair in melanoma

Although an increased risk of the skin cancer melanoma in people with Parkinsons Disease (PD) has been shown in multiple studies, the mechanisms involved are poorly understood, but increased expression of the PD-associated protein alpha-synuclein (Syn) in melanoma cells may be important. Our previous work suggests that Syn can facilitate DNA double-strand break (DSB) repair, promoting genomic stability. We now show that Syn is preferentially enriched within the nucleolus in the SK-MEL28 melanoma cell line, where it colocalizes with DNA damage markers and DSBs. Inducing DSBs specifically within nucleolar ribosomal DNA (rDNA) increases Syn levels near sites of damage. Syn knockout increases DNA damage within the nucleolus at baseline, after specific rDNA DSB induction, and prolongs the rate of recovery from this induced damage. Syn is important downstream of ATM signaling to facilitate 53BP1 recruitment to DSBs, reducing micronuclei formation and promoting cellular proliferation, migration, and invasion.

cell biology↗