Splicing protein LSM5 linked to aggressive growth in osteosarcoma cells

LSM5, a member of the Sm-like protein family that participates in pre-mRNA splicing, is over-expressed across many cancer types and appears tied to malignant behaviour in osteosarcoma, according to an integrative pan-cancer analysis published in Clinical and Experimental Medicine. The study, led by Hui Deng and Yuan-xi Leng with Ya-yun Liu, combined public tumour databases with laboratory experiments in osteosarcoma cells to characterise the protein’s expression landscape and its possible role in tumour biology.

Using data from the TCGA and GEO databases, the researchers examined LSM5 expression, exploratory tumour-versus-normal discrimination, prognostic significance and associations with genomic instability across cancer types. They report that LSM5 was broadly over-expressed across cancer types and positively correlated with tumour status and genomic instability. Single-cell transcriptomic data from the TISCH2 database were integrated to map LSM5 expression patterns across cell types, revealing a cell cycle-dependent expression pattern, meaning the protein’s levels track with the phase of the cell division cycle.

In osteosarcoma specifically, high LSM5 expression was associated with shorter survival in two public cohorts, positioning the protein as a candidate prognostic marker. The authors emphasise that this association warrants further investigation rather than constituting a validated clinical tool. Because the findings rest on retrospective analysis of public datasets, they describe associations rather than demonstrating that LSM5 drives cancer progression on its own.

To probe function directly, the team performed experiments in osteosarcoma cells. When LSM5 was knocked down, the cells showed reduced migration in wound healing assays, reduced invasion and migration in Transwell assays, reduced EdU incorporation indicating less DNA synthesis, and reduced tumoursphere formation, a measure of stem-like self-renewal capacity. Flow cytometry showed that knockdown was associated with arrest of the cells in the G0/G1 phase of the cell cycle. At the molecular level, knockdown was accompanied by upregulation of p53 and p21, both of which restrain cell-cycle progression, and downregulation of Cyclin D1, which promotes the G1/S transition. Overexpressing LSM5 produced the opposite pattern, strengthening the association between the protein and these malignant phenotypes in this cell model.

Taken together, the authors conclude that LSM5 expression is associated with the G1/S transition and with the abundance of p53, p21 and Cyclin D1 in osteosarcoma cells. The study’s scope is important to keep in view: the pan-cancer expression and survival analyses are computational and exploratory, the single-cell findings describe expression patterns rather than causal mechanisms, and the functional assays were conducted in cell lines rather than in patients. The work does not establish LSM5 as a therapeutic target or a clinically validated biomarker, and the authors frame it as a candidate that merits further study. Nevertheless, by linking a splicing-related protein to cell-cycle control, genomic instability and survival outcomes across cancers, and by providing early functional evidence in osteosarcoma cells, the analysis offers a starting point for future research into how altered pre-mRNA splicing machinery may contribute to osteosarcoma, a bone cancer in which new prognostic and mechanistic markers remain actively sought.

Subject of Research: The role of the splicing protein LSM5 in osteosarcoma and pan-cancer expression

Article Title: LSM5 is associated with malignant phenotypes in osteosarcoma: an integrative pan-cancer analysis

Article References: Deng, H., Liu, Y.-Y., & Leng, Y.-X. (2026). LSM5 is associated with malignant phenotypes in osteosarcoma: an integrative pan-cancer analysis. Clinical and Experimental Medicine. https://doi.org/10.1007/s10238-026-02361-7

Image Credits: AI Generated

DOI: 10.1007/s10238-026-02361-7

Keywords: LSM5, osteosarcoma, pan-cancer analysis, pre-mRNA splicing, genomic instability, cell cycle, G1/S transition, p53, p21, Cyclin D1, prognostic marker, TCGA