SLMO2 is a potential prognostic and immunological biomarker in human pan-cancer.

SLMO2 is a lipid transporter that transports phosphatidylserine to the interior of mitochondria, also known as PRELID3B, which plays an important role in lipid metabolism. It has also been reported to be involved in the growth process of breast and lung tumors. However, its functions and underlying mechanisms in cancer progress remain elusive, and the potential as pan-cancer biomarker and therapeutic target remains unexplored. Using the TCGA project and GEO database, we performed pan-cancer analysis of SLMO2, which including the expression pattern, prognostic value, mutation landscape, methylation modification, protein-protein interaction network and the relationship between SLMO2 expression and immune infiltration. KEGG enrichment analysis was also performed to predict function and relevant cellular pathways of SLMO2. In addition, proliferation and migration assays were performed to detect the proliferation and metastasis capacity of breast cancer and lung cancer cells. In our study, we found that SLMO2 was overexpressed in pan-cancer and the elevated expression of SLMO2 was correlated with poorer prognosis. SLMO2 mutations were distributed in a variety of tumors and correlated with prognosis. Promoter methylation analysis showed that SLMO2 methylation levels were lower in most tumors compared with normal tissues, while a few tumors showed increased methylation levels of SLMO2. SLMO2 expression was also positively correlated with immune infiltration of MDSCs. Further pathway enrichment analysis indicated that SLMO2 was involved in regulating of cytoplasmic transport and other oncogenic processes. In vitro experiments have shown that SLMO2 promotes the proliferation and migration of breast cancer and lung cancer cells. In conclusion, our findings suggested that SLMO2 was a potential prognostic and immunological marker in pan-cancer. This study suggested a potential strategy for targeting SLMO2 to treat tumors, including manipulating tumor growth or the tumor microenvironment, especially the infiltration of MDSC.

[Preparation and bioactivity evaluation of SA-mIL15 fusing protein].

AIM: To prepare and characterize streptavidin-tagged murine interleukin-15 fusion proteins. METHODS: pET24a-SA-L-mIL15 and pET21a-mIL15-L-SA plasmids were constructed and expressed in Rosetta (DE3) host bacteria to generate SA/mIL15 fusion proteins. SA-mIL15 fusion protein was purified through the Ni-NTA affinity chromatography, and mIL15-SA fusion protein through anion exchange chromatography, followed by refolding. The efficiency of surface modification of the fusion proteins on the biotinylated RM-1 tumor cells was evaluated by a flow cytometer. MTT method was used to evaluate the proliferating effect of SA/mIL15 fusion proteins on mouse spleen lymphocytes stimulated by ConA. RESULTS: Both SA-mIL15 and mIL15-SA fusion proteins were highly expressed in Rosetta (DE3) at about 20% of total bacterial proteins. They exhibited the bi-functionality: proliferation-promoting activity of mIL15 on mouse spleen lymphocytes with the specific activity of 1x10(6); IU/mg for SA-mIL15 or 2 x 10(5); IU/mg for mIL15-SA, and SA-mediated high-affinity binding to the biotinylated surfaces of RM-1 tumor cells with about 95% surface modification efficiency. CONCLUSION: SA/mIL15 bi-functional fusion proteins were generated, which made feasible the development of mIL15-surface-modified cancer cell vaccine.