Tspan13, short for Tetraspanin 13, is a cell-surface protein belonging to the tetraspanin family. Tetraspanins are four-transmembrane segmented proteins, and Tspan13 has been implicated in various cellular processes. Although its exact functions are still being explored, it has been associated with signaling pathways such as the CXCR4/CXCL12 signaling pathway, which is important in cell migration and homing [1].

In leukemia, Tet2 deficiency leads to increased expression of Tspan13. This occurs through the accumulation of methyl-5-cytosine (m5C) modification in Tspan13 mRNA, recognized by YBX1, which increases Tspan13 transcript stability. The up-regulation of Tspan13 activates the CXCR4/CXCL12 signaling, promoting leukemia stem cell (LSC) homing to the bone marrow niche and enhancing their self-renewal and proliferation [1].

In papillary thyroid cancer (PTC), Tspan13 is up-regulated, and this up-regulation is associated with shorter overall survival. miR-369-3p, which is down-regulated in PTC, targets Tspan13. Overexpression of miR-369-3p suppresses PTC cell proliferation and promotes apoptosis, and silencing of Tspan13 mimics these effects [2].

In breast cancer, miR-4732-5p can directly target the 3'-UTR of Tspan13, suppressing its expression. miR-4732-5p may act as a tumor suppressor in breast cancer initiation but as a tumor promoter in progression [3].

In osteosarcoma cells, hTERT promotes tumor progression by enhancing Tspan13 expression, and knocking down Tspan13 in hTERT-overexpressing cells enhances apoptosis and suppresses mesenchymal properties [4].

In prostate cancer, Tspan13 is overexpressed, and its expression inversely correlates with Gleason score and PSA preoperative levels, while directly correlating with the presence of prostatic intraepithelial neoplasia in tumor tissue [5].

In conclusion, Tspan13 plays crucial roles in multiple disease conditions, especially in cancer development and progression. Studies in these disease models have revealed its significance in cell proliferation, apoptosis, migration, and homing. Understanding the function of Tspan13 through these model-based research can potentially provide new therapeutic targets for treating leukemia, thyroid cancer, breast cancer, osteosarcoma, and prostate cancer.