Salivary gland adenoid cystic carcinoma (SACC) is one of the most common malignant tumors, with high aggressive potential in the oral and maxillofacial regions. Lissencephaly 1 (LIS1) is a microtubule‑organizing center‑associated protein that regulates the polymerization and stability of microtubules by mediating the motor function of dynein. Recent studies have suggested that LIS1 plays a potential role in the malignant development of tumors, such as in mitosis and migration. However, the role of LIS1 in SACC development and its related molecular mechanisms remain unclear. Thus, the effects of LIS1 on the proliferation, apoptosis, invasion and metastasis of SACC were studied, in vivo and in vitro. The results of immunohistochemical staining showed that LIS1 was highly expressed in SACC tissues, and its expression level was associated with malignant progression. In vitro, the results of CCK‑8, TUNEL, wound healing and Transwell assays demonstrated that LIS1 promotes proliferation, inhibits apoptosis, and enhances the migration and invasion of SACC‑LM cells. In vivo, knockdown of LIS1 effectively suppressed the growth of subcutaneous tumors in a mouse xenograft and distant metastasis of tumor cells in the metastasis model. The co‑immunoprecipitation, immunofluorescence and western blot results also revealed that LIS1 binds to cytoplasmic linker protein 170 (CLIP170) to form a protein complex (LIS1/CLIP170), which activates the cell division control protein 42 homolog (Cdc42) signaling pathway to modulate the proliferation and anti‑apoptosis of tumor cells, and enhanced invasion and metastasis by regulating the formation of invadopodia and the expression of MMPs in SACC‑LM cells. Therefore, the present study demonstrated that LIS1 is a cancer promoter in SACC, and the molecular mechanism of the LIS1/CLIP170/Cdc42 signaling pathway is involved in the malignant progression, which offers a promising strategy for targeted therapy of SACC.
Keywords: cell division control protein 42 homolog; lissencephaly 1; malignancy; metastasis; microtubule‑associated protein; salivary gland adenoid cystic carcinoma.