PURPOSE: Leucine-rich repeats and immunoglobulin-like domains 1 (LRIG1) are an inhibitor of receptor tyrosine kinases (RTKs) that was discovered in recent years, and many studies showed that LRIG1 is a tumor suppressor gene and may be related to tumor drug resistance. In this study, we explored whether LRIG1 protein expression can improve the chemosensitivity of glioma cells and what was its mechanism. MATERIALS AND METHODS: We collected 93 cases of glioma tissues and detected the expression of LRIG1 and BCL-2. We constructed a multidrug resistance cell line U251/multidrug resistance (MDR) and examined the change of LRIG1 and BCL-2 at mRNA and protein expression levels. LRIG1 expression was upregulated in U251/MDR cells and we detected the change of multidrug resistance. Meanwhile, we changed the expression of LRIG1 and BCL-2 and explored the relationship between LRIG1 and BCL-2. Finally, we also explored the relationship between LRIG1 and RTKs. RESULTS: LRIG1 was negatively correlated with BCL-2 expression in glioma tissue and U251/MDR cells, and upregulation of LRIG1 can enhance chemosensitivity and inhibit BCL-2 expression. Furthermore, LRIG1 was negatively correlated with RTKs in U251/MDR cells. CONCLUSION: These results demonstrated that LRIG1 can improve chemosensitivity by modulating BCL-2 expression and RTK signaling in glioma cells.
Astrocytoma/drug therapy/genetics/metabolism ; Cell Line, Tumor ; Drug Resistance, Neoplasm/genetics/*physiology ; Gene Expression Regulation, Neoplastic ; Gene Knockdown Techniques ; Glioma/drug therapy/*metabolism ; Humans ; Membrane Glycoproteins/metabolism/*physiology ; Proto-Oncogene Proteins c-bcl-2/*metabolism ; RNA, Messenger/metabolism ; Receptor Protein-Tyrosine Kinases/metabolism

Adenocarcinoma ; genetics ; metabolism ; Angiomyolipoma ; etiology ; Antibiotics, Antineoplastic ; therapeutic use ; Astrocytoma ; etiology ; Brain Neoplasms ; etiology ; Breast Neoplasms ; genetics ; metabolism ; Gene Expression Regulation, Neoplastic ; Genes, Tumor Suppressor ; Humans ; Kidney Neoplasms ; etiology ; Lung Neoplasms ; genetics ; metabolism ; Mutation ; Sirolimus ; therapeutic use ; TOR Serine-Threonine Kinases ; antagonists & inhibitors ; metabolism ; Tuberous Sclerosis ; complications ; drug therapy ; genetics ; metabolism ; Tumor Suppressor Proteins ; genetics ; metabolism