6520

SLC3A2

solute carrier family 3 (amino acid transporter heavy chain), member 2;SLC3A2;solute carrier family 3 (amino acid transporter heavy chain), member 2

4F2 cell-surface antigen heavy chain|CD98 heavy chain|antigen defined by monoclonal antibody 4F2, heavy chain|antigen identified by monoclonal antibodies 4F2, TRA1.10, TROP4, and T43|lymphocyte activation antigen 4F2 large subunit|monoclonal antibody 44D7

11q13

protein-coding

The significance of L-type amino acid transporter (LAT) 1 expression remains unclear in the metastatic process of human neoplasms, whereas experimental studies have demonstrated that LAT1 is associated with the metastatic process of cancer cells. We compared the immunohistochemical expression of LAT1 and CD98 between the primary site and a concordant pulmonary metastatic site in 93 cancer patients, all of whom had undergone thoracotomy. LAT1, CD98, Ki-67 labeling index, vascular endothelial growth factor (VEGF), CD31, and CD34 were analyzed by immunohistochemical staining in the resected tumors of 93 cancer patients: 45 colon cancers; nine breast cancers; eight head and neck cancers; 11 genital cancers; 14 soft-tissue sarcomas; and six other cancers. The expression of these markers was significantly higher in the metastatic sites than in the primary sites. In total, the positive rates of LAT1, CD98, Ki-67, VEGF, CD31, and CD34 were 40, 24, 56, 41, 45, and 39%, respectively, in the primary sites and 65, 45, 84, 67, 73, and 61%, respectively, in the metastatic sites. LAT1 expression was closely correlated with CD98 expression, angiogenesis, and cell proliferation. The association between LAT1 and CD98 expression was strongest in the primary and metastatic sites. The present study suggests that overexpression of LAT1 and CD98 has an important role to play in the metastatic process of variable human neoplasms. Moreover, LAT1 expression was significantly correlated with cell proliferation and angiogenesis.

Anti-tumor drug resistance and cancer metastasis are always clinically coincidental, which are conducted by different molecules such as P-glycoprotein (P-gp) and CD147, respectively. P-gp and CD147/CD98hc complex are both found highly expressed on cisplatin resistant ovarian cancer cell line SKOV3/DDP but only slightly expressed on its parent cell SKOV3. RNAi targeting CD98hc or CD147 both reduce their own and P-gp expression as well as cisplatin IC50 of drug-resistant tumor cells. CD147 interference only reduced membrane CD98hc rather than its intracellular forms. Stop of CD98hc also diminished CD147 translation. Cloned potential CD98hc promoter region showed promoter activity in luciferase assay under cisplatin pressure. Intracellular cisplatin accumulation was found increased in RNAi groups and the efflux ability of cisplatin resistant SKOV3 cells was disrupted as well. CD147 has been reported to play an important role in tumor metastasis. Taken together, CD98hc was for the first time revealed to be a bridge between MDR phenotype and tumor metastasis.