Published online May 6, 2022. doi: 10.12998/wjcc.v10.i13.3989
Peer-review started: April 21, 2021
First decision: August 8, 2021
Revised: August 17, 2021
Accepted: February 25, 2022
Article in press: February 25, 2022
Published online: May 6, 2022
Processing time: 373 Days and 17.8 Hours
Metabolic reprogramming has been identified as a core hallmark of cancer. Solute carrier family 2 is a major glucose carrier family. The solute carrier family 2 is an important carrier for glucose to enter target cells, and its ability to transport glucose is the first rate-determining step in tumor metabolic reprogramming. It consists of 14 members, and we mainly study solute carrier family 2 member 1 (SLC2A1) and solute carrier family 2 member 2 (SLC2A2) here.
Hepatocellular carcinoma (HCC) is still characterized by late diagnosis and limited effective treatment options. Immune checkpoint inhibitors are also less effective than expected. The discovery of new biomarkers indicating the patient's immune status is essential for the treatment of HCC with immune checkpoint inhibitors.
To identify if SLC2A1 and SLC2A2 were associated with immune infiltration in addition to participating in the metabolic reprogramming in HCC.
SLC2A1 and SLC2A2 expression were tested in HepG2 cells, HepG215 cells, and multiple databases. The clinical characteristics of SLC2A1 and SLC2A2 were examined by multiple databases. The correlation between SLC2A1 and SLC2A2 was analyzed by multiple databases. The functions and pathways in which SLC2A1, SLC2A2, and neighbor genes were involved were discussed. Immune infiltration levels and immune marker genes associated with SLC2A1 and SLC2A2 were discussed by multiple databases.
SLC2A1 was increased but the expression level SLC2A2 was decreased in HepG2 cells, HepG215 cells, and liver cancer patients. The expression levels of SLC2A1 and SLC2A2 were related to HCC progression. Interestingly, the expression levels of SLC2A1 and SLC2A2 were negatively correlated. Further, high SLC2A1 expression and low SLC2A2 expression were related to poor overall survival and relapse-free survival. Moreover, SLC2A1, SLC2A2, and neighbor genes played a major role in the occurrence and development of tumors. Notably, SLC2A1 was positively correlated with tumor immune infiltration, while SLC2A2 was negatively correlated with tumor immune infiltration. Particularly, SLC2A2 methylation was positively correlated with lymphocytes.
SLC2A1 and SLC2A2 are independent therapeutic targets for HCC, and they are quintessential marker molecules for predicting and regulating the number and status of immune cells in HCC.
Clinical trials showed that programmed cell death 1 and cytotoxic T-lymphocyte associated protein 4 antibodies improved clinical outcomes in a few patients or were not effective at all in HCC. Therefore, recognition molecules representing the patient's immune status will help identify subgroups sensitive to immunomodulatory drugs. Moreover, some independent target molecules associated with the tumor immune microenvironment are worth exploring in HCC.