KCNJ2 Facilitates Clear Cell Renal Cell Carcinoma Progression and Glucose Metabolism

Abstract

Background: Clear cell renal cell carcinoma (ccRCC) is marked by aggressive characteristics and a poor prognosis. The involvement of KCNJ2, an inward rectifying potassium channel, in the progression of ccRCC, along with its potential roles in immune modulation and metabolic pathways, remains unclear. Methods: The Cancer Genome Atlas (TCGA) database was utilized to analyze the gene expression, clinicopathological characteristics, and clinical relevance of KCNJ2. The prognostic value of KCNJ2 in ccRCC was evaluated with Kaplan-Meier survival analysis and receiver operating characteristic curve analyses. The TCGA-KIRC dataset was utilized to analyze tumor microenvironment (TME), focusing on tumor-infiltrating immune cells and immunomodulators. The biological functions of KCNJ2 were investigated in vitro using CCK-8, flow cytometry, wound healing, transwell, qRT-PCR, and Western blotting assays. Results: KCNJ2 expression was notably higher in ccRCC than in normal kidney tissues, with increased levels associated with advanced tumor stages. However, KCNJ2 did not exhibit obvious prognostic value. Coexpression analysis identified associations with genes implicated in energy metabolism. Analysis of the TME and immune profile indicated a link between KCNJ2 expression and immune cell infiltration, along with particular immune checkpoints. In vitro studies demonstrated that KCNJ2 overexpression enhanced cell proliferation, migration, invasion, glucose production, and ATP generation. Conclusion: KCNJ2 plays a crucial role in ccRCC progression through affecting glucose metabolism and immune responses. Our findings reveal the functional role of KCNJ2 in promoting tumor progression and metabolic reprogramming in ccRCC, highlighting its therapeutic potential as a novel target for ccRCC treatment. Further studies are essential to clarify the mechanisms by which KCNJ2 affects ccRCC biology and to evaluate its clinical relevance.

Keywords: KCNJ2; clear cell renal cell carcinoma; glucose metabolism; progression.

Figure 1

High expression of KCNJ2 in ccRCC. ⁣^∗∗∗p < 0.001 versus normal kidney tissues.

Figure 2

KCNJ2 expression across subgroups with different clinical characteristics. Box plots depict the relative mRNA expression of KCNJ2 across various ccRCC patient groups: (a) age, (b) gender, (c) tumor grade, (d) distant metastasis status, (e) nodal metastasis status, (f) cancer stages, (g) primary tumor size and extent, and (h) comparison of clinical characteristics between KCNJ2 high and low expression subgroups.

Figure 3

Prognostic significance of KCNJ2 in ccRCC. (a) Kaplan–Meier survival curve analysis of OS. (b) Kaplan–Meier survival curve analysis of PFS. (c) ROC curve analysis of the survival rate.

Figure 4

Associations between KCNJ2 expression with immune infiltration and immune checkpoints in ccRCC. (a–c) Analysis of the relationship between immune infiltration level and KCNJ2 expression in ccRCC patients. (d) Heatmap illustrating the correlation between KCNJ2 expression and immune checkpoints utilizing the TCGA-KIRC dataset. ⁣^∗p < 0.05, ⁣^∗∗p < 0.01, and ⁣^∗∗∗p < 0.001.

Figure 5

Impacts of KCNJ2 on cell growths, apoptosis, migration, and invasiveness in ccRCC. (a, b) qRT-PCR and Western blot analysis of KCNJ2 mRNA and protein levels in ccRCC cell lines and the human renal tubular epithelial cell line. (c) Western blot analysis of the efficiency of KCNJ2 overexpression or knockdown. (d) Cell viability of A498 cells was measured by CCK-8 assay. (e) Cell apoptosis rate of A498 cells was measured by flow cytometry assay. (f) Wound healing in A498 cells. (g, h) Cell migration and invasion abilities were detected by transwell assays. (i, j) The mRNA and protein changes of apoptosis, migration, and invasion-related genes were detected by qRT-PCR and Western blot assay. ⁣^∗∗p < 0.01 and ⁣^∗∗∗p < 0.001.

Figure 6

Impacts of KCNJ2 on glucose metabolism in ccRCC cells. (a–c) Cellular glucose levels, ATP levels, and LDH activity of A498 cells. ⁣^∗p < 0.05 and ⁣^∗∗∗p < 0.001.