Renal Cell Carcinoma (RCC) is on the top 10 of the most incident cancers worldwide, being a third of patients diagnosed with advanced disease, for which no curative therapies are currently available. Thus, new effective therapeutic strategies are urgently needed. Herein, we tested the antineoplastic effect of newly synthesized 3-nitroflavanones (MLo1302) on RCC cell lines. 786-O, Caki2, and ACHN cell lines were cultured and treated with newly synthesized 3-nitroflavanones. IC50 values were calculated based on the effect on cell viability assessed by MTT assay, after 72 h of exposure. MLo1302 displayed antineoplastic properties in RCC cell lines through marked reduction of cell viability, increased apoptosis and DNA damage, and morphometric alterations indicating a less aggressive phenotype. MLo1302 induced a significant reduction of global DNA methylation and DNMT mRNA levels, increasing global DNA hydroxymethylation and TET expression. Moreover, MLo1302 decreased DNMT3A activity in RCC cell lines, demethylated and re-expressed hypermethylated genes in CAM-generated tumors. A marked in vivo decrease in tumor growth and angiogenesis was also disclosed. MLo1302 disclosed antineoplastic and demethylating activity in RCC cell lines, constituting a potential therapeutic agent for RCC patients.