The effect of DDIT3 on luminal A type breast cancer

Abstract

Purpose: To analyze the phenotypic changes of breast cancer (BC) cell before and after DDIT3 knockdown/overexpression, and preliminarily explore the regulatory mechanism. Also, to analyze the relationship between DDIT3 and prognosis by combining with bioinformatics methods, which provide a basis for further research on DDIT3 targeted treatment of BC. Methods: Loss- and gain-of-function studies, DDIT3 in MCF-7 (luminal A), and RNA-seq analysis were employed to investigate the functional impact of DDIT3 on BC cell proliferation and drug resistance. The relationship between DDIT3 and the prognosis of BC patients was systematically assessed using the tissue microarray technique along with qRT-PCR and publicly available data. Results: Survival analysis showed that patients with lower DDIT3 expression in luminal A type BC or BC patient which were undergoing endocrine therapy had a poorer prognosis, and DDIT3 expression was associated with overall survival (OS) significant. Following the knockdown of DDIT3 in MCF-7 cells, the proliferation rate was significantly increased, and drug resistance ability was just reversed. On the contrary, overexpression of DDIT3 had a relative inhibitory effect on target cell proliferation. Notably, the inhibition of DDIT3 expression upregulated TP63 and downregulated PDGFR, with the results being exactly opposite after the overexpression of DDIT3. Conclusion: These results have revealed that DDIT3 plays a critical role in luminal A type BC cell proliferation and TAM resistance, and it holds potential prognostic value in BC. Overall, DDIT3 may exert its functions in luminal A type BC by modulating the expression of TP63 and PDGFR.