Prognostic effects of the expression of inhibitor of DNA-binding family members on patients with lung adenocarcinoma.

The basic helix-loop-helix (bHLH) transcription factors are negatively regulated by inhibitor of DNA-binding (ID) proteins. Several studies have demonstrated that ID family proteins are dysregulated in a variety of cancer types, including in lung adenocarcinoma (LUAD). In current study, the prognostic value of ID family members was evaluated by investigating publicly accessible databases, including Oncomine, Kaplan-Meier plotter, UALCAN and the Human Protein Atlas. It was observed that the mRNA expression of all ID members was downregulated in LUAD tumor tissues compared with those in normal tissues according to the Oncomine and UALCAN databases. Additionally, increased mRNA expression levels of ID2 and ID1 were associated with improved and poorer survival time, respectively. Notably, ID3 and ID4 expression was not associated with survival in patients with LUAD. At the protein level, high ID2 significantly predicted an improved survival outcome while high ID1 is associated with shorter survival time. Thus, the results indicate that the ID proteins, particularly ID2, exhibit significant prognostic value in LUAD. More studies are required to elucidate the underlying molecular mechanisms behind the role of the ID family in the development of LUAD.