Metastasis‑associated
lung adenocarcinoma transcript 1 (MALAT1) is a long non‑coding
RNA that is overexpressed in various human
cancers, including
breast cancer. Evidence has associated the function of the α‑2,8‑sialyltransferase (ST8SIA) family with
breast cancer. The present study aimed to investigate the potential roles of MALAT1 in
breast cancer development and progression using analyses of both
breast cancer tissues and cell lines. The
mRNA levels of MALAT1,
microRNA (miR)‑26a/26b and ST8SIA4 were detected by reverse transcription‑quantitative PCR (RT‑qPCR) and the
protein level of ST8SIA4 was assessed by western blot analysis. Cell proliferation, invasion and migration were detected by CCK‑8, wound healing and Transwell assays, respectively. Interactions between MALAT1 and miR‑26a/26b were assessed using fluorescence in situ hybridization,
RNA immunoprecipitation and
luciferase reporter assays. Herein, different levels of MALAT1 were primarily observed in human
breast cancer samples and cells. Upregulated MALAT1 was a crucial predictor of poor
breast cancer prognosis. Altered MALAT1 modulated cell progression in
breast cancer. Moreover, miR‑26a/26b was confirmed as a direct regulator of MALAT1, and ST8SIA4 was predicted as a target of miR‑26a/26b. Functional analysis in human
breast cancer cell lines demonstrated that MALAT1 modulated
breast cancer cell tumorigenicity by acting as a competing endogenous
lncRNA (
ceRNA) to regulate ST8SIA4 levels by sponging miR‑26a/26b. The identification of the MALAT1/miR‑26a/26b/ST8SIA4 axis which contributes to
breast cancer progression may constitute a potential new therapeutic target.