Diabetes regulated anti-inflammatory lncRNA is overexpressed in triple-negative breast cancer and predicts chemoresistance and tumor recurrence.

Diabetes regulated anti-inflammatory lncRNA (DRAIR) has been characterized as a critical player in type 2 diabetes mellitus. However, its role in other human diseases is unclear. Our preliminary sequencing analysis revealed an altered DRAIR level in triple-negative breast cancer (TNBC). We then explored the involvement of DRAIR in TNBC. In this study, plasma was collected from healthy controls (n = 60) and TNBC patients (n = 60). Non-tumor tissues and paired TNBC were also collected from TNBC patients. All TNBC patients received surgical resection of the primary tumors and chemotherapy. The 60 TNBC patients were divided into high and low plasma DRAIR level groups with median plasma DRAIR level as the cutoff value, and the occurrence of chemoresistance after treatment and tumor recurrence during a 5-year follow-up was monitored. Cell proliferation and viability were analyzed with BrdU assay and MTT assay, respectively. We found that plasma DRAIR levels were higher in TNBC patients than in controls. In addition, DRAIR expression in TNBC tissues was also significantly increased in TNBC tissues compared to the paired non-tumor tissues. Plasma DRAIR was positively and significantly related to DRAIR levels in TNBC tissues but not in non-tumor tissues. Patients in the high plasma DRAIR level group showed a significantly higher rate of chemoresistance after treatment and tumor recurrence during the follow-up. DRAIR promoted tumor cell proliferation and increased cell viability under doxorubicin treatment. Therefore, DRAIR is overexpressed in TNBC and predicts chemoresistance and tumor recurrence.