Long non‑coding RNA signatures in breast cancer: Properties as biomarkers?

Breast cancer represents the most common type of cancer in females worldwide. The survival rates for breast cancer patients have been increasing since 1990. However, in 2023 breast cancer is still the second most common cause of malignancy-associated death in women. One decisive reason is the increase of treatment resistance and low therapy response. Therefore, new therapy targets and predictive markers for the response to treatment are needed. The present study analyzed the potential effects triggered by different breast cancer treatments on the transcriptional expression of 12 pre-selected long non-coding (lnc) RNAs and the proliferation markers Cyclin D1 and Ki-67 in six different breast cancer cell lines (BT-474, MDA-MB-231, BT-20, T-47D, SKBR-3 and MCF-7). The results revealed that lncRNA cytoskeleton regulator RNA may be an appropriate biomarker for the response to treatment with both epirubicin and gemcitabine (P<0.001). NF-ĸB interacting lnc RNA may be a marker for therapy response (P<0.001), while HOX transcript antisense RNA overexpression suggested resistance to treatment (P<0.001) with epirubicin. The transcriptional expression of lncRNA BC4 increased during treatment with epirubicin and gemcitabine, which indicated therapy response. Overall, the present data suggested that the aforementioned lncRNAs have a promising potential as biomarkers to detect early therapy response or resistance in and therefore should be analyzed in more detail.