Docosahexaenoic Acid (DHA) Impairs Docetaxel-Induced Up-regulation of miR-30a-5p and miR-126-5p Tumor Suppressors in Gastric Cancer Cell Line

Owing to the synergistic effects of omega-3 fatty acids with chemotherapeutic agents in boosting response rates in gastric cancer (GC) patients, they became a promising addition to cancer therapy. Due to microRNAs (miRNAs) involvement in various cellular functions, their alterations in response to therapeutic interventions can offer insight into the efficacy of treatments. Our objective was to investigate docosahexaenoic acid (DHA) effects in conjunction with docetaxel on miR-30a-5p and miR-126-5p expressions in the MKN-45 cell line.

The CancerMIRNome database was used to investigate miR-30a-5p and miR-126-5p expression changes, as well as their relation to diagnosis and survival in GC patients. Then, MKN-45 cells were treated with docetaxel, DHA, and their combination. Later, RT-qPCR was performed to measure miR-30a-5p and miR-126-5p expression levels.

It was discovered that miR-30a-5p and miR-126-5p expression were both decreased in GC patients and associated with GC diagnosis and survival, respectively. Following treatment with docetaxel and docetaxel-DHA, miR-30a-5p and miR-126-5p expression levels increased. Of course, the increase in miRNAs' expression observed in the combination form was not as strong as docetaxel alone. DHA alone decreased miR-30a-5p and miR-126-5p expressions.

miR-30a-5p and miR-126-5p have important roles in GC tumorigenesis, and response to docetaxel and DHA. Attenuating effects of DHA on miR-30a-5p and miR-126-5p expression levels appear to counteract the beneficial effects of docetaxel on these miRNAs. Therefore, even though there is evidence of the anti-cancer effects of DHA in GC, not all DHA effects are anti-cancer.