Vol. 2, Issue 1, Part A (2022)

Purpose: Aberrant expression of miRNA in tumor cells have been studied for almost a decade for their association with survival. This systematic review summarizes the miRNAs found to have increased expression in doxorubicin-resistant breast cancer cells, their roles in cell survival, and clinical utility of creating a miRNA panel to detect doxorubicin-resistance. Methods: A search in PubMed and Google Scholar was performed to identify studies published until July 2021 on miRNAs associated with doxorubicin-resistance in breast cancer cells. Articles selected for inclusion were evaluated for risk of bias and assessed for quality by using MOOSE guidelines. The identified miRNAs and their roles in cell survival were summarized. Results: A total of 8 studies were included in this systematic review. Most of the studies were primary research of miRNAs associated with doxorubicin-resistance as well as the function of the gene products they produce and their role in chemoresistance. Six different miRNAs with increased expression in doxorubicin-resistant cells relative to parental breast cancer cells (miRNA-200, miRNA-31, miRNA-141, miRNA-429, miRNA-21, miRNA-181) were described in more than one study. Conclusion: This systematic review is limited by lack of homogeneity between the included studies owing to sparse data on the subject. Because of the multifactorial process of chemoresistance, several variables and their individual effects on miRNA expression levels are not accounted for consistently across studies due to limited data. More studies are needed to substantiate the increasing evidence that these miRNAs can characterize a chemoresistant phenotype. In the future, the identification of miRNA expression levels in chemoresistant cancer cells can aid in directing therapies to combat their respective mechanism of resistance.