Background and Purpose: Breast cancer still remains to be one of the most threatening cancer types in women. Recent studies have allowed scientists to better investigate the potential use of natural compounds in the treatment of breast cancers. Usnic acid is a secondary metabolite extracted from lichen species and has many biological activities. The response of microRNAs regulated by drug molecules may provide useful diagnostic and prognostic biomarkers, as well as potential therapeutics for breast cancers. Although the aberrant expression of microRNAs was observed after drug treatment, the regulatory mechanisms remain partially known. Micro RNAs (miRNAs) play an important role in gene regulation at the post-transcriptional level. Methods: In this study, we used quantitative Real-Time PCR (qRT-PCR) technology to demonstrate that usnic acid significantly changes the expression profile of miRNAs. Results: Eleven miRNAs were significantly and differentially expressed in breast cancer cells after treatment with usnic acid. Three miRNAs were up-regulated, while eight were down-regulated in usnic acid treated cells. Target prediction and GO analysis revealed many target genes and their related pathways that are potentially regulated by usnic acid regulated differentially expressed miRNAs. We found that usnic acid treatment caused significant changes in the expression of hsa-miR-5006-5p, hsa-miR-892c-3p, hsa-miR-4430, hsa-miR-5194, hsa-miR-3198, hsa-miR-3171, hsa-miR-933 and hsa-miR-185-3p in breast cancer cells. Conclusions: Usnic acid response miRNAs might play important regulatory roles in the tumorigenesis and development of breast cancer, and they could serve as prognostic predictors for breast cancer patients.

Background Breast cancer is the most frequently diagnosed cancer, and no effective treatment solution has yet been found. The number of studies based on the research of novel natural compounds in the treatment of breast cancer has been increasing in recent years. The anticancer properties of natural compounds are related to the regulation of microRNA (miRNA) expression. Therefore, changing the profile of miRNAs with the use of natural products is very important in cancer treatment. However, the role of vulpinic acid and related miRNAs in breast cancer progression remains unknown. Vulpinic acid, methyl (as2E)-2-(3-hydroxy-5-oxo-4-phenylfuran-2-ylidene)-2 phenylacetate, is a natural product extracted from the lichen species and shows an anticancer effect on different cancer cells. Methods This study examines the effects of vulpinic acid on the miRNA levels of breast cancer (MCF-7) cells and its relationship with cell proliferation and apoptosis levels. The antiproliferative effect of vulpinic acid was screened against MCF-7 breast cancer cells and MCF-12A breast epithelial cells using the xCELLigence real-time cell analysis system. We analyzed the altered miRNA expression profile in MCF-7 breast cancer cells versus MCF-12A cells following their response to vulpinic acid through microarray analysis. The microarray analysis results were confirmed through quantitative real-time PCR and bioinformatics analysis. Results The results of the miRNA array and bioinformatic analyses demonstrated that 12 miRNAs were specifically responsive to vulpinic acid in MCF-7 breast cancer cells. This is the first study to reveal that vulpinic acid inhibits the expression of 12 miRNAs and suppresses breast cancer cell proliferation. The study also revealed that vulpinic acid may downregulate the expression of 12 miRNAs by repressing the FOXO-3 gene. The miRNA targets were mainly found to play a role in the apoptosis, cell cycle and MAPK pathways. Moreover, Bcl-2, Bax, procaspase-3 and procaspase-9 protein levels were assessed by western blot analysis for validation of apoptosis at the protein level. Conclusion This study revealed the molecular mechanisms of vulpinic acid on breast cancer and showed that vulpinic acid regulates apoptosis signaling pathways by decreasing the expression of miRNAs. The miRNA expression patterns illuminate the underlying effect of vulpinic acid in breast cancer treatment. Graphical Abstract

Sporopollenin-mediated controlled drug delivery has been studied extensively owing to its physicochemical and biological charachteristics. In the present study, sporopollenin was successfully extracted from pollen grains of C. libani and P. nigra followed by the loading of a commonly known anticancer drug Oxaliplatin. Both the drug loading and physicochemical features were confirmed by using light microscopy, FT-IR, SEM and TGA. For the first time, real-time cell analyzer system, xCELLigence, was employed to record the Oxaliplatin-loaded and sporopollenin-mediated cell death (CaCo-2 and Vero cells) in real time. Both the assays confirmed the slow release of Oxaliplatin from sporopollenin for around 40–45 h. The expression of MYC and FOXO-3 genes significantly increased in CaCo2 cell and decreased non-cancerous Vero cell confirming that sporopollenin-mediated controlled release of Oxaliplatin was promoting apoptosis cell death preventing the spread of its negative effects to nearby healthy cells. All the results suggested that C. libani and P. nigra could be suitable candidates for slow delivery of drugs.

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Sporopollenin-mediated controlled drug delivery has been studied extensively owing to its physicochemical and biological charachteristics. In the present study, sporopollenin was successfully extracted from pollen grains of C. libani and P. nigra followed by the loading of a commonly known anticancer drug Oxaliplatin. Both the drug loading and physicochemical features were confirmed by using light microscopy, FT-IR, SEM and TGA. For the first time, real-time cell analyzer system, xCELLigence, was employed to record the Oxaliplatin-loaded and sporopollenin-mediated cell death (CaCo-2 and Vero cells) in real time. Both the assays confirmed the slow release of Oxaliplatin from sporopollenin for around 40-45 h. The expression of MYC and FOXO-3 genes significantly increased in CaCo2 cell and decreased non-cancerous Vero cell confirming that sporopollenin-mediated controlled release of Oxaliplatin was promoting apoptosis cell death preventing the spread of its negative effects to nearby healthy cells. All the results suggested that C. libani and P. nigra could be suitable candidates for slow delivery of drugs.