Distinct microRNA expression pattern in breast cancer cells following anti-neoplastic treatment: A systematic review and functional analysis of microRNA target genes.

Breast cancer remains a significant cause of mortality in females worldwide, despite advances in technology and treatment. MicroRNA expression in breast cancer is studied both as potential biomarkers and for therapeutic purposes. Accumulated evidence revealed microRNA profile of various types of cancer cells following antineoplastic treatment. The progression of research in this area provides better understanding on the anti-cancer mechanism of various natural compounds and drugs specifically on the microRNA regulation. Hence, we aim to systematically review differentially expressed microRNA in MCF-7, a commonly studied breast cancer cell line, after treatment with anti-neoplastic agents. Relevant keywords were used to screen for research articles that reported on the differentially expressed microRNAs in experimental models of MCF-7 before and after anti-neoplastic treatment. Target genes of microRNAs were identified from MiRTarbase and further in silico functional analysis of the target genes were performed using DAVID bioinformatic resources. Two upregulated microRNAs (mir-200c and let-7d) and 3 downregulated microRNAs (mir-27a, mir-27b and mir-203) were identified by highest number of studies. Three microRNAs (let-7a, mir-23a and mir-7) showed inconsistent direction of expression. Genes functional analysis revealed the regulatory effect of microRNA on genes related to angiogenesis, hypoxia, P53, FoxO and PI3K-AKT signalling. Clusters of genes associated to the pathway of angiogenesis, cancers, cell proliferation and apoptosis were noted through protein-protein interaction analysis. MicroRNAs, especially the mir-200c, let-7d, mir-27a, mir-27b and mir-203 from this review could be further validated experimentally to serve as molecular target or biomarkers for anti-neoplastic therapy.

Simple and rapid detection of Salmonella strains by direct PCR amplification of the hilA gene.

The suitability of a PCR procedure using a pair of primers targeting the hilA gene was evaluated as a means of detecting Salmonella species. A total of 33 Salmonella strains from 27 serovars and 15 non-Salmonella strains from eight different genera were included. PCR with all the Salmonella strains produced a 784 bp DNA fragment that was absent from all the non-Salmonella strains tested. The detection limit of the PCR was 100 pg with genomic DNA and 3 x 10(4) c.f.u. ml(-1) with serial dilutions of bacterial culture. An enrichment-PCR method was further developed to test the sensitivity of the hilA primers for the detection of Salmonella in faecal samples spiked with different concentrations of Salmonella choleraesuis subsp. choleraesuis serovar Typhimurium. The method described allowed the detection of Salmonella Typhimurium in faecal samples at a concentration of 3 x 10(2) c.f.u. ml(-1). In conclusion, the hilA primers are specific for Salmonella species and the PCR method presented may be suitable for the detection of Salmonella in faeces.