Detection of Calreticulin as a Candidate Prognostic Biomarker in Invasive Breast Carcinoma from a Biological Scaffold-Based 3D Co-culture System

@#Introduction: Breast cancer is the most common cancer in women and the world’s second leading cause of death in women, after lung cancer. Calreticulin (CRT), an endoplasmic reticulum (ER) multipurpose protein, has been proposed as a potential biomarker for breast cancer. However, reports on the correlation between CRT expression and cell invasiveness in breast cancer micro-tissues are scarce. Thus, in the current study, we analyzed the potential correlation between CRT and invasiveness of breast cancer in a biological scaffold-based 3D co-culture system. Methods: MCF7, MDA-MB-231 and MCF-10A breast cell lines were co-cultured in a 3-dimensional (3D) system with MRC-5 lung fibroblast cell line in the cell density ratio of 3:1. Thereafter, calreticulin gene and protein expression levels were determined based on quantitative reverse transcription-polymerase chain reaction (RT-qPCR) and immunohistochemistry, respectively. Moreover, via RT-qPCR analysis, the gene expression levels of calreticulin-related candidate metastasis genes in breast cancer micro-tissues were carried out. Results: The results showed occasional foci of lumen-like morphology in the non-cancerous breast micro-tissues and the formation of solid clusters for breast cancer micro-tissues. Moreover, immunohistochemistry results revealed protein expression of calreticulin in non-cancerous and cancerous breast micro-tissues with cytoplasmic and nucleic acid localizations. It was found that PCMT1 and ER-α genes were significantly downregulated (p < 0.01) in invasive breast cancer micro-tissues. Conclusion: This study suggests that CRT and CRT-related candidate metastasis genes may potentially serve as prognostic biomarkers in invasive breast carcinoma.

The Potentiality of Citral in Targeting Breast Cancer Multicellular Tumour Spheroids (MTS)

@#Introduction: As the high incidence of breast cancer has a profound impact on a global scale, there is a critical need to improve the clinical outcome of the patients, including efforts to utilize bioactive natural products as treatment or preventive measures. Citral, the essential oil of lemongrass has been reported to possess cytotoxicity in breast cancer cell line . The aim of present study was to determine the capability of citral in targeting aldehyde dehydrogenase-positive (ALDH+) cells in breast cancer cells. Methods: Both MCF-7 and MDA-MB-231 cells were cultured in serum-free media to generate multicellular tumour spheroids for the evaluation of citral as an antiproliferative agent. The cells were treated with identified IC50 (50±4.30 µM and 56±3.17 µM of citral, respectively) to investigate the cytotoxicity of citral. Staining using Propidium Iodide (PI) and Hoechst 33342 was carried out to determine cell proliferation and viability. Finally, ALDH+ cells were quantified via ALDEFLUOR assay. Analysis of differences was carried out by analysis of variance (ANOVA) and independent t-test with p<0.05 considered statistically significant. Results: The size of spheroids in both cancer cell lines were reduced after treatment with the citral. PI and Hoechst 33342 staining also revealed that citral gave rise to a mixture of cells that are normal and undergoing apoptosis and necrosis. ALDEFLUOR assay analysis revealed citral significantly (p <0.05 ) inhibited the population of ALDH+ cells in MCF7 cells. Conclusion: It was demonstrated that citral reduced the ALDH+ cell population in MCF7 breast cancer spheroids by inhibiting the ALDH activity.

Matrix Metallopeptidase 3 Polymorphisms: Emerging genetic Markers in Human Breast Cancer Metastasis / 한국유방암학회지

Matrix metallopeptidase 3 or MMP3, is a zinc-dependent proteolytic enzyme that is involved in various physiological processes via modification of the extracellular matrix. In particular, its over-expression has been associated with cancer metastasis and tumor growth in various cancers including breast cancer. MMP3 gene expression is regulated by several factors such as DNA polymorphisms which also serve as risk factors for breast cancer. As such, DNA polymorphisms of MMP3 have the potential to be utilized as genetic biomarkers for prediction and prognosis of metastatic breast cancer. Presently, genome-wide association studies of MMP3 gene polymorphisms which are associated with breast cancer risk and patient survival in a variety of populations are reviewed. In order to understand the potential role of MMP3 polymorphisms as genetic markers for breast cancer metastasis, the domain structure of MMP3, the regulation of its expression and its role in breast cancer metastasis are also briefly discussed in this review. The emergence of MMP3 gene polymorphisms as prognostic biomarker candidates for breast cancer metastasis may contribute towards improving targeted therapies and categorization of breast cancer cases in order to provide a better and more accurate prognosis.

Development and Validation of High Resolution Melting Assays for High-Throughput Screening of BDNF rs6265 and DAT1 rs40184

@#Introduction: One of the commonly used techniques for mutation screening is High Resolution Melting (HRM) analysis. HRM is a post PCR method that relies on the detection of the fluorescent signals acquired due to the release of DNA intercalated dyes upon the melting of dsDNA to ssDNA. The method is simple, inexpensive and does not require post PCR-handling, making it suitable for high throughput screening. Methods: This study aimed to develop and validate HRM technique for the screening of two disease-associated single nucleotide polymorphisms (SNPs) namely BDNF rs6265 and DAT1 rs40184 using a total of 30 gDNA samples. The obtained results were confirmed and validated by sequencing. Results: HRM analysis showed that the predicted genotypes of BDNF rs6265 and DAT1 rs40184 among all the gDNA samples were in 100% concordance with the sequencing results, making it an accurate and sensitive method for the detection of SNPs. Conclusions: The application of HRM can accurately determine the genotype of BDNF rs6265 and DAT1 rs40184 SNPs, making it a promising tool for rapid and high-throughput screening of targeted SNPs in a large population study.

MiR-3099 is Overexpressed in Differentiating 46c Mouse Embryonic Stem Cells upon Neural Induction

Background: MicroRNAs (miRNAs) have a crucial role in gene expression regulation and protein synthesis, especially in the central nervous system. In developing mouse embryos a novel miRNA, miR-3099, is highly expressed, particularly in the central nervous system. This study aims to determine the expression of miR-3099 during cellular differentiation of 46C mouse embryonic stem cells after neural induction with N2/B27 medium. Methods: 46C mouse embryonic stem cells were subjected to neural induction with N2/B27 medium. At 0, 3, 7, 11, 17, and 22 days after neural induction, the cells were screened for various pluripotent, progenitor, and differentiating/differentiated cells markers by immunocytochemistry and reverse-transcriptase polymerase chain reaction (RT-PCR). Stem-loop pulse RT-PCR was performed to determine the expression of miR-3099 at all selected time points after neural induction. Results: Our findings showed that after induction, mouse embryonic stem cells differentiated into heterogeneous pools of cells containing neurons, astrocytes, and oligodendrocytes. Mouse embryonic stem cells and neural progenitor/precursor cells were also present in culture up to day 22 as indicated by RT-PCR analysis. Elucidation of miR-3099 expression during in vitro neural induction revealed that this miRNA was expressed throughout the differentiation process of 46C mouse embryonic stem cells. miR-3099 was expressed at higher levels on day 11, 17, and 22 as compared to day 0, 3 and 7 after neural induction. Conclusion: The level of miR-3099 expression was higher in differentiated mouse embryonic stem cells after neural induction. This finding suggested that miR-3099 might play a role in regulating neural stem cell differentiation. However, further characterisation of miR-3099 in a better characterised or optimised differentiated neural stem cell culture would provide increased understanding of the cellular function and molecular targets of miR-3099, especially in neuron development.

Neural Commitment of Embryonic Stem Cells through the Formation of Embryoid Bodies (EBs)

An embryonic stem cell (ESC) is a good tool to generate neurons in vitro and can be used to mimic neural development in vivo. It has been widely used in research to examine the role of cell signalling during neuronal development, test the effects of drugs on neurons, and generate a large population of functional neurons. So far, a number of protocols have been established to promote the differentiation of ESCs, such as direct and indirect differentiation. One of the widely used protocols to generate neurons is through the spontaneous formation of multicellular aggregates known as embryonic bodies (EBs). However, for some, it is not clear why EB protocol could be the protocol of choice. EB also is known to mimic an early embryo; hence, knowing the similarities between EB and an early embryo is essential, particularly the information on the players that promote the formation of EBs or the aggregation of ESCs. This review paper focuses on these issues and discusses further the generation of neural cells from EBs using a well-known protocol, the 4−/4+ protocol.