Differential Expression Profile of miR-27b, miR-29a, and miR-155 in Chronic Lymphocytic Leukemia and Breast Cancer Patients.

Over the past decade, studies on microRNA (miRNA) and cancer quickly became known. miRNAs are small non-coding RNAs that play a vital role in regulation of gene expression. In the present study, the expression of miR-27b, miR-29a, and miR-155, their prognostic roles, and their potential targets in chronic lymphocytic leukemia (CLL) and breast cancer (BC) by qRT-PCR were investigated. In two case-control studies, qRT-PCR was used to analyze the peripheral blood serum of 15 CLL patients and tissue samples of 15 BC patients for the expression of miR-27b, miR-29a, and miR-155. miRNA expression levels were calculated using the qRT-PCR method. The results revealed a significant increase in the expression of all miRNAs in patients with BC and CLL compared with respective healthy groups (p < 0.001). In BC patients, there was a significant difference between the expression of miR-155 and miR-29a (p < 0.05), miR-155 and miR-27b (p < 0.01), and miR-27b and miR-29a (p < 0.001). In CLL patients, a significant difference between expression of both miR-27b and miR-29a compared with expression of miR-155 (p < 0.001) was found. Furthermore, a significant association between miR-155 and prevascular invasion was found. Significantly, elevated circulating miRNAs were shown to be BC specific and could differentiate BC tissues from the controls. It was demonstrated that miRNAs used in this study and their expression profiles can be developed as biomarkers for early diagnosis and prognosis of CLL and BC. Further studies utilizing a larger test group of patients would provide identification of miRNAs as key players in intercellular interactions.

A Comparative Study of HOTAIR Expression in Breast Cancer Patient Tissues and Cell Lines.

OBJECTIVE: Recent data suggest that increased levels of the HOTAIR long non-coding RNA (lncRNA) are involved in the development of various types of malignancy, including breast cancer. The aim of present study was to investigate HOTAIR lncRNA expression profile in breast cancer (BC) patients and cell lines. MATERIALS AND METHODS: In this experimental study, expression level of HOTAIR lncRNA was evaluated in BC and normal tissues of 15 patients as well as MDA-MB-231, MCF-7 and MCF-10A cell lines, using quantitative reversetranscription polymerase chain reaction (qRT-PCR). HOTAIR lncRNA expression levels were estimated using 2-ΔΔCt method. Further, receiver operating characteristic (ROC) curve analysis was done to evaluate the selected lncRNA diagnostic potential. The Cox's proportional hazards regression model was performed to evaluate the predictive value of this lncRNA level in BC patients. RESULTS: The results of present study demonstrated no significant difference in the expression of HOTAIR lncRNA in MCF7 and MDA-MB-231 cancer cell lines compared to MCF-10A as normal cell line (P>0.05). However, we observed a significantly increase in the expression of HOTAIR in BC patients compared to normal tissues (P<0.001). Significant associations were found between gene expression and tumour size and margin. We found 91.1% sensitivity and 95.7% specificity of circulating HOTAIR with an area under the ROC curve of 0.969. The Kaplan-Meier analysis indicated significant correlation between HOTAIR expression and overall survival. CONCLUSION: This study demonstrated that expression of HOTAIR is increased in BC and might be associated with its progression. According to these findings, HOTAIR expression could be proposed as biomarkers for BC early diagnosis and prognosis.

Evaluation of the Radiosensitizing Potency of Bromelain for Radiation Therapy of 4T1 Breast Cancer Cells.

Breast cancer (BC) remains the leading cause of death in women worldwide, despite the improvements of cancer screening and treatment methods. Recently, development of novel anticancer drugs for the improved prevention and treatment of BC is in the center of research. The anticancer effects of bromelain, as enzyme extract derived from the pineapples, contains chemicals that interfere with the growth of tumor cells. The aim of this study was to evaluate the effect of radiosensitizing of bromelain in 4T1 BC cells. This investigation utilized the 3-(4,5-dimethylthiazol-2-yl)-2,5-dimethyltetrazolium bromide assay to characterize the cytotoxicity of bromelain. Colony formation method was used to establish the truth of the capability of bromelain to make sensitive to radiation therapy. Flowcytometry performed to define the contribution the apoptosis effect to bromelain mediated radiosensitization of 4T1 cells. Bromelain reduced growth and proliferation of 4T1 cell as a concentration-dependence manner significantly. The survival of 4T1 cancer cells was decreased after combined treatment in a number and size-dependent manner with regard to the control group (P < 0.05). Combination of bromelain with radiation does not influence 4T1 cell apoptosis. The results suggested that bromelain can inhibit the growth and proliferation and reduce survival of 4T1 BC cells and might be used as a candidate radiosensitizer in BC patient.

ARA lncRNA, is upregulated in liver and breast tumor tissues.

Important regulatory roles of long non-coding RNAs (lncRNAs) have been recently found, and reported as useful biomarkers in cancer. To identify a potential expression of the new discovered lncRNA (ARA), during promotes cell proliferation, apoptosis inhibit, migration and cell cycle arrest, we firstly evaluate its expression in two cancer tissues (breast cancer and liver cancer) and then compared its variability expression in tumor versus non-tumor samples. Expression profile of ARA lncRNA was evaluated using qRT-PCR in paired tumor and marginal non-tumor samples collected from patients who had been referred to the Shiraz General. After RNA extraction from tissue samples, cDNA synthesis and RT-qPCR method were performed according to the protocols. ARA lncRNA expression level was calculated using 2-ΔΔCt method. Principal-component analysis followed by receiver operating characteristic curve analyses was performed to evaluate the diagnostic potential of selected lncRNA. Our data revealed a significant upregulation (P < 0.001) of ARA in breast and liver tumor tissues, in comparison to same patients non-tumor marginal samples. Also, there was a significant difference between the expression of ARA lncRNA in breast cancer and liver cancer patients (P < 0.05). In conclusion, the results of our study suggest a possible role of ARA lncRNA in proliferation of breast and liver tissues, as well as its potential usefulness as a novel diagnostic biomarker for breast and liver tumors.