Down-regulation of LINC-ROR, HOXA-AS2 and MEG3 in gastric cancer.

Long non-coding RNAs (lncRNAs) have been identified as modulators of gastric carcinogenesis. Evaluation of expression amounts of these transcripts is a primary but essential step for recognition of the role of lncRNAs in the carcinogenesis. Therefore, we compared expressions of LINC-ROR, HOXA-AS2, MEG3 and HOTTIP lncRNAs in gastric cancer samples and nearby non-cancerous samples. Expression levels of LINC-ROR, HOXA-AS2 and MEG3 lncRNAs have been lower in gastric cancer samples compared with nearby non-cancerous samples (Expression ratios = 0.26, 0.37 and 0.36; P values = 0.021, 0.015 and 0.032, respectively). However, expression levels of HOTTIP were not significantly different between gastric cancer tissues and nearby tissues (P value = 0.43). HOTTIP expression was associated with tumor size (P value = 0.04). In addition, MEG3 expression was associated with site of primary tumor (P = 0.0003). Expressions of LINC-ROR and HOXA-AS2 were not associated with any clinical or pathological parameter. ROC curve analysis revealed that HOXA-AS2 and LINC-ROR could significantly differentiate between gastric cancer samples and nearby non-cancerous tissues (AUC values = 0.68 and 0.64; P values = 0.01 and 0.04, respectively). Taken together, the current investigation provides clues for contribution of LINC-ROR, HOXA-AS2 and MEG3 lncRNAs in gastric carcinogenesis and warrants further mechanistical assays.

Expression levels of ABCG2 and CD61 genes in breast cancer tissues of Iranian population.

Breast cancer as the most common female cancer is a malignancy with heterogeneous course. Dysregulation of several genes has been associated with development of this malignancy. Among these genes are the stem cell markers CD61 and breast cancer resistance protein (BCRP or ATP-binding cassette super-family G member 2 (ABCG2)). ABCG2 is one of the major efflux transporters implicated in multidrug resistance in cancer cells. In the present study, we compared expression of CD61 and ABCG2 transcripts between 30 breast cancer tissues and matched adjacent non-cancerous tissues (ANCTs) using real time qPCR technique. There was no significant difference in expression of CD61 or ABCG2 between tumoral tissues and ANCTs (Expression ratios = 1.21 and 0.98, P values = 0.55 and 0.96, respectively). There was a trend toward association between relative expression of CD61 (tumoral tissues versus ANCTs) and patients' age (P = 0.05) in a way that older patients tended to over-express this marker in their tumoral tissues compared with the matched ANCTs. Moreover, there was a significant association between expression of this gene and tumor size (P = 0.04) in a way that all tumors with sizes less than 2 cm showed down-regulation of CD61 (as compared with the matched ANCTs). Expression of CD61 was significantly higher in tumor tissues with extracapsular nodal extension compared with confined lesions (P = 0.007). Moreover, expression of ABCG2 was significantly higher in tumor tissues of patients aged less than 55 years compared with older patients (P = 0.04). There was no significant correlation between expression of CD61 and ABCG2 either in tumoral tissues or in ANCTs. The current investigation shows association or trends toward association between expression of two cancer stem cell markers and some clinical data of breast cancer patients such as extracapsular nodal extension, age and tumor size which might imply their importance in the pathogenesis of breast cancer.

Expression analysis of CD24 and CD44 transcripts in Iranian breast cancer patients.

BACKGROUND: The importance of cancer stem cells (CSCs) in initiation and progression of breast cancer has been well established. This population of cells is characterized by high expression of CD44 and low expression of CD24. OBJECTIVE: However, the relative abundance of CD24 and CD44 transcripts in breast cancer tissues and adjacent non-cancerous tissues (ANCTs) has not been quantified yet. METHODS: In the present investigation, we assessed expression of CD24 and CD44 at transcript level in breast cancer tissues and ANCTs in association with clinical determinants of patients' outcome and parameters that predict response to therapeutic options. RESULTS: There was no significant difference in expression of CD24 and CD44 in breast cancer tissues compared with ANCTs (Expression ratios: 1.03 and 0.84, P values: 0.92 and 0.61, respectively). However, CD44 expression was associated with tumor size in a way this gene was up-regulated in all of small sized (≤2 cm) tumors compared with the corresponding ANCTs (P value = 0.04). Besides, CD44 expression was significantly higher in tumors with extracapsular nodal extension compared with those without extension (P = 0.04). Expression of CD24 was higher in grade 3 tumors compared with grade 2 tumors (P = 0.04). CONCLUSION: Expression levels of CD24 and CD44 were correlated with each other in ANCTs but not in tumoral tissues. The current study shows another aspect of CSC markers in the development of breast cancer.