Expression assessment of a panel of long non-coding RNAs in gastric malignancy.

BACKGROUND: Long non-coding RNAs (lncRNAs) have several important functions in the regulation of cell homeostasis and cell fate. Consequently, abnormal transcription of lncRNAs has been correlated with malignant transformation of cells. These human transcripts have been shown to participate in the progression of gastric cancer. METHODS: In the current project, we evaluated expression of a panel of lncRNAs including HULC, MALAT1, FAS-AS1, GAS5, PVT1, OIP5-AS1 and THRIL in 30 gastric cancer tissues and paired adjacent non-cancerous tissues (ANCTs) using quantitative real-time PCR. RESULTS: HULC, OIP5-AS1 and THRIL transcription quantities were significantly lower in gastric tumors compared to ANCTs (P values = .02, 0.02 and 0.007, respectively). Relative transcription quantities of HULC, MALAT1, OIP5-AS1, PVT1, FAS-AS1 and THRIL were associated with the site of the primary tumor (P values = .002, 0.003, 0.002, 0.002, 0.002, and 0.001, respectively). Moreover, relative expression levels of PVT1 were associated with history of smoking (P value = .04). Correlations were identified between transcript quantities of these lncRNAs in both tumor samples and ANCTs. Receiver operating characteristic curve assessment demonstrated that THRIL had the highest diagnostic power among the mentioned lncRNAs (area under curve (AUC) = 0.72, P value = .001). HULC and OIP5-AS1 ranked afterwards (AUC values of 0.69 and 0.68; P values = .005 and 0.007, respectively). CONCLUSION: The current investigation underscores the dysregulation of these transcripts in gastric cancer specimens and suggests a number of these transcripts for further assessments of their suitability as cancer biomarkers.

Assessment of SGO1 and SGO1-AS1 contribution in breast cancer.

Shugoshin-like protein 1 (SGO1) participated in the proper progression of mitosis. This fundamental role has indicated the importance of this gene in the pathogenesis of cancer as a disorder of mitotic cell division. A previous high throughput study of long non-coding RNAs (lncRNAs) expression in lung cancer has identified aberrant expression of SGO1-antisense 1 (SGO1-AS1) in these specimens. In the current study, we quantified expression of SGO1 and SGO1-AS1 in 39 breast cancer tissues and their paired adjacent non-cancerous tissues (ANCTs). Expression of SGO1-AS1 was considerably decreased in tumoral tissues compared with ANCTs (expression ratio = 0.49, P value = 0.03). However, we could not identify significant difference in expression of SGO1 between these two sets of specimens (expression ratio = 2.9, P value = 0.2). Transcript quantities of SGO1-AS1 were associated with age at disease onset (P= 0.01). Expression of either gene was associated with hormone receptors status or clinical features such as grade and stage. There was an inverse correlation between expressions of genes in both sets of samples. Finally, transcript amounts of SGO1-AS1 could distinguish these two sets of samples with accuracy of 63% (P value = 0.03). Our results imply significance of SGO1-AS1 in breast cancer and necessitate conduction of mechanistic studies to find the molecular pathways in this regard.