PIK3CA Mutation Analysis in Iranian Patients with Gastric Cancer

Backgrounda: Aberrant activation of phosphatidylinositol-3 kinases (PI3K)/AKT/mTOR (mammalian target of rapamycin) pathway is a critical event during gastric cancer progression. Selective function of AKT inhibitor AZD5363 in PI3KCA mutant gastric cancer necessitates the assessment of PI3KCA mutations in these patients. Methods: The study included 100 patients with gastric cancer who underwent surgical resection at Imam Reza Hospital, Tehran, Iran, between January 2009 and December 2016. Mutations in codon 1047 of PIK3CA were evaluated by tetra-primer ARMS-PCR and direct sequencing methods. Results: We detected p.H1047R and p.H1047L in eight and three samples, respectively. Also, a significant association was found between PIK3CA mutations and lymphatic invasion. Kaplan-Meier analysis demonstrated no significant differences in overall survival between patients with and without mutations. Conclusion: Our study detected gain-of-function mutations in exon 20 of PI3KCA gene in 11% of gastric cancer patients. Future studies are needed to assess the mutation rate in other regions of this gene to find eligible patients for targeted therapies.

Expression analysis of long non-coding ATB and its putative target in breast cancer.

BACKGROUND: A long noncoding RNA (lncRNA) activated by transforming growth factor (TGF)-ß (lncRNA-ATB) has been recently shown to promote the invasion-metastasis cascade in various types of cancers via upregulation of some targets including ZEB1. OBJECTIVES: The aim of the present study was to elucidate the expression of lncRNA-ATB and ZEB in breast cancer patients. METHODS: The expression of these genes was evaluated by real-time reverse transcription polymerase chain reaction in tumor samples form 50 newly diagnosed breast cancer patients as well as their corresponding adjacent non-cancerous tissues (ANCTs). Patients were divided into subsequent groups according to the median lncRNA-ATB expression. RESULTS: LncRNA-ATB has been shown to be downregulated in about two third of tumor samples compared with their ANCTs.A significant association has been found between ZEB1 expression and Ki-67 status. In addition, we demonstrated a correlation between expression of lncRNA-ATB and ZEB1 in tumor samples and not in ANCTs. CONCLUSION: Collectively, out data show downregulation of lncRNA-ATB in a significant number of breast tumor tissues compared with ANCTs and imply that lncRNA-ATB might have distinct roles in the pathogenesis of different cancers or even different subtypes of a certain cancer which should be evaluated in future studies.

Expression Study and Clinical Correlations of MYC and CCAT2 in Breast Cancer Patients

Background: Colon cancer-associated transcript 2 (CCAT2) is a newly recognized lncRNA transcribed from the 8q24 genomic region. It functions as an oncogene in various types of cancers including breast cancer, in which it affects Wnt/ß-catenin pathway. Previous studies have shown a putative interaction between this lncRNA and MYC proto-oncogene. Methods: In the current study, we evaluated the expression of CCAT2 in breast cancer tissues with regards to the expression of its target MYC. In addition, we assessed the relationship between CCAT2 and MYC expression levels in tumor tissues and the clinical prognostic characteristics of breast cancer patients. Results: MYC expression levels were significantly up-regulated in tumor tissues compared with adjacent non-cancerous tissues (ANCTs), while such analysis showed no statistically significant difference between these two tissue types in CCAT2 expression. Starkly increased CCAT2 gene expression levels were found in 12/48 (25%) of cancer tissue samples compared with their corresponding ANCTs. Furthermore, significant inverse correlations were found between CCAT2 expression and stage, as well as lymph node involvement. Besides, a significant inverse correlation was found between the relative MYC expression in tumor tissues compared with their corresponding ANCTs and disease stage. Conclusion: These results highlight the significance of MYC and CCAT2 expressions in the early stages of breast cancer development and suggest a potentially significant role for CCAT2 in a subset of breast cancer patients, which could be applied as a potential therapeutic target in these patients.

Association of MiR-146a Expression and Type 2 Diabetes Mellitus: A Meta-Analysis.

Although deregulation of miR-146a has been reported in type 2 diabetes repeatedly, the direction of deregulation events (up or down) remained to be inconsistent in literatures. Therefore, in this study we performed a meta-analysis on the possible association between miR-146a expression levels and type 2 diabetes. A systematic literature searching of PubMed, ISI Web of Science and Google Scholar was performed up to the end of September 2016. Finally, a total of 12 studies including 344 diabetic patients and 316 controls were selected for meta-analysis. All statistical analysis was performed using the metafor package with R software. Moreover, publication bias was assessed by Egger's and sensitivity analysis was applied on the meta-analysis. The results are presented as log10 odds ratios (logORs), 95% confidence intervals (CI) with relevant P values. The results revealed that miR-146a was downregulated in type 2 diabetes cases compared with normal subjects (P=0.01, logOR:-4.76, 95% CI:-8.41, -1.11). Furthermore, sub-group analysis showed that the association between miR-146a expression levels and type 2 diabetes in whole blood (P<0.001) and PBMCs (P<0.001) samples were significant. However, this association was not significant in the serum (P=0.67) and plasma (P=0.90) samples. Our finding suggests that miR-146a downregulation could be associated with type 2 diabetes susceptibility. Further investigations with larger sample size are required to evaluate this association in the type 2 diabetes pathogenesis.

Comparative expression analysis of hypoxia-inducible factor-alpha and its natural occurring antisense in breast cancer tissues and adjacent noncancerous tissues.

Hypoxia-inducible factors (HIFs) have been shown to be upregulated in tumor tissues and linked with tumor progression and metastasis in breast cancer. Among regulatory mechanisms for HIF expression is a natural occurring antisense named aHIF, which has been shown to be overexpressed in breast cancer and influence the level of the HIF-1α transcript. In the present study, we analyzed the expression of HIF-1α and aHIF in breast cancer tissues versus adjacent noncancer tissues (ANCTs) in relation with the clinical and biological behavior of the tumors. aHIF has been shown to be expressed in 67.4% of invasive ductal carcinoma samples, while none of ANCTs showed its expression. HIF-1α has been expressed in all of tumors and 90% of ANCTs. Comparison of HIF-1α expression level between tumor and ANCT tissues showed a total upregulation in tumor samples. No statistically significant association has been found between the level of HIF-1α expression in tumor samples and clinicopathologic and demographic characteristics such as age, tumor size, estrogen receptor status, progesterone receptor status, HER2/neu expression level, lymph node status, histological grade, and stage except for a weak correlation between HIF-1α expression and Ki-67 status. Besides, we could not detect any significant correlation between relative expression of HIF-1α and aHIF in tumor samples. Collectively, these data suggest that aHIF overexpression can be used as a potential biomarker in breast cancer. However, further studies are needed for the evaluation of its mechanism of action in regulation of HIF-1α expression in different pathological conditions. HIF-1α overexpression results in the upregulation of several genes that participated in cancer-associated pathways such as proliferation, angiogenesis, and glucose metabolism. We showed that HIF-1α is upregulated in breast tumor samples compared with adjacent noncancerous tissues. Its expression has been associated with Ki-67 status. Its natural occurring antisense is only expressed in tumor tissues. Thus, it can be used as a potential biomarker in breast cancer.

The Role of Long Non-Coding RNAs in Breast Cancer.

Long non-coding RNA (lncRNA) genes are an important population of non-coding RNAs with defined key roles in normal development as well as tumorigenesis process. Evidences suggest that they can be classified as tumor suppressor genes or oncogenes according to their functions and expression pattern in tumoral tissues. They have been shown to regulate the plasticity of cancer stem cells. Their important roles in the regulation of cancer-related pathways in addition to deregulation of their expression in a number of cancers have suggested that they can be used as markers for cancer detection and prognosis, as well as targets for cancer treatment. Deregulation of a number of lncRNAs, such as HOTAIR, XIST, MALAT, and H19 has been detected in breast cancer samples and cell lines. In addition, the association between lncRNAs signature and breast cancer patients' survival has been assessed in various studies. Here, the expression patterns of lncRNAs in breast cancer, as well as their significance in prognosis and patient treatment are discussed.

Detection of Superior Markers for Polymerase Chain Reaction Diagnosis of Breast Cancer Micrometastasis in Sentinel Lymph Nodes.

Breast cancer is the most prevalent type of cancer among women around the world, and mortality is primarily caused by micro-metastatic disease. The complex mechanisms of breast cancer invasion and metastasis are intrinsically related to the malignant cell type so that early detection of micro-metastases can help prolongation of survival for patient. The aim of the present research work was evaluation of the expression status of mammoglobin protein as a candidate molecular marker in the negative sentinel lymph node (SLN). Fifty tumor specimens, and 50 normal adjacent breast tissue samples from the same patients were selected on the basis of having more than 10% tumor content for RNA extraction from SLNs. Tumor samples and normal adjacent breast tissue were archived in the form of frozen fresh tissue in liquid nitrogen. Real-time PCR was performed on a Bioner life express gradient thermal cycler system. Mammoglobin gene overexpression in breast cancer metastasis was investigated. Single marker results were mammaglobin 66.7% and CK19 50.0%, with 58.3% for the two in combination. Due to improved outcome with at least 3 genes (83.3%), it seems, triple marker evaluation will be most likely useful for detecting micro-metastases instead of studying separate genes.

Expression analysis of four long noncoding RNAs in breast cancer.

Breast cancer is a molecularly heterogeneous disease which necessitates a search for markers to provide a more specific classification of this disorder. Long noncoding RNAs as the important subset of noncoding transcripts have been shown to be involved in tumorigenic processes. So, they may be used as markers for early detection of cancer and evaluation of cancer prognosis. In addition, they can be applied as therapeutic targets. In this study, we analyzed expression of four long noncoding RNAs (lncRNAs) namely SOX2OT, PTPRG-AS1, ANRASSF1, and ANRIL in 38 breast cancer tissues and their adjacent noncancerous tissues (ANCTs). ANRASSF1 expression was not detected in any noncancerous tissue. All lncRNAs showed significant overexpression in tumor tissues compared with ANCTs. No association was found between gene expressions and individual clinical data such as tumor stage, grade, size and hormone receptor status except for ANRASSF1 expression and Her2/neu status. In addition, ANRASSF1 and ANRIL expressions were significantly higher in triple negative samples. This study suggests a putative role for these lncRNAs in breast cancer and implies that they can be used as potential cancer biomarkers.