Real-Time PCR Data Processing Shown by the Analysis of Colorectal Specific Candidate Genes, ERCC1, RRM1 and TS in Relation to β2M as Endogenous Control

Uncovering Tumour Heterogeneity through PKR and nc886 Analysis in Metastatic Colon Cancer Patients Treated with 5-FU-Based Chemotherapy

Colorectal cancer treatment has advanced over the past decade. The drug 5-fluorouracil is still used with a wide percentage of patients who do not respond. Therefore, a challenge is the identification of predictive biomarkers. The protein kinase R (PKR also called EIF2AK2) and its regulator, the non-coding pre-mir-nc886, have multiple effects on cells in response to numerous types of stress, including chemotherapy. In this work, we performed an ambispective study with 197 metastatic colon cancer patients with unresectable metastases to determine the relative expression levels of both nc886 and PKR by qPCR, as well as the location of PKR by immunohistochemistry in tumour samples and healthy tissues (plasma and colon epithelium). As primary end point, the expression levels were related to the objective response to first-line chemotherapy following the response evaluation criteria in solid tumours (RECIST) and, as the second end point, with survival at 18 and 36 months. Hierarchical agglomerative clustering was performed to accommodate the heterogeneity and complexity of oncological patients’ data. High expression levels of nc886 were related to the response to treatment and allowed to identify clusters of patients. Although the PKR mRNA expression was not associated with chemotherapy response, the absence of PKR location in the nucleolus was correlated with first-line chemotherapy response. Moreover, a relationship between survival and the expression of both PKR and nc886 in healthy tissues was found. Therefore, this work evaluated the best way to analyse the potential biomarkers PKR and nc886 in order to establish clusters of patients depending on the cancer outcomes using algorithms for complex and heterogeneous data.

Identification of placental genes linked to selective intrauterine growth restriction (IUGR) in dichorionic twin pregnancies: gene expression profiling study

A linkage of dichorionic (DC) twin pregnancies with selective intrauterine growth restriction (IUGR) to alterations in placental gene expression is unclear. The aim of the study was to identify placental genes related to hypoxia, adipogenesis and human growth which may contribute to IUGR development. The study group (IUGR/AGA) comprised dichorionic (DC) twin pregnancies, where the weight of the twins differed by > 15%; in addition, one twin was small for gestational age (< 10th percentile-SGA) (IUGR) while the other was appropriate for gestational age (> 10th percentile-AGA). In the control group (AGA/AGA), both fetuses were AGA and their weights differed by < 15%. In the first step (selection), placental expression of 260 genes was analysed by commercial PCR profiler array or qPCR primer assay between six pairs of IUGR/AGA twins. In the second stage (verification), the expression of 20 genes with fold change (FC) > 1.5 selected from the first stage was investigated for 75 DC pregnancies: 23 IUGR/AGA vs. 52 AGA/AGA. The expression of Angiopoetin 2, Leptin and Kruppel-like factor 4 was significantly higher, and Glis Family Zinc Finger 3 was lower, in placentas of SGA fetuses (FC = 3.3; 4.4; 1.6; and - 1.8, respectively; p < 0.05). The dysregulation of gene expression related to angiogenesis and growth factors in placentas of twins born from IUGR/AGA pregnancies suggest that these alternations might represent biological fetal adaptation to the uteral condition. Moreover, DC twin pregnancies may be a good model to identify the differences in placental gene expression between SGA and AGA fetuses.

Increased expression of the gene encoding stearoyl-CoA desaturase 1 in human bladder cancer

Bladder cancer is a common disease and a significant cause of death worldwide. There is thus great interest in identifying a diagnostic and prognostic biomarker, as well as gaining an understanding of the molecular basis of bladder cancer. Stearoyl-CoA desaturase 1 gene (SCD1) is highly overexpressed in many human cancers. However, the expression of SCD1 has not yet been investigated in patients with bladder cancer. Here, we document that (a) the SCD1 is highly overexpressed in human bladder cancer; (b) high expression of SCD1 is more frequently observed in the late stage of disease and patients with lymph node metastasis; (c) bladder cancer patients with a higher SCD1 mRNA level have a poorer survival rate than those with normal SCD1 expression. Overall, this is the first report to indicate an association between SCD1 mRNA level and clinical indicators of human bladder cancer. Our study has provided evidence supporting the potential role of SCD1 as a biomarker for human bladder cancer prognosis.

Differential miRNA-Expression as an Adjunctive Diagnostic Tool in Neuroendocrine Tumors of the Lung

Pulmonary malignancies with neuroendocrine differentiation represent a rare subclass of lung carcinomas, which vary in the extent of differentiation and grade of biological aggressiveness. In particular, neuroendocrine tumors are classified into well differentiated typical and atypical carcinoids as well as poorly differentiated large cell neuroendocrine and small cell lung carcinomas. Tiny MicroRNAs have been identified as reliable classifiers in distinct cancer types and seem to play important roles in cellular processes like regulation of cell growth, differentiation and apoptosis. In the present study, two different microRNAs (miR-21 and miR-34a) were explored for their involvements in pathogenesis of subtypes and finally in differential diagnosis of pulmonary neuroendocrine tumors. miR-21 was upregulated in poorly differentiated neuroendocrine tumors (mean rank: 26.8; 28.75) as compared to carcinoids (mean rank: 12.33; 12.07) with a significance of 0.00033. High-expression levels of miR-34a were associated with atypical carcinoids (p = 0.010). A close association is implicated between the elevated miR-21 values in high-grade and miR-34a patterns in low-grade atypical neuroendocrine lung carcinomas, which could potentially be exploited as practical supportive markers for differential lung cancer diagnosis in routine. However, some additional extended research and validation studies are needed to utilize them as routine markers or potential molecular targets for personalized medicine.