Expression and Functional Assessment of Some Featured Coding and Non-coding RNAs Encoded by 8q24 Chromosomal Region in CML Patients

Background: The association between the human chromosomal 8q24 region and cancer development remains dim. The proto-oncogene MYC is known as the most prominent target of this chromosomal region. However, numerous cancer-associated genetic alterations in the region extend beyond the MYC locus. Accordingly, it is likely that the MYC oncogene is not the only target of these carcinogenesis-related alterations. Objectives: In the present study, the expression of MYC and the correlation between MYC and two non-coding RNAs, namely PVT1 (circular and linear forms) and CASC11, which are residents of the 8q24 region in the MYC neighborhood, were investigated in chronic myeloid leukemia (CML). Methods: Real-time polymerase chain reaction (PCR) was used to assess BCR-ABL transcripts and categorize positive and negative (normal) samples for CML. Afterward, real-time PCR was exploited to evaluate the expression of different genes, including MYC, linear PVT1, circular PVT (CircPVT1), CASC11, and ACTB in CML and normal samples. Results: We found that the expression of linear PVT1 is significantly increased in CML compared with normal samples. However, CircPVT1, CASC11, and MYC did not show significantly altered expression between CML and normal groups. The experimental and in silico analyses of the correlation coefficients of gene expressions suggested changes in the correlations between the gene expressions in CML compared with normal samples. We also assessed the miR-trapping potential of PVT1 and CASC11 and the possible effects of these interactions on signaling pathways. Our findings indicated that these lncRNAs could have a possible regulatory link with critical pathways associated with leukemogenesis. Conclusions: Our results indicate that non-coding genes surrounding MYC within the 8q24 region might have regulatory roles in CML carcinogenesis.

Single Nucleotide Polymorphisms within the 8Q24 Region are Not Associated with the Risk of Intraductal Papillary Mucinous Neoplasms of the Pancreas

Background & Aims: Intraductal papillary mucinous neoplasms (IPMNs) of the pancreas have been reported to be associated with an increased risk of developing extra-pancreatic malignancies. A common genetic background has been hypothesised to be responsible for such an association. Human chromosomal region 8q24 has been associated with many types of cancer. The majority of these associations lie at approximately 128 Mb on chromosome 8. We conducted a study in order to examine the association between IPMN and single nucleotide polymorphisms (SNPs) from the 8q24 region, namely rs10505477, rs6983267, rs7014346, rs6993464, previously reported to influence general cancer susceptibility. Methods. The study was performed on 117 IPMN cases and 231 controls. Cases were enrolled at the Digestive Endoscopy Unit, Policlinico Agostino Gemelli from January, 2010 to June, 2011, with either a prevalent or incident IPMN diagnosis. Status of SNPs was determined using a StepOne Real-time PCR system (Applied Biosystems) and TaqMan SNP Genotyping Assay™ 40X. Unconditional multiple logistic regression models were used to estimate odds ratios and 95% confidence intervals for the association of selected SNPs and IPMNs. Results. Cases were more likely to report a 1st degree family history of cancer (p<0.001), as well as heavy smoking (p=0.001) and heavy drinking habits (p<0.001). No significant association was observed between IPMN and selected SNPs. The results were confirmed also when stratified according to any 1st-degree family history of cancer. Conclusion. Patients with IPMN do not have a higher prevalence of SNPs in the human chromosomal region 8q24 in respect to the control population. Abbreviations: CASC8: cancer susceptibility candidate 8; CRC: colorectal cancer; ENPP2: ectonucleotide pyrophosphatase/phosphodiesterase 2; EPM: extra-pancreatic malignancy; eQTLs: expression quantitative trait loci; IPMN: intraductal papillary mucinous neoplasm; MYC: myelocytomatosis viral oncogene homolog gene; NOV: nephroblastoma over-expressed gene; PCR: polymerase chain reaction; POU5F1P1: POU class 5 homeobox 1 pseudogene 1 gene; S-MRCP: magnetic resonance cholangiopancreatography with secretin stimulation; SNP: single nucleotide polymorphism; TCF4: transcription factor 4.