Identification of Recurrence-Related microRNAs from Bone Marrow in Hepatocellular Carcinoma Patients

Hepatocellular carcinoma (HCC) is a poor-prognosis cancer due to its high rate of recurrence. microRNAs (miRNAs) are a class of small non-coding RNA molecules that affect crucial processes in cancer development. The objective of this study is to identify the role of miRNAs in patient bone marrow (BM) and explore the function of these molecules during HCC progression. We purified miRNAs from bone marrow cells of seven HCC patients, and divided them into three fractions by cell surface markers as follows: CD14+ (macrophage), CD14−/CD45+ (lymphocyte), and CD14−/CD45−/EpCAM+ (epithelial cell). We employed microarray-based profiling to analyze miRNA expression in the bone marrow of patients with HCC. Differentially expressed miRNAs were significantly different between fractions from whole bone marrow, macrophages, and lymphocytes, and depended on stages in tumor progression. Differences in expression of miRNAs associated with cell proliferation also varied significantly between HCC patients with recurrence, multiple tumors, and advanced clinical stages. These results suggest that miRNA profiles in separated fractions of BM cells are associated with HCC progression

A temporal shift of the evolutionary principle shaping intratumor heterogeneity in colorectal cancer

Advanced colorectal cancer harbors extensive intratumor heterogeneity shaped by neutral evolution; however, intratumor heterogeneity in colorectal precancerous lesions has been poorly studied. We perform multiregion whole-exome sequencing on ten early colorectal tumors, which contained adenoma and carcinoma in situ. By comparing with sequencing data from advanced colorectal tumors, we show that the early tumors accumulate a higher proportion of subclonal driver mutations than the advanced tumors, which is highlighted by subclonal mutations in KRAS and APC. We also demonstrate that variant allele frequencies of subclonal mutations tend to be higher in early tumors, suggesting that the subclonal mutations are subject to selective sweep in early tumorigenesis while neutral evolution is dominant in advanced ones. This study establishes that the evolutionary principle underlying intratumor heterogeneity shifts from Darwinian to neutral evolution during colorectal tumor progression

Hierarchical clustering showing the expression levels of the differentially expressed genes in a comparison of CRC patients with the pre-<i>miR-146a</i>/C (CC/CG) genotype and without the pre-<i>miR-146a</i>/C (GG) genotype.

<p>Red spots indicate upregulated and blue spots indicate downregulated probes compared with reference probes. On the top, clustering results of CRC patients are shown (dendrogram). Red bar indicates the CC/CG genotype and the blue bar indicates the GG genotype. On the left side, clustering results of the differentially expressed genes between the two genotypes are shown.</p

<i>miR-146a</i> Polymorphism (rs2910164) Predicts Colorectal Cancer Patients’ Susceptibility to Liver Metastasis - Fig 2

<p>Gene Set Enrichment Analysis (GSEA): Enriched gene sets for CRC patients with the C allele (CC/CG); KEGG_NOTCH_SIGNALING_PATHWAY (A) and V$STAT3_01 (B).</p

<i>miR-146a</i> Polymorphism (rs2910164) Predicts Colorectal Cancer Patients’ Susceptibility to Liver Metastasis - Fig 4

<p>Downregulated <i>miR-146a</i> (A) and upregulated NUMB (B) expression of CRC cell lines with pre-miR-146a/C transfected with miR-146a inhibitor or negative control.</p

Comparative analysis of the clinicopathological findings affected by miR-146a polymorphism.

<p>Comparative analysis of the clinicopathological findings affected by miR-146a polymorphism.</p

Genotyping of miR-146a polymorphism in 7 CRC cell lines.

<p>Genotyping of miR-146a polymorphism in 7 CRC cell lines.</p