Soft agar colonies were stained with 0.5 μM of calcein-AM solution (Life Technologies) and counted 5-14 days after plating with an Acumen eX3 multiplate reader (TTP LabTech Ltd., Melbourn, UK). Data were derived from five independent experiments. Percent inhibition was defined as percent Navitoclax cell line reduction in average number of colonies formed
in siBCL9 or siMTDH cells, relative to siControl cells (set to 100%), in each assay. P values between siControl and siBCL9 or siMTDH samples were calculated using a two-sample t test. To characterize the genomic landscape of HCC, we compiled a collection of snap-frozen tumor and adjacent nontumor liver tissues from 286 patients who were treated with surgical resection (Table 1). Both RNA and DNA were isolated from all samples and profiled on the Illumina Human HT-12 v4 BeadChips and Human Omni1-Quad SNP genotyping arrays (Illumina), respectively.
Based on the SNP genotyping array data, we derived the somatic copy number profiles of the 286 HCCs using their matched nontumor liver tissue as references. On average, there are 200 somatic copy number gain events and 247 somatic copy number loss events per HCC, accounting for 12.0% and 11.3% of the genome, respectively. A genome-wide view of the segmented copy numbers revealed that most chromosome arms have undergone large-scale copy number gains or losses, with frequent gains observed on 1q, 6p, 7p, 7q, 8q, 13q, and 17q and frequent losses on 1p, 4q, 8p, 9p, 9q, 13p, 16p, and 16q (Fig. 1A). We also MI-503 supplier devised a CIN score, which is a single metric that summarizes the extent of CNAs in individual tumors (see Patients and Methods). We found that the CIN scores were positively associated with various features of tumor progression, such as American Joint Committee on Cancer (AJCC) stage, Edmondson grade, and tumor size, in agreement with our understanding of somatic CNAs as a cumulative process as a tumor
advances (Table 1). On the other hand, the CIN scores were negatively associated with patients’ buy ZD1839 age, the Child-Pugh score, and cirrhosis, which reflect overall liver function and pathological state of the non-HCC liver (Table 1). In addition to clinical HCC samples, we also profiled 30 HCC cell lines on the same gene expression and SNP genotyping array platforms. Overall, the spectrum of CNAs in HCC cell lines recapitulates primary HCCs (Fig. 1A). To assess the extent to which somatic CNAs in HCC drive downstream transcriptional programs, we calculated the correlation between a gene’s somatic copy number and its mRNA expression in cis across our patient cohort. Overall, there were 3,152 genes for which at least 10% (i.e., correlation coefficient ≥0.316) of their expression variation can be explained by their own copy number changes, whereas by chance only one gene was expected at the same level of correlation (FDR = 3.17 × 10−4) (Supporting Fig. 1A).