Comprehensive genomic variation profiling of cervical intraepithelial neoplasia and cervical cancer identifies potential targets for cervical cancer early warning.

BACKGROUND: To better understand the pathogenesis of cervical cancer (CC), we systematically analysed the genomic variation and human papillomavirus (HPV) integration profiles of cervical intraepithelial neoplasia (CIN) and CC. METHODS: We performed whole-genome sequencing or whole-exome sequencing of 102 tumour-normal pairs and human papillomavirus probe capture sequencing of 45 CCs, 44 CIN samples and 25 normal cervical samples, and constructed strict integrated workflow of genomic analysis. RESULTS: Mutational analysis identified eight significantly mutated genes in CC including four genes (FAT1, MLL3, MLL2 and FADD), which have not previously been reported in CC. Targetable alterations were identified in 55.9% of patients. In addition, HPV integration breakpoints occurred in 97.8% of the CC samples, 70.5% of the CIN samples and 42.8% of the normal cervical samples with HPV infection. Integrations of high-risk HPV strains in CCs, including HPV16, 18, 33 and 58, also occurred in the CIN samples. Moreover, gene mutations were detected in 52% of the CIN specimens, and 54.8% of these mutations occurred in genes that also mutated in CCs. CONCLUSION: Our results lay the foundation for a deep understanding of the molecular mechanisms and finding new diagnostic and therapeutic targets of CC.

Clonal Characteristics of Circulating B Lymphocyte Repertoire in Primary Biliary Cholangitis.

Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by elevated serum anti-mitochondrial Ab and lymphocyte-mediated bile duct damage. This study was designed to reveal the clonal characteristics of B lymphocyte repertoire in patients with PBC to facilitate better understanding of its pathogenesis and better management of these patients. Using high-throughput sequencing of Ig genes, we analyzed the repertoire of circulating B lymphocytes in 43 patients with PBC, and 34 age- and gender-matched healthy controls. Compared with healthy controls, PBC patients showed 1) a gain of 14 new clones and a loss of 8 clones; 2) a significant clonal expansion and increased relative IgM abundance, which corresponded with the elevated serum IgM level; 3) a significant reduction of clonal diversity and somatic hypermutations in class-switched sequences, which suggested a general immunocompromised status; 4) the reduction of clonal diversity and enhancement of clonal expansion were more obvious at the cirrhotic stage; and 5) treatment with ursodeoxycholic acid could increase the clonal diversity and reduce clonal expansion of the IgM repertoire, with no obvious effect on the somatic hypermutation level. Our data suggest that PBC is a complex autoimmune disease process with evidence of B lymphocyte clonal gains and losses, Ag-dependent ogligoclonal expansion, and a generally compromised immune reserve. This new insight into the pathogenesis of PBC opens up the prospect of studying disease-relevant B cells to better diagnose and treat this devastating disease.

An epigenomic landscape of cervical intraepithelial neoplasia and cervical cancer using single-base resolution methylome and hydroxymethylome.

BACKGROUND: Cervical cancer (CC) is the second leading cause of cancer death among women worldwide. Epigenetic regulation of gene expression through DNA methylation and hydroxymethylation plays a pivotal role during tumorigenesis. In this study, to analyze the epigenomic landscape and identify potential biomarkers for CCs, we selected a series of samples from normal to cervical intra-epithelial neoplasia (CINs) to CCs and performed an integrative analysis of whole-genome bisulfite sequencing (WGBS-seq), oxidative WGBS, RNA-seq, and external histone modifications profiling data. RESULTS: In the development and progression of CC, there were genome-wide hypo-methylation and hypo-hydroxymethylation, accompanied by local hyper-methylation and hyper-hydroxymethylation. Hydroxymethylation prefers to distribute in the CpG islands and CpG shores, as displayed a trend of gradual decline from health to CIN2, while a trend of increase from CIN3 to CC. The differentially methylated and hydroxymethylated region-associated genes both enriched in Hippo and other cancer-related signaling pathways that drive cervical carcinogenesis. Furthermore, we identified eight novel differentially methylated/hydroxymethylated-associated genes (DES, MAL, MTIF2, PIP5K1A, RPS6KA6, ANGEL2, MPP, and PAPSS2) significantly correlated with the overall survival of CC. In addition, no any correlation was observed between methylation or hydroxymethylation levels and somatic copy number variations in CINs and CCs. CONCLUSION: Our current study systematically delineates the map of methylome and hydroxymethylome from CINs to CC, and some differentially methylated/hydroxymethylated-associated genes can be used as the potential epigenetic biomarkers in CC prognosis.

The diagnostic and prognostic usage of circulating tumor DNA in operable hepatocellular carcinoma.

Circulating tumor DNA (ctDNA) is a promising noninvasive biomarker for hepatocellular carcinoma (HCC). In this study, we aimed to assess the diagnostic and prognostic value of ctDNA in HCC. Twenty-six operable HCC, 10 hepatitis and 10 cirrhosis patients were enrolled in this study. Treatment-naïve blood samples were collected from all patients, nevertheless resected tissue and postoperative blood samples were only collected from HCC patients. A custom-designed sequencing panel covering 354 genes was used to identify somatic mutations. Collectively, we identified 139 somatic mutations from 25 HCC baseline plasma samples (96.2%). TP53 (50.00%) was the most common mutant gene, and R249S was the most recurrent mutation (19.2%). Twenty-three patients (88.5%) carried at least one ctDNA mutation validated in matched tissue, and the driver mutations exhibited an advanced concordance than non-driver mutations (67.6% vs. 33.8%, P = 0.0002). For HCC patients, the number of mutations in ctDNA (R2 = 0.1682, P = 0.0375), maximal variant allele frequency (VAF) in ctDNA (R2 = 0.4974, P < 0.0001) and ctDNA concentration (R2 = 0.2676, P = 0.0068) were linearly correlated with tumor size. Multiple circulating cell-free DNA (cfDNA) parameters could be used in differentiating malignant lesions from benign lesions, and the performance was no less than blood alpha-fetoprotein (AFP). HCC patients with detectable mutation in postoperative plasma had a poor DFS than those without (17.5 months vs. 6.7 months, HR = 7.655, P < 0.0001), and postoperative cfDNA status (HR = 10.293, P < 0.0001) was an independent risk factors for recurrence. In conclusion, ctDNA profiling is potentially valuable in differential diagnosis and prognostic evaluation of HCC.

Molecular Characterization of HBV DNA Integration in Patients with Hepatitis and Hepatocellular Carcinoma.

Infection by chronic hepatitis B virus (HBV) is one of the major causes of liver cirrhosis and primary hepatocellular carcinoma (HCC). Viral DNA integration into the host cell genome is a key mechanism of hepatocarcinogenesis. However, the molecular characterization and the potential clinical implications of HBV DNA integration into patients suffering from different hepatitis and HCC remain unclear. In this study, we analyzed HBV integrations in patients with hepatitis B and HCC using HBV probe-based capturing and next-generation sequencing. The results revealed that the sizes of the HBV integrations ranged from 28 bp to 3215 bp, including the full-length HBV DNA sequence. The integration breakpoints were preferentially distributed in the viral enhancer, X protein, and core protein regions of the HBV genome. The number of HBV integrations followed an increasing trend from hepatitis to HCC, which was positively correlated with the HBV virus load in patients with hepatitis. The number of HBV integrations in the HBeAg positive chronic hepatitis B group was significantly greater than that in the other hepatitis B groups (P < 0.05). However, the relative abundance of HBV integrations was significantly higher in HCC tissues than in the adjacent liver tissues. Interestingly, 61.6% (8/13) of HBV-human DNA integration fragments could be detected at the RNA level. Our results also showed that HBV integration-targeted genes (ITGs) were significantly enriched in many cancer-related pathways, such as MAPK, extracellular matrix (ECM)-receptor interaction, and the hedgehog signaling pathway. Individuals with HBV integrations exhibited shorter disease-free survival (DFS) and overall survival (OS) than those without HBV integrations in some ITGs including LINC00293 (long intergenic non-protein coding RNA 293; DFS P = 0.008, OS P = 0.009), FSHB (follicle stimulating hormone beta subunit; DFS P = 0.05, OS P = 0.186), and LPHN3 (latrophilin-3; DFS P = 0.493, OS P = 0.033). This study determined the underlying mechanism of HBV DNA integration in liver diseases and laid the foundation for future studies on the pathogenesis of liver cancer.

Immune repertoire: A potential biomarker and therapeutic for hepatocellular carcinoma.

The immune repertoire (IR) refers to the sum of B cells and T cells with functional diversity in the circulatory system of one individual at any given time. Immune cells, which reside within microenvironments and are responsible for protecting the human body, include T cells, B cells, macrophages, and dendritic cells. These dedicated immune cells have a characteristic structure and function. T and B cells are the main lymphocytes and are responsible for cellular immunity and humoral immunity, respectively. The T cell receptor (TCR) and B cell receptor (BCR) are composed of multiple peptide chains with antigen specificity. The amino acid composition and sequence order are more diverse in the complementarity-determining regions (including CDR1, CDR2 and CDR3) of each peptide chain, allowing a vast library of TCRs and BCRs. IR research is becoming increasingly focused on the study of CDR3 diversity. Deep profiling of CDR3s using high-throughput sequencing is a powerful approach for elucidating the composition and distribution of the CDR3s in a given sample, with in-depth information at the sequence level. Hepatocellular carcinoma (HCC) is one of the most common malignancies in the world. To identify novel biomarkers for diagnosis and drug targets for therapeutic interventions, several groups attempted to describe immune repertoire characteristics of the liver in the physiological environment or/and pathological conditions. This paper reviews the recent progress in IR research on human diseases, including hepatocellular carcinoma, attempting to depict the relationships between hepatocellular carcinogenesis and the IR, and discusses the possibility of IR as a potential biomarker and therapeutic for hepatocellular carcinoma.

Identification of characteristic TRB V usage in HBV-associated HCC by using differential expression profiling analysis.

Liver cancer is one of the most common cancers worldwide. CDR3 sequencing-based immune repertoire can be closely associated with cancer prognosis and development. Identifying the specific interaction between the TCR and cellular antigens is important for developing novel immunotherapeutic approaches for the treatment of cancer. The rearranged TCRß loci amplified using Vß- and Jß-specific primers by multi-PCR and sequenced using high-throughput sequencing (HTS) in liver cancers were compared with those of T cells from healthy adult peripheral blood and from adjacent liver tissue. The T-cell repertoires within each tumor show strong similarity to one another but are distinct from those of the circulating T-cell repertoire. In addition, our results demonstrate that there are significant differences in the T-cell repertoires of HCC (hepatocellular carcinoma), ICC (intrahepatic cholangiocarcinoma), and MHC (mixed hepatocellular and cholangiocellular carcinoma). Furthermore, we found that the highly expanded clone (HEC) ratio in blood samples from liver cancer patients differed significantly from those in the blood of healthy adults and hepatitis patients (p < 0.001). The above results suggest that comparison of the T-cell repertoires of tissue and blood could be used to distinguish liver cancer patients from healthy adults and from hepatitis patients. In the future, the diversity of CDR3 sequences in liver cancer may prove to be a useful and novel biomarker for detecting aggressive tumors with high invasive or metastatic capacity.

Analysis of hepatitis B virus genotyping and drug resistance gene mutations based on massively parallel sequencing.

Drug resistance to nucleoside analogs is a serious problem worldwide. Both drug resistance gene mutation detection and HBV genotyping are helpful for guiding clinical treatment. Total HBV DNA from 395 patients who were treated with single or multiple drugs including Lamivudine, Adefovir, Entecavir, Telbivudine, Tenofovir and Emtricitabine were sequenced using the HiSeq 2000 sequencing system and validated using the 3730 sequencing system. In addition, a mixed sample of HBV plasmid DNA was used to determine the cutoff value for HiSeq-sequencing, and 52 of the 395 samples were sequenced three times to evaluate the repeatability and stability of this technology. Of the 395 samples sequenced using both HiSeq and 3730 sequencing, the results from 346 were consistent, and the results from 49 were inconsistent. Among the 49 inconsistent results, 13 samples were detected as drug-resistance-positive using HiSeq but negative using 3730, and the other 36 samples showed a higher number of drug-resistance-positive gene mutations using HiSeq 2000 than using 3730. Gene mutations had an apparent frequency of 1% as assessed by the plasmid testing. Therefore, a 1% cutoff value was adopted. Furthermore, the experiment was repeated three times, and the same results were obtained in 49/52 samples using the HiSeq sequencing system. HiSeq sequencing can be used to analyze HBV gene mutations with high sensitivity, high fidelity, high throughput and automation and is a potential method for hepatitis B virus gene mutation detection and genotyping.