Novel targets and therapeutic strategies for the treatment of hepatocellular carcinoma (HCC)

Liver cancer is a leading cause of cancer-related mortality worldwide and accounts for more than 800.000 deaths per year. Hepatocellular carcinoma (HCC) is a common cancer with high lethality, which is diagnosed most often at advanced stages when surgical or local treatment options are not possible. For the treatment of advanced HCC, sorafenib has been the only approved systemic treatment for nearly 10 years. Lately however, a number of additional compounds targeting tumour-specific signalling pathways, such as regorafenib, lenvatinib, and cabozantinib, and most recently, ramucirumab, provided positive results in phase-3 clinical trials. In addition, the approval of nivolumab as second-line treatment revealed the importance of the immune response in determining the development in HCC and set the stage for extensive clinical research with these agents. These new therapeutic options for HCC have significantly prolonged the life expectancy in patients with advanced-stage disease and collectively provided evidence that targeted therapy in different lines of treatment is a feasible strategy also for HCC. Nevertheless, a great individual variability in clinical benefits in response to these agents can be observed, and prognosis remains extremely poor in the majority of patients not responding to the treatments. By the two presented research projects, we aimed at assessing new therapeutic targets and possible therapeutic strategies for the treatment of HCC. In the first project, which was previously published in the form of an abstract, we explored the possibility of enhancing the therapeutic potential of sorafenib by its combination with the novel and clinically viable PI3K-Akt-Tor inhibitor copanlisib. To this regard, we found that copanlisib possesses potent anticancer activity as single agent and acts synergistically in combination with sorafenib in human HCC, hereby representing a rational potential therapeutic option for advanced HCC. In the second project, which was also presented and published as an abstract, we investigated the role of olfactomedin 4 (OLFM4), a glycoprotein predominantly expressed in bone marrow and gastrointestinal tract, in the pathogenesis of HCC. By performing immunohistochemical staining in human HCC tissues and functional in vitro assays of Huh7 and HepG2 cell lines, we provided the first report on a possible role of this molecule in determining the development of HCC by showing that increased expression of OLFM4 is a common event in the pathogenesis of this tumor with independent prognostic significance. Our preclinical results from these two studies, which are presented in the form of the two different manuscripts about to be submitted or published, warrant further investigation of PI3K-Akt-Tor signalling as a mechanism of cancer development and chemoresistance during HCC treatment, as well as of the role played by OLFM4 in determining invasion and metastasis in this tumor

Whole exome sequencing identifies frequent somatic mutations in cell-cell adhesion genes in chinese patients with lung squamous cell carcinoma

Lung squamous cell carcinoma (SQCC) accounts for about 30% of all lung cancer cases. Understanding of mutational landscape for this subtype of lung cancer in Chinese patients is currently limited. We performed whole exome sequencing in samples from 100 patients with lung SQCCs to search for somatic mutations and the subsequent target capture sequencing in another 98 samples for validation. We identified 20 significantly mutated genes, including TP53, CDH10, NFE2L2 and PTEN. Pathways with frequently mutated genes included those of cell-cell adhesion/Wnt/Hippo in 76%, oxidative stress response in 21%, and phosphatidylinositol-3-OH kinase in 36% of the tested tumor samples. Mutations of Chromatin regulatory factor genes were identified at a lower frequency. In functional assays, we observed that knockdown of CDH10 promoted cell proliferation, soft-agar colony formation, cell migration and cell invasion, and overexpression of CDH10 inhibited cell proliferation. This mutational landscape of lung SQCC in Chinese patients improves our current understanding of lung carcinogenesis, early diagnosis and personalized therapy

High-coverage whole-genome analysis of 1220 cancers reveals hundreds of genes deregulated by rearrangement-mediated cis-regulatory alterations.

The impact of somatic structural variants (SVs) on gene expression in cancer is largely unknown. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole-genome sequencing data and RNA sequencing from a common set of 1220 cancer cases, we report hundreds of genes for which the presence within 100 kb of an SV breakpoint associates with altered expression. For the majority of these genes, expression increases rather than decreases with corresponding breakpoint events. Up-regulated cancer-associated genes impacted by this phenomenon include TERT, MDM2, CDK4, ERBB2, CD274, PDCD1LG2, and IGF2. TERT-associated breakpoints involve ~3% of cases, most frequently in liver biliary, melanoma, sarcoma, stomach, and kidney cancers. SVs associated with up-regulation of PD1 and PDL1 genes involve ~1% of non-amplified cases. For many genes, SVs are significantly associated with increased numbers or greater proximity of enhancer regulatory elements near the gene. DNA methylation near the promoter is often increased with nearby SV breakpoint, which may involve inactivation of repressor elements

Retrospective evaluation of whole exome and genome mutation calls in 746 cancer samples

Funder: NCI U24CA211006Abstract: The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC) curated consensus somatic mutation calls using whole exome sequencing (WES) and whole genome sequencing (WGS), respectively. Here, as part of the ICGC/TCGA Pan-Cancer Analysis of Whole Genomes (PCAWG) Consortium, which aggregated whole genome sequencing data from 2,658 cancers across 38 tumour types, we compare WES and WGS side-by-side from 746 TCGA samples, finding that ~80% of mutations overlap in covered exonic regions. We estimate that low variant allele fraction (VAF < 15%) and clonal heterogeneity contribute up to 68% of private WGS mutations and 71% of private WES mutations. We observe that ~30% of private WGS mutations trace to mutations identified by a single variant caller in WES consensus efforts. WGS captures both ~50% more variation in exonic regions and un-observed mutations in loci with variable GC-content. Together, our analysis highlights technological divergences between two reproducible somatic variant detection efforts

Nano-fumed silica as a novel pollutant that inhibits the algicidal effect of <i>p</i>-hydroxybenzoic acid on <i>Microcystis aeruginosa</i>

<p>Nanomaterials and/or contaminants are becoming more common in the developing world, but their effects on interspecific interactions are rarely reported, particularly in aquatic ecosystems. Thus, the present study determined the effects of the novel pollutant nano-fumed silica (NFS) on algal control by a macrophyte via the allelochemical <i>p</i>-hydroxybenzoic acid in a microcosm test. The allelochemical <i>p-</i>hydroxybenzoic acid caused significant decreases in chlorophyll <i>a</i>, but increased the amount of superoxide anion radicals (<math><msubsup>O<mn>2</mn><mrow><mo>∙</mo><mo>−</mo></mrow></msubsup></math>) and the electric conductivity in <i>Microcystis aeruginosa</i>. The 50% inhibitory concentration (IC₅₀) for <i>p</i>-hydroxybenzoic acid was 0.919 mmol/L in microalga during the exponential phase. Interestingly, NFS at 100–1600 mg/L had clear stimulatory effects on <i>M. aeruginosa</i>. When NFS at 800 mg/L was combined with different concentrations of <i>p</i>-hydroxybenzoic acid, the IC₅₀ for <i>p</i>-hydroxybenzoic acid was 1.045 mmol/L. Thus, NFS significantly reduced the algicidal effect exhibited by <i>p</i>-hydroxybenzoic acid on <i>M. aeruginosa.</i> Furthermore, NFS might act as a silicon nutrient and enhance allelopathic resistance in <i>M. aeruginosa</i> to inhibit the algicidal effects of macrophytes via allelopathy. These findings suggest that before algal control is considered using macrophyte allelopathy, it is essential to remove the pollutant NFS from polluted lakes.</p

Comparative Response of HCC Cells to TKIs: Modified in vitro Testing and Descriptive Expression Analysis

Introduction: Although the treatment paradigm for hepatocellular carcinoma (HCC) has recently shifted in favour of checkpoint inhibitor (CPI)-based treatment options, the tyrosine kinase inhibitors (TKI) currently approved for the treatment of HCC are expected to remain the cornerstone of HCC treatment alone or in combination with CPIs. Despite considerable research efforts, no biomarker capable of predicting the response to specific TKIs has been validated. Thus, personalized approaches to HCC may aid in determining optimal treatment lines for 2nd and 3rd lines. To identify new biomarkers, we examined differential sensitivity and investigated potential transcriptomic predictors.Methods: To this aim, the sensitivity of nine HCC cell lines to sorafenib, lenvatinib, regorafenib, and cabozantinib was evaluated by a prolonged treatment scheme to determine their respective growth rate inhibition concentrations (GR50). Subgroups discriminated by GR50 values underwent differential expression and gene set enrichment analysis (GSEA).Results: The nine cell lines showed broadly different sensitivities to different TKIs. GR50 values of sorafenib and regorafenib clustered closer in all cell lines, whereas treatments with lenvatinib and cabozantinib showed diversified GR50 values. GSEA showed the activation of specific pathways in sensitive vs non-sensitive cell lines. A signature consisting of 14 biomarkers (GAGE12H, GJB6, PTCHD3, PRH1-PRR4, C6orf222, HBB, C17orf99, GOLGA6A, CRYAA, CCL23, RP11-347C12.3, RP11-514O12.4, FAM180B, and TMPRSS4) discriminates the cell lines' response into three distinct treatment profiles: 1) equally sensible to sorafenib, regorafenib and cabozantinib, 2) sensible to lenvatinib, and 3) more sensible to regorafenib than sorafenib.Conclusion: We observed diverse responses to either of the four TKIs. Subgroup analysis of TKI effectiveness showed distinct transcriptomic profiles and signaling pathways associated with responsiveness. This prompts more extensive studies to explore and validate pharmacogenomic and transcriptomic strategies for a personalized treatment approach, particularly after the failure of CPI treatment

Combined hepatocellular-cholangiocarcinoma: biology, diagnosis, and management

Background Combined hepatocellular-cholangiocarcinoma (cHCC-iCCA) is a rare type of primary liver cancer displaying characteristics of both hepatocytic and cholangiocytic differentiation. Summary Because of its aggressive nature, patients with cHCC-iCCA exhibit a poorer prognosis than those with HCC. Surgical resection and liver transplantation may be considered as curative treatment approaches; however, only a minority of patients are eligible at the time of diagnosis and postoperative recurrence rates are high. For cases that are not eligible for surgery, locoregional and systemic therapy are often administered based on treatment protocols applied for HCC or iCCA. Owing to the rarity of this cancer, there are still no established standard treatment protocols; therefore, the choice of therapy is often personalized and guided by the suspected predominant component. Further, the genomic and molecular heterogeneity of cHCC-iCCA can severely compromise the efficacy of the available therapies. Key Messages In the present review, we summarize the latest advances in cHCC-iCCA and attempt to clarify its terminology and molecular biology. We provide an overview of the etiology of cHCC-iCCA and present new insights into the molecular pathology of this disease that could contribute to further studies aiming to improve the patient outcomes through new systemic therapies