Identification of Dhx15 as a Major Regulator of Liver Development, Regeneration, and Tumor Growth in Zebrafish and Mice.

RNA helicase DHX15 plays a significant role in vasculature development and lung metastasis in vertebrates. In addition, several studies have demonstrated the overexpression of DHX15 in the context of hepatocellular carcinoma. Therefore, we hypothesized that this helicase may play a significant role in liver regeneration, physiology, and pathology. Dhx15 gene deficiency was generated by CRISPR/Cas9 in zebrafish and by TALEN-RNA in mice. AUM Antisense-Oligonucleotides were used to silence Dhx15 in wild-type mice. The hepatocellular carcinoma tumor induction model was generated by subcutaneous injection of Hepa 1-6 cells. Homozygous Dhx15 gene deficiency was lethal in zebrafish and mouse embryos. Dhx15 gene deficiency impaired liver organogenesis in zebrafish embryos and liver regeneration after partial hepatectomy in mice. Also, heterozygous mice presented decreased number and size of liver metastasis after Hepa 1-6 cells injection compared to wild-type mice. Dhx15 gene silencing with AUM Antisense-Oligonucleotides in wild-type mice resulted in 80% reduced expression in the liver and a significant reduction in other major organs. In addition, Dhx15 gene silencing significantly hindered primary tumor growth in the hepatocellular carcinoma experimental model. Regarding the potential use of DHX15 as a diagnostic marker for liver disease, patients with hepatocellular carcinoma showed increased levels of DHX15 in blood samples compared with subjects without hepatic affectation. In conclusion, Dhx15 is a key regulator of liver physiology and organogenesis, is increased in the blood of cirrhotic and hepatocellular carcinoma patients, and plays a key role in controlling hepatocellular carcinoma tumor growth and expansion in experimental models.

Metallothionein-3 is a multifunctional driver that modulates the development of sorafenib-resistant phenotype in hepatocellular carcinoma cells.

BACKGROUND & AIMS: Metallothionein-3 (hMT3) is a structurally unique member of the metallothioneins family of low-mass cysteine-rich proteins. hMT3 has poorly characterized functions, and its importance for hepatocellular carcinoma (HCC) cells has not yet been elucidated. Therefore, we investigated the molecular mechanisms driven by hMT3 with a special emphasis on susceptibility to sorafenib. METHODS: Intrinsically sorafenib-resistant (BCLC-3) and sensitive (Huh7) cells with or without up-regulated hMT3 were examined using cDNA microarray and methods aimed at mitochondrial flux, oxidative status, cell death, and cell cycle. In addition, in ovo/ex ovo chick chorioallantoic membrane (CAM) assays were conducted to determine a role of hMT3 in resistance to sorafenib and associated cancer hallmarks, such as angiogenesis and metastastic spread. Molecular aspects of hMT3-mediated induction of sorafenib-resistant phenotype were delineated using mass-spectrometry-based proteomics. RESULTS: The phenotype of sensitive HCC cells can be remodeled into sorafenib-resistant one via up-regulation of hMT3. hMT3 has a profound effect on mitochondrial respiration, glycolysis, and redox homeostasis. Proteomic analyses revealed a number of hMT3-affected biological pathways, including exocytosis, glycolysis, apoptosis, angiogenesis, and cellular stress, which drive resistance to sorafenib. CONCLUSIONS: hMT3 acts as a multifunctional driver capable of inducing sorafenib-resistant phenotype of HCC cells. Our data suggest that hMT3 and related pathways could serve as possible druggable targets to improve therapeutic outcomes in patients with sorafenib-resistant HCC.

Sensitization of cholangiocarcinoma cells to chemotherapy through BCRP inhibition with ß-caryophyllene oxide.

Cholangiocarcinomas (CCAs) are cancers originated in the biliary tree, which are characterized by their high mortality and marked chemoresistance, partly due to the activity of ATP-binding cassette (ABC) export pumps, whose inhibition has been proposed as a strategy for enhancing the response to chemotherapy. We have previously shown that ß-caryophyllene oxide (CRYO) acts as a chemosensitizer in hepatocellular carcinoma by inhibiting ABCB1, MRP1, and MRP2. Here, we have evaluated the usefulness of CRYO in inhibiting BCRP and improving the response of CCA to antitumor drugs. The TCGA-CHOL cohort (n = 36) was used for in silico analysis. BCRP expression (mRNA and protein) was assayed in samples from intrahepatic (iCCA) and extrahepatic (eCCA) tumors (n = 50) and CCA-derived cells (EGI-1 and TFK-1). In these cells, BCRP-dependent mitoxantrone transport was determined by flow cytometry. At non-toxic concentrations, CRYO inhibited BCRP function, which enhanced the cytostatic effect of drugs used in the treatment of CCA. The BCRP ability to confer resistance to a panel of antitumor drugs was determined in Chinese hamster ovary (CHO) cells with stable BCRP expression. At non-toxic concentrations, CRYO markedly reduced BCRP-induced resistance to known substrate drugs (mitoxantrone and SN-38) and cisplatin, gemcitabine, sorafenib, and 5-FU but not oxaliplatin. Neither CRYO nor cisplatin alone significantly affected the growth of BCRP-expressing tumors subcutaneously implanted in immunodeficient mice. In contrast, intratumor drug content was enhanced when administered together, and tumor growth was inhibited. In sum, the combined treatment of drugs exported by BCRP with CRYO can improve the response to chemotherapy in CCA patients.

Liver FoxO1 overexpression is positively associated with the degree of liver injury in cirrhotic patients.

Objectives: Chronic liver disease and related complications, cirrhosis and hepatocellular carcinoma, are associated with high mortality. Curative treatments, partial hepatectomy or liver transplantation, have limited applicability in patients with cirrhosis due to the poor liver regenerative capacity. Thus, we need to find new diagnostic and therapeutic alternatives, to block the disease progression and to improve the survival of patients. In this context, preclinical studies have demonstrated the key role of the protein kinase B (Akt) in liver dysfunction, but the status of Akt and its targets in patients with chronic hepatopathy remains unknown. Aims: To determine the activation status of the Akt pathway and their association with liver functionality in cirrhotic patients. Methods: This retrospective study includes liver tissue samples from 36 hepatectomized patients with (n=27) and without (n=9) cirrhosis. Multiplex analysis of proteins involved in the Akt/mTOR pathway was performed using a Luminex panel and Western blot. Conventional liver function tests were determined in serum before resection surgery. Results: Akt and forkhead box protein O1 (FoxO1) are overexpressed in the liver of cirrhotic patients: (2.1 vs. 1.0 densitometric relative units (DRU); p<0.01, and 9.5 vs. 4.4 DRU; p<0.01, respectively). FoxO1 showed the best correlation with markers of liver injury (aspartate aminotransferase (ASAT): r=0.51, p<0.05; alanine aminotransferase (ALAT): r=0.49, p<0.05), and was the only enzyme in the Akt pathway identified as an independent predictor of ASAT and ALAT levels. Conclusions: The intrahepatic expression of FoxO1 could have clinical utility as a potential prognostic marker for patients with advanced liver disease.

Metabolic liver cancer: associations of rare and common germline variants in one-carbon metabolism and DNA methylation genes.

Animal studies implicate one-carbon metabolism and DNA methylation genes in hepatocellular carcinoma (HCC) development in the setting of metabolic perturbations. Using human samples, we investigated the associations between common and rare variants in these closely related biochemical pathways and risk for metabolic HCC development in a multicenter international study. We performed targeted exome sequencing of 64 genes among 556 metabolic HCC cases and 643 cancer-free controls with metabolic conditions. Multivariable logistic regression was used to calculate odds ratios (ORs) and 95% confidence intervals (CIs), adjusting for multiple comparisons. Gene-burden tests were used for rare variant associations. Analyses were performed in the overall sample and among non-Hispanic whites. The results show that among non-Hispanic whites, presence of rare functional variants in ABCC2 was associated with 7-fold higher risk of metabolic HCC (OR = 6.92, 95% CI: 2.38-20.15, P = 0.0004), and this association remained significant when analyses were restricted to functional rare variants observed in ≥2 participants (cases 3.2% versus controls 0.0%, P = 1.02 × 10-5). In the overall multiethnic sample, presence of rare functional variants in ABCC2 was nominally associated with metabolic HCC (OR = 3.60, 95% CI: 1.52-8.58, P = 0.004), with similar nominal association when analyses were restricted to functional rare variants observed in ≥2 participants (cases 2.9% versus controls 0.2%, P = 0.006). A common variant in PNPLA3 (rs738409[G]) was associated with higher HCC risk in the overall sample (P = 6.36 × 10-6) and in non-Hispanic whites (P = 0.0002). Our findings indicate that rare functional variants in ABCC2 are associated with susceptibility to metabolic HCC in non-Hispanic whites. PNPLA3-rs738409 is also associated with metabolic HCC risk.

Polymorphism AGT2 (rs4762) is involved in the development of dermatologic events: Proof-of-concept in hepatocellular carcinoma patients treated with sorafenib.

BACKGROUND: Dermatologic adverse events (DAEs) are associated with a better outcome in patients with hepatocellular carcinoma (HCC) irrespective of the therapeutic agent received. The exact mechanisms associated with the development of DAEs are unknown although several studies point to direct toxicity of tyrosine kinase inhibitors (TKIs) to the skin or an immune-mediated reaction triggered by the oncologic treatment. As is the case in other conditions, individual genetic variants may partially explain a higher risk of DAEs. AIM: To evaluate the contribution of several gene variants to the risk of developing DAEs in HCC patients treated with TKIs. METHODS: We first analyzed 27 single-nucleotide polymorphisms (SNPs) from 12 genes selected as potential predictors of adverse event (AE) development in HCC patients treated with sorafenib [Barcelona Clinic Liver Cancer 1 (BCLC1) cohort]. Three additional cohorts were analyzed for AGT1 (rs699) and AGT2 (rs4762) polymorphisms-initially identified as predictors of DAEs: BCLC2 (n = 79), Northern Italy (n = 221) and Naples (n = 69) cohorts, respectively. The relation between SNPs and DAEs and death were assessed by univariate and multivariate Cox regression models, and presented with hazard ratios and their 95% confidence intervals (95%CI). RESULTS: The BCLC1 cohort showed that patients with arterial hypertension (AHT) (HR = 1.61; P value = 0.007) and/or AGT SNPs had an increased risk of DAEs. Thereafter, AGT2 (rs4762) AA genotype was found to be linked to a statistically significant increased probability of DAEs (HR = 5.97; P value = 0.0201, AA vs GG) in the Northern Italy cohort by multivariate analysis adjusted for BCLC stage, ECOG-PS, diabetes and AHT. The value of this genetic marker was externally validated in the cohort combining the BCLC1, BCLC2 and Naples cohorts [HR = 3.12 (95%CI: 1.2-8.14), P value = 0.0199, AGT2 (rs4762) AA vs AG genotype and HR = 2.73 (95%CI: 1.18-6.32) P value = 0.0188, AGT2 (rs4762) AA vs GG genotype]. None of the other gene variants tested were found to be associated with the risk of DAE development. CONCLUSION: DAE development in HCC patients receiving TKIs could be explained by the AGT2 (rs4762) gene variant. If validated in other anti-oncogenic treatments, it might be considered a good prognosis marker.

miR-200c-3p, miR-222-5p, and miR-512-3p Constitute a Biomarker Signature of Sorafenib Effectiveness in Advanced Hepatocellular Carcinoma.

BACKGROUND: Sorafenib constitutes a suitable treatment alternative for patients with advanced hepatocellular carcinoma (HCC) in whom atezolizumab + bevacizumab therapy is contraindicated. The aim of the study was the identification of a miRNA signature in liquid biopsy related to sorafenib response. METHODS: miRNAs were profiled in hepatoblastoma HepG2 cells and tested in animal models, extracellular vesicles (EVs), and plasma from HCC patients. RESULTS: Sorafenib altered the expression of 11 miRNAs in HepG2 cells. miR-200c-3p and miR-27a-3p exerted an anti-tumoral activity by decreasing cell migration and invasion, whereas miR-122-5p, miR-148b-3p, miR-194-5p, miR-222-5p, and miR-512-3p exerted pro-tumoral properties by increasing cell proliferation, migration, or invasion, or decreasing apoptosis. Sorafenib induced a change in EVs population with an increased number of larger EVs, and promoted an accumulation of miR-27a-3p, miR-122-5p, miR-148b-3p, miR-193b-3p, miR-194-5p, miR-200c-3p, and miR-375 into exosomes. In HCC patients, circulating miR-200c-3p baseline levels were associated with increased survival, whereas high levels of miR-222-5p and miR-512-3p after 1 month of sorafenib treatment were related to poor prognosis. The RNA sequencing revealed that miR-200c-3p was related to the regulation of cell growth and death, whereas miR-222-5p and miR-512-3p were related to metabolic control. CONCLUSIONS: The study showed that Sorafenib regulates a specific miRNA signature in which miR-200c-3p, miR-222-5p, and miR-512-3p bear prognostic value and contribute to treatment response.

DNA Methylation Regulates a Set of Long Non-Coding RNAs Compromising Hepatic Identity during Hepatocarcinogenesis.

BACKGROUND: Long noncoding RNAs (lncRNAs) are emerging as key players in cancer, including hepatocellular carcinoma (HCC). Here we identify the mechanism implicated in the HCC inhibition of a set of lncRNAs, and their contribution to the process of hepatocarcinogenesis. METHODS AND RESULTS: The top-ranked 35 lncRNAs downregulated in HCC (Top35 LNDH) were validated in several human HCC cohorts. We demonstrate that their inhibition is associated with promoter hypermethylation in HCC compared to control tissue, and in HCC human cell lines compared to primary hepatocytes. Moreover, demethylating treatment of HCC human cell lines induced the expression of these lncRNAs. The Top35 LNDH were preferentially expressed in the adult healthy liver compared to other tissues and fetal liver and were induced in well-differentiated HepaRG cells. Remarkably, their knockdown compromised the expression of other hepato-specific genes. Finally, the expression of the Top35 LNDH positively correlates with the grade of tumor differentiation and, more importantly, with a better patient prognosis. CONCLUSIONS: Our results demonstrate that the selected Top35 LNDH are not only part of the genes that compose the hepatic differentiated signature but participate in its establishment. Moreover, their downregulation through DNA methylation occurs during the process of hepatocarcinogenesis compromising hepatocellular differentiation and HCC patients' prognosis.

The pituitary tumour-transforming gene 1/delta-like homologue 1 pathway plays a key role in liver fibrogenesis.

BACKGROUND AND AIMS: PTTG1 is almost undetectable in adult livers but is highly expressed in hepatocarcinoma. While little is known about its involvement in liver fibrosis, PTTG1 expression is associated with DLK1. We assessed the role of the PTTG1/DLK1 pathway in fibrosis progression and the potential therapeutic effect of PTTG1 silencing in fibrosis. METHODS: Pttg1 and Dlk1 were studied in liver and isolated cell populations of control and fibrotic rats and in human liver biopsies. The fibrotic molecular signature was analysed in Pttg1-/- and Pttg1+/+ fibrotic mice. Finally, Pttg1 silencing was evaluated in rats as a novel antifibrotic therapy. RESULTS: Pttg1 and Dlk1 mRNA selectively increased in fibrotic rats paralleling fibrosis progression. Serum DLK1 concentrations correlated with hepatic collagen content and systemic and portal haemodynamics. Human cirrhotic livers showed greater PTTG1 and DLK1 transcript abundance than non-cirrhotic, and reduced collagen was observed in Pttg1 Pttg1-/- mice. The liver fibrotic molecular signature revealed lower expression of genes related to extracellular matrix remodelling including Mmp8 and 9 and Timp4 and greater eotaxin and Mmp13 than fibrotic Pttg1+/+ mice. Finally, interfering Pttg1 resulted in reduced liver fibrotic area, lower α-Sma and decreased portal pressure than fibrotic animals. Furthermore, Pttg1 silencing decreased the transcription of Dlk1, collagens I and III, Pdgfrß, Tgfrß, Timp1, Timp2 and Mmp2. CONCLUSIONS: Pttg1/Dlk1 are selectively overexpressed in the cirrhotic liver and participate in ECM turnover regulation. Pttg1 disruption decreases Dlk1 transcription and attenuates collagen deposition. PTTG1/DLK1 signalling is a novel pathway for targeting the progression of liver fibrosis.

OncomiRs miR-106a and miR-17 negatively regulate the nucleoside-derived drug transporter hCNT1.

High-affinity uptake of natural nucleosides as well as nucleoside derivatives used in anticancer therapies is mediated by human concentrative nucleoside transporters (hCNTs). hCNT1, the hCNT family member that specifically transports pyrimidines, is also a transceptor involved in tumor progression. In particular, oncogenesis appears to be associated with hCNT1 downregulation in some cancers, although the underlying mechanisms are largely unknown. Here, we sought to address changes in colorectal and pancreatic ductal adenocarcinoma-both of which are important digestive cancers-in the context of treatment with fluoropyrimidine derivatives. An analysis of cancer samples and matching non-tumoral adjacent tissues revealed downregulation of hCNT1 protein in both types of tumor. Further exploration of the putative regulation of hCNT1 by microRNAs (miRNAs), which are highly deregulated in these cancers, revealed a direct relationship between the oncomiRs miR-106a and miR-17 and the loss of hCNT1. Collectively, our findings provide the first demonstration that hCNT1 inhibition by these oncomiRs could contribute to chemoresistance to fluoropyrimidine-based treatments in colorectal and pancreatic cancer.

Early diarrhoea under sorafenib as a marker to consider the early migration to second-line drugs.

BACKGROUND: Despite atezolizumab and bevacizumab (A + B) is currently the first-line treatment for hepatocellular carcinoma (HCC) patients, some patients will not be adequate for this combination. In the setting of sorafenib some adverse events have been proposed as prognostic factors. OBJECTIVE: To characterize the early diarrhoea development as prognostic factor in 344 HCC patients. METHODS: The development of early diarrhoea in sorafenib treatment defined as patients who developed diarrhoea and needed dose modification within the first 60 days of treatment (e-diarrhoea) and 3-grouping variables were analysed: Patients with e-diarrhoea, patients who developed diarrhoea after the first 60 days of treatment (L-diarrhoea) and patients that never developed diarrhoea (never diarrhoea). RESULTS: The median overall survival in sorafenib treated patients was significantly different across groups (6.8 months for e-diarrhoea, 26.7 months for L-diarrhoea and 13.3 months for never-diarrhoea). The emergence of e-diarrhoea was associated with poor outcomes (hazard ratio [HR] 1.84 [95%CI 1.15-2.95]), while there was no increased/decreased risk of dismal evolution in patients with L-diarrhoea (HR 0.66 [95%CI 0.42-1.03]). CONCLUSION: The emergence of e-diarrhoea in HCC patients treated with sorafenib is an early predictor of dismal evolution under this therapy. Thus, prompt identification of these non-responders may be useful for an early switch to second-line therapies.

Anti-miR-518d-5p overcomes liver tumor cell death resistance through mitochondrial activity.

Dysregulation of miRNAs is a hallmark of cancer, modulating oncogenes, tumor suppressors, and drug responsiveness. The multi-kinase inhibitor sorafenib is one of the first-line drugs for advanced hepatocellular carcinoma (HCC), although the outcome for treated patients is heterogeneous. The identification of predictive biomarkers and targets of sorafenib efficacy are sorely needed. Thus, selected top upregulated miRNAs from the C19MC cluster were analyzed in different hepatoma cell lines compared to immortalized liver human cells, THLE-2 as control. MiR-518d-5p showed the most consistent upregulation among them. Thus, miR-518d-5p was measured in liver tumor/non-tumor samples of two distinct cohorts of HCC patients (n = 16 and n = 20, respectively). Circulating miR-518d-5p was measured in an independent cohort of HCC patients receiving sorafenib treatment (n = 100), where miR-518d-5p was analyzed in relation to treatment duration and patient's overall survival. In vitro and in vivo studies were performed in human hepatoma BCLC3 and Huh7 cells to analyze the effect of miR-518d-5p inhibition/overexpression during the response to sorafenib. Compared with healthy individuals, miR-518d-5p levels were higher in hepatic and serum samples from HCC patients (n = 16) and in an additional cohort of tumor/non-tumor paired samples (n = 20). MiR-518d-5p, through the inhibition of c-Jun and its mitochondrial target PUMA, desensitized human hepatoma cells and mouse xenograft to sorafenib-induced apoptosis. Finally, serum miR-518d-5p was assessed in 100 patients with HCC of different etiologies and BCLC-stage treated with sorafenib. In BCLC-C patients, higher serum miR-518d-5p at diagnosis was associated with shorter sorafenib treatment duration and survival. Hence, hepatic miR-518d-5p modulates sorafenib resistance in HCC through inhibition of c-Jun/PUMA-induced apoptosis. Circulating miR-518d-5p emerges as a potential lack of response biomarker to sorafenib in BCLC-C HCC patients.

Mutational profile of skin lesions in hepatocellular carcinoma patients under tyrosine kinase inhibition: a repercussion of a wide-spectrum activity.

BACKGROUND/AIM: Dermatological adverse events (DAE) in hepatocellular carcinoma (HCC) patients treated with sorafenib predicts better outcome. Some turn into skin lesions (SL) requiring pathology examination. We describe incidence, characteristics and molecular profile of SL in HCC patients treated with sorafenib. MATERIALS AND METHODS: SL were prospectively collected in 311 HCC patients who started sorafenib. SL from sorafenib cohort were compared to those from a control patient group selected to match SL type and demographics. HRAS, KRAS and BRAF mutations were analyzed by CAST-PCR, mutated p53 and MAPK pathway activation by immunohistochemistry and immune infiltration by hematoxylin-eosin staining. RESULTS: Eighty-eight out of 311 patients developed DAE and 7.4% SL required histological assessment. Most frequent lesions were keratoacanthomas (n = 4), squamous-cell carcinomas (SCC)(n = 5), basal-cell carcinomas (BCC)(n = 3) and seborrheic keratosis (n = 5). HRAS and KRAS mutations were detected in 4 SL, while no mutations showed in control SL. Nuclear pERK immunostaining was identified in 33.3% of cases versus 5.3% of controls. Most SL (90%) from patients with DAE were proliferative with intense immune infiltration (73%). CONCLUSIONS: The onset of SL and their molecular profile did not impact negatively on patient's prognosis, but intense proliferation of SL may reflect compensatory activation of MAPK pathway and warrants their close monitoring.

Activated Lymphocytes and Increased Risk of Dermatologic Adverse Events during Sorafenib Therapy for Hepatocellular Carcinoma.

Advanced hepatocellular carcinoma patients treated with sorafenib who develop early dermatologic adverse events (eDAEs) have a better prognosis. This may be linked to immune mechanisms, and thus, it is relevant to assess the association between peripheral immunity and the probability of developing eDAEs. Peripheral blood mononuclear cells of 52 HCC patients treated with sorafenib were analyzed at baseline and throughout the first eight weeks of therapy. T, B, Natural Killer cells, and their immune checkpoints expression data were characterized by flow cytometry. Cytokine release and immune-suppression assays were carried out ex vivo. Cox baseline and time-dependent regression models were applied to evaluate the probability of increased risk of eDAEs. DNAM-1, PD-1, CD69, and LAG-3 in T cells, plus CD16 and LAG-3 in NK cells, are significantly associated with the probability of developing eDAEs. While NK DNAM-1+ cells express activation markers, T DNAM-1+ cells induce immune suppression and show immune exhaustion. This is the first study to report an association between immune checkpoints expression in circulating immune cells and the increased incidence of eDAEs. Our results support the hypothesis for an off-target role of sorafenib in immune modulation. We also describe a novel association between DNAM-1 and immune exhaustion in T cells.

Pharmacokinetics and pharmacogenetics of sorafenib in patients with hepatocellular carcinoma: Implications for combination trials.

BACKGROUND & AIMS: Sorafenib and lenvatinib are the first-line treatments approved in hepatocellular carcinoma (HCC), but information is lacking about the relationships between their pharmacokinetics, patients pharmacogenetic profiles, adverse events (AE) and overall survival. We aimed to elucidate these relationships of tyrosine Kinase Inhibitors, such as sorafenib, in order to improve the design of trials testing it in combination with checkpoint inhibitors. METHODS: We assessed the pharmacokinetics of sorafenib and its N-oxide metabolite at day-0, day-7, day-30, day-60, day-90, day-120, day-150 and day-180 and nine single-nucleotide polymorphisms (SNP) in five genes related to sorafenib metabolism/transport to identify the best point for starting the combination between tyrosine kinases and checkpoint inhibitors. RESULTS: We prospectively included 49 patients (96% cirrhotic, 37% hepatitis-C, 82% Child-Pugh-A and 59% BCLC-C). Pharmacokinetic values peaked at day-7 and progressively declined until day-60. In the 16 patients without further dose modifications after day-60, pharmacokinetic values remained stable through day-180 (sorafenib P = .90; N-oxide P = .93). Pharmacokinetic values were higher in patients with early dermatological adverse events and lower in patients with early diarrhoea. Sorafenib and N-oxide pharmacokinetic values varied linearly with different alleles of MRP2*3972. CONCLUSIONS: Sorafenib's pharmacokinetics is heterogeneous across HCC patients. This heterogeneity affects adverse events development and must be taken into account in setting the dose and timing of its combination with checkpoint inhibitors.

Regorafenib Alteration of the BCL-xL/MCL-1 Ratio Provides a Therapeutic Opportunity for BH3-Mimetics in Hepatocellular Carcinoma Models.

BACKGROUND: The multikinase inhibitor regorafenib, approved as second-line treatment for hepatocellular carcinoma (HCC) after sorafenib failure, may induce mitochondrial damage. BH3-mimetics, inhibitors of specific BCL-2 proteins, are valuable drugs in cancer therapy to amplify mitochondrial-dependent cell death. METHODS: In in vitro and in vivo HCC models, we tested regorafenib's effect on the BCL-2 network and the efficacy of BH3-mimetics on HCC treatment. RESULTS: In hepatoma cell lines and Hep3B liver spheroids, regorafenib cytotoxicity was potentiated by BCL-xL siRNA transfection or pharmacological inhibition (A-1331852), while BCL-2 antagonism had no effect. Mitochondrial outer membrane permeabilization, cytochrome c release, and caspase-3 activation mediated A-1331852/regorafenib-induced cell death. In a patient-derived xenograft (PDX) HCC model, BCL-xL inhibition stimulated regorafenib activity, drastically decreasing tumor growth. Moreover, regorafenib-resistant HepG2 cells displayed increased BCL-xL and reduced MCL-1 expression, while A-1331852 reinstated regorafenib efficacy in vitro and in a xenograft mouse model. Interestingly, BCL-xL levels, associated with poor prognosis in liver and colorectal cancer, and the BCL-xL/MCL-1 ratio were detected as being increased in HCC patients. CONCLUSION: Regorafenib primes tumor cells to BH3-mimetic-induced cell death, allowing BCL-xL inhibition with A-1331852 or other strategies based on BCL-xL degradation to enhance regorafenib efficacy, offering a novel approach for HCC treatment, particularly for tumors with an elevated BCL-xL/MCL-1 ratio.

Bespoken Nanoceria: An Effective Treatment in Experimental Hepatocellular Carcinoma.

BACKGROUND AND AIMS: Despite the availability of new-generation drugs, hepatocellular carcinoma (HCC) is still the third most frequent cause of cancer-related deaths worldwide. Cerium oxide nanoparticles (CeO2 NPs) have emerged as an antioxidant agent in experimental liver disease because of their antioxidant, anti-inflammatory, and antisteatotic properties. In the present study, we aimed to elucidate the potential of CeO2 NPs as therapeutic agents in HCC. APPROACH AND RESULTS: HCC was induced in 110 Wistar rats by intraperitoneal administration of diethylnitrosamine for 16 weeks. Animals were treated with vehicle or CeO2 NPs at weeks 16 and 17. At the eighteenth week, nanoceria biodistribution was assessed by mass spectrometry (MS). The effect of CeO2 NPs on tumor progression and animal survival was investigated. Hepatic tissue MS-based phosphoproteomics as well as analysis of principal lipid components were performed. The intracellular uptake of CeO2 NPs by human ex vivo perfused livers and human hepatocytes was analyzed. Nanoceria was mainly accumulated in the liver, where it reduced macrophage infiltration and inflammatory gene expression. Nanoceria treatment increased liver apoptotic activity, while proliferation was attenuated. Phosphoproteomic analysis revealed that CeO2 NPs affected the phosphorylation of proteins mainly related to cell adhesion and RNA splicing. CeO2 NPs decreased phosphatidylcholine-derived arachidonic acid and reverted the HCC-induced increase of linoleic acid in several lipid components. Furthermore, CeO2 NPs reduced serum alpha-protein levels and improved the survival of HCC rats. Nanoceria uptake by ex vivo perfused human livers and in vitro human hepatocytes was also demonstrated. CONCLUSIONS: These data indicate that CeO2 NPs partially revert the cellular mechanisms involved in tumor progression and significantly increase survival in HCC rats, suggesting that they could be effective in patients with HCC.

Relationship between changes in the exon-recognition machinery and SLC22A1 alternative splicing in hepatocellular carcinoma.

Changes in the phenotype that characterizes cancer cells are partly due to altered processing of pre-mRNA by the spliceosome. We have previously reported that aberrant splicing plays an essential role in the impaired response of hepatocellular carcinoma (HCC) to sorafenib by reducing the expression of functional organic cation transporter type 1 (OCT1, gene SLC22A1) that constitutes the primary way for HCC cells to take up this and other drugs. The present study includes an in silico analysis of publicly available databases to investigate the relationship between alternative splicing of SLC22A1 pre-mRNA and the expression of genes involved in the exon-recognition machinery in HCC and adjacent non-tumor tissue. Using Taqman Low-Density Arrays, the findings were validated in 25 tumors that were resected without neoadjuvant chemotherapy. The results supported previous reports showing that there was a considerable degree of alternative splicing of SLC22A1 in adjacent non-tumor tissue, which was further increased in the tumor in a stage-unrelated manner. Splicing perturbation was associated with changes in the profile of proteins determining exon recognition. The results revealed the importance of using paired samples for splicing analysis in HCC and confirmed that aberrant splicing plays an essential role in the expression of functional OCT1. Changes in the exon recognition machinery may also affect the expression of other proteins in HCC. Moreover, these results pave the way to further investigations on the mechanistic bases of the relationship between the expression of spliceosome-associated genes and its repercussion on the appearance of alternative and aberrant splicing in HCC.

Identification of Coding and Long Noncoding RNAs Differentially Expressed in Tumors and Preferentially Expressed in Healthy Tissues.

The Cancer Genome Atlas (TCGA) and Genotype-Tissue Expression (GTEx) datasets allow unprecedented gene expression analyses. Here, using these datasets, we performed pan-cancer and pan-tissue identification of coding and long noncoding RNA (lncRNA) transcripts differentially expressed in tumors and preferentially expressed in healthy tissues and/or tumors. Pan-cancer comparison of mRNAs and lncRNAs showed that lncRNAs were deregulated in a more tumor-specific manner. Given that lncRNAs are more tissue-specific than mRNAs, we identified healthy tissues that preferentially express lncRNAs upregulated in tumors and found that testis, brain, the digestive tract, and blood/spleen were the most prevalent. In addition, specific tumors also upregulate lncRNAs preferentially expressed in other tissues, generating a unique signature for each tumor type. Most tumors studied downregulated lncRNAs preferentially expressed in their tissue of origin, probably as a result of dedifferentiation. However, the same lncRNAs could be upregulated in other tumors, resulting in "bimorphic" transcripts. In hepatocellular carcinoma (HCC), the upregulated genes identified were expressed at higher levels in patients with worse prognosis. Some lncRNAs upregulated in HCC and preferentially expressed in healthy testis or brain were predicted to function as oncogenes and were significantly associated with higher tumor burden, and poor prognosis, suggesting their relevance in hepatocarcinogenesis and/or tumor evolution. Taken together, therapies targeting oncogenic lncRNAs should take into consideration the healthy tissue, where the lncRNAs are preferentially expressed, to predict and decrease unwanted secondary effects and increase potency. SIGNIFICANCE: Comprehensive analysis of coding and noncoding genes expressed in different tumors and normal tissues, which should be taken into account to predict side effects from potential coding and noncoding gene-targeting therapies.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/79/20/5167/F1.large.jpg.