Surgical management of liver tumors.

Two percent of pediatric malignancies arise primarily in the liver; roughly 60% of these cancers are hepatoblastoma (HB). Despite the rarity of these cases, international collaborative efforts have led to the consistent histological classification and staging systems, which facilitate ongoing clinical trials. Other primary liver malignancies seen in children include hepatocellular carcinoma (HCC) with or without underlying liver disease, fibrolamellar carcinoma (FLC), undifferentiated embryonal sarcoma of the liver (UESL), and hepatocellular neoplasm not otherwise specified (HCN-NOS). This review describes principles of surgical management of malignant pediatric primary liver tumors, within the context of comprehensive multidisciplinary care.

EZH2 is a key component of hepatoblastoma tumor cell growth.

BACKGROUND: Enhancer of zeste homolog 2 (EZH2) catalyzes the trimethylation of histone H3 at lysine 27 via the polycomb recessive complex 2 (PRC2) and plays a time-specific role in normal fetal liver development. EZH2 is overexpressed in hepatoblastoma (HB), an embryonal tumor. EZH2 can also promote tumorigenesis via a noncanonical, PRC2-independent mechanism via proto-oncogenic, direct protein interaction, including ß-catenin. We hypothesize that the pathological activation of EZH2 contributes to HB propagation in a PRC2-independent manner. METHODS AND RESULTS: We demonstrate that EZH2 promotes proliferation in HB tumor-derived cell lines through interaction with ß-catenin. Although aberrant EZH2 expression occurs, we determine that both canonical and noncanonical EZH2 signaling occurs based on specific gene-expression patterns and interaction with SUZ12, a PRC2 component, and ß-catenin. Silencing and inhibition of EZH2 reduce primary HB cell proliferation. CONCLUSIONS: EZH2 overexpression promotes HB cell proliferation, with both canonical and noncanonical function detected. However, because EZH2 directly interacts with ß-catenin in human tumors and EZH2 overexpression is not equal to SUZ12, it seems that a noncanonical mechanism is contributing to HB pathogenesis. Further mechanistic studies are necessary to elucidate potential pathogenic downstream mechanisms and translational potential of EZH2 inhibitors for the treatment of HB.

Dr. Allen Oldfather Whipple (1881-1963): Namesake of the pancreaticoduodenectomy.

Allen O. Whipple was an American surgeon who popularized the pancreaticoduodenectomy (Whipple procedure) for periampullary cancer, which remains the gold standard for pancreatic tumor resections. Whipple was educated at Princeton University (B.S., 1904) and Columbia University College of Physicians and Surgeons (M.D., 1908). He swiftly ascended the academic ranks, culminating in his appointment as Professor of Surgery at Columbia and Director of Surgical Services at Presbyterian Hospital in 1921. Whipple published three criteria (Whipple's triad) for evaluating hyperinsulinism secondary to pancreatic insulinoma. He also revived interest in portocaval anastomosis to reduce portal hypertension, determining it to be a consequence of liver disease. During his 40-year career, Whipple introduced the concept of multidisciplinary teams and prospective data collection. He also shaped the structure of surgical training as President of the American Surgical Association and Chairman of the American Board of Surgery. Beyond the walls of the operating room, Whipple was a Renaissance Man whose childhood in Persia (Iran) engendered a lifelong interest in the region's art, culture, history, and medicine. Dr. Allen Oldfather Whipple is remembered as a pioneering physician and surgeon beloved by those who trained under him.

Retreatment with Cisplatin May Provide a Survival Advantage for Children with Relapsed/Refractory Hepatoblastoma: An Institutional Experience.

BACKGROUND: Hepatoblastoma (HB) is the most common liver malignancy in children. There is no standard of care for management of relapsed/refractory HB (rrHB) and reports in the literature are limited. OBJECTIVE: To describe presenting features, biology, treatment strategies, and outcomes for pediatric patients with relapsed/refractory hepatoblastoma. METHODS: An IRB-approved retrospective institutional review of patients with rrHB who presented for consultation and/or care from 2000-2019. Clinical, radiographic, and histologic data were collected from all patients. RESULTS: Thirty subjects were identified with a median age of 19.5 months (range 3-169 months) at initial diagnosis and 32.5 months (range 12-194 months) at time of first relapse. 63% of subjects were male, 70% Caucasian, and 13% were born premature. Three subjects had a known cancer predisposition syndrome. Eight patients had refractory disease while 22 patients had relapsed disease. Average time from initial diagnosis to relapse or progression was 12.5 months. Average alpha-fetoprotein (AFP) at initial diagnosis was 601,203 ng/mL (range 121-2,287,251 ng/mL). Average AFP at relapse was 12,261 ng/mL (range 2.8-201,000 ng/mL). For patients with tumor sequencing (n = 17), the most common mutations were in CTNNB1 (13) and NRF2 (4). First relapse sites were lungs (n = 12), liver (n = 11) and both (n = 6). More than one relapse/progression occurred in 47% of subjects; 6 had ≥3 relapses. Pathology in patients with multiply relapsed disease was less differentiated including descriptions of small cell undifferentiated (n = 3), pleomorphic (n = 1), transitional liver cell tumor (n = 2) and HB with carcinoma features (n = 1). All subjects underwent surgical resection of site of relapsed disease with 7 subjects requiring liver transplantation. Overall survival was 50%. Survival was associated with use of cisplatin at relapse (78.6% with vs. 25% without, p = 0.012). The most common late effect was ototoxicity with at least mild sensorineural hearing loss found in 80% of subjects; 54% required hearing aids. CONCLUSIONS: Retreatment with cisplatin at the time of relapse may provide an advantage for some patients with hepatoblastoma. Multiply relapsed disease was not uncommon and not associated with a worse prognosis. Careful attention should be paid to cumulative therapy-induced toxicity while concurrently aiming to improve cure.

Quality of Life Outcomes for Patients Who Underwent Conventional Resection and Liver Transplantation for Locally Advanced Hepatoblastoma.

Hepatoblastoma is the most common malignant liver tumor of childhood, with liver transplant and extended resection used as surgical treatments for locally advanced tumors. Although each approach has well-described post-operative complications, quality-of-life outcomes have not been described following the two interventions. Long-term pediatric survivors of hepatoblastoma who underwent conventional liver resection or liver transplantation at a single institution from January 2000-December 2013 were recruited to complete quality-of-life surveys. Survey responses for the Pediatric Quality of Life Generic Core 4.0 (PedsQL, n = 30 patient and n = 31 parent surveys) and Pediatric Quality of Life Cancer Module 3.0 (PedsQL-Cancer, n = 29 patient and n = 31 parent surveys) were collected from patients and parents. The mean total patient-reported PedsQL score was 73.7, and the parent-reported score was 73.9. There were no significant differences in scores on the PedsQL between patients who underwent resection compared to those who underwent transplantation (p > 0.05 for all comparisons). On the PedsQL-Cancer module, procedural anxiety scores were significantly lower for patients who underwent resection as compared to transplant (M = 33.47 points less, CI [-60.41, -6.53], p-value 0.017). This cross-sectional study demonstrates that quality of life outcomes are overall similar among patients receiving transplants and resections. Patients who received a resection reported worse procedural anxiety.

Structural and Functional Impact of Posttranslational Modification of Glypican-3 on Liver Carcinogenesis.

Glypican-3 (GPC3) is a cell-surface glycoprotein that is frequently overexpressed in hepatocellular carcinoma (HCC). GPC3 undergoes extensive posttranslational modification (PTM) including cleavage and glycosylation. This review focuses on the structure and function of GPC3 in liver cancer, highlighting the PTM of the tertiary and quaternary structures of GPC3 as a potential oncogenic regulatory mechanism. We propose that the function of GPC3 in normal development can vary with extensive PTM and that dysregulation of these processes leads to disease. Defining the regulatory impact of these modifications can provide a deeper understanding of the role of GPC3 in oncogenesis, epithelial-mesenchymal transition, and drug development. Through review of current literature, this article provides a unique perspective on the role of GPC3 in liver cancer, focusing on potential regulatory mechanisms of PTM on GPC3 function at the molecular, cellular, and disease level.

Customized Postoperative Therapy Improves Bile Drainage in Biliary Atresia: A Single Center Preliminary Report.

BACKGROUND: Controversies in management of biliary atresia (BA) after hepatoportoenterostomy (HPE) lead to variable treatment protocols. We implemented standardized medical management after HPE, customizing the use of antibiotics and corticosteroids based on patient-specific factors. METHODS: In this retrospective analysis, 20 consecutive infants underwent HPE for BA and were compared to a historical cohort. Analysis of successful biliary drainage 3 months after HPE (defined as serum total bilirubin <2 mg/dL) was the primary endpoint; survival with native liver at 2 years was the secondary endpoint. RESULTS: Sixteen of 20 (80%) infants had successful bile drainage, compared to 8 of 20 (40%) infants in the historical cohort (P = 0.0225). Sixteen of 20 patients in the new protocol have reached 2 years of age or required liver transplantation. Among the sixteen, 11 (68.8%) are alive with native livers versus 10 of 20 (50%) in the historical cohort (P = 0.0970). CONCLUSION: This preliminary report suggests the potential benefit of tailored use of postoperative antibiotics and corticosteroids in improving biliary drainage after HPE. LEVEL OF EVIDENCE: III.

Integrated analysis using ToppMiR uncovers altered miRNA- mRNA regulatory networks in pediatric hepatocellular carcinoma-A pilot study.

BACKGROUND: Pediatric hepatocellular carcinoma (HCC) is a group of liver cancers whose mechanisms behind their pathogenesis and progression are poorly understood. AIM: We aimed to identify alterations in the expression of miRNAs and their putative target mRNAs in not only tumor tissues of patients with pediatric HCC but also in corresponding non-tumorous background livers by using liver tissues without underlying liver disease as a control. METHODS AND RESULTS: We performed a small-scale miRNA and mRNA profiling of pediatric HCC (consisting of fibrolamellar carcinoma [FLC] and non-FLC HCC) and paired liver tissues to identify miRNAs whose expression levels differed significantly from control livers without underlying liver disease. ToppMiR was used to prioritize both miRNAs and their putative target mRNAs in a gene-annotation network, and the mRNA profile was used to refine the prioritization. Our analysis generated prioritized lists of miRNAs and mRNAs from the following three sets of analyses: (a) pediatric HCC versus control; (b) FLC versus control; and (c) corresponding non-tumorous background liver tissues from the same patients with pediatric HCC versus control. No liver disease liver tissues were used as the control group for all analyses. Many miRNAs whose expressions were deregulated in pediatric HCC were consistent with their roles in adult HCC and/or other non-hepatic cancers. Our gene ontology analysis of target mRNAs revealed enrichment of biological processes related to the sustenance and propagation of cancer and significant downregulation of metabolic processes. CONCLUSION: Our pilot study indicates that alterations in miRNA-mRNA networks were detected in not only tumor tissues but also corresponding non-tumorous liver tissues from patients with pediatric HCC, suggesting multi-faceted roles of miRNAs in disease progression. Our results may lead to novel hypotheses for future large-scale studies.

10 Year Analysis of Pediatric Surgery Fellowship Match and Operative Experience: Concerning Trends?

OBJECTIVE: This paper aims to evaluate the pediatric surgery training pipeline vis-à-vis the pediatric surgery match and operative experience of pediatric surgery fellows. SUMMARY OF BACKGROUND DATA: Pediatric surgery remains a competitive surgical subspecialty. However, there is concern that operative experience for pediatric surgery fellows is changing. This paper examines the selectivity of the pediatric surgery match, along with the operative experience of pediatric surgery fellows to characterize the state of pediatric surgery training. METHODS: The pediatric surgery fellowship match was analyzed from the National Resident Matching Program data from 2010 to 2019. Selectivity among fellowships was compared using analysis of variance with Dunnett test. Operative log data for pediatric fellows was analyzed using the Accreditation Council for Graduate Medical Education case logs from 2009 to 2019. Linear regression analysis was used to evaluate trends in operative volume over time. RESULTS: Pediatric surgery had the highest proportion of unmatched applicants (47.2% ± 5.3%) and lowest proportion of unfilled positions (1.4% ± 1.6%) when compared to other National Resident Matching Program surgical fellowships. Accreditation Council for Graduate Medical Education case log analysis revealed a statistically significant decrease in cases for graduating fellows (-5.3 cases/year, P < 0.05). Total index cases decreased (-4.7 cases/year, P < 0.01, R 2 = 0.83) such that graduates in 2019 completed 59 fewer index operations than graduates in 2009. CONCLUSION: Although pediatric surgery fellowship remains highly selective there has been a decline in the operative experience for graduating fellows. This highlights the need for evaluation of training paradigms and operative exposure in pediatric surgery to ensure the training of competent pediatric surgeons.

Inhibition of Glypican-3 Cleavage Results in Reduced Cell Proliferation in a Liver Cancer Cell Line.

INTRODUCTION: Glypican-3 (GPC3) is a surface-bound proteoglycan overexpressed in pediatric liver cancer and utilized clinically as an immunohistochemical tumor marker. Furin is a proprotein convertase that is ubiquitously expressed and shown to modify GPC3 post-translationally. In experimental models of epithelial-based cancers, furin inhibition decreased tumor cell migration and proliferation representing a potential therapeutic target. METHODS: Using a synthetic furin inhibitor, we evaluated proliferation, migration, protein, and RNA expression in two liver cancer cell lines, HepG2 (GPC3-positive) and SKHep1 cells (GPC3-negative). Total furin protein and GPC3 protein expression were assessed to evaluate functional levels of furin. RESULTS: There was a reduction in HepG2 proliferation with addition of furin inhibitor at the 48-h timepoint, however there was an increase in HepG2 migration. CONCLUSIONS: GPC3 cleavage in hepatoblastoma (HB) has a role in cell proliferation with therapeutic potential, however furin inhibition is not an appropriate target for GPC3-expressing HB due to increased migration which may enhance metastatic potential.

ß-catenin cancer-enhancing genomic regions axis is involved in the development of fibrolamellar hepatocellular carcinoma.

Fibrolamellar hepatocellular carcinoma (FLC) is a disease that occurs in children and young adults. The development of FLC is associated with creation of a fusion oncoprotein DNAJB1-PKAc kinase, which activates multiple cancer-associated pathways. The aim of this study was to examine the role of human genomic regions, called cancer-enhancing genomic regions or aggressive liver cancer domains (CEGRs/ALCDs), in the development of FLC. Previous studies revealed that CEGRs/ALCDs are located in multiple oncogenes and cancer-associated genes, regularly silenced in normal tissues. Using the regulatory element locus intersection (RELI) algorithm, we searched a large compendium of chromatin immunoprecipitation-sequencing (ChIP) data sets and found that CEGRs/ALCDs contain regulatory elements in several human cancers outside of pediatric hepatic neoplasms. The RELI algorithm further identified components of the ß-catenin-TCF7L2/TCF4 pathway, which interacts with CEGRs/ALCDs in several human cancers. Particularly, the RELI algorithm found interactions of transcription factors and chromatin remodelers with many genes that are activated in patients with FLC. We found that these FLC-specific genes contain CEGRs/ALCDs, and that the driver of FLC, fusion oncoprotein DNAJB1-PKAc, phosphorylates ß-catenin at Ser675, resulting in an increase of ß-catenin-TCF7L2/TCF4 complexes. These complexes increase a large family of CEGR/ALCD-dependent collagens and oncogenes. The DNAJB1-PKAc-ß-catenin-CEGR/ALCD pathway is preserved in lung metastasis. The inhibition of ß-catenin in FLC organoids inhibited the expression of CEGRs/ALCDs-dependent collagens and oncogenes, preventing the formation of the organoid's structure. Conclusion: This study provides a rationale for the development of ß-catenin-based therapy for patients with FLC.

A developmentally prometastatic niche to hepatoblastoma in neonatal liver mediated by the Cxcl1/Cxcr2 axis.

BACKGROUND AND AIMS: Hepatoblastoma (HB) is the most common pediatric liver cancer. Its predominant occurrence in very young children led us to investigate whether the neonatal liver provides a protumorigenic niche to HB development. APPROACH AND RESULTS: HB development was compared between orthotopic transplantation models established in postnatal day 5 (P5) and 60 (P60) mice (P5Tx and P60Tx models). Single-cell RNA-sequencing (sc-RNAseq) was performed using tumor and liver tissues from both models and the top candidate cell types and genes identified are investigated for their roles in HB cell growth, migration, and survival. CONCLUSIONS: We found that various HB cell lines including HepG2 cells were consistently and considerably more tumorigenic and metastatic in the P5Tx model than in the P60Tx models. Sc-RNAseq of the P5Tx and P60Tx HepG2 models revealed that the P5Tx tumor was more hypoxic and had a larger number of activated hepatic stellate cells (aHSCs) in the tumor-surrounding liver that express significantly higher levels of Cxcl1 than those from the P60Tx model. We found these differences were developmentally present in normal P5 and P60 liver. We showed that the Cxcl1/Cxcr2 axis mediated HB cell migration and was critical to HB cell survival under hypoxia. Treating HepG2 P60Tx model with recombinant CXCL1 protein induced intrahepatic and pulmonary metastasis and CXCR2 knockout (KO) in HepG2 cells abolished their metastatic potential in the P5Tx model. Lastly, we showed that in tumors from patients with metastatic HB, there was a similar larger population of aHSCs in the tumor-surrounding liver than in localized tumors, and tumor hypoxia was uniquely associated with prognosis of patients with HB among pediatric cancers. We demonstrated that the neonatal liver provides a prometastatic niche to HB development through the Cxcl1/Cxcr2 axis.

Identification of distinct tumor cell populations and key genetic mechanisms through single cell sequencing in hepatoblastoma.

Hepatoblastoma (HB) is the most common primary liver malignancy of childhood, and molecular investigations are limited and effective treatment options for chemoresistant disease are lacking. There is a knowledge gap in the investigation of key driver cells of HB in tumor. Here we show single cell ribonucleic acid sequencing (scRNAseq) analysis of human tumor, background liver, and patient derived xenograft (PDX) to demonstrate gene expression patterns within tumor and to identify intratumor cell subtype heterogeneity to define differing roles in pathogenesis based on intracellular signaling in pediatric HB. We have identified a driver tumor cell cluster in HB by genetic expression which can be examined to define disease mechanism and treatments. Identification of both critical mechanistic pathways combined with unique cell populations provide the basis for discovery and investigation of novel treatment strategies in vitro and in vivo.

Association between Elevated Urine Neutrophil Gelatinase-Associated Lipocalin and Postoperative Acute Kidney Injury in Neonates.

OBJECTIVE: To examine the incidence of postoperative neonatal acute kidney injury (AKI) following general surgical procedures and to test the hypothesis that postoperative urine neutrophil gelatinase-associated lipocalin (uNGAL) concentrations predict AKI. The secondary objective was to evaluate for an association between AKI and hospital mortality. STUDY DESIGN: Prospective observational study of infants undergoing abdominal and thoracic surgical procedures in the neonatal intensive care unit from October 2018 to March 2020. The primary outcome was incidence of neonatal AKI (defined by the neonatal modified Kidney Diseases Improving Global Outcomes criteria) following each procedure to postoperative day 5. Severe AKI was defined as stage 2 or 3 AKI. Urine samples were obtained pre- and postoperatively at 6 time points to evaluate for levels of uNGAL. Secondary outcomes were in-hospital mortality and length of stay. RESULTS: Subjects (n = 141) underwent a total of 192 general surgical procedures during the study period. Neonatal AKI and severe AKI occurred following 36 (18%) and 15 (8%) procedures (n = 33 subjects). Percent change of uNGAL from 24 hours preoperatively to 24 hours postoperatively was greater in subjects with neonatal AKI (190.2% [IQR 0.0, 1666.7%] vs 0.7% [IQR -31.2%,140.2%], P = .0374). The strongest association of uNGAL and AKI occurred at 24 hours postoperatively (area under the receiver operator curves of 0.81, 95% CI 0.72, 0.89). Increased mortality risk was observed in subjects with any postoperative AKI (aOR 11.1 95% CI 2.0, 62.8, P = .0063) and severe AKI (aOR 13.8; 95% CI 3.0, 63.1, P = .0007). CONCLUSION: Elevation in uNGAL 24 hours postoperative was associated with AKI. Neonates with postoperative AKI had increased mortality.

HDAC1-Dependent Repression of Markers of Hepatocytes and P21 Is Involved in Development of Pediatric Liver Cancer.

BACKGROUND & AIMS: Epigenetic regulation of gene expression plays a critical role in the development of liver cancer; however, the molecular mechanisms of epigenetic-driven liver cancers are not well understood. The aims of this study were to examine molecular mechanisms that cause the dedifferentiation of hepatocytes into cancer cells in aggressive hepatoblastoma and test if the inhibition of these mechanisms inhibits tumor growth. METHODS: We have analyzed CCAAT/Enhancer Binding Protein alpha (C/EBPα), Transcription factor Sp5, and histone deacetylase (HDAC)1 pathways from a large biobank of fresh hepatoblastoma (HBL) samples using high-pressure liquid chromatography-based examination of protein-protein complexes and have examined chromatin remodeling on the promoters of markers of hepatocytes and p21. The HDAC1 activity was inhibited in patient-derived xenograft models of HBL and in cultured hepatoblastoma cells and expression of HDAC1-dependent markers of hepatocytes was examined. RESULTS: Analyses of a biobank showed that a significant portion of HBL patients have increased levels of an oncogenic de-phosphorylated-S190-C/EBPα, Sp5, and HDAC1 compared with amounts of these proteins in adjacent regions. We found that the oncogenic de-phosphorylated-S190-C/EBPα is created in aggressive HBL by protein phosphatase 2A, which is increased within the nucleus and dephosphorylates C/EBPα at Ser190. C/EBPα-HDAC1 and Sp5-HDAC1 complexes are abundant in hepatocytes, which dedifferentiate into cancer cells. Studies in HBL cells have shown that C/EBPα-HDAC1 and Sp5-HDAC1 complexes reduce markers of hepatocytes and p21 via repression of their promoters. Pharmacologic inhibition of C/EBPα-HDAC1 and Sp5-HDAC1 complexes by Suberoylanilide hydroxamic acid (SAHA) and small interfering RNA-mediated inhibition of HDAC1 increase expression of hepatocyte markers, p21, and inhibit proliferation of cancer cells. CONCLUSIONS: HDAC1-mediated repression of markers of hepatocytes is an essential step for the development of HBL, providing background for generation of therapies for aggressive HBL by targeting HDAC1 activities.

Indocyanine green is a sensitive adjunct in the identification and surgical management of local and metastatic hepatoblastoma.

BACKGROUND: Hepatoblastoma is the most common primary pediatric liver malignancy. Indocyanine green (ICG) has been described as an adjunct to resection in small series. Its utility remains undefined in larger cohorts. METHODS: Records for 29 patients diagnosed with hepatoblastoma who received ICG prior to surgical resection from 2017 to 2020 at a single institution were retrospectively reviewed. The primary outcome was correlation between intraoperative ICG-avidity and histologic presence of hepatoblastoma. A secondary outcome included the histologic margin designation for resected liver specimens. RESULTS: ICG sensitivity was 91% for 120 resected thoracic specimens from 21 patients. Specificity was 57%. In 10% of operations, HB-positive specimens were resected solely on ICG-avidity. In an additional 40% of cases, ICG assisted in localizing a preoperatively diagnosed lesion. ICG sensitivity during thoracotomy and thoracoscopic surgery was 95 and 74%, respectively; primary and relapsed disease demonstrated sensitivity of 94 and 73%, respectively. Sensitivity was 92% for 25 resected liver specimens from nine patients with all parenchymal margins grossly negative for disease. Four multifocal lesions were identified with two resected solely by ICG-avidity. CONCLUSIONS: ICG is a sensitive adjunct for identifying local and metastatic hepatoblastoma, including lesions not visualized on preoperative imaging, and delineating margins during liver resection. False positives limit specificity; however, there were no adverse outcomes from additional resections. We noted that thoracoscopic surgery can be completed safely in patients with less significant disease burden, and conversion to thoracotomy, if necessary, is straightforward.

Olaparib Inhibits Tumor Growth of Hepatoblastoma in Patient-Derived Xenograft Models.

BACKGROUND AND AIMS: Hepatoblastoma (HBL) is a devastating pediatric liver cancer with multiple treatment options, but it ultimately requires surgery for a cure. The most malicious form of HBL is a chemo-resistant aggressive tumor that is characterized by rapid growth, metastases, and poor response to treatment. Very little is known of the mechanisms of aggressive HBL, and recent focuses have been on developing alternative treatment strategies. In this study, we examined the role of human chromosomal regions, called aggressive liver cancer domains (ALCDs), in liver cancer and evaluated the mechanisms that activate ALCDs in aggressive HBL. RESULTS: We found that ALCDs are critical regions of the human genome that are located on all human chromosomes, preferentially in intronic regions of the oncogenes and other cancer-associated genes. In aggressive HBL and in patients with Hepatocellular (HCC), JNK1/2 phosphorylates p53 at Ser6, which leads to the ph-S6-p53 interacting with and delivering the poly(adenosine diphosphate ribose) polymerase 1 (PARP1)/Ku70 complexes on the oncogenes containing ALCDs. The ph-S6-p53-PARP1 complexes open chromatin around ALCDs and activate multiple oncogenic pathways. We found that the inhibition of PARP1 in patient-derived xenografts (PDXs) from aggressive HBL by the Food and Drug Administration (FDA)-approved inhibitor olaparib (Ola) significantly inhibits tumor growth. Additionally, this is associated with the reduction of the ph-S6-p53/PARP1 complexes and subsequent inhibition of ALCD-dependent oncogenes. Studies in cultured cancer cells confirmed that the Ola-mediated inhibition of the ph-S6-p53-PARP1-ALCD axis inhibits proliferation of cancer cells. CONCLUSIONS: In this study, we showed that aggressive HBL is moderated by ALCDs, which are activated by the ph-S6-p53/PARP1 pathway. By using the PARP1 inhibitor Ola, we suppressed tumor growth in HBL-PDX models, which demonstrated its utility in future clinical models.

Evolving applications of fluorescence guided surgery in pediatric surgical oncology: A practical guide for surgeons.

Fluorescence-guided surgery (FGS) is an increasingly available and popular method of visual field augmentation. The basic premise of FGS entails injection of fluorescent indocyanine green (ICG) and subsequent detection with a near-infrared (NIR) camera. For pediatric surgical oncologists, FGS remains experimental but is a promising modality for identifying tumor margins, locating metastases, performing sentinel lymph node biopsies, protecting peritumoral structures of interest, and facilitating reconstruction. Familiarity with basic ICG pharmacokinetics and NIR detection optics is critical for surgeons wishing to judiciously use FGS, as its success is firmly grounded in a thorough understanding of its capabilities and limitations. In this practical guide, we outline several well-described and innovative FGS applications by disease type, including their methods of administration, modes of detection, and typical ICG dosing paradigms. LEVEL OF EVIDENCE: V.

"Complimenting the Complement": Mechanistic Insights and Opportunities for Therapeutics in Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is the most common primary malignancy of the liver and a leading cause of death in the US and worldwide. HCC remains a global health problem and is highly aggressive with unfavorable prognosis. Even with surgical interventions and newer medical treatment regimens, patients with HCC have poor survival rates. These limited therapeutic strategies and mechanistic understandings of HCC immunopathogenesis urgently warrant non-palliative treatment measures. Irrespective of the multitude etiologies, the liver microenvironment in HCC is intricately associated with chronic necroinflammation, progressive fibrosis, and cirrhosis as precedent events along with dysregulated innate and adaptive immune responses. Central to these immunological networks is the complement cascade (CC), a fundamental defense system inherent to the liver which tightly regulates humoral and cellular responses to noxious stimuli. Importantly, the liver is the primary source for biosynthesis of >80% of complement components and expresses a variety of complement receptors. Recent studies implicate the complement system in liver inflammation, abnormal regenerative responses, fibrosis, carcinogenesis, and development of HCC. Although complement activation differentially promotes immunosuppressive, stimulant, and angiogenic microenvironments conducive to HCC development, it remains under-investigated. Here, we review derangement of specific complement proteins in HCC in the context of altered complement regulatory factors, immune-activating components, and their implications in disease pathogenesis. We also summarize how complement molecules regulate cancer stem cells (CSCs), interact with complement-coagulation cascades, and provide therapeutic opportunities for targeted intervention in HCC.

The role of surgical shunts in the treatment of pediatric portal hypertension.

BACKGROUND: Portal diversion by surgical shunt plays a major role in the treatment of medically refractory portal hypertension. We evaluate our center's experience with surgical shunts for the treatment of pediatric portal hypertension. METHODS: All patients who underwent surgical shunt at a single institution from 2008 to 2017 were reviewed. The primary outcome was intervention-free shunt patency. RESULTS: In this study, 34 pediatric patients underwent portal shunt creation. The median age was 7.7 years (interquartile range 4.3-12.0). Twenty-nine patients (85%) had prehepatic portal hypertension and 5 patients (15%) had intrahepatic portal hypertension. The primary manifestations of portal hypertension were esophageal varices (97%) and gastrointestinal bleeding (77%). Eighteen patients (53%) underwent meso-Rex bypass, 10 patients (29%) underwent splenorenal shunt, and 6 patients (18%) underwent mesocaval shunt. Outcomes were notable for minimal wound complications (9%), rebleeding events (12%), and mortality (3%). In the postoperative setting, 10 patients (29%) experienced a shunt complication (occlusion or stenosis), 4 of which occurred in the early postoperative period and required urgent intervention. The 1-year and 5-year "primary patency" patency rates were 71% and 66%, respectively. CONCLUSION: Children suffer significant morbidity from the sequelae of portal hypertension. Our experience reinforces the feasibility of surgical shunts as an effective treatment option associated with low rates of morbidity and mortality.