Immune checkpoint inhibitors in liver transplantation: Current practice, challenges, and opportunities.

Immune checkpoint inhibitors are becoming a mainstay of cancer treatment. While first studied and approved for patients with unresectable disease, due to their efficacy, they are becoming increasingly used in the perioperative period across many cancer types. In patients with HCC, immune checkpoint inhibitors have now become the standard of care in the advanced setting and have shown promising results in the adjuvant setting after liver resection. While these drugs continue to show promise, their role in the peritransplant setting still remains a question. In this review, we explore the current use of this class of medications in patients with HCC, as well as the immunologic role of the pathways that they inhibit. We also identify potential for future research opportunities to better understand the role of these medications.

Intratumoral γδ T-Cell Infiltrates, Chemokine (C-C Motif) Ligand 4/Chemokine (C-C Motif) Ligand 5 Protein Expression and Survival in Patients With Hepatocellular Carcinoma.

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is an aggressive malignancy which is often associated with a complex tumor microenvironment attributable to etiology-induced cellular inflammation. γδ T cells are known to detect and react to chronic inflammation, which is linked to cancer development, progression, and metastasis. Our recent genomic study revealed an increased infiltration of several immune cell types, including γδ T cells, in tumor microenvironments of a Thai HCC subtype associated with a good prognosis. APPROACH AND RESULTS: Here, we quantified the amount of γδ T cells using a γδ T-cell-specific gene signature in 247 Chinese HCC patients. We also validated the γδ T-cell signature in American HCC patients. Additionally, such an association was only found in tumor transcriptomic data, but not in adjacent nontumor transcriptomic data, suggesting a selective enrichment of γδ T cells in the tumor microenvironment. Moreover, the γδ T-cell signature was positively correlated with the expression of natural killer cell receptor genes, such as NKG2D and cytolytic T-cell genes granzymes and perforin, suggesting a stronger T-cell-mediated cytotoxic activity. Furthermore, we found that the γδ T-cell-specific gene expression is positively correlated with the expression of chemokine (C-C motif) ligand 4 (CCL4)/chemokine (C-C motif) ligand 5 (CCL5) and C-C chemokine receptor type 1 (CCR1)/C-C chemokine receptor type 5 (CCR5), the receptors for γδ T cells. We validated these results using immunohistochemical analysis of formalin-fixed, paraffin-embedded tumor biopsies from 182 HCC patients. Moreover, we found evidence of CCL4/CCL5-mediated recruitment of γδ T cells both in vitro and in a murine orthotopic Hepa1-6 HCC model. CONCLUSIONS: We propose that CCL4/CCL5 may interact with their receptor, CCR1/CCR5, which may facilitate the recruitment of γδ T cells from peripheral blood or peritumor regions to the tumor regions. Consequently, an increasing infiltration of γδ T cells in tumors may enhance antitumor immunity and improve patients' prognosis.

Treatment and outcomes of hepatocellular carcinoma in patients with Sickle cell disease: a population-based study in the U.S.

BACKGROUND: Sickle cell disease (SCD) is a rare hemoglobinopathy which can result in chronic liver disease and cirrhosis. Patients with SCD have an increased risk of hematologic malignancy, but the prevalence of hepatocellular carcinoma (HCC) in this population is unknown. Herein, the association of SCD with HCC was examined using registry data. METHODS: The SEER-Medicare database was queried to identify patients diagnosed with HCC between 2000 and 2015, and further stratified by SCD status. Propensity matching was performed to examine cancer-related survival and treatment outcomes. RESULTS: Overall 56,934 patients with HCC were identified, including 81 patients with SCD. Patients with SCD more frequently had cirrhosis [48.1% (39/81) vs 23.5% (13,377/56,853), p < 0.01] yet presented with smaller tumors [<5 cm: 51.9% (42/81) vs 38.5% (21,898/56,853), p = 0.01]. After propensity matching, SCD was not associated with attenuated survival (aHR 0.73 95%CI 0.52-1.01). When stratified by treatment, patients with SCD had equivalent outcomes to chemotherapy (p = 0.65), TACE/TARE (p = 0.35), resection (p = 0.15) and transplantation (p = 0.67) when compared to non-SCD patients. CONCLUSION: This study confirms that a subset of patients with SCD will develop HCC. Importantly, therapeutic options for HCC should not be limited by pre-existing SCD, and similar survival should be expected when compared to non-SCD patients.

Gallbladder squamous cell carcinoma: An analysis of 1084 cases from the National Cancer Database.

BACKGROUND/OBJECTIVES: Gallbladder squamous cell carcinoma (SCC) is an uncommon malignancy whose rarity has made it particularly challenging to study. We utilized a national database to shed light on the clinicopathologic characteristics, management patterns, and survival associated with these tumors. METHODS: Patients with gallbladder SCC were identified in the National Cancer Database. Clinicopathologic and treatment characteristics were recorded and compared with adenocarcinoma for context. Univariate and multivariable survival analyses were completed for patients who underwent resection. RESULTS: Overall, 1084 patients with SCC and 23 958 patients with adenocarcinoma were identified. Compared with those with adenocarcinoma, patients with SCC had higher grade tumors (P < .001) and were diagnosed at a later stage (P < .001). Patients with SCC were more likely to undergo radical cholecystectomy (17% vs 9%; P < .001), but had a higher rate of margin positivity (36% vs 29%; P < .001). SCC histology was associated with worse survival compared with adenocarcinoma, even after adjusting for R0 resections (13 vs 29 months; P < .001). On multivariable analysis, SCC histology was independently associated with abbreviated survival (P = .003). CONCLUSIONS: Gallbladder SCCs are aggressive cancers that often present at an advanced stage. Complete surgical extirpation should be pursued when feasible. However, prognosis is worse than that of adenocarcinoma, even after R0 resection.

Tumor grade may be used to select patients with multifocal hepatocellular carcinoma for resection.

BACKGROUND: While resection is a recommended treatment for patients with stage 1 hepatocellular carcinoma (HCC), it remains controversial for multifocal disease. We sought to identify patients with multifocal HCC with survival after resection similar to patients with clinical stage 1 HCC. METHODS: The National Cancer Database was queried to identify patients that underwent resection for HCC. RESULTS: In this study, 2990 patients with a single tumor, and 1087 patients with multifocal disease confined to one lobe underwent resection. In the multifocal cohort, patients with clinical stage 3 (HR 1.54, CI 1.31-1.81, p < 0.0001) or 4 (HR 2.27, CI 1.57-3.29, p < 0.0001) disease, and those with moderately-differentiated (HR 1.32, CI 1.06-1.64, p = 0.012) or poorly differentiated/undifferentiated tumors (HR 1.53, CI 1.20-1.95, p = 0.0006) were associated with worse overall survival (OS). There was no difference in OS between patients with well-differentiated clinical stage 2 multifocal HCC and those with all grades of clinical stage 1 HCC (median of 84.8 (CI 66.3-107.2) vs 76.2 months (CI 71.2-81.3), respectively, p = 0.356). CONCLUSIONS: Patients with well-differentiated, clinical stage 2 multifocal HCC confined to one lobe experience similar OS following hepatic resection to patients with clinical stage 1 disease. These findings may impact the management of select patients with multifocal HCC.

Resection and chemotherapy is the optimal treatment approach for patients with clinically node positive intrahepatic cholangiocarcinoma.

BACKGROUND: Clinically lymph node positive (cLNP) intrahepatic cholangiocarcinoma (ICC) carries a poor prognosis, without clear management guidelines for the practicing clinician. We sought to evaluate current practice patterns for cLNP ICC, including associations with survival. METHODS: The National Cancer Database was queried for patients with cLNP ICC, without extrahepatic metastases. RESULTS: We identified 1023 patients with cLNP ICC, 77%% (n = 784) of whom received chemotherapy alone. Resection was undertaken in 23% (n = 239) of patients and was most commonly utilized in combination with chemotherapy (n = 150). Median survival for all patients was 13.6 months. Patients undergoing resection in combination with chemotherapy were associated with an improved survival (22.5 months) as compared to those patients receiving chemotherapy alone (11.9 months) or resection alone (12.4 months) (p < 0.01). Finally, we compared the survival of patients with cLNP ICC with that of patients with pathologically proved lymph node positive (pLNP) ICC, all of whom were treated with resection with chemotherapy, and found no difference in survival (22.5 months-19.3 months, p = 0.99, respectively). CONCLUSIONS: While the decision to pursue resection for ICC is multifactorial and patient specific, the presence of clinically positive LNs should not represent a contraindication.

Laparoscopic Approach to Intrahepatic Cholangiocarcinoma is Associated with an Exacerbation of Inadequate Nodal Staging.

INTRODUCTION: Laparoscopic approach to liver resection is feasible and safe, though its utilization with intrahepatic cholangiocarcinoma (ICC) remains poorly documented. We sought to evaluate the use laparoscopy for ICC, and to examine adherence to oncologic standards. METHODS: The National Cancer Database was queried for patients who underwent resection for ICC. Patients were stratified by laparoscopic (LLR) versus open liver resection (OLR). Clinicopathologic parameters and hospital volumes were recorded. RESULTS: In total, 2309 patients with ICC underwent hepatic resection (1997 OLR, 312 LLR) between 2010 and 2015. LLR increased from 12 to 16% during the study period and was utilized more commonly than OLR for wedge and segmental resections (56% vs. 33%, p < 0.001). Nodal evaluation was performed in 58% of all patients with ICC and was significantly more common in patients undergoing OLR (61%, n = 1210) versus LLR (39%, n = 120), p < 0.001. Of the 120 patients undergoing LLR with any nodal evaluation, 31% (n = 37) had a single node evaluated. Patients who underwent LLR were less likely to have ≥ 6 lymph nodes evaluated compared with those who underwent OLR (9% vs. 15%, respectively, p < 0.001). CONCLUSIONS: The use of laparoscopy for ICC is associated with an exacerbation of inadequate nodal evaluation compared with open resections.

Practice patterns of VTE chemoprophylaxis after discharge following hepatic and pancreatic resections for cancer: A survey of hepatopancreatobiliary surgeons.

Patients with hepatopancreatobiliary (HPB) malignancies undergoing resection are prone to venous thromboembolism (VTE), and current guidelines recommend up to 28 days of chemoprophylaxis after major surgery. We sought to determine the practice patterns among HPB surgeons for use of chemoprophylaxis after discharge. A survey on VTE chemoprophylaxis after oncologic HPB operations was distributed to attending surgeons at the 18 HPB fellowship training programs in the United States and Canada. Of the HPB surgeons surveyed, 44 (44%) responded. VTE prophylaxis is used by 93% of respondants in the inpatient postoperative setting. Chemoprophylaxis after discharge for pancreaticoduodenenctomy and distal pancreatectomy is utilized by 45% and 39% of respondants, respectively. Of those who prescribe chemoprophylaxis after discharge, 79% and 88% prescribe it for the recommended 28 days after pancreaticoduodenectomy and distal pancreatectomy, respectively. Chemoprophylaxis after discharge for major and minor hepatectomy is utilized by 39% and 26% of respondents, respectively. Of those who prescribe chemoprophylaxis after discharge, 67% and 55% provide it for the recommended 28 days after major and minor hepatectomy, respectively. Despite documented prolonged postoperative thrombogenic risk, the use of chemoprophylaxis following discharge after pancreatic and liver resections for cancer was moderate among surveyed HPB surgeons.

Electrophysiological Findings in Common Median-Ulnar Nerve Interconnections and Their Clinical Implications.

Median and ulnar nerve interconnections commonly occur in the brachial plexus, forearm, and hand. Each is classified based on location, fiber type (sensory fibers, motor fibers, or both), and directionality (ie, carrying fibers from median to ulnar or vice versa). There are 4 main interconnections found in the forearm and hand: Martin-Gruber and Marinacci anastomoses in the forearm and Riche-Cannieu and Berrettini anastomoses in the hand. The presence of an interconnection may skew electrodiagnostic findings, possibly resulting in misdiagnosis and iatrogenic injury. Clinicians should perform nerve studies of both nerves at proximal and distal stimulation sites to rule out interconnections and guide treatment. This review details anatomy, electrodiagnostic findings, and clinical approach.

Tumor grade and sex should influence the utilization of portal lymphadenectomy for early stage intrahepatic cholangiocarcinoma.

BACKGROUND: Portal lymphadenectomy for intrahepatic cholangiocarcinoma (ICC) is encouraged for staging purposes, though it is under-utilized for clinically early-stage tumors. We sought to determine if any factor knowable prior to resection influences rates of portal lymph node metastases. METHODS: The Surveillance, Epidemiology, and End Results (SEER) Program (1973-2014) database was queried to identify patients with T1/T2 ICC undergoing resection. Patients were stratified by lymph node (LN) status. Patients deemed LN negative required examination of six or more LNs (AJCC guidelines). RESULTS: One-hundred and fifty-two patients were included in the analysis (LN negative: 38, LN positive: 114). Patients with LN negative cancers experienced prolonged overall survival as compared to patients with positive LNs (median 77 months vs 19 months, respectively p < 0.001). Twelve patients had well-differentiated tumors (G1), 92 patients had moderately-differentiated tumors (G2) and 58 patients had poorly-differentiated tumors (G3). Tumor grade (OR 3.9, CI 1.1-13.7, p = 0.031) and male sex (OR 2.6, CI 1.1-6.1, p = 0.022) were associated with positive LNs on multivariable logistic regression analysis. CONCLUSION: Intermediate/High grade and male sex are associated with high rates of lymph node metastasis for patients with early-stage ICC, which portends abbreviated overall survival.

An Examination of Applicants and Factors Associated with Matriculation to Complex General Surgical Oncology Fellowship Training Programs.

BACKGROUND: The demand for training in complex general surgical oncology (CGSO) fellowships currently exceeds the number of positions offered; however, there are scarce data defining the applicant pool or characteristics associated with successful matriculation. Our study described the applicant population and to determine factors associated with acceptance into the fellowship. STUDY DESIGN: Data were extracted from the Electronic Residency Application System for applicants in 2015 and 2016 and stratified based on matriculation status. Applicant demographics, including medical education, residency, and research achievements, were analyzed. Academic productivity was quantified using the number of peer-reviewed publications as well as the journal with the highest impact factor in which an applicant's work was published. RESULTS: Data were gathered on a total of 283 applicants, of which 105 matriculated. The overall population was primarily male (63.2%), Caucasian (40.6%), educated at a U.S. allopathic medical school (53.4%), and trained at a university-based General Surgery residency (55.5%). Education at a U.S. allopathic school (OR = 5.63, p < 0.0001), university-based classification of the applicant's surgical residency (OR = 4.20, p < 0.0001), and a residency affiliation with a CGSO fellowship (OR = 2.61, p = 0.004) or National Cancer Institute designated Comprehensive Cancer Center (OR = 3.16, p < 0.001) were found to be associated with matriculation. Matriculants published a higher number of manuscripts than nonmatriculants (median of 10 vs. 4.5, p < 0.0001) and more frequently achieved publication in journals with higher impact factors (p < 0.0001). CONCLUSIONS: This study represents the first objective description of the CGSO fellowship applicant pool. Applicants' medical school, residency, and research data points correlated with successful matriculation.

Evaluation of technical urinary tract complications in kidney transplantation recipients with a prolonged dialysis history.

BACKGROUND: The kidney transplant waiting list continues to expand, resulting in prolonged dialysis times exceeding 8 years before transplantation in some regions. The relationship between long-term dialysis and urinary tract complications after kidney transplant remains largely unexplored. This study aims to evaluate post-kidney transplant complications in patients with a history of prolonged dialysis. METHODS: A single-center, retrospective cohort study of patients maintained on dialysis ≥8 years before kidney transplant between January 2000 and July 2020 was conducted. Clinical variables, including demographics and comorbidities, were reviewed. The primary objective was the development of a technical urinary tract complication. Secondary outcomes included any postoperative complication by type, stratified by medical and surgical complications. RESULTS: Overall, 376 patients met the inclusion criteria. The mean pre-kidney transplant dialysis time was 10.2 ± 2.6 years. The majority (65.7%) of the study participants were anuric. Four patients (1.1%) experienced a urine leak, and 8 patients (2.1%) had a ureteral stricture. Any complication was observed in 111 (29.5%) patients, with urinary tract infections being the most common. Urinary catheters remained in place for a median of 4 (3, 5) days. Drains were commonly used (62.8%) for a median of 5 (4, 6) days. CONCLUSION: In our large, single-center experience with kidney transplants in high-risk patients with prolonged dialysis and anuria, the technical urinary tract complications rate remained low. With the current literature consisting of small cohorts and having relatively short pre-kidney transplant dialysis periods, our analysis addresses the shortcomings of the literature while suggesting that this patient population may not truly be "high risk."

Perioperative Multimodal Anesthetic Care Incorporating Transversus Abdominis Plane Block Is Associated With Reduced Narcotic Use in Laparoscopic Sleeve Gastrectomy.

BACKGROUND: Laparoscopic sleeve gastrectomy (LSG) is the most commonly performed bariatric surgery performed in North America. As our knowledge of the importance in limiting narcotic use in postoperative patients increases, we sought to evaluate the effect of transversus abdominis plane (TAP) blocks on inpatient narcotic use in patients undergoing LSG. METHODS: A retrospective review of LSG performed at a single institution by 3 bariatric surgeons was performed. All cases over a 15-month period were included, and anesthesia records were reviewed to stratify patients that received a TAP block and those that did not. Demographic, as well as surgical, outcomes were collected for all patients. Narcotic utilization, as reported in morphine equivalents (ME), was evaluated between the 2 groups. RESULTS: 384 LSG patients were identified, of which 37 (9.6%) received a TAP block. There was no statistically significant difference in postoperative morbidity, length of stay, or readmission between groups. Median narcotic utilization in hospital days 1 and 2 in patients with TAP blocks was 49 ME (Interquartile Range (IQR) 14.5-84.5) to 82.5 ME (IQR 57.4-106) in the no-TAP group (P < .001). After controlling for multiple demographic- and patient-related cofactors, multiple linear regression analysis demonstrated TAP block patients utilized 22.48 ME less than the no-TAP group (P < .001) in the first 2 days of their hospitalization. DISCUSSION: Patients that received a TAP block as a part of their perioperative anesthetic care utilized less in-hospital narcotics than those patients that did not receive a TAP block. TAP blocks should be considered as part of a multimodal pain control strategy for patients undergoing LSG.

Video-assisted thoracoscopic surgery pleurectomy: a suitable alternative for treating malignant pleural effusions.

BACKGROUND: Malignant pleural effusions (MPEs) are common manifestations of metastatic cancers and are associated with a dismal prognosis. Talc pleurodesis has been proven to be effective in the management of MPEs, however, class-action lawsuits linking talc to ovarian adenocarcinoma have rendered it unavailable at many institutions. As a result, surgeons have resorted to less effective chemical pleurodesis as an alternative to indwelling pleural drainage catheters. Given the absence of talc, we explored the effectiveness of video-assisted thoracoscopic surgery (VATS) partial pleurectomy (VPP) for treating MPEs. METHODS: We performed a retrospective review of patients with MPEs managed after talc became unavailable at our institution. Between 2016 and 2018, we identified five patients who refused pleural drainage catheters and underwent VPP. Symptoms at presentation included fatigue, dyspnea, and pleuritic chest pain. All had unilateral MPEs (left n=3, right n=2). VPP included removal of parietal surfaces of the pleura other than the pleura overlying the subclavian vessels, the mediastinum, and the lung viscera. RESULTS: There were no significant perioperative adverse events and post-operative pain was well controlled. Chest tubes were removed between post-operative day (POD) 3 and 7. Follow-up time ranged from four to 36 weeks. All patients had symptomatic relief and radiographic evidence of improved MPEs. No patients required re-interventions. One patient expired six months after surgery while the remaining four were alive at last follow-up. CONCLUSIONS: VPP offers an effective alternative to chemical pleurodesis for managing MPEs in patients who prefer to avoid pleural drainage catheters.

Characteristics of Matriculants to Thoracic Surgery Residency Training Programs.

BACKGROUND: Thoracic surgery (TS) residency positions are in high demand. There is no study describing the nationwide attributes of successful matriculants in this specialty. We examined the characteristics of TS resident applicants and identified factors associated with acceptance. METHODS: Applicant data from 2014 to 2017 application cycles was extracted from the Electronic Residency Application System and stratified by matriculation status. Medical education, type of general surgery residency, and research achievements were analyzed. The number of peer-reviewed publications and the corresponding impact factor for the journals where they were published were quantified. RESULTS: There were 492 applicants and 358 matriculants. The overall population was primarily male (79.5%), white (55.1%), educated at United States allopathic medical schools (66.5%), and trained at university-based general surgery residencies (59.6%). Education at United States allopathic schools (odds ratio [OR], 2.54; P < .0001), being a member of the American Osteopathic Association (OR, 3.27; P = .021), general surgery residency affiliation with a TS residency (OR, 2.41; P = .0003) or National Cancer Institute designated Comprehensive Cancer Center (OR, 1.76; P = .0172), and being a first-time applicant (OR, 4.71, P < .0001) were independently associated with matriculation. Matriculants published a higher number of manuscripts than nonmatriculants (median of 3 vs 2, P < .0001) and more frequently published in higher impact journals (P < .0001). CONCLUSIONS: Our study includes objective and quantifiable data from recent application cycles and represents an in-depth examination of applicants to TS residency. The type of medical school and residency, as well as academic productivity, correlate with successful matriculation.

Patient Comorbidities Drive High Mortality Rates Associated with Major Liver Resections Irrespective of Hospital Volume.

INTRODUCTION: Major hepatectomies are utilized to manage primary hepatic malignancies. Reports from high-volume centers (HVCs) with minimal perioperative mortality focus on multiple aspects of perioperative care, although patient-specific factors remain unelucidated. We identified patient factors associated with outcomes and examined whether these contribute to survival differences. METHODS: We queried the National Cancer Database (2006-2015) for patients with primary liver malignancies managed with major hepatectomy. Facilities were dichotomized by volume (high volume: >15 hepatectomies/year). Perioperative outcomes were compared based on patient demographic and clinical characteristics as well as center volume. RESULTS: 4263 patients were included with 78.5% receiving care in low-volume centers (LVCs). 90-day postoperative mortality was higher in LVCs vs. HVCs (12% vs. 7.5%; P < .001). Factors associated with undergoing surgery in LVCs included: living in areas with lower income (P = .006) and education (P < .001), having nonprivate insurance (P < .001), residing near the care center (P < .001), and having a comorbidity score (CDS) >1 (P = .014). Patients with CDS ≤ 1 had higher 90-day mortality in LVCs (11.3% vs. 6.6%; P < .001) and had similar outcomes in LVCs and HVCs (15.6% vs. 13.7% P = .6). Patients with CDS > 1 were more likely to receive care in LVCs (16.3% vs. 12.7%; P < .001). CONCLUSION: Reduced perioperative mortality following major hepatectomy in HVCs is driven by optimal management of patients with low CDS. However, nearly 1 in 5 patients who undergo major hepatectomies have a high CDS and approximately 15% of them succumb in the perioperative period irrespective of the treating centers' experience.

Bidirectional chemotherapy in patients with gastric cancer and peritoneal metastasis.

Gastric cancer is a lethal malignancy due to the combination of late-stage presentation, propensity for early metastasis, and lack of effective systemic therapies. Given the high rates of gastric peritoneal metastasis, both macro- and microscopic, regional therapy represents both an attractive and rational treatment option for patients given its success in other peritoneal surface malignancies. Bidirectional chemotherapy (intraperitoneal and intravenous) for treatment of metastatic gastric cancer has not been evaluated prospectively in a contemporary North American cohort. Here we present the rationale and design of a phase II clinical trial of intraperitoneal paclitaxel in combination with intravenous paclitaxel and oral capecitabine. We hypothesize that the combination of systemic and regional chemotherapy may result in improved progression free survival (PFS) for patients with gastric adenocarcinoma and peritoneal-only metastasis. In addition to studying clinical outcomes associated with this treatment regimen, both basic and translational science efforts are planned to better understand this complex malignancy.

PKM2 inhibition may reverse therapeutic resistance to transarterial chemoembolization in hepatocellular carcinoma.

BACKGROUND: Therapeutic options for patients with hepatocellular carcinoma (HCC) are limited. Transarterial chemoembolization (TACE) is an interventional procedure used to deliver chemotherapy and embolizing agents directly to the tumor and is the procedure of choice for patients with intermediate stage HCC. While effective, more than 40% of patients do not respond to therapy, highlighting the need to investigate possible mechanisms of resistance. We sought to evaluate mechanisms of TACE resistance and evaluate a potential therapeutic target to overcome this resistance. METHODS: Using a prognostic gene signature which predicts TACE response (TACE Navigator) in a cohort of HCC patients who received TACE, patients were classified as responders and non-responders. Transcriptomic and gene pathway analysis were used to identify potential drivers of TACE resistance. Knockdown of the gene encoding rate limiting enzyme PKM2 using shRNA in HCC cell lines, as well as pharmacologic inhibition of PKM2 with shikonin using an in vitro TACE model measured response to chemotherapy under hypoxia. Finally, we replicated the TACE model with shikonin using patient derived cell line organoids (PDC). Functional studies were performed in vitro using immunoblotting, quantitative polymerase chain reaction, glycolysis and hypoxia assays. RESULTS: In patient non-responders, we identified enrichment of the glycolysis pathway, specifically of the gene encoding the rate-limiting enzyme PKM2. We identified four HCC cell lines which recapitulated a TACE responder-like and non-responder-like phenotype. PKM2 knockdown in HCC cell lines demonstrated a less proliferative and aggressive phenotype as well as improved drug sensitivity to both doxorubicin and cisplatin. In vitro TACE model demonstrated that TACE non-responder-like cells overcame therapeutic resistance and rendered them susceptible to therapy through PKM2 knockdown. Lastly, we obtained similar results using a pharmacologic PKM2 inhibitor, shikonin in both cell lines, and PDC organoids. CONCLUSION: Elevated PKM2 is associated with treatment resistance and abbreviated survival in patients receiving TACE. Elevated PKM2 in vitro is associated with increased utilization of the glycolysis pathway, resulting in oxygen independent cell metabolism. Through PKM2 knockdown as well as with pharmacologic inhibition with shikonin, non-responder cells can be reprogrammed to act as responders and could improve TACE efficacy in patients.

AGO2 Mediates MYC mRNA Stability in Hepatocellular Carcinoma.

Deregulated RNA-binding proteins (RBP), such as Argonaute 2 (AGO2), mediate tumor-promoting transcriptomic changes during carcinogenesis, including hepatocellular carcinoma (HCC). While AGO2 is well characterized as a member of the RNA-induced silencing complex (RISC), which represses gene expression through miRNAs, its role as a bona fide RBP remains unclear. In this study, we investigated AGO2's role as an RBP that regulates the MYC transcript to promote HCC. Using mRNA and miRNA arrays from patients with HCC, we demonstrate that HCCs with elevated AGO2 levels are more likely to have the mRNA transcriptome deregulated and are associated with poor survival. Moreover, AGO2 overexpression stabilizes the MYC transcript independent of miRNAs. These observations provide a novel mechanism of gene regulation by AGO2 and provide further insights into the potential functions of AGO2 as an RBP in addition to RISC. IMPLICATIONS: Authors demonstrate that the RBP Argonaute 2 stabilizes the MYC transcript to promote HCC.