Comparison of post-hepatectomy long-term survival outcome between non-colorectal non-neuroendocrine and colorectal liver metastases: A population-based propensity-score matching analysis

BACKGROUND

Hepatectomy is an established treatment for colorectal liver metastasis (CLM) or neuroendocrine liver metastasis. However, its role in non-colorectal non-neuroendocrine liver metastasis (NCNNLM) is controversial. This study aims to compare long-term survival outcomes after hepatectomy between NCNNLM and CLM in a population-based cohort.

METHODS

From 2009 to 2018, curative hepatectomy were performed in 964 patients with NCNNLM (n ​= ​133) or CLM (n ​= ​831). Propensity score (PS) matching was performed. Short-term and long-term outcomes were compared between PS-matched groups. Univariate and multivariate analyses were performed to identify prognostic factors affecting survival.

RESULTS

There were 133 patients in the NCNNLM group and 266 patients in the CLM group. The mortality (1.5 ​% vs 1.5 ​%) and morbidity (19.5 ​% vs 20.3 ​%) rates were comparable between the two groups. There was no statistically significant difference in 5-year overall (48.9 ​% vs 39.8 ​%) and recurrence-free (25.1 ​% vs 23.4 ​%) survival rates between NCNNLM and CLM groups. A high pre-operative serum bilirubin level, severe postoperative complications and multiple tumors were independent prognostic factors for poor survival.

CONCLUSION

Hepatectomy for selected patients with NCNNLM can achieve similar long-term oncological outcomes as those with CLM. High serum bilirubin, severe postoperative complication and multiple tumors are poor prognostic factors for survival.

Comparison of clinical outcome between laparoscopic and open hepatectomy of high difficulty score for hepatocellular carcinoma: a propensity score analysis

BACKGROUND

Laparoscopic liver resection (LLR) of high difficulty score is technically challenging. There is a lack of clinical evidence to support its applicability in terms of the long-term survival benefits. This study aims to compare clinical outcomes between LLR and the open liver resection of high difficulty score for hepatocellular carcinoma (HCC).

MATERIALS AND METHODS

From 2010 to 2020, using Iwate criteria, 424 patients underwent liver resection of high difficulty score by the laparoscopic (n = 65) or open (n = 359) approach. Propensity score (PS) matching was performed between the two groups. Short-term and long-term outcomes were compared between PS-matched groups. Univariate and multivariate analyses were performed to identify prognostic factors affecting survival.

RESULTS

The laparoscopic group had significantly fewer severe complications (3% vs. 10.8%), and shorter median hospital stays (6 days vs. 8 days) than the open group. Meanwhile, the long-term oncological outcomes were comparable between the two groups, in terms of the tumor recurrence rate (40% vs. 46.1%), the 5-year overall survival rate (75.4% vs. 76.2%), and the 5-year recurrence-free survival rate (50.3% vs. 53.5%). The high preoperative serum alpha-fetoprotein level, multiple tumors, and severe postoperative complications were the independent poor prognostic factors associated with worse overall survival. The surgical approach (Laparoscopic vs. Open) did not influence the survival.

CONCLUSION

LLR of high difficulty score for selected patients with HCC has better short-term outcomes than the open approach. More importantly, it can achieve similar long-term survival outcomes as the open approach.

Accurate identification of structural variations from cancer samples

Structural variations (SVs) are commonly found in cancer genomes. They can cause gene amplification, deletion and fusion, among other functional consequences. With an average read length of hundreds of kilobases, nano-channel-based optical DNA mapping is powerful in detecting large SVs. However, existing SV calling methods are not tailored for cancer samples, which have special properties such as mixed cell types and sub-clones. Here we propose the Cancer Optical Mapping for detecting Structural Variations (COMSV) method that is specifically designed for cancer samples. It shows high sensitivity and specificity in benchmark comparisons. Applying to cancer cell lines and patient samples, COMSV identifies hundreds of novel SVs per sample.

'Potentially curative therapies' for hepatocellular carcinoma: how many patients can actually be cured?

BACKGROUND

Treatment of hepatocellular carcinoma (HCC) is predicated on early diagnosis such that 'curative therapies' can be successfully applied. The term 'curative' is, however, poorly quantitated. We aimed to complement our previous work by developing a statistical model to predict cure after ablation and to use this analysis to compare the true curative potential of the various 'curative' therapies.

METHODS

We accessed data from 1571 HCC patients treated in 5 centres receiving radiofrequency (RFA) or microwave (MWA) ablation and used flexible parametric modelling to determine the curative fraction. The results of this analysis were then combined with our previous estimations to provide a simple calculator applicable to all patients undergoing potentially curative therapies.

RESULTS

The cure fraction was 18.3% rising to about 40% in patients with good liver function and very small tumours.

CONCLUSION

Cure for HCC treated with ablation occurs in the order of 20% to 30%, similar to that achievable by resection but much inferior to transplantation where the analogous figure is >70%. We provide a 'calculator' that permits clinicians to estimate the chance of cure for any individual patient, based on readily available clinical features.

Minimally invasive versus open liver resection for hepatocellular carcinoma: a propensity score matching analysis of 224 patients

PURPOSE

To compare the peri-operative and long-term survival outcomes of minimally invasive liver resection (MILR) (robotic or laparoscopic) with open liver resection (OLR) in patients with hepatocellular carcinoma (HCC).

METHODS

Data of patients who underwent liver resection for HCC were reviewed from a prospectively collected database. Outcomes of MILR were compared with those of OLR. A propensity score matching analysis with a ratio of 1:1 was performed to minimise the potential bias in clinical pathological factors.

RESULTS

From January 2003 to December 2017, a total of 705 patients underwent liver resection for HCC. Amongst them, 112 patients received MILR and 593 patients received OLR. After propensity score matching, there were 112 patients in each of the MILR and OLR groups. Patients were matched by age, sex, hepatitis status, presence of cirrhosis, platelet count, albumin level, bilirubin level, alkaline phosphatase (ALP) level, alanine transferase (ALT) level, creatinine level, tumour differentiation, tumour size, tumour number, presence of tumour rupture, presence of vascular invasion, extent of liver resection (minor/major) and difficulty score. The 1-, 3- and 5-year overall survival rates were 94.4%, 90.4% and 82.3% in the MILR group vs 95.4%, 80.5% and 71.8% in the open group (p = 0.240). The 1-, 3- and 5-year disease-free survival rates were 81.0%, 63.1% and 55.8% in the MILR group vs 79.1%, 58.1% and 45.7 in the open group (p = 0.449). The MILR group demonstrated significantly less blood loss (p < 0.001), less blood transfusion (p = 0.004), lower post-operative complications (p < 0.001) and shorter hospital stay (p < 0.001) when compared with the OLR group.

CONCLUSIONS

Our data shows MILR yielded superior post-operative outcomes to OLR, with comparable survival outcomes.

The Impact of Involved Resection Margin on Recurrence and Survival After Pancreaticoduodenectomy for Periampullary Carcinoma, with Emphasis on Pancreatic Head Carcinoma

BACKGROUND

The supposed adverse effect of involved resection margin during pancreaticoduodenectomy (PD) for periampullary carcinoma or pancreatic head carcinoma (CaP) on long-term oncological outcomes is still inconclusive.

METHODS

This is a retrospective study on periampullary carcinoma undergoing PD. Patients with R0 (margin clear) resection were compared to patients with R1 (microscopically directly involved margin) resection. Patients with gross involved margin (R2 resection) were excluded. Long-term oncological outcomes measured included incidence and site of recurrent disease, overall survival (OS) and disease-free survival (DFS). A subgroup analysis was made on patients with CaP.

RESULTS

Between January 2003 and December 2019, 203 PD were identified for present study. The incidence of R1 resection was common (12% in periampullary carcinoma and 20% in CaP). In periampullary carcinoma, R1 resection had greater proportion of CaP, lesser proportion of carcinoma of ampulla (CaA), more perineural invasion, more lymph node (LN) metastasis. R1 group had a shorter OS and DFS, but no difference in the incidence and site of recurrent disease. In the subgroup of CaP (91 patients), R1 group did not differ from R0 group except for more LN metastasis. There was no difference in incidence and site of recurrent disease, OS and DFS. On multivariable analysis, R1 resection was not an independent factor for OS and DFS for periampullary carcinoma or for CaP only.

CONCLUSION

Involved resection margin was not uncommon. It was not associated with higher incidence of recurrent disease including local recurrence, and was not an independent prognosticator for OS and DFS.

Asia-Pacific multicentre randomized trial of laparoscopic versus open major hepatectomy for hepatocellular carcinoma (AP-LAPO trial)

BACKGROUND

Hepatocellular carcinoma is the sixth most common malignancy in the world. Major hepatectomy (resection of greater than or equal to three liver segments) is needed if a tumour is large or close to major blood vessels. Despite low mortality, open major hepatectomy is associated with high rates of tumour recurrence that limits survival. Laparoscopic major hepatectomy has been proposed as an alternative approach with potential oncological benefits. This study compares laparoscopic major hepatectomy with open major hepatectomy for hepatocellular carcinoma in a randomized trial.

METHODS

The Asia-Pacific multicentre randomized trial of laparoscopic versus open major hepatectomy for hepatocellular carcinoma (AP-LAPO trial) is an open-labelled multicentre randomized trial to be conducted in five centres in the Asia-Pacific region. The study will test the hypothesis that laparoscopic major hepatectomy for hepatocellular carcinoma is associated with less tumour recurrence and better survival compared with open major hepatectomy; the primary outcome being 2-year recurrence-free survival. Secondary outcomes include hospital mortality, postoperative complications according to the Clavien-Dindo classification, time to functional recovery, quality of life, long-term survival, and postoperative serum surgical stress-related cytokines.

RESULTS AND CONCLUSION

The AP-LAPO trial will determine whether laparoscopic major hepatectomy offers oncological benefits to patients with hepatocellular carcinoma compared with open major hepatectomy.

REGISTRATION NUMBER

NCT04852211 (http://www.clinicaltrials.gov) registered on 21 April 2021.

PROTOCOL VERSION

AP-LAPO trial version 01 (1 December 2021).

Single Cell and Plasma RNA Sequencing for RNA Liquid Biopsy for Hepatocellular Carcinoma

BACKGROUND

Human plasma contains RNA transcripts released by multiple cell types within the body. Single-cell transcriptomic analysis allows the cellular origin of circulating RNA molecules to be elucidated at high resolution and has been successfully utilized in the pregnancy context. We explored the application of a similar approach to develop plasma RNA markers for cancer detection.

METHODS

Single-cell RNA sequencing was performed to decipher transcriptomic profiles of single cells from hepatocellular carcinoma (HCC) samples. Cell-type-specific transcripts were identified and used for deducing the cell-type-specific gene signature (CELSIG) scores of plasma RNA from patients with and without HCC.

RESULTS

Six major cell clusters were identified, including hepatocyte-like, cholangiocyte-like, myofibroblast, endothelial, lymphoid, and myeloid cell clusters based on 4 HCC tumor tissues as well as their paired adjacent nontumoral tissues. The CELSIG score of hepatocyte-like cells was significantly increased in preoperative plasma RNA samples of patients with HCC (n = 14) compared with non-HCC participants (n = 49). The CELSIG score of hepatocyte-like cells declined in plasma RNA samples of patients with HCC within 3 days after tumor resection. Compared with the discriminating power between patients with and without HCC using the abundance of ALB transcript in plasma [area under curve (AUC) 0.72)], an improved performance (AUC: 0.84) was observed using the CELSIG score. The hepatocyte-specific transcript markers in plasma RNA were further validated by ddPCR assays. The CELSIG scores of hepatocyte-like cell and cholangiocyte trended with patients' survival.

CONCLUSIONS

The combination of single-cell transcriptomic analysis and plasma RNA sequencing represents an approach for the development of new noninvasive cancer markers.

Acute kidney injury following hepatectomy and its impact on long-term survival for patients with hepatocellular carcinoma

Background

Acute kidney injury (AKI) is increasingly being recognized after hepatectomy. This study aimed to identify factors predicting its occurrence and its impact on long-term outcome among patients with hepatocellular carcinoma (HCC).

Methods

This was a retrospective analysis of the incidence of AKI, factors predicting its occurrence, and its impact on patients undergoing hepatectomy between September 2007 and December 2018. A subgroup analysis included patients with histologically proven HCC.

Results

The incidence of AKI was 9.2 per cent in 930 patients. AKI was associated with increased mortality, morbidity, posthepatectomy liver failure (PHLF), and a longer hospital stay. On multivariable analysis, study period December 2013 to December 2018, diabetes mellitus, mean intraoperative BP below 72.1 mmHg, operative blood loss exceeding 377ml, high Model for End-Stage Liver Disease (MELD) score, and PHLF were predictive factors for AKI. Among 560 patients with HCC, hypertension, BP below 76.9 mmHg, blood loss greater than 378ml, MELD score, and PHLF were predictive factors. The 1-, 3-, and 5-year overall survival rates were 74.1, 59.2, and 51.6 per cent respectively for patients with AKI, and 91.8, 77.9, and 67.3 per cent for those without AKI. Corresponding 1-, 3-, and 5-year disease-free survival rates were 56.9, 42.3, and 35.4 per cent respectively in the AKI group, and 71.7, 54.5, and 46.2 per cent in the no-AKI group. AKI was an independent predictor of survival in multivariable analysis.

Conclusion

AKI is associated with longer hospital stay, and higher morbidity and mortality rates. It is also associated with shorter long-term survival among patients with HCC. To avoid AKI, control of blood loss and maintaining a reasonable BP (72–77 mmHg) during hepatectomy is important.

A non-linear ensemble model-based surgical risk calculator for mixed data from multiple surgical fields

BACKGROUND

The misestimation of surgical risk is a serious threat to the lives of patients when implementing surgical risk calculator. Improving the accuracy of postoperative risk prediction has received much attention and many methods have been proposed to cope with this problem in the past decades. However, those linear approaches are inable to capture the non-linear interactions between risk factors, which have been proved to play an important role in the complex physiology of the human body, and thus may attenuate the performance of surgical risk calculators.

METHODS

In this paper, we presented a new surgical risk calculator based on a non-linear ensemble algorithm named Gradient Boosting Decision Tree (GBDT) model, and explored the corresponding pipeline to support it. In order to improve the practicability of our approach, we designed three different modes to deal with different data situations. Meanwhile, considering that one of the obstacles to clinical acceptance of surgical risk calculators was that the model was too complex to be used in practice, we reduced the number of input risk factors according to the importance of them in GBDT. In addition, we also built some baseline models and similar models to compare with our approach.

RESULTS

The data we used was three-year clinical data from Surgical Outcome Monitoring and Improvement Program (SOMIP) launched by the Hospital Authority of Hong Kong. In all experiments our approach shows excellent performance, among which the best result of area under curve (AUC), Hosmer-Lemeshow test ([Formula: see text]) and brier score (BS) can reach 0.902, 7.398 and 0.047 respectively. After feature reduction, the best result of AUC, [Formula: see text] and BS of our approach can still be maintained at 0.894, 7.638 and 0.060, respectively. In addition, we also performed multiple groups of comparative experiments. The results show that our approach has a stable advantage in each evaluation indicator.

CONCLUSIONS

The experimental results demonstrate that NL-SRC can not only improve the accuracy of predicting the surgical risk of patients, but also effectively capture important risk factors and their interactions. Meanwhile, it also has excellent performance on the mixed data from multiple surgical fields.

Development and validation of a novel nomogram predicting 10-year actual survival after curative hepatectomy for hepatocellular carcinoma

INTRODUCTION

Although hepatectomy is a curative treatment modality for hepatocellular carcinoma (HCC), the associated 10-year long-term actual survival are rarely reported. This study aims to develop and validate a predictive nomogram for 10-year actual survivors with HCC.

MATERIALS AND METHODS

From 2004 to 2009, 753 patients with curative hepatectomy for HCC (development set, n = 325; validation set, n = 428) were included. In development set, comparison of clinic-pathological data was made between patients surviving ≥10 years and those surviving <10 years. Good independent prognostic factors identified by multivariate analysis were involved in a nomogram development, which was validated internally and externally using validation set.

RESULTS

On multivariate analysis, five independent good prognostic factors for 10-year survival were identified, including young age (OR = 0.943), good ASA status (≤2) (OR = 2.794), higher albumin level (OR = 1.116), solitary tumor (OR = 2.531) and absence of microvascular invasion (OR = 3.367). A novel nomogram was constructed with C-index of 0.801 (95% CI 0.762-0.864). A cut-off point of 167.5 had a sensitivity of 0.794 and specificity of 0.730. Internal validation using bootstrap sampling and external validation using validation set revealed C-index of 0.792 (95% CI, 0.741-0.853) and 0.761 (95% CI, 0.718-0.817).

CONCLUSION

A novel nomogram for 10-year HCC survivor using age, ASA status, preoperative albumin, tumor number and presence of microvascular tumor invasion was developed and validated with high accuracy.

A narrative review of gallbladder adenomyomatosis: what we need to know

Gallbladder adenomyomatosis (GA) is increasingly encountered in clinical practice due to increasing use of imagings especially ultrasound (US). Clinicians need to know what is the implication of this condition and its proper management. GA is a degenerative and proliferative disease characterized by excessive epithelial proliferation associated with hypertrophy of muscularis propria. This leads to outpouchings of mucosa into or beyond the muscle layer forming intramural diverticula recognized as Rokitansky-Aschoff sinuses (RAS). Three types of GA are recognised: fundal, segmental and diffuse type. In fundal GA, there is focal thickening involving the GB fundus. In segmental GA, there is circumferential overgrowth of the GB wall that leads to formation of compartments. In diffuse GA, there is disseminated thickening and irregularity of the mucosa and muscularis. The pathogenesis of GA is unknown. It commonly occurs in middle age with equal sex distribution. Diagnosis of GA is by imagings showing thickened gallbladder wall containing cysts. Characteristic features are “comet-tail” artefacts and “twinkling” artefacts on US, “pearl-necklace sign” on magnetic resonance imaging (MRI) and “rosary sign” on computed tomography (CT). Cholecystectomy should be offered for symptomatic GA of any type. For asymptomatic GA, cholecystectomy may be considered for segmental type for its increased risk of malignancy and for diffuse type for its difficult visualization of any coexisting malignancy. Asymptomatic fundal GA can be safely observed with US. How frequent and how long should a fundal GA be monitored with US remains unknown. In case of diagnostic doubt, cholecystectomy should always be offered to avoid overlooked malignancy.

Comparison of long-term survival outcome after curative hepatectomy between selected patients with non-colorectal and colorectal liver metastasis: A propensity score matching analysis

BACKGROUND

Liver resection is an established treatment of choice for colorectal liver metastasis (CLM). However, the role of hepatectomy for non-colorectal liver metastasis (NCLM) is less clear.

PATIENTS AND METHOD

From 2004 to 2017, 264 patients received curative hepatectomy for NCLM (n = 28) and CLM (n = 236). Propensity score (PS) matching was performed between two groups, with respect to the significant confounding factors. Short-term and long-term outcomes were compared between PS matched groups. Univariate analysis was performed to identify prognostic factors affecting overall and recurrence-free survival.

RESULTS

After PS matching, there were 28 patients in NCLM group and 56 patients in CLM group. With a median follow-up of 34 months, there was no significant difference in 5-year overall survival rate between NCLM and CLM groups (62% vs. 39%) (P = 0.370). The 5-year recurrence-free survival rate was also comparable between NCLM and CLM groups (23% vs. 22%) (P = 0.707). Use of pre-operative systemic therapy (hazard ratio: 2.335, CI 1.157-4.712), multifocal tumors (hazard ratio: 1.777, CI 1.010-3.127), tumor size (hazard ratio: 1.135, CI 1.012-1.273), R1 resection (hazard ratio: 2.484, CI 1.194-5.169) and severe complications (hazard ratio: 6.507, CI 1.454-29.124), but not tumor type (NCLM vs. CLM), were associated with poor overall survival.

CONCLUSION

Hepatectomy for NCLM can achieve similar oncological outcomes in selected patients as those with CLM. Significant prognostic factors were identified associating with worse overall survival.

Nuclear FOXP3 inhibits tumor growth and induced apoptosis in hepatocellular carcinoma by targeting c-Myc

The status of FOXP3 and its isoforms in hepatocellular carcinoma (HCC) is unclear. We aimed to investigate the expression and function of FOXP3 and its isoforms in HCC. The study was performed on 84 HCC patients, HCC cell lines and a mouse tumor model. The levels of FOXP3 and its isoforms were determined by nested PCR, quantitative real-time PCR and immunohistochemistry (IHC) staining. The correlation between their levels and clinicopathologic characteristics was analyzed. The full length of FOXP3 (FOXP3) and exon 3-deleted FOXP3 (FOXP3Δ3) were found to be the major isoforms in HCC. The levels of FOXP3Δ3 mRNA and protein in HCC tumor samples were not significantly different from their adjacent normal tissues. The high expression of FOXP3 protein in HCC patients showed a good overall survival. The overexpression of FOXP3 significantly reduced tumor cell proliferation, migration and invasion. The immunofluorescence result indicated that FOXP3 needed to be translocated into the nucleus to exert its inhibitory function. The luciferase assay demonstrated that FOXP3 could be synergistic with Smad2/3/4 to inhibit the oncogene c-Myc. The co-immunoprecipitation results further revealed that FOXP3 could interact with Smad2/3/4. The chromatin immunoprecipitation (ChIP) assay showed that both FOXP3 and Smad2/3/4 bound the promoter of the c-Myc to inhibit it. The in vivo mouse tumor model study confirmed the inhibitory effect of FOXP3. Collectively, the expression of tumor FOXP3 can inhibit the growth of HCC via suppressing c-Myc directly or indirectly via interacting with Smad2/3/4. Therefore, FOXP3 is a tumor suppressor in HCC.

Targeting hepatocyte growth factor/c-mesenchymal-epithelial transition factor axis in hepatocellular carcinoma: Rationale and therapeutic strategies

Hepatocellular carcinoma (HCC) is a leading cause of cancer mortality worldwide. The outcome of current standard treatments, as well as targeted therapies in advanced stages, are still unsatisfactory. Attention has been drawn to novel strategies for better treatment efficacy. Hepatocyte growth factor/c-mesenchymal-epithelial transition factor (HGF/c-Met) axis has been known as an essential element in the regulation of liver diseases and as an oncogenic factor in HCC. In this review, we collected the evidence of HGF/c-Met as a tumor progression and prognostic marker, discussed the anti-c-Met therapy in vitro, summarized the outcome of c-Met inhibitors in clinical trials, and identified potential impetus for future anti-c-Met treatments. We also analyzed the inconsistency of HGF/c-Met from various publications and offered reasonable explanations based on the current understanding in this area. In conclusion, HGF/c-Met plays a crucial role in the progression and growth of HCC, and the strategies to inhibit this pathway may facilitate the development of new and effective treatments for HCC patients.

Impact of Intermittent Pringle Maneuver on Long-Term Survival After Hepatectomy for Hepatocellular Carcinoma: Result from Two Combined Randomized Controlled Trials

BACKGROUND

Hepatectomy remains an important curative treatment for hepatocellular carcinoma (HCC). Intermittent Pringle maneuver (IPM) is commonly applied during hepatectomy for control of bleeding. Whether the ischemia/reperfusion injury brought by IPM adversely affects the operative outcomes is controversial. This study aims to examine whether the application of IPM during hepatectomy affects the long-term outcomes.

METHODS

Two randomized controlled trials (RCT) have been carried out previously to evaluate the short-term outcomes of IPM. The present study represented a post hoc analysis on the HCC patients from the first RCT and all patients from the second RCT, and the long-term outcomes were evaluated.

RESULTS

There were 88 patients each in the IPM group and the no-Pringle-maneuver (NPM) group. The patient demographics, type and extent of liver resection and histopathological findings were comparable between the two groups. The 1-, 3-, 5-year overall survival in the IPM and NPM groups was 92.0%, 82.0%, 72.1% and 93.2%, 68.8%, 58.1%, respectively (P = 0.030). The 1-, 3-, 5-year disease-free survival in the IPM and NPM groups was 73.6%, 56.2%, 49.7% and 71.6%, 49.4%, 40.3%, respectively (P = 0.366). On multivariable analysis, IPM was a favorable factor for overall survival (P = 0.035). Subgroup analysis showed that a clamp time of 16-30 min (P = 0.024) and cirrhotic patients with IPM (P = 0.009) had better overall survival.

CONCLUSION

IPM provided a better overall survival after hepatectomy for patients with HCC. Such survival benefit was noted in cirrhotic patients, and the beneficial duration of clamp was 16-30 min.

TRIAL REGISTRATION

NCT00730743 and NCT01759901 ( http://www.clinicaltrials.gov ).

En bloc transdiaphragmatic lung resection for locally advanced hepatocellular carcinoma: a case report

A 56-year-old man presented with an 11-cm hepatocellular carcinoma (HCC) at segment 7 of liver. To induce left liver hypertrophy, a sequential transarterial chemoembolization (TACE) and portal vein embolization before right hepatectomy were adopted. However, the tumor further increased in size despite TACE and invaded through the diaphragm to the right lung base. Anterior approach right hepatectomy with en bloc wedge resection of the involved right lower lobe of lung by endovascular staplers via transdiaphragmatic approach was performed. The diaphragmatic defect was closed with Goretex mesh. Patient made an uneventful recovery. Pathology confirmed a 12.5 cm poorly differentiated HCC invading through diaphragm to lung. During follow-up, patient developed a 6 cm recurrence at left lung base 17 months after surgery for which he received sorafenib therapy. However, the lung mass further increased in size with new liver recurrence at segment 3 despite treatment. He succumbed 2 years and 3 months after surgery.

ERAS in minimally invasive hepatectomy

Open hepatectomy is associated with significant post-operative morbidity and mortality profile. The use of minimally invasive approach for hepatectomy can reduce the post-operative complication profile and total length of hospital stay. Enhanced recovery after surgery (ERAS) programs involve evidence-based multimodal care pathways designed to achieve early recovery for patients undergoing major surgery. This review will discuss the published evidence, challenges and future directions for ERAS in minimally invasive hepatectomy.

Genomic and Epigenomic Features of Primary and Recurrent Hepatocellular Carcinomas

BACKGROUND & AIMS

Intratumor heterogeneity and divergent clonal lineages within and among primary and recurrent hepatocellular carcinomas (HCCs) produce challenges to patient management. We investigated genetic and epigenetic variations within liver tumors, among hepatic lesions, and between primary and relapsing tumors.

METHODS

Tumor and matched nontumor liver specimens were collected from 113 patients who underwent partial hepatectomy for primary or recurrent HCC at 2 hospitals in Hong Kong. We performed whole-genome, whole-exome, or targeted capture sequencing analyses of 356 HCC specimens collected from multiple tumor regions and matched initial and recurrent tumors. We performed parallel DNA methylation profiling analyses of 95 specimens. Genomes and epigenomes of nontumor tissues that contained areas of cirrhosis or fibrosis were analyzed. We developed liver cancer cell lines that endogenously expressed a mutant form of TP53 (R249S) or overexpressed mutant forms of STAT3 (D170Y, K348E, and Y640F) or JAK1 (S703I and L910P) and tested the abilities of pharmacologic agents to reduce activity. Cells were analyzed by immunoblotting and chromatin immunoprecipitation with quantitative polymerase chain reaction.

RESULTS

We determined the monoclonal origins of individual tumors using a single-sample collection approach that captured more than 90% of mutations that are detected in all regions of tumors. Phylogenetic and phyloepigenetic analyses showed interactions and codependence between the genomic and epigenomic features of HCCs. Methylation analysis showed a field effect in cirrhotic liver tissues that predisposes them to tumor development. Comparisons of genetic features showed that 52% of recurrent HCCs derive from the clonal lineage of the initial tumor. The clonal origin of recurrent HCCs allowed construction of a temporal map of genetic alterations that were associated with tumor recurrence. Activation of JAK signaling to STAT was a characteristic of HCC progression via mutations that are associated with response to drug sensitivity. The combination of a mutation that increases the function of TP53 and the 17p chromosome deletion might provide liver cancer cells with a replicative advantage. Chromatin immunoprecipitation analysis of TP53 with the R249S substitution showed its interaction with genes that encode chromatin regulators (MLL1 and MLL2). We validated MLL1 and MLL2 as direct targets of TP53R249S and affirmed their association in the cancer genome atlas data set. The MLL-complex antagonists MI-2-2 (inhibitor of protein interaction) and OICR-9492 (inhibitor of activity) specifically inhibited proliferation of HCC cells that express TP53R249S at nanomolar concentrations.

CONCLUSIONS

We performed a systematic evaluation of intra- and intertumor genetic heterogeneity in HCC samples and identified genetic and epigenetic changes that are associated with tumor progression and recurrence. We identified chromatin regulators that are up-regulated by mutant TP53 in HCC cells and inhibitors that reduce proliferation of these cells. DNA methylation patterns in cirrhotic or fibrotic liver tissues might be used to identify those at risk of HCC development.

FOX transcription factor family in hepatocellular carcinoma

The pathogenesis of hepatocellular carcinoma (HCC) is a multistep process, involving the progressive accumulation of molecular alterations and transcriptomic alterations. The Forkhead-box (FOX) transcription factor family is characterized by its unique DNA binding domain (FKH or winged-helix domain). Human FOX family consists of about 17 subfamilies, at least 43 members. Some of them are liver-enriched transcription factors, suggesting that they may play a crucial role in the development or/and functions of the liver. Dysregulation of FOX transcription factors may contribute to the pathogenesis of HCC because they can activate or suppress the expression of various tumor-related molecules, and pinpoint different molecular and cellular events. Here we summarized, analyzed and discussed the status and the functions of the human FOX family of transcription factors in HCC, aiming to help the further development of them as potential therapeutic targets or/and diagnostic/prognostic markers for HCC.

Immediate and long-term impact of the COVID-19 pandemic on delivery of surgical services

Background

The ongoing pandemic is having a collateral health effect on delivery of surgical care to millions of patients. Very little is known about pandemic management and effects on other services, including delivery of surgery.

Methods

This was a scoping review of all available literature pertaining to COVID-19 and surgery, using electronic databases, society websites, webinars and preprint repositories.

Results

Several perioperative guidelines have been issued within a short time. Many suggestions are contradictory and based on anecdotal data at best. As regions with the highest volume of operations per capita are being hit, an unprecedented number of operations are being cancelled or deferred. No major stakeholder seems to have considered how a pandemic deprives patients with a surgical condition of resources, with patients disproportionally affected owing to the nature of treatment (use of anaesthesia, operating rooms, protective equipment, physical invasion and need for perioperative care). No recommendations exist regarding how to reopen surgical delivery. The postpandemic evaluation and future planning should involve surgical services as an essential part to maintain appropriate surgical care for the population during an outbreak. Surgical delivery, owing to its cross-cutting nature and synergistic effects on health systems at large, needs to be built into the WHO agenda for national health planning.

Conclusion

Patients are being deprived of surgical access, with uncertain loss of function and risk of adverse prognosis as a collateral effect of the pandemic. Surgical services need a contingency plan for maintaining surgical care in an ongoing or postpandemic phase.

The FKH domain in FOXP3 mRNA frequently contains mutations in hepatocellular carcinoma that influence the subcellular localization and functions of FOXP3

The transcription factor forkhead box P3 (FOXP3) is a biomarker for regulatory T cells and can also be expressed in cancer cells, but its function in cancer appears to be divergent. The role of hepatocyte-expressed FOXP3 in hepatocellular carcinoma (HCC) is unknown. Here, we collected tumor samples and clinical information from 115 HCC patients and used five human cancer cell lines. We examined FOXP3 mRNA sequences for mutations, used a luciferase assay to assess promoter activities of FOXP3's target genes, and employed mouse tumor models to confirm in vitro results. We detected mutations in the FKH domain of FOXP3 mRNAs in 33% of the HCC tumor tissues, but in none of the adjacent nontumor tissues. None of the mutations occurred at high frequency, indicating that they occurred randomly. Notably, the mutations were not detected in the corresponding regions of FOXP3 genomic DNA, and many of them resulted in amino acid substitutions in the FKH region, altering FOXP3's subcellular localization. FOXP3 delocalization from the nucleus to the cytoplasm caused loss of transcriptional regulation of its target genes, inactivated its tumor-inhibitory capability, and changed cellular responses to histone deacetylase (HDAC) inhibitors. More complex FKH mutations appeared to be associated with worse prognosis in HCC patients. We conclude that mutations in the FKH domain of FOXP3 mRNA frequently occur in HCC and that these mutations are caused by errors in transcription and are not derived from genomic DNA mutations. Our results suggest that transcriptional mutagenesis of FOXP3 plays a role in HCC.

A Fast Online Monitoring Approach for Surgical Risks

Risk monitoring has been widely used in health care, further, control charts are often used as monitoring methods for surgical outcomes. Most of the methods can only detect step shifts of position parameters, but cannot take measures on scale parameters. In this paper, we proposed four methods based on EWMA control charts, namely SESOP, STSSO, SESOP-MFIR and STSSO-MFIR, to improve the existing monitoring methods. Specifically, SESOP standardizes variable on the basis of an EWMA charting method; STSSO replaces the statistics of the original EWMA charting method with the score test statistics; for SESOP-MFIR and STSSO-MFIR, we upgrade their control limits from asymptotic to time-varying based on SESOP and STSSO, which enhance the timeliness of the earlier shifts monitoring. In order to verify the improvement of surgical outcomes monitoring, we respectively carry out simulation experiment and a practical application on ESOP and our four methods. SESOP can raise the overall efficiency of detecting shifts; STSSO led to a significant increase in the monitoring stability, especially for small volatilities; the optimization brought by SESOP-MFIR and STSSO-MFIR are more obvious, that the speed of detecting earlier shifts can even be reduced to half of the existing methods. Then, we apply these methods to the SOMIP program of Hong Kong, SESOP-MFIR and STSSO-MFIR have the best performance and can detect early shifts in time. According to the results, the methods we proposed can monitor both early shifts and scale parameters and improve the performance of surgical outcome monitoring in different degrees compared to those existing methods.

The chances of hepatic resection curing hepatocellular carcinoma

BACKGROUND & AIMS

The popular sense of the word "cure" implies that a patient treated for a specific disease will return to have the same life expectancy as if he/she had never had the disease. In analytic terms, it translates into the concept of statistical cure which occurs when a group of patients returns to having similar mortality to a reference population. The aim of this study was to assess the probability of being cured from hepatocellular carcinoma (HCC) by hepatic resection.

METHODS

Data from 2,523 patients undergoing resection for HCC were used to fit statistical cure models, to compare disease-free survival (DFS) after surgery to the survival expected for patients with chronic hepatitis and/or cirrhosis and the general population, matched by sex, age, race/ethnicity and year of diagnosis.

RESULTS

The probability of resection enabling patients with HCC to achieve the same life expectancy as those with chronic hepatitis and/or cirrhosis was 26.3%. The conditional probability of achieving this result was time-dependent, requiring about 8.9 years to be accomplished with 95% certainty. Considering the general population as a reference, the cure fraction decreased to 17.1%. Uncured patients had a median DFS of 1.5 years. In multivariable analysis, patient's age and the risk of early HCC recurrence (within 2 years) were independent determinants of the chance of cure (p <0.001). The chances of being cured ranged between 36.0% for individuals at low risk of early recurrence to approximately 3.6% for those at high risk.

CONCLUSION

Estimates of the chance of being cured of HCC by resection showed that cure is achievable, and its likelihood increases with the passing of recurrence-free time. The data presented herein can be used to inform decision making and to provide patients with accurate information.

LAY SUMMARY

Data from 2,523 patients who underwent resection for hepatocellular carcinoma were used to estimate the probability that resection would enable treated patients to achieve the same life expectancy as patients with chronic hepatitis and/or cirrhosis, and the general population. Herein, the cure model suggests that in patients with hepatocellular carcinoma, resection can enable patients to achieve the same life expectancy as those with chronic liver disease in 26.3% of cases and as the general population in 17.1% of cases.

Genomic and Epigenomic Features of Primary and Recurrent Hepatocellular Carcinomas

BACKGROUND & AIMS

Intratumor heterogeneity and divergent clonal lineages within and among primary and recurrent hepatocellular carcinomas (HCCs) produce challenges to patient management. We investigated genetic and epigenetic variations within liver tumors, among hepatic lesions, and between primary and relapsing tumors.

METHODS

Tumor and matched nontumor liver specimens were collected from 113 patients who underwent partial hepatectomy for primary or recurrent HCC at 2 hospitals in Hong Kong. We performed whole-genome, whole-exome, or targeted capture sequencing analyses of 356 HCC specimens collected from multiple tumor regions and matched initial and recurrent tumors. We performed parallel DNA methylation profiling analyses of 95 specimens. Genomes and epigenomes of nontumor tissues that contained areas of cirrhosis or fibrosis were analyzed. We developed liver cancer cell lines that endogenously expressed a mutant form of TP53 (R249S) or overexpressed mutant forms of STAT3 (D170Y, K348E, and Y640F) or JAK1 (S703I and L910P) and tested the abilities of pharmacologic agents to reduce activity. Cells were analyzed by immunoblotting and chromatin immunoprecipitation with quantitative polymerase chain reaction.

RESULTS

We determined the monoclonal origins of individual tumors using a single sample collection approach that captured more than 90% of mutations that are detected in all regions of tumors. Phylogenetic and phylo-epigenetic analyses revealed interactions and codependence between the genomic and epigenomic features of HCCs. Methylation analysis revealed a field effect in cirrhotic liver tissues that predisposes them to tumor development. Comparisons of genetic features revealed that 52% of recurrent HCCs derive from the clonal lineage of the initial tumor. The clonal origin if recurrent HCCs allowed construction of a temporal map of genetic alterations that associated with tumor recurrence. Activation of JAK signaling to STAT was a characteristic of HCC progression via mutations that associate with response to drug sensitivity. The combination of a mutation that increases the function of TP53 and the 17p chromosome deletion might provide liver cancer cells with a replicative advantage. Chromatin immunoprecipitation analysis of TP53 with the R249S substitution revealed its interaction with genes that encode chromatin regulators (MLL1 and MLL2). We validated MLL1 and MLL2 as direct targets of TP53^R249S and affirmed their association in the Cancer Genome Atlas dataset. The MLL-complex antagonists MI-2-2 (inhibitor of protein interaction) and OICR-9492 (inhibitor of activity) specifically inhibited proliferation of HCC cells that express TP53^R249S at nanomolar concentrations.

CONCLUSIONS

We performed a systematic evaluation of intra- and intertumor genetic heterogeneity in HCC samples and identified genetic and epigenetic changes that associate with tumor progression and recurrence. We identified chromatin regulators that are upregulated by mutant TP53 in HCC cells and inhibitors that reduce proliferation of these cells. DNA methylation patterns in cirrhotic or fibrotic liver tissues might be used to identify those at risk of HCC development.

ER-residential Nogo-B accelerates NAFLD-associated HCC mediated by metabolic reprogramming of oxLDL lipophagy

Non-alcoholic fatty liver disease (NAFLD) is the hepatic manifestation of the metabolic syndrome that elevates the risk of hepatocellular carcinoma (HCC). Although alteration of lipid metabolism has been increasingly recognized as a hallmark of cancer cells, the deregulated metabolic modulation of HCC cells in the NAFLD progression remains obscure. Here, we discovers an endoplasmic reticulum-residential protein, Nogo-B, as a highly expressed metabolic modulator in both murine and human NAFLD-associated HCCs, which accelerates high-fat, high-carbohydrate diet-induced metabolic dysfunction and tumorigenicity. Mechanistically, CD36-mediated oxLDL uptake triggers CEBPβ expression to directly upregulate Nogo-B, which interacts with ATG5 to promote lipophagy leading to lysophosphatidic acid-enhanced YAP oncogenic activity. This CD36-Nogo-B-YAP pathway consequently reprograms oxLDL metabolism and induces carcinogenetic signaling for NAFLD-associated HCCs. Targeting the Nogo-B pathway may represent a therapeutic strategy for HCC arising from the metabolic syndrome.

Robotic versus laparoscopic hepatectomy: application of the difficulty scoring system

BACKGROUND

The development of robotic system may help to relieve the difficulties encountered during laparoscopic hepatectomy. A difficulty scoring system (DSS) was developed to assess the difficulty of various laparoscopic liver resection procedures. The aim of this study is to explore if the DSS is applicable in robotic hepatectomy and to compare the outcomes of robotic hepatectomy and laparoscopic hepatectomy among different difficulty levels.

METHODS

Clinical data from all consecutive patients who underwent robotic and conventional laparoscopic hepatectomy at the Prince of Wales Hospital, Hong Kong, were prospectively collected and reviewed. The difficulty level of operations was graded using the DSS. Perioperative outcomes of robotic and conventional laparoscopic hepatectomy were compared at each difficulty level.

RESULTS

A total of 107 and 94 patients underwent robotic and laparoscopic hepatectomy during the study period, respectively. Among them, 16 and 2 patients were operated for recurrent pyogenic cholangitis, respectively, and were excluded because no mark for tumour location can be assigned. For robotic hepatectomy, a higher DSS was significantly correlated with higher minor complication rate (p = 0.001), more intraoperative blood loss (p = 0.002), longer operation time (p < 0.001) and longer post-operative hospital stay (p < 0.001). The mean DSS scores of robotic and laparoscopic hepatectomy were 4.5 and 3.6, respectively. (p = 0.004). For cases with low (DSS 1-3) and intermediate (DSS 4-6) difficulty level, there was no significant difference in operative blood loss, operation time and overall complications rate. Only 2 cases (2.2%) with high difficulty level were operated with laparoscopic approach while 20% of patients operated with robotic approach had DSS > 6.

CONCLUSIONS

DSS significantly correlated with surgical outcomes in patient who underwent robotic hepatectomy. Perioperative outcomes following robotic and conventional laparoscopic hepatectomy were similar in cases with low and intermediate difficulty. However, robotic system allowed minimally invasive approach in cases with higher difficulty level.

Loss of tumor suppressor IGFBP4 drives epigenetic reprogramming in hepatic carcinogenesis

Genomic sequencing of hepatocellular carcinoma (HCC) uncovers a paucity of actionable mutations, underscoring the necessity to exploit epigenetic vulnerabilities for therapeutics. In HCC, EZH2-mediated H3K27me3 represents a major oncogenic chromatin modification, but how it modulates the therapeutic vulnerability of signaling pathways remains unknown. Here, we show EZH2 acts antagonistically to AKT signaling in maintaining H3K27 methylome through epigenetic silencing of IGFBP4. ChIP-seq revealed enrichment of Ezh2/H3K27me3 at silenced loci in HBx-transgenic mouse-derived HCCs, including Igfbp4 whose down-regulation significantly correlated with EZH2 overexpression and poor survivals of HCC patients. Functional characterizations demonstrated potent growth- and invasion-suppressive functions of IGFBP4, which was associated with transcriptomic alterations leading to deregulation of multiple signaling pathways. Mechanistically, IGFBP4 stimulated AKT/EZH2 phosphorylation to abrogate H3K27me3-mediated silencing, forming a reciprocal feedback loop that suppressed core transcription factor networks (FOXA1/HNF1A/HNF4A/KLF9/NR1H4) for normal liver homeostasis. Consequently, the in vivo tumorigenicity of IGFBP4-silenced HCC cells was vulnerable to pharmacological inhibition of EZH2, but not AKT. Our study unveils chromatin regulation of a novel liver tumor suppressor IGFBP4, which constitutes an AKT-EZH2 reciprocal loop in driving H3K27me3-mediated epigenetic reprogramming. Defining the aberrant chromatin landscape of HCC sheds light into the mechanistic basis of effective EZH2-targeted inhibition.

Orientation-aware plasma cell-free DNA fragmentation analysis in open chromatin regions informs tissue of origin

Cell-free DNA (cfDNA) in human plasma is a class of biomarkers with many current and potential future diagnostic applications. Recent studies have shown that cfDNA molecules are not randomly fragmented and possess information related to their tissues of origin. Pathologies causing death of cells from particular tissues result in perturbations in the relative distribution of DNA from the affected tissues. Such tissue-of-origin analysis is particularly useful in the development of liquid biopsies for cancer. It is therefore of value to accurately determine the relative contributions of the tissues to the plasma DNA pool in a simultaneous manner. In this work, we report that in open chromatin regions, cfDNA molecules show characteristic fragmentation patterns reflected by sequencing coverage imbalance and differentially phased fragment end signals. The latter refers to differences in the read densities of sequences corresponding to the orientation of the upstream and downstream ends of cfDNA molecules in relation to the reference genome. Such cfDNA fragmentation patterns preferentially occur in tissue-specific open chromatin regions where the corresponding tissues contributed DNA into the plasma. Quantitative analyses of such signals allow measurement of the relative contributions of various tissues toward the plasma DNA pool. These findings were validated by plasma DNA sequencing data obtained from pregnant women, organ transplantation recipients, and cancer patients. Orientation-aware plasma DNA fragmentation analysis therefore has potential diagnostic applications in noninvasive prenatal testing, organ transplantation monitoring, and cancer liquid biopsy.

Correlations of health-related quality of life with serum inflammatory indicators IL-8 and mIBI in patients with hepatocellular carcinoma

Purpose

Health-related quality of life (HRQoL) is a significant prognostic factor for overall survival in hepatocellular carcinoma (HCC) patients, and this is independent of stage and liver function. Inflammation plays a significant role in HCC development and progression. It was hypothesized that the inflammatory status of HCC patients may affect their HRQoL. The relationship between HRQoL and inflammatory status was explored using indicators IL-8 level and modified inflammation-based index (mIBI, based on IL-8, C-reactive protein, and albumin).

Methods

From 2007-2011, HCC patients were enrolled prospectively. Baseline HRQoL assessment utilized the European Organization for Research and Treatment of Cancer (EORTC) QLQ-C30 and QLQ-HCC18; clinical and laboratory data were collected at diagnosis. Two summary indices, C30 and HCC18 index-scores, were calculated. Correlation analyses were performed between HRQoL and inflammatory markers.

Results

In the 445 patients studied, significant correlations were found between IL-8 levels and EORTC QLQ-C30, QLQ-HCC18, C30, and HCC18 index-scores. The strongest correlated factors were those reflective of constitutional symptoms, namely QLQ-C30 "appetite loss" (with Pearson's correlation coefficient, r=0.322, P<0.0001); QLQ-C30 "fatigue" (r=0.311, P<0.0001); QLQ-C30 "role functioning" (r=-0.305, P<0.0001); QLQ-HCC18 "nutrition" (r=0.317, P<0.0001); and QLQ-HCC18 "fatigue" (r=0.306, P<0.0001). In addition, moderate but significant correlations were also observed with HCC18 index score (r=0.321, P<0.0001), and C30 index score (r=0.306, P<0.0001). HRQoL factors were also significantly correlated with mIBI.

Conclusion

Baseline HRQoL using the conventional assessments of EORTC QLQ-C30 and QLQ-HCC18, as well as C30 and HCC18 index-scores, significantly correlated with inflammatory indicators (IL-8 level and mIBI) in HCC patients. Among the strongest correlations were those between IL-8 level and the two index-scores, as well as HRQoL aspects that represent constitutional symptoms. When paralleled with molecular findings, traditional HRQoL assessment in HCC has gained a new level of understanding: pattern recognition within an HRQoL instrument could potentially identify patients with more severe inflammatory state.

Enhanced recovery after surgery for liver resection

INTRODUCTION

Enhanced recovery after surgery (ERAS) reduces postoperative length of hospital stay and patient stress response to liver surgery. The aim of the present study was to evaluate the efficacy and feasibility of an ERAS programme for liver resection.

METHODS

A multidisciplinary ERAS protocol was implemented for both open and laparoscopic liver resection in a tertiary hospital in Hong Kong. The clinical outcomes of patients who underwent liver resection and underwent the ERAS perioperative programme were compared with those who received a conventional perioperative programme between September 2015 and July 2016. Propensity score matching analysis was used to minimise background differences.

RESULTS

A total of 20 patients who underwent liver resection were recruited to the ERAS programme. Their clinical outcomes were compared with another 20 patients who received hepatectomy under a conventional perioperative programme after propensity score matching. The ERAS programme was associated with a significantly shorter length of hospital stay (P=0.033) without an increase in complication rates in patients who underwent open liver resection. There was no such significant association in patients who underwent laparoscopic liver resection. No patients required readmission in this cohort.

CONCLUSIONS

The ERAS perioperative programme for liver resection is safe and feasible. It significantly shortened the hospital stay after open liver resection but not after laparoscopic liver resection.

Homology-independent multiallelic disruption via CRISPR/Cas9-based knock-in yields distinct functional outcomes in human cells

BACKGROUND

Cultured human cells are pivotal models to study human gene functions, but introducing complete loss of function in diploid or aneuploid cells has been a challenge. The recently developed CRISPR/Cas9-mediated homology-independent knock-in approach permits targeted insertion of large DNA at high efficiency, providing a tool for insertional disruption of a selected gene. Pioneer studies have showed promising results, but the current methodology is still suboptimal and functional outcomes have not been well examined. Taking advantage of the promoterless fluorescence reporter systems established in our previous study, here, we further investigated potentials of this new insertional gene disruption approach and examined its functional outcomes.

RESULTS

Exemplified by using hyperploid LO2 cells, we demonstrated that simultaneous knock-in of dual fluorescence reporters through CRISPR/Cas9-induced homology-independent DNA repair permitted one-step generation of cells carrying complete disruption of target genes at multiple alleles. Through knocking-in at coding exons, we generated stable single-cell clones carrying complete disruption of ULK1 gene at all four alleles, lacking intact FAT10 in all three alleles, or devoid of intact CtIP at both alleles. We have confirmed the depletion of ULK1 and FAT10 transcripts as well as corresponding proteins in the obtained cell clones. Moreover, consistent with previous reports, we observed impaired mitophagy in ULK1-/- cells and attenuated cytokine-induced cell death in FAT10-/- clones. However, our analysis showed that single-cell clones carrying complete disruption of CtIP gene at both alleles preserved in-frame aberrant CtIP transcripts and produced proteins. Strikingly, the CtIP-disrupted clones raised through another two distinct targeting strategies also produced varied but in-frame aberrant CtIP transcripts. Sequencing analysis suggested that diverse DNA processing and alternative RNA splicing were involved in generating these in-frame aberrant CtIP transcripts, and some infrequent events were biasedly enriched among the CtIP-disrupted cell clones.

CONCLUSION

Multiallelic gene disruption could be readily introduced through CRISPR/Cas9-induced homology-independent knock-in of dual fluorescence reporters followed by direct tracing and cell isolation. Robust cellular mechanisms exist to spare essential genes from loss-of-function modifications, by generating partially functional transcripts through diverse DNA and RNA processing mechanisms.

Cancer stem cells in hepatocellular carcinoma: an overview and promising therapeutic strategies

The poor clinical outcome of hepatocellular carcinoma (HCC) patients is ascribed to the resistance of HCC cells to traditional treatments and tumor recurrence after curative therapies. Cancer stem cells (CSCs) have been identified as a small subset of cancer cells which have high capacity for self-renewal, differentiation and tumorigenesis. Recent advances in the field of liver CSCs (LCSCs) have enabled the identification of CSC surface markers and the isolation of CSC subpopulations from HCC cells. Given their central role in cancer initiation, metastasis, recurrence and therapeutic resistance, LCSCs constitute a therapeutic opportunity to achieve cure and prevent relapse of HCC. Thus, it is necessary to develop therapeutic strategies to selectively and efficiently target LCSCs. Small molecular inhibitors targeting the core stemness signaling pathways have been actively pursued and evaluated in preclinical and clinical studies. Other alternative therapeutic strategies include targeting LCSC surface markers, interrupting the CSC microenvironment, and altering the epigenetic state. In this review, we summarize the properties of CSCs in HCC and discuss novel therapeutic strategies that can be used to target LCSCs.