Cellular and Molecular Biology of Cancer Stem Cells of Hepatocellular Carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer death globally. The cancer stem cells (CSCs) of HCC are responsible for tumor growth, invasion, metastasis, recurrence, chemoresistance, target therapy resistance and radioresistance. The reported main surface markers used to identify liver CSCs include epithelial cell adhesion/activating molecule (EpCAM), cluster differentiation 90 (CD90), CD44 and CD133. The main molecular signaling pathways include the Wnt/ß-catenin, transforming growth factors-ß (TGF-ß), sonic hedgehog (SHH), PI3K/Akt/mTOR and Notch. Patients with EpCAM-positive alpha-fetoprotein (AFP)-positive HCC are usually young but have advanced tumor-node-metastasis (TNM) stages. CD90-positive HCCs are usually poorly differentiated with worse prognosis. Those with CD44-positive HCC cells develop early metastases. Those with CD133 expression have a higher recurrence rate and a shorter overall survival. The Wnt/ß-catenin signaling pathway triggers angiogenesis, tumor infiltration and metastasis through the enhancement of angiogenic factors. All CD133+ liver CSCs, CD133+/EpCAM+ liver CSCs and CD44+ liver CSCs contribute to sorafenib resistance. SHH signaling could protect HCC cells against ionizing radiation in an autocrine manner. Reducing the CSC population of HCC is crucial for the improvement of the therapy of advanced HCC. However, targeting CSCs of HCC is still challenging.

Aldo-keto reductase family member C3 (AKR1C3) promotes hepatocellular carcinoma cell growth by producing prostaglandin F2α.

Hepatocellular carcinoma (HCC) is a leading cause of death worldwide. Current therapies are effective for HCC patients with early disease, but many patients suffer recurrence after surgery and have a poor response to chemotherapy. Therefore, new therapeutic targets are needed. We analyzed gene expression profiles between HCC tissues and normal adjacent tissues from public databases and found that the expression of genes involved in lipid metabolism was significantly different. The analysis showed that AKR1C3 was upregulated in tumors, and high AKR1C3 expression was associated with a poorer prognosis in HCC patients. In vitro, assays demonstrated that the knockdown of AKR1C3 or the addition of the AKR1C3 inhibitor indomethacin suppressed the growth and colony formation of HCC cell lines. Knockdown of AKR1C3 in Huh7 cells reduced tumor growth in vivo. To explore the mechanism, we performed pathway enrichment analysis, and the results linked the expression of AKR1C3 with prostaglandin F2 alpha (PGF2α) downstream target genes. Suppression of AKR1C3 activity reduced the production of PGF2α, and supplementation with PGF2α restored the growth of indomethacin-treated Huh7 cells. Knockdown of the PGF receptor (PTGFR) and treatment with a PTGFR inhibitor significantly reduced HCC growth. We showed that indomethacin potentiated the sensitivity of Huh7 cells to sorafenib. In summary, our results indicate that AKR1C3 upregulation may promote HCC growth by promoting the production of PGF2α, and suppression of PTGFR limited HCC growth. Therefore, targeting the AKR1C3-PGF2α-PTGFR axis may be a new strategy for the treatment of HCC.

Liver collision tumor of primary hepatocellular carcinoma and neuroendocrine carcinoma: A rare case report.

BACKGROUND: Hepatocellular carcinoma (HCC) can occasionally develop with other non-HCC cell types, either in a combined type or collision type. A collision tumor is defined as two histopathologically distinct tumors of the same organ lacking a clear transition zone. Hepatic collision tumors are rare. Among them, "hepatocellular carcinoma-hepatic neuroendocrine carcinoma" (HCC-NEC) collision tumors are especially rare and information about them is rarely published. CASE SUMMARY: A 48-year-old man with typical findings of HCC underwent consecutive therapies, including radiofrequency ablation and embolization prior to resection. Diagnosis of the HCC-NEC collision tumor in the right liver and another HCC in the left liver was established following surgical resection. The patient displayed NEC metastasis following resection and succumbed to septicemia after 2 more rounds of chemotherapy. To our knowledge, this is the 25th reported case of mixed HCC-NEC tumor. The rarity of HCC-NEC collision tumors and the absence of diagnostic criteria make it difficult to differentiate this condition from simple liver tumors, especially in patients with chronic liver disease. CONCLUSION: Our case highlights the difficulty in accurately diagnosing HCC-NEC in the absence of histological evidence. The prognosis is poor for this condition, although ultrasound-guided liver biopsy can be helpful to establish a prompt diagnosis. Further accumulation of such cases could help establish an accurate diagnosis earlier. Early discovery of NEC may allow for better treatment strategies and better prognoses.

Upper Gastrointestinal Cancer and Liver Cirrhosis.

The extended scope of upper gastrointestinal cancer can include esophageal cancer, gastric cancer and pancreatic cancer. A higher incidence rate of gastric cancer and esophageal cancer in patients with liver cirrhosis has been reported. It is attributable to four possible causes which exist in cirrhotic patients, including a higher prevalence of gastric ulcers and congestive gastropathy, zinc deficiency, alcohol drinking and tobacco use and coexisting gut microbiota. Helicobacter pylori infection enhances the development of gastric cancer. In addition, Helicobacter pylori, Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans also contribute to the development of pancreatic cancer in cirrhotic patients. Cirrhotic patients (especially those with alcoholic liver cirrhosis) who undergo liver transplantation have a higher overall risk of developing de novo malignancies. Most de novo malignancies are upper gastrointestinal malignancies. The prognosis is usually poor. Considering the surgical risk of upper gastrointestinal cancer among those with liver cirrhosis, a radical gastrectomy with D1 or D2 lymph node dissection can be undertaken in Child class A patients. D1 lymph node dissection can be performed in Child class B patients. Endoscopic submucosal dissection for gastric cancer or esophageal cancer can be undertaken safely in selected cirrhotic patients. In Child class C patients, a radical gastrectomy is potentially fatal. Pancreatic radical surgery should be avoided in those with liver cirrhosis with Child class B or a MELD score over 15. The current review focuses on the recent reports on some factors in liver cirrhosis that contribute to the development of upper gastrointestinal cancer. Quitting alcohol drinking and tobacco use is important. How to decrease the risk of the development of gastrointestinal cancer in those with liver cirrhosis remains a challenging problem.

MXD3 Promotes Obesity and the Androgen Receptor Signaling Pathway in Gender-Disparity Hepatocarcinogenesis.

Obesity is closely linked to metabolic diseases, particularly non-alcoholic steatohepatitis (NASH) or non-alcoholic fatty liver disease (NAFLD), ultimately leading to hepatocellular carcinoma (HCC). However, the molecular mechanisms of NASH-associated HCC (NAHCC) remain elusive. To explore the impact of Max dimerization protein 3 (MXD3), a transcription factor that regulates several cellular functions in disorders associated with metabolic diseases, we conditionally expressed Mxd3 proteins using Tet-on mxd3 transgenic zebrafish (MXs) with doxycycline (MXs + Dox) or without doxycycline (MXs - Dox) treatment. Overexpression of global MXD3 (gMX) or hepatic Mxd3 (hMX) was associated with obesity-related NAFLD pathophysiology in gMX + Dox, and liver fibrosis and HCC in hMX + Dox. Oil Red O (ORO)-stained signals were seen in intravascular blood vessels and liver buds of larval gMX + Dox, indicating that Mxd3 functionally promotes lipogenesis. The gMX + Dox-treated young adults exhibited an increase in body weight and visceral fat accumulation. The hMX + Dox-treated young adults showed normal body characteristics but exhibited liver steatosis and NASH-like phenotypes. Subsequently, steatohepatitis, liver fibrosis, and NAHCC were found in 6-month-old gMX + Dox adults compared with gMX - Dox adults at the same stage. Overexpression of Mxd3 also enhanced AR expression accompanied by the increase of AR-signaling pathways resulting in hepatocarcinogenesis in males. Our results demonstrate that global actions of Mxd3 are central to the initiation of obesity in the gMX zebrafish through their effects on adipogenesis and that MXD3 could serve as a therapeutic target for obesity-associated liver diseases.

The Role of Endoglin in Hepatocellular Carcinoma.

Endoglin (CD105) is a type-1 integral transmembrane glycoprotein and coreceptor for transforming growth factor-ß (TGF-ß) ligands. The endoglin/TGF-ß signaling pathway regulates hemostasis, cell proliferation/migration, extracellular matrix (ECM) synthesis and angiogenesis. Angiogenesis contributes to early progression, invasion, postoperative recurrence, and metastasis in hepatocellular carcinoma (HCC), one of the most widespread malignancies globally. Endoglin is overexpressed in newly formed HCC microvessels. It increases microvessel density in cirrhotic and regenerative HCC nodules. In addition, circulating endoglin is present in HCC patients, suggesting potential for use as a diagnostic or prognostic factor. HCC angiogenesis is dynamic and endoglin expression varies by stage. TRC105 (carotuximab) is an antibody against endoglin, and three of its clinical trials were related to liver diseases. A partial response was achieved when combining TRC105 with sorafenib. Although antiangiogenic therapy still carries some risks, combination therapy with endoglin inhibitors or other targeted therapies holds promise.

The Role of Smoothened in Cancer.

Smoothened (SMO) belongs to the Hedgehog (HH) signaling pathway, which regulates cell growth, migration, invasion and stem cells in cancer. The HH signaling pathway includes both canonical and noncanonical pathways. The canonical HH pathway functions through major HH molecules such as HH ligands, PTCH, SMO and GLI, whereas the noncanonical HH pathway involves the activation of SMO or GLI through other pathways. The role of SMO has been discussed in different types of cancer, including breast, liver, pancreatic and colon cancers. SMO expression correlates with tumor size, invasiveness, metastasis and recurrence. In addition, SMO inhibitors can suppress cancer formation, reduce the proliferation of cancer cells, trigger apoptosis and suppress cancer stem cell activity. A better understanding of the role of SMO in cancer could contribute to the development of novel therapeutic approaches.

Upregulation of RelB in the miR-122 knockout mice contributes to increased levels of proinflammatory chemokines/cytokines in the liver and macrophages.

OBJECTIVE: MicroRNA-122 (miR-122) is the most abundant miRNA in the liver and it plays an important role in regulating liver metabolism and tumor formation. Previous studies also reveal an anti-inflammatory function of miR-122; however, relatively little is known about the mechanisms by which miR-122 suppresses inflammation. This study aims to search the effect of miR-122 on proinflammatory chemokines/cytokines production in mice. METHODS: Quantitative real-time PCR, Western blot analysis, and ELISA were performed to examine gene expression. TargetScan, miRanda, and microT v3.0 were used to search for possible miR-122 target sites in the 3'-untranslated regions (3'-UTR) of candidate genes. Luciferase reporter assay and site-directed mutagenesis were applied to verify miR-122 target sequences. LPS was applied to peritoneal macrophages and mice to evaluate inflammatory response. RESULTS: The expression of proinflammatory chemokines, including Ccl2, Ccl4, Ccl20, Cxcl2, and Cxcl10, and Relb in the livers of miR-122 knockout (KO) mice was increased. We identified Relb as a direct miR-122 target. Overexpressing RelB in the mouse liver increased the expression of Ccl2, Ccl4, Ccl20, Cxcl2, and Cxcl10. Peritoneal macrophages from miR-122 KO mice had a higher level of RelB, and they showed a stronger NF-κB activation and more TNF-α and IL-6 secretion after LPS stimulation. Overexpression of RelB in a macrophage cell line augmented LPS-induced TNF-α and IL-6 production. miR-122 KO mice showed a greatly increased mortality rate and generated a stronger and lasting inflammatory response to LPS. CONCLUSIONS: Deletion of miR-122 caused an upregulation of proinflammatory chemokines and RelB in the liver. Increased RelB may contribute to increases in these chemokine in the liver. Intriguingly, deletion of miR-122 also enhanced the sensitivity of macrophages and mice to LPS. Our results reveal that reducing RelB expression is a new mechanism by which miR-122 regulates inflammation.

Liver Fibrosis and Inflammation under the Control of ERK2.

Chronic liver injury could lead the formation of liver fibrosis, eventually some would develop to hepatocellular carcinoma (HCC), one of the leading malignancies worldwide. The aim of the study is to dissect the role of extracellular signal-regulated kinase 2 (ERK2) signaling in liver fibrosis and inflammation. The choline-deficient, ethionine-supplemented (CDE) diet could lead to fatty livers and generate oval cells, activate hepatocyte stellate cell (HSC) and recruit immune cells as the liver fibrosis model mice. WT and ERK2 deficient (ERK2-/-) mice were compared in terms of liver weight/body weight, liver function, liver fibrosis markers and the differential gene expression in hepatotoxicity. ERK2-/- mice display the less degree of liver fibrosis when compared to WT mice. The protein level of alpha smooth muscle (α-SMA) was reduced and several hepatocellular carcinoma-related genes such as MMP9, FoxM1 were down-regulated. In addition, the cell proliferation and the percentages of activated T cells were reduced in ERK2-/- mice upon liver injury. Therefore, ERK2 plays an important role in regulating liver cirrhosis and inflammation.

Sonic Hedgehog Signaling in Organogenesis, Tumors, and Tumor Microenvironments.

During mammalian embryonic development, primary cilia transduce and regulate several signaling pathways. Among the various pathways, Sonic hedgehog (SHH) is one of the most significant. SHH signaling remains quiescent in adult mammalian tissues. However, in multiple adult tissues, it becomes active during differentiation, proliferation, and maintenance. Moreover, aberrant activation of SHH signaling occurs in cancers of the skin, brain, liver, gallbladder, pancreas, stomach, colon, breast, lung, prostate, and hematological malignancies. Recent studies have shown that the tumor microenvironment or stroma could affect tumor development and metastasis. One hypothesis has been proposed, claiming that the pancreatic epithelia secretes SHH that is essential in establishing and regulating the pancreatic tumor microenvironment in promoting cancer progression. The SHH signaling pathway is also activated in the cancer stem cells (CSC) of several neoplasms. The self-renewal of CSC is regulated by the SHH/Smoothened receptor (SMO)/Glioma-associated oncogene homolog I (GLI) signaling pathway. Combined use of SHH signaling inhibitors and chemotherapy/radiation therapy/immunotherapy is therefore key in targeting CSCs.

Sonic Hedgehog signaling pathway as a potential target to inhibit the progression of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-associated mortality worldwide. Hepatocarcinogenesis involves numerous interlinked factors and processes, including the Sonic hedgehog (Shh) signaling pathway, which participates in the carcinogenesis, progression, invasiveness, recurrence and cancer stem cell maintenance of HCC. The Shh signaling pathway is activated by ligands that bind to their receptor protein, Protein patched homolog (Ptch). The process of Shh ligand binding to Ptch weakens the inhibition of smoothened homolog (SMO) and activates signal transduction via glioma-associated oncogene homolog (Gli) transcription factors. The overexpression of Shh pathway molecules, including Shh, Ptch-1, Gli and SMO has been indicated in patients with HCC. It has also been suggested that the Shh signaling pathway exhibits cross-talk between numerous other signaling pathways. The inactivation of the Shh signaling pathway reduces HCC growth, increases radio-sensitivity and increases the beneficial effect of chemotherapy in HCC treatment. Therefore, inhibition of the Shh pathway may be an effective target therapy that can be used in the treatment of HCC.

Liver Transplantation After Downstagings of Ruptured Advanced Hepatocellular Carcinoma in Cirrhotic Liver: Is It Advisable? A Case Report.

Spontaneous rupture of hepatocellular carcinoma (HCC), defined as T4 in TNM stage by the American Joint Committee on Cancer (eighth edition), is a serious life-threatening complication. Effective treatment remains challenging because of a high 1-month mortality, a short median survival, and the potential of peritoneal metastasis. We reported on a case that received a living related donor liver transplantation (LDLT) after successful consecutive downstaging therapies. A 63-year-old man with alcohol-related liver cirrhosis and multiple HCC developed spontaneous rupture and hemoperitoneum. He received 3 sessions of transcatheter hepatic arterial chemoembolization and target therapy with sorafenib. Computed tomography scans and magnetic resonance imaging after 11 months of treatment showed that the patient's HCCs fulfilled the Milan criteria and the University of California San Francisco criteria prior to LDLT. The perioperative course was rather smooth. After discharge, interval follow-up computed tomography studies of chest and liver and a whole-body bone scan showed no tumor recurrence or metastasis up to 20 months post-operation. Successful downstaging therapies of ruptured HCC to fulfill Milan criteria to receive liver transplantation is advisable in highly selected patients.

Reappraisal of Failures in Downstaging Treatment of Hepatocellular Carcinoma Prior to Liver Transplant-Preliminary Report on the Impact of Underestimations of Tumor Numbers and Tumor Sizes as Measured From Imaging Before Transplant.

Downstaging treatment of hepatocellular carcinoma (HCC) prior to liver transplant (LT) is an accepted strategy to meet the Milan criteria. However, after transplant surgery, a reality is noted that the number or/and the size of some HCCs measured from the liver explants is different from that measured from the pre-LT imaging. If tumor number or tumor size measured from the liver explants was beyond that measured from pre-LT imaging, we define it as "failed downstaging." Among 27 patients who received downstaging therapies, there are 11 "number reduction failures" and 6 "size reduction failures." We attribute the discrepancy to 2 possible reasons; one is that the pre-LT imaging after downstaging could not completely detect all the HCC; the other is that the time interval between the downstaging and LT is long enough to develop new HCCs. After follow-up, 6 patients developed HCC recurrence. The significant factors affecting recurrence include tumor size from postdownstaging imaging (P = .048), tumor number ≥ 2 (P = .007), multiple sessions of downstaging (P = .03), ratio of neutrophil to lymphocyte (P = .047), and tumor number from liver explant (borderline P = .05). Tumor recurrence after LT is significantly higher in those with "size reduction failure" (P = .048). The interval between LT and tumor recurrence is significantly shorter in those with "size reduction failure" (P = .04). To decrease underestimations of HCC, combining various imaging studies including the computed tomographic scan, magnetic resonance imaging, and contrast ultrasonography is needed to increase the accuracy before LT. Repeated imaging studies at short intervals of no more than 3 months are necessary during a long wait. How to minimize the underestimations of HCC to determine the appropriate candidacy for LT is an important goal for transplantation surgeons.

Novel use of percutaneous thrombosuction to rescue the early thrombosis of the conduit vein graft after living donor liver transplantation.

A 54-year-old woman with liver cirrhosis and hepatocellular carcinoma received a living donor liver transplant. Thrombosis of the segmental hepatic vein occurred on postoperative day 7. We undertook percutaneous catheter thrombosuction under local anesthesia to extract the thrombus successfully without re-exploration. Thrombosuction has been used for thrombosis of the cardiovascular system, limbs, and brain. We first used it in hepatic venous thrombus after liver transplantation. This procedure is simple, less invasive, feasible, safe, repeatable, and effective.

Laparoscopic donor hepatectomy.

Laparoscopic liver resection has been applied to treat most indications for liver resection during the past two decades. According to the literature, patient numbers have increased exponentially as a result, and surgical difficulty has increased as well. In expert centers, laparoscopic anatomical hemihepatectomy and major liver resection more than 3 segments have become the acceptable treatment. Moreover, with surgical innovations and accumulated experience, living donor liver transplantation has become an established treatment choice for patients on the transplant waiting list. It is even considered an inevitable choice in regions with limited access to organs from deceased donors. However, significant morbidity and rare but catastrophic mortality are associated with donor hepatectomy and remain major concerns. Therefore, to decrease the incidence of complications, a minimally invasive approach in donor hepatectomy was adopted in the early 2000s. Initially, a minimally invasive approach was used for left lateral sectionectomy for pediatric liver transplant, then for laparoscopy-assisted hemihepatectomy and pure laparoscopic/robotic right donor hepatectomy, and more recently, for adult living donor liver transplantation. The extent of procedure complexity and potential complications depends on the approach and the size of the graft to be harvested. Early results from expert teams have seemed promising in terms of shortened donor recovery and improved perioperative outcomes. However, the combination of these two highly sophisticated surgical procedures raise more concerns about donor safety, especially with regard to unexpected events during the operation. A high level of evidence is very difficult to achieve in this highly specialized surgical practice with limited penetration. Therefore, an international registry has been suggested to determine the risks and benefits before the use of laparoscopic right donor hepatectomy spreads.

Glioma-Associated Oncogene Homolog Inhibitors Have the Potential of Suppressing Cancer Stem Cells of Breast Cancer.

Overexpression of Sonic Hedgehog signaling (Shh) pathway molecules is associated with invasiveness and recurrence in breast carcinoma. Therefore, inhibition of the Shh pathway downstream molecule Glioma-associated Oncogene Homolog (Gli) was investigated for its ability to reduce progression and invasiveness of patient-derived breast cancer cells and cell lines. Human primary breast cancer T2 cells with high expression of Shh signaling pathway molecules were compared with breast cancer line MDA-MB-231 cells. The therapeutic effects of Gli inhibitors were examined in terms of the cell proliferation, apoptosis, cancer stem cells, cell migration and gene expression. Blockade of the Shh signaling pathway could reduce cell proliferation and migration only in MDA-MB-231 cells. Hh pathway inhibitor-1 (HPI-1) increased the percentages of late apoptotic cells in MDA-MB-231 cells and early apoptotic cells in T2 cells. It reduced Bcl2 expression for cell proliferation and increased Bim expression for apoptosis. In addition, Gli inhibitor HPI-1 decreased significantly the percentages of cancer stem cells in T2 cells. HPI-1 worked more effectively than GANT-58 against breast carcinoma cells. In conclusion, HPI-1 could inhibit cell proliferation, reduce cell invasion and decrease cancer stem cell population in breast cancer cells. To target Gli-1 could be a potential strategy to suppress breast cancer stem cells.

Tropism of liver epithelial cells toward hepatocellular carcinoma in vitro and in vivo with altering gene expression of cancer stem cells.

BACKGROUND: Rat liver epithelial (RLE) cells could inhibit the proliferation and invasiveness of hepatoma cells in vitro. This study is to understand the tropism and the effect of RLE cells on mouse hepatoma cells both in vitro and in vivo. METHODS: RLE cells were isolated from new-born rats and characterized their stem cell markers. Co-culture and HCC mouse model was established to detect therapeutic effect of RLE cells. RESULTS: RLE cells (including Thy-1+ RLE cells, Thy-1- RLE cells, RLE cells) displayed a selective tropism toward ML-1 hepatoma cells both in vitro and in vivo. They altered the gene expression of some cancer stem cell markers in the liver tumor. CONCLUSION: Liver epithelial cells have a selective tropism toward HCC in vitro and in vivo. They could alter the gene expression of cancer stem cells.

Role of C-X-C chemokine ligand 12/C-X-C chemokine receptor 4 in the progression of hepatocellular carcinoma.

The efficacy of the current non-surgical treatments for advanced hepatocellular carcinoma (HCC) remains limited and novel treatments are required to improve patient outcomes. The majority of HCCs develop from chronically damaged tissue that contains a high degree of inflammation and fibrosis, which promotes tumor progression and resistance to therapy. Understanding the interaction between stromal components and cancer cells (and the signaling pathways involved in this interaction) could aid the identification of novel therapeutic targets. Numerous studies have demonstrated a marked association between high C-X-C chemokine receptor 4 (CXCR4) expression and the invasiveness, progression and metastasis of HCC. The present review will investigate the different roles of CXCR4 in the progression of HCC and discuss possible future treatments. Through the C-X-C chemokine ligand 12 (CXCL12)/CXCR4 signaling pathway, ephrin A1 activation enhances the migration of endothelial progenitor cells to HCC to enable the neovascularization of tumors. There is an association between nuclear CXCR4 expression and the lymph node metastasis of HCC to distant areas. CXCR4 enhances cell migration in vitro and cell homing in vivo. CXCR4 levels are concentrated at the border of a tumor and in perivascular areas, inducing invasive behavior. The binding of CXCL12 to CXCR4 activates intracellular signaling pathways and induces crosstalk with transforming growth factor-ß signaling, which enhances the migration of cancer cells. The CXCL12/CXCR4 axis also activates expression of matrix metalloproteinase 10, which further stimulates migration. CXCR4 is likely to crosstalk with the sonic hedgehog signaling pathway, contributing to tumor invasiveness and supporting the cancer stem-cell population; as a result, CXCR4 can be regarded as a cancer stem-cell marker. CXCR4 influences interstitial fluid flow-induced invasion. CXCR4 expression and HCC cell migration are promoted by α-fetoprotein, which activates AKT/mechanistic target of rapamycin signaling. CXCR4 also has the potential to affect sorafenib treatment for HCC. Targeting the CXCL12/CXCR4 signaling pathway may, therefore, be a promising strategy in HCC treatment.

Overcoming sorafenib evasion in hepatocellular carcinoma using CXCR4-targeted nanoparticles to co-deliver MEK-inhibitors.

Sorafenib is a RAF inhibitor approved for several cancers, including hepatocellular carcinoma (HCC). Inhibition of RAF kinases can induce a dose-dependent "paradoxical" upregulation of the downstream mitogen-activated protein kinase (MAPK) pathway in cancer cells. It is unknown whether "paradoxical" ERK activation occurs after sorafenib therapy in HCC, and if so, if it impacts the therapeutic efficacy. Here, we demonstrate that RAF inhibition by sorafenib rapidly leads to RAF dimerization and ERK activation in HCCs, which contributes to treatment evasion. The transactivation of RAF dimers and ERK signaling promotes HCC cell survival, prevents apoptosis via downregulation of BIM and achieves immunosuppression by MAPK/NF-kB-dependent activation of PD-L1 gene expression. To overcome treatment evasion and reduce systemic effects, we developed CXCR4-targeted nanoparticles to co-deliver sorafenib with the MEK inhibitor AZD6244 in HCC. Using this approach, we preferentially and efficiently inactivated RAF/ERK, upregulated BIM and down-regulated PD-L1 expression in HCC, and facilitated intra-tumoral infiltration of cytotoxic CD8+ T cells. These effects resulted in a profound delay in tumor growth. Thus, this nano-delivery strategy to selectively target tumors and prevent the paradoxical ERK activation could increase the feasibility of dual RAF/MEK inhibition to overcome sorafenib treatment escape in HCC.

Graft calcification caused by a torsion of the hepatic vein after a living-related donor liver transplantation.

 The torsion of vessels after liver transplantation rarely occurs. Likewise, calcification of a liver graft has seldom been reported. This report details a case which had torsion of the left hepatic vein on the seventh day after living-related donor liver transplantation. The torsion was reduced soon after re-exploration; however, congestion with partial necrosis of the graft occurred. On the follow-up imaging studies, some resolution of necrosis and graft regeneration were found, yet geographic calcification of the liver graft appeared.The patient died of pneumonia after 13 weeks, post-operation. The avoidance such torsion of vessels is necessary and important.