Rationale of personalized immunosuppressive medication for hepatocellular carcinoma patients after liver transplantation

Validation of Risk Estimation of Tumor Recurrence After Transplant Score in Patients With Hepatocellular Carcinoma Treated by Liver Transplant

OBJECTIVES

Recurrent hepatocellular carcinoma can occur after liver transplant in up to 15% of cases. Recurrent hepatocellular carcinoma is associated with a dismal prognosis and subsequently a futile liver transplant in most instances. A validated prognostic scoring system forrecurrent hepatocellular carcinoma that combines both pretransplant factors and explant characteristics has not been available until lately. The Risk Estimation of Tumor Recurrence After Transplant ("RETREAT") score was recently validated. In this study, we analyzed this score for patients treated by liver transplant at our institution.

MATERIALS AND METHODS

Between August 2006 and December 2019, 73 adult patients within Milan criteria underwentlivertransplantfor hepatocellular carcinoma at our center.

RESULTS

Follow-up ranged from 24.3 to 149.9 months with a mean of 45.98 ± 33.3 months. The overall 5-year patient survival, graft survival, and tumor-free survival rates were 78.6%, 90.1%, and 86.3%, respectively. Recurrent hepatocellular carcinoma cases exclusively occurred in patients with score of 3 or more points, with incidence increasing from 0% in those who had scores of ≤2 points to 30.8% in those who had scores of 3 to 5 points and to 66.7% in those who had >5 points (P < .001).

CONCLUSIONS

The Risk Estimation of Tumor Recurrence After Transplant ("RETREAT") score predicted the occurrence of recurrent hepatocellular carcinoma in our patients and correlated significantly with its incidence. Patients with scores of >5 points were at a very high risk for recurrent hepatocellular carcinoma and should be closely monitored using laboratory and magnetic resonance imaging.

Predictors of post-recurrence survival in hepatocellular carcinoma patients following liver transplantation: Systematic review and meta-analysis

BACKGROUND

Data on predictors of post-recurrence survival (PRS) of recurrent hepatocellular carcinoma (HCC) after liver transplantation (LT) have not been reviewed and analysed systematically. We aimed to systematically analyse all published data on the predictors for PRS.

METHODS

In accordance with PRISMA and MOOSE guidelines, online search of PubMed and EMBASE databases was done for all reports that evaluate the predictors of PRS based on multivariate analyses. Cumulative analyses of hazard ratios (HRs) and their corresponding 95% CIs were conducted to assess the potential predictors of PRS.

RESULTS

Twenty-three studies met the inclusion criteria. Among the 11,868 patients involved, 1921 (16%) had HCC recurrence within a median time of 16 months. The following were recurrence and tumour-related predictors: time to recurrence (<1 year; HR: 1.97; p < 0.001), AFP level at recurrence(≥100 ng/ml; HR: 1.82; p < 0.001), multiple recurrence (HR: 1.22; p < 0.001), bone recurrence (HR: 2.10; p < 0.001), poor differentiation (HR: 1.52; p < 0.001), intrahepatic recurrence (HR: 0.91; p = 0.03), extrahepatic recurrence (HR: 1.87; p < 0.001), Milan criteria at LT (HR: 1.34; p < 0.001), microvascular invasion (HR: 1.59; p < 0.001), multiorgan recurrence (HR: 1.28; p < 0.001), and recurrent HCV infection (HR: 1.21; p < 0.001). The treatment-related predictors were as follows: surgical resection (HR: 0.33; p < 0.001), mTOR inhibitors (HR: 0.63; p < 0.001), sorafenib (HR: 1.00; p = 0.01), palliative treatment (HR: 3.07; p < 0.001), RFA (HR: 0.47; p < 0.001), and radiotherapy (HR: 1.19; p < 0.001).

CONCLUSIONS

Systematic evaluation of these predictors could guide surgeons to design risk-adapted algorithms for the management of post-LT HCC recurrence to construct reliable predictive models and to design future prospective studies or clinical trials.

Doxorubicin hydrochloride enhanced antitumour effect of CEA-regulated oncolytic virotherapy in live cancer cells and a mouse model

Oncolytic adenovirus (OA) has attracted increasing attention due to their specific proliferation in tumour cells and resulting in lysis of tumour cells. To further improve the antitumour effect of OA, in this study, we combined CD55-TRAIL-IETD-MnSOD (CD55-TMn), a CEA-controlled OA constructed previously, and chemotherapy to investigate their synergistic effect and possible mechanisms. MTT assay was performed to detect antitumour effects. Hoechst 33 342 and flow cytometric analysis were used to examine cell apoptosis. Western blotting was performed to examine cell pyroptosis and apoptosis mechanism. Animal experiment was used to detect antitumour effect of doxorubicin hydrochloride (Dox) combined with CD55-TMn in vivo. We firstly found that Dox promotes gene expression mediated by CEA-regulated OA and virus progeny replication by activating phosphorylation of Smad3, and Dox can enhance antitumour effect of CEA-regulated CD55-TMn by promoting cell apotopsis and cell pyroptosis. Thus, our results provide an experimental and theoretical basis on tumour therapy by combination treatment of the oncolytic virotherapy and chemotherapy and it is expected to become a novel strategy for liver cancer therapy.

Sirolimus and MMF are insufficient immunosuppressants for regulation of the proliferation of CD133+EpCAM+ cell populations in HCC cell lines

Studies on effective immunosuppressive strategies for the management of patients undergoing a liver transplantation (LT) due to hepatocellular carcinoma (HCC) are limited. In the present study, immunosuppressive candidates predicted to exhibit beneficial immunosuppressive and tumor-suppressive effects in patients with HCC were assessed using Huh7 and HEP3B HCC cells, which have high proportions of CD133+EpCAM+ cancer stem cell (CSC) populations. The immunosuppressants assessed were sirolimus, tacrolimus, cyclosporine A and mycophenolate mofetil (MMF), and their activities were assessed on CSCs. Sirolimus and MMF reduced the proliferation of Huh7 and HEP3B cells; however, the proportion of CD133+EpCAM+ was notably increased in treated Huh7 cells. Sirolimus treatment alone resulted in G0-G1 cell cycle arrest at all doses in all Huh7 and CD133-EpCAM- populations; however, CD133+EpCAM+ populations showed only slight G1 arrest at higher doses only. In contrast, S-phase arrest was induced at all doses in the Huh7, CD133-EpCAM- and CD133+EpCAM+ populations by MMF. Sirolimus and MMF effectively reduced the proliferation of Huh7 and HEP3B cells, but did not exert a notable effect on the CD133+EpCAM+ cells. Therefore, therapeutic strategies utilizing Sirolimus and MMF should be further studied in vivo for regulation of CSC populations in order to reduce HCC recurrence rates.

Suppression of Hepatocellular Carcinoma by Mycophenolic Acid in Experimental Models and in Patients

BACKGROUND

Tumor recurrence is a major complication following liver transplantation (LT) as treatment for hepatocellular carcinoma (HCC). Immunosuppression is an important risk factor for HCC recurrence, but conceivably may depend on the type of immunosuppressive medication. Mycophenolic acid (MPA) is a currently widely used immunosuppressant. This study investigated the effects of MPA on HCC.

METHODS

Three human HCC cell lines and organoids from mouse primary liver tumor were used as experimental models. MTT, Alamar Blue assay, cell cycle analysis, colony formation, and [3H]-thymidine assays were performed. An LT database was used for retrospective analysis of the effect of mycophenolate mofetil, the prodrug of MPA, on HCC recurrence.

RESULTS

With clinically achievable concentrations, MPA effectively inhibited HCC cell proliferation and single-cell colony-forming unit. In short-term experiments, MPA effectively elicited S phase arrest in HCC cell lines. In addition, the initiation and growth of liver tumor organoids were effectively inhibited by MPA. Most importantly, the use of mycophenolate mofetil in patients with HCC-related LT was significantly associated with less tumor recurrence and improved patient survival.

CONCLUSIONS

MPA can specifically counteract HCC growth in vitro and tumor recurrence in LT patients. These results warrant prospective clinical trials into the role of MPA-mediated immunosuppression following LT of patients with HCC.

The interleukin-17 G-197A polymorphism is associated with cyclosporine metabolism and transplant rejection in liver transplant recipients

Aim: This study aimed to investigate the effect of and mechanism involved in the IL-17 SNP on cyclosporine metabolism and outcomes of liver transplantation (LT). Materials & methods: The IL-17 genotype, IL-17 expression, postoperative outcome and cyclosporine concentration were reviewed in 106 LT recipients. The functional relevance of rs2275913 was evaluated by luciferase assay. Furthermore, L02 cells were treated with IL-17 recombinant protein or/and pregnane X receptor (PXR) knockdown lentiviruses, then the expression of PXR, CYP3A4, CYP3A5 and IL-17R were detected by PCR and western blotting. Result: The significant distribution difference at IL-17 locus G-197A was confirmed between patients with and without rejection (p = 0.035). Patients with acute rejection showed higher IL-17 level than those without rejection. Cyclosporine concentration was associated with the different IL-17 genotype (p < 0.05). Luciferase assay revealed that 197G genotype had higher luciferase activity than that in 197A genotype (p = 0.009). Furthermore, IL-17 recombinant protein remarkably promoted the expressions of PXR, CYP3A4 and CYP3A5 (p < 0.01), but not IL-17R. PXR knockdown significantly inhibited the mRNA levels of CYP3A4 and CYP3A5 but not IL-17R (p < 0.01), while IL-17 recombinant protein had no influence on the expressions of CYP3A4 and CYP3A5 when PXR was downregulated. Conclusion: This study revealed the possible association of IL-17 G-197A with cyclosporine metabolism and transplant rejection after LT, which might be partly related to the upregulations of CYP3A4/5 dependent on PXR.

The therapeutic effects of nicotinamide in hepatocellular carcinoma through blocking IGF-1 and effecting the balance between Nrf2 and PKB

Insulin growth factor (IGF) family and their receptors play a great role in tumors' development. In addition, IGF-1 enhances cancer progression through regulating cell proliferation, angiogenesis, immune modulation and metastasis. Moreover, nicotinamide is association with protection against cancer. Therefore, we conducted this research to examine the therapeutic effects of nicotinamide against hepatocellular carcinoma (HCC) both in vivo and in vitro through affecting IGF-1 and the balance between PKB and Nrf2. HCC was induced in rats by 200 mg/kg, ip thioacetamide. The rat survival, number and size of tumors and serum α-fetoprotein (AFP) were measured. The gene and protein levels of IGF-1, Nrf2, PKB and JNK-MAPK were assessed in rat livers. In addition, HepG2 cells, human HCC cell lines, were treated with different concentrations of nicotinamide. We found that nicotinamide enhanced the rats' survival and reduced the number and size of hepatic tumors as well as it reduced serum AFP and HepG2 cells survival. Nicotinamide ameliorated HCC-induced reduction in the expression of Nrf2. Moreover, nicotinamide blocked HCC-induced elevation in IGF-1, PKB and JNK-MAPK. In conclusion, nicotinamide produced cytotoxic effects against HCC both in vivo and in vitro. The cytotoxic activity can be explained by inhibition of HCC-induced increased in the expression of IGF-1 and leads to disturbances in the balance between the cell death signal by PKB and MAPK; and the cell survival signal by Nrf2, directing it towards cell survival signals in normal liver cells providing more protection for body against tumor.

Clinical use of an immune monitoring panel in liver transplant recipients: A prospective, observational study

Immunosuppressive therapy greatly contributed to making liver transplantation the standard treatment for end-stage liver diseases. However, it remains difficult to predict and measure the efficacy of pharmacological immunosuppression. Therefore, we used a panel of standardized, commonly available, biomarkers with the aim to describe their changes in the first 3 weeks after the transplant procedure and assess if they may help therapeutic drug monitoring in better tailoring the dose of the immunosuppressive drugs. We prospectively studied 72 consecutive patients from the day of liver transplant (post-operative day #0) until the post-operative day #21. Leukocytes, neutrophils, lymphocytes (CD4+, CD8+), natural killer cells, monocytes, immunoglobulins and tacrolimus serum levels were measured on peripheral blood (at day 0, 3, 7, 14, 21 after surgery). Patients who developed infections showed significantly higher CD64+ monocytes on post operative day #7. IgG levels were lower on post operative day #3 among patients who later developed infections. We also found that a sharp decrease in IgA from post operative day #0 to 3 (-226 mg/dL in the ROC curve analysis) strongly correlates with the onset of infections among HCV- patients. No specific markers of rejection emerged from the tested panel of markers. Our results show that some early changes in peripheral blood white cells and immunoglobulins may predict the onset of infections and may be useful in modulating the immunosuppressive therapy. However, a panel of commonly available, standardized biomarkers do not support in improving therapeutic drug monitoring ability to individualize immunosuppressive drugs dosing.

Vitamin D potentiates anti-tumor activity of 5-fluorouracil via modulating caspase-3 and TGF-β1 expression in hepatocellular carcinoma-induced in rats

We investigated the role of vitamin D (Vit D) alone and in combination with 5-fluorouracil (5-FU) in thioacetamide (TAA)-induced hepatocellular carcinoma (HCC) in rats. Fifty male Sprague-Dawley rats were randomized into a control group and 4 groups that received TAA (200 mg/kg, i.p.) twice per week for 16 weeks. These 4 groups were further divided as follows: HCC group; 5-FU group (75 mg/kg, i.p., once weekly for 3 weeks starting from the 12th week); Vit D group (200 IU/kg daily by oral tube for 16 weeks); and 5-FU + Vit D group (received the previously mentioned dosage regimens of 5-FU and Vit D). HCC was detected by histopathological changes in liver sections and the elevation of serum α-fetoprotein (AFP). Treatment with 5-FU + Vit D significantly decreased gene expression of nuclear factor erythroid 2-related factor 2 (NrF2) and transforming growth factor β1 (TGF-β1) at both the gene and protein level and serum AFP concentrations in comparison with their corresponding monotherapy. Moreover, 5-FU + Vit D treatment enhanced apoptosis by increasing caspase-3 gene and protein expression. Conclusively, Vit D enhances antitumor activity of 5-FU in an HCC-induced model and improves liver function of treated animals. Combination therapy in a TAA-induced HCC rat model was more effective than 5-FU or Vit D through the modulation of TGF-β1, caspase-3, and NrF2 expressions.

Validation of a Risk Estimation of Tumor Recurrence After Transplant (RETREAT) Score for Hepatocellular Carcinoma Recurrence After Liver Transplant

Importance

Several factors are associated with increased hepatocellular carcinoma (HCC) recurrence after liver transplantation (LT), but no reliable risk score has been established to determine the individual risk for HCC recurrence.

Objective

We aimed to develop and validate a Risk Estimation of Tumor Recurrence After Transplant (RETREAT) score for patients with HCC meeting Milan criteria by imaging.

Design, Setting, and Participants

Predictors of recurrence were tested in a development cohort of 721 patients who underwent LT between 2002 and 2012 at 3 academic transplant centers (University of California-San Francisco; Mayo Clinic, Rochester; and Mayo Clinic, Jacksonville) to create the RETREAT score. This was subsequently validated in a cohort of 341 patients also meeting Milan criteria by imaging who underwent LT at the University of Toronto transplant center using the C concordance statistic and net reclassification index.

Main Outcomes and Measures

Characteristics associated with post-LT HCC recurrence.

Results

A total of 1061 patients participated in the study; 77.8% (825) were men, and the median (IQR) age was 58.2 (53.3-63.9) years in the development cohort and 56.4 (51.7-61.0) years in the validation cohort (P < .001). In the development cohort of 721 patients (542 men), median α-fetoprotein (AFP) level at the time of LT was 8.3 ng/mL; 9.4% had microvascular invasion (n = 68), and 22.1% were beyond Milan criteria on explant (n = 159) owing to understaging by pretransplantation imaging. Cumulative probabilities of HCC recurrence at 1 and 5 years were 5.7% and 12.8%, respectively. On multivariable Cox proportional hazards regression, 3 variables were independently associated with HCC recurrence: microvascular invasion, AFP at time of LT, and the sum of the largest viable tumor diameter and number of viable tumors on explant. The RETREAT score was created using these 3 variables, with scores ranging from 0 to 5 or higher that were highly predictive of HCC recurrence (C statistic, 0.77). RETREAT was able to stratify 5-year post-LT recurrence risk ranging from less than 3% with a score of 0 to greater than 75% with a score of 5 or higher. The validation cohort (n = 340; 283 men) had significantly higher microvascular invasion (23.8% [n = 81], P < .001), explant beyond Milan criteria (37.3% [n = 159], P < .001), and HCC recurrence at 5 years (17.9% [n = 159], P = .03). RETREAT showed good model discrimination (C statistic, 0.82; 95% CI, 0.77-0.86) and superior recurrence risk classification compared with explant Milan criteria (net reclassification index, 0.40; P = .001) in the validation cohort.

Conclusions and Relevance

We have developed and validated a simple and novel prognostic score that may improve post-LT HCC surveillance strategies and help identify patients who may benefit from future adjuvant therapies.

GP73-regulated oncolytic adenoviruses possess potent killing effect on human liver cancer stem-like cells

Cancer stem cells (CSCs), also known as tumor-initiating cells, are highly metastatic, chemo-resistant and tumorigenic, and are critical for cancer development, maintenance and recurrence. Oncolytic adenovirus could targetedly kill CSCs and has been acted as a promising anticancer agent. Currently, a novel GP73-regulated oncolytic adenovirus GD55 was constructed to specifically treat liver cancer and exhibited obvious cytotoxicity effect. However, there remains to be confirmed that whether GD55 could effectively eliminate liver CSCs. We first utilized the suspension culture to enrich the liver CSCs-like cells, which acquires the properties of liver CSCs in self-renewal, differentiation, quiescence, chemo-resistance and tumorigenicity. The results indicated that GD55 elicited more significant cytotoxicity and stronger oncolytic effect in liver CSC-like cells compared to common oncolytic virus ZD55. Additionally, GD55 possessed the greater efficacy in suppressing the growth of implanted tumors derived from liver CSC-like cells than ZD55. Furthermore, GD55 induced remarkable apoptosis of liver CSC-like cells in vitro and in vivo, and inhibited the propogation of cells and angiogenesis in xenograft tumor tissues. Thus, GD55 may virtually represent an attractive therapeutic agent for targeting liver CSCs to achieve better clinical outcomes for HCC patients.

Optimization of immunosuppressive medication upon liver transplantation against HCC recurrence

The introduction of liver transplant listing criteria for hepatocellular cancer (HCC) has significantly improved oncological outcomes and survival. But despite this HCC recurrence is still problematic. There is emerging evidence that the choice of immunosuppression (IS) after transplant for HCC can influence oncological survival and HCC recurrence. The following is a short summary of what has been published on HCC recurrence with the different classes of immunosuppressive agents in present use, concluding with the possible rationalization of the use of these immunosuppressive agents in the post-transplant patient at high risk of recurrence.

Hepatocellular carcinoma: A comprehensive review

Hepatocellular carcinoma (HCC) is rapidly becoming one of the most prevalent cancers worldwide. With a rising rate, it is a prominent source of mortality. Patients with advanced fibrosis, predominantly cirrhosis and hepatitis B are predisposed to developing HCC. Individuals with chronic hepatitis B and C infections are most commonly afflicted. Different therapeutic options, including liver resection, transplantation, systemic and local therapy, must be tailored to each patient. Liver transplantation offers leading results to achieve a cure. The Milan criteria is acknowledged as the model to classify the individuals that meet requirements to undergo transplantation. Mean survival remains suboptimal because of long waiting times and limited donor organ resources. Recent debates involve expansion of these criteria to create options for patients with HCC to increase overall survival.

Differential Sensitivities of Fast- and Slow-Cycling Cancer Cells to Inosine Monophosphate Dehydrogenase 2 Inhibition by Mycophenolic Acid

As uncontrolled cell proliferation requires nucleotide biosynthesis, inhibiting enzymes that mediate nucleotide biosynthesis constitutes a rational approach to the management of oncological diseases. In practice, however, results of this strategy are mixed and thus elucidation of the mechanisms by which cancer cells evade the effect of nucleotide biosynthesis restriction is urgently needed. Here we explored the notion that intrinsic differences in cancer cell cycle velocity are important in the resistance toward inhibition of inosine monophosphate dehydrogenase (IMPDH) by mycophenolic acid (MPA). In short-term experiments, MPA treatment of fast-growing cancer cells effectively elicited G0/G1 arrest and provoked apoptosis, thus inhibiting cell proliferation and colony formation. Forced expression of a mutated IMPDH2, lacking a binding site for MPA but retaining enzymatic activity, resulted in complete resistance of cancer cells to MPA. In nude mice subcutaneously engrafted with HeLa cells, MPA moderately delayed tumor formation by inhibiting cell proliferation and inducing apoptosis. Importantly, we developed a lentiviral vector-based Tet-on label-retaining system that enables to identify, isolate and functionally characterize slow-cycling or so-called label-retaining cells (LRCs) in vitro and in vivo. We surprisingly found the presence of LRCs in fast-growing tumors. LRCs were superior in colony formation, tumor initiation and resistance to MPA as compared with fast-cycling cells. Thus, the slow-cycling compartment of cancer seems predominantly responsible for resistance to MPA.

Chronic hepatitis E in solid-organ transplantation: the key implications of immunosuppressants

PURPOSE OF REVIEW

Solid-organ recipients infected with hepatitis E virus (HEV) bear an extremely high risk of developing chronic hepatitis, although this virus only causes acute infection in the general population. Immunosuppressive medication universally used after transplantation to prevent organ rejection appears to be a main risk factor for developing chronic infection. This review aims to overview and emphasize the current clinical and experimental evidence regarding the key implications of immunosuppressants in chronic hepatitis E.

RECENT FINDINGS

Over 60% of organ recipients who are infected with HEV develop chronic hepatitis. Immunosuppressant treatment after transplantation was identified as a key risk factor. Therefore, dose reduction or even withdrawal of immunosuppressants is considered as the first intervention strategy to achieve viral clearance in these patients. Otherwise, ribavirin, as an off-label medication, is considered as an antiviral treatment, with compelling outcomes observed so far. Interestingly, in addition to a common immunosuppression property that can favour HEV infection in general, different types of immunosuppressants may exert differential impacts on the infection course in patients. Furthermore, potential interaction may exist between particular immunosuppressant and ribavirin. With the recent development of a cell culture system for HEV, experimental research has been initiated to investigate how immunosuppressive drugs interact with HEV infection.

SUMMARY

On the basis of the current evidence, it remains impossible to define an optimal immunosuppressive protocol for these HEV-infected patients. However, the realization of this clinical issue and the initiation of translational research using cell culture models of HEV have been represented as milestones in this field.

Review on immunosuppression in liver transplantation

The optimal level of immunosuppression in solid organ transplantation, in particular for the liver, is a delicate balance between the benefit of preventing rejection and the adverse side effects of immunosuppression. There is uncertainty about when this level is achieved in any individual recipient. Immunosuppression regimens vary between individual centers and changes with time as new agents and data are available. Presently concerns about the adverse side effects of calcineurin inhibitor, the main class of immunosuppressive agents used in liver transplantation (LT), has led to consideration of the use of antibody induction therapies for patients at higher risk of developing adverse side effects. The longevity of the transplanted organ is potentially improved by better management of rejection episodes and special consideration for tailoring of immunosuppression to the individual with viral hepatitis C, hepatocellular carcinoma or pregnancy. This review provides an overview of the current strategies for post LT immunosuppression and discusses modifications to consider for special patient populations.

Anti-tumor effects of metformin in animal models of hepatocellular carcinoma: a systematic review and meta-analysis

BACKGROUND

Several studies have reported that metformin can reduce the risk of hepatocellular carcinoma (HCC) in diabetes patients. However, the direct anti-HCC effects of metformin have hardly been studied in patients, but have been extensively investigated in animal models of HCC. We therefore performed a systematic review and meta-analysis of animal studies evaluating the effects of metformin on HCC.

METHODS

We collected the relevant studies by searching EMBASE, Medline (OvidSP), Web of Science, Scopus, PubMed Publisher, and Google Scholar. Studies were included according to the following inclusion criteria: HCC, animal study, and metformin intervention. Study quality was assessed using SYRCLE's risk of bias tool. A meta-analysis was performed for the outcome measures: tumor growth (tumor volume, weight and size), tumor number and incidence.

RESULTS

The search resulted in 573 references, of which 13 could be included in the review and 12 included in the meta-analysis. The study characteristics of the included studies varied considerably. Two studies used rats, while the others used mice. Only one study used female animals, nine used male, and three studies didn't mention the gender of animals in their experiments. The quality of the included studies was low to moderate based on the assessment of their risk of bias. The meta-analysis showed that metformin significantly inhibited the growth of HCC tumour (SMD -2.20[-2.96,-1.43]; n=16), but no significant effect on the number of tumors (SMD-1.05[-2.13,0.03]; n=5) or the incidence of HCC was observed (RR 0.62[0.33,1.16]; n=6). To investigate the potential sources of significant heterogeneities found in outcome of tumor growth (I2=81%), subgroup analyses of scales of growth measures and of types of animal models used were performed.

CONCLUSION

Metformin appears to have a direct anti-HCC effect in animal models. Although the intrinsic limitations of animal studies, this systematic review could provide an important reference for future preclinical animal trials of good quality and clinical development.

Hepatoprotective and anti-tumor effects of targeting MMP-9 in hepatocellular carcinoma and its relation to vascular invasion markers

The current study aims to evaluate the hepatoprotective and antitumor efficacy of doxycycline, as an matrix metalloproteases-9 (MMP-9) inhibitor, in an in vivo model of hepatocellular carcinoma (HCC). HCC was induced experimentally by thiocetamide (200 mg/kg) in rats that were treated with doxycycline (5 mg/kg for 16 weeks). Tumor severity was evaluated by measuring α-fetoprotein (AFP) levels, histopathologically by investigating liver sections stained with hematoxylin/eosin and assessing the survival rate. Liver homogenates were used for the measurements of MMP-9, fascin and hepatic heparan sulfate proteoglycan (HSPG) levels. Oxidative stress markers [malonaldehyde (MDA) and glutathione] as well as fibroblast growth factor-2 (FGF-2) gene expression were also among the assessed indicators. HCC in human and animal samples showed significant elevation in the levels of MMP-9 (231.7, 90 %), fascin (33.17, 140 %), as well as FGF-2 gene expression (342 % in animal samples; all respectively), associated with a significant decrease in hepatic HSPG level. Treatment of rats with doxycycline increased the animal survival rate (90 %) and decreased serum AFP level. Moreover, doxycycline ameliorated fibrosis and the induced massive hepatic tissue breakdown. It also restored the integrity of hepatic HSPGs and showed a magnificent inhibitory effect of tumor invasion cascade by significantly reducing the activities of MMP-9 (42 %) and fascin (50 %), as well as reducing the gene expression of FGF-2 (85.7 %). Furthermore, the antioxidant impact of doxycycline was evidenced by the significant elevation in glutathione level and depressing MDA level. To this end, doxycycline, proved promising hepatoprotective and antitumor activity and opens, thereby, a new horizon against vascular migration ability of the tumor cells.

Strategies to improve outcome of patients with hepatocellular carcinoma receiving a liver transplantation

Liver transplantation is the only therapeutic option which allows to treat both, the hepatocellular carcinoma and the underlying liver disease. Indeed, liver transplantation is considered the standard of care for a subset of patients with cirrhosis and hepatocellular carcinoma. However, tumour recurrence rates are as high as 20%, and once the recurrence is established the therapeutic options are scarce and with little impact on prognosis. Strategies to minimize tumour recurrence and thus to improve outcome may be classified into 3 groups: (1) An adequate selection of candidates for liver transplantation by using the Milan criteria; (2) An optimized management within waiting list including prioritization of patients at high risk of tumour progression, and the implementation of bridging therapies, particularly when the expected length within the waiting list is longer than 6 mo; and (3) Tailored immunosuppression comprising reduced exposure to calcineurin inhibitors, particularly early after liver transplantation, and the addition of mammalian target of rapamycin inhibitors. In the present manuscript the available scientific evidence supporting these strategies is comprehensively reviewed, and future directions are provided for novel research approaches, which may contribute to the final target: to cure more patients with hepatocellular carcinoma and with an improved long term outcome.

Multipotent mesenchymal stromal cells in liver cancer: implications for tumor biology and therapy

Remodeling of tumor microenvironment is a hallmark in the pathogenesis of liver cancer. Being a pivotal part of tumor stroma, multipotent mesenchymal stromal cells (MSCs), also known as mesenchymal stem cells (MSCs), are recruited and enriched in liver tumors. Owing to their tumor tropism, MSCs are now emerging as vehicles for anticancer drug/gene delivery against liver cancer. However, the exact impact of MSCs on liver cancer remains elusive, as a variety of effects of these cells that have been reported included a plethora of tumor-promoting effects and anti-oncogenic properties. This review aims to dissect the mechanistic insight regarding this observed discrepancy in different experimental settings of liver cancer. Furthermore, we call for caution using MSCs to treat liver cancer or even premalignant liver diseases, before conclusive evidence for safety and efficacy having been obtained.

Cutaneous Metastases from Primary Hepatobiliary Tumors as the First Sign of Tumor Recurrence following Liver Transplantation

Cutaneous metastasis from hepatobiliary tumors is a rare event, especially following liver transplantation. We report our experience with two cases of cutaneous metastases from both hepatocellular carcinoma and mixed hepatocellular/cholangiocarcinoma following liver transplantation, along with a review of the literature.