A Switch in the Dynamics of Intra-Platelet VEGF-A from Cancer to the Later Phase of Liver Regeneration after Partial Hepatectomy in Humans

Predicting liver regeneration following major resection

Breakdown of synthesis, excretion and detoxification defines liver failure. Post-hepatectomy liver failure (PHLF) is specific for liver resection and a rightfully feared complication due to high lethality and limited therapeutic success. Individual cytokine and growth factor profiles may represent potent predictive markers for recovery of liver function. We aimed to investigate these profiles in post-hepatectomy regeneration. This study combined a time-dependent cytokine and growth factor profiling dataset of a training (30 patients) and a validation (14 patients) cohorts undergoing major liver resection with statistical and predictive models identifying individual pathway signatures. 2319 associations were tested. Primary hepatocytes isolated from patient tissue samples were stimulated and their proliferation was analysed through DNA content assay. Common expression trajectories of cytokines and growth factors with strong correlation to PHLF, morbidity and mortality were identified despite highly individual perioperative dynamics. Especially, dynamics of EGF, HGF, and PLGF were associated with mortality. PLGF was additionally associated with PHLF and complications. A global association-network was calculated and validated to investigate interdependence of cytokines and growth factors with clinical attributes. Preoperative cytokine and growth factor signatures were identified allowing prediction of mortality following major liver resection by regression modelling. Proliferation analysis of corresponding primary human hepatocytes showed associations of individual regenerative potential with clinical outcome. Prediction of PHLF was possible on as early as first postoperative day (POD1) with AUC above 0.75. Prediction of PHLF and mortality is possible on POD1 with liquid-biopsy based risk profiling. Further utilization of these models would allow tailoring of interventional strategies according to individual profiles.

Influence of cytokines, circulating markers and growth factors on liver regeneration and post-hepatectomy liver failure: a systematic review and meta-analysis

The pathophysiology of post-hepatectomy liver failure is not entirely understood but is rooted in the disruption of normal hepatocyte regeneration and homeostasis. Current investigations of post-hepatectomy liver failure and regeneration are focused on evaluation of circulating hepatic function parameters (transaminases, cholestasis, and coagulation parameters), volumetry and hepatic hemodynamics. However, identification of biochemical factors associated with regeneration and post hepatectomy liver failure is crucial for understanding the pathophysiology and identification of patients at risk. The objective of the present systematic review was to identify circulating factors associated with liver regeneration and post hepatectomy liver failure in patients undergoing hepatectomy. The quantitative analysis was intended if studies provided sufficient data. Electronic databases (MEDLINE via PubMed, Web of Knowledge, Cochrane Library and WHO International Clinical Trials Registry Platform) were searched for publications on cell signaling factors in liver regeneration and post-hepatectomy liver failure following liver resection in clinical setting. No date restriction was given. No language restriction was used. Studies were assessed using MINORS. This study was registered at PROSPERO (CRD42020165384) prior to data extraction. In total 1953 publications were evaluated for titles and abstracts after exclusion of duplicates. Full texts of 167 studies were further evaluated for inclusion. 26 articles were included in the review and 6 publications were included in the meta-analyses. High levels of serum hyaluronic acid even preoperatively are associated with PHLF but especially increased levels early after resection are predictive of PHLF with high sensitivity and specificity. Postoperative elevation of HA to levels between 100 and 500 ng/ml is increased the risk for PHLF ([OR] = 246.28, 95% [CI]: 11.82 to 5131.83; p = 0.0004) Inteleukin-6 levels show contradicting result in association with organ dysfunction. HGF positively correlates with liver regeneration. Overall, due to heterogeneity, scarcity, observational study design and largely retrospective analysis, the certainty of evidence, assessed with GRADE, is very low. High levels of serum hyaluronic acid show a strong association with PHLF and increased levels after resection are predictive of PHLF with high sensitivity and specificity, even on POD1. Interleukin-6 levels need to be studied further due to contradictive results in association with organ dysfunction. For HGF, no quantitative analysis could be made. Yet, most studies find positive correlation between high HGF levels and regeneration. Prospective studies investigating HGF and other growth factors, hyaluronic acid and interleukins 1 and 6 in correlation with liver regeneration measured sequentially through e.g. volumetry, and liver function parameters, preferably expanding the analysis to include dynamic liver function tests, are needed to sufficiently illustrate the connection between biomolecule levels and clinical outcomes.

Evaluation of VEGF-A in platelet and microRNA-126 in serum after coronary artery bypass grafting

Platelet functions are thought to contribute to clinical outcomes after heart surgery. This study was conducted to assess the pivotal roles of vascular endothelial growth factor-A (VEGF-A) and microRNA-126 (miR-126) during coronary artery bypass grafting (CABG). Whole blood was collected for platelet isolation from 67 patients who underwent CABG surgery between July 2013 and March 2014. VEGF-A and miR-126 levels in serum, plasma, and platelets were measured at various time points and compared with clinical characteristics. The platelet count was decreased at 3 days after CABG. This dynamic change in platelet count was larger after conventional coronary artery bypass (CCAB) than off-pump coronary artery bypass (OPCAB). VEGF-A in the same number of platelets (IP-VEGF-A) was increased at 3 days after CABG, followed by an increase of VEGF-A in serum (S-VEGF-A) at 7 days after surgery. The miR-126-3p level in serum (S-miR-126-3p) increased rapidly after CABG and then decreased below preoperative levels. The IP-VEGF-A level on day 7 after CABG in patients with peripheral artery disease (PAD), who suffered from endothelial dysfunction, was higher compared with patients without PAD. Conversely, S-miR-126-3p on day 7 after surgery was lower in patients with PAD than in patients without PAD. Low levels of S-miR-126-3p due to endothelial dysfunction may lead to high IP-VEGF-A, which is closely related to complications after CABG.

Bivalent property of intra-platelet VWF in liver regeneration and HCC recurrence: A prospective multicenter study

BACKGROUND AND AIMS

A striking difference has been observed in structure and functional properties between plasma and platelet von Willebrand factor (VWF). While the existing evidence has revealed a clinical relevance of plasma VWF-Ag in liver regeneration (LR) and different cancers, this study was designed to explore the properties of intra-platelet (IP) and serum VWF-Ag in patients with hepatocellular carcinoma (HCC) undergoing partial hepatectomy.

METHODS

A total of 40 patients undergoing partial hepatectomy were prospectively recruited from 3 institutions. VWF-Ag concentrations were evaluated mainly in serum and platelet extracts. Patients were followed-up for postoperative liver dysfunction and HCC recurrence.

RESULTS

We observed a post-resection increase in the concentration of VWF-Ag in serum and platelet. Patients with postoperative liver dysfunction had substantially reduced serum and IP VWF-Ag concentrations. After a 2-year follow-up, patients with higher post-resection serum and IP VWF-Ag concentrations were found to develop early HCC recurrence. Likewise, IP VWF-Ag was able to independently predict post-resection early HCC recurrence.

CONCLUSION

This multicenter, prospective, pilot study demonstrates a bivalent property of IP VWF in LR and oncological outcome; low preoperative VWF appeared to have a negative association on post-resection liver dysfunction, whereas, patients with higher post-resection VWF-Ag concentrations were found to have early HCC recurrence.

Markers of liver regeneration-the role of growth factors and cytokines: a systematic review

BACKGROUND

Post-hepatectomy liver failure contributes significantly to postoperative mortality after liver resection. The prediction of the individual risk for liver failure is challenging. This review aimed to provide an overview of cytokine and growth factor triggered signaling pathways involved in liver regeneration after resection.

METHODS

MEDLINE and Cochrane databases were searched without language restrictions for articles from the time of inception of the databases till March 2019. All studies with comparative data on the effect of cytokines and growth factors on liver regeneration in animals and humans were included.

RESULTS

Overall 3.353 articles comprising 40 studies involving 1.498 patients and 101 animal studies were identified and met the inclusion criteria. All included trials on humans were retrospective cohort/observational studies. There was substantial heterogeneity across all included studies with respect to the analyzed cytokines and growth factors and the described endpoints.

CONCLUSION

High-level evidence on serial measurements of growth factors and cytokines in blood samples used to predict liver regeneration after resection is still lacking. To address the heterogeneity of patients and potential markers, high throughput serial analyses may offer a method to predict an individual's regenerative potential in the future.

Platelets and Hepatocellular Cancer: Bridging the Bench to the Clinics

Growing interest is recently being focused on the role played by the platelets in favoring hepatocellular cancer (HCC) growth and dissemination. The present review reports in detail both the experimental and clinical evidence published on this topic. Several growth factors and angiogenic molecules specifically secreted by platelets are directly connected with tumor progression and neo-angiogenesis. Among them, we can list the platelet-derived growth factor, the vascular endothelial growth factor, the endothelial growth factor, and serotonin. Platelets are also involved in tumor spread, favoring endothelium permeabilization and tumor cells’ extravasation and survival in the bloodstream. From the bench to the clinics, all of these aspects were also investigated in clinical series, showing an evident correlation between platelet count and size of HCC, tumor biological behavior, metastatic spread, and overall survival rates. Moreover, a better understanding of the mechanisms involved in the platelet–tumor axis represents a paramount aspect for optimizing both current tumor treatment and development of new therapeutic strategies against HCC.

Relevance of VEGFA in rat livers subjected to partial hepatectomy under ischemia-reperfusion

Abstract

We examined the effects of VEGFA on damage and regeneration in steatotic and non-steatotic livers of rats submitted to PH under I/R, and characterized the underlying mechanisms involved. Our results indicated that VEGFA levels were decreased in both steatotic and non-steatotic livers after surgery. The administration of VEGFA increased VEGFA levels in non-steatotic livers, reducing the incidence of post-operative complications following surgery through the VEGFR2-Wnt2 pathway, independently of Id1. Unexpectedly, administration of VEGFA notably reduced VEGFA levels in steatotic livers, exacerbating damage and regenerative failure. After exogenous administration of VEGFA in steatotic animals, circulating VEGFA is sequestered by the high circulating levels of sFlt1 released from adipose tissue. Under such conditions, VEGFA cannot reach the steatotic liver to exert its effects. Consequently, the concomitant administration of VEGFA and an antibody against sFlt1 was required to avoid binding of sFlt1 to VEGFA. This was associated with high VEGFA levels in steatotic livers and protection against damage and regenerative failure, plus improvement in the survival rate via up-regulation of PI3K/Akt independently of the Id1-Wnt2 pathway. The current study highlights the different effects and signaling pathways of VEGFA in liver surgery requiring PH and I/R based in the presence of steatosis.

Key messages

VEGFA administration improves PH+I/R injury only in non-steatotic livers of Ln animals.

VEGFA benefits are exerted through the VEGFR2-Wnt2 pathway in non-steatotic livers.

In Ob rats, exogenous VEGFA is sequestered by circulating sFlt1, exacerbating liver damage.

Therapeutic combination of VEGFA and anti-sFlt1 is required to protect steatotic livers.

VEGFA+anti-sFlt1 treatment protects steatotic livers through a VEGFR2-PI3K/Akt pathway.

Electronic supplementary material

The online version of this article (10.1007/s00109-019-01811-y) contains supplementary material, which is available to authorized users.

Predictive Value of Diminished Serum PDGF-BB after Curative Resection of Hepatocellular Cancer

Purpose

Platelet derived growth factor-BB (PDGF-BB) has emerged as one of the key cytokines in malignant transformation of different cells. PDGF-BB also exhibits a potent mitogenic effect on liver cells; studies have advocated clinical implications of monitoring serum PDGF-BB (sPDGF-BB) in patients with liver disease. We thus investigated the predictive relevance of perioperative sPDGF-BB after curative resection of hepatocellular carcinoma (HCC).

Methods

We evaluated perioperative sPDGF-BB in a prospective homogenous cohort of 40 patients diagnosed with HCC. During the first two-year follow-up, patients were evaluated every three months for postresection HCC recurrence.

Results

Patients who developed recurrence during two-year follow-up were found to have lower concentration of sPDGF-BB than those without recurrence in both pre- and postoperative settings (P < 0.05 and P < 0.001, resp.). We validated that the reduced postoperative sPDGF-BB (< 2133.29 pg/mL) was associated with an increased incidence of postresection HCC recurrence [area under curve (AUC) > 0.8, 95% confidence interval (CI) = 0.68 - 0.94, P < 0.001]; furthermore, we were able to demonstrate that postoperative sPDGF-BB was an independent predictor of HCC recurrence (hazard ratio = 5.64, 95% CI = 1.56 - 20.30, P < 0.01).

Conclusions

These findings provide a new insight into an association between diminished perioperative sPDGF-BB and HCC recurrence. Patients with low perioperative sPDGF-BB progressed early HCC recurrence. Therefore, evaluating perioperative sPDGF-BB may provide useful clinical information to characterize patients with postresection HCC recurrence.

Therapeutic implication of platelets in liver regeneration -hopes and hues

Mounting evidence highlights platelet involvement in liver regeneration via interaction with liver cells, growth factors release, and signaling contributions. Existing research suggests a compelling biological rationale for utilizing platelet biology, with the goal of improving liver function and accelerating its regenerative potential. Despite its expanding application in several clinical areas, the contribution of the platelet and its therapeutic implementation in liver regeneration so far has not yet fulfilled the initial high expectations. Areas covered: This review scrutinizes the progress, current updates, and discusses how recent understanding - particularly in the clinical implications of platelet-based therapy - may enable strategies to introduce and harness the therapeutic potential of the platelet during liver regeneration. Expert commentary: Several clinical and translational studies have facilitated a platform for the development of platelet-based therapy to enhance liver regeneration. While some of these therapies are effective to augment liver regeneration, the others have had some detrimental outcomes. The existing evidence represents a challenge for future projects that are focused on directly incorporating platelet-based therapies to induce liver regeneration.

Preoperative Thrombocytopenia May Predict Poor Surgical Outcome after Extended Hepatectomy

Background

It is a novel idea that platelet counts may be associated with postoperative outcome following liver surgery. This may help in planning an extended hepatectomy (EH), which is a surgical procedure with high morbidity and mortality.

Aim

The aim of this study was to evaluate the predictive potential of platelet counts on the outcome of EH in patients without portal hypertension, splenomegaly, or cirrhosis.

Methods

A series of 213 consecutive patients underwent EH (resection of ≥ five liver segments) between 2001 and 2016. The association of preoperative platelet counts with posthepatectomy liver failure (PHLF), morbidity (based on Clavien-Dindo classification), and 30-day mortality was evaluated using multivariate analysis.

Results

PHLF was detected in 26.3% of patients, major complications in 26.8%, and 30-day mortality in 11.3% of patients. Multivariate analysis revealed that the preoperative platelet count is an independent predictor of PHLF (odds ratio [OR] 4.4, 95% confidence interval [CI] 1.3-15.0, p=0.020) and 30-day mortality (OR 4.4, 95% CI 1.1-18.8, p=0.043).

Conclusions

Preoperative platelet count is associated with PHLF and mortality following extended liver resection. This association was independent of other related parameters. Prospective studies are needed to evaluate the predictive role and to determine the impact of preoperative correction of platelet count on postoperative outcomes after EH.

Deciphering Platelet Kinetics in Diagnostic and Prognostic Evaluation of Hepatocellular Carcinoma

Liver pathophysiology can, directly and indirectly, impose morphological or biochemical abnormalities of the platelets. Conversely, platelets are also able to regulate the promitogenic and profibrotic signals on liver pathobiology. Platelet contribution to the liver pathophysiology is typically facilitated by the platelet-derived growth factors that are sequestered in different subsets of alpha and dense granules, and the release of these growth factors is synchronized according to the stage and type of liver disease or injury. Thus, platelets harbor clinically relevant information with potential diagnostic and prognostic implications in liver diseases. Hepatocellular carcinoma (HCC) largely influences the platelet kinetics, and a growing body of evidence has recognized its association with HCC occurrence or prognosis. This narrative review summarizes the progress made on implicating platelet as a diagnostic and prognostic tool for HCC; the review also dissects the contradictory results from earlier studies and reflects how combining platelet-based information may enable more reliable test for diagnostic and prognostic evaluation of HCC.

Shaping the future of liver surgery: Implementation of experimental insights into liver regeneration

Background

While liver surgery has become a safe and feasible operation technique, the incidence of postoperative liver dysfunction still remains a central problem. Approximately 10% of patients undergoing liver resection were shown to develop liver dysfunction, which is associated with an increased risk of morbidity and mortality. Yet, to date there is no effective treatment option for postoperative liver dysfunction available. The development of postoperative liver dysfunction was linked to a disruption in the liver's potential to regenerate. Thus, it is importance to elucidate the underlying mechanisms of liver regeneration and to find potential therapeutic targets for the treatment of patients with postoperative liver dysfunction.

Methods

A review of the literature was carried out.

Results

We report on potential future interventions for improvement of liver regeneration after surgical resection. Moreover, we evaluate the benefits and drawbacks of hepatic progenitor cell therapy and hematopoietic stem cell therapy. However, the most significant improvement seems to come from molecular targets. Indeed, von Willebrand factor and its pharmacologic manipulation are among the most promising therapeutic targets to date. Furthermore, using the example of platelet-based therapy, we stress the potentially adverse effects of treatments for postoperative liver dysfunction.

Conclusion

The present review reports on the newest advances in the field of regenerative science, but also underlines the need for more research in the field of postoperative liver regeneration, especially in regard to translational studies.

Post-Resection Exhaustion of Intra-Platelet Serotonin: Also an Indicator of Early Hepatocellular Carcinoma Recurrence?

Purpose: Serotonin (5-hydroxytryptamine, 5-HT) is well known for its growth stimulatory effect on several types of carcinoma and tumor cells. Since a large portion of 5-HT is stored and transported by platelets, the aim of this study was to assess the influence of platelet-sequestered 5-HT on post-resection hepatocellular carcinoma (HCC) recurrence.

Methods: This pilot study was conducted in a cohort of forty patients diagnosed with HCC undergoing partial hepatectomy. 5-HT levels in serum, plasma and intra-platelet (IP) were monitored preoperatively and four weeks after liver resection. The patients were followed every three months after the surgery.

Results: Follow-up was standardized to a fixed length of time. Fifteen patients (37.5%) developed HCC recurrence during 18 months follow-up. Patients with recurrence had significantly reduced serum and IP 5-HT levels at four weeks of liver resection (P = 0.003 and P = 0.014 respectively). Accordingly, in the Cox regression hazard model, serum and IP 5-HT were able to independently predict the recurrence (hazard ratio = 0.1, 95% confidence interval = 0.01 - 0.75 and hazard ratio = 0.1, 95% confidence interval = 0.01 - 0.89 respectively). The optimal cut-off value of 42.77 ng/ml for serum [area under the curve (AUC): 0.78, P = 0.003] and 0.3117 ng per 10⁶ platelets (AUC: 0.733, P = 0.015), on receiver operating characteristic (ROC) curve corresponded to maximum sensitivity and specificity of prediction. The disease free interval was significantly worse in patients with low serum and IP 5-HT (P = 0.001 and P = 0.029 respectively).

Conclusion: IP 5-HT monitored during early follow-up, after liver resection may represent a useful marker of early HCC recurrence.

CtBP2 is associated with angiogenesis and regulates the apoptosis of prostate cancer cells

Angiogenesis is associated with prostate cancer (PCa) development and progression. Aberrant expression of C-terminal binding protein (CtBP)2 has been observed in PCa, but whether its change in expression plays a significant role in angiogenesis has not been completely characterized. we attempted to integrate and analyze the genome-wide association study (GWAS) of follicle stimulating hormone receptor (FSHR) and CtBP2, the Cancer Genome Atlas (TCGA) data and CtBP2 binding data in CistromeMap (18) to explore the mechanism of CtBP2 in PCa, and performed pathway enrichment analysis. We revealed that the top 6 pathways were closely related with angiogenesis. We used siRNA and overexpression plasmids to silence and overexpress CtBP2 expression. Altered expression of CtBP2 affected the expression of VEGFA, FSHR, FHL2 and SMAD3 which are closely related with angiogenesis. In addition, silencing of CtBP2 markedly increased the apoptosis of PCa cells in vitro, and decreased the expression of IL-8, AT2R, CCND1 and MMP9 which are associated with cancer progression. These results highlight the association between CtBP2 and angiogenesis in PCa and indicate that CtBP2 may be a potential therapeutic target for PCa.