Major hepatic resection may suppress the growth of tumours remaining in the residual liver

Major hepatectomy decreased tumor growth in an experimental model of bilobar liver metastasis

BACKGROUND/PURPOSE

Two-stage hepatectomy (TSH), is associated with a risk of drop-out due to tumoral progression following portal vein occlusion (PVO). We explored the impact of majorhepatectomy on tumor growth by objective radiological measures comparing to PVO and minor hepatectomy, using a model of bilobar colorectal liver metastasis (CLM).

METHODS

CLM were induced in 48 BDIX rats by injection of DHDK12-cells. 7 days after cells injection, animals were distributed into 4 groups of equal number (n = 12): portal vein ligation (PVL), sham laparotomy (sham), minor (30%Phx) and major (70%Phx) hepatectomy. MR imaging was used for in vivo analysis of tumor implantation, growth and volumes.

RESULTS

At POD10, tumour volumes were homogeneously distributed among the 4 groups. Lower TV were significantly observed after 70%Phx comparing to PVL at POD17 (0.63 ± 0.14cm3 vs 0.9 ± 0.16cm3, p = 0.008) and to the 3 others groups at POD24: 1.78 ± 0.38cm3 vs 3.2 ± 0.62cm3 (PVL, p = 0.019), 2.41 ± 0.74cm3 (Sham, p = 0.024) and 2.32 ± 0.59cm3 (30%PHx, p = 0.019).

CONCLUSION

We confirmed in a reproducible model that contrary to PVO, a major hepatectomy decreases the growth of CLM in the remnant liver. This result leads to questioning the usual TSH and justifies exploring alternative strategies. The "major hepatectomy first-approach" should be an option to be evaluated.

Bilobar versus unilobar multiple colorectal liver metastases: a propensity score analysis of surgical outcomes and recurrence patterns

BACKGROUND

Bilobar multiple colorectal liver metastases (MCLM) are often considered incurable or associated with a poor prognosis even after R0 resection. This study was designed to compare the long-term outcomes and recurrence patterns after one-stage resection in patients with bilobar versus unilobar MCLM.

METHODS

The records of patients undergoing parenchymal-sparing intent hepatectomy between 1994 and 2015 were reviewed. Survival and recurrence patterns were analyzed by propensity score matching.

RESULTS

The study population included 140 patients: 81 patients with bilobar MCLM versus 59 patients with unilobar MCLM. In the propensity score matching analysis (bilobar, n = 35 vs. unilobar, n = 35), the short-term outcomes did not differ between the two groups. Five-year overall survival (54.8% in bilobar vs. 51.2% in unilobar; P = 0.388) and recurrence-free survival (28.5% in bilobar vs. 36.2% in unilobar; P = 0.261) also did not differ. No significant differences were found in liver-only recurrence (22.9% in bilobar vs. 25.7% in unilobar; P = 1.000) and other recurrence patterns.

CONCLUSIONS

The clearance of bilobar MCLM by one-stage resection of parenchymal-sparing intent provided comparable long-term survival to unilobar MCLM.

Elevated MTSS1 expression associated with metastasis and poor prognosis of residual hepatitis B-related hepatocellular carcinoma

Background

Hepatectomy generally offers the best chance of long-term survival for patients with hepatocellular carcinoma (HCC). Many studies have shown that hepatectomy accelerates tumor metastasis, but the mechanism remains unclear.

Methods

An orthotopic nude mice model with palliative HCC hepatectomy was performed in this study. Metastasis-related genes in tumor following resection were screened; HCC invasion, metastasis, and some molecular alterations were examined in vivo and in vitro. Clinical significance of key gene mRNA expression was also analyzed.

Results

Metastasis suppressor 1 (MTSS1) located in the central position of gene function net of residual HCC. MTSS1 was up-regulated in residual tumor after palliative resection. In hepatitis B-related HCC patients undergone palliative hepatectomy, those with higher MTSS1 mRNA expression accompanied by activation of matrix metalloproteinase 2 (MMP2) in residual HCC, had earlier residual HCC detection after hepatectomy and poorer survival when compared to those with lower MTSS1. In different cell lines, the levels of MTSS1 mRNA increased in parallel with metastatic potential. MTSS1 down regulation via siRNA decreased MMP2 activity, reduced invasive potentials of HCC by 28.9 % in vitro, and averted the deteriorated lung metastatic extent in vivo.

Conclusions

The poor prognosis of hepatitis B-related HCC patients following palliative hepatectomy associates with elevated MTSS1 mRNA expression; therefore, MTSS1 may provide a new research field for HCC diagnosis and treatment.

Electronic supplementary material

The online version of this article (doi:10.1186/s13046-016-0361-8) contains supplementary material, which is available to authorized users.

Darbepoetin-α promotes neovascularization and cell proliferation in established colorectal liver metastases

BACKGROUND

The erythropoietin-analogue darbepoetin-α (DPO) improves liver function and regeneration after hepatectomy (Phx), however, also enhances Phx-induced tumor cell engraftment and neovascularization. Because it is unknown whether DPO also enhances the growth of established tumors, we herein studied the effect of DPO on established colorectal liver metastases after Phx.

METHODS

CT26.WT cells were implanted into the liver of BALB/c mice. Five days after tumor establishment, animals underwent 50% Phx and received 10 μg/kgBW DPO or saline. Non-Phx animals with DPO or saline-treatment served as controls. Seven days after Phx tumors were analyzed regarding blood vessel formation, leukocyte adhesion, cell proliferation, apoptotic cell death, and growth using intravital fluorescence microscopy, histology, and immunohistochemistry.

RESULTS

The growth of established colorectal liver metastases was slightly stimulated after DPO-treatment in hepatectomized and non-hepatectomized animals. However, tumor vessel formation and tumor cell proliferation were significantly enhanced after DPO-treatment in hepatectomized and non-hepatectomized mice compared with controls. Apoptotic cell death and leukocyte-endothelial cell interaction were significantly reduced after DPO-treatment.

CONCLUSION

Our study indicates that DPO-treatment promotes neovascularization and cell proliferation in established colorectal liver metastases of hepatectomized and non-hepatectomized mice. DPO-application in patients with colorectal liver metastases might promote tumor progression and should therefore be avoided.

Herbal compound "Songyou Yin" reinforced the ability of interferon-alfa to inhibit the enhanced metastatic potential induced by palliative resection of hepatocellular carcinoma in nude mice

Background

Liver resection is a widely accepted treatment for hepatocellular carcinoma (HCC). Our previous clinical study showed that the rate of palliative resection was 34.0% (1958-2008, 2754 of 8107). However, the influence of palliative resection on tumor metastasis remains controversial. The present study was conducted to evaluate the effect of palliative resection on residual HCC and to explore interventional approaches.

Methods

Palliative resection was done in an orthotopic nude mice model of HCC (MHCC97H) with high metastatic potential. Tumor growth, invasion, metastasis, lifespan, and some molecular alterations were examined in vivo and in vitro. Mice that underwent palliative resection were treated with the Chinese herbal compound "Songyou Yin," interferon-alfa-1b (IFN-α), or their combination to assess their effects.

Results

In the palliative resection group, the number of lung metastatic nodules increased markedly as compared to the sham operation group (14.3 ± 4.7 versus 8.7 ± 3.6, P < 0.05); tumor matrix metalloproteinase 2 (MMP2) activity was elevated by 1.4-fold, with up-regulation of vascular endothelial growth factor (VEGF) and down-regulation of tissue inhibitor of metalloproteinase 2 (TIMP2). The sera of mice undergoing palliative resection significantly enhanced cell invasiveness by 1.3-fold. After treatment, tumor volume was 1205.2 ± 581.3 mm³, 724.9 ± 337.6 mm³, 507.6 ± 367.0 mm³, and 245.3 ± 181.2 mm³ in the control, "Songyou Yin," IFN-α, and combination groups, respectively. The combined therapy noticeably decreased the MMP2/TIMP2 ratio and prolonged the lifespan by 42.2%. Moreover, a significant (P < 0.001) reduction of microvessel density was found: 43.6 ± 8.5, 34.5 ± 5.9, 23.5 ± 5.6, and 18.2 ± 8.0 in the control and treatment groups, respectively.

Conclusion

Palliative resection-stimulated HCC metastasis may occur, in part, by up-regulation of VEGF and MMP2/TIMP2. "Songyou Yin" reinforced the ability of IFN-α to inhibit the metastasis-enhancing potential induced by palliative resection, which indicated its potential postoperative use in patients with HCC.

Angiogenesis: multiple masks in hepatocellular carcinoma and liver regeneration

Hepatocellular carcinoma (HCC) is naturally resistant to radiotherapy and cytotoxic chemotherapy, leaving surgery as the mainstream therapeutic approach. However, the 5-year recurrence rate after curative resection is as high as 61.5%. The background hepatitis B- or C-induced cirrhosis and the presence of micrometastases at the time of surgery have been regarded as two main causes of recurrence. Recently, accumulating evidence suggests that growth factors and cytokines released during the physiological process of post-surgical liver regeneration could induce the activation of dormant micrometastatic lesions. The establishment of neovasculature to support either liver regeneration or HCC growth involves multiple cell types including liver sinusoidal endothelial cells, Kupffer cells, hepatic stellate cells, and circulating endothelial progenitors. The crosstalks among these cells are driven by multiple molecules and signaling pathways, including vascular endothelial growth factors and their receptors, platelet-derived growth factor, the angiopoietin/Tie family, hepatocyte growth factor/c-Met signaling, and others. Anti-angiogenic agent targeting liver cancer vasculature has been reported to be able to generate limited survival benefit of the patients. In this review, discussions are focused on various angiogenic mechanisms of HCC and liver regeneration, as well as the prevailing anti-angiogenic strategies.

Use of bioluminescence imaging to detect enhanced hepatic and systemic tumor growth following partial hepatectomy in mice

BACKGROUND

The impact of partial hepatectomy on intra-hepatic and distant tumor growth is a matter of controversy. Utilizing a highly sensitive tumor imaging strategy, we sought to demonstrate whether this growth-acceleration occurs, and to develop an animal model with which to investigate potential therapeutic strategies.

METHODS

Mice bearing constitutively-active luciferase-expressing tumor cells were subjected to either 70% partial hepatectomy (PH; n=10) or a sham operation (n=11). Mice were sacrificed 14 days later and remnant livers (or anatomic equivalents in the control group) and lungs harvested for bioluminescence detection.

RESULTS

Remnant liver weights were significantly increased in PH compared to equivalent lobes in sham-operated animals (t-test; p=0.005). Tumor burden as measured by bioluminescence was significantly higher in both liver and lung specimens in the PH group (Wilcoxon's Rank Sum test; p=0.01 and 0.004, respectively).

CONCLUSIONS

Following PH, enhanced metastatic growth was depicted regionally and systemically with bioluminescence imaging providing an objective measure of tumor burden. This preclinical model can help to identify adjuvant therapies that can influence both tumor growth and liver regeneration.

Major but not minor hepatectomy accelerates engraftment of extrahepatic tumor cells

BACKGROUND

The effect of hepatectomy and hepatic regeneration on intra- and extrahepatic tumor growth is still controversially discussed. Herein we studied the effect of minor (30%) or major (70%) hepatectomy on engraftment of extrahepatic tumor cells, and the role of tumor neovascularization and tumor cell migration.

METHODS

Green fluorescent protein (GFP)-transfected CT26.WT colorectal cancer cells were implanted in dorsal skinfold chambers of syngeneic BALB/c mice. Animals underwent 30% (30%Phx, n = 8) or 70% hepatectomy (70%Phx, n = 8). Sham-operated animals served as controls (n = 8). Angiogenesis and neovascularization as well as tumor cell migration, proliferation and growth were studied over 14 days using intravital fluorescence microscopy, histology and immunohistochemistry.

RESULTS

After both minor and major hepatectomy tumor proliferating cell nuclear antigen (PCNA) expression increased significantly (P < 0.05) when compared with nonhepatectomized controls. However, only major but not minor hepatectomy accelerated neovascularization (P < 0.05) and tumor cell migration (P < 0.05). This was associated with a significantly (P < 0.05) enhanced tumor growth after 70%Phx when compared with 30%Phx and controls. The rate of apoptotic cell death was not affected by major or minor hepatectomy.

CONCLUSION

Regeneration after major hepatectomy accelerates extrahepatic tumor cell engraftment, most probably by acceleration of neovascularization and induction of tumor cell migration.

Portal vein ligation and partial hepatectomy differentially influence growth of intrahepatic metastasis and liver regeneration in mice

BACKGROUND/AIMS

Since modern treatment of liver metastases includes serial hepatectomies and portal vein obstruction, we investigated the effects of portal vein ligation (PVL) and partial hepatectomy (PH) on tumor growth.

METHODS

The effects of 70% PH and PVL on liver and lung metastases were evaluated in mice. Tumor growth and liver regeneration were assessed by morphometry and immunohistochemistry for PCNA and BrdU. The effect of growth factors of liver regeneration on CT-26 cells was tested in vitro, and TGF-beta secretion of CT-26 cells was measured by ELISA. RNA synthesis of TGF-beta and activin A was measured by RT-PCR.

RESULTS

Liver regeneration after PH and PVL was similar in tumor-free mice. Intrahepatic tumor growth was lower after PH than after PVL (p=0.016). Extrahepatic tumor growth was not different. In contrast to PVL, liver regeneration was delayed after PH in metastatic livers (p=0.001). Tested growth factors of liver regeneration stimulated CT-26 cells in vitro, and CT-26 secreted significant amounts of TGF-beta in vitro and in vivo.

CONCLUSIONS

Although similar in tumor-free mice, liver regeneration significantly differed between PVL and PH in metastatic livers. In addition, PH and PVL differently affected intrahepatic tumor growth.

A model of partial hepatectomy in mice

A versatile, simple, and reproducible model of hepatectomy is essential for the study of liver regeneration and its effects on various pathological processes. A murine model of liver resection and regeneration suitable for research is described. Male inbred CBA mice 6-8 wk old were used in all experiments. The contribution of the hepatic lobes to the total liver mass was determined by wet weight measurements. Resection of 37% (n = 10) and 70% (n = 10) liver volume was performed using hemostatic clips to ligate the hepatic lobe pedicles. Animals were recovered and subsequently killed 21 days postoperatively Liver mass was determined and compared to control animals (n = 17) to assess the completeness of liver regeneration. There were no operative deaths in animals undergoing either 37% or 70% hepatectomy. The procedures could be performed expediently, and animal recovery was complete. Liver mass (grams) assessed 21 days postoperatively [mean (SE)] in both the 37% resection, 1.76 g (0.07), and 70% resection, 1.56 g (0.05), groups was not significantly different from control animals, 1.64 g (0.07) (p =.265). Thus, partial hepatectomy can be performed safely and rapidly in mice using haemostatic clip ligation of hepatic lobes, with no impairment to the subsequent process of liver regeneration.

Effects of human hepatocyte growth factor on the proliferation of human hepatocytes and hepatocellular carcinoma cell lines

BACKGROUND

Hepatocyte growth factor (HGF) has been suggested to initiate both hepatocyte and tumor cell proliferation after partial hepatectomy, thereby supporting local tumor recurrence. The aim of this study was to clarify the role of HGF in the regeneration of human hepatocyte and the growth of residual hepatocellular carcinoma cells after liver resection.

PATIENTS/METHODS

36 patients who underwent partial hepatectomy for hepatocellular carcinoma (HCC) or living liver donation have been analyzed for HGF serum levels at day -1 through day 5 following surgery using an enzyme-linked immunosorbent assay. Isolated human hepatocytes and HCC cell lines (Hep 3B, Hep G2) were treated either with recombinant human (rh)-HGF, or sera from the 36 patients in the presence or absence of anti-HGF in order to measure their proliferative capacity using (3)H-thymidine incorporation.

RESULTS

Basal HGF levels were significantly higher in HCC than in healthy patients (1,573 +/- 131 vs. 778 +/- 64 pg/ml; p < 0.001), however, the postoperative rise of HGF in healthy patients was higher (9,608 +/- 3111 vs. 2,060 +/- 148 pg/ml) than in HCC patients. Incubation of human hepatocytes and Hep 3B cells with rh-HGF revealed a dose-dependent increase in DNA synthesis, while anti-HGF partially abolished this effect. Sera from normal and resected HCC patients stimulated DNA synthesis only in human hepatocytes, whereas it was inhibited in HCC cell lines.

CONCLUSION

HGF plays an important role in hepatocyte proliferation but contrary to in vitro results, HGF does not play a major role for the progression of hepatocarcinoma cells in vivo.

The molecular physiology of liver regeneration following partial hepatectomy

The ability of the liver to regenerate after resection has been known for many years. Two reports from Germany in the late 1800s probably mark the introduction of the phenomenon into the scientific literature, but in the early 1900s the first reviews of this subject had appeared in the English literature. Predating these early scientific reports the legends from the Greek mythology described the fate of Prometheus. As punishment for defying Zeus and revealing the secret of fire to man, Prometheus was chained to a rock and each day had part of his liver ripped out by an eagle which, returning the following day, repeated the torture because his liver regenerated itself overnight. Although the speed of regeneration in the Greek legend is somewhat greater than that observed either clinically or in the laboratory, the myth does serve to emphasise the remarkable ability of the liver to repeatedly regenerate following repeated resections. This review aims to summarise the more recent literature concerning the early molecular events accompanying liver regeneration and to integrate this with the existing knowledge of this subject.

Microwave coagulation therapy accelerates growth of cancer in rat liver

BACKGROUND/AIMS

Although microwave coagulation therapy (MCT) has been performed for liver cancer, there has been no report examining the influence of this therapy on the growth of possible remnant cancer.

METHODS

A solid cube of AH-130 cells (ascites hepatoma cell line) was implanted into the left lateral lobe of the rat liver. Five days later, MCT was applied to the middle liver lobe of these rats. Tumor growth and cytokine levels in plasma and the liver were compared between rats that underwent MCT and rats that did not.

RESULTS

The mean tumor weight in the MCT group (222.6+/-51.5 mg, mean+/-SD) was significantly greater than that in the control group (126.7+/-19.7 mg, P<0.01) at postoperative day (POD) 5. Immunohistochemistry for anti-proliferating cell nuclear antigen showed the labeling index in the MCT group (90.4%) to be higher than that in the control group (76.7%, P<0.01). Liver basic fibroblast growth factor and transforming growth factor-beta 1 levels in the MCT group on POD 3 were significantly higher than levels in the control group.

CONCLUSIONS

The present study suggests the clinically important finding that MCT accelerates the growth of small residual tumors in the liver.