Increased growth of colorectal liver metastasis following partial hepatectomy

The role of ischaemia-reperfusion injury and liver regeneration in hepatic tumour recurrence

The risk of cancer recurrence after liver surgery mainly depends on tumour biology, but preclinical and clinical evidence suggests that the degree of perioperative liver injury plays a role in creating a favourable microenvironment for tumour cell engraftment or proliferation of dormant micro-metastases. Understanding the contribution of perioperative liver injury to tumour recurrence is imperative, as these pathways are potentially actionable. In this review, we examine the key mechanisms of perioperative liver injury, which comprise mechanical handling and surgical stress, ischaemia-reperfusion injury, and parenchymal loss leading to liver regeneration. We explore how these processes can trigger downstream cascades leading to the activation of the immune system and the pro-inflammatory response, cellular proliferation, angiogenesis, anti-apoptotic signals, and release of circulating tumour cells. Finally, we discuss the novel therapies under investigation to decrease ischaemia-reperfusion injury and increase regeneration after liver surgery, including pharmaceutical agents, inflow modulation, and machine perfusion.

Impact of rapid hypertrophy of tourniquet associating liver partition and portal vein ligation in the tumor progression pathways compared to two stage hepatectomy in patients with colorectal liver metastases

BACKGROUND

It is not known if the inflammatory phenomena related to highly accelerated regeneration activate any signaling pathways that are associated with a major stimulus to colorectal liver metastases (CRLM) disease in tourniquet associating liver partition and portal vein ligation for staged hepatectomy (T-ALPPS) compared to two stage hepatectomy (TSH).

METHODS

Between January 2012 and April 2018, we prospectively performed biopsies from future liver remnant and deportalized lobe in CRLM patients undergoing T-ALPPS in both stages. Immunohistopathological analysis was performed on the above tissue samples and compared to biopsy samples from patients who underwent TSH for CRLM at our center between September 2000 and August 2011.

RESULTS

A total of 42 patients (20 TSH and 22 T-ALPPS) were included. There were no differences in the rates of recurrence, overall survival or any of the factors analyzed relating to tumor progression between stages 1 and 2. Regarding the anti-tumor effect, there was a significant reduction in the number of T-CD8 infiltrates in the second stage of TSH (12.5 vs. 5.5, p = 0.02).

CONCLUSION

The results suggest that liver regeneration with T-ALPPS does not induce higher tumor progression or significant immunological changes in the tumor environment when compared to classical TSH.

α-Fetoprotein contributes to the malignant biological properties of AFP-producing gastric cancer

This study aimed to investigate whether α-fetoprotein (AFP) could affect the malignant behavior of AFP-producing gastric cancer (AFP-GC) and to explore the relationship between AFP and mesenchymal-epithelial transition factor (c-Met) in AFP-GC. In this study, 23 patients with AFP-GC (AFP[+]) and 18 patients with common gastric cancer (AFP[-]) were evaluated for the c-Met expression using immunohistochemical analysis. The AFP-GC cell line, GCIY, was used. The AFP endoribonuclease-prepared small interfering RNA (siRNA) and eukaryotic AFP overexpression vector were used to increase/knockdown the expression of AFP. Afterward, the c-Met expression was evaluated by polymerase chain reaction and western blot. The proliferation, migration, and invasion of GCIY cells were estimated before and after the AFP overexpression/knockdown. The c-Met expression in both groups was the same (p > 0.05), and AFP[+] group had a higher positive incidence of the c-Met expression than the AFP[-] group (p < 0.01). Furthermore, the c-Met expression frequency was decreased by AFP knockdown and increased by AFP overexpression (p < 0.01). The cell counting kit-8 cell proliferation assay, cell invasion, and migration assays confirmed that the AFP could affect the malignant biological behavior of AFP-GC. These findings suggest that AFP contributes to the malignant biological properties of AFP-GC and the high expression of c-Met in AFP-GC.

Activation of Sphingomyelin Phosphodiesterase 3 in Liver Regeneration Impedes the Progression of Colorectal Cancer Liver Metastasis Via Exosome-Bound Intercellular Transfer of Ceramides

BACKGROUND & AIMS

The machinery that prevents colorectal cancer liver metastasis (CRLM) in the context of liver regeneration (LR) remains elusive. Ceramide (CER) is a potent anti-cancer lipid involved in intercellular interaction. Here, we investigated the role of CER metabolism in mediating the interaction between hepatocytes and metastatic colorectal cancer (CRC) cells to regulate CRLM in the context of LR.

METHODS

Mice were intrasplenically injected with CRC cells. LR was induced by 2/3 partial hepatectomy (PH) to mimic the CRLM in the context of LR. The alteration of corresponding CER-metabolizing genes was examined. The biological roles of CER metabolism in vitro and in vivo were examined by performing a series of functional experiments.

RESULTS

Induction of LR augmented apoptosis but promoted matrix metalloproteinase 2 (MMP2) expression and epithelial-mesenchymal transition (EMT) to increase the invasiveness of metastatic CRC cells, resulting in aggressive CRLM. Up-regulation of sphingomyelin phosphodiesterase 3 (SMPD3) was determined in the regenerating hepatocytes after LR induction and persisted in the CRLM-adjacent hepatocytes after CRLM formation. Hepatic Smpd3 knockdown was found to further promote CRLM in the context of LR by abolishing mitochondrial apoptosis and augmenting the invasiveness in metastatic CRC cells by up-regulating MMP2 and EMT through promoting the nuclear translocation of β-catenin. Mechanistically, we found that hepatic SMPD3 controlled the generation of exosomal CER in the regenerating hepatocytes and the CRLM-adjacent hepatocytes. The SMPD3-produced exosomal CER critically conducted the intercellular transfer of CER from the hepatocytes to metastatic CRC cells and impeded CRLM by inducing mitochondrial apoptosis and restricting the invasiveness in metastatic CRC cells. The administration of nanoliposomal CER was found to suppress CRLM in the context of LR substantially.

CONCLUSIONS

SMPD3-produced exosomal CER constitutes a critical anti-CRLM mechanism in LR to impede CRLM, offering the promise of using CER as a therapeutic agent to prevent the recurrence of CRLM after PH.

Hepatic arterial infusion with nanoliposomal irinotecan leads to significant regression of tumor size of colorectal liver metastases in a CC531 rat model

Long-term therapy for unresectable colorectal liver metastases remains challenging. Intraarterial treatments aim to avoid systemic adverse effects of chemotherapy. Nanoliposomal cytotoxic drugs manage to increase the drug concentration within the tumor while reducing toxicity in healthy tissue.  In this study we analyzed the effect of hepatic arterial infusion (HAI) with nanoliposomal irinotecan with or without the combination of embolization particles in a rat model for colorectal liver metastases. For the study 32 WAG/Rij rats received subcapsular tumor implantation with CC531 rat colonic adenocarcinoma cells. After ten days tumor size was assessed via ultrasound and animals underwent HAI. One group served as control receiving NaCl 0.9 % (Sham), the three treatment groups received either nanoliposomal irinotecan (HAI nal iri), Embocept® S (HAI Embo) or Embocept® S and nanoliposomal irinotecan (HAI Embo+nal iri). Three days after treatment animals were sacrificed after assessment of tumor size. As a result all treatment groups showed a significant reduction in tumor growth compared to Sham (p<0.05). Expression of the apoptosis marker caspase-3 was enhanced in HAI nal iri and HAI Embo+nal iri compared to Sham and HAI Embo and  even significantly enhanced after HAI Embo+nal iri in comparison to Sham (p<0.05). We were able to show that HAI with Embocept® S led to significantly reduced tumor growth while HAI with nanoliposomal irinotecan alone or in combination with Embocept® S even led to a reduction of tumor size. Thus, we demonstrate that intraarterial treatment with nanoliposomal irinotecan effectively inhibits tumor growth in a rat model of colorectal liver metastases and demands further investigation.

A Randomized Phase II Trial of Adjuvant Hepatic Arterial Infusion and Systemic Therapy With or Without Panitumumab After Hepatic Resection of KRAS Wild-type Colorectal Cancer

OBJECTIVE/BACKGROUND

The purpose was to determine whether adding Pmab versus no Pmab to an adjuvant regimen of hepatic arterial infusion (HAI) of floxuridine (FUDR) plus systemic (SYS) leucovorin, fluorouracil, and irinotecan (FOLFIRI) improves 15-month recurrence-free survival for patients with RAS wild-type colorectal cancer. Secondary endpoints included overall survival, toxicity, and influence of predictive biomarkers.

METHODS

This phase II trial randomized patients with KRAS wild-type resected colorectal liver metastases to adjuvant HAI FUDR + SYS FOLFIRI +/- Pmab (NCT01312857). Patients were stratified by clinical risk score and previous chemotherapy. Based on an exact binomial design, if one arm had ≥24 patients alive and disease-free at 15 months that regimen was considered promising for further investigation.

RESULTS

Seventy-five patients were randomized. Patient characteristics and toxicity were not different in the 2 arms, except for rash in +Pmab arm. Grade 3/4 elevation in bilirubin or alkaline phosphatase did not differ in the 2 arms. Twenty-five (69%; 95% CI, 53-82) patients in the Pmab arm versus 18 (47%; 95% CI, 32-63) patients in the arm without Pmab were alive and recurrence-free at 15 months. Only the Pmab arm met the decision rule, while the other arm did not. After median follow-up of 56.6 months, 3-year recurrence-free survival was 57% (95% CI, 43-76) and 42% (95% CI, 29-61), and 3-year overall survival was 97% (95% CI, 90-99) and 91% (95% CI, 83-99), +/- Pmab, respectively.

CONCLUSIONS

The addition of Pmab to HAI FUDR + SYS FOLFIRI showed promising activity without increased biliary toxicity and should be further investigated in a larger trial.

Role of FGF15 in Hepatic Surgery in the Presence of Tumorigenesis: Dr. Jekyll or Mr. Hyde?

The pro-tumorigenic activity of fibroblast growth factor (FGF) 19 (FGF15 in its rodent orthologue) in hepatocellular carcinoma (HCC), as well as the unsolved problem that ischemia-reperfusion (IR) injury supposes in liver surgeries, are well known. However, it has been shown that FGF15 administration protects against liver damage and regenerative failure in liver transplantation (LT) from brain-dead donors without tumor signals, providing a benefit in avoiding IR injury. The protection provided by FGF15/19 is due to its anti-apoptotic and pro-regenerative properties, which make this molecule a potentially beneficial or harmful factor, depending on the disease. In the present review, we describe the preclinical models currently available to understand the signaling pathways responsible for the apparent controversial effects of FGF15/19 in the liver (to repair a damaged liver or to promote tumorigenesis). As well, we study the potential pharmacological use that has the activation or inhibition of FGF15/19 pathways depending on the disease to be treated. We also discuss whether FGF15/19 non-pro-tumorigenic variants, which have been developed for the treatment of liver diseases, might be promising approaches in the surgery of hepatic resections and LT using healthy livers and livers from extended-criteria donors.

Partial hepatectomy enhances the growth of CC531 rat colorectal cancer cells both in vitro and in vivo

Partial hepatectomy (PHx) is the gold standard for the treatment of colorectal cancer liver metastases. However, after removing a substantial amount of hepatic tissue, growth factors are released to induce liver regeneration, which may promote the proliferation of liver micrometastases or circulating tumour cells still present in the patient. The aim of this study is to assess the effect of PHx on the growth of liver metastases induced by intrasplenic cell inoculation as well as on in vitro proliferation of the same cancer cell line. Liver tumours were induced in 18 WAG/RijHsd male rats, by seeding 250,000 syngeneic colorectal cancer cells (CC531) into the spleen. The left lateral lobe of the liver was mobilized and in half of the animals it was removed to achieve a 40% hepatectomy. Twenty-eight days after tumour induction, the animals were sacrificed and the liver was removed and sliced to assess the relative tumour surface area (RTSA%). CC531 cells were cultured in presence of foetal calf serum, non-hepatectomised (NRS) or hepatectomized rat serum (HRS), and their proliferation rate at 24, 48, and 72 h was measured. RTSA% was significantly higher in animals which had undergone PHx than in the controls (non-hepatectomised) (46.98 ± 8.76% vs. 18.73 ± 5.65%; p < 0.05). Analysing each lobe separately, this difference in favour of hepatectomized animals was relevant and statistically significant in the paramedian and caudate lobes. But in the right lobe the difference was scarce and not significant. In vitro, 2.5% HRS achieved stronger proliferative rates than the control cultures (10% FCS) or their equivalent of NRS. In this experimental model, a parallelism has been shown between the effect of PHx on the growth of colorectal cancer cells in the liver and the effect of the serum on those cells in vitro.

Postoperative liver regeneration does not elicit recurrence of colorectal cancer liver metastases after major hepatectomy

BACKGROUND AND OBJECTIVES

Recurrence is a frequent concern in curatively resected CRC liver metastases. Translational research suggests that regeneration upon hepatectomy may also alleviate metastatic recurrence; however, the significance in patients is unclear. We therefore sought to study the effect of liver regeneration on tumor recurrence in patients.

METHODS

In this retrospective cohort study, we included 58 out of 186 potentially eligible patients from our prospectively maintained database of CRC liver metastasis patients between 2001 and 2012 with a median follow-up of 42 months who underwent a formal right or left hemihepatectomy. Liver regeneration in CT volumetry was correlated with recurrence of CRC liver metastases and overall survival.

RESULTS

Liver regeneration increased up to 14 months to 21.0% for left and 122.6% for right hemihepatectomy, respectively, with comparable final volumes. Regeneration was independent of initial tumor stage, number of metastases, and preoperative chemotherapy. Patients with lower liver regeneration showed earlier recurrence of CRC liver metastases (p = 0.006). Overall survival did not differ in patients with weak versus strong liver regeneration.

CONCLUSIONS

The extent of liver regeneration after major hepatectomy does not impede overall survival. Therefore, our data encourage aggressive therapeutical regimes for CRC liver metastases involving major hepatectomies as part of a curative approach.

Colorectal Cancer Stem Cells in the Progression to Liver Metastasis

Colorectal carcinoma (CRC) is a leading cause of cancer mortality. Tumorigenesis is a dynamic process wherein cancer stem cells (CSCs) and their microenvironment promote initiation, progression, and metastasis. Metastatic colonization is an inefficient process that is very complex and is poorly understood; however, in most cases, metastatic disease is not curable, and resistance mechanisms tend to develop against conventional treatments. An understanding of the underlying mechanisms and factors that contribute to the development of metastasis in CRC can aid in the search for specific therapeutic targets for improving standard treatments. In this review, we summarize current knowledge regarding tumor biology and the use of stroma cells as prognostic factors and inflammatory inducers associated with the use of tumor microenvironments as a promoter of cancer metastasis. Moreover, we look into the importance of CSC, pericytes, and circulating tumor cells as mechanisms that lead to liver metastasis, and we also focus on the cellular and molecular pathways that modulate and regulate epithelial–mesenchymal transition. Finally, we discuss a novel therapeutic target that can potentially eliminate CSCs as a CRC treatment.

Hepatic arterial infusion of irinotecan and EmboCept® S results in high tumor concentration of SN-38 in a rat model of colorectal liver metastases

Intraarterial chemotherapy for colorectal liver metastases (CRLM) can be applied alone or together with embolization particles. It remains unclear whether different types of embolization particles lead to higher intratumoral drug concentration. Herein, we quantified the concentrations of CPT-11 and its active metabolite SN-38 in plasma, liver and tumor tissue after hepatic arterial infusion (HAI) of irinotecan, with or without further application of embolization particles, in a rat model of CRLM. Animals underwent either systemic application of irinotecan, or HAI with or without the embolization particles Embocept^® S and Tandem™. Four hours after treatment concentrations of CPT-11 and SN-38 were analyzed in plasma, tumor and liver samples by high-performance liquid chromatography. Additionally, DNA-damage and apoptosis were analyzed immunohistochemically. Tumor tissue concentrations of SN-38 were significantly increased after HAI with irinotecan and EmboCept^® S compared to the other groups. The number of apoptotic cells was significantly higher after both HAI with irinotecan and EmboCept^® S or Tandem™ loaded with irinotecan compared to the control group. HAI with irinotecan and EmboCept^® S resulted in an increased SN-38 tumor concentration. Both HAI with irinotecan and EmboCept^® S or Tandem™ loaded with irinotecan were highly effective with regard to apoptosis.

Simultaneous curative resection of double colorectal carcinoma with synchronous bilobar liver metastases

Synchronous colorectal carcinoma (SCRC) indicates more than one primary colorectal carcinoma (CRC) discovered at the time of initial presentation, accounts for 3.1%-3.9% of CRC, and may occur either in the same or in different colorectal segments. The accurate preoperative diagnosis of SCRC is difficult and diagnostic failures may lead to inappropriate treatment and poorer prognosis. SCRC requires colorectal resections tailored to individual patients, based on the number, location, and stage of the tumours, from conventional or extended hemicolectomies to total colectomy or proctocolectomy, when established predisposing conditions exist. The overall perioperative risks of surgery for SCRC seem to be higher than for solitary CRC. Simultaneous colorectal and liver resection represents an appealing surgical strategy in selected patients with CRC and synchronous liver metastases (CRLM), even though the cumulative risks of the two procedures need to be adequately evaluated. Simultaneous resections have the noticeable advantage of avoiding a second laparotomy, give the opportunity of an earlier initiation of adjuvant therapy, and may significantly reduce the hospital costs. Because an increasing number of recent studies have shown good results, with morbidity, perioperative hospitalization, and mortality rates comparable to staged resections, simultaneous procedures can be selectively proposed even in case of complex colorectal resections, including those for SCRC and rectal cancer. However, in patients with multiple bilobar CRLM, major hepatectomies performed simultaneously with colorectal resection have been associated with significant perioperative risks. Conservative or parenchymal-sparing hepatectomies reduce the extent of hepatectomy while preserving oncological radicality, and may represent the best option for selected patients with multiple CRLM involving both liver lobes. Parenchymal-sparing liver resection, instead of major or two-stage hepatectomy for bilobar disease, seemingly reduces the overall operative risk of candidates to simultaneous colorectal and liver resection, and may represent the most appropriate surgical strategy whenever possible, also for patients with advanced SCRC and multiple bilobar liver metastases.

Role of Kupffer cells in the progression of CRC liver metastases after the first stage of ALPPS

Associated liver partition and portal vein ligation for staged hepatectomy (ALPPS) has been suggested as a potential therapy for extensive bilobar liver tumors, although in some circumstances this technique may induce tumor progression, a fact still not well studied. Our aim was to study tumor hepatic progression induced by the first step of ALPPS in a WAG/Rij rat syngenic model of metastatic colorectal carcinoma by subcapsular CC531 cell line inoculation. ALPPS induced: tumor progression on deportalized lobe and metastases; expression of hepatic vasculogenic factors (HIF1-α and VEGF); and a dramatic increase of Kupffer cells (KCs) and tumor-associated macrophages (TAMs). Interestingly, KCs expressed COX-2 (M1 polarization), while TAMs expressed mainly arginase-1 (M2 polarization). ALPPS also induced a decrease of tumor-infiltrating lymphocytes and an increase of intrahepatic T lymphocytes. Thus, ALPPS technique seems to induce a hypoxic environment, which enhances hepatic HIF1-α and VEGF expression and may promote KCs and TAMs polarization. Consequently, the regenerative stimulus seems to be driven by a pro-inflammatory and hypoxic environment, in which M1 intrahepatic macrophages expressing COX-2 and T-Lymphocytes play a key role, facts which may be related with the tumor progression observed.

Characterization of novel low passage primary and metastatic colorectal cancer cell lines

In vitro models are essential to understanding the molecular characteristics of colorectal cancer (CRC) and the testing of therapies for CRC. Many efforts to establish and characterize primary CRC cell lines have been published, most describing a small number of novel cell lines. However, there remains a lack of a large panel of uniformly established and characterized cell lines. To this end we established 20 novel CRC cell lines, of which six were derived from liver metastases. Genetic, genomic and transcriptomic profiling was performed in order to characterize these new cell lines. All data are made publically available upon publication.

By combining mutation profiles with CNA and gene expression profiles, we generated an overall profile of the alterations in the major CRC-related signaling pathways. The combination of mutation profiles with genome, transcriptome and methylome data means that these low passage cell lines are among the best characterized of all CRC cell lines. This will allow researchers to select model cell lines appropriate to specific experiments, facilitating the optimal use of these cell lines as in vitro models for CRC. All cell lines are available for further research.

The Differences of c-Met Expression Between AFP-Producing Gastric Cancer and Common Gastric Cancer

Background

Alpha-fetoprotein (AFP)–producing gastric cancer is a distinct type of gastric cancer with a high incidence of liver metastasis. c-Met is considered to play an important role in liver metastasis of gastric cancer.

Objective

The purpose of this study was to compare the expression of c-Met in AFP-producing gastric cancer and gastric cancers not producing AFP.

Methods

We evaluated 23 patients with AFP-producing gastric cancer (AFP+) and 18 patients with common gastric cancer (AFP–) were evaluated for c-Met expression using immunohistochemical analysis.

Results

The incidence of c-Met expression in 2 groups was the same (P &gt; 0.05), but the AFP+ group had a higher strong positive rate of c-Met expression than the AFP– group (P &lt; 0.01).

Conclusion

The higher expression of c-Met might be the reason for the high incidence of liver metastasis in AFP-producing gastric cancer.

Increased kinetic growth rate during late phase liver regeneration impacts the risk of tumor recurrence after colorectal liver metastases resection

BACKGROUND

Although experimental data strongly support the pro-tumorigenic role of postoperative liver regeneration, this hypothesis has not been clinically investigated. We aimed to examine the impact of liver regeneration determined by volumetric imaging on recurrence following resection of colorectal liver metastasis (CRLM).

METHODS

Resected liver volume was subtracted from total liver volume (TLV) to define postoperative remnant liver volume (RLV_p). Early and late kinetic growth rates (KGR) were defined as the postoperative increases in liver volume within 2-3 and 8-10 months from surgery, respectively, divided by the corresponding time interval.

RESULTS

Median early and late KGR was 2.6%/month (IQR: -0.9 to 12.3) and 1.0%/month (IQR: -0.64 to 2.91), respectively. Late KGR predicted intrahepatic recurrence after 1 year from surgery (AUC 0.677, P = 0.011). Specifically, patients with a late KGR ≥1% had a higher cumulative risk of recurrence compared with patients with a KGR <1% (P = 0.038). In multivariate analysis, KGR ≥1% independently predicted recurrence (P = 0.027).

DISCUSSION

A KGR ≥1% during the late regeneration phase was associated with increased risk of intrahepatic recurrence. These data may inform the timing of adjuvant therapy administration and focus surveillance strategies for high-risk patients.

ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) does not affect proliferation, apoptosis, or angiogenesis as compared to standard liver resection for colorectal liver metastases

Background

ALPPS (associating liver partition and portal vein ligation for staged hepatectomy) is a novel two-stage strategy to induce rapid hypertrophy of the future liver remnant (FLR) when patients are in danger of postoperative liver failure due to insufficient FLR. However, the effects of ALPPS on colorectal liver metastases (CRLM) are not clear so far. The aim of our study was to determine whether ALPPS induces proliferation, apoptosis, or vascularization compared to standard (one-stage) liver resection.

Methods

Six patients who underwent ALPPS were matched with 12 patients undergoing standard liver resection regarding characteristics of the metastases (size, number), time of appearance (syn-/metachronous), preoperative chemotherapy, primary tumor (localization, TNM stage, grading), and patient variables (gender, age). The largest resected metastasis was used for the analyses. Tissue was stained for tumor cell proliferation (Ki67), apoptosis (TUNEL, caspase-3), vascularization (CD31), and pericytes (αSMA).

Results

Vascularization (CD31; p = 0.149), proliferation (Mib-1; p = 0.244), and αSMA expression (p = 0.205) did not significantly differ between the two groups, although a trend towards less proliferation and αSMA expression was observed in patients undergoing ALPPS. Concerning apoptosis, caspase-3 staining showed significantly fewer apoptotic cells upon ALPPS (p < 0.0001), but this was not confirmed by TUNEL staining (p = 0.7344).

Conclusions

ALPPS does not induce proliferation, apoptosis, or vascularization of CRLM when compared to standard liver resection.

Association between Ki67 Index and Clinicopathological Features in Colorectal Cancer

BACKGROUND

Conflicting results have been reported about the association between the Ki67 labeling index (Ki67-Li) and clinical outcome in patients with colorectal cancer (CRC).

PATIENTS AND METHODS

Ki67 expression was assessed by immunohistochemistry (IHC) in 2,233 consecutive CRC cases.

RESULTS

We determined 992 cases to have a low and 1,241 cases to have a high Ki67-Li (representing an approximately 44-56% breakdown in distribution between low versus high patients designated by phenotype). Stage III patients with a high Ki67-Li had higher 3-year disease-free survival (DFS) and overall survival (OS) than those with a low Ki67-Li (DFS 70 vs. 61%; p = 0.02 and OS 75 vs. 64%; p = 0.008). We also found significantly improved 3-year progression-free survival (PFS) for stage IV patients in the high versus the low Ki67-Li group (PFS 14 vs. 10%; p = 0.02). Yet, we found no statistical differences in prognosis for stage I and II patients and in OS for stage IV patients between high versus low Ki67-Li (p > 0.05).

CONCLUSION

Our results suggest that high Ki67-Li can be an independent prognostic biomarker to aid the assessment of patient outcomes in both stage III and IV CRC.

The anthelmintic niclosamide inhibits colorectal cancer cell lines via modulation of the canonical and noncanonical Wnt signaling pathway

BACKGROUND

Wnt/β-catenin signaling is known to play an important role in colorectal cancer (CRC). Niclosamide, a salicylamide derivative used in the treatment of tapeworm infections, targets the Wnt/β-catenin pathway. The objective of this study was to investigate niclosamide as a therapeutic agent against CRC.

METHODS

The antiproliferative effects of 1, 3, 10, and 50 μM concentrations of niclosamide on human (SW480 and SW620) and rodent (CC531) CRC cell lines were determined by MTS assay and direct cell count. The lymphoid enhancer-binding factor 1/transcription factor (LEF/TCF) reporter assay monitored the activity of Wnt signaling. Immunofluorescence staining demonstrated the expression pattern of active β-catenin. Gene expression of canonical and noncanonical Wnt signaling components was analyzed using qRT-PCR. Western blot analysis was performed with antibodies detecting nuclear localization of β-catenin and c-jun.

RESULTS

Cell proliferation in CRC cell lines was blocked dose dependently after 12 and 24 h of incubation. The Wnt promoter activity of LEF/TCF significantly decreased with niclosamide concentrations of 10 and 50 μM after 12 h of incubation. Active β-catenin did not shift from the nuclear to the cytosolic pool. However, canonical target genes (met, MMP7, and cyclin D1) as well as the coactivating factor Bcl9 were downregulated, whereas the noncanonical key player c-jun was clearly activated.

CONCLUSIONS

Niclosamide treatment is associated with an inhibitory effect on CRC development and reduced Wnt activity. It may exert its effect by interfering with the nuclear β-catenin-Bcl9-LEF/TCF triple-complex and by upregulation of c-jun representing noncanonical Wnt/JNK signaling. Thus, our findings warrant further research into this substance as a treatment option for patients with advanced CRC.

GPI/AMF inhibition blocks the development of the metastatic phenotype of mature multi-cellular tumor spheroids

Epithelial-mesenchymal transition (EMT) and cellular invasiveness are two pivotal processes for the development of metastatic tumor phenotypes. The metastatic profile of non-metastatic MCF-7 cells growing as multi-cellular tumor microspheroids (MCTSs) was analyzed by determining the contents of the EMT, invasive and migratory proteins, as well as their migration and invasiveness potential and capacity to secrete active cytokines such as the glucose phosphate isomerase/AMF (GPI/AMF). As for the control, the same analysis was also performed in MCF-7 and MDA-MB-231 (highly metastatic, MDA) monolayer cells, and in stage IIIB and IV human metastatic breast biopsies. The proliferative cell layers (PRL) of mature MCF-7 MCTSs, MDA monolayer cells and metastatic biopsies exhibited increased cellular contents (2-15 times) of EMT (β-catenin, SNAIL), migratory (vimentin, cytokeratin, and fibronectin) and invasive (MMP-1, VEGF) proteins versus MCF-7 monolayer cells, quiescent cell layers of mature MCF-7 MCTS and non-metastatic breast biopsies. The increase in metastatic proteins correlated with substantially elevated cellular abilities for migration (18-times) and invasiveness (13-times) and with the higher level (6-times) of the cytokine GPI/AMF in the extracellular medium of PRL, as compared to MCF-7 monolayer cells. Interestingly, the addition of the GPI/AMF inhibitors erythrose-4-phosphate or 6-phosphogluconate at micromolar doses significantly decreased its extracellular activity (>80%), with a concomitant diminution in the metastatic protein content and migratory tumor cell capacity, and with no inhibitory effect on tumor lactate production or toxicity on 3T3 mouse fibroblasts. The present findings provide new insights into the discovery of metabolic inhibitors to be used as complementary therapy against metastatic and aggressive tumors.

Tumour growth stimulation following partial hepatectomy in mice is associated with increased upregulation of c-Met

Hepatic resection is the preferred option for curative treatment of colorectal liver metastasis (CLM). However, this is associated with significant recurrence rates in both hepatic and extrahepatic sites. The upregulation of growth factors required for liver regeneration after resection is thought to stimulate the growth of micrometastases. The current study describes temporal changes in the expression of hepatocyte growth factor receptor (c-Met), epidermal growth factor receptor (EGFR) and insulin growth factor I receptor (IGF-IR) in an orthotopic mouse model of liver resection and tumour induction. Mice underwent 70% hepatectomy and induction of liver metastases through intrasplenic injection of colorectal cancer cells. Control groups included sham-operated mice and 70% hepatectomy alone. The expression levels of liver and tumour c-Met, EGFR and IGF-IR were quantified by quantitative RT-PCR at different time points. 70% liver resection stimulates tumour growth; increases the expression of c-Met within established tumours and surrounding liver parenchyma; downregulates EGFR expression and increases IGF-IR expression within the liver parenchyma. In conclusion, we demonstrate in our mouse model that major hepatectomy stimulates engraftment and growth of CLM and that this effect is probably due to the upregulation of c-Met as a result of the liver regeneration process. Liver IGF-IR may also contribute to this phenomenon through a paracrine effect on tumour growth. This study provides support for the role of c-Met in the stimulation of tumour growth after resection possibly through the promotion of tumour cell proliferation.