Pathobiology of colorectal cancer hepatic metastases with an emphasis on prognostic factors

Orosomucoid 1 promotes colorectal cancer progression and liver metastasis by affecting PI3K/AKT pathway and inducing macrophage M2 polarization

Approximately 25-30% of those affected by colorectal cancer (CRC), the most prevalent gastrointestinal malignancy, develop metastases. The survival rate of patients with liver metastasis of CRC (CRLM) remains low owing to its unpredictability and a lack of biomarkers that can be applied to distinguish groups at higher risk for CRLM among patients with CRC. Therefore, our study aimed to find biomarkers that can predict the risk of CRLM. Screening of the Gene Expression Omnibus database, supported by an analysis of clinically obtained tissue and serum data using qPCR and ELISA, in an attempt to identify relevant biomarkers, enabled us to determine that orosomucoid 1 (ORM1) was differentially expressed in liver metastases and primary tumors of patients with CRC. Functionally, overexpression of ORM1 promoted the epithelial-mesenchymal transition and the proliferative, migratory, and invasive activities of MC38 cells and activated the PI3K/AKT signaling pathway. Moreover, MC38 cells overexpressing ORM1 enhanced the tumor immune microenvironment by promoting macrophage M2 polarization and elevating interleukin-10 (IL-10) expression. In vivo experiments further confirmed in vitro results, indicating that liver metastases elevated by ORM1 were partially attenuated by the depletion of macrophages or IL-10. Considered together, ORM1 promotes CRC progression and liver metastasis by regulating tumor cell growth and inducing macrophage M2 polarization, which mediates tumor immune tolerance, and thus acts as a potential predictive marker and therapeutic target in CRLM.

ANGPTL2+cancer-associated fibroblasts and SPP1+macrophages are metastasis accelerators of colorectal cancer

Background

Liver metastasis (LM) is a leading cause of cancer-related deaths in CRC patients, whereas the associated mechanisms have not yet been fully elucidated. Therefore, it is urgently needed to deeply explore novel metastasis accelerators and therapeutic targets of LM-CRC.

Methods

The bulk RNA sequencing data and clinicopathological information of CRC patients were enrolled from the TCGA and GEO databases. The single-cell RNA sequencing (scRNA-seq) datasets of CRC were collected from and analyzed in the Tumor Immune Single-cell Hub (TISCH) database. The infiltration levels of cancer-associated fibroblasts (CAFs) and macrophages in CRC tissues were estimated by multiple immune deconvolution algorithms. The prognostic values of genes were identified by the Kaplan-Meier curve with a log-rank test. GSEA analysis was carried out to annotate the significantly enriched gene sets. The biological functions of cells were experimentally verified.

Results

In the present study, hundreds of differentially expressed genes (DEGs) were selected in LM-CRC compared to primary CRC, and these DEGs were significantly associated with the regulation of endopeptidase activity, blood coagulation, and metabolic processes. Then, SPP1, CAV1, ANGPTL2, and COLEC11 were identified as the characteristic DEGs of LM-CRC, and higher expression levels of SPP1 and ANGPTL2 were significantly associated with worse clinical outcomes of CRC patients. In addition, ANGPTL2 and SPP1 mainly distributed in the tumor microenvironment (TME) of CRC tissues. Subsequent scRNA-seq analysis demonstrated that ANGPTL2 and SPP1 were markedly enriched in the CAFs and macrophages of CRC tissues, respectively. Moreover, we identified the significantly enriched gene sets in LM-CRC, especially those in the SPP1+macrophages and ANGPTL2+CAFs, such as the HALLMARK_EPITHELIAL_MESENCHYMAL_TRANSITION and the HALLMARK_COMPLEMENT. Finally, our in vitro experiments proved that ANGPTL2+CAFs and SPP1+macrophages promote the metastasis of CRC cells.

Conclusion

Our study selected four characteristic genes of LM-CRC and identified ANGPTL2+CAFs and SPP1+macrophages subtypes as metastasis accelerators of CRC which provided a potential therapeutic target for LM-CRC.

Artificial Downregulation of Ribosomal Protein L34 Restricts the Proliferation and Metastasis of Colorectal Cancer by Suppressing the JAK2/STAT3 Signaling Pathway

The highly conserved ribosomal protein L34 (RPL34) has been reported to play an essential role in the progression of diverse malignancies. RPL34 is aberrantly expressed in multiple cancers, although its significant in colorectal cancer (CRC) is currently unclear. Here, we demonstrated that RPL34 expression was higher in CRC tissues than in normal tissues. Upon RPL34 overexpression, the ability of proliferation, migration, invasion, and metastasis of CRC cells were significantly enhanced in vitro and in vivo. Furthermore, high expression of RPL34 accelerated cell cycle progression, activated the JAK2/STAT3 signaling pathway, and induced the epithelial-to-mesenchymal transition (EMT) program. Conversely, RPL34 silencing inhibited the CRC malignant progression. Utilizing immunoprecipitation assays, we identified the RPL34 interactor, the cullin-associated NEDD8-dissociated protein 1 (CAND1), which is a negative regulator of cullin-RING ligases. CAND1 overexpression reduced the ubiquitin level of RPL34 and stabilized RPL34 protein. CAND1 silencing in CRC cells resulted in a decrease in the ability of proliferation, migration, and invasion. CAND1 overexpression promoted CRC malignant phenotypes and induced EMT, and RPL34 knockdown rescued CAND1-induced CRC progression. In summary, our study indicates that RPL34 acts as a mediator, is stabilized by CAND1, and promotes proliferation and metastasis, in part, through the activation of the JAK2/STAT3 signaling pathway and induction of EMT in CRC.

Phenotypic Characterization of Colorectal Liver Metastases: Capsule versus No Capsule and the Potential Role of Epithelial Mesenchymal Transition

Background: Colorectal liver metastases (CRLM) can be encased in a fibrous capsule separating cancer from normal liver tissue, which correlates with increased patient survival. This study investigated the cellular and molecular components of capsule formation and the possible role of epithelial mesenchymal transition (EMT). Methods: From 222 patients with CRLM, 84 patients (37.8%) were categorized to have CRLM encased with a capsule. A total of 34 CRLM from 34 selected patients was analyzed in detail by EMT pathway-profiling and custom PCR arrays to identify differences in gene expression between CRLM with (n = 20) and without capsule (n = 14). In parallel, those 34 CRLM were used to analyze 16 gene products at the metastasis margin via immunohistochemistry. Results: Encapsulated CRLM showed an elevated expression of signal transduction pathways and effector molecules involved in EMT. E-cadherin and keratin-19 were more prevalent, and transcription as well as translation (immunohistochemistry) of pGSK-3-β, SOX10, tomoregulin-1, and caldesmon were increased. By contrast, the loss of E-cadherin and the prevalence of snail-1 were increased in CRLM without capsule. Collagen I and III and versican were identified as capsule components with extracellular matrix fibers running concentrically around the malignant tissue and parallel to the invasive front. Caldesmon was also demonstrated as a capsule constituent. Conclusions: The fibrous capsule around CRLM can be produced by cells with mesenchymal characteristics. It functions as a protective border by both the features of fiber architecture and the inhibition of invasive growth through EMT recruiting mesenchymal cells such as myofibroblasts by transformation of surrounding epithelial or even carcinoma cells. By contrast, EMT demonstrated in non-encapsulated CRLM may lead to a more mesenchymal, mobile, and tissue-destructive carcinoma cell phenotype and facilitate malignant spread.

Construction of a DDR-related signature for predicting of prognosis in metastatic colorectal carcinoma

Background

Colorectal cancer (CRC) is the third most prevalent malignancy and the one of most lethal cancer. Metastatic CRC (mCRC) is the third most common cause of cancer deaths worldwide. DNA damage response (DDR) genes are closely associated with the tumorigenesis and development of CRC. In this study, we aimed to construct a DDR-related gene signature for predicting the prognosis of mCRC patients.

Methods

The gene expression and corresponding clinical information data of CRC/mCRC patients were obtained from Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. A prognostic model was obtained and termed DDRScore by the multivariate Cox proportional hazards regression in the patients with mCRC. The Kaplan-Meier (K-M) and Receiver Operating Characteristic (ROC) curves were employed to validate the predictive ability of the prognostic model. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway were performed for patients between the high-DDRscore and low-DDRscore groups.

Results

We constructed a prognostic model consisting of four DDR-related genes (EME2, MSH4, MLH3, and SPO11). Survival analysis showed that patients in the high-DDRscore group had a significantly worse OS than those in the low-DDRscore group. The area under the curve (AUC) value of the ROC curve of the predictive model is 0.763 in the training cohort GSE72970, 0.659 in the stage III/IV colorectal cancer (CRC) patients from The Cancer Genome Atlas (TCGA) data portal, and 0.639 in another validation cohort GSE39582, respectively. GSEA functional analysis revealed that the most significantly enriched pathways focused on nucleotide excision repair, base excision repair, homologous recombination, cytokine receptor interaction, chemokine signal pathway, cell adhesion molecules cams, ECM-receptor interaction, and focal adhesion.

Conclusion

The DDRscore was identified as an independent prognostic and therapy response predictor, and the DDR-related genes may be potential diagnosis or prognosis biomarkers for mCRC patients.

Multimodality liver directed treatment for colorectal liver metastasis: Array of complementary options can improve outcomes - A single centre experience from India

AIM

Complimentary use of Liver directed therapies (LDTs) with systemic chemotherapy has improved oncologic outcomes in colorectal liver metastasis (CRLM). We analysed institutional results of multimodality management.

Methods

Retrospective analysis of prospectively maintained database of CRLM patients managed with LDT including surgical resection, Ablation, Transarterial chemoembolization (TACE) or Transarterial radioembolization (TARE) between November 2011 to March 2020. Management plan was decided in multidisciplinary meeting. Resectable tumours underwent surgical resection or ablation or both in some cases. Borderline resectable or unresectable disease was treated with down staging chemotherapy or TACE/TARE followed by resection or ablation. All patients received adjuvant chemotherapy. Factors influencing survival were analysed.

Results

Out of total 375 patients, surgery alone was done in 191 (50.93%) patients while surgery with other LDT in 26 patients (6.93%). Ablation alone was done in 100 (26.66%) whereas TACE/TARE were done as standalone treatment in 21 (5.6%) and 7 (1.86%) patients respectively. TACE + ablation was done in 28 (7.46%) and TARE + ablation was done in 2(0.53%) patients.5-year Overall Survival(OS) was 49.8% while Event free survival(EFS) was 21.4%. The median OS and EFS for surgical group was significantly better than non-surgical group (78 V/s 39 months; p<0.05 and 20 V/s 15 months p <0.005). The resectable (78 months) group had better median OS as compared to borderline resectable and Unresectable group (39 months and 29 months). Male gender, resectable disease and surgical intervention were associated with improved OS.

Conclusion

Although surgery remains the mainstay of treatment, complementary use of non-surgical LDT with systemic therapy offers possibility of good outcomes in advanced liver limited disease. Our experience highlights the impact of multidisciplinary care in optimizing CRLM treatment.

Cancer-derived exosomal HSPC111 promotes colorectal cancer liver metastasis by reprogramming lipid metabolism in cancer-associated fibroblasts

Tumor metastasis is a hallmark of cancer. The communication between cancer-derived exosomes and stroma plays an irreplaceable role in facilitating pre-metastatic niche formation and cancer metastasis. However, the mechanisms underlying exosome-mediated pre-metastatic niche formation during colorectal cancer (CRC) liver metastasis remain incompletely understood. Here we identified HSPC111 was the leading upregulated gene in hepatic stellate cells (HSCs) incubated with CRC cell-derived exosomes. In xenograft mouse model, CRC cell-derived exosomal HSPC111 facilitated pre-metastatic niche formation and CRC liver metastases (CRLM). Consistently, CRC patients with liver metastasis had higher level of HSPC111 in serum exosomes, primary tumors and cancer-associated fibroblasts (CAFs) in liver metastasis than those without. Mechanistically, HSPC111 altered lipid metabolism of CAFs by phosphorylating ATP-citrate lyase (ACLY), which upregulated the level of acetyl-CoA. The accumulation of acetyl-CoA further promoted CXCL5 expression and secretion by increasing H3K27 acetylation in CAFs. Moreover, CXCL5-CXCR2 axis reinforced exosomal HSPC111 excretion from CRC cells and promoted liver metastasis. These results uncovered that CRC cell-derived exosomal HSPC111 promotes pre-metastatic niche formation and CRLM via reprogramming lipid metabolism in CAFs, and implicate HSPC111 may be a potential therapeutic target for preventing CRLM.

Small Interfering RNA in Colorectal Cancer Liver Metastasis Therapy

Colorectal cancer (CRC) is associated with numerous genetic disorders and cellular abnormalities, and liver metastasis is a common health concern in patients with CRC. Exploring newer and more efficient therapies to block liver metastasis is pivotal for prolonging patient survival. Therefore, small interfering RNAs (siRNAs) are expected to be remarkable tools capable of regulating gene expression by participating in a process called RNA interference (RNAi). RNAi is a biological process among eukaryotes wherein specific messenger RNA (mRNA) molecules are destroyed and gene expression is inhibited. This technology is a promising therapeutic agent in the treatment of CRC liver metastasis (CRLM). Nevertheless, crucial problems in siRNA therapeutics, including inherent poor serum stability and nonspecific uptake into biological systems, must be recognized. For this reason, delivery systems are being developed in an attempt to solve these problems. Here, we discuss the utility of siRNA therapy for the treatment of CRCLM by targeting the major metastasis-related signaling pathways. siRNA therapy has the potential to be one of the most effective methods for CRLM treatment in the future.

Combined Inhibition of p38MAPK and PIKfyve Synergistically Disrupts Autophagy to Selectively Target Cancer Cells

In nutrient-poor conditions, autophagy buffers metabolic stress and counteracts the effects of chemotherapy and radiation on cancer cells, which depend on autophagy for survival. However, clinical trials targeting autophagy have failed to produce successful anticancer treatments using currently available inhibitors. Recent studies have shown that PIKfyve kinase inhibitors disrupt lysosome function in autophagy and can selectively kill certain cancer cells. Analysis of biochemical changes caused by PIKfyve inhibition revealed that resistant cells contain significantly higher levels of cellular p38MAPK protein and phosphorylation. Expression of the lysosomal protein, lysosomal-associated membrane protein 2, carrying phosphomimetic mutations of the p38MAPK phosphorylation sites prevented all effects caused by PIKfyve inhibition-induced lysosome dysfunction. Thus, the activation of p38MAPK in response to PIKfyve inhibition revealed a novel compensatory role in maintaining lysosome function in autophagy. The functional cooperation between the cellular PIKfyve and p38MAPK pathways in regulating lysosome homeostasis was especially important in cancer cells. Combined inhibition of PIKfyve and p38MAPK activities synergistically blocked autophagy-mediated protein degradation, prevented cathepsin maturation, and markedly reduced the viability of multiple cancer cell types without affecting the viability of normal cells. Furthermore, combined PIKfyve and p38MAPK inhibitors synergistically reduced tumor growth in mice bearing xenografts of human colorectal adenocarcinoma, suggesting a novel way to target cancer cells by prolonged inhibition of autophagy using lower drug concentrations. SIGNIFICANCE: This study demonstrates that PIKfyve and p38MAPK cooperate to regulate lysosome homeostasis and their combined inhibition synergistically blocks autophagy to reduce cancer cell viability in vitro and in vivo.

Localized and triggered release of oxaliplatin for the treatment of colorectal liver metastasis

Purpose: The aim of this study was to develop and evaluate a liposome formulation that deliver oxaliplatin under magnetic field stimulus in high concentration to alleviate the off-target effects in a rat model of colorectal liver metastases (CRLM).

Materials and Methods: Hybrid liposome-magnetic nanoparticles loaded with Cy5.5 dye and oxaliplatin (L-NIR- Fe₃O₄/OX) were synthesized by using thermal decomposition method. CRLM (CC-531) cell viability was assessed and rats orthotopically implanted with CC-531 cells were treated with L-NIR-Fe₃O₄/OX or by drug alone via different routes, up to 3 cycles of alternating magnetic field (AMF). Optical and MR imaging was performed to assess the targeted delivery. Biodistribution and histology was performed to determine the distribution of oxaliplatin.

Results: L-NIR-Fe₃O₄/OX presented a significant increase of oxaliplatin release (~18%) and lower cell viability after AMF exposure (p<0.001). Optical imaging showed a significant release of oxaliplatin among mesenteric vein injected (MV) group of animals. MR imaging on MV injected animals showed R2* changes in the tumor regions at the same regions immediately after infusion compared to the surrounding liver (p<0.001). Biodistribution analysis showed significantly higher levels of oxaliplatin in liver tissues compared to lungs (p<0.001) and intestines (p<0.001) in the MV animals that received AMF after L-NIR- Fe₃O₄/OX administration. Large tumor necrotic zones and significant improvement in the survival rates were noted in the MV animals treated with AMF.

Conclusion: AMF triggers site selective delivery of oxaliplatin at high concentrations and improves survival outcomes in colorectal liver metastasis tumor bearing rats.

Biofunctionalized Hybrid Magnetic Gold Nanoparticles as Catalysts for Photothermal Ablation of Colorectal Liver Metastases

Purpose To demonstrate that anti-MG1 conjugated hybrid magnetic gold nanoparticles (HNPs) act as a catalyst during photothermal ablation (PTA) of colorectal liver metastases, and thus increase ablation zones. Materials and Methods All experiments were performed with approval of the institutional animal care and use committee. Therapeutic and diagnostic multifunctional HNPs conjugated with anti-MG1 monoclonal antibodies were synthesized, and the coupling efficiency was determined. Livers of 19 Wistar rats were implanted with 5 × 10⁶ rat colorectal liver metastasis cell line cells. The rats were divided into three groups according to injection: anti-MG1-coupled HNPs (n = 6), HNPs only (n = 6), and cells only (control group, n = 7). Voxel-wise R2 and R2* magnetic resonance (MR) imaging measurements were obtained before, immediately after, and 24 hours after injection. PTA was then performed with a fiber-coupled near-infrared (808 nm) diode laser with laser power of 0.56 W/cm² for 3 minutes, while temperature changes were measured. Tumors were assessed for necrosis with hematoxylin-eosin staining. Organs were analyzed with inductively coupled plasma mass spectrometry to assess biodistribution. Therapeutic efficacy and tumor necrosis area were compared by using a one-way analysis of variance with post hoc analysis for statistically significant differences. Results The coupling efficiency was 22 μg/mg (55%). Significant differences were found between preinfusion and 24-hour postinfusion measurements of both T2 (repeated measures analysis of variance, P = .025) and T2* (P < .001). Significant differences also existed for T2* measurements between the anti-MG1 HNP and HNP-only groups (P = .034). Mean temperature ± standard deviation with PTA in the anti-MG1-coated HNP, HNP, and control groups was 50.2°C ± 7.8, 51°C ± 4.4, and 39.5°C ± 2.0, respectively. Inductively coupled plasma mass spectrometry revealed significant tumor targeting and splenic sequestration. Mean percentages of tumor necrosis in the anti-MG1-coated HNP, HNP, and control groups were 38% ± 29, 14% ± 17, and 7% ± 8, respectively (P = .043). Conclusion Targeted monoclonal antibody-conjugated HNPs can serve as a catalyst for photothermal ablation of colorectal liver metastases by increasing ablation zones. ^© RSNA, 2017.

Decision Making in Interventional Oncology: Intra-arterial Therapies for Metastatic Colorectal Cancer-Y90 and Chemoembolization

Colorectal cancer is the third most common cancer in the United States and the liver is the most common site of metastatic disease. The presence and extent of hepatic metastases are a major prognostic indicator. Although surgical resection is the accepted first-line therapy for colorectal liver metastasis, only 20 to 25% of patients are eligible for resection due to the extent and location of disease. This article discusses the current role of transarterial therapies in the treatment of colorectal liver metastases.

Radiosurgery for liver metastases. A single institution experience

AIM

To report our initial results on the use of radiosurgery for treatment of liver metastases.

BACKGROUND

In recent years there has been increasing interest in the use of stereotactic body radiation therapy to treat metastatic disease to the liver as an alternative to interventional procedures.

MATERIALS AND METHODS

Between November 2008 and June 2015 a total of 36 LINAC-based radiosurgeries using VMAT were performed in 27 patients with liver metastases from 10 different primary sites. Doses ranged from 21 Gy to 60 Gy in 1 to 5 fractions. In all patients the volume of liver receiving less than 15 Gy was more than 700 cc. The volume treated with the prescription dose ranged from 1 cc to 407 cc with a median of 58 cc. All patients but one received systemic treatment.

RESULTS

Overall median survival for the entire group is 9 months (ranging from 1 to 67 months). Local recurrence free survival ranged from 4 to 67 months with a median of 14 months. Twenty patients (80%) survived more than six months. Three patients treated for oligometastases were alive after 3 years. Grade 0 toxicity was encountered in 22/27 patients, Grade 1 toxicity in 5/27 and only 1/27 patient experienced Grade 2 toxicity. No patient experienced grade 3-4 toxicity.

CONCLUSION

Based on these initial results we conclude that SBRT for treating liver metastases with radiosurgery is safe and effective for treating one or multiple lesions as long as normal tissue constraints for liver are respected.

Dual Anti-Metastatic and Anti-Proliferative Activity Assessment of Two Probiotics on HeLa and HT-29 Cell Lines

OBJECTIVE

Lactobacilli are a group of probiotics with beneficial effects on prevention of cancer. However, there is scant data in relation with the impacts of probiotics in late-stage cancer progration, especially metastasis. The present original work was aimed to evaluate the anti-metastatic and anti-proliferative activity of lactobacillus rhamnosus supernatant (LRS) and lactobacillus crispatus supernatant (LCS) on the human cervical and colon adenocarcinoma cell lines (HeLa and HT-29, respectively).

MATERIALS AND METHODS

In this experimental study, the anti-proliferative activities of LRS and LCS were determined through MTT assay. MRC-5 was used as a normal cell line. Expression analysis of CASP3, MMP2, MMP9, TIMP1 and TIMP2 genes was performed by quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR), following the cell synchronization.

RESULTS

Supernatants of these two lactobacilli had cytotoxic effect on HeLa, however LRS treatment was only effective on HT-29 cell line. In addition, LRS had no side-effect on normal cells. It was shown that CASP3 gene expression has been reduced after treatment with supernatants of two studied lactobacilli. According to our study, LRS and LCS are efficacious in the prevention of metastasis potency in HeLa cells with decreased expression of MMP2, MMP9 and increased expression of their inhibitors. In the case of HT-29 cells, only LRS showed this effect.

CONCLUSION

Herein, we have demonstrated two probiotics which have anti-metastatic effects on malignant cells and they can be administrated to postpone late-stage of cancer disease. LRS and LCS are effective on HeLa cell lines while only the effect of LRS is significant on HT-29, through cytotoxic and anti-metastatic mechanisms. Further assessments are required to evaluate our results on the other cancer cell lines, in advance to use these probiotics in other extensive trial studies.

Clinical results of mean GTV dose optimized robotic guided SBRT for liver metastases

Background

We retrospectively evaluated the efficacy and toxicity of gross tumor volume (GTV) mean-dose-optimized and real-time motion-compensated robotic stereotactic body radiation therapy (SBRT) in the treatment of liver metastases.

Methods

Between March 2011 and July 2015, 52 patients were treated with SBRT for a total of 91 liver metastases (one to four metastases per patient) with a median GTV volume of 12 cc (min 1 cc, max 372 cc). The optimization of mean GTV dose was prioritized during treatment planning at the potential cost of planning target volume (PTV) coverage reduction while adhering to safe normal tissue constraints. The delivered median GTV biological effective dose (BED₁₀) was 142.1 Gy₁₀ (range, 60.2 Gy₁₀ –165.3 Gy₁₀) and the prescribed PTV BED₁₀ ranged from 40.6 Gy₁₀ to 112.5 Gy₁₀ (median, 86.1 Gy₁₀). We analyzed local control (LC), progression-free interval (PFI), overall survival (OS), and toxicity.

Results

Median follow-up was 17 months (range, 2–49 months). The 2-year actuarial LC, PFI, and OS rates were 82.1, 17.7, and 45.0 %, and the median PFI and OS were 9 and 23 months, respectively. In univariate analysis histology (p < 0.001), PTV prescription BED₁₀ (HR 0.95, CI 0.91–0.98, p = 0.002) and GTV mean BED₁₀ (HR 0.975, CI 0.954–0.996, p = 0.011) were predictive for LC. Multivariate analysis showed that only extrahepatic disease status at time of treatment was a significant factor (p = 0.033 and p = 0.009, respectively) for PFI and OS. Acute nausea or fatigue grade 1 was observed in 24.1 % of the patients and only 1 patient (1.9 %) had a side effect of grade ≥ 2.

Conclusions

Robotic real-time motion-compensated SBRT is a safe and effective treatment for one to four liver metastases. Reducing the PTV prescription dose and keeping a high mean GTV dose allowed the reduction of toxicity while maintaining a high local control probability for the treated lesions.

Characterization of CC-531 as a Rat Model of Colorectal Liver Metastases

Purpose

Surgical resection of colorectal liver metastases is not achievable in more than 70% of the cases. Although the liver directed therapies have become a part of the stand of care, lack of a preclinical model impedes the assessment of toxicity and therapeutic benefits attributed several candidate drugs or treatment regimens that can be designed. In the present study we aim develop and characterize a rat colorectal liver metastasis model.

Materials and Methods

Growth characteristics of CC-531 cells were determined in vitro followed by subcapsular liver implantation in syngeneic WAG/Rij rats. Tumor growth progression was followed over 3 weeks by ultrasound (US) and magnetic resonance imaging (MRI). Growth characteristics were also assessed by histopathology and immunohistochemistry in harvested tumor tissues.

Results

The doubling time of CC-531 cells was found be under 24hrs and all the implanted rats grew tumors. US imaging showed hypoechoic masses and MRI showed contrast enhancement representing complex tumor microenvironments. Hematoxylin and Eosin staining confirmed tumor growth and uniform CD31 staining in tumor confirmed even vessel density.

Conclusion

CC-531 can be used as a metastatic rat tumor colorectal liver metastases model with well-defined characteristics that can be readily followed by imaging whilst having a therapeutic window for interventions.

Safety analysis of the oncological outcome after vein-preserving surgery for colorectal liver metastases detached from the main hepatic veins

PURPOSE

Recent studies have reported that margins alone do not predict survival in patients with a positive chemotherapy response. The aim of this retrospective study is to analyze the surgical and oncological outcomes of patients who underwent chemotherapy and liver resection for colorectal liver metastases (CRLM) with lesions detached from the main hepatic veins, comparing the vein-preserving (VP) approach with traditional surgery.

METHODS

Fourteen patients undergoing VP surgery from January 2006 to January 2013 were matched in a 1:2 ratio with a control group (CG) of 28 patients undergoing traditional resection.

RESULTS

The median follow-up was 43 months. The radiological response was classified as 'partial response' in eight VP patients and 11 controls (57 vs. 39 %, p = 0.249) and as 'stable disease' in three VP patients and 9 controls (21 vs. 32 %, p = 0.465). Ten VP (71.4 %) and twenty CG patients (71.4 %) experienced tumor relapse (p = 0.99). No venous edge recurrences were recorded in the VP group, whereas 1/13 (7.7 %) was observed in the control group (p = 0.99). The pathological response rate was 64 vs. 39 % (p = 0.037) in VP and CG patients, respectively. The 5-year recurrence-free survival rate was 24 % for VP patients and 25 % for CG patients (p = 0.431).

CONCLUSION

In patients with a positive CT response, CRLM can be detached from the hepatic veins, as the oncological outcome is similar to that of a larger resection. The VP approach offers the possibility to enlarge the surgical indications, thus optimizing future surgical treatment chances.

Stereotactic radiation therapy for liver metastases: factors affecting local control and survival

Purpose

To report on outcome and toxicity of stereotactic body radiotherapy (SBRT) for liver metastases in patients not eligible for surgery.

Methods

From 2000 to 2009, 74 patients with 91 liver metastases from different primaries have been treated with SBRT at our institution. Median planning target volume was 123 ccm (range: 10.6-1074 ccm). Treatment consisted of 3–5 fractions with 5–12.5 Gy/ fraction prescribed to the surrounding 60-95% isodose with daily image guidance. Regular follow-up included CT or MRI imaging until tumor progression.

Results

Median local recurrence-free interval was 23 months with a local control rate of 74.7%, 48.3% and 48.3% after 1, 2 and 3 years. Only minimum biologically effective dose (BED) to gross tumor volume (GTV) remained as independent significant factor for local control in multivariate analysis. No local recurrences were observed in lesions (n = 12) which received a minimal BED to the GTV of 120 Gy. Including 26 local recurrences, 67 patients (91%) showed disease progression after SBRT with a median time of 5 months. Median overall survival was 27 months with survival rates of 77%, 30% and 27% at 1, 3 and 5 years. On multivariate analysis only GTV volume remained as independent significant prognostic factor for overall survival (p = 0.002). No grade 3 to 5 acute toxicity and no grade 4 or 5 late toxicity occurred.

Conclusion

SBRT for liver metastases was well tolerated in this non-selected patient cohort and yielded good local control despite the considerable size of most lesions treated. Long-term survival is possible after SBRT.

Electronic supplementary material

The online version of this article (doi:10.1186/s13014-015-0369-9) contains supplementary material, which is available to authorized users.

Widespread FRA1-dependent control of mesenchymal transdifferentiation programs in colorectal cancer cells

Tumor invasion and metastasis involves complex remodeling of gene expression programs governing epithelial homeostasis. Mutational activation of the RAS-ERK is a frequent occurrence in many cancers and has been shown to drive overexpression of the AP-1 family transcription factor FRA1, a potent regulator of migration and invasion in a variety of tumor cell types. However, the nature of FRA1 transcriptional targets and the molecular pathways through which they promote tumor progression remain poorly understood. We found that FRA1 was strongly expressed in tumor cells at the invasive front of human colorectal cancers (CRCs), and that its depletion suppressed mesenchymal-like features in CRC cells in vitro. Genome-wide analysis of FRA1 chromatin occupancy and transcriptional regulation identified epithelial-mesenchymal transition (EMT)-related genes as a major class of direct FRA1 targets in CRC cells. Expression of the pro-mesenchymal subset of these genes predicted adverse outcomes in CRC patients, and involved FRA-1-dependent regulation and cooperation with TGFβ signaling pathway. Our findings reveal an unexpectedly widespread and direct role for FRA1 in control of epithelial-mesenchymal plasticity in CRC cells, and suggest that FRA1 plays an important role in mediating cross talk between oncogenic RAS-ERK and TGFβ signaling networks during tumor progression.

Randomized multicentre trial of gadoxetic acid-enhanced MRI versus conventional MRI or CT in the staging of colorectal cancer liver metastases

BACKGROUND

This multicentre international randomized trial compared the impact of gadoxetic acid-enhanced magnetic resonance imaging (MRI), MRI with extracellular contrast medium (ECCM-MRI) and contrast-enhanced computed tomography (CE-CT) as a first-line imaging method in patients with suspected colorectal cancer liver metastases (CRCLM).

METHODS

Between October 2008 and September 2010, patients with suspected CRCLM were randomized to one of the three imaging modalities. The primary endpoint was the proportion of patients for whom further imaging after initial imaging was required for a confident diagnosis. Secondary variables included confidence in the therapeutic decision, intraoperative deviations from the initial imaging-based surgical plan as a result of additional operative findings, and diagnostic efficacy of the imaging modalities versus intraoperative and pathological extent of the disease.

RESULTS

A total of 360 patients were enrolled. Efficacy was analysed in 342 patients (118, 112 and 112 with gadoxetic acid-enhanced MRI, ECCM-MRI and CE-CT respectively as the initial imaging procedure). Further imaging was required in 0 of 118, 19 (17.0 per cent) of 112 and 44 (39.3 per cent) of 112 patients respectively (P < 0.001). Diagnostic confidence was high or very high in 98.3 per cent of patients for gadoxetic acid-enhanced MRI, 85.7 per cent for ECCM-MRI and 65.2 per cent for CE-CT. Surgical plans were changed during surgery in 28, 32 and 47 per cent of patients in the respective groups.

CONCLUSION

The diagnostic performance of gadoxetic acid-enhanced MRI was better than that of CE-CT and ECCM-MRI as the initial imaging modality. No further imaging was needed in the gadoxetic acid-enhanced MRI group and comparison of diagnostic efficacy parameters demonstrated the diagnostic superiority of gadoxetic acid-enhanced MRI.

REGISTRATION NUMBER

NCT00764621(http://clinicaltrials.gov); EudraCT number: 2008-000583-16 (https://eudract.ema.europa.eu/).

MACC1 - a novel target for solid cancers

INTRODUCTION

The metastatic dissemination of primary tumors is directly linked to patient survival in many tumor entities. The previously undescribed gene metastasis-associated in colon cancer 1 (MACC1) was discovered by genome-wide analyses in colorectal cancer (CRC) tissues. MACC1 is a tumor stage-independent predictor for CRC metastasis linked to metastasis-free survival.

AREAS COVERED

In this review, the discovery of MACC1 is briefly presented. In the following, the overwhelming confirmation of these data is provided supporting MACC1 as a new remarkable biomarker for disease prognosis and prediction of therapy response for CRC and also for a variety of additional forms of solid cancers. Lastly, the potential clinical utility of MACC1 as a target for prevention or restriction of tumor progression and metastasis is envisioned.

EXPERT OPINION

MACC1 has been identified as a prognostic biomarker in a variety of solid cancers. MACC1 correlated with tumor formation and progression, development of metastases and patient survival representing a decisive driver for tumorigenesis and metastasis. MACC1 was also demonstrated to be of predictive value for therapy response. MACC1 is a promising therapeutic target for anti-tumor and anti-metastatic intervention strategies of solid cancers. Its clinical utility, however, must be demonstrated in clinical trials.

Aggressive treatment of patients with metastatic colorectal cancer increases survival: a scandinavian single-center experience

Background. We examined overall and disease-free survivals in a cohort of patients subjected to resection of liver metastasis from colorectal cancer (CRLM) in a 10-year period when new treatment strategies were implemented. Methods. Data from 239 consecutive patients selected for liver resection of CRLM during the period from 2002 to 2011 at a single center were used to estimate overall and disease-free survival. The results were assessed against new treatment strategies and established risk factors. Results. The 5-year cumulative overall and disease-free survivals were 46 and 24%. The overall survival was the same after reresection, independently of the number of prior resections and irrespectively of the location of the recurrent disease. The time intervals between each recurrence were similar (11 ± 1 months). Patients with high tumor load given neoadjuvant chemotherapy had comparable survival to those with less extensive disease without neoadjuvant chemotherapy. Positive resection margin or resectable extrahepatic disease did not affect overall survival. Conclusion. Our data support that one still, and perhaps to an even greater extent, should seek an aggressive therapeutic strategy to achieve resectable status for recurrent hepatic and extrahepatic metastases. The data should be viewed in the context of recent advances in the understanding of cancer biology and the metastatic process.

Co-expression of CD133(+)/CD44(+) in human colon cancer and liver metastasis

Although relatively good therapeutic results are achieved in non-advanced cancer, the prognosis of the advanced colon cancer still remains poor, dependent on local or distant recurrence of the disease. One of the factors responsible for recurrence is supposed to be cancer stem cells (CSCs) or tumor-initiating cells, which are a population of cancer cells with ability to perpetuate themselves through self-renewal and to generate differentiated cells, thought to be responsible for tumor recurrence. This study globally approach the possible role of tissue-derived stem cells in the initiation of colon cancer and its metastatic process in the liver. Fresh surgical specimens from colon cancer, non-tumor tissue and liver metastasis were obtained directly from the operating room, examined, and immediately processed. CSCs were selected under serum-free conditions and characterized by CD44 and CD133 expression levels. CD133(+)/CD44(+) cell populations were then investigated in paraffin-embedded tissues and circulating tumor cells isolated from peripheral blood of the same group of colon cancer patients. Our data demonstrate that metastatic properties of cell populations from blood and liver metastasis, differently from primitive tumors, seem to be strictly related to the phenotype CD133 positive and CD44 positive.

PI3K expression and PIK3CA mutations are related to colorectal cancer metastases

AIM: To assess the significance of phosphatidylinositol 3-kinase (PI3K) in colorectal cancer (CRC) and toxicity of LY294002 in CRC cells with different metastatic abilities.

METHODS: Sixty formalin-fixed and paraffin-embedded CRC tumor specimens were investigated. Adjacent normal colonic mucosa specimens from 10 of these cases were selected as controls. PI3K protein was detected by immunohistochemistry and PIK3CA mutations were investigated by gene sequencing analysis. A flow-cytometry-based apoptosis detection kit was used to determine PI3K inhibitor-induced apoptosis in CRC cell lines SW480 and SW620. Expression of phosphorylated protein kinase B in CRC cell lines was detected by Western blotting.

RESULTS: There was a significant difference in the proportion of primary lesions (30%, 18/60) vs metastatic lesions (46.7%, 28/60) that were positive for PI3K (P < 0.05). Mutations were detected in exon 9 (13.3%) and exon 20 (8.3%). Out of 60 cases, seven mutations were identified: two hotspot mutations, C.1633G>A resulting in E545A, and C.3140A>G resulting in H1047R; two novel missense mutations C.1624G>A and C.3079G>A; and three synonymous mutations (C.1641G>A, C.1581C>T and C.3027T>A). Exposure of SW480 cells to PI3K inhibitor for 48 h resulted in a significant increase of apoptotic cells in a dose-dependent manner [3.2% apoptotic cells in 0 μmol/L, 4.3% in 5 μmol/L, 6.3% in 10 μmol/L (P < 0.05), and 6.7% in 20 μmol/L (P < 0.05)]. Moreover, PI3K inhibitor induced a similar significant increase of apoptotic cells in the SW620 cell line for 48 h [3.3% apoptotic cells in 0 μmol/L, 13.3% in 5 μmol/L (P < 0.01), 19.2% in 10 μmol/L (P < 0.01), and 21.3% in 20 μmol/L (P < 0.01)].

CONCLUSION: High PI3K expression is associated with CRC metastasis. PI3K inhibitor induced apoptosis in CRC cells and displayed strong cytotoxicity for highly metastatic cells. PI3K inhibition may be an effective treatment for CRC.

Cell-free supernatants from probiotic Lactobacillus casei and Lactobacillus rhamnosus GG decrease colon cancer cell invasion in vitro

Probiotics have been shown to have a preventative role in colorectal carcinogenesis but research concerning their prophylactic potential in the later stages of colorectal cancer, specifically metastasis is limited. This study explored the potential of cell-free supernatants (CFS) from 2 probiotic Lactobacillus sp., Lactobacillus casei and Lactobacillus rhamnosus GG, to inhibit colon cancer cell invasion by influencing matrix metalloproteinase-9 (MMP-9) activity and levels of the tight junction protein zona occludens-1 (ZO-1) in cultured metastatic human colorectal carcinoma cells. HCT-116 cells were treated with CFS from L. casei, L. rhamnosus, or Bacteroides thetaiotaomicron (a gut commensal); or with uninoculated bacterial growth media. Treatment with CFS from both Lactobacillus sp. decreased colorectal cell invasion but treatment with CFS from B. thetaiotaomicron did not. CFS from both Lactobacillus sp. decreased MMP-9 and increased ZO-1 protein levels. L. rhamnosus CFS also lowered MMP-9 activity. To begin elucidating the secreted bacterial factor conveying these responses, Lactobacillus sp. CFS were fractionated into defined molecular weight ranges and cell invasion assessed. Fractionation revealed that the inhibitory activity was contained primarily in the >100 kDa and 50-100 kDa fractions, suggesting the inhibitory compound may be a macromolecule such as a protein, nucleic acid, or a polysaccharide.

Regulatory T-cell-mediated inhibition of antitumor immune responses is associated with clinical outcome in patients with liver metastasis from colorectal cancer

Adaptive regulatory T cells (Tregs) contribute to an immunosuppressive microenvironment in colorectal cancer (CRC). Here, we examined whether the level of Treg-mediated inhibition of antitumor immune responses in patients with metastatic CRC (metCRC) selected for liver resection is associated with clinical outcome. Preoperatively and at follow-ups, we did flow-based phenotyping, examined antitumor immunity using peptides from carcinoembryonic antigen (CEA) protein in the presence or absence of CD4(+)CD25(+)CD127(dim/-) cells (Tregs) and determined cytokine and PGE(2) levels in patient blood samples. At 18 months post-surgery, 8 patients were disease free (7 alive and 1 dead of unrelated cause) and 10 had experienced disease recurrence (7 alive and 3 dead of metCRC). Prior to surgery, the patients demonstrated Treg-mediated suppression of TNFα and IFNγ expression that could be perturbed through the PGE(2)/cAMP pathway and the immune suppression was significantly higher in the group that later developed disease recurrence (P = 0.046). Furthermore, the post-surgery plasma PGE(2) levels were related to the clinical outcome (PGE(2) levels of 280 ± 47 vs. 704 ± 153 pg/ml (mean ± SEM) for disease free and recurrent disease, respectively). T-cell phenotyping revealed higher frequencies of COX-2(+) cells in the patients with recurrent disease. These findings support the notion that the level of Treg-mediated suppression of adaptive antitumor immune responses at the time of surgery may influence later clinical outcome of metCRC and provide valuable prognostic information.

Overexpression of survivin is correlated with increased invasion and metastasis of colorectal cancer

BACKGROUND

The aim of this study was to investigate the association of survivin expression with metastasis of colorectal cancer (CRC).

METHODS

RT-PCR and Western blot assays were performed to detect survivin expression in CRC cells and normal intestinal epithelial cell. The expression of survivin gene was also detected in 15 CRC tissues, surrounding and adjacent colon tissues. Moreover, survivin expression in 48 CRC tissues with or without lymph node metastasis was analyzed. Multivariate analysis for lymph node metastasis was performed using logistic regression model. RNA interference was used to inhibit survivin expression in CRC cells and analyze its effect on invasion and metastasis of CRC cells.

RESULTS

The expression levels of survivin mRNA and protein were higher in CRC cells than in normal intestinal epithelial cell line. The average levels of survivin mRNA and protein were higher in CRC tissues than surrounding or adjacent colon tissues (P < 0.05). High survivin expression was an independent factor for predicting lymph node metastasis of CRC (P = 0.043). RNAi-mediated survivin knockdown could significantly inhibit in vitro invasion and in vivo metastasis of CRC cells, which might be inactivation of matrix metalloproteinases.

CONCLUSION

Targeting survivin will be a potential strategy to suppress metastasis of CRC.

Liver metastases from colorectal cancer: how to best complement medical treatment with surgical approaches

Colorectal liver metastases (CLM) represent a major challenge for oncologists and surgeons. In fact, in this setting, the optimal treatment of patients can achieve a long-term survival and sometimes a definitive cure of disease. In recent years, improvements in both medical therapies and surgical approaches have led to an increased rate of patients considered amenable for surgery on CLM. New perspectives in the management of CLM underline the need for a comprehensive assessment of patient and tumor characteristics, to integrate technical and prognostic issues into an individualized therapeutic strategy in different patient subgroups. The multidisciplinary evaluation from the onset and during treatment remains the key element to maximizing the benefit of more intensive treatment modalities.