Colon Cancer Hepatic Metastasis Research Articles

Abstract LB441: An intravenous compatible oncolytic vaccinia virus treated hepatic metastasis of colon cancer through extensive cancer cell killing and activation of cytotoxic effector differentiation

Abstract Colorectal cancer (CRC) is the third most common cancer worldwide and nearly 50% of CRC patients develop liver metastasis during the course of their disease. Treatment of colorectal cancer liver metastasis (CRLM) has been particularly challenging due to tolerogenic nature of liver immune microenvironment as well as an eventual development of therapy resistance to standard chemotherapy regimen. One promising area of cancer immunotherapy is oncolytic virotherapy that can selectively destroy tumor cells and stimulate anti-tumor immune response. In this study, we systemically administered mSJ-650, an intravenous compatible oncolytic Wyeth strain vaccinia virus that expresses human complement regulatory protein CD55 and murine GM-CSF in place of viral thymidine kinase gene and has a deletion of the viral K2L gene, and evaluated its anti-tumor efficacy in CRLM. Mouse CRLM was induced by intrasplenic injection of 5×105 MC38-OVA cancer cells. Following tumor nodules formation in the liver, low dose (1×106 pfu) or high dose (3×106 pfu) of mSJ-650 was administered multiple times via tail vein and liver was harvested for evaluation of anti-tumor efficacy. Flow cytometry analysis was performed to investigate changes in hepatic and tumor immune microenvironment upon mSJ-650 treatment. Liver and tumor tissue were stained for immunofluorescence imaging of viral replication within the tumor cells and subsequent oncolysis by the virus. Systemic administration of mSJ-650 showed potent anti-tumor efficacy and led to significant reduction in metastatic nodule formation in liver even at low dose. The anti-tumor efficacy was mediated by tumor cell-specific viral distribution and replication, followed by lytic egress of mSJ-650 from infected tumor cells. Anti-tumor efficacy of mSJ-650 also accompanied a dramatic shift in immunologically tolerant hepatic microenvironment to immune-stimulatory one by decreasing proportion of myeloid-derived suppressor cells, Kupffer cells, and monocyte-derived macrophages (MDMs) in the liver while increasing CD8+ T cell infiltration by 2~3 folds. Moreover, mSJ-650 treatment was associated with phenotypic change in hepatic immune cells, as evidenced by Kupffer cell and MDM polarization to M1 phenotype and elevated expression of activation markers and cytotoxic molecules in CD8+ T cells. Changes in hepatic immune microenvironment were also observed in tumor nodules, especially in those completely surrounded by adjacent liver tissue, suggesting that anti-tumor immune response in tumor bed is potentiated by reprogramming of tumor-adjacent hepatic immune microenvironment. Systemic administration of mSJ-650 demonstrated superior anti-tumor efficacy in CRLM which was mediated by direct tumor cell killing and tumor-adjacent hepatic immune microenvironment reprogramming by the virus. Citation Format: Eunhye Kim, Yeonsoo Yang, Solchan Won, Namhee Lee, Songyi Lee, Mi-Ju Park, Byung-Jin Jung, Yun-Kyoung Hong, Hang-Rae Kim, Dong-Sup Lee, Keunhee Oh. An intravenous compatible oncolytic vaccinia virus treated hepatic metastasis of colon cancer through extensive cancer cell killing and activation of cytotoxic effector differentiation [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 2 (Late-Breaking, Clinical Trial, and Invited Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(7_Suppl):Abstract nr LB441.

Deletion of mTOR in liver epithelial cells enhances hepatic metastasis of colon cancer.

Activation of the mechanistic target of rapamycin (mTOR) pathway is frequently found in cancer, but mTOR inhibitors have thus far failed to demonstrate significant antiproliferative efficacy in the majority of cancer types. Besides cancer cell-intrinsic resistance mechanisms, it is conceivable that mTOR inhibitors impact on non-malignant host cells in a manner that ultimately supports resistance of cancer cells. Against this background, we sought to analyze the functional consequences of mTOR inhibition in hepatocytes for the growth of metastatic colon cancer. To this end, we established liver epithelial cell (LEC)-specific knockout (KO) of mTOR (mTORLEC ) mice. We used these mice to characterize the growth of colorectal liver metastases with or without partial hepatectomy to model different clinical settings. Although the LEC-specific loss of mTOR remained without effect on metastasis growth in intact liver, partial liver resection resulted in the formation of larger metastases in mTORLEC mice compared with wildtype controls. This was accompanied by significantly enhanced inflammatory activity in LEC-specific mTOR KO livers after partial liver resection. Analysis of NF-ĸB target gene expression and immunohistochemistry of p65 displayed a significant activation of NF-ĸB in mTORLEC mice, suggesting a functional importance of this pathway for the observed inflammatory phenotype. Taken together, we show an unexpected acceleration of liver metastases upon deletion of mTOR in LECs. Our results support the notion that non-malignant host cells can contribute to resistance against mTOR inhibitors and encourage testing whether anti-inflammatory drugs are able to improve the efficacy of mTOR inhibitors for cancer therapy. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Tissue-Engineered “Metastases”: Treatment of Hepatic Colon Tumors with a Dual Action Autotaxin Inhibitor-Lysophosphatidic Acid Receptor Antagonist

Lysophosphatidic acid (LPA) acts via G protein coupled receptors (GPCRs) to regulate critical cellular functions and pathophysiological levels of LPA or its receptors are linked to cancer initiation, progression and metastasis. LPA is biosynthesized by the lysophospholipase D activity of autotaxin(ATX/lysoPLD), a known factor for tumorigenesis. By attenuating both LPA signaling and LPA production, we expected to observe synergistic anti-cancer therapeutic effects. In vitro, treatment of human colon cancer cells (HCT 116) with BrP-LPA, a potent dual action ATX inhibitor and pan-LPA GPCR antagonist, significantly reduced cell proliferation, migration and invasion. Next, a tissue-engineered xenograft model to mimic hepatic metastasis of colon cancer was used to evaluate BrP-LPA efficacy in vivo. HCT 116 cells were suspended in Extracel™, a synthetic extracellular matrix (sECM), and injected directly into the livers of nude mice (n = 8). After 1 week, BrP-LPA in saline buffer was administered for two weeks by intraperitoneal injection (10 mg/kg) twice per week. Controls were injected with saline buffer only. The BrP-LPA treated group showed reduced liver tumor weight (p < 0.05) and reduced tumor volume (p < 0.05) relative to controls. This study is the first demonstration of the effects of a dual action ATX inhibitor/LPA antagonist on colon cancer cells, and the first example of a tissue-engineered hepatic colon cancer “metastases” as a platform for anti-cancer drug evaluation. The results suggest that attenuation of signaling through the LPA pathway offers a promising therapeutic target for reducing colon cancer growth and metastasis.

CircPTK2 (hsa_circ_0005273) as a novel therapeutic target for metastatic colorectal cancer

BackgroundAs a novel class of noncoding RNAs, circRNAs have been recently identified to regulate tumorigenesis and aggressiveness. However, the function of circRNAs in colorectal cancer (CRC) metastasis remains unclear. We aimed to identify circRNAs that are upregulated in CRC tissues from patients and study their function in CRC metastasis.MethodsWe compared six pairs of CRC tissues and their matched adjacent non-tumor tissues by using circRNA microarray. We first evaluated the expression of circPTK2 (hsa_circ_0005273) in fresh tissues from CRC tumors and corresponding adjacent tissues by qPCR analysis. CircPTK2 expression levels in the tissue microarray with 5 years of survival information were determined by RNA-ISH analysis. Meanwhile, the expression levels of circulating circPTK2 were further analyzed according to the patients’ clinical features. We analyzed cell apoptosis, colony formation, migration, and invasion in CRC cells. To further elucidate the effect of circPTK2 in CRC metastasis, we also conducted a colon cancer hepatic and pulmonary metastasis experiment. We used RNA biotin-labeled pull down and mass spectrometry to identify the target of circPTK2. We established a PDTX model to evaluate the effect of shRNA specifically targeting circPTK2 on tumor metastasis.ResultsWe identified a novel circRNA, circPTK2, which is back-spliced of three exons (exons 27, 28 and 29) of PTK2 by using circRNA microarray, bioinformatics and functional studies. CircPTK2 was elevated in CRC tissues and positively associated with tumor growth and metastasis. CRC patients with increased circPTK2 expression were positively correlated with poorer survival rates. Furthermore, our studies showed that circPTK2 could promote EMT of CRC cells in vitro and in vivo by binding to vimentin protein on sites Ser38, Ser55 and Ser82. We further demonstrated the interaction of circPTK2 and vimentin mediated the regulation of CRC by knockdown or overexpression of vimentin. In addition, we revealed that tail vein injection of shRNA specifically targeting circPTK2 blunt tumor metastasis in a patient-derived CRC xenograft model.ConclusionsCollectively, these results demonstrate that circPTK2 exerts critical roles in CRC growth and metastasis and may serve as a potential therapeutic target for CRC metastasis, and also a promising biomarker for early diagnosis of metastasis.

Retinoblastoma binding protein 4 up-regulation is correlated with hepatic metastasis and poor prognosis in colon cancer patients

BackgroundRetinoblastoma binding protein 4 (RBBP4) plays an essential role in the development of multiple cancers. However, its relationship with prognosis in colon cancer and colon cancer hepatic metastasis has not been elucidated. The aim of this study was to explore the relationship between RBBP4 expression and prognosis of colon cancer patients and to evaluate RBBP4 as a new prognostic marker in these patients. MethodsEighty colon cancer patients underwent surgical resection of the colon were enrolled. Among them, forty colon cancer patients suffered with hepatic metastasis. The colon cancer tissues, para-colon cancer tissues, and hepatic metastatic cancer tissues were collected from the pathological department for further analysis. The expression of RBBP4 proteins was examined by immunohistochemistry and correlated with clinicopathological parameters. The Cancer Genome Atlas (TCGA) database was used to validate the expression and explore its relationship with clinical characteristics. ResultsRBBP4 was up-regulated in the colon cancer tissues compared with the para-colon cancer tissues. The analysis of TCGA database verified the upregulation of RBBP4 in the colon cancer tissues and RBBP4 overexpression was correlated with nerve invasion and poor outcomes of chemotherapy. Moreover, the positive rate of RBBP4 expression in 40 colon cancer patients with hepatic metastasis was higher in the hepatic metastatic cancer tissues (39/40, 97.5%) than in the colon cancer tissues (26/40, 65.0%). Our clinicopathological analysis showed that RBBP4 expression was significantly correlated with vascular invasion, hepatic metastasis, and lymph node involvement (all P < 0.05). Additionally, the survival analysis demonstrated that RBBP4 over-expression was correlated with poor prognosis. ConclusionsRBBP4 was upregulated in the colon cancer. RBBP4 may be a novel predictor for poor prognosis of colon cancer and colon cancer hepatic metastasis.

Expression of miR-454-3p and its effect on proliferation, invasion and metastasis of colon cancer

To study the expression of miR-454-3p in colon cancer and its effect on colon cancer proliferation, invasion and hepatic metastasis. Specimens of tumor tissues and paired adjacent tissues were collected from 20 patients with colorectal cancer for detecting the expression levels of miR-454-3p using in situ hybridization. Colon cancer cell line SW480 was transfected with a lentiviral vector to induce miR-454-3p over-expression, and the changes in cell proliferation and invasion were observed using cell counting kit-8 (CCK-8), clone formation assay and Transwell experiment. The effect of miR- 454-3p over-expression on hepatic metastasis of colon cancer was assessed in BALB/c mouse models. The results of in situ hybridization showed a significantly increased expression level of miR-454-3p in colon cancer tissues as compared with normal colon tissues (P &lt; 0.05). In SW480 cells, over-expression of miR-454-3p significantly promoted the cell proliferation and invasion (P &lt; 0.05). In BALB/c mice, SW480 cells over-expressing miR-454-3p showed a significantly higher potential for liver metastases than the control cells (P &lt; 0.05). miR-454-3p is overexpressed in the tumor tissues in patients with colorectal cancer and participates in the progression of colorectal cancer by promoting cancer cell proliferation, invasion, and liver metastasis. miR-454-3p may serve as a novel biomarker for colorectal cancer diagnosis and prognostic evaluation.

CDK8 Selectively Promotes the Growth of Colon Cancer Metastases in the Liver by Regulating Gene Expression of TIMP3 and Matrix Metalloproteinases.

: Unresectable hepatic metastases of colon cancer respond poorly to existing therapies and are a major cause of colon cancer lethality. In this study, we evaluated the therapeutic viability of targeting the mediator kinase CDK8, an early clinical stage drug target, as a means to suppress metastasis of colon cancer. CDK8 was amplified or overexpressed in many colon cancers and CDK8 expression correlated with shorter patient survival. Knockdown or inhibition of CDK8 had little effect on colon cancer cell growth but suppressed metastatic growth of mouse and human colon cancer cells in the liver. This effect was due in part to inhibition of already established hepatic metastases, indicating therapeutic potential of CDK8 inhibitors in the metastatic setting. In contrast, knockdown or inhibition of CDK8 had no significant effect on the growth of tumors implanted subcutaneously, intrasplenically, or orthotopically in the cecum. CDK8 mediated colon cancer growth in the liver through downregulation of matrix metalloproteinase (MMP) inhibitor TIMP3 via TGFβ/SMAD-driven expression of a TIMP3-targeting microRNA, miR-181b, along with induction of Mmp3 in murine or MMP9 in human colon cancer cells via Wnt/β-catenin-driven transcription. These findings reveal a new mechanism for negative regulation of gene expression by CDK8 and a site-specific role for CDK8 in colon cancer hepatic metastasis. Our results indicate the utility of CDK8 inhibitors for the treatment of colon cancer metastases in the liver and suggest that CDK8 inhibitors may be considered in other therapeutic settings involving TGFβ/SMAD or Wnt/β-catenin pathway activation. SIGNIFICANCE: These findings demonstrate that inhibition of the transcription-regulating kinase CDK8 exerts a site-specific tumor-suppressive effect on colon cancer growth in the liver, representing a unique therapeutic opportunity for the treatment of advanced colon cancer.Graphical Abstract: http://cancerres.aacrjournals.org/content/canres/78/23/6594/F1.large.jpg.

Complement 5a stimulates macrophage polarization and contributes to tumor metastases of colon cancer

Inflammatory cells such as macrophages can play a pro-tumorigenic role in the tumor stroma. Tumor-associated macrophages (TAMs) generally display an M2 phenotype with tumor-promoting activity; however, the mechanisms regulating the TAM phenotype remain unclear. Complement 5a (C5a) is a cytokine-like polypeptide that is generated during complement system activation and is known to promote tumor growth. Herein, we investigated the role of C5a on macrophage polarization in colon cancer metastasis in mice. We found that deficiency of the C5a receptor (C5aR) severely impairs the metastatic ability of implanted colon cancer cells. C5aR was expressed on TAMs, which exhibited an M2-like functional profile in colon cancer liver metastatic lesions. Furthermore, C5a mediated macrophage polarization and this process relied substantially on activation of the nuclear factor-kappa B (NF-κB) pathway. Finally, analysis of human colon carcinoma indicated that C5aR expression is negatively associated with tumor differentiation grade. Our results demonstrate that C5aR has a central role in regulating the M2 phenotype of TAMs, which in turn, contributes to hepatic metastasis of colon cancer through NF-κB signaling. C5a is a potential novel marker for cancer prognosis and drugs targeting complement system activation, specifically the C5aR pathway, may offer new therapeutic opportunities for colon cancer management.

Abstract 4896: Role of CDK8 in colon cancer hepatic metastasis

Abstract About half of all colon cancer patients will develop liver metastases and the 5-year survival for these patients is less than 13%, making colon cancer the second most lethal cancer worldwide. Cyclin dependent kinase 8 (CDK8), which regulates transcription but not cell cycle progression, has been identified as an oncogene amplified in many colon cancers. CDK8 acts as a positive mediator of oncogenic transcription pathways regulated by Wnt/beta-catenin and TGF-beta, both of which are strongly associated with tumor metastasis. In a colon cancer liver metastasis model based on splenic injection of CT26 murine colon carcinoma cells, treatment with Senexin B, a highly selective small-molecule inhibitor of CDK8 and its paralog CDK19, strongly inhibited metastatic growth in the liver and prolonged the survival of mice with hepatic metastases. In contrast to the effect on liver metastasis, CDK8 inhibition had little or no effect on cell growth in culture or at primary tumor sites. Hepatic metastasis was inhibited to the same extent when Senexin B was administered starting from the time of tumor injection or only during a later part of the study, suggesting that the drug affected metastatic growth in the liver rather than just initial colonization. Liver metastasis was similarly decreased by CDK8 knockdown in CT26 cells, suggesting that the anti-metastatic activity of Senexin B was due at least in part to its effect on tumor cells. Transcription profiling indicated that CDK8 inhibition by shRNA or Senexin B strongly decreased the expression of metastasis-associated metalloproteinases MMP 13, MMP10, and MMP3 and at the same time drastically increased the expression of TIMP3, a metalloproteinase inhibitor. TIMP3 overexpression in CT26 cells, like CDK8 inhibition, decreased hepatic metastasis. CDK8 inhibition also blocked TGF-beta or Wnt3a-stimulated transwell Matrigel invasion of CT26 cells in vitro. Knockdown of beta-catenin in CT26 cells decreased the expression of MMP3 and MMP13, while knockdown of SMAD4 (transcriptional mediator of TGF-beta pathway) induced TIMP3 expression. Beta-catenin knockdown decreased both the primary tumor growth in the spleen and metastatic growth in the liver, whereas SMAD4 knockdown, like that of CDK8, selectively inhibited liver metastasis. Senexin B also suppressed hepatic metastasis after splenic injection of human HCT116 colon carcinoma cells. In summary, our data identified CDK8 as a key transcriptional regulator of colon cancer metastatic growth in the liver, interacting with TGF-beta and Wnt/beta-catenin pathways and regulating the expression of MMPs and Timp3. CDK8/19 inhibitors, which are now entering clinical trials, may be effective for the treatment of hepatic metastasis of colon cancer. Citation Format: Jiaxin Liang, Mengqian Chen, Mythreye Karthikeyan, M. Marjorette Pena, Daniel Hughes, Vimala Kaza, Chang-Uk Lim, Eugenia Broude, Igor B. Roninson. Role of CDK8 in colon cancer hepatic metastasis [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 4896. doi:10.1158/1538-7445.AM2017-4896

Gastrointestinal perforation during regorafenib administration in a case with hepatic metastases of colon cancer

Although common side effects of regorafenib include hand-and-foot syndrome and diarrhoea, the incidence of gastrointestinal perforation is reportedly unknown. We describe our experience with the case of a 65-year-old woman treated with regorafenib as a third-line therapy for progressive caecal cancer with multiple hepatic metastases after 4 and 6 courses of systemic mFOLFOX6 + bevacizumab (BV) and FOLFIRI + BV chemotherapy, respectively. The patient used regorafenib for 32 days but visited our hospital with abdominal pain during the second course. She was diagnosed with acute appendicitis and treated conservatively with antibiotics. The abdominal findings did not improve, and a computed tomography evaluation on day 4 of hospitalization revealed free air lateral to the caecal tumour, liver surface, and epigastric region. The patient underwent same-day emergency surgery based on a diagnosis of gastrointestinal perforation with generalized peritonitis. Upon observing digestive fluid leakage into the peri-ileocaecal area and a 5-mm perforation in the appendix, the patient was diagnosed with peritonitis due to gastrointestinal perforation. Ileocaecal resection with D2 debridement was performed, and a colostomy was opened into the ileum and ascending colon. We conclude that our patient developed gastrointestinal perforation during regorafenib therapy and note that clinicians should be aware of this possible complication in patients with a history of prior treatment with BV.

Effect of combination therapy of siRNA targeting growth hormone receptor and 5-fluorouracil in hepatic metastasis of colon cancer.

The aim of this study was to investigate the effects of small interfering RNA (siRNA) targeting human growth hormone receptor (hGHR) combined with 5-fluorouracil (5-FU) on the hepatic metastasis of colon cancer. The animal model of liver metastases using human SW480 colon cancer cells was established on BALB/c mice and the siRNA interfering plasmid targeting hGHR gene was constructed. The tumor-bearing mice were randomly divided into the saline control, plasmid, growth hormone (GH), 5-FU, 5-FU+plasmid and 5-FU+plasmid+GH groups. The liver metastasis in each group was observed. All the animals showed liver metastases and using siRNA-interfering plasmid treatment the incidence of liver metastases was significantly reduced in the tumor groups compared to the saline or GH group. The combined treatment of interfering plasmid and 5-FU slightly decreased the incidence of liver metastases in the tumor groups compared to the plasmid alone or 5-FU alone treatment, although the findings were not statistically significant. On the basis of the combination of interfering plasmid and 5-FU, the additional GH did not increase the incidence of liver metastases (P>0.05), but improved the weight loss of the mice (P<0.05) induced by the inhibition of GHR and toxicity of 5-FU. The present results showed that siRNA targeting hGHR is able to reduce the incidence of liver metastases of human SW480 colon cancer cells in mice. Thus, GHR may be important in tumor metastasis.

Acute and innocuous CpG-C immune stimulation potentiates host resistance to hepatic metastases of colon cancer and protects against immunosuppressive effects of surgery

Liver metastases are a major cause of cancer-related mortality. Marginating-hepatic (MH)-NK cells are strategically located in the liver sinusoids to physically interact and lyse circulating tumor cells. In cancer patients, the short peri-operative period is now recognized as critical in determining the progression of remaining malignant disease into established metastases. However, the benefits of immune stimulation have rarely been studied peri-operatively, given the short time frame and contraindications to surgery. To overcome these obstacles, we herein employed a new synthetic TLR-9 agonist, CpG-C, which has minimal adverse effects in rodents and humans. Our results indicated that a single pre-operative CpG-C administration tripled MH-NK cell numbers, and dramatically increased their per-cell NK cytotoxicity against the standard YAC-1 and the syngeneic CT26 colon cancer cell lines. Furthermore, CpG-C treatment protected mice from laparotomy-induced immune suppression, based on examining MH-NK cytotoxicity levels and several molecular markers of NK-cell function, including NKp46, CD49b, CD11b, and NKG2A. Importantly, this short and innocuous CpG-C treatment dramatically reduced the number of hepatic metastases developed 3-weeks following surgical inoculation of CT26 through the hepatic portal vein. These beneficial effects are mediated through activation of NK cells, as NK depletion by anti-asialo GM1 completely abrogated them. Overall, this approach is feasible in cancer patients, and may introduce a new peri-operative intervention to improve long-term cancer outcomes during the critical and unexploited peri-operative time frame.

Downregulation of CDK-8 inhibits colon cancer hepatic metastasis by regulating Wnt/β-catenin pathway.

Liver metastasis is a major cause of mortality from colon cancer. To investigate the role of cyclin-dependent kinase 8 (CDK8) in the progression of colon cancer hepatic metastasis. In this present study, human colon cancer HCT116 or HCT116-LUC-GFP cells were transfected with Lentiviral vector-mediated knockdown of CDK-8. After transfection, metastasis and invasion potential of colon cancer cell was investigated by wound healing and transwell invasion assays, respectively. A mice model of colon cancer liver metastases was established and observed with bioluminescence imaging. The protein expression of CDK-8, β-catenin, E2F1, MMP-7 and E-cadherin in liver tissues were detected by Western Blot. Our results revealed that lentiviral vector-mediated knockdown of CDK-8 inhibited metastasis and invasion of colon cancer cells in vitro and in vivo, respectively. Protein expression of CDK-8, β-catenin, MMP-7 and E-cadherin were inhibited, but protein expression of E2F1 was enhanced. In sum, our data provided compelling evidence that CDK-8 played a significant role in colon cancer hepatic metastasis by regulating the Wnt/β-catenin signal pathway and might sever as a potential therapeutic target for colon cancer patients.

Complement 5a Enhances Hepatic Metastases of Colon Cancer via Monocyte Chemoattractant Protein-1-mediated Inflammatory Cell Infiltration

Complement 5a (C5a), a potent immune mediator generated by complement activation, promotes tumor growth; however, its role in tumor metastasis remains unclear. We demonstrate that C5a contributes to tumor metastases by modulating tumor inflammation in hepatic metastases of colon cancer. Colon cancer cell lines generate C5a under serum-free conditions, and C5a levels increase over time in a murine syngeneic colon cancer hepatic metastasis model. Furthermore, in the absence of C5a receptor or upon pharmacological inhibition of C5a production with an anti-C5 monoclonal antibody, tumor metastasis is severely impaired. A lack of C5a receptor in colon cancer metastatic foci reduces the infiltration of macrophages, neutrophils, and dendritic cells, and the role for C5a receptor on these cells were further verified by bone marrow transplantation experiments. Moreover, C5a signaling increases the expression of the chemokine monocyte chemoattractant protein-1 and the anti-inflammatory molecules arginase-1, interleukin 10, and transforming growth factor β, but is inversely correlated with the expression of pro-inflammatory molecules, which suggests a mechanism for the role of C5a in the inflammatory microenvironment required for tumor metastasis. Our results indicate a new and potentially promising therapeutic application of complement C5a inhibitor for the treatment of malignant tumors.

The impact of surgical extent and sex on the hepatic metastasis of colon cancer

Extensive oncological surgeries were previously suggested to increase cancer recurrence rates. We herein studied the impact of different surgical procedures and sex on colorectal cancer liver metastasis, employing several tumor inoculation approaches in BALB/c mice. Experimental hepatic metastases of the syngeneic CT26 colorectal cancer line were induced either by intra-portal inoculation or intra-splenic inoculation, employing different tumor loads. Following intra-splenic inoculation, the entire spleen or an injected hemi-spleen was removed. Additionally, the magnitude of the surgical trauma accompanying the injection procedure was manipulated. Increasing the surgical trauma by adding laparotomy or extending the length of the surgery and hypothermia did not significantly affect the number of liver metastases or liver weight for any of the injection methods and tumor loads. The development of metastasis was significantly greater in males than in females under all conditions studied--a difference not explained by the direct effects of sex hormones on in vitro CT26 proliferation or vitality. Concurring with less controlled clinical observations, the surgical extensiveness did not significantly affect CT26 hepatic metastasis, potentially due to a ceiling effect of the surgical trauma on the metastatic process. The sexual dimorphism observed for the CT26 metastasis should be investigated in the context of surgical stress and considering anti-CT26 immunoreactivity.

Imaging of mesenchymal stem cell recruitment into the stroma of hepatic colon cancer metastases using the sodium iodide symporter (NIS)

Imaging of mesenchymal stem cell recruitment into the stroma of hepatic colon cancer metastases using the sodium iodide symporter (NIS)

Modulating the interaction of CXCR4 and CXCL12 by low-molecular-weight heparin inhibits hepatic metastasis of colon cancer

Liver metastasis is the major obstacle for prolonging the survival of colon cancer patients. Low-molecular-weight heparin (LMWH), a common drug for venous thromboembolism, has displayed beneficial effects in improving the survival of cancer patients, though the mechanism remains unclear. This study aimed to investigate the effects of LMWH on hepatic metastasis of colon cancer and its underlying molecular mechanism by targeting the interaction of the chemokine receptor CXCR4 and its ligand CXCL12 (formerly known as stromal cell-derived factor 1α, SDF-1α), as the CXCR4-CXCL12 axis has been shown to regulate the interaction of cancer cells and stroma. Experimental results revealed that LMWH (Enoxaparin, 3500-5500 Da) inhibited the CXCL12-stimulated proliferation, adhesion and colony formation of human colon cancer HCT-116 cells that highly expressed CXCR4. Interestingly, LMWH or an anti-CXCR4 blocking antibody diminished the migrating and invading abilities of HCT116 cells stimulated by the recombinant CXCL12 protein or liver homogenates which contained endogenous CXCL12 protein. Although LMWH did not significantly inhibit the growth of subcutaneous colon tumors, it significantly suppressed the formation of hepatic metastasis established by intrasplenic injection of colon cancer cells in nude Balb/c mice and also downregulated the expression of CXCL12 in hepatic sinusoidal endothelial cells. The results suggest that LMWH inhibits the formation of hepatic metastasis of colon cancer by disrupting the interaction of CXCR4 and CXCL12, supporting that perioperative administration of LMWH may help to prevent the seeding and subsequent growth of hepatic metastases of colon cancer cells.

Oxaliplatin in combination with liver-specific expression of interleukin 12 reduces the immunosuppressive microenvironment of tumours and eradicates metastatic colorectal cancer in mice

Background and aimsNew options are needed for the management and prevention of colorectal cancer liver metastases. Interleukin 12 (IL-12) is an immunostimulatory cytokine with proven antitumour effect in animal models....

The density of macrophages in the invasive front is inversely correlated to liver metastasis in colon cancer

BackgroundAlthough an abundance of evidence has indicated that tumor-associated macrophages (TAMs) are associated with a favorable prognosis in patients with colon cancer, it is still unknown how TAMs exert a protective effect. This study examined whether TAMs are involved in hepatic metastasis of colon cancer.Materials and methodsOne hundred and sixty cases of pathologically-confirmed specimens were obtained from colon carcinoma patients with TNM stage IIIB and IV between January 1997 and July 2004 at the Cancer Center of Sun Yat-Sen University. The density of macrophages in the invasive front (CD68TFHotspot) was scored with an immunohistochemical assay. The relationship between the CD68TFHotspot and the clinicopathologic parameters, the potential of hepatic metastasis, and the 5-year survival rate were analyzed.ResultsTAMs were associated with the incidence of hepatic metastasis and the 5-year survival rate in patients with colon cancers. Both univariate and multivariate analyses revealed that the CD68TFHotspot was independently prognostic of survival. A higher 5-year survival rate among patients with stage IIIB after radical resection occurred in patients with a higher macrophage infiltration in the invasive front (81.0%) than in those with a lower macrophage infiltration (48.6%). Most importantly, the CD68TFHotspot was associated with both the potential of hepatic metastasis and the interval between colon resection and the occurrence of hepatic metastasis.ConclusionThis study showed evidence that TAMs infiltrated in the invasive front are associated with improvement in both hepatic metastasis and overall survival in colon cancer, implying that TAMs have protective potential in colon cancers and might serve as a novel therapeutic target.

Dietary Vitamin A Supplementation Decreases Colorectal Cancer Liver Metastases in Mice

Previously, we showed that retinol inhibited all‐trans‐retinoic acid (ATRA)‐resistant human colon cancer cell invasion via a retinoic acid receptor‐independent mechanism in vitro. The objective of the current study was to determine if dietary retinol inhibited the metastasis of ATRA‐resistant colon cancer cells in a nude mouse xenograft model. Ninety female nude mice (BALB/cAnNCr‐nu/nu) aged 6 to 8 weeks old were intrasplenically injected with 2 x 106 wild type HCT‐116 ATRA‐resistant human colon cancer cells. Purified AIN‐76 rodent diet was consumed pre‐injection. Immediately following injection the mice were randomly assigned to diets containing 2,400 (control), 12,000, 25,000, 50,000, 100,000 or 200,000 IU vitamin A/kg diet as retinyl palmitate. These diets provided 1, 5, 10, 20, 40 and 80X the daily vitamin A requirement of mice. The mice consumed these diets for five weeks prior to sacrifice. Livers and spleens were excised at the time of sacrifice and examined for the presence of primary tumors (spleen) or metastases (liver). Consumption of diets containing 50,000, 100,000, or 200,000 IU vitamin A/kg diet resulted in a decrease in tumor incidence to 72.6%, 72.6%, and 45.2%, respectively, of control. Thus, supplemental dietary vitamin A may be an effective chemotherapeutic agent to decrease the hepatic metastasis of colon cancer.Grant Funding SourceNIH grant # 5 R21 CA120414‐02 to M.L.