Metastasis Of Human Colon Cancer Research Articles

Parecoxib expresses anti-metastasis effect through inhibition of epithelial-mesenchymal transition and the Wnt/β-catenin signaling pathway in human colon cancer DLD-1 cell line.

Colorectal cancer is the third leading cause of cancer death in Taiwan. Current treatments involve combination of surgical resection, radiation, and chemotherapy. These treatments have demonstrated to increased five-year survival of a patient with colorectal cancer. However, metastasis is a major capability of cancer cells that causes poor prognosis, recurrence, and even death. Epidemiological and clinical studies have suggested the use of non-steroidal anti-inflammatory drugs (NSAIDs) as an effective class of compounds to prevent colon cancer. Parecoxib is an NSAID and the only parenterally administered selective cyclooxygenase (COX)-2 inhibitor. In this study, we evaluated whether parecoxib inhibits the metastasis of DLD-1 human colon cancer cells, a COX-2 null cell line, and the underlying mechanism. Cell migration of the DLD-1 cells was significantly inhibited by parecoxib treatment as shown by the Transwell migration assay. This enhanced anti-migration effect was correlated with the attenuated phosphorylation of Akt, expression of vimentin (a mesenchymal marker), and β-catenin, and corresponded with the upregulated GSK3β and E-cadherin (an epithelial marker). These findings suggested that parecoxib could inhibit the epithelial-mesenchymal transition (EMT) and metastasis in human colon cancer cells by downregulating β-catenin. Thus, parecoxib could provide a novel prospective strategy for a combination treatment with chemotherapeutic drugs against metastasis of human colon cancer.

Peptide-functionalized metal-organic framework nanocomposite for ultrasensitive detection of secreted protein acidic and rich in cysteine with practical application

In this work, we have prepared peptide-functionalized metal-organic frameworks (MOFs) as signal-amplifying tags for the detection of secreted protein acidic and rich in cysteine (SPARC). Furthermore, enzyme-MOF nanocomposites are fabricated via a coprecipitation strategy between horse radish peroxidase (HRP) and ZIF-90, where ZIF-90 is used as a protective support for HRP immobilization. Meanwhile, the peptide sequence has been designed as SPARC-binding peptide, which imparts biorecognition functionality to HRP@ZIF-90 for performing a colorimetric sensor. Therefore, during the test, HRP molecules can be quickly released from nanocomposites by acidic condition to catalyze chromogenic reaction, enabling the ultrasensitive detection of SPARC with a low detection limit of 30 fg/mL. Moreover, the content of SPARC in colon cancer tissues with different degrees of differentiation can be determined with this sensor, demonstrating that the expression of SPARC is closely related to the occurrence, invasion and metastasis of human colon cancer. These results may show the potential applications of this biosensor in SPARC fundamental research as well as clinical diagnosis in the future.

TIMP1 is a prognostic marker for the progression and metastasis of colon cancer through FAK-PI3K/AKT and MAPK pathway.

BackgroundTissue inhibitor matrix metalloproteinase 1 (TIMP1) plays a vital role in carcinogenesis, yet its precise functional roles and regulation remain unclear. In this study, we aim to investigate its biological function and clinical significance in human colon cancer.MethodsWe analyzed the expression of TIMP1 in both public database (Oncomine and TCGA) and 94 cases of primary colon cancer and matched normal colon tissue specimens. The underlying mechanisms of altered TIMP1 expression on cell tumorigenesis, proliferation, and metastasis were explored in vitro and in vivo.ResultsTIMP1 was overexpressed in colon tumorous tissues and lymph node metastasis specimens than in normal tissues. The aberrant expression of TIMP1 was significantly associated with the regional lymph node metastasis (p = 0.033), distant metastasis (p = 0.039), vascular invasion (p = 0.024) and the American Joint Committee on Cancer (AJCC) stage (p = 0.026). Cox proportional hazards model showed that TIMP1 was an independent prognostic indicator of disease-free survival (HR = 2.603, 95 % CI: 1.115–6.077, p = 0.027) and overall survival (HR = 2.907, 95 % CI: 1.254–6.737, p = 0.013) for patients with colon cancer. Consistent with this, our findings highlight that suppression of TIMP1 expression decreased proliferation, and metastasis but increased apoptosis by inducing TIMP1 specific regulated FAK-PI3K/AKT and MAPK pathway.ConclusionTIMP1 might play an important role in promoting tumorigenesis and metastasis of human colon cancer and function as a potential prognostic indicator for colon cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s13046-016-0427-7) contains supplementary material, which is available to authorized users.

Prostaglandin E2 inhibits resveratrol-induced apoptosis through activation of survival signaling pathways in HCT-15 cell lines

The COX-2 metabolite prostaglandin E2 (PGE2) promotes inflammation and progression of several cancers, including colon cancer. Resveratrol (3,5,4′-trihydroxy-trans-stilbene) induces apoptosis in cell lines and inhibits the invasion and metastasis of human colon cancer. PGE2 inhibits resveratrol-induced cell death; however, the underlying mechanisms are poorly understood. Therefore, the present study investigates the protection and survival effect of PGE2 against resveratrol-induced apoptosis in a human colorectal carcinoma (HCT-15) cell line. HCT-15 cells were treated with resveratrol and/or PGE2, and apoptotic cell death was assessed based on flow cytometry and the generation of reactive oxygen species (ROS). Resveratrol reduced HCT-15 cell viability and induced cell death through the production of ROS and the activation of caspase-3. Resveratrol treatment degraded poly (ADP-ribose) polymerase (PARP) in response to caspase-3 cleavage. Resveratrol treatment also decreased the activation of Ras-Raf-Erk and nuclear factor-κB (NF-κB) pathways and downregulated COX-2 expression, but did not regulate the secretion of extracellular PGE2. However, PGE2 exposure reversed resveratrol-induced oxidative stress and apoptosis, possibly through activation of the Ras-Raf-Erk pathway. PGE2 also positively regulated NF-κB activation and markedly increased the nuclear appearance of p50 and p65 subunits. Thus, this study provides insight into the mechanisms of resveratrol-induced apoptosis. Our results suggest that the inhibition of PGE2 and PGE2-induced activation of Ras-Raf-Erk and NF-κB signaling pathways may provide an alternative therapeutic strategy for the treatment and prevention of colon cancer.

Abstract 5068: Treatment with regorafenib inhibits the tumor-promoting effect of bone marrow-derived mesenchymal stem cells in an orthotopic nude mice model of colon cancer

Abstract Bone marrow-derived mesenchymal stem cells (MSCs) have been reported to migrate to tumor stroma as well as injured tissue. We reported that, in an orthotopic nude mice model of colon cancer, MSCs travel to tumor stroma and differentiate into carcinoma-associated fibroblasts (CAFs), and then, they promote growth and metastasis of colon cancer. We also found that CAFs express platelet-derived growth factor receptor-beta (PDGFR-β), at a high level and that imatinib therapy targeting PDGFR in CAFs combined with administration of a cytotoxic drug significantly inhibits growth and metastasis of human colon cancer. A novel oral multi-kinase inhibitor, regorafenib not only inhibits oncogenic receptor tyrosine kinases such as c-KIT, RET, and B-RAF, but also inhibits stromal cells which express VEGFR1-3, TIE2, PDGFR-β, and fibroblast growth factor receptor 1 (FGFR1). These cell surface receptor tyrosine kinases are known to be involved in tumor neovascularization, vessel stabilization, lymphatic vessel formation as well as activation of stroma. We examined whether the effect of MSCs on tumor growth and metastasis was inhibited by regorafenib. KM12SM human colon cancer cells alone or KM12SM cells mixed with MSCs in a 1:2 ratio were transplanted into the cecal wall of nude mice. Orthotopic transplantation of KM12SM cells + MSCs, in comparison to transplantation of KM12SM cells alone, resulted in tumors of greater weight and volume, and higher rate of lymphatic metastasis. Co-injection of MSCs with tumor cells promoted tumor growth and metastasis of colon cancer by enhancing angiogenesis, lymphangiogenesis, and tumor cell proliferation and by inhibiting tumor cell apoptosis. When CRC tumor + MSCs bearing animals were treated with regorafenib (by oral gavage once daily at 10 mg/kg for 35 days), primary tumor size or the number of lymph node metastases were significantly decreased compared to those treated with vehicle, and reached to the level with no significant difference from KM12SM tumor cells alone. Our data suggest that targeting tumor microenvironmental signaling pathways by regorafenib influences the interaction between bone marrow-derived MSCs and tumor cells and, hence, inhibits the progressive growth of colon cancer. Citation Format: Kei Shinagawa, Yasuhiko Kitadai, Ryo Yuge, Mieko Onoyama, Shinji Tanaka, Wataru Yasui, Kazuaki Chayama. Treatment with regorafenib inhibits the tumor-promoting effect of bone marrow-derived mesenchymal stem cells in an orthotopic nude mice model of colon cancer. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 5068. doi:10.1158/1538-7445.AM2015-5068

MTOR and PDGF Pathway Blockade Inhibits Liver Metastasis of Colorectal Cancer by Modulating the Tumor Microenvironment

Tumor growth and metastasis are not determined by cancer cells alone but also by a variety of stromal cells, and platelet-derived growth factor receptors (PDGF-Rs) are overexpressed by various stromal cell populations. Activation of PI3K-AKT-mTOR signaling is frequently observed in many cancer types. We investigated whether the mTOR inhibitor everolimus, alone or in combination with the PDGF-R tyrosine kinase inhibitor nilotinib, can inhibit growth and metastasis of human colon cancer. The effects of nilotinib and everolimus on tumor growth and metastasis were examined in an orthotopic mouse model of human colon cancer and a model of liver metastasis. After treatment with nilotinib (versus distilled water), the stromal reaction of xenografts growing in the cecal wall and liver was significantly decreased. After treatment with everolimus, the stromal reaction did not decrease, but tumor cell proliferation and microvessel density decreased. With the two drugs in combination, both stromal reaction and tumor cell proliferation decreased and apoptosis of tumor cells increased, resulting in remarkable inhibition of tumor growth at both the orthotopic and the metastatic site. Concurrent inhibition of tumor cells and activated stromal cells by a PDGF-R tyrosine kinase inhibitor and an mTOR inhibitor used in combination may represent a novel therapeutic approach for colorectal cancer.

TPX2 is a novel prognostic marker for the growth and metastasis of colon cancer

BackgroundWe have previously demonstrated an aberrant overexpression of the microtubule-associated protein TPX2 in colon cancer using a genome-wide gene expression profiling analysis. Here, we aim to investigate its expression pattern, clinical significance, and biological function in colon cancer.MethodsTPX2 expression was analyzed in human colon cancer cell lines and tumor samples. The effect of TPX2 on cell proliferation, tumorigenesis, and metastasis was examined in vitro and in vivo.ResultsTPX2 was overexpressed in 129 of the 203 (60.8%) colon cancer metastatic lesions, with the expression being significantly higher than that in primary cancerous tissue and normal colon mucosa. Overexpression of TPX2 was significantly associated with clinical staging, vessel invasion, and metastasis. In survival analyses, patients with TPX2 overexpression had worse overall survival and metastasis free survival, suggesting that deregulation of TPX2 may contribute to the metastasis of colon cancer. Consistent with this, suppression of TPX2 expression inhibited proliferation and tumorigenicity of colon cancer cells both in vitro and in vivo. Strikingly, we found that TPX2 knockdown significantly attenuated the migration and invasion ability of colon cancer cells, which was further shown to be mechanistically associated with AKT-mediated MMP2 activity.ConclusionsThese findings suggest that TPX2 plays an important role in promoting tumorigenesis and metastasis of human colon cancer, and may represent a novel prognostic biomarker and therapeutic target for the disease.

Abstract 3345: Induction of apoptosis by high levels of oscillatory shear strain: proof of concept in a human colon cancer metastasis cell line.

Abstract Purpose / Introduction: Mechanotransduction is a biological process enabling cells to convert mechanical cues into biological responses[1]. The apoptotic status of many cell types is regulated by the mechanical conditions of their environment [2,3]. In this context, and due to the incompressible nature of tissues, it is theoretically thinkable to selectively induce cellular death by the controlled application of low frequency oscillatory shear strain. Unlike e.g. HIFU (high intensity focused ultrasounds), here the energy deposited would by far not be sufficient to mechanically rupture cells, but would instead trigger specific signals within the cell. We establish the proof of concept for this proclaimed effect in a cell line of colon cancer metastasis. Subjects and Methods: DHDK12 colon cancer metastasis cells were grown in conventional conditions. At confluency, one plate was subjected for 4 hrs to a 90Hz uniaxial sinusoidal motion parallel to the cell layer by a rigidly linked modal exciter. One control plate was left without any vibration. The strain levels induced in the cell monolayer were measured on a control plate loaded with a thin layer of agarose gel (2g/l) and covered with liquid to simulate the medium. Shear strain images were obtained on a 7T MRI system using a spin echo elastography sequence synchronized with a 90Hz vibration of the imaged plate (TE/TR = 39/1744 ms) with 4 wave offsets, 3 encoding directions and a 300 μm isotropic resolution. Strain was evaluated as the maximum shear strain (difference between maximum and minimum eigenvalues of the strain tensor). At the end of the experiment, cells were, colored with trypan blue and the proportion of colored vs. uncolored cells was estimated using a hematocytometer. Levels of caspase-3 were assessed by western blotting, using β-actin as the loading marker. Results: Using shear strain imagin, it was determined that the setup yielded very elevated maximum shear strains on the order of 5.5 ± 1.1 % in the first 300μm immediately above the plastic surface. Vibrations were sufficient to induce cell death, as observed by the 4.2X increase in the count of dead cells after vibrations (pre: 2.9±1.5%, post: 4.5±1.4% for the control plate, vs. pre: 5.3±2.6%, post: 22.3±3.9 % for the vibrated plate). Caspase-3 levels were elevated in the cells having undergone vibrations, indicating that an activation of the apoptosis pathway was involved in the observed increase in cell deaths. Discussion/Conclusion: We show that the application of 5% maximum shear strain at 90Hz for 4 hours has the ability to induce apoptosis in vitro on a human cell line of cancer metastasis. This proof of concept indicates that the selective application of high strain shear waves of low frequency may become a viable alternative for tumor therapy. [1] Ingber, FASEB 2006 20(7) [2] Jaalouk, Nat Rev Mol Cell Biol, 2009 10(1) [3] Cheng, PLOS One, 2009 4(2) Citation Format: Philippe Garteiser, Sabrina Doblas, Simon Lambert, Mouniya Mebarki, Valerie Vilgrain, Bernard E. Van Beers, Valerie Paradis, Ralph Sinkus. Induction of apoptosis by high levels of oscillatory shear strain: proof of concept in a human colon cancer metastasis cell line. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3345. doi:10.1158/1538-7445.AM2013-3345

Validation of TPX2 as a novel prognostic marker for malignant progression and metastasis of colon cancer.

442 Background: We previously identified aberrant overexpression of TPX2 in colon cancer by using a genome-wide gene expression profiling analysis. Here, we aimed to investigate its expression pattern, clinical significance, and biological function in colon cancer. Methods: The expression of TPX2 was analyzed in human colon cancer cell lines and tumor samples. The effect of TPX2 on cell proliferation, tumorigenesis and metastasis was examined in vitro and in vivo. Results: Overexpression of TPX2 was found in metastatic lesion of colon cancer, significantly higher than primary cancererous tissue and normal colon mucosa. Overexpression of TPX2 was significantly associated with the clinical staging, vessel invasion and metastasis. In survival analyses, patients with TPX2 expression had worse overall survival and metastasis free survival, suggesting that deregulation of TPX2 may contribute to the metastasis of colon cancer. Consistently, Silencing TPX2 inhibited proliferation and tumorigenicity of colon cancer cells both in vitro and in vivo. Strikingly, we found that TPX2 knockdown significantly attenuated the migration and invasion ability of colon cancer cells, which was further shown to be mechanistically associated with AKT mediated MMP9 activity. Conclusions: These findings suggest that TPX2 plays an important role in promoting tumorigenesis and metastasis of human colon cancer and may represent a novel prognostic biomarker and therapeutic target for the disease.

Stroma‐directed imatinib therapy impairs the tumor‐promoting effect of bone marrow‐derived mesenchymal stem cells in an orthotopic transplantation model of colon cancer

Bone marrow-derived mesenchymal stem cells (MSCs) are reported to contribute to formation of tumor-promoting stromal cells. We reported recently that, in an orthotopic nude mice model of colon cancer, MSCs traveled to tumor stroma, where they differentiated into carcinoma-associated fibroblast (CAF)-like cells. We also found that CAFs express platelet-derived growth factor receptor (PDGFR) at a high level and that imatinib therapy targeting PDGFR in CAFs inhibits growth and metastasis of human colon cancer. These findings led us to examine whether the tumor-promoting effect of MSCs is impaired by blockade of PDGFR signaling achieved with imatinib. Orthotopic transplantation and splenic injection of human MSCs along with KM12SM human colon cancer cells, in comparison with transplantation of KM12SM cells alone, resulted in significantly greater promotion of tumor growth and liver metastasis. The KM12SM + MSC xenograft enhanced cell proliferation and angiogenesis and inhibited tumor cell apoptosis. When tumor-bearing animals were treated with imatinib, there was no significant increase in primary tumor volume or total volume of liver metastases, despite the KM12SM+MSC xenograft, and survival in the mixed-cell group was prolonged by imatinib treatment. Moreover, the ability of MSCs to migrate to tumor stroma was impaired, and the number of MSCs surviving in the tumor microenvironment was significantly decreased. In in vitro experiments, treatment with imatinib inhibited migration of MSCs. Our data suggest that blockade of PDGF signaling pathways influences the interaction between bone marrow-derived MSCs and tumor cells in the tumor microenvironment and, hence, inhibits the progressive growth of colon cancer.

Abstract 519: Blockade of PDGFR signaling impairs the tumor promoting effect of bone marrow-derived mesenchymal stem cells in colon cancer

Abstract Bone marrow-derived mesenchymal stem cells (MSCs) are reported to migrate to tumor stroma as well as injured tissue. We reported recently that, in an orthotopic nude mice model of colon cancer, MSCs traveled to tumor stroma, where they differentiated into carcinoma-associated fibroblasts (CAF)-like cells. We have also found that CAFs express platelet-derived growth factor receptor (PDGFR) at a high level and that imatinib therapy targeting PDGFR in CAFs combined with administration of a cytotoxic drug significantly inhibits growth and metastasis of human colon cancer. These findings led us to examine whether the tumor promoting effect of MSCs is impaired by blockade of PDGFR signaling achieved with imatinib. KM12SM colon cancer cells alone or KM12SM cells mixed with MSCs in a 1:2 ratio were transplanted into the cecal wall of nude mice. Orthotopic transplantation of KM12SM cells mixed with MSCs, in comparison to transplantation of KM12SM cells alone, resulted in tumors of greater weight. The survival rate was significantly lower in the mixed-cell group. Co-injection of MSCs with tumor cells promotes tumor growth and metastasis of colon cancer by enhancing angiogenesis and tumor migration and invasion and by inhibiting tumor cell apoptosis. When tumor bearing animals were treated with imatinib (by gavage once daily at 50 mg/kg for 35 days), there was no significant increase in primary tumor volume or number of metastases with the KM12SM+MSC xenograft and the lower survival rate in the mixed-cell group was prolonged by the treatment. Moreover, migratory ability of MSCs to tumor stroma was impaired, and MSCs surviving in the tumor microenvironment were significantly decreased. In in vitro experiments, treatment with imatinib inhibited migration and proliferation of MSCs. Our data suggest that blockade of PDGFR signaling pathways influences the interaction between bone marrow-derived MSCs and tumor cells in the tumor microenvironment and, hence, inhibits the progressive growth of colon cancer. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 519. doi:10.1158/1538-7445.AM2011-519

The CCL21/CCR7 pathway plays a key role in human colon cancer metastasis through regulation of matrix metalloproteinase-9

Purpose CC chemokine receptor 7 (CCR7) and matrix metalloproteinase-9 (MMP-9) have been associated with lymph node metastasis in human colon cancer. Studies have suggested a potential link between CCR7 and MMP-9 in cancer; however, the molecular mechanism by which C–C ligand 21/CCR7 promotes tumour dissemination in human colon cancer is not well understood. Thus, we aimed to determine whether MMP-9 is regulated by the C–C ligand 21/CCR7 in human colon cancer. Method RNA interference technology was employed to detect effect of CCR7 deficiency on the expression of MMP-9 in SW480 human colon cancer cells. We also evaluated the ability of CCR7 short hairpin RNA to inhibit MMP-9 production and tumour invasion in a xenografted mouse model by using whole-body fluorescence imaging and gelatin zymography. Result We found that CCR7 short hairpin RNA significantly inhibited C–C ligand 21/CCR7-induced up-regulation of MMP-9 in SW480 cells. Furthermore, knockdown of CCR7 significantly limited the production of MMP-9 and colon cancer metastasis in a xenografted mouse model. Mice that received SW480/control cells had progressively enlarging tumours and more lymphatic metastases, and these animals did not survive as long as mice that received SW480/CCR7 − cells. Conclusion MMP-9 and CCR7 may be useful targets for the treatment of lymphatic metastasis in colon cancer.

The Involvement of WNT Signaling Pathway in Human Colon Cancer Metastasis

Colon cancer is one of the most common cancers. Mortality from colon cancer mainly derives from its metastases. The mechanisms for colon metastasis are not clear. Aberrant WNT signals have been commonly observed in human colon cancer. Therefore, we hypothesize that WNT signaling pathway participates in the metastasis of colon cancer. To test this hypothesis, we used the cell line models SW480 and SW620, which are poorly and highly metastatic colon cancer cell lines, respectively. SW480 was established from a primary human colon cancer, while SW620 was from a lymph node metastasis in the same patient a year later. mRNA expression of genes involved in WNT pathway were detected in SW480 and SW620 by real‐time PCR. WNT5a decreased 1000 times in SW620 compared to SW480. N‐Myc downstream‐regulated gene 1 (NDRG1), which was reported to inhibit WNT pathway by interacting with WNT co‐receptors, decreased 10 times. On the other hand, secreted frizzled‐related protein 1(sFRP1), another WNT signaling antagonist, increased 3 times in SW620. The significant difference of WNT signaling observed between SW480 and SW620 showed strong correlation between the WNT signaling pathway and the invasive ability of colon cancer cells. Mechanisms of this interaction between WNT signaling pathway and colon cancer metastasis are under future investigation. This research was supported by the University of Illinois at Urbana‐Champaign.

Role of CXCL8/CXCR1 in the metastasis of human colon cancer

Role of CXCL8/CXCR1 in the metastasis of human colon cancer

The cancer stem cell marker CD133 has high prognostic impact but unknown functional relevance for the metastasis of human colon cancer

In colon cancer, CD133 has recently been used to enrich for a subset of tumour cells with tumour-initiating capabilities and was therefore suggested to mark colon cancer stem cells. However, this molecule has surprisingly been shown to lack functional importance for tumour initiation itself. Herein, we investigated whether CD133 may be relevant for colon cancer metastasis in patients, and as metastasis requires several additional biological characteristics besides tumour initiation, we examined the effects of knocking down CD133 expression in colon cancer cell lines on proliferation, migration, invasion, and colony formation. We demonstrate that high CD133 expression correlates strongly with synchronous liver metastasis in a matched case-control collection, while siRNA-mediated knock down of this factor has no significant effect on the mentioned biological characteristics. Thus, we conclude that CD133 expression is a marker with high prognostic impact for colon cancer, while it seems to have no obvious functional role as a driving force of this malignancy.

Regulation of Prostate Cancer Progression by Galectin-3

Galectin-3, a beta-galactoside-binding protein, has been implicated in a variety of biological functions including cell proliferation, apoptosis, angiogenesis, tumor progression, and metastasis. The present study was undertaken to understand the role of galectin-3 in the progression of prostate cancer. Immunohistochemical analysis of galectin-3 expression revealed that galectin-3 was cleaved during the progression of prostate cancer. Galectin-3 knockdown by small interfering RNA (siRNA) was associated with reduced cell migration, invasion, cell proliferation, anchorage-independent colony formation, and tumor growth in the prostates of nude mice. Galectin-3 knockdown in human prostate cancer PC3 cells led to cell-cycle arrest at G(1) phase, up-regulation of nuclear p21, and hypophosphorylation of the retinoblastoma tumor suppressor protein (pRb), with no effect on cyclin D1, cyclin E, cyclin-dependent kinases (CDK2 and CDK4), and p27 protein expression levels. The data obtained here implicate galectin-3 in prostate cancer progression and suggest that galectin-3 may serve as both a diagnostic marker and therapeutic target for future disease treatments.

Src activity alters α3 integrin expression in colon tumor cells

Src kinase has been linked to increased motility in the progression and metastasis of human colon cancer, although the mechanisms are not fully understood. Integrins are involved in metastasis by mediating attachment and migration of cells, as well as through transducing signals. This study examines the link between Src and integrin activity in the metastatic process in colon cancer cells. To determine Src involvement in integrin expression, the human colon cancer cell line, HCT116, was transfected with an activated Src construct and assayed for its ability to attach to and migrate across collagen and laminin. These cells attached more readily and migrated less rapidly on the extracellular matrix (ECM) than did cells transfected with empty vector. Examination of integrin levels showed a decrease in the alpha3 subunit in Src transfected cells as well as decreased cell surface localization of alpha3 integrin. The downregulation of alpha3 integrin was reversed by inhibition of Src and by inhibition of MAP kinase. Inhibition of alpha3 integrin using shRNA resulted in decreased MMP7 secretion, a possible cause of decreased invasion with low alpha3 integrin expression. This study shows that Src overexpression downregulates alpha3 integrin total protein expression and localization to the cell surface of HCT116 colon cancer cells. This indicates that Src activity may enhance metastasis by altering alpha3 integrin expression.

Effect of Endostatin and SU6668 combined with 5-FU on human colon cancer xenograft in nude mice

To investigate the effect of Endostatin and SU6668 combined with 5-FU on the growth and metastasis of human colon cancer in vivo and its mechanism. Metastatic model of human colon cancer was established by orthotopic implantation of human tumor tissue into colon wall of nude mice. Twelve days later, mice were randomly divided into saline water control, Endostatin, SU6668, Endostatin plus SU6668, and Endostatin plus SU6668 and 5-FU groups, intraperitoneal injected respectively every day for four weeks. Six weeks after implication, the tumor weight, inhibition rates, intratumoral microvessel density (MVD) and metastasis were evaluated after the mice were sacrificed. Compared with the control, tumor growth was significantly inhibited in mice treated respectively with Endostatin, SU6668, Endostatin plus SU6668 and Endostatin plus SU6668 and 5-FU with an inhibition rate of 0, 64.9%, 63.5%, 76.4% and 88.2% respectively,and MVD decreased significantly in treated groups [(18.10+/-5.65) vs (2.75+/-0.75), (3.17+/-0.58), (0.94+/-0.42) and (0.36+/-0.45)]. The incidences of peritoneal and region lymph node metastases were significantly inhibited in Endostatin, SU6668, Endostatin plus SU6668 and Endostatin plus SU6668 and 5-FU (90% vs 16.7%, 25%, 0 and 0; 90% vs 0, 0, 0 and 0). The growth and metastasis of human colon cancer implanted in nude mice were significantly inhibited in Endostatin, SU6668, Endostatin plus SU6668, and Endostatin plus SU6668 and 5-FU, and the effect of Endostatin plus SU6668 and 5-FU was the most obviously. Endostatin plus SU6668 and 5-FU has strong inhibitory effect both on tumor growth and metastasis of human colon cancer.

Coagulation abnormalities in patients with metastatic colon cancer on bevacizumab therapy

14578 Background: Bevacizumab (Avastin) is a recombinant humanized monoclonal antibody to vascular endothelial growth factor (VEGF) that functions as an anti-angiogenic agent. VEGF is a glycoprotein, important for regulation of angiogenesis in normal and pathologic cells and is required for the maintenance of immature blood vessels, found in tumors. In addition to direct antiangiogenic effects, bevacizumab improves chemotherapy delivery by altering tumor vasculature as well as decreasing the size and number of liver tumors in mouse xenograft model of human colon cancer metastases. This study aimed to look for predictors of the development of major toxicities such as bleeding and clotting that would increase the incidence of such events in patients with metastatic colorectal carcinoma on Bevacizumab therapy. Methods: The study was a retrospective analysis over the past 2 years, reviewing the charts of 59 successive patients receiving bevacizumab in our institution. Particular emphasis was placed on age, gender, tumor type and location, location of metastases, chemotherapy regiment/number of cycles, past medical history, hemoglobin/hematocrit values, PT/INR values, liver function tests and albumin values at the time of the diagnosis and event. Utilizing univariant and multivariant analysis the goal was to determine contributing risk factors for increased incidence of bleeding and clotting. Results: 20.3% of the patients were found to have a major complication, such as clotting or bleeding. Once analyzed, there were four statistically significant indicators (p < 0.05) that predicted for the incidence of either one of the events. They included older patient age, low albumin values at the time of the event (as defined by the institution value of less than 3.6), location of the tumor (cecum, ascending colon and sigmoid colon were predominant), and the site of the metastasis (liver and lung). Conclusions: Clotting and bleeding complications in patients on Bevacizumab are not uncommon. It is clear that age, low albumin values, metastatic site and tumor location contribute to an increased incidence of such events in patients with metastatic colon cancer on Bevacizumab therapy. [Table: see text]

934. Gene Therapy for Colon Cancer by Adeno-Associated Viral Vector-Mediated Transfer of Apolipoprotein(a) Kringles

Top of pageAbstract We previously demonstrated the anti-angiogenic activities of apolipoprotein (a) (apo (a)) kringles LK68 and LK8 in vitro and in vivo. Gene transfer of these kringles mediated by adeno-associated viral vectors (AAV) further elucidated a potential anti-metastatic and anti-tumor activity of LK68 and LK8 in vivo. In the present study, we further evaluated the therapeutic potential of gene therapy with recombinant AAV carrying LK68 gene (rAAV-LK68) in the treatment of colon cancer. Intramuscular administration of rAAV- LK68 (1 |[times]| 109 infectious units/mouse) appeared to extend the latent period of the tumors and reduced the rate of tumor growth, compared to the negative control groups. rAAV-produced LK68 inhibited tumor growth by more than 65% (P<0.0069 versus each negative control group) in immuno-deficient mice bearing subcutaneously transplanted human colon tumor cells. Furthermore, rAAV-LK68 administration reduced by 85% (P<0.0094 versus each negative control group) the number of tumor nodules metastasized to the liver, when evaluated in a murine hepatic metastasis model. Histological and immunohistochemical analyses of the tumor sections showed that rAAV-produced LK68 inhibited tumor angiogenesis by more than 60% (P<0.01 versus negative control group) and triggered threefold more tumor apoptosis, compared to the negative control. Therefore, anti-angiogenecity induced by rAAV-LK68 administration was presumed to trigger suppression of tumor growth and metastasis. These results collectively suggest that rAAV-LK68 is a potent agent to inhibit tumor growth and hepatic metastasis of human colon cancer.