Metastatic Colorectal Cancer Tissues Research Articles

IHC-based predictive biomarker for irinotecan response.

548 Background: For gastro-intestinal cancers, irinotecan is used as first or second line, either as single agent or in combination therapy. The patient response rate is low and drug resistance mechanism is not understood. Irinotecan like other topoisomerase I inhibitors (camptothecin and their analogues, CPTs) are not MDR substrates, topoI mutations are rare and other potential mechanisms have not been validated. One of the most distinct cellular responses to CPT is the proteolytic degradation of topoI by the ubiquitin proteosomal pathways (UPP) and the rate of topoI degradation determines the drug response. Using a functional proteomic approach we have defined the mechanism of UPP mediated topoI degradation and have identified the molecular determinant of CPT resistance. We have demonstrated that higher basal level of topoI-pS10 drives rapid topoI ubiquitination and degradation in response to CPT. Methods: We have raised mouse monoclonal antibody that specifically binds with topoI-pS10 for immunohistochemistry (IHC) staining of the formalin fixed paraffin embedded (FFPE) slides. In our first cohort of retrospective study, 48 metastatic colorectal cancer tissues were immunostained with anti-topoI-pS10 and nuclear staining was quantitatively analyzed. Results: Data were summarized with descriptive statistics. ROC analysis was used to assess diagnostic characteristics across different thresholds. Mean and median positive nucleation values correlated strongly with drug response. Median nucleation level among non-responders was 69% compared to 9% for responders (Wilcoxon p = 0.0006). ROC analysis demonstrated an optimal threshold between 30-40% nucleation. Using a threshold of 35%, the estimated sensitivity was 82% (95% CI 56-95) and specificity was 77% (57-89). Estimated positive and negative predicted values were 67% (43-85) and 88% (69-97) respectively. We have also got similar results in 80 patient gastric cancer retrospective studies. Conclusions: Basal level of topoI-pS10 can be used as a predictive biomarker for topoI inhibitors. Our IHC based test can be adopted in clinical pathology settings to determine the topoI-pS10 level and stratify the patient population for CPT based therapy.

LYAR promotes colorectal cancer cell mobility by activating galectin-1 expression.

Colorectal cancer (CRC) is one of the leading causes of cancer-related death worldwide. However, the molecular mechanisms of CRC pathogenesis are not fully understood. In this study, we report the characterization of LYAR (Ly-1 antibody reactive clone) as a key regulator of the migration and invasion of human CRC cells. Immunohistochemistry analysis demonstrated that LYAR is expressed at a higher level in metastatic CRC tissues. We found that LYAR promoted the migratory and invasive capabilities of CRC cells. Gene expression profile analysis of CRC cells showed that LGALS1, which encodes the galectin-1 protein, was a potential target of LYAR. The ChIP assay and gene reporter assays indicated that LYAR directly bound to the LGALS1 promoter. The ectopic expression of galectin-1 partially restored the mobile potential of LYAR knocked-down cells, which suggests that galectin-1 contributed to the LYAR-promoted cell migration and invasion of CRC cells. Thus, this study revealed a novel mechanism by which the transcription factor LYAR may promote tumor cell migration and invasion by upregulating galectin-1 gene expression in CRC.

MiR-622 inhibited colorectal cancer occurrence and metastasis by suppressing K-Ras.

Colorectal cancer (CRC) is one of the leading causes of cancer death worldwide, with many oncogenes and anti-oncogenes involved. MicroRNAs (miRNAs) are a class of small, noncoding RNA molecules that can adjust downstream targets. Accumulating evidence has revealed that microRNAs govern the occurrence and development of cancer. Here, we studied the role of miR-622 in CRC and clarified the underlying mechanism. We detected that miR-622 was down-regulated in colorectal tumor tissues and cell lines and that miR-622 was lower in metastatic CRC tissues compared with that in non-metastatic specimens. Furthermore, we confirmed that miR-622 inhibited tumor proliferation and migration in vitro. Through dual-luciferase reporter assay, we found kirsten rat sarcoma (K-Ras) gene was the direct target of miR-622. More importantly, K-Ras overexpression can rescue the inhibitory effect of miR-622 on CRC development. All these data were validated in colon xenograft tumor model. MiR-622-K-Ras signal pathway was a potentially new direction in the development of screening target and therapeutic treatments for CRC. © 2015 Wiley Periodicals, Inc.

Correlation between DPYD gene variation and KRAS wild type status in colorectal cancer

AimsFailure and side effects of combined cytotoxic therapy are challenges in the treatment of metastatic colorectal cancer (CRC). DPYD gene variations can potentially predict toxicity to 5-fluorouracil (FU)-based therapy and...

Abstract 1446: Induction of epithelial-to-mesenchymal transition (EMT) by SL-15 knockdown contributes to anoikis resistance in human colorectal cancer metastases

Abstract Purpose of the study: Metastasis or systemic dissemination of cancer cells into secondary organs is responsible for 90% of cancer-related fatalities. Our team previously screened out SL-15 as therapeutic target of gastric cancer through the analysis of gene expression profiling. In this study, we investigated the roles of human SL-15 in colorectal cancer (CRC) metastasis. Experimental procedures: SL-15 levels of metastatic liver CRC tissues and of primary CRC tissues as well as of adjacent nontumour tissues were compared using quantitative RT-PCR. Transwell and wound healing methods were used to determine the migration/invasion abilities of CRC cells. Flow cytometery analysis was performed to measure the apoptotic ratio as well as the levels of E-cadherin/p53/SL-15. Confocal observation and Western blot analysis were used for studying the underlying mechanisms of small interfering RNA against SL-15 (siSL-15)-induced CRC metastasis. Results: The level of SL-15 was higher in the order of metastatic liver CRC tissues, primary CRC tissues and then the adjacent nontumor tissues. siSL-15 significantly induced the migration/invasion of CRC cells that was almost entirely suppressed by the co-expression of SL-15. Importantly, the application of siSL-15 contributes to anoikis resistance of CRC cells via the upregulation of zinc finger E-box-binding homeobox 1 (ZEB1) in stem-like subtype CRC cells and intestinal trefoil factor (ITF) in goblet- like subtype CRC cells by the inhibition of glycogen synthase kinase 3 β (GSK3β) and of β-catenin degradation, thereby leading to downregulation of E-cadherin as well as p53 degradation. Importantly, the interactions among SL-15/p53/GSK3β that were dissociated upon the application of siSL-15 were determined. Conclusions: SL-15 is more highly up-regulated in metastatic liver CRC cancer than in primary CRC cancer and the adjacent nontumor tissue: SL-15 knockdown contributes to anoikis resistance of CRC cells and CRC metastasis via inducing epithelial-to-mesenchymal transition as well as p53 degradation due to the dissociation of SL-15 with GSK3β and p53. Citation Format: Soo Young Jun, Hyun-Soo Cho, Jeong-Ju Lee, Jun-Ho Ahn, Ji-Yong Yoon, Jae-Hye Lee, Min Hyuk Choi, Nam-Soon Kim. Induction of epithelial-to-mesenchymal transition (EMT) by SL-15 knockdown contributes to anoikis resistance in human colorectal cancer metastases. [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 1446. doi:10.1158/1538-7445.AM2015-1446

MicroRNA-106b promotes colorectal cancer cell migration and invasion by directly targeting DLC1.

BackgroundGrowing evidence suggests that microRNAs (miRNAs) play an important role in tumor development, progression and metastasis. Aberrant miR-106b expression has been reported in several cancers. However, the role and underlying mechanism of miR-106 in colorectal cancer (CRC) have not been addressed.MethodsQuantitative RT-PCR(qRT-PCR) was performed to evaluate miR-106b levels in CRC cell lines and patient specimens. Cell proliferation was detected using MTT assay, and cell migration and invasion ability were evaluated by wound healing assay and transwell assay. The target gene of miR-106b was determined by qRT-PCR, western blot and luciferase assays.ResultsmiR-106b was significantly up-regulated in metastatic CRC tissues and cell lines, and high miR-106b expression was associated with lymph node metastasis and advanced clinical stage. In addition, miR-106b overexpression enhances, whereas miR-106b depletion reduces CRC cell migration and invasion. Moreover, we identify DLC1 as a direct target of miR-106b, reveal its expression to be inversely correlated with miR-106b in CRC samples and show that its re-introduction reverses miR-106b-induced CRC cell migration and invasion. Furthermore, survival analyses showed the patients with high mi-106b/low DLC1 had shorter overall survival (OS) and disease-free survival (DFS) rates, and confirmed miR-106b may be an independent prognostic factor for OS and DFS in CRC patients.ConclusionsOur findings indicate that miR-106b promotes CRC cell migration and invasion by targeting DLC1. This miRNA may serve as a potential prognostic biomarker and therapeutic target for CRC.

Co-evolution of somatic variation in primary and metastatic colorectal cancer may expand biopsy indications in the molecular era.

IntroductionMetastasis is thought to be a clonal event whereby a single cell initiates the development of a new tumor at a distant site. However the degree to which primary and metastatic tumors differ on a molecular level remains unclear. To further evaluate these concepts, we used next generation sequencing (NGS) to assess the molecular composition of paired primary and metastatic colorectal cancer tissue specimens.Methods468 colorectal tumor samples from a large personalized medicine initiative were assessed by targeted gene sequencing of 1,321 individual genes. Eighteen patients produced genomic profiles for 17 paired primary:metastatic (and 2 metastatic:metastatic) specimens.ResultsAn average of 33.3 mutations/tumor were concordant (shared) between matched samples, including common well-known genes (APC, KRAS, TP53). An average of 2.3 mutations/tumor were discordant (unshared) among paired sites. KRAS mutational status was always concordant. The overall concordance rate for mutations was 93.5%; however, nearly all (18/19 (94.7%)) paired tumors showed at least one mutational discordance. Mutations were seen in: TTN, the largest gene (5 discordant pairs), ADAMTS20, APC, MACF1, RASA1, TP53, and WNT2 (2 discordant pairs), SMAD2, SMAD3, SMAD4, FBXW7, and 66 others (1 discordant pair).ConclusionsWhereas primary and metastatic tumors displayed little variance overall, co-evolution produced incremental mutations in both. These results suggest that while biopsy of the primary tumor alone is likely sufficient in the chemotherapy-naïve patient, additional biopsies of primary or metastatic disease may be necessary to precisely tailor therapy following chemotherapy resistance or insensitivity in order to adequately account for tumor evolution.

MALAT1 promotes colorectal cancer cell proliferation/migration/invasion via PRKA kinase anchor protein 9

Our previous studies have shown that the 3′ end of metastasis associated lung adenocarcinoma transcript 1 (MALAT1) is involved in colorectal cancer (CRC) cell proliferation and migration/invasion in vitro. The role and mechanism of MALAT1 in CRC metastasis in vivo, however, remain largely unknown. In the present study, we found that MALAT1 was up-regulated in human primary CRC tissues with lymph node metastasis. Overexpression of MALAT1 via RNA activation promoted CRC cell proliferation, invasion and migration in vitro, and stimulated tumor growth and metastasis in mice in vivo. Conversely, knockdown of MALAT1 inhibited CRC tumor growth and metastasis. MALAT1 regulated at least 243 genes in CRC cells in a genome-wide expression profiling. Among these genes, PRKA kinase anchor protein 9 (AKAP-9) was significantly up-regulated at both mRNA and protein levels. AKAP-9 was highly expressed in CRC cells with metastatic potential and human primary CRC tissues with lymph node metastasis, but not in normal cells or tissues. Importantly, knockdown of AKAP-9 blocked MALAT1-mediated CRC cell proliferation, migration and invasion. These data indicate that MALAT1 may promote CRC tumor development via its target protein AKAP-9.

Expression and Significance of Interleukin 1α mRNA in Colorectal Cancer

Quantitative analysis for the relative mRNA expression of interleukin 1α (IL-1α) in colorectal cancer and cancer-adjacent tissues, the clinical significance of which will be investigated. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to analyze the relative mRNA levels of IL-1α in 42 colorectal cancer tissues and corresponding cancer-adjacent tissues, statistically analyzing the co-relation of IL-1α mRNA levels with the differentiation, clinical stages and metastatic status of cancer. The relative content of IL-1α mRNA in colorectal tissues was 1.18 ± 0.80, and that in cancer-adjacent tissues was 0.74 ± 0.49, with a significant difference between the two groups (t=-3.12, P=0.003). The relative content of IL-1α mRNA in advance-staged (stage III-IV) colorectal cancer tissues was 1.50 ± 0.93, which was significantly higher than that in early-staged colorectal cancer tissues (1.50 ± 0.93 vs. 0.89 ± 0.52, t=-2.67, P=0.01). The relative content of IL-1α mRNA in metastatic colorectal cancer tissues was 1.59 ± 0.90, which was significantly higher than that in non-metastatic colorectal cancer tissues (1.59 ± 0.90 vs. 0.84 ± 0.50, P=0.002). Expression of IL-1α mRNA in colorectal cancer tissues is significantly elevated, and has a positive co-relation with the clinical stages and metastatic status, suggesting IL-1α might play a role in the initiation and progression of colorectal cancer.

MicroRNA-182 targets special AT-rich sequence-binding protein 2 to promote colorectal cancer proliferation and metastasis.

BackgroundIncreasing evidence has revealed that microRNAs (miRNA) played a pivotal role in regulating cancer cell proliferation and metastasis. The deregulation of miR-182 has been identified in colorectal cancer (CRC). However, the role and mechanism of miR-182 in CRC have not been completely understood yet.MethodsThe expression levels of miR-182 in CRC tissues and CRC cell lines were examined by performing stem-loop quantitative RT-PCR. The stable over-expression miR-182 cell lines and control cell lines were constructed by lentivirus infection. Subsequently, CCK-8 assay, plate colony formation assay, cell migration, invasion assay and experimental animal models were performed to detect the biological functions of miR-182 in vitro and in vivo. A luciferase reporter assay was conducted to confirm target associations. Western blot and immunohistochemical analysis were performed to examine the expression changes of molecular markers that are regulated by miR-182.ResultsWe found that miR-182 expression is increased in CRC cells that originated from metastatic foci and human primary CRC tissues with lymph node metastases. The ectopic expression of miR-182 enhanced cell proliferation, invasion, and migration in vitro. Stable overexpression of miR-182 also facilitated tumor growth and metastasis in vivo too. Further research showed that miR-182 could directly target the 3’untranslated region (3’UTR) of SATB2 mRNA and subsequently repress both the mRNA and protein expressions of SATB2, which we identified in previous studies as a CRC metastasis-associated protein. Restoring SATB2 expression could reverse the effects of miR-182 on CRC cell proliferation and migration. Investigations of possible mechanisms underlying these behaviors induced by miR-182 revealed that miR-182 induced epithelial-mesenchymal transition (EMT) by modulating the expression of key cellular molecules in EMT.ConclusionsOur results illustrated that the up-regulation of miR-182 played a pivotal role in CRC tumorigenesis and metastasis, which suggesting a potential implication of miR-182 in the molecular therapy for CRC.

Higher Quality of Molecular Testing, an Unfulfilled Priority: Results from External Quality Assessment for KRAS Mutation Testing in Colorectal Cancer

Precision medicine is now a key element in clinical oncology. RAS mutational status is a crucial predictor of responsiveness to anti-epidermal growth factor receptor agents in metastatic colorectal cancer. In an effort to guarantee high-quality testing services in molecular pathology, the European Society of Pathology has been organizing an annual KRAS external quality assessment program since 2009. In 2012, 10 formalin-fixed, paraffin-embedded samples, of which 8 from invasive metastatic colorectal cancer tissue and 2 artificial samples of cell line material, were sent to more than 100 laboratories from 26 countries with a request for routine KRAS testing. Both genotyping and clinical reports were assessed independently. Twenty-seven percent of the participants genotyped at least 1 of 10 samples incorrectly. In total, less than 5% of the distributed specimens were genotyped incorrectly. Genotyping errors consisted of false negatives, false positives, and incorrectly genotyped mutations. Twenty percent of the laboratories reported a technical error for one or more samples. A review of the written reports showed that several essential elements were missing, most notably a clinical interpretation of the test result, the method sensitivity, and the use of a reference sequence. External quality assessment serves as a valuable educational tool in assessing and improving molecular testing quality and is an important asset for monitoring quality assurance upon incorporation of new biomarkers in diagnostic services.

Elevated MicroRNA-31 Expression Regulates Colorectal Cancer Progression by Repressing Its Target Gene SATB2

Several studies have brought about increasing evidence to support the hypothesis that miRNAs play a pivotal role in multiple processes of carcinogenesis, including cell growth, apoptosis, differentiation, and metastasis. In this study, we investigated the potential role of miR-31 in colorectal cancer (CRC) aggressiveness and its underlying mechanisms. We found that miR-31 increased in CRC cells originated from metastatic foci and human primary CRC tissues with lymph node metastases. Furthermore, the high-level expression of miR-31 was significantly associated with a more aggressive and poor prognostic phenotype of patients with CRC (p < 0.05). The stable over-expression of miR-31 in CRC cells was sufficient to promote cell proliferation, invasion, and migration in vitro. It facilitated tumor growth and metastasis in vivo too. Further studies showed that miR-31 can directly bind to the 3’untranslated region (3’UTR) of SATB2 mRNA and subsequently repress both the mRNA and protein expressions of SATB2. Ectopic expression of SATB2 by transiently transfected with pCAG-SATB2 vector encoding the entire SATB2 coding sequence could reverse the effects of miR-31 on CRC tumorigenesis and progression. In addition, ectopic over-expression of miR-31 in CRC cells induced epithelial-mesenchymal transition (EMT). Our results illustrated that the up-regulation of miR-31 played an important role in CRC cell proliferation, invasion, and metastasis in vitro and in vivo through direct repressing SATB2, suggesting a potential application of miR-31 in prognosis prediction and therapeutic application in CRC.

E2A suppresses invasion and migration by targeting YAP in colorectal cancer cells

BackgroundE2A gene, which encodes two basic helix–loop–helix (bHLH) transcription factors E12 and E47, has been identified as regulator of B lymphoid hematopoiesis and suppressor of lymphoma. E47 protein was found to decrease E-cadherin expression and induce epithelial-mesenchymal transition (EMT). However, the role of E2A in colorectal cancer (CRC) metastasis is still elusive.MethodsqRT-PCR and semi-qRT-PCR were performed to determine mRNA level of E2A in CRC specimens and colorectal cancer cells. RNAi was employed to downregulate E2A expression and subsequent protein level change was evaluated by immunoblot. Cell invasion and migration capacity were detected by transwell assay using cell culture inserts with or without basement membrane matrix, respectively.ResultsE2A expression was decreased in metastatic CRC tissues. Invasion and migration assays showed downregulation of E2A increased metastatic capacity of CRC cells while forced expression of E12 or E47 could offset this effect. Both E12 and E47 suppressed EMT induced by E2A downregulation. Moreover, Yes-Associated Protein (YAP) was a downstream target of E2A and suppression of YAP inhibited the pro-migration/invasion of E2A deficiency.ConclusionOur results suggest that E2A suppresses CRC cell metastasis, at least partially if not all, by inhibiting YAP expression.

MicroRNA-221 promotes colorectal cancer cell invasion and metastasis by targeting RECK

MicroRNAs (miRNAs) have recently emerged as regulators of metastasis. We provide insight into the behavior of miR-221 in colorectal cancer (CRC) metastasis by showing that miR-221 is significantly upregulated in metastatic CRC cell lines and tissues. miR-221 overexpression enhances, whereas miR-221 depletion reduces CRC cell migration and invasion in vitro and metastasis in vivo. We identify RECK as a direct target of miR-221, reveal its expression to be inversely correlated with miR-221 in CRC samples and show that its re-introduction reverses miR-221-induced CRC invasiveness. Collectively, miR-221 is an oncogenic miRNA which may regulate CRC migration and invasion through targeting RECK.

The Expression of Ezrin is Increased in Colorectal Cancer Metastasis Compared to Primary Tumors

Colorectal cancer (CRC) is a leading cause of cancer related mortality. Majority of these deaths are from metastatic disease. The purpose of this study was to use a proteomics approach in primary and metastatic human CRC tissues generated in an orthotopic murine model to identify novel protein targets for developing new therapies against advanced CRC.

Concordant KRAS Mutations in Primary and Metastatic Colorectal Cancer Tissue Specimens: A Meta-Analysis and Systematic Review

A meta-analysis was performed to compare KRAS gene mutations in colorectal cancer tissue samples with primary and metastatic colorectal cancers. A total of 19 publications with 986 paired primary and distant metastases and 171 paired primary and lymph node metastases showed that KRAS genotype was highly concordant in primary and distant metastatic tumors, indicating that either type of tumor tissue could be useful as a source to detect KRAS mutations for selection of anti-EGFR therapy. However, lymph-node-metastatic tumors might not be suitable for diagnostic analysis of KRAS mutations due to an obvious discordant rate between primary and lymph-node-metastatic tumors.

CD133+CXCR4+ colon cancer cells exhibit metastatic potential and predict poor prognosis of patients

BackgroundColorectal cancer (CRC), which frequently metastasizes to the liver, is one of the three leading causes of cancer-related deaths worldwide. Growing evidence suggests that a subset of cells exists among cancer stem cells. This distinct subpopulation is thought to contribute to liver metastasis; however, it has not been fully explored in CRC yet.MethodsFlow cytometry analysis was performed to detect distinct subsets with CD133 and CXCR4 markers in human primary and metastatic CRC tissues. The 'stemness' and metastatic capacities of different subpopulations derived from the colon cancer cell line HCT116 were compared in vitro and in vivo. The roles of epithelial-mesenchymal transition (EMT) and stromal-cell derived factor-1 (SDF-1) in the metastatic process were also investigated. A survival curve was used to explore the correlation between the content of CD133+CXCR4+ cancer cells and patient survival.ResultsIn human specimens, the content of CD133+CXCR4+ cells was higher in liver metastases than in primary colorectal tumors. Clonogenic and tumorigenic cells were restricted to CD133+ cells in the HCT116 cell line, with CXCR4 expression having no impact on the 'stemness' properties. We found that CD133+CXCR4+ cancer cells had a high metastatic capacity in vitro and in vivo. Compared with CD133+CXCR4- cells, CD133+CXCR4+ cancer cells experienced EMT, which contributed partly to their metastatic phenotype. We then determined that SDF-1/CXCL12 treatment could further induce EMT in CD133+CXCR4+ cancer cells and enhance their invasive behavior, while this could not be observed in CD133+CXCR4- cancer cells. Blocking SDF-1/CXCR4 interaction with a CXCR4 antagonist, AMD3100 (1,10-[1,4-phenylenebis(methylene)]bis-1,4,8,11 -tetraazacyclotetradecane octahydrochloride), inhibited metastatic tumor growth in a mouse hepatic metastasis model. Finally, a high percentage of CD133+CXCR4+ cells in human primary CRC was associated with a reduced two-year survival rate.ConclusionsStrategies targeting the SDF-1/CXCR4 interaction may have important clinical applications in the suppression of colon cancer metastasis. Further investigations on how high expression of CXCR4 and EMT occur in this identified cancer stem cell subset are warranted to provide insights into our understanding of tumor biology.

Abstract 1467: The potential role of de novo lipogenesis in the regulation of cell motility and invasion in colorectal cancer

Abstract The signaling networks that determine progression of cancer to a more aggressive metastatic phenotype include multiple alterations in the oncogenic pathways as well as significant changes in cellular metabolism. ATP-citrate lyase (ACLY) and Fatty Acid Synthase (FASN), key enzymes of lipid biogenesis, are significantly up-regulated and activated in many cancers and their activity is associated with poor prognosis, higher risk of disease recurrence, and death. Even though the role of neoplastic lipogenesis in providing proliferative and survival advantages to cancer cells has been defined, the impact of aberrant activation of lipogenic enzymes on the progression of cancer and development of metastases remains unknown. The purpose of the present study was to determine (i) the expression and/or activity of lipogenic enzymes in human colorectal cancer (CRC) tissues and cells, and (ii) the effect of their inhibition on signaling pathways involved in the regulation of migration and invasion. METHODS: Expression of FASN was analyzed in primary CRCs, matched liver metastasis and normal mucosa using Accumax Tissue Array. Expression of FASN and ACLY was also determined in CRC cell lines by Western blot. KM20, HT29, and HCT116 CRC cells with stable knockdown of ACLY and FASN were established, and downstream signaling pathways were analyzed (Western blot). Effect of inhibition of FASN on cell morphology (immunofluorescence microscopy), invasion (Boyden Chamber Assay), and endothelial cell adhesion was assessed. RESULTS: Expression of FASN was significantly higher in primary tumor and in liver metastases as compared to normal colon mucosa. FASN and ACLY were also highly expressed in CRC cell lines. Inhibition of lipogenic enzymes decreased migration and invasion of CRC cells. Mechanisms underlying these effects included disruption of CD44/c-MET signaling and decreased expression of pAkt, pFAK, RhoA, and RAC1. Furthermore, inhibition of FASN decreased the adherence of CRC cells to HMVEC-L endothelial cells.CONCLUSIONS: Increased expression of FASN and ACLY in both non-invasive and metastatic cell lines and CRC tissues suggest the potential role of de novo lipogenesis in the progression of CRC. Supporting this hypothesis, the current study demonstrates, for the first time, that inhibition of lipogenesis disrupts CD44/c-MET signaling which is well known to promote metastasis in several cancers including CRC. Furthermore, decreased expression of RhoA, Rac1, and pFAK, accompanied by changes in the actin cytoskeleton and the finding that inhibition of FASN attenuates the interaction of cancer cells with endothelial cells, suggests that activation of lipogenic enzymes plays a role in regulation of cancer cell motility and formation of metastasis. Together, these findings suggest that de novo lipogenesis may be a potential therapeutic target for early and advanced stages of CRC. 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 1467. doi:10.1158/1538-7445.AM2011-1467

Abstract 5197: Identification of prognostic cancer stem cell marker profiles in aggressive metastatic colorectal cancer

Abstract Background: Despite recent advances in screening and treatment, metastatic colorectal cancer (CRC) remains a leading cause of cancer-related death in the United States. A subset of patients with metastatic disease to the liver may achieve long-term survival with metastasectomy. However, the majority of patients with liver metastases have a median survival of approximately 2 years despite treatment. Several studies have proposed that cancer stem cells (CSC) may be linked to metastasis, treatment resistance and recurrence, but to date, no one has examined whether the expression of CSC markers can be prognostic indicators of recurrence and overall survival in metastatic CRC. Methods: Formalin-fixed, paraffin-embedded metastatic CRC tissue samples were obtained from patients treated with metastasectomy of liver disease. Using standard immunohistochemical techniques, tissue samples were stained with antibodies to previously characterized CSC markers CD166, CD133, CD44 and CD26. Cellular expression patterns for solitary and multiple CSC markers were analyzed using an automated open source image quantification program (CellProfiler 2.0). Expression profiles were then correlated to patient outcomes (disease recurrence and overall survival). Results: Variable expression of CSC markers was seen between long- and short-term survival as well as rate of recurrence. Patients with an increased overall survival showed a higher level of CD44 expression. Co-expression of CD44 and CD166 correlated to increased disease-free survival. Conclusion: In this study, we identify a subset of CSC markers that correlates to disease behavior and tumor biology in metastatic CRC. Further delineation of CSC profiles may give valuable clues to therapeutic resistance as well as offer new therapeutic targets in the treatment of this disease. 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 5197. doi:10.1158/1538-7445.AM2011-5197

Promotion of colorectal cancer growth and metastasis by the LIM and SH3 domain protein 1

BackgroundLIM and SH3 protein 1 (LASP-1), initially identified from a cDNA library of metastatic axillary lymph nodes of breast cancer patients, is a specific focal adhesion protein involved in numerous...