Potential Colorectal Cancer Research Articles

Abstract 5189: RNA editing in rhoq promotes invasion potential in colorectal cancer

Abstract RNA editing can increase RNA sequence variation without alteration of DNA sequence. By comparing whole genome and transcriptome sequence data of a rectal cancer, we have found a novel tumor specific RNA editing in RHOQ. The A-to-I editing results in substitution of sparagine with serine at residue 136. We observed higher level of the RHOQ RNA editing in tumor compared with normal tissue in colorectal cancer. The degree of RNA editing was associated with RhoQ activity in colorectal cancer cell lines. RhoQ N136S amino acid substitution increased RhoQ activity, actin cytoskeletal reorganization, and invasion potential. KRAS mutation further increased the invasion potential of RhoQ N136S in vitro. Among colorectal cancer patients, recurrence was more frequently observed in patients with tumors having edited RHOQ and mutant KRAS. Collectively, we show that RNA editing is another mechanism of sequence alteration contributing to colorectal cancer progression. Citation Format: Hwang-Phill Kim, Sae-Won Han, Kyung-Hun Lee, Kyu Joo Park, Jeong-Sun Seo, Jong-Il Kim, Tae-You Kim. RNA editing in rhoq promotes invasion potential in colorectal cancer. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 5189. doi:10.1158/1538-7445.AM2014-5189

Abstract 1123: Fucosylated TGF-ß receptors transduce a signal for epithelial-mesenchymal transition in colorectal cancer cells

Abstract Background: Transforming growth factor-ß (TGF-ß) is a major inducer of epithelial-mesenchymal transition (EMT) in different cell types. TGF-ß-mediated EMT is thought to contribute to tumor cell spread and metastasis. Sialyl Lewis antigens synthesized by fucosyltransferase (FUT) 3 and FUT6 are highly expressed in patients with metastatic colorectal cancer (CRC) and are utilized as tumor markers for cancer detection and evaluation of treatment efficacy. However, the role of FUT3 and FUT6 in augmenting the malignant potential of CRC induced by TGF-ß is unclear. Methods: CRC cell lines were transfected with siRNAs for FUT3/6 and were examined by cell proliferation, invasion, and migration assays. The expression and phosphorylation status of TGF-ß downstream molecules were analyzed by western blot. Fucosylation of TGF-ß receptor was examined by lectin blot analysis. Results: Inhibition of FUT3/6 expression by siRNAs suppressed the fucosylation of type I TGF-ß receptor and phosphorylation of the downstream molecules, thereby inhibiting the invasion and migration of CRC cells by EMT. Citation Format: Rishu Takimoto, Masahiro Hirakawa, Fumito Tamura, Makoto Yoshida, Michihiro Ono, Yasushi Sato, Takahiro Osuga, Junji Kato. Fucosylated TGF-ß receptors transduce a signal for epithelial-mesenchymal transition in colorectal cancer cells. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1123. doi:10.1158/1538-7445.AM2014-1123

Abstract 1138: Aberrant expression of Plastin3 (PLS3) induces liver metastasis via enhancing the epithelial-mesenchymal transition and stemness in colorectal cancer (CRC)

Abstract Background PLS3 gene, located on chromosome Xq23, encodes a protein 10 product (PLS3) that reduces F-actin disassembly and inhibits cofilin-mediated depolymerization of actin fibers. We previously reported that PLS3 is a novel marker for circulating tumor cells in colorectal cancer (CRC), and the high expression of PLS3 in tumor tissue is associated with a poor prognosis in patients with primary CRC. In this study, we investigated its role in functional significance for metastatic potential of CRC performing in vitro and in vivo studies. Method Four patients with surgically resected both primary CRC and liver metastasis were included in this study. Those tissues were performed with the PLS3-immunohistochemical examination (PLS3-IHC). In vitro, we cultured LOVO, DLD-1 and HCT116 which caused no liver metastasis by injecting them into the spleen of NOD/SCID mice. We stably enhanced the expression of PLS3 in the cells by transfecting the lentiviral vector expressing PLS3. The expression levels of EMT-related genes were examined with real time RT-PCR. The migration, invasion and sphere formation assay were also performed. In vivo, NOD/SCID mice were divided into two groups, which included mice transplanted with only PLS3-transfected cells and mice transplanted with PLS3-transfected and PLS3-attenuated cells together, by injecting into the spleen. We calculated the established primary splenic tumors and liver metastasis. PLS3-IHC was also performed to the sacrificed tissues. Result (1) In the PLS3-IHC of four CRC samples, all the liver metastasis tissues included stained areas, but only one primary tissue showed PLS3-staining. This was the evidence that cancer cells expressing PLS3 had metastatic properties. (2) PLS3-transfected cells had the significant decrease of E-cadherin, while the expression levels of TWIST, ZEB and vimentin were significantly higher in PLS3-transfected than PLS3-attenuated cells. PLS3-transfected LOVO significantly induced invasion and migration, compared to PLS3-attenuatd LOVO. In the sphere formation assay, the high expression of PLS3 significantly increased the proportion of sphere generating cells (DLD-1) (p<0.001). (3) In vivo, PLS3-transfected cells (DLD-1 and HCT116) significantly induced the growth of liver metastasis. The volumes of liver metastasis of mice transplanted with the mixtures were significantly smaller than those of only PLS3-transfected cells. The liver metastasis tissues showed only stained areas in both groups in PLS3-IHC. However, the established splenic tumor of mice transplanted with the mixtures displayed not only the stained but also the nonstained areas in PLS3-IHC. Conclusion In conclusion, our study suggests experimental evidence to support the functional significance of PLS3 to induce epithelial-mesenchymal trandition, stemness and liver metastasis of human CRC. Citation Format: Masami Ueda, Keishi Sugimachi, Junji Kurashige, Shotarou Sakimura, Hidenari Hirata, Ryutarou Uchi, Yuki Takano, Hiroki Ueo, Tae Matsumura, Yoshiaki Shinden, Hidetoshi Eguchi, Tomoya Sudo, Masaki Mori, Koshi Mimori. Aberrant expression of Plastin3 (PLS3) induces liver metastasis via enhancing the epithelial-mesenchymal transition and stemness in colorectal cancer (CRC). [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 1138. doi:10.1158/1538-7445.AM2014-1138

866: Screening of Lactobacillus reuteri strains for their short chain fatty acids production, stability and potential in colorectal cancer: In-vitro analysis

866: Screening of Lactobacillus reuteri strains for their short chain fatty acids production, stability and potential in colorectal cancer: In-vitro analysis

Molecular Diagnostic Applications in Colorectal Cancer.

Colorectal cancer, a clinically diverse disease, is a leading cause of cancer-related death worldwide. Application of novel molecular diagnostic tests, which are summarized in this article, may lead to an improved survival of colorectal cancer patients. Distinction of these applications is based on the different molecular principles found in colorectal cancer (CRC). Strategies for molecular analysis of single genes (as KRAS or TP53) as well as microarray based techniques are discussed. Moreover, in addition to the fecal occult blood testing (FOBT) and colonoscopy some novel assays offer approaches for early detection of colorectal cancer like the multitarget stool DNA test or the blood-based Septin 9 DNA methylation test. Liquid biopsy analysis may also exhibit great diagnostic potential in CRC for monitoring developing resistance to treatment. These new diagnostic tools and the definition of molecular biomarkers in CRC will improve early detection and targeted therapy of colorectal cancer.

RNA Editing in RHOQ Promotes Invasion Potential in Colorectal Cancer

RNA Editing in RHOQ Promotes Invasion Potential in Colorectal Cancer

RNA editing in RHOQ promotes invasion potential in colorectal cancer

RNA editing can increase RNA sequence variation without altering the DNA sequence. By comparing whole-genome and transcriptome sequence data of a rectal cancer, we found novel tumor-associated increase of RNA editing in ras homologue family member Q (RHOQ) transcripts. The adenosine-to-inosine (A-to-I) editing results in substitution of asparagine with serine at residue 136. We observed a higher level of the RHOQ RNA editing in tumor compared with normal tissue in colorectal cancer (CRC). The degree of RNA editing was associated with RhoQ protein activity in CRC cancer cell lines. RhoQ N136S amino acid substitution increased RhoQ activity, actin cytoskeletal reorganization, and invasion potential. KRAS mutation further increased the invasion potential of RhoQ N136S in vitro. Among CRC patients, recurrence was more frequently observed in patients with tumors having edited RHOQ transcripts and mutations in the KRAS gene. In summary, we show that RNA editing is another mechanism of sequence alteration that contributes to CRC progression.

Hollow spheroids beyond the invasive front and malignant potential of colorectal cancer.

418 Background: Hollow spheroid (HS) is a morophogenesis after budding at invasion front of colorectal cancer (CRC) tissue. HS formation of CRC cells has been shown to be induced by Carcinoembryonic Antigen-related Cell Adhesion Molecule 1 (CEACAM1) long cytoplasmic isoform dominance condition in three-dimensional (3D) in vitro culture. The aim of the current study is to address the existence and the clinical implication of HS in colorectal cancer. Methods: Immunohistochemical analyses were conducted with CEACAM1, CEACAM1-L, to address the existence of CEACAM1 expressing HS beyond the invasion front of CRC. The risk factors for metastases and survival were calculated using univariate and multivariate analyses on clinical samples from 164 patients with CRC. To investigate the role of HS for chemoresistance to 5-fluorouracil (5-FU), the risk factors for recurrence after adjuvant chemotherapy were calculated using univariate and multivariate analyses on clinical samples from 82 patients with Stage III CRC. Results: Immunohistochemical analyses showed that CEACAM1 expressing HS existed at the invasion front of colorectal cancer tissues. A multivariate analysis showed that the HS is an independent risk factor for lymph node metastasis (p = 0.004) and distant metastasis (p = 0.002). HS was also identified to be an independent prognostic factor by a Cox proportional hazards model (p = 0.020). The Kaplan-Meier evaluation for the overall survival analysis showed that HS was significantly associated with a shorter survival (p < 0.0001). Moreover, a multivariate analysis for recurrence after adjuvant chemotherapy showed that the HS is an independent risk factor (p = 0.0079). These results suggested that HS indicates malignant and chemoresistant phenotype. Conclusions: HS was significantly correlated with CRC metastasis, poor survival and chemoresistance to 5-FU. HS beyond the invasion front of CRC can be useful for diagnosis of malignant potential, and may be novel therapeutic target.

P7 peptides targeting bFGF sensitize colorectal cancer cells to CPT-11

The low survival rate of patients with colorectal cancer (CRC) is mainly due to the drug resistance of tumor cells to chemotherapeutic agents. It has been reported that basic fibroblast growth factor (bFGF) is an essential factor involved in the epigenetic mechanisms of drug resistance, which provides a novel potential target for improving the sensitivity of tumor cells to chemotherapeutic agents. In this study, we first demonstrate that a novel bFGF antagonist, peptide P7, previously isolated by phage display technology, reversed bFGF-induced resistance to irinotecan hydrochloride (CPT-11), and counteracted the anti-apoptotic effects of bFGF on CPT-11-treated HT-29 cells. Further experiments indicated that the inhibition of Akt activation, the suppression of bFGF internalization, the increase in the Bax to Bcl-2 ratio and the downregulation of cytokeratin 8 (CK8) by P7 may contribute to the counteracting of the anti-apoptotic effects of bFGF, and further reversal of bFGF-induced resistance to CPT-11. Our results suggest that peptide P7 may have therapeutic potential in CRC as a sensitizer to chemotherapeutic agents by targeting bFGF.

Overexpression of N-cadherin is correlated with metastasis and worse survival in colorectal cancer patients

N-cadherin is related to the progression and metastases of several solid carcinomas. However, it was still unclear whether N-cadherin is overexpressed in colorectal malignant tumors that have stronger malignant tendency. In this study, we used immunohistochemistry to detect the expression patterns of N-cadherin in both the primary tumors and their normal mucosa tissues of 120 patients with colorectal cancer. We revealed that N-cadherin was expressed in 78.3% (94/120) of colorectal tumor tissues and in only 9.2% (11/120) of paired distant normal mucosa tissues with a significant difference (P=0.000). The low, moderate, and high expression of N-cadherin protein was 42.5%, 30.8%, and 26.7%, respectively. N-cadherin overexpression was associated with advanced TNM stage, lymph nodes metastasis and distant metastasis (P<0.05). Patients with N-cadherin overexpressed showed the obvious lower overall survival rate than those with moderate and low expression, and patients with low expression had a better survival rate than those with moderate and high expression (P<0.05). In conclusion, high N-cadherin expression may lead to tumor aggressiveness and metastatic potential in colorectal cancer, and may prove to be a possible prognostic factor.

Abstract 3137: Functional analysis of the chr13q22.1 pancreatic cancer risk locus suggests allele-specific effects on DIS3 expression.

Abstract Pancreatic cancer is the 10th most common cancer and 4th most common cause of cancer mortality in the United States. A genome wide association study has revealed pancreatic cancer susceptibility loci on chromosomes 13q22.1, 1q32.1 and 5p15.33. The chr13q22.1 region contains the most significant of all risk SNPs, rs9543325, (P= 3.27 x 10−11) which is located in a gene desert. The nearest genes are KLF5, KLF12, PIBF1, DIS3 and BORA, which range in distance from 265kb to 586kb, respectively, from the most significant variants. Given the high linkage disequilibrium across this risk locus, there are many candidate functional variants to consider. Imputation in the region did not improve the signal but gave a set of highly correlated SNPs which likely includes the functional variant(s). In an effort to identify the functional variant(s) we performed eQTL analyses to test the association between the genotypes of these candidate SNPs and expression of nearby genes. Among 100 normal pancreatic tissue samples, DIS3 showed the strongest association with SNPs in our risk locus (P-values as low as 0.0004). Mutations in DIS3 have been identified in acute myeloid leukemia and multiple myeloma, and its expression has been correlated with metastatic potential in colorectal cancer, suggesting this gene could be important in pancreatic cancer biology. Chromosome Conformation Capture (3C) was performed to test for physical interactions between the risk locus and nearby genes. This assay confirmed the three dimensional proximity of the risk locus and DIS3 promoter. Sub-regions of the risk locus were then cloned upstream of a minimal promoter controlling luciferase expression to assay for potential allele specific enhancer/silencer activity. This assay revealed a sub-region downstream of rs9543325 that causes allele-specific silencing. These results suggest that a sub-region of the chr13q22.1 risk locus has allele-specific effects on DIS3 expression, which may have implications in the susceptibility to pancreatic cancer. Citation Format: Jason Hoskins, Abdisamad Ibrahim, Jinping Jia, Irene Collins, Hemang Parikh, Gloria M. Petersen, Laufey Amundadottir. Functional analysis of the chr13q22.1 pancreatic cancer risk locus suggests allele-specific effects on DIS3 expression. [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 3137. doi:10.1158/1538-7445.AM2013-3137

Association of decreased mitochondrial DNA content with the progression of colorectal cancer

BackgroundExperimental data suggest that mitochondria is involved in tumorigenesis. However, little is known about the qualitative and quantitative changes of mtDNA in colorectal cancer tissues. We therefore conducted possible correlations of the mitochondrial DNA (mtDNA) copy number in colorectal cancer (CRC) with clinical and pathological findings and CRC prognosis.MethodsmtDNA copy numbers in CRC cancer tissue and adjacent non-cancerous tissue samples were measured using quantitative real-time polymerase chain reaction analyses from 60 patients admitted to our hospital. We examined the correlation of mtDNA copy numbers and clinicopathologic parameters of CRC patients. The correlation between mtDNA copy number and three-year survival was analyzed.ResultsThe mtDNA copy number was lower in CRC tissue compared with the corresponding non-cancerous colorectal tissue (mean: 108.60 ± 20.11 vs. 153.68 ± 25.72) and was significantly correlated with lymph-node metastasis. Patients with a lower mtDNA copy number tended to have lower 3-year survival than patients with a higher mtDNA copy number assessed by Kaplan–Meier curves, but the correlation was not significant (overall survival, 63.0 vs 83%).ConclusionsThese results suggest that a reduced copy number of mtDNA is correlated with malignant potential in CRC.

190. Liver-metastatic potential of colorectal cancer is related to stromal composition of the tumor

190. Liver-metastatic potential of colorectal cancer is related to stromal composition of the tumor

P-0205 Activity of Antioxidant Enzymes in Colorectal Cancer

ABSTRACT Introduction The development of colorectal cancer is a multistage process associated with multiple somatic mutations and abnormalities in cell proliferation. One of possible factors related to these disorders is the oxidative stress associated with increased production and levels of reactive oxygen species and / or activity inhibition of antioxidant barrier in cancer cells. The aim of this study was to examine selected parameters of antioxidant barrier in colorectal cancer. The activity of superoxide dismutase, glutathione peroxidase and malondialdehyde, which is the product of lipid peroxidation was determined. Methods Enzyme activity was studied in normal and tumor tissues taken from patients with colorectal cancer. The study group included 72 patients: 13 with a cancerous tumor located in the right half of the colon, 16 with the left half of colon tumor, 18 of the sigmoid colon cancer and 25 with rectal cancer. Samples of tumor tissue and healthy mucosa were collected from each patient. Enzyme activity was determined according to the location of the tumor, clinical stage (S) and histopathological grading (G). The testing ready-to-use kits were used for the determination of Oxis Research International, Inc. The activity of superoxide dismutase (SOD), glutathione peroxidase (GSH) and malondialdehyde (MDA) was determined. Results A statistically significant increase of activity of superoxide dismutase (SOD), glutathione peroxidase (GSH) and malondialdehyde (MDA) was found in tumor tissue compared with normal tissue. There were no significant differences in the activity of the enzymes depending on the location of the cancerous tumor, clinical stage of cancer or histopathological grading (G). Conclusion 1. Increased antioxidant potential in colorectal cancer may be associated with increased levels of reactive oxygen species and an increase in generation of lipid peroxidation products. 2. Clinical stage and histopathological grading of the tumor does not alter the activity of antioxidant enzymes. 3. The activity of antioxidant enzymes does not change depending on the location of the cancerous tumor.

Abstract 4930: Integrative analysis of genome-wide methylation and expression profiles for metastatic colorectal cancer

Abstract In colorectal cancer (CRC) care, treatment decisions depend on efforts to estimate the metastatic potential of tumors. The liver is one of the most common metastatic sites of CRC and prognosis of CRC patients often reflects metastases to distant sites. However, the molecular mechanisms for further development of CRC with metastasis to the liver, lung, brain, bone and lymph nodes are unknown. The aim of this study was to stratify patients based on DNA methylation status and identify not one biomarker gene, but functional motif for metastatic potential of CRC. Using Illumina HumanMethylation 27 harboring approximately 27,000 CpG loci, we performed genome-wide methylation analysis for 74 CRC samples including 36 patients with liver metastasis and 38 without any distant metastasis. As a control, their corresponding colorectal mucosa was used. Consistent with our previous data, using non-negative matrix factorization and consensus clustering analysis, samples were clustered into three groups; high-, intermediate-, and low-methylation epigenotypes. Next, tumor samples were classified based on gene expression profile in each methylation cluster. Gene Set Enrichment Analysis was applied for expression data, which could identify that Rhodopsin kinase was activated in CRC samples with liver metastasis. Then genes included in this kinase were analyzed by Network Hidden Key molecule miner (NetHike) algorithm. NetHike, which we recently developed as network analysis, demonstrated that CXCR4 was one of key molecule for liver metastasis of CRC. In NetHike algorithm, several information such as methylation status and gene expression was inputted which would be integrated on known signaling pathways. In CXCR4 and its neighbors as a functional motif of CRC metastasis, CXCL12 was methylated without gene expression aberration. On the other hand, CXCR4, CCR5, and ARRB2 were not methylated, of which expression was increased, suggesting that integration and mapping of some gene information effectively identify activated gene pathways in some clusters, and may be missed only by conventional analyses. Taken together, network-based analysis could find the potential functional motif and integration of various gene expression aberrations and methylation status also could stratify CRC patients with liver metastasis and without metastasis. We plan to make an exhaustive exploration to discover the some novel functional topologies that have both expression and methylation aberrations and might be related to the mechanism of CRC metastasis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 4930. doi:1538-7445.AM2012-4930

Utility of micro-ribonucleic acid profile for predicting recurrence of rectal cancer

BackgroundIn early-stage rectal cancer, the surgeon must decide between the high morbidity of radical surgery and the high recurrence rates of local excision. A prognostic marker could improve patient selection and lower recurrence rates. Micro-ribonucleic acids (miRNAs), small RNAs that often inhibit tumor suppressors, have shown prognostic potential in colorectal cancer. We hypothesized that high miRNA levels in malignant tissue from early-stage rectal cancer patients could predict recurrence after local excision. Materials and methodsWe identified 17 early-stage rectal cancer patients treated with local excision between 1990 and 2005, four of whom had recurrences. Total RNA was extracted from benign and malignant tissue and used in quantitative real-time reverse transcriptase polymerase chain reaction to probe for miR-20a, miR-21, miR-106a, miR-181b, and miR-203. MiRNA data were evaluated for association with recurrence using univariate analysis with Wilcoxon rank sum test. ResultsMalignant tissue in both patients who had recurrences and patients who did not have recurrences had equivalently high levels of miRNA. However, the benign tissue of patients who recurred contained significantly higher levels of all five miRNAs when compared with the benign tissue of nonrecurrent patients despite having no histological differences. ConclusionsThis is the first study to show that high miRNA levels of histologically benign tissue obtained from the surgical margin of locally excised rectal cancers can predict recurrence. The malignant miRNA levels did not have predictive value. Further investigation of miRNAs is needed to explore their potential for a more accurate prognosis of rectal cancer.

FOXM1 expression correlates with tumor invasion and a poor prognosis of colorectal cancer

FOXM1, a member of the Forkhead Box (Fox) family of transcription factors, plays a critical role in tumor development and metastasis. The aim of this study was to elucidate its role in colorectal cancer (CRC), particularly prognosis and metastasis. Semi-quantitative RT-PCR and Western blot assays were used to measure the expression levels of FOXM1 mRNA and protein in 15 CRC and adjacent normal mucosa tissues. Immunohistochemical assay was performed to detect FOXM1 protein expression in 112 CRC tissues and further determine its clinicopathological and prognostic significance. RNA interference (RNAi) was used to knockdown endogenous FOXM1 expression in CRC cell lines and to analyze the effects of FOXM1 knockdown on migration and invasion of CRC cells. The relative expression levels of FOXM1 mRNA and protein were significantly higher in CRC tissues than in adjacent normal mucosa tissues (P<0.01). In addition, the immunostaining of FOXM1 protein was stronger in CRC tissues than in adjacent normal mucosa tissues. By statistical analysis, we showed that high FOXM1 expression was closely correlated with the presence of lymph node metastasis, incidence of liver metastasis, and advanced TNM stage. Moreover, the cumulative 5-year survival rate of CRC patients with high FOXM1 expression was lower than that of those with low FOXM1 expression (P=0.0047). Multivariate analysis showed that the status of FOXM1 expression was an independent prognostic factor for CRC patients (P=0.025). Furthermore, RNAi-mediated FOXM1 knockdown could significantly inhibit growth, migration and invasion of CRC cells. Our results showed that FOXM1 over-expression is a molecular marker predicting increased invasive/metastatic potential of CRC and a poorer prognosis.

Utility of MiRNA Profile for Predicting Recurrence of Rectal Cancer

Background In early-stage rectal cancer, the surgeon must decide between the high morbidity of radical surgery and the high recurrence rates of local excision. A prognostic marker could improve patient selection and lower recurrence rates. MicroRNAs (miRNAs), small RNAs that often inhibit tumor suppressors, have shown prognostic potential in colorectal cancer. We hypothesized that high miRNA levels in malignant tissue from early-stage rectal cancer patients could predict recurrence after local excision.

Abstract 5234: CEACAM1 expressing spheroid with a hollow beyond the invasive margin indicates the malignant potential of colorectal cancer

Abstract BACKGROUND: Spheroid with hollow (SWH) induced by Carcinoembryonic Antigen-related Cell Adhesion Molecule 1 (CEACAM1) and inner cells apoptosis is observed in three-dimensional (3D) in vitro culture and in an in vivo mouse model. However, it is unclear whether SWH exists in clinical cancer tissue. The aim of the current study is to address which cytoplasmic domain of CEACAM1 is responsible for SWH formation, and to elucidate the existence and the implication of SWH in colorectal cancer. METHODS: To address which cytoplasmic domain of CEACAM1 is responsible for SWH formation, 3D culture was conducted to investigate lumen formation of colorectal cancer cells (LS174T and HT29) transfected with CEACAM1-4L (long cytoplasmic isoform), -4S (short cytoplasmic isoform), or shRNA for CEACAM1. Immunohistochemical analyses were conducted with CEACAM1, CEACAM1-L (long cytoplasmic isoform) and M30 (cleaved cytokeratin 18 fragment) as an apoptosis marker on clinical samples from 164 patients with colorectal cancer. The risk factors for metastases and survival were calculated using univariate and multivariate analyses. RESULTS: In 3D culture experiment, CEACAM1-L is responsible for lumen formation of colorectal cancer cells. Knock down of CEACAM1 or over-expression of CEACAM1-4S inhibited lumen formation, indicating that modulation of CEACAM1 can control SWH structure. Immunohistochemical analyses showed that CEACAM1 expressing spheroid with hollow accompanying with central cells apoptosis shown by M30 staining existed at the invasion front of colorectal cancer tissues. All of SWH was stained by CEACAM1 and CEACAM1-L. It means that SWH at the invasion front has already acquired tumor initiating property. A multivariate analysis showed that the SWH is an independent risk factor for lymph node metastasis (p=0.004) and distant metastasis (p=0.002). The SWH was also identified to be an independent prognostic factor by a Cox proportional hazards model (p=0.020). The Kaplan-Meier evaluation for the overall survival analysis showed that SWH was significantly associated with a shorter survival (p&amp;lt;0.0001). These results suggested that CEACAM1 expressing SWH indicates metastatic and malignant phenotype. CONCLUSIONS: CEACAM1-L expressing SWH was significantly correlated with colorectal cancer metastasis and poor survival, suggesting that the SWH can be metastatic phenotype. SWH at the invasion front of colorectal cancer can be useful for diagnosis of malignancy, and morphological control of SWH by modulation of CEACAM1 may be novel therapeutic strategy. 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 5234. doi:10.1158/1538-7445.AM2011-5234

Association between age and synchronous liver metastasis in female colorectal cancer patients

The purpose of this study is to investigate the relationship between age and synchronous liver metastasis in female colorectal cancer patients. Clinical and pathological data from 655 consecutive female patients who were treated in Qilu Hospital from January 2000 to January 2010 were reviewed. First, the patients were divided into two groups: 60 years or younger and 61 years or older. A chi-square test was adopted to analyse the difference in clinicopathological characteristics between the two groups. Then, they were classified into two groups according to liver metastasis. Univariate analysis and logistic multivariate regression analysis were adopted to discriminate risk factors of liver metastasis. The chi-square test demonstrated that significant difference existed between the younger and the older groups in terms of liver metastasis (P < 0.001), lymph node metastasis (P < 0.001), tumour localization (P < 0.001), tumour invasion depth (P < 0.001), type of tumour (P < 0.001), tumour cell differentiation (P < 0.001) and venous invasion (P < 0.001). Univariate analysis demonstrated that seven factors are associated with liver metastasis. Logistic regression analysis indicated that age (P = 0.005), tumour size (P < 0.001), tumour invasion depth (P = 0.001), tumour cell differentiation (P = 0.029) and type of tumour (P < 0.001) are independent risk factors of liver metastasis. The liver metastatic potential of colorectal cancer may be different between younger and older female patients. Age may independently influence liver metastasis in female colorectal cancer patients.