Clinical Outcome In Colorectal Cancer Research Articles

KRAS, NRAS, BRAF mutations and high counts of poorly differentiated clusters of neoplastic cells in colorectal cancer: observational analysis of 175 cases

A novel grading system based on the counting of poorly differentiated clusters (PDC) of neoplastic cells at the invasive margin and in the tumour stroma was recently introduced among the histological parameters predictive of adverse clinical outcome in colorectal cancer (CRC). The aim of this study was to correlate the histological grade based on PDC and the mutational status of KRAS, NRAS and BRAF genes in 175 consecutive CRCs. The highest PDC count under the objective lens of a ×20 microscopic field in each tumour was considered for grading assessment, so that PDC counts <5, 5-9 and ≥10 PDCs were defined grade 1, grade 2 and grade 3, respectively. Hotspots mutations were identified using the MassArray platform. Overall, there were 42 (24%) mutated tumours. Mutational status was significantly associated with high pT stage (p = 0.0021), advanced pTNM stage (p = 0.0018), nodal metastases (p = 0.006), tumour budding (p = 0.022) and high PDC grade (p = 0.0022). KRAS mutations were significantly associated with PDC grade (p = 0.0379), while BRAF mutations were associated with PDC-G3 although statistical significance was not reached. No significant associations were found between NRAS and PDC. The significant association between mutated KRAS and PDC grade suggests that KRAS mutations may be involved in the formation of PDC.

Protein phosphatase methylesterase-1 (PME-1) expression predicts a favorable clinical outcome in colorectal cancer.

Colorectal cancer (CRC) accounts for high mortality. So far, there is lack of markers capable of predicting which patients are at risk of aggressive course of the disease. Protein phosphatase‐2A (PP2A) inhibitor proteins have recently gained interest as markers of more aggressive disease in certain cancers. Here, we report the role of PP2A inhibitor PME‐1 in CRC. PME‐1 expression was assessed from a rectal cancer patient cohort by immunohistochemistry, and correlations were performed for various clinicopathological variables and patient survival. Rectal cancer patients with higher cytoplasmic PME‐1 protein expression (above median) had less recurrences (P = 0.003, n = 195) and better disease‐free survival (DFS) than the patients with low cytoplasmic PME‐1 protein expression (below median). Analysis of PPME‐1 mRNA expression from TCGA dataset of colon and rectal adenocarcinoma (COADREAD) patient cohort confirmed high PPME1 expression as an independent protective factor predicting favorable overall survival (OS) (P = 0.005, n = 396) compared to patients with low PPME1 expression. CRC cell lines were used to study the effect of PME‐1 knockdown by siRNA on cell survival. Contrary to other cancer types, PME‐1 inhibition in CRC cell lines did not reduce the viability of cells or the expression of active phosphorylated AKT and ERK proteins. In conclusion, PME‐1 expression predicts for a favorable outcome of CRC patients. The unexpected role of PME‐1 in CRC in contrast with the oncogenic role of PP2A inhibitor proteins in other malignancies warrants further studies of cancer‐specific function for each of these proteins.

GATA2 rs2335052 Polymorphism Predicts the Survival of Patients with Colorectal Cancer.

BackgroundGATA binding protein 2 (GATA2) is a transcription factor that has essential roles in hematologic malignancies and progression of various solid tumors. Our previous studies suggested that high GATA2 expression is associated with recurrence of colorectal cancer (CRC). However, the influence of GATA2 single nucleotide polymorphisms (SNPs) on the survival of CRC remains unknown.MethodsWe genotyped GATA2 SNP rs2335052 using Sanger sequencing after PCR amplification, and determined GATA2 expression by immunohistochemistry in a cohort of 180 CRC patients. Kaplan-Meier survival analysis and Cox proportional hazard regression were used to analyze the association between the GATA2 rs2335052 genotypes and the clinical outcome of CRC.ResultsWe found that there was no significant correlation between the rs2335052 genotypes and the expression of GATA2. However, the Kaplan-Meier survival analysis suggested that the carriers of the A-allele of SNP rs2335052 were significantly associated with increased risk of recurrence and reduced disease-free survival (DFS), compared with those carrying the variant genotype of GG in rs2335052 (P = 0.021). Moreover, univariate and multivariate Cox regression analyses revealed that GATA2 SNP rs2335052 was an independent risk factor for the DFS of CRC patients.ConclusionOur results demonstrated that GATA2 SNP rs2335052 is an independent predictor for prognosis of CRC patients. This raised the possibility that SNP rs2335052 may serve as a potential indicator for predicting recurrence of CRC after curative colectomy.

Mitochondrial DNA polymorphisms, its copy number change and outcome in colorectal cancer.

BackgroundMitochondrion is a small organelle inside the eukaryotic cells. It has its own genome (mtDNA) and encodes for proteins that are critical for energy production and cellular metabolism. Mitochondrial dysfunctions have been implicated in cancer progression and may be related to poor prognosis in cancer patients. In this study we hypothesized that genetic variations in mtDNA are associated with clinical outcome in colorectal cancer patients.MethodsWe tested the associations of six mtDNA polymorphisms [MitoT479C, MitoT491C, MitoT10035C, MitoA13781G, 10398 (A/G), and 16189 (T/C)] and the mtDNA copy number change with overall survival (OS) and disease-free survival (DFS) times. Two mtDNA polymorphisms were genotyped using the TaqMan® SNP genotyping technique and the genotypes for the remaining four mtDNA polymorphisms were obtained by the Illumina® HumanOmni1-Quad genome wide SNP genotyping platform in 536 patients. The mtDNA copy number change (in tumor tissues with respect to non-tumor tissues) was estimated using the quantitative real time polymerase chain reaction for 274 patients. Associations of these mtDNA variations with OS and DFS were tested using the Cox regression method.ResultsIn both univariate and multivariable analyses, none of the six mtDNA polymorphisms were associated with OS or DFS. 39.6 and 60.4% of the patients had increased and decreased mtDNA copy number in their tumor tissues when compared to their non-tumor rectum or colon tissues, respectively. However, in contrast to previous findings, the change in the mtDNA copy number was associated with neither OS nor DFS in our patient cohort.ConclusionsOur results suggest that the mitochondrial genetic markers investigated in this study are not associated with outcome in colorectal cancer.Electronic supplementary materialThe online version of this article (doi:10.1186/s13104-015-1250-5) contains supplementary material, which is available to authorized users.

KIF2A overexpression and its association with clinicopathologic characteristics and unfavorable prognosis in colorectal cancer.

Kinesin superfamily protein 2A (KIF2A), an M type nonmotile microtubule depolymerase, has received attention for its role in carcinogenesis and prognostic value in several types of cancer. In this study, we evaluated the expression of KIF2A and its potential and robustness to predict clinical outcomes in colorectal cancer (CRC) patients. The messenger RNA (mRNA) expression of KIF2A was determined in 20 pairs of cancerous and adjacent nontumor tissues by real-time polymerase chain reaction. KIF2A immunohistochemistry was performed on tissue microarray (TMA), composed of 182 CRC and 179 matched adjacent nontumor tissues from surgery, 23 chronic colitis, 43 low-grade, and 18 high-grade intraepithelial neoplasias acquired through intestinal endoscopic biopsy. Univariate and multivariate Cox regression models were used to perform survival analyses. Both KIF2A mRNA and protein product exhibited CRC tissue-preferred expression, when compared with benign tissues. The high KIF2A expression was significantly correlated to TNM stage (P = 0.046) and tumor status (T) (P = 0.007). In univariate and multivariate analyses, high KIF2A expression showed a major prognostic value regarding 5-year survival. The influences of KIF2A expression on the survival were further proven by Kaplan-Meier survival analysis. This study demonstrated CRC tissue-preferred expression pattern of the KIF2A and suggested that high KIF2A expression might serve as an independent maker for poor prognosis in CRC patients.

Overexpression of the Promigratory and Prometastatic PTK7 Receptor Is Associated with an Adverse Clinical Outcome in Colorectal Cancer.

Biomarkers and novel therapeutic targets are urgently needed in colorectal cancer (CRC). The pseudo tyrosine kinase receptor 7 (PTK7) is involved in planar cell polarity and it is deregulated in various malignancies, including CRC. Yet, little is known about its protein expression in human CRC, or about a possible correlation of its expression with clinical endpoints. Using a clinically annotated Tissue MicroArray (TMA) produced from from 192 consecutive CRC patients treated by initial surgery, we examined PTK7 expression by immunohistochemistry in tumoral tissue and matched normal mucosae, and correlated its expression with clinico-pathological features and patient outcome. PTK7 depletion by specific shRNA in HCT116 and HCT15 CRC cell lines was found to affect cell proliferation, resistance to drugs and cell migration. Tumor growth and metastatic phenotype were investigated in vivo using a xenograft mouse model of CRC cells with modulated expression of PTK7 levels. PTK7 was significantly up-regulated in CRC tissue as compared to matched healthy mucosae, and significant overexpression was found in 34% of patients. PTK7 overexpression was significantly associated with a reduced metastasis-free survival in non-metastatic patients. In HCT116 and HCT15 cells, shRNA PTK7 reduced migration but did not affect cell proliferation and resistance to drugs. In a xenograft mouse of HCT15 cells, downregulation of PTK7 led to reduced tumor growth, whereas its overexpression in PTK7-negative cancer cells led to increased metastatic events. PTK7 expression thus represents a potential prognostic biomarker and a novel therapeutic target in CRC.

Abstract #207: The Impact of Diabetes Mellitus and Fasting Glucose Levels on Clinical Outcomes in Colorectal Cancer.

Abstract #207: The Impact of Diabetes Mellitus and Fasting Glucose Levels on Clinical Outcomes in Colorectal Cancer.

HPIP is upregulated in colorectal cancer and regulates colorectal cancer cell proliferation, apoptosis and invasion.

Hematopoietic pre-B cell leukemia transcription factor (PBX)-interacting protein (HPIP) was shown to play a role in cancer development and progression. However, the role of HPIP in colorectal cancer (CRC) is unknown. Here, we report that HPIP is overexpressed in most of CRC patients and predicts poor clinical outcome in CRC. HPIP promotes CRC cell proliferation via activation of G1/S and G2/M checkpoint transitions, concomitant with a marked increase of the positive cell cycle regulators, including cyclin D1, cyclin A, and cyclin B1. HPIP inhibits CRC cell apoptosis accompanied by the decreased levels of BAX and PIG3, the inducers of apoptosis, and the increased level of the apoptosis inhibitor BCL2. HPIP blocks caspase-3-mediated cleavage of PARP, an important apoptosis marker. HPIP promotes CRC cell migration and invasion, and regulates epithelial-mesenchymal transition (EMT), which plays a critical role in cancer cell migration and invasion. Activation of MAPK/ERK1/2 and PI3k/AKT pathways is required for HPIP modulation of CRC cell proliferation, migration and EMT. Moreover, HPIP knockdown suppresses colorectal tumor growth in nude mice. These data highlight the important role of HPIP in CRC cell proliferation and progression and suggest that HPIP may be a useful target for CRC therapy.

Nuclear DICKKOPF-1 as a biomarker of chemoresistance and poor clinical outcome in colorectal cancer.

Sporadic colorectal cancer (CRC) insurgence and progression depend on the activation of Wnt/β-catenin signaling. Dickkopf (DKK)-1 is an extracellular inhibitor of Wnt/β-catenin signaling that also has undefined β-catenin-independent actions. Here we report for the first time that a proportion of DKK-1 locates within the nucleus of healthy small intestine and colon mucosa, and of CRC cells at specific chromatin sites of active transcription. Moreover, we show that DKK-1 regulates several cancer-related genes including the cancer stem cell marker aldehyde dehydrogenase 1A1 (ALDH1A1) and Ral-binding protein 1-associated Eps domain-containing 2 (REPS2), which are involved in detoxification of chemotherapeutic agents. Nuclear DKK-1 expression is lost along CRC progression; however, it remains high in a subset (15%) of CRC patients (n = 699) and associates with decreased progression-free survival (PFS) after chemotherapy administration and overall survival (OS) [adjusted HR, 1.65; 95% confidence interval (CI), 1.23-2.21; P = 0.002)]. Overexpression of ALDH1A1 and REPS2 associates with nuclear DKK-1 expression in tumors and correlates with decreased OS (P = 0.001 and 0.014) and PFS. In summary, our findings demonstrate a novel location of DKK-1 within the cell nucleus and support a role of nuclear DKK-1 as a predictive biomarker of chemoresistance in colorectal cancer.

FBXW7 mutation analysis and its correlation with clinicopathological features and prognosis in colorectal cancer patients.

This study aimed to determine the prognostic value of mutations in the tumor suppressor gene FBXW7 for clinical outcomes in colorectal cancer (CRC). Between January 2000 and December 2009, FBXW7 mutations in tumor tissues from 1,519 CRC patients at Taipei Veterans General Hospital were assessed using a MassArray system. We compared the clinicopathological variables and prognosis between the wild-type and mutant tumor tissue groups. FBXW7 mutations were present in 114/1,519 CRC patients (7.5%). In stage I/II CRC patients, mutant FBXW7 was more common than wild-type FBXW7 (62.3% vs. 50.8%). CRC patients with FBXW7 mutations did not differ significantly in their 5-year overall survival (OS). Stage I/II CRC patients with FBXW7 mutations had lower OS, but this difference was not significant (71.6% vs. 78.2%). Among FBXW7 tumors, S582L was the most frequent mutation type (19.3%), followed by R465H (16.6%), R505C (14.9%) and R479Q (14.9%). Subgroup analysis of FBXW7 mutants showed that R465H/R465C/R479Q had better 5-year OS than other mutant types (76.9% vs. 56.0%; p=0.012). There was no strong association between patient prognosis and FBXW7 mutations in our large-scale study.

Combined detection of plasma GATA5 and SFRP2 methylation is a valid noninvasive biomarker for colorectal cancer and adenomas.

To investigate GATA5, SFRP2, and ITGA4 methylation in plasma DNA as noninvasive biomarkers for colorectal cancer (CRC) or adenomas. There were 57 CRC patients, 30 adenomas patients, and 47 control patients enrolled in this study. Methylation-specific polymerase chain reaction was used to determine the promoter methylation status of GATA5, SFRP2, and ITGA4 genes in plasma DNA, and their association with clinical outcome in CRC. The predictive ability of GATA5, SFRP2, and ITGA4 methylation, individually or in combination, to detect CRC or adenomas was further analyzed. Hypermethylated GATA5 was detected in plasma in 61.4% (35/57) of CRC cases, 43.33% (13/30) of adenoma cases, and 21.28% (10/47) of control cases. The hypermethylation of SFRP2 was detected in 54.39% (31/57), 40.00% (12/30), and 27.66% (13/47) in plasma samples from CRC, adenomas, and controls, respectively. ITGA4 methylation was detected in 36.84% (21/57) of plasma samples of CRC patients and in 30.00% (9/30) of plasma samples from patients with colorectal adenomas, and the specificity of this individual biomarker was 80.85% (9/47). Moreover, GATA5 methylation in the plasma was significantly correlated with larger tumor size (P = 0.019), differentiation status (P = 0.038), TNM stage (P = 0.008), and lymph node metastasis (P = 0.008). SFRP2 and ITGA4 methylation in plasma significantly correlated with differentiation status (SFRP2, P = 0.012; ITGA4, P = 0.007), TNM stage (SFRP2, P = 0.034; ITGA4, P = 0.021), and lymph node metastasis (SFRP2, P = 0.034; ITGA4, P = 0.021). From the perspective of predictive power and cost-performance, using GATA5 and SFRP2 together as methylation markers seemed the most favorable predictor for CRC (OR = 8.06; 95%CI: 2.54-25.5; P < 0.01) and adenomas (OR = 3.35; 95%CI: 1.29-8.71; P = 0.012). A combination of GATA5 and SFRP2 methylation could be promising as a marker for the detection and diagnosis of CRC and adenomas.

Prognostic Significance of Tissue Leptin Expression in Colorectal Cancer Patients.

PurposeLeptin is encoded by the ob gene and is involved in the control of food intake and energy expenditure. Recent studies have implicated leptin expression to be an indicator of tumor features and prognosis. The purpose of this study was to investigate the association of tissue expression of leptin with the clinicopathological characteristics and clinical outcomes in colorectal cancer patients.MethodsPatients who had undergone a curative surgical resection for a colorectal adenocarcinoma from 2000 to 2004 were included in the study. Immunohistochemical analyses of leptin expression were performed, and clinicopathological parameters were evaluated.ResultsClinical data and tumor tissues of 146 patients were evaluated. The mean age was 68.6 ± 11.3 years, and 61.0% were men. Immunohistochemically, the rates of negative, weak, moderate, and strong leptin expression were 2.7% (4 of 146), 5.5% (8 of 146), 43.2% (63 of 146), and 48.6% (71 of 146), respectively. We compared the negative, weak, and moderate expression group (group A) with the strong expression group (group B). Leptin expression was inversely associated with nodal stage (P = 0.007) between the two groups. Leptin expression was not significantly associated with differentiation (P = 0.37), T stage (P = 0.16), and American Joint Committee on Cancer stage (P = 0.49), and no significant differences in the disease-free and the overall survivals (P = 0.78 and P = 0.61) were observed.ConclusionResults demonstrated an inverse association of nodal stage with high leptin expression. Higher leptin expression level might predict better oncologic outcome. However, further studies are warranted to identify the exact role of leptin expression in colorectal cancer.

MicroRNA-7 expression in colorectal cancer is associated with poor prognosis and regulates cetuximab sensitivity via EGFR regulation.

MicroRNA-7 (miR-7) has been reported to be a tumor suppressor in all malignancies including colorectal cancer (CRC). However, its significance for CRC clinical outcomes has not yet been explored. The potential for miR-7 to act as a tumor suppressor by coordinately regulating the epidermal growth factor receptor (EGFR) signaling pathway at several levels was examined. We investigated the tumor inhibitory effect of miR-7 in CRC, with particular focus on the relationship between miR-7 and the EGFR pathway. Quantitative reverse transcription-PCR was used to evaluate miR-7 expression in 105 CRC cases to determine the clinicopathologic significance of this miRNA. The regulation of EGFR by miR-7 was examined with miR-7 precursor-transfected cells. Furthermore, we investigated whether miR-7 suppresses proliferation of CRC cells in combination with cetuximab, a monoclonal antibody against EGFR. Multivariate analysis indicated that low miR-7 expression was an independent prognostic factor for poor survival (P = 0.0430). In vitro assays showed that EGFR and RAF-1 are direct targets of miR-7, which potently suppressed the proliferation of CRC cells, and, interestingly, that the growth inhibitory effect of each of these was enhanced by cetuximab. miR-7 is a meaningful prognostic marker. Furthermore, these data indicate that miR-7 precursor, alone or in combination with cetuximab, may be useful in therapy against CRC.

Nuclear expression of histone deacetylases and their histone modifications predicts clinical outcome in colorectal cancer.

Epigenetic changes are of crucial importance in cancer development and are potentially reversible; they are therefore targets of interest for anti-cancer therapy. The aim of this study was to investigate the clinical prognostic value of the histone deacetylases SIRT1, HDAC1 and HDAC2 and the histone modifications H4K16Ac and H3K56Ac in colorectal cancer. The epigenetic markers were immunohistochemically stained on tissue microarrays containing colorectal tumours (n = 254) and normal colorectal tissues (n = 50). Nuclear expression was assessed on the semi-automated Ariol system. Multivariate trend survival analyses of the combined markers showed better patient survival and less tumour recurrence when more markers showed high nuclear expression. For the combination of the histone deacetylases and H3K56Ac, the hazard ratio (HR) for overall survival (OS) was 0.82 [95% confidence interval (CI) 0.72-0.94; P = 0.005] and the HR for distant recurrence-free survival (DRFS) was 0.77 (95% CI 0.64-0.92; P = 0.003) per additional marker showing high expression. Similarly, for the combination of histone deactylases and H4K16Ac, HRs of 0.86 (95% CI 0.76-0.97; P = 0.01) for OS and 0.79 (95% CI 0.68-0.93; P = 0.006) for DRFS were observed per additional marker showing high expression. The studied epigenetic markers showed clinical prognostic value in colorectal cancer, both as individual markers and when combined into multimarker analyses. These results indicate that epigenetic mechanisms play an important role in colorectal carcinogenesis.

Abstract CT320: Longitudinal observational study to simultaneously evaluate multiple blood-based biomarkers to track the emergence of metastasis and drug resistance in colorectal cancer

Abstract Background. Colorectal cancer (CRC) is the 3rd most common cancer globally. In cancer, the 2 most critical events that adversely affect outcomes are the emergence of metastasis and drug resistance. Blood-based markers permit the non-invasive serial monitoring of patients in order to study and track the emergence and evolution of metastasis and drug resistance. The multiple varied platforms utilize different components of blood (buffy coat, whole blood, plasma). We seek to establish a longitudinal observational study to simultaneously evaluate multiple blood-based biomarkers to track patient outcomes in colorectal cancer. Methods. In a planned 800 patient study, we prospectively recruit patients with all stages of CRC, focusing on patients with stage 3/4 CRC. At each patient's venipuncture performed during his/her routine clinical care, we serially collect additional blood specimens. All major components of the collected blood (buffy coat, red cells, whole blood and plasma) are stored. In patients undergoing primary tumor resection or metastasectomy, frozen tissue specimens are also prospectively collected and banked for subsequent biomarker analysis. A prospective electronic database of clinical information and patient outcomes is simultaneously maintained for the purpose of correlation with molecular assays. Results. To date, we have recruited 450 patients and obtained their serial blood samples. Blood is prospectively collected in an optimized manner to support the pre-analytical requirements of the different platforms. This includes whole blood for immediate assay performance (circulating tumor cells), buffy coat for immediate analysis or storage for pooled analysis (cell based assays, germline polymorphisms, white cell gene expression and assays on peripheral blood mononuclear cells), plasma for storage for pooled analysis (circulating cell free nucleic acids including DNA, miRNA, RNA and methylated DNA, novel proteomic tumor markers, cytokines). Optimization of pre-analytical processing, transport and storage parameters was carried out to enable studies across multiple platforms in this same cohort of patients to be performed in a prospective longitudinal manner. Conclusions. In this ongoing study, we have established a system for the simultaneous evaluation of multiple blood-based biomarkers operating on the various components of blood. Together with paired tissue specimens and a prospectively maintained electronic clinical database, comprehensive comparisons and correlative studies to monitor for metastasis and drug resistance and clinical outcomes in CRC across time can be carried out. Citation Format: Clarinda Chua, Rachel Ten, Thinzar Aung, Maricel Ang, Thein Htut Oo, Su Pin Choo, Matthew Ng, Iain Beehuat Tan. Longitudinal observational study to simultaneously evaluate multiple blood-based biomarkers to track the emergence of metastasis and drug resistance 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 CT320. doi:10.1158/1538-7445.AM2014-CT320

Abstract 5165: Molecular features reflecting biological and functional ages in elderly colorectal cancer patients

Abstract Aging is a physiological process that is accompanied by functional decline over time. Also, aging is the single biggest risk factor for developing cancer and limitation of active cancer treatment. The number of elderly patients with colorectal cancer (CRC) has increased, however, the knowledge of the clinical outcomes of colorectal cancer in elderly patients are limited. Elderly CRC patients are a very heterogeneous population because the aging process caused complex co-morbidities and chronological age cannot predict the biological and functional changes. In this study, we analyzed cDNA microarray data using integration of receiver operating characteristic (ROC) curve and protein-protein interaction (PPI) network information, demonstrating the aging effect of cancer based on large scale data. We identified molecular features that discriminate 120 elderly (70 ≥age) and 31 young (40 ≤ age) CRC patients. Elderly group had distinct molecular features compared with the young group, and we suggest that these features may underlie the different cancer characteristics of colorectal cancer based on aging. First, we quantified the molecular features of total 15815 probes using ROC analysis. The ROC representing the performance of enolase superfamily member 1 (ENOSF1, rTS) corresponded to an area under curve (AUC) of 0.73 in the training set and 0.71 in the test set. Also the 82 differentially expressed genes (DEGs) over 2 fold with high significance (p&amp;lt;0.01) between the two groups, which were selected as the age-related genes. To identify the key molecules, we performed a PPI network analysis with topological metrics such as degree and betweenness centrality (BC) using the graph module.As a result, we found that down regulated EGFR, and AR could be key molecules in the PPI network having higher degree and BC scores in young group, while FOXO1, downstream signal of EGFR, was upregulated. On the other hand, the down-regulated EWSR1 and PTPN11 could be key molecules in elderly group, which were closely connected with SLC26A3 in PPI network. In previous studies, the SLC26A3 expression was significantly decreased in adenomas (polyps) and adenocarcinomas of the colon. But our result was shown the SCL26A3 overexpression in only elderly group. We suggest that elderly CRC has distinct molecular characteristics from young CRC and therefore, that the expression signatures of DEGs and PPI may improve the understanding of molecular pathogenesis and clinical behaviors in elderly CRC. Citation Format: Woo Sun Kwon, Park Daeui, Hye Ryun Kim, Hei-Cheul Jeung, Hyoung Oh Jeong, Jin-Hyuk Choi, Joong Bae Ahn, Hyun Cheol Chung, Hae Young Chung, Sun Young Rha. Molecular features reflecting biological and functional ages in elderly colorectal cancer patients. [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 5165. doi:10.1158/1538-7445.AM2014-5165

AQP5: a novel biomarker that predicts poor clinical outcome in colorectal cancer.

The aquaporins(AQPs) are water channel proteins that exhibit several properties related to tumor development. However, the expression and clinical significance of AQP5 in colorectal cancer, particularly the correlation with circulating tumor cells(CTCs), has not been elucidated. The aim of the present study was to determine whether or not the expression of AQP5 is a strong prognostic biomarker for colorectal cancer. The results showed that of 45 tumor specimens, 14(31.1%) had high levels of expression of AQP5, 29(64.4%) exhibited a moderate (intermediate) level of staining, and 2(4.4%) had an absence of AQP5 staining. AQP5 was only occasionally detected in para-neoplastic [3/45(6.67%)] and normal tissues [3/45 (6.67%)]. AQP5 protein overexpression frequently accompanied gene amplification detection with fluorescence insitu hybridization(FISH). Moreover, AQP5 expression in colorectal cancer cells was upregulated compared to normal colon cells. AQP5 overexpression was also associated with TNM stage(P=0.002), lymph node metastasis(P=0.016), and distant metastasis(P=0.000). The relationships between age, gender, histologic grade and tumor size with expression of AQP5 were not significant(P>0.05). A positive correlation between the number of CTCs and AQP5 expression(P<0.05) was demonstrated. In addition, patients who did not express AQP5 had a superior cumulative survival rate compared to patients with AQP5 positivity. AQP5 may be used as a novel biomarker for colorectal cancer aggressiveness and metastasis, but it does not reflect drug resistance.

A 5-gene classifier from the carcinoma-associated fibroblast transcriptomic profile and clinical outcome in colorectal cancer.

Based on 108 differentially expressed genes between carcinoma-associated fibroblasts (CAFs) and paired normal colonic fibroblasts we recently reported, a 5-gene classifier for relapse prediction in Stage II/III colorectal cancer (CRC ) was developed. Its predictive value was validated in datasets GSE17538, GSE33113 and GSE14095. An additional validation was performed in a metacohort (n=317) and 142 CRC patients by means of RT-PCR. The 5-gene classifier was significantly associated with increased relapse risk and death from CRC across all validation series of Stage II/III patients used. Multivariate Cox regression analyses confirmed the independent prognostic value of the stromal classifier (HR=2.67; P=0.002). Post-test probabilities provided evidence of the suitability of the 5-gene classifier in clinical practice, identifying a subgroup of Stage-II patients who were at high risk of relapse. Moreover, the a priory worst prognosis mesenchymal subtype of tumours can be stratified according to the physiological status of their carcinoma-associated fibroblasts. In conclusion the CAFs-derived 5-gene classifier provides more accurate information about outcome than conventional clinicopathological criteria and it could be useful to take clinical decisions, especially in Stage II. Additionally, the classifier put into relevance the CAF's intratumoral heterogeneity and might contribute to find relevant targets for depleting adequate CAFS subtypes.

Genetic variations in the HIF1A gene modulate response to adjuvant chemotherapy after surgery in patients with colorectal cancer.

Hypoxia-inducible factor 1α (HIF-1α) plays an important role in regulating cell survival and angiogenesis, which are critical for tumor growth and metastasis. Genetic variations of HIF1A have been shown to influence the susceptibility to many kinds of human tumors. Increased expression of HIF-1α has also been demonstrated to be involved in tumor progression. However, the prognostic value of single nucleotide polymorphisms (SNPs) in the HIF1A gene remains to be determined in most cancer types, including colorectal cancer (CRC). In this study, we sought to investigate the predictive role of HIF1A SNPs in prognosis of CRC patients and efficacy of chemotherapy. We genotyped two functional SNPs in HIF1A gene using the Sequenom iPLEX genotyping system and then assessed their associations with clinicopathological parameters and clinical outcomes of 697 CRC patients receiving radical surgery using Cox logistic regression model and Kaplan Meier curves. Generally, no significant association was found between these 2 SNPs and clinical outcomes of CRC. In stratified analysis of subgroup without adjuvant chemotherapy, patients carrying CT/TT genotypes of rs2057482 exhibited a borderline significant association with better overall survival when compared with those carrying CC genotype [Hazard ratio (HR), 0.47; 95% confidence interval (95% CI): 0.29-0.76; P < 0.01]. Moreover, significant protective effects on CRC outcomes conferred by adjuvant chemotherapy were exclusively observed in patients carrying CC genotype of rs2057482 and in those carrying AC/CC genotype of rs2301113. Genetic variations in HIF1A gene may modulate the efficacy of adjuvant chemotherapy after surgery in CRC patients.

A mutant BRAF V600E-specific immunohistochemical assay: correlation with molecular mutation status and clinical outcome in colorectal cancer.

The B-type Raf kinase (BRAF) V600E mutation is a well-established biomarker for poor prognosis in metastatic colorectal cancer (mCRC) and is a highly attractive drug target. A barrier to the development of new therapies targeting BRAF V600E in mCRC is the low prevalence of mutations (approximately 10 %) and the current need for access to sequencing-based technologies which are not routinely available outside of large cancer centres. Availability of a standardised immunohistochemistry (IHC) test, more suited to routine pathology practice, would provide much broader access to patient identification. We sought to evaluate the accuracy and clinical utility of a recently developed BRAF V600E IHC method as a prognostic biomarker in a large cohort of community-based CRC patients. Archival tumour samples from 505 patients with stage I–IV CRC were immunohistochemically tested with two antibodies, pBR1 for total BRAF and VE1 for BRAF V600E. Cases were assessed by two blinded pathologists, and results were compared to BRAF V600E mutation status determined using DNA sequencing. Discordant cases were retested with a BRAF V600E SNaPshot assay. BRAF mutation status was correlated with overall survival (OS) in stage IV CRC. By DNA sequencing and IHC, 505 and 477 patients were respectively evaluable. Out of 477 patients, 56 (11. 7 %) had BRAF V600E mutations detected by sequencing and 63 (13.2 %) by IHC. Using DNA sequencing results as the reference, sensitivity and specificity for IHC were 98.2 % (55/56) and 98.1 % (413/421), respectively. IHC had a positive predictive value (PPV) of 87.3 % (55/63) and a negative predictive value (NPV) of 99.8 % (413/414). Compared to DNA sequencing plus retesting of available discordant cases by SNaPshot assay, IHC using the VE1 antibody had a 100 % sensitivity (59/59), specificity (416/416), NPV (416/416) and PPV (59/59). Stage IV CRC patients with BRAF V600E protein detected by IHC exhibited a significantly shorter overall survival (hazard ratio = 2.20, 95 % CI 1.26–3.83, p = 0.005), consistent with other published series. Immunohistochemistry using the BRAF V600E VE1 antibody is an accurate diagnostic assay in CRC. The test provides a simple, clinically applicable method of testing for the BRAF V600E mutation in routine practice.