Development Of Colon Carcinoma Research Articles

A nine-gene signature to improve prognosis prediction of colon carcinoma

ABSTRACT This study aims to establish a gene model that can robustly and effectively predict the prognosis of colon carcinoma patients via bioinformatics. Data along with clinical information in GSE39582 Series Matrix were firstly downloaded from Gene Expression Omnibus (GEO) database. Next, differentially expressed genes (DEGs) were obtained through “edgeR” analysis. Finally, a risk predication model was established through a series of regression analyses, and then prognostic performance of the model was comprehensively evaluated though Kaplan-Meier and receiver operating characteristic (ROC) analysis. Gene set enrichment analysis (GSEA) was further performed. Totally, 846 DEGs were obtained by analyzing the gene expression data in GSE39582 dataset. A 9-gene signature-based risk predication model was established via regression analyses, and the model-based risk score was formulated as: Riskscore = (−0.1214) * TNFRSF11A + (−0.2617) * TMEM97 + (−0.1041) * LGR5 + 0.0973 * KLK10 + 0.1655 * HOXB8 + 0.227 * FKBP10 + (−0.1312) * CXCL13 + (−0.1316) * CXCL10 + 0.2593 * CD36. Kaplan-Meier curve showed that colon carcinoma patients in the high-risk group had a lower survival rate. GSEA showed that high-risk group and low-risk group displayed significant difference in biological pathways including ECM RECEPTOR INTERACTION. Besides, correlation analysis between the riskscore of the model and clinical features of patients revealed that the model could effectively predict the prognosis of patients in different ages (age>65, age<65) and stages (tumor_stage I/II, tumor_stage III/IV, T3&T4, N0&N1, N2&N3, M0). This study provides a robust model for the prognosis prediction of colon carcinoma, and lays a basis for researching the molecular mechanism underlying the development of colon carcinoma.

Clinical Significance and Oncogenic Activity of GRWD1 Overexpression in the Development of Colon Carcinoma.

ObjectiveGRWD1 (glutamate-rich WD40 repeat containing 1) is a multifunctional protein involved in multiple cellular regulatory pathways, particularly those associated with cell growth control. GRWD1 is represented as a potential oncogene in several cancers, however, the function and mechanism of GRWD1 in the development of colon cancer are still unknown.Materials and MethodsIHC was used to detect the expression of GRWD1 in colon carcinoma tissues. CCK-8, colony formation, and EdU were used to measure the cell proliferation after GRWD1 knockdown and overexpression. The distribution of the cell cycle was analyzed by flow cytometry. The effect of GRWD1 knockdown on migration and invasion was analyzed by wound healing and transwell assays.ResultsOverexpression of GRWD1 in colon carcinoma tissues was associated with pathological grading, tumor size, N stage, TNM stage, and poor survival. GRWD1 had high sensitivity and specificity in distinguishing colon cancer from noncancerous tissues, and might be served as an independent prognosis in colon carcinoma patients. Knockdown of GRWD1 significantly inhibited the cell proliferation and colony formation, and induced cell cycle arrest and more drug susceptibility, and suppressed the migration and invasion. GRWD1 exhibited these oncogenic activities might be associated with its regulation on the expression of PCNA and Ki67, Cyclin A2 and Cyclin B1, ABCC1 and GSTP1, MTA1 and MTA2.ConclusionGRWD1 may play an oncogenic activity in the development of colon carcinoma and its overexpression was associated with malignant characteristics and poor survival outcome of colon carcinoma. GRWD1 might be a potential target for future therapy.

Anti-inflammatory and metabolic reprogramming effects of MENK produce antitumor response in CT26 tumor-bearing mice.

Methionine enkephalin (MENK), an endogenous opioid peptide, has a role in nervous system, immune system, and anticancer therapy. Inflammation, metabolism and cancer are closely intertwined with each other. This study is to identify the correlation of the antitumor effects of MENK with systemic inflammation, liver metabolism, and immune cells as myeloid-derived suppressor cells (MDSCs). We established a subcutaneous CT26 colon carcinoma model and a cyclophosphamide-induced immunosuppressive model subjected to MENK. AML12 and MDSCs were used as in vitro models. The results showed that MENK treatment degraded tumor growth and inhibited proinflammatory cytokines both in tumor tissues and serum. The MENK-treated tumor mice showed normalized liver function with glycolipid metabolic homeostasis. No inhibitory effect on CT26 tumor cell in vitro, but only reduced lipid synthesis in AML12 were presented by MENK. Meanwhile, MENK invigorated immune response in both two animal models by markedly suppressing MDSCs and enhancing T cells response. In vitro MENK-treated MDSCs showed reduced glycolysis and less ROS production, which was mediated by PI3K/AKT/mTOR pathway. Opioid receptor antagonist naltrexone reversed most of the regulation. These results illustrate that MENK preventing development of colon carcinoma might be correlated with the suppression of inflammation, improving metabolism in liver as well as in MDSCs partly through opioid receptor, which brings new elements supporting the adjuvant therapy for tumor by MENK.

Uncovering the Anticancer Potential of Murine Cytomegalovirus against Human Colon Cancer Cells

Human cytomegalovirus (HCMV) components are often found in tumors, but the precise relationship between HCMV and cancer remains a matter of debate. Pro-tumor functions of HCMV were described in several studies, but an association between HCMV seropositivity and reduced cancer risk was also evidenced, presumably relying on recognition and killing of cancer cells by HCMV-induced lymphocytes. This study aimed at deciphering whether CMV influences cancer development in an immune-independent manner. Using immunodeficient mice, we showed that systemic infection with murine CMV (MCMV) inhibited the growth of murine carcinomas. Surprisingly, MCMV, but not HCMV, also reduced human colon carcinoma development in vivo. In vitro, both viruses infected human cancer cells. Expression of human interferon-β (IFN-β) and nuclear domain (ND10) were induced in MCMV-infected, but not in HCMV-infected human colon cancer cells. These results suggest a decreased capacity of MCMV to counteract intrinsic defenses in the human cellular host. Finally, immunodeficient mice receiving peri-tumoral MCMV therapy showed a reduction of human colon cancer cell growth, albeit no clinical sign of systemic virus dissemination was evidenced. Our study, which describes a selective advantage of MCMV over HCMV to control human colon cancer, could pave the way for the development of CMV-based therapies against cancer.

Antitumor immunity of DNA vaccine based on CTLA-4 fused with HER2 against colon carcinoma

Cytotoxic T-lymphocyte-associated protein 4 (CTLA-4) negatively regulates the T cell activation and competes with CD28 in binding with B7.1/B7.2 molecules. Fusion of the extracellular region of CTLA-4 and a specific antigen is an effective method for improving the immune efficacy of DNA vaccines. This study aimed to investigate the effects of DNA vaccine of human epidermal growth factor receptor-2 (HER2) fused with CTLA-4 on the development of colon carcinoma in mice and to identify the potential immune mechanisms underlying its effects. We constructed recombinant plasmids corresponding to the control group, individual antigen group, and fusion antigen group. Then, mice were intramuscularly injected with the corresponding plasmids and exposed to electrical pulses. Immunogenicity was evaluated at 2 weeks after the last immunization. Furthermore, to investigate the antitumor immune effects of the recombinant plasmid, we established a mouse model of HER2 expression in transplanted tumors. Experimental results showed that the recombinant plasmids expressing fusion antigen induced a stronger cellular immune response. Inoculation of the HER2-CTLA-4 plasmid exerted the strongest inhibitory effect on HER2 expression-mediated tumor growth in mice. These results highlight the potential of the CTLA-4 fusion DNA vaccine as a therapeutic vaccine against colon cancer based on HER2 and CTLA-4.

Decreased Expression of Claudin 1, 3, 4, 5 and 7: A New Prognostic Marker in Colon Carcinoma

Background and objective: Claudins are members of a large family of tissue specific adherent proteins which have been suggested as tumor markers. In this study we analyzed the protein expression of claudin 1, 3, 4, 5 and 7, their clinical significance and association with tumor growth pattern in colon carcinoma. Methods: Immunohistochemical staining (IHC) was used to detect the expression of claudin 1, 3, 4, 5 and 7 in samples diagnosed with colon carcinoma as well as the adjacent normal mucosa. Complexity index (CI) was calculated using images of cytokeratin-8 stained slides of the tumours using Photoshop CS, Fovea Pro, and Image J computer programs. The results from the IHC and CI were correlated to clinicopathological parameters as well as 5-years survival of the patients diagnosed with colon carcinoma. Results: Significantly high staining intensity was observed in normal mucosa as compared to colon cancer tissue for claudin 4 (p=0.031) and 7 (p=0.011) and number of stained cells for claudin 4 (p=0.001). A significant association was also observed between weaker expression at the invasive front of the tumor tissue and heterogenous expression of claudin 1 (p=0.000), claudin 3(p=0.003), claudin 5(p=0.001) and claudin 7(p=0.000). There was no significant correlation between the expression of claudins, CI and clinicopathological parameters. Similarly, no significant association was found between claudin expression and 5-year survival of the patients diagnosed with colon carcinoma. Conclusion: Altered expression of claudin 1, 3, 4, 5 and 7 in colon carcinoma cells may play a promoting role in colon carcinoma development and is inversely proprtional to higher expression at invasive front of the tumor. Claudin protein expression can be used as a tumor marker since the expression generally is weaker in tumor tissue compared to the normal mucosa.

Inhibitory effect of emodin on fatty acid synthase, colon cancer proliferation and apoptosis.

Fatty acid synthase (FASN) is a key anabolic enzyme for de novo fatty acid synthesis, which is important in the development of colon carcinoma. The high expression of FASN is considered a promising molecular target for colon cancer therapy. Emodin, a naturally occurring anthraquinone, exhibits an anticancer effect in various types of human cancer, including colon cancer; however, the molecular mechanisms remain to be fully elucidated. Cell viability was evaluated using a Cell Counting Kit-8 assay. The apoptosis rate of cells was quantified via flow cytometry following Annexin V/propidium iodide staining. FASN activity was measured by monitoring oxidation of nicotinamide adenine dinucleotide phosphate at a wavelength of 340 nm, and intracellular free fatty acid levels were detected using a Free Fatty Acid Quantification kit. Western blot analysis and reverse transcription-polymerase chain reaction were used to detect target gene and protein expression. The present study was performed to investigate whether the gene expression of FASN and its enzymatic activity are regulated by emodin in a human colon cancer cell line. Emodin markedly inhibited the proliferation of HCT116 cells and a higher protein level of FASN was expressed, compared with that in SW480, SNU-C2A or SNU-C5 cells. Emodin significantly downregulated the protein expression of FASN in HCT116 cells, which was caused by protein degradation due to elevated protein ubiquitination. Emodin also inhibited intracellular FASN enzymatic activity and reduced the levels of intracellular free fatty acids. Emodin enhanced antiproliferation and apoptosis in a dose- and time-dependent manner. The combined treatment of emodin and cerulenin, a commercial FASN inhibitor, had an additive effect on these activities. Palmitate, the final product of the FASN reaction, rescued emodin-induced viability and apoptosis. In addition, emodin altered FASN-involved signaling pathways, including phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinases/extracellular signal-regulated kinases 1/2. These results suggested that emodin-regulated cell growth and apoptosis were mediated by inhibiting FASN and provide a molecular basis for colon cancer therapy.

The increasingly anti-tumor effect of a colonic carcinoma DNA vaccine carrying HER2 by the adjuvanticity of IL-12

The present study aimed to determine the effect of recombinant DNA vaccine-based human epidermal growth factor receptor-2 (HER2) and Interleukin 12 (IL-12) on the development of colonic carcinoma in mice and the potential immune mechanisms involved. Recombinant plasmids pVAX1-HER2, pVAX1-IL-12 and pVAX1-HER2-IL-12 were constructed, and injected into female mice intramuscularly (i.m.) followed by an electric pulse. The humoral and cellular immune responses after immunization were examined by enzyme linked immunosorbent assay (ELISA) and enzyme-linked immunospot assay (ELISPOT), respectively. To evaluate the anti-tumor efficacy of the plasmids, a mouse model with a HER2-expressing tumor was designed. Mice vaccinated with the HER2-IL-12 plasmid generated the strongest inhibition efficacy on the growth of HER2-expressing tumors and prolonged mouse survival. These observations emphasized the potential of IL-12 as an adjuvant for DNA vaccines and of vaccines based on HER2 and IL-12 as a promising treatment for colonic carcinoma.

Regulation of the RhoA/ROCK/AKT/β-catenin pathway by arginine-specific ADP-ribosytransferases 1 promotes migration and epithelial-mesenchymal transition in colon carcinoma.

Arginine-specific ADP-ribosytransferases 1 (ART1) is able to modify the arginine of specific proteins by mono-ADP-ribosylation. We previously reported that the expression of ART1 in human colon adenocarcinoma tissues was higher than in adjacent tissues. Herein, we primarily revealed that ART1 could regulate the epithelial-mesenchymal transition (EMT) and, therefore, the development of colon carcinoma. In CT26 cells, which overexpressed ART1 by lentiviral transfection, the following were promoted: alterations of spindle-like non-polarization, expression of EMT inducers and mesenchymal markers, migration, invasion and adhesion. However, epithelial marker expression was decreased. Correspondingly, knockdown of ART1 in CT26 cells had the opposite effects. The effect of ART1 on EMT and carcinoma metastasis was also verified in a liver metastasis model of BALB/c mice. To further explore the molecular mechanism of ART1 in EMT, CT26 cells were treated with several specific inhibitors and gene silencing. Our data suggest that ART1 could regulate EMT by regulating the RhoA/ROCK1/AKT/β-catenin pathway and its downstream factors (snail1, vimentin, N-cadherin and E-cadherin) and that it therefore plays an important role in the progression of colon carcinoma.

Expressions of UHRF1, P53 and their clinical significances in colon carcinoma

Objective To investigate the expression levels and clinical significances of ubiquitin-like with PHD and ring finger domains 1 (UHRF1) and P53 in colon carcinoma. Methods The expressions of UHRF1 and P53 in 70 colon cancer tissues and 30 normal colon ones were detected by means of immunohistochemistry to analyze the correlation of these two proteins in the occurrence and development of colon carcinoma, and the relationship between their expressions and clinico-pathological factors as well as prognosis was discussed. Results The expression levels of UHRF1 and P53 in cancer tissues were significantly higher than those of cancer-adjacent tissues (87.1% vs. 56.7%, χ2=11.366, P=0.001; 64.3% vs. 6.7%, χ2=27.988, P=0.000) and showed a positive correlation between the two proteins (r=0.248, P=0.038). Both UHRF1 and P53 were associated with TNM stages (χ2=4.426, P=0.049; χ2=6.000, P=0.016) and the depth of invasion (χ2=12.553, P=0.002; χ2=4.904, P=0.036). However, they were irrelevant with the age (χ2=0.473, P=0.494; χ2=0.090, P=0.799) and gender (χ2=2.297, P=0.166; χ2=0.512, P=0.617) of patients, as well as the size (χ2=0.638, P=0.481; χ2=2.392, P=0.215) and histological grading of tumors (χ2=2.088, P=0.352; χ2=0.303, P=0.859). Kaplan-Meier analysis showed that the median survival time of patients with UHRF1, P53 positive expression was 21.83 months that was lower than patients with UHRF1 positive expression of 24.49 months (Z=-0.624, P=0.533). Both former of which was distinctly lower than that of negative ones of 37.33 months (Z=-2.856, P=0.004; Z=-2.694, P=0.007). Conclusion Both UHRF1 and P53 are highly expressed in colon cancer tissues, which imply that UHRF1 and P53 may be strongly related with colon cancer development and can be a predictor for colon cancer prognosis. Key words: Colon neoplasms; Tumor suppressor protein p53; Ubiquitin-like with PHD and ring finger domains 1

Antisense oligonucleotides against microRNA-21 reduced the proliferation and migration of human colon carcinoma cells.

BackgroundColon carcinoma is one of the commonly tumors that threaten human beings as its highly morbidity and mortality. Recent evidences suggested that microRNA-21 (miR-21) played an important role in the development of colon carcinoma and might be a potential biological marker for the diagnosis and prognosis of colon carcinoma. However, the potential effect of miR-21 based therapeutic studies in colon carcinoma remains to be fully elucidated.MethodsIn present study, we constructed an eukaryotic expression vector encoding antisense oligonucleotides against miR-21 (termed as p-miR-21-ASO) and the expression of miRNA-21 in human colon cancer was detected by Real-time PCR. To assess its possible effect on the proliferation and migration capacity of human colon carcinoma cells in vitro, CCK-8 assay, colony formation assay and cell invasion, as well as migration assay, were performed respectively. Moreover, PTEN, one of target molecules of miRNA-21, was analyzed by Western blot and Fluorescence activated cell sorter assay. Finally, the transduction of AKT and ERK pathways in human colon carcinoma cells was determined by Western blot.ResultsWe found that transiently transfection of p-miR-21-ASO could efficiently decrease the relative expression of miR-21 in human colon carcinoma HCT116 cells, accompanied by impaired proliferation and clone formation. Furthermore, we found that down-regulation of miR-21 also could significantly abrogate the invasion and migration capacity in vitro, as well as the expression of vascular endothelial growth factor which is critical for the metastatic capacity of colon carcinoma cells. Mechanistic evidence showed that down-regulation of miR-21 increased the expression of its target molecule PTEN in HCT116 cells. Finally, we revealed that the expression level of both phosphor-ERK1/2 and phosphor-AKT also were altered.ConclusionsTherefore, our data suggested miR-21 ASO against miR-21 might be a useful strategy to alter the expression of miR-21 in colon carcinoma cells, which was helpful for the development of miR-21-based therapeutic strategies against clinical colon carcinoma.Electronic supplementary materialThe online version of this article (doi:10.1186/s12935-015-0228-7) contains supplementary material, which is available to authorized users.

Apaf-1和AEG-1在结肠癌中的表达及意义

Objective To study the expressions of apoptotic protease activating factor-1(Apaf-1) and astrocyte elevated gene-1(AEG-1) in colonic carcinoma, and to explore their correlations with the clinical pathological features. Methods The expressions of Apaf-1 and AEG-1 were detected in 63 colonic carcinoma samples and 30 normal colonic mucosa adjacent to tumor nest by immunohistochemical method, and their correlations with clinical features of colonic carcinoma were analyzed. Results The positive expressions of Apaf-1 and AEG-1 in colonic carcinoma were 23.81% (15/63) and 68.25% (43/63), respectively. The positive expre-ssions of Apaf-1 and AEG-1 in normal colonic mucosa were 76.67% (23/30) and 26.67% (8/30), respectively. The positive expression rate of AEG-1 was significantly higher in colonic carcinoma than that in normal tissue (χ2=14.192, P=0.000). However, the expression of Apaf-1 was signi-ficantly lower in colonic carcinoma than that in normal tissue (χ2=23.497, P=0.000). The expression of Apaf-1 was negatively correlated to the expression of AEG-1 (r=-0.339, P=0.007). The expressions of AEG-1 and Apaf-1 were associated with differentiation degree (χ2=4.643, P=0.031; χ2=12.034, P=0.001) and clinical stage (χ2=6.628, P=0.010; χ2=8.246, P=0.004), but they were not correlated with age (χ2=1.462, P=0.227; χ2=2.401, P=0.121) and tumor size (χ2=0.333, P=0.564; χ2=0.590, P=0.442). Conclusion The expression of AEG-1 is up-regulated in colonic carcinoma, but the expression of Apaf-1 is down-regulated, with a significant negative correlation. Apaf-1 and AEG-1 may be closely related to the occurrence and development of colon carcinoma. Therefore, combination detection of Apaf-1 and AEG-1 may be more valuable for the prognosis evaluation of colonic carcinoma. Key words: Colonic neoplasms; Astrocyte elevated gene-1; Apoptotic protease activating factor-1

Optimizing long-circulating liposomes for delivery of simvastatin to C26 colon carcinoma cells

Simvastatin (SIM) is a lipophilic statin that has potential benefits for prevention and treatment of several types of malignancies. However, its low water solubility and the toxicity associated with administration of high doses recommend it for encapsulation in carriers able to deliver the therapeutic dose in the tumor. In this work, liposomes with long-circulating properties were proposed as delivery systems for SIM. The objective of this study was to optimize the formulation of SIM-loaded long-circulating liposomes (LCL-SIM) by using D-optimal experimental design. The influence of phospholipids concentration, phospholipids to cholesterol molar ratio and SIM concentration was studied on SIM liposomal concentration, encapsulation efficiency and liposomal size. The optimized formulation had liposomal SIM concentration 6238 µg/ml, EE % of 83.4 % and vesicle size of 190.5 nm. Additionally we evaluated the in vitro cytotoxicity of the optimized liposomal SIM (LCL-SIM-OPT) on C26 murine colon carcinoma cells cultivated in monoculture as well as in co-culture with murine peritoneal macrophages at a cell density ratio that provides an approximation of physiological conditions of colon carcinoma development in vivo. Our preliminary studies suggested that LCL-SIM-OPT exerted cytotoxicity on C26 cells probably via enhancement of oxidative stress in co-culture environment.

Altered expression levels of IDH2 are involved in the development of colon cancer

IDH2 encodes a mitochondrial metabolic enzyme that converts isocitrate to α-ketoglutarate (α-KG) by reducing nicotinamide adenine dinucleotide phosphate (NADP+) to NADPH and participates in the citric acid cycle for energy production. Notably, this gene has been shown to be critical for cell proliferation. The abnormal expression of IDH2 has been reported in several types of cancer, and mutations in IDH2 have been identified in gliomas and acute myelogenous leukemia. The overexpression of IDH2 has been reported in endometrial, prostate and testicular cancer as well as in Kashin-Beck disease. In this study, we observed that IDH2 expression was significantly downregulated in early phase but was upregulated in advanced phase colon carcinoma compared to peritumoral tissues. In addition, we demonstrated that the growth of a colon carcinoma cell line was inhibited by IDH2-siRNA and increased following transfection with an IDH2-overexpressing plasmid. These results indicate that IDH2 may play a unique role in the development of colon carcinoma.

Expression of leptin and p-mTOR and their clinicopathological significance in human colon carcinoma

To investigate the relationship between the expression of leptin, p-mTOR protein and the pathogenesis, development and clinicopathological features in colon carcinoma. The expression of leptin and p-mTOR protein was evaluated by immunohistochemical methods in 40 normal colon mucosas, 40 colon adenomatous polyps and 108 cases of colon carcinomas. The relationship between the staining pattern and clinicopathogical features was examined. The positive rates of detection of leptin in normal colon mucosa, adenomatous polyps and colon carcinomas were 10% (4/40), 27.5% (11/40), and 71.3% (77/108), respectively; with significant differences among the three groups (P<0.05). The positive rates of p-mTOR protein in the normal colon mucosa, the adenomatous polyps, and the colon carcinomas were 2.5% (1/40), 20% (8/40), and 61.1% (66/108), respectively; with significant differences among the three groups (P<0.05). The expression of leptin and p-mTOR proteins were related to invasive depth, TNM stages, lymph node metastasis, distant metastasis and tumor differentiation (P<0.05), but not to age, sex, or site (P>0.05). In colon carcinoma tissues, leptin expression was positively correlated with p-mTOR expression (P<0.01). Leptin and p-mTOR proteins may play important roles in the occurrence and development of colon carcinoma. The detection of leptin and p-mTOR may be helpful for evaluation of the prognosis of the patient with colon carcinoma.

LMTK3 polymorphism in patients with metastatic colon cancer.

471 Background: LMTKs are a family of serine-threonine-tyrosine kinases. LMTK3 isoform is a potent regulator of estrogen receptor activity LMTK3 gene polymorphisms affect DFS and OS of breast cancer patients. Cumulative evidence implies that estrogen receptor signalling plays a role in colon carcinoma development and progression. We investigated whether the LMTK3 rs9989661 SNP is a prognostic factor in patients with advanced colon cancer. Methods: 318 patients with metastatic colon cancer treated at the USC/Norris Comprehensive Cancer Center or the LA County/USC Medical Center were included in this study. Genomic DNA was extracted from white blood cells of peripheral blood samples using the QiaAmp kit (Qiagen, Valencia, CA). The LMTK3 polymorphism was genotyped by PCR-RFLP. The association between the LMTK3 polymorphism and overall survival was examined using the log-rank test and multivariate Cox-model. Results: There were 141 females and 177 males, with a median age of 58 years (range 25-86). The cohort comprised 234 whites, 43 Asians, 15 Blacks, 24 Hispanics, and 2 Native Americans. The median survival was 13.7 months with a median follow-up of 2.3 years. The median overall survival was 16.6 vs. 12.8 months for patients with C/- vs. patients with T/T (HR=0.78; 95% CI: 0.56-1.08; p=0.055). At a multivariate analysis restricted to subjects with left-sided disease (n=126) the median OS for patients with C/- genotype was 23.8 months compared to 14.9 months of T/T patients (HR=0.51; 95%CI: 0.28-0.91; p=0.014). Conclusions: This study suggests that LMTK3 may be an independent prognostic factor for patients with metastatic colon cancer and raise the issue of possible disparities according to primary tumor location. Our group produced similar results also in the adjuvant setting. Functional correlative preclinical analyses and external clinical validation studies are currently ongoing.

Birt-Hogg-Dubé Syndrome and Familial Adenomatous Polyposis: An Association or a Coincidence?

An association between Birt-Hogg-Dubé syndrome (BHDS) and colon cancer remains conjectural, but herein we describe a case who may illustrate a significant link between them. The 60-year-old woman was diagnosed at 28 years of age with colon carcinoma and familial adenomatous polyposis (FAP). She also had repeated pneumothoraces, and was diagnosed with BHDS following the finding of pneumothorax in her son. We confirmed the presence of germline mutations in both her folliculin (FLCN) and adenomatous polyposis coli (APC) genes. The family pedigree suggested that a de novo FLCN mutation might have contributed to the development of colon carcinoma at a younger age than her family members.

K-ras mutations are correlated to lymph node metastasis and tumor stage, but not to the growth pattern of colon carcinoma

In colorectal carcinoma, pathological assessment of tumors is essential for determining therapy and prognosis of the disease. Molecular associations of tumor complexity index and genetic alternations can be helpful to understand the tumor progression mechanism. Oncogenic K-ras is one of the major colorectal cancer associated genes, and is mutated in up to 50% of colorectal cancers. In this current study, we correlated tumor complexity index with mutations in K-ras codon 12, 13, and 61 in association with different clinicopathological parameters such as TNM stage, localization, sex, and age. Formalin-fixed paraffin embedded tissue blocks from colon cancer samples was selected from 88 patients diagnosed with adenocarcinoma. Mutations in the K-ras gene were detected using pyrosequencing technique. Tumor complexity index was calculated using immunohistochemically stained images of the tumor outline of the specimens and then analyzing these pictures using Photoshop CS, Fovea Pro, and Image J computer programs. Statistical analysis was performed with SPSS. K-ras mutations were detected in 17 (19.3%) colon cancer samples. Most of the samples were at a lower complexity index. No correlation was observed between K-ras mutations and complexity index. However, K-ras mutations were correlated with regional lymph node metastasis and tumor stages and complexity index with tumor wall penetration. In conclusion, complexity index and K-ras mutations are independent events; however, both correlate with tumor progression and are important in the biologic development of colon carcinoma.

Expression of the nuclear bile acid receptor/farnesoid X receptor is reduced in human colon carcinoma compared to nonneoplastic mucosa independent from site and may be associated with adverse prognosis

The nuclear bile acid receptor/farnesoid X receptor (FXR; NR1H4) is involved in bile acid homeostasis, cell proliferation and apoptosis and has been linked to intestinal carcinogenesis in mice. Aim of this study was to analyze FXR expression in human normal intestinal mucosa and colon carcinoma. We achieved systematic mapping of FXR expression of human intestinal mucosa and analysis of 75 human colon carcinomas using FXR immunohistochemistry on formalin-fixed, paraffin-embedded tissue. FXR expression gradually decreased from terminal ileum to the sigmoid colon with strongest expression in the terminal ileum (p < 0.001). FXR expression in carcinomas was reduced compared to peritumoral nonneoplastic mucosa (p < 0.000). Loss of FXR expression was significantly correlated with grading in tumors of the right colon (p = 0.008). FXR expression in tumor and normal tissue showed an inverse correlation with stage. FXR expression in tumor was inversely correlated with clinical outcome. No association was found with patients' age and sex. In nonneoplastic mucosa FXR expression concurred with low expression of Ki-67. In carcinomas, no association was found between FXR expression and Ki-67 and cyclin D1, respectively. Development of colon carcinoma in humans is associated with reduced FXR expression independent of site and may reflect an impaired defense against potentially carcinogenic bile acids along their intestinal gradient. In contrast to normal colon mucosa, FXR expression in carcinomas is not associated with low proliferation. Colon carcinomas with FXR expression seem to be associated with lower stage and a more favourable outcome compared to FXR negative carcinomas.

Gender-related survival differences associated with polymorphic variants of estrogen receptor-β (ERβ) in patients with metastatic colon cancer

Estrogen replacement therapy in women has demonstrated a protective effect in the development of colonic carcinomas. Gender-related differences in the development of colonic carcinomas have also been reported. Estrogen receptor beta (ERβ) is expressed in colon carcinomas and has demonstrated prognostic value in colon cancer patients. This study investigated an ERβ 3’ non-coding polymorphism associated with transcriptional activity to determine clinical outcome in patients with metastatic colon cancer. Genomic DNA from 318 metastatic colon cancer patients, 177 males and 141 females, were collected from 1992 to 2003. These patients were analyzed for CA repeat polymorphism of the ERβ gene. Gender-related survival differences were associated with an ERβ (CA)n repeat polymorphism (P for interaction=0.003, the likelihood ratio test). Female patients with any short <22 (CA)n repeat alleles had shorter overall survival compared to female patients that had both long ≥22 (CA)n repeat alleles. In the male patients the opposite overall survival difference was found. This study supports the role of an ERβ (CA)n repeat polymorphism as a prognostic marker in metastatic colon cancer; however, this prognostic factor had opposite implications based on gender.