Cadherin-catenin expression in primary colorectal cancer: a survival analysis.

Both cell adhesion and cell signalling events are mediated by components of the cadherin-catenin complex. Loss of expression of the components of this complex have been shown to correlate with invasive behaviour in many tumour types although their exact role in colorectal cancer remains unclear. Immunohistochemical analysis of the expression of components of the cadherin-catenin complex in colorectal cancers from 60 patients was undertaken. Loss of memberanous expression of E-cadherin, alpha-catenin and beta-catenin was demonstrated in 52%, 85% and 40% of tumours respectively. Focal nuclear expression of beta-catenin (< 75% of cells per section), usually associated with cytoplasmic expression, was clearly demonstrated in 19 (32%) tumours while widespread nuclear expression (> 75% of tumour cells per section) was seen in 11 (18%) tumours. Loss of membranous alpha-catenin expression significantly correlated with tumour de-differentiation (P = 0.009). There was a trend towards an association between advanced tumour stage and loss of membranous expression of alpha-catenin or beta-catenin, although these associations were not statistically significant. Univariate analysis revealed that advanced Dukes' stage, tumour de-differentiation, loss of membranous beta-catenin expression, cytoplasmic beta-catenin expression and widespread nuclear expression of beta-catenin all correlated with short survival following apparently curative resection of the primary tumour. However, only Dukes' stage (P = 0.002), tumour grade (P = 0.02) and widespread nuclear expression of beta-catenin (P = 0.002) were independent predictors of short survival. Disturbed growth signalling events in colorectal tumours are thought to result in nuclear accumulation of beta-catenin. Consequently, tumours with widespread nuclear expression of beta-catenin are likely to have severely abnormal growth characteristics, and which therefore might be predictive of short survival in these patients.     

The E-cadherin repressor Snail is associated with lower overall survival of ovarian cancer patients

Epithelial ovarian cancer is the leading cause of death among female genital malignancies. Reduced expression of the cell adhesion molecule E-cadherin was previously shown to be associated with adverse prognostic features. The role of the E-cadherin repressor Snail in ovarian cancer progression remains to be elucidated. We analysed formalin-fixed and paraffin-embedded specimens of 48 primary ovarian tumours and corresponding metastases for expression of E-cadherin and Snail by immunohistochemistry. We found a significant correlation between E-cadherin expression in primary cancers and their corresponding metastases (P<0.001). This correlation was found for Snail expression as well (P<0.001). There was a significant (P=0.008) association of reduced E-cadherin expression in primary ovarian cancer with shorter overall survival. Similarly, Snail expression in corresponding metastases (P=0.047) was associated with reduced overall survival of the patients. Additionally, the group of patients showing reduced E-cadherin and increased Snail immunoreactivity in primary tumours and corresponding metastases, respectively, had a significantly higher risk of death (P=0.002 and 0.022, respectively) when compared to the patient group with the reference expression profile E-cadherin positive and Snail negative. Taken together, the results of our study show that the E-cadherin repressor Snail is associated with lower overall survival of ovarian cancer patients.     

Predominant expression of truncated EpCAM is associated with a more aggressive phenotype and predicts poor overall survival in colorectal cancer

Regulated intramembrane proteolysis (RIP) has been shown to be an important mechanism for oncogenic activation of EpCAM through nuclear translocation of the intracellular domain EpICD. Recently, we identified two different membranous EpCAM variants namely EpCAM^MF (full‐length) and EpCAM^MT (truncated) to be expressed in the majority of human epithelial tumors. The aim of our study was to evaluate the potential role of these two protein variants as additional prognostic biomarkers in colorectal cancer. In most studies only one antibody targeting the extracellular domain of EpCAM (EpEX) has been used, whereas in the present study additionally an antibody which detects the intracellular domain (EpICD) was applied to discriminate between different EpCAM variants. Using immunohistochemistry, we analyzed the expression of EpCAM^MF and EpCAM^MT variants in 640 patients with colorectal cancer and determined their correlations with other prognostic factors and clinical outcome. A statistically significant association was observed for EpCAM^MT with advanced tumor stage (p < 0.001), histological grade (p = 0.01), vascular (p < 0.001) and marginal (p = 0.002) invasion. Survival analysis demonstrated reduced overall survival (p < 0.004) in patients with tumors expressing the EpCAM^MT phenotype when compared to patients with tumors expressing the EpCAM^MF variant. In conclusion, this study for the first time indicates that expression of EpCAM^MT is associated with a more aggressive phenotype and predicts poor survival in patients with colorectal cancer.     

Loss of expression of the double strand break repair protein ATM is associated with worse prognosis in colorectal cancer and loss of Ku70 expression is associated with CIN

Repair of double strand DNA breaks (DSBs) is pivotal in maintaining normal cell division and disruption of this system has been shown to be a key factor in carcinogenesis. Loss of expression of the DSB repair proteins have previously been shown to be associated with poorer survival in colorectal cancer. We wished to ascertain the relationship of altered expression of the DSB repair proteins γ-H2AX (gamma-H2AX), ATM and Ku70 with biological and clinico-pathological features of colorectal cancer. 908 tumours from the VICTOR clinical trial of stage II/III colorectal cancer were analysed for expression of γ-H2AX, ATM and Ku70 using immunohistochemistry. Expression levels were correlated with CIN and with disease-free survival, correcting for microsatellite instability, BRAF/KRAS mutation status, Dukes stage, chemo/radiotherapy, age, gender and tumour location. Down-regulated Ku70 expression was associated with chromosomal instability (p=0.029) in colorectal cancer. Reduced ATM expression was an independent marker of poor disease-free survival (HR=1.67, 95% CI 1.11-2.50, p=0.015). For Ku70, further studies are required to investigate the potential relationship of non-homologous end joining with chromosomal instability. Loss of ATM expression might serve as a biomarker of poor prognosis in colorectal cancer.     

Matrilysin-2 expression in colorectal cancer is associated with overall survival of patients

Tumor recurrence and metastasis are pressing issues of patients with colorectal cancer who receive surgery. Matrilysin-2 (MMP-26) has been proved to play an important role during invasion and metastasis of some human solid tumor. We aimed to investigate the clinical significance and prognostic value of matrilysin-2 in human colorectal cancer. Colorectal cancer and adjacent normal samples from 201 patients were collected. Matrilysin-2 expression level was investigated by immunohistochemistry assay, and its association with overall survival of patients was analyzed by statistical analysis. Results showed that matrilysin-2 expression level significantly elevated in colorectal cancer compared with adjacent normal specimens. Matrilysin-2 expression was also found to be associated with cancer invasion, lymph node metastasis, distant metastasis, and TNM stage. In addition, survival analysis showed that elevated matrilysin-2 expression was associated with poor overall survival of patients. Cox's proportional hazards model indicated that matrilysin-2 was an independent prognostic marker for patients with colorectal cancer. The present study found that the expression of matrilysin-2 increased in colorectal cancer and was associated with tumor progression. It also provided the first evidence that matrilysin-2 expression was an independent prognostic factor for patients with colorectal cancer, which might be a high specific biomarker for colorectal cancer.     

FHL2沉默对骨肉瘤U2OS细胞增殖与凋亡的影响

目的 探讨沉默FHL2表达对骨肉瘤U2OS细胞的增殖和凋亡的影响及其相关机制的研究。方法 通过构建FHL2的shRNA干扰载体pLKO.1,制备慢病毒并感染U2OS细胞,分为shFHL2目的基因干扰组（shFHL2）和无关序列对照组（SCR）;感染96 h后采用实时定量PCR（QPCR）和Western blotting检测两组FHL2 mRNA和蛋白水平。采用MTT方法检测细胞增殖,流式细胞术分析细胞凋亡和细胞周期的变化,Western blotting检测FHL2干扰后U2OS细胞相关信号通路的蛋白表达变化。利用双荧光素酶报告基因系统检测FHL2对p53下游基因转录调控的影响。结果与SCR组比较,shFHL2组感染96 h后FHL2 mRNA和蛋白水平均降低（P＜0.05）。shFHL2组感染24、48、72、96 h的细胞增殖比分别为1.73±0.08、2.49±0.38、3.26±0.45和4.28±0.29,其中96 h的细胞增殖比低于SCR组（P＜0.05）;shFHL2组感染96 h的细胞凋亡率为（17.55±1.05）％,高于SCR组的（7.73±1.12）％,差异有统计学意义（P＜0.05）;shFHL2组感染96 h的G0／G1期细胞为（68.18±0.78）％,高于SCR组的（59.73±2.28）％,差异有统计学意义（P＜0.05）。干扰FHL2表达能够显著上调p53、p21和Bax的表达水平并能增强p53对Bax启动子的促转录活性。结论 沉默FHL2表达可明显抑制骨肉瘤U2OS细胞增殖并促进细胞凋亡,使细胞阻滞于G0／G1期;FHL2介导了p53对Bax启动子的转录调节作用。FHL2可能会成为新的肿瘤治疗靶点,其机制与p53／Bax和p53／p21通路相关。     

eIF4E binding protein 1 expression is associated with clinical survival outcomes in colorectal cancer

eIF4E binding protein 1 (4E-BP1), is critical for cap-dependent and cap-independent translation. This study is the first to demonstrate that 4E-BP1 expression correlates with colorectal cancer (CRC) progression. Compared to its expression in normal colon epithelial cells, 4E-BP1 was upregulated in CRC cell lines and was detected in patient tumor tissues. Furthermore, high 4E-BP1 expression was statistically associated with poor prognosis. Hypoxia has been considered as an obstacle for cancer therapeutics. Our previous data showed that YXM110, a cryptopleurine derivative, exhibited anticancer activity via 4E-BP1 depletion. Here, we investigated whether YXM110 could inhibit protein synthesis under hypoxia. 4E-BP1 expression was notably decreased by YXM110 under hypoxic conditions, implying that cap-independent translation could be suppressed by YXM110. Moreover, YXM110 repressed hypoxia-inducible factor 1α (HIF-1α) expression, which resulted in decreased downstream vascular endothelial growth factor (VEGF) expression. These observations highlight 4E-BP1 as a useful biomarker and therapeutic target, indicating that YXM110 could be a potent CRC therapeutic drug.     

The TERT variant rs2736100 is associated with colorectal cancer risk

Background:

Polymorphic variation at the 5p15.33 (TERT–CLPTM1L) locus is associated with the risk of many cancers but a relationship with colorectal cancer (CRC) risk has yet to be defined.

Methods:

We used data from six genome-wide association studies (GWAS) of CRC, linkage disequilibrium mapping and imputation, to examine the relationship between 73 single-nucleotide polymorphisms at 5p15.33 and CRC risk in detail.

Results:

rs2736100, which localises to intron 2 of TERT, provided the strongest evidence of an association with CRC (P=2.28 × 10⁻⁴). The association was also shown in an independent series of 10 047 CRC cases and 6918 controls (P=0.02). A meta-analysis of all seven studies (totalling 16 039 cases, 16 430 controls) provided increased evidence of association (P=2.49 × 10⁻⁵; per allele odds ratio=1.07). The association of rs2736100 on CRC risk was shown to be independent of 15 low-penetrance variants previously identified.

Conclusion:

The rs2736100 association demonstrates an influence of variation at 5p15.33 on CRC risk and further evidence that the 5p15.33 (TERT–CLPTM1L) locus has pleiotropic effects (reflecting generic or lineage-specific effects) on cancer risk.     

FHL2 exhibits anti-proliferative and anti-apoptotic activities in liver cancer cells

FHL2 displays tumor promoting or tumor suppressing activities depending on the types of tumor cells. In this study, we demonstrated that FHL2 overexpression inhibits the proliferation of human HCC cells Hep3B through cell cycle regulation by decreasing cyclin D1 expression while increasing the expressions of p21 and p27. FHL2 overexpression also inhibits migration and invasion of Hep3B cells through the regulation of epithelial-mesenchymal transition. Surprisingly, we also demonstrated an antiapoptotic function for FHL2 overexpression with increased resistance to doxorubicin-induced apoptosis, which indicates the separation of anti-proliferative and anti-apoptotic role of FHL2. Taken together, our results indicate FHL2 could exert anti-apoptotic effect independent of tumor growth suppression.     

Lactate dehydrogenase A negatively regulated by miRNAs promotes aerobic glycolysis and is increased in colorectal cancer

Reprogramming metabolism of tumor cells is a hallmark of cancer. Lactate dehydrogenase A (LDHA) is frequently overexpressed in tumor cells. Previous studies has shown higher levels of LDHA is related with colorectal cancer (CRC), but its role in tumor maintenance and underlying molecular mechanisms has not been established. Here, we investigated miRNAs-induced changes in LDHA expression. We reported that colorectal cancer express higher levels of LDHA compared with adjacent normal tissue. Knockdown of LDHA resulted in decreased lactate and ATP production, and glucose uptake. Colorectal cancer cells with knockdown of LDHA had much slower growth rate than control cells. Furthermore, we found that miR-34a, miR-34c, miR-369-3p, miR-374a, and miR-4524a/b target LDHA and regulate glycolysis in cancer cells. There is a negative correlation between these miRNAs and LDHA expression in colorectal cancer tissues. More importantly, we identified a genetic loci newly associated with increased colorectal cancer progression, rs18407893 at 11p15.4 (in 3′-UTR of LDHA), which maps to the seed sequence recognized by miR-374a. Cancer cells overexpressed miR-374a has decreased levels of LDHA compared with miR-374a-MUT (rs18407893 at 11p15.4). Taken together, these novel findings provide more therapeutic approaches to the Warburg effect and therapeutic targets of cancer energy metabolism.     

c-erbB-2 is not a major factor in the development of colorectal cancer

We have investigated c-erbB-2 protein expression in a large cohort of well-characterized colorectal tumours, and in a subset of lymph node metastases. We have also evaluated a Val(655)Ile single nucleotide polymorphism, which is associated with an increased risk of breast cancer, in a subset of the colorectal cancer patients and in healthy control subjects. Immunohistochemical studies revealed that while 81.8% of tumours expressed c-erbB-2, in the majority of cases equivalent levels of c-erb-B2 were seen in adjacent normal mucosa. Colon tumours were significantly more likely to express c-erbB-2 than rectal tumours (P=0.015). Only 52.4% of the metastases displayed staining patterns concordant with their primary tumour, indicating that determination of c-erbB-2 protein in colorectal tumours cannot predict the status of lymph node metastases. PCR--RFLP analysis of the Val(655)Ile single nucleotide polymorphism demonstrated that allele frequencies were identical between colorectal cancer patients and a control group of Caucasian subjects (Ile=0.80 and Val=0.20 in each case), indicating that it is not related to the risk of developing colorectal cancer in this population. Furthermore, there was no relationship between c-erbB-2 protein expression and gene polymorphism (P=0.58). In terms of prognosis, no association was seen between either c-erbB-2 protein expression or the presence of the Val allele and patient survival (P>0.05 in each case), suggesting that c-erbB-2 is not a prognostic marker in colorectal cancer.     

High Pin1 expression is associated with tumor progression in colorectal cancer

BACKGROUND AND OBJECTIVES: Peptidyl prolyl cis-trans isomerase (Pin1) isomerizes only phosphorylated serine or threonine residues preceding proline in certain proteins and affects the protein function. Pin1 interacts with many signaling pathways, including Wnt signaling pathway that is crucial for colorectal tumorigenesis. Pin1 promotes cyclin D1 over-expression directly or through the stabilization of beta-catenin. Pin1 is over-expressed in some cancers such as prostate and breast cancers. This study aimed to determine whether Pin1 plays a role in colorectal tumorigenesis through the upregulation of beta-catenin and cyclin D1. METHODS: Immunohistochemical analyses were performed on 105 colorectal cancer tissue samples using anti-Pin1, anti-beta-catenin, and anti-cyclin D1 antibodies. We examined the relationships between Pin1 expression and clinicopathological factors, prognosis, and beta-catenin/cyclin D1 expression. RESULTS: High Pin1 expression was observed in 40 cases (38%) and positively correlated with histological type (P=0.0240), depth of invasion (P=0.0051), and staging (P=0.0027) of colorectal tumors. High Pin1 expression was also correlated with the over-expressions of both beta-catenin (P=0.0225) and cyclin D1 (P=0.0137). CONCLUSIONS: These results suggest that Pin1 plays an important role in colorectal tumorigenesis, presumably by increasing beta-catenin and cyclin D1 expressions.     

NEAT expression is associated with tumor recurrence and unfavorable prognosis in colorectal cancer

Long noncoding RNAs (lncRNAs) have recently been identified to be involved in various diseases including cancer. NEAT1 is a recently identified lncRNA with its function largely unknown in human malignancy. In the present study, we investigated NEAT1 expression in 239 cases of clinical colorectal cancer specimens and matched normal tissues. Statistical methods were utilized to analyze the association of NEAT1 with clinical features, disease-free and overall survival of patients. Results showed that NEAT1 expression in colorectal cancer was up-regulated in 72.0% (172/239) cases compared with corresponding normal counterparts, and related to tumor differentiation, invasion, metastasis and TNM stage. Kaplan-Meier analysis proved that NEAT1 was associated with both disease-free survival and overall survival of patients with colorectal cancer that patients with high NEAT1 expression tend to have unfavorable outcome. Moreover, cox’s proportional hazards analysis showed that high NEAT1 expression was an independent prognostic marker of poor outcome. These results provided the first evidence that the expression of NEAT1 in colorectal cancer may play an oncogenic role in colorectal cancer differentiation, invasion and metastasis. It also proved that NEAT1 may serve as an indicator of tumor recurrence and prognosis of colorectal cancer.     

Metastatic colorectal cancer and type 2 diabetes: prognostic and genetic interactions

The present study was undertaken to analyze prognostic and genetic interactions between type 2 diabetes and metastatic colorectal cancer. Patients’ survival was depicted through the Kaplan–Meier product limit method. Prognostic factors were examined through the Cox proportional‐hazards regression model, and associations between diabetes and clinical‐pathologic variables were evaluated by the χ² test. In total, 203 metastatic colorectal cancer patients were enrolled. Lymph nodes (P = 0.0004) and distant organs (> 2 distant sites, P = 0.0451) were more frequently involved in diabetic patients compared with those without diabetes. Diabetes had an independent statistically significant negative prognostic value for survival. Highly selected patients with cancer and/or diabetes as their only illness(es) were divided into three groups: (a) seven oligo‐metastatic patients without diabetes, (b) 10 poly‐metastatic patients without diabetes, and (c) 12 poly‐metastatic diabetic patients. These groups of patients were genetically characterized through the Illumina NovaSeq 6000 (San Diego, CA, USA) platform and TruSigt™Oncology 500 kit, focusing on genes involved in diabetes and colorectal cancer. Gene variants associated with diabetes and cancer were more frequent in patients in group 3. We found that type 2 diabetes is a negative prognostic factor for survival in colorectal cancer. Diabetes‐associated gene variants could concur with malignancy, providing a rational basis for innovative models of tumor progression and therapy.     

FHIT基因在结直肠癌中的表达及其与细胞凋亡抑制的相关性

Objective： To investigate the expression of fragile histidine triad （FHIT） protein in normal colorectal tissue, colorectal adenoma and colorectal cancer （CRC）, and to study the relationships between the expression of FHIT protein and the clinical pathology, the apoptosis-associated protein （Bcl-2, Bax, Survivin）, apoptosis in colorectal cancer. Methods： Tissue microarray （TMA） and immunohistochemistry SP were used to detect the expression of FHIT gene, Bcl-2, Bax and Survivin in 16 cases of the normal colorectal tissue, 16 cases of colorectal adenoma and 80 cases of the colorectal cancer. TUNEL was used to detect the apoptosis index （Al） in 80 cases of the colorectal cancer. Results： （1） The positive rates of FHIT gene expression in normal colorectal tissue, colorectal adenoma and adenocancer were 93.75%, 68.75% and 46.25% respectively. There were no significant differences in the relationships between the FHIT gene expression and histological types, the gender as well as the age （P〉0.05）. There were significant relationships between FHIT gene expression and lymph node metastasis, histological grades, Duke＇s system as well as the 5-year survival rate after operation. （2） The positive rates of Bax, Bcl-2 and Survivin in colorectal adenocancer were 72.50%, 51.25%, 77.50% respectively. The expression of FHIT gene was positively correlated with that of Bcl-2, Bax and Survivin. （3） The mean AI in FHIT negative tumors was significantly lower than that in FHIT positive tumors （P〈0.01）. Conclusion： FHIT gene may play a role in the oncogenesis and progression of colorectal cancer. The abnormal regulation of apoptosis may play an important role in the pathogenesis of colorectal cancer.