Deciphering the epigenetic network in colorectal cancer

The sequential accumulation of genetic alterations has been classically considered responsible for the origin and subsequent progression of colorectal cancer, although recent cumulative data provide strong evidence of the significance of epigenetic changes in the development of this multi‐step malignancy. Among the epigenetic alterations, miRNAs deregulation has emerged as an exciting and promising field in cancer research. In a recent issue of the Journal of Pathology, Wang and colleagues identify miR‐149 as being silenced by methylation in colorectal cancer. The authors also identified Sp1 as a target of miR‐149. These intriguing observations have important biological prognostic and therapeutic implications.     

Spectrum of K ras mutations in Pakistani colorectal cancer patients

The incidence of colorectal cancer (CRC) is increasing daily worldwide. Althoughdifferent aspects of CRC have been studied in other parts of the world, relativelylittle or almost no information is available in Pakistan about different aspects ofthis disease at the molecular level. The present study was aimed at determining thefrequency and prevalence of K ras gene mutations in Pakistani CRCpatients. Tissue and blood samples of 150 CRC patients (64% male and 36% female) wereused for PCR amplification of K ras and detection of mutations bydenaturing gradient gel electrophoresis, restriction fragment length polymorphismanalysis, and nucleotide sequencing. The K ras mutation frequencywas found to be 13%, and the most prevalent mutations were found at codons 12 and 13.A novel mutation was also found at codon 31. The dominant mutation observed was a Gto A transition. Female patients were more susceptible to K rasmutations, and these mutations were predominant in patients with a nonmetastaticstage of CRC. No significant differences in the prevalence of K rasmutations were observed for patient age, gender, or tumor type. It can be inferredfrom this study that Pakistani CRC patients have a lower frequency of Kras mutations compared to those observed in other parts of the world, andthat K ras mutations seemed to be significantly associated withfemale patients.     

Comprehensive expression analysis of TNF-related apoptosis-inducing ligand and its receptors in colorectal cancer: Correlation with MAPK alterations and clinicopathological associations

TNF-related, apoptosis-inducing ligand (TRAIL) apoptotic pathway constitutes a promising therapeutic target due to high selectivity and low toxicity of TRAIL targeting agents when administered in combination therapies. 106 colorectal cancers were examined for: relative mRNA expression of TRAIL pathway genes, decoy receptors TRAIL-R3 and TRAIL-R4 promoter methylation and the presence of KRAS, NRAS, BRAF mutations. Elevated mRNA levels were observed in 26%, 15%, 13%, 12% and 10% of the cases for TRAIL-R4, TRAIL-R3, TRAIL-R2, TRAIL-R1 and TRAIL genes respectively. Reduced mRNA levels were detected in 77%, 65%, 64%, 60% and 37% of the cases for TRAIL, TRAIL-R2, TRAIL-R3, TRAIL-R1 and TRAIL-R4 genes respectively. TRAIL-R3 and TRAIL-R4 promoter methylation was detected in 55% and 16% of the analysed samples respectively. TRAIL-R1, TRAIL-R2 elevated relative mRNA levels inversely correlated with tumor stage (p?=?.036, p?=?.048). Strong linear correlations of TRAIL receptors’ mRNA levels were found: TRAIL-R1/TRAIL-R2 (R?=?0.653, p?<?.001), TRAIL-R2/TRAIL-R3 (R?=?0.573, p?<?.001). Finally, relative expression of TRAIL was correlated with KRAS, BRAF and NRAS mutation status, defining an inverse correlation between increased TRAIL expression and the absence of mutations in Mitogen-activated protein kinase (MAPK) pathway.In conclusion, simultaneous analysis of TRAIL pathway membrane components, pointed towards a significant deregulation of mRNA expression in colorectal tumours. Death receptor overexpression was an indicator of a less aggressive phenotype. The multiple expression patterns of TRAIL pathway components in colorectal tumours underscore the importance of patient selection in order to achieve maximum efficiency with TRAIL targeted therapy.     

Distribution of KRAS and BRAF mutations in Moroccan patients with advanced colorectal cancer

Targeted therapies have an increasing importance in digestive oncology. To our knowledge, we are the first to report the distribution of KRAS and BRAF mutations in Moroccan patients with advanced colorectal cancer (CRC) in order to introduce targeted therapy in the arsenal of therapeutic modalities for management of this cancer in Morocco. In this study, 92 samples obtained from patients with CRC were tested for the presence of the nine most common mutations in the KRAS gene and BRAF gene. Among the tested patients, 76.09% of patients had wt-KRAS genotype and 23.91% were KRAS mutants and the majority of mutations would result in an amino acid substitution of glycine by aspartic acid (68.2%) The predominant mutations are G>A transitions and G>T transversions. Around 5% (5.43%) of the tested patients bore the V600E mutation in BRAF gene. Only one patient showing to have the V600E mutation in BRAF was also mutated-KRAS. Summing up the results about the KRAS and the BRAF mutation carriers from our study, the portion of potentially non responsive patients for the anti-EGFR treatment is 28.26%.     

APRIL调节基质金属蛋白酶的表达对结直肠癌细胞转移侵袭能力的影响

目的 研究增殖诱导配体(a proliferation-inducing ligand,APRIL)对结直肠癌(colorectal cancer,CRC)细胞转移侵袭能力和基质金属蛋白酶(matrix metalloproteinases,MMPs)表达的影响,以进一步明确APRIL在CRC转移中的作用.方法 APRIL基因的小干扰RNA质粒载体(siRNAAPRIL)转染人CRC细胞SW480,APRIL重组蛋白(rhAPRIL)刺激CRC细胞HCT-116,Transwell小室转移及侵袭试验分析APRIL对CRC细胞转移及侵袭能力的影响;RT-PCR、ELISA检测MMPs的表达变化.结果 siRNA-APRIL转染的SW480细胞Transwell小室试验转移及侵袭细胞数显著减少(P＜0.05),rhAPRIL刺激的HCT-116细胞Transwell小室试验转移及侵袭细胞数显著增多(P＜0.05);MMP-2、MMP-9及TIMP-1 mRNA,分泌型的MMP-2、MMP-9蛋白表达在转染或刺激前后差别均有统计学意义(P＜0.05);MMP的抑制剂GM6001处理后,SW480对照组和rhAPRIL刺激后的HCT-116细胞Transwell小室侵袭细胞数显著减少(P＜0.05).结论 APRIL通过调节MMPs的表达促进结直肠癌的侵袭和转移,可为结直肠癌转移的干预及治疗提供新的靶点.     

大肠癌相关抗原LEA在大肠癌诊断中的意义

目的:探讨LEA在大肠癌中的表达及意义。方法:采用免疫组织化学S-P法检测140例大肠癌组织和100例大肠非癌组织LEA与CEA的表达。结果:LEA表达与肿瘤分化程度有相关性,对高分化腺癌表现出更高的选择性（P<0.01）,CEA单抗对高、中、低分化腺癌选择性相似（P>0.05）,LEA在腺瘤中表达的阳性率,明显高于癌旁粘膜和正常粘膜;LEA在正常粘膜标记的阳性率明显低于CEA（P<0.05）。结论:LEA的表达与大肠癌组织的分化程度有关,LEA可作为大肠癌早期诊断的辅助指标。     

The cathepsin family and their role in colorectal cancer

Cathepsins are a class of globular proteases, initially described as intracellular peptide hydrolases, although several cathepsins also have extracellular functions. Cathepsins B, C, F, H, L, K, O, S, V, W, and X are cysteine proteases of the papain family, and represent the largest and best-known class of the cathepsins. Cathepsin G is a serine carboxypeptidases, and cathepsins D and E are aspartic proteases. Cathepsins are synthesized as inactive proenzymes and processed to become mature and active enzymes. Endogenous protein inhibitors, such as cystatins and some serpins, inhibit active enzymes. As primarily lysosomal proteases, cathepsins play important roles in proteolysis during physiological processes, as well as in several diseases. On the basis of their ability to degrade extracellular matrix proteins, cathepsins have been implicated to play a role in invasion and metastasis of colorectal cancer. In the present review, the role of cathepsins in the disease process of colorectal cancers and the correlation of cathepsin expression and activity with clinicopathological features is discussed. Furthermore, we give an overview of the recent developments of cathepsins in animal models and in in vitro experiments of colorectal disease, and provide information on inhibitors of cathepsins as possible therapeutics.     

Copy number alterations of chromosomal regions enclosing protein tyrosine phosphatase receptor-like genes in colorectal cancer

Protein tyrosine phosphatases that act in different cellular pathways are described most commonly as tumor suppressors, but also as oncogenes. Their role has previously been described in colorectal cancer, as well as in gastric, breast, thyroid, prostate, ovarian, pancreatic, glioma, liver, leukemia and many other cancers.In a previous study, we have described protein tyrosine phosphatase receptor type T, M, Z1 and Q genes (PTPRT, PTPRM, PTPRZ1 and PTPRQ) hypermethylated in sporadic colorectal cancer. Thus, in this study, we examined the relation of unbalanced chromosomal alterations within regions covering these four protein tyrosine phosphatase genes with this cancer.One hundred and two cancer tissues were molecularly characterized, including analysis of the BRAF and K-ras mutations and methylator phenotype. The analysis of chromosomal aberrations was performed using Comparative Genomic Hybridization.We observed amplification of three regions containing genes coding for PTPs, such as PTPRZ1 (7q31.3, amplified in 23.5% of cases), PTPRQ (12q21.2, amplified in 5.9% of cases), PTPRT (20q12, amplified in 29.4% of cases), along with deletions in the region of PTPRM (18p11.2, deleted in 21.6% of cases). These data may suggest that in sporadic colorectal cancer PTPRZ1, PTPRT, PTPRQ probably act as oncogenes, while PTPRM acts as a tumor suppressor gene. Our study also revealed that gains on chromosome 20q12 and losses on chromosome 18p11.2 are connected with the absence of the BRAF mutation and the conventional adenocarcinoma pathway.     

Frequency and type of KRAS mutations in routine diagnostic analysis of metastatic colorectal cancer

Mutation analysis of the KRAS oncogene is now established as a predictive biomarker in colorectal cancer (CRC). Large prospective clinical trials have shown that only CRCs with wild-type KRAS respond to anti-epidermal growth factor receptor (EGFR) treatment. Therefore, mutation analysis is mandatory before treatment, and reliable benchmarks for the frequency and types of KRAS mutations have to be established for routinely testing large numbers of metastatic CRCs.     

79例中国人结直肠癌 APC 基因突变分析

目的：研究中国人结直肠癌中 APC 基因的突变频率及分布特点。方法应用聚合酶链反应（ PCR ）产物直接测序法,对79例中国结直肠癌患者肿瘤标本中 APC 基因突变密集区（ MCR ）中的突变进行检测,并对该基因突变与相关临床病理参数之间的关系进行分析。结果在79例肿瘤标本中检出 APC 基因的总突变率为31.6％（25／79）。点突变频率为20.3％（16／79）,其中有12例无义突变及4例错义突变;另有11％（9／79）的突变是由缺失或插入导致的移码突变。12例无义突变及9例移码突变导致截短突变（27％）,占总突变率的84％。 APC 基因突变表现为区域密集,密码子1281-1352和1411-1465为突变频率较高的2个区段,其突变率分别为16.5％和15.2％。突变频率较高的位点为密码子1450、1421、1306和1286。统计分析结果显示,癌组织中 APC 基因突变与患者的年龄、性别、肿瘤位置、浸润深度、淋巴结转移情况、分期、大体分型和组织分化程度无关。结论中国人结直肠癌中存在较高频率的 APC 基因突变,截短突变为其主要突变类型。同时,本研究在 APC 基因的 MCR 中发现2个突变热点区及4个潜在突变热点。     

Correlation of Nrf2, NQO1, MRP1, cmyc and p53 in colorectal cancer and their relationships to clinicopathologic features and survival

Due to emergence of resistant tumor populations, prognosis for metastatic colorectal cancer (CRC) patients remains poor and five-year survival rate is still very low. To guide clinicians in selecting treatment option for CRC patients, reliable markers predictive of poor clinical outcome are desirable. This study analyzed the correlation of NF-E2-related factor 2 (Nrf2), NAD(P)H quinine oxidoreductase 1 (NQO1), multidrug resistant protein 1 (MRP1), cmyc and p53 in CRC and their relationships to Duke’s stage and clinical prognosis. 76 specimens of CRC tissues were immunohistochemically investigated using Nrf2, NQO1, MRP1, cmyc and p53 antibodies. IHC stain showed that Nrf2, NQO1, MRP1, cmyc and p53 were highly expressed in CRC tissues compared with adjacent non-tumor tissues. Significant positive correlations were found between the expression of Nrf2 and that of NQO1, MRP1, cmyc and p53. Moreover, there was significant correlation between the high level of Nrf2, NQO1, MRP1, p53 expression and Duke’s stage, as well as poor clinical prognosis. We confirmed that Nrf2, NQO1, MRP1, and p53 expression exhibits considerable heterogeneity according to CRC clinical stage and prognosis. Nrf2 is the most promising biomarker in identifying a poor prognostic group of CRC.     

MSI status is associated with distinct clinicopathological features in BRAF mutation colorectal cancer: A systematic review and meta-analysis

BackgroundMicrosatellite stable (MSS) BRAF p.V600E mutation colorectal cancer (BRAF-CRC) has a poor prognosis, whereas microsatellite instability (MSI) in BRAF-CRC is associated with a favorable prognosis. Although usually considered a single clinical entity, the MSI BRAF-CRC subtype shows some distinct characteristics in comparison with the MSS BRAF-CRC subtype.MethodsWe conducted a meta-analysis to investigate the influence of clinicopathological features on MSI status in BRAF-CRC. We searched publications up to March 2019 from PubMed, Embase, and the Cochrane Library. The effect of MSI status on outcome parameters was assessed using odds ratios (ORs) with 95% confidence intervals (CIs) and fixed- or random-effects models according to the heterogeneity.ResultsAfter reviewing 2839 reports, 16 eligible studies including 1381 patients with BRAF-CRC met the criteria. The MSI BRAF-CRC subtype was associated with older age, female sex (OR = 1.70; 95% CI = 1.35–2.14; P < 0.00001), proximal tumor location (OR = 5.10; 95% CI = 3.70–7.03; P < 0.00001), early TNM stage (OR = 5.28; 95% CI = 3.93–7.09; P < 0.00001), and poor differentiation (OR = 2.29; 95% CI = 1.60–3.28; P < 0.00001).ConclusionsMSI was significantly correlated with distinct favorable clinicopathological characteristics in BRAF-CRC. These results suggest that MSI status should be considered as a stratification factor for better management of the BRAF-CRC.     

AMACR expression in colorectal cancer is associated with left-sided tumor localization

Alpha-methylacyl-CoA racemase (AMACR) is an enzyme playing an important role in the beta-oxidation of branched-chain fatty acids and fatty acid derivatives. Altered expression levels of AMACR have been described in various cancers including colorectal cancer (CRC). To determine the potential prognostic impact of AMACR expression, we analyzed 1,315 CRC on a tissue microarray (TMA) by immunohistochemistry (IHC). Clinical follow-up data were available from all cancer patients. Positive AMACR staining was observed in 1,074 (81.7%) of the 1,315 cases including 276 cancers with weak (21.0%) and 798 cancers with strong staining (60.7%). AMACR IHC was significantly associated with tumor grade, stage, non-mucinous phenotype, and left-sided tumor localization (p < 0.0001 each). AMACR positivity was observed in 65.8% of cancers from the right-sided colon, in 73.2% of cancers from the colon transversum, in 81.1% of cancers from the colon descendens, and in 88.9% of the distal left-sided cancers (sigma and rectum; p < 0.0001). However, AMACR staining results were unrelated to clinical outcome. It is concluded that AMACR cannot serve as a prognostic marker in CRC. We hypothesize that the association of AMACR expression with tumor localization may be related to differences in the metabolism/exposure to fatty acids occurring along the colon.     

直肠癌患者围术期血液流变学的变化

目的：探讨直肠癌患者麻醉手术期间及术后早期血液流变性的变化。方法：选择ASAⅠ-Ⅱ级行直肠癌根治手术的病人共30例,年龄40-60岁,在麻醉前、麻醉后30min、术毕（麻醉苏醒时）、术后24、48、72h分别采肘静脉血,检测Hηb、Lηb、ESR、Hct、EAI、EDI、ERI等。结果：与麻醉前比较,麻醉期间Hηb、Lηb、ηr、ηp、Hct、ESR、EAI、ERI均降低,其中Hηb、Lηb、ηp、Hct、ESR与麻醉前比较明显降低（P〈0．05或P〈0．01）;术后早期各血液流变学指标逐渐升高：（1）Hηb、Lηb、ηr、ηp、ESR、EAI至术后72h时超出正常值范围;（2）EDI在术后24h-72h明显降低（P〈0．05）。结论：（1）直肠癌患者患者在麻醉手术前存在明显的血液流变性变化,表现为血液粘滞性增高;（2）麻醉手术期间血液流变性指标降低,血液粘度降低;（3）术后早期患者全血还原粘度、红细胞聚集指数、全血粘度等血液流变学指标逐渐升高,红细胞变形指数明显降低,对保持微循环灌注和避免术后早期血栓形成十分不利。     

武汉地区1998例结直肠癌临床病理特征分析

目的分析武汉地区结直肠癌的临床病理特征及发病特点。方法回顾性分析1998年至2013年在武汉市第八医院收治的1 998例结直肠癌临床及病理资料,比较其主要症状、性别、年龄、肿瘤部位、组织类型、病理分级及临床病理分期的差异。结果本组最常见症状为血便及大便次数增多,好发部位主要位于直肠,组织学类型以管状腺癌腺癌为主,淋巴结转移与肿瘤的分化程度、侵袭程度及TNM分期有关。结论武汉地区男性结直肠癌的发病率显著高于女性,老年人仍是结直肠癌的高发人群,但青壮年也占相当大的比例。大部分患者就诊时已是中晚期。     

Polymorphisms in the DUSP10 gene are associated with sex-specific colorectal cancer risk in a Han population

Aims and background: Colorectal cancer (CRC) is common, especially in developed countries. CRC is a multifactorial disease influenced by both environmental and genetic factors. In this study, we investigated the role of genetic polymorphisms in the dual specificity protein phosphatase 10 (DUSP10) gene especially in sex-specific. Methods: We selected nine DUSP10 tag single nucleotide polymorphisms (tSNPs) previously reported to be associated with colorectal cancer risk of in a case-control study from Xi’an city of China. Results: In females, three SNPs were associated with decreased CRC risk: rs11118838, rs12724393, and rs908858. However, in males, only one SNP, rs908858, was associated with decreased CRC risk. Using a log-additive model, the rs11118838 “C” allele and the rs12724393 “G” allele were associated with decreased CRC risk in females, while the rs908858 “G” allele was associated with decreased CRC risk in both females and males. In addition, haplotype analysis also found “CG” and “CCT” were associated with the decreased CRC risk in females. Conclusions: Our findings suggest that DUSP10 polymorphisms influence the risk of developing CRC in Han Chinese and emphasize that sex should be considered in the design and analysis of health studies and biomedical research.     

NGS-based oncogenic mutations analysis in advanced colorectal cancer patients improves targeted therapy prediction

Background

Characterization of genetic alterations has been revealed to be important to predict the outcomes of targeted therapy in cancer. We here aimed to assess the mutation profiling of 526 colorectal cancer (CRC) patients by next-generation sequencing (NGS) to enable a more personalized anti-EGFR treatment.

结直肠腺瘤和结直肠癌患者外周血Tc17和 Treg 细胞的变化

目的检测结直肠腺瘤和结直肠癌患者外周血中Tc17与Treg细胞比例的变化,并分析二者相关性。方法流式细胞术检测30例结直肠腺瘤、33例结直肠腺癌患者和20例健康对照者外周血中Tc17和Treg细胞比例;ELISA检测其血清中IL-17A和IL-23水平。结果结直肠腺瘤和结直肠癌患者外周血中Tc17和Treg 细胞比例及细胞因子IL-17 A和IL-23水平均高于对照组（ P＜0．05）。结直肠癌组Tc17细胞比例及细胞因子IL-17A和IL-23水平均高于结直肠腺瘤组（P＜0．05）,而Treg细胞比例在两组间并无统计学意义（ P＞0．05）。基于疾病进展,结直肠腺瘤Ⅰ级和早期结直肠癌组Tc17细胞比例及细胞因子IL-17A和IL-23水平分别高于相应的结直肠腺瘤Ⅱ级和晚期结直肠癌组（P＜0．05）,Treg 细胞比例变化与 Tc17细胞变化相反,但二者无相关性（r ＝-0．227, P＝0．073）。结论结直肠腺瘤和结直肠癌患者外周血Tc17和Treg细胞比例随着疾病进展呈相反的变化趋势,但二者并不存在相关性。     

Tumor-infiltrating lymphocytes and dendritic cells in human colorectal cancer: their relationship to KRAS mutational status and disease recurrence

The prognosis of newly diagnosed colorectal cancer patients relies mostly on tumor-node metastasis classification. However, analyses of tumor-infiltrating lymphocytes and several molecular markers have also shown promising prognostic value. Mutations in the proto-oncogene KRAS, which occur early in colorectal carcinogenesis, have been demonstrated to be common in human colorectal cancer (CRC); however, their prognostic significance remains controversial. We examined the correlations between KRAS mutational status and tumor-infiltrating immune cells with respect to CRC recurrence. Mutations in KRAS were identified in 45.5% of the primary carcinomas in our cohort of patients: 65% in codon 12 and 35% in codon 13. Although codon 13 KRAS mutations were associated with disease relapse, they were present in both disease-free and relapsed patients. However, disease-free and relapsed patients differed markedly in their patterns of tumor-infiltrating immune cells. There was a trend toward decreased density of tumor-infiltrating lymphocytes (TILs) within the group of relapsed cases. In addition, relapsed patients with codon 13 mutations had markedly lower levels of tumor-infiltrating mature DC-LAMP(+) dendritic cells (DCs) and higher frequency of CD1a(+) cells compared with disease-free patients. Our data suggest that CRC patients with low levels of TILs, a high CD1a(+)/DC-LAMP(+) tumor-infiltrating DC ratio, and a KRAS mutation in codon 13 are at a high risk of disease recurrence.     

结直肠癌患者8号染色体微卫星改变的研究

目的研究结直肠癌(colorectal cancer,CRC)患者8号染色体微卫星改变的情况,探讨结直肠癌发病的分子机制.方法应用聚合酶链反应(polymerase chain reaction,PCR)、聚丙烯酰胺凝胶电泳及银染色方法,选取8号染色体上4个微卫星住点,对34例结直肠癌患者的癌组织、癌旁组织及其相应正常组织的微卫星改变情况进行检测分析.结果①34例患者中有14例至少在一个位点发生微卫星改变,总检出率为41.18%,其中D8S135、D8S255、20.59%、17.65%及11.76%.癌旁组织中未检测到微卫星改变.②发生两个以上位点改变的10例,在有微卫星改变的患者中占71.42%.结论在8号染色体所选位点上存在较高频率的微卫星改变,提示可能存在与结直肠癌发病密切相关的基因,为结直肠癌的早期诊断提供了一个有意义检测指标.