Serum-plasma matched metabolomics for comprehensive characterization of benign thyroid nodule and papillary thyroid carcinoma.

Metabolomics offers a noninvasive methodology to identify metabolic markers for pathogenesis and diagnosis of diseases. This work aimed to characterize circulating metabolic signatures of benign thyroid nodule (BTN) and papillary thyroid carcinoma (PTC) via serum-plasma matched metabolomics. A cohort of 1,540 serum-plasma matched samples and 114 tissues were obtained from healthy volunteers, BTN and PTC patients enrolled from 6 independent centers. Untargeted metabolomics was determined by liquid chromatography-quadrupole time-of-flight mass spectrometric and multivariate statistical analyses. The use of serum-plasma matched samples afforded a broad-scope detection of 1,570 metabolic features. Metabolic phenotypes revealed significant pattern differences for healthy versus BTN and healthy versus PTC. Perturbed metabolic pathways related mainly to amino acid and lipid metabolism. It is worth noting that, BTN and PTC showed no significant differences but rather overlap in circulating metabolic signatures, and this observation was replicated in all study centers. For differential diagnosis of healthy versus thyroid nodules (BTN + PTC), a panel of 6 metabolic markers, namely myo-inositol, α-N-phenylacetyl-L-glutamine, proline betaine, L-glutamic acid, LysoPC(18:0) and LysoPC(18:1) provided area under the curve of 97.68% in the discovery phase and predictive accuracies of 84.78-98.18% in the 4 validation centers. Taken together, serum-plasma matched metabolomics showed significant differences in circulating metabolites for healthy versus nodules but not for BTN versus PTC. Our results highlight the true metabolic nature of thyroid nodules, and potentially decrease overtreatment that exposes patients to unnecessary risks.

Erbin interacts with c-Cbl and promotes tumourigenesis and tumour growth in colorectal cancer by preventing c-Cbl-mediated ubiquitination and down-regulation of EGFR.

The epidermal growth factor receptor (EGFR) is implicated in many types of cancer, including colorectal cancer (CRC), and has become one of the most common candidates for targeted therapy. Here, we found that Erbin, a member of the leucine-rich repeat and PDZ domain (LAP) family, plays a key role in EGFR signalling. Erbin inhibited EGFR ubiquitination and stabilized the EGFR protein by interacting with c-Cbl. Moreover, the PDZ domain of Erbin was critical for the interaction between Erbin and c-Cbl and EGFR ubiquitination. Interestingly, Erbin expression was elevated in tumour samples from CRC patients, increased in advanced clinical stage disease and correlated with EGFR expression. In vivo studies using mouse xenograft models of CRC showed that Erbin promotes tumour growth, and that the effects of Erbin on tumour growth are mainly related to the regulatory effects of Erbin on EGFR. The azoxymethane (AOM)-induced colon carcinogenesis model in Erbin(ΔC) (/) (ΔC) mice, with the PDZ domain of Erbin deleted, demonstrated that the PDZ domain of Erbin and its regulation of EGFR signalling are necessary for the tumourigenesis and tumour growth of CRC. We found that Erbin promotes tumourigenesis and tumour growth in CRC by stabilizing EGFR. Our study sheds light on developing Erbin, especially its PDZ domain, as a potential target for CRC treatment.

Waist-to-Height Ratio: a simple, effective and practical screening tool for childhood obesity and metabolic syndrome.

OBJECTIVE: This study aimed to evaluate the diagnostic value of Waist-to-Height Ratio in early detection of obesity and metabolic syndrome in Chinese children and adolescents. METHOD: A cross-sectional study was conducted in six cities in China in 2010 with 16,914 children and adolescents aged 7-17 years. Participants were randomly divided into the training and testing sets. Diagnostic values were estimated using sensitivity, specificity and areas under receiver operating characteristic curves. RESULTS: The coefficients of variation of Waist-to-Height Ratio among age groups were lower than that of body mass index and waist circumstance. The area under receiver operating characteristic curve of Waist-to-Height Ratio was 0.968 in boys and 0.949 in girls for general obesity evaluation, and 0.983 in boys and 0.984 in girls for central obesity. The optimal cut-offs of Waist-to-Height Ratio were 0.47 in boys and 0.45 in girls in the training set and validated in the testing set. For metabolic syndrome evaluation, the sensitivity and specificity were 0.858 and 0.825 in boys, 0.864 and 0.812 in girls under the suggested cut-offs. CONCLUSION: Waist-to-Height Ratio was a simple, effective and practical tool for mass screening childhood obesity and metabolic syndrome in China. It will have potential values in public health practice.

Overexpression of MMP-1 and VEGF-C is associated with a less favorable prognosis in esophageal squamous cell carcinoma.

BACKGROUND: This study addresses the association of matrix metalloproteinase-1 (MMP-1) and vascular endothelial growth factor-C (VEGF-C) expression in esophageal squamous cell carcinoma (SCC) with clinicopathologic characteristics in the patients. MATERIAL AND METHODS: We profiled the expression of MMP-1 and VEGF-C by cDNA microarray in 4 cases and by reverse transcription-polymerase chain reaction (RT-PCR) in 14 cases of esophageal SCC. Another 90 cases were reviewed by immunohistochemical examination of paraffin-embedded sections. RESULTS: Expression of MMP-1 and VEGF-C mRNA in normal esophageal tissue and tumor tissue was compared. Data were fully consistent with the results of RT-PCR. Immunohistochemistry showed that compared to the normal mucosa MMP-1 and VEGF-C protein expression was upregulated in both esophageal atypical hyperplasia (n = 16) and esophageal SCC. Depth of tumor invasion, lymph node metastasis, and clinical stage were directly associated with prognosis in all cases. Furthermore, median overall survival and disease-free survival were significantly shorter in patients with a higher expression of MMP-1 and VEGF-C than in patients with lower expression levels. CONCLUSION: We demonstrated that the expression of both MMP-1 and VEGF-C mRNA and protein was upregulated in esophageal SCC tissues. Protein expression was associated with progressive tumor stage and poor prognosis in patients with esophageal SCC.

[Optimization of genomic DNA extraction with magnetic bead- based semi-automatic system].

OBJECTIVE: To develop a rapid and effective method for genomic DNA extraction with magnetic bead-based semi-automatic system. METHODS: DNA was extracted from whole blood samples semi-automatically with nucleic acid automatic extraction system.The concentration and purity of samples was determined by UV-spectrophotometer. Orthogonal design was used to analyze the main effect of lysis time, blood volume, magnetic bead quantity and ethanol concentration on the DNA yield; also the 2-way interaction of these factors. RESULTS: Lysis time, blood volume, magnetic bead quantity and ethanol concentration were associated with DNA yield (P<0.05), but no interaction existed. DNA yield was higher under the condition with 15 min of lysis time, 100 µl of blood volume, 80 µl of magnetic beads and 80 % of ethanol. A significant association was found between the magnetic bead quantity and DNA purity OD260/OD280 (P=0.008). Interaction of blood volume and lysis time also existed (P=0.013). DNA purity was better when the extracting condition was 40 µl of magnetic beads, 15 min of lysis time and 100 µl of blood volume. Magnetic beads and ethanol concentration were associated with DNA purity OD260/OD230 (P=0.017 and P<0.05), the result was better when magnetic beads was 40 µl and ethanol concentration was 80 %. CONCLUSION: The results indicate that the optimized conditions with 40 µl magnetic beads will generate higher quality of genomic DNA from the whole blood samples.

Colorectal cancer, one entity or three.

Understanding of the mechanism of colorectal carcinogenesis has been gaining momentum for some years on account of its high incidence and impact on the lives of individuals affected. Different genetic abnormalities have been found in colorectal cancers from different sites. For example, proximal colon cancer is usually related to the nucleotide instability pathway, as microsatellite instability (MSI). However, distal colon cancer is usually associated with specific chromosomal instability (CIN). The development of cancer at the rectum, though similar to that at the colon, displays its own unique features. These differences might be partially attributed to different embryological development and physiological circumstances. Environmental factors such as diet and alcohol intake also differ in their role in the development of tumors in the three segments, proximal colon, distal colon, and rectum. "Proximal shift" of colon cancer has been known for some time, and survival rates of colorectal cancer are higher when rectal cancers are excluded, both of which emphasize the three different segments of colorectal cancer and their different properties. Meanwhile, colonic and rectal cancers are distinctive therapeutic entities. The concept of three entities of colorectal cancer may be important in designing clinical trails or therapeutic strategies. However, the dispute about the inconsistency of data concerning the site-specific mechanism of colorectal carcinoma does exist, and more evidence about molecular events of carcinogenesis and targeted therapy needs to be collected to definitely confirm the conception.

[Use of Apc(Min/+) mouse model in the studies of intestinal tumors].

More than thirty kinds of mutant or knockout mice bearing intestinal neoplasm have been reported up to the present. Apc(Min/+) mouse holding multiple intestinal neoplasia, provides an appropriate model to evaluate human familial adenomatous polyposis. APC is an important tumor-suppressor gene in the Wnt pathway, which is involved in the pivotal signal transduction cascade in animal embryogenesis and colorectal carcinogenesis. Apc(Min/+) mouse model was presented as aspects of the strain background, genotype/phenotype, divergent canonical Wnt signaling pathway, methylation of tumor-suppressor gene, TGF-b signaling pathway and multidrug resistance gene, etc. This review also introduced the application and signification of the mouse model in studies of anti-colorectal tumor drugs.

[Exploration of carcinogenesis based on tree models using CGH data].

Comparative genomic hybridization (CGH) can detect chromosomal deletions and amplifications of tumors, and various laboratories and public databases have accumulated a large number of CGH data, providing the opportunity to analyze the molecular mechanism of tumorigenesis in the whole genome. Tree models are generally used to study the history of biological formation and evolution in the field of bioinformatics, and evolutionary relationships between species are usually represented using phylogenetic tree. Tree models are also powerful bioinformatics tools to analyze CGH data and explore carcinogenesis. Two common tree models, the branching tree and the distanced-based tree, as well as their basic principles, methods are introduced detailedly, several technical problems in construction of tree models are discussed, and their applications in cancer research are reviewed systematically in this paper. As a generalization of single path linear model, tree models can more accurately conclude multigene, multistep, multipathway process of tumorigenesis, exploring the molecular mechanism of tumorigenesis from different angels. Apart from CGH data, tree models can be used to analyze various types of data, including high-resolution data (e.g., array-CGH data).

[Hypomethylation of 5'CpG island of insulin-like growth factor binding protein-related protein 1 is associated with its overexpression in colorectal cancer].

OBJECTIVE: To investigate the methylation status of 5'CpG island of insulin-like growth factor binding protein-related protein 1 (IGFBP-rP1) in colorectal cancer and its relationship with gene expression and clinicopathologic parameters. METHODS: Semi-quantitative reverse transcription-PCR (RT-PCR) was used to detect the expression of IGFBP-rP1 in 46 cases of colorectal cancer and their matched normal mucosa. Methylation-specific PCR (MSP) was applied to evaluate the methylation status of 5'CpG island of IGFBP-rP1. Colon cancer cell lines LoVo and SW620 were treated with demethylation agent 5-aza-2'-deoxycytidine (5-aza-dC), followed by RT-PCR and MSP detection. RESULTS: At the mRNA level, the expression of IGFBP-rP1 was higher in colorectal cancer tissue than that in the matched normal mucosa (P < 0.05). IGFBP-rP1 was methylated in 28/46 (60.9%) cases of colorectal cancer and 37/46 (80.4%) matched normal mucosa samples (P < 0.05). A negative correlation was found between IGFBP-rP1 expression and its methylation status. The expression of IGFBP-rP1 was restored in LoVo and SW620 after treatment with 5-aza-dC and MSP confirmation of its demethylation status. No relationships was found between the methylation status and clinicopathologic parameters. CONCLUSIONS: IGFBP-rP1 expression is negatively correlated with its methylation status in colorectal cancer. DNA methylation is one of the mechanisms regulating the expression of IGFBP-rP1. Hypomethylation of IGFBP-rP1 gene with its overexpression plays an important role in the initiation and development of colorectal cancer.

[Biological effects and toxicology studies of melamine and its derivative cyanuric acid].

Melamine (Tripolycyanamide) and its derivatives have recently become a public concern on food safety. To better understand melamine and its major derivative cyanuric acid.literature on their chemical properties, metabolism, biological effects, relevant toxicology studies, and the detection methods is reviewed. Studies indicate that the acute toxicity of melamine and cyanuric acid is low. In mammalian, these compounds are hardly metabolized in vivo and are rapidly eliminated in the urine. When used in large dosage,these compounds demonstrate marked renal toxicity,as well as toxic effect towards heart. The renal toxicity is exemplified by the calculi formation, acute renal failure, and subsequently induced carcinomas of the urinary bladder. Among the tested species, male cats and rats are more prone to be affected by the compounds. The HPLC/MS/MS is becoming the mainstay of the detection methods. Despite of the achieved knowledge on melamine and cyanuric acid, further research is warranted to unveil the mechanism of underlying susceptibility of kidney, to develop better analytic methods,and to explore possible biomarkers for better clinical diagnosis.

Ribosomal proteins and colorectal cancer.

The ribosome is essential for protein synthesis. The composition and structure of ribosomes from several organisms have been determined, and it is well documented that ribosomal RNAs (rRNAs) and ribosomal proteins (RPs) constitute this important organelle. Many RPs also fill various roles that are independent of protein biosynthesis, called extraribosomal functions. These functions include DNA replication, transcription and repair, RNA splicing and modification, cell growth and proliferation, regulation of apoptosis and development, and cellular transformation. Previous investigations have revealed that RP regulation in colorectal carcinomas (CRC) differs from that found in colorectal adenoma or normal mucosa, with some RPs being up-regulated while others are down-regulated. The expression patterns of RPs are associated with the differentiation, progression or metastasis of CRC. Additionally, the recent literature has shown that the perturbation of specific RPs may promote certain genetic diseases and tumorigenesis. Because of the implications of RPs in disease, especially malignancy, our review sought to address several questions. Why do expression levels or categories of RPs differ in different diseases, most notably in CRC? Is this a cause or consequence of the diseases? What are their possible roles in the diseases? We review the known extraribosomal functions of RPs and associated changes in colorectal cancer and attempt to clarify the possible roles of RPs in colonic malignancy.

[BTEB/KLF9 and its transcriptional regulation].

BTEB/KLF9(basic transcription element-binding protein/Krüppel-like transcription factor 9), a member of Krüppel-like transcriptional factors, is a zinc finger protein involved in regulating gene transcription in eukaryocyte. Substantial expression of BTEB mRNA is detected in a variety of cell lines and tissues, but BTEB protein is not consistent with its mRNA. BTEB regulates transcription through its carboxyl-terminal C2H2 zinc finger motif binding to GC or GT/CACC box, a sort of cis-acting elements, which is wildly distributed in promoters, enhancers and control regions of many genes. BTEB/KLF9 functions as a transcription factor by direct or functional interaction with other transcription factors and/or coactivators/corepressors, and plays a role in reproductive system, cell proliferation, differentiation, and cell cycle regula-tion.

[Differential expression of secretagogin and glucose-related protein 78 in colorectal carcinoma: a proteome study].

OBJECTIVE: To identify the differentially expressed proteins or peptides and potential biomarkers of tumorigenesis for colorectal cancers. METHODS: Immobilized pH gradient two-dimensional gel electrophoresis (2-DE) was used to separate and obtain the differentially expressed protein spots between colorectal cancers and matched normal mucosa. Liquid chromatography/mass spectrometry (LC-MS/MS) was used to characterize these proteins. Selected candidate proteins were further studied by Western blot, semi-quantitative RT-PCR and immunohistochemical staining. RESULTS: Thirty-five protein spots showed marked expression changes (more than 5-fold) in colorectal carcinoma compared to normal mucosa. Fifteen proteins were up regulated and 20 were down regulated. Fourteen of these proteins were identified by tandem mass spectrometry, among which secretagogin (SCGN) was down-regulated and glucose-related protein (GRP) 78 was up-regulated in the tumors. The SCGN down-regulation was further supported by Western blot and RT-PCR analyses. Immunohistochemistry revealed that SCGN was strongly expressed in neuroendocrine cells of the colonic crypts and 53 of 54 (98%) neuroendocrine tumors. At protein level, although GRP78 was up regulated in colorectal carcinoma, there was no difference in the mRNA expression level between the tumor and paired normal mucosa. CONCLUSIONS: The 2-DE combined with MS is a powerful tool for screening potential tumor biomarkers. The differentially expressed candidate proteins identified by 2-DE may be of significance in understanding the tumorigenesis of the colon cancer. SCGN is a potential biomarker for neuroendocrinal differentiation. GRP78 up-regulation in colorectal carcinomas may be related to its post-translational modification.

[Sclerosing angiomatoid nodular transformation of spleen].

OBJECTIVE: To study the clinicopathologic features of sclerosing angiomatoid nodular transformation of spleen and its differential diagnosis. METHODS: The clinicopathologic characteristics and immunophenotype of 4 cases of sclerosing angiomatoid nodular transformation of spleen were studied. RESULTS: Histologically, all cases were characterized by multiple angiomatoid nodules of various sizes in a fibrosclerotic stroma. The nodules were round and sometimes convoluted. They were composed of slit-like, irregular-shaped or slightly dilated vascular spaces lined by plump endothelial cells and interspersed with a population of spindly or ovoid cells. Immunohistochemical study showed a heterogeneous staining pattern, with the lining cells of the small capillaries expressing CD34 and those of the sinusoid-like structures expressing CD8. CD31 highlighted both the lining cells and interspersed cells, resulting in a complex meshwork. The lining cells were also focally positive for CD68. Smooth muscle actin revealed conglomerates of spindly shaped cells around and between the vascular channels. These spindly shaped cells in the intervening stroma were focally positive for actin, but negative for desmin, CD21 and CD35. CONCLUSIONS: Sclerosing angiomatoid nodular transformation is a rarely encountered benign lesion of the spleen, which should be distinguished from other angiomatoid tumors and tumor-like lesions.

Identification of a novel VNTR polymorphism in C6orf37 and its association with colorectal cancer risk in Chinese population.

BACKGROUND: C6orf37 was a gene up-regulated in colorectal adenoma in our previous study. A variable region of C6orf37 sequence was found when we blasted its full sequence with NCBI nucleotide database. METHODS: RT-PCR and sequencing were conducted to identify the variable region of C6orf37 as VNTR. DHPLC was applied to detect the VNTR genotypes in 122 colorectal carcinoma patients and 166 healthy controls. RESULTS: A novel VNTR sequence found in C6orf37 second exon was composed of 15 base pair consensus sequence encoding 5-amino-acid (G-G-D-F-G). The repeat timePOST alleles contain three repeats (a), 4 repeats (b) and 5 repeats (c), respectively, which produced 3 homozygotes (a/a, b/b and c/c) and 3 heterozygotes (a/b, a/c and b/c). a, b, c allele frequencies were 0.145, 0.304, 0.551, respectively in Chinese population. Heterozygosity (H) was 0.583. Polymorphism information content (PIC) was 0.510. The distribution of genotypes and allele frequencies of the VNTR reached no significant difference between patients and healthy controls and there was no correlation between VNTR polymorphism and colorectal cancer clincopathological features. CONCLUSION: A novel VNTR polymorphism in C6orf37 exists in Chinese population and is not associated with colorectal cancer risk.

[The correlation between polymorphisms of matrix metalloproteinase-2 and -9 genes and colorectal cancer of Chinese patients].

OBJECTIVE: To investigate whether the polymorphisms of matrix metalloproteinase-2 (MMP-2) and -9 (MMP-9) promoters contribute to the development and progression of colorectal cancer in Chinese population. METHODS: the PCR-based denaturing high-performance liquid chromatography or PCR-restriction fragment length polymorphism technique respectively was applied to analyze the MMP-2 -1306C/T and MMP-9 -1562C/T polymorphisms in normal group (126 individuals) and colorectal cancer group (126 cases). Genotype frequencies were compared between patients and matched controls, and the association of genotypes with clinical-pathological parameters was studied. RESULTS: The frequency of the CC genotype in the MMP-2 gene polymorphism was significantly increased in colorectal cancer patients when compared with controls (P<0.05), and individuals with the CC genotype had an increased risk of developing colorectal cancer compared to those with CT+TT genotypes (OR: 1.959; 95%CI: 1.055-3.637). Significant correlation was found between the depth of tumor invasion and MMP-2 -1306C/T polymorphism in colorectal cancer patients. However, the genotype frequencies of MMP-9 -1562C/T in colorectal cancer patients were similar to those in control subjects. CONCLUSION: Our results indicate that MMP-2 -1306 C/T polymorphism may be associated with genetic susceptibility to colorectal cancer and the invasive capability of colorectal cancer in Chinese patients. And it is easier for the CC genotype cancer to invade through bowel wall.

Anticancer effects of Chinese herbal medicine, science or myth?

Currently there is considerable interest among oncologists to find anticancer drugs in Chinese herbal medicine (CHM). In the past, clinical data showed that some herbs possessed anticancer properties, but western scientists have doubted the scientific validity of CHM due to the lack of scientific evidence from their perspective. Recently there have been encouraging results, from a western perspective, in the cancer research field regarding the anticancer effects of CHM. Experiments showed that CHM played its anticancer role by inducing apoptosis and differentiation, enhancing the immune system, inhibiting angiogenesis, reversing multidrug resistance (MDR), etc. Clinical trials demonstrated that CHM could improve survival, increase tumor response, improve quality of life, or reduce chemotherapy toxicity, although much remained to be determined regarding the objective effects of CHM in human in the context of clinical trials. Interestingly, both laboratory experiments and clinical trials have demonstrated that when combined with chemotherapy, CHM could raise the efficacy level and lower toxic reactions. These facts raised the feasibility of the combination of herbal medicines and chemotherapy, although much remained to be investigated in this area.