RESUMO
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.
Assuntos
Biomarcadores Tumorais/sangue , Metabolômica/métodos , Câncer Papilífero da Tireoide/sangue , Neoplasias da Glândula Tireoide/sangue , Nódulo da Glândula Tireoide/sangue , Adolescente , Adulto , Idoso , Criança , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Câncer Papilífero da Tireoide/diagnóstico , Câncer Papilífero da Tireoide/metabolismo , Neoplasias da Glândula Tireoide/diagnóstico , Neoplasias da Glândula Tireoide/metabolismo , Nódulo da Glândula Tireoide/diagnóstico , Nódulo da Glândula Tireoide/metabolismo , Adulto JovemRESUMO
BACKGROUND: Pathogenesis and diagnostic biomarkers for diseases can be discovered by metabolomic profiling of human fluids. If the various types of coronary artery disease (CAD) can be accurately characterized by metabolomics, effective treatment may be targeted without using unnecessary therapies and resources. OBJECTIVES: The authors studied disturbed metabolic pathways to assess the diagnostic value of metabolomics-based biomarkers in different types of CAD. METHODS: A cohort of 2,324 patients from 4 independent centers was studied. Patients underwent coronary angiography for suspected CAD. Groups were divided as follows: normal coronary artery (NCA), nonobstructive coronary atherosclerosis (NOCA), stable angina (SA), unstable angina (UA), and acute myocardial infarction (AMI). Plasma metabolomic profiles were determined by liquid chromatography-quadrupole time-of-flight mass spectrometry and were analyzed by multivariate statistics. RESULTS: We made 12 cross-comparisons to and within CAD to characterize metabolic disturbances. We focused on comparisons of NOCA versus NCA, SA versus NOCA, UA versus SA, and AMI versus UA. Other comparisons were made, including SA versus NCA, UA versus NCA, AMI versus NCA, UA versus NOCA, AMI versus NOCA, AMI versus SA, significant CAD (SA/UA/AMI) versus nonsignificant CAD (NCA/NOCA), and acute coronary syndrome (UA/AMI) versus SA. A total of 89 differential metabolites were identified. The altered metabolic pathways included reduced phospholipid catabolism, increased amino acid metabolism, increased short-chain acylcarnitines, decrease in tricarboxylic acid cycle, and less biosynthesis of primary bile acid. For differential diagnosis, 12 panels of specific metabolomics-based biomarkers provided areas under the curve of 0.938 to 0.996 in the discovery phase (n = 1,086), predictive values of 89.2% to 96.0% in the test phase (n = 933), and 85.3% to 96.4% in the 3-center external sets (n = 305). CONCLUSIONS: Plasma metabolomics are powerful for characterizing metabolic disturbances. Differences in small-molecule metabolites may reflect underlying CAD and serve as biomarkers for CAD progression.
Assuntos
Doença da Artéria Coronariana/diagnóstico , Doença da Artéria Coronariana/metabolismo , Metabolômica , Idoso , Doença da Artéria Coronariana/classificação , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: Aberrant expression of ten-eleven translocation 1 (TET1) plays a critical role in tumor development and progression. We systematically summarized the latest research progress on the role and mechanisms of TET1 in cancer biology. DATA SOURCES: Relevant articles published in English from 1980 to April 2016 were selected from the PubMed database. The terms "ten-eleven translocation 1," "5mC," "5hmC," "microRNA," "hypoxia," and "embryonic stem cell" were used for the search. STUDY SELECTION: Articles focusing on the role and mechanism of TET1 in tumor were reviewed, including clinical and basic research articles. RESULTS: TET proteins, the key enzymes converting 5-methylcytosine to 5-hydroxymethylcytosine, play vital roles in DNA demethylation regulation. Recent studies have shown that loss of TET1 is associated with tumorigenesis and can be used as a potential biomarker for cancer therapy, which indicates that TET1 serves as tumor suppressor gene. Moreover, besides its dioxygenase activity, TET1 could induce epithelial-mesenchymal transition and act as a coactivator to regulate gene transcription, such as developmental regulator in embryonic stem cells (ESCs) and hypoxia-responsive gene in cancer. The regulation of TET1 is also correlated with microRNA in a posttranscriptional modification process. Hence, it is complex but critical to comprehend the mechanisms of TET1 in the biology of ESCs and cancer. CONCLUSIONS: TET1 not only serves as a demethylation enzyme but also plays multiple roles during tumorigenesis and progression. More studies should be carried out to elucidate the exact mechanisms of TET1 and its associations with cancer before considering it as a therapeutic tool.
Assuntos
Carcinogênese/metabolismo , Oxigenases de Função Mista/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Animais , Biomarcadores/metabolismo , Carcinogênese/genética , Carcinogênese/patologia , Humanos , MicroRNAs/genética , Oxigenases de Função Mista/genética , Proteínas Proto-Oncogênicas/genéticaRESUMO
We investigated the influence of gut microbiotal metabolism on the pharmacokinetics of berberine in healthy male Africans and Chinese. The Cmax and AUC in the Africans were 2.67-fold and 2.0-fold higher than the Chinese, respectively. Microbiotal compositions by 16S rRNA pyrosequencing showed higher abundance of the genera Prevotella, Bacteroides, and Megamonas (34.22, 13.88, and 10.68%, respectively) in the Chinese than the Africans (30.08, 9.43, and 0.48%, respectively). Scatter plot showed a strong negative correlation between the microbiotal abundance and the berberine AUC, especially for the genus Prevotella (r = -0.813) and its species. A more extensive metabolism was observed in Chinese with 1.83-fold higher metabolites, possibly contributing to the lower AUC than the Africans. In conclusion, significant PK differences of berberine were observed between Africans and Chinese, which is partly attributable to variations in gut microbiota and its corresponding metabolic capacity.
Assuntos
Berberina/sangue , Microbioma Gastrointestinal , Adulto , Povo Asiático , População Negra , Humanos , MasculinoRESUMO
PURPOSE: This work aims to identify differential metabolites and predicting molecular subtypes of breast cancer (BC). METHODS: Plasma samples were collected from 96 BC patients and 79 normal participants. Metabolic profiles were determined by liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry based on multivariate statistical data analysis. RESULTS: We observed 64 differential metabolites between BC and normal group. Compared to human epidermal growth factor receptor 2 (HER2)-negative patients, HER2-positive group showed elevated aerobic glycolysis, gluconeogenesis, and increased fatty acid biosynthesis with reduced Krebs cycle. Compared with estrogen receptor (ER)-negative group, ER-positive patients showed elevated alanine, aspartate and glutamate metabolism, decreased glycerolipid catabolism, and enhanced purine metabolism. A panel of 8 differential metabolites, including carnitine, lysophosphatidylcholine (20:4), proline, alanine, lysophosphatidylcholine (16:1), glycochenodeoxycholic acid, valine, and 2-octenedioic acid, was identified for the classification of BC subtypes. These markers showed potential diagnostic value with average area under the curve at 0.925 (95% CI 0.867-0.983) for the training set (n=51) and 0.893 (95% CI 0.847-0.939) for the test set (n=45). CONCLUSION: Human plasma metabolomics is useful in identifying differential metabolites and predicting breast cancer subtypes.
Assuntos
Neoplasias da Mama/sangue , Metaboloma , Metabolômica/métodos , Adulto , Idoso , Idoso de 80 Anos ou mais , Biomarcadores Tumorais/sangue , Biomarcadores Tumorais/metabolismo , Neoplasias da Mama/classificação , Neoplasias da Mama/metabolismo , Cromatografia Líquida , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Espectrometria de Massas , Pessoa de Meia-Idade , Análise Multivariada , Prognóstico , Receptor ErbB-2/metabolismo , Receptores de Estrogênio/metabolismoRESUMO
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.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Proteínas de Transporte/metabolismo , Transformação Celular Neoplásica/metabolismo , Neoplasias Colorretais/metabolismo , Receptores ErbB/metabolismo , Proteínas Proto-Oncogênicas c-cbl/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/genética , Animais , Proteínas de Transporte/genética , Transformação Celular Neoplásica/genética , Neoplasias Colorretais/genética , Progressão da Doença , Regulação para Baixo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , UbiquitinaçãoRESUMO
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.
Assuntos
Programas de Rastreamento/métodos , Síndrome Metabólica/diagnóstico , Obesidade Infantil/diagnóstico , Razão Cintura-Estatura , Adolescente , Criança , China , Estudos Transversais , Feminino , Humanos , Masculino , Obesidade Abdominal/diagnóstico , Curva ROC , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Colorectal cancer (CRC) is steadily increasing in China. Colorectal adenoma (CRA) is the most important precancerous disease of CRC. Screening for colorectal tumors can aid early diagnosis. Advances in endoscopic mucosal resection and endoscopic submucosal dissection can aid the early treatment of colorectal tumors. Furthermore, because of high risk of recurrence after removal of adenomas under endoscopy, factors contributing to recurrence, the follow-up mode and the interval established, and the feasibility of application and the time of various chemical preventions should be concerned. However, a relevant consensus on the screening, early diagnosis and treatment, and prevention of colorectal tumors in China is lacking. SUMMARY: The consensus recommendations include epidemiology, pathology, screening, early diagnosis, endoscopic treatment, monitoring and follow-up, and chemoprevention of colorectal tumors in China. KEY MESSAGE: This is the first consensus on the prevention, screening, early diagnosis and treatment of CRA and CRC in China based on evidence in the literature and on local data. PRACTICAL IMPLICATIONS: Through reviewing the literature, regional data and passing the consensus by an anonymous vote, gastroenterology experts from all over China launch the consensus recommendations in Shanghai. The incidence and mortality of CRC in China has increased, and the incidence or detection rate of CRA has increased rapidly. Screening for colorectal tumors should be performed at age 50-74 years. Preliminary screening should be undertaken to find persons at high risk, followed by colonoscopy. A screening cycle of 3 years is recommended for persistent interventions. Opportunistic screening is a mode suitable for the current healthcare system and national situation. Colonoscopy combined with pathological examination is the standard method for the diagnosis of colorectal tumors. CRA removal under endoscopy can prevent CRC to some extent, but CRA has an obvious recurrence trend. The follow-up interval after the removal or surgery of colorectal tumors should be different with lesions. Primary prevention of CRA includes improved diet with more fiber, supplements containing calcium and vitamin D, supplements containing folic acid for those with low hemoglobin levels, and cessation of tobacco smoking. Non-steroidal anti-inflammatory drugs and selective cyclooxygenase-2 inhibitors have been recognized to prevent recurrence after adenoma removal.
Assuntos
Neoplasias Colorretais/diagnóstico , Difosfatos/metabolismo , Glioma/diagnóstico , Transtornos Mieloproliferativos/diagnóstico , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA/métodos , Trifosfato de Adenosina/metabolismo , Neoplasias Colorretais/genética , Metilação de DNA , Glioma/genética , Humanos , Isocitrato Desidrogenase/genética , Janus Quinase 2/genética , Mutação , Transtornos Mieloproliferativos/genética , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas p21(ras) , Moldes Genéticos , Proteínas ras/genéticaAssuntos
Apoptose , Autofagia , Neoplasias/patologia , Animais , Antineoplásicos/uso terapêutico , Proteínas Reguladoras de Apoptose/metabolismo , Autofagia/fisiologia , Proteína Beclina-1 , Humanos , Proteínas de Membrana/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Transdução de Sinais , Serina-Treonina Quinases TOR/metabolismo , Proteína Supressora de Tumor p53/metabolismoRESUMO
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.
Assuntos
Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/metabolismo , Carcinoma de Células Escamosas/mortalidade , Neoplasias Esofágicas/metabolismo , Neoplasias Esofágicas/mortalidade , Metaloproteinase 1 da Matriz/análise , Fator C de Crescimento do Endotélio Vascular/análise , Carcinoma de Células Escamosas/diagnóstico , China/epidemiologia , Neoplasias Esofágicas/diagnóstico , Feminino , Humanos , Incidência , Masculino , Prognóstico , Medição de Risco , Análise de Sobrevida , Taxa de Sobrevida , Regulação para CimaAssuntos
Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/genética , Polimorfismo Genético , Neoplasias da Mama/genética , Neoplasias da Mama/metabolismo , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Neoplasias Colorretais/genética , Neoplasias Colorretais/metabolismo , Neoplasias do Endométrio/genética , Neoplasias do Endométrio/metabolismo , Feminino , Frequência do Gene , Predisposição Genética para Doença , Neoplasias de Cabeça e Pescoço/genética , Neoplasias de Cabeça e Pescoço/metabolismo , Humanos , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Proteína 5 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Proteínas de Ligação a Fator de Crescimento Semelhante a Insulina/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Masculino , Neoplasias Ovarianas/genética , Neoplasias Ovarianas/metabolismo , Regiões Promotoras Genéticas , Neoplasias da Próstata/genética , Neoplasias da Próstata/metabolismoRESUMO
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.
Assuntos
DNA/isolamento & purificação , Separação Imunomagnética/métodos , Análise de Variância , DNA/sangue , HumanosAssuntos
Carcinoma Papilar/patologia , Neoplasias Colorretais/patologia , Neoplasias Gastrointestinais/patologia , Tumores Neuroendócrinos/classificação , Lesões Pré-Cancerosas/patologia , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Humanizados , Antineoplásicos/uso terapêutico , Caderinas/genética , Caderinas/metabolismo , Cetuximab , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/genética , Consenso , Dissidências e Disputas , Sistemas de Liberação de Medicamentos , Transição Epitelial-Mesenquimal , Neoplasias Gastrointestinais/classificação , Genes ras , Humanos , Mutação , Invasividade Neoplásica , Síndromes Neoplásicas Hereditárias/genética , Síndromes Neoplásicas Hereditárias/metabolismo , Síndromes Neoplásicas Hereditárias/patologia , Tumores Neuroendócrinos/patologia , Neoplasias Gástricas/genética , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologiaAssuntos
Neoplasias do Colo/classificação , Neoplasias do Colo/patologia , Neoplasias Retais/classificação , Neoplasias Retais/patologia , Polipose Adenomatosa do Colo/genética , Polipose Adenomatosa do Colo/patologia , Neoplasias do Colo/genética , Neoplasias Colorretais Hereditárias sem Polipose/diagnóstico , Neoplasias Colorretais Hereditárias sem Polipose/genética , DNA Glicosilases/metabolismo , Humanos , Pólipos Intestinais/patologia , Metástase Linfática , Estadiamento de Neoplasias , Tumores Neuroendócrinos/classificação , Tumores Neuroendócrinos/patologia , Lesões Pré-Cancerosas/patologia , Neoplasias Retais/genética , Organização Mundial da SaúdeRESUMO
Regenerating gene IV (RegIV), a member of the regenerating gene family discovered in 2001, has been found to be involved in malignancy in several different organs including the stomach, colorectum, pancreas and prostate, but the overall expression profile of RegIV has not been reported. To learn more about RegIV, we evaluated its distribution by immunohistochemistry (IHC) in a total of 360 samples including 24 types of normal tissue, 40 benign and malignant lesions, and 18 neuroendocrine tumors. We found that in normal tissues, in addition to its relative specificity for the gastrointestinal tract, RegIV was detected in the adrenal gland and mammary gland. Among all the malignancies of various histological types under evaluation, RegIV was found mostly in adenocarcinomas. Studies on additional sets of colorectal tumor samples showed that RegIV expression was predominant in colorectal adenoma (87.5%) and peritumoral tissue (100%) but not in cancer tissue (30.8%). Among neuroendocrine tumors, RegIV had a relatively restricted expression to those of digestive system.
Assuntos
Adenocarcinoma/metabolismo , Biomarcadores Tumorais/metabolismo , Trato Gastrointestinal/metabolismo , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Lectinas Tipo C/biossíntese , Tumores Neuroendócrinos/metabolismo , Feminino , Perfilação da Expressão Gênica , Humanos , Imuno-Histoquímica/métodos , Lectinas Tipo C/fisiologia , Masculino , Proteínas Associadas a Pancreatite , Sensibilidade e Especificidade , Distribuição TecidualRESUMO
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.