Long non-coding RNA colon cancer-associated transcript 1-Vimentin axis promoting the migration and invasion of HeLa cells / 中华医学杂志(英文版)

BACKGROUND@#Long non-coding RNA colon cancer-associated transcript 1 (CCAT1) is involved in transforming multiple cancers into malignant cancer types. Previous studies underlining the mechanisms of the functions of CCAT1 primarily focused on its decoy for miRNAs (micro RNAs). However, the regulatory mechanism of CCAT1-protein interaction associated with tumor metastasis is still largely unknown. The present study aimed to identify proteome-wide CCAT1 partners and explored the CCAT1-protein interaction mediated tumor metastasis.@*METHODS@#CCAT1-proteins complexes were purified and identified using RNA antisense purification coupled with the mass spectrometry (RAP-MS) method. The database for annotation, visualization, and integrated discovery and database for eukaryotic RNA binding proteins (EuRBPDB) websites were used to bioinformatic analyzing CCAT1 binding proteins. RNA pull-down and RNA immunoprecipitation were used to validate CCAT1-Vimentin interaction. Transwell assay was used to evaluate the migration and invasion abilities of HeLa cells.@*RESULTS@#RAP-MS method worked well by culturing cells with nucleoside analog 4-thiouridine, and cross-linking was performed using 365 nm wavelength ultraviolet. There were 631 proteins identified, out of which about 60% were RNA binding proteins recorded by the EuRBPDB database. Vimentin was one of the CCAT1 binding proteins and participated in the tumor metastasis pathway. Knocked down vimetin ( VIM ) and rescued the downregulation by overexpressing CCAT1 demonstrated that CCAT1 could enhance tumor migration and invasion abilities by stabilizing Vimentin protein.@*CONCLUSION@#CCAT1 may bind with and stabilize Vimentin protein, thus enhancing cancer cell migration and invasion abilities.

Identification of immune-related prognostic signature for colon adenocarcinoma based on weighted gene co-expression network analysis / 细胞与分子免疫学杂志

Objective To identify immune-related molecular markers in an attempt to predict prognosis of colon adenocarcinoma (COAD). Methods Immune related genes (IREGs) was analyzed based on the TCGA database. Weighted gene co-expression network analysis (WGCNA) and Cox regression analysis were used to establish risk models. According to the median risk score, COAD patients were divided into high risk and low risk groups. The prognostic difference were compared between the two groups. The function of the model was validated using GEO. Results A total of 1015 IREGs was obtained. The established model consisted of three genes: RAR related orphan receptor C (RORC), leucine-rich repeat Fli-I-interacting protein 2 (LRRFIP2) and lectin galactoside-binding soluble galectin 4 (LGALS4). The high-risk group had significantly poorer prognosis than low-risk group in the GEO database, and it was validated using a GEO database. Further analysis via univariate and multivariate Cox regression analyses revealed that risk model could function as independent prognostic factor for COAD patients. Conclusion The risk model based on IREGs can predict the prognosis of patients with COAD.

Astragalus polysaccharide inhibits IDO1 expression in colon tumor microenvironment to increase intratumoral CD8~+ T cell infiltration / 中国中药杂志

This study aims to investigate the regulatory effects of Astragalus polysaccharide(APS) and APS combined with 5-fluorouracil(5-FU) on indoleamine-2,3-dioxygenase(IDO1) in the colon tumor microenvironment. Sixty Balb/c mice were randomized into a blank group, a model group, an APS group, an APS + 5-FU group, an APS + low-dose 5-FU group, and a 5-FU group. A tumor model was established by subcutaneous transplantation with CT-26 mouse colon cancer cells in other groups except the blank group. After successful modeling, each group was treated with corresponding drugs for 7 days. The general condition, body weight, and tumor volume of the mice were observed and measured daily during the treatment period. The mice were sacrificed at the end of treatment, and the tumor suppression rate and spleen index of the mice were calculated. Western blot and fluorescence quantitative PCR were employed to determine the protein and mRNA levels, respectively, of IDO1 in the tumor tissue of mice. High performance liquid chromatography was employed to measure the levels of tryptophan(Trp) and kynurenine(Kyn) in the tumor tissue of mice. Hematoxylin-eosin(HE) staining was performed to observe the histological changes of the tumor tissue, and immunohistochemistry to detect the changes of CD4 and CD8 expression in the tumor tissue. Compared with that in the model group, the tumor volume of mice in each treatment group significantly reduced. The body weights of mice in APS + 5-FU group and 5-FU group significantly reduced from day 4 to day 7 of treatment. In addition, the APS + 5-FU group and 5-FU group showed significantly decreased spleen index. The protein and mRNA levels of IDO1 were significantly down-regulated in the APS, APS + 5-FU, and APS + low-dose 5-FU groups. The drug interventions significantly increased the Trp content and decreased the Kyn content. The APS + 5-FU group showed significantly reduced infiltration of CD4~+ T lymphocytes and increased infiltration of CD8~+ T lymphocytes. APS inhibited the expression of IDO1 in the colon tumor microenvironment to increase CD8~+ T lymphocyte infiltration, and the combination of APS with 5-FU demonstrated better effect.

Anemoside B4 regulates fatty acid metabolism reprogramming in mice with colitis-associated cancer / 中国中药杂志

The study aimed to investigate the effect of anemoside B4(B4) on fatty acid metabolism in mice with colitis-associated cancer(CAC). The CAC model was established by azoxymethane(AOM)/dextran sodium sulfate(DSS) in mice. Mice were randomly divided into a normal group, a model group, and low-, medium-, and high-dose anemoside B4 groups. After the experiment, the length of the mouse colon and the size of the tumor were measured, and the pathological alterations in the mouse colon were observed using hematoxylin-eosin(HE) staining. The slices of the colon tumor were obtained for spatial metabolome analysis to analyze the distribution of fatty acid metabolism-related substances in the tumor. The mRNA levels of SREBP-1, FAS, ACCα, SCD-1, PPARα, ACOX, UCP-2, and CPT-1 were determined by real-time quantitative PCR(RT-qPCR). The results revealed that the model group showed decreased body weight(P<0.05) and colon length(P<0.001), increased number of tumors, and increased pathological score(P<0.01). Spatial metabolome analysis revealed that the content of fatty acids and their derivatives, carnitine, and phospholipid in the colon tumor was increased. RT-qPCR results indicated that fatty acid de novo synthesis and β-oxidation-related genes, such as SREBP-1, FASN, ACCα, SCD-1, ACOX, UCP-2, and CPT-1 mRNA expression levels increased considerably(P<0.05, P<0.001). After anemoside B4 administration, the colon length increased(P<0.01), and the number of tumors decreased in the high-dose anemoside B4 group(P<0.05). Additionally, spatial metabolome analysis showed that anemoside B4 could decrease the content of fatty acids and their derivatives, carnitine, and phospholipids in colon tumors. Meanwhile, anemoside B4 could also down-regulate the expression of FASN, ACCα, SCD-1, PPARα, ACOX, UCP-2, and CPT-1 in the colon(P<0.05, P<0.01, P<0.001). The findings of this study show that anemoside B4 may inhibit CAC via regulating fatty acid metabolism reprogramming.

Expression of Runt-related Transcription Factor 3 in Human Colon Cancer Cell Line HCT-116 Resistant to 5-Fluorouracil and the Mechanism of Drug Resistance / 中国医学科学院学报

Objective To establish a human colon cancer cell line HCT-116/5-FU resistant to 5-fluorouracil(5-FU)and explore the relationship between runt-related transcription factor 3(RUNX3)and drug resistance of colorectal cancer.Methods The human colon cancer cell line HCT-116/5-FU with resistance to 5-FU was established by low concentration gradient increment combined with high-dose intermittent shock.CCK-8 method was used to determine the half maximal inhibitory concentration(IC

Low miR-1273a expression predicts poor prognosis of colon cancer and facilitates tumor cell proliferation, migration, and invasion

MicroRNAs (miRNAs) have been indicated to be frequently dysregulated in various cancers and promising biomarkers for colon cancer. The present study aimed to assess the prognostic significance and biological function of miR-1273a in colon cancer. The expression levels of miR-1273a was estimated using quantitative real-time polymerase chain reaction. Kaplan-Meier survival curves and Cox regression analysis were used to evaluate the prognostic value of miR-1273a in patients of colon cancer. The effects of miR-1273a on cell proliferation, migration, and invasion were investigated by cell experiments. The expression of miR-1273a was downregulated in colon cancer tissues and tumor cell lines compared with the normal controls (all P<0.001). The aberrant expression of miR-1273a was associated with vascular invasion (P=0.005), differentiation (P=0.023), lymph node metastasis (P=0.021), and TNM stage (P=0.004). The patients with low miR-1273a expression had low overall survival compared with the patients with high miR-1273a expression (log-rank P=0.002). miR-1273a was detected to be an independent prognostic biomarker for patients. Furthermore, the results of cell experiments revealed that miR-1273a downregulation promoted, while miR-1273a upregulation suppressed the cell proliferation, migration, and invasion. In conclusion, all data indicated that a downregulated expression of miR-1273a predicted poor prognosis for colon cancer and enhanced tumor cell proliferation, migration, and invasion. Thus, we suggest that methods to promote miR-1273a expression may serve as novel therapeutic strategies in colon cancer.

Independent prognostic genes and mechanism investigation for colon cancer

PROPOSE: We aimed to explore the potential molecular mechanism and independent prognostic genes for colon cancer (CC). METHODS: Microarray datasets GSE17536 and GSE39582 were downloaded from Gene Expression Omnibus. Meanwhile, the whole CC-related dataset were downloaded from The Cancer Genome Atlas (TCGA) database. Differentially expressed mRNA (DEMs) were identified between cancer tissue samples and para-carcinoma tissue samples in TCGA dataset, followed by the KEGG pathway and GO function analyses. Furthermore, the clinical prognostic analysis including overall survival (OS) and disease-free survival (DFS) were performed in all three datasets. RESULTS: A total of 633 up- and 321 down-regulated mRNAs were revealed in TCGA dataset. The up-regulated mRNAs were mainly assembled in functions including extracellular matrix and pathways including Wnt signaling. The down-regulated mRNAs were mainly assembled in functions like Digestion and pathways like Drug metabolism. Furthermore, up-regulation of UL16-binding protein 2 (ULBP2) was associated with OS in CC patients. A total of 12 DEMs including Surfactant Associated 2 (SFTA2) were potential DFS prognostic genes in CC patients. Meanwhile, the GRP and Transmembrane Protein 37 (TMEM37) were two outstanding independent DFS prognostic genes in CC. CONCLUSIONS: ULBP2 might be a potential novel OS prognostic biomarker in CC, while GRP and TMEM37 could be served as the independent DFS prognostic genes in CC. Furthermore, functions including extracellular matrix and digestion, as well as pathways including Wnt signaling and drug metabolism might play important roles in the process of CC.

Heart Rate Variability Correlates to Functional Aerobic Impairment in Hemodialysis Patients / Variabilidade RR ao Esforço Correlaciona-se com Déficit Funcional Aeróbico em Pacientes em Hemodiálise

Background: Autonomic dysfunction (AD) is highly prevalent in hemodialysis (HD) patients and has been implicated in their increased risk of cardiovascular mortality. Objective: To correlate heart rate variability (HRV) during exercise treadmill test (ETT) with the values obtained when measuring functional aerobic impairment (FAI) in HD patients and controls. Methods: Cross-sectional study involving HD patients and a control group. Clinical examination, blood sampling, transthoracic echocardiogram, 24-hour Holter, and ETT were performed. A symptom-limited ramp treadmill protocol with active recovery was employed. Heart rate variability was evaluated in time domain at exercise and recovery periods. Results: Forty-one HD patients and 41 controls concluded the study. HD patients had higher FAI and lower HRV than controls (p<0.001 for both). A correlation was found between exercise HRV (SDNN) and FAI in both groups. This association was independent of age, sex, smoking, body mass index, diabetes, and clonidine or beta-blocker use, but not of hemoglobin levels. Conclusion: No association was found between FAI and HRV on 24-hour Holter or at the recovery period of ETT. Of note, exercise HRV was inversely correlated with FAI in HD patients and controls. (Arq Bras Cardiol. 2015; [online]. ahead print, PP.0-0) .

Fundamento: A disfunção autonômica (DA) é altamente prevalente em pacientes em hemodiálise (HD) e tem sido implicada no risco aumentado de mortalidade cardiovascular. Objetivo: Correlacionar a variabilidade RR (VRR) durante o teste ergométrico (TE) com o déficit funcional aeróbico (FAI) em pacientes em HD e em um grupo controle. Métodos: Trata-se de um estudo transversal no qual as variáveis analisadas foram obtidas através de exame clínico, coleta de sangue, ecocardiograma transtorácico, Holter de 24 horas e TE. Foi realizado TE em esteira pelo protocolo de rampa, limitado por sintomas, com recuperação ativa. A VRR foi avaliada no domínio do tempo no exercício e na recuperação separadamente. Resultados: Quarenta e um pacientes em HD e 41 controles concluíram o estudo. Pacientes em HD tinham maior FAI e menor VRR do que os controles (p <0,001 para ambos). Houve correlação entre FAI e VRR no exercício (SDNN) em ambos os grupos. Esta associação foi independente de idade, sexo, tabagismo, índice de massa corporal, diabetes, clonidina, betabloqueador, mas não dos níveis de hemoglobina. Conclusão: A VRR no exercício foi inversamente correlacionada com o FAI em pacientes em HD e controles. Não foram observadas associações do FAI com VRR no Holter ou no período de recuperação do TE. .

Carga de doença no Brasil: um olhar sobre o álcool e a cirrose não viral / Disease burden in Brazil: an investigation into alcohol and non-viral cirrhosis

O uso/dependência de álcool é importante fator de risco para o desenvolvimento da cirrose. O objetivo deste artigo é descrever e analisar o DALY (Disability Adjusted Life Years), o YLL (Years of Life Lost) e o YLD (Years Lived with Disability) de uso/dependência de álcool e da cirrose de etiologia não viral no Brasil, em 2008. O DALY foi calculado pela soma do YLL e do YLD. Para o YLL, foi utilizada a média dos óbitos de 2007-2009 no país. Através da revisão de dados epidemiológicos e do uso da ferramenta DisMod, a prevalência de cada um dos agravos foi modelada, gerando dados de incidência para o cálculo do YLD. O álcool e a cirrose foram responsáveis, respectivamente, por 3% e 1% do DALY total. Considerando-se as dez primeiras causas de DALY para homens, o uso/ dependência de álcool ocupou a segunda, terceira e sexta posições nas idades de 15-29, 30-44 e 45-59 anos, respectivamente. A cirrose ocupou a oitava posição no grupo de 30-44 anos; a quinta, no de 45-59 e a oitava, no de 60-69. A distribuição dos agravos por faixa etária sugere que intervenções direcionadas ao uso/dependência de álcool terão efeitos na carga de cirrose alcoólica no país.

Alcohol use/dependence are an important risk factor for cirrhosis of the liver. The article aims to describe and conduct a comparative analysis of Disability Adjusted Life Years (DALY), Years of Life Lost (YLL) and Years Lived with Disability (YLD) of alcohol use disorders and non-viral cirrhosis in Brazil in 2008. DALY was calculated as the sum of YLL and YLD. For YLL estimates, the mean number of deaths from 2007- 2009 in the country was considered. After revision of epidemiological data, prevalence of each disease was modelled with the DisMod tool, which generated incidence data for YLD estimates. Alcohol and non-viral cirrhosis were responsible for 3% and 1% of total DALYs, respectively. In both diseases, men contributed to a greater proportion of DALYs. Among the first ten causes of DALYs, alcohol use disorders occupied the second, third and sixth positions at the ages of 15-29, 30-44 and 45- 59, respectively. Non-viral cirrhosis was the eighth cause of DALY in the 30-44 age group in men; the fifth, in the 45-59 group and the eighth, in the 60-69 group. Age distribution suggests that interventions directed against alcohol use/dependence would have effects on the burden of alcoholic cirrhosis in the country.

Phospholipid Remodeling and Eicosanoid Signaling in Colon Cancer Cells.

Phospholipid remodeling and eicosanoid synthesis are central to lipid-based inflammatory reactions. Studies have revealed that membrane phospholipid remodeling by fatty acids through deacylation/reacylation reactions increases the risk of colorectal cancers (CRC) by allowing the cells to produce excess inflammatory eicosanoids, such as prostaglandins, thromboxanes and leukotrienes. Over the years, efforts have been made to understand the lipid remodeling pathways and to design anti-cancer drugs targeting the enzymes of eicosanoid biosynthesis. Here, we discuss the recent progress in phospholipid remodeling and eicosanoid biosynthesis in CRC.

Mutación del gen KRAS en el cáncer de colon y recto / KRAS gene mutation in colorectal cancer

Background: KRAS oncogene is involved in colorectal carcinogenesis in 22 to 45% of cases. Aim: To determine the frequency, types and distribution of KRAS mutations in colorectal cancer. Material and Methods: KRAS mutations studies were carried out in primary tumors and metastases of colo-rectal cancer from 56 women aged 60 ± 14 years and 53 men aged 61 ± 11 years. Formalin fixed and paraffin embedded tissue samples were evaluated using RFLP (Restriction Fragment Length Polymorphism) and direct sequencing. Results: Primary tumors were located in the colon and rectum in 82 (75.2%) and 24 cases (20%), respectively. In three cases the extraction site of the tumor sample was unknown. In 46 cases (42.2%) KRAS mutations were demonstrated. The main point mutations were located in codon 12 (80.4%), G12D (39.1%), G12V (24.2%), G12S (6.5%), G12A (4.3%); G12C (4.3%), G12R (2.1%) and 19.6% at codon 13 (G13D). No differences were demonstrated in the frequency and distribution of mutations by gender, age, primary versus metastatic tumors or tumor location. Conclusions: In this series, 42% of colorectal cancer tissue samples had KRAS mutations. Their frequency and distribution are similar to those reported in the literature, except for G12C mutation.

Protective effect of MUC2 siRNA against colon cancer growth through the induction of apoptosis

Mucinous colorectal cancers are highly aggressive phenotype presenting with more advanced disease and a poor prognosis. The biological mechanisms involved are unclear, but appear to be linked to mucin glycoprotein overexpression like MUC2. While the role of MUC2 in colon cancer metastasis is established, the biological events and molecular pathways modulated by MUC2 are still unknown. In this study, mucin expressing human colon cancer cells LS174T were grown 'in vitro' and MUC2 expression was inhibited by MUC2 small interfering RNA molecules [siRNA]. Cell culture and soft agar growth were measured to determine the overall effect on viability. Apoptosis was investigated by measuring protein level of polyADP-ribose polymerase [PARP], caspases-3 and -8. Finally, in vivo LS174T xenografts where grown in nude mice, different treatments included MUC siRNA, scramble siRNA or saline where administered, via tail vein injection, twice a week for two weeks. Results showed that upon treatment with MUC2-siRNA there was a 5-fold reduction cell culture growth and 9-fold reduction in soft agar growth in LS174T cells. A 3 to 5-fold increase in apoptosis was mediated by caspase-8 activation. Systemic administration of MUC2 siRNA markedly inhibited tumor growth in colon cancer xenografts grown in nude mice. Tumor growth inhibition was 59% by comparing MUC2 siRNA treatment and control siRNA treatments. There was no significance difference in tumor growth between control siRNA and normal saline treatment groups [p>0.05]. We conclude that MUC2 expression appears to protect LS174T colon cancer cells from apoptosis through extrinsic apoptosis pathway. We hypothesize that contrary to previous notions that MUC2 is a secreted glycoprotein involved in digestion and gastrointestinal tract lubrication, it appears to be involved in maintenance of LS174T cell viability. MUC2 may represent a therapeutic target in mucinous colorectal carcinomas

CHEK2 1100DELC germline mutation: a frequency study in hereditary breast and colon cancer Brazilian families / Mutação germinativa 1100delC no gene CHEK2: estudo da frequência em famílias brasileiras com câncer de mama e cólon hereditários

CONTEXT: CHEK2 encodes a cell cycle checkpoint kinase that plays an important role in the DNA damage repair pathway, activated mainly by ATM (Ataxia Telangiectasia Mutated) in response to double-stranded DNA breaks. A germline mutation in CHEK2, 1100delC, has been described as a low penetrance allele in a significant number of families with breast and colorectal cancer in certain countries and is also associated with increased risk of contralateral breast cancer in women previously affected by the disease. About 5%-10% of all breast and colorectal cancers are associated with hereditary predisposition and its recognition is of great importance for genetic counseling and cancer risk management. OBJECTIVES: Here, we have assessed the frequency of the CHEK2 1100delC mutation in the germline of 59 unrelated Brazilian individuals with clinical criteria for the hereditary breast and colorectal cancer syndrome. METHODS: A long-range PCR strategy followed by gene sequencing was used. RESULTS: The 1100delC mutation was encountered in the germline of one (1.7%) individual in this high risk cohort. This indicates that the CHEK2 1100delC is not commonly encountered in Brazilian families with multiple diagnoses of breast and colorectal cancer. CONCLUSION: These results should be confirmed in a larger series of families and further testing should be undertaken to investigate the molecular mechanisms underlying the hereditary breast and colorectal cancer phenotype.

INTRODUÇÃO: CHEK2 codifica uma proteína quinase envolvida em um ponto de checagem do ciclo celular que desempenha um papel importante na via de reparação do DNA, danos ativados principalmente por ATM (Ataxia Telangiectasia Mutado) em resposta a danos na dupla hélice do DNA. A mutação germinativa 1100delC no gene CHEK2 tem sido descrita como um alelo de baixa penetrância em um número significativo de famílias com câncer de mama e cólon em certos países e também está associada com risco aumentado de câncer de mama contralateral em mulheres previamente afetadas pela doença. Cerca de 5%-10% de todos os cânceres de mama e colorretais estão associados a predisposição hereditária e o seu reconhecimento é de grande importância para o aconselhamento genético e gestão do risco de câncer. OBJETIVOS: Neste estudo foi avaliada a frequência da mutação germinativa 1100delC no gene CHEK2 em 59 diferentes indivíduos brasileiros com critérios clínicos para a síndrome de câncer de mama e cólon hereditários. MÉTODO: Utilizamos como estratégia a realização do PCR de longo alcance seguido de sequenciamento. RESULTADOS: A mutação 1100delC foi encontrada em um indivíduo (1,7%), indicando que esta mutação germinativa não é comumente encontrada em famílias brasileiras com múltiplos diagnósticos de câncer de mama e câncer colorretal. CONCLUSÃO: Estes resultados devem ser confirmados em uma série maior de famílias, e estudos adicionais devem ser realizados para investigar a patologia molecular do fenótipo HBCC.

Evaluation of the expression of self renewal genes [Oct-4, Nanog, Sox2, Nucleostemin, Bmi and Zfx] in bladder, colon and prostate cancers and in cancer cell lines [LNCaP, HepG2, HT-29, CaCo[2], HT-1376]

Uncontrolled self renewal plays a direct function in different types of carcinoma progression. Here we examined the expression of self renewal regulatory factors such as Oct4, Nanog, Sox2, Nucleostemin, Zfx, Bmi-1 in colon, prostate, bladder and liver cancers in human samples and cancer cell lines. We used RT-PCR to examine the expression of these genes in 10 tumors of bladder, 5 tumors of prostate, 5 tumors of colon, 5 normal tissues of colon, and cancer cell lines. The expression of Oct-4 and Nucleostemin at protein level was further determined by immunocytochemical [ICC] analysis in cancer cell lines. We designed specific primers to amplify a segment of Oct4, Nanog, Sox2, Nucleostemin, Bmi and Zfx. As expected DNA fragment of these genes based on designated primer was amplified in the PCR reaction. We detected the expression of these genes in almost all of the examined tumor samples and cancer cell lines that we used. Oct4 and Nucleostemin proteins were expressed in both nuclear and cytoplasmic in cancer cell lines. No immunoreactivity was observed in negative controls, which were incubated in the absence of primary antibody. Collectively, our results indicated that in a tumor population a rare subpopulation of cells within the tumor cell mass has the potential of self renewal, and suggested that their expression can be used as potential tumor markers in diagnosis and/or prognosis of tumors. These results confirm the potential value of the cancer stem-cell theory in cancer therapy

[Assessment of the expression of self renewal genes [Tcl1, Tbx3, Dppa4 and Esrrb] in bladder, liver, colon and prostate cancers]

Here we examined the expression of self renewal regulatory factors such as, Esrrb, Tcl1, Tbx3 and Dppa4 in several tissue samples of cancers and cancer cell lines. These genes are required for efficient self renewal of embryonic stem cells. Caco2, HT-29, HT 1376, Ln Cap, and HepG2 cells were cultured in T25 flasks. Considering the clinical and laboratory findings, human tumor samples were obtained under direct supervision of the medical specialists. Then we evaluated expression of self renewal genes [Tbx3, Tcl1, Esrrb, Dppa4] by reverse transcriptase polymerase chain reaction [RT-PCE] in the above mentioned cells and human tumor samples. To confirm the validity of the laboratory tests, we studied negative control samples and internal control genes. Our data revealed the expression of self renewal genes [TCL1, TBX3, ESRRB and DPPA4] in bladder, liver, prostate and colon cancers and also cancer cell lines. Colon, liver, prostate and bladder cancer cells can express TCL1, TBX3, ESRRB and DPPA4 genes, which are specific markers of stem cells. Therefore in malignant cells of the above mentioned cancers, some cells have the characteristics of stem cells and can play an essential role in the proliferation of malignant cells

Effects of Chromosomal Polyploidy on Survival of Colon Cancer Cells / 대한소화기학회지

BACKGROUND/AIMS: Tetraploid cells are frequently observed in the inflamed mucosal epithelial cells of the patients with Barrett's esophagus or chronic ulcerative colitis. Polyploidy often occurs during cell fusion, abortive cell cycle, and endoreplication. Most tetraploid cells are engaged to apoptotic pathway, but some remaining stable tetraploid cells consequently cause aneuploidization and chromosomal instability. We investigated whether tetraploid cells could acquire survival advantage and hold a dominant position for natural selection. METHODS: We established tetraploid cell line (HCT116GH) from parental diploid colorectal cancer cell line (HCT116) via PEG-mediated cell fusion and compared its cell viability, cell cycle response and apoptotic fractions responded to H2O2 with diploid HCT116 and p53 suppressed HCT116/H6 cell lines. RESULTS: Using MTT assay, plating efficiency and clonogenicity, we evaluated the survival of each cell line. Tetraploid cell line HCT116GH demonstrated an 83 fold greater resistance to 100 microM H2O2 than the parental diploid HCT116, and 6 fold greater than even the p53 negative diploid HCT116/E6. Cellular sensitivity, G2/M arrests, and apoptotic proportion were observed less in response to H2O2 in HCT116GH compared with HCT116 and HCT116/E6. HCT116GH expressed lower level of p53 and p21 than diploid HCT116. CONCLUSIONS: Stable tetraploid cell lines showed enhanced viability in comparison to parental diploid cell lines. The enhanced viability observed in tetraploidization surpassed that from downregulation of p53. Frequent appearance of tetraploid cells in stressful condition can be caused by natural selection owing to their enhanced viability and may consequently contribute to cancer cell transformation.

Intravenous KITENIN shRNA Injection Suppresses Hepatic Metastasis and Recurrence of Colon Cancer in an Orthotopic Mouse Model

KITENIN (KAI1 C-terminal interacting tetraspanin) promotes invasion and metastasis in mouse colon cancer models. In the present study, we evaluated the effects of KITENIN knockdown by intravenous administration of short hairpin RNAs (shRNAs) in an orthotopic mouse colon cancer model, simulating a primary or adjuvant treatment setting. We established orthotopic models for colon cancer using BALB/c mice and firefly luciferase-expressing CT-26 (CT26/Fluc) cells. Tumor progression and response to therapy were monitored by bioluminescence imaging (BLI). In the primary therapy model, treatment with KITENIN shRNA substantially delayed tumor growth (P = 0.028) and reduced the incidence of hepatic metastasis (P = 0.046). In the adjuvant therapy model, KITENIN shRNA significantly reduced the extent of tumor recurrence (P = 0.044). Mice treated with KITENIN shRNA showed a better survival tendency than the control mice (P = 0.074). Our results suggest that shRNA targeting KITENIN has the potential to be an effective tool for the treatment of colon cancer in both adjuvant and metastatic setting.

Genética del cáncer de colon / Genetics of colon cancer

Colon cancer (CC) is a prevalent disease, with 800,000 new cases annually worldwide. In Chile the mortality is 6.2 per 100,000 inhabitants, which has increased in recent years, being more common in developed countries. Although, CC are most sporadic forms (70 percent), there are patients with family history (30 percent) and 10 percent have a hereditary component, with a predisposition to the formation of tumors, including CC, the most studied syndrome are: Familial Adenomatous Polyposis (FAP), Peutz-Jeghers syndrome and hereditary non-polyposis colon cancer (HNPCC).The progresses made by the human genome sequencing have allowed to known mutations in oncogenes and tumor suppressor genes that occur in a cell of the normal intestinal mucosa and lead to carcinogenic transformation. This review is an update of the known genes related to the sporadic form of the CC, as well as the most common inherited forms of CC. It is important that health professionals, be aware of developments in this area, because they are who should promote in the community a timely screening for patients with increased risk factors for CC, with the aim of giving an accurate counseling for decrease the morbidity and mortality of this condition.

Study of 5 HT[3] and 5 HT[4] receptors expression in HT29 cell line and human colon adenocarcinoma tissues

Serotonin [5HT] has been shown to be a mitogenic factor in several carcinomas. Its mitogenic effect is elicited through a wide range of 5HT receptor subtypes. In this study, the effects of 5HT, 5HT[3] [1-phenylbiguanide hydrochloride] and 5HT[4] [cisapride] agonists in promoting the growth of the HT29 cell line and the growth-inhibition effect of the 5HT[3] receptor antagonist [Y-25130 hydrochloride] and 5HT4 receptor antagonist [RS 23597-190] were investigated. The expressions of 5HT[3] and 5HT[4] receptors in human colon cancer tissues and the HT29 cell line were studied. The growth-promoting and growth-inhibition effects of 5-HT, 5HT[3] and 5HT[4] agonists and antagonists on the HT29 cell line were studied using MTT assay. Receptor expression has been demonstrated by western blotting. The results showed that 5HT, 5HT[3], and 5HT[4] agonists caused significant proliferation of HT29 cells. 5HT[3] and 5HT[4] receptor antagonists had an inhibitory effect on the growth of these cells. Western blot analysis gave bands from colon tissue extracts and the HT29 cell line. The results indicate which 5HT[3] and 5HT[4] receptors are significantly expressed in both colon cancer tissue and the HT29 cell line. Expression for the 5HT[3] receptor is more potent. Furthermore, 5HT plays a mitogenic role in colon cancer cells and antagonists of 5HT[3], and 5HT[4] receptors can inhibit cancer cell growth