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PubMed2003

Safety of intravenous administration of a canarypox virus encoding the human wild-type p53 gene in colorectal cancer patients.

Overexpression of p53 occurs in more than 50% of colorectal cancers. Therefore, p53 represents an attractive target antigen for immunotherapy. We assessed the safety of a canarypox virus encoding the human wild-type p53 gene given intravenously to end-stage colorectal cancer patients in a three-step dose escalation study aimed at inducing p53 immune responses. Patients with metastatic disease of p53-overexpressing colorectal cancers were vaccinated three times at 3-week intervals, each time with 10(6.5) CCID(50) (CCID(50)=cell culture infectious dose 50%; group 1, n=5), 10(7.0) CCID(50) (group 2, n=5) or 10(7.5) CCID(50) (group 3, n=6). Vital signs and the occurrence of adverse events were monitored and blood was analyzed for biochemical and hematological parameters as well as signs of auto-immune safety. In all, 16 patients were enrolled and 15 patients completed three vaccinations. No anaphylactic reaction or unwanted auto-immune reactions were observed. A total of 16 serious adverse events (SAEs) occurred: 10 in group 1, three in group 2 and three in group 3. All SAEs were tumor-related complications. There was no difference in the frequency of adverse events between the three groups, except for fever. Fever was the only vaccination-related adverse event consistently observed and was most frequent and outspoken in the group 3 patients. The majority was a grade 1 or 2 fever (93%) and grade 3 fever (7%) was observed in three patients of group 3. Some patients showed humoral and cellular responses against p53, following vaccinations. After having completed his initial treatment cycle, one patient (group 2) received a second treatment cycle of three doses of 10(7.5) CCID(50) and subsequently showed stable disease. All other patients showed progressive disease. We conclude that ALVAC-p53 can be administered intravenously to colorectal cancer patients without serious toxicity or pathological autoimmunity and can induce immune responses against p53.

Adult↗
PubMed1998

Decreased expression of the adenomatous polyposis coli (Apc) and mutated in colorectal cancer (Mcc) genes in mouse lung neoplasia.

A decrease in the intracellular concentrations of the transcripts for some tumor suppressor genes has been found during murine lung tumorigenesis; for p15INK4b and p16INK4a, this was due to homozygous deletions. We report here a decrease in the mRNA levels of the mutated in colorectal cancer (Mcc) and adenomatous polyposis coli (Apc) genes in mouse lung tumors and some neoplastic cell lines. This was assessed both by northern blotting and reverse transcriptase-polymerase chain reaction of RNA isolated from lung tumors that had been induced by urethane, N-nitrosodiethylamine, or 3-methylcholanthrene in (A/J x C57BL/6) F1 or A/J mice. A reduced amount of both Mcc and Apc messages was also seen when two neoplastic cell lines, a spontaneous transformant (E9) and a line derived from a chemically induced solid tumor (82-132), were compared with two independently derived nontumorigenic cell lines (E10 and C10); E9 was derived from E10, and all of these lines are probably of alveolar type 2 cell origin. A cell line derived from a chemically induced papillary lung tumor probably of bronchiolar Clara cell origin (LM2) had Mcc mRNA levels similar to those of C10 and E10 but reduced Apc mRNA levels. A line (p53-823) derived from a papillary tumor that arose in a mouse with a mutated p53 transgene had a reduced amount of the Mcc gene product only. These differential changes in the relative amounts of Apc and Mcc messages in LM2 and p53-823) cells may serve as useful models for studying the regulation of their expression. Both messages had half-lives of 6-9 h in normal E10 and neoplastic E9 cells, so decreased message stability does not account for these reductions. This is the first report of estimated degradation rates of these mRNAs. Apc and Mcc message content did not vary as a function of growth status of the cell lines. Single-strand conformation polymorphism analysis did not reveal mutations in Apc coding regions known to have a high mutation frequency in human colon tumors. Loss of heterozygosity of Apc and Mcc was not found in tumors that developed in the F1 mice, implying a lack of allelic deletions. These changes in tumor suppressor gene expression may contribute to the development and maintenance of neoplasia in lung epithelium.

Animals↗
PubMed2003

[Mining microarray gene expression data of metastatic colorectal cancer by literature profiling].

OBJECTIVE: To search new metastatic colorectal cancer-related genes. METHODS: Metastatic colorectal cancer microarray gene expression data was mined by literature profiling, which was based on the analysis of literature profiles generated by extracting the frequencies of certain terms from the abstracts in the Medline literature database. The terms are then filtered on the basis of both repetitive occurrence and co-occurrence among multiple gene entries. Clustering analysis was subsequently performed on the retained frequency values, shaping a coherent picture of the functional relationship among the heterogeneous genes identified in the long lists. The clustering result was analyzed against the result of document analysis and experiment. RESULTS AND CONCLUSION: Two new genes (TIAM1 and NM23H1) with potential relation to metastatic colorectal cancer were identified.

Colorectal Neoplasms↗
PubMed1994

Mutations of Ki-ras and p53 genes in colorectal cancer and their prognostic significance.

The series of genetic changes leading to malignancy in colorectal cancer is well reported. This includes mutational activation of the proto-oncogene Ki-ras and mutation/deletion of the p53 tumour suppressor gene. The frequency of these mutations was investigated in a panel of 52 colorectal cancer patients using a combination of immunocytochemistry and non-radioactive, digoxigenin-labelled in situ hybridisation. Sixty two per cent (32 of 52) of the study population were positive for p53 overexpression and 36% (19 of 52) positive for Ki-ras mutation. Twenty seven per cent (14 of 52) of the patients expressed both mutations. Mutation of either the p53 or the Ki-ras gene did not correlate with Dukes's stage, tumour differentiation or 5 year survival rate of the patients. Most of the rectal carcinoma specimens (11 of 15) showed p53 over-expression but the significance of this was not supported statistically. Thus detection of molecular changes is becoming more amenable to incorporation into routine histological carcinoma assessment because of the advent of non-radioactive labelling in in situ hybridisation and antibodies suitable for paraffin wax embedded specimens. The significance of these mutations in disease prognosis, however, remains questionable.

Colonic Neoplasms↗
PubMed2003

Analysis of the transcription regulator, CNOT7, as a candidate chromosome 8 tumor suppressor gene in colorectal cancer.

Loss of heterozygosity (LOH) on the short arm of chromosome 8 occurs at high frequencies in many tumor types, including colorectal carcinoma. We have previously used microcell-mediated chromosome transfer (MMCT) to map an approximately 7.7 Mb colorectal cancer suppressor region (CRCSR) at 8p22-23.1. We have now taken a candidate gene approach to identify the putative tumor suppressor gene located within the CRCSR. CNOT7 encodes a subunit of the CCR4-Not transcription complex and is located at 8p22. We showed that CNOT7 is expressed in normal colonic mucosa and in colonic crypt cells, as well as in colorectal cell lines and primary tumors. We assembled a panel of 88 primary colorectal tumors comprising 20 MSI-high (high microsatellite instability), 19 MSI-low and 49 MSS (microsatellite stable) tumors for mutation analysis of the CNOT7 gene. Denaturing high-performance liquid chromatography (DHPLC) analysis of the entire coding region of the CNOT7 gene revealed only one somatic missense mutation in an MSS tumor. The rarity of somatic mutations in CNOT7, and its expression in primary colorectal tumors and cell lines, suggests that CNOT7 is not the target tumor suppressor gene in the 8p22-23.1 CRCSR.

Carcinoma, Squamous Cell↗
PubMed2006

[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.

Adult↗
PubMed1998

Close correlation between mutations of E2F4 and hMSH3 genes in colorectal cancers with microsatellite instability.

Defects in mismatch repair function can lead to the microsatellite instability (MI+; replication error) phenotype in certain human cancers. We previously reported that MI+ tumor-specific repeat number alteration at 13 consecutive trinucleotide (CAG) repeats within a coding exon of the E2F4 gene is a possible target of the defective repair pathway. Additional investigations revealed that E2F4 mutations are common (11 of 17 cases, 65%, mostly deletions) in a subset of human colorectal cancers with extensive MI+ phenotype, with respect to the proportion of loci affected and that most of these E2F4-mutated tumors (9 of 11, 82%) were accompanied by frameshift mutations in a polyadenine stretch within the seventh exon of the hMSH3 gene, a known mismatch repair gene that is responsible for repair of mismatch loops of two to four nucleotides. However, neither of these mutations was detected in 15 tumors with a lower incidence of MI+ loci. Similar repeat number alterations were less frequent in CAG repeats from other genes in all of the MI+ tumors we examined. These results indicate the presence of a novel cascade of mutational events that may be involved in acquisition of the malignant phenotype of human colorectal cancers with genetic instability.

Colorectal Neoplasms↗
PubMed2006

The relationship between 5-fluorouracil sensitivity and single nucleotide polymorphisms of the orotate phosphoribosyl transferase gene in colorectal cancer.

Orotate phosphoribosyl transferase (OPRT) is an enzyme playing an important role in exertion of the effect of 5-fluorouracil (5-FU). A type of gene polymorphism, single nucleotide polymorphism (SNP), is considered to be a factor affecting individual differences in exertion of drug effects, and its analysis has recently made progress. We investigated the correlation between SNP of OPRT and 5-FU sensitivity in colon and rectal cancers. The subjects were 31 patients with colorectal cancer who underwent surgical excision between December 2003 and July 2004 at our department. Of SNP of OPRT, 638G/C, 1050T/A, and 1336A/G located in the coding region were analyzed by invader assay. The growth inhibition rate (% IR) of colorectal cancer by 5-FU was obtained by the CDDST method, and 5-FU sensitivity was compared among strains (wild-, homo-, and hetero-types) of each polymorphism. There was no relationship between the strains and 5-FU sensitivity in any of the SNPs. The investigated SNPs of OPRT may have no major influence on 5-FU sensitivity. However, there are many unknown factors in the relationship between SNP of OPRT and 5-FU sensitivity, and SNP analysis of other regions is necessary.

Aged↗
PubMed2005

Expression profile of cancer-testis genes in 121 human colorectal cancer tissue and adjacent normal tissue.

PURPOSE: Among tumor antigens identified to date, cancer-testis (CT) antigens, which are coded by CT genes, are identified as a group of highly attractive targets for cancer vaccines. This study is the first to analyze the mRNA expression and possible correlation with pathologic characteristics of multiple CT genes in a large cohort of colorectal cancer (CRC) patients. EXPERIMENTAL DESIGN: The expression of 10 individual CT genes in 121 CRC and adjacent tissues were analyzed by RT-PCR method. The presence of autologous antibodies against NY-ESO-1 was examined in serum samples by ELISA. To confirm the protein expression, immunohistochemistry was done for detecting the NY-ESO-1 antigen in mRNA-positive CRC tissues. RESULTS: The CT genes were detected with various frequencies in CRC tissue, SCP-1, 1.7%; SSX-2, 2.5%; SSX-4, 2.5%; SSX-1, 5.0%; CT10, 6.6%; NY-ESO-1, 9.9%; MAGE-1, 11.6%; LAGE-1, 15.7%; MAGE-4, 22.3%; and MAGE-3, 27.3%. In 56.2% of tumor tissues examined in this study, at least one CT gene was detected. In contrast, no CT gene expression was found in cancer adjacent tissues. Among 10 CT genes investigated, NY-ESO-1 and LAGE-1 are of particular interest because their mRNA expression in CRC was rarely reported before. In our study, NY-ESO-1 mRNA was found to express in 9.9% of the samples, and also correlated significantly with stages (P = 0.041) and local lymph node metastasis (P = 0.002). In addition, we also identified one NY-ESO-1 antibody-positive serum sample. MAGE-4 mRNA was expressed at a high frequency in tumor tissues with vessel emboli samples (P = 0.025). CONCLUSIONS: These results suggested that CT genes, especially NY-ESO-1 and LAGE-1, do express in CRC. More than 50% of the CRC patients in this study express at least one CT gene, making them eligible for CT vaccination. NY-ESO-1 gene may serve as a marker for local metastasis and advanced disease. MAGE-4 gene is significantly associated with the vessel emboli.

Adult↗
PubMed2001

A C/T polymorphism in the urokinase-type plasminogen activator gene in colorectal cancer.

Urokinase plasminogen activation system can play an important role in the appearance and progression of many cancers. Urokinase-type plasminogen activator (uPA) is implicated in the control of cell adhesion and invasion, and is regarded as a strong prognostic marker in colorectal cancer. A C-->T substitution (the C/T polymorphism) in the nucleotide sequence encoding the kringle structure of uPA results in an alteration from proline to leucine at position 121. This substitution may be directly or indirectly involved in the decreased affinity for uPA substrates. In the present work the distribution of genotypes and frequencies of alleles of the C/T polymorphism were investigated. Tumour tissues and distal mucosa samples were obtained from 40 patients with colorectal cancer. Blood samples from sex and age matched healthy individuals served as control. The C/T polymorphism was determined by PCR amplification using the allele specific primers. No differences between genotypes of the C/T polymorphism in cancer tissue and distant mucosa of each patient were found. The distributions of the genotypes in both patients and control differed significantly (p < 0.05) from that predicted by the Hardy-Weinberg distribution. A distinct preference of heterozygotes (70% - patients, 65% - controls) was observed in both patients and controls. Additionally, there were no differences in the frequencies of the C and T alleles in both groups. The C/T polymorphism of the uPA gene may not be linked with colorectal cancer.

Adult↗
PubMed1997

Analysis of a polyadenine tract of the transforming growth factor-beta type II receptor gene in colorectal cancers by non-gel-sieving capillary electrophoresis.

We developed a method to analyze a polyadenine tract, the (A)10 repeat, within the cysteine-rich domain of the transforming growth factor-beta (TGF-beta) type II receptor gene using a non-gel-sieving capillary electrophoresis technique and applied it to the DNA diagnosis of colorectal cancers. This method consists of single-strand DNA amplification of the (A)10 repeat by an asymmetric PCR technique and capillary electrophoresis. A higher concentration of dATP in the PCR reaction mixture led to more specific amplification of the (A)10 repeat. Under the optimal electrophoretic conditions, one nucleotide difference could be determined in 8 to 32 nucleotides. One or two base deletions of the (A)10 repeat in colorectal cancers could be detected under these conditions within 30 min, and the results coincided with those obtained on DNA sequencing analyses. According to a sensitivity study, we could detect the deleted sequence if it was present in 12.5% or more of the wild-type allele. The reproducibility of this technique was satisfactory because the intraassay imprecision (CV) (n = 10) was 1.4%. These results indicate that capillary electrophoretic analysis of small repeated sequences results in easier handling and more feasible automation, compared with conventional gel electrophoretic analysis.

Autoanalysis↗
PubMed2006

Single nucleotide polymorphisms of the APC gene and colorectal cancer risk: a case-control study in Taiwan.

BACKGROUND: Colorectal cancer (CRC), which has become especially prevalent in developed countries, is currently the third highest cause of cancer mortality in Taiwan. Mutation of the adenomatous polyposis coli (APC) gene, a tumour suppressor, is thought to be an early event in colorectal tumourigenesis. To date, however, no large-scale screening for APC gene variants in Chinese subjects has been performed. The present study was undertaken to identify APC gene variants that are significantly associated with the occurrence of CRC in Taiwanese subjects. METHODS: In order to compare the genotype distribution of variant sites, the full-length APC genes of 74 healthy individuals and 80 CRC patients were sequenced. RESULTS: Among the 154 Taiwanese subjects examined in this study, three new mutations, but no previously reported mutations, were found. One deletion at codon 460 leading to a frameshift and two missense mutations resulting in p.V1125A and p.S1126R substitutions were identified. Additionally, three high risk genotypes associated with three single nucleotide polymorphisms and one low risk genotype at codon 1822 were identified. CONCLUSION: The findings of this case-control study are consistent with the proposal that Taiwanese subjects differ from other subjects with respect to phenotypic presentation of APC and CRC risk.

Adult↗
PubMed2005

Association between mutations in the CARD15/NOD2 gene and colorectal cancer in a Greek population.

Epidemiological observations suggest that cancer arises from chronically inflamed tissues. Inflammatory bowel disease (IBD) is a typical example since patients with longstanding IBD are at increased risk for development of colorectal cancer (CRC). Therefore, genetic factors predisposing to or implicated in the chronic inflammatory process in IBD may simultaneously predispose to CRC. Recently CARD15/NOD2 has been associated with IBD, which further strengthens the notion that the inflammatory response plays a crucial role in this disease. Several mutations have been identified in the CARD15/NOD2 gene, which appear with significantly higher frequency in patients with IBD. In this report, we have examined the frequency of the 3 major mutations R702W, G908R and 3020insC of the CARD2/NOD2 gene in a series of 104 consecutive Greek patients with sporadic colorectal cancer and 100 healthy individuals. The frequency of all the mutations was significantly elevated compared to the control population (R702W, OR=5.00, p=0.023; G908R, OR=2.78, p=0.025; 3020insC, OR=2.44, p=0.017). Patients with advanced stage tumors were more frequently carriers of at least 1 variant in the CARD15/NOD2 gene (p=0.009). Our results suggest that CARD2/NOD2 may be a genetic factor that predispose to sporadic colorectal cancer.

Aged↗
PubMed2004

Role of the dependence receptor DCC in colorectal cancer pathogenesis.

More than a decade ago, the DCC (deleted in colorectal cancer) gene was proposed as a putative tumor suppressor gene. Data supporting this proposal included observations that one DCC allele was deleted in roughly 70% of colorectal cancers, some cancers had somatic mutations of the DCC gene, and DCC expression was often reduced or absent in colorectal cancer tissues and cell lines. Despite subsequent studies which have supported DCC's potential role as a tumor suppressor gene, the rarity of point mutations identified in DCC coding sequences, the lack of a tumor predisposition phenotype in mice heterozygous for DCC inactivating mutations, and the presence of other known and candidate tumor suppressor genes on chromosome 18q have raised questions about DCC's candidacy. Following its initial characterization, the DCC protein was identified as a transmembrane receptor for netrins, key factors in axon guidance in the developing nervous system. At first glance, the established role of DCC and netrin-1 during organization of the spinal cord could be viewed as a further challenge to the position that DCC inactivation might play a significant role in tumorigenesis. However, recent observations on DCC's functions in intracellular signaling have renewed interest in the potential contribution of DCC inactivation to cancer. In particular, data indicate that, when engaged by netrin ligands, DCC may activate downstream signaling pathways. Moreover, in settings where netrin is absent or at low levels, DCC can promote apoptosis. Here, we review DCC's candidacy as a tumor suppressor gene, with an emphasis on how recent molecular analyses of DCC have offered support for the notion that DCC may function as a tumor suppressor gene.

Apoptosis↗
PubMedDate not supplied

Genetic heterogeneity of variable number tandem repeats in thymidylate synthase gene in colorectal cancer patients.

PURPOSE: To analyze the genetic variability in a variable number of tandem repeats (VNTR) in the thymidylate synthase (TS) enhancer promoter region and assess the influence of functional alterations in mismatch repair genes by analyzing constitutional and tumoral DNA from patients with colorectal adenocarcinoma with a high microsatellite instability (MSI-H) or microsatellite stability (MSS) status. PATIENTS AND METHODS: Patients who underwent surgery for colorectal adenocarcinoma were selected from the colorectal database of our institute and, on the basis of MSI status, assigned to a study group and a control group: group A, MSI-H; group B, MSS. Microsatellite status was investigated using the Bethesda recommended panel (BAT-26, BAT-25, D2S123, D5S346, D17S250). In MSI-H patients an additional analysis was made of the microsatellite loci D18S61 and D18S58, both mapping in the region containing the TS gene (18p11.2-11.32). Based on the number of altered microsatellites (> or = 2, 1, or 0), tumors were considered as having high (MSI-H) or low (MSI-L) instability or microsatellite stability (MSS), respectively. Genotyping for thymidylate synthase promoter polymorphism was carried out on constitutional and tumor DNA of each patient by PCR amplification of the polymorphic region. RESULTS: MSI-H was found in 55 patients (group A) and MSS in 50 patients (group B). In none of the MSI-H patients was microsatellite instability found in the additional D18S61 and D18S58 loci. In five group A and ten group B cases the analysis was not performed because constitutional DNA and/or tumoral DNA were not amplifiable. Homozygotes for the triple repeat variant (3R/3R) displayed only the large PCR product, homozygotes for the double repeat variant (2R/2R) displayed only the smaller PCR product, while heterozygotes (2R/3R) displayed both the larger and smaller PCR products. In 3/50 (6%) group A patients and 5/40 (12%) group B patients repeat variations were found in tumoral DNA. CONCLUSION: Our findings demonstrate that there is genetic homogeneity between constitutional and tumoral DNA but do not support the hypothesis that mismatch repair genes are involved in VNTR recombinant events in TS gene variability.

Adenocarcinoma↗
PubMed2003

Mutational analysis of TGF-beta type II receptor, Smad2, Smad3, Smad4, Smad6 and Smad7 genes in colorectal cancer.

Transforming growth factor-beta(TGF-beta) is known to play an important role in controlling embryonal development, cell proliferation and homeostasis. The purpose of this study is to elucidate the involvement of the TGF-beta pathway in colorectal carcinogenesis. DNA was extracted from 100 patients with colorectal cancer. Then, all coding regions of the TGF-beta type II receptor (TRII) and the genes for Smad2, Smad3, Smad4, Smad6, and Smad7 were analyzed by PCR-SSCP and direct sequencing. Also, a LOH analysis of 18q21, where the Smad2 and Smad4 genes are located, was performed. We detected 11 cases of frameshift mutation in the TRII gene (11%) and 5 cases of point mutations in the Smad4 gene (5.0%); LOH at 18q21 was detected with 33% frequency. No abnormalities were found in the genes for Smad2, Smad3, Smad6, and Smad7. These results suggest that the abnormalities of TRII and Smad4 play an important role inhibiting TGF-beta signaling in colorectal carcinogenesis.

Base Sequence↗