Nucleotide excision repair gene ERCC1 polymorphisms contribute to cancer susceptibility: a meta-analysis.

Individual studies of the associations between excision repair cross-complimentary group 1 (ERCC1) polymorphisms and cancer susceptibility have shown inconclusive results. To derive a more precise estimation of the relationship between three well-characterised polymorphisms on ERCC1 and the risk of cancer, we performed a meta-analysis based on 48 publications. We used odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the associations. We found that ERCC1 17677A (rs3212961) variant genotypes were associated with significantly increased overall risk of cancer without substantial heterogeneity (AA versus CC, OR = 1.36, 95% CIs: 1.10-1.68; AC versus CC: OR = 1.11, 95% CIs: 0.99-1.26; dominant comparison: AA/AC versus CC: OR = 1.15, 95% CIs: 1.02-1.29; recessive comparison: AA versus AC/CC: OR = 1.25, 95% CIs: 1.05-1.49). The ERCC1 19007 C (rs11615) allele had null effects on overall risk of cancer; but in the stratified analyses, we observed an elevated association in Asian populations with homozygote variants and hospital-based controls. In addition, during further stratified analyses of cancer groups, homozygote variants were found that are associated with lung cancer and smoking-related cancers. Also, the observed ERCC1 19007 C heterozygote variant contributes to the development of skin cancer. However, the ERCC1 8092C > A (rs3212986) polymorphism did not appear to have an effect on cancer risk. Additionally, no evidence of publication bias was observed in these polymorphisms. Our meta-analysis supports the conclusion that the ERCC1 17677A > C and ERCC1 19007T > C polymorphisms, but not the ERCC1 8092C > A polymorphism, are low-penetrance risk factors for cancer development.

Cyclin D1 G870A polymorphism and colorectal cancer susceptibility: a meta-analysis of 20 populations.

PURPOSE: Studies investigating the association between genetic polymorphism of cyclin D1 (CCND1) G870A and risk of colorectal cancer (CRC) reported conflicting results. In order to derive a more precise estimation of the relationship, a meta-analysis was performed. MATERIALS AND METHODS: We performed an extensive search of relevant studies and carried out a meta-analysis, including 20 studies with 5,975 cases and 8,333 controls, to obtain a more precise estimate. RESULTS: Overall, significantly elevated colorectal cancer risk was associated with variant allele 870A when all studies were pooled (AA vs. GG: OR = 1.23, 95% CI = 1.04-1.44; GA vs. GG: OR = 1.13, 95% CI = 1.01-1.26; dominant model: OR = 1.16, 95% CI = 1.03-1.31). In the subgroup analysis by ethnicity, significantly increased risks were detected among Caucasians (AA vs. GG: OR = 1.27, 95% CI = 1.04-1.44; dominant model: OR = 1.17, 95% CI = 1.02-1.34).We also observed sporadic CRC with an increased cancer susceptibility (AA vs. GG: OR = 1.24, 95% CI = 1.04-1.48; dominant model: OR = 1.17, 95% CI = 1.04-1.33), when colorectal cancer was stratified into sporadic CRC and hereditary nonpolyposis colorectal cancer (HNPCC). However, no significant associations were found in both Asians and HNPCC patients for all genetic models. CONCLUSION: Result suggests that the cyclin D1 870A allele is a low-penetrant risk factor for developing sporadic colorectal cancer, especially among Caucasians.

Relationship between growth hormone 1 genetic polymorphism and susceptibility to colorectal cancer.

The aim of this study was to evaluate the relationship between smoking, alcohol drinking and genetic polymorphism of the growth hormone 1 gene (GH1) T1663A with reference to colorectal cancer. We conducted a case-control study with 315 cases of colorectal cancer and 438 population-based controls in the Jiangsu Province, China. GH1 T1663A genotypes were identified using PCR-RFLP (restriction fragment length polymorphism) methods. Information on smoking and drinking was collected using a questionnaire. Odds ratios (ORs) were estimated with an unconditional logistic model. The distribution of T/T and A/A genotypes was significantly different between controls and cases (chi(2)(MH)=3.877, P=0.049). Compared with the GH1 T/T genotype, the A/A genotype was at a decreased risk of developing colorectal cancer (sex-, age-, body mass index-, smoking- and alcohol drinking-adjusted OR=0.56, 95% confidence interval: 0.34-0.90). Smoking was not associated with the risk of colorectal cancer, whereas alcohol drinking was associated with an increased risk of colorectal cancer. Among nonsmokers or nondrinkers, individuals who had the GH1 A/A genotype were at a decreased risk of developing colorectal cancer compared with individuals who had the GH1 T allele. These results show that the GH1 T1663A A/A genotype can decrease the risk for colorectal cancer.

Alcohol dehydrogenase-2 and aldehyde dehydrogenase-2 genotypes, alcohol drinking and the risk for esophageal cancer in a Chinese population.

To investigate the relationship among alcohol dehydrogenase-2 (ADH2) and aldehyde dehydrogenase-2 (ALDH2) genetic polymorphisms, alcohol consumption and the susceptibility to esophageal cancer in a Chinese population, we conducted a case-control study with 221 cases and 191 population-based controls in the Taixing city of Jiangsu Province of China. ADH2 and ALDH2 genotypes were examined using PCR and denaturing high-performance liquid chromatography. Alcohol drinkers with the ALDH2 A allele showed a significantly increased risk of esophageal cancer compared with drinkers with the ALDH2 G/G genotype (odds ratio (OR)=3.08, 95% confidence interval (CI): 1.65-5.78) or nondrinkers with any genotype (OR=3.05, 95% CI: 1.49-6.25). Drinkers with the ALDH2 A allele and a cumulative amount of alcohol consumption > or =2.5 (kg * years) were at a significantly higher risk of developing esophageal cancer (OR=11.93, 95% CI: 3.17-44.90) compared with individuals with ALDH2 G/G genotypes and a cumulative amount of alcohol consumption <2.5 (kg * years). A dose-dependent positive result was found between cumulative amount of alcohol consumption and risk of esophageal cancer in individuals carrying the ALDH2 A allele (P=0.023) and the homozygous ALDH2 G allele (P=0.047). Compared with individuals carrying both ALDH2 G/G and ADH2 A/A alleles and with a cumulative amount of alcohol consumption <2.5 (kg * years), drinkers carrying both ALDH2 A and ADH2 G alleles and with a cumulative amount of alcohol consumption > or =2.5 (kg * years) showed a significantly elevated risk of esophageal cancer (OR=53.15, 95% CI: 4.24-666.84). This result suggests that to help lower their risk for esophageal cancer, persons carrying the ALDH2 A allele should be encouraged to reduce their consumption of alcoholic beverages.

[Association of IVS10+12G>A polymorphism in hMSH2 gene with colorectal cancer in Chinese].

OBJECTIVE: To investigate the association of the single-nucleotide polymorphism (SNP) IVS10+12 G>A in hMSH2 gene with colorectal cancer in a Chinese population of Jiangsu province. METHODS: A case-control study to investigate whether this SNP affects the risk of developing colorectal cancer was conducted. Subjects included 108 colorectal cancer patients and 180 healthy individuals. Peripheral white blood cell DNA was obtained from all subjects. The hMSH2 gene IVS10+12 G>A was genotyped using a PCR-based DHPLC, the existence of IVS10+12 G>A was verified by DNA sequencing. RESULTS: The allele frequency of the IVS10+12 G>A in the hMSH2 gene in the healthy individuals was 51.7%. There was significant difference in the frequency of the IVS10+12 G>A between patients and healthy controls (P<0.05), and between familial patients and healthy controls (P<0.05). There was also significant difference of the frequency of the IVS10+12 G>A between patients younger than 50 years, and patients with high consumption of fried food and pickled vegetable and healthy controls respectively (P<0.05). CONCLUSION: This SNP may be associated with colorectal cancers in Chinese. Further investigation with larger sample size is needed.

Antithrombotic Therapy for Patients With Left Ventricular Mural Thrombus.

BACKGROUND: Contemporary data are lacking regarding the prognosis and management of left ventricular thrombus (LVT). OBJECTIVES: The purpose of this study was to quantify the effect of anticoagulation therapy on LVT evolution using sequential imaging and to determine the impact of LVT regression on the incidence of thromboembolism, bleeding, and mortality. METHODS: From January 2011 to January 2018, a comprehensive computerized search of LVT was conducted using 90,065 consecutive echocardiogram reports. Only patients with a confirmed LVT were included after imaging review by 2 independent experts. Major adverse cardiovascular events (MACE), which included death, stroke, myocardial infarction, or acute peripheral artery emboli, were determined as well as major bleeding events (BARC ≥3) and all-cause mortality rates. RESULTS: There were 159 patients with a confirmed LVT. Patients were treated with vitamin K antagonists (48.4%), parenteral heparins (27.7%), and direct oral anticoagulants (22.6%). Antiplatelet therapy was used in 67.9% of the population. A reduction of the LVT area from baseline was observed in 121 patients (76.1%), and total LVT regression occurred in 99 patients (62.3%) within a median time of 103 days (interquartile range: 32 to 392 days). The independent correlates of LVT regression were a nonischemic cardiomyopathy (hazard ratio [HR]: 2.74; 95% confidence interval [CI]: 1.43 to 5.26; p = 0.002) and a smaller baseline thrombus area (HR: 0.66; 95% CI: 0.45 to 0.96; p = 0.031). The frequency of MACE was 37.1%; mortality 18.9%; stroke 13.3%; and major bleeding 13.2% during a median follow-up of 632 days (interquartile range: 187 to 1,126 days). MACE occurred in 35.4% and 40.0% of patients with total LVT regression and those with persistent LVT (p = 0.203). A reduced risk of mortality was observed among patients with total LVT regression (HR: 0.48; 95% CI: 0.23 to 0.98; p = 0.039), whereas an increased major bleeding risk was observed among patients with persistent LVT (9.1% vs. 12%; HR 0.34; 95% CI: 0.14 to 0.82; p = 0.011). A left ventricular ejection fraction ≥35% (HR: 0.46; 95% CI: 0.23 to 0.93; p = 0.029) and anticoagulation therapy >3 months (HR: 0.42; 95% CI: 0.20 to 0.88; p = 0.021) were independently associated with less MACE. CONCLUSIONS: The presence of LVT was associated with a very high risk of MACE and mortality. Total LVT regression, obtained with different anticoagulant regimens, was associated with reduced mortality.

A suppressor of multiple extracellular matrix-degrading proteases and cancer metastasis.

Cancer metastasis remains the most poorly understood process in cancer biology. It involves the degradation of extracellular matrix (ECM) proteins by a series of 'tumour-associated' proteases. Here we report the identification of a novel protease suppressor, NYD-SP8, which is located on human chromosome 19q13.2. NYD-SP8 encodes a 27 kD GPI-anchored cell surface protein, which shows structural homology to urokinase plasminogen activator receptor (uPAR). Co-immunoprecipitation experiments showed that NYD-SP8 binds to uPA/uPAR complexes and interfere with active uPA production. Overexpression of NYD-SP8 results in reducing activities of the three major classes of proteases known to be involved in ECM degradation, including uPA, matrix metalloproteinases (MMPs) and cathepsin B, leading to suppression of both in vitro and in vivo cancer cell invasion and metastasis. These data demonstrate an important role of NYD-SP8 in regulating ECM degradation, providing a novel mechanism that modulates urokinase signalling in the suppression of cancer progression.

[Promoter hypermethylation and loss of heterozygosity of the APC gene in patients with familial adenomatous polyposis].

OBJECTIVE: To investigate the status of hypermethylation in the promoter 1A region of the adenomatus polyposis coli (APC) gene in 3 familial adenomatous polyposis (FAP) pedigrees and to screen large fragment deletions in the APC gene. METHODS: DNA from tumor tissues and corresponding normal tissues of 5 FAP patients was modified by sodium bisulfite. Then the methylation status of the APC gene was analyzed by methylation specific-PCR (MSP) and DNA sequencing. Multiplex ligation-dependent probe amplification (MLPA) was used to screen aberrations involving large fragments from all the 15 exons and promoter region of APC gene. RESULTS: No methylation was present in normal tissues. Hypermethylation was found in tumor tissues of one proband and her son. Loss of heterozygosity was observed in another patient from the same FAP family. CONCLUSION: Aberrant methylation of the APC promoter region provides an important mechanism for impairing APC function and may occur early during colon neoplasia progression. Loss of heterozygosity may play a role in patients with classical polyposis.

Allele 2 of the interleukin-1 receptor antagonist gene (IL1RN*2) is associated with a decreased risk of primary lung cancer.

IL-1 receptor antagonist (IL-1ra), a structural variant of IL-1, binds to the same IL-1 receptor and acts as a competitive inhibitor of IL-1 bioactivity. IL-1ra protein has been widely investigated and found to be associated with different human malignancies. In the second intron of the IL-1RN gene, there is a functional polymorphism of a variable number of tandem repeats (VNTR), which is characterized as having an importance role in regulating the serum IL-1ra levels, human immune response and cancer risk. We genotyped this VNTR of IL-1RN in a case-control study of 885 histologically confirmed lung cancer patients and 1024 cancer-free controls frequency-matched to the cases on age and sex in a Chinese population to evaluate the association of this variant and lung cancer risk. We found that the presence of the allele 2 of IL-1RN (IL-RN*2) was associated with a 32% significantly decreased risk of lung cancer (adjusted OR, 0.68; 95% CI, 0.52-0.89). Stratified analyses revealed that the reduced risks associated with the genotypes with IL-RN*2allele (I/II and II/II) were more evident in non-smokers (adjusted OR, 0.53; 95% CI, 0.35-0.79) and in subjects with squamous cell carcinoma (adjusted OR, 0.49; 95% CI, 0.31-0.76). These findings support our priori hypothesis that the IL1RN*2 allele may contribute to lung cancer risk in the Chinese population. More functional data for this IL1RN polymorphism are warranted to explore its role in lung carcinogenesis.

Functional polymorphisms of matrix metalloproteinase-9 are associated with risk of occurrence and metastasis of lung cancer.

PURPOSE: Matrix metalloproteinase 9 (MMP-9) plays critical roles in cancer development and aggression. Nonsynonymous single-nucleotide polymorphisms (SNP) in the functional domain of the MMP-9 gene may influence substrate and inhibitor binding and contribute to cancer predisposition and aggression. PATIENTS AND METHODS: To test our hypothesis that common nonsynonymous SNPs, R279Q, P574R, and R668Q, in MMP-9 are associated with lung cancer development and metastasis, we conducted a case-control study of 744 patients with incident lung cancer and 747 cancer-free controls in Southeast China. Multivariate logistic regression analysis was used to calculate adjusted odds ratio (OR) and 95% confidence interval (95% CI). RESULTS: We found that compared with the 279QQ genotype, the 279RR genotype was associated with significant elevated risk of lung cancer with metastasis (adjusted OR, 1.79; 95% CI, 1.03-3.08), whereas the 574PR heterozygote and 574PP homozygote had 1.46-fold (95% CI, 0.94-2.26) and 1.69-fold elevated risk (95% CI, 1.10-2.60), respectively, compared with the 574RR genotype. When we examined the combined effect of R279Q and P574R and used the 279R and 574P as the risk alleles, a significantly increased risk of lung cancer was associated with both the genotypes containing "1 to 2 risk alleles" (adjusted OR, 2.16; 95% CI, 1.30-3.59) and containing ">2 risk alleles" (adjusted OR, 2.44; 95% CI, 1.48-4.03), and it was more pronounced in 290 lung cancer cases with metastasis [adjusted OR, 2.30 (95% CI, 1.09-4.85) for the 1 to 2 risk alleles subgroup and adjusted OR, 2.82 (95% CI, 1.35-5.88) for the >2 risk alleles subgroup], compared with those without any risk alleles. However, no overall significant associations were observed between R668Q and lung cancer risk in this study population. CONCLUSION: These findings indicate that the potentially functional polymorphisms, MMP-9 P574R and R279Q, may confer the biomarker in the occurrence and metastasis of primary lung cancer. Further functional studies including these two genetic variants are warranted to confirm our findings.

Transabdominal transanal resection of distal rectal cancer after high dose preoperative radiotherapy: a Chinese experience in preserving sphincter function.

BACKGROUND: The combination of high dose preoperative radiotherapy and transanal abdominal transanal radical proctosigmoidectomy and colo-anal anastomosis as a sphincter-preserving method has never been performed in mainland China. OBJECTIVES: To assess the feasibility and efficacy of high dose preoperative radiotherapy and TATA as a sphincter-preserving method in Jiangsu, an economically well-developed region of China with a population of 70 million people. METHODS: From September 1994 to September 2000, 25 consecutive patients with pathologically confirmed distal rectal adenocarcinoma were treated preoperatively with a total dose of 45-46 Gy at 1.8-2.0 Gy per fraction during 5 weeks. Sphincter-preserving surgery by TATA was performed 4-6 weeks after radiotherapy. RESULTS: Acute toxicity of preoperative radiotherapy was tolerable. Eight percent of the patients presented pathologic complete tumor response after preoperative radiotherapy. All patients underwent TATA as scheduled. During a median follow-up of 70 months, the 5 year survival rate was 88%. The 5 year survival rate for those tumors down-staged to pathological TO or to pT1 was 100%. CONCLUSIONS: High dose preoperative radiotherapy and TATA as a sphincter-preserving method was feasible and efficient in Chinese patients with distal rectal cancer. In this study, the subset of patients with a good response to radiotherapy had a better clinical outcome.

[A novel APC gene germline mutation in a familial adenomatous polyposis pedigree].

OBJECTIVE: To detect the adenomatous polyposis coli (APC) gene germline mutation in the proband and her family members with familial adenomatous polyposis (FAP). METHODS: The diagnosis of a patient with FAP was validated by colonoscopy, pathology and the family history. The systematic screening with multiplex ligation-dependent probe amplification (MLPA), denaturing high-performance liquid chromatography (DHPLC) and DNA sequencing were carried out to detect APC gene germline mutations. RESULTS: A novel mutation c.1999 C >T (Q667X) of APC, which leads to premature termination of the protein, was identified in this family. This mutation manifested an aggressive form of FAP with early onset of colorectal adenocarcinoma and colonic adenoma. CONCLUSION: The mutation of APC Q667X is the cause of clinical phenotype of this family with FAP, and the prophylactic colectomy for the affected family members should be considered.

[The expression of mutation p53 gene from circulating cancer cells of peripheral blood and the clinical significance in detecting the patients with colorectal cancer].

OBJECTIVE: To study the clinical significance of detecting p53 gene mutation expression in colorectal cancer cells of peripheral blood. METHODS: Flow cytometry (FCM) was used to detect p53 gene mutation expression in peripheral blood cancer cells of 128 patients with colorectal cancer. Experimental data were analyzed by SPSS (v.11.0) software. RESULTS: The lymph node metastasis showed the significant difference statistically (P<0.01) between p53 positive and negative expression in the colorectal cancer patients. The mutation p53 expression associated with existing histological differentiation (r=0.8476, P<0.05). A lymph node metastasis difference was observed between left and right colorectal cancers of mutation p53 positive expression. CONCLUSION: Detecting the mutation p53 expression in cancer cells of peripheral blood might be helpful to the early diagnosis of colorectal cancer.

Flow injection immunoassay for carcinoembryonic antigen combined with time-resolved fluorometric detection.

Time-resolved fluorescence has been developed for immunoassay to obtain higher sensitivity than usual immunoassays. In this paper, a simple, sensitive and specific method was developed for immunoassay of serum carcinoembryonic antigen (CEA) by combining time-resolved fluoroimmunoassay (TRFIA) and flow injection analysis. Based on a sandwich immunoassay format, a monoclonal antibody immobilized immunoaffinity column inserted in a flow system was used for immunoreactions. The cleaved solution was collected after the reaction between the immunocomplex in the immunoaffinity column and the enhancement solution that was used to cleave the Eu-labels from the immunocomplex, and then detected by time-resolved fluorescence. Serum CEA could be detected in the linear range from 2.5 to 100 ng/ml with a correlation coefficient of 0.997 and the detection limit of 1.0 ng/ml. Twenty human serum samples detected by this method were in good agreement with the results obtained by the electrochemiluminescence immunoassay. This method could be further developed for fast practical clinical detection of serum CEA levels.

Clinical Observations on Treatment for Chinese Patients with Gastrointestinal Stromal Tumors.

BACKGROUND: To investigate the diagnostic and treatment methods for Chinese patients with gastrointestinal stromal tumor (GIST). MATERIALS AND METHODS: From January 2004 to June 2014, patients diagnosed with primary GIST and treated by a single medical team in the Department of Digestive Disease of XuYi Hospital of Traditional Chinese Medicine were retrospectively recruited. Re-examination and follow-up was conducted regularly and abdominal enhanced CT, blood biochemistry and responses to surgery or imatinib were recorded. RESULTS: A total of 15 patients were enrolled, including 9 male and 6 female patients, with an average age of 54 years (ranging from 32-81 years). The primary symptoms were abdominal uncomfortable in 5 patients, abdominal pain in 6 patients as well as nausea and vomiting in 4 patients. One patient was diagnosed with bowl obstruction at the first visit. All patients were treated with surgery, and tumor site was confirmed 1 esophagus, 6 stomach, 4 small bowel, and 4 colorectal and all patients were pathologically diagnosed with GIST. Immunochemical test positive for CD 117 was found 12 patients, and positive for CD 34 in7 patients. The median follow-up time was 24 months (range of 3-63). Three metastasis were confirmed 1.5, 2 and 2.6 years postoperatively. Three patients were treatment by imatinib postoperatively. CONCLUSIONS: Surgery remains the main treatment method for Chinese patients with GIST and imatinib could be feasible and safe for treating Chinese patients with GIST.

Carcinoma microsatellite instability status as a predictor of benefit from fluorouracil-based adjuvant chemotherapy for stage II rectal cancer.

PURPOSE: Rectal cancers with high microsatellite-instable have clinical and pathological features that differentiate them from microsatellite-stable or low- frequency carcinomas, which was studied rarely in stage II rectal cancer, promoting the present investigation of the usefulness of microsatellite-instability status as a predictor of the benefit of adjuvant chemotherapy with fluorouracil in stage II rectal cancer. PATIENTS AND METHODS: Data of 460 patients who underwent primary anterior resection with a double stapling technique for rectal carcinoma at a single institution from 2008 to 2012 were retrospectively collected. All patients experienced a total mesorectal excision (TME) operation. Survival analysis were analyzed using the Cox regression method. RESULTS: Five-year rate of disease-free survival (DFS) was noted in 390 (84.8%) of 460 patients with stage II rectal cancer. Of 460 tissue specimens, 97 (21.1%) exhibited high-frequency microsatellite instability. Median age of the patients was 65 (50-71) and 185 (40.2%) were male. After univariate and multivariate analysis, microsatellite instability (p= 0.001), female sex (p< 0.05) and fluorouracil-based adjuvant chemotherapy (p< 0.001), the 3 factors were attributed to a favorable survival status independently. Among 201 patients who did not receive adjuvant chemotherapy, those cancers displaying high-frequency microsatellite instability had a better 5-year rate of DFS than tumors exhibiting microsatellite stability or low-frequency instability (HR, 13.61 [95% CI, 1.88 to 99.28]; p= 0.010), while in 259 patients who received adjuvant chemotherapy, there was no DFS difference between the two groups (p= 0.145). Furthermore, patients exhibiting microsatellite stability or low-frequency instability who received adjuvant chemotherapy had a better 5-year rate of DFS than patients did not (HR, 5.16 [95% CI, 2.90 to 9.18]; p< 0.001), while patients exhibiting high-frequency microsatellite instability were not connected with increased DFS (p= 0.696). It was implied that female patients had better survival than male. CONCLUSION: Survival status after anterior resection of rectal carcinoma is related to the microsatellite instability status, adjuvant chemotherapy and gender. Fluorouracil-based adjuvant chemotherapy benefits patients of stage II rectal cancer with microsatellite-stable or low microsatellite-instable, but not those with high microsatellite- instable. Additionally, free of adjuvant chemotherapy, carcinomas with high microsatellite-instable have a better 5-year rate of DFS than those with microsatellite-stable or low microsatellite-instable, and female patients have a better survival as well.

Analysis of Small Fragment Deletions of the APC gene in Chinese Patients with Familial Adenomatous Polyposis, a Precancerous Condition.

BACKGROUND: Familial adenomatous polyposis (FAP) is an autosomal dominant inherited disease mainly caused by mutations of the adenomatous polyposis coli (APC) gene with almost complete penetrance. These colorectal polyps are precancerous lesions that will inevitable develop into colorectal cancer at the median age of 40-year old if total proctocolectomy is not performed. So identification of APC germline mutations has great implications for genetic counseling and management of FAP patients. In this study, we screened APC germline mutations in Chinese FAP patients, in order to find novel mutations and the APC gene germline mutation characteristics of Chinese FAP patients. MATERIALS AND METHODS: The FAP patients were diagnosed by clinical manifestations, family histories, endoscope and biopsy. Then patients peripheral blood samples were collected, afterwards, genomic DNA was extracted. The mutation analysis of the APC gene was conducted by direct polymerase chain reaction (PCR) sequencing for micromutations and multiplex ligation-dependent probe amplification (MLPA) for large duplications and/or deletions. RESULTS: We found 6 micromutations out of 14 FAP pedigrees, while there were no large duplications and/or deletions found. These germline mutations are c.5432C>T(p. Ser1811Leu), two c.3926_3930delAAAAG (p.Glu1309AspfsX4), c.3921_3924delAAAA (p.Ile1307MetfsX13), c3184_3187delCAAA(p.Gln1061AspfsX59) and c4127_4126delAT (p.Tyr1376LysfsX9), respectively, and all deletion mutations resulted in a premature stop codon. At the same time, we found c.3921_3924delAAAA and two c.3926_3930delAAAAG are located in AAAAG short tandem repeats, c3184_3187delCAAA is located in the CAAA interrupted direct repeats, and c4127_4128 del AT is located in the 5'-CCTGAACA-3' ,3'-ACAAGTCC-5 palindromes (inverted repeats) of the APC gene. Furthermore, deletion mutations are mostly located at condon 1309. CONCLUSIONS: Though there were no novel mutations found as the pathogenic gene of FAP in this study, we found nucleotide sequence containing short tandem repeats and palindromes (inverted repeats), especially the 5 bp base deletion at codon 1309, are mutations in high incidence area in APC gene.

[Study of in vivo micronucleus formation in lymphocytes from the patients and its relation to malignant degrees of colorectal cancer].

OBJECTIVE: To investigate the association of the micronucleus (MN) formation in lymphocytes from patients with the malignant degrees of colorectal cancer. METHODS: The MN test in capillary blood lymphocytes was conducted in 112 patients randomly selected from in-hospital patients before therapy. Experimental data were analyzed by SPSS (v.10.1) software. RESULTS: The differences in the frequency of MN between 7 pathological types of colorectal cancers and controls were statistically significant (P<0.01). The frequency of MN increased with the decrease of the histological differentiation in colorectal cancer, and the statistically significant differences were seen between low differentiation group and the other differentiation groups in colorectal cancers. CONCLUSION: There is a significant correlation between MN formation and the malignant degrees of colorectal cancer, and MN formation will be a useful biomarker for the identification of malignant degrees of colorectal cancer before operation or for the screening of high risk subgroup.

[Mutation analysis on MSH2 and MLH1 genes in patients of colorectal cancer at early age].

OBJECTIVE: To investigate the etiological role of function and construction alteration in mismatch repair genes MSH2 and MLH1 in the patients onset of colorectal cancers (CRC) at early ages. METHODS: The genomic DNA was extracted from the tumor tissues and normal colon tissues during operation and subjected to analysis of microsatellite instability (MSI) in 42 Chinese patients aged less than 50 with CRC. Mutation screenings were performed with denaturing high-performance liquid chromatography (DHPLC) followed by DNA sequencing of DNA samples with variant peaks, and genomic deletion detection with quantitative multiplex PCR (Q-M-PCR) in the patients uncovered with MSI(+). RESULTS: 22 out of the 42 (52.4%) patients investigated were microsatellite instability positive (MSI(+)), 10/42 MSI(+)-H and 12/42 MSI(+)-L. 8 kinds of DNA germline alterations, 5 polymorphisms and 3 novel point mutations, were found in 9 patients with MSI(+). A large DNA (exon 1-6) deletion in MSH2 gene and a missense mutation Met242Ile in MLH1 gene were unveiled in CRC tissues of two patients with MSI(+)-H. CONCLUSION: Mutations of mismatch repair genes are frequent in Chinese patients of CRC with onset at early ages.