Analysis of APC gene variants in a pedigree affected with familial adenomatous polyposis / 中华医学遗传学杂志

OBJECTIVE@#To explore the genetic basis for a pedigree affected with familial adenomatous polyposis (FAP).@*METHODS@#The proband, with recurrence of blood in the stool, was diagnosed with FAP by endoscopy, pathological examination and a family history. She was subjected to next generation sequencing to detect genetic variant. Suspected variant was verified by Sanger sequencing of members from her pedigree.@*RESULTS@#The proband, her mother and brother were found to carry a heterozygous c.532-1G>A variant of the APC gene, which may lead to aberrant splicing of mRNA resulting in a truncated protein, which may lose its normal function and promote the tumorigenesis. Based on the American College of Medical Genetics and Genomics standards and guidelines, c.532-1G>A variant of APC gene was predicted to be pathogenic(PVS1+PP1+PP4+PP5).@*CONCLUSION@#The c.532-1G>A variant of the APC gene probably underlay the pathogenesis of FAP in this pedigree.

Expression of e-cadherin and wnt pathway proteins betacatenin, apc, tcf-4 and survivin in gastric adenocarcinoma: clinical and pathological implication / Expressão da e-caderina e das proteínas da via de sinalização wnt betacatenina, apc, tcf-4 e survivina no adenocarcinoma gástrico: implicações clínica e patológica

ABSTRACT Background: Gastric cancer is the fifth most frequent cancer and the third most common cause of cancer-related deaths worldwide.It has been reported that Wnt/ betacatenin pathway is activated in 30-50% of these tumors. However,the deregulation of this pathway has not been fully elucidated. Aim: To determine the expression of E-cadherin, betacatenin, APC, TCF-4 and survivin proteins in gastric adenocarcinoma tissues and correlate with clinical and pathological parameters. Method: Seventy-one patients with gastric adenocarcinoma undergoing gastrectomy were enrolled. The expression of E-cadherin, betacatenin, APC, TCF-4 and survivin proteins was detected by immunohistochemistryand related to the clinical and pathological parameters. Results: The expression rates of E-cadherin in the membrane was 3%; betacatenin in the cytoplasm and nucleus were 23,4% and 3,1% respectively; APC in the cytoplasm was 94,6%; TCF-4 in the nucleus was 19,4%; and survivin in the nucleus 93,9%. The expression rate of E-cadherin was correlated with older patients (p=0,007), while betacatenin with tumors <5 cm (p=0,041) and APC with proximal tumors (p=0,047). Moreover, the expression of TCF-4 was significantly higher in the diffuse type (p=0,017) and T4 tumors (p=0,002). Conclusion: The Wnt/betacatenin is not involved in gastric carcinogenesis. However, the high frequency of survivin allows to suggest that other signaling pathways must be involved in the transformation of gastric tissue.

RESUMO Racional: O câncer gástrico encontra-se entre as principais neoplasias malignas do mundo sendo o quinto mais incidente e o terceiro em relação ao índice de mortalidade. Acredita-se que a via Wnt/betacatenina esteja ativada em 30-50% desses tumores, porém a desregulação dela ainda não está completamente esclarecida. Objetivo: Avaliar a imunoexpressão das proteínas E-caderina, betacatenina, APC, TCF-4 e survivina em tecidos de adenocarcinoma gástrico e correlacioná-las com as variáveis clínicas dos doentes e anatomopatológicas do tumor. Método: Foram coletados os dados clínicos e anatomopatológicos dos prontuários de 71 doentes com adenocarcinoma gástrico submetidos à gastrectomia. O material obtido na operação foi submetido à análise imunoistoquímica e a frequência da expressão de cada proteína pôde ser analisada de acordo com a sua localização na célula e relacionada com as variáveis clinicopatológicas. Resultados: A graduação percentualda expressão e da localização das proteínas foi a seguinte: E-caderina em 3% na membrana; betacatenina em 23,4% no citoplasma e 3,1% no núcleo; APC em 94,6% no citoplasma; TCF-4 em19,4% no núcleo; e survivina em 93,9% no núcleo. Houve relação entre expressão da proteína E-caderina com a idade mais avançada (p=0,007); betacatenina com tumores <5 cm de diâmetro (p=0,041);APC com tumores proximais (p=0,047); e TCF-4 com tipo difuso da classificação de Lauren (p=0,017) e com o grau de penetração tumoral (p=0,002). Conclusão: A via Wnt/betacatenina não está envolvida na carcinogênese gástrica. Porém, a frequência elevada de survivina permite sugerir que outras vias sinalizadoras devam estar envolvidas na transformação do tecido gástrico.

Analysis of C.3925_3929 deletional mutations of APC gene in pedigrees with familial adenomatous polyposis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze the characteristics of germline mutations of adenomatous polyposis coli (APC) gene in pedigrees affected with familial adenomatous polyposis (FAP).</p><p><b>METHODS</b>Genomic DNA was extracted from peripheral blood samples from members of the 13 FAP pedigrees. Multiplex ligation-dependent probe amplification (MLPA) was used to detect large fragment deletions of the APC gene. Subsequently, potential mutation was screened from all exons of the APC gene with PCR amplification and direct sequencing.</p><p><b>RESULTS</b>Germline mutations have been identified in 5 FAP pedigrees, which included c.3184_3187delCAAA, c.5432C>T, c.3925_3928delAAAA and c.3925_3929del AAAAG(in two pedigrees). Small deletional mutations were found primarily in the area of AAAAG tandem repeat sequences.</p><p><b>CONCLUSION</b>C.3925_3929 located in AAAAG tandem repeats is probably the hot spot for APC gene mutations, which are mostly deletional mutations, especially the 5 bp base deletion at codon 1309.</p>

Diálogo y respeto: bases para la construcción de un sistema de salud intercultural para las comunidades indígenas de Puerto Nariño, Amazonas, Colombia / Dialogue and respect: the basis for constructing an intercultural health system for indigenous communities in Puerto Nariño, Amazonas, Colombia

Este artículo presenta las concepciones sobre salud-enfermedad y las propuestas en torno al sistema sanitario planteadas por las comunidades indígenas pertenecientes a las etnias Tikuna, Cocama y Yagua del municipio de Puerto Nariño en el departamento del Amazonas, Colombia. El estudio se realizó entre los años 2010 y 2013. Las herramientas utilizadas para obtener los datos fueron la observación participante, la entrevista y los grupos de discusión. La investigación evidenció falta de información y entendimiento muy profundos por parte de los organismos estatales de salud. Como demanda principal, las comunidades indígenas piden ser escuchadas cuando se tomen decisiones que afectan a su salud o a su manera de entenderla. Se espera que los resultados obtenidos sean tenidos en cuenta en la elaboración de futuros programas de salud y aporten una base para la construcción de un sistema de salud intercultural adecuado para el municipio de Puerto Nariño.

This paper presents the ideas on health and disease as well as proposals regarding the health care system voiced by indigenous communities belonging to the Tikunas, Cocama and Yagua ethnicities of the Puerto Nariño municipality in the department of Amazonas, Colombia. The study was conducted between 2010 and 2013. The tools used to obtain the data were participant observation, interviews and discussion groups. The study evidenced a profound lack of information and understanding on the part of state health agencies. As a principal demand, indigenous communities ask to be heard when decisions affecting their health or their way of understanding health are made. These results should be taken into account in the development of future health programs and provide a basis for the construction of an adequate intercultural health system for the town of Port Nariño.

Analysis of APC gene mutation in a familial adenomatous polyposis pedigree / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To analyze mutation of adenomatous polyposis coli (APC) gene in a family affected with familial adenomatous polyposis.</p><p><b>METHODS</b>The diagnosis was made based on clinical manifestations, family history, presence of numerous polyps in the colon as well as pathological examination. Peripheral blood samples were collected, and genomic DNA was extracted. Potential mutation of the APC gene was detected by polymerase chain reaction (PCR) and DNA sequencing. After finding the mutation in the proband, the same mutation was screened among other family members. The mutation was also confirmed with PCR-restriction fragment length polymorphism (RFLP), with which 100 unrelated healthy controls were examined.</p><p><b>RESULTS</b>A novel heterozygous nonsense mutation c.2891T>G (L964X) of the APC gene was identified in this pedigree. The mutation has led to premature termination of translation. The same mutation was not detected among the 100 healthy controls.</p><p><b>CONCLUSION</b>The c.2891T>G (L964X) of the APC gene probably underlies the familial adenomatous polyposis in this pedigree. The combined DNA sequencing and PCR-RFLP method is efficient and accurate for the diagnosis.</p>

CTNNB1, AXIN1 and APC expression analysis of different medulloblastoma variants

OBJECTIVES: We investigated four components of the Wnt signaling pathway in medulloblastomas. Medulloblastoma is the most common type of malignant pediatric brain tumor, and the Wnt signaling pathway has been shown to be activated in this type of tumor. METHODS: Sixty-one medulloblastoma cases were analyzed for β-catenin gene (CTNNB1) mutations, β-catenin protein expression via immunostaining and Wnt signaling pathway-related gene expression. All data were correlated with histological subtypes and patient clinical information. RESULTS: CTNNB1 sequencing analysis revealed that 11 out of 61 medulloblastomas harbored missense mutations in residues 32, 33, 34 and 37, which are located in exon 3. These mutations alter the glycogen synthase kinase-3β phosphorylation sites, which participate in β-catenin degradation. No significant differences were observed between mutation status and histological medulloblastoma type, patient age and overall or progression-free survival times. Nuclear β-catenin accumulation, which was observed in 27.9% of the cases, was not associated with the histological type, CTNNB1 mutation status or tumor cell dissemination. The relative expression levels of genes that code for proteins involved in the Wnt signaling pathway (CTNNB1, APC, AXIN1 and WNT1) were also analyzed, but no significant correlations were found. In addition, large-cell variant medulloblastomas presented lower relative CTNNB1 expression as compared to the other tumor variants. CONCLUSIONS: A small subset of medulloblastomas carry CTNNB1 mutations with consequent nuclear accumulation of β-catenin. The Wnt signaling pathway plays a role in classic, desmoplastic and extensive nodularity medulloblastoma variants but not in large-cell medulloblastomas.

Expression of Wnt5a, APC, β-catenin and their clinical significance in human colorectal adenocarcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the expression of Wnt5a gene mRNA and Wnt5a, APC, β-catenin proteins in human colorectal adenocarcinoma (CRC) and explore its clinical significance.</p><p><b>METHODS</b>Wnt5a mRNA level was measured in 30 patients with CRC and paired non-tumor tissues by real-time PCR. Immunohistochemical staining of Wnt5a, APC, β-catenin was performed in samples of 62 patients with CRC using SP system.</p><p><b>RESULTS</b>The relative expression level of Wnt5a mRNA in fresh CRC is 0.1232 ± 0.0140, which is significantly higher than that in adjacent colorectal mucosa (0.0497 ± 0.0074, P = 0.02). A low expression of Wnt5a protein was observed in 38 of 62 CRC. Wnt5a protein expression was closely correlated with the tumor types and the degree of tumor differentiation (P < 0.05). There was no apparent relationship with lymph node metastasis, depth of myometrial invasion and TNM stages (P > 0.05). APC protein was decreased in 38 of 62 CRC. The expression of APC was closely correlated with the tumor types (P < 0.05). There was no apparent relationship with the degree of tumor differentiation, lymph node metastasis, depth of myometrial invasion and TNM stages (P > 0.05). The expression of β-catenin was observed in cytoplasm and/or cell nuclei in 50 of 62 CRC. The positive rate of β-catenin expression was closely correlated with the degree of tumor differentiation, lymph node metastasis, depth of myometrial invasion and TNM stages (P < 0.05). There was no apparent relationship with the tumor types (P > 0.05). The expressions of Wnt5a (r = 0.271, P = 0.027) and APC (r = 0.343, P = 0.004) were correlated with that of β-catenin in CRC, respectively, but there was no correlation between the expressions of Wnt5a and APC protein (r = 0.218, P = 0.078) in the tumors.</p><p><b>CONCLUSIONS</b>Wnt5a, APC and β-catenin genes might be involved in the carcinogenesis and development of CRC. It is hypothesized that down-regulation of APC and Wnt5a proteins may be one of causes of ectopic expression of β-catenin in CRC.</p>

Expression of DNA methylation of APC in peripheral blood and tumor tissue in patients with esophageal squamous cell carcinoma / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the relationship between methylation status of APC gene in both peripheral blood and tumor tissues and clinical-pathology characteristics in patients with esophageal squamous cell carcinoma(ESCC), and to study the dynamic change of APC methylation in peripheral blood in the perioperative period.</p><p><b>METHODS</b>Real-time MSP technique was used to detect methylation status of APC in tumor tissues, adjacent normal tissues and peripheral blood on the day before the surgery, intraoperative, postoperative day 7 in 76 cases with ESCC. Sixty healthy volunteers matched by age and gender were randomly selected as controls.</p><p><b>RESULTS</b>The methylation rate of APC in tumor tissue and peripheral blood was 44.74%(34/76) and 42.11%(32/76), respectively, which were significantly higher than that in adjacent normal tissue and controls [6.58%(5/76) and 1.67%(1/60), P=0.000]. The methylation rates showed good agreement between tumor tissues and peripheral blood, which could be verified by ROC curve(A Zeta=0.849, P=0.000). APC methylation rate was significantly related to pathological staging, lymph node metastasis, depth of invasion, and invasion of nerve and vessel (P<0.05). The results demonstrated that family history of cancer was independently associated with APC methylation in peripheral blood(P<0.05). DNA methylation rates in peripheral blood showed an initial increase and then decreased in the preoperative period, intraoperative and postoperative.</p><p><b>CONCLUSION</b>The methylation rates of APC among free DNA in peripheral blood in patients with ESCC reflect tumor progression, and decrease with the solid tumour resection.</p>

Correlation of BRCA1 and APC aberrant methylation with the response to anthracycline-based neoadjuvant chemotherapy in primary breast cancer / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the correlation of hypermethylation of BRCA1 and APC gene promoters with the response to anthracycline-based neoadjuvant chemotherapy in primary breast cancer.</p><p><b>METHODS</b>One hundred and forty patients with primary breast cancer received anthracycline-based neoadjuvant chemotherapy, and pretreatment hypermethylation status of BRCA1 and APC genes promoters was detected by methylation-specific PCR.</p><p><b>RESULTS</b>Of the 140 patients, 30 (21.4%) achieved pathological complete response (pCR), and methylation rates of BRCA1 and APC gene promoters were 21.4% (30/140) and 18.3% (24/131), respectively. Among the 110 patients with unmethylated BRCA1 gene, 28 (25.5%) achieved pCR, while in the 30 patients with methylated BRCA1 gene, only 2 (6.7%) had a pCR, with a significant difference between the two groups (chi(2) = 4.94, P = 0.026). However, no statistically significant correlation was found between the methylation of APC gene and pCR to neoadjuvant chemotherapy in this cohort of patients (P > 0.05).</p><p><b>CONCLUSION</b>Primary breast cancer with an unmethylated BRCA1 gene is prone to achieve a pathological complete response to anthracycline-based neoadjuvant chemotherapy than those with a methylated BRCA1 gene. BRCA1 methylation status may be a useful predictor for anthracycline-based neoadjuvant chemotherapy in primary breast cancer patients.</p>

Expression of beta-catenin and adenomatous polyposis coli protein and correlation between them in the development of mouse tooth germ / 华西口腔医学杂志

<p><b>OBJECTIVE</b>To examine the distributions of beta-catenin and adenomatous polyposis coli (APC) protein in the tooth germ, and obtain the messages of function of the two factors and the relationship between them.</p><p><b>METHODS</b>Mice were selected and cohabited with the ratio of female mice to male ones being 2:1, and Embryo day 0.5 was confirmed based on the finding of vaginal plug. The distributions of beta-catenin and APC protein in the Embryos on day 13.5, 14.5, 15.5, 16.5, 17.5 were examined in the paraffin-embedded sections by immunohistochemistry methods.</p><p><b>RESULTS</b>During E13.5 d to E17.5 d, positive expression of beta-catenin was found in the oral epithelium and the dental lamina, and became more and more strong. The staining were whole cell. During the bud stage, strong positive expression of APC protein was found in the oral epithelium and the dental lamina, but the expression displayed a down-regulation tendency. The staining was the cytomembrane and cytoplasm. There was negative correlation between beta-catenin and APC protein (P<0.01).</p><p><b>CONCLUSION</b>The result of beta-catenin suggests its contribution in the early development of enamel organ and the proliferation of cell. Coincidance of the two factors staining site was found, according to the statistics.</p>

Abnormalities of chromosome 8, APC and beta-catenin genes in aggressive fibromatosis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the role of abnormalities of chromosome 8, APC and beta-catenin genes in tumorigenesis of aggressive fibromatosis.</p><p><b>METHODS</b>Trisomy 8 was detected by interphase fluorescence in situ hybridization (FISH). The APC gene and beta-catenin gene mutations were detected by denaturing high performance liquid chromatography (DHPLC) and direct sequence analysis after the PCR transition.</p><p><b>RESULTS</b>The rate of trisomy 8 in recurrent tumors (62.5%, 5/8) was significantly higher than that in the primary tumors (8.3%, 1/12). Somatic substitution of APC gene was found in 18 of 69 (26.1%) aggressive fibrometases. Somatic transition of beta-catenin gene was detected in 13 of 69 (18.8%) and mutation at codon 41 in exon 3 involving threonine residues implicated in the degradation of beta-catenin. The abnormal expression of beta-catenin had no significant correlation with the mutation of APC or beta-catenin gene. The group with positively expressed beta-catenin protein showed a significant higher c-myc protein expression than those without (P = 0.001). The Ki-67 index was extremely low in all the lesions. The apoptosis index (AI) of the groups with positively expressed c-myc and cyclin D1 showed significantly lower AI than those without.</p><p><b>CONCLUSION</b>Trisomy 8 may serve as a useful predictor of recurrence in aggressive fibromatosis. There are somatic mutations of the APC and beta-catenin genes in the aggressive fibromatosis, and there are abnormalities in the Wnt signaling pathway. These abnormalities may result in the aberrances of cell proliferation and apoptosis, which are likely to be import factors in the tumorigenesis.</p>

IQ domain GTPase-activating protein 1 mediates the process of injury and repair in bronchial epithelial cells / 生理学报

The process of injury and repair in airway epithelium involves cell spreading and migration followed by cell proliferation. IQ domain GTPase-activating protein 1 (IQGAP1) acts in a series of cell processes, but has not been clarified in lung epithelial cells. In this study, a widely used model of injury and repair in vitro by scratching bronchial epithelial cells (BECs) was utilized to investigate the function of IQGAP1. The results showed that IQGAP1 was abundant in BECs of mouse, rat, pig and human. IQGAP1 was colocalized with tubulin cytoskeleton, but was destroyed by nocodazole, a microtubule disassembly reagent. IQGAP1 mRNA and protein expressions increased at 6-9 h after scratching. In addition, overexpression of IQGAP1 translocated β-catenin from the cytoplasm into the nucleus and activated the Tcf/Lef signal. Scratching altered the associations of IQGAP1 with β-catenin, adenomatous polyposis coli (APC) and cytoplasmic linker protein-170 (CLIP-170). Silencing IQGAP1 expression by small interference RNA (siRNA) blocked the wound closure. It is concluded that IQGAP1 signal is involved in the wound closure of BECs induced by scratching.

Promoter hypermethylation and loss of heterozygosity of the APC gene in patients with familial adenomatous polyposis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>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.</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Frequent promoter hypermethylation of several tumor suppressor genes in gastric carcinoma and foveolar epithelium / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the promoter hypermethylation of several tumor suppressor genes in gastric carcinoma (GC) tissue and adjacent normal gastric foveolar epithelium (GFE).</p><p><b>METHODS</b>Methylation specific PCR (MSP) was used to examine the promoter methylation of tumor suppressor genes E-cadherin, hMLH1, APC and MGMT in paraffin-embedded gastric cancer tissue and adjacent normal foveolar epithelium in 106 cases.</p><p><b>RESULTS</b>The positive rate of genes promoter methylation was 44.3% (47/106 cases) and 72.6% (77/106 cases) at one or more genes tested in the normal GFE and GC tissue, respectively. There was a significant difference in the positive rates of gene promoter methylation between normal GFE and GC tissue (P = 0.0001). There was a significant association with Laurén classification, degree of differentiation and pTNM staging in GC (P < 0.05), but no significant association with Ming's classification (P > 0.05).</p><p><b>CONCLUSION</b>Tumor suppressor genes promoter methylation is frequently present in GC and adjacent normal gastric foveolar epithelium, especially in Laurén diffuse type GC, poorly differentiated GC, mucus-secreting (signet ring) cell GC and pTNM stage III and IV GC. Our findings indicate that the gene promoter methylation is a common and early event in GC carcinogensis.</p>

Spatial-temporal distribution of glycogen synthase kinase 3beta and adenomatous polyposis coli protein are involved in the injury and repair of airway epithelial cells induced by scratching / 生理学报

To investigate the roles of glycogen synthase kinase 3beta (GSK3beta) and adenomatous polyposis coli (APC) protein in wound repair of airway epithelial cells (AECs), we established a wound model of airway epithelium in vitro. Then the following tests were undertaken: (1) Western blot was used to detect the levels of total GSK3beta and phosphorylated GSK3beta in human bronchial epithelial (16HBE) cells; (2) The localizations of APC protein was observed by using immunofluorescence technique; (3) Immunoprecipitation was used to investigate the relationship between APC protein and GSK3beta during the repair of 16HBE cells. The results were as follows: (1) The level of phosphorylated GSK3beta increased 0.5 h after scratching (P<0.05), reached a maximum at 6 h (P<0.05), and maintained until 12 h, while the total level of GSK3beta remained constant; (2) Results of immunofluorescence study showed that APC protein clustered with tubulin in the region of the migrating leading cells 6 h after scratching, which was dissimilar with that in the cells 0 h after scratching; (3) GSK3beta and APC protein were immunoprecipitated and analysed on SDS-PAGE. We found that GSK3beta and APC protein were precipitated, indicating that the two proteins existed in a complex. After scratching, dissociation of the two proteins occurred. Taken together, we conclude that scratching caused a decrease in phosphorylation of GSK3beta, and that reduced phosphorylation of GSK3beta promoted APC protein to bind to the plus ends of microtubules and stabilize the growing ends. These observations suggest that APC protein and GSK3beta may synergistically play an important role in the repair of airway epithelium.

Effect of Hydralazine on demethylation status and expression of APC gene, proliferation and apoptosis of human cervical cancer cell lines / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the correlation between methylation status and gene expression of APC (adenomatous polyposis coli) gene in HeLa, CaSki and SiHa cell lines of cervical carcinoma, and explore the effect of hydralazine on the transcription regulation of the 5'CpG island demethylation of APC gene and the proliferation and apoptosis of the cell lines.</p><p><b>METHODS</b>Methylation status and the expression of APC gene were analyzed using methylated specific PCR, RT-PCR and FQ-PCR methods. The expression of beta-catenin protein which correlates closely with APC was detected by SP method after treatment with Hydralazine. MTT and FCM assays were used to observe the changes of proliferation activity and apoptosis of the cells after Hydralazine treatment.</p><p><b>RESULTS</b>(1) APC gene was methylated or hemimethylated respectively in HeLa and CaSki cell lines, at the same time, APC gene was not methylated in SiHa cell. (2) After having been treated by 40 micromol/L Hydralazine for 72 hours, growth inhibitory ratios of HeLa, CaSki and SiHa cell lines were (52.12 +/- 3.78)%, (44.31 +/- 2.59)% and (47.73 +/- 4.73)% respectively, on the contrary, normal cell HECV's growth inhibitory ratio was only (27.18 +/- 0.79)%. APC gene in HeLa and CaSki cell lines which were treated by 40 micromol/L Hydralazine for 72 hours was demethylated and expressed positively, the expression of APC mRNA in HeLa, CaSki and SiHa cell lines increased to 10.35, 11.40 and 0.73 times respectively. (3) Hydralazine, when used at the concentration of 40 micromol/L for 72 hours, induced S phase and G2/M phase arrest and apoptosis in HeLa and CaSki cells. beta-catenin protein can be expressed in cell membrane after treatment with Hydralazine.</p><p><b>CONCLUSION</b>APC gene methylation plays an important role in the carcinogenesis of cervical cells and can re-express after the treatment with Hydralazine which also could inhibit the growth of the cervical cancer cells.</p>

A estória biomolecular do pólipo adenomatoso / The biomolecular story of adenomatous polyps

Um dos principais objetivos do estudo da biologia molecular é compreender os mecanismos bioquímicos capazes de determinar o comportamento biológico das células em seus respectivos tecidos conforme observado à microscopia e macroscopia. A análise histológica da mucosa colonica normal nos mostra que esta é uma estrutura essencialmente dinâmica, com uma grande rotatividade em suas células, a qual é determinada pela concentração nestas células das proteínas que atuam sobre o controle do ciclo celular. Dentre estas, a proteína APC é aparentemente um elemento chave, promovendo a inibição da ação estimulante sobre as divisões celulares exercida por outras proteínas de grande relevância, como a beta-catenina e a survivina. Além de representar a marca genotípica da polipose adenomatosa familiar, a mutação da proteína APC parece desempenhar uma função de gatilho nos processos de desequilíbrio proliferativo observado no processo neoplásico colorretal, o qual pode variar desde a formação de um pequeno adenoma (ou carcinoma intramucoso) até o desenvolvimento de neoplasias invasivas avançadas. A utilização da imunoistoquímica nos permite demonstrar esta relação entre as concentrações de proteínas e o aspecto histológico, representando uma importante ferramenta para um conhecimento cada vez melhor do processo de carcinogênese colorretal.

A novel APC gene germline mutation in a familial adenomatous polyposis pedigree / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the adenomatous polyposis coli (APC) gene germline mutation in the proband and her family members with familial adenomatous polyposis (FAP).</p><p><b>METHODS</b>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.</p><p><b>RESULTS</b>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.</p><p><b>CONCLUSION</b>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.</p>

Dynamic changes of adenomatous polyposis coli protein and glycogen synthase kinase 3beta in the repair of the injured airway epithelial cells in smoking mice / 生理学报

To investigate the roles of adenomatous polyposis coli (APC) protein and glycogen synthase kinase 3beta (GSK3beta) of smoking murine model in the repair of the injured airway epithelial cells (AECs) in different stages, 30 male Kun-Ming mice were randomly divided into two groups, the control group and the smoking group. There were 24 mice in smoking group, and 6 animals were separately killed at the end of the 1st, 4th, 8th and 12th week after smoking. Then the following tests were undertaken: (1) HE staining of lung section to observe the morphological changes of the bronchi in the smoking mice. (2) Immunohistochemical staining of APC protein and GSK3beta in the AECs. (3) Western blot was used to detect the levels of APC protein, GSK3beta and phosphorated GSK3beta (p-GSK3beta) in pulmonary tissue. (4) Observing the localizations of APC protein and GSK3beta in the AECs by immunofluorescence technique. The results showed: (1) AECs showed changes of predominant injury (1-, 4-week), repair (8-week) and reinjury (12-week) along with smoking time prolonged. The experimental results indicated that the model of smoking mice was duplicated successfully. (2) Immunohistochemical results showed that the expression of APC protein in the AECs increased after 1-week smoking (0.458 +/- 0.062 vs 0.399 +/- 0.060, P< 0.05 vs control), but was significantly decreased at the end of the 4th week (0.339+/- 0.056, P<0.01 vs control) and increased at the end of the 8th and 12th week (0.387 +/- 0.041, 0.378 +/- 0.037, P<0.05 vs 4-week). The expression of GSK3beta in the AECs of smoking mice obviously decreased (P<0.01 or P<0.05 vs control). (3) Western blot showed that the expressions of APC protein and GSK3beta in lung tissue were consistent with the results of immunohistochemistry; and the levels of p-GSK3beta in all smoking models were higher than that in control. (4) The results of immunofluorescence showed that APC protein was localized mainly near the regions of epithelial cell membrane at the end of the 1st and 8th week after smoking, which were dissimilar with the localization in control, and this change was not seen in the location of GSK3beta. Taken together, these results demonstrate that the expressions and localizations of APC protein, GSK3beta and the activity of GSK3beta are dynamically changed in the AECs with experimental smoking injury at different phases, suggesting that APC protein and GSK3beta may be involved in the regulation of migration and proliferation of AECs, and play an important role in the process of repair of airway epithelium injury.

Promoter methylation and mRNA expression of APC gene in MCF10 breast cancer model / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the promoter methylation status and mRNA expression of APC gene in MCF10 model of breast cancer progression.</p><p><b>METHODS</b>Methylation specific PCR and sodium bisufite genomic sequencing were employed to detect the methylation status of APC promoter 1A in normal breast tissues, conventional breast cancer cell line MCF-7 and MCF10 model cell lines including MCF10A (breast hyperplastic cell line, non-tumorigenic), MCF10AT (pre-malignant cell lines, producing slowly progressing hyperplastic and dysplastic lesions), MCF10DCIS.com (breast ductal carcinoma in-situ cell line, producing ductal carcinoma in-situ), MCF10CA1a, MCF10CA1d, MCF10CA1h cell lines (invasive breast carcinoma cell line, forming aggressive tumors of different morphology and metastatic potential). In addition, mRNA expression of APC was determined by reverse transcriptase PCR and real-time PCR assays.</p><p><b>RESULTS</b>Hypomethylation of APC promoter 1A was identified in hyperplastic cell line MCF10A, pre-malignant cell line MCF10AT, ductal carcinoma in-situ cell line MCF10DCIS.com, invasive carcinoma cell lines MCF10CA1a, MCF10CA1d, MCF10CA1h and normal breast tissue. MCF-7 showed partial methylation at the promoter. Statistically significant reduction of APC mRNA expression was not found in all MCF10 cell lines and MCF-7, compared with that of normal breast tissue (MCF10AT, MCF10CA1a, MCF10CA1d, MCF10CA1h and MCF10DCIS.com showed reduced mRNA expressions of APC at 0.27, 0.96, 1.78, 2.70, and 2.03 times respectively. MCF10A and MCF-7 even showed an increase of APC mRNA expression at 0.02 and 0.33 times, respectively).</p><p><b>CONCLUSION</b>The aberrant promoter methylation of APC is not related to the breast cancer progression, at least in the MCF10 model system.</p>