Preliminary screening for microsatellite instability and loss of heterozygosity in the deleted in colorectal cancer (DCC) gene among Filipino patients with colorectal adenocarcinoma

OBJECTIVE: This study aimed to detect the presence of microsatellite (MSI) and loss of heterozygosity (LOH) of the Deleted in Colorectal Cancer (DCC) gene in normal and tumor tissues of Filipino colorectal cancer patients and examine its correlation with age, gender, tumor grade, tumor stage and site of lesion.METHODS: Paired frozen normal and tumor tissues from thirtynine (39) patients with colorectal adenocarcinoma were used by polymerase chain reaction (PCR). Single strand conformation polymorphism - polyacrylamide gel electrophoresis (SSCP - PAGE) was used to determine MSI and restriction fragment length polymorphism (RFLP) was used to study LOH.RESULTS: Based on our data, out of the 39 patients, 10 showed LOH of the DCC gene using the LOH markers VNTR, M2 and M3, while no MSI was detected in the samples using the MSI markers BAT25 and BAT26. Correlation with clinicopathological characteristics showed that there is significance for the site of lesion. The LOH has correclation with tumor samples from the colon but not with those from the rectum.CONCLUSION: Preliminary screening for MSI and LOH of the DCC gene shows that occurrences of colorectal cancer among Filipino patients can be correlated with LOH of the DCC gene with colorectal cancer in a Filipino sample population.

Role of DCC(Deleted in Colorectal Cancer) Gene in Oral Squamous Cell Carcinoma

Chromosome 18q alteration plays a key role in colorectal tumorigenesis, and loss of heterozygosity at 18q is associated with a poor prognosis in colon cancer. DCC(Deleted in Colorectal Cancer) is a putative tumor- suppressor gene at 18q21 that encodes a transmembrane protein with structural similarity to neural cell adhesion molecule that is involved in both epithelial and neuronal cell differentiation. DCC is implicated in regulation of cell growth, survival and proliferation. Thus, tumor progression in squamous cell carcinoma, stomach cancer, colorectal cancer correlates with downregulation of DCC expression. The mechanism for DCC suppression is associated with hypermethylation of the DCC gene promoter region. Hence, the goal of this study is to identify the promoter methylation responsible for the down-regulation of DCC expression in oral squamous cell carcinoma. 12 of tissue specimens for the study are excised and gathered from 12 patients who are diagnosed as SCC in department of OMS, dental hospital, dankook university. To find expression of DCC in each tissue samples, immunohistochemical staining, RT-PCR gene analysis and methylation specific PCR are processed. The results are as follows. 1. In the DCC gene RT-PCR analysis, 5(41.6%) of 12 specimens of oral squamous cell carcinoma did not expressed DCC gene. 2. In the promoter methylation specific PCR analysis, 5(41.6%) of 12 specimens showed promoter methylation of DCC gene. 3. In the immunohistochemical staining of poor differentiated and invasive oral squamous cell carcinoma, loss of DCC expression was observed. These findings suggest that methylation of the DCC gene may play a role in loss of gene expression in invasive oral squamous cell carcinoma.

Estudo da relação entre a imunoexpressão das proteínas caderina-E e DCC com o grau de diferenciação celular e o estadiamento TNM do adenocarcinoma colorretal / Study of the expression of E-cadherin and DCC proteins with cell differentiation degree and staging in colorectal adenocarcinoma

OBJETIVO: Avaliar a relação de duas proteínas que participam do mecanismo de adesão celular com o grau de diferenciação celular e os estadiamentos TNM (T: tumor, N: linfonodo, M: metástase) I e IV no câncer de cólon e reto. MÉTODOS: Foram estudados cem pacientes (54 homens e 46 mulheres) tratados por adenocarcinoma colorretal, estádios I (44) e IV (56). Os cortes histológicos do tecido tumoral foram examinados por técnica de imuno-histoquímica em relação à imunoexpressão das proteínas caderina-E e delect in colon cancer (DCC), sendo classificados como positivos quando se detectou a imunoexpressão dessas proteínas em 50 por cento ou mais das células tumorais. RESULTADOS: Para o TNM, imunoexpressão da caderina-E estádio I: positiva em 72,7 por cento e negativa em 35,7 por cento ; estádio IV: positiva em 64,3 por cento e negativa em 35,7 por cento. Proteína DCC: 43,2 por cento positiva e 56,8 por cento negativa no estádio I, e 50 por cento positiva e 50 por cento negativa no estádio IV. Em relação ao grau de diferenciação celular, imunoexpressão da caderina-E - GI: positiva em 70 por cento e negativa em 30 por cento; GII: positiva em 68,4 por cento e 31,6 por cento negativa; GIII: 63,6 por cento positiva e 36,4 por cento negativa. Imunoexpressão da DCC - GI: 40 por cento positiva e 60 por cento negativa; GII: 46,8 por cento positiva e 53,2 por cento negativa; GIII: 54,5 por cento positiva e 45,5 por cento negativa. Não houve diferença significativa entre os grupos. CONCLUSÃO: Os resultados dessa pesquisa permitem concluir que não há relação da imunoexpressão das proteínas caderina-E e DCC com o estadiamento TNM (I e IV) e o grau de diferenciação celular no carcinoma colorretal.

OBJECTIVE: Evaluate the relationship of two proteins, which take part in the same mechanism of cell adhesion, with the cell differentiation degree and TNM staging I and IV in colorectal cancer. METHODS: One-hundred patients (54 men and 46 women), who have received treatment for colorectal cancer, stages I (44) and IV (56), have been studied. Histological cuts of tumor tissue were examined by the immunohistochemical technique as to the expression of E-cadherin and delect in colon cancer (DCC) proteins, being classified as positive whenever it was detected immunoexpression of such proteins in 50 percent or more tumor cells. RESULTS: For TNM, E-cadherin immunoexpression for stage I: positive in 72.7 percent and negative in 35.7 percent; stage IV: positive in 64.3 percent and negative in 35.7 percent. For DCC protein: 43.2 percent positive and 56.8 percent negative in stage I, and 50 percent positive and 50 percent negative in stage IV. Regarding the cell differentiation degree, the immunoexpression of E-cadherin - GI: positive in 70 percent and negative in 30 percent; GII: positive in 68.4 percent and negative in 31.6 percent; GIII: positive in 63.6 percent and negative in 36.4 percent. The immunoexpression of DCC - GI: 40 percent positive and 60 percent negative; GII: 46.8 percent positive and 53.2 percent negative; GIII: 54.5 percent positive and 45.5 percent negative. There was no significant difference among groups. CONCLUSION: The results of this research make it possible to come to the conclusion that there is no relationship between the immunoexpression of E-cadherin and DCC proteins with TNM staging (I and IV) and cell differentiation degree in colorectal cancer.

Study on loss of heterozygosity and microsatellite instability in hepatocellular carcinoma / 中华病理学杂志

<p><b>OBJECTIVE</b>To investigate the role of loss of heterozygosity (LOH) in tumor suppressor genes (TSG) and microsatellite instability (MSI) in hepatocarcinogenesis, as well as their correlation with clinicopathologic features.</p><p><b>METHODS</b>LOH in 6 TSG (APC, DCC, MCC, OGG1, p53 and RB1) was detected in 36 informative cases of hepatocellular carcinoma (HCC), among 92 surgically resected HCC. Thirteen polymorphic microsatellite markers were also studied in 15 of these cases by microdissection-based PCR amplification and direct DNA sequencing. The correlation between genetic alterations and clinicopathologic features was analyzed.</p><p><b>RESULTS</b>The overall incidence of LOH in HCC was 41.7% (15/36). There was no LOH in MCC gene. 46.2% (6/13) microsatellites showed LOH in 9 of the 15 cases of HCC (60%). Certain clinicopathologic differences were observed between cases (number = 7) with LOH in APC, OGG1 and DCC ("type I") and cases (number = 8) with LOH in p53 and RB1 ("type II"). The mean tumor size of these two types was 2.9 (+/- 1.7) cm and 7.2 (+/- 3.4) cm, respectively (P < 0.01); and the mean survival was 72.0 (+/- 38.6) months, and 51.0 (+/- 30.4) months, respectively (P < 0.05).</p><p><b>CONCLUSIONS</b>Compared with MSI pathway, LOH pathway plays a more important role in the development of HCC. A multistep hepatocarcinogenesis is likely, with LOH in APC, OGG1 and DCC ("type I") being an early event and LOH in p53 and RB1 ("type II") being a late event. On the other hand, MCC gene seems to play no role in the whole process.</p>

Monitoramento e avaliação dos efeitos colaterais da quimioterapia em pacientes com câncer de cólon / Monitoring and evaluation of side effects of chemotherapy in patients with colon cancer

Este estudo objetivou monitorar e avaliar a ocorrência e grau de intensidade da náusea, vômito e diarréia em pacientes com neoplasia de cólon, submetidos à quimioterapia ambulatorial, que receberam informações de enfermagem para o manejo desses sintomas. Fizeram parte do estudo 17 pacientes tratados com 5-Fluorouracil e baixas doses de ácido folínico, no Ambulatório de Quimioterapia de Adultos do Hospital São Paulo/Universidade Federal de São Paulo. Foram elaborados instrumentos para o registro da ocorrência e grau de intensidade desses sintomas e folhetos com informações sobre o seu manejo. As informações e o seguimento foram realizados pela enfermeira do setor, durante as consultas de enfermagem. Os resultados evidenciaram que a maioria dos pacientes (82,4 por cento) apresentou pelo menos um dos sinais e sintomas estudados, entre o primeiro e o 21º dias do ciclo de tratamento. A náusea foi o sintoma mais freqüente (76,5 por cento), com pico no 4º e 5º dias do ciclo, seguida da diarréia (70,5 por cento), com pico no 7º dia e, por último o vômito (53,0 por cento), com pico no 5º dia. Quanto ao grau de intensidade desses sintomas, a maioria dos pacientes situou-se no grau 1, estabelecido como aceitável para o estudo, indicando que as orientações de enfermagem e o acompanhamento contínuo contribuíram para a maior efetividade do manejo desses sintomas por parte dos pacientes

P53 and Rb tumor suppressor gene alterations in gastric cancer

A inativação de genes supressores tumorais tem sido freqüentemente observada na carcinogênese gástrica. O nosso objetivo foi estudar o envolvimento dos genes p53, APC, DCC e Rb no câncer gástrico. MÉTODO: Vinte e dois casos de câncer gástrico foram estudados por PCR-LOH (reação de polimerase em cadeia- perda de alelo heterozigoto) dos genes p53, APC, DCC e Rb; e por PCR-SSCP (reação de polimerase em cadeia- polimorfismo de conformação de cadeia única) dos exons 5-6 e exons 7-8 do gene p53, empregando 35S-dATP e expressão de p53 por imunoperoxidase com monoclonal anti-p53. RESULTADOS E DISCUSSAO: Perda de alelo heterozigoto não foi detectada nos genes estudados; deleção homozigótica foi observada no gene Rb em 23% (3/13) dos casos de câncer gástrico do tipo intestinal. Desvio de motilidade de banda nos exons 5-6 e/ou exons 7-8, indicando mutação do gene p53 foi encontrada em 18 casos (81.8%). A expressão de p53 foi positiva nas células de câncer gástrico em 14 casos (63.6%). A mucosa gástrica normal não corou com anti-p53, portanto, a reatividade imune deve representar formas mutantes. A correlação de desvio de motilidade de banda e expressão imune de p53 não foi significante (p=0.90). Não houve correlação entre as alterações genéticas e a extensão da doença. CONCLUSAO: A inativação dos genes p53 e Rb tem papel na carcinogênese gástrica no nosso meio. A perda do gene Rb observada apenas no câncer gástrico do tipo intestinal deve ser avaliada posteriormente em associação com infecção pelo Helicobacter pylori. O gene p53 estava afetado em ambos os tipos histopatológicos.

DCC Gene and Protein Expression in Colorectal Cancer

PURPOSE: The germline, or somatic, inactivation of tumor suppressor genes, through point mutation, or deletion, plays an important role in carcinogenesis. Several gene alterations, such as adenomatous polyposis coli (APC), deleted in colorectal cancer (DCC) and p53, have been detected in the development of colorectal cancer. Within these genes, a loss of heterozygosity (LOH) at the DCC gene locus was frequently associated with colorectal tumors, and the LOH of the DCC gene, and the expression of the DCC protein, might be related to malignant formation and metastasis. The aim of this study was to determine the DCC LOH and the expression of DCC protein in colorectal cancers, and evaluate their prognostic value and relationship with the clinicopathological data. MTHODE: Fifty colorectal cancer tissues were obtained from resected specimens. Using formalin-fixed paraffin- embedded sections as a source of DNA, we examined the DCC protein in the tissue through immunohistochemical stainings and immunoblotting analysis, the DCC LOH through a polymerase chain reaction (PCR) and single strand conformation polymorphism (SSCP). RESULTS: DCC LOH was observed in 24 of the 50 patients (48.0%). The expression of the DCC protein was decreased in the cancer tissue (62.3 23.6%) compared with the adjacent normal mucosa inform the immunoblotting analysis. A decreased DCC protein expression was also observed from the immunohistochemistry, which coincided with the immunoblotting analysis. However, both the DCC LOH and the decreased DCC protein were not related to the clinical and pathological parameters, such as location of tumor, tumor size, histological type and the venous, and lymphatic invasions. There were significant correlations between the DCC protein expression and tumor progression, and hematogenous metastasis (P<.05). CONCLUSIONS: A decreased expression of the DCC protein was noted in human colorectal cancers, and there was a significant relationship between the expression of the DCC protein and distant metastasis, but there was no correlation between the DCC LOH and distant metastasis. These results suggest that the expression of the DCC protein might be related to tumor progression and metastatic potential, and the DCC protein immunoreactivity may be a useful prognostic factor in patients with colorectal cancers.

Sarcoma de Kaposi diseminado con compromiso pleuropulmonar en un paciente con SIDA / Diseminated Kaposi's sarcoma with pleuropulmonar commitment in a patient with AIDS

Se presenta un paciente con diagnóstico de enfermedad HIV/SIDA en etapa avanzada y sarcoma de Kaposi (SK) diseminado con compromiso cutaneo-mucoso extenso. Ingresa por cuadro de fiebre, dolor toracico derecho y disnea progresiva. La Rx de tórax evidenció derrame pleural derecho, cuya punción y aspiración con biopsia puso de manifiesto un líquido serohemático. El estudio histopatológico arrojó diagnóstico de compromiso pleural por SK. Se le inició tratamiento con terapia antirretroviral en base a AZT mas ddC y ciclos de bleomicina más vincristina a dosis habituales cada 15 días. Se obtuvo mejoría parcial desde el punto de vista clínico y radiológico. Concluimos afirmando que en un paciente con diagnóstico de SK diseminado la aparición de un derrame pleural con líquido serohemático debe hacer sospechar la misma etiologia

Utilization of microsatellites for the analysis of genomic alterations in colorectal cancers in Brazil

Two different pathogenetic mechanisms are proposed for colorectal cancers. One, the so-called "classic pathway", is the most common and depends on multiple additive mutational events (germline and/or somatic) in suppressor genes and oncogenes, frequently involving chromosomal deletions in key genomic regions. Methodologically this pathway is recognizable by the phenomenon of loss of heterozygosity. On the other hand, the "mutator pathway" depends on early mutational loss of the mismatch repair system (germline and/or somatic) leading to accelerated accumulation of gene mutations in critical target genes and progression to malignancy. Methodologically this second pathway is recognizable by the phenomenon of microsatellite instability. The distinction between these pathways seems to be more than academic since there is evidence that the tumors emerging from the mutator pathway have a better prognosis. We report here a very simple methodology based on a set of tri-, tetra-and pentanucleotide repeat microsatellites allowing the simultaneous study of microsatellite instability and loss of heterozygosity which could allocate 70 per cent of the colorectal tumors to the classic or the mutator pathway. The ease of execution of the methodology makes it suitable for routine clinical typing.

The Expression of DCC Protein in Colorectal Carcinomas

Colorectal cancer is one of the malignant tumours of which molecular genetic alterations have been much unveiled among the human cancers. In the multi-stepwise process to the carcinogenesis, it has been recently revealed that the neoplastic growth is originated either from the activiation of oncogene through its mutation, rearragement and amplification, or from the inactivation of the tumour suppression gene through its mutation and deletion. DCC(Deleted in colon cancer) protein is the product of DCC gene, the representative of tumor suppressor genes. The alteration of DCC protein may be related with the aggressiveness of carcinoma and metastasis. As a result, the prognosis of the cancer may be also thought to be affected. Now the prognosis of colorectal cancer mainly depends on pathologic staging, but there are some variations of survival and recurrence among the patients in same stage. Then this study is aimed to reveal the significance of alteration of DCC protein as an independent factor related to prognosis. Twenty three cancer tissues were obtained from the rejected specimens of colorectal carcinomas. We exacted the DCC gene products in the cancer tissues by the methods of immunohistochemical stains and Western blots. We also analyzed the relationships between the alteration of DCC proteins and the status of regional lymph node metastasis or the serum levels of CEA's(carcinoembryonic antigen). As results, we found the abscence or very scanty stains of DCC protein by Western lot in 14 cancer tissues of available 19 cases, but there were all negative responses in immunohistochemical stains. In contrast with above results, there were all positively stains of DCC proteins in corresponding 23 normal colorectal tissues by both the methods. There was no significantly statistical relation between the alteration of DCC proteins and the status of regional lymph node metastasis or the serum level of CEA. In conclusion, we can confirm that the DCC proteins are abscent or very scanty in colorectal cancer tissues and that may be related with the process of carcinogenesis. But the role of DCC protein loss as an independent prognostic factor was not found in this study.