Evaluation of the criterion of partial loss of heterozygous in tumor tissues / 法医学杂志

OBJECTIVE@#To evaluate the applicability of partial loss of heterozygous (pLOH) criteria in tumor tissues with Identifiler system.@*METHODS@#Eight thousand four hundred and twenty eight heterozygous loci of the 696 unrelated individuals (UIP) genotyped with Identifiler Kit were randomly paired by locus to construct odds ratio of allelic peak height (or area under allelic curve) according to the given formula. Similarly, odds ratios of allelic peak height (or area under allelic curve) of the 896 heterozygous loci of 77 pairs of tumor and homologous normal tissues (TNP) were also acquired. Curve fitting was performed to determine the distribution of the odds ratio. The proportion of pLOH in two groups was determined with odds ratio less than 0.5 or higher than 2.0. Compared the relevance ratio of allelic peak height and peak area by chi2 test.@*RESULTS@#The odds ratio of both peak height and peak area presented normal distribution in UIP (4214 heterozygous loci pairs) and TNP group (896 heterozygous loci pairs). There was 0.12% of normal heterozygous in UIP group erroneously presumed as pLOH with current criteria (< 0.5 or > 2.0). There was no significantly difference between the calling rate based on two types of odd ratio (P = -0.5632).@*CONCLUSION@#It is feasible to determine the pLOH in tumor tissue with Identifiler system by both peak height and peak area according to the standards of the odds ratio less than 0.5 or higher than 2.0.

Evaluation of allelic alterations in 13 CODIS STR loci in tumor tissues from human digestive system / 法医学杂志

OBJECTIVE@#To study genetic alterations in 13 CODIS STR loci in various tumor tissue samples from human digestive system.@*METHODS@#Malignant tumor tissues and blood samples taken from 55 different unrelated individuals were collected. DNA samples were extracted using Chelex100 extraction kit, amplified using Profiler and Cofiler PCR amplification kit and analyzed using API 310 analyzer.@*RESULTS@#Aberrant cell divisions were detected in all of the 55 tumor tissue samples, with STR alternations detected in two samples including allelic alteration, partial and complete loss or unbalance of heterozygosity. Moreover, the alternations might occur simultaneously at more than one loci.@*CONCLUSION@#Caution must be taken in STR analysis of tumor tissue samples since the exclusion loci in forensic identification or paternity testing may be resulted from mutations in the tumor tissue.

Tumores digestivos simultáneos / Simultaneous digestive tumors

Synchronous and metachronous gastrointestinal tumors are well know entities, describing malignant tumors placed in the same organ, at the time of initial diagnosis or during the follow-up control. I would like to present two cases of malignant tumors placed in different organs of the digestive tube, at the time of diagnosis, coining the name simultaneous for these entities, stating laboratory finding and signo-symptomatologic interpretation difficulties, and proposing endoscopic approach as a valid diagnostic method.

Oncogenes: sua importância nos tumores do aparelho digestivo / Oncogenes: its importance in tumors of digestive apparatus

Os proto-oncogenes säo seqüências de nucleotídeos que integram normalmente o genoma. A proteína codificada por estes genes têm importante funçäo na proliferaçäo e regeneraçäo celular. Fatores externos, como vírus, fumo, radiaçäo, podem levar à mutaçäo, deleçäo ou translocaçäo destes genes. Os genes resultantes säo chamados de oncogenes, pois podem levar à transformaçäo neoplásica das células. No aparelho digestivo, o oncogene ras aparece com grande freqüênica nos adenocarcinomas de cólon e pâncreas