Identification of an intermediate signature that marks the initial phases of the colorectal adenoma-carcinoma transition.

The colorectal adenoma-carcinoma sequence describes the stepwise progression from normal to dysplastic epithelium and then to carcinoma. Only a small proportion of colorectal adenomas (CRAs) progress to colorectal carcinomas (CRCs). Endoscopic intervention is currently being used on patients with high grade dysplasia CRAs, with diameters of >1 cm, or villous components of >25% who are at higher risk than other CRA sufferers. During the process, biopsy samples are taken for conventional histological diagnosis, but poor pathomorphological sensitivity and specificity greatly limit the diagnostic accuracy. Unfortunately, there are no reliable molecular criteria available that can predict the potential development of CRA to CRC. Gene expression profiles of normal colorectal mucosa (NOR), CRA and different Dukes' stages of CRC biopsy specimens, which represent the gradual progress of the CRA to CRC sequence, were determined by Affymetrix technology. Representative regulated genes were further analyzed by quantitative real-time PCR (qRT-PCR) and immunohistochemistry (IHC). Intersectional analyses of discriminative expression signatures of CRC vs. CRA and CRA vs. NOR allowed the identification of an intermediate signature of 463 probe sets (psets) that mark the NOR--> CRA-->CRC progression. This signature represents a reservoir of candidate markers for the early diagnosis of higher-risk CRA, thus allowing for timely therapeutic intervention and more selective treatment. A further 279 CRC-specific psets pointing to the malignant transition from CRA to CRC were identified and these could represent potential therapeutic targets for CRC. The reliability of the results was further confirmed by qRT-PCR and IHC analyses of the 4-gene sets randomly selected from the 463 psets.

[Study on the relationship between HBV infection and polymorphism of CIITA G-944C gene among Jinuo, Dai and Aini minority populations in Yunnan province].

OBJECTIVE: To explore the relationship between HBV infection and the genotypes and allele frequencies of CIITA G-944C gene polymorphism in three minority populations (Jinuo, Dai and Aini population) in Xishuangbanna district, Yunnan province. METHODS: Polymerase chain reaction and sequencing method were used to study the genotypes and allele frequencies distributions of CIITA G-944C gene polymorphism in those three populations. Relationship between the genotypes distribution and HBV infection results were also analyzed. RESULTS: The rates on HBV infection and HBsAg carrier status in Aini minority population were 89.2% and 16.3%, which were significantly higher than in Jinuo (27.9% and 3.9%, χ(2) = 135.196 and 10.361, P = 0.000 and 0.001) and Dai population (44.9% and 6.6%, χ(2) = 96.783 and 8.748, P = 0.000 and 0.003) while among Aini population it was significantly different with the other two minority populations. The CC genotype and C allele frequencies were more distributed in Aini population than in the other two minority populations. In contrast, the GG genotype and G allele frequencies were lower than the other two minority populations, with χ(2) rates between Aini and Jinuo population were 11.841 and 12.208 and the P as 0.003 and 0.000 respectively while the χ(2) rates between Aini and Dai population were 23.902 and 20.220 with P value as 0.000 and 0.000. The genotypes frequencies of CIITA G-944C was significantly different in the infected individuals (IF) group and health control (HC) group in Jinuo population (χ(2) = 6.150 and 4.911, P = 0.046 and 0.027). When compared with HBsAg(+) group and HBsAg(-) group, the genotypes and allele frequencies were different in Aini population and the total three minority populations (χ(2) rates in Jinuo minority were 8.650 and 5.034 with P values as 0.013 and 0.025). However, the χ(2) rates in the whole population were 13.047 and 9.416 with P values as 0.001 and 0.002, respectively. The distribution of CC genotype and C allele gene in HBsAg(+) group was increasing. Data from non-condition logistic regression analysis and adjusting for confounding factors, the HBsAg(+) group had a significantly increase of HBsAg(-) group under the C allele Recessive Model (P = 0.000; OR = 2.964; 95%CI: 1.609 - 5.460). CONCLUSION: The genotypes and allele frequencies distribution of CIITA G-944C were different in the three ethnic populations. Polymorphism of this gene was closely associated with HBsAg carrier. The CC genotype patients were more easily to become HBsAg carrier.

Novel hepatitis B virus subgenotype in the southern Yunnan Province of China.

Hepatitis B virus (HBV) infection is highly prevalent in China. To identify the genotypes of HBV in the southern Yunnan Province of China, full-length HBV genomes were extracted from 1 Dai and 4 Hani HBV carriers and linked with the pMD T-18 vector. For each patient, 3-10 clones were sequenced directly and a consensus sequence was created. Genotypic and serotypic analysis revealed 4 HBV/B (2 B2 with adw2 and 2 new subgenotypes with ayw1) and 1 HBV/C (C1 with adrq+) genotypes. The divergences of the entire genome sequences of the new subgenotype were 0-0.9% and 2.99-6.48% between other known HBV/B. Divergences in other coding regions revealed that it was more similar to B3 and B4 in the precore/core gene (2.02 and 2.09%, respectively), and similar to B3 and B5 in the preS1/S2/S gene (2.24 and 2.78%, respectively). Phylogenetic trees using the precore/core and X genes both revealed a new clad separating from the major trunk of genotype B with a 99% bootstrap value. These results show that the 2 consensus isolates are a mosaic of B3-B5, which we designated to subgenotype B6. Considering the geographical distances, the relationship between B6 and other HBV/B subgenotypes (B3-B5) and HBV evolution needs to be further studied.

Virologic characteristics of hepatitis B virus in patients infected via maternal-fetal transmission.

AIM: To determine whether HBV with the same characteristics causes dissimilar mutations in different hosts. METHODS: Full-length HBV genome was amplified and linked with pMD T18 vector. Positive clones were selected by double-restriction endonuclease digestion (EcoRI and HindIII) and PCR. Twenty seven clones were randomly selected from an asymptomatic mother [at two time points: 602 (1 d) and 6022 (6 mo)] and her son [602 (S)], and the phylogenetic and mutational analysis was performed using BioEditor, Clustal X and MEGA software. Potential immune epitopes were determined by the Stabilized Matrix Method (SMM), SMM-Align Method and Emini Surface Accessibility Prediction. RESULTS: All of the 27 sequences were genotype C, the divergence between the mother and son was 0%-0.8%. Compared with another 50 complete sequences of genotype C, the mother and her son each had 13 specific nucleotides that differed from the other genotype C isolates. AA 1-11 deletion in preS1 was the dominant mutation in the mother (14/18). The 1762T/1764A double mutation existed in all clones of the mother, 3 of them were also coupled with G1896A mutation, but none were found in the son. 17 bp deletion starting at nucleotide 2330 was the major mutation (5/9) in the son, which caused seven potential HLA class I epitopes and one B cell epitope deletion, and produced a presumptive new start codon, downstream from the original one of the P gene. CONCLUSION: The HBV strain in the son came from his mother, and discrepant mutation occurred in the mother and her son during infection.