Increased expression of cellular retinol-binding protein 1 in laryngeal squamous cell carcinoma.

PURPOSE: To investigate the genomic alterations in larynx carcinomas (LaCa) tissues and its prognostics values in predicting survival. METHODS: To analyse the aberrations in the genome of LaCa patients, we used array comparative genomic hybridization in 19 human laryngeal tumour samples. DNA samples were also subjected to detect human papillomavirus (HPV) sequences by polymerase chain reaction (PCR). Copy number gain was confirmed by real-time PCR. The cellular retinol-binding protein 1 (CRBP-1) gene expression was also confirmed by immunohistochemistry assay on LaCa tissues. To identify prognostic feature, CRBP-1 gene gain was correlated to patient survival. RESULTS: The most common gains were detected for CRBP-1 and EGFR genes, while DNA lost in RAF-1 gene. Immunohistochemistry assay was revealed strong expression of CRBP1 protein in those cases with CRBP-1 gene gain. The CRBP-1 gene gain and its expression correlated significantly with survival (P = 0.003). Cox regression analysis indicated that CRBP-1 expression level was a factor of survival (P = 0.008). HPV sequences were detected in 42% of the samples, and did not show any relationship with specific gene alterations. CONCLUSION: Our data shows that CRBP-1 gene gain can be determined by immunohistochemistry on routinely processed tissue specimens, and could support as a potential novel marker for long-term survival in laryngeal squamous cell carcinoma.

Specific mutation screening of TP53 gene by low-density DNA microarray.

TP53 is the most commonly mutated gene in human cancers. Approximately 90% of mutations in this gene are localized between domains encoding exons 5 to 8. The aim of this investigation was to examine the ability of the low density DNA microarray with the assistance of double tandem hybridization platform to characterize TP53 mutational hotspots in exons 5, 7, and 8 of the TP53. Nineteen capture probes specific to each potential mutation site were designed to hybridize to specific site. Virtual hybridization was used to predict the stability of hybridization of each capture probe with the target. Thirty-three DNA samples from different sources were analyzed for mutants in these exons. A total of 32 codon substitutions were found by DNA sequencing. 24 of them a showed a perfect correlation with the hybridization pattern system and DNA sequencing analysis of the regions scanned. Although in this work we directed our attention to some of the most representative mutations of the TP53 gene, the results suggest that this microarray system proved to be a rapid, reliable, and effective method for screening all the mutations in TP53 gene.

Chromosomal imbalances in four new uterine cervix carcinoma derived cell lines.

BACKGROUND: Uterine cervix carcinoma is the second most common female malignancy worldwide and a major health problem in Mexico, representing the primary cause of death among the Mexican female population. High risk human papillomavirus (HPV) infection is considered to be the most important risk factor for the development of this tumor and cervical carcinoma derived cell lines are very useful models for the study of viral carcinogenesis. Comparative Genomic Hybridization (CGH) experiments have detected a specific pattern of chromosomal imbalances during cervical cancer progression, indicating chromosomal regions that might contain genes that are important for cervical transformation. METHODS: We performed HPV detection and CGH analysis in order to initiate the genomic characterization of four recently established cervical carcinoma derived cell lines from Mexican patients. RESULTS: All the cell lines were HPV18 positive. The most prevalent imbalances in the cell lines were gains in chromosomes 1q23-q32, 3q11.2-q13.1, 3q22-q26.1, 5p15.1-p11.2, this alteration present as a high copy number amplification in three of the cell lines, 7p15-p13, 7q21, 7q31, 11q21, and 12q12, and losses in 2q35-qter, 4p16, 6q26-qter, 9q34 and 19q13.2-qter. CONCLUSIONS: Analysis of our present findings and previously reported data suggest that gains at 1q31-q32 and 7p13-p14, as well as losses at 6q26-q27 are alterations that might be unique for HPV18 positive cases. These chromosomal regions, as well as regions with high copy number amplifications, coincide with known fragile sites and known HPV integration sites. The general pattern of chromosomal imbalances detected in the cells resembled that found in invasive cervical tumors, suggesting that the cells represent good models for the study of cervical carcinoma.