Proangiogenic signature in advanced laryngeal carcinoma after microRNA expression profiling.

The aim of this study is to evaluate which dysregulated angiomiRs compose the specific proangiogenic microRNA signature of advanced laryngeal cancer and review the literature. Thirty-six samples from twelve patients with advanced laryngeal carcinoma were collected. Total RNA was extracted and microRNA global profiling was performed using Agilent Technologies Microarray Kit. Fifty-nine microRNAs were found to have significantly different expression levels. Eleven microRNAs from the whole group were sorted as regulators of tumor angiogenesis (angiomiRs): seven were up-regulated-miR-1246, miR-181b 5p, miR-18a 5p, miR-21 3p, miR-210 3p, miR-503 5p, miR-93 5p and four were down-regulated-miR148a 5p, miR-145 5p, miR-204 5p, miR-125b 5p. For none of those microRNAs we found heterogeneity in tumor tissue. We are the first to report the specific proangiogenic microRNA signature in advanced laryngeal carcinoma and we confirm and amplify findings from previous studies that expand our perception of a specific "molecular state" of angiogenesis that is distinctive only for laryngeal cancer.

Strong Correlation Between mRNA Expression Levels of HIF-2α, VEGFR1, VEGFR2 and MMP2 in Laryngeal Carcinoma.

The hypoxia that arises due to the rapid proliferation of tumor cells is a fundamental driving force for the canonical pathway of neovascularization. In the current study we report a very strong correlation between mRNA expression levels of HIF-2α (but not HIF-1α), VEGFR-1, VEGFR-2 and MMP2 in ex vivo samples from laryngeal carcinoma. Sixty-three samples from patients with histopathologically verified carcinoma of the larynx were examined in this study. Total RNA was isolated from both normal and tumor fresh frozen tissues of each patient and real-time quantitative PCR reactions were performed. The mRNA expression levels of HIF-1α, HIF-2α, VEGFR1, VEGFR2 and MMP2 were acquired. We found strong positive correlations between mRNA expression levels of HIF-2α and VEGFR-1, r s (98) = .671, p < .0005; HIF-2α and VEGFR-2, r s (98) = .742, p < .0005; HIF-2α and MMP2, r s (98) = .566, p < .0005; VEGFR-1 and VEGFR-2, r s (98) = .791, p < .0005; VEGFR-1 and MMP2, r s (98) = .709, p < .0005; VEGFR-2 and MMP2, r s (98) = .793, p < .0005. Our results provide evidence for the regulatory connection between HIF-2α and VEGFR-1, VEGFR-2 and MMP2 in the light of ETS1/ HIF-2α regulatory axis on a non-in-vitro level in carcinoma tissue, uncover some of the differences between the homologues HIF-1α and HIF-2α and round up and support the results from different experimental models in this field.

Macrophageal infiltration and microvessel density in laryngeal carcinoma: study of 52 cases.

Angiogenesis is one of the six originally constituted hallmarks of cancer that has been extensively studied in the last two decades. The aim of our study is to assess the microvessel and macrophageal density in laryngeal carcinoma and its clinicopathological correlations. We immunohistochemically assessed microvessel density (CD34) and macrophage count (CD68) using microarray techniques and then looked for clinicopathological correlations. The mean micro-vessel density in the study group was 14.27 ± 12.92 vessels in a ×200 field with a mean macrophageal infiltration density of 5.19 ± 4.32. Median microvessel density was significantly higher in patients with metastasis than in patients without metastasis. Additionally, linear regression established that macrophageal infiltration density could predict microvessel density in laryngeal carcinoma. We found no association between either factor and recurrence rate or other clinical characteristics. Our study adds additional data to a problem that has been widely studied during the last two decades, even if controversies in this area still remain.

Microsatellite instability and promoter hypermethylation of MLH1 and MSH2 in patients with sporadic colorectal cancer.

PURPOSE: Inactivation of the genes involved in DNA mismatch repair (MMR) is associated with microsatellite instability (MSI) and loss of heterozygosity (LOH). The aim of the current study was to assess the presence of MSI and promoter hypermethylation of MLH1 and MSH2 in Bulgarian PATIENTS WITH SPORADIC COLORECTAL CANCER (CRC) AND TO ANALYZE THEIR POSSIBLE EFFECT ON THE DEVELOPMENT, PROGRESSION AND PROGNOSIS OF THE DISEASE. METHODS: We examined MSI in 126 patients with sporadic CRC and the methylation status of the MLH1 and MSH2 promoter regions in the cases with MSI/LOH by using a panel of 5 microsatellite markers (BAT26, D5S346, D18S35, D2S123 and FGA) and methyl-specific PCR (MSP) of bisulfite converted DNA. RESULTS: MSI/LOH was found in 36 (28.6%) patients. Among them, 30 were analyzed for promoter hypermethylation of MLH1 and we detected hypermethylation in 15 (50%) of them, whereas promoter hypermethylation of MSH2 was observed only in one case. The presence of MSI/LOH was associated with younger age (p=0.002), more advanced stage (III/IV stage) (p=0.029), lower degree of differentiation (p=0.001), and right-sided tumor localization (p=0.0002), but not with overall survival (log rank, p=0.566). CONCLUSION: Our data suggest that sporadic CRCs with MSI/LOH are more aggressive, develop earlier and progress faster to more advanced stage. The most frequent cause of failure of DNA MMR system appeared to be the hypermethylation of CpG islands of the promoter region of MLH1, whereas the methylation of MSH2 was a rare event.