c-MYC and h-TERT co-expression in colon adenocarcinoma: a tissue microarray digitized image analysis.

PURPOSE: c-MYC oncogene is frequently deregulated by amplification in colon adenocarcinoma. c-MYC also activates telomerase by inducing expression of its catalytic subunit (h-TERT). Furthermore, telomerase activation plays a crucial role in tumorigenesis by sustaining cellular immortality. Our aim was to evaluate the significance of c-MYC and h-TERT co-expression in colon adenocarcinoma. METHODS: Sixty paraffin embedded primary colon adenocarcinomas were cored at 1.5 mm diameter and transferred to one microarray block. Immunohistochemistry was performed using anti-h-TERT, and c - MYC antibodies. A quantitative digitized macro was performed to evaluate their expression. RESULTS: c-MYC and h-TERT overexpression was observed in 27 (45%) and 28 (46.6%) cases, respectively. Co-over expression of those genes was observed in 17 (28.3%) cases and found to be statistically significant (p=0.001). The results also showed a strong association between c-MYC and grade of differentiation of the examined neoplasms (p=0.0217rpar;. CONCLUSION: Simultaneous c-MYC and h-TERT deregulation is a relatively frequent genetic event in colon adenocarcinoma. Because c-MYC overexpression is correlated with progressive disease - due to colon adenocarcinoma dedifferentiation - inhibition of its activity combined with h-TERT regulated expression is a new target for novel therapeutic regimens.

Gene numerical imbalances in cytological specimens based on fluorescence/chromogenic in situ hybridization analysis.

Design and development of novel targeted therapeutic strategies is an innovation in handling patients with solid malignancies including breast, colon, lung, head & neck or even pancreatic and hepatocellular carcinoma. For a long time, immunohistocytochemistry (IHC/ICC) has been performed as a routine method in almost all labs for evaluating protein expression. Modern molecular approaches show that identification of specific structural and numerical imbalances regarding genes involved in signal transduction pathways provide important data to the oncologists. Alterations in molecules such as epidermal growth factor receptor (EGFR), HER2/neu, PTEN or Topoisomerase IIa affect the response rates to specific chemotherapeutic agents modifying also patients' prognostic rates. In situ hybridization (ISH) techniques based on fluorescence and chromogenic variants (FISH/CISH) or silver in situ hybridization (SISH) are applicable in both tissue and cell substrates. Concerning cytological specimens, FISH/CISH analysis appears to be a fast and very accurate method in estimating gene/chromosome ratios. In this paper, we sought to evaluate the usefulness of FISH/ CISH analysis in cytological specimens, describing also the advantages and disadvantages of these methods from the technical point of view.

PTEN expression in non small cell lung carcinoma based on digitized image analysis.

PURPOSE: HER2 depended signalling pathway is dereg-ulated in a subset of non small cell lung carcinoma (NSCLC). The tumor suppressor gene PTEN (10q21) regulates the HER2/PI3K/Akt signalling pathway. Our aim was to evaluate PTEN protein expression in NSCLC based on a quantitative analysis method correlating also the results with clinicopathological parameters. METHODS: Protein expression was determined by immunohistochemistry (IHC) in 61 paraffin-embedded cases of patients with NSCLC. Digital image analysis (staining intensity levels) was performed in the corresponding immunostained slides. RESULTS: Loss of PTEN expression was observed in 24 (39.34%) cases, low expression in 29 (47.54%) and overexpression in 8 (13.12%) cases. Multivariate analysis determined that PTEN overexpression was associated with lower risk to develop metastases (p=0.05). CONCLUSION: PTEN deregulation is a relatively frequent genetic event in NSCLC, associated with progressive metastatic process in those patients. Because of binding to the ErbB2 receptor, trastuzumab stabilizes and activates PTEN gene, and loss of its expression negatively affects the response rates in such patients.