Clinical and histopathologic evaluation of the expression of Ha-ras and fes oncogene products in lung cancer

Oncogene and tumor-suppressor gene products as serum biomarkers in occupational-derived lung cancer

Since lung cancer is the most frequent occupational cancer and one of the leading causes of cancer mortality in the world, it is one of the biggest challenges for research. In the literature, there are inconsistent results regarding the utility of the serum biomarkers p53, anti-p53 antibodies, EGF receptor or Ras. Based on the published results, routine use of these biomarkers for detection of occupationally derived lung carcinomas is not currently recommended. In this review, we summarize the literature and discuss the relevance of these oncogene and tumor-suppressor gene products as serum biomarkers in occupational-derived lung cancer.

Expression of c-Fes Protein Isoforms Correlates with Differentiation in Myeloid Leukemias

The cellular fes gene encodes a 93-kilodalton protein-tyrosine kinase (p93) that is expressed in both normal and neoplastic myeloid cells. Increased c-Fes expression is associated with differentiation in normal myeloid cells and cell lines. Our hypothesis was that primary leukemia cells would show a similar pattern of increased expression in more differentiated cells. Therefore, we compared c-Fes expression in cells with an undifferentiated, blast phenotype (acute myelogenous leukemia--AML) to cells with a differentiated phenotype (chronic myelogenous leukemia--CML). Instead of differences in p93 expression levels, we found complex patterns of c-Fes immunoreactive proteins that corresponded with differentiation in normal and leukemic myeloid cells. The "blast" pattern consisted of c-Fes immunoreactive proteins p93, p74, and p70; the "differentiated" pattern showed two additional c-Fes immunoreactive proteins, p67 and p62. Using mRNA from mouse and human cell lines, we found deletion of one or more exons in the c-fes mRNA. Those deletions predicted truncation of conserved domains (CDC15/FCH and SH2) involved in protein-protein interactions. No deletions were found, however, within the kinase domain. We infer that alternative splicing generates a family of c-Fes proteins. This may be a mechanism to direct the c-Fes kinase domain to different subcellular locations and/or substrates at specific stages of myeloid cell differentiation.

Kinase inhibitors in cancer therapy: a look ahead

The most essential kinases involved in cell membrane receptor activation, signal transduction and cell cycle control or programmed cell death and their interconnections are reviewed. In tumours, the genes of many of those kinases are mutated or amplified or the proteins are overexpressed. The use of key kinases offers the possibility to screen in vitro for synthetic small molecule kinase inhibitors. In view of the many interconnections of cellular kinases, their role in preventing or inducing programmed cell death and the possibility that a considerable number of signal transducing proteins are still unknown, cellular test systems are recommended in which the respective key kinase or one of its main partner molecules are overexpressed.

Comparison of chromosomal imbalances in neuroendocrine and non-small-cell lung carcinomas

Lung carcinomas are represented by non-small-cell lung carcinomas (NSCLC) and neuroendocrine carcinomas (NE) which differ in their clinical presentation and prognosis. We used comparative genomic hybridization (CGH) to characterize and compare the chromosomal pattern of 11 NSCLC and 11 high-grade NE lung carcinomas. Overall, the total number of aberrations was higher in NSCLC than in high-grade NE lung tumors (p < 0.05) and gains predominated over losses in NSCLC (p < 0.0003). Gains common to both lung tumor phenotypes were detected in 1p, 1q, 3q, 5p, 6p, 8q, 12, 17q, 19p, 19q, 20p, 20q, and X, whereas common losses were found in 2q, 3p, 4p, 4q, 5q, 8p, 9p, 10p, 11p, 11q, 13q, and 17p. Major gains on 18q and losses on 2p and 16q were exclusively detected in high-grade NE lung tumors. On the other hand, major gains on 2p and 15q and losses on 21q were found only in NSCLC. Furthermore, gains within 22q11-q12 and 7p12-p15 were associated with NSCLC (p < 0.05). The differences in the pattern and distribution of genetic changes observed in NSCLC as opposed to high-grade NE lung carcinomas suggest the existence of distinct tumorigenic pathways between these two major classes of lung tumors.

Analysis of Fes kinase activity in myeloid cell growth and differentiation

Fes is a nonreceptor protein tyrosine kinase that has been implicated in a variety of cytokine signal transduction pathways, as well as differentiation of myeloid cells. To address the role of Fes in these processes, we overexpressed a kinase-defective Fes protein in the factor-dependent cell-lines, TF-1 and 32D. Proliferative responses to GM-CSF and interleukin 3, and the induction of differentiation by G-CSF were not altered by expression of the kinase mutant Fes protein, indicating that Fes kinase activity is not critical for these biological events in these cell lines.

Immunodetection of the p21-ras products in human normal and preneoplastic tissues and solid tumors: a review

Immunohistochemical detection of p21-ras to identify and characterize preneoplastic or neoplastic lesions in human tissues is reviewed. Information concerning the commercially available antibodies is presented. Antibodies DWP, Ras-10, Y13-259, YA6-172, NCC-001, and NCC-004 are fully documented with respect to their behavior in appropriate specificity tests and appear to be reliable reagents. After reviewing the data we have identified three groups of tissues or organs with respect to positive immunostaining for p21-ras as the significant criterion of malignancy. These three groups comprise (1) tissues for which no definite conclusion could be drawn (colon, lung, bladder, ovary, and neural and odontogenic tissues) despite occasional claims to the contrary, (2) tissues for which conclusions were negative (pancreas and stomach), and (3) tissues for which p21-ras staining positively discriminated malignant from normal tissues (liver, uterus, and salivary gland). Immunohistochemically detectable levels of products from a mutated ras gene could be demonstrated in a fraction of the samples from colon, lung, and bladder carcinomas, as well as in some histologically normal tissues adjacent to a colon carcinoma. The possibility that a higher relative intensity of the immunostaining reaction for p21-ras might discriminate malignant tissues from normal tissues or benign lesions in breast, pancreas, stomach, lung, uterus, or thyroid samples is suggested. Further studies now appear warranted and a strategy is proposed to validate the conclusions reached thus far.