Multicolor fluorescence in situ hybridization characterization of cytogenetically polyclonal hematologic malignancies

Idiopathic pulmonary fibrosis: an altered fibroblast proliferation linked to cancer biology

The fibrotic process that characterizes idiopathic pulmonary fibrosis (IPF) is commonly considered the result of a recurrent injury to the alveolar epithelium followed by an uncontrolled proliferation of fibroblasts. However, based on considerable scientific evidence, it has been recently hypothesized that IPF might be considered a neoproliferative disorder of the lung because this disease exhibits several pathogenic features similar to cancer. Indeed, epigenetic and genetic abnormalities, altered cell-to-cell communications, uncontrolled proliferation, and abnormal activation of specific signal transduction pathways are biological hallmarks that characterize the pathogenesis of IPF and cancer. IPF remains a disease marked by a survival of 3 years, and little therapeutic progress has been made in the last few years, underlining the urgent need to improve research and to change our approach to the comprehension of this disease. The concept of IPF as a cancer-like disease may be helpful in identifying new pathogenic mechanisms that can be borrowed from cancer biology, potentially leading to different and more effective therapeutic approaches. Such vision will hopefully increase the awareness of this disease among the public and the scientific community.

Intratumor diversity and clonal evolution in cancer--a skeptical standpoint

Clonal evolution in cancer is intimately linked to the concept of intratumor cellular diversity, as the latter is a prerequisite for Darwinian selection at the micro-level. It has been frequently suggested in the literature that clonal evolution can be promoted by an elevated rate of mutation in tumor cells, so-called genomic instability, the mechanisms of which are now becoming increasingly well characterized. However, several issues need clarification before the presumably complex relationship between mutation rate, intratumor diversity, and clonal evolution can be understood sufficiently well to translate into models that predict the course of tumor disease. In particular, it has to be clarified which of the proposed mechanisms for genomic instability that are able to generate daughter cells with sufficient viability to form novel clones, how clones with different genomic changes differ phenotypically from each other, and what the selective forces are that guide competition among diverse clones in different microenvironments. Furthermore, standardized measurements of mutation rates at the chromosome level, as well as genotypic and phenotypic diversity, are essential to compare data from different studies. Finally, the relationship between clonal variation brought about by genomic instability, on the one hand, and cellular differentiation hierarchies, on the other hand, should be explored to put genomic instability in the context of the tumor stem cell hypothesis.

Diagnostic challenges in the myelodysplastic syndromes: the current and future role of genetic and immunophenotypic studies

Myelodysplastic syndromes (MDS) comprise a clinically and pathologically diverse collection of hematopoietic neoplasms, most commonly presenting with peripheral cytopenias typically in the context of bone marrow hypercellularity. Mechanistically, at least in the early phases of the disease, this apparently paradoxical picture is primarily due to ineffective hematopoiesis, which is accompanied by a variety of morphologic abnormalities in hematopoietic cells. The identification of recurrent, clinically relevant cytogenetic defects in MDS has spurred the research of molecular mechanisms that contribute to its inception as well as to the development of heterogeneous subtypes. Although conventional cytogenetic analyses remain a diagnostic mainstay in MDS, the application of contemporary techniques including molecular cytogenetics, microarray technologies and multiparametric flow cytometry may ultimately reveal new diagnostic parameters that are theoretically more objective and sensitive than current morphologic approaches. This review aims to outline the role of genetic and immunophenotypic studies in the evaluation of MDS, including findings that may potentially influence future diagnostic classifications, which could refine prognostication and ultimately facilitate the growth of targeted therapies.

Identification of complex chromosome abnormalities in esophageal carcinoma cells KYSE450 by multicolor fluorescence in situ hybridization

AIM: To establish the technique of multicolor fluorescence in situ hybridization (M-FISH) for identification of chromosome aberrations in esophageal carcinoma cell line KYSE450.

METHODS: Two pools of 12-color whole-chromosome painting (WCP) probes were designed and labeled by degenerate oligonucleotide primer-polymerase chain reaction (DOP-PCR). FISH was performed twice on the same metaphase spreads. The karyotype was analyzed by the combination of inverted DAPI banding and M-FISH.

RESULTS: Repetitive 12-color M-FISH was successfully established and the cytogenetic abnormalities in KYSE450 cells were characterized. There were 54 chromosomes in the cell line, but only those numbered 13, 21 and X were normal. DNA losses were observed at parts of chromosomes 4, 7, 11, 12, 18 and 19. Chromosomal gains and translocations occurred at chromosome 1, 2, 3, 4, 5, 6, 7, 8, 9, 11, 12, 14, 15, 16, 17, 18 and 19. Chromosome 22 showed monosomy, and no chromosomes 10, 20 and Y were detected.

CONCLUSION: The established 12-color M-FISH is useful for the analysis of chromosomes in the whole genome of human tumors. KYSE450 cell line presents multiple cytogenetic abnormalities, which are in accordance with those occurred in primary esophageal squamous cell carcinoma.