Human pathology

chromosomal imbalance

Chromosomal imbalances such as deletions and amplifications are common rearrangements in most tumors.

Specific rearrangements are consistently associated with specific tumor types or stages, implicating the role of the genes in a region of chromosomal imbalance in tumor initiation and progression.

Tumor-specific patterns of large-scale chromosomal imbalances characterize most forms of cancer.

Large-scale chromosomal imbalances are crucial for tumor pathogenesis and have an impact on the global transcriptional profile of cancer cells, and that some imbalances even initiate cancer.

The genes and genetic pathways that have been dysregulated by such imbalances remain surprisingly elusive.

Many genes are affected by the regions of gain and loss, and there are complex interactions and relationships that occur between these genes, hindering their identification.

The study of untranslated RNA sequences, such as microRNAs, is in its infancy, and it is likely that such sequences are also dysregulated by chromosomal imbalance, contributing to pathogenesis.

Comparative genomic hybridization (CGH)

The development of comparative genomic hybridization (CGH) has obviated the need to obtain metaphase spreads from tumors, so that the chromosomal imbalances in many solid tumors may be revealed using an extracted genomic DNA sample.

However, the resolution of the cytogenetic method remains and the extreme technical difficulty of CGH has restricted its use.

Conceptually, DNA microarray-based CGH is an obvious solution to all of the limitations of conventional CGH. Although arrays have been used for CGH studies, their success has been limited by poor specific signal-to-noise ratios.

Human pathology

chromosomal imbalance

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