What is Fluorescence In Situ Hybridization (FISH)?
Fluorescence In Situ Hybridization, commonly abbreviated as FISH, is a molecular cytogenetic technique that uses fluorescent probes to bind to specific DNA sequences. This technique allows for the visualization of genetic material in cells, including chromosomes, to detect and localize the presence or absence of specific DNA sequences.
How is FISH used in Cancer Diagnosis?
FISH is widely used in cancer diagnosis to detect chromosomal abnormalities, such as translocations, amplifications, and deletions, which are often associated with various types of cancer. By identifying these genetic alterations, FISH helps in diagnosing specific types of cancers like leukemia, lymphoma, and solid tumors, thereby guiding treatment decisions.
It is highly sensitive and specific, providing accurate detection of genetic abnormalities.
FISH can be performed on a variety of sample types, including fresh, frozen, or paraffin-embedded tissues.
The technique allows for the analysis of individual cells, which is particularly useful in heterogeneous tumor samples.
It provides rapid results compared to other methods like karyotyping.
Breast Cancer: Detecting HER2 gene amplification, which can influence treatment options.
Leukemia: Identifying chromosomal translocations, such as the Philadelphia chromosome in chronic myeloid leukemia.
Lung Cancer: Detecting ALK gene rearrangements and ROS1 gene fusions.
Lymphoma: Identifying specific translocations like t(14;18) in follicular lymphoma.
Polymerase Chain Reaction (PCR): While PCR is highly sensitive and can detect small amounts of DNA, FISH provides spatial information about the genetic material within the cell, which PCR cannot.
Karyotyping: Karyotyping provides a broad overview of chromosomal abnormalities but lacks the specificity and resolution of FISH.
Next-Generation Sequencing (NGS): NGS offers comprehensive genomic information, but FISH is faster and more cost-effective for detecting specific genetic alterations.
FISH can only detect known genetic abnormalities for which specific probes are available.
The technique requires specialized equipment and expertise, which may not be available in all laboratories.
It may not be as effective in detecting low-level genetic changes or mutations.
Future Perspectives of FISH in Cancer Research
The future of FISH in cancer research is promising. Ongoing advancements aim to improve the sensitivity and specificity of FISH probes, allowing for the detection of an even broader range of genetic alterations. Additionally, combining FISH with other technologies, such as
immunohistochemistry and NGS, may provide more comprehensive insights into the genetic landscape of cancers, ultimately improving diagnosis, prognosis, and treatment strategies.
