BCL-2 by FISH

BCL-2 (B-cell lymphoma 2) is a gene associated with the regulation of apoptosis (programmed cell death) in cells. Abnormalities in the BCL-2 gene, such as translocations or gene rearrangements, are frequently found in various types of lymphomas, particularly B-cell non-Hodgkin lymphomas (NHL). Fluorescence In Situ Hybridization (FISH) is a molecular technique used to detect and assess BCL-2 gene abnormalities in cancer cells. Here’s how BCL-2 testing by FISH works:

• Sample Collection: A tissue sample, typically obtained through a biopsy or surgical procedure, is collected from the patient. This tissue sample contains lymphoma cells.
• Tissue Preparation: The collected tissue sample is processed and prepared for FISH analysis. This may involve fixing the tissue and preparing thin sections on glass slides.
• FISH Probe Preparation: Specific DNA probes are designed to target the BCL-2 gene region. These probes are labeled with fluorescent molecules that emit distinct colors when exposed to specific wavelengths of light.
• Hybridization: The tissue sample is incubated with the DNA probes. If there are abnormalities in the BCL-2 gene, such as translocations or rearrangements, the DNA probes will bind to the corresponding target sequences.
• Fluorescent Labeling: When the DNA probes bind to the target BCL-2 gene sequences, they emit fluorescent signals. These signals can be visualized and analyzed using a fluorescent microscope.
• Imaging and Analysis: The tissue sample is examined under the fluorescent microscope. The number and pattern of fluorescent signals are assessed. Abnormalities, such as BCL-2 gene translocation or rearrangement, are identified based on the presence of altered patterns of fluorescence signals.

BCL-2 FISH testing is particularly important in the diagnosis and classification of various B-cell NHL subtypes. Different subtypes of B-cell NHL can have distinct genetic alterations, and the detection of BCL-2 gene abnormalities can help pathologists and oncologists refine their diagnosis and treatment strategies.

For example, the t(14;18) translocation, which involves the BCL-2 gene, is a hallmark genetic alteration in follicular lymphoma. Detecting this translocation can aid in confirming the diagnosis of follicular lymphoma and may have implications for treatment decisions.

The results of BCL-2 FISH testing provide valuable information about the genetic characteristics of lymphoma cells. These results can help guide treatment decisions, including the selection of specific therapies or the assessment of the lymphoma’s aggressiveness.