ROS1 Break Apart FISH Probe - CE

The ROS1 Break Apart FISH Probe localizes to the ROS1 gene allowing confirmation of rearrangements of the gene.

The ROS1 proto-oncogene encodes a protein with tyrosine kinase activity. This protein is highly expressed in several tumor types. The protein may function as a growth or differentiation factor receptor.

Empire Genomics has developed a ROS1 Break Apart probe which can be used to detect a rearrangement of the ROS1 gene. The probe comes labeled in green and orange, and is customizable to meet your needs.

CE Marked (Orange-Green color option only).

The ROS1 gene codes for the ROS1 tyrosine kinase insulin receptor, a type I integral membrane protein that binds cell growth and differentiation signaling factors1. Rearrangements of ROS1 have been implicated in a multitude of cancers, including NSCLC, gastric cancer, ovarian cancer, colorectal cancer, and various epithelial malignancies2,3. These translocations produce fusion proteins, constitutively activating the kinase domain of ROS1, leading to unchecked cell proliferation2.

The most well documented ROS1 studies are those on non-small cell lung cancer. ROS1 translocations, although only present in 1-2% of NSCLC cases, have distinct cytogenetic characteristics that enable more targeted treatment of the disease4. For example, ROS1 translocations only occur in the absence of other common oncogenes; EGFR mutations, KRAS mutations and ALK rearrangements are, for the most part, only present in non-ROS1 tumors4. ROS1 translocations also have age and lifestyle implications – patients with the rearrangement are usually female, younger, and never-smokers2,5.

Perhaps the most exciting discovery that has come out of establishing ROS1 as an oncogene in NSCLC is the gene’s response to targeted chemotherapy. Crizotinib, a drug that had previously been used to target ALK-positive NSCLC, has proven just as effective in fighting ROS1 tumors. The drug attacks both genes in the same way, by inhibiting their kinase domains, thereby down-regulating the cell proliferation pathway that leads to tumor development. ROS1 tumors have proven highly responsive to Crizotinib; in one study, the drug completely eradicated tumor growth in a patient with late stage NSCLC in a matter of weeks, while a larger study on NSCLC adenocarcinomas reported an 80% response rate to the drug4,5.

ROS1 translocations are relatively rare in cases of the gene’s associated cancers. However, if rearrangements are present, kinase domain inhibitors (like Crizotinib) are highly effective, gene-specific treatment options. The gene will continue to serve as an important biomarker for NSCLC and other cancers, hopefully helping researcher to understand the oncogenic mechanisms of tyrosine kinase receptors on a deeper level.

Loci: 6q22