Noninvasive Detection of Epidermolysis Bullosa–Associated Squamous Cell Carcinoma
Posted: Tuesday, July 10, 2018
A noninvasive liquid biopsy, which identifies a tumor marker gene, cancer-type (Ct)-SLCO1B3, in tumor-derived extracellular vesicles, may prove to be an effective option for detecting squamous cell carcinoma in patients with recessive dystrophic epidermolysis bullosa (RDEB-SCC). Yuchen Sun, PhD, of Paracelsus Medical University in Salzburg, Austria, and colleagues, described their studies in a letter to the editor in the Journal of Investigative Dermatology.
“Our data establish Ct-SLCO1B3 as a robust and reliable tumor marker in RDEB-SCC that could be exploited as a biomarker for this cancer,” stated the researchers, “highlighting the feasibility of this minimally invasive method...particularly once it has metastasized beyond the skin.”
Patients with RDEB carry a mutation in COL7A1, a gene essential for maintaining the integrity of the basement membrane zone in the skin and mucous membranes. Due to repeated cycles of infection and chronic inflammation, they develop highly aggressive squamous cell carcinoma at sites of persistent wounds. Because metastases to internal tissues are difficult to detect upon regular checkups, invasive biopsies are often necessary.
There are two variant transcripts of SLCO1B3: the normal liver-type (Lt) transcript and the aforementioned Ct transcript. Using semiquantitative real-time polymerase chain reaction, the investigators detected Ct-SLCO1B3 transcripts in all patient-derived RDEB-SCC cell lines, as well as in several tumor biopsies taken from patients. However, Ct-SLCO1B3 was not detected in either nontumor RDEB keratinocyte or normal human keratinocyte lines, nor were Lt-SLCO1B3 transcripts detected in any nonmalignant keratinocyte line.