Researchers from Houston University College of Pharmacy, led by Associate Professor Gomika Udugamasooriya, have discovered a new
biomarker for
cancer stem cells called plectin, a protein found on cancer stem cells. They have also at the same time identified possible therapeutic drug candidates.
University of Houston College of Pharmacy associate professor Gomika Udugamasooriya.
Credit: University of Houston
In the arena of cancer biology, not all
biomarkers are created equal. These molecules that alert oncologists that an abnormal process may be underway can appear as an array of aberrant proteins, such as hormones, enzymes or signaling molecules, and vary from patient to patient. Because they are a mixed and varied chemical and compounds, no one drug exists to attack them.
But now, a University of Houston College of Pharmacy associate professor has discovered a new
biomarker in
cancer stem cells that govern cancer survival and spread, and it's raising hope that drug discovery to kill
cancer stem cells could follow suit.
Speaking to
Thailand Medical News, associate professor Gomika Udugamasooriya, lead researcher said, "We have found a new
biomarker, the protein plectin, on cancer stem cells. We believe plectin may be a more common biomarker that could lead to broadly applicable drug development. Plectin is a structural protein, predominantly expressed intracellularly, but whose translocation onto thecell surface is linked to tumor invasion and metastasis."
Typically, all cancerous tumors contain a small subset of drug-resisting, self-renewing, and highly metastatic cells called tumor-initiating cells, or
cancer stem cells, responsible for 90% of cancer deaths.
Professor Udugamasooriya's process of discovering the
biomarker and a drug-lead is different than conventional two-step discoveries, where researchers first find a biomarker and then develop a drug. He did both at once, developing 400,000 potential synthetic chemical compounds (peptoids) and used them to capture the specific biomarker performing his unique, but simple two-color cell screen. From almost half a million, only three peptoids targeted
cancer stem cells and not the remaining cancer cells from the same patient. When those peptoids were used to pulldown their targets, one of them was identified as plectin, proving that it is a unique biomarker for
cancer stem cells.
Professor Udugamasooriya added "Our studies show both genotypic and phenotypic correlations between plectin and lung
cancer stem cells, as well as association of high plectin expression with poor patient survival in lung adenocarcinoma, potentially identifying plectin as a biomarker for lung
cancer stem cells."
As plectin assists in shaping cells, it is pivotal to the spread of cancer, helping
cancer stem cells
g> wend their way through the body.
Research scientists are desperately trying to find ways to handle these stubborn cancer stem cells to wipe out tumors. Professor Udugamasooriya predicts that this will be a more common drug target than current ones, because all tumors want to spread.
The team from Houston University are planning clinical trials in early 2020 and also a few international cohort studies.
The findings of the study was published in the journal of Nature Scientific Reports.
Reference: Aaron C. Raymond et al, Unbiased peptoid combinatorial cell screen identifies plectin protein as a potential biomarker for lung cancer stem cells, Scientific Reports (2019). DOI: 10.1038/s41598-019-51004-3 
