Stem cells hidden in tumors may resist treatment

the Oncology Nurse Advisor take:

Researchers are examining the functioning of cancer stem cells with regard to treatment resistance. Although the ability of stem cells to transform themselves into almost any kind of cell has great value in a variety of medical applications, the ability of cancer stem cells to adapt and resist cancer therapy is a new concern.

A mouse study conducted at Washington University School of Medicine has shown the presence of these stem cells not only in aggressive cancer but also in slower growing tumors as well.

The research team, led by senior author David H. Gutmann, MD, PhD, used a mouse model of neurofibromatosis type 1 low-grade brain tumors to examine cancer stem cells and to see if they had the capability to form tumors if transplanted into healthy mice without cancer.

The cancer stem cells could indeed form tumors in this manner. Cancer stem cells produce more copies of the protein Abcg1 than standard stem cells, which helps them survive stress. 

The genetic disorder neurofibromatosis type 1(NF1) affects 1 in 2,500 babies and is responsible for a range of defects and disabilities, such as impaired vision, attention deficit hyperactivity disorder (ADHD), and heart and bone defects. Optic glioma is a brain tumor commonly seen in children with NF1.

This research determined that the drugs used to inhibit a cell growth pathway in optic glioma treatment are less effective versus the cancer stem cells, and the drug dosage may need to be increase as much as tenfold to compensate.

The study leaders feel that these cancer stem cells that have not yet developed into specialized cells represent a significant treatment obstacle that will require new strategies to overcome.