JERUSALEM, Sept. 23 (Xinhua) -- Israeli and U.S. researchers found that glioblastoma brain cancer cells come in four states and can transition from one state to another, the Weizmann Institute of Science (WIS) in central Israel reported on Monday.

The study, published in the journal Cell, was led by researchers from WIS, Massachusetts General Hospital (MGH) in Boston and the Salk Institute for Biological Studies in La Jolla, California.

The findings might point to ways of developing future therapies to the incurable glioblastoma.

Glioblastoma tumors differ from one patient to the next, and even cells within each tumor differed greatly from one another.

According to the researchers, it is possible that no therapy has yet worked well because each drug kills only a subset of the tumor cells, and a successful future therapy will need to attack all four states.

The research team resorted to advanced technology called single-cell RNA sequencing, which provides information about gene expression in individual cells.

The team obtained tumor samples from 28 glioblastoma patients and created profiles of gene expression in some 24,000 tumor cells.

Using unique algorithms, they were able to correlate gene expression patterns with cell division and other normal and aberrant cellular activities.

This analysis enabled the scientists to identify four different cell subtypes, each characterized by its own gene activation program.

It was found that cancer cells hijack gene activation programs of developing cells, and these programs drive the growth of the tumors.

Then, the scientists "barcoded" glioblastoma cells into mice and tracked them over time, demonstrating that tumor cells do indeed transition between different cellular states.

In another experiment, they implanted human glioblastoma cells into mice, seeing that the cells later changed their identity.

The precise glioblastoma characterization points the way toward targeting future therapies against all tumor subtypes, after determining how each subtype responds to drugs.

The findings can also be applied to characterize the subtypes that occur in other cancers.