A Maintenance Man in the Wrong Place
Heat shock protein 70 (Hsp70) is produced by cells during exertion or when subjected to heat, and acts as a kind of custodian: in the interior of the cell, it repairs or eliminates incorrectly folded proteins. In cancer cells, however, it sits on the surface of the cell. When on the surface it may influence the adhesion of the cells, and so assist the spread of metastases. Using scanning probe microscopy, the unusual behavior of Hsp70 has been investigated by Dr. Constanze Lamprecht within the framework of her LIT project, as a part of the team of Dr. Andreas Ebner.
Oncologists from the Technical University of Munich have recognized that Hsp70 reduces the success of patient therapies, and can be associated with the formation of metastases. To conduct further research at the molecular level, they brought the JKU’s biophysicist on board.
“The central question for us was what Hsp70 is really doing outside the cancer cells, on the membrane, when in healthy cells it is on the inside, in the cellular fluid,” says Ebner. In order to find out, the team artificially created a membrane with Hsp70. Using the methods of biosensory scanning probe microscopy, they were able to determine the force with which Hsp70 anchors itself to the cell membrane, along with how strongly individual cancer cells anchor themselves to lung cells. When Hsp70 encounters an appropriate lipid membrane a pore forms, even at very low concentrations, through which the protein passes from the interior to the exterior of the cell. “This is quite unusual,” says Ebner.
It is not yet clear whether healthy cells become cancer cells due to the “improper” accumulation of the protein on the outside of the membrane, or whether the cell first becomes a cancer cell and the protein then slips out.
In any case, it is suspected that Hsp70 is involved in the creation of metastases, which drastically reduce the chances of recovering from cancer. In the future, it may play an important role in blood analysis as a cancer marker.
Assoc. Univ. Prof. Dr. Andreas Ebner developed an interest in natural sciences at school and ultimately decided to come to JKU to study industrial engineering (including business administration) with a focus on technical chemistry because he thought that “chemistry would allow me to get to the bottom of things.”
The topic of his master’s thesis was - “by chance” - close to the field of biophysics, in which he went on to complete his PhD and was awarded habilitation.
Ebner values the close interconnection of his research field with other fields, such as medical technology, chemistry and physics. “Something new is happening all the time. It is always a challenge when somebody says, ‘That’s impossible!’ So far we’ve always been able to find a solution.”
In 2013, Ebner and his team were awarded the Houska Award for an ultra-sensitive, stable and easy to handle sensor for scanning force microscopy which they developed with their industrial partner SCL-Sensortech. A reduction in the sensors’ size and improvements in their chemical and technical properties have made the technique accessible to a significantly larger audience.
“Since researchers are always sceptics, such recognition is a pleasing acknowledgement of one’s work,” says Ebner.