The research analysed the changes in the metabolism of cancerous and healthy cells subjected to radiation, revealing the existence of changes in the response of the lipids and proteins to different doses of radiation. The research has just been published in its entirety in the international Vibrational Spectroscopy scientific journal.
The work at the BioCruces Research Institute was led by university teacher Pedro Bilbao, Head of the Oncological Radiotherapy Service at the University Hospital of Cruces (Barakaldo in the Basque province of Bizkaia) and Professor of Radiology at the Faculty of Medicine of the UPV/EHU, and by university teacher José Luis R. Arrondo, from the Biophysics Unit at the UPV/EHU. To undertake this, funding was received from two grants: from the Department of Health and Consumer Affairs of the Basque Government; and from the Ministry of Science and Innovation (now known as the Ministry of Economy and Competitiveness).
As Mr Bilbao pointed out, “radiotherapy is the second therapeutic arm for curing cancer, after surgery. Nevertheless, there is a wide field for improvement by way of enhancing their beneficial cancericide effects and reducing side effects in healthy cells. In this vein, knowledge about how cell metabolism (cancerous and healthy cells) react to different doses of radiation is a line of research of great interest”.
Thus, the advances in studying the technique of infrared microespectrometry analysis, by means of what is known as two-dimensional correlation spectroscopy (2DCOS), “will give us new possibilities for studying variations produced in proteins, lipids and nucleic acids at different doses of radiation and over different time periods. All this has been applied in two distinct cell lines: (healthy) human oral keratinocytes (HOK) from mucous, and squamous carcinoma cells (SCC-25) from the tongue”, explained Dr. Arrondo.
To carry this out, infrared spectra of both cancerous and healthy cells divided into three regions (proteins, lipids and nucleic acids) were studied. Then, “using the 2DCOS system of analysis, the correlation between the various variables was established; in each cell line and the effect of the radiation dose compared to the control was seen. The effect of the length of time of irradiation was also measured. Finally, the correlation between cancerous and healthy cells at different doses and for different times was measured”, explained José Luis R. Arrondo.
The team stated that it had been shown that “the response of the proteins and lipids of both cancerous and healthy cells show structural differences when radiation is applied”.
In the region of the lipids, “the synchronous maps of the healthy cells did not show significant differences to the radiation doses (100, 200 and 600 cGy), as was the case of cancerous cells, although the normal and cancerous maps are different. The asynchronous maps are, however, different in both cases, although in the tumoural cells the spectrum recovers in 24 hours, something which does not occur in healthy cells”.
With respect to proteins, the different radiation doses did not affect healthy cells but they did in cancerous cells where, moreover, the effects are different after time, depending on the dosage.
The region of the nucleic acids show similar behaviour to that of proteins: healthy cells are not affected, while cancerous ones are, depending on the dosage.
As an example, Dr Bilbao pointed out that “it was observed that a radiation of 100 centigrays (cGy) affects normal cells more than the cancerous ones, while at 200 cGy the changes induced by the irradiation caused variation in the latter. The increase in intensity does not change the schema of the synchronous maps in normal cells, but high doses of radiation are associated with lack of metabolic activity in cancerous cells”.
A technique that opens new doors
According to José Luis R. Arrondo, “the results of the research show that infrared microespectrometry, together with the analysis of the spectra obtained by 2DCOS, is a useful technique for studying the metabolic changes produced in cancerous cells subjected to irradiation”.
Nevertheless, he stressed that “its most ideal application requires additional technical approaches, principally in the computational field, from the analysis of a spectrum to complex probabilistic and neuronal and even artificial networks, comprendiendo image. It is undoubtedly a pathway to good results in the medium and long term in the fight against cancer”.