Healthy and cancerous cells lining the oesophagus fluoresce in different ways, report French researchers.

Geneviève Bourg-Heckly, of the Université Pierre and Marie Curie, Paris, and colleagues measured the fluorescence spectra of normal and two types of malignant cells from the lining of the oesophagus. 

'We have already established that near-UV induced autofluorescence showed statistically significant differences between tumoral and healthy oesophageal tissue,' said Bourg-Heckly, 'but the tissue spectra are complicated by overlapping emissions from collagen and intracellular molecules related to metabolism, such as NAD(P)H and flavins.' 

Bourg-Heckly investigated whether cellular autofluoresence plays a role in the spectral differences observed between normal and tumoral tissues, and whether this is related to metabolism changes induced by cancer cell formation.

Using cells rather than tissue allowed the authors to isolate the contribution of intracellular fluorescence in the tissue spectra. The team found that malignant cells had a much higher fluorescence intensity, which could be attributed to a higher amount of the coenzyme marker NAD(P)H in these cells. 

The work is important, according to Anna Cleta Croce, from the Istituto di Genetica Molecolare, Pavia, Italy, because it 'gives an excellent confirmation of the potentials of autofluorescence spectroscopy for the characterisation of the metabolic state of cell populations,' she said.

'Application of suitable spectral analysis procedures makes this technique a powerful investigation tool to obtain information on cell components, with the advantage of a real time, in situ investigation on living cells,' Croce added

Bourg-Heckly's team now plans to study what causes this increase of NAD(P)H when normal cells transform into abnormal cells, and to examine other intracellular molecules in the same way.

These cellular spectra will also be useful reference spectra when modelling tissue fluorescence, Bourg-Heckly said, which should develop the role of fluorescence spectroscopy as a diagnostic tool to detect pre-cancerous and cancerous growths in their early stages in vivo. 

Susan Batten