MDR1 gene expression in peripheral blood as a marker of treatment response in lung cancer

• Published in: Journal of clinical oncology Vol. 30; no. 30_suppl; p. 96
• Main Authors: Luque, Raquel, Gonzalez Flores, Encarnacion, Delgado, Juan Ramon, Melguizo, Consolación, Prados, Jose Carlos, Gonzalez Astorga, Beatriz, Ortiz, Raul, Sánchez Toro, Carmen, Valdivia, Javier, Aránega, Antonia
• Format: Journal Article
• Language: English
• Published: 20-10-2012
• ISSN: 0732-183X; 1527-7755
• DOI: 10.1200/jco.2012.30.30_suppl.96

Abstract only
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Background: Non-small cell lung cancer (NSCLC) is sometimes chemoresistant and does not respond to treatment; several factors are involved in the development of chemoresistance, such as multidrug resistance (MDR) phenotype, mainly. Methods: We studied MDR1 gene expression in peripheral blood PMN of 23 patients with NSCLC, advanced stages in most of the cases, who had not received treatment previously, before (hour 0) and after (hour 6) paclitaxel-carboplatin treatment. RNA was obtained from PMN pellet by means of the protocol of trizol. RNA was checked with agarose gels, and later RT-PCR technique was carried out using specific primers. Expression levels were randomly distributed, so that overexpression under 3 was considered low level of expression, and overexpression above 4 was considered high level of expression. Results: After treatment, we found overexpression of MDR1 in 22 patients. High levels were found in 11 patients, and low levels were observed in the other 11 patients. No relation was found between this fact and the treatment response or survival rate. No significant differences in expression were found in the other variables: gender, tobacco habit, weight loss at the diagnosis, tumour staging, and tumor histology. Conclusions: We can conclude that MDR1 expression in peripheral blood is not a predictive factor for treatment response nor a prognostic factor of the disease. Despite these results, further studies are necessary on molecular biology of NSCLC in order to try to establish subgroups of patients based on genetic profiles, in which the use of microarrays could be very useful.