Changes in gene expression associated with stable drug and radiation resistance in small cell lung cancer cells are similar to those caused by a single X-ray dose.

Small cell lung cancer (SCLC) initially responds well to chemotherapy and fractionated radiotherapy, but resistance to these treatments eventually develops in the vast majority of cases. To understand how resistance develops in the H69 SCLC cell line, we compared the changes in gene expression associated with 37.5 Gy fractionated X-ray treatment that produced the stable radiation- and drug-resistant H69/R38 cell subline to the changes associated with a single 4- or 8-Gy X-ray treatment.

Cellular models of drug- and radiation-resistant small cell lung cancer.

Background: The H69-EPR, H69-CP, H69-VP and H69/R38 resistant sublines of the classic small cell lung cancer (SCLC) line have proven useful in studies of resistance and its circumvention with paclitaxel.

Materials And Methods: The suppressor/oncogene profile of these sublines determined by Western and Northern blot was compared to the variant H82 SCLC cell profile. Two-dimensional electrophoresis/mass spectrometry was used to determine the effect of paclitaxel on protein expression.

Fractionated irradiation of H69 small-cell lung cancer cells causes stable radiation and drug resistance with increased MRP1, MRP2, and topoisomerase IIalpha expression.

Purpose: After standard treatment with chemotherapy and radiotherapy, small-cell lung cancer (SCLC) often develops resistance to both treatments. Our aims were to establish if fractionated radiation treatment alone would induce radiation and drug resistance in the H69 SCLC cell line, and to determine the mechanisms of resistance.

Methods And Materials: H69 SCLC cells were treated with fractionated X-rays to an accumulated dose of 37.