Low-dose fractionated radiation potentiates the effects of cisplatin independent of the hyper-radiation sensitivity in human lung cancer cells.

Published

Journal Article

In this study, the role of hyper-radiation sensitivity (HRS) in potentiating the effects of cisplatin by low-dose fractionated radiation (LDFRT) was evaluated in four human non-small cell lung cancer cell lines. Presence of HRS and cisplatin enhancement ratio (CER) by LDFRT/2 Gy was assessed using colony-forming and apoptotic assays. Cell-cycle disturbances were studied by flow cytometry. Expression of genes involved in apoptosis was assessed using real-time reverse transcriptase PCR arrays. H-157 cells showed a distinct HRS region, followed by UKY-29 and A549 cells, whereas it was absent in H460 cells, which when lack HRS showed maximum CER with LDFRT (4 × 0.5 Gy) both by clonogenic inhibition and by apoptosis compared with single fraction of 2 Gy whereas the most radioresistant A549 cells had the least CER, with no significant differences between LDFRT or 2 Gy. Interestingly, in H-157 cells, a more pronounced CER was observed with LDFRT when assessed by apoptosis but clonogenic inhibition-CER was higher with 2 Gy than with LDFRT. Excluding H-157 cells, the CER by LDFRT was inversely proportional to radioresistance [(determined by D(0), the dose to reduce survival by 67% from any point on the linear portion of the survival curve or surviving fraction (SF) at 2 Gy (SF(2))] of the cells. LDFRT alone or in combination with cisplatin induced larger number of proapoptotic genes than 2 Gy or cisplatin + 2 Gy in cells showing HRS when compared to H460 cells that lack HRS. These findings indicate that chemopotentiation by LDFRT is correlated more with the intrinsic radiation sensitivity of the non-small lung cancer cells than the HRS phenomenon whereas the mode of cell killing is both through apoptosis and clonogenic inhibition.

Full Text

Duke Authors

Cited Authors

  • Gupta, S; Koru-Sengul, T; Arnold, SM; Devi, GR; Mohiuddin, M; Ahmed, MM

Published Date

  • February 2011

Published In

Volume / Issue

  • 10 / 2

Start / End Page

  • 292 - 302

PubMed ID

  • 21216938

Pubmed Central ID

  • 21216938

Electronic International Standard Serial Number (EISSN)

  • 1538-8514

Digital Object Identifier (DOI)

  • 10.1158/1535-7163.MCT-10-0630

Language

  • eng

Conference Location

  • United States