Growth hormone protects colorectal cancer cells from radiation by improving the ability of DNA damage repair

  • Authors:
    • Xiao‑Yu Wu
    • Che Chen
    • Xue‑Quan Yao
    • Qin‑Hong Cao
    • Zhe Xu
    • Wei‑Su Li
    • Fu‑Kun Liu
    • Gang Li
  • View Affiliations

  • Published online on: April 24, 2014     https://doi.org/10.3892/mmr.2014.2185
  • Pages: 486-490
Metrics: Total Views: 0 (Spandidos Publications: | PMC Statistics: )
Total PDF Downloads: 0 (Spandidos Publications: | PMC Statistics: )


Abstract

The present study aimed to examine the effects of recombinant human growth hormone (rhGH) on the sensitivity of a colorectal cancer cell line to radiotherapy, and to investigate its association with DNA damage and repair. Flow cytometry and immunofluorescence were employed to detect growth hormone receptor (GHR) expression in nine human colorectal cancer cell lines. A colony forming assay was performed to measure the colorectal cancer cell proliferation post‑radiotherapy, as an indicator of radiotherapy sensitivity. The comet assay results were interpreted as an indicator of radiotherapy‑induced DNA damage, and growth arrest and DNA damage 45 (GADD45) and apurinic/apyrimidinic endonuclease (APEN) protein expression were quantified with western blot analysis from the same cell lines. The results demonstrated that the colony‑forming efficiency (CFE) was significantly increased in HCT‑8 cells subject to radiotherapy and rhGH pretreatment compared with the cells treated with radiotherapy alone, in a dose‑dependent manner (0‑100 mg/l). This effect was enhanced under high doses of radiation (8 Gy; 52.1±2.9 vs. 21.0±2.7; P<0.001) and was ameliorated with GHR neutralizing antibody exposure. By contrast, rhGH pre‑incubation did not change the colony formation rate in GHR(‑) LOVO cells. rhGH intervention reduced the early HCT‑8 cell DNA damage (21.53±2.88 vs. 36.56±3.93; P=0.003) as well as the following plateau phase, compared with cells treated with radiotherapy alone (5.5±0.42 vs. 9.07±0.84; P=0.012). rhGH upregulated GADD45 and APEN protein expression, which is associated with cellular stress responses and DNA damage repair (P=0.007). The results suggest that rhGH is able to protect colorectal cancer cells from radiation through the interaction with GHR, which is associated with the promotion of DNA damage repair activity.
View Figures
View References

Related Articles

Journal Cover

July-2014
Volume 10 Issue 1

Print ISSN: 1791-2997
Online ISSN:1791-3004

Sign up for eToc alerts

Recommend to Library

Copy and paste a formatted citation
x
Spandidos Publications style
Wu XY, Chen C, Yao XQ, Cao QH, Xu Z, Li WS, Liu FK and Li G: Growth hormone protects colorectal cancer cells from radiation by improving the ability of DNA damage repair. Mol Med Rep 10: 486-490, 2014
APA
Wu, X., Chen, C., Yao, X., Cao, Q., Xu, Z., Li, W. ... Li, G. (2014). Growth hormone protects colorectal cancer cells from radiation by improving the ability of DNA damage repair. Molecular Medicine Reports, 10, 486-490. https://doi.org/10.3892/mmr.2014.2185
MLA
Wu, X., Chen, C., Yao, X., Cao, Q., Xu, Z., Li, W., Liu, F., Li, G."Growth hormone protects colorectal cancer cells from radiation by improving the ability of DNA damage repair". Molecular Medicine Reports 10.1 (2014): 486-490.
Chicago
Wu, X., Chen, C., Yao, X., Cao, Q., Xu, Z., Li, W., Liu, F., Li, G."Growth hormone protects colorectal cancer cells from radiation by improving the ability of DNA damage repair". Molecular Medicine Reports 10, no. 1 (2014): 486-490. https://doi.org/10.3892/mmr.2014.2185