Protein expression following gamma-irradiation relevant to growth arrest and apoptosis in colon cancer cells with mutant p53

• We previously found that p53, p73, survivin and PRL were implicated in the outcome of radiotherapy in rectal cancer patients. In the present study, we tried to understand mechanisms of colon cancer cell line response to radiation based on protein expression related to proliferation and apoptosis. KM12C, KM12SM and KM12L4a, cell lines with one origin, were radiated with 0, 10 or 15 Gy γ-radiation. Radiosensitivity was determined with cell cycle and apoptosis analysis, and protein expression of TAp73, ΔNp73, mutated p53, survivin and PRL-3 was determined by Western blot. KM12C showed transient G2-arrest, low apoptosis and up-regulation of resistance factors such as PRL-3. In KM12C expression of ΔNp73 increased after 10Gy, but not after 15Gy. KM12SM had permanent G2-arrest, low apoptosis and showed up-regulation of the anti-apoptotic survivin and down-regulation of the pro-apoptotic TAp73 and the radioresistance factor PRL-3 was down-regulated. KM12L4a, the most radiosensitive cell line, showed up-regulation of TAp73 and down-regulation/no up-regulation of resistance factors such as ΔNp73, survivin and PRL-3 after radiation. In conclusion, the KM12C cell line was more radioresistant than KM12L4a regarding apoptosis and certain apoptotic proteins. The radiosensitivity of KM12L4a might partly depend on the lack of up-regulation of proteins negative for the outcome of radiotherapy.  

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Cancer och onkologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Cancer and Oncology (hsv//eng)

Nyckelord

Oncology

Onkologi

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)