| 1. |
- Pfeifer, Daniella, et al.
(författare)
-
Protein expression following gamma-irradiation relevant to growth arrest and apoptosis in colon cancer cells with mutant p53
- 2009
-
Ingår i: Journal of Cancer Research and Clinical Oncology. - : Springer Science and Business Media LLC. - 0171-5216 .- 1432-1335. ; 135:11, s. 1583-1592
-
Tidskriftsartikel (refereegranskat)abstract
- 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.
|
|
| 2. |
- Wallin, Åsa, 1976-, et al.
(författare)
-
Anticancer effect of SN-38 on colon cancer cell lines with different metastatic potential
- 2008
-
Ingår i: Oncology Reports. - : Spandidos Publications. - 1021-335X .- 1791-2431. ; 19:6, s. 1493-1498
-
Tidskriftsartikel (refereegranskat)abstract
- SN-38 is an active metabolite of the topoisomerase I inhibitor irinotecan. The mechanism behind its antitumor effect in colorectal cancer is not fully understood. In this study, we examined the response of colon cancer cell lines with different metastatic potential to SN-38. The parental human colon cancer cell line KM12C and its two highly metastatic derivatives KM12SM and KM12L4a were cultivated in 5% CO2 at 37°C for 24 h and then exposed to SN-38 (2.5 µg/ml) at 37°C for 4, 24 and 48 h, respectively. The cell cycle was measured by flow cytometry, apoptotic activity was determined by flow cytometry and immunocytochemistry and the expression of topoisomerase I, Bax and survivin proteins were examined by Western blot. The exposure of the cells to SN-38 induced S-phase and G2 arrest (P<0.0001) and the KM12L4a cells had the highest response in a time-dependent manner (P<0.0001). The rates of apoptosis in the KM12SM (P=0.001) and KM12L4a cell lines (P=0.01) were increased time-dependently, though there was no such change in the KM12C cells. The expression of topoisomerase I protein was decreased in each cell line tested and the expression of Bax protein was increased, especially in KM12L4a. In conclusion, the effect of SN-38 on the colon cancer cell lines was mediated via conducting S-phase and G2 arrest and apoptosis. This effect was found in the cell lines with higher metastatic potentials, indicating that SN-38 can be used to treat advanced colon cancers.
|
|
