Limits...
MI-63: a novel small-molecule inhibitor targets MDM2 and induces apoptosis in embryonal and alveolar rhabdomyosarcoma cells with wild-type p53.

Canner JA, Sobo M, Ball S, Hutzen B, DeAngelis S, Willis W, Studebaker AW, Ding K, Wang S, Yang D, Lin J - Br. J. Cancer (2009)

Bottom Line: Treatment with MI-63 reduced cell viability by 13.4% and by <1%, respectively, at 72 h in both RH36 and RH18 cell lines expressing wild-type p53.MI-63 was compared with Nutlin-3, a known MDM2 inhibitor, and was found to be more potent in the inhibition of cell proliferation/viability.These results indicate that MI-63 is a potent therapeutic agent for RMS cells expressing wild-type p53 protein.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Nationwide Children's Hospital, Columbus, OH, USA.

ABSTRACT

Background: Interruption of the role of p53s as a tumour suppressor by MDM2 may be one of the mechanisms by which cancer cells evade current therapy. Blocking the inhibition of wild-type p53 by MDM2 in cancer cells should reactivate p53's tumour suppressor functions and enhance current cancer treatments. MI-63 is a novel non-peptide small molecule that has shown strong binding affinity (K(i)=3 nM) for MDM2; however, its effects on paediatric cancer cells and the specific mechanism of tumour suppressor reactivation have not been evaluated.

Methods: Rhabdomyosarcoma (RMS), the most common childhood soft tissue sarcoma, expresses either wild-type or mutant p53 protein. We examined the inhibitory effects of MI-63 in embryonal RMS (ERMS) and alveolar RMS (ARMS) cell lines expressing wild-type or mutated p53.

Results: Treatment with MI-63 reduced cell viability by 13.4% and by <1%, respectively, at 72 h in both RH36 and RH18 cell lines expressing wild-type p53. In contrast, RH30 and RD2 cells expressing p53 mutants are resistant to MI-63 treatment. An increased expression of p53, p21(WAF1), and Bax protein was observed after treatment with MI-63 in RMS cells with wild-type p53, and apoptosis was confirmed by cleaved PARP and caspase-3 expression. However, RD2 and RH30 RMS cells, as well as human normal skeletal muscle cells, showed a minimal increase in p53 signalling and no induction of cleaved PARP and caspase-3. MI-63 was compared with Nutlin-3, a known MDM2 inhibitor, and was found to be more potent in the inhibition of cell proliferation/viability. Further, synergy was observed when MI-63 was used in combination with doxorubicin.

Conclusion: These results indicate that MI-63 is a potent therapeutic agent for RMS cells expressing wild-type p53 protein.

Show MeSH

Related in: MedlinePlus

The effect of MI-63 on the cell viability of ERMS/ARMS cells. (A, B) Rhabdomyosarcoma cells with wild-type p53, RH36 and RH18, showing decreased cell proliferation when treated with MI-63. (C, D) Rhabdomyosarcoma cells with mutated p53, RD2 and RH30, showing decreased cell proliferation when treated with MI-63.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC2736841&req=5

fig3: The effect of MI-63 on the cell viability of ERMS/ARMS cells. (A, B) Rhabdomyosarcoma cells with wild-type p53, RH36 and RH18, showing decreased cell proliferation when treated with MI-63. (C, D) Rhabdomyosarcoma cells with mutated p53, RD2 and RH30, showing decreased cell proliferation when treated with MI-63.

Mentions: An ERMS cell line with wild-type p53, RH36, incubated with 5 and 10 μM of MI-63 for 1–3 days, was evaluated. MTT assay showed decreased cell proliferation/viability across 3 days of exposure with 5 and 10 μM of MI-63 (48.7%±5.41 and 48.7%±11.02 on day 1; 35.9%±26.56 and 35.6%±28.47 on day 2; 13.4%±16.11 and 9.8%±15.30 on day3) (Figure 3A). Similarly, a histologic ARMS cell line with wild-type p53, RH18, was incubated with 5 and 10 μM of MI-63 for the same duration. MTT assay identified decreased cell viability in RH18 cells (77.3%,±5.44 and 60.9%±9.83 on day 1; 20.9%±2.05 and 18.2%±18.74 on day 2; <1%±0 and <1%±0 on day3) (Figure 3B).


MI-63: a novel small-molecule inhibitor targets MDM2 and induces apoptosis in embryonal and alveolar rhabdomyosarcoma cells with wild-type p53.

Canner JA, Sobo M, Ball S, Hutzen B, DeAngelis S, Willis W, Studebaker AW, Ding K, Wang S, Yang D, Lin J - Br. J. Cancer (2009)

The effect of MI-63 on the cell viability of ERMS/ARMS cells. (A, B) Rhabdomyosarcoma cells with wild-type p53, RH36 and RH18, showing decreased cell proliferation when treated with MI-63. (C, D) Rhabdomyosarcoma cells with mutated p53, RD2 and RH30, showing decreased cell proliferation when treated with MI-63.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2736841&req=5

fig3: The effect of MI-63 on the cell viability of ERMS/ARMS cells. (A, B) Rhabdomyosarcoma cells with wild-type p53, RH36 and RH18, showing decreased cell proliferation when treated with MI-63. (C, D) Rhabdomyosarcoma cells with mutated p53, RD2 and RH30, showing decreased cell proliferation when treated with MI-63.
Mentions: An ERMS cell line with wild-type p53, RH36, incubated with 5 and 10 μM of MI-63 for 1–3 days, was evaluated. MTT assay showed decreased cell proliferation/viability across 3 days of exposure with 5 and 10 μM of MI-63 (48.7%±5.41 and 48.7%±11.02 on day 1; 35.9%±26.56 and 35.6%±28.47 on day 2; 13.4%±16.11 and 9.8%±15.30 on day3) (Figure 3A). Similarly, a histologic ARMS cell line with wild-type p53, RH18, was incubated with 5 and 10 μM of MI-63 for the same duration. MTT assay identified decreased cell viability in RH18 cells (77.3%,±5.44 and 60.9%±9.83 on day 1; 20.9%±2.05 and 18.2%±18.74 on day 2; <1%±0 and <1%±0 on day3) (Figure 3B).

Bottom Line: Treatment with MI-63 reduced cell viability by 13.4% and by <1%, respectively, at 72 h in both RH36 and RH18 cell lines expressing wild-type p53.MI-63 was compared with Nutlin-3, a known MDM2 inhibitor, and was found to be more potent in the inhibition of cell proliferation/viability.These results indicate that MI-63 is a potent therapeutic agent for RMS cells expressing wild-type p53 protein.

View Article: PubMed Central - PubMed

Affiliation: Department of Pediatrics, Nationwide Children's Hospital, Columbus, OH, USA.

ABSTRACT

Background: Interruption of the role of p53s as a tumour suppressor by MDM2 may be one of the mechanisms by which cancer cells evade current therapy. Blocking the inhibition of wild-type p53 by MDM2 in cancer cells should reactivate p53's tumour suppressor functions and enhance current cancer treatments. MI-63 is a novel non-peptide small molecule that has shown strong binding affinity (K(i)=3 nM) for MDM2; however, its effects on paediatric cancer cells and the specific mechanism of tumour suppressor reactivation have not been evaluated.

Methods: Rhabdomyosarcoma (RMS), the most common childhood soft tissue sarcoma, expresses either wild-type or mutant p53 protein. We examined the inhibitory effects of MI-63 in embryonal RMS (ERMS) and alveolar RMS (ARMS) cell lines expressing wild-type or mutated p53.

Results: Treatment with MI-63 reduced cell viability by 13.4% and by <1%, respectively, at 72 h in both RH36 and RH18 cell lines expressing wild-type p53. In contrast, RH30 and RD2 cells expressing p53 mutants are resistant to MI-63 treatment. An increased expression of p53, p21(WAF1), and Bax protein was observed after treatment with MI-63 in RMS cells with wild-type p53, and apoptosis was confirmed by cleaved PARP and caspase-3 expression. However, RD2 and RH30 RMS cells, as well as human normal skeletal muscle cells, showed a minimal increase in p53 signalling and no induction of cleaved PARP and caspase-3. MI-63 was compared with Nutlin-3, a known MDM2 inhibitor, and was found to be more potent in the inhibition of cell proliferation/viability. Further, synergy was observed when MI-63 was used in combination with doxorubicin.

Conclusion: These results indicate that MI-63 is a potent therapeutic agent for RMS cells expressing wild-type p53 protein.

Show MeSH
Related in: MedlinePlus