The molecular characterisation of unusual subcutaneous spindle cell lesion of breast

Takano, Elena A.; Rogers, Toni-Maree; Young, Richard J.; Rayoo, Mukta; Kostos, Phillip; Ferguson, Ross; Campbell, Ian; Dębiec‐Rychter, Maria; Fox, Stephen B.

doi:10.1136/jclinpath-2011-200629

Cited by 2 publications

(1 citation statement)

References 40 publications

(41 reference statements)

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“…Analyses were undertaken essentially as published. 49 Target detection used were as follows: Vysis LSI MDM2 Spectrum Orange Probe (Abbott Molecular, Des Plaines, IL, USA) and Vysis CEP 12 (D12Z3) Spectrum Green Probe (Abbott Molecular) or Poseidon MDM4 (1q32) and SE 1 Control Probe (Kreatech Diagnostics, Amsterdam, The Netherlands). Fifty tumor nuclei per case were assessed for each case using the following criteria: a case was considered amplified if the ratio was >2.0 and not amplified if the ratio was≤2.0.…”

Section: Methodsmentioning

confidence: 99%

Targeting Mdmx to treat breast cancers with wild-type p53

et al. 2015

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The function of the tumor suppressor p53 is universally compromised in cancers. It is the most frequently mutated gene in human cancers (reviewed). In cases where p53 is not mutated, alternative regulatory pathways inactivate its tumor suppressive functions. This is primarily achieved through elevation in the expression of the key inhibitors of p53: Mdm2 or Mdmx (also called Mdm4) (reviewed). In breast cancer (BrCa), the frequency of p53 mutations varies markedly between the different subtypes, with basal-like BrCas bearing a high frequency of p53 mutations, whereas luminal BrCas generally express wild-type (wt) p53. Here we show that Mdmx is unexpectedly highly expressed in normal breast epithelial cells and its expression is further elevated in most luminal BrCas, whereas p53 expression is generally low, consistent with wt p53 status. Inducible knockdown (KD) of Mdmx in luminal BrCa MCF-7 cells impedes the growth of these cells in culture, in a p53-dependent manner. Importantly, KD of Mdmx in orthotopic xenograft transplants resulted in growth inhibition associated with prolonged survival, both in a preventative model and also in a treatment model. Growth impediment in response to Mdmx KD was associated with cellular senescence. The growth inhibitory capacity of Mdmx KD was recapitulated in an additional luminal BrCa cell line MPE600, which expresses wt p53. Further, the growth inhibitory capacity of Mdmx KD was also demonstrated in the wt p53 basal-like cell line SKBR7 line. These results identify Mdmx growth dependency in wt p53 expressing BrCas, across a range of subtypes. Based on our findings, we propose that Mdmx targeting is an attractive strategy for treating BrCas harboring wt p53.

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Section: Methodsmentioning

confidence: 99%