Multi-kinase inhibitors interact with sildenafil and ERBB1/2/4 inhibitors to kill tumor cells in vitro and in vivo

Laurence Booth, Thomas Albers, Jane L. Roberts, Mehrad Tavallai, Andrew Poklepovic, Iryna O. Lebedyeva, Paul Dent

Research output: Contribution to journalArticlepeer-review

20 Scopus citations


We have recently demonstrated that multi-kinase inhibitors such as sorafenib and pazopanib can suppress the detection of chaperones by in situ immuno-fluorescence, which is further enhanced by phosphodiesterase 5 inhibitors. Sorafenib and pazopanib inhibited the HSP90 ATPase activity with IC50 values of ~1.0 μM and ~75 nM, respectively. Pazopanib docked in silico with two possible poses into the HSP90 ATP binding pocket. Pazopanib and sildenafil combined to reduce the total protein levels of HSP1H/p105 and c-MYC and to reduce their co-localization. Sorafenib/ pazopanib combined with sildenafil in a [GRP78+HSP27] -dependent fashion to: (i) profoundly activate an eIF2α/Beclin1 pathway; (ii) profoundly inactivate mTOR and increase ATG13 phosphorylation, collectively resulting in the formation of toxic autophagosomes. In a fresh PDX isolate of NSCLC combined knock down of [ERBB1+ERBB3] or use of the ERBB1/2/4 inhibitor afatinib altered cell morphology, enhanced ATG13 phosphorylation, inactivated NFκB, and further enhanced [sorafenib/ pazopanib + sildenafil] lethality. Identical data to that with afatinib were obtained knocking down PI3K p110α/β or using buparlisib, copanlisib or the specific p110α inhibitor BYL719. Afatinib adapted NSCLC clones were resistant to buparlisib or copanlisib but were more sensitive than control clones to [sorafenib + sildenafil] or [pazopanib + sildenafil]. Lapatinib significantly enhanced the anti-tumor effect of [regorafenib + sildenafil] in vivo; afatinib and BYL719 enhanced the anti-tumor effects of [sorafenib + sildenafil] and [pazopanib] in vivo, respectively.

Original languageEnglish (US)
Pages (from-to)40398-40417
Number of pages20
Issue number26
StatePublished - 2016
Externally publishedYes


  • Chaperones
  • ERBB
  • PI3K
  • Pazopanib
  • Sorafenib

ASJC Scopus subject areas

  • Oncology


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