Predictive Immunohistochemical Markers Related to Drug Selection for Patients Treated with Sunitinib or Sorafenib for Metastatic Renal Cell Cancer.

Targeted drug decisions in metastatic renal cell carcinoma are exclusively made on the basis of clinical criteria. We investigated whether these biomarkers (HIF-1α, HIF-2α, CAIX, VEGF, VEGFR1, VEGFR2, VEGFR3, PDGFB, PDGFRA, PDGFRB, CD31, CD44, bcl-xL, KIT, p21, CXCR4, PTEN, (CSF)-1R, RET, and FLT-3) can predictive the different effects between sunitinib and sorafenib treatments and are available to guide targeted drug selection. We enrolled all patients who underwent nephrectomy with postoperative sunitinib- or sorafenib-treatment at our institution from 2007 to 2012. Immunohistochemical approach was applied to assess the potential differential effects of immunostainings between sunitinib- and sorafenib-treated groups. We found that patients with high HIF-2α, CD31 expression showed greater relative PFS and OS benefit and patients with high CAIX expression presented greater relative OS benefit from sunitinib than from sorafenib, patients with high VEGFR1 or PDGFRB expression levels exhibited worse relative PFS benefit from sunitinib than from sorafenib. Namely high HIF-2α, CD31, and CAIX expression levels along with low VEGFR1 and PDGFRB expression levels improved the benefit of sunitinib treatment compared with sorafenib treatment. These results can identify whether patients can benefit more from sunitinib or sorafenib for drug selection guidance, eventually with precision medicine.

Epigallocatechin gallate promotes p53 accumulation and activity via the inhibition of MDM2-mediated p53 ubiquitination in human lung cancer cells.

Epigallocatechin gallate (EGCG), which is derived from green tea, is well known for its chemopreventive activity. Several studies have shown that p53 plays an important role in the activity of EGCG; however, the mechanism by which EGCG regulates p53 requires further investigation. In the present study, we showed that EGCG inhibits anchorage-independent growth of human lung cancer cells by upregulating p53 expression. EGCG treatment can substantially increase p53 stability, promote nuclear localization of p53 and decrease nuclear accumulation of MDM2. We also found that EGCG increases the phosphorylation of p53 at Ser15 and Ser20 and enhances its transcriptional activity. Although EGCG promotes MDM2 expression in a p53-dependent manner, the interaction between MDM2 and p53 was significantly inhibited following EGCG treatment, which resulted in the inhibition of MDM2-mediated p53 ubiquitination. Thus, our results suggest that the stabilization and activation of p53 may partly contribute to the anticancer activity of EGCG.