Expression of PBRM1 as a prognostic predictor in metastatic renal cell carcinoma patients treated with tyrosine kinase inhibitor.

OBJECTIVE: PBRM1, located on 3p21, functions as a tumor suppressor and somatic mutation of PBRM1 is frequent in clear cell renal cell carcinoma (ccRCC). This study aims to determine the influence of PBRM1 expression on the prognosis of patients with mRCC receiving tyrosine kinase inhibitor (TKI) treatment. METHODS: We identified 116 mRCC patients who were administered sunitinib or sorafenib as first-line therapy, between January 2006 and December 2016 at our institution. PBRM1 expression was assessed by immunohistochemistry. The Kaplan-Meier method was used to estimate the progression-free survival (PFS) and overall survival (OS), log-rank test was used to compare the survival outcomes between patients with low and high PBRM1 expression levels, and the Cox proportional hazard regression model was used to estimate the prognostic value. Prognostic accuracy was determined using Harrell concordance index, and nomograms were built to evaluate the prognosis of mRCC. RESULTS: Patients with low PBRM1 expression had significantly shorter median PFS (9 vs 26 months, P < 0.001) and OS (21 vs 44 months, P < 0.001) than those with high expression. Multivariate analysis showed that PBRM1 expression was an independent predictor of PFS (HR 1.975, P = 0.013) and OS (HR 2.282, P = 0.007). The model built by the addition of PBRM1 improved the C-index of PFS and OS to 0.72 and 0.82, respectively. CONCLUSIONS: The expression of PBRM1 could be a significant prognostic factor for mRCC patients treated with targeted therapy, and it increases the prognostic accuracy of the established prognostic model.

Sunitinib or Sorafenib as Neoadjuvant Therapy May not Improve the Survival Outcomes of Renal Cell Carcinoma with Tumor Thrombus.

OBJECTIVES: The purpose of this work was to investigate the effect of sorafenib or sunitinib as neoadjuvant therapy on the survival outcomes of renal cell carcinoma (RCC) with tumor thrombus. METHODS: A total of 92 RCC patients with tumor thrombus were included in this 2-center retrospective research from January 2007 to December 2014. Sorafenib and sunitinib were administered as neoadjuvant therapy in 9 patients and 14 patients, respectively, and 69 patients constituted non-neoadjuvant therapy groups. The Kaplan-Meier method was used to estimate the recurrence-free survival (RFS) and overall survival (OS). Log-rank test was used to compare the survival outcomes of patients with or without neoadjuvant therapy. RESULTS: The overall median RFS and OS time for all 92 patients were 28 months (95% CI 17-39 months) and 42 months (95% CI 30-54 months). Patients with neoadjuvant therapy had no significantly longer median RFS (30 vs. 28 months, p = 0.376) and OS (45 vs. 42 months, p = 0.702) than those without neoadjuvant therapy. CONCLUSIONS: Neoadjuvant therapy of sorafenib or sunitinib might not improve survival outcomes for high risk RCC patients with tumor thrombus. Thus, neoadjuvant therapy for RCC with tumor thrombus should be considered cautiously.

Elucidation of the Intestinal Absorption Mechanism of Loganin in the Human Intestinal Caco-2 Cell Model.

Loganin, iridoid glycosides, is the main bioactive ingredients in the plant Strychnos nux-vomica L. and demonstrates various pharmacological effects, though poor oral bioavailability in rats. In this study, the intestinal absorption mechanism of loganin was investigated using the human intestinal Caco-2 cell monolayer model in both the apical-to-basolateral (A-B) and the basolateral-to-apical (B-A) direction; additionally, transport characteristics were systematically investigated at different concentrations, pHs, temperatures, and potential transporters. The absorption permeability (PappAB) of loganin, which ranged from 12.17 to 14.78 × 10-6cm/s, was high at four tested concentrations (5, 20, 40, and 80µM), while the major permeation mechanism of loganin was found to be passive diffusion with active efflux mediated by multidrug resistance-associated protein (MRP) and breast cancer resistance protein (BCRP). In addition, it was found that loganin was not the substrate of efflux transporter P-glycoprotein (P-gp) since the selective inhibitor (verapamil) of the efflux transporter exhibited little effects on the transport of loganin in the human intestinal Caco-2 cells. Meanwhile, transport from the apical to the basolateral side increased 2.09-fold after addition of a MRP inhibitor and 2.32-fold after addition of a BCRP inhibitor. In summary, our results clearly demonstrate, for the first time, a good permeability of loganin in the human intestinal Caco-2 cell model and elucidate, in detail, the intestinal absorption mechanism and the effects of transporters on iridoid glycosides compounds.