Tumor microenvironment heterogeneity: challenges and opportunities

Potential impact of PD-L1 (SP-142) immunohistochemical heterogeneity in clear cell renal cell carcinoma immunotherapy

Intratumor heterogeneity (ITH) detection remains a challenge in modern oncology because it can have a direct impact on the success of new therapies. Anti-PD-1/PD-L1 immunotherapy is an emerging treatment modality that is showing great promise for clear cell renal cell carcinoma (CCRCC) patients with advanced disease. Patient selection for such therapy relies upon the immunohistochemical detection of PD-1/PD-L1, however the degree of ITH for these markers among tumor cells and/or inflammatory mononuclear infiltrates remains unknown. Therefore, we analyzed PD-L1 (SP-142) expression in the tumor inflammatory cells of 22 CCRCC cases with the aim to define the pattern of PD-L1 expression, and to compare the reliability of current tumor sampling protocols (RS) with a multisite tumor sampling strategy (MSTS). While the RS protocol identified 5/22 (22.7%) of cases that were positive for PD-L1 expression, MSTS identified 10/22 (45.45%) of cases. This suggests that RS may miss a proportion of CCRCC patients that might benefit from immunotherapy. In addition, MSTS demonstrated that positive and negative regions of PD-L1 expression are very variable within each tumor.

Curcumol attenuates epithelial-mesenchymal transition of nasopharyngeal carcinoma cells via TGF-β1

The current study aimed to identify the effect and primary mechanism of Curcumol on the migration of nasopharyngeal carcinoma (NPC) cells in vitro and in vivo. Curcumol was dissolved in absolute ethyl alcohol and the experiment was performed in NPC 5–8F cells in vitro and in vivo. The effect of different concentrations of Curcumol on cell migration was determined using wound healing and Transwell assays. A cell counting kit-8 (CCK-8) assay was also performed in order to determine cell viability. Flow cytometry was used to detect the effect of Curcumol on apoptosis. The expression of epithelial-mesenchymal transition (EMT)-associated proteins and genes was evaluated by western blotting, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and ELISA. In addition, the antitumor activity of Curcumol was investigated in female BALB/C nude mice with orthotopic tumor implants. The results indicated that cell apoptosis was increased and the viability of NPC 5–8F cells was decreased following treatment with Curcumol at doses of 0.1, 0.2 and 0.4 µM/ml. The results of in vivo experiments indicated that tumor growth and weight were decreased following Curcumol administration. Furthermore, the results of western blotting and RT-qPCR demonstrated that Curcumol altered the level of E-cadherin and N-cadherin in a dose-dependent manner in vivo. Curcumol also regulated the secretion of protein markers in the serum that were associated with EMT and TGF-β1 in the 5–8F xenograft mouse model. Thus, the results indicated that Curcumol induced TGF-β1-mediated EMT arrest by regulating E-cadherin and N-cadherin, which may prevent further development of NPC.