A systems biology approach to investigate the mechanism of action of trabectedin in a model of myelomonocytic leukemia.

This study was designed to investigate the mode of action of trabectedin in myelomonocytic leukemia cells by applying systems biology approaches to mine gene expression profiling data and pharmacological assessment of the cellular effects. Significant enrichment was found in regulons of target genes inferred for specific transcription factors, among which MAFB was the most upregulated after treatment and was central in the transcriptional network likely to be relevant for the specific therapeutic effects of trabectedin against myelomonocytic cells. Using the Connectivity Map, similarity among transcriptional signatures elicited by treatment with different compounds was investigated, showing a high degree of similarity between transcriptional signatures of trabectedin and those of the topoisomerase I inhibitor, irinotecan, and an anti-dopaminergic antagonist, thioridazine. The study highlights the potential importance of systems biology approaches to generate new hypotheses that are experimentally testable to define the specificity of the mechanism of action of drugs.

Identification of high-grade serous ovarian cancer miRNA species associated with survival and drug response in patients receiving neoadjuvant chemotherapy: a retrospective longitudinal analysis using matched tumor biopsies.

BACKGROUND: Neoadjuvant chemotherapy (NACT) has been recognized as a reliable therapeutic strategy in patients with unresectable advanced epithelial ovarian cancer (EOC). The molecular events leading to platinum (Pt) response in NACT settings have hitherto not been explored. In the present work, longitudinal changes of miRNA expression profile were investigated to identify miRNA families with prognostic role in high-grade serous EOC patients who received the NACT regimen. PATIENTS AND METHODS: One hundred sixty-four matched tumor biopsies taken at initial laparoscopic evaluation and at interval-debulking surgery (IDS) after four courses of Pt-based therapy were selected from 82 stage IIIC-IV high-grade serous-EOC patients that were judged unsuitable for complete primary debulking and subjected the NACT protocol. miRNA profiling by microarray, real-time PCR and immuno-histochemical staining for Smad2 phosphorylation (P-Smad2) were used for data analysis. RESULTS: Analysis revealed that 369 miRNAs were differentially expressed in matched biopsies (referred to as DEMs). DEMs were not scattered across the genome, but clustered into families: miR-199, let-7, miR-30, miR-181 and miR-29. Multivariate analysis showed that miR-199a-3p, miR-199a-5p, miR-181a-5p and let-7g-5p associated with overall and progression-free survival (P < 0.05); miR-199a-3p, miR-199a-5p and miR-181a-5p associated with residual tumor volume and Pt-free interval (P < 0.05). Immuno-histochemical staining confirmed an enrichment of P-Smad2, a marker of transforming growth factor-ß activation, in tumors from patients with shorter PFS and OS, and with high levels of expression of miR-181a-5p (P < 0.05). Kaplan-Meier curves plotting concomitant expression of P-Smad2 and miR-181a-5p show significant differences in PFS and OS compared with those depicting the expression of each biomarker alone (P < 0.001). CONCLUSIONS: This study describes several miRNA families with a prognostic role in the NACT setting. It also confirms that concomitant analysis of P-Smad2 and miR-181a-5p in surgical samples may be capable of identifying those ovarian cancer patients with poor outcome and little chance of response to Pt-based NACT.

The soluble glycoprotein NMB (GPNMB) produced by macrophages induces cancer stemness and metastasis via CD44 and IL-33.

In cancer, myeloid cells have tumor-supporting roles. We reported that the protein GPNMB (glycoprotein nonmetastatic B) was profoundly upregulated in macrophages interacting with tumor cells. Here, using mouse tumor models, we show that macrophage-derived soluble GPNMB increases tumor growth and metastasis in Gpnmb-mutant mice (DBA/2J). GPNMB triggers in the cancer cells the formation of self-renewing spheroids, which are characterized by the expression of cancer stem cell markers, prolonged cell survival and increased tumor-forming ability. Through the CD44 receptor, GPNMB mechanistically activates tumor cells to express the cytokine IL-33 and its receptor IL-1R1L. We also determined that recombinant IL-33 binding to IL-1R1L is sufficient to induce tumor spheroid formation with features of cancer stem cells. Overall, our results reveal a new paracrine axis, GPNMB and IL-33, which is activated during the cross talk of macrophages with tumor cells and eventually promotes cancer cell survival, the expansion of cancer stem cells and the acquisition of a metastatic phenotype.