Supplementary MaterialsSupplementary figure legends 41388_2018_394_MOESM1_ESM. Loss- and gain-of-function experiments by HMGA1-specific depletion and overexpression in dedifferentiated and myxoid liposarcoma cells showed the contribution of this oncogenic factor in cell proliferation, motility, invasion, and drug resistance. The in vitro and in vivo treatment of myxoid liposarcoma with trabectedin, a drug with a potent anti-tumor activity, revealed downregulation of AVN-944 ic50 HMGA1, E2F1, and its-downstream targets, vimentin FASN and ZEB1, indicating a critical role of trabectedin in inhibiting the mesenchymal markers of these tumors through the HMGA1/E2F1 axis. These data were also confirmed in patients tumor biopsies being HMGA1, E2F1, and vimentin expression significantly reduced upon trabectedin therapy, administered as neo-adjuvant chemotherapy. Furthermore, trabectedin treatment inhibits in vitro NFkB pathway in mixoyd liposarcoma sensitive but not in resistant counterparts, and the inhibition of NFkB pathway re-sensitizes the resistant cells to trabectedin treatment. These data support the rational for combining NFkB inhibitors with AVN-944 ic50 trabectedin in liposarcoma patients, who have become resistant to the drug. Introduction Liposarcoma (LPS) is the most common amongst soft tissue sarcomas AVN-944 ic50 (STS), a complex and heterogeneous group of more than 50 neoplasms arising from mesenchymal cells. LPS accounts for 45% of retroperitoneal tumors and 24% of limbs tumors [1]. LPS themselves are heterogeneous adipocyte tumors and are morphologically classified into four subtypes: well differentiated AVN-944 ic50 LPS (WDLS), dedifferentiated LPS (DDLS), myxoid LPS (MLS), and pleomorphic LPS (PLS) [2]. Different genetic alterations characterize the different subtypes. Amplification of the chromosome segment 12q13C15, which carries the oncogenes and (or that characterize MLS, and modulates the production of cytokines and chemokines causing a profound alteration of tumor microenvironment [17, 18]. In addition, trabectedin impairs the function of the High Mobility Group A (HMGA) proteins reducing the binding to their responsive promoters. This mechanism is believed to be relevant for drug activity as in some cell lines it is influenced by expression of HMGA [19]. Previous studies identified HMGA1-oncogene as a key transcription factor enriched in human embryonic stem (ES) cells, and adult stem cells [20, 21]. The expression of HMGA1 was correlated with the tumor aggressiveness, low level of differentiation, resistance to therapies and poor prognosis in the majority of epithelial tumors [22]. The gene encodes the low molecular weight HMGA1a and HMGA1b chromatin remodeling proteins, which bind the minor groove of AT-rich DNA sequences [23]. HMGA proteins do not possess transcriptional activating domain name, but form multiple protein complexes that, altering chromatin structure and orchestrating the assembly of transcription factor complexes, regulate the transcription of several genes [24C26]. Rearrangements of the HMGA1 gene are present in benign adipocyte tumors characterized by 6p21 chromosome aberrations [27, 28], suggesting a role in fusion transcript-mediated LPS progression. Here, we evaluated whether HMGA1 plays a role in specific LPS subtypes and contributes to LPS response/resistance to trabectedin treatment. Results In vivo HMGA1 expression is usually higher in DDLS and MLS than in DLPS In order to evaluate the HMGA1 expression in LPS subtypes, we performed RT-PCR and IHC analyses of LPS specimens derived from a cohort of 68 patients surgically treated at the Regina Elena National Cancer Institute. The pathologist confirmed, by RT-PCR and Fish analyses, the amplification, the loss and the re-arrangement of genes that characterize the karyotype disorders of all LPS included in this study. As reported in Fig. ?Fig.1a,1a, we analyzed 15 WDLS, 15 DDLS, 26 MLS, and 12 PLS. We showed for the first time that 100% of MLSs were highly positive for HMGA1 expression (score 2+/3+), 60% of DDLS (score 1+/3+), 83% of pleomorphic (score 1+/3+), while only 40% of WDLS was positive for HMGA1 (score 1+/3+) (Fig. ?(Fig.1a).1a). RT-PCR analysis confirmed the IHC data of DDLS and MLS expressing significantly higher level AVN-944 ic50 of HMGA1 mRNA (Fig. ?(Fig.1b)1b) than WDLS (test was performed for the comparison of results from qRT-PCR and from all other different test (* em P /em ? ?0.05, ** em P /em ? ?0.001, *** em P /em ? ?0.0001). Electronic supplementary material Supplementary physique legends(126K, docx) Physique S1(2.6M, tif) Physique S2(2.6M, tif) Physique S3(2.6M, tif) Physique S4(2.6M, tif) Physique S5(2.6M, tif) Acknowledgements We thank PharmaMar for providing us trabectedin, Dr. Alessandra.