The HMGB1-2 Ovarian Cancer Interactome. The Role of HMGB Proteins and Their Interacting Partners MIEN1 and NOP53 in Ovary Cancer and Drug-Response

Abstract

High mobility group box B (HMGB) proteins are overexpressed in different types of cancers such as epithelial ovarian cancers (EOC). We have determined the first interactome of HMGB1 and HMGB2 in epithelial ovarian cancer (the EOC-HMGB interactome). Libraries from the SKOV-3 cell line and a primary transitional cell carcinoma (TCC) ovarian tumor were tested by the Yeast Two Hybrid (Y2H) approach. The interactome reveals proteins that are related to cancer hallmarks and their expression is altered in EOC. Moreover, some of these proteins have been associated to survival and prognosis of patients. The interaction of MIEN1 and NOP53 with HMGB2 has been validated by co-immunoprecipitation in SKOV-3 and PEO1 cell lines. SKOV-3 cells were treated with different anti-tumoral drugs to evaluate changes in HMGB1, HMGB2, MIEN1 and NOP53 gene expression. Results show that combined treatment of paclitaxel and carboplatin induces a stronger down-regulation of these genes in comparison to individual treatments. Individual treatment with paclitaxel or olaparib up-regulates NOP53, which is expressed at lower levels in EOC than in non-cancerous cells. On the other hand, bevacizumab diminishes the expression of HMGB2 and NOP53. This study also shows that silencing of these genes affects cell-viability after drug exposure. HMGB1 silencing causes loss of response to paclitaxel, whereas silencing of HMGB2 slightly increases sensitivity to olaparib. Silencing of either HMGB1 or HMGB2 increases sensitivity to carboplatin. Lastly, a moderate loss of response to bevacizumab is observed when NOP53 is silenced.

Pivotal role of High-Mobility Group Box 2 in ovarian folliculogenesis and fertility

“…Higher expression of HMGB2 is correlated with carcinogenesis, whereas it is decreased in senescent cells and adipose tissues [12][13][14][15][16][17]. HMGB2 is involved in multiple cellular events, such as gene transcription, recombination, replication, and repair processes [18].…”

Single cell-derived spheroids capture the self-renewing subpopulations of metastatic ovarian cancer

“…5e ) and uncovered in sMOCS the following two key insights: (i) a downregulation of processes related to cancer cell death mediated through the action of v-rel avian reticuloendotheliosis viral oncogene homolog A (RELA/P65), mitogen activated protein kinase 9 and 14 (MAPK9, MAPK14), protein kinase C delta type (PRKCD) and interleukin 1 beta (IL1B); (ii) an up-regulation of the functions related to the development of epithelial tissue and cell migration, mainly mediated by IL1B, C-X-C motif chemokine 8 and 12 (CXCL8, CXCL12) and tumor growth factor beta 1 (TGFB1). The same results have been confirmed from bulk RNAseq performed on 2D primary cells and sMOCS: DEGs between sMOCS and 2D cells principally relied on genes involved in cholesterol biosynthesis and pathways related to tumor progression (i.e., Hypoxia Inducible Factors (HIFs) signaling genes have been shown to stimulate Notch and Oct4 pathways which control stem cell self-renewal and multipotency [ 48 ]; high mobility group box-B protein (HMGB) that promotes tumor growth and metastasis in epithelial OC [ 49 ], IL-6/JAK/STAT3 pathway which is involved in proliferation, invasiveness and metastasis of tumour cells [ 50 ]) confirming the ability of sMOCS in enriching for CICs (Fig. 5f ).…”

HMGB1 Protein Interactions in Prostate and Ovary Cancer Models Reveal Links to RNA Processing and Ribosome Biogenesis through NuRD, THOC and Septin Complexes

“…siRNAs directed against HMGB1 (siRNA-HMGB1: s20254 Silencer Select) and unspecific control (siRNAControl2: 4390846) were purchased from Ambion Inc. (Thermo Fisher Scientific, Inc., Waltham, MA, USA). Transfection of cells and verification of mRNA and HMGB1 protein downregulation by qRT-PCR and Western blot were done as previously described [ 9 ].…”

“…RNA samples from PC-3 and DU-145 cell cultures were obtained using GeneJET RNA Purification Kit (Thermo Fisher Scientific, Inc., Waltham, MA, USA). Reaction conditions for thermal cycling and relative expression calculation were already described [ 9 ].…”

“…The role of interactomics in expanding the advancement of biomedical science in cancer research and therapy is well established [ 7 ]. We have previously reported interactome studies of HMGB1 and HMGB2 proteins in prostate [ 8 ] and ovary [ 9 ] cancer cells based on the yeast two-hybrid approach, but the number of proteins identified was low. To extend the in vivo discovery in cancer cells, we have undertaken a different HMGB1-interactome analysis approach based on immunoprecipitation (IP) and mass spectrometry (MS) in PC-3 and SKOV-3 cell lines that represent models for prostate and ovarian cancer, respectively.…”