Project description:Plasma small noncoding RNA levels were measured in breast cancer patients and healthy control women, to determine whether any of these were associated with either patient prognosis, or as diagnostic markers for breast cancer.
Project description:To screen candidate methylation markers for early detection of breast cancer, we performed methylated-CpG island recovery assay combined with CpG island array on 61982 CpG sites across 4162 genes in 10 breast tumor tissues and 10 non-tumor breast tissues. We detected 70 significantly hypermethylated genes in breast tumor tissues, including many novel hypermethylated genes such as ITGA4, NFIX, OTX2 and FGF12. Direct bisulfite sequencing showed widespread methylations occurred in intragenic regions of WT1, PAX6 and ITGA4 genes and promoter region of OTX2 in breast cancer tissue. COBRA assay in independent tumor and non-tumor samples confirmed that WT1, OTX2 and PAX6 genes were hypermethylated in breast cancer tissues. To explore the relationship between methylation and gene expression, gene expression profiling analysis was performed in 8 breast tumor tissues and 8 non-tumor breast tissues. We found that some hypermethylated genes in breast cancer were not expressed in breast tissues. RT-PCR assay showed that WT1 and PITX2 were only weakly expressed in the breast tumor tissues and weren’t expressed in most non-tumor breast tissues. OTX2 and PAX6 weren’t expressed in both breast tumor tissues and non-tumor tissues. Unpaired experiments, breast cancer tissue vs. normal cancer tissue. Biological replicates: 10 breast cancer tissue replicates, 10 normal breast tissue replicates.
Project description:To screen candidate methylation markers for early detection of breast cancer, we performed methylated-CpG island recovery assay combined with CpG island array on 61982 CpG sites across 4162 genes in 10 breast tumor tissues and 10 non-tumor breast tissues. We detected 70 significantly hypermethylated genes in breast tumor tissues, including many novel hypermethylated genes such as ITGA4, NFIX, OTX2 and FGF12. Direct bisulfite sequencing showed widespread methylations occurred in intragenic regions of WT1, PAX6 and ITGA4 genes and promoter region of OTX2 in breast cancer tissue. COBRA assay in independent tumor and non-tumor samples confirmed that WT1, OTX2 and PAX6 genes were hypermethylated in breast cancer tissues. To explore the relationship between methylation and gene expression, gene expression profiling analysis was performed in 8 breast tumor tissues and 8 non-tumor breast tissues. We found that some hypermethylated genes in breast cancer were not expressed in breast tissues. RT-PCR assay showed that WT1 and PITX2 were only weakly expressed in the breast tumor tissues and weren’t expressed in most non-tumor breast tissues. OTX2 and PAX6 weren’t expressed in both breast tumor tissues and non-tumor tissues. Unpaired experiments, breast tumor tissues vs. breast non-tumor tissues. Biological replicates: 8 breast cancer tissue replicates, 8 breast non-tumor tissue replicates.
Project description:We performed an unbiased cell viability-based pooled shRNA screen on 59 cell lines to identify novel epigenetic and transcriptional dependencies of multiple cancer types, including leukemia, neuroblastoma, breast, colorectal, prostate, and rhabdoid tumors. Here, we identified Tricho-Rhino-Phalangeal Syndrome Type I protein (TRPS1) as one of the most significant hits specific for breast cancer cell lines. Downregulation of TRPS1 resulted in cell cycle arrest and apoptosis increase in vitro and impaired tumorigenic capacity in vivo. We characterized TRPS1 genomic targets and protein interactome. We identified GATAD2B as an important partner of TRPS1, uncovering novel epigenetic network crucial for breast cancer cell survival.
Project description:We performed an unbiased cell viability-based pooled shRNA screen on 59 cell lines to identify novel epigenetic and transcriptional dependencies of multiple cancer types, including leukemia, neuroblastoma, breast, colorectal, prostate, and rhabdoid tumors. Here, we identified Tricho-Rhino-Phalangeal Syndrome Type I protein (TRPS1) as one of the most significant hits specific for breast cancer cell lines. Downregulation of TRPS1 resulted in cell cycle arrest and apoptosis increase in vitro and impaired tumorigenic capacity in vivo. We characterized TRPS1 genomic targets and protein interactome. We identified GATAD2B as an important partner of TRPS1, uncovering novel epigenetic network crucial for breast cancer cell survival.
Project description:Understanding the dynamics of endogenous protein-protein interactions in complex networks is pivotal in deciphering the mechanisms underlying diseases such as cancer. To enable the in-depth analysis of protein interactions in chromatin-associated protein complexes, we have previously developed a method termed RIME (Rapid Immunoprecipitation Mass spectrometry of Endogenous proteins). Here, we present a quantitative multiplexed method (qPLEX-RIME), which integrates RIME with isobaric labelling and tribrid mass spectrometry for the study of protein interactome dynamics in a quantitative fashion with increased sensitivity. Using the qPLEX-RIME method, we delineated the temporal changes of the Estrogen Receptor alpha (ERα) interactome in breast cancer cells treated with 4-hydrotamoxifen and we successfully identified endogenous ERα-associated proteins in human Patient Derived Xenograft (PDX) tumours and in primary human breast cancer clinical tissue. Our results demonstrate that the combination of RIME with isobaric labelling offers a powerful tool for the in-depth and quantitative characterization of protein interactome dynamics which is applicable to clinical samples.
Project description:Triple negative breast cancer (TNBC) is an aggressive subtype of breast cancer with limited therapeutic opportunities. Recently, splicing factors have gained attention as potential targets for cancer treatment. We performed an RNAi screen targeting 244 individual splicing factors to systematically evaluate their role in TNBC cell proliferation. We identified nine splicing factors, including SNRPD2, SNRPD3 and NHP2L1, of which depletion inhibited proliferation in two TNBC cell lines by deregulation of sister chromatid cohesion (SCC) via increased sororin intron 1 retention and down-regulation of SMC1, MAU2 and ESPL1. Protein-protein interaction analysis of SNRPD2, SNRPD3 and NHP2L1 identified that seven out of the nine identified splicing factors belong to the same spliceosome complex including novel componentSUN2 that was also critical for efficient sororin splicing. Finally, sororin transcript levels are highly correlated to various proliferation markers in BC patients, suggesting that deregulating sororin levels through targeting of the relevant splicing factors might be a potential strategy to treat TNBC
Project description:Plasticity delineates cancer subtypes with more or less favourable outcomes. In breast cancer, triple-negative is the subtype that lacks the expression of major differentiation markers (i.e. estrogen receptor [ER]), ant its high cellular plasticity results in higher aggressiveness and poor prognosis compared to other subtypes. Whether plasticity poses a vulnerability to cancer cells remains elusive. Here, we show that cancer cell plasticity can be exploited to differentiate triple-negative breast cancer. Using a high-throughput reporter drug screen with 9,501 compounds, we identify three polo-like kinase 1 (PLK1) inhibitors as major inducers of ER protein expression and downstream activity in triple-negative breast cancer cells via the transcription factor BATF. PLK1 inhibition upregulates a cell differentiation program characterized by increased DNA damage, mitotic arrest and ultimately cell death. Notably, cells surviving PLK1 inhibition have decreased tumorigenic potential, and targeting PLK1 in already established tumours reduces tumour growth both in cell line and patient-derived xenograft models. In addition, genes upregulated upon PLK1 inhibition are correlated with expression in normal breast tissue and confer better overall survival in breast cancer patients. Our results indicate that differentiation therapy based on PLK1 inhibition might be an alternative strategy to treat triple-negative breast cancer.