Project description:Epithelial-mesenchymal transition (EMT) is a key cellular process involved in development and disease progression. Single-cell transcriptomes can reveal intermediate EMT states observed in tumors, but previous studies focused on time-dependent responses in epithelial cells after stimulation with EMT signals as an in vitro model for understanding EMT progression, so it was unclear how transcriptomes can change in response to different levels of EMT inducer. Here, we performed single-cell RNA-sequencing with human mammary epithelial cells treated with various concentrations of TGF-β. We found that the dose-dependent EMT harbors multiple intermediate states at the single-cell level after two weeks of treatment, suggesting a stable EMT continuum. After correcting batch effects from experiments, we performed comparative analyses of the dose- and time-dependent EMT. We found that the dose-dependent EMT shows a stronger anti-correlation between epithelial and mesenchymal transcriptional programs and a better resolution of stages of EMT compared to the time-dependent progress. These properties enable more power to detect genes whose expressions are associated with EMT. Nonetheless, our analyses showed cell clusters unique to the time-dependent EMT, which correspond to en route cell populations that do not appear at steady states. Furthermore, combining dose- and time-dependent cell clusters gave rise to more accurate prognosis for cancer patients compared to individual EMT spectrum.
Project description:Epithelial-mesenchymal transition (EMT) is a key cellular process involved in development and disease progression. Single-cell transcriptomes can reveal intermediate EMT states observed in tumors, but previous studies focused on time-dependent responses in epithelial cells after stimulation with EMT signals as an in vitro model for understanding EMT progression, so it was unclear how transcriptomes can change in response to different levels of EMT inducer. Here, we performed single-cell RNA-sequencing with human mammary epithelial cells treated with various concentrations of TGF-β. We found that the dose-dependent EMT harbors multiple intermediate states at the single-cell level after two weeks of treatment, suggesting a stable EMT continuum. After correcting batch effects from experiments, we performed comparative analyses of the dose- and time-dependent EMT. We found that the dose-dependent EMT shows a stronger anti-correlation between epithelial and mesenchymal transcriptional programs and a better resolution of stages of EMT compared to the time-dependent progress. These properties enable more power to detect genes whose expressions are associated with EMT. Nonetheless, our analyses showed cell clusters unique to the time-dependent EMT, which correspond to en route cell populations that do not appear at steady states. Furthermore, combining dose- and time-dependent cell clusters gave rise to more accurate prognosis for cancer patients compared to individual EMT spectrum.
Project description:PHF8 exerts distinct functions in different types of cancer. However, the mechanisms underlying its specific functions in each case remain obscure. To establish whether overexpression of PHF8 regulates the TGF-β induced the epithelial-mesenchymal transition (EMT), we treated MCF10A-Mock (control) and MCF10A-PHF8wt (overexpressing wild-type PHF8) cells with TGF-β1 for 0, 24, 48 and 72 hours and performed RNA-seq in biological duplicates. Our data indicated that EMT gene signatures were significantly enriched in MCF10A-PHF8 cells with TGF-β1 treatment at all time points, strongly indicating that PHF8 overexpression induces a sustained EMT signaling program. mRNA profiles of MCF10A-Mock (control) and MCF10A-PHF8 with TGF-β1 treatment for 0, 24, 48 and 72 hours were generated by RNA-seq, in duplicate, using HiSeq2500 instrument.
Project description:PHF8 exerts distinct functions in different types of cancer. However, the mechanisms underlying its specific functions in each case remain obscure. To establish whether overexpression of PHF8 regulates the TGF-β induced the epithelial-mesenchymal transition (EMT), we treated MCF10A-Mock (control) and MCF10A-PHF8wt (overexpressing wild-type PHF8) cells with TGF-β1 for 0, 24, 48 and 72 hours and performed RNA-seq in biological duplicates. Our data indicated that EMT gene signatures were significantly enriched in MCF10A-PHF8 cells with TGF-β1 treatment at all time points, strongly indicating that PHF8 overexpression induces a sustained EMT signaling program.
Project description:Transforming growth factor- (TGF-) signaling is a critical driver of epithelial–mesenchymal transition (EMT) and cancer progression. However, the regulatory roles of long non-coding RNAs (lncRNAs) in TGF--induced EMT and cancer progression are not well understood. Here, we identified an unannotated nuclear lncRNA LETS1 (LncRNA Enforcing TGF- Signaling 1) as a novel TGF-/SMAD target gene. Loss of LETS1 attenuates TGF--induced EMT, migration and extravasation in breast and lung cancer cells. LETS1 potentiates TGF-/SMAD signaling by stabilizing cell surface TGF- type I receptor (TRI) and thereby forms a positive feedback loop. Mechanistically, LETS1 inhibits TRI polyubiquitination by inducing the orphan nuclear receptor 4A1 (NR4A1) expression, a critical determinant of a destruction complex for inhibitory SMAD7. An unbiased interactome analysis identified the Nuclear Factor of Activated T Cells (NFAT5) as a protein partner of LETS1 to mediate activation of NR4A1 promoter. Overall, our findings characterize LETS1 as an EMT-promoting lncRNA and elucidate the mechanism by which nuclear LETS1 potentiates TGF- receptor signaling.
Project description:Our group is interested in epithelial-to-mesenchymal transition (EMT), in particular, TGF-beta induced EMT. TGF-beta signalling has been shown to be an important factor in the induction of EMT and it has been demonstrated that adding TGF-beta to epithelial cells in culture is a convenient way to study the process of EMT. In response to TGF-beta, Smad2 and 3 are activated, and form complexes with Smad4, which then regulate transcription of target genes through interactions with other DNA binding transcription factors. In the induction of EMT, the activated Smads mediate transcriptional regulation through three families of transcription factors, resulting in repression of epithelial marker gene expression and activation of mesenchymal gene expression (Xu J, et al. 2009) <br></br> Also investigated in this study is the role of H2A.Z in EMT. H2A.Z is an evolutionary conserved and a metazoan essential histone variant of the H2A class. Mice deficient in H2A.Z die during early development but the reason for this is unknown (Faast et al. 2001). Previously, our laboratory showed that the loss of H2A.Z in Xenpous laevis impaired cell movement required for the formation of the mesoderm and neural crest (Ridgway et al. 2004). Given that mesoderm formation is critically dependent upon EMT, we therefore wondered whether H2A.Z might be a chromatin regulator of EMT. We transfected MDCK cells with a lentiviral vector to express a construct encoding an shRNA targeting canine H2A.Z as we wanted to test the hypothesis that H2A.Z is involved in the maintenance of cellular identity and that its loss might trigger de-differentiation. <br></br> In order to investigate changes in histone variant H2A.Z occupancy associated with TGF-beta induced epithelial-to-mesenchymal transition (EMT) we performed H2A.Z ChIP-Seq in untreated and TGFb-treated MDCK cells. The MDCK cell line has been extensively used as a model system for EMT because they convert fully from the epithelial to the mesenchymal state in response to TGF-beta. <br></br>Please note that RNA-seq data generated in conjunction to this ChIP-seq data set were also deposited at ArrayExpress under accession number E-MTAB-5628 ( https://www.ebi.ac.uk/arrayexpress/experiments/E-MTAB-5628 ).
Project description:Recent studies demonstrate that Ca2+ signaling has an important role in EMT. Use of Ca2+ blockers such as 2APB can inhibit cell migration induced by TGF-β. Interestingly, we see an unexpected increase in Snail expression upon Ca2+ blocker treatment of both MCF10A and NMuMG cells; this increase is not observed with 2APB treatment alone. Therefore, we believe that 2APB plays a synergistic role with TGF-β in Snail induction. We propose to investigate the gene networks that change following 2APB +TGF-β treatment.
Project description:EMT is a developmental process, which can be reactivated in cancer cells. Cancer cells maintaining EMT in the circulation may have pro-metastatic properties. We used microarrays to profile EMT-related gene expression changes after 14 d of TGF-b1 treatment. EpRas cells were cultured in standard conditions either in the presence of absence of recombinant TGF-b1 (2 ng/ml) for 14 d. After this period, RNA was isolated from triplicate wells of treated and non-treated cells, and hybridized on Affymetrix microarrays.
Project description:EMT, Epithelial to mesenchymal transition is a developmental biology process associated with migration, known to be involved in cancer metastasis. To study this process, we used the breast epithelial cell line MCF10A that enter in EMT after treatment with the cytokine TGFB or by expression of EMT transcriptor factor SNAIL.