Teri Klein, Postdoctoral Faculty Sponsor
Cytochrome P450 2D6 (CYP2D6) is a highly polymorphic gene whose protein product metabolizes more than 20% of clinically used drugs. Genetic variations in CYP2D6 are responsible for interindividual heterogeneity in drug response that can lead to drug toxicity and ineffective treatment, making CYP2D6 one of the most important pharmacogenes. Prediction of CYP2D6 phenotype relies on curation of literature-derived functional studies to assign a functional status to CYP2D6 haplotypes. As the number of large-scale sequencing efforts grows, new haplotypes continue to be discovered, and assignment of function is challenging to maintain. To address this challenge, we have trained a convolutional neural network to predict functional status of CYP2D6 haplotypes, called Hubble.2D6. Hubble.2D6 predicts haplotype function from sequence data and was trained using two pre-training steps with a combination of real and simulated data. We find that Hubble.2D6 predicts CYP2D6 haplotype functional status with 88% accuracy in a held-out test set and explains 47.5% of the variance in in vitro functional data among star alleles with unknown function. Hubble.2D6 may be a useful tool for assigning function to haplotypes with uncurated function, and used for screening individuals who are at risk of being poor metabolizers.
View details for DOI 10.1371/journal.pcbi.1008399
View details for PubMedID 33137098
Purpose: Effective targeting of cancer stem cells is necessary and important for eradicating cancer and reducing metastasis-related mortality. Understanding of cancer stemness-related signaling pathways at the molecular level will help control cancer and stop metastasis in the clinic.Experimental Design: By analyzing miRNA profiles and functions in cancer development, we aimed to identify regulators of breast tumor stemness and metastasis in human xenograft models in vivo and examined their effects on self-renewal and invasion of breast cancer cells in vitro To discover the direct targets and essential signaling pathways responsible for miRNA functions in breast cancer progression, we performed microarray analysis and target gene prediction in combination with functional studies on candidate genes (overexpression rescues and pheno-copying knockdowns).Results: In this study, we report that hsa-miR-206 suppresses breast tumor stemness and metastasis by inhibiting both self-renewal and invasion. We identified that among the candidate targets, twinfilin (TWF1) rescues the miR-206 phenotype in invasion by enhancing the actin cytoskeleton dynamics and the activity of the mesenchymal lineage transcription factors, megakaryoblastic leukemia (translocation) 1 (MKL1), and serum response factor (SRF). MKL1 and SRF were further demonstrated to promote the expression of IL11, which is essential for miR-206's function in inhibiting both invasion and stemness of breast cancer.Conclusions: The identification of the miR-206/TWF1/MKL1-SRF/IL11 signaling pathway sheds lights on the understanding of breast cancer initiation and progression, unveils new therapeutic targets, and facilitates innovative drug development to control cancer and block metastasis. Clin Cancer Res; 23(4); 1091-103. ©2016 AACR.
View details for DOI 10.1158/1078-0432.CCR-16-0943
View details for Web of Science ID 000393885700023
View details for PubMedID 27435395
View details for PubMedCentralID PMC5247402
Chemotherapy resistance frequently drives tumour progression. However, the underlying molecular mechanisms are poorly characterized. Epithelial-to-mesenchymal transition has been shown to correlate with therapy resistance, but the functional link and signalling pathways remain to be elucidated. Here we report that microRNA-30c, a human breast tumour prognostic marker, has a pivotal role in chemoresistance by a direct targeting of the actin-binding protein twinfilin 1, which promotes epithelial-to-mesenchymal transition. An interleukin-6 family member, interleukin-11 is identified as a secondary target of twinfilin 1 in the microRNA-30c signalling pathway. Expression of microRNA-30c inversely correlates with interleukin-11 expression in primary breast tumours and low interleukin-11 correlates with relapse-free survival in breast cancer patients. Our study demonstrates that microRNA-30c is transcriptionally regulated by GATA3 in breast tumours. Identification of a novel microRNA-mediated pathway that regulates chemoresistance in breast cancer will facilitate the development of novel therapeutic strategies.
View details for DOI 10.1038/ncomms2393
View details for Web of Science ID 000316614600063
View details for PubMedID 23340433
Metastasis remains a significant challenge in treating cancer. A better understanding of the molecular mechanisms underlying metastasis is needed to develop more effective treatments. Here, we show that human breast tumor biomarker miR-30c regulates invasion by targeting the cytoskeleton network genes encoding twinfilin 1 (TWF1) and vimentin (VIM). Both VIM and TWF1 have been shown to regulate epithelial-to-mesenchymal transition. Similar to TWF1, VIM also regulates F-actin formation, a key component of cellular transition to a more invasive mesenchymal phenotype. To further characterize the role of the TWF1 pathway in breast cancer, we found that IL-11 is an important target of TWF1 that regulates breast cancer cell invasion and STAT3 phosphorylation. The miR-30c-VIM/TWF1 signaling cascade is also associated with clinical outcome in breast cancer patients.
View details for DOI 10.1007/s10549-012-2346-4
View details for Web of Science ID 000313201100005
View details for PubMedID 23224145
View details for PubMedCentralID PMC3583223
Lactate dehydrogenase-elevating virus (LDV) can infect transplantable mouse tumors or xenograft tumors in mice through LDV-contaminated mouse biological materials, such as Matrigel, or through mice infected with LDV. LDV infects specifically mouse macrophages and alters immune system and tumor phenotype. The traditional approaches to remove LDV from tumor cells, by transplanting tumors into rats or culturing tumor cells in vitro, are inefficient, labor-intensive and time-consuming. Furthermore, these approaches are not feasible for primary tumor cells that cannot survive tissue culture conditions or that may change phenotype in rats. This study reports that fluorescence-activated cell sorting (FACS) is a simple and efficient approach for purifying living primary human breast tumor cells from LDV(+) mouse stromal cells, which can be completed in a few hours. When purified from Matrigel contaminated LDV(+) tumors, sorted human breast tumor cells, as well as tumors grown from sorted cells, were shown to be LDV-free, as tested by PCR. The results demonstrate that cell sorting is effective, much faster and less likely to alter tumor cell phenotype than traditional methods for removing LDV from xenograft models. This approach may also be used to remove other rodent-specific viruses from models derived from distinct tissues or species with sortable markers, where virus does not replicate in the cells to be purified.
View details for DOI 10.1016/j.jviromet.2011.02.015
View details for Web of Science ID 000290836400014
View details for PubMedID 21354210
View details for PubMedCentralID PMC3086718