Browsing by Author "Wendt, Michael K."

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    CDHu40: a novel marker gene set of neuroendocrine prostate cancer
    (Oxford University Press, 2024) Liu, Sheng; Nam, Hye Seung; Zeng, Ziyu; Deng, Xuehong; Pashaei, Elnaz; Zang, Yong; Yang, Lei; Li, Chenglong; Huang, Jiaoti; Wendt, Michael K.; Lu, Xin; Huang, Rong; Wan, Jun; Medical and Molecular Genetics, School of Medicine
    Prostate cancer (PCa) is the most prevalent cancer affecting American men. Castration-resistant prostate cancer (CRPC) can emerge during hormone therapy for PCa, manifesting with elevated serum prostate-specific antigen levels, continued disease progression, and/or metastasis to the new sites, resulting in a poor prognosis. A subset of CRPC patients shows a neuroendocrine (NE) phenotype, signifying reduced or no reliance on androgen receptor signaling and a particularly unfavorable prognosis. In this study, we incorporated computational approaches based on both gene expression profiles and protein-protein interaction networks. We identified 500 potential marker genes, which are significantly enriched in cell cycle and neuronal processes. The top 40 candidates, collectively named CDHu40, demonstrated superior performance in distinguishing NE PCa (NEPC) and non-NEPC samples based on gene expression profiles. CDHu40 outperformed most of the other published marker sets, excelling particularly at the prognostic level. Notably, some marker genes in CDHu40, absent in the other marker sets, have been reported to be associated with NEPC in the literature, such as DDC, FOLH1, BEX1, MAST1, and CACNA1A. Importantly, elevated CDHu40 scores derived from our predictive model showed a robust correlation with unfavorable survival outcomes in patients, indicating the potential of the CDHu40 score as a promising indicator for predicting the survival prognosis of those patients with the NE phenotype. Motif enrichment analysis on the top candidates suggests that REST and E2F6 may serve as key regulators in the NEPC progression.
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    Spleen tyrosine kinase-mediated autophagy is required for epithelial-mesenchymal plasticity and metastasis in breast cancer
    (American Association for Cancer Research, 2019-04-15) Shinde, Aparna; Hardy, Shana D.; Kim, Dongwook; Akhand, Saeed Salehin; Jolly, Mohit Kumar; Wang, Wen-Hung; Anderson, Joshua C.; Khodadadi, Ryan B.; Brown, Wells S.; George, Jason T.; Liu, Sheng; Wan, Jun; Levine, Herbert; Willey, Christopher D.; Krusemark, Casey J.; Geahlen, Robert L.; Wendt, Michael K.; Medical and Molecular Genetics, School of Medicine
    The ability of breast cancer cells to transiently transition between epithelial and mesenchymal states contributes to their metastatic potential. Therefore, driving tumor cells into a stable mesenchymal state, as opposed to complete tumor cell eradication, presents an opportunity to pharmacologically limit disease progression by promoting an asymptomatic state of dormancy. Here we compare a reversible model of epithelial-mesenchymal transition (EMT) induced by TGF-β to a stable mesenchymal phenotype induced by chronic exposure to the ErbB kinase inhibitor lapatinib. Only cells capable of returning to an epithelial phenotype resulted in skeletal metastasis. Gene expression analyses of the two mesenchymal states indicated similar transition expression profiles. A potently downregulated gene in both datasets was spleen tyrosine kinase (SYK). In contrast to this similar diminution in mRNA, kinome analyses using a peptide array and DNA-conjugated peptide substrates showed a robust increase in SYK activity upon TGF-β-induced EMT only. SYK was present in cytoplasmic RNA processing depots known as P-bodies formed during the onset of EMT, and SYK activity was required for autophagy-mediated clearance of P-bodies during mesenchymal-epithelial transition (MET). Genetic knockout of autophagy related 7 (ATG7) or pharmacological inhibition of SYK activity with fostamatib, a clinically approved inhibitor of SYK, prevented P-body clearance and MET, inhibiting metastatic tumor outgrowth. Overall, the current study suggests assessment of SYK activity as a biomarker for metastatic disease and the use of fostamatinib as a means to stabilize the latency of disseminated tumor cells.