Biology subjects

Cress, A. E.

Publications and source records attributed to Cress, A. E..

4 recordsLinked to original sources

bioRxiv2025

Transient centrosome loss in cultured prostate epithelial cells induces chromosomal instability to produce an oncogenic genotype that correlates with poor clinical outcomes

Chromosomal instability (CIN) is a hallmark of prostate cancer that strongly correlates with metastatic burden and appears prominently in both primary cancer and metastatic disease. Low Gleason score primary prostate tumors display pervasive centrosome loss, a known mechanistic driver of CIN, that disrupts normal spindle assembly and increases mitotic errors. Previously, we found that transient depletion of centrosomes in immortalized, non-tumorigenic prostate epithelial cells (PrEC) induced a burst of CIN, generating cell lines capable of forming xenograft tumors. Here, we use a multi-omics approach to identify the oncogenic alterations caused by transient centrosome loss. By integrating genomic and transcriptomic data of the prostate lines, we identified a consensus set of focal copy-number variations (CNVs) induced by centrosome loss in cultured cells that are also detectable within a subset of samples from a prostate cancer patient cohort. Using this CNV signature, we were able to derive a unique transcriptomic signature from prostate cancer patient samples that showed strong predictive value for adverse clinical outcomes. In summary, our experimental system uses centrosome loss to promote a punctuated burst of genomic crisis that is characteristic of genome evolution during prostate cancer progression. Consequently, this prostate cancer model produced recurrent structural variations that are detectable in patient samples and associate with worse outcomes. Graphic Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/653266v1_ufig1.gif" ALT="Figure 1"> View larger version (55K): org.highwire.dtl.DTLVardef@ac4c9org.highwire.dtl.DTLVardef@fd9961org.highwire.dtl.DTLVardef@160e20corg.highwire.dtl.DTLVardef@198bf0e_HPS_FORMAT_FIGEXP M_FIG C_FIG

cancer biology↗

bioRxiv2024

Inhibition of PIM kinase in tumor associated macrophages suppresses inflammasome 1 activation and sensitizes prostate cancer to immunotherapy

Immunotherapy has changed the treatment paradigm for many types of cancer, but immune checkpoint inhibitors (ICIs) have not shown benefit in prostate cancer (PCa). Chronic inflammation contributes to the immunosuppressive prostate tumor microenvironment (TME) and is associated with poor response to ICIs. The primary source of inflammatory cytokine production is the inflammasome. Here, we identify PIM kinases as important regulators of inflammasome activation in tumor associated macrophages (TAMs). Analysis of clinical data from a cohort of treatment naive, hormone responsive PCa patients revealed that tumors from patients with high PIM1/2/3 display an immunosuppressive TME characterized by high inflammation (IL-1{beta} and TNF) and a high density of repressive immune cells, most notably TAMs. Strikingly, macrophage-specific knockout of PIM reduced tumor growth in syngeneic models of prostate cancer. Transcriptional analyses indicate that eliminating PIM from macrophages enhanced the adaptive immune response and increased cytotoxic immune cells. Combined treatment with PIM inhibitors and ICIs synergistically reduced tumor growth. Immune profiling revealed that PIM inhibitors sensitized PCa tumors to ICIs by increasing tumor suppressive TAMs and increasing the activation of cytotoxic T cells. Collectively, our data implicate macrophage PIM as a driver of inflammation that limits the potency of ICIs and provides preclinical evidence that PIM inhibitors are an effective strategy to improve the efficacy of immunotherapy in prostate cancer.

cancer biology↗

bioRxiv2021

Direct phosphorylation and stabilization of HIF-1α by PIM1 kinase drives angiogenesis in solid tumors

Angiogenesis is essential for sustained growth of solid tumors. Hypoxia-inducible factor 1 (HIF-1) is a master regulator of angiogenesis and constitutive activation of HIF-1 is frequently observed in human cancers. Thus, understanding mechanisms governing the activation of HIF-1 is critical for successful therapeutic targeting of tumor angiogenesis. Herein, we establish a new regulatory mechanism responsible for the constitutive activation of HIF-1 in cancer, irrespective of oxygen tension. PIM1 kinase directly phosphorylates HIF-1 at threonine 455, a previously uncharacterized site within its oxygen-dependent degradation domain. This phosphorylation event disrupts the ability of prolyl hydroxylases (PHDs) to bind and hydroxylate HIF-1, interrupting its canonical degradation pathway and promoting constitutive transcription of HIF-1 target genes. Overexpression of PIM1 is sufficient to stabilize HIF-1 in normoxia and stimulate angiogenesis in a HIF-1-dependent manner in vivo. CRISPR mutants of HIF-1 (Thr455D) showed increased tumor growth, proliferation and angiogenesis. Moreover, T455D xenograft tumors were refractory to the anti-angiogenic and cytotoxic effects of PIM inhibitors. These data identify a new signaling axis responsible for hypoxia-independent activation of HIF-1 and expand our understanding of the tumorigenic role of PIM1 in solid tumors.

cancer biology↗

bioRxiv2018

Androgen Receptor-Induced Integrin α6β1 and Adhesion to Laminin Promotes Survival andDrug Resistance in Castration-Resistant Prostate Cancer through BNIP3

Although castration-resistant prostate cancers no longer respond to anti-androgen therapies, the androgen receptor (AR) is still required to promote tumor survival. However, the signaling pathways downstream of AR that promote this survival are not well known. We recently identified an AR-dependent survival pathway whereby AR induction of integrin 6{beta}1 and adhesion to laminin activates NF-kB/RelA signaling and Bcl-xL. This pathway acts in parallel with the PI3K/Akt pathway in Pten-null tumor cells such that combined inhibition of both PI3K and integrin 6{beta}1 is required to kill tumor cells adherent to laminin. However, PTEN-null castration-resistant tumors were not effectively inhibited by this combination. We discovered that BNIP3, a hypoxia-induced BH3-only, pro-mitophagic Bcl2 family member, is induced by androgen in castration-resistant cells through integrin 6{beta}1 signaling to HIF1. Furthermore, castration-resistant cells adherent to laminin were much more efficient at inducing autophagy in response to androgen. Androgen blocked the ability of the PI3K inhibitor PX-866 to kill castration-resistant tumors, but this was reversed by loss of BNIP3. Although BNIP3 was dispensable for androgen-induced autophagy, its mitophagy function was required for BNIP3 to promote resistance to PI3K inhibition. Thus, adhesion to laminin triggers signaling through AR/6{beta}1/HIF1 in castration-resistant cells to drive the expression of BNIP3 and cooperates with AR/6{beta}1-mediated autophagy, both of which contribute to PI3K resistance through induction of mitophagy.

cancer biology↗