EDC3 phosphorylation regulates growth and invasion through controlling P-body formation and dynamics.

Regulation of mRNA stability and translation plays a critical role in determining protein abundance within cells. Processing bodies (P-bodies) are critical regulators of these processes. Here, we report that the Pim1 and 3 protein kinases bind to the P-body protein enhancer of mRNA decapping 3 (EDC3) and phosphorylate EDC3 on serine (S)161, thereby modifying P-body assembly. EDC3 phosphorylation is highly elevated in many tumor types, is reduced upon treatment of cells with kinase inhibitors, and blocks the localization of EDC3 to P-bodies. Prostate cancer cells harboring an EDC3 S161A mutation show markedly decreased growth, migration, and invasion in tissue culture and in xenograft models. Consistent with these phenotypic changes, the expression of integrin ß1 and α6 mRNA and protein is reduced in these mutated cells. These results demonstrate that EDC3 phosphorylation regulates multiple cancer-relevant functions and suggest that modulation of P-body activity may represent a new paradigm for cancer treatment.

Phosphorylation of DEPDC5, a component of the GATOR1 complex, releases inhibition of mTORC1 and promotes tumor growth.

The Pim and AKT serine/threonine protein kinases are implicated as drivers of cancer. Their regulation of tumor growth is closely tied to the ability of these enzymes to mainly stimulate protein synthesis by activating mTORC1 (mammalian target of rapamycin complex 1) signaling, although the exact mechanism is not completely understood. mTORC1 activity is normally suppressed by amino acid starvation through a cascade of multiple regulatory protein complexes, e.g., GATOR1, GATOR2, and KICSTOR, that reduce the activity of Rag GTPases. Bioinformatic analysis revealed that DEPDC5 (DEP domain containing protein 5), a component of GATOR1 complex, contains Pim and AKT protein kinase phosphorylation consensus sequences. DEPDC5 phosphorylation by Pim and AKT kinases was confirmed in cancer cells through the use of phospho-specific antibodies and transfection of phospho-inactive DEPDC5 mutants. Consistent with these findings, during amino acid starvation the elevated expression of Pim1 overcame the amino acid inhibitory protein cascade and activated mTORC1. In contrast, the knockout of DEPDC5 partially blocked the ability of small molecule inhibitors against Pim and AKT kinases both singly and in combination to suppress tumor growth and mTORC1 activity in vitro and in vivo. In animal experiments knocking in a glutamic acid (S1530E) in DEPDC5, a phospho mimic, in tumor cells induced a significant level of resistance to Pim and the combination of Pim and AKT inhibitors. Our results indicate a phosphorylation-dependent regulatory mechanism targeting DEPDC5 through which Pim1 and AKT act as upstream effectors of mTORC1 to facilitate proliferation and survival of cancer cells.

Synthesis of 2-Oxoquinoline Derivatives as Dual Pim and mTORC Protein Kinase Inhibitors.

Compound VBT-5445 was identified as an inhibitor to block the association of Pim and the protein Enhancer of Decapping 3 (EDC3), a Pim substrate, which normally functions to enhance the decapping of messenger RNA (mRNA). It was also shown to inhibit both the Pim and mTORC protein kinases. The activity of this compound class can be fine-tuned by structural modification. A series of VBT analogs were designed, synthesized, and evaluated. These compounds decrease the growth of multiple cancer types, including pancreas, prostate, breast, lung, and leukemia. Notably, 6-methyl (GRG-1-31, 6d), 4-Bromo (GRG-1-34, 6e), 4-Chloro (GRG-1-35, 6f), and phenylthio substituted (GRG-1-104, 6n) derivatives are highly potent at inhibiting tumor growth. The ability of these compounds to block cancer growth in vitro is highly correlated with their activity as mTORC inhibitors. The toxicity of GRG 1-34 is low in mice treated with twice-daily gavage for 30 days and did not induce weight loss. Pharmacokinetics of a single oral dose demonstrated a peak concentration at 0.5 hours after gavage. In summary, further development of this compound class has the potential to inhibit important signaling pathways and impact cancer treatment.

Structure-activity relationships for antibacterial to antifungal conversion of kanamycin to amphiphilic analogues.

Novel fungicides are urgently needed. It was recently reported that the attachment of an octyl group at the O-4″ position of kanamycin B converts this antibacterial aminoglycoside into a novel antifungal agent. To elucidate the structure-activity relationship (SAR) for this phenomenon, a lead compound FG03 with a hydroxyl group replacing the 3″-NH2 group of kanamycin B was synthesized. FG03's antifungal activity and synthetic scheme inspired the synthesis of a library of kanamycin B analogues alkylated at various hydroxyl groups. SAR studies of the library revealed that for antifungal activity the O-4″ position is the optimal site for attaching a linear alkyl chain and that the 3″-NH2 and 6″-OH groups of the kanamycin B parent molecule are not essential for antifungal activity. The discovery of lead compound, FG03, is an example of reviving clinically obsolete drugs like kanamycin by simple chemical modification and an alternative strategy for discovering novel antimicrobials.

Improving Coccidioidomycosis Testing for Emergency Department Patients With Suspect Community-Acquired Pneumonia: Analysis of Provider Attitudes and the Effect of a Targeted Intervention.

Coccidioidomycosis is a common cause of community-acquired pneumonia in endemic regions. Approximately 20 000 cases of coccidioidomycosis occur annually; however, this statistic is limited by a widespread lack of testing. Here, we analyze emergency medicine provider attitudes toward coccidioidal testing and assess the effect of an intervention to improve testing rates.

A drug safety evaluation of pemigatinib for advanced cholangiocarcinoma.

INTRODUCTION: Pemigatinib is a selective small-molecule inhibitor of the fibroblast growth factor receptor (FGFR) 1-3. FGFR is associated with increased cell division, proliferation, and survival. Inhibition of this receptor is an effective treatment against tumors driven by activated fusions in FGFR2. AREAS COVERED: The drug was first evaluated in patients with advanced solid tumors and demonstrated a manageable safety profile, with the most common adverse events being oscillations in blood phosphate levels, fatigue, gastrointestinal symptoms, and skin and ocular toxicities. Pemigatinib was further evaluated in a phase II cohort study of patients with previously treated locally advanced or metastatic cholangiocarcinoma harboring FGFR2 genomic alterations. After a median follow-up of 17.8 months, the objective response rate in patients with tumors harboring FGFR2 fusions or rearrangements was 35.5% (95% CI, 26.5-45.4). Based on these results, the FDA granted accelerated approval on 17 April 2020, to pemigatinib, for the treatment of adults with previously treated, unresectable locally advanced or metastatic cholangiocarcinoma with an FGFR2 fusion or another rearrangement. Articles selected for this review were based on reported studies indexed in PubMed (2010-2023). EXPERT OPINION: Future perspectives in the treatment of FGFR2 fused cholangiocarcinoma include the evaluation of pemigatinib in previously untreated patients and possible active combinations or sequencing strategies with other drugs.

Novel precision therapies for cholangiocarcinoma: an overview of clinical trials.

INTRODUCTION: The treatment landscape of biliary cancers is rapidly changing. Inhibitors against the actionable targets FGFR and IDH1 are now being included in the treatment guidelines of multiple countries for patients with advanced cholangiocarcinoma. However, there remains an unmet need in identifying the mechanisms of resistance and treatment strategies involving possible tumor sequencing. AREAS COVERED: In this review article, we address clinical trials evaluating FGFR, IDH, BRAF and HER2 inhibitors in advanced cholangiocarcinoma. We also review the mechanisms of resistance described thus far and approaches to overcome them. Articles selected for this review were based on reported studies indexed in PubMed (2010-2022). EXPERT OPINION: Precision medicine in biliary cancers has already been incorporated into the treatment landscape of the disease in many countries. Fusions of FGFR2 and mutations in IDH1 are the first drivers with targetable treatments approved in these cancers. HER2 and BRAF would be the next drivers with possible tumor-agnostic or cholangiocarcinoma-specific approvals. The advent of ctDNA could improve the accessibility of sequencing and recruitment in these clinical trials. However, limitations of detecting fusions should be considered and addressed in these platforms.

The long noncoding RNA H19 regulates tumor plasticity in neuroendocrine prostate cancer.

Neuroendocrine (NE) prostate cancer (NEPC) is a lethal subtype of castration-resistant prostate cancer (PCa) arising either de novo or from transdifferentiated prostate adenocarcinoma following androgen deprivation therapy (ADT). Extensive computational analysis has identified a high degree of association between the long noncoding RNA (lncRNA) H19 and NEPC, with the longest isoform highly expressed in NEPC. H19 regulates PCa lineage plasticity by driving a bidirectional cell identity of NE phenotype (H19 overexpression) or luminal phenotype (H19 knockdown). It contributes to treatment resistance, with the knockdown of H19 re-sensitizing PCa to ADT. It is also essential for the proliferation and invasion of NEPC. H19 levels are negatively regulated by androgen signaling via androgen receptor (AR). When androgen is absent SOX2 levels increase, driving H19 transcription and facilitating transdifferentiation. H19 facilitates the PRC2 complex in regulating methylation changes at H3K27me3/H3K4me3 histone sites of AR-driven and NEPC-related genes. Additionally, this lncRNA induces alterations in genome-wide DNA methylation on CpG sites, further regulating genes associated with the NEPC phenotype. Our clinical data identify H19 as a candidate diagnostic marker and predictive marker of NEPC with elevated H19 levels associated with an increased probability of biochemical recurrence and metastatic disease in patients receiving ADT. Here we report H19 as an early upstream regulator of cell fate, plasticity, and treatment resistance in NEPC that can reverse/transform cells to a treatable form of PCa once therapeutically deactivated.

PIM protein kinases regulate the level of the long noncoding RNA H19 to control stem cell gene transcription and modulate tumor growth.

The proviral integration site for Moloney murine leukemia virus (PIM) serine/threonine kinases have an oncogenic and prosurvival role in hematological and solid cancers. However, the mechanism by which these kinases drive tumor growth has not been completely elucidated. To determine the genes controlled by these protein kinases, we carried out a microarray analysis in T-cell acute lymphoblastic leukemia (T-ALL) comparing early progenitor (ETP-ALL) cell lines whose growth is driven by PIM kinases to more mature T-ALL cells that have low PIM levels. This analysis demonstrated that the long noncoding RNA (lncRNA) H19 was associated with increased PIM levels in ETP-ALL. Overexpression or knockdown of PIM in these T-ALL cell lines controlled the level of H19 and regulated the methylation of the H19 promoter, suggesting a mechanism by which PIM controls H19 transcription. In these T-ALL cells, the expression of PIM1 induced stem cell gene expression (SOX2, OCT-4, and NANOG) through H19. Identical results were found in prostate cancer (PCa) cell lines where PIM kinases drive cancer growth, and both H19 and stem cell gene levels. Small molecule pan-PIM inhibitors (PIM-i) currently in clinical trials reduced H19 expression in both of these tumor types. Importantly, the knockdown of H19 blocked the ability of PIM to induce stem cell genes in T-ALL cells, suggesting a novel signal transduction cascade. In PCa, increases in SOX2 levels have been shown to cause both resistance to the androgen deprivation therapy (ADT) and the induction of neuroendocrine PCa, a highly metastatic form of this disease. Treatment of PCa cells with a small molecule pan-PIM-i reduced stem cell gene transcription and enhanced ADT, while overexpression of H19 suppressed the ability of pan-PIM-i to regulate hormone blockade. Together, these results demonstrate that the PIM kinases control the level of lncRNA H19, which in turn modifies stem cell gene transcription regulating tumor growth.

Synthesis and anticancer structure activity relationship investigation of cationic anthraquinone analogs.

We have synthesized a series of novel 4,9-dioxo-4,9-dihydro-1H-naphtho[2,3-d][1,2,3]triazol-3-ium salts, which can be viewed as analogs of cationic anthraquinones. Unlike the similar analogs that we have reported previously, these compounds show relatively weak antibacterial activities but exert strong anticancer activities (low µM to nM GI50), in particular, against melanoma, colon cancer, non-small cell lung cancer and central nervous system (CNS) cancer. These compounds are structurally different from their predecessors by having the aromatic group, instead of alkyl chains, directly attached to the cationic anthraquinone scaffold. Further investigation in the structure-activity relationship (SAR) reveals the significant role of electron donating substituents on the aromatic ring in enhancing the anticancer activities via resonance effect. Steric hindrance of these groups is disadvantageous but is less influential than the resonance effect. The difference in the attached groups at N-1 position of the cationic anthraquinone analog is the main structural factor for the switching of biological activity from antibacterial to anticancer. The discovery of these compounds may lead to the development of novel cancer chemotherapeutics.