Background Cyclin-dependent kinase 12 (CDK12) regulates general gene transcription elongation and plays multiple roles in RNA splicing, DNA damage-response, cell cycle, and genomic stability. However, transcriptional partners that guide CDK12-specific gene programs have not been identified. Genomic alterations in CDK12 have been observed in multiple cancers, exhibiting both pro-tumorigenic and tumor-suppressive functions, suggesting a context-dependent mechanism of action.Methods CDK12 copy number alterations and gene expression levels were analyzed in matched primary and brain metastatic patient tumors. Clinical significance was assessed by immunohistochemistry in a large cohort of primary breast cancer patient tumors. RNA sequencing, ChIP sequencing, and molecular studies were conducted to explore CDK12's mechanism of action, and pharmacological studies were performed both in vitro and in vivo using models of advanced (endocrine-resistant and metastatic) estrogen receptor positive (ER+) disease.Results CDK12 amplifications and gene overexpression were observed in brain metastatic tumors. In ER+ primary patient tumors, high CDK12 protein expression was significantly associated with poor overall survival, particularly within the ER+/HER2-negative group. In ER+ endocrine resistant models, CDK12 regulated estrogen signaling pathways, with ER/MED1 identified as the master transcriptional complex directing CDK12-specific pro-tumorigenic gene programs. Pharmacological inhibition of CDK12 significantly reduced viability in endocrine resistant and metastatic cell and organoid models in vitro, and decreased metastatic spread in vivo.Conclusion This work describes a novel mechanism for CDK12, suggesting a potential vulnerability in ER+ breast cancer. These findings provide a basis for further investigation into the role of CDK12 inhibition as a therapeutic approach, particularly in advanced disease settings.
In this breastmilk pharmacokinetic study of women undergoing hepatitis C virus treatment with sofosbuvir/velpatasvir, sofosbuvir, GS-331007 (sofosbuvir metabolite), and velpatasvir concentrations in breast milk were 13%, 1.2%, and 41% of maternal plasma concentrations, respectively. The estimated infant daily dose from breastmilk was <1% of the weight-adjusted dose for children.
MK-2048 is a potent second-generation HIV integrase inhibitor that has demonstrated acceptable safety and pharmacokinetics (PKs) in clinical trials of vaginal formulations. The substrate-type interactions between MK-2048 and the transporters/metabolizing enzymes that are highly expressed in the human female reproductive tract (FRT) were evaluated. The interactions between MK-2048 and P-gp/BCRP were investigated using a cellular bidirectional permeability assay, while those between MK-2048 and MRP4 were assessed using a vesicular uptake assay. Reaction phenotyping was performed to characterize the interactions between MK-2048 and CYP1A1 and CYP1B1. Using human cervicovaginal fluids (CVFs), MK-2048’s solubility was determined using a thermodynamic solubility method and its protein binding was determined using a rapid equilibrium dialysis method. Our study shows an efflux of MK-2048 in P-gp/BCRP-overexpressing MDCKII cells, which was reduced by a P-gp/BCRP inhibitor. Uptake of MK-2048 in MRP4/control vesicles was found to be ATP-independent. MK-2048 was metabolized by the CYP1A1 enzyme but not by CYP1B1. These data confirm that MK-2048 is a substrate of P-gp, BCRP, and CYP1A1, but is not a substrate of MRP4 or CYP1B1. MK-2048 displays low solubility and high protein binding in human CVF. This data suggests that MK-2048 may potentially interact with drugs that modulate the activity of P-gp, BCRP, and CYP1A1.
Abstract Introduction Ovarian Cancer (OvCa) is an aggressive malignancy with poor survival outcomes, driven in part by an immunosuppressive tumor microenvironment (TME). Tumor-associated neutrophils (TANs) and macrophages (TAMs) promote immune tolerance and resistance to immunotherapy, limiting treatment efficacy. We recently identified tumor-secreted epidermal growth factor-like 6 (EGFL6) as a promoter of an immunosuppressive phenotype and inducer of spleen tyrosine kinase (SYK) signaling in infiltrating myeloid cells. In this study, we investigate the impact of SYK inhibitor R788 on OvCa tumor progression and whether SYK inhibition could reverse Egfl6-dependent immunosuppressive state in myeloid cells. Methods OvCa patient tumors were assessed to determine the correlation between EGFL6 and SYK expression in myeloid cells. A syngeneic mouse model of Egfl6 +/- OvCa cells was used to elucidate the effect of SYK inhibition on tumor progression and the immune TME. In addition, the effect of R788 on anti-tumor immunity alone or in combination with Paclitaxel was also determined. Results R788 (fostamatinib) reduced the proliferation of OvCa cells, as well as myeloid cells, in a dose-dependent manner. In vivo experiments showed that administration of R788 significantly improved the survival rate and reduced ascites volume in both control and Egfl6-overexpressing tumors, and combination of R788 along with Paclitaxel provided a synergistic effect in Egfl6+ tumors. We found that R788 decreased the number of TANs and reduced VEGF, M-CSF, and CXCL5 levels in ascites. Moreover, single-cell RNA-sequencing revealed that R788 drastically reprogrammed the immune TME, with SYK inhibition associated with a) depletion of specific CCL8+ TAMs and CXCL2+ TANs; and b) reduced number of exhausted TIGIT+CTL4+ CD8 T cells. Conclusion Our findings establish the role of an EGFL6-SYK regulatory axis in OvCa progression and identify SYK inhibitor R788 as a promising therapeutic agent to induce an anti-tumor immune response in OvCa patients. Funding Source NIH-National Cancer Institute Grant R01CA276279 (awarded to S.C.) Topic Categories Tumor Immunology: Cellular Responses and Tumor Microevironment (TIME)
BACKGROUND:More favorable maternal cardiovascular health (CVH) is linked to a lower risk of adverse pregnancy outcomes (APOs). OBJECTIVES:The aim of the study was to estimate the proportion of APOs that could be prevented if maternal CVH was improved. METHODS:Pregnant participants ≥18 years and without prepregnancy hypertension or gestational diabetes from the Nulliparous Pregnancy Outcomes Study were included. First trimester CVH was assessed by current physical activity, diet, sleep, nicotine use, body mass index, and blood pressure. CVH scores ranged from 0 to 100, with higher scores representing better CVH. APOs included new-onset hypertensive disorders of pregnancy, gestational diabetes, and preterm birth. Multivariable logistic regression models assessed the association of early pregnancy CVH and APOs, and impact fractions estimated the proportion of APOs that could be prevented if maternal CVH was improved. RESULTS:Participants (N = 8,927) were 27.2 years (SD: 5.4), and 25.3% experienced an APO. A lower CVH score was associated with a higher APO risk (adjusted OR: 1.46; 95% CI: 1.39-1.54). An estimated 12% of APOs would be prevented if a hypothetical intervention shifted all participants with a CVH score <50 to 50 points (5.8% of participants). Moreover, a dose-response relationship was observed with 15% and 40% of APOs estimated to be prevented if a hypothetical intervention shifted participants with a CVH score <80 to 80 points (51.4% of participants) or shifted everyone to 100 points (96.6% of participants), respectively. Similar findings were observed for each APO subtype. CONCLUSIONS:In this cohort of nulliparous pregnant individuals, potential benefits of improving maternal CVH to reduce APOs are considerable.
