Essential gene screening identifies the bromodomain-containing protein BRPF1 as a new actionable target for endocrine therapy-resistant breast cancers.

Identifying master epigenetic factors controlling proliferation and survival of cancer cells allows to discover new molecular targets exploitable to overcome resistance to current pharmacological regimens. In breast cancer (BC), resistance to endocrine therapy (ET) arises from aberrant Estrogen Receptor alpha (ERα) signaling caused by genetic and epigenetic events still mainly unknown. Targeting key upstream components of the ERα pathway provides a way to interfere with estrogen signaling in cancer cells independently from any other downstream event. By combining computational analysis of genome-wide 'drop-out' screenings with siRNA-mediated gene knock-down (kd), we identified a set of essential genes in luminal-like, ERα + BC that includes BRPF1, encoding a bromodomain-containing protein belonging to a family of epigenetic readers that act as chromatin remodelers to control gene transcription. To gather mechanistic insights into the role of BRPF1 in BC and ERα signaling, we applied chromatin and transcriptome profiling, gene ablation and targeted pharmacological inhibition coupled to cellular and functional assays. Results indicate that BRPF1 associates with ERα onto BC cell chromatin and its blockade inhibits cell cycle progression, reduces cell proliferation and mediates transcriptome changes through the modulation of chromatin accessibility. This effect is elicited by a widespread inhibition of estrogen signaling, consequent to ERα gene silencing, in antiestrogen (AE) -sensitive and -resistant BC cells and pre-clinical patient-derived models (PDOs). Characterization of the functional interplay of BRPF1 with ERα reveals a new regulator of estrogen-responsive BC cell survival and suggests that this epigenetic factor is a potential new target for treatment of these tumors.

Ultrasmall Carbon Nanodots as Theranostic Nanoheaters for Precision Breast Cancer Phototherapy: Establishing the Translational Potential in Tumor-in-a-Dish Models.

This study investigates the remarkable attributes of sulfur-doped carbon nanodots (CDs) synthesized in high yield and a narrow size distribution (4.8 nm). These CDs exhibit notable features, including potential bioelimination through renal clearance and efficient photothermal conversion in the near-infrared region with multicolor photoluminescence across the visible spectrum. Our research demonstrates high biocompatibility and effective near-infrared (NIR)-triggered photothermal toxicity when targeting mammospheres and patient-derived tumor organoids. Moreover, the study delves into the intricate cellular responses induced by CD-mediated hyperthermia. This involves efficient tumor mass death, activation of the p38-mitogen-activated protein kinase (MAPK) pathway, and upregulation of genes associated with apoptosis, hypoxia, and autophagy. The interaction of CDs with mammospheres reveals their ability to penetrate the complex microenvironment, impeded at 4 °C, indicating an energy-dependent endocytosis mechanism. This observation underscores the CDs' potential for targeted drug delivery, particularly in anticancer therapeutics. This investigation contributes to understanding the multifunctional properties of sulfur-doped CDs and highlights their promising applications in cancer therapeutics. Utilizing 3-D tumor-in-a-dish patients' organoids enhances translational potential, providing a clinically relevant platform for assessing therapeutic efficacy in a context mirroring the physiological conditions of cancerous tissues.

Kidney Injury After Minimal Radiographic Contrast Administration in Patients With Acute Coronary Syndromes.

BACKGROUND: Acute kidney injury (AKI) is common in patients with acute coronary syndromes (ACS) treated by percutaneous coronary intervention. OBJECTIVES: Contrast media (CM) volume minimization has been advocated for prevention of AKI. The DyeVert CM diversion system (Osprey Medical, Inc) is designed to reduce CM volume during coronary procedures. METHODS: In this randomized, single-blind, investigator-driven clinical trial conducted in 4 Italian centers from February 4, 2020 to September 13, 2022, 550 participants with ACS were randomly assigned in a 1:1 ratio to the following: 1) the contrast volume reduction (CVR) group (n = 276), in which CM injection was handled by the CM diversion system; and 2) the control group (n = 274), in which a conventional manual or automatic injection syringe was used. The primary endpoint was the rate of AKI, defined as a serum creatinine (sCr) increase ≥0.3 mg/dL within 48 hours after CM exposure. RESULTS: There were 412 of 550 (74.5%) participants with ST-segment elevation myocardial infarction (211 of 276 [76.4%] in the CVR group and 201 of 274 [73.3%] in the control group). The CM volume was lower in the CVR group (95 ± 30 mL vs 160 ± 23 mL; P < 0.001). Seven participants (1 in the CVR group and 6 in the control group) did not have postprocedural sCr values. AKI occurred in 44 of 275 (16%) participants in the CVR group and in 65 of 268 (24.3%) participants in the control group (relative risk: 0.66; 95% CI: 0.47-0.93; P = 0.018). CONCLUSIONS: CM volume reduction obtained using the CM diversion system is effective for prevention of AKI in patients with ACS undergoing invasive procedures. (REnal Insufficiency Following Contrast MEDIA Administration TriaL IV [REMEDIALIV]: NCT04714736).

MCT4-driven CAF-mediated metabolic reprogramming in breast cancer microenvironment is a vulnerability targetable by miR-425-5p.

Multiple oncogenic alterations contribute to breast cancer development. Metabolic reprogramming, deeply contributing to tumor microenvironment (TME) education, is now widely recognized as a hallmark of cancer. The reverse Warburg effect induces cancer-associated fibroblasts (CAFs) to produce and secrete L-lactate, enhancing malignant characteristics such as neoangiogenesis, metastatic dissemination, and treatment resistance. Monocarboxylate transporter (MCT) 4 is involved in lactate efflux from CAFs into stromal and epithelial cells. Here, we first assess the expression of miR-425-5p and its target MCT4 in breast cancer CAFs and normal fibroblasts. We analyzed the metabolic changes induced by miR-425-5p in CAFs and its role in the education of breast cancer epithelial cells. We show that miR-425-5p-induced MCT4 knockdown decreased lactate extrusion from CAFs and its availability in the TME. miR-425-5p overexpression induced profound metabolic transformation in CAFs, ultimately influencing breast cancer metabolism. Furthermore, miR-425-5p impaired the capacity of CAFs to sustain vessel formation and breast cancer cell migration, viability, and proliferation. These findings emphasize the key role of miR-425-5p in breast cancer metabolism and aggressiveness, and its possible importance for breast cancer therapy and monitoring.