Exosome transfer from stromal to breast cancer cells regulates therapy resistance pathways.

Stromal communication with cancer cells can influence treatment response. We show that stromal and breast cancer (BrCa) cells utilize paracrine and juxtacrine signaling to drive chemotherapy and radiation resistance. Upon heterotypic interaction, exosomes are transferred from stromal to BrCa cells. RNA within exosomes, which are largely noncoding transcripts and transposable elements, stimulates the pattern recognition receptor RIG-I to activate STAT1-dependent antiviral signaling. In parallel, stromal cells also activate NOTCH3 on BrCa cells. The paracrine antiviral and juxtacrine NOTCH3 pathways converge as STAT1 facilitates transcriptional responses to NOTCH3 and expands therapy-resistant tumor-initiating cells. Primary human and/or mouse BrCa analysis support the role of antiviral/NOTCH3 pathways in NOTCH signaling and stroma-mediated resistance, which is abrogated by combination therapy with gamma secretase inhibitors. Thus, stromal cells orchestrate an intricate crosstalk with BrCa cells by utilizing exosomes to instigate antiviral signaling. This expands BrCa subpopulations adept at resisting therapy and reinitiating tumor growth.

Distinct, sex-dependent miRNA signatures in piglet hippocampus induced by a clinically relevant isoflurane exposure: a pilot study.

PURPOSE: To evaluate the effects of sex on miRNA expression in the hippocampus after isoflurane anesthesia in a neonatal piglet model. METHODS: Six male and 6 female piglets, aged 3-5 days, were anesthetized with 2% isoflurane in room air for 3 h. Full physiologic monitoring was observed. Untreated animals (6 male, 6 female) served as controls. Expression of miRNAs in hippocampus was assessed. RESULTS: In controls, miRNA expression in the hippocampus was highly conserved between males and females. However, 17/326 displayed sex-dependent differences: 10 miRNAs were more highly expressed in males; 7 showed lower expression in males than females. Isoflurane was associated with changes in the expression of distinct subsets of miRNAs in both males and females. In females, 14/326 miRNAs were significantly changed (3 downregulated; 11 upregulated); in males, 17/326 miRNAs were changed (7 downregulated; 10 upregulated). There was no overlap in significantly changed miRNAs between isoflurane-exposed males and females. CONCLUSIONS: In the neonatal piglet hippocampus, miRNA expression was highly conserved. There was no overlap in miRNA expression between isoflurane-exposed males and females, suggesting sex differences in isoflurane-induced miRNA expression. These results support the hypothesis that a clinically relevant exposure to isoflurane induces distinct miRNA signatures in the hippocampus of neonatal male and female piglets. Their functional relevance in anesthesia-induced neurotoxicity remains unknown, although changes in specific miRNAs may either contribute to or protect against anesthesia-induced neurotoxicity.

Selective induction of IL-1ß after a brief isoflurane anesthetic in children undergoing MRI examination.

PURPOSE: To determine if isoflurane anesthesia without surgery causes systemic inflammation in children. Inflammation is targeted as responsible for the development of many neurologic pathologies. The effect will be evaluated by measuring serum cytokine levels before and after isoflurane anesthesia. The possible neurotoxic effect of anesthetic agents is a concern in pediatric anesthesia. Questions remain as to the true effects of anesthesia alone on systemic inflammation. The current study assesses systemic inflammatory response to general anesthesia in children not exposed to surgical stress. METHODS: Twenty-five patients, aged 6 months to 11 years undergoing MRI scanning were recruited. Patients with ASA Physical Status Classification >II, known neurologic disease, prematurity, recent infection, or current treatment with anti-inflammatory medications were excluded. Each patient received a sevoflurane induction, peripheral intravenous catheterization, and laryngeal mask airway placement. Isoflurane was titrated to ensure adequate depth of anesthesia. Two peripheral blood samples were obtained: one immediately after placement of the PIV and one upon arrival to the post-anesthesia care unit. Serum cytokine levels were compared between pre- and post-isoflurane time points using paired t tests. RESULTS: For all patients, interleukin-1ß increased after isoflurane when compared to pre-isoflurane samples (pre = 25.97 ± 9.01, post = 38.53 ± 16.56, p = 0.0002). Serum levels of IL-6 (pre = 2.28 ± 2.27, post = 2.04 ± 2.15, p = 0.146) and tumor necrosis factor-α (pre = 94.26 ± 18.07, post = 85.84 ± 12.12, p = 0.057) were not significantly changed. Interleukin-10 and vascular endothelial growth factor were undetectable in pre- and post-isoflurane samples at a minimum detection threshold of 6.6 and 10 pg/ml, respectively. CONCLUSIONS: A brief (approximately 60 min) exposure to isoflurane general anesthesia, without induced surgical stress, significantly increased serum IL-1ß, a selective activation marker of systemic inflammation (IL-1ß pathway).

Thyroid Cancer Incidence and Tumor Size in New Mexico American Indians, Hispanics, and Non-Hispanic Whites, 1992 to 2019.

BACKGROUND: The incidence of thyroid cancer in the United States has risen dramatically since the 1970s, driven by an increase in the diagnosis of small tumors. There is a paucity of published New Mexico (NM) specific data regarding thyroid cancer. We hypothesized that due to New Mexico's unique geographic and cultural makeup, the incidence of thyroid cancer and tumor size at diagnosis in this state would differ from that demonstrated on a national level. METHODS: The New Mexico Tumor Registry (NMTR) was queried to include all NM residents diagnosed with thyroid cancer between 1992 and 2019. For 2010 to 2019, age-adjusted incidence rates were calculated via direct method using the 2000 United States population as the adjustment standard. Differences in incidence rate and tumor size by race/ethnicity and residence (metropolitan vs non-metropolitan) were assessed with rate ratios between groups. For 1992 to 2019, temporal trends in age-adjusted incidence rates for major race/ethnic groups in NM [Non-Hispanic White (NHW), Hispanic, and American Indian (AI)] were assessed by joinpoint regression using National Cancer Institute software. RESULTS: Our study included 3,161 patients for the time period 2010 to 2019, including NHW (1518), Hispanic (1425), and AI (218) cases. The overall incidence rates for NM AIs were lower than those for Hispanics and NHWs because of a decreased incidence of very small tumors (<1.1 cm). The incidence rates for large tumors (>5.1 cm) was equivalent among groups. In the early 2000s, Hispanics also had lower rates of small tumors when compared to NHWs but this trend disappeared over time. CONCLUSION: AIs in New Mexico have been left out of the nationwide increase in incidental diagnosis of small thyroid tumors. This same pattern was noted for Hispanics in the early 2000s but changed over time to mirror incidence rates for NHWs. These data are illustrative of the health care disparities that exist among New Mexico's population and how these disparities have changed over time.

Spinal anesthesia for pediatric urological surgery: Reducing the theoretic neurotoxic effects of general anesthesia.

BACKGROUND: Spinal anesthesia (SA) is an effective technique that has been used in children for years. With growing concern with regard to the risks of general anesthesia (GA), we developed a SA program to provide an alternative option. We present our initial experience with this program. OBJECTIVE: To implement a SA program at a large tertiary care pediatric center and assess the safety and efficacy of the technique as an alternative to GA for urologic surgery. STUDY DESIGN/METHODS: We prospectively collected data on all children undergoing SA at our institution. We recorded demographics, procedure, time required for placement of the SA, length of surgery, success of lumbar puncture, success of attaining adequate surgical anesthesia, need for supplemental systemic sedation, conversion to GA, and perioperative complications. RESULTS: SA was attempted in 105 consecutive children (104 boys, 1 girl) with a mean age of 7.4 ± 4.3 months (range 19 days-24 months) and mean weight of 8.3 ± 1.7 kg (range 3.5-13.7). Placement of the SA was successful in 93/105 children (89%). Inability to achieve lumbar puncture (cerebrospinal fluid was not obtained) meant that SA was abandoned in seven (7%) patients and GA was administered. In five patients in whom SA was successful and surgery was begun, 5/93 (5%) required conversion to GA: two because of evisceration of intestine through large hernia defects related to coughing and abdominal irritation, two because of lack of motor blockade despite an adequate sensory block, and one because of an inability to place an intravenous catheter in the lower extremities (required per SA protocol). If necessary, an intravenous catheter can be placed in the upper extremity, but this must be weighed against the fact that the block has already been placed and is of limited duration. Overall, SA was successful (SA was placed and surgery was completed without conversion to GA) in 88/105 children (84%). No additional sedation and no systemic anesthetic agents were required in 75/88 children (85%). The average time required to place the SA was 3.8 ± 2.7 min (range 1-12). The average time for the surgical procedure was 38.3 ± 23.1 min (range 10-122). No patient required conversion to GA because of recession of block. There were no surgical complications. DISCUSSION/CONCLUSIONS: SA is a safe and efficacious technique for routine pediatric urological procedures. SA should be considered for cases such as neonatal torsion or patients with significant cardiac or pulmonary comorbidities when the risks of GA are often weighed against the risks of non-intervention.

Holliday Junction Thermodynamics and Structure: Coarse-Grained Simulations and Experiments.

Holliday junctions play a central role in genetic recombination, DNA repair and other cellular processes. We combine simulations and experiments to evaluate the ability of the 3SPN.2 model, a coarse-grained representation designed to mimic B-DNA, to predict the properties of DNA Holliday junctions. The model reproduces many experimentally determined aspects of junction structure and stability, including the temperature dependence of melting on salt concentration, the bias between open and stacked conformations, the relative populations of conformers at high salt concentration, and the inter-duplex angle (IDA) between arms. We also obtain a close correspondence between the junction structure evaluated by all-atom and coarse-grained simulations. We predict that, for salt concentrations at physiological and higher levels, the populations of the stacked conformers are independent of salt concentration, and directly observe proposed tetrahedral intermediate sub-states implicated in conformational transitions. Our findings demonstrate that the 3SPN.2 model captures junction properties that are inaccessible to all-atom studies, opening the possibility to simulate complex aspects of junction behavior.