Detectable clonal mosaicism and its relationship to aging and cancer

In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of >2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 × 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 × 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases

Using Personal Response Devices as a Method to Study Visitor Experience at Informal Science Learning Environments

In recent years, there has been a growing need for designed settings like museums and science centers to collect visitor data. Visitor data can help these settings secure funding and provide valuable information on visitor experience, which can be used to improve programming. Unfortunately, many institutions struggle in developing effective data collection systems due to the lack of time, resources, and/or expertise. Furthermore, few studies have examined ways in which designed settings can run visitor studies, leaving staff at these settings with limited information on how data might be effectively collected. This study examined the potential of using personal response systems as a method for collecting survey data. Data collection took place at a local science center that runs a space-themed role-play for visiting school groups. Over the course of six months, 448 students responded to the survey immediately after they completed the role-play. Results showed that use of personal response systems increased response rate over previous survey methods. Furthermore, the self-reported multiple-choice survey data provided valuable information for the center. Findings from this investigation suggest that the student experience depended on the roles they were assigned. As a check on the validity of the survey, I compared the survey results with additional data from the science center program and found they were consistent. This consistency indicates that information collected by personal response systems can help the science center learn about and improve their program. Findings from this study provide evidence that personal response systems could form part of a successful data collection system for designed settings. The technology allowed for quick and efficient data collection and provided data in a form that was immediately useful for the institution. With personal response systems, staff can make measurements concerning many different factors about the program, gather visitor data, and make more informed decisions

Ultrasonic Generation of Pulsatile and Sequential Therapeutic Delivery Profiles from Calcium-Crosslinked Alginate Hydrogels

Control over of biological processes can potentially be therapeutically regulated through localized biomolecular deliveries. While implantable hydrogels can provide localized therapeutic deliveries, they do not traditionally provide the temporally complex therapeutic delivery profiles required to regulate complex biological processes. Ionically crosslinked alginate hydrogels have been shown to release encapsulated payloads in response to a remotely applied ultrasonic stimulus, thus potentially enabling more temporally complex therapeutic delivery profiles. However, thorough characterizations of how different types of therapeutic payloads are retained and ultrasonically released need to be performed. Additionally, the impact of potentially disruptive ultrasonic stimulations on hydrogel structure and temperature need to be characterized to better understand what range of ultrasonic signals can be used to trigger release. To perform these characterizations, calcium-crosslinked alginate hydrogels were loaded with various model macromolecules (dextrans), chemotherapeutics, and protein signaling factors and exposed to a variety of single-pulse and multi-pulse ultrasonic signals at various amplitudes and durations. In response to single-pulsed ultrasonic exposures, quantifications of molecular release, degree of gel erosion, and increase in hydrogel temperature revealed that the ultrasonic stimulations required for statistically significant therapeutic deliveries often eroded and heated the gels to unacceptable levels. However, multi-pulse ultrasonic exposures were shown to achieve significant amounts of therapeutic release while keeping gel erosion and temperature increase at modest levels. Finally, experiments were performed demonstrating that ultrasonic stimulation could be used to generate drug release profiles shown to have potential therapeutic benefits (e.g., pulsatile and sequential anticancer delivery profiles). This work underscores the potential of using ultrasonically responsive polymeric hydrogels for providing on-demand control over more complex therapeutic deliver profiles and enhancing drug delivery strategies in cancer therapies and beyond

The Cytotoxic Effects of Novel Flavonoids CT1 and CT3 on Breast Cancer Cells are Independent of the Presence of ER, PR, and HER2 Receptors

Introduction: Breast cancer is the most frequently diagnosed cancer found in women across the world, with an estimated 2.3 million new cases occurring in 2020. Additionally, over 684,000 deaths annually are attributed to breast cancer across the globe, making it the most common cause of cancer-related death in women. Further, treatment of breast cancer relies heavily on whether or not the cancer cells express estrogen, progesterone, and HER 2 receptors and this expression profile is often related to how quickly the cells grow and spread. In the United States, breast cancer cells that are hormone receptor positive and HER-2 negative make up about 73% of breast cancer cases, and cells that do not express any receptor and are known as triple negative, make up around 12% of cases (American Cancer Society, 2019). With that being said, CT1 and CT3 are novel compounds that have a cytotoxic effect on cell lines representing up to 85% of all breast cancer subtypes in the United States. Methods: The leaves of Chromolaena tacotana that contains the flavonoids CT1 and CT3 were dried and placed in a soxhlet extractor using dichloromethane (CH2Cl2) to extract the chlorophyll. The flavonoids were extracted using a column chromatography eluted with trichloromethane (CHCl3), a 1:1 dilution of CHCl3:methanol and methanol, followed by isolation and purification of the compounds. Human breast cancer cell lines MCF7, MDA-MB-231, and SKBr3 were treated with CT1 and CT3 at concentrations of 5, 10, 20, 40 and 80 µM, followed by incubation for 24 hours. To assess cell viability an MTT assay was conducted by adding a 5-diphenyl-tetrazolium bromide reagent. The purple-colored formazan crystals were solubilized with acidified isopropanol, then analyzed by spectrophotometry. Results: CT1 appeared to have the most cytotoxic effects compared to CT3 on MCF7. The opposite effect was observed for SKBr3 with CT3 showing the most effects as compared to CT1. No differential effect was observed on MDA-MB-231 since both CT1 and CT3 showed similar inhibition of cell viability. Conclusions: The results from the different breast cancer cell lines SKBr3, MCF7, and MDA-MB-231 vary based on how they responded to CT1 and CT3. CT3 was more effective on SKBr3 than CT1. CT1 was more effective on MCF7 than CT3. For MDA-MB-231, both CT1 and CT3 showed similar significant cytotoxic effects. The antiproliferative effects of CT1 and CT3 appear to be concentration dependent on all cells studied. In view of the results from MDA-MB-231 triple negative breast cancer cell line, the cytotoxic effect of the flavonoids is not dependent on the presence of estrogen, progesterone, or HER2 receptors on breast cancer cells. Further studies on the mechanism of action are necessary to elucidate the molecular targets of CT1 and CT3

Structurally Related Flavonoids CT1 and CT3 Have Cytotoxic Activity On Triple Negative MDA-MB-231 Breast Cancer Cells By Targeting The MEK-ERK Pathway

Breast cancer is the most commonly diagnosed cancer in women with an estimated 287,850 cases in 2022. Approximately 684,000 deaths each year are associated with breast cancer across the world. Risk factors of breast cancer include increased estrogen exposure, family history of breast cancer, and environmental factors. Treatment of breast cancer is highly dependent on the presence of HER2, estrogen, and progesterone receptors. Breast cancers that present with increased receptors for estrogen, progesterone, and HER2 are typically the least aggressive and the easiest to treat. The percentage of cases in the United States associated with hormone receptor positive and HER-2 negative or positive are approximately 82%. Absence of receptors for estrogen, progesterone, and HER2 is known as triple negative breast cancer. In the United States, only about 10% of cases are associated with this form. However, it is considered the most aggressive and difficult to treat. Two emerging flavonoids known as CT1 and CT3 have shown cytotoxic activity against cell lines that represent some of the most common breast cancers: MCF7, MDA-MB-231, and SKBr3. CT1 and CT3 were extracted from the leaves of Chromolaena tacotana using a Soxhlet extractor and the compounds then underwent isolation and purification. The cells were then treated with CT1 or CT3 at concentrations of 5, 10, 20, 40 and 80 µM. MTT assays were then used to determine cell viability. MDA-MB-231, the most aggressive type of breast cancer cells, responded to both CT1 and CT3. The most profound cytotoxic effects of CT1 were seen with MCF7 and MDA-MB-231, while CT3 exhibited a greater toxicity against SKBr3 cells. Preliminary results indicate that CT1 and CT3 target the MEK-ERK signaling pathway. Further studies need to be completed to determine mechanistically how these compounds lead to receptor-independent toxicity

Detectable clonal mosaicism and its relationship to aging and cancer

In an analysis of 31,717 cancer cases and 26,136 cancer-free controls from 13 genome-wide association studies, we observed large chromosomal abnormalities in a subset of clones in DNA obtained from blood or buccal samples. We observed mosaic abnormalities, either aneuploidy or copy-neutral loss of heterozygosity, of > 2 Mb in size in autosomes of 517 individuals (0.89%), with abnormal cell proportions of between 7% and 95%. In cancer-free individuals, frequency increased with age, from 0.23% under 50 years to 1.91% between 75 and 79 years (P = 4.8 x 10(-8)). Mosaic abnormalities were more frequent in individuals with solid tumors (0.97% versus 0.74% in cancer-free individuals; odds ratio (OR) = 1.25; P = 0.016), with stronger association with cases who had DNA collected before diagnosis or treatment (OR = 1.45; P = 0.0005). Detectable mosaicism was also more common in individuals for whom DNA was collected at least 1 year before diagnosis with leukemia compared to cancer-free individuals (OR = 35.4; P = 3.8 x 10(-11)). These findings underscore the time-dependent nature of somatic events in the etiology of cancer and potentially other late-onset diseases