Yap, J. C. H.

Abstract Black women experience significant disparities in morbidity and mortality related to hereditary breast and ovarian cancer (HBOC). Early identification of women with HBOC is essential for proactive screening and timely diagnosis. However, evidence suggests that Black women receive genetic testing for HBOC at lower rates than their White counterparts. We conducted in-depth qualitative interviews with 107 Black women with a personal or family history of breast or ovarian cancer, to understand their perceptions of their familial risk of HBOC and interest in genetic testing. In phase 1 of this study, participants were recruited from the networks of patient support organizations and historically Black sororities representing mostly highly educated and well insured patients. In phase 2, participants were recruited from a family medicine safety net clinic in Jacksonville, FL for socioeconomic diversity. Participants in both cohorts frequently expressed a lack of awareness about their family cancer history and identified many barriers to family disclosure of a cancer diagnosis. These include a culture of silence around medical issues and a belief that personal difficulties should be kept to oneself. Practical and cultural barriers to family history sharing were magnified among those with lower socioeconomic status. Many participants in both cohorts indicated a strong desire to understand their own risk of HBOC. They also expressed interested in genetic testing to proactively mitigate risk to themselves and future generations. Understanding of the potential relevance of HBOC testing to one’s personal health and post-test actionability was variable across both groups, although perceptions of genetic testing were generally favorable. These findings suggest that culturally tailored educational materials and alternative clinical modalities to collect family health history may be beneficial to improve timely identification of Black women who meet NCCN Guidelines for HBOC testing. Specifically, greater attention should be given to addressing barriers that led to underestimation of HBOC risk among patients experiencing disparities driven by adverse social determinants of health. Citation Format: Kirsten Riggan, Jane Yap, Ewan Cobran, Michele Halyard, Sarah James, Marion Kelly, Daphne Phillips, Megan Allyse. Perceptions and Experiences of Black Women on Family History Sharing and Genetic Testing for Hereditary Breast and Ovarian Cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-09-08.

Airway inflammation and pro-inflammatory cytokines such as tumor necrosis factor alpha (TNFα) underlie the pathophysiology of respiratory diseases, including asthma. Previously, we showed that TNFα selectively activates the inositol-requiring enzyme 1α (IRE1α)/X-box binding protein 1 spliced (XBP1s) ER stress pathway in human airway smooth muscle (hASM) cells. The ER stress pathway is activated by the accumulation of unfolded proteins in the ER. Accordingly, chemical chaperones such as 4-phenylbutyrate (4-PBA) may ameliorate ER stress activation. In the present study, we hypothesize that 4-PBA mitigates TNFα induced ER stress in hASM cells. hASM cells were isolated from bronchiolar tissue obtained from 5 donors with no history of current smoking or respiratory diseases. hASM cells were serum-deprived for 48 h, and phenotype confirmed by expression of smooth muscle actin and fusiform morphology. hASM cells from the same donor were then separated into 4 12-h treatment groups: 1) TNFα (20 ng/mL), 2) TNFα + 4-PBA (30 min pretreatment), and 3) untreated control. Protein expression and phosphorylation of IRE1α and XBP1s were determined by Western blot. Gene expression of XBP1s was analyzed by PCR. We found that TNFα induced IRE1α phosphorylation and XBP1 splicing, which were significantly reduced by pretreatment with 4-PBA. These results support our hypothesis and suggest that, in the presence of chemical chaperone 4-PBA, TNFα induced ER stress is significantly decreased. R01HL 157984 (GCS) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

The impact of airway inflammation is mediated by pro-inflammatory cytokines such as tumor necrosis factor alpha (TNFα), which underlies several respiratory diseases, including COVID-19, asthma, chronic bronchitis, and chronic obstructive pulmonary disease (COPD). In human airway smooth muscle (hASM) cells, exposure to TNFα leads to an accumulation of unfolded proteins in the ER, which triggers a homeostatic ER stress response activating a signaling cascade to restore normal function. Previously, we showed that TNFα selectively activates the inositol-requiring enzyme 1α (IRE1α)/X-box binding protein 1 (XBP1) ER stress pathway in hASM cells. Most likely, the protein unfolding in hASM cells caused by TNFα results from an increase in reactive oxygen species (ROS) formation. We hypothesize that ER stress induced by TNFα is mitigated by the ROS scavenger TEMPOL. Primary hASM cells were isolated from bronchiolar tissue samples obtained from 5 patients (both sexes included) who had no history of respiratory diseases. hASM cells were serum deprived for 48 h before treatment with 1) TNFα (20 ng/ml) for 12 h; 2) TEMPOL (500 μM) for 30 min followed by TNFα (20 ng/ml) for 12 h; and 3) untreated control for 12 h. At the end of the treatment period, hASM cells were processed for determination of protein expression through Western blotting. Activation of the ER stress response was assessed by phosphorylation of IRE1α and splicing of XBP1. Confirming our previous results, we found that 12 h TNFα exposure induced an ER stress response in hASM cells, evidence by phosphorylation of IRE1α and XBP1 splicing. Treating hASM cells with TEMPOL before exposure to TNFα mitigated the ER stress response. These results support our hypothesis and indicate that ROS scavenging prevents TNFα induced protein unfolding and triggering of the IRE1α/XBP1 ER stress pathway. R01HL 157984 (GCS) This is the full abstract presented at the American Physiology Summit 2023 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.