Citations

Abstract Background To nurture a new online community for health behavior change, a fruitful strategy is to recruit “seed users” to create content and encourage participation. Purpose This study evaluated the impact of support from seed users in an online community for smoking cessation among people living with HIV/AIDS and explored the linguistic characteristics of their interactions. Methods These secondary analyses examined data from a randomized trial of a smoking cessation intervention for HIV+ smokers delivered via an online health community (OHC). The analytic sample comprised n = 188 participants randomized to the intervention arm who participated in the community. Independent variables were OHC interactions categorized by participant interlocutor type (study participant, seed user) and interaction type (active, passive). The primary outcome was biochemically verified 7-day abstinence from cigarettes measured 3 months post-randomization; 30-day abstinence was examined for robustness. Results Logistic regression models showed that participants’ interactions with seed users were a positive predictor of abstinence but interactions with other study participants were not. Specifically, the odds of abstinence increased as the number of posts received from seed users increased. Exploratory linguistic analyses revealed that seed users wrote longer comments which included more frequent use of “we” and “you” pronouns and that study participants users used more first-person singular pronouns (“I”). Conclusions Seeding a community at its inception and nurturing its growth through seed users may be a scalable way to foster behavior change among OHC members. These findings have implications for the design and management of an OHC capable of promoting smoking cessation.

Lipids play crucial biological roles in health and disease, including in cancers. The phosphatidylinositol 3-kinase (PI3K) signaling pathway is a pivotal promoter of cell growth and proliferation in various types of cancer. The somatic mutations in PIK3CA , the gene coding for the catalytic subunit p110α of PI3K, are frequently present in cancer cells, including breast cancer. Although the most prominent mutants, represented by single amino acid substitutions in the helical domain in exon 9 (E545K) and the kinase domain in exon 20 (H1047R) are known to cause a gain of PI3K function, activate AKT signaling and induce oncogenic transformation, the effect of these mutations on cellular lipid profiles has not been studied. We carried out untargeted lipidomics using liquid chromatography-tandem mass spectrometry to detect the lipid alterations in mammary gland epithelial MCF10A cells with isogenic knockin of these mutations. A total of 536 species of lipids were analyzed. We found that the levels of monosialogangliosides, signaling molecules known to enhance cell motility through PI3K/AKT pathway, were significantly higher in both mutants. In addition, triglycerides and ceramides, lipid molecules known to be involved in promoting lipid droplet production, cancer cell migration and invasion, were increased, whereas lysophosphatidylcholines and phosphatidylcholines that are known to inhibit cancer cell motility were decreased in both mutants. Our results provide novel insights into a potential link between altered lipid profile and carcinogenesis caused by the PIK3CA hotspot mutations. In addition, we suggest untargeted lipidomics offers prospects for precision/personalized medicine by unpacking new molecular substrates of cancer biology.