Knockdown of circZMIZ1 enhances the anti-tumor activity of CD8+ T cells to alleviate hepatocellular carcinoma.

ZMIZ1 acts as an oncogene in hepatocellular carcinoma (HCC). circZMIZ1 (hsa_circ_0018964) derives from ZMIZ1; its underlying mechanism in HCC has not been reported. Peripheral blood and peripheral blood mononuclear cells (PBMCs) were obtained from HCC patients and healthy volunteers. CD8+ T cells were sorted from PBMCs of HCC patients. Applying flow cytometry, cell apoptosis and the proportion of KCNJ2/CD8+ T cells were examined. The cytotoxicity of CD8+ T cells against HCC cells was evaluated. The interaction among circZMIZ1, miR-15a-5p, and KCNJ2 was investigated by dual luciferase assay, RNA immunoprecipitation, and RNA pull-down assay. An orthotopic mouse model of HCC was constructed by intrahepatic injection of H22 cells. Upregulation of circZMIZ1 and KCNJ2 and downregulation of miR-15a-5p were observed in peripheral blood and PBMCs of HCC patients. The proportion of KCNJ2/CD8+ T cells was also increased in HCC patients. circZMIZ1 knockdown restrained apoptosis of CD8+ T cells and elevated cytotoxicity of CD8+ T cells. Mechanically speaking, circZMIZ1 elevated KCNJ2 expression by sponging miR-15a-5p. miR-15a-5p inhibitor reversed circZMIZ1 silencing-mediated inhibition of apoptosis and promotion of cytotoxicity in CD8+ T cells. In vivo, orthotopic mice of HCC exhibited increased expression of circZMIZ1 and KCNJ2, elevated proportion of KCNJ2/CD8+ T cells, and decreased expression of miR-15a-5p. This work demonstrated that circZMIZ1 inhibited the anti-tumor activity of CD8+ T cells in HCC by regulating the miR-15a-5p/KCNJ2 axis. This provides a theoretical basis for the development of effective circZMIZ1 in tumor immunotherapy.

Association Between Social Media Use and Cancer Screening Awareness and Behavior for People Without a Cancer Diagnosis: Matched Cohort Study.

BACKGROUND: The use of social media in communications regarding cancer prevention is rapidly growing. However, less is known about the general population's social media use related to cancer screening awareness and behavior for different cancers. OBJECTIVE: We aimed to examine the relationship between social media use and cancer screening awareness and behavior among people without a cancer diagnosis. METHODS: Data were collected from the Health Information National Trends Survey 5 Cycle 1 to 3 in the United States (n=12,227). Our study included 10,124 participants without a cancer diagnosis and 3 measures of screening awareness (those who had heard of hepatitis C virus [HCV], human papillomavirus [HPV], and the HPV vaccine) and 4 measures of behavior (those who had prostate-specific antigen tests, Papanicolaou tests for cervical cancer, as well as breast cancer and colon cancer tests). Propensity-score matching was conducted to adjust for the sociodemographic variables between the social media user and nonuser participants. Multivariable logistic regression was used to assess the association of social media use by gender. Jackknife replicate weights were incorporated into the analyses. RESULTS: Of the 3794 matched participants, 1861 (57.6% weighted) were male, and the mean age was 55.5 (SD 0.42) years. Compared to social media nonusers, users were more likely to have heard of HCV (adjusted odds ratio [aOR]=2.27, 95% CI, 1.29-3.98 and aOR=2.86, 95% CI, 1.51-5.40, for male and female users, respectively) and HPV (aOR=1.82, 95% CI, 1.29-2.58 and aOR=2.35, 95% CI, 1.65-3.33, for male and female users, respectively). In addition, female users were more likely to have heard of the HPV vaccine (aOR=2.06, 95% CI, 1.41-3.00). No significant associations were found between social media use and prostate-specific antigen tests in males, Papanicolaou tests and breast cancer tests in females, or colon cancer tests in both male and female users. CONCLUSIONS: While social media services can potentially promote cancer screening awareness in the general population, but they did not improve screening behavior after adjusting for socioeconomic status. These findings strengthened our understanding of social media use in targeting health communications for different cancers.