RGS12 Is a Novel Tumor-Suppressor Gene in African American Prostate Cancer That Represses AKT and MNX1 Expression
CANCER RESEARCH
Authors: Wang, Yongquan; Wang, Jianghua; Zhang, Li; Karatas, Omer Faruk; Shao, Longjiang; Zhang, Yiqun; Castro, Patricia; Creighton, Chad J.; Ittmann, Michael
Abstract
African American (AA) men exhibit a relatively high incidence and mortality due to prostate cancer even after adjustment for socioeconomic factors, but the biological basis for this disparity is unclear. Here, we identify a novel region on chromosome 4p16.3 that is lost selectively in AA prostate cancer. The negative regulator of G-protein signaling RGS12 was defined as the target of 4p16.3 deletions, although it has not been implicated previously as a tumor-suppressor gene. RGS12 transcript levels were relatively reduced in AA prostate cancer, and prostate cancer cell lines showed decreased RGS12 expression relative to benign prostate epithelial cells. Notably, RGS12 exhibited potent tumor-suppressor activity in prostate cancer and prostate epithelial cell lines in vitro and in vivo. We found that RGS12 expression correlated negatively with the oncogene MNX1 and regulated its expression in vitro and in vivo. Further, MNX1 was regulated by AKT activity, and RGS12 expression decreased total and activated AKT levels. Our findings identify RGS12 as a candidate tumor-suppressor gene in AA prostate cancer, which acts by decreasing expression of AKT and MNX1, establishing a novel oncogenic axis in this disparate disease setting. (C) 2017 AACR.
Down-regulation of diesel particulate matter-induced airway inflammation by the PDZ motif peptide of ZO-1
JOURNAL OF CELLULAR AND MOLECULAR MEDICINE
Authors: Kang, Dong Hee; Lee, Tae-Jin; Kim, Ji Wook; Shin, Yu Som; Kim, Ju Deok; Ryu, Sung Won; Ryu, Siejeong; Choi, Yung Hyun; Kim, Cheol Hong; You, EunAe; Rhee, SangMyung; Song, Kyoung Seob
Abstract
Although diesel airborne particulate matter (PM2.5) has been known to play a role in many human diseases, there is no direct evidence that therapeutic drugs or proteins can diminish PM2.5-induced diseases. Nevertheless, studies examining the negative control mechanisms of PM2.5-induced diseases are critical to develop novel therapeutic medications. In this study, the consensus PDZ peptide of ZO-1 inhibited PM2.5-induced inflammatory cell infiltration, pro-inflammatory cytokine gene expression, and TEER in bronchoalveolar lavage (BAL) fluid and AM cells. Our data indicated that the PDZ domain in ZO-1 is critical for regulation of the PM2.5-induced inflammatory microenvironment. Therefore, the PDZ peptide may be a potential therapeutic candidate during PM-induced respiratory diseases.