1. Shenzhen Key Laboratory for Systems Medicine in Inflammatory Diseases, School of Medicine, Shenzhen Campus of Sun Yat-Sen University, The Seventh Affiliated Hospital of Sun Yat-sen University, Sun Yat-sen University, Shenzhen, China.
2. Medical College of Georgia-Augusta University, Augusta, GA 30912, United States.
3. Department of Hematology and Shenzhen Bone Marrow Transplantation Public Service Platform, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen University, Shenzhen 518060, China.
# These authors contributed equally to this work.
TJP1, an adaptor protein of the adhesive barrier, has been found to exhibit distinct oncogenic or tumor suppressor functions in a cell-type dependent manner. However, the role of TJP1 in kidney renal clear cell carcinoma (KIRC) remains to be explored. The results showed a marked down-regulation of TJP1 in KIRC tissues compared to normal tissues. Low expression of TJP1 was significantly associated with high grade and poor prognosis in KIRC. Autophagosome aggregation and LC3 II conversion demonstrated that TJP1 may induce autophagy signaling in 786-O and OS-RC-2 cells. Knockdown of TJP1 led to a decrease in the expression of autophagy-related genes, such as BECN1, ATG3, and ATG7. Consistently, TJP1 expression showed a significant positive correlation with these autophagy-related genes in KIRC patients. Furthermore, the overall survival analysis of KIRC patients based on the expression of autophagy-related genes revealed that most of these genes were associated with a good prognosis. TJP1 overexpression significantly suppressed cell proliferation and tumor growth in 786-O cells, whereas the addition of an autophagy inhibitor diminished its inhibitory function. Taken together, these results suggest that TJP1 serves as a favorable prognostic marker and induces autophagy to suppress cell proliferation and tumor growth in KIRC.
Keywords: KIRC, Tight junction protein 1, autophagy, proliferation