Programmed cell death 2 functions as a tumor suppressor in osteosarcoma.
OBJECTIVES
To investigate the role of programmed cell death 2 (PDCD2) in osteosarcoma (OS), along with correlations between PDCD2 and CD4(+)/CD8(+).


METHODS
Sprague-Dawley (SD) rats were randomly assigned to control group and OS group. The OS group rats were subjected to induce models of OS by transplantation with UMR106 cells. Peripheral blood was collected to test the percentages of the CD4(+) and CD8(+) cell subsets using flow cytometry (FCM). Western blotting was performed to determine the PDCD2 protein level. The correlations between PDCD2 and CD4(+)/CD8(+) were analyzed by Pearson correlation coefficient. Besides, specific small interfering RNAs (siRNA) against PDCD2 and nonspecific (NS)-siRNA were transfected into UMR106 cells. Cell viability and invasive ability were determined after transfection.


RESULTS
CD4(+) cells percentages were significantly decreased in the OS group, while CD8(+) cells were significantly increased (P < 0.05). The PDCD2 protein levels were markedly lower than that in the control group (P < 0.05). Additionally, PDCD2 was positively correlated with CD4(+) (R(2) = 0.66, P < 0.05), but was negatively correlated with CD8(+) (R(2) = -0.94, P < 0.05). Moreover, the cell viability and invasion ability were significantly higher than that in the control group and the NS siRNA group after transfection with PDCD2 siRNA (P < 0.05).


CONCLUSION
These results suggest that PDCD2 is involved in the pathogenesis of OS, and PDCD2 may play an important role in tumor suppression. These mechanisms might be related to immune response induced by CD4(+) and CD8(+) T cells.
['Yang|Yuanxun|Y|', 'Jin|Yan|Y|', 'Du|Wenxi|W|']
D000818:Animals D051017:Apoptosis Regulatory Proteins D001859:Bone Neoplasms D015496:CD4-Positive T-Lymphocytes D018414:CD8-Positive T-Lymphocytes D045744:Cell Line, Tumor D002465:Cell Movement D049109:Cell Proliferation D002470:Cell Survival D015972:Gene Expression Regulation, Neoplastic D016246:Lymphocytes, Tumor-Infiltrating D008297:Male D009361:Neoplasm Invasiveness D012516:Osteosarcoma D034622:RNA Interference D017207:Rats, Sprague-Dawley D015398:Signal Transduction D013997:Time Factors D014162:Transfection D025521:Tumor Suppressor Proteins
programmed cell death 2 Osteosarcoma CD4+ CD8+