Effects of MEG3 on tumor growth in vivo . (A) The tumor volume was calculated once every three days after injection of SPC-A1 cells stably transfected with PCDNA-MEG3 or empty vector. Points, mean (n = 3); bars indicate S.D. (B) Tumor weights are represented as means of tumor weights ± s.d. (C) QPCR analysis of MEG3 expression in tumor tissues formed from SPC-A1/MEG3, SPC-A1/NC. (D). Tumors developed from PCDNA-MEG3 transfected SPC-A1 cells showed lower PCNA protein levels than tumors developed by control cells. Upper: H & E staining; Lower: immunostaining. *P < 0.05, **P < 0.01 and N.S. not significant.