Objective:To detect the expressions of survivin, galectin-3 and thyroid peroxidase in papillary thyroid microcarcinoma ( PTMC) and cancer adjacent normal tissue to explore the clinical significant.The correlations between the expressions of survivin,Gal-3 and TPO with BRAFV600E gene mutation in PTMC were analyzed.Methods: The expressions of survivin,Gal-3 and TPO were measured by immunohistochemical ( IHC ) method in 56 cases of PTMC tissue and adjacent normal tissue; BRAFV600E mutation was detected by PCR amplification and subsequently sequencing.Chi square test was used to analyse the relation in the expression rates of survivin,Gal-3 and TPO and BRAFV600E gene mutation.Results:The survivin and Gal-3 were strongly expressed but TPO was negatively expressed.The survivin and Gal-3 were negative in adjacent normal tissues but TPO was expressed.There were sig-nificant differences in the expression rates of survivin, Gal-3 and TPO between PTMC tissue and adjacent normal tissue (all P<0.001).The BRAFV600E mutation rate (32.1%) and the expression rates of survivin,Gal-3 and TPO in PTMC tissue were found to be positively related to lymph node metastases (P=0.009,P=0.025,P=0.007,P=0.008),and negatively related to gender and age (all P>0.05).There were no correlation was found between the expressions of survivin,Gal-3,TPO and the BRAFV600E gene mutation in PTMC(all P>0.05).Conclusion: The strong expressions of survivin and Gal-3,the mild expression of TPO and BRAF mutation may be important in the development of PTMC,and the detection of BRAFV600E gene mutation and the expressions of survivin, Gal-3 and TPO could be used to the judgment of pathogenetic condition and prognostic outcomes.

Objective To investigate the effects and mechanism of retinoie acid on B16 marina mel-anoma cells and human melanocytes in vitro. Methods B16F10 murine melanoma cells and human mela-noeytes were cultured in culture medium which contains different concentration of components, including retinoic acid. Using reverse transcription-polymerase chain reaction (RT-PCR) mRNA expression of the tyrosinase was detected. Tyrosinase activity, melanin content and cell proliferation rate were also deter-mined. Results Retinoieacid exhibited an inhibitory effect on the expression of tyrosinase mRNA. As the concentration of retinoic acid was 100 μmol/L, treating for 72 h, the expression of tyrosinase mRNA de-creased 30.13 %, retinoic acid exhibited an inhibitory effect on tyrosinase activity and melanin production at high concentration (>500 μmol/L), and it could promote the cell proliferation. Retinoic acid and hy-droqninone could be cooperative at high concentration (1 000 μmol/L), and enhanced the down regulation of tyrosinase activity and melanin content. Retinoic acid could also mitigate the inhibitory effect of hydro-quinone on cell proliferation, so as to protect the cells from injury. Hydroquinone had no effect on tyrosi-nase gene expression at mRNA level. Conclusion Retinoic acid inhibits the synthesis of melanin by the genetic regulation at mRNA level.