Immunohistochemical study of Ki67, CD34 and p53 expression in human tooth buds.
OBJECTIVE
Establishment of Ki67, p53 and CD34 expression in human tooth buds of different stages of odontogenetic development.


METHODS
Tissue samples containing tooth buds were removed from the incisor areas of human fetuses in different stages of development (weeks 9-10, 12-13, 13-16, 21-24), and from the canine and molar areas of 21-24 weeks fetuses. The tissue fragments were fixed using formalin and were processed using common histological techniques with paraffin embedding. Immunostaining for Ki67, p53 and CD34 has been performed using the dextran method and moist heat antigen retrieval (except for CD34). The resulting slides were photographed and quantitatively evaluated.


RESULTS
Ki67 immunoexpression decreases with advancement of the developmental stage of the tooth bud: in the inner enamel epithelium, between weeks 9 and 16 (IEE), in the preameloblasts (PB) between weeks 13 and 16, in the ameloblasts (AB) between weeks 21 and 24; outer enamel epithelium (OEE); stratum intermedium (SI); in the dental papilla: between weeks 9 and 10 in the dental papilla (DP), between weeks 13 and 16 in the outer layer of the dental papilla (DP1) and in the central layer of the dental papilla (DP2). Likewise, we noted Ki67 expression in the odontoblast layer (O) and pulp (P), between weeks 21 and 24. Concerning CD34 expression, we observed a decrease from weeks 9-10 until weeks 13-16, followed by an increase until weeks 21-24 of intrauterine life. From weeks 9-10, we observed a constant decrease of expression until weeks 13-16, followed by an increase during weeks 21-24.


CONCLUSIONS
All Ki67, p53 and CD34 have been identified in the tooth bud. Ki67 expression gradually decreases with the embryonic development of the tooth, while p53 and CD34 expression decreases from weeks 9-10 to weeks 13-16 of intrauterine life, followed by an increase until weeks 21-24.
Department of Anatomy and Embryology, University of Medicine and Pharmacy of Tirgu Mures, Romania; papzsuzsa@yahoo.com.
Monica Cristina
MC
Muica Nagy-Bota
Zsuzsanna
Z
Pap
Lóránd
L
Denes
Alexandru
A
Ghizdavăţ
Klara
K
Brînzaniuc
Adina Simona
AS
Lup Coşarcă
Manuela
M
Chibelean Cireş-Mărginean
Mariana
M
Păcurar
Zoltán
Z
Pávai
D018952:Antigens, CD34 / Q000378:metabolism*; D006801:Humans; D007150:Immunohistochemistry; D007180:Incisor / Q000166:cytology / Q000378:metabolism; D019394:Ki-67 Antigen / Q000378:metabolism*; D014083:Tooth Germ / Q000166:cytology / Q000378:metabolism*; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism*
D018952:Antigens, CD34; D019394:Ki-67 Antigen; D016159:Tumor Suppressor Protein p53