Inter-laboratory consistency and variability in the buccal micronucleus cytome assay depends on biomarker scored and laboratory experience: results from the HUMNxl international inter-laboratory scoring exercise.
The buccal micronucleus cytome (BMNcyt) assay in uncultured exfoliated epithelial cells from oral mucosa is widely applied in biomonitoring human exposures to genotoxic agents and is also proposed as a suitable test for prescreening and follow-up of precancerous oral lesions. The main limitation of the assay is the large variability observed in the baseline values of micronuclei (MNi) and other nuclear anomalies mainly related to different scoring criteria. The aim of this international collaborative study, involving laboratories with different level of experience, was to evaluate the inter- and intra-laboratory variations in the BMNcyt parameters, using recently implemented guidelines, in scoring cells from the same pooled samples obtained from healthy subjects (control group) and from cancer patients undergoing radiotherapy (treated group). The results indicate that all laboratories correctly discriminated samples from the two groups by a significant increase of micronucleus (MN) and nuclear bud (NBUD) frequencies and differentiated binucleated (BN) cells, associated with the exposure to ionizing radiation. The experience of the laboratories was shown to play an important role in the identification of the different cell types and nuclear anomalies. MN frequency in differentiated mononucleated (MONO) and BN cells showed the greatest consistency among the laboratories and low variability was also detected in the frequencies of MONO and BN cells. A larger variability was observed in classifying the different cell types, indicating the subjectivity in the interpretation of some of the scoring criteria while reproducibility of the results between scoring sessions was very good. An inter-laboratory calibration exercise is strongly recommended before starting studies with BMNcyt assay involving multiple research centers.
Environmental Carcinogenesis Unit, IRCCS AOU San Martino-IST, L.go Rosanna Benzi, 10 16132 Genoa, Italy.
Claudia
C
Bolognesi
Department of Chemical Safety and Cancer Prevention, Institute of Cancer Research, Medical University of Vienna, Austria Borschkegasse 8A, 1090 Vienna, Austria.
Siegfried
S
Knasmueller
Department of Chemical Safety and Cancer Prevention, Institute of Cancer Research, Medical University of Vienna, Austria Borschkegasse 8A, 1090 Vienna, Austria.
Armen
A
Nersesyan
Environmental Carcinogenesis Unit, IRCCS AOU San Martino-IST, L.go Rosanna Benzi, 10 16132 Genoa, Italy.
Paola
P
Roggieri
Clinical Epidemiology Unit, IRCCS AOU San Martino-IST, L.go Rosanna Benzi, 10 16132 Genoa, Italy.
Marcello
M
Ceppi
Clinical Epidemiology Unit, IRCCS AOU San Martino-IST, L.go Rosanna Benzi, 10 16132 Genoa, Italy.
Marco
M
Bruzzone
Environmental Toxicology Group, Institute for Ecology of Industrial Areas, Kossutha 6 Street, 40-844 Katowice, Poland.
Ewa
E
Blaszczyk
The Witold Pilecki State School of Higher Education, Maksymiliana Kolbego 8 Street, Oswiecim 32-600, Poland.
Danuta
D
Mielzynska-Svach
Mutagenesis Unit, Institute for Medical Research and Occupational Health, Ksaverska cesta 2, 10 000 Zagreb, Croatia.|Unit of Clinical and Molecular Epidemiology, IRCCS San Raffaele Pisana, Via di Val Cannuta, 247, 00166 Rome, Italy.
Mirta
M
Milic
Unit of Clinical and Molecular Epidemiology, IRCCS San Raffaele Pisana, Via di Val Cannuta, 247, 00166 Rome, Italy.|Department of Human Sciences and Quality of Life Promotion, San Raffaele University, Via di Val Cannuta, 247, 00166 Rome, Italy.
Stefano
S
Bonassi
Laboratory of Genetic Toxicology, Lutheran University of Brazil (ULBRA), Av. Farroupilha, 8001, 92425-900 Canoas-RS, Brazil.
Danieli
D
Benedetti
Laboratory of Genetic Toxicology, Lutheran University of Brazil (ULBRA), Av. Farroupilha, 8001, 92425-900 Canoas-RS, Brazil.
Juliana
J
Da Silva
Laboratory of Toxicogenomics and Nutrigenomics, Botucatu Medical School, UNESP - São Paulo State University, Rua Mario Rubens Montenegro, S/N, Rubião Jr, 18618-687, Botucatu-SP, Brazil.
Raphael
R
Toledo
Laboratory of Toxicogenomics and Nutrigenomics, Botucatu Medical School, UNESP - São Paulo State University, Rua Mario Rubens Montenegro, S/N, Rubião Jr, 18618-687, Botucatu-SP, Brazil.
Daisy Maria Fávero
DM
Salvadori
Universidad de los Andes Laboratorio de Genética Humana (LGH), Carrera 1E No, 18A-10 Bogotá, Colombia.
Helena
H
Groot de Restrepo
Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Vecna pot 111, 1000 Ljubljana, Slovenia.
Metka
M
Filipic
Department of Genetic Toxicology and Cancer Biology, National Institute of Biology, Vecna pot 111, 1000 Ljubljana, Slovenia.
Klara
K
Hercog
Faculty of Pharmacy, Department of Toxicology, Gazi University 06330, Hipodrom, Ankara, Turkey.
Ayça
A
Aktas
Faculty of Pharmacy, Department of Toxicology, Gazi University 06330, Hipodrom, Ankara, Turkey.
Sema
S
Burgaz
Institute of Environmental Health, Medical University of Vienna, Kinderspitalgasse 15, 1090 Vienna, Austria.
Michael
M
Kundi
German Federal Environment Agency, Heinrich-Heine-Straße 12, 08645 Bad Elster, Germany.
Tamara
T
Grummt
Genome Health and Personalised Nutrition, CSIRO Health and Biosecurity, Gate 13, Kintore Avenue, South Australia 5000, Australia and.
Philip
P
Thomas
Genome Health and Personalised Nutrition, CSIRO Health and Biosecurity, Gate 13, Kintore Avenue, South Australia 5000, Australia and.
Maryam
M
Hor
School of Public Health, Center for Environmental Research and Children's Health, University of California, Berkeley, 733 University Hall, Berkeley, CA 94720-7360, USA.
Maria
M
Escudero-Fung
School of Public Health, Center for Environmental Research and Children's Health, University of California, Berkeley, 733 University Hall, Berkeley, CA 94720-7360, USA.
Nina
N
Holland
Genome Health and Personalised Nutrition, CSIRO Health and Biosecurity, Gate 13, Kintore Avenue, South Australia 5000, Australia and.
Michael
M
Fenech
D000328:Adult; D000368:Aged; D004784:Environmental Monitoring / Q000379:methods; D005260:Female; D006801:Humans; D007753:Laboratories / Q000592:standards; D008297:Male; D048629:Micronuclei, Chromosome-Defective; D015162:Micronucleus Tests / Q000379:methods* / Q000592:standards; D008875:Middle Aged; D009061:Mouth Mucosa / Q000528:radiation effects*; D009369:Neoplasms / Q000532:radiotherapy*; D015203:Reproducibility of Results