Davide Malacarne

Azienda Ospedaliera Universitaria San Martino di Genova, Genova, Liguria, Italy

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Publications (8)25.15 Total impact

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    ABSTRACT: BACKGROUND: Chromosomal Instability and aneuploidy may represent biomarkers of oral exposure to damaging agents and early signs of clinical disease according to the theory of "oral field cancerization". METHODS: The hypothesis was tested that the DNA Index values, obtained by high-resolution DNA flow cytometry, may potentially contribute to oral cancer risk prediction. For this purpose, the DNA Index of oral fields of normal appearing mucosa and oral potentially malignant disorders in 165 consecutive patients was tested for association with dysplasia and/or the oral sub-sites of tongue and floor of the mouth taken as high-risk intermediate end-points surrogate of cancer clinical end-points. The association was evaluated by logistic regression using patient gender, age, tobacco cigarette smoking habit and alcohol abuse as confounding variables. RESULTS: Different DNA Index models provided evidence of statistical significant associations. Subdividing the DNA Index values in diploid, near-diploid aneuploid and high or multiple aneuploid from both oral potentially malignant disorders and oral normal appearing mucosa, Odds Ratios respectively of 1, 4.3 (p=0.001) and 18.4 (p<0.0005) were obtained. CONCLUSIONS: Routine DNA Index analysis by high-resolution DNA flow cytometry appears potentially useful to complement dysplasia and sub-site analysis for assessment of oral cancer risk-prediction and for a better management of the patients with oral potentially malignant disorders. Work is in progress to validate the present findings in a prospective study with clinical end-points. Impact: Identifying DNA abnormalities in oral pre-malignancy may lead to biomarkers of oral exposure and cancer risk and potentially to more effective prevention measures.
    Cancer Epidemiology Biomarkers &amp Prevention 04/2013; · 4.56 Impact Factor
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    ABSTRACT: Oral fields of visually normal and non-dysplastic mucosa (ODFs) may represent the precursors of oral potentially malignant lesions (OPMLs). Aim of the study was to provide new evidence for the concept of the "field carcinogenesis" model by comparing the ODF and OPML genomic aberration profiles obtained by high resolution DNA flow cytometry (hr DNA-FCM) and array-Comparative Genomic Hybridization (a-CGH). A second aim was to investigate if specific CGH aberrations were associated with DNA aneuploidy. Nineteen patients with single OPMLs were recruited for the study. In parallel with obtaining samples of OPML tissue from 11 leukoplakias without dysplasia (nd-OPMLs) and 8 with dysplasia (d-OPMLs), we also obtained samples from distant ODFs. DNA aneuploid nuclei detected by hr DNA-FCM were physically separated, based on DNA content, from the DNA diploid components with a DNA-FCM-Sorter. These relatively pure subpopulations of epithelial nuclei were then submitted to DNA extraction and a-CGH for a genome-wide analysis of DNA copy number aberrations (CNAs). The frequencies of DNA aneuploidy (DI ≠ 1) among ODFs and OPMLs were respectively 5.3% and 32%. The DI aneuploid values of ODFs and nd-OPMLs were all near-diploid (DI ≠ 1 and DI ≤ 1.4), while for d-OPMLs were high-aneuploid (DI > 1.4) in 40% of the cases. CNA averages were 1.9 in ODFs and 6.5 in OPMLs. The gain of the chromosomal region 20q13.33-qter was observed in 37% of both ODFs and corresponding OPMLs. Additional common regions included 7p22.2-pter, 11p15.5-pter and 16p13.3-pter where gains were observed. Furthermore, gains of 20q13.31-q13.33 and of 5p13.33-pter and loss of 9p21.3 were detected at high frequency (respectively, at 62.5%, 50% and 50%) only in d-OPMLs. In particular, loss at 9p21.3, gain at 5p13.33-pter and gain of 20q13.31-q13.33 were associated with DNA aneuploidy (p = 0.00004; p = 0.0005; p = 0.01). ODFs and OPMLs showed common CNAs in specific chromosomal regions suggesting that they may represent early events of the natural history of oral carcinogenesis according to the field effect cancerization and may contribute to the ODF-OPML transition. In addition, loss at 9p21.3 and gains at 5p13.33-pter and 20q13.31-q13.33 may contribute to DNA aneuploidization.
    Cellular oncology (Dordrecht). 12/2011; 35(1):43-52.
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    ABSTRACT: To test the hypothesis that cigarette smokers develop oral potentially malignant disorders or carcinomas in preferential anatomical subsites. The association of smoking habit with the presence of oral lesions in specific anatomical subsites was assessed in 123 patients using the odds ratio analysis. When compared to all the other subsites, the relative frequency of smokers with lesions was higher in the buccal mucosa and in the floor of the mouth (FOM) (P=0.002 and P=0.005), while it was lower in the tongue (P<0.0005). Smokers were about 7 years younger than non-smokers (P=0.008). The association of smoking and age suggests that smoking may contribute to generate a field of injury that leads to lesions in shorter periods than other causes. The stronger relationship of smoking with lesions in the buccal mucosa and FOM than in the tongue suggests that tissue characteristics mediate the effects of tobacco.
    Journal of Oral Pathology and Medicine 03/2011; 40(3):214-7. · 2.06 Impact Factor
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    ABSTRACT: The mucosae of the oral cavity are different at the histological level but appear all equally exposed to common genotoxic agents. As a result of this exposure, changes in the mucosal epithelia may develop giving rise to Oral Potentially Malignant Lesions (OPMLs), which with time may in turn progress to Oral Squamous Cell Carcinomas (OSCCs). Therefore, much effort should be devoted to identify features able to predict the likeliness of progression associated with an OPML. Such features may be helpful in assisting the clinician to establish both appropriate therapies and follow-up schedules. Here, we report a pilot study that compared the occurrence of DNA aneuploidy and chromosomal copy number aberrations (CNAs) in the OPMLs from different oral anatomical subsites. Samples from histologically diagnosed OPMLs were processed for high resolution DNA flow cytometry (hr DNA-FCM) in order to determine the relative DNA content expressed by the DNA index (DI). Additionally, array-Comparative Genomic Hybridization (a-CGH) analysis was performed on DNA obtained from diploid nuclei suspensions directly. When aneuploid nuclei were detected, these were physically separated from diploid nuclei on the base of their DI values by means of a DNA-FCM-Sorter in order to improve the a-CGH analysis. Tongue OPMLs were more frequently associated with DNA aneuploidy and CNAs than OPMLs arising from all the other mucosal subsites. We suggest that the follow-up and the management of the patients with tongue OPMLs should receive a distinctive special attention. Clearly, this hypothesis should be validated in a prospective clinical study.
    BMC Cancer 01/2011; 11:445. · 3.33 Impact Factor
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    ABSTRACT: Oral potentially malignant lesions (OPMLs) with dysplasia and aneuploidy are thought to have a high risk of progression into oral squamous cell carcinomas (OSCCs). Non-dysplastic "oral distant fields" (ODFs), characterized by clinically normal appearing mucosa sited at a distance from co-existing OPMLs, and non-dysplastic OPMLs may also represent an early pre-cancerous state. ODFs, OPMLs without and with dysplasia and OSCCs were investigated by high resolution DNA content flow cytometry (FCM). ODFs and OPMLs without dysplasia were DNA aneuploid respectively in 7/82 (8.5%) and 25/109 (23%) cases. "True normal oral mucosa" and human lymphocytes from healthy donors were DNA diploid in all cases and were used as sex specific DNA diploid controls. Dysplastic OPMLs and OSCCs were DNA aneuploid in 12/26 (46%) and 12/13 (92%) cases. The DNA aneuploid sublines were characterized by the DNA Index (DI not =1). Aneuploid sublines in ODFs and in non-dysplastic and dysplastic OPMLs were near-diploid (DI<1.4) respectively in all, 2/3 and 1/3 of the cases. DNA aneuploid OSCCs, instead, were characterized prevalently by multiple aneuploid sublines (67%), which were commonly (57%) high-aneuploid (DI> or =1.4). DNA near-diploid aneuploid sublines in ODFs and OPMLs appear as early events of the oral carcinogenesis in agreement with the concept of field effect. Near-diploid aneuploidization is likely to reflect mechanisms of loss of symmetry in the chromosome mitotic division. High DNA aneuploid and multiple sublines in OPMLs with dysplasia and OSCCs suggest, instead, mechanisms of "endoreduplication" of diploid and near-diploid aneuploid cells and chromosomal loss. High resolution DNA FCM seems to enable the separation of subsequent progression steps of the oral carcinogenesis.
    Cellular oncology: the official journal of the International Society for Cellular Oncology 01/2010; 32(5-6):373-83. · 4.17 Impact Factor
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    ABSTRACT: To date there are still no reliable biomarkers for oral potentially malignant disorders (PMDs) to predict the risk of progression to squamous cell carcinoma (SCC). Within a prospective clinical trial of patients with PMDs, DNA content flow cytometry (DNA FCM) was evaluated for 60 PMDs using fresh samples obtained by a dermatological curette. There were 6/42 PMDs without dysplasia, but with DNA aneuploidy, versus 8/18 with both dysplasia and aneuploidy (p=0.02). When the tongue and the buccal mucosa, the two most common sites in the present series of cases were compared, dysplastic PMDs were mainly located on the tongue (p=0.01). Tobacco smokers, who preferentially developed PMDs in the buccal mucosa at a younger age than non-smokers (p=0.002), had fewer dysplastic PMDs than did non-smokers (p=0.01). Dysplasia was significantly linked to DNA aneuploidy (p=0.03) in smokers. The present data suggest that aneuploidy is an early event in oral carcinogenesis and that the influence of tobacco varies according to subsite and patient age. When DNA FCM of PMD samples are obtained by curette scraping, extensive areas can be covered with a minimally invasive, rapid, inexpensive procedure. Moreover DNA FCM of these samples appears easy amenable to routine analysis. Further research on larger numbers of PMDs should be carried out to determine whether DNA FCM plays a role in the prediction of risk of PMD transformation.
    Oral Oncology 06/2009; 45(10):887-90. · 2.70 Impact Factor
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    ABSTRACT: The origin and mechanisms of chromosomal instability are still widely unknown. We previously investigated a limited number of human sporadic colorectal cancers (CRCs) and observed a statistically different occurrence of KRAS and p53 mutations among predetermined subgroups of tumors with different degrees of DNA aneuploidy. The aim of the present study was to further verify these observations by including BRAF gene analysis and by investigating a larger series of cases subdivided into Dukes' stages A to D to reconstruct some form of chronological modulation for events during CRC progression. KRAS, p53, BRAF mutations and flow cytometric DNA Index were evaluated by established techniques in a series of 135 human sporadic CRCs. p53, KRAS and BRAF mutations were found in 39%, 34%, and 4% of tumors, respectively. The frequency of p53 mutations increased from 15% for stage A to 48% for stage D and was highest in near-diploid (DI < 1.4 and DI does not equal 1) and high-aneuploid (DI > 1.6) tumors. A similar correlation between gene mutations and DI values was observed for KRAS. The simultaneous presence of KRAS and p53 mutations was observed in only 11% of cases. Moreover, the co-occurrence of p53 and KRAS mutations was only observed in near-diploid and high-aneuploid tumors. Our findings suggest that KRAS and p53 gene mutations, which are rarely simultaneous and are associated with specific DI aneuploid values, do not represent a synergistic evolutionary pathway but may influence mechanisms of chromosomal instability.
    Cellular oncology: the official journal of the International Society for Cellular Oncology 01/2006; 28(4):161-6. · 4.17 Impact Factor
  • Mauro Risio, Davide Malacarne, Walter Giaretti
    Cellular oncology: the official journal of the International Society for Cellular Oncology 02/2005; 27(5-6):363-6. · 4.17 Impact Factor