Argyrophilic nucleolar organizer regions in the evaluation of tumour progression in the oral mucosa: correlation with tissue pathology

Ocimum basilicum L. (basil) presents pro-apoptotic activity in an Ehrlich's experimental tumor murine model

PURPOSE

This study aimed to evaluate the therapeutic effect of an ethanol extract of Ocimum basilicum L. (EEOb) aerial parts against Ehrlich's experimental tumor (EET) in mice.

METHODS

Swiss mice were divided into two groups (control and treated; n = 6). On day 21, all mice were inoculated subcutaneously with 2 × 106 (0.05 mL) EET cells in the left paw for solid tumor development. This study lasted 28 days. Treatment began 24 hours after inoculation with EET. Measurements of dorsoplantar thickness were used to assess tumor growth. The paw pad was collected for histopathological analysis and stained using the argyrophilic nucleolar organizing regions (AgNOR) technique and immunohistochemistry for proliferating cell nuclear antigen, Bcl-2 and Bax.

RESULTS

The treatment of animals with EEOb at 100 mg/kg intraperitoneally was able to reduce the growth (Control = 3.7 ± 0.1 mm vs. EEOb = 5.7 ± 0.2 mm) and the number of AgNORs of solid Ehrlich tumor. The antitumor effect of EEOb was associated with the induction of apoptosis of tumoral cell, as suggested by the reduction of the content of Bcl-2 induced by extract.

CONCLUSIONS

The study demonstrated that daily administration of EEOb is able to reduce the growth of EET by induce apoptosis of tumoral cells.

Quantitative analysis of argyrophilic nuclear organizer regions in giant cell lesions of jaws

BACKGROUND

Giant cell lesions of the jaws are considerably similar according to histopathologic characteristics yet show different clinical behaviors. These lesions include central giant cell granuloma (CGCG), aneurysmal bone cyst, Cherubism, and Brown tumor associated with hyperparathyroidism. The present study aimed to investigate AgNORs count in these lesions as a proliferative marker and to determine whether it can be used to discriminate between them or not.

METHODS

Forty-one cases of giant cell lesions of jaws were retrived from Oral Pathology Department (1987-2007). They included 21 cases of CGCG, eight cases of aneurysmal bone cyst (ABC), six cases of Cherubism, six cases of Brown tumor. The mean AgNORs count was calculated for all cases. To compare mean AgNORs in groups of lesions, ANOVA test was performed.

RESULTS

Mean AgNOR counts were: (0/85 +/- 0/29) in CGCG, (0/76 +/- 0/32) in ABC (0/87 +/- 0/10) in Cherubism and (0/82 +/- 0/16) in Brown tumor. A significant difference was not observed in AgNOR counts among these groups of lesions.

CONCLUSIONS

Jaws giant cell containing lesions have no acceptable differences in mean AgNORs.

PCNA/AgNOR and Ki-67/AgNOR double staining in oral squamous cell carcinoma

This study was performed on oral squamous cell carcinomas (OSCC) in order to investigate the relation between the number of interphase silver-stained nucleolar organizer regions (AgNORs) and the immunolabeling of proliferation-associated markers, using antibodies to Ki-67 and proliferating cell nuclear antigen (PCNA). Fifteen consecutive cases of oral squamous cell carcinoma were used and a double staining technique was performed in order to quantify the number of NORs in PCNA-positive and -negative cells as well as in Ki-67-positive and -negative cells. Our results showed a higher mean number of AgNORs in PCNA- and Ki-67-positive cells than in PCNA- and Ki-67-negative cells. We concluded that there is an association between cell proliferation and AgNOR score in OSCC.

Evaluation of argyrophilic nucleolar organizer regions in tongue squamous cell carcinomas

Using a silver staining technique, argyrophilic nucleolar organizer regions (AgNORs) were studied on the biopsy specimens taken from 67 tongue squamous cell carcinomas (SCCs), and the relations of the results of AgNORs to the clinicopathological findings, to the labelling indices of proliferating cell nuclear antigen (PCNA LI), and to the outcomes of the disease were investigated. The mean numbers of AgNORs per cell were 1.67 +/- 0.19 (n = 27) in the control squamous epithelia and 3.58 +/- 1.15 (n = 67) in the tongue SCCs, respectively, and a significant difference was found between the two groups (P < 0.0001). Concerning the clinicopathological findings, the mean numbers of AgNORs in the progressive cases (T3, T4), in the factor N-positive groups (N1, N2), and in the advanced stages (stages III, IV) were statistically higher than those in T1, T2, N0, and earlier stage (stages I, II) tumours, respectively. Similarly, a higher value of the AgNOR count was present in the histological grade III or diffuse invasive tumour. There was also a directly significant correlation between the AgNOR counts and the labelling indices of PCNA (r = 0.53, P < 0.0001). Concerning the outcome of the disease, the mean numbers of AgNORs were higher in the group with local recurrence or with lymph-node metastasis. A lower rate of 5 years' survival was found in the high value group (63.5%) of AgNORs compared with that of the low value group (86.0%), with a significant difference between the two groups (P < 0.05). The results suggest that AgNORs may reflect the degree of malignancy and cellular proliferation in tongue SCCs.

Argyrophilic nucleolar organizer regions (AgNORs) in ameloblastomas and adenomatoid odontogenic tumours (AOTs)

Twenty-two cases of ameloblastoma and ten cases of adenomatoid odontogenic tumour (AOT) were analyzed comparatively by the AgNOR technique. Ameloblastomas were distributed into three groups according to their clinical behaviour: primary lesions without recurrences (PLWTR), 5 cases; primary lesions with recurrences (PLWR), 4 cases; and recurrences, 13 cases. The cases were also regrouped according to their histological pattern: follicular (9 cases), plexiform (7 cases), acanthomatous (4 cases) and unicystic (2 cases). Considering histological patterns, there was a significant statistical difference only between follicular and plexiform types. There were no significant differences between the group of ameloblastomas and the group of AOTs or between the three groups of ameloblastomas with different clinical behaviour. Our results strongly suggest that the distinct clinical behaviour of ameloblastomas and AOT is not correlated with their cellular proliferation ratio. Thus, the infiltrative ability of the ameloblastomas is probably not related to the cellular proliferation index of these tumours.

Standardized AgNOR analysis of the invasive tumour front in oral squamous cell carcinomas

In the last decade, silver staining of nucleolar organizer region-associated proteins (AgNORs) has been widely used in tumour pathology both for diagnostic and for prognostic purposes. However, a reliable and reproducible assessment of these proteins on routinely processed archival tissues has only become possible since the recent introduction of standardized staining method and computer-aided morphometric analysis. In the present study, the AgNOR content at the invasive front of 80 squamous cell carcinomas of the floor of the mouth/tongue was investigated using this novel approach, with regard to prognosis and a variety of clinico-pathological parameters. All standardized AgNOR parameters [mean of AgNOR number, mean of AgNOR area, coefficients of variation (CV) of both AgNOR number and area] were statistically significantly associated with the clinical course. The strongest correlation was found for the AgNOR-area univariate analysis (P = 0.006). In multivariate analysis, the mean of AgNOR number could independently predict both overall (P = 0.01) and disease-free survival (P = 0.001). It is concluded that standardized staining and computer-aided analysis of AgNORs are prerequisites for an objective and reproducible AgNOR assessment, which has potential as a supplementary diagnostic and prognostic tool in oral cancer.

Evaluation of argyrophilic nucleolar organizer regions (AgNORs) in oral carcinomas in relation to human papillomavirus infection and cytokinetics

The numbers of argyrophilic nucleolar organizer regions (AgNORs) were quantified in oral carcinomas (n = 39) with or without human papillomavirus (HPV) infection. The AgNOR counts of the HPV-positive samples (7.15 +/- 2.13) were not significantly (P = 0.09) higher than those of the HPV-negative ones (6.16 +/- 1.89). Furthermore, the lesions infected with multiple HPV types had greater counts than those with HPV type 16/18 infection alone. Significant differences were observed between the mean counts of the poorly (10.50 +/- 0.54), moderately (7.31 +/- 1.07) and well- (5.12 +/- 0.85) differentiated carcinomas. The mean AgNOR numbers in the oral carcinomas at TNM stages III/IV were found to be significantly (P < 0.01) higher than the numbers in corresponding stage II lesions. Cytokinetics of the lesions assessed by the bromodeoxyuridine (Brdu) labelling index (LI%) showed a linear correlation (r = 0.91; P < 0.0001) with their respective mean AgNOR counts.

Lectin histochemistry of oral premalignant and malignant lesions: correlation of JFL and PNA binding pattern with tumour progression

The expression of glycoconjugates specific to Jack fruit lectin (JFL) and peanut agglutinin (PNA) in various clinicopathological stages of tumour progression in the oral mucosa were studied. These included various clinical forms of dysplastic and non-dysplastic oral leucoplakias, carcinomas, normal keratinising (gingiva) and non-keratinising (buccal mucosa) epithelia. It was seen that the binding patterns of PNA and JFL in the epithelial cells of various types of oral lesions were more or less similar. Normal non-keratinising epithelium showed mild membrane staining only in the spinal layers, while normal keratinising epithelium showed a moderate membrane staining and mild cytoplasmic staining in all layers. Moderate membrane and mild cytoplasmic staining were observed in leucoplakias, irrespective of various clinical or histological types. In carcinomas, the intensity of lectin binding was high, particularly in the membrane of differentiated cells. Correlation analysis of the binding pattern of PNA and JFL showed significant correlation in the membrane and cytoplasm of all layers with histological stages of tumour progression. The present study thus showed that PNA and JFL may be used as cytochemical probes in differentiating malignancy from benign lesions of the oral mucosa.