Nuclear Organizer Regions Research Articles

Farnesol alleviates diethyl nitrosamine induced inflammation and protects experimental rat hepatocellular carcinoma.

Hepatocellular carcinoma is a well-known internal malignancy with increased worldwide mortality. The increased progression rate is closely associated with chronic liver diseases such as cirrhosis. Chemical carcinogens cause tumor advocacy over free radical metabolites to causes numerous biochemical and molecular changes that bring oxidative stress. In addition, inflammatory cells and its growth factor promotes the progression of liver cancer through deregulates the numerous cellular signaling pathways involved in normal cellular proliferation. Plant derived phytochemicals have a better complimentary potency to defend against a wide array of free radical mediated diseases such as cancer. More recently, we have evaluated the anticancer effect of Farnesol against DEN induced hepatocellular carcinoma in male wistar albino rats. However, the possible mechanism in which Farnesol attributes its anticancer effect against DEN induced liver cancer remains unknown. Hence in the present study, an attempt has been made to reduce the oxidative stress by appraise the antioxidant effect by Farnesol in DEN induced hepatocellular carcinoma. Elevated oxidative stress markers with concomitant decreased cellular antioxidants levels were observed in DEN induced hepatic tissues. Further, proliferating nuclei with increased proliferating cell nucleolar antigen (PCNA) and inflammatory mediator expression were observed in DEN induced rats. Oral supplementation of Farnesol to DEN induced rats significantly decrease the oxidative stress markers and increase the cellular antioxidant status. Moreover, Farnesol treatment decreases the argyrophilic nuclear organizer region and PCNA along with decreased expression of inflammatory mediators suggest that Farnesol treatment restores DEN induced hepatic abnormalities and protects liver from cancer progression.

Proliferative activity of various grades and types of breast carcinoma using AgNOR (Argyrophilic Nuclear Organizer Region) expression and its prognostic significance

A communal disease of the breast is breast cancer which happens mainly in women. Breast cancer is the most common cancer in women in both the developed and less developed world. The potential biological aggressiveness and behavior of breast neoplasm are of prognostic significance in tumor pathology and this can be assessed by measuring the tumor proliferative activity and malignant transformation. One of such markers is AgNOR (Argyrophilic Nuclear Organizer Region). A search of database sites such as PUBMED, Google Scholar, and Web of Science, as well as, other sources of literature available across public libraries was conducted to obtain information related to the topic. This review has presented a critical discussion on histologically assessing the proliferative activity of various grades and types of breast carcinoma using AgNOR expression and its prognostic significance. This exposé is anticipated to enlighten research scientists on specific management and assessing targets of tumors, which may merit prospective research into developing an appropriate mechanism for assessing the proliferative activity of breast cancer to help solve medical issues relating to cancers.

Argyrophilic Nuclear Organizer Regions (AgNORs) staining to identify premalignant and malignant of the prostate lesions

Introduction:There are no standard criteria defining how prominent or how frequent the nucleoli must be before they are sufficient to warrant a diagnosis of high-grade PIN. Histopathology remains as the gold standard for diagnosis of these putative precursor lesions of prostatic carcinoma. Identification of these lesions of prostate helps in early detection of carcinoma and guides the urologist to give an appropriate management to the patient. Methods: This is diagnostic test study with cross sectional design. It was conducted at Anatomical Pathology Department in Universitas Sumatera Utara, Medan, Indonesia. There were total 55 cases taken for this study. AgNORs staining was evaluated in all cases. Results: There is a significance difference between premalignant and malignant lesions that were stained by AgNORs (p value <0,001). The AgNORs value of malignant lesions is higher than premalignant lesions. Conclusion: Histochemical AgNORs staining can help in confound and hesitate cases to distinguish premalignant and malignant of the prostate lesions.

Effect of MGHPPGP Peptide Administered during the Post-Traumatic Period on Morphometric Parameters of the Neocortex and Hippocampus, Hepatocytes, and Epithelium of the Tongue and Small Intestine in Rats.

The effect of glyproline-containing peptide MGHPPGP (Met-Glu-His-Phe-Pro-Gly-Pro) was studied in experiments on male Wistar rats with modeled traumatic brain injury. The peptide was administered intraperitoneally in a dose of 1 mg/kg in 3 h and on days 2, 3, 4, 5 after injury. We evaluated morphometric parameters of the epithelial cells of the tongue, small intestine, and liver cells (AgNOR staining), neuronal layers II and V of the neocortex of the parietal lobe and hippocampal CA1 field (staining with gallocyanin) were evaluated in the post-traumatic period. Traumatic brain injury (TBI) was induced in rats by using the impact model (WDM; weight drop method). MGHPPGP peptide corrected the activity indicators of the nuclear organizer regions in epitheliocytes of the tongue.

Assessment of proliferative index in different grades of breast cancers using AgNOR (Agyrophilic Nuclear Organizer Region) expression

Nucleolar organiser regions (NORs) are loops of DNA which are responsible for ribosomal RNA (rRNA) transcription in the nucleus of cells. NORs can be selectively stained by silver methods. The NORs agyrophilia is due to a group of nucleolar proteins, which have affinity for silver (Agyrophilic Nucleolar Organizer Regions, AgNOR proteins). The aim of the present study is to assess proliferative index in different grades of invasive ductal carcinoma (IDC) by using AgNOR as a marker. A total of 18 formalin fixed paraffin-embedded breast tissue blocks were retrieved from the archives of the histopathology department of the Komfo Anokye Teaching Hospital, Ghana. The tissue blocks included 17 IDC, (with 8 as grade 2 IDC, 9 as grade 3 IDC) and 1 normal breast tissues. Tissue sections were diagnosed and graded following haematoxylin and eosin (H&E) staining. Silver staining was used to demonstrate the presence of AgNOR. The AgNOR dots were manually counted in 50 and 100 cells. The mean AgNOR count (mAgNOR) and proliferative index, (pAgNOR, percentage of cells with ≥5 AgNOR dots per nucleus), significantly increased with increasing grade of IDC. The mAgNOR and pAgNOR were low in normal breast, (at p-value less than 0.05). There was no significant difference in the mAgNOR and pAgNOR score for counting 50 and 100 cells (at a p-value of 0.01). mAgNOR and pAgOR increases with increase in grade of IDC and hence can be used to assess proliferative index of IDC.

Genistein regulates tumor microenvironment and exhibits anticancer effect in dimethyl hydrazine-induced experimental colon carcinogenesis.

Colon cancer is one of the leading causes of cancer mortality, worldwide. Cancer stem cells are attractive targets for therapeutic interventions since their abnormal growth may trigger tumor initiation, progression, and recurrence. Colon cancer in rats were induced with 1, 2-dimethyl hydrazine (DMH) and treated with genistein, an isoflavone rich in the soy food products, which also possesses various biological activities. Genistein treatment regulates enzymatic and non-enzymatic anti-oxidants in the DMH-induced colonic tissue microenvironment. Alcian blue staining in colonic tissue reveals that mucin secretion was found to be depleted in DMH-induced group of animals. The alterations were normalized in the genistein-treated groups. Also, the mast cell population and collagen deposition were reduced as compared to induced group. Genistein treatment reduces the prognostic marker Argyrophilic nuclear organizer region (AgNOR) and proliferating cell nucleolar antigen (PCNA) in DMH-induced group of rats. DMH administration induces oxidative stress, whereas genistein activates nuclear factor-erythroid 2 related factor 2 (Nrf-2) and its downstream target hemoxygenase-1 (HO-1). Colonic stem cell marker protein CD133, CD44, and β-catenin expressions were found to be increased in DMH-induced group of animals as compared to control group of rats. Genistein treatment suppressed the expression of these stem cell markers suggesting rapid dysfunctional activation and proliferation of colonic stem cell-induced by DMH. The results of this study indicate that genistein administration in rats restored the colonic niche that was damaged by DMH and inhibits colon cancer progression. © 2016 BioFactors, 42(6):623-637, 2016.

MODELLING OF SURVIVAL OF PATIENTS WITH COLON ADENOCARCINOMA BASED ON MULTIVARIABLE ANALYSIS OF THE STATE OF CANCER CELL NUCLEAR APPARATUS

The creation of a mathematical model of survival in patients with colon adenocarcinoma based on multivariable analysis of the state of cancer cell nuclear apparatus. The study was performed on 141 samples of biopsy materials or material obtained during surgical treatment of the patients with colon adenocarcinoma or benign colon neoplasms with the use of histological, morphometric, densitometric, immunohistochemical and mathematical methods. It has been shown that each discrete pattern of the state of adenocarcinoma cell nuclei (quantity of DNA, the number and volume of nuclear organizer regions, expression rates of Ki-67, Bcl-2 and p53) is prognostically invalid in the case of its separate use. Combination of these characteristics significantly enhances prognostic validity of the survival model. Based on equation of Cox proportional hazards, survival model of good quality for the patients with moderately and poorly differentiated adenocarcinoma and increased average DNA content in tumor cell nuclei has been created. The proposed survival model for colon adenocarcinoma demonstrates the quality twice superior to the model based on the use of tumor grade only (G) which in fact is presently used as a sole common independent histological criterion of prognosis.

Effect of Launaea procumbens extract on oxidative marker, p53, and CYP 2E1: a randomized control study

BackgroundEthyl acetate extracts of Launaea procumbens is used for the treatment of liver dysfunction as an herbal medicine in Pakistan. In this study, the protective effects of ethyl acetate extracts were evaluated against CCl4-induced liver injuries in rat.MethodsTo examine the protective effects against oxidative stress of carbon tetrachloride in rats, 30 male rats were equally divided into 5 groups (6 rats). Among five groups, one was treated with CCl4 (3 ml/kg i.p. in olive oil b.w.) twice a week for 4 weeks. Others were orally fed with extracts (100, 200 mg/kg b.w.), with CCl4 twice a week for 4 weeks.ResultsAdministration of CCl4 altered the serum marker enzymes, lipid profile, CYP 2E1, p53 expression, antioxidant enzymes, nuclear organizer regions (AgNORs), and DNA. Supplement of L. procumbens ameliorated the effects of CCl4, improved CYP 2E1, p53, and increased the activities of antioxidant enzymes while activity of liver marker enzymes (ALP, ALT, AST, g-GT) and contents of lipid per oxidation contents (TBARS), AgNORs, and DNA fragmentation were decreased. Similarly body weight was increased while liver and relative liver weight was decreased with co-administration of various extracts, suggesting that L. procumbens effectively protect liver against the CCl4-induced oxidative damage in rats.ConclusionThe hepatoprotective and free radical scavenging effects might be due to the presence of bioactive constituents in the extract.

Argyrophilic nuclear organizer region and p73 expression in head and neck squamous cell carcinomas: Teammates or adversaries?

Context:Head and neck squamous cell carcinoma (HNSCC) consists of squamous cell carcinomas (SCCs) arising in the upper aerodigestive tract and accounts for 5% of cancers worldwide. In Malaysia, cancers of the nasopharynx, larynx, tongue and oral cavity are among the top twenty most common cancers in men. Argyrophilic nuclear organizer regions (AgNORs) are increased from normal mucosa to premalignant lesions to malignant lesions and have been associated with tumor grade and prognosis of patients. Although p73 is not mutated in human cancers, high levels of p73 expression have been associated with tumor differentiation status and patient prognosis.Aims:To investigate the correlation between AgNORs and p73 immunoexpression.Settings and Design:Fifty-two formalin-fixed, paraffin-embedded HNSCC cases and ten controls were collected from the Hospital.Subjects and Methods:Tissue blocks were sectioned, dewaxed and rehydrated before silver nitrate staining to determine the AgNOR count and immunohistochemical staining to determine the p73 expression. Adopting the scoring system used by Chen et al. for p73 staining, the proportion of positively stained cells in the whole epithelial layer was determined. Staining was considered positive if >10% of epithelial cells were stained.Statistical Analysis Used:Spearman's correlation coefficient was calculated using SPSS 18 software to determine the relationship between the p73 score against tumor differentiation, mean AgNOR counts and tumor grade and between the mean AgNOR count and p73 score.Results:Positive results were found in the immunoexpression of p73. Positive results were seen with the staining of AgNOR; however, in comparison with the entire sample size, a significant correlation between mean AgNOR count and p73 immunohistochemical expression was not obtained.Conclusions:AgNOR count showed a linear and decreasing trend as the p73 score increases. This correlation was statistically insignificant.

The case report on cutaneous myxoma or invasive myxomatosis in Blackfin sea catfish (Arius jella Day, 1877)

The presence of cutaneous myxoma is reported in a Blackfin sea catfish (Arius jella) from Vellar estuary, Parangipettai, southeast coast of India. The gross morphology revealed fleshy with gelatinous distended tumourous growths on both sides of the fish attached to the caudal peduncle region. Tumour overlying the epidermis was ulcerated, hyperemic and hyperchromatic. Histologically, the tumourous growth was characterized by bland spindloid cells embedded in an abundant myxoid extracellular matrix. The tumour masses were present within the dermis and covered with a thin attenuated layer of epidermis. Neoplastic cells were histochemically positive for alcian blue, argyrophilic nuclear organizer regions, Masson’s trichrome, periodic acid-Schiff, and toluidine blue and negative for Oil Red O. On the basis of the histological and histochemical findings, this tumour was diagnosed as cutaneous myxoma or invasive myxomatosis.

Role of cyclin D1 immunoreactivity and AgNOR staining in the evaluation of benign and malignant lesions of the prostate.

Purpose:Prostatic carcinoma is a common and growing public health problem. Histological evaluation is fairly adequate for assessing tumor differentiation, but tumor proliferative activity is difficult to measure. Increasing evidence suggests that the factors controlling cell cycle progression also modulate the rate of ribosome biogenesis. Despite the influence of cyclin D1 and argyrophilic nuclear organizer region (AgNOR) on prostate cancer proliferation, few studies have evaluated the diagnostic importance of these markers. Therefore, the present study was carried out to analyze the diagnostic value of the proliferative markers cyclin D1 and AgNOR in various prostatic lesions and to determine whether any association or relation between these markers and different Gleason grades exists.Methods:A total 50 cases of various prostatic lesions were studied. Tumor grade, AgNOR staining, and cyclin D1 expression were evaluated in all cases. Correlations between the intensity and differential localization of these markers and Gleason grades were evaluated.Results:The mean AgNOR count in cases of prostatic intraepithelial neoplasia was high compared with cases of benign prostatic hyperplasia (BPH) but lower than that of carcinoma cases. The intensity of cyclin D1 expression was high in carcinoma. A total of 14 cases (46.67%) showed strong positivity. No significant correlation was found between the intensity of cyclin D1 expression, AgNOR count, and histologic grades of prostatic carcinoma, whereas a significant correlation was observed between intensity and percentage expression of cyclin D1 in BPH and carcinoma (P<0.01). Nuclear as well as cytoplasmic positivity was seen among various grades of carcinoma.Conclusions:AgNOR count and cyclin D1 may be helpful in distinguishing between BPH and carcinoma of the prostate but may not be used as reliable indicators of the grade of prostatic adenocarcinoma because of overlapping values in various grades. However, further studies on larger samples are required to elucidate the role of these markers in identification of premalignant lesions.

Ribosomal DNA Organization Patterns within the Dinoflagellate Genus Alexandrium as Revealed by FISH: Life Cycle and Evolutionary Implications

Dinoflagellates are a group of protists whose genome differs from that of other eukaryotes in terms of size (contains up to 250pg per haploid cell), base composition, chromosomal organization, and gene expression. But rDNA gene mapping of the active nucleolus in this unusual eukaryotic genome has not been carried out thus far. Here we used FISH in dinoflagellate species belonging to the genus Alexandrium (genome sizes ranging from 21 to 170 pg of DNA per haploid genome) to localize the sequences encoding the 18S, 5.8S, and 28S rRNA genes. The results can be summarized as follows: 1) Each dinoflagellate cell contains only one active nucleolus, with no hybridization signals outside it. However, the rDNA organization varies among species, from repetitive clusters forming discrete nuclear organizer regions (NORs) in some to specialized "ribosomal chromosomes" in other species. The latter chromosomes, never reported before in other eukaryotes, are mainly formed by rDNA genes and appeared in the species with the highest DNA content. 2) Dinoflagellate chromosomes are first characterized by several eukaryotic features, such as structural differentiation (centromere-like constrictions), size differences (dot chromosomes), and SAT (satellite) chromosomes. 3) NOR patterns prove to be useful in discriminating between cryptic species and life cycle stages in protists.

Correlation of mitotic indices, AgNor count, Ki-67 and Bcl-2 with grade and stage in papillary urothelial bladder cancer.

To evaluate the mutual inter-relationship of mitotic indices, argyrophilic nuclear organizer regions (AgNOR) count, Ki-67 and B-cell lymphoma 2 protein (bcl-2) in papillary urothelial bladder cancer (pUBC), and their correlation with grade and stage. To establish the cut-off values of these markers to detect high grade and muscle invasive bladder cancer. Fifty-four patients with primary pUBC who underwent transurethral resection / radical cystectomy were analyzed retrospectively. Cell proliferation was assessed by Ki-67 labelling index, mean AgNOR count, mitotic count, mitotic activity index and mitosis/ volume index. Immunohistochemistry was done to see bcl-2 and Ki-67 expression. Correlation of these indices with tumor grade and stage and amongst themselves was assessed. The receiver operating characteristic (ROC) curves were drawn to establish the cut-off values. We found a strong positive correlation of mitotic indices and Ki-67 with tumor grade (P = .000), stage (P < .05) and bcl-2 (P = .000). AgNOR count correlated positively with the grade (P = .006), mitotic indices and Ki-67 (P = .032) but not with tumor stage and bcl-2. Cytoplasmic bcl-2 immunopositivity was seen in 42.3% of low grade pUBC and 85.7% of high grade pUBC cases (P = .001). bcl-2 positivity was seen in 85% of muscle invasive pUBC as compared to only 52.9% of superficial cases. Ki-67 ≥ 32.5%, ≥ 14 mitoses/10 high power fields (hpf), ≥ 11.20 mitoses/mm2, ≥ 0.75 mitoses/100 tumor cells and AgNOR ≥ 11.55 are 100% specific for high grade bladder carcinoma. Ki-67 ≥ 59% and mitoses ≥ 36.50 per 10 hpf can indicate muscle invasion with 100% specificity. Cut-off values for Ki-67, mitotic indices and AgNOR can confirm high grade bladder carcinoma in equivocal cases. Ki-67 and mitotic count can serve as potential and reliable indicators of muscle invasion.

Physical mapping of 18S and 5S genes in pelagic species of the genera Caranx and Carangoides (Carangidae)

In Carangidae, Caranx is taxonomically controversial because of slight morphological differences among species, as well as because of its relationship with the genus Carangoides. Cytogenetic data has contributed to taxonomic and phylogenetic classification for some groups of fish. In this study, we examined the chromosomes of Caranx latus, Caranx lugubris, and Carangoides bartholomaei using classical methods, including conventional staining, C-banding, silver staining for nuclear organizer regions, base-specific fluorochrome, and 18S and 5S ribosomal sequence mapping using in situ hybridization. These 3 species showed chromosome numbers of 2n = 48, simple nuclear organizer regions (pair 1), and mainly centromeric heterochomatin. However, C. latus (NF = 50) and C. bartholomaei (NF = 50) showed a structurally conserved karyotype compared with C. lugubris (NF = 54), with a larger number of 2-armed chromosomes. The richness of GC-positive heterochromatic segments and sites in 5S rDNA in specific locations compared to the other 2 species reinforce the higher evolutionary dynamism in C. lugubris. Cytogenetic aspects shared between C. latus and C. bartholomaei confirm the remarkable phylogenetic proximity between these genera.

Pericentromeric location of the telomeric DNA sequences on the European grayling chromosomes

The chromosomal characteristics, locations and variations of the C-band positive heterochromatin and telomeric DNA sequences were studied in the European grayling karyotype (Thymallus thymallus, Salmonidae) using conventional C-banding, endonucleases digestion banding, silver nitrate (AgNO3), chromomycin A3 and 4′,6-diamidino-2-phenylindole staining techniques as well as fluorescence in situ hybridization (FISH) and primed in situ labelling. Original data on the chromosomal distribution of segments resistant to AluI restriction endonuclease and identification of the C-banded heterochromatin presented here have been used to characterize the grayling karyotype polymorphism. Structural and length polymorphism of the chromosome 21 showing a conspicuous heterochromatin block adjacent to the centromere seems to be the result of the deletion and inversion. Two pairs of nuclear organizer regions (NOR)-bearing chromosomes were found to be polymorphic in size and displaying several distinct forms. FISH with telomeric peptide nucleic acid probe enabled recognition of the conservative telomeric DNA sequences. The karyotype of the thymallid fish is thought to experienced numerous pericentric inversions and internal telomeric sites (ITSs) observed at the pericentromeric regions of the six European grayling metacentric chromosomes are likely relics of the these rearrangements. None of the ITS sites matched either chromosome 21 or NOR bearing chromosomes.

Standardized karyotype and idiogram of Thai’s native cattle, Bos indicus (Artiodactyla, Bovidae) by convention staining, G-banding, C-banding and NOR-banding techniques

Cytogenetics of Thai’s native cattle ( Bos indicus ) at Rajamangala University of Technology Isan, Surin Campus, was studied. Blood samples were taken from two males and two females. After standard whole blood lymphocyte culture at 37 O C for 72 hours in presence of colchicine, the metaphase spreads were performed on microscopic slide and air-dried. Cytogenetic techniques including conventional staining, G-, C- and NOR-bandings were applied to the chromosomes. The diploid chromosomes number was 2 n =60, the fundamental numbers (NF) were 61 in male and 62 in female. All autosomes were acrocentric with 18 large, 20 medium and 20 small acrocentric chromosomes. The X chromosome was a large submetacentric and the Y was the smallest acrocentric. From G-banding, each chromosome pair appeared with clearly differentiated. C-banding shown C-positive at centromeric region of all chromosomes. NOR-banding staining for nuclear organizer regions (NORs) showed 6 NORs represented at telomeric end of chromosomes. The karyotype formula of Thai’s native cattle was as follows: 2 n (diploid) 60 = L a 18 +M a 20 +S a 20 + sex chromosomes

Raptor, a positive regulatory subunit of mTOR complex 1, is a novel phosphoprotein of the rDNA transcription machinery in nucleoli and chromosomal nucleolus organizer regions (NORs)

Raptor is the key scaffolding protein that recruits mTOR substrates to rapamycin-sensitive mTOR complex 1 (mTORC1), a molecular integrator of mitogenic and nutrient/energy environmental inputs into protein translation and cell growth. Although Raptor phosphorylation on various sites is pivotal in the regulation of mTORC1 activity, it remains to be elucidated whether site-specific phosphorylation differentially distributes Raptor to unique subcellular compartments. When exploring the spatiotemporal cell cycle dynamics of six different phospho (P)-Raptor isoforms (Thr706, Ser722, Ser863, Ser792 and Ser877), a number of remarkable events differentially defined a topological resetting of P-RaptorThr706 on interphasic and mitotic chromosomes. In interphase nuclei, P-RaptorThr706 co-localized with fibrillarin, a component of the nucleolar small nuclear ribonucleoprotein particle, as well as with RNA polymerase I, the enzyme that transcribes nucleolar rRNA. Upon Actinomycin D-induced nucleolar segregation and disaggregation, P-RaptorThr706 was excluded from the nucleolus to accumulate at discrete nucleoplasmic bodies. During mitosis, CDK1 inhibition-induced premature assembly of nucleoli relocated fibrillarin to the surrounding regions of chromosomal-associated P-RaptorThr706, suggesting that a subpopulation of mitotic P-RaptorThr706 remained targeted at chromosomal loops of rDNA or nuclear organizer regions (NORs). At the end of mitosis and cytokinesis, when reassembly of incipient nucleoli begins upon NORs activation of rDNA transcription, fibrillarin spatially reorganized with P-RaptorThr706 to give rise to daughter nucleoli. Treatment with IGF1 exclusively hyperactivated nuclear P-RaptorSer706 and concomitantly promoted Ser2481 autophosphorylation of mTOR, which monitors mTORC1-associated catalytic activity. Nucleolar- and NOR-associated P-RaptorSer706 may physically link mTORC1 signaling to ever-growing nucleolus plurifunctionality including ribosome biogenesis, cell stress sensor and cell cycle/aging control.

Cytogenetic peculiarities of the cervical epithelium in inflammatory diseases

The functional status of epithelial cells in inflammatory diseases of the cervix has been studied with the use of cytogenetic methods of detection of chromosome nucleolar organizers. The highest level of proliferation and rRNA synthesis was detected in cylindrical epithelial cells using indexes of compact and transitional nucleolonemic types of nuclear organizer regions; an elevated level of proliferation and rRNA synthesis was found in the squamous epithelial cells of the intermediate layer, and a low level of proliferation and rRNA synthesis was found in the squamous epithelial cells of the superficial layer.

Quantitative and qualitative analysis of argyrophilic nuclear organizer regions in follicular cyst, keratocystic odontogenic tumor and ameloblastoma

Multicystic ameloblastoma is a benign odontogenic tumor that exhibits a more aggressive behavior than keratocystic odontogenic tumor (KCOT) and follicular cyst. The purpose of the study was to evaluate the proliferation index nuclear organizer regions (NORs) and their distribution among the four odontogenic lesions with known different clinical invasive behavior. In a descriptive-analytical cross-sectional study, 60 paraffin blocks of odontogenic lesions were prepared for silver nitrate staining. For the quantitative analysis, 100 cells were counted at ×100 and the mean value was calculated. The morphometric analysis of NORs showed that they can be distributed into normal (round to oval-shaped) and abnormal (large, bean-shaped and cluster-shaped) groups. One-way analysis of variance (ANOVA) and multiple comparison with Tukey test were used for the statistical analysis of the results. The argyrophilic NOR (AgNOR) numbers in multicystic ameloblastoma, unicystic ameloblastoma, KCOT, and follicular cyst were 7.4 ± 2.7, 6.1 ± 2.56, 4.7 ± 1.84, and 2.82 ± 1.052, respectively. The difference between ameloblastoma (unicystic and multicystic types) and either_KCOT, or follicular cyst was statistically significant (P<0.001) and, (P=0.001), respectively. In follicular cysts, normal AgNOR dots were not detected outside the nuclei. NOR histological patterns of KCOT were large, bean shaped and rarely cluster shaped and it was cluster-shaped in multicystic and unicystic ameloblastoma. The current study suggests that determination of clinical behavior of ameloblastoma in comparison with KCOT and follicular cyst in silver nitrate staining is related to higher proliferation activity and different NORs' distribution pattern. However, further clinical follow-up studies must be performed to prove this.

Role of quantitative nuclear cytomorphometric and NOR dots count in prediction of carcinogenic induced oral cellular proliferative activity

Introduction: To find a better way for predicting the cellular proliferative activity of apparently healthy oral epithelium exposed to certain carcinogens. Methods: The nuclear area (NA) and nucleolar organizer regions (NORs) counts were compared with that of cytological atypia in 100 cases of epithelia exposed to toombak (carcinogen), 100 controls (non­exposed) and two cases of squamous cell carcinoma (SCC), as internal controls. Results: Significant differences in AgNOR (p<0.001) mean count and NA mean values (P<0.001) were identified between cases and controls. Significant differences were also noted in AgNOR mean count and NA mean values between cases and two cases of SCC. Conclusions: AgNOR mean count and NA are useful markers for prediction of cytologically non­evident proliferative activity of oral mucosa exposed to carcinogens.