Immunohistochemical study of DNA topoisomerase I, DNA topoisomerase II alpha, p53, and Ki-67 in oral preneoplastic lesions and oral squamous cell carcinomas

(S)-10-Hydroxycamptothecin Inhibits Esophageal Squamous Cell Carcinoma Growth In Vitro and In Vivo Via Decreasing Topoisomerase I Enzyme Activity

Topoisomerase (TOP) I plays a major role in the process of supercoiled DNA relaxation, thereby facilitating DNA replication and cell cycle progression. The expression and enzymatic activity of TOP I is positively correlated with tumor progression. Although the anticancer activity of (S)-10-Hydroxycamptothecin (HCPT), a TOP I specific inhibitor, has been reported in various cancers, the effect of HCPT on esophageal cancer is yet to be examined. In this study, we investigate the potential of HCPT to inhibit the growth of ESCC cells in vitro and verify its anti-tumor activity in vivo by using a patient-derived xenograft (PDX) tumor model in mice. Our study revealed the overexpression of TOP I in ESCC cells and treatment with HCPT inhibited TOP I enzymatic activity at 24 h and decreased expression at 48 h and 72 h. HCPT also induced DNA damage by increasing the expression of H2A.X^S139. HCPT significantly decreased the proliferation and anchorage-independent growth of ESCC cells (KYSE410, KYSE510, KYSE30, and KYSE450). Mechanistically, HCPT inhibited the G2/M phase cell cycle transition, decreased the expression of cyclin B1, and elevated p21 expression. In addition, HCPT stimulated ESCC cells apoptosis, which was associated with elevated expression of cleaved PARP, cleaved caspase-3, cleaved caspase-7, Bax, Bim, and inhibition of Bcl-2 expression. HCPT dramatically suppressed PDX tumor growth and decreased the expression of Ki-67 and TOP I and increased the level of cleaved caspase-3 and H2A.X^S139 expression. Taken together, our data suggested that HCPT inhibited ESCC growth, arrested cell cycle progression, and induced apoptosis both in vitro and in vivo via decreasing the expression and activity of TOP I enzyme.

Analyte-driven self-assembly of graphene oxide sheets onto hydroxycamptothecin-functionalized upconversion nanoparticles for the determination of type I topoisomerases in cell extracts

Type I topoisomerases (TOPOI), a potential diagnostic biomarker and a target for chemotherapeutic agents, play essential roles in DNA replication, transcription, chromosome segregation, and recombination. It is essential to develop analytical methods for accurate detection of TOPOI in biological fluids for early diagnosis of diseases. Here we show an assay for TOPOI on the basis of the target-induced self-assembly of graphene oxide (GO) sheets onto hydroxycamptothecin-functionalized upconversion nanoparticles (HCPT-UCNPs). The dipole-dipole coupling of HCPT-UCNPs (donor) and GO (acceptor) regulated by TOPOI enables Förster resonance energy transfer between the donor and the acceptor. Integration of minimal autofluorescence and highly specific affinity into the developed nanosensor allows reliable detection of TOPOI in the nanomolar range with the detection limit of 0.29 nM. The detection of TOPOI in breast cancer cells with recoveries from 96.3 to 103.7% shows the availability of the proposed assay in complicated samples. Graphical abstract ᅟ.

Molecular markers in oral lichen planus: A systematic review

Oral lichen planus (OLP) is a chronic inflammatory mucosal disease that is usually detected in 0.5–2.2% of the human population. Among these, only 0.5–2.9% of the lesions progress to carcinoma. However, there are no prognostic markers available presently to recognize the increased risk in malignant transformation of the lesions. Selected markers for cell proliferation, adhesion, apoptosis and lymphocytic infiltration were analyzed by immunohistochemistry in addition to static cytometry for DNA content. The concept linking OLP and oral squamous cell carcinoma states that chronic inflammation results in crucial DNA damage, which further progresses to development of carcinoma. Even though in the past decade, enormous information has been accumulated on malignant potential of OLP, its transformation still remains unclear. Hence, the purpose of this article was to review cellular and molecular markers to understand the pathogenesis of OLP and its progression toward malignancy.

Topoisomerase I expression is associated with prognosis in postoperative non-small cell lung cancer patients

Background

Biomarkers may help to improve non‐small cell lung cancer (NSCLC) prognosis. However, the prognostic effect of topoisomerase I (Topo I) on NSCLC is unknown. We evaluated the clinicopathologic and prognostic significance of tumor Topo I and thymidylate synthase (TS) protein expression in postoperative NSCLC patients.

Methods

One hundred and fifteen patients with postoperative NSCLC were enrolled. Topo I and TS protein were detected in removed tumors by immunohistochemistry. The correlations between Topo I/TS protein expression and clinicopathologic characters and outcomes of patients were analyzed.

Results

Increased expression of Topo I was found in 57 (49.6%) tumors. The largest diameter of the tumor was significantly different between patients with high and low Topo I expression (P = 0.035). TS staining showed that 35 (30.4%) carcinomas were TS positive. The level of TS expression was correlated with tumor differentiation (P = 0.037). Patients with low Topo I expression had significantly longer overall survival (OS) than those with high expression (P = 0.004). The correlation between Topo I expression and OS was demonstrated among patients with squamous cell carcinoma (P = 0.030) and patients in pathological tumor node metastasis stage I (P = 0.027). Topo I expression was positively correlated with TS expression in tumor tissue (R = 0.251, P = 0.007).

Conclusions

Low Topo I expression is an independent favorable prognostic factor for longer OS in postoperative NSCLC patients, especially in squamous cell carcinoma. There is a correlation between the expression of TS and Topo I in removed tumor tissue.

Biomarker-guided repurposing of chemotherapeutic drugs for cancer therapy: a novel strategy in drug development

Cancer is a leading cause of mortality worldwide and matters are only set to worsen as its incidence continues to rise. Traditional approaches to combat cancer include improved prevention, early diagnosis, optimized surgery, development of novel drugs, and honing regimens of existing anti-cancer drugs. Although discovery and development of novel and effective anti-cancer drugs is a major research area, it is well known that oncology drug development is a lengthy process, extremely costly and with high attrition rates. Furthermore, those drugs that do make it through the drug development mill are often quite expensive, laden with severe side-effects and unfortunately, to date, have only demonstrated minimal increases in overall survival. Therefore, a strong interest has emerged to identify approved non-cancer drugs that possess anti-cancer activity, thus shortcutting the development process. This research strategy is commonly known as drug repurposing or drug repositioning and provides a faster path to the clinics. We have developed and implemented a modification of the standard drug repurposing strategy that we review here; rather than investigating target-promiscuous non-cancer drugs for possible anti-cancer activity, we focus on the discovery of novel cancer indications for already approved chemotherapeutic anti-cancer drugs. Clinical implementation of this strategy is normally commenced at clinical phase II trials and includes pre-treated patients. As the response rates to any non-standard chemotherapeutic drug will be relatively low in such a patient cohort it is a pre-requisite that such testing is based on predictive biomarkers. This review describes our strategy of biomarker-guided repurposing of chemotherapeutic drugs for cancer therapy, taking the repurposing of topoisomerase I (Top1) inhibitors and Top1 as a potential predictive biomarker as case in point.

DNA topoisomerase II alpha: a favorable prognostic factor in colorectal caner

PURPOSE

There is a lack of study concerning expression of Topoisomerase IIα (Topo IIα) and long-term results in colorectal cancer patients. We aimed to investigate the relationship between expression of Topo IIα and clinicopathological parameters including overall survival in colorectal cancer.

METHODS

Paraffin-fixed specimens from a large prospective cohort of colorectal cancer patients who had been followed up for 4 years were assayed immunohistochemically.

RESULTS

Of 490 colorectal cancer patients accessible for Topo IIα expression, expression of Topo IIα was scored as (-) in 4 (0.8%) patients, (+) in 41 (8.4%) patients, (++) in 396 (80.8%) patients, and (+++) in 49 (10.0%) patients. Overexpression of Topo IIα was found to be related with lower T stage (p = 0.042), lower N stage (p = 0.038), and a lower incidence of recurrence with nearly significance (p = 0.053). Kaplan-Meier analyses showed that overexpression of Topo IIα was related with prolonged overall survival (p = 0.022) and disease-free survival (p = 0.036). Multivariate analyses showed that elevated serum CEA (p < 0.001), elevated serum CA199 (p = 0.002), poor differentiation (p = 0.001), advanced Dukes stage (p < 0.001), and lower expression of Topo IIα (p = 0.017) were independent predictive factors for poor prognosis.

CONCLUSIONS

Topo IIα expression is a valuable prognostic indicator for colorectal cancer and would be useful in treatment selection for early colorectal cancer and malignant colorectal polyps resected under endoscopy, especially when it is used in combination with serum CEA, CA199, and differentiation.

Abnormal cell-cycle expression of the proteins p27, mdm2 and cathepsin B in oral squamous-cell carcinoma infected with human papillomavirus

Since the role of human papillomavirus (HPV) infection in oral carcinogenesis is still unclear, the purpose of this study was to verify the association between the expression of p27, mdm2 and cathepsin B and by HPV-related oral lesions. Fifty-five oral biopsies were studied and HPV detection and typing (6/11, 16, 18, 31 and 33) were performed using polymerase chain reaction techniques. The distribution p27, mdm2 and cathepsin B was determined by immunohistochemistry. Twenty-one (38%) out of the 55 oral lesions tested positive for HPV, of which 6 (33%) were HPV 6/11, 1 (5%) was HPV 16, 14 (72%) were HPV 18 and none was HPV 33/31. Among the 55 biopsies, immunopositivity for p27, mdm2 and cathepsin B was observed in 17 (30.9%), 37 (67.2%) and 37 (67.2%), respectively. Among 21 HPV-positive oral lesions, immunopositivity of mdm2, p27 and cathepsin B was found, respectively, in 6 (33%) out of 18 benign lesions (BL), 4 (22%) out of 18 potential malignant epithelial lesions (PMEL) and 11 (57.9%) out of 19 malignant lesions (ML). High-risk HPV types may be associated with oral carcinoma, by cell-cycle control dysregulation, contributing to oral carcinogenesis and the overexpression of mdm2, p27 and cathepsin B.

Significance of topoisomerase IIIβ expression in breast ductal carcinomas: strong associations with disease-specific survival and metastasis

Topoisomerases are ubiquitous nuclear enzymes that regulate DNA structure in eukaryotic cells. The role of topoisomerase IIIβ, the newest member of the topoisomerase family, in the clinical outcome of breast cancer is still poorly understood. This study aims to investigate the immunoexpression of topoisomerase IIIβ in breast cancer and its relationships with clinicopathologic features and immunohistochemical markers of prognostic significance in breast pathology. Using tissue microarrays containing 171 cases of primary invasive breast cancer, we analyzed the immunoexpression of topoisomerase IIIβ, estrogen receptor, progesterone receptor, HER-2, BRCA-1, p53, and Ki67. Immunostaining for topoisomerase IIIβ was found in 33.9% of breast carcinomas, and immunopositivity was correlated with distant metastasis (P = .036) and death (P = .006). Decreased expression of topoisomerase IIIβ correlated with low expression of Ki67 (P < .001) and negativity for HER-2 (P < .001), BRCA-1 (P = .001), and p53 (P < .001). In the multivariate analysis, topoisomerase IIIβ expression was a significant predictor of survival (hazard ratio, 3.006 [95% confidence interval, 1.582-5.715]; P = .001). In conclusion, topoisomerase IIIβ expression can be a useful marker in assessing the prognosis of patients with breast cancer and is an independent predictor of survival.

Topoisomerase I and IIalpha protein expression in primary colorectal cancer and recurrences following 5-fluorouracil-based adjuvant chemotherapy

Purpose

Human DNA topoisomerases I and II (topo-I and -II) are essential for vital cellular processes such as DNA replication, transcription, translation, recombination, and repair. In the present study, we correlate topo-I and -II expression and outcome after chemotherapy in primary and relapsed colorectal cancer.

Patients and methods

Patients with colorectal cancer that had recurred, following surgery and adjuvant chemotherapy and underwent a second operation were included in the present study. All had undergone surgical resection of the primary tumor and received post-operatively 5-FU-based (5FU + Leucovorin, Mayo Clinic regimen) adjuvant chemotherapy. Tumor tissue was collected at the initial operation from the primary tumor and at the time of recurrence (during the second operation following chemotherapy). All tissue samples were analyzed for levels of expression of both topo-I and topo-IIa using standard three-step immunohistochemistry on paraffin sections.

Results

Forty patients were included. Levels of expression of topo-I and topo-II were higher in malignant cells from tumor recurrences compared to primary tumors (P = 0.0001 for both). There was a statistically significant positive relationship between patients age and levels of topo-I (P = 0.011) and topo-II (P = 0.011) expression.

Conclusions

The study results reported here underscore the role of topoisomerase expression in colorectal cancer and suggest a potential role in tumor recurrence.

The significance of Epstein Barr virus (EBV) & DNA topoisomerase II alpha (DNA-Topo II alpha) immunoreactivity in normal oral mucosa, oral epithelial dysplasia (OED) and oral squamous cell carcinoma (OSCC)

Background

Head and neck cancer including oral cancer is considered to develop by accumulated genetic alterations and the major pathway is cancerization from lesions such as intraepithelial dysplasia in oral leukoplakia and erythroplakia. The relationship of proliferation markers with the grading of dysplasia is uncertain. The involvement of EBV in oral carcinogenesis is not fully understood.

Aim

The present study was designed to investigate the role of EBV and DNA Topoisomerase II∝ (DNA-Topo II∝) during oral carcinogenesis and to examine the prognostic significance of these protein expressions in OSCCs.

Methods

Using specific antibodies for EBV and DNA-Topo II∝, we examined protein expressions in archival lesion tissues from 16 patients with oral epithelial dysplasia, 22 oral squamous cell carcinoma and 20 normal oral mucosa by immunohistochemistry. Clinical information was obtained through the computerized retrospective database from the tumor registry.

Results

DNA-Topo II∝ was expressed in all examined specimens. Analysis of Variance ANOVA revealed highly significant difference (P < 0.01) in young aged labial tissues and significant (P ≤ 0.05) in gingival and not significant (P > 0.05) in inferior surface of tongue and in hard palatal tissues. Significant differences were observed between OEDs and NSE (P < 0.001) and SCCs and controls (P < 0.001), also, significant differences could be observed between SCCs and OEDs. DNA-Topo II∝ expression was significantly higher in tumors of low differentiation versus tumors of moderate and high differentiation (P < 0.001), DNA-Topo II∝ expression was correlated with age, tumor size, tumor stage, node metastasis and tumor differentiation, but not with gender and tumor site. None of normal squamous epithelium (NSE) expressed EBV. Heterogenous reactivity for EBV was observed through the series of dysplasia and squamous cell carcinoma. Its expression increased progressively with lymph node metastasis and low tumor differentiation, but no significant association could be observed with other clinicopathological parameters. EBV protein expression was increased with elevated Topo II-∝ LI in OEDs and OSCCs. A tendency to positive correlation between EBV and Topo II∝ expression was observed in OEDs but not in OSCCs.

Conclusion

EBV and DNA Topo II-αLI expression are possible indicators in oral carcinogenesis and may be valuable diagnostic and prognostic indices in oral carcinoma.

DNA topoisomerase I and IIalpha expression in penile carcinomas: assessing potential tumour chemosensitivity

OBJECTIVE

To examine the tissue expression of DNA topoisomerase I (Topo I) and IIalpha (Topo II), to pursue the possibility of future chemotherapy regimens for squamous cell carcinoma of the penis (SCCP), as high expression of Topo I might indicate sensitivity to the camptothecins, whereas high Topo II might indicate sensitivity to etoposide.

PATIENTS AND METHODS

In all, 73 patients with SCCP were reviewed and then tissue samples microarrayed. These were then stained with immunohistochemistry for Topo I, Topo II and Ki-67. Tumour stage, grade and type were available.

RESULTS

Topo II showed a strong positive correlation with the proliferation index as measured by Ki-67 (P < 0.001) but no correlation with Topo I. There were also strong correlations between tumour grade and Ki-67, and Topo II expression (both P < 0.001). Tumour type was also strongly correlated with Topo II and Ki-67 expression, with the highest expression in basaloid carcinomas and the lowest in verrucous carcinomas. However, Topo I expression was not correlated with any other tumour variable.

CONCLUSION

The expression of Topo I is grade- and type-independent, and chemotherapy using the camptothecins is unlikely to be effective. The strong positivity of Topo II in high-grade and basaloid SCCPs suggests that treatment with etoposide or other Topo II 'poisons' might be a better target for future clinical trials.

Topoisomerase I protein expression in primary colorectal cancer and recurrences after 5-FU-based adjuvant chemotherapy

PURPOSE

Our aim was to investigate whether chemotherapy with 5-FU induces an alteration in the levels of topoisomerase I (topo I) in colorectal neoplastic tissues

METHODS

Twenty-five colorectal cancer patients were included in our study; these had undergone surgical resection of the primary tumor, received post-operatively 5-FU-based adjuvant chemotherapy and then suffered from recurrences. In a standard three-step immunohistochemical procedure, a monoclonal antibody to topo I was applied in both specimens from each patient (one from the primary location and a second one from the recurrence). Statistical analysis was subsequently performed.

RESULTS

Malignant cells from the recurrences displayed a statistical significant increase, concerning the levels of topoisomerase I, by comparison with the primary tumors (P=0.01). The increase in topo I levels did not demonstrate significant correlations with Duke's stage (Fisher's Exact Test P value=0.496), differentiation grade (P value=0.661), localization (P value=0.072), patient sex (P value=0.434), nor with relapse free interval (P value=0.493). There was a statistically significant relationship between the age of patients and increase in topo I levels (P=0.011).

CONCLUSIONS

Topo I expression may be part of the malignant cells' phenotype in recurrent colorectal carcinomas, suggesting a potential role for Topo I in the acquisition of a metastatic phenotype. The increase of topo I immunohistochemical status is likely to be attributed to 5-FU and given the fact that high levels of topo I correlate with sensitivity to camptothecin, advanced colorectal cancer patients seem to benefit from topo I targeted anticancer drug therapy.

Immunohistochemical study of DNA topoisomerase I, p53, and Ki-67 in uterine carcinosarcomas

Uterine carcinosarcomas (UCs) are highly aggressive neoplasms for which no effective adjuvant therapy has been established. The aim of this study was to test potential indicators of UC sensitivity to topoisomerase I (topo I)-targeted drugs. Laboratory studies have shown that the cellular response to topo I-targeted drugs is dependent on topo I expression, DNA replication rate, and activity of the apoptotic pathway. Therefore, this study investigated expression of topo I, a proliferation marker Ki-67, and the apoptosis initiator p53 in 20 cases of UC. Formalin-fixed paraffin-embedded tissue sections were immunostained with monoclonal antibodies against topo I, Ki-67, and p53. The hospital records of all 20 patients with UC were reviewed. Twelve (60%) of 20 cases showed increased expression of topo I. Staining for Ki-67 showed elevated expression in 15 (75%) of 20 cases. Fourteen cases (70%) showed positive staining for p53 in more than 20% of the tumor cells. However, analysis of the relationship between immunohistochemical results and clinical parameters revealed no correlations with topo I expression. There were no significant correlations between the expression of topo I and Ki-67 (P = .704), or topo I and p53 (P = .465). Significantly increased expression of topo I, Ki-67, and p53 in UC tumor cells suggests sensitivity to topo I-targeted drug treatment.

Expression of human MCM6 and DNA Topo II alpha in craniopharyngiomas and its correlation with recurrence of the tumor

Craniopharyngioma often recurs after resection resulting in poor outcome for the affected patients. The reliable criteria for predicting the tumor behavior are still lacking. It has been suggested that proliferative potential of the tumor cells is necessary for recurrence. Present study evaluated the cell multiplication activity, which is possibly related to relapse in 32 patients with adamantine epithelioma (AE) and 31 patients with squamous papillary tumor (SP). For this tissue specimens from their primary and recurring tumors were collected and immunohistochemical analysis of the expression of minichromosome maintenance protein 6 (MCM6) and DNA topoisomerase II alphalpha (DNA Topo II alpha) in the tumor sections was performed by quantitative microscopy. It was found that the MCM6 label index (LI) was significantly higher in AE than that of SP, and in the primary tumors of both subtypes the LIs of tumors with recurrence were higher than those without recurrence. There was a strong linear positive correlation between MCM6 LI and DNA Topo II alpha LI (r = 0.713; p = 0.000) in the craniopharyngiomas studied. The median MCM6 LI of the total 20 recurrent craniopharyngiomas (31.49%) was not significantly different from that of their primary tumors (29.65%). The long term risk of tumor recurrence is higher in AE than SP and it is associated with MCM6 and DNA Topo II alpha expression.

Immunohistochemical study on topoisomerase IIα, Ki-67 and cytokeratin-19 in oral lichen planus lesions

Oral lichen planus (OLP) is a chronic muco-cutaneous inflammatory disease defined as a precancerous condition. We determined the expression patterns of proliferation markers topoisomerase IIalpha (topo IIalpha) and Ki-67 and an intermediated filament protein cytokeratin-19 (CK-19) in atrophic OLP. These markers were selected because our recent microarray analysis indicated they might aid in identification of potentially malignant lesions. The expression patterns were correlated with the DNA content of these lesions shown to be useful in detection lesions at risk for malignant transformation of OLP. A series of 81 formalin-fixed, paraffin-embedded biopsies from 70 patients suffering from atrophic OLP were immunostained with monoclonal antibodies against topo IIalpha, Ki-67 and CK-19 using standard methods. Of the 70 patients, there were eight patients who had dysplastic changes in OLP lesions. During the follow-up, altogether five patients got cancer in the OLP area even though no dysplastic changes were present in the preceding lesion. On light microscopy, 500 cells were examined in the basal and parabasal epithelial layers of biopsy samples at 400x magnification. All biopsy samples were topo IIalpha positive and approximately 70% of the counted cells were positive. Strong staining of topo IIalpha was significantly correlated with dysplasia (P = 0.019), basal cell hyperplasia (P = 0.005) and ulceration (P = 0.008) in the samples. Ki-67 was expressed in all samples but only 36% of the cells were positive. CK-19 positivity was found in 29% of the specimens. Histological parameters were not related to either Ki-67 or CK-19. The comparison of the staining patterns with the DNA content of lesions showed that strongly stained cells with topo IIalpha were significantly more frequent in the samples with 2.5cER higher than 15% than in those below 15% (P = 0.013; Mann-Whitney). The percentage of the measured cells is 2.5cER exceeding the 2.5c value on the DNA scale. We earlier showed that this cut-off value of 2.5cER discriminated DNA aneuploidy. To conclude, topo IIalpha is a proliferation and also an apoptotic marker in atrophic OLP lesions and it might have a predictive value in oral lichen planus lesions prone to develop malignancy.

Intracranial hemangiopericytomas: correlation of topoisomerase IIalpha expression with biologic behavior

BACKGROUND

Meningeal hemangiopericytomas are aggressive tumors that have a high rate of recurrence despite gross total resection and radiation therapy. Topoisomerase, a cell proliferation marker, is also a target of certain chemotherapeutic agents, and its nuclear levels are speculated to predict efficacy of targeted therapy. The aim of this study was to correlate the topoisomerase IIalpha proliferation index (TPI) with biologic behavior in intracranial hemangiopericytomas.

METHODS

Clinical, radiological, and management data in 27 patients with intracranial hemangiopericytoma admitted between 1990 and 2003 were reviewed. Immunohistochemistry was performed on all the tumors using a monoclonal antibody to topoisomerase IIalpha, and the proliferation index was calculated. The effect of TPI on outcome was sought.

RESULTS

The male/female ratio was 15:12. The mean age at presentation was 31.33 years. A radical excision of tumor was done in 18, subtotal excision in 2, partial excision in 4, and a biopsy in 3 patients. Tumor recurrence was noted in 15 (55.6%) of the 27 patients (mean follow-up duration, 51.5 months). The time to recurrence ranged from 7 months to 8 years (mean, 49 months). The 5-year recurrence-free survival was 33.8% in patients with a TPI of 5% or greater, and 72% in patients with a TPI of less than 5%. The relative risk of recurrence was 2.9 times greater in patients with a TPI 5% or greater as compared with those a TPI of less than 5%.

CONCLUSION

Our study suggests that cases with a radical excision, radiation therapy, or a TPI index of less than 5% have a longer recurrence-free survival. A TPI of 5% or greater is a reliable predictor of recurrence.

Nano-biocapteurs pour la recherche et les diagnostics des maladies inflammatoires et du cancer

As part of the ongoing search for ways to decrease the mortality of different pathological conditions related to cancer and inflammatory diseases, nanotechnologies currently under evaluation offer potentially attractive tools for innovative methodologies for early diagnosis, new bioimaging techniques and therapeutic strategies. Nano-tools can be employed for various functions, such as the detection of lesions at very early stages of disease development, extremely precise anatomical localization, or evaluation of the efficacy of medications specifically targeted against cells and pathological tissues. We have synthesized homogeneous CdSe/ZnS (core/shell) highly fluorescent nanocrystals (NC) detectable as individual nanoparticules with a routine fluorescent microscope. These NC are at least 10-fold brighter than the best organic fluorophores and at least 1000-fold more stable against photobleaching than AlexaFluor, for example. When conjugated with proteins, DNA or with drugs, NCs may be excited with the light of any wavelength from UV through visible spectral region providing a range of fluorescence colors depending on their diameter. These properties provide excellent perspectives for high through-put multiplexing and long-term tracking of labeled precursors for days or even weeks. We present here NC applications for ultrasensitive detection of p-glycoprotein, cytokeratins, LCA, Ki67, etc. both on the cellular level and in pathological human surgical specimens.

Characteristics of benign lymphoadenosis of oral mucosa

AIM: To investigate the pathological characteristics and carcinogenesis mechanism of benign lymphoadenosis of oral mucosa (BLOM).

METHODS: The expressions of Ki-67, CD34 and apoptosis were evaluated by immunohistochemical SP staining in 64 paraffin-embedded tissue samples. Of them, 9 were from BLOM with dysplasia, 15 from BLOM without dysplasia, 15 from oral squamous cell carcinoma (OSCC), 15 from oral precancerosis, and 10 from normal tissues. Cell proliferation, apoptosis and angiogenesis of tissue samples were also analyzed.

RESULTS: The expression of Ki-67 in BLOM with dysplasia, oral precancerosis and OSCC was significantly higher than in BLOM without dysplasia and normal mucosa. The microvascular density (MVD) in BLOM with and without dysplasia, oral precancerosis, and OSCC was significantly higher than in normal mucosa. Apoptosis in BLOM and oral precancerosis was significantly higher than in OSCC and normal mucosa.

CONCLUSION: Benign lymphoadenosis of oral mucosa has potentialities of cancerization.