Spectroscopic and microscopic comparisons of cell topology and chemistry analysis of mouse embryonic stem cell, somatic cell and cancer cell.

While embryonic stem cells and cancer cells are known to have many similarities in signalling pathways, healthy somatic cells are known to be different in many ways. Characterization of embryonic stem cell is crucial for cancer development and cancer recurrence due to the shared signalling pathways and life course with cancer initiator and cancer stem cells. Since embryonic stem cells are the sources of the somatic and cancer cells, it is necessary to reveal the relevance between them. The past decade has seen the importance of interdisciplinary studies and it is obvious that the reflection of the physical/chemical phenomena occurring on the cell biology has attracted much more attention. For this reason, the aim of this study is to elementally and topologically characterize the mouse embryonic stem cells, mouse lung squamous cancer cells, and mouse skin fibroblast cells by using Atomic Force Microscopy (AFM), X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM) supported with Electron Dispersive Spectroscopy (EDS) techniques in a complementary way. Our AFM findings revealed that roughness data of the mouse embryonic stem cells and cancer cells were similar and somatic cells were found to be statistically different from these two cell types. However, based on both XPS and SEM-EDS results, surface elemental ratios vary in mouse embryonic stem cells, cancer cells and somatic cells. Our results showed that these complementary spectroscopic and microscopic techniques used in this work are very effective in cancer and stem cell characterization and have the potential to gather more detailed information on relevant biological samples.

Zinc oxide nanoparticles induce photocatalytic cell death in human head and neck squamous cell carcinoma cell lines in vitro.

The aim of this study was to determine the photocatalytic effects of zinc oxide (ZnO) NPs in combination with UVA-1 in human head and neck squamous cell carcinoma (HNSCC) cell lines in vitro. NP characteristics and intracellular distribution were described by transmission electron microscopy (TEM). After pre-incubation with ZnO NPs in concentrations of 0.002-20 µg/ml, the HNSCC cell lines HLaC 78 and UD-SCC 7A as well as primary oral mucosa cells (pOMCs) were treated with UVA-1. Cell survival and vitality was observed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazoliumbromide-(MTT)-assay and fluorescein diacetate test. Apoptosis was assessed by annexin-V propidium iodide flow cytometry. Intranuclear distribution of the rod-shaped particles was observed in 3.5% of HNSCC and in 0.5% of pOMCs. UVA-1 irradiation of 15 min in combination with 0.2 and 2 µg/ml of ZnO NP dispersion was shown to reduce the vitality of cancer cell lines significantly in comparison to cells without NP exposure or UVA-1 treatment only. For HLaC 78, a significant reduction in viable cells was already seen at 10 min of UVA-1 treatment and a ZnO NP concentration of 2 µg/ml. Flow cytometry indicated that cell death occurred primarily through necrosis. In pOMCs, vitality was not influenced either by UVA-1 treatment or ZnO NP exposure up to 2 µg/ml or a combination of both. ZnO NPs showed cytotoxicity at 20 µg/ml without UVA-1. Due to their photocatalytic properties, ZnO NPs may induce cell death in human HNSCC cell lines in vitro. Further studies will evaluate a possible benefit in adjuvant cancer therapy.

Spatial allelic imbalance of BCL2 genes and chromosome 18 territories in nonneoplastic and neoplastic cervical squamous epithelium.

Several studies suggest a correlation between genome architecture and gene function. To elucidate mechanisms of gene positioning during cell differentiation and malignant transformation we investigated the nuclear positions of the BCL2 alleles and chromosome 18 territories in different layers of nonneoplastic cervical squamous epithelium and cervical squamous carcinomas in relation to gene expression. Fluorescence in situ hybridization and three-dimensional (3D) image analysis using tissue sections revealed that one BCL2 allele was located more peripherally than the other one in nuclei of the basal layer of nonneoplastic epithelium. During terminal cell differentiation the outer BCL2 allele showed a shift towards the nuclear center. In BCL2-expressing carcinomas the inner BCL2 allele was located more peripherally compared with the basal layer of nonneoplastic epithelium. Our results suggest a functional relevance of unequal allelic BCL2 gene positioning and support the hypothesis that transcriptional BCL2 activation is associated with BCL2 relocation towards the nuclear periphery.

ASCUS, mature metaplastic type. Cytologic diagnosis and follow-up.

OBJECTIVE: To study the cytologic criteria for follow-up of mature metaplastic cells within the atypical squamous cells of undetermined significance (ASCUS) category. STUDY DESIGN: Squamous epithelial abnormalities between January 1994 and June 1997 at our institution totaled 2,632 and included squamous carcinoma (1), high grade squamous intraepithelial lesions (278), low grade squamous intraepithelial lesions (875) and ASCUS (1,478). From the ASCUS group, 134 (9.06%) were metaplastic; 89 were selected for review. Criteria for case selection were follow-up with tissue biopsy or at least two Pap smears and no previous epithelial abnormality. Patients ranged from 27 to 70 years of age. Parameters tabulated included number of abnormal cells per slide, their architecture, cell size, shape, cytoplasmic hue and texture, nuclear size and contour, chromatin pattern and nucleoli. Additionally, specimens were reviewed for hormonal status and inflammation. The findings were correlated with follow-up data. RESULTS: Cells generally appeared single or in loose, monolayered sheets of three to seven cells per group. The cells were well demarcated, polygonal or oval and ranged from 11 to 30 microns with cyanophilic or eosinophilic thickened cytoplasm. The round to oval nuclei with slight irregularity showed a minimally increased nuclear/cytoplasmic ratio with stippled chromatin. Upon review, 69 smears were confirmed as ASCUS-M. Follow-up revealed 42 with benign findings, 9 with persistent ASCUS/ASCUS-M and 18 with low grade squamous intraepithelial lesions. CONCLUSION: In mature metaplastic cells with minimal atypia in patients with no previous or concurrent dysplasia, the follow-up details were similar to those described for ASCUS-superficial/immediate squamous cells. These patients could be followed conservatively.