Nuclear co-expression of p21 and p27 induced effective cell-cycle arrest in T24 cells treated with BCG.

A proposed mechanism underlying the effect of bacillus Calmette-Guérin (BCG) treatment for bladder cancer cells is as follows: BCG-induced crosslinking of cell-surface receptors results in the activation of signaling cascades, including cell-cycle regulators. However, the clinical significance of cell-cycle regulators such as p21 and p27 is controversial. Here we investigated the relationship between BCG exposure and p21 and p27. We used confocal laser microscopy to examine the expression levels of pKi67, p21 and p27 in T24 cells (derived from human urothelial carcinoma) exposed six times to BCG. We performed dual immunofluorescence staining methods for p21 and p27 and observed the localization of nuclear and cytoplasm expressions. We investigated the priority of p27 over p21 regarding nuclear expression by using p27 Stealth RNAi™ (p27-siRNA). With 2-h BCG exposure, the nuclear-expression level of p21 and p27 was highest, while pKi67 was lowest. The percentage of double nuclear-expression of p21 and p27 in BCG cells was significantly higher than that in control cells during the 1st to 6th exposure (P < 0.05), and the expression of pKi67 showed the opposite of this pattern. Approximately 10% of the nuclear p21 was independent of p27, whereas the cytoplasmic p21 was dependent on p27. Our results suggested that the nuclear co-expression of p21 and p27 caused effective cell-cycle arrest, and thus the evaluation of the nuclear co-expression of p21 and p27 might help determine the effectiveness of BCG treatment.

Serum starvation induces abnormal spindle location, RhoA delocalization, and extension of intercellular bridge with the midbody.

Serum starvation induces binucleation in HeLa cells, but the effects of serum starvation on mitosis and the significance of binucleation remain unknown. We investigated the effect of serum starvation on mitosis and analyzed the growth of binucleated cells. The frequency of binucleation caused by cytokinesis failure in DMEM without FBS (0% medium) was higher than that in DMEM with FBS (10% medium). In 0% medium, the metaphase spindle location was off-center, and RhoA localization significantly lacked symmetry. The frequency of the extension of intercellular bridge with the midbody in 0% medium was significantly higher than that in 10% medium. Moreover, all mononucleated mitotic cells caused bipolar mitosis and produced only mononucleated daughter cells, but binucleated cells produced various nucleated cells by multipolar mitosis in 0% medium. These results suggest that serum starvation may have various effects on mitosis, and binucleated cells may be related to formation of aneuploidy.

Diagnostic value of squamous cell change associated with endometrial carcinoma: A cytopathologic approach.

BACKGROUND: To determine the frequency of squamous cell change associated with endometrial carcinoma, to evaluate the relationship between squamous cell change and clinicopathological features, and to assess cytological findings for squamous cells with and without nuclear atypia in endometrial smears. METHODS: In 103 cases of endometrioid adenocarcinoma of the endometrium having both histological and cytological specimens, the frequencies and relationships between the presence and absence of squamous cell changes were evaluated, as were the clinicopathological features of such changes. In endometrial smears, squamous cells with and without nuclear atypia were clinicopathologically assessed. RESULTS: Squamous cell changes were found in 58.3% of cases that had both histological and cytological preparations. There were no significant differences between the group with squamous cell changes and the group without in any of the clinicopathological features. In the cytological smears, 70.0% of the 60 cases that showed squamous cell changes in both preparations did not have nuclear atypia of squamous cells, while 30.0% of those cases had atypia. The group of cases with squamous cells without atypia tended to be better differentiated than the group with atypia. Vessels were permeated significantly more often in the group with atypia than in the group without. CONCLUSIONS: Our data suggest the importance of observing squamous cells in endometrial cytology, especially concerning findings on nuclei with vs without atypia, when endometrial carcinoma is suspected.

Binucleated HeLa cells are formed by cytokinesis failure in starvation and keep the potential of proliferation.

Many cytological studies have reported that the numbers of binucleated cells were elevated in various tumors. However, binucleated cells are observed in not only malignant tumors but also normal tissues. Thus, the clinical significance of binucleated cells is controversial. Here we attempted to elucidate the characteristics of binucleated HeLa cells using time-lapse microscopy. To examine the frequency, viability, proliferation, and formation mechanism of binucleated cells, we grew HeLa cells on chamber slides and tissue culture dishes in DMEM supplemented with (10, 3, 1 and 0.5 % media) and without fetal bovine serum (0 % medium). The proliferation was evaluated by the medium improvement examination (cultured for 2 more days in 10% medium after culturing in 0% medium; starvation). In the 0 % medium, 150 binucleated cells were formed by cytokinesis failure. There were significantly more binucleated cells in the 0 % medium than in the 10, 3, 1 and 0.5 % media. About twice the number of binucleated cells underwent mitosis in the improvement examinations than in the serum-free examination. We found here that starvation induced the binucleation of HeLa cells and that some binucleated cells can reproduce. These findings might be helpful for understanding binucleated cells in tumors.

Identification of intranuclear inclusions is useful for the cytological diagnosis of ovarian clear cell carcinoma.

OBJECTIVE: The aim of this study was to clarify the diagnostic significance of the presence of intranuclear inclusions in clear cell carcinoma (CCC). MATERIALS AND METHODS: We analyzed 98 imprint specimens and 53 ascites specimens from 98 ovarian carcinoma cases [28 CCCs, 37 serous carcinomas (SCs), 22 endometrioid carcinomas (ECs), and 11 mucinous carcinomas (MCs)]. We examined (1) frequency of intranuclear inclusion-positive cases of each ovarian carcinoma subtype, using imprint specimens, (2) frequency of intranuclear inclusion-positive cells of each ovarian carcinoma subtype, using imprint specimens, (3) frequency of intranuclear inclusion-positive cases of each ovarian carcinoma subtype, using ascites specimens, and (4) sensitivity and specificity of the presence of intranuclear inclusions for the cytological diagnosis of CCC. RESULTS: (1) The frequency of intranuclear inclusion-positive cases in CCC (96.4%) was significantly higher than in SC (13.5%), EC (13.6%), and MC (18.2%) (P < 0.001). Two or more intranuclear inclusions in a single nucleus were observed only in CCC. (2) The frequency of intranuclear inclusion-positive cells in CCC (median, 0.41%) was significantly higher than in non-CCC subtypes (0.010%) (P < 0.001). (3) Using ascites specimens, the frequency of intranuclear inclusion-positive cases in CCC (78.6%) was significantly higher than in SC (10.3%), EC (0%), and MC (0%) (P < 0.001). (4) The sensitivity of intranuclear inclusions was 96.4%, and the specificity was 85.7%. CONCLUSIONS: The identification of intranuclear inclusions, in particular a high frequency and multiple intranuclear inclusions in a single nucleus, is useful for the cytological diagnosis of CCC. Furthermore, these results may be applicable to ascites cytology.

Quantitative image analysis of nuclear chromatin distribution for cytological diagnosis.

OBJECTIVE: We previously reported on the classification of the nuclear chromatin distribution into 3 types, that is peripheral (P), mixed (M) and central (C), which were related to the malignancy of cervical glandular lesions. However, the classification was subjective as it was performed by visual assessment. In the present study, quantitative assessment of nuclear chromatin distribution using image analysis by computer was applied for objective classification of cervical squamous epithelial lesions, which are the most common cervical lesions. STUDY DESIGN: A total of 130 cells (44 cells of type P, 78 of type M and 8 of type C) from cytological specimens of cervical squamous epithelial lesions (dysplasia, squamous cell carcinoma) were analyzed. An image analysis program was developed as a plug-in macro program of an existing image processing software. The radial distribution (RD) value, which represents the gradient of the staining intensity from the center to the edge of a nucleus, was defined as an index of the chromatin distribution. RESULTS: The RD values calculated in type P, type M and type C cells showed significant statistical differences as assessed by the t test (p < 0.001). CONCLUSIONS: Quantification of the nuclear chromatin distribution by image analysis is fast and highly objective. The RD value could be useful as an index for malignancy.