Enhanced cell kinetics, p53 accumulation and high p21WAF1 expression in chronic cholecystitis: comparison with background mucosa of gallbladder carcinomas

AIMS: Since neoplasia resulting from chronic inflammation has recently attracted increasing attention, we have investigated surgically removed gallbladders to examine the relationship between chronic cholecystitis and carcinogenesis. METHODS AND RESULTS: The mucosa of 108 cholecystectomy specimens without gallbladder cancer and 54 surgically resected gallbladder carcinomas were classified into three groups according to the degree of lymphocytic infiltration, and assessed immunohistochemically for Ki67, p53, p21WAF1 and apoptosis. In gallbladder mucosa without carcinoma, all four parameters tended to increase with the inflammation score (IS). Significantly positive correlations were revealed between Ki67 and p53, Ki67 and p21WAF1, and p53 and p21WAF1. However, in gallbladder carcinoma cases, values of p53 and p21WAF1 for background mucosa were elevated as compared to the mucosa of cholecystitis with low IS, but there was no correlation between their expression and IS, except for Ki67. CONCLUSIONS: Severe chronic cholecystitis is associated with acceleration of epithelial cell turnover, damaged cells being eliminated by apoptosis. The background mucosa of gallbladder carcinomas showed similar cell proliferative activity (Ki67) to that in cholecystitis, with no parallel changes of p53 and p21WAF1 expression, suggesting the possibility of unknown cofactors causing genomic damage.     

IN SITU ANALYSIS OF TISSUE DYNAMICS AND p53 EXPRESSION IN HUMAN GASTRIC MUCOSA

In situ tissue dynamics were studied in 12 cases of human gastric mucosa, including normal gastric body mucosa and gastric glands with intestinal metaplasia, obtained from gastrectomy specimens of adenocarcinoma. Cell proliferation was determined by Ki67 immunoreactivity. DNA fragmentation was studied in situ by TdT-mediated dUTP-biotin nick end labelling (TUNEL). In addition, p53 expression was examined by both immunohistochemistry and mRNA in situ hybridization. In the oxyntic gastric glands, Ki67 immunoreactivity was observed exclusively in the proliferative zone and TUNEL-positive cells were present predominantly in the surface foveolar epithelium. In the gastric glands with complete intestinal metaplasia, Ki67-positive cells were present in the lower portion of the glands and TUNEL-positive cells in the superficial epithelium. In the gastric glands with incomplete intestinal metaplasia, TUNEL-positive cells were detected in the lower gastric glands adjacent to cells immunoreactive for Ki67; the proportion of these gastric glands with TUNEL-positive cells (40 out of 108 glands) was significantly higher than for oxyntic glands (94 out of 620 glands) or for glands with complete metaplasia (31 out of 254 glands). Relatively strong p53 immunoreactivity and mRNA hybridization were also observed in the proliferative and apoptotic areas of gastric glands with incomplete intestinal metaplasia. These results indicate that incomplete intestinal metaplasia is associated with increased cell turnover and p53 overexpression, possibly in response to various noxious or DNA-damaging stimuli.     

Overexpression of p53 protein and Ki67 proliferative index in hepatocellular carcinoma:

The overexpression of p53 protein and the Ki67 proliferative index was evaluated in 96 hepatocellular carcinomas (HCC), 67 in cirrhotic livers and 29 in non-cirrhotic ones, and in 13 non-carcinomatous lesions, all surgically resected from Italian patients. Overexpression of p53 was detected only in carcinomatous lesions, and was significantly related to the grade of HCC ( P < 0.001). In fact, p53 was observed in 7/7 (100%) cases of grade IV, 13/43 (30.3%) of grade III, and 10/ 46 (21.7%) of grade II. The relationship between p53 and Ki67 scores was determined in serial sections from corresponding areas of both diffuse and patchy immunoreactivity. In the overall population, p53-positive tumors showed a significantly higher Ki67 score (15.9 ± 5.5% vs 9.2 ± 4.3% [ P < 0.001]). This observation was evident in all grades of HCC.     

Functional overexpression of wild‐type p53 correlates with alveolar cell differentiation in the developing human lung

At 15 weeks after conception (a.c.), the human pulmonary acinus is lined by distal low‐columnar and more proximal cuboidal cells that are successive stages in alveolar type II cell differentiation (pseudoglandular period of lung development). From 16 weeks a.c. onward, there are also 'flatter' cells that are intermediate stages in the differentiation of cuboidal type II cells into squamous type I cells (canalicular period). We investigated the role of wild‐type p53 protein and the proliferation marker Ki‐67 in the differentiation of type II and type I cells in these two periods. Serial sections from fetal lungs (n = 30) were immunoincubated with antibodies against p53 and Ki‐67. The presence of prospective type II and type I cells was confirmed using immunohistochemistry for surfactant protein SP‐A as a differentiation marker and light and electron microscopy. The p53 and Ki‐67 positive nuclei were quantified per alveolar cell phenotype (i.e., low‐columnar; cuboidal; flatter). The occurrence of cell apoptosis was studied using propidium iodide (PI) and 4′,6′‐diamino‐2‐phenylindol dihydrochloride (DAPI) staining. The combined increase in p53 expression and decrease in Ki‐67 expression during alveolar epithelial cell differentiation suggests that wild‐type p53 protein plays a role in the differentiation of alveolar type II and type I cells in the human lung, and that this function is mediated through cell cycle arrest. The rare incidence of apoptotic nuclei in alveolar type II cells, together with their absence in alveolar type I cells, supports the view that p53 is involved in the differentiation, rather than the death, of alveolar epithelial cells. Anat Rec 263:25–34, 2001. © 2001 Wiley‐Liss, Inc.     

Missense mutation with/without nonsense mutation of the p53 gene is associated with large cell morphology in human malignant lymphoma

Mutations in p53 gene exons 5-9 were studied in 44 non-Hodgkin's lymphomas (NHL) consisting of 35 B-NHL and 9 T-NHL. Missense mutations were found in two diffuse large B-cell lymphomas (DLBL) and one peripheral T-cell lymphoma (unspecified). Double transversion missense and nonsense mutations were detected in one DLBL and one adult T-cell leukemia/lymphoma. Silent mutations were found in two DLBL. Detailed histomorphological study showed that cases harboring p53 missense mutation with/without nonsense mutation tended to have larger nuclei with much more prominent nucleoli. Cytomorphometric analysis was therefore conducted by measuring the gross area of 100 lymphoma cell nuclei in 44 cases and the results were compared between lymphomas harboring p53 missense mutation with/without nonsense mutation and lymphomas harboring p53 silent mutation or lacking mutation. It was found that the lymphomas harboring p53 missense mutation with/without nonsense mutation had a highly significantly larger nuclear gross area than lymphomas with silent p53 mutation or lacking mutation (two-sample t-test, P < 0.00001; Exact Wilcoxon rank-sum test, P < 0.00001). This result suggests that p53 mutation might induce enlargement of neoplastic cell nuclei by some molecular mechanism.     

Expression of CD44s and CD44v6 in transitional cell carcinomas of the urinary bladder: comparison with tumour grade, proliferative activity and p53 immunoreactivity of tumour cells

Alterations of CD44 glycoproteins have been shown to play an important role in progression of various malignancies, including urothelial cancer. We investigated expression patterns of CD44s and CD44v6 in transitional cell carcinoma (TCC) of the urinary bladder in relation to tumour grade, proliferative activity, and immunoreactivity for p53. The selected markers were detected immunohistochemically in 122 samples of TCC. We found a close relationship between CD44s and CD44v6 expression and tumour grade. The extension of positive staining for CD44s and CD44v6 towards the luminal surface was a predominant feature of differentiated carcinomas (grades 1 and 2), suggesting deranged maturation of cancer cells related to their neoplastic transformation. Heterogeneous expression of CD44s and CD44v6 predominated in poorly differentiated tumours (G3-4). However, areas of squamous differentiation within the high-grade tumours displayed strong immunoreactivity for both CD44s and CD44v6. The proliferative activity and p53 overexpression increased with the dedifferentiation of the tumour. The results of this study are discussed in relation to the significance of CD44 expression in TCC and to the explanation for controversial results reported in previous studies on the relationship between CD44 expression and the biological behaviour of urothelial cells.     

非霍奇金淋巴瘤中McM7、p53和Ki-67的表达

目的 探讨McM7、p53和Ki-67在非霍奇金淋巴瘤（NHL）中表达的意义及相互关系。方法 应用组织芯片和免疫组化S-P法检测McM7、p53和Ki-67在9例反应性增生淋巴结、175例NHL组织中的表达。结果 NHL各组中McM7标记指数（1abelling index,LI）均高于Ki-67 LI;惰性组中McM7 LI和Ki-67 LI低于侵袭性组和高度侵袭性组,差异有显著性（P＜0．05）。NHL中p53表达的阳性率为23．4％,p53在惰性组、侵袭性组及高度侵袭性组之间的表达差异无显著性（P＞0．05）。Ki-67、p53和McM7三者在NHL中的表达呈平行关系（P＜0．01）。结论 McM7是反映细胞增殖的良好指标,作用优于Ki-67,其表达指数与NHL的组织分型、细胞增殖及恶性程度有关。p53基因突变在大多数NHL的发生、发展中可能并不是一个主要的分子事件。     

SOX11 is useful in differentiating cyclin D1‐positive diffuse large B‐cell lymphoma from mantle cell lymphoma

Hsiao S‐C, Cortada I R, Colomo L, Ye H, Liu H, Kuo S‐Y, Lin S‐H, Chang S‐T, Kuo T U, Campo E & Chuang S‐S
(2012) Histopathology  61, 685–693 SOX11 is useful in differentiating cyclin D1‐positive diffuse large B‐cell lymphoma from mantle cell lymphoma Aims: To characterize the frequency and clinicopathological features of cyclin D1‐positive diffuse large B‐cell lymphoma (DLBCL) and the usefulness of SOX11 in the differential diagnosis from mantle cell lymphoma (MCL). Methods and results: We retrospectively stained 206 consecutive DLBCLs for cyclin D1, and identified three (1.5%) positive cases, comprising two in the elderly with necrosis, and a third with a starry‐sky pattern. All three cases shared the same non‐germinal centre B‐cell (non‐GCB) phenotype [CD5?/CD10?/bcl‐6+/MUM1+/SOX11?], Epstein–Barr virus (EBV) negativity, and absence of CCND1 aberrations by fluorescence in‐situ hybridization. The third case showed both BCL6 and MYC rearrangements: a double‐hit lymphoma. In the same period there were 22 MCLs, all expressing cyclin D1, with 89% cases expressing SOX11, a frequency that is statistically different from cyclin D1‐positive DLBCL. Notably, we identified a pleomorphic MCL initially misdiagnosed as DLBCL. A separate cohort of 98 DLBCL cases was negative for SOX11, with only one case expressing cyclin D1 with a GCB phenotype (CD10+/bcl‐6+/MUM1?). The two patients with tumour necrosis rapidly died of disease. The other two were in complete remission after immunochemotherapy. Conclusions: Cyclin D1‐positive DLBCLs are rare, and they are negative for SOX11 or CCND1 aberration. SOX11 is useful in differentiating cyclin D1‐positive DLBCL from MCL.     

Enhancer of zeste homolog 2 expression is associated with tumor cell proliferation and metastasis in gastric cancer

Choi JH, Song YS, Yoon JS, Song KW, Lee YY. Enhancer of zeste homolog 2 expression is associated with tumor cell proliferation and metastasis in gastric cancer. APMIS 2010; 118: 196–202. The enhancer of zeste homolog 2 (EZH2), a member of the polycomb group of proteins, plays an important role in cell proliferation and cell cycle regulation. EZH2 is overexpressed in aggressive forms of prostate, breast, bladder, and endometrial cancers. However, the role of EZH2 expression in gastric cancer has not been fully determined. This study was conducted to investigate the correlation between EZH2 and cell cycle‐related molecules, and the clinical value of EZH2 expression in gastric cancer. We analyzed EZH2 expression using Western blotting in AGS, MKN‐28, SNU‐16, SNU‐484, SNU‐601, and SNU‐638 gastric cancer cell lines. After transfection of EZH2 siRNA into MKN‐28 cells, the change in cell cycle‐related molecules was assessed by Western blot analysis. Expression of EZH2, Ki‐67, and p53 was determined by immunohistochemical staining of tissue microarrays from specimens of 137 cases of resected gastric cancer. We found high expressions of EZH2 in all of the tested gastric cancer cell lines. RNA interference of EZH2 induced upregulation of p53 and HDAC1 and downregulation of cyclin D1 and cyclin E. High EZH2 expression was observed in 60.6% of gastric cancers and in 6.7% of non‐neoplastic gastric tissues (p < 0.01); 40.1% were positive for p53 in gastric cancers. High EZH2 expression was correlated with Ki‐67 and p53 expressions and was significantly associated with distant metastases and non‐signet ring cells. Our results suggest that high EZH2 expression is associated with tumor cell proliferation and metastasis in gastric cancer.     

Expression of topoisomerase II alpha, Ki-67 and p53 in early stage laryngeal carcinomas not featuring vocal cord fixation

AIM: To determine whether topoisomerase II alpha (topoIIa) expression is an additional prognostic marker for less advanced stage laryngeal cancers first treated without surgery. Ki-67 and p53 protein levels were also assessed for comparison. EXPERIMENTAL DESIGN: Formalin-fixed, paraffin-embedded tumor material from 63 cases of squamous cell carcinoma (SCC) of the larynx (glottis, stages 0,1,2) was immunohistochemically stained for topoIIa, Ki-67 (MIB-1) and p53 (DO-7) and the results were compared with clinicopathologic findings. RESULTS: There were 7 stage 0 (TisN0M0), 33 stage I (T1N0M0), and 23 stage II (T2N0M0) SCCs with the TNM classification. Significant differences between carcinomas and normal mucosa were found for the topoIIa-LI, Ki-67-LI, and topoIIa-to-Ki-67 ratio. Regarding histologic grade, a significant difference in topoIIa-to-Ki-67 ratio was evident between well or moderately and poorly differentiated lesions. There were 19 cases of recurrence and 44 cases of nonrecurrence, but no significant differences were found for either of the indices or their ratio. No significant variation with p53 positivity was evident with reference to histologic differentiation, T-factor, clinical course, or proliferation. CONCLUSIONS: The results demonstrate that the topoIIa-to-Ki-67 ratio is a more sensitive parameter reflecting proliferation, for histologic grading of less advanced laryngeal SCCs, than topoIIa- or Ki-67-LIs.     

Ki67 and p53 immunohistochemistry reduces interobserver variation in assessment of Barrett's oesophagus

AIMS: To devise clinically applicable methods for assessing p53 and Ki67 immunohistochemical (IHC) reactivity in Barrett's oesophagus (BE) and to compare the interobserver agreement between these methods and routine haematoxylin and eosin (H&E) evaluation. METHODS AND RESULTS: One hundred and fifteen biopsies diagnosed as BE, selected from the files of the University Hospital MAS, Malmo, were re-evaluated for dysplasia by three pathologists. For IHC analysis areas with the most prominent positivity were evaluated. The mean of p53+ epithelial nuclei/high-power field (HPF) was obtained by counting between 1 and 5 HPFs/biopsy. A proliferation quotient (PQ) was obtained by dividing the number of Ki67+ epithelial nuclei in the upper half by the lower half of the mucosa, using two HPFs. Mean kappa values were 0.24, 0.71 and 0.52 for H&E, p53 and Ki67 evaluations, respectively. There was a correlation between increasing severity of dysplasia, IHC measurable overexpression of p53 and shift of the mucosal proliferation zone towards the surface, measured as PQ. CONCLUSIONS: The described methods for p53 and Ki67 evaluation are more reproducible than routine H&E evaluation of BE. Furthermore, the IHC methods correlate with the severity of dysplasia and are useful supplementary prognostic markers.     

Expression of Bcl-2 and p53 correlates with the morphology of gastric neoplasia

The growth of a tumour can be determined by an interplay between cell proliferation and loss. The expression of apoptosis-related proteins (Bcl-2 and p53), cell proliferation (Ki-67), and apoptotic cell death were investigated using immunohistochemistry and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling in gastric neoplams, to evaluate whether they correlate with the morphology of the tumour. The materials included ten cases of gastric adenoma and 40 cases of early gastric carcinoma consisting of differentiated adenocarcinomas (n=20) and undifferentiated carcinomas (n=20). All cases of adenoma and eight cases of differentiated adenocarcinoma were of the elevated type, while 12 differentiated adenocarcinomas and all of the undifferentiated carcinomas were of the depressed type. The diffuse expression of Bcl-2 was observed in all cases of adenoma and seven out of eight (88 per cent) of elevated-type differentiated adenocarcinoma. In contrast, Bcl-2 expression was absent or focal in the depressed type of carcinoma. Overexpression of p53 was found exclusively in the depressed type of carcinoma. Thus, Bcl-2 and p53 expression was associated with tumour morphology. It seemed unlikely that Bcl-2 and p53 expression was involved in the morphogenesis of the gastric tumours through inhibiting apoptotic cell death, since the degree of apoptosis in Bcl-2-positive gastric tumours was rather higher than that in Bcl-2-negative ones and it did not differ significantly between p53-positive and p53-negative tumours. Instead, the diffuse distribution of Bcl-2 correlated with the superficial distribution of Ki-67-positive proliferating cells, and the overexpression of p53 had a tendency to correlate with the diffuse distribution of proliferating cells. These results suggest that diffuse Bcl-2 expression and a superficial distribution of proliferating cells may contribute to the elevated configuration, and that overexpression of p53 and a diffuse distribution of proliferating cells may result in the depressed configuration in the relatively early stages of gastric tumourigenesis. © 1998 John Wiley & Sons, Ltd.     

p21WAF1/Cip1 expression is associated with cell differentiation but not with p53 mutations in squamous cell carcinomas of the larynx

p21^WAF1/Cip1 is a recently identified gene involved in cell cycle regulation through cyclin-CDK-complex inhibition. The expression of this gene in several cell lines seems to be induced by wild-type, but not mutant, p53. p21^WAF1/Cip1 expression has been studied at both mRNA and protein levels in a series of 49 normal mucosae and squamous cell carcinomas of the larynx. A significant association was found between mRNA and protein expression in tumours (P<0·0001). p21^WAF1/Cip1 expression was strongly associated with squamous cell differentiation of carcinomas, because six of seven (86 per cent) undifferentiated carcinomas (grade 4) showed very low levels of p21^WAF1/Cip1 expression, whereas 41 out of 42 (98 per cent) carcinomas with squamous cell differentiation (grades 1–3) had normal or high levels of p21^WAF1/Cip1 expression (P<0·0001). In addition, p21^WAF1/Cip1 expression was topologically related to the squamous differentiation of tumour cells with a distribution similar to that seen in normal squamous epithelium. No correlation was found between p21^WAF1/Cip1 expression and the global S-phase of the carcinomas. p53 mutations (exons 5–9) were found in ten carcinomas with p21^WAF1/Cip1 expression, but no p53 mutations were detected in three p21^WAF1/Cip1-negative tumours. In conclusion, p21^WAF1/Cip1 expression is frequently upregulated in squamous cell carcinomas of the larynx and is associated with tumour cell differentiation. p21^WAF1/Cip1 expression in these tumours is independent of p53 gene mutations. © 1997 John Wiley & Sons, Ltd.     

p21WAF1/Cip1 is associated with cyclin D1CCND1 expression and tubular differentiation but is independent of p53 overexpression in human breast carcinoma

p21^WAF1/Cip1 is an inhibitor of cdk/cyclin complexes, and thus regulates the cell cycle. p21 is also related to cell differentiation and is regulated by wild-type p53, although p53-independent regulatory pathways have been proposed. In order to analyse p21 expression as well as its relationship with p53 in human breast cancer, an immunohistochemical analysis was undertaken of 77 breast carcinomas, 16 of them with an in situ component; 30 adjacent normal tissue samples; and five non-neoplastic specimens. Forty-four infiltrating carcinomas (57 per cent) were p21-positive. Expression of p21 was also observed in pre-invasive lesions, whereas normal ducts were negative or focally and weakly positive. p21 expression was associated with high histological grade (II+III) (P-0·017) and poor tubule formation (P-0·002), and was significantly less frequent in lobular carcinomas (P-0·0001). p21 positivity also correlated with increased proliferation, but this seemed to be dependent on the histological grade. Twenty carcinomas (26 per cent) showed p53 overexpression, but this was not associated with p21 negativity, suggesting the existence of p53-independent mechanisms for p21 regulation in vivo. Cyclin D1^CCND1 expression was analysed in the same series and an association between p21 and cyclin D1 expression was found, since 23 of 26 cyclin D1-positive carcinomas were p21-positive (P<0·001 …). In conclusion, p21 is frequently overexpressed in breast carcinomas and this occurs in the early stages of neoplastic progression. This overexpression seems to be independent of p53 status and might be involved in cyclin D1 modulation. © 1998 John Wiley & Sons, Ltd.     

Expression of p21/WAF-1, status of apoptosis and p53 mutation in esophageal squamous cell carcinoma with HPV infection

Human papilloma virus (HPV) is regarded as a causative carcinogenic agent in anogenital squamous cell carcinoma (SCC), but there is controversy about its etiologic role in esophageal SCC (ESCC). In this study, we attempted to clarify whether HPV infection plays a crucial role in the development of ESCC by analysis of multiple factors. These included: detection of HPV DNA; evaluation of immunohistochemical assays for HPV-related cell cycle regulators and apoptosis by the terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling method; and genetic analysis of the p53 gene. Twenty of the 48 ESCC examined (42%) were found to be positive for the HPV genome by polymerase chain reaction. They comprised 16 cases with the HPV16 subtype, three with the HPV18 subtype, and one with both HPV16 and 18. Immunohistochemical analysis revealed that the expression of p21/WAF-1 was significantly decreased in HPV-positive cases (chi2 = 9.2614; P = 0.0023). Furthermore, the 10 apoptosis-negative (< or =10%) cases of HPV-positive SCC were almost exclusively p21/WAF-1-negative (chi2 = 12.1406; P = 0.0005), indicating the significance of the relationship between HPV infection and the phenotype that is expected from HPV-induced inhibition of p53. Although 14 cases possessed missense and deletion mutations of the p53 gene (of which four mutations were found in HPV-positive ESCC), no accumulation of the mutation was defined in the phenotype, suggesting that distinct mutation processes might be involved in HPV-negative and -positive ESCC. The data provide significant support for the hypothesis that HPV infection may play a crucial role in the oncogenesis of some ESCC.     

Expression of cyclins,p53, and Ki-67 in cervical squamous cell carcinomas: overexpression of cyclin A is a poor prognostic factor in stage Ib and II disease

We previously reported the overexpression of cyclins in uterine cervical carcinoma; however, their clinicopathological significance remained undetermined. In the present study, we examined the immunohistochemical expression of cyclins (D1, E, A, B1), p53 and Ki-67 in squamous cell carcinoma (stage Ib+II; 80 cases, stage III+IV; 23 cases). Correlations between the expression of cyclins and clinicopathological parameters and patient survival were statistically evaluated. The results indicated that in the normal squamous epithelium, the expression of cyclins and Ki-67 was sporadically observed in the parabasal layer. Of the 103 cervical carcinomas, overexpression of cyclins D1, E, A, B1 and p53 was observed in 13 (13%), 23 (22%), 25 (24%), 18 (18%) and 23 (22%) cases, respectively, with a slight predominance in advanced stage tumors. The expression of cyclin D1, E, A and p53 significantly correlated with that of Ki-67 (Spearmans rank correlation). Univariate and multivariate analyses revealed that lymph node metastasis and cyclin A overexpression were independent prognostic factors for unfavorable outcomes in stage Ib+II patients. These findings suggest that the overexpression of various cyclins is involved in the acquisition of the vigorous growth potential of cervical carcinoma cells, and that cyclin A is an independent prognosticator of cervical carcinoma in early stages.     

Expression of cell cycle-regulatory proteins, MIB-1, p16, p53, and p63, in squamous cell carcinoma of conjunctiva: not associated with human papillomavirus infection

Squamous cell carcinoma (SCC), the most common primary malignant tumor of the conjunctiva, has a variable clinical presentation and immunohistochemical profile. Abundant cell cycles exist, including MIB-1 (Ki67 antigen), p16, p53, and p63, within the conjunctiva SCC. This investigation first reports the expressions of cell cycle markers in SCC. A retrospective study was conducted between December 1976 and June 2004, comprising 13 consecutive patients with conjunctiva SCC who were treated with surgical excision. Detailed clinical parameters were also reviewed. Overexpression of MIB-1, p16, p53, and p63 genes were studied by immunohistochemistry. Genechip containing 39 subtypes was used to elucidate human papillomavirus (HPV). The study group contained 13 (100%) men, with a mean age of 68±18 years and follow-up period of 20±17 months. The sample included four (33%) SCC located in the left eye and two (17%) recurrent SCC. Overexpression of the p53 and p63 was considerably higher than that of the p16 (P<0.01). HPV DNA was not detected in any of the 13 cases. This work first examined the immunohistochemical overexpression of cell cycle (MIB-1, p16, p53, and p63) in SCC. This investigation then showed that the expression of cell cycles in SCC was associated with key tumor clinicopathological features. This approach can help distinguish the potential roles of cell cycle in the development of SCC.