Expression of cyclin D1 in normal, metaplastic, hyperplastic endometrium and endometrioid carcinoma suggests a role in endometrial carcinogenesis

Expression of Cyclin D1 in Hyperplasia and Carcinoma of Endometrium and Its Correlation with Histologic Grade, Tumor Type, and Clinicopathological Features

Background  Endometrial carcinoma is often preceded by characteristic histopathologic lesions known as endometrial hyperplasia. Estrogen, p53, PTEN, and overexpression of cyclin D1 appear to be involved in the development of endometrial carcinogenesis.

Design  We evaluated and compared the expression profile of cyclin D1 expressions in 50 endometrial samples submitted as either endometrial curetting ( n = 34) or hysterectomy ( n = 16) specimens, which were diagnosed as simple hyperplasia ( n = 10), complex hyperplasia ( n = 06), atypical hyperplasia ( n = 04), and endometrial carcinoma ( n = 20). Ten cases of normal proliferative and secretory endometrium were selected as controls. Breast cancer with known cyclin D1 expression was selected as a positive control in each immunohistochemistry run.

Results  Cyclin D1 was significantly overexpressed in glands with complex hyperplasia and endometrial adenocarcinoma compared with proliferative or secretory endometrium and simple hyperplasia. A statistical difference was found in the extent of cyclin D1 positivity of simple hyperplasia and carcinoma of the endometrium ( p < 0.005). No statistical difference was seen between complex hyperplasia and carcinoma and clinicopathologic parameters in endometrioid carcinomas. All cases of clear cell carcinoma and serous carcinoma showed cyclin D1 immunoreactivity. Significant statistical difference was seen between cyclin D1 expression and only one clinicopathologic parameter, i.e., menopausal status in endometrial carcinomas

Conclusion  Cyclin D1 over expression may be an early event in endometrial carcinogenesis and cyclin D1 over expression may be an informative biomarker to recognize subsets of endometrial lesions that may be precancerous and therefore amenable to surgical therapy.

Immunohistochemical evaluation of p63 and cyclin D1 in oral squamous cell carcinoma and leukoplakia

Objectives

There are only a limited number of studies on cyclin D1 and p63 expression in oral squamous cell carcinoma (OSCC) and leukoplakia. This study compared cyclin D1 and p63 expression in leukoplakia and OSCC to investigate the possible correlation of both markers with grade of dysplasia and histological grade of OSCC.

Materials and Methods

The study included a total of 60 cases, of which 30 were diagnosed with OSCC and 30 with leukoplakia, that were evaluated immunohistochemically for p63 and cyclin D1 expression. Protein expression was correlated based on grades of dysplasia and OSCC.

Results

Out of 30 cases of OSCC, 23 cases (76.7%) were cyclin D1 positive and 30 cases (100%) were p63 positive. Out of 30 cases of leukoplakia, 21 cases (70.0%) were cyclin D1 positive and 30 (100%) were p63 positive (P<0.05).

Conclusion

The overall expression of cyclin D1 and p63 correlated with tumor differentiation, and increases were correlated with poor histological grades, from well-differentiated to poorly-differentiated SCC. Increased cyclin D1 and p63 expression was associated with the severity of leukoplakia. Based on these results cyclin D1 and p63 products can be a useful tool for improved leukoplakia prognosis.

Immunohistochemical evaluation of p63 and cyclin D1 in oral squamous cell carcinoma and leukoplakia

Objectives

There are only a limited number of studies on cyclin D1 and p63 expression in oral squamous cell carcinoma (OSCC) and leukoplakia. This study compared cyclin D1 and p63 expression in leukoplakia and OSCC to investigate the possible correlation of both markers with grade of dysplasia and histological grade of OSCC.

Materials and Methods

The study included a total of 60 cases, of which 30 were diagnosed with OSCC and 30 with leukoplakia, that were evaluated immunohistochemically for p63 and cyclin D1 expression. Protein expression was correlated based on grades of dysplasia and OSCC.

Results

Out of 30 cases of OSCC, 23 cases (76.7%) were cyclin D1 positive and 30 cases (100%) were p63 positive. Out of 30 cases of leukoplakia, 21 cases (70.0%) were cyclin D1 positive and 30 (100%) were p63 positive (P<0.05).

Conclusion

The overall expression of cyclin D1 and p63 correlated with tumor differentiation, and increases were correlated with poor histological grades, from well-differentiated to poorly-differentiated SCC. Increased cyclin D1 and p63 expression was associated with the severity of leukoplakia. Based on these results cyclin D1 and p63 products can be a useful tool for improved leukoplakia prognosis.

Cyclin D1 is significantly associated with stage of tumor and predicts poor survival in endometrial carcinoma patients

Cyclin D1 overexpression has been described to have oncogenic role and association with diagnosis, prognosis and survival in various tumors. This study will describe the immunohistochemical phenotype of cyclin D1, and investigate the correlation between these patterns of expression and clinicopathological parameters of endometrial carcinomas, to conclude the clinical relevance of cyclin D1 expression in the evolution of endometrial neoplasms. This study employed 101 endometrial tissue samples which include 71 endometrial carcinomas and thirty normal and benign endometrium cases. All these tissue samples were used in the assembly of tissue microarrays which have been utilized afterward in immunohistochemistry staining to detect cyclin D1 expression. Forty (56.3%) cases of endometrial carcinomas showed brown nuclear expression of cyclin D1 including 36 (61%) cases of endometrioid carcinomas, and 3 (33.3%) cases of serous carcinomas. Twenty three (76.6%) cases of control group demonstrated nuclear expression. High score cyclin D1 immunohistochemical staining has been significantly linked with patient age (P=0.0001). Large proportion of high score cyclin D1 immunohistochemical staining was observed in females who are <40years of age while high proportions of negative staining were observed in older age groups. Histologic type of tissue was also significantly related to cyclin D1 immunohistochemical staining (P-value=0.0001), high staining is more common in normal proliferative and secretory endometrium while serous carcinoma is more prevalent with negative staining. Stage of tumor was significantly associated with cyclin D1 immunohistochemical staining (P-value=0.029), proportion of stage III and IV are higher in negative cyclin D1 immunostaining. Significantly higher proportion of high score cyclin D1 immunostaining is observed in controls while higher proportion of negative cyclin D1 immunostaining is observed among carcinoma cases (P-value=0.0001). No significant associations between cyclin D1 immunohistochemical staining and grade, recurrence and alive status were observed. Significant different survival distributions were observed (P-value=0.011) and poor survival behavior was correlated with negative cyclin D1 immunohistochemical staining. In conclusion, greater frequency of cyclin D1 expression was revealed in normal endometrial tissues in comparison with carcinomas. The distribution pattern of cyclin D1 immunoexpression suggests poor prognoses in endometrial carcinoma patients.

CRKL overexpression promotes cell proliferation and inhibits apoptosis in endometrial carcinoma

The v-Crk avian sarcoma virus CT10 oncogene homolog-like (CRKL) protein is important in cancer progression. However, its expression pattern and biological roles in human endometrial carcinoma remain unexplored. The potential mechanism of CRKL-induced cancer progression is still unclear. The present study aimed to explore the expression pattern and biological roles of CRKL in human endometrial carcinoma. Using immunohistochemistry, it was observed that the CRKL protein was overexpressed in 50.5% (44/87) of endometrial carcinoma tissues. Plasmid transfection of CRKL into Ishikawa cells was performed, and CRKL overexpression promoted cell proliferation, colony formation and cell cycle transition in the transfected cells. In addition, CRKL overexpression inhibited cell apoptosis in Ishikawa cells treated with cisplatin, with decreased caspase-3 and caspase-9 cleavage. Further analysis revealed that CRKL upregulated the expression of cyclin D1, cyclin E, B cell lymphoma (Bcl)-2 and survivin, and downregulated Bcl-2 associated X protein expression. In conclusion, the present study demonstrated that CRKL overexpression in endometrial carcinoma contributes to malignant cell growth and resistance to apoptosis, possibly through Bcl-2.

Cyclin D1 and Ki-67 expression in normal, hyperplastic and neoplastic endometrium

Background:

Proliferation and differentiation of cancer cells are regulated by various cell cycle promoting and inhibiting factors. Our knowledge about these proteins and mechanisms regulating cell cycle progression has increased dramatically in recent years.

Aim:

The present study was undertaken to examine the expression profile of cell cycle regulatory proteins in normal proliferative endometrium, hyperplasias (simple, complex and atypical) and endometrial carcinoma in a quantitative approach as also to assess correlations of Cyclin D1 expression with Ki-67 a proliferation marker.

Settings and Design:

A retrospective case control study in a tertiary referral centre.

Materials and Methods:

We evaluated and compared the expression profile of Cyclin D1 and Ki-67 expressions in 61 endometrial samples submitted as either endometrial curetting or hysterectomy specimens, which were diagnosed as simple hyperplasia (n =11), complex hyperplasia (n = 13), atypical hyperplasia (n = 7), and endometrial carcinoma (n = 20).

Results:

There was increased expression of Cyclin D1 and Ki-67 in patients with endometrial carcinoma relative to proliferative endometrium and simple hyperplasia, but there was no such difference between cases of atypical hyperplasia and endometrial carcinoma. Cyclin D1 expression had a positive correlation with Ki-67 expression. Cyclin D1 together with Ki-67 may be a marker for endometrial carcinogenesis and tumor cell proliferation.

The role of androst-5-ene-3β,17β-diol (androstenediol) in cell proliferation in endometrium of women with polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) show high prevalence of endometrial hyperplasia and adenocarcinoma. Endometrial proliferation is increased, evaluated by high levels of Ki67 (cell cycle marker) and low levels of p27 (negative regulator of cell cycle). Nevertheless, endometrial changes in cyclin D1 (positive regulator of cell cycle) in PCOS-women are not described. Androst-5-ene-3β,17β-diol (androstenediol), steroid with estrogenic activity present in endometria, could be related to increased endometrial cell proliferation. The objective of this study was to determine protein content of cyclin D1 and androstenediol levels in endometria from PCOS and control-women and to evaluate the possible mechanism favoring cell proliferation associated with hormonal characteristics of patients. Therefore, cyclin D1 protein content in PCOS-women and control-endometrial tissue were assessed by western blot and immunohistochemistry. The androstenediol levels were evaluated by ELISA. To further analyze the effect of steroids (androstenediol, 17β-estradiol, testosterone) in cell proliferation, levels of proteins cyclin D1, p27 and Ki67 were evaluated in an in vitro model of stromal endometrial cells T-HESC and St-T1b. An increase in cyclin D1 and androstenediol was observed in tissues from PCOS-women relative to control group (p<0.05). In the in vitro model, androstenediol exerted increase in cyclin D1 (p<0.05) and a decrease in p27 protein level (p<0.05), while Ki67 in St-T1b cells increased under this stimulus (p<0.05). Testosterone produces opposite effects in the levels of the above markers (p<0.05). Therefore, the hormonal imbalance associated with this syndrome could alter endometrial tissue homeostasis, promoting cell proliferation. Androstenediol is a molecule that could be involved by stimulating proliferation, whereas testosterone elicits a role of cell cycle repressor.

The WWOX tumor suppressor gene in endometrial adenocarcinoma

Endometrial cancer is a lethal malignancy, the causes of which remain to be determined. The aim of the present study, carried out on tumor samples from 79 patients, was to evaluate the role of the WWOX tumor suppressor gene in endometrial adenocarcinoma. The expression levels of WWOX and its protein content were assessed in normal endometrium and cancer samples. Quantitative PCR was used to assess the correlation between the expression levels of WWOX and the genes involved in the proliferation (MKI67), apoptosis (BAX, BCL2), signal transduction (EGFR), cell cycle (CCNE1, CCND1), cell adhesion (CDH1) and transcription regulation (TP73, NCOR1). The relationship between loss of hetero-zygosity (LOH) and WWOX mRNA levels was also investigated using high resolution melting. Results of the present study demonstrated a positive correlation of WWOX expression with BCL2 and CCND1 and a negative correlation with BAX, CDH1, NCOR1 and BCL2/BAX ratio. The results also showed that loss of heterozygosity at two analyzed loci of the WWOX gene is frequent in patients with endometrial cancer and that WWOX expression levels are lower in tumor samples than in normal tissue. In conclusion, WWOX may be involved in endometrial cancer.

Insulin promotes proliferation, survival, and invasion in endometrial carcinoma by activating the MEK/ERK pathway

The involvement of insulin in endometrial carcinoma (EC) was investigated using radioimmunoassay, Western blot, immunoprecipitation, MTT, and Annexin V-FITC/PI assays in tissue samples and cultured cells. Serum levels of insulin, p-p52Shc, p-p46Shc, Shc·Grb2 complexes, p-MEK, p-ERK, and cyclin D1 were elevated in patients with EC. Expression of key proteins in the MEK/ERK pathway, including p-p52Shc, Shc·Grb2 complexes, p-MEK, p-ERK, and cyclin D1, was significantly higher in patients with advanced FIGO stage, high grade, and lymph-node metastasis and correlated positively with serum insulin concentration. Insulin promotes Ishikawa 3-H-12 cell proliferation, survival, and invasion, and these effects induced by insulin were significantly blocked by MEK inhibitor PD98059. Insulin thus promotes EC cell proliferation, survival, and invasion via the MEK/ERK pathway.

ER-α36, a novel variant of ER-α, mediates estrogen-stimulated proliferation of endometrial carcinoma cells via the PKCδ/ERK pathway

BACKGROUND

Recently, a variant of ER-α, ER-α36 was identified and cloned. ER-α36 lacks intrinsic transcription activity and mainly mediates non-genomic estrogen signaling. The purpose of this study was to investigate the function and the underlying mechanisms of ER-α36 in growth regulation of endometrial Ishikawa cancer cells.

METHODS

The cellular localization of ER-α36 and ER-α66 were determined by immunofluorescence in the Ishikawa cells. Ishikawa endometrial cancer control cells transfected with an empty expression vector, Ishikawa cells with shRNA knockdown of ER-α36 (Ishikawa/RNAiER36) and Ishikawa cells with shRNA knockdown of ER-α66 (Ishikawa/RNAiER66) were treated with E2 and E2-conjugated to bovine serum albumin (E2-BSA, membrane impermeable) in the absence and presence of different kinase inhibitors HBDDE, bisindolylmaleimide, rottlerin, H89 and U0126. The phosphorylation levels of signaling molecules and cyclin D1/cdk4 expression were examined with Western blot analysis and cell growth was monitored with the MTT assay.

RESULTS

Immunofluorescence staining of Ishikawa cells demonstrated that ER-α36 was expressed mainly on the plasma membrane and in the cytoplasm, while ER-α66 was predominantly localized in the cell nucleus. Both E2 and E2-BSA rapidly activated PKCδ not PKCα in Ishikawa cells, which could be abrogated by ER-α36 shRNA expression. E2-and E2-BSA-induced ERK phosphorylation required ER-α36 and PKCδ. However, only E2 was able to induce Camp-dependent protein kinase A (PKA) phosphorylation. Furthermore, E2 enhances cyclin D1/cdk4 expression via ER-α36.

CONCLUSION

E2 activates the PKCδ/ERK pathway and enhances cyclin D1/cdk4 expression via the membrane-initiated signaling pathways mediated by ER-α36, suggesting a possible involvement of ER-α36 in E2-dependent growth-promoting effects in endometrial cancer cells.

Expression of cell cycle regulatory proteins in endometrial adenocarcinoma: variations in conventional tumor areas and in microcystic, elongated and fragmented glands

Endometrial adenocarcinomas may show a distinctive pattern of invasion characterized by the presence of microcystic, elongated and fragmented glands, often most evident along the advancing tumor margin. Earlier, we have shown that these changes appear restricted to low-grade endometrioid carcinomas, many of which show focal mucinous differentiation and lymphovascular space invasion. However, the molecular alterations associated with this morphological alteration are not known. In this study, we have examined immunoreactivity for the cell cycle regulatory proteins cyclin D1, p16 and beta-catenin in 22 endometrial carcinomas, specifically comparing the results in conventional tumor areas and in foci in which the glands exhibited microcystic, elongated and fragmented appearances. The conventional neoplastic glands exhibited cyclin D1 and p16 expression in most cases, with >50% tumor cells positive in 8 cases and 11 tumors, respectively. Membranous expression of beta-catenin was usually preserved, with variable cytoplasmic and nuclear staining. Cyclin D1 and beta-catenin predominantly stained cells at the peripheral or basal aspect of the conventional glands, whereas p16 was more uniformly expressed centrally. Tumor foci composed of microcystic, fragmented and elongated glands showed strong expression of cyclin D1 and p16, sometimes in contrast to unstained contiguous or adjacent conventional neoplastic elements, and there was also loss or fragmentation of membranous beta-catenin staining. Intravascular tumor cells also expressed cyclin D1 and p16 and therefore the immunostains often highlighted subtle foci of lymphovascular invasion. The heterogeneous expression of cell cycle regulatory proteins within endometrial adenocarcinoma illustrates the importance of assessing microanatomical variations in immunoreactivity, particularly at the advancing margin of tumors. The upregulation of cyclin D1 and p16, together with loss of membranous beta-catenin expression in microcystic, fragmented and elongated glands, is similar to epithelial-mesenchymal transitions observed in other malignancies and suggests that this pattern of invasion represents an active rather than a degenerative cellular process.

The influence of the Cyclin D1 870 G>A polymorphism as an endometrial cancer risk factor

Background

Cyclin D1 is integral for the G1 to S phase of the cell cycle as it regulates cellular proliferation. A polymorphism in cyclin D1, 870 G>A, causes overexpression and supports uncontrollable cellular growth. This polymorphism has been associated with an increased risk of developing many cancers, including endometrial cancer.

Methods

The 870 G>A polymorphisms (rs605965) in the cyclin D1 gene was genotyped in an Australian endometrial cancer case-control population including 191 cases and 291 controls using real-time PCR analysis. Genotype analysis was performed using chi-squared (χ²) statistics and odds ratios were calculated using unconditional logistic regression, adjusting for potential endometrial cancer risk factors.

Results

Women homozygous for the variant cyclin D1 870 AA genotype showed a trend for an increased risk of developing endometrial cancer compared to those with the wild-type GG genotype, however this result was not statistically significant (OR 1.692 95% CI (0.939–3.049), p = 0.080). Moreover, the 870 G>A polymorphism was significantly associated with family history of colorectal cancer. Endometrial cancer patients with the homozygous variant AA genotype had a higher frequency of family members with colorectal cancer in comparison to endometrial cancer patients with the GG and combination of GG and GA genotypes (GG versus AA; OR 2.951, 95% CI (1.026–8.491), p = 0.045, and GG+GA versus AA; OR 2.265, 95% CI (1.048–4.894), p = 0.038, respectively).

Conclusion

These results suggest that the cyclin D1 870 G>A polymorphism is possibly involved in the development of endometrial cancer. A more complex relationship was observed between this polymorphism and familial colorectal cancer.

Immunohistochemical markers in endometrial hyperplasia: is there a panel with promise? A review

OBJECTIVE

Despite advances in defining the biology of endometrial carcinomas, there has been little progress in determining markers that distinguish preinvasive endometrial proliferations. The goal of this literature review was to identify studies on endometrial hyperplasia (EH) that describe markers with potential to predict response to progestin therapy or potential for progression to invasive disease.

METHODS

Articles published between January 2000 and October 2006 were identified using the key words endometrial hyperplasia and progesterone receptor or estrogen receptor or biologic marker or immunohistochemistry/immunohistochemical. Articles that reported immunohistochemical studies on specimens of human EH +/-endometrioid endometrial carcinoma with a normal comparison group were included. Only those who reported hyperplasia with atypia separately from nonatypical hyperplasia and with a sample size greater than 10 specimens for the sum of complex and atypical samples were included.

RESULTS

A total of 289 abstracts were reviewed and 150 articles potentially met inclusion criteria. Of these, 123 described immunohistochemical studies on human EH specimens. Only 46 met all criteria for analysis of 61 different markers.

CONCLUSIONS

PTEN seems to have the greatest potential for diagnostic utility in EH, perhaps in combination with Bcl-2 and Bax. However, more uniform and rigorous studies are required to confirm these and additional markers' utility diagnostically in a diagnostic panel. As a major clinical priority is to determine which lesions can be treated medically and which require surgical intervention, focusing future studies on markers that distinguish response to hormone therapy or are involved in hormone regulation, will be important future considerations.

Correlation of cyclin D1 and cyclin D3 overexpression with the loss of PTEN expression in endometrial carcinoma

Cyclins D1 and D3 play key roles in cell cycle progression. The downregulation of cyclin D3 was associated with phosphatase and tensin homolog deleted on chromosome ten-(PTEN)-induced cell cycle arrest. We attempted to determine whether cyclin D1 and D3 overexpression is correlated with PTEN inactivation in endometrioid endometrial cancer (EEC). The expression of PTEN, cyclin D1, and cyclin D3 were determined by immunohistochemical analysis in 105 EEC specimens. Forty-three percent of the EEC demonstrated loss of PTEN expression. Cyclin D3 was overexpressed in only 18% of the EEC specimens and was not associated with tumor grade. Cyclin D1 was overexpressed in 64% of the specimens and was more common in moderate or high-grade tumors (P = 0.002 and P = 0.02, respectively). The overexpression of cyclin D3 was not correlated with loss of PTEN in the EEC. The overexpression of cyclin D1 was much higher in grade 1 tumors with negative PTEN than tumors with positive PTEN expression (67% vs 26%). The overexpression of cyclin D3 was neither frequent nor correlated with the loss of PTEN expression. The overexpression of cyclin D1 was higher in the low-grade tumors with negative PTEN expression than tumors with positive PTEN expression. Overexpression of cyclin D1 is frequent in moderate or high-grade EECs and likely results from multiple mechanisms.

Myelopoiesis in the Liver of Stillborns With Evidence of Intrauterine Infection

Context.—Chorioamnionitis is the maternal and fetal response to an ascending intrauterine infection. The fetal response is manifested by funisitis and chorionic vasculitis, or as neutrophils within pulmonary spaces. Human hematopoiesis occurs in the liver primarily during the 6th to 22nd weeks of gestation.

Objective.—To establish the relationship between the presence of an intrauterine infection and the degree of fetal hepatic myelopoiesis in second- and third-trimester fetuses.

Design.—Liver and lungs from 49 fetal autopsies, 20 to 41 weeks of gestational age, and their associated placentas and membranes were analyzed for evidence of intrauterine infection and hepatic myelopoiesis. Hematoxylin-eosin– stained sections from fixed tissues were evaluated for the presence of amnionic fluid infection, defined by the presence of acute chorioamnionitis or funisitis. The degree of portal hematopoiesis, myelopoiesis and intra-alveolar neutrophils was assessed semiquantitatively with hematoxylin-eosin–stained sections and immunohistochemically with antimyeloperoxidase. The Kruskal-Wallis 1-way analysis of variance and the Wilcoxon-Mann-Whitney test were used to determine the significance of any observed difference.

Results.—The degree of portal and lobular myelopoiesis was significantly greater with the presence of inflammation in both the membranes and umbilical cord, and correlated with the presence of intra-alveolar neutrophils (P &lt; .001). A high correlation between the hematoxylin-eosin and immunohistochemistry assessment of myeloid cells was noted.

Conclusions.—There is increased portal and lobular myelopoiesis in 20-week to 41-week gestational age fetal livers that is associated with intrauterine ascending infection. The presence of increased portal or lobular myelopoiesis suggests the presence of an active fetal response to an intrauterine ascending infection.

p16, p14, p53, cyclin D1, and steroid hormone receptor expression and human papillomaviruses analysis in primary squamous cell carcinoma of the endometrium

Pathogenetically, endometrioid adenocarcinomas of the endometrium are associated with hyperestrogenism and serous papillary carcinomas with alterations of p53. The etiology of primary endometrial squamous cell carcinoma (ESCC), however, is speculative. The purpose of this study was to evaluate the role of p14, p16, p53, cyclin D1, steroid hormone receptors, and human papillomaviruses (HPV) infection in the pathogenesis of primary endometrial squamous cell carcinoma. The expression of p16, p14, p53, cyclin D1, and steroid hormone receptors (estrogen, progesterone, and androgen) was examined immunohistochemically in 8 primary ESCCs. HPV analysis was performed using general primers and HPV typing. The median age of the patients was 62.1 years. Four cases showed positive nuclear and cytoplasmic p16 staining in an insular pattern, and 1 case nuclear positivity for p53 and estrogen receptors, respectively. Four of 8 cases were positive for progesterone receptor analysis and cyclin D1. All cases were negative for p14 and androgen receptor staining. All but one case were negative for HPV analysis. Five patients were alive with and without evidence of disease after a mean follow-up of 6.1 years. The results of this study suggest that alterations of the p16 pathway may play an etiologic role in at least a proportion of the ESCC, but without any association to HPV infection. Factors known to play a pathogenetic role in types 1 and 2 of endometrial carcinomas are not associated with primary ESCC. However, prognostically, ESCCs are more related to type 1 cancers.

Expression of cyclin H in normal and cancerous endometrium, its correlation with other cyclins, and association with clinicopathologic parameters

Cyclins are known as regulatory proteins in cell cycle. Cyclin H is a part of cyclin H/Cdk7/Mat1 complex, which is necessary for cellular proliferation. This study was designed to investigate the correlation of cyclin H expression with tumorigenesis of the endometrium and clinicopathologic variables. Immunohistochemical staining using labeled streptavidin-biotin complex was performed on formalin-fixed, paraffin-embedded endometrial tissues of the proliferative, hyperplastic, and carcinomatous types. Immunostaining for cyclins A, B1, D1, D3, E, H, and cyclin dependent kinase 2 were evaluated. The expression of cyclins A, D1, D3, and H in hyperplasia was significantly more frequent than those of proliferative phase and less than those of endometrioid adenocarcinoma. The expression of cyclin H was correlated with lymphvascular space invasion and clinical stage in carcinoma but not with myometrial invasion, lymph node metastasis, and menopause status. The expression of cyclin H could be involved in the transformation of the endometrium into malignancy and might be a marker for more proliferative and malignant features. It might be one of the biomarkers for determining proliferative activity in endometrial hyperplasia and endometrioid adenocarcinoma.

The association between polycystic ovaries and endometrial cancer

BACKGROUND

Women with polycystic ovary syndrome (PCOS) are assumed to be at increased risk of endometrial cancer (EC), albeit of a more differentiated type with better prognosis than in normal women. This study was designed to test these assumptions, as evidence for them is lacking.

METHODS

The prevalence of polycystic ovaries (PCO), as a marker of PCOS, was investigated in ovarian sections from 128 women with EC and 83 with benign gynaecological conditions. The expression of the prognostic markers p53, Ki67, Bcl2 and cyclin D1 was also investigated by immunohistochemistry in endometrial tumours from 11 women with PCO and 16 with normal ovaries.

RESULTS

Overall, PCO were similarly prevalent in women with EC (8.6%) and benign controls (8.4%); however, in women aged <50 years, PCO were more prevalent in women with EC (62.5 versus 27.3%, P = 0.033). Cyclin D1-expressing endometrial tumours tended to be more prevalent in women with PCO compared to normal ovaries (36.4 versus 6.25%, respectively, P = 0.071). Bcl2-, p53- and Ki67-expressing tumours were similarly prevalent.

CONCLUSIONS

The association between PCOS and EC appears confined to premenopausal women. The tendency for cyclin D1-expressing endometrial tumours to be more prevalent in women with PCO challenges the assumption that EC prognosis is improved in women with PCOS.

Expression and significance of tumor-related genes in HCC

AIM: To investigate the expression and clinical significance of DEK, cyclin D1, insulin-like growth factor II (IGF-II), glypican 3 (GPC3), ribosomal phosphoprotein 0 (rpP0) mRNA in hepatocellular carcinoma (HCC) and its paraneoplastic tissues.

METHODS: The expression of mRNAs of DEK, cyclin D1, IGF-II, GPC3 and rpP0 mRNA was detected in HCC and its paraneoplastic tissues by multiplex RT-PCR.

RESULTS: By the simplex RT-PCR, the overexpression of mRNAs of DEK, cyclin D1, IGF-II, GPC3, rpP0 mRNA in HCC and its paraneoplastic tissues was 78.1%, 87.5%, 87.5%, 75.0%, 81.3% and 15.6%, 40.6%, 37.5%, 21.9%, 31.3% respectively (P < 0.05). By the multiplex RT-PCR, at least one of the mRNAs was detected in all HCC samples and in 75.0% of paraneoplastic samples (P > 0.05). However, all these five mRNAs were found in 68.8% of HCC samples, but only in 9.4% of paraneoplastic tissues (P < 0.05). The positive expression of mRNAs of DEK, cyclin D1, IGF-II, GPC3, rpP0 in well- and poorly-differentiated HCC was 89.0%, 66.7%, 66.7%, 66.7%, 77.8% and 73.9%, 95.7%, 95.7%, 95.7%, 82.6%, respectively (P > 0.05). The expression of these genes in HCCs with α-feto protein (AFP) negative and positive was 90.0%, 80.0%, 90.0%, 90.0%, 90.0% and 72.7%, 86.3%, 77.3%, 90.9%, 68.2% respectively (P > 0.05).

CONCLUSION: The expression of DEK, cyclin D1, IGF-II, GPC3, rpP0 mRNA in HCC is much higher in HCC than in its paraneoplastic tissues. Multiplex RT-PCR assay is an effective, sensitive, accurate, and cost-effective diagnostic method of HCC.

Cyclin D1 polymorphism and the risk of endometrial cancer

OBJECTIVES

The common G to A single nucleotide polymorphism (G870A) in the splice donor region of exon 4 enhances alternate splicing, and produces a longer half-life cyclin D1 (CCND1). This study was aimed at investigating the possible association between the G870A polymorphism in CCND1 and the risk of endometrial cancer.

METHODS

We assessed the association between the CCND1 G870A polymorphism and the risk of endometrial cancer in a hospital-based case-control study among 231 Korean women (77 cases; 154 matched controls). Controls were matched to cases with respect to age, menopausal status, and hormone therapy status.

RESULT

The allele frequencies of the case subjects (A, 0.45; G, 0.55) were significantly different from those of control subjects (A, 0.58; G, 0.42) (P = 0.008). All case and control subjects were in Hardy-Weinberg equilibrium. The AA genotype was associated with a significantly elevated odds ratio (OR) of 3.18 [95% confidence interval (CI) 1.38-7.37, P = 0.007], and the AG genotype was associated with an OR of 1.38 (95% CI 0.65-2.89). When we combined the GG and AG genotypes as a reference genotype, we found that the OR for the AA genotype was 2.53 (95% CI 1.34-4.80, P = 0.004), supporting a recessive model for the A allele. Conditional logistic regression adjusted for various risk factors of endometrial cancer revealed positive associations between the AA genotype and an increased risk of endometrial cancer (OR 3.16, 95% CI 1.18-8.43, P = 0.022). However, no significant difference in endometrial cancer stage or grade was observed between the CCND1 genotypes.

CONCLUSION

Our data suggest that the CCND1 polymorphism is associated with an increased risk of endometrial cancer. To validate this association, a large-scale population-based study is needed.

Significance of hormone receptor status and tumor vessels in normal, hyperplastic and neoplastic endometrium

The aims of this study were to identity the roles of tumor vessels and hormone receptor status in normal, hyperplastic, and neoplastic endometrium, and to explore their relationships with other prognostic factors of endometrial adenocarcinoma. Endometrial curettage specimens of proliferative phase and secretory phase endometrium, simple hyperplasia with or without atypia, complex hyperplasia with or without atypia, and grade 1 adenocarcinoma were examined for estrogen receptor alpha (ER alpha), progesterone receptor (PgR), Ki-67 labeling index (LI), cyclin D1, microvessel density (MVD), and area of venules (AV) using an immunoperoxidase method. The results showed high levels of ER alpha in complex hyperplasia, and high levels of PgR in simple hyperplasia without atypia. Expression of ER alpha in the endometrium decreased in a stepwise manner from complex hyperplasia without atypia to grade 1 adenocarcinoma. Expression of PgR in the endometrium decreased in a stepwise manner from simple hyperplasia without atypia to grade 1 adenocarcinoma. In contrast, the expressions of Ki-67 LI, cyclin D1, MVD and AV in the endometrium increased in a stepwise manner from normal, simple or complex hyperplasia with or without atypia to grade 1 adenocarcinoma. These changes may become irreversible on progression from simple or complex hyperplasia to neoplasia.

Molecular alterations associated with cyclin D1 overexpression in endometrial cancer

Cyclin D1 is frequently overexpressed in human neoplasias by gene rearrangement and amplification. In addition, Ras, PTEN and beta-catenin appear to modulate cyclin D1 levels. Since the causes of cyclin D1 overexpression are poorly understood in EC, we investigated whether or not this alteration is due to cyclin D1 gene amplification or to RAS, PTEN and beta-catenin mutation. We analyzed cyclin D1 expression in 18 AEHs, 65 EECs and 27 NEECs by immunohistochemistry as well as CCND1 gene amplification by FISH. In EECs, mutations in K-RAS, PTEN, beta-catenin and CCND1 were studied by PCR-SSCP and sequencing and MSI was evaluated by analyzing BAT-25 and BAT-26 microsatellites. Contingency tests were used to evaluate the relationships between variables. Cyclin D1 overexpression was not observed in AEHs but was present in 13.8% of EECs and 11.2% of NEECs (p = 0.031). CCND1 amplification was more frequent in NEECs (26.3%) than in EECs (2.1%) (p = 0.002). In EECs, cyclin D1 overexpression was not associated with mutations in K-RAS, PTEN or beta-catenin. However, in EECs with beta-catenin mutations, cyclin D1 was expressed mainly by cells expressing beta-catenin in the cytoplasm and nucleus but not in those with membranous expression. Finally, cyclin D1 overexpression was associated with MSI (p = 0.047). The molecular alterations associated with cyclin D1 overexpression differ in the 2 clinicopathologic types of EC. Cyclin D1 overexpression is associated with gene amplification in NEECs and with nucleocytoplasmic expression of beta-catenin and MSI in EECs.

Alterations of pRb1-cyclin D1-cdk4/6-p16(INK4A) pathway in endometrial carcinogenesis

The retinoblastoma protein pathway (pRb1-cyclin D1-cdk4/6-p16(INK4A)) participates in the regulation of the cellular processes at the transition of G1/S phases of the cell-cycle. Derailments of this pathway, caused either by lack of pRb1 or p16(INK4A) expression or overexpression of cyclin D1 and/or cdk4/6, are implicated in the deregulation of the cell-cycle machinery, resulting in uncontrolled cell proliferation, tumor heterogeneity, invasion and metastasis. Several studies conducted so far have assessed the deregulation of the pRb1-pathway components in various human tumors and cell-lines, provided these pathway alterations play an obligatory role in tumorigenesis. This review briefly summarizes the current information on the pRb1-cyclin D1-cdk4/6-p16(INK4A) alterations in sporadic uterine cancer, placing emphasis on the influence on the dualistic model of endometrial carcinogenesis.

Expression of cyclin D1 in normal, hyperplastic and neoplastic endometrium and its correlation with Ki-67 and clinicopathological variables

METHODS

We investigated cyclin D1 expression in proliferative endometrium, endometrial hyperplasia and endometrioid adenocarcinoma, and examined the correlation of cyclin D1 expression with Ki67 as a cell proliferation associated marker. Immunohistochemical expression of cyclin D1 and Ki67 were studied in 30 cases with endometrial carcinoma, 14 cases with atypical hyperplasia, 15 cases with simple hyperplasia and 30 cases with proliferative endometrium.

RESULTS

One out of 30 patients (3.3%) with proliferative endometrium, 1 out of 14 patients (7.1%) with atypical hyperplasia, and 8 out of 30 patients (26.6%) with endometrial carcinoma were found to have immunoreactivity to cyclin D1. All cases of simple hyperplasia had negative staining for cyclin D1. A positive immunoreaction for Ki67 was obtained in all cases. Statistically significant difference was found in cyclin D1 immunoreactivity between both proliferative endometrium and adenocarcinoma, and simple hyperplasia and adenocarcinoma (p<0.05). In patients with adenocarcinoma, cyclin D1 immunoreactive cases had higher mean Ki67 values compared with the non-immunoreactive ones (p<0.05). Ki67 and cyclin D1 immunoreactivity had no impact on overall survival. Univariate analysis revealed a significant relationship between survival and grade and stage (p<0.01). Cyclin D1 expression was not correlated with age, depth of myometrial invasion, lymphovascular space involvement, grade, lymph node metastasis and stage.

CONCLUSION

Cyclin D1 expression in endometrial carcinoma is higher than proliferative endometrium and simple hyperplasia. These findings support that cyclin D1 may play a role in endometrial carcinogenesis.

Cyclin D1 gene (CCND1) mutations in endometrial cancer

Cyclin D1 is frequently overexpressed in human neoplasias by gene rearrangement and amplification, but no mutations in the CCND1 gene have so far been reported. However, in vitro mutagenesis of CCND1 has shown that substitutions affecting threonine 286 residue produced cyclin D1 nuclear accumulation, by interfering with protein degradation and induced neoplastic transformation in murine fibroblasts. To test whether similar genetic changes may occur in vivo, we analysed a series of 60 endometrioid endometrial carcinomas (EECs) for cyclin D1 expression and gene amplification by immunohistochemistry and FISH, respectively. Two of 17 carcinomas showing cyclin D1 expression in more than 5% of neoplastic cells, but without gene amplification, were found to harbor single-base substitutions in CCND1 that changed proline 287 into threonine and serine, respectively. Both cases expressed cyclin D1 in more than 50% of neoplastic cells. Additionally, seven tumors with cyclin D1 overexpression of an independent series of 59 EECs were also analysed, and a 12-bp in-frame deletion that eliminated amino acids 289-292 was detected in one case with cylin D1 expression in more than 50% of neoplastic cells. In contrast, no mutations of the CCND1 gene were detected in a set of breast carcinomas with cyclin D1 overexpression without gene amplification. In summary, our data indicate that mutations of CCND1, which probably render the protein insensitive to degradation, represent a previously unreported mechanism of cyclin D1 overexpression in human tumors in vivo.