Nuclear and cytoplasmic c-myc staining in endometrial carcinoma and their relationship to survival

c-Myc Drives inflammation of the maternal-fetal interface, and neonatal lung remodeling induced by intra-amniotic inflammation

Background: Intra-amniotic inflammation (IAI) is associated with increased risk of preterm birth and bronchopulmonary dysplasia (BPD), but the mechanisms by which IAI leads to preterm birth and BPD are poorly understood, and there are no effective therapies for preterm birth and BPD. The transcription factor c-Myc regulates various biological processes like cell growth, apoptosis, and inflammation. We hypothesized that c-Myc modulates inflammation at the maternal-fetal interface, and neonatal lung remodeling. The objectives of our study were 1) to determine the kinetics of c-Myc in the placenta, fetal membranes and neonatal lungs exposed to IAI, and 2) to determine the role of c-Myc in modulating inflammation at the maternal-fetal interface, and neonatal lung remodeling induced by IAI. Methods: Pregnant Sprague-Dawley rats were randomized into three groups: 1) Intra-amniotic saline injections only (control), 2) Intra-amniotic lipopolysaccharide (LPS) injections only, and 3) Intra-amniotic LPS injections with c-Myc inhibitor 10058-F4. c-Myc expression, markers of inflammation, angiogenesis, immunohistochemistry, and transcriptomic analyses were performed on placenta and fetal membranes, and neonatal lungs to determine kinetics of c-Myc expression in response to IAI, and effects of prenatal systemic c-Myc inhibition on lung remodeling at postnatal day 14. Results: c-Myc was upregulated in the placenta, fetal membranes, and neonatal lungs exposed to IAI. IAI caused neutrophil infiltration and neutrophil extracellular trap (NET) formation in the placenta and fetal membranes, and neonatal lung remodeling with pulmonary hypertension consistent with a BPD phenotype. Prenatal inhibition of c-Myc with 10058-F4 in IAI decreased neutrophil infiltration and NET formation, and improved neonatal lung remodeling induced by LPS, with improved alveolarization, increased angiogenesis, and decreased pulmonary vascular remodeling. Discussion: In a rat model of IAI, c-Myc regulates neutrophil recruitment and NET formation in the placenta and fetal membranes. c-Myc also participates in neonatal lung remodeling induced by IAI. Further studies are needed to investigate c-Myc as a potential therapeutic target for IAI and IAI-associated BPD.

Verdinexor, a Selective Inhibitor of Nuclear Exportin 1, Inhibits the Proliferation and Migration of Esophageal Cancer via XPO1/c-Myc/FOSL1 Axis

Esophageal carcinoma (EC) ranks sixth among cancers in mortality worldwide and effective drugs to reduce EC incidence and mortality are lacking. To explore potential anti-esophageal cancer drugs, we conducted drug screening and discovered that verdinexor, a selective inhibitor of nuclear exportin 1 (XPO1/CRM1), has anti-esophageal cancer effects both in vivo and in vitro. However, the mechanism and role of verdinexor in esophageal cancer remain unknown. In the present study, we observed that verdinexor inhibited the proliferation and migration of EC cells in vitro and suppressed tumor growth in vivo. Additionally, we found that verdinexor induced cleavage of PARP and downregulated XPO1, c-Myc, and FOSL1 expression. RNA-sequence analysis and protein-protein interaction (PPI) analysis revealed that verdinexor regulated the XPO1/c-Myc/FOSL1 axis. The results of immunoprecipitation and proximity ligation assays confirmed that verdinexor disrupted the interaction between XPO1 and c-Myc. Overexpression of c-Myc rescued the inhibition of cell proliferation and cell migration caused by verdinexor. Overexpressed FOSL1 restored the inhibited migration by verdinexor. Taken together, verdinexor inhibited cell proliferation and migration of esophageal cancer via XPO1/c-Myc/FOSL1 axis. Our findings provide a new option for the development of anti-esophageal cancer drugs.

FBXO17 Inhibits the Wnt/β-Catenin Pathway and Proliferation of Ishikawa Cells

Uterine corpus endometrial carcinoma (UCEC) is one of the most common types of cancer in women, and the incidence is rapidly increasing. Studies have shown that various signaling pathways serve crucial roles in the tumorigenesis of UCEC, amongst which the Wnt/β-catenin pathway is of great interest due to its crucial role in cell proliferation and the huge potential as a therapeutic target. In the present study, it was shown that FBXO17, which is a member of the F-box family, is abnormally downregulated in UCEC tissues compared with non-tumor endometrial tissues, and this was significantly associated with the clinical histological grade, as well as the abnormal proliferation of the UCEC cell line, Ishikawa, both in vitro and in vivo. Besides, the results suggested that FBXO17 may inhibit the Wnt/β-catenin signaling pathway and influence the expression of adhesion molecules, such as E-cadherin and N-cadherin in Ishikawa cells. In conclusion, these findings indicate that FBXO17 is a novel inhibitor of endometrial tumor development and it likely exerts effects via regulation of the Wnt signaling pathway.

Construction of miRNA-mRNA Regulatory Network and Prognostic Signature in Endometrial Cancer

Introduction

This bioinformatic study confirmed a new miRNA-mRNA regulatory network and a prognostic signature in endometrial cancer (EC).

Materials and Methods

We downloaded RNA-seq and miRNA-seq data of EC from the TCGA database, then used EdegR package to screen differentially expressed miRNAs and mRNAs (DE-miRNAs and DE-mRNAs). Then, we constructed a regulatory network of EC-associated miRNAs and hub genes by Cytoscape, and determined the expression of unexplored miRNAs in EC tissues and normal adjacent tissues by quantitative Real-Time PCR (qRT-PCR). A prognostic signature model and a predictive nomogram were constructed. Finally, we explored the association between the prognostic model and the immune cell infiltration.

Results

A total of 11,531 DE-mRNAs and 236 DE-miRNAs, as well as 275 and 118 candidate DEGs for upregulated and downregulated DE-miRNAs were screened out. The miRNA-mRNA network included 5 downregulated and 13 upregulated DE-miRNAs. qRT-PCR proved that the expression levels of miRNA-18a-5p, miRNA-18b-5p, miRNA-449c-5p and miRNA-1224-5p and their target genes (NR3C1, CTGF, MYC, and TNS1) were consistent with our predictions. Univariate and multivariate Cox proportional hazards regression analyses of the hub genes revealed a significant prognostic value of NR3C1, EZH2, AND GATA4, and these genes were closely related to eight types of immune infiltration cells.

Conclusion

We identified three genes as candidate biomarkers for EC, which may provide a theoretical basis for targeted therapy.

Prognostic Value of c-Myc Immunohistochemical Expression in Muscle Invasive Urothelial Carcinoma of the Urinary Bladder: A Retrospective Study

Objective:

This study aimed to investigate the immunohistochemical expression of c-Myc in muscle invasive urothelial carcinoma (MIUC) of the urinary bladder and to evaluate the correlation of c-Myc expression with different clinicopathological parameters and outcome, including a relatively new histopathological tumor characteristic that is the growth pattern of tumor invasion.

Methods:

A total of 66 formalin-fixed and paraffin-embedded sections of MIUC obtained from radical cystectomy specimens were enrolled. The sections were stained with c-Myc antibody using immunohistochemistry technique.

Results:

Tumor cells showed variability in nuclear c-Myc expression according to the growth pattern of invasion. The median H-score of nuclear expression of infiltrative pattern was significantly higher than that of non-infiltrative pattern (p<0.001). Nuclear expression of c-Myc in tumor tissue had a significant association with poor prognostic factors (sarcomatoid variant (p<0.001), perineural invasion (p=0.037), lymphovascular invasion (p<0.001), lymph node metastasis (p<0.001), distant metastasis (p=0.042) and advanced stage grouping (p=0.001). Kaplan Meier survival analysis demonstrated that c-Myc expression could not be significantly correlated with overall survival or disease free survival rates.

Conclusion:

Nuclear c-Myc seems to have a prominent role in epithelial to mesenchymal transition with consequential in tumor progression and metastasis, while it is not as much useful to predict the clinical behavior of patients with MIUC.

JQ1 suppresses tumor growth via PTEN/PI3K/AKT pathway in endometrial cancer

Overexpression of c-Myc is associated with worse outcomes in endometrial cancer, indicating that c-Myc may be a promising target for endometrial cancer therapy. A novel small molecule, JQ1, has been shown to block BRD4 resulting in inhibition of c-Myc expression and tumor growth. Thus, we investigated whether JQ1 can inhibit endometrial cancer growth in cell culture and xenograft models. In PTEN-positive endometrial cancer cells, JQ1 significantly suppressed cell proliferation via induction of G1 phase arrest and apoptosis in a dose-dependent manner, accompanied by a sharp decline in cyclin D1 and CDK4 protein expression. However, PTEN-negative endometrial cancer cells exhibited intrinsic resistance to JQ1, despite significant c-Myc inhibition. Moreover, we found that PTEN and its downstream PI3K/AKT signaling targets were modulated by JQ1, as evidenced by microarray analysis. Silencing of PTEN in PTEN-positive endometrial cancer cells resulted in resistance to JQ1, while upregulation of PTEN in PTEN-negative endometrial cancer cells increased sensitivity to JQ1. In xenografts models of PTEN-positive and PTEN-knock-in endometrial cancer, JQ1 significantly upregulated the expression of PTEN, blocked the PI3K/AKT signaling pathway and suppressed tumor growth. These effects were attenuated in PTEN-negative and PTEN-knockdown xenograft models. Thus, JQ1 resistance appears to be highly associated with the status of PTEN expression in endometrial cancer. Our findings suggest that targeting BRD4 using JQ1 might serve as a novel therapeutic strategy in PTEN-positive endometrial cancers.

Bcl-2 and c-Myc expression in oral dysplasia and oral squamous cell carcinoma: An immunohistochemical study to assess tumor progression

Introduction

Oral cancer is a multistep process involving foul play of proto-oncogenes that induce cell proliferation, inactivation of tumor suppressor gene and cessation of programmed cell death. Among various proto-oncogenes, the nature and behavior of Bcl-2 and c-Myc in oral precancerous/cancerous lesions were obscured which require further assessment for better understanding of etiology, treatment and prognosis.

Aim

The aim of the study is to assess the expression of Bcl-2 and c-Myc in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC).

Materials and Methods

This retrospective study of 70 (oral dysplasia [30], OSCC [30] and normal gingiva [10]) is immunohistochemically assessed for Bcl-2 and c-Myc for distribution, intensity, percentage of positive cells, localization and immunoreactive scores using ImageJ software.

Results

Bcl-2 showed 60% and 37% positivity within dysplasia and OSCC, respectively (P = 0.03); c-Myc showed 87% and 90% positivity within dysplasia and OSCC, respectively. In OSCC, c-Myc showed moderate intensity (P = 0.04). Average percentage of positive cells expressing c-Myc and Bcl-2 increased proportionally within grades of dysplasia (P = 0.000 and P = 0.008, respectively), whereas in OSCC, only c-Myc showed significant expression (P = 0.021). Localization of c-Myc was seen in the nucleus among OSCC (P = 0.01). c-Myc and Bcl-2 showed moderate immunoreactivity in dysplasia (P = 0.005 and P = 0.013, respectively), whereas in OSCC, moderate immunoreactivity of c-Myc (P = 0.05) was observed.

Conclusion

Variable expression of c-Myc and Bcl-2 reveals that these proteins act in synergism in early phases of carcinogenesis, whereas in later stages, due to the diminished activity of Bcl-2, c-Myc interacts incoordination with other oncogenes contributing to tumor progression.

Cytoplasmic expression of C-MYC protein is associated with risk stratification of mantle cell lymphoma

Aim

To investigate the association of C-MYC protein expression and risk stratification in mantle cell lymphoma (MCL), and to evaluate the utility of C-MYC protein as a prognostic biomarker in clinical practice.

Methods

We conducted immunohistochemical staining of C-MYC, Programmed cell death ligand 1 (PD-L1), CD8, Ki-67, p53 and SRY (sex determining region Y) -11 (SOX11) to investigate their expression in 64 patients with MCL. The staining results and other clinical data were evaluated for their roles in risk stratification of MCL cases using ANOVA, Chi-square, and Spearman’s Rank correlation coefficient analysis.

Results

Immunohistochemical staining in our study indicated that SOX11, Ki-67 and p53 presented nuclear positivity of tumor cells, CD8 showed membrane positivity in infiltrating T lymphocytes while PD-L1 showed membrane and cytoplasmic positivity mainly in macrophage cells and little in tumor cells. We observed positive staining of C-MYC either in the nucleus or cytoplasm or in both subcellular locations. There were significant differences in cytoplasmic C-MYC expression, Ki-67 proliferative index of tumor cells, and CD8 positive tumor infiltrating lymphocytes (CD8+TIL) among three risk groups (P = 0.000, P = 0.037 and P=0.020, respectively). However, no significant differences existed in the expression of nuclear C-MYC, SOX11, p53, and PD-L1 in MCL patients with low-, intermediate-, and high risks. In addition, patient age and serum LDH level were also significantly different among 3 groups of patients (P = 0.006 and P = 0.000, respectively). Spearman’s rank correlation coefficient analysis indicated that cytoplasmic C-MYC expression, Ki-67 index, age, WBC, as well as LDH level had significantly positive correlations with risk stratification (P = 0.000, 0.015, 0.000, 0.029 and 0.000, respectively), while CD8+TIL in tumor microenvironment negatively correlated with risk stratification of patients (P = 0.006). Patients with increased positive cytoplasmic expression of C-MYC protein and decreased CD8+TIL appeared to be associated with a poor response to chemotherapy, but the correlation was not statistically significant.

Conclusion

Our study suggested that assessment of cytoplasmic C-MYC overexpression and cytotoxic T lymphocytes (CTLs) by immunohistochemical staining might be helpful for MCL risk stratification and outcome prediction. However, large cohort studies of MCL patients with complete follow up are needed to validate our speculation.

Downregulation of the Genes Involved in Reprogramming (SOX2, c-MYC, miR-302, miR-145, and P21) in Gastric Adenocarcinoma

PURPOSE

Many cell signaling pathways essential for normal stem cell development are involved in cancer initiation and progression. In the present study, motivated by a possible contribution of reprogramming process in induction of cancer, we compared the expression level of main genes involved in iPS generation, i.e., miR-302, miR-145, SOX2, c-MYC, and P21, in a series of tumor and non-tumor tissues of stomach.

METHODS

A total number of 34 tumors and their matched non-tumor (as control) gastric surgical specimens were obtained. The expression of the candidate genes was evaluated by using real-time PCR and immunohistochemistry (IHC) techniques.

RESULTS

Our data revealed a significant downregulation of miR-302b, P21, and miR-145 genes in intestinal and SOX2 gene in diffuse type of tumor samples. SOX2, but not the other genes, showed a significant downregulation in both proximal (cardia and fundus) and distal (body and antrum) sites of stomach. Based on receiver-operating characteristic (ROC) analyses, the highest total area under the curve (AUC) was found for SOX2 (AUC = 82 %, P < 0.001). Interestingly, all tumor samples revealed a negative signal for c-MYC expression, while non-tumor samples represented an intense cytoplasmic staining.

CONCLUSIONS

Despite the fact that some hESC-specific genes are upregulated in tumors, our data revealed a significant downregulation of all candidate genes, except for c-MYC, in tumor samples of stomach. Moreover, ROC data demonstrated that SOX2 gene expression index is a better potential biomarker of gastric cancer, compared to other tested genes. SOX2 expression has a good sensitivity and specificity to discriminate correctly between tumor/non-tumor and also high/low grades of tumor malignancy. It seems downregulation of miR-302b, miR-145, and P21 could contribute to gastric tumor initiation and progression.

Correlation Between the Clinical Parameters and Tissue Phenotype in Patients Affected by Deep-Infiltrating Endometriosis

The current study aimed to identify and validate an applicable immunohistochemistry panel including Ki-67, c-MYC, estrogen receptor-α (ER-α), and progesterone receptor isoforms A/B (PR-A/B) in correlation with clinicopathological parameters in patients affected by deep infiltrating endometriosis. Tissue microarrays were prepared from a cohort of 113 patients. Phenotypic profile of the panel molecules was evaluated in glands and stroma in parallel with microvessels and stroma density measurements. Principal component analysis was performed on 8 immunohistochemical variables, 2 histological variables, and 8 subgroups of clinical parameters. The immunohistochemical profiling showed consistent Ki-67 immunostaining in 17.9% of the samples and c-MYC in 83.1%, while intense ER-α immunoreactivity was detected in 84% of the samples and PR-A/B isoforms in 24.1% of them. The combination of clinical parameters and tissue phenotype allowed a stratification of endometriosis-affected patients. Such novel phenotypical and clinical correlation could be helpful in the future studies for a better stratification of the disease aiming at a personalized patient care.

SALL4 as an Epithelial-Mesenchymal Transition and Drug Resistance Inducer through the Regulation of c-Myc in Endometrial Cancer

SALL4 plays important roles in the development and progression of many cancers. However, the role and molecular mechanism of SALL4 in endometrial cancer remain elusive. In the present research, we have demonstrated that the expression of SALL4 was upregulated in endometrial cancer and correlated positively with tumor stage, metastases and poor survival of patients. The overexpression of SALL4 promoted the invasiveness in endometrial cancer cells, as indicated by the upregulation of mesenchymal cell marker N-cadherin and downregulation of the epithelial marker E-cadherin, and invasion assays in vitro. Additionally, there was also an increase in drug resistance in these cell models due to the upregulation of ATP-binding cassette multidrug transporter ABCB1 expression. Moreover, we also found that ABCB1 was critical for SALL4-induced drug resistance. In contrast, SALL4 knockdown restored drug sensitivity, reversed EMT, diminished cell metastasis and suppressed the downregulation of E-cadherin and the upregulation of N-cadherin and ABCB1. Furthermore, we showed that SALL4 upregulated c-Myc expression and c-Myc was a direct target for SALL4 by ChIP assay, depletion of c-Myc with siRNA abolished the SALL4-induced downregulation of E-cadherin, upregulation of N-cadherin and ABCB1, suggesting that c-Myc was a downstream target for SALL4 and required for SALL4-induced EMT, invasion and drugs resistance in endometrial cancer cells. These results indicated that SALL4 could induce EMT and resistance to antineoplastic drugs through the regulation of c-Myc. SALL4 and c-Myc may be novel therapeutic targets for endometrial cancer.

Brain vascular pericytes following ischemia have multipotential stem cell activity to differentiate into neural and vascular lineage cells

Brain vascular pericytes (PCs) are a key component of the blood-brain barrier (BBB)/neurovascular unit, along with neural and endothelial cells. Besides their crucial role in maintaining the BBB, increasing evidence shows that PCs have multipotential stem cell activity. However, their multipotency has not been considered in the pathological brain, such as after an ischemic stroke. Here, we examined whether brain vascular PCs following ischemia (iPCs) have multipotential stem cell activity and differentiate into neural and vascular lineage cells to reconstruct the BBB/neurovascular unit. Using PCs extracted from ischemic regions (iPCs) from mouse brains and human brain PCs cultured under oxygen/glucose deprivation, we show that PCs developed stemness presumably through reprogramming. The iPCs revealed a complex phenotype of angioblasts, in addition to their original mesenchymal properties, and multidifferentiated into cells from both a neural and vascular lineage. These data indicate that under ischemic/hypoxic conditions, PCs can acquire multipotential stem cell activity and can differentiate into major components of the BBB/neurovascular unit. Thus, these findings support the novel concept that iPCs can contribute to both neurogenesis and vasculogenesis at the site of brain injuries.

The impact of C-MYC gene expression on gastric cancer cell

The upregulation or mutation of C-MYC has been observed in gastric, colon, breast, and lung tumors and in Burkitt's lymphoma. However, little is known about the role C-MYC plays in gastric adenocarcinoma. In the present study, we intended to investigate the influence of C-MYC on the growth, proliferation, apoptosis, invasion, and cell cycle of the gastric cancer cell line SGC7901 and the gastric cell line HFE145. C-MYC cDNA was subcloned into a constitutive vector PCDNA3.1 followed by transfection in normal gastric cell line HFE145 by using liposome. Then stable transfectants were selected and appraised. Specific inhibition of C-MYC was achieved using a vector-based siRNA system which was transfected in gastric cancer cell line SGC7901. The apoptosis and cell cycles of these clones were analyzed by using flow cytometric assay. The growth and proliferation were analyzed by cell growth curves and colony-forming assay, respectively. The invasion of these clones was analyzed by using cell migration assay. The C-MYC stable expression clones (HFE-Myc) and C-MYC RNAi cells (SGC-MR) were detected and compared with their control groups, respectively. HFE-Myc grew faster than HFE145 and HFE-PC (HFE145 transfected with PCDNA3.1 vector). SGC-MR1, 2 grew slower than SGC7901 and SGC-MS1, 2 (SGC7901 transfected with scrambled control duplexes). The cell counts of HFE-Myc in the third, fourth, fifth, sixth, and seventh days were significantly more than those of control groups (P < 0.05). Those of SGC-MR1, 2 in the fourth, fifth, sixth, and seventh days were significantly fewer than those of control groups (P < 0.05). Cell cycle analysis showed that proportions of HFE-Myc and SGC-MR cells in G0-G1 and G2-M were different significantly with their control groups, respectively (P < 0.05). The apoptosis rate of HFE-Myc was significantly higher than those of control groups (P < 0.05). Results of colony-forming assay showed that the colony formation rate of HFE-Myc was higher than those of control groups; otherwise, the rate of SGC-MR was lower than those of their control groups (P < 0.05). The results of cell migration assay showed that there were no significant differences between experimental groups and control groups (P > 0.05). In conclusion, C-MYC can promote the growth and proliferation of normal gastric cells, and knockdown of C-MYC can restrain the growth and proliferation of gastric cancer cells. It can induce cell apoptosis and help tumor cell maintain malignant phenotype. But it can have not a detectable influence on the ability of invasion of gastric cancer cells.

Novel molecular profiles of endometrial cancer-new light through old windows

Endometrial carcinoma (EC) is the most common gynecological malignancy in the western world. A widely accepted dualistic model, which has been established on a morphological basis, differentiates EC into two broad categories: Type I oestrogen-dependent adenocarcinoma with an endometrioid morphology and Type II non-oestrogen-dependent EC with a serous papillary or clear cell morphology. Molecular genetic evidence indicates that endometrial carcinoma, as described in other malignancies, likely develops as the result of a stepwise accumulation of alterations in cellular regulatory pathways, such as oncogene activation and tumor suppressor gene inactivation, which lead to dysfunctional cell growth. These molecular alterations appear to be specific in Type I and Type II cancers. In type I endometrioid endometrial cancer, PTEN gene silencing in conjunction with defects in DNA mismatch repair genes, as evidenced by the microsatellite instability phenotype, or mutations in the K-ras and/or beta-catenin genes, are recognized major alterations, which define the progression of the normal endometrium to hyperplasia, to endometrial intraepithelial neoplasia, and then on to carcinoma. In contrast, Type II cancers show mutations of TP53 and Her-2/neu and seem to arise from a background of atrophic endometrium. Nevertheless, despite the great effort made to establish a molecularly-based histological classification, the following issues must still be clarified: what triggers the tumor cells to invade the myometrium and what causes vascular or lymphatic dissemination, finally culminating in metastasis? RUNX1, a transcription factor, was recently identified as one of the most highly over-expressed genes in a microarray study of invasive endometrial carcinoma. Another candidate gene, which may be associated with an initial switch to myometrial infiltration, is the transcription factor ETV5/ERM. These studies, as well as those conducted for other genes possibly involved in the mitotic checkpoint as a major mechanism of carcinogenesis in non-endometrioid endometrial cancer, could help in understanding the differences in the biology and the clinical outcome among histological types.

Genistein-induced proteome changes in the human endometrial carcinoma cell line, ishikawa

Epidemiological studies have shown that Asian populations display a lower incidence of hormone-dependant cancers, cardiovascular disease, osteoporosis, and menopausal ailments compared to Western societies. Available data support the proposal that lower incidence is associated with the high dietary consumption of isoflavones, such as genistein. This study used two-dimensional electrophoresis to characterize the effect of genistein on the proteome of an endometrial tumor cell model, namely the Ishikawa cell line. Proteome maps displaying approx 1800 proteins were obtained from cells treated with vehicle or genistein at physiologically attainable concentrations of 0.5, 5, or 50 μM or supra-physiological concentration, 500 μM. The effects of genistein on protein expression were characterized using image analysis software. A total 65 protein spots displayed a significant decrease in expression and 32 proteins displayed a significant increase in expression. Of these protein spots, 29 were randomly selected for characterization by matrix assisted laser desorption/ionization tandem mass spectrometry, yielding 18 different proteins. This type of analysis enabled the characterization of a wide range of cellular proteins and allowed for the identification of functional and biochemical pathways that may be regulated or affected by genistein, including cellular transcription, cell proliferation, stress response, or modulation of oncogenic pathways.

Endometrial cancer

Endometrial cancer is the most common gynaecological malignancy in the developed world. The majority of cases can be divided into two broad categories based on clinico-pathological and molecular characteristics; Type I oestrogen-dependent with endometrioid morphology and Type II non-oestrogen-dependent with serous papillary or clear cell morphology. As has been described for other malignancies, such as colorectal carcinoma, the transition from normal endometrium to carcinoma is thought to involve a stepwise accumulation of alterations in cellular regulatory pathways leading to dysfunctional cell growth. This article reviews the current knowledge of the molecular changes commonly associated with endometrial cancer and presents possible progression models.

The association between p53 expression, stage and histological features in endometrial cancer

OBJECTIVE

Alterations of the p53 gene have been widely suggested to be relevant to the development of endometrial carcinoma. However, contradictory results have been reported when immunohistochemical determination of p53 expression has been correlated with stage and histological features of the tumours.

STUDY DESIGN

Pathology findings were reviewed and p53 immunoperoxidase staining was performed in 240 cases of endometrial carcinoma.

RESULTS

Uterine papillary serous adenocarcinomas showed significantly higher p53 overexpression than uterine endometrioid adenocarcinomas (100.0% versus 61.0%, p<0.005). p53 overexpression was significantly higher in the secretory variant (85.7%) than in the typical endometrioid carcinoma (60.0%) (p<0.05). p53 expression did not differ between early (stage I) and advanced (stage II-IV) carcinomas. Likewise, no difference was observed in p53 expression among different architectural grades. The incidence of metastasis to lymph nodes was similar in p53 positive (13.7%) and in p53 negative tumours (12.5%).

CONCLUSION

In the present series, p53 immunostaining did not differ between cases with different FIGO stages or histologic characteristics of the tumours. No simple relationship exists between the immunohistochemical determination of p53 expression and the biological aggressiveness of endometrial carcinomas.

β-catenin expression, DNA ploidy and clinicopathological features in ovarian cancer: A study in 253 patients

The CTNNB1 gene and its product beta-catenin, a regulator of the Wnt signalling pathway, is often mutated and deregulated in human malignancies. Down stream targets of the Wnt signalling pathway are linked to genomic instability. In this study, the impact of beta-catenin expression on genomic instability in ovarian carcinoma, as determined by DNA ploidy, was investigated. Expression of beta-catenin was examined by immunohistochemistry in 253 ovarian carcinomas. The results were related to genomic instability and clinicopathological features of the patients. Membrane associated staining of beta-catenin was detected in nearly all cases with no correlation to clinical parameters. Most of the samples also had cytoplasmic (84%), while only 13% had nuclear beta-catenin localisation. A significant association between beta-catenin expression (cytoplasmic and nuclear) and histological subtype and degree of differentiation was observed. Nuclear beta-catenin was almost exclusively present in endometroid carcinomas. 53% of all endometroid tumours were positive for nuclear beta-catenin expression (P<0.0001). Mucinous carcinomas had the highest degree of cytoplasmic beta-catenin expression (92%), followed by endometroid (92%), mixed (90%), serous (82%), unclassified adenocarcinomas (81%), carcinomas clear cell and (70%), (P=0.01). Tumours with differentiation grade 1 (16%) and 2 (24%) had higher nuclear beta-catenin expression than grade 3 and clear cell carcinomas (6%) (P=0.012). Better prognostic outcome was found for patients with nuclear beta-catenin localisation as compared to the cases without (P=0.027). In conclusion, the study showed no correlation between beta-catenin expression in ovarian carcinoma and FIGO stage and genomic instability as determined by DNA ploidy status. However, nuclear beta-catenin expression was strongly associated with endometroid histological subtype. Finally, in ovarian cancer, although beta-catenin staining seems to be of prognostic importance with respect to nuclear staining in univariate analysis, only DNA ploidy status, histological grade and FIGO staging were of independent prognostic significance in multivariate analysis.

Combined c-Myc and caveolin-1 expression in human prostate carcinoma predicts prostate carcinoma progression

BACKGROUND

Over-expression of the oncogene c-Myc has been implicated in the development and progression of human prostate carcinoma. However, previous assessments of c-Myc expression have not revealed its potential for predicting prostate carcinoma progression. Caveolin-1 is associated with prostate carcinoma progression and is a downstream target gene of c-Myc. The observation that caveolin-1 can suppress c-Myc-induced apoptosis suggested the potential for cooperation between c-Myc and caveolin-1 in malignant progression. In this study, the authors evaluated the prognostic potential of combined c-Myc and caveolin-1 expression in human prostate carcinoma progression.

METHODS

Immunostaining with c-Myc and caveolin-1-specific antibodies was performed on paraffin sections from 104 radical prostatectomy specimens from men with lymph node negative prostate carcinoma. Combined c-Myc and caveolin-1 immunostaining scores were related with the clinical and pathologic features and the probability of prostate-specific antigen recurrence after surgery.

RESULTS

The combination of c-Myc and caveolin-1 immunopositivity correlated positively with Gleason score (rho = 0.219; P = 0.0253) and positive surgical margin (rho = 0.333; P = 0.0006). The combination of positive c-Myc and caveolin-1 in patients with clinically confined prostate carcinoma was a significant prognostic marker for the time to disease progression after surgery in both univariate analysis (P = 0.0039; hazard ratio, 3.035) and multivariate analysis (P = 0.0114; hazard ratio, 2.916).

CONCLUSIONS

The coexpression of c-Myc and caveolin-1 showed potential as a useful prognostic marker for human prostate carcinoma. The current results suggest interactions between c-Myc and caveolin-1 in the progression of human prostate carcinoma.

Immunohistochemical analysis of c-myc, c-jun and estrogen receptor in normal, hyperplastic and neoplastic endometrium

To evaluate the role of c-jun and c-myc proto-oncogenes in normal, hyperplastic and neoplastic endometrium in relation to estrogen receptor (ER) status and to investigate whether these genes can be related to other histopathological features of endometrial carcinoma, 32 endometrial carcinomas, 38 endometrial hyperplasias and 22 cyclic endometria (10 proliferative and 12 secretory) were evaluated histologically. Endometrial hyperplasia cases were classified as simple and complex hyperplasia without atypia, and atypical hyperplasia. Endometrial carcinoma cases were subtyped according to the International Society of Gynecological Pathologists. Modified FIGO system was used for both grading and staging. Immunohistochemical examination was performed using antibodies to ER-alpha, c-myc and c-jun with streptavidin-biotin-peroxidase technique. The mean percentage of ER-alpha positive cells changed cyclically during the menstrual cycle, and it was the highest (96%) and the lowest (31.6%) in proliferative and carcinomatous endometrium, respectively. There was a statistically significant difference between proliferative and secretory phases and proliferative and carcinomatous endometrium in relation to ER-alpha staining (p<0.05). There was also a statistically significant difference with respect to ERalpha reactivity between secretory phase and each hyperplastic group, as well as between the carcinoma group and each hyperplastic group (p<0.05). Although not significant, the mean percentage of c-myc expressing cells in the carcinoma group was higher (15.3%) than that of proliferative phase and hyperplastic groups. The mean percentage of c-jun positive cells in proliferative endometrium was slightly higher than in secretory endometrium, and it was the highest in atypical hyperplastic endometrium (28.3%), but there was no statistically significant difference between the groups. In carcinoma cases, a positive correlation was observed between c-jun positivity and tumor grade (p=0.027, r=0.3908), but such a correlation with c-myc was not found. A positive correlation was detected between ER-alpha and c-myc expression (p=0.038, r=0.3686). A progressive loss of ER seems to be correlated with increasing malignant transformation. C-myc expression might play a role in the development of endometrial carcinoma via ER. The association between c-jun and ER appears to be lost in endometrial carcinoma. The relationship between c-myc, c-jun and ER appears to be altered in endometrial carcinoma compared to that of menstrual endometrium.