The Immunohistochemical Expression of MCM-3, -5, and -7 Proteins in the Uterine Fibroids.

Uterine fibroids are the most common mesenchymal uterine neoplasms; their prevalence is estimated in 40%-60% of women under 35 and in 70%-80% of women over 50 years of age. The current research aims to focus on the etiopathogenesis of uterine fibroids, the factors that affect their growth, and markers with diagnostic and prognostic properties. The MCM (minichromosome maintenance) protein family consists of peptides whose primary function is participation in the molecular mechanism of creating replication forks while regulating DNA synthesis. The aim of this work was to determine the proliferative potential of uterine fibroid cells based on the expression of the Ki-67 antigen and the MCMs-i.e., MCM-3, MCM-5, and MCM-7. In addition, the expression of estrogen (ER) and progesterone (PgR) receptors was evaluated and correlated with the expression of the abovementioned observations. Ultimately, received results were analyzed in terms of clinical and pathological data. MATERIALS AND METHODS: In forty-four cases of uterine fibroids, immunohistochemical reactions were performed. A tissue microarray (TMA) technique was utilized and analyzed cases were assessed in triplicate. Immunohistochemistry was performed using antibodies against Ki-67 antigen, ER, PgR, MCM-3, MCM-5, and MCM-8 on an automated staining platform. Reactions were digitalized by a histologic scanner and quantified utilizing dedicated software for nuclear analysis. Assessment was based on quantification expression of the three histiospots, each representing one case in TMA. RESULTS: In the study group (uterine fibroids), statistically significant stronger expression of all the investigated MCMs was observed, as compared to the control group. In addition, moderate and strong positive correlations were found between all tested proliferative markers. The expression of the MCM-7 protein also correlated positively with ER and PgR. With regard to clinical and pathological data, there was a negative correlation between the expression of MCMs and the number of both pregnancies and births. Significant reductions in MCM-5 and MCM-7 expression were observed in the group of women receiving oral hormonal contraceptives, while smoking women showed an increase in MCM-7, ER, and PgR. CONCLUSIONS: Uterine fibroid cells have greater proliferative potential, as evaluated by expression of the Ki-67 antigen and MCMs, than unaltered myometrial cells of the uterine corpus. The expression of MCM-7 was found to have strong or moderate correlations in all assessed relations. In the context of the clinical data, as well evident proliferative potential of MCMs, further studies are strongly recommended.

miR-107 regulates the effect of MCM7 on the proliferation and apoptosis of colorectal cancer via the PAK2 pathway.

Microchromosome maintenance protein 7 (MCM7), a DNA replication permitting factor, plays an essential role in initiating DNA replication. MCM7 is reported to be involved in tumor formation and progression, whereas the expression profile and molecular function of MCM7 in colorectal cancer (CRC) remain unknown. In this study, we aimed to evaluate the clinical significance and biological function of MCM7 in CRC and investigated whether MCM7 can be used for a differential diagnosis in CRC and whether it may serve as a more sensitive proliferation marker for CRC evaluation. Moreover, immunohistochemical analysis of MCM7 was performed in a total of 89 specimens, and high MCM7 expression levels were associated with worse overall survival (OS) in CRC patients. Furthermore, the cell functional test suggested that lentivirus-mediated silencing of MCM7 with shRNA in CRC cells significantly inhibited cellular proliferation and promoted apoptosis in vitro and inhibited tumor growth in vivo. Additionally, mechanistic studies further demonstrated that P21-activated protein kinase 2 (PAK2) was regulated by MCM7 via microarray analysis and cell functional recovery tests, and miR-107 played a role in regulating expression MCM7 via miRNA microarray analysis and 3'UTR reporter assays. Taken together, our results suggest that the miR-107/MCM7/PAK2 pathway may participate in cancer progression and that MCM7 may serve as a prognostic biomarker in CRC.

The Expression of MCM7 is a Useful Biomarker in the Early Diagnostic of Gastric Cancer.

The aim of this study was to investigate the expression of minichromosome maintenance complex component 7 (MCM7) in gastric mucosal lesions, further to find its potential effect as a biomarker to distinguish intraepithelial neoplasia from gastric mucosal lesions. MCM7 and Ki67 were detected in 93 cases of gastric mucosal lesions by immunohistochemistry. MCM7 and Ki67 expression in GT were lowest compared with other groups (P<0.001), meanwhile there were significant differences compared with Group IM and other groups in MCM7 and Ki67 expression (P<0.001). MCM7 and Ki67 expression in GSC were highest (P<0.05). Groups of LGN, HGN and GIC had no significant differences in MCM7 expression (P>0.05), but there was significant difference compared with Group LGN and Group GIC in Ki67 expression (P<0.05). MCM7 expression elevated with tumor grade increasing and had positive correlation with Ki67 significantly (r=0.940, P<0.001). Furthermore, in some cases, some tumor cells were immunoreactive to MCM7 but negative to Ki67. So we concluded that MCM7 is helpful for us to make differential diagnosis in pathological grade, MCM7 combination of Ki67 may serve as more sensitive proliferation markers for evaluation of gastric carcinoma and precancerous lesions.

RNAi-mediated knockdown of MCM7 gene on CML cells and its therapeutic potential for leukemia.

MCM7 is one of the subunits of MCM2-7 complex, which is essential to DNA replication licensing and the control of cell cycle progression. It has been demonstrated that MCM7 participates in mRNA transcription and DNA damage regulation as well. MCM7 gene is found to be over-expressed in multiple cancers, but there are few reports about its effect in leukemia. Recent studies have proven that MCM7 expression has a relationship with diagnosis and prognosis, which has led to their potential clinical application as a marker for cancer screening. RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression, typically by causing the destruction of specific mRNA molecules. It is a valuable research tool, which is widely used in cell culture and living organisms as well as in medicine recent years. It is indicated that RNAi application for targeting functional carcinogenic molecules, tumor resistance to chemotherapy and radiotherapy is required in cancer treatment. Gene products knockdown by RNAi technology exerts anti-proliferative and pro-apoptotic effects upon cell culture systems, animal models and in clinical trials in the most studies. In the present study, we found that MCM7 highly expressed in K562 cells rather than that in normal neutrophils. Thus, lentivirus-mediated shRNA targeting MCM7 was used to suppress its endogenous expression in K562 cells and develop a novel therapeutic strategy for leukemia.

Upregulated expression of BCL2, MCM7, and CCNE1 indicate cisplatin-resistance in the set of two human bladder cancer cell lines: T24 cisplatin sensitive and T24R2 cisplatin resistant bladder cancer cell lines.

PURPOSE: The mechanism of resistance to cisplatin during treatment of bladder cancer (BC) has been a subject of intense investigation in clinical research. This study aims to identify candidate genes associated with resistance to cisplatin, in order to understand the resistance mechanism of BC cells to the drug, by combining the use of microarray profiling, quantitative reverse transcription-polymerase chain reaction (RT-PCR), and Western blot analyses. MATERIALS AND METHODS: The cisplatin sensitive human BC cell line (T24) and the cisplatin resistant BC cell line, T24R2, were used for microarray analysis to determine the differential expression of genes that are significant in cisplatin resistance. Candidate upregulated genes belonging to three well-known cancer-related KEGG (Kyoto Encyclopedia of Genes and Genomes) pathways (p53 tumor suppressor, apoptosis, and cell cycle) were selected from the microarray data. These candidate genes, differentially expressed in T24 and T24R2, were then confirmed by quantitative RT-PCR and western blot. A fold change ≥2 with a p-value <0.05 was considered significant. RESULTS: A total of 18 significantly upregulated genes were detected in the three selected cancer-related pathways in both microarray and RT-PCR analyses. These genes were PRKAR2A, PRKAR2B, CYCS, BCL2, BIRC3, DFFB, CASP6, CDK6, CCNE1, STEAP3, MCM7, ORC2, ORC5, ANAPC1, and ANAPC7, CDC7, CDC27, and SKP1. Western blot analyses also confirmed the upregulation of BCL2, MCM7, and CCNE1 at the protein level, indicating their crucial association with cisplatin resistance. CONCLUSIONS: The BCL2, MCM7, and CCNE1 genes might play distinctive roles in cisplatin resistance in BC.

Evaluation of Minichromosome Maintenance Protein 7 and c-KIT as Prognostic Markers in Feline Cutaneous Mast Cell Tumours.

Mast cell tumours (MCTs) are a common skin tumour in cats, but there is currently no histological grading system or reliable prognostic marker for this species (unlike the situation for dogs). This study utilized a set of 71 feline cutaneous MCTs with known clinical outcomes to assess the potential of various prognostic markers, including the cellular proliferation marker minichromosome maintenance protein (MCM)-7, mitotic index and various KIT labelling characteristics, including KIT positivity, KIT labelling pattern and KIT immunoreactivity score (IS). Of the factors studied, the mitotic index and the KIT labelling pattern were the only features associated significantly with survival times, while the proliferation marker MCM7 and the KIT IS were not. The study also highlights the variability of KIT labelling characteristics between tumours, which may prevent use of this marker as a diagnostic and prognostic tool.

Overexpression of G9a and MCM7 in oesophageal squamous cell carcinoma is associated with poor prognosis.

AIMS: Histone methyltransferase G9a has been primarily understood as a co-repressor of gene expression, but it has been shown that G9a also positively regulates nuclear receptor-mediated transcription. MCM7, a critical component of the DNA replication licensing complex, is amplified and overexpressed in a variety of human malignancies. The objectives of the present study were to study the relationship between the expression of G9a and MCM7 and the pathological grade, clinical stage and prognosis of oesophageal squamous cell carcinoma (OSCC). METHODS AND RESULTS: We collected 139 formalin-fixed and paraffin-embedded tissues from patients with OSCC and surveyed them by tissue microarray-based immunohistochemical staining. Associations between the expression of MCM7 and G9a and clinicopathological parameters and prognosis of OSCC were examined. From tissue microarray immunohistochemistry staining results, we found that nuclear staining intensity for MCM7 and G9a was associated with histological grade (both P < 0.001), tumour depth (P = 0.050, 0.034), lymph node metastasis (P = 0.001, 0.009) and tumour stage (P < 0.001, =0.003). G9a expression was correlated with that of MCM7. G9a overexpression independently predicted poor cancer-specific survival in OSCC (hazard ratio 0.05, 95% confidence interval 0.006-0.417, P = 0.006) and MCM7 (hazard ratio 0.05, 95% confidence interval 0.013-0.441, P = 0.004). OSCC patients whose tumours showed double-positive expression of G9a and MCM7 (G9a(+) MCM7(+) ) had much shorter survival than those from either the G9a or MCM7 low expression groups (G9a(-) MCM7(-) , G9a(+) MCM7(-) , G9a(-) MCM7(+) ). CONCLUSIONS: MCM7 and G9a may serve as effective prognostic factors and could also be used as biomarkers for predicting various clinical outcomes of OSCCs in the Chinese population.

Examining Nek2 as a better proliferation marker in non-small cell lung cancer prognosis.

The purpose of this study is to identify a better potential biomarker for the prognosis of patients with non-small cell lung cancer (NSCLC). The expressions of Nek2, MCM7, and Ki-67 were evaluated in 270 NSCLC tissues using immunohistochemical and immunofluorescence techniques. Associations between protein expression and clinical pathologic characters were assessed, and the impact on overall survival was analyzed. We detected high levels of Nek2, MCM7, and Ki-67 expression in 25.9, 35.2, and 24.4 % of NSCLC tissues, respectively. Overexpressions of Nek2 were detected more frequently in high T-stage and N-stage cases (P = 0.000, 0.011). The expressions of Nek2, MCM7, and Ki-67 were correlated with each other. Kaplan-Meier curves indicated that patients with overexpression of Nek2, MCM7, and Ki-67 had a poorer overall survival rate compared to those with low expression for all stages (P = 0.000). In particular, the patients with Nek2 overexpression had the most negative prognosis. Multivariate Cox regression analysis showed that Nek2, MCM7, and Ki-67 are independent prognostic indicators for NSCLC. Our data suggest that among Nek2 kinase, MCM7, and Ki-67, it is Nek2 kinase that is the more effective tumor proliferation marker of poor prognosis for NSCLC patients. Thus, Nek2 may represent a new potential target for NSCLC therapeutic intervention.

MCM7 serves as a prognostic marker in diffuse-type gastric adenocarcinoma and siRNA-mediated knockdown suppresses its oncogenic function.

MCM7 (mini-chromosome maintenance protein 7) is essential for the initiation of genomic replication as a component of the pre-replication complex. The present study aimed to analyze its expression, clinical significance and biological functions in gastric adenocarcinoma (GAC). The MCM7 protein was upregulated in all 9 GAC cell lines. In 6 paired primary GACs, MCM7 was upregulated in tumor compared with the corresponding non-tumorous gastric tissues. In normal gastric epithelium tissue, MCM7 was strictly expressed in the proliferative compartment. MCM7 knockdown by siRNA in gastric cancer cell line AGS and NCI-N87 significantly suppressed cell proliferation, inhibited monolayer colony formation, reduced cell invasion and induced late apoptosis. Its nuclear expression correlated with advanced age and poorer disease specific survival in diffuse-type GACs. All the findings supported that MCM7 might play an oncogenic role in gastric tumorigenesis. It serves as a potential prognostic marker and therapeutic target in diffuse-type GACs.

TGFß/Smad signalling in psoriatic epidermis models exposed to salt water soaks and narrowband ultraviolet B radiation.

The role of transforming growth factor-ß1 (TGFß1) and Smad signalling has not been established in psoriasis treatment. We aimed to investigate the effect of combined treatment with salt water soaks and ultraviolet radiation on the expression of TGFß1/Smad signalling proteins in a psoriatic model. We studied mRNA expression (real-time RT-PCR) of TGFß1, TGFß receptor type I (TGFßRI), Smad2, Smad3, Smad4, Smad7, minichromosome maintenance protein 7, and involucrin in normal as well as psoriatic epidermis models (PEM) which were treated for three consecutive days with differently concentrated salt water solutions [(3% NaCl; 30% NaCl, 30% Dead Sea salt water (DSSW)] and subsequent narrowband ultraviolet B (NB-UVB). In PEM, TGFß1 and Smad3 was significantly increased as compared to normal epidermis models. By contrast, TGFßRI mRNA was significantly decreased in PEM. Significant increase of mRNA levels of TGFß1, TGFßRI, Smad2 and Smad3 was predominantly observed in non-irradiated and irradiated PEM pre-treated with 30% NaCl and/or DSSW which was paralleled by increase of involucrin mRNA. In PEM pre-treated with DSSW, TGFßRI, Smad2, Smad3, Smad4, and Smad7 mRNA was significantly higher in irradiated PEM when compared to non-irradiated samples. It has been shown that TGFß1/Smad signalling is altered in a psoriatic model and may play a role in the mode of action of salt water soaks and NB-UVB phototherapy of psoriasis.