Overexpression of cyclins A and B as markers of neoplastic glandular lesions of the cervix

Role of NSC319726 in ovarian cancer based on the bioinformatics analyses

Aim

This study aimed to explore the molecular mechanisms of NSC319726 in ovarian cancer by bioinformatics analyses.

Methods

Gene expression profile GSE35972 was downloaded from the Gene Expression Omnibus database. The data set contains six samples, including three samples of TOV112D cells untreated and three samples of TOV112D cells treated with NSC319726. The differentially expressed genes (DEGs) between untreated and treated samples were analyzed using the limma package. Kyoto Encyclopedia of Genes and Genomes pathway analysis was performed using the signaling pathway impact analysis package, followed by the functional annotation of DEGs and protein–protein interaction network construction. Finally, the subnetwork was identified, and Gene Ontology functional enrichment analysis was performed on the DEGs enriched in the subnetwork.

Results

A total of 120 upregulated and 126 downregulated DEGs were identified. Six Kyoto Encyclopedia of Genes and Genomes pathways were significantly perturbed by DEGs, and the pathway of oocyte meiosis was identified as the most perturbed one. Oocyte meiosis was enriched by eight downregulated DEGs, such as ribosomal protein S6 kinase, 90 kDa, and polypeptide 6 (RPS6KA6). After functional annotation, eight transcription factors were upregulated (such as B-cell CLL/lymphoma 6 [BCL6]), and three transcription factors were downregulated. Seven tumor suppressor genes, such as forkhead box O3 (FOXO3), were upregulated. Additionally, in the protein–protein interaction network and subnetwork, cyclin B1 (CCNB1) and cell division cycle 20 (CDC20) were hub genes, which were also involved in the functions related to mitotic cell cycle.

Conclusion

NSC319726 may play an efficient role against ovarian cancer via targeting genes, such as RPS6KA6, BCL6, FOXO3, CCNB1, and CDC20, which are involved in oocyte meiosis pathway.

Identification of genes and pathways associated with pancreatic ductal adenocarcinoma by bioinformatics analyses

This study aimed to explore the underlying genes and pathways associated with pancreatic ductal adenocarcinoma (PDAC) by bioinformatics analyses. Gene expression profile GSE43795 was downloaded from the Gene Expression Omnibus database. The differentially expressed genes (DEGs) between six PDAC and five non-neoplastic pancreatic tissue samples were analyzed using the limma package. Gene ontology (GO) and pathway enrichment analyses of DEGs were performed, followed by functional annotation and protein-protein interaction (PPI) network construction. Finally, the sub-network was identified and pathway enrichment analysis was performed on the contained DEGs. A total of 374 downregulated and 559 upregulated DEGs were identified. The downregulated DEGs were enriched in GO terms associated with digestion and transport and pathways related to metabolism, while the upregulated DEGs were enriched in GO terms associated with the cell cycle and mitosis and pathways associated with the occurrence of cancer including the cell cycle pathway. Following functional annotation, the oncogene pituitary tumor-transforming 1 (PTTG1) was upregulated. In the PPI network and sub-network, cell division cycle 20 (CDC20) and BUB1 mitotic checkpoint serine/threonine kinase B (BUB1B) were hub genes with high connectivity degrees. Additionally, DEGs in the sub-network including cyclin B1 (CCNB1) were mainly enriched in the cell cycle and p53 signaling pathways. In conclusion, the cell cycle and p53 signaling pathways may play significant roles in PDAC, and DEGs including CDC20, BUB1B, CCNB1 and PTTG1 may be potential targets for PDAC diagnosis and treatment.

Multiple biomarkers in molecular oncology. I. Molecular diagnostics applications in cervical cancer detection

The screening for cervical carcinoma and its malignant precursors (cervical neoplasia) currently employs morphology-based detection methods (Papanicolaou [Pap] smear) in addition to the detection of high-risk human papillomavirus. The combination of the Pap smear with human papillomavirus testing has achieved significant improvements in sensitivity for the detection of cervical disease. Diagnosis of cervical neoplasia is dependent upon histology assessment of cervical biopsy specimens. Attempts to improve the specificity of cervical disease screening have focused on the investigation of molecular biomarkers for adjunctive use in combination with the Pap smear. Active research into the genomic and proteomic alterations that occur during human papillomavirus-induced neoplastic transformation have begun to characterize some of the basic mechanisms inherent to the disease process of cervical cancer development. This research continues to demonstrate the complexity of multiple genomic and proteomic alterations that accumulate during the tumorigenesis process. Despite this diversity, basic patterns of uncontrolled signal transduction, cell cycle deregulation, activation of DNA replication and altered extracellular matrix interactions are beginning to emerge as common features inherent to cervical cancer development. Some of these gene or protein expression alterations have been investigated as potential biomarkers for screening and diagnostics applications. The contribution of multiple gene alterations in the development of cervical cancer suggests that the application of multiple biomarker panels has the potential to develop clinically useful molecular diagnostics. In this review, the application of biomarkers for the improvement of sensitivity and specificity of the detection of cervical neoplasia within cytology specimens will be discussed.

The cyclins: a family of widely expressed tumor antigens?

Continuous cell division is a hallmark of cancer and cell-cycle regulators therefore represent relevant target molecules for tumor therapy. Among these targets the cyclins are of particular interest as they are overexpressed in various tumor entities with little expression in normal tissue. Here we review evidence that these molecules are recognized by the immune system, summarize why cyclins A, B and D in particular appear to be interesting targets for active and passive immunotherapy, and discuss whether the entire family could be an interesting novel class of tumor antigens for cancer treatment and prevention.

Healthy individuals have T-cell and antibody responses to the tumor antigen cyclin B1 that when elicited in mice protect from cancer

We previously identified the aberrantly expressed cell cycle regulator cyclin B1 as a tumor antigen recognized by antibodies and T cells from patients with breast, lung, and head and neck cancers. Ordinarily expressed only transiently in the G2/M stage of the cell cycle in normal cells, cyclin B1 is constitutively expressed at high levels in the cytoplasm of these and many other tumor types, leading to its recognition by the cancer patient's immune system. We report here an unexpected observation that cyclin B1-specific antibody and memory CD4 and CD8 T cells are also found in many healthy individuals who have no history of cancer. Moreover, young as well as older healthy people have these responses suggesting that events other than cancer, which occur either early in life or throughout life, may lead to aberrant cyclin B1 expression and anti-cyclin B1 immunity. The role, if any, of immunity to this tumor-associated antigen is not known. We wanted to determine specifically whether immunity to cyclin B1 might be important in the immunosurveillance of cyclin B1+ tumors. We therefore tested in mice the effectiveness of vaccine-elicited anti-cyclin B1 immunity against a cyclin B1+ mouse tumor that was chosen based on our published observation that cyclin B1 overexpression is associated with the lack of p53 function. We found that cyclin B1 DNA prime-protein boost vaccine protected mice from a challenge with a tumor cell line that was established from a tumor arising in the p53(-/-) mouse that spontaneously overexpresses cyclin B1.

Early detection of cervical carcinomas: finding an overall approach

BACKGROUND

Infection with human papillomavirus (HPV) is a necessary, but not sufficient condition for the emergence of cervical cancer. Cervical cancer develops over several years through a series of precursor lesions that can be detected by cytological screening. The majority of these lesions, however, regress spontaneously. The challenge of cancer screening is to detect those patients who are at high risk of tumor progression.

METHODS

Selective literature review on cervical cancer screening in light of current guidelines and recommendations.

RESULTS AND CONCLUSION

Since the recently introduced vaccination against HPV does not provide full protection against cervical cancer, screening programs must continue. HPV vaccination and early detection of cervical carcinomas should be organized into a combined prevention program with systematic documentation, quality control, and active invitation to participate. It is assumed that the reduction in prevalence of precancerous lesions as a result of vaccination will have a negative impact on the efficiency of cytological early detection. Therefore, the existing screening procedures should be optimized and complemented by new techniques. Already available for screening is the detection of HPV DNA. Further promising biomarkers are currently being investigated in international studies, but no conclusions on their potential efficacy can yet be drawn.

Comparing normal primary endocervical adenoepithelial cells to uninfected and influenza B virus infected human cervical adenocarcinoma HeLa cells

Human adenocarcinoma HeLa cells surviving infection with low (10(-9) units), medium (10(-6) units), and high (10(-2) units) influenza B titers were compared to their uninfected precursors and to normal endocervical adenoepithelial and metaplastic cells using Papanikolaou-staining method and immunocytochemistry. Normal primary endocervical and infected HeLa cells surviving infection shared similar morphologic, phenotypic, and divisional patterns that differed drastically from those of uninfected HeLa cells. The number of infected hosts surviving 6-7 days of viral exposure did not change during 3-week follow-up period, and their cyclin E levels suggested that they had been arrested to the G1 phase of the cell cycle by viral stress. Our findings suggest that in addition to apoptosis, nononcogenic viral stress activated the expression of endocervical metaplastic-like motifs in surviving hosts. A mechanism of cell response to nononcogenic viral stress was proposed to explain these findings. We conclude that nononcogenic respiratory viruses specifically target and eliminate abnormal cells ectopically overexpressing appropriate receptors and may complement current treatments of cervical cancer.

Cell Cycle Regulators p105, p107, Rb2/p130, E2F4, p21CIP1/WAF1, Cyclin A in Predicting Cervical Intraepithelial Neoplasia, High-Risk Human Papillomavirus Infections and Their Outcome in Women Screened in Three New Independent States of the Former Soviet Union

BACKGROUND

The growth-controlling functions of the high-risk human papillomaviruses (HPV) depend on their ability to interact with several cellular proteins, including the key regulatory proteins of the cell cycle. We have examined the value of cell cycle regulatory proteins as predictors of the intermediate end point markers in cervical carcinogenesis: (a) grade of cervical intraepithelial neoplasia (CIN), (b) high-risk HPV type, (c) clearance/persistence of high-risk HPV, and (d) disease outcome in women participating in a multicenter follow-up study in three New Independent States countries.

METHODS

Totally, 232 biopsy samples tested high-risk HPV-positive and/or Papanicolaou smear-positive women were immunohistochemically stained for the following cell cycle markers: p105, p107, p130, E2F4, p21(CIP1/WAF1/SDI1), cyclin A, and Ki-67. In addition, apoptotic index (AI) and mitotic index (MI) were determined in H&E-stained sections. Prospective follow-up data were available to disclose the clinical and virological outcome of the lesions.

RESULTS

The expression of Ki-67, p21(CIP1/WAF1/SDI1), and cyclin A and AI and MI values were markedly increased in high-grade lesions, but only MI was an independent predictor of CIN3 in multivariate analysis. Cyclin A was the only independent predictor of high-risk HPV (odds ratio, 1.09; 95% confidence interval, 1.01-1.18; P = 0.021), exceeding the predictive power of CIN grade and high-grade squamous intraepithelial lesion Papanicolaou smears. None of these markers provided any useful predictive information as to the clinical and virological outcomes during the follow-up. Highly significant correlations (P = 0.0001) were found between AI and MI as well as between MI and cyclin A, Ki-67 and p21(CIP1/WAF1/SDI1), Ki-67 and cyclin A, and p21(CIP1/WAF1/SDI1) and cyclin A followed by that between p105 and cyclin A (P = 0.001) and p105 and p130 (P = 0.002).

CONCLUSIONS

All tested factors related to cell cycle were increased, but only MI and cyclin A was an independent predictor of CIN3 and high-risk HPV carriage, respectively.

The pathology and management of endocervical glandular neoplasia

The incidence of cervical glandular intraepithelial neoplasia and adenocarcinoma is rising, and our limited knowledge about these lesions presents the gynecologist with a management dilemma. Recently, pathologists have paid increasing attention to the diagnosis and pathogenesis of adenocarcinoma of the cervix. Although there is no uniformity in the management of these lesions, nonradical surgery appears to give satisfactory results especially in young women who want to preserve their fertility. This review focuses on the issues surrounding the histologic diagnosis of endocervical glandular abnormalities, including their classification, and discusses the management of cervical preinvasive glandular disease, including follow-up after treatment.

Molecular diagnostic assays for cervical neoplasia: emerging markers for the detection of high-grade cervical disease

The accurate detection and diagnosis of cervical carcinoma and its malignant precursors (collectively referred to as high-grade cervical disease) represents one of the current challenges in clinical medicine and cytopathology. The advent of molecular diagnostics and the use of whole-genome profiling using DNA microarrays promises to yield improved understanding of the disease process with the subsequent development of more accurate diagnostic procedures based upon these discoveries. Recent reports describing a variety of experimental approaches have identified a series of candidate genes that are overexpressed in cervical carcinoma. In this article, representative examples of these markers and the resulting translational research will be reviewed within the context of improved cervical disease detection. An emerging class of markers, the minichromosome maintenance protein family of DNA licensing factors (MCM-2, MCM-6, MCM-7), shows promise for the specific detection of high-grade cervical disease using simple antibody-based immunochemistry formats. These proteins are overexpressed in cervical disease as a result of infection by oncogenic strains of human papillomavirus (HPV) and subsequent uncontrolled activation of gene transcription and aberrant S-phase induction, mediated through the E2F transcription factor pathway. This behavior appears to be a hallmark of high-grade cervical disease and provides the link between oncogenic HPV infections and the molecular behavior of cervical neoplasia (CN). The use of these molecular descriptors of CN in simple immunochemistry formats compatible with conventional cytology preparations is anticipated to improve the screening and detection of cervical disease within the healthcare system.

Cyclin A is a c-Jun target gene and is necessary for c-Jun-induced anchorage-independent growth in RAT1a cells

Overexpression of c-Jun enables Rat1a cells to grow in an anchorage-independent manner. We used an inducible c-Jun system under the regulation of doxycycline in Rat1a cells to identify potential c-Jun target genes necessary for c-Jun-induced anchorage-independent growth. Induction of c-Jun results in sustained expression of cyclin A in the nonadherent state with only minimal expression in the absence of c-Jun. The promoter activity of cyclin A2 was 4-fold higher in Rat1a cells in which c-Jun expression was induced compared with the control cells. Chromatin immunoprecipitation demonstrated that c-Jun bound directly to the cyclin A2 promoter. Mutation analysis of the cyclin A2 promoter mapped the c-Jun regulatory site to an ATF site at position -80. c-Jun was able to bind to this site both in vitro and in vivo, and mutation of this site completely abolished promoter activity. Cyclin A1 was also elevated in c-Jun-overexpressing Rat1a cells; however, c-Jun did not regulate this gene directly, since it did not bind directly to the cyclin A1 promoter. Suppression of cyclin A expression via the introduction of a cyclin A antisense sequences significantly reduced the ability of c-Jun-overexpressing Rat1a cells to grow in an anchorage-independent fashion. Taken together, these results suggest that cyclin A is a target of c-Jun and is necessary but not sufficient for c-Jun-induced anchorage-independent growth. In addition, we demonstrated that the cytoplasmic oncogenes Ras and Src transcriptionally activated the cyclin A2 promoter via the ATF site at position -80. Using a dominant negative c-Jun mutant, TAM67, we showed that this transcriptional activation of cyclin A2 requires c-Jun. Thus, our results suggest that c-Jun is a mediator of the aberrant cyclin A2 expression associated with Ras/Src-induced transformation.