Expression of extracellular matrix proteins in cervical squamous cell carcinoma--a clinicopathological study

HPV8 activates cellular gene expression mainly through Sp1/3 binding sites

The human papillomavirus type 8 (HPV8) is associated with skin cancer development. The goal of this study was to investigate the effects of HPV8 oncoproteins on cellular gene expression and the identification of key regulators. We performed affymetrix microarray analyses to identify differentially expressed genes and common sequence motifs and identified Sp1/3 binding sites as being crucial. In transient transfection assays, we confirmed that HPV8-E7 stimulates the activity of Sp1/3 promoters. Interestingly, the HPV8-E7L23A mutant, which cannot trigger keratinocyte invasion was unable to activate fibronectin gene expression. In skin models or HPV8 positive skin cancers we found a peculiar deposition of fibronectin in the dermal compartment, and a correlation of Sp3 and fibronectin in the nucleus of HPV8-positive keratinocytes. Taken together, we identified that HPV8-E7 exerts control over cellular gene expression through Sp1/3 binding motifs, which may contribute to HPV8-mediated keratinocyte transformation and subsequent fibronectin-dependent invasion.

Decreased expression of the plasminogen activator inhibitor type 1 is involved in degradation of extracellular matrix surrounding cervical cancer stem cells

The plasminogen activator (PA) system consists of plasminogen activator inhibitor type 1 (PAI-1), urokinase-type plasminogen activator and its receptor (uPA and uPAR). PAI-1 inhibits the activation of uPA (which converts plasminogen to plasmin), and is involved in cancer invasion and metastasis, by remodeling the extracellular matrix (ECM) through regulating plasmin. Cancer stem cells (CSCs) are a small subset of cells within tumors, and are thought to be involved in tumor recurrence and metastasis. Considering these facts, we investigated the relationship between PAI-1 and cervical CSCs. We used ALDH1 as a marker of cervical CSCs. First, we demonstrated that culturing ALDH1-high cells and ALDH-low cells on collagen IV-coted plates increased their expression of active PAI-1 (ELISA), and these increases were suggested to be at mRNA expression levels (RT-qPCR). Secondly, we demonstrated PAI-1 was indeed involved in the ECM maintenance. With gelatin zymography assays, we found that ALDH1-high cells and ALDH-low cells expressed pro-matrix metalloproteinase-2 (pro-MMP-2) irrespective of their coatings. With gelatinase/collagenase assay kit, we confirmed that collagenase activity was increased when ALDH1-low cells were exposed to TM5275, a small molecule inhibitor of PAI-1. Putting the data together, we hypothesized that cancer cells adhered to basal membrane secrete abundant PAI-1, on the other hand, cancer cells (especially CSCs rather than non-CSCs) distant from basal membrane secrete less PAI-1, which makes the ECM surrounding CSCs more susceptible to degradation. Our study could be an explanation of conflicting reports, where some researchers found negative impacts of PAI-1 expression on clinical outcomes and others not, by considering the concept of CSCs.

Problematic issues in the staging of endometrial, cervical and vulval carcinomas

The International Federation of Gynecology and Obstetrics (FIGO) staging of tumours of the uterine corpus, cervix and vulva was revised in 2009. The greatest impact of the revised staging was on carcinomas of the uterine corpus. Uterine sarcomas are now staged separately. Changes to the staging system for vulvar carcinomas largely reflect the significance of lymph node status. Only minor amendments have been introduced for cervical carcinomas, which remain the only gynaecological tumours to be staged clinically. These revisions, based on recent evidence, require careful, more detailed assessment of several histological parameters at each anatomical site. The present review deals with the evidence and rationale underpinning the revisions, and includes practical guidance on tumour staging. This covers the assessment and measurement of myoinvasion and evaluation of cervical, parametrial, serosal and vaginal involvement in carcinomas of the uterine corpus; the identification and accurate measurement of stromal invasion in cervical and vulvar carcinomas; the assessment of unusual variants of carcinoma at each of these sites; and the assessment of lymph node involvement.

Near-infrared micro-Raman spectroscopy for in vitro detection of cervical cancer

Near-infrared Raman spectroscopy is a powerful analytical tool for detecting critical differences in biological samples with minimum interference in the Raman spectra from the native fluorescence of the samples. The technique is often suggested as a potential screening tool for cancer. In this article we report in vitro Raman spectra of squamous cells in normal and cancerous cervical human tissue from seven patients, which have good signal-to-noise ratio and which were found to be reproducible. These preliminary results show that several Raman features in these spectra could be used to distinguish cancerous cervical squamous cells from normal cervical squamous cells. In general, the Raman spectra of cervical cancer cells show intensity differences compared to those of normal squamous cell spectra. For example, several well-defined Raman peaks of collagen in the 775 to 975 cm(-1) region are observed in the case of normal squamous cells, but these are below the detection limit of normal Raman spectroscopy in the spectra of invasive cervical cancer cells. In the high frequency 2800 to 3100 cm(-1) region, it is found that the peak area under the CH stretching band is lower by a factor of approximately six in the spectra of cervical cancer cells as compared with that of the normal cells. The Raman chemical maps of regions of cancer and normal cells in the cervical epithelium made from the spectral features in the 775 to 975 cm(-1) and 2800 to 3100 cm(-1) regions are also found to show good correlation with each other.

HPV16 E7 oncogene expression in normal human epithelial cells causes molecular changes indicative of an epithelial to mesenchymal transition

Cancer-associated epithelial to mesenchymal transition (EMT) is crucial for invasion and metastasis. Molecular hallmarks of EMT include down-regulation of the epithelial adhesion protein E-cadherin and de-novo expression of N-cadherin and the mesenchymal intermediate filament proteins vimentin and fibronectin. Expression of HPV16 E7 in normal human epithelial cells caused increased levels of vimentin and fibronectin, whereas the epithelial adhesion protein E-cadherin was expressed at decreased levels. Similar expression patterns of vimentin, fibronectin and E-cadherin were also detected in cells expressing HPV16 E6 and E7 or the entire HPV16 early transcriptional unit. HPV16 E6 and E7 were each able to induce N-cadherin expression. Interestingly, these changes in expression levels of EMT-associated proteins are not similarly reflected at the level of mRNA expression, suggesting that HPV16 oncoproteins also modulate EMT through non-transcriptional mechanisms. Hence, HPV16 oncoproteins may contribute to malignant progression through EMT induction.

The 67 kDa laminin receptor: structure, function and role in disease

The 67LR (67 kDa laminin receptor) is a cell-surface receptor with high affinity for its primary ligand. Its role as a laminin receptor makes it an important molecule both in cell adhesion to the basement membrane and in signalling transduction following this binding event. The protein also plays critical roles in the metastasis of tumour cells. Isolation of the protein from either normal or cancerous cells results in a product with an approx. molecular mass of 67 kDa. This protein is believed to be derived from a smaller precursor, the 37LRP (37 kDa laminin receptor precursor). However, the precise mechanism by which cytoplasmic 37LRP becomes cell-membrane-embedded 67LR is unclear. The process may involve post-translational fatty acylation of the protein combined with either homo- or hetero-dimerization, possibly with a galectin-3-epitope-containing partner. Furthermore, it has become clear that acting as a receptor for laminin is not the only function of this protein. 67LR also acts as a receptor for viruses, such as Sindbis virus and dengue virus, and is involved with internalization of the prion protein. Interestingly, unmodified 37LRP is a ribosomal component and homologues of this protein are found in all five kingdoms. In addition, it appears to be strongly associated with histones in the eukaryotic cell nucleus, although the precise role of these interactions is not clear. Here we review the current understanding of the structure and function of this molecule, as well as highlighting areas requiring further research.

Angiogenesis in gynecological oncology-mechanism of tumor progression and therapeutic targets

The purpose of this article is to review the current literature pertaining to various angiogenic stimulators and angiogenesis inhibitors in gynecological malignancies and the relevance of these markers in the prognosis of these diseases. We also summarize the antiangiogenic drugs currently in development and in clinical use in gynecological oncology. The information was obtained from a computer search of MEDLINE for studies published in the English language regarding angiogenesis and angiogenesis inhibitors in gynecological malignancies between 1970 and December 2003; additional sources were identified through cross-referencing. In ovarian cancer, various different angiogenic activators have been found to correlate with microvessed density (MVD), stage, lymph node and peritoneal metastasis, and survival. In cervical cancer, correlation has been seen between increased angiogenic markers and stage, grade, tumor size, and survival. Studies in endometriat cancer show correlation of angiogenic markers with stage, grade, MVD, and survival. Whereas, in gestational trophoblastic neoplasm (GTD) only few markers have been studied, and some correlated with progression. Information on anti angiogenic drugs currently in ongoing and upcoming trials in gynecological malignancies is also presented. Angiogenesis factors may have a prognostic role to play in patients with gynecological cancers and should continue to be investigated as clinically useful tumor markers. Antiangiogenic-targeted therapies offer an attractive strategy for clinical investigation in gynecologic oncology.

Biomarkers of human cutaneous squamous cell carcinoma from tissues and cell lines identified by DNA microarrays and qRT-PCR

Squamous cell carcinoma (SCC) is the second most common form of skin cancer in Caucasians. Here we report on the identification of biomarkers of human cutaneous SCC cell lines in vitro and tissue samples in vivo using DermArray and PharmArray DNA microarrays, consisting of ca. 7400 unique human cDNAs. Differentially expressed genes were identified in two facial skin SCC cell lines (SCC 12 and SCC 13) compared to normal keratinocytes, and three cutaneous SCC tissue samples compared to normal skin. Quantitative validations of up- and down-regulated biomarkers were performed by qRT-PCR on 23 biomarker genes for the cell lines and 20 biomarker genes for the tumor tissues. In addition, three oral SCC cell lines were also included in the qRT-PCR validations for comparison, and the biomarker profiles were highly similar between the cutaneous and the oral SCC cell lines for all 23 biomarkers examined. The expression profiles for a variety of non-cutaneous SCC types, such as head-and-neck, oral, and lung, have been previously published. This report is the first to describe biomarkers for cutaneous SCC in two contexts, in vitro and in vivo. Although there was minimal overlap between the two different contexts using DNA microarrays, five genes were found common to both the cell lines and tissues, namely fibronectin 1, annexin A5, glyceraldehyde 3-phosphate dehydrogenase, zinc-finger protein 254, and huntingtin-associated protein interacting protein. Some of our previously published biomarkers of normal keratinocytes were down-regulated in SCC, suggestive of the dedifferentiated status of the transformed cells. While recent reports have identified some of the same genes as SCC biomarkers, for instance in head-and-neck cancer, thereby validating our approach, we have identified some novel biomarkers for cutaneous disease. These biomarker lists may be useful in molecular diagnostics of non-melanoma skin cancer, and a subset of the biomarkers might serve as suitable targets for drug discovery efforts of therapies for SCC.

Transforming growth factor-beta1 induces tumor stroma and reduces tumor infiltrate in cervical cancer

Cervical carcinomas consist of tumor cell nests surrounded by varying amounts of intratumoral stroma containing different quantities and types of immune cells. Besides controlling (epithelial) cell growth, the multifunctional cytokine transforming growth factor-beta(1) (TGF-beta(1)) is involved in the formation of stroma and extracellular matrix (ECM) and in immunosuppression. Several malignancies are known to be associated with enhanced production of TGF-beta(1), repression or mutation of TGF-beta transmembrane receptors, or mutations at the postreceptor intracellular signaling pathway. The aim of our study was to investigate the role of tumor cell-derived TGF-beta(1) on the amount of intratumoral stroma; the deposition of collagen IV, fibronectin, and laminin; and the tumor infiltrate in cervical carcinoma. The expression of TGF-beta(1) mRNA in 108 paraffin-embedded cervical carcinomas was detected by mRNA in situ hybridization. Immunohistochemistry was used to investigate the amount of tumor stroma and ECM proteins and the extent of the tumor infiltrate. Plasminogen activator inhibitor-1 (PAI-1) protein expression in tumor cells was determined to verify the biological activity of TGF-beta(1.) Cytoplasmatic TGF-beta(1) mRNA expression in tumor cells was significantly correlated with the amount of intratumoral stroma and the deposition of collagen IV. TGF-beta(1) mRNA expression in every tumor was accompanied by PAI-1 expression, indicating biological activity of TGF-beta(1). An inverse relationship between TGF-beta(1) mRNA expression in tumor cells and the extent of the tumor infiltrate was demonstrated. Our results indicate that cervical cancer cells affect the amount and the composition of the intratumoral stroma and the tumor infiltrate by the production and secretion of TGF-beta(1).

Reduced expression of plakoglobin correlates with adverse outcome in patients with neuroblastoma

Plakoglobin and its homologue beta-catenin are cytoplasmic proteins that mediate adhesive functions by interacting with cadherin receptors and signaling activities by interacting with transcription factors. It has been suggested that plakoglobin can suppress tumorigenicity whereas beta-catenin can act as an oncogene. We investigated the correlation between the expression pattern of N-cadherin, beta-catenin, and plakoglobin and tumor behavior in primary tumors of 20 neuroblastoma patients of all stages and in 11 human neuroblastoma cell lines. N-cadherin and beta-catenin were detected in 9 of 11 and 11 of 11 cell lines, respectively, whereas plakoglobin was undetectable or severely reduced in 6 of 11 cell lines. Tumor cells from 16 of 20 patients expressed N-cadherin and 20 of 20 patients expressed beta-catenin at levels similar to those of normal ganglion cells. Plakoglobin was undetectable in 9 of 20 tumors. Plakoglobin deficiency in the primary tumors was significantly associated with adverse clinical outcome. Five of the patients with plakoglobin-negative tumors died whereas four patients are alive without evident disease. In contrast, all patients with plakoglobin-positive tumors are alive; 2 of 11 are alive with the disease and 9 of 11 are alive without evident disease. These results suggest that down-regulation of plakoglobin may be of prognostic value for neuroblastoma patients as predictor of poor outcome.

Topoisomerase II immunostaining as a prognostic marker for survival in ovarian cancer

OBJECTIVE

This study aimed to evaluate topoisomerase II compared to Ki-67 expression as a marker for tumor behavior and for prognosis of patients with ovarian cancer.

METHODS

In order to screen for potential prognostic markers, two groups of patients with advanced stage (FIGO stages III and IV) epithelial ovarian carcinoma were selected based on differences in survival (mean survival, 11 years versus 2 years). Pathology slides were reviewed, and immunohistochemistry using antibodies to topoisomerase II and Ki-67 was performed on the original cell blocks. No patients were lost to follow-up.

RESULTS

Detectable expression of topoisomerase II was present in 70.0 +/- 30.3% of cells in patients with rapidly progressing disease, compared to only 12.3 +/- 12.4% of cells in long-term survivors (P = 0.0001). Ki-67 expression was also more frequent in short-term survivors compared to long-term survivors, but the difference was less prominent than with topoisomerase II (P = 0.01). Specificity and sensitivity as prognostic factors reached 88.2 and 93.8% for topoisomerase II, compared to 55.6 and 88.2% for Ki-67.

CONCLUSIONS

Topoisomerase II expression as detected by immunohistochemistry in tumor samples emerged as a promising clinically relevant biomarker for survival in advanced epithelial ovarian cancer.