Altered expression of CD44 and variant isoforms in human adenocarcinoma of the endocervix during progression

Redox Potential and ROS-Mediated Nanomedicines for Improving Cancer Therapy

SIGNIFICANCE

The overabundance of reactive oxygen species (ROS) and antioxidants in cancer cells represents a challenge for therapeutic intervention, while also providing an opportunity for the development of new strategies to improve clinical therapeutic outcomes. Recent Advances: Nanotechnology has advanced tremendously in recent decades and now offers many potential opportunities to leverage altered redox status to improve conventional therapies. Highly tunable nanoparticle delivery systems have shown great promise for improving the following: (i) chemotherapy via selective redox-sensitive drug release in tumor cells and limited systemic toxicity; (ii) photodynamic therapy via enhancing photoactivation and/or ROS production; and (iii) radiation therapy via enhancing ROS production. Great progress has also been made regarding novel nanoparticle-mediated therapies to enhance tumor cell death via ROS generation and angiogenic inhibition.

CRITICAL ISSUES

Current anticancer therapies are limited by systemic side effects and resistance. The inherent heterogeneity and hypoxic status of solid tumors impose significant barriers for even the most rationally designed nanoparticle systems. In addition, few comprehensive biodistribution and toxicity evaluations exist, and clinical efficacy remains to be established. The practicality of many nanoparticle systems is compromised by variable in vivo responses and scale-up difficulties due to complicated chemistry and prohibitive manufacturing costs.

FUTURE DIRECTIONS

As nanoparticle design continues to advance, improved therapeutic efficacy will likely follow. Actively targeted systems may improve distribution specificity but more positive clinical demonstrations are needed. Further investigation into systemic and intracellular distribution as well as toxicity will improve understanding of how these nanoparticle systems can be applied to improve existing therapies.

Hepatocyte nuclear factor (HNF)-1β and its physiological importance in endometriosis

Endometriosis is associated with pelvic pain and female infertility. Endometriosis induces inflammation and is vulnerable to oxidative stress damage. To update and summarize the literature concerning the mechanisms that serve to protect genomic DNA from the oxidative damage, the present study reviews the English-language literature for biochemical studies on the transcription factor hepatocyte nuclear factor (HNF)-1β target genes. Findings demonstrated that retrograde flow of the menstrual blood might give rise to endometriosis. Iron may have a significant impact on endometriosis gene expression. HNF-1β regulates tissue-specific gene expression in endometriosis, as well as the expression of several genes, including CD44v9, which binds several molecules, including hyaluronan, epidermal growth factor receptor (EGFR), leukemia-associated Rho-guanine nucleotide exchange factor (LARG), IQ motif containing GTPase activating protein 1 (IQGAP1), macrophage migration inhibitory factor (MIF), major histocompatibility complex, class II invariant chain (CD74), cystine transporter subunit (xCT), Fas and extracellular matrix (ECM) proteins. The CD44v9 system is involved in cell migration, growth, survival, anti-apoptosis, immune response and anti-oxidative stress through maintaining higher levels of antioxidants. HNF-1β may serve to alleviate damage and promote survival of cells experiencing stress by upregulating antioxidant protein expression. This review expands current knowledge on the molecular mechanisms underlying the oxidative stress protection provided by HNF-1β and provides evidence that elevated HNF-1β activity might be associated with the CD44v9-dependent signaling cascades.

Abnormal immunoexpression of cell adhesion molecules (CAMs) in cervical cancer

The purpose of this study was to examine the immunoexpression of cell adhesion molecules (CAMs) E-cadherin, CD44s, and CD44v3 in cervical cancer and compare it with that in benign exo-endocervical tissue. In all, 81 cervical cancer biopsy specimens and 22 benign controls were included. Primary monoclonal antibodies NHC-38, F10-44-2, and 3G5 for E-cadherin, CD44s, and CD44v3 were used, respectively. Statistical significance was evaluated by the χ(2) test. Antigen expression was significantly different in cervical cancer specimens compared with controls, showing marked decrease in membrane expression: E-cadherin, 6.5% and 77.3% (P < .000); CD44s, 3.9% and 81.8% (P < .000); and CD44v3, 0% and 81.8% (P < .000), respectively. The immunoexpression was significantly heterogeneous in carcinomas (P < .034) and adenocarcinomas (P < .000) for E-cadherin and CD44s. For CD44v3, no case of cancer showed immunostaining in membranes. These findings reaffirm that cell adhesion is markedly altered in cervical cancer. The authors suggest that these proteins could serve as markers for invasive cervical neoplasia.

Downregulation of BRG-1 repressed expression of CD44s in cervical neuroendocrine carcinoma and adenocarcinoma

Neuroendocrine carcinomas of the uterine cervix are rare tumors with early metastases, highly aggressive clinical behavior, and poor clinical outcome. Several adhesion molecules like cadherins have been tested in an attempt to explain their unique characteristics. Cluster differentiation 44 (CD44) is a widely expressed cell surface glycoprotein that serves as an adhesion molecule in cell-to-substrate and cell-to-cell interaction. We have examined the expression of the standard CD44 (CD44s) by immunohistochemical stains in the paraffin-embedded cervical neoplasm tissue of 17 cases of primary cervical neuroendocrine carcinoma, 28 cases of cervical adenocarcinoma, and 50 cases of cervical squamous cell carcinoma. Loss of CD44s expression was found in 16 of 17 neuroendocrine carcinomas, 14 of 28 adenocarcinomas, and three of 50 squamous cell carcinomas. The differences were statistically significant. We also examined immunohistochemically the expression of the BRG-1 subunit of the SWI-SNF complex, which has been reported to regulate the expression of CD44 in all cases. Loss of BRG-1 expression was observed in 12/16, 6/14, and 1/3 CD44s-negative neuroendocrine carcinomas, adenocarcinomas, and squamous cell carcinomas, respectively. This study suggests that loss of the CD44s molecule may imply special biological behaviors of cervical neuroendocrine carcinomas, and loss of expression of BRG-1 may contribute to this.

Symposium part IV: investigative approaches to endocervical pathology

There is continuing interest in the study of adenocarcinoma of the cervix and its precursors because of its increase in incidence, both absolute and relative, to squamous neoplasia and the complexity of benign glandular lesions with which endocervical neoplasia may be confused. Investigative techniques may be applied as aids to diagnosis, as prognostic markers, and to further our understanding of etiopathogenesis. This article focuses on recent developments in the four areas of epithelial glycoproteins, molecular markers, cell proliferation markers, and human papillomaviruses as applied to endocervical pathology. Although immunohistochemistry remains dominant, a wide range of other techniques is discussed.

Altered CD44 variant 6 expression in FIGO stage IB cervical carcinoma

OBJECTIVE

CD44 is an adhesion molecule which plays an important role in metastatic cascade by mediating tumor cell interaction with the endothelium and the subendothelial matrix. In this study CD44v6 expression was immunohistochemically investigated on 88 uterine cervical cancers. Correlation between expression and prognostic variables and the survival was examined.

METHODS

Eighty-eight patients with stage IB disease, treated primarily with surgery, were examined histopathologically and immunohistochemically. CD44v6 expressions of tumoral tissue and the nonneoplastic tissue nearby were examined using antiCD44v6 monoclonal antibody. CD44v6 expression was compared to the known clinicopathologic prognostic variables and survival of patients.

RESULTS

Nonneoplastic epithelium of the sections showed CD44v6 expression predominantly in basal and parabasal layers at least in traces. CD44v6 overexpression in neoplastic islands was evaluated as "general," "basal" (only in the basal portion of neoplastic islands), and "nonbasal" (also in the central portion of the neoplastic islands) separately. When expression and prognostic variables were compared, CD44v6 non-basal expression was found to be significant in nonsquamous cancers, when the tumor diameter was greater than 3 cm and in the tumors that showed recurrences. Univariate survival analysis with the Kaplan-Meier method showed that only the age of the patient is significantly correlated with disease-free survival. Interestingly when the same analysis was done for 5-year overall survival, diameter of the primary tumor, depth of cervical stromal invasion, existence and number of lymph node involvement, positivity for general CD44v6 expression, and positivity for nonbasal expression were found to be statistically significant. Furthermore multivariate analysis with Cox regression showed that nonbasal CD44v6 expression and lymph node involvement are independent variables for 5-year overall survival.

CONCLUSION

These results indicate that CD44v6 expression is associated with some of the important clinicopathologic prognostic variables and appears to be a predictor of advanced pathological-surgical stage of early clinical stage cervical carcinoma. CD44v6 nonbasal expression is significantly correlated with overall survival.

Surrogate biomarkers of HPV infection in cervical neoplasia screening and diagnosis

The current prevention of cervical cancer and elimination of its precursors is predicated on the identification of cervical cytologic abnormalities and their histologic confirmation. This strategy, although effective, depends on both sensitivity and specificity of cytology and precise histologic distinction between precursor lesions and their mimics during biopsy interpretation. The effective application of diagnostic criteria is operator dependent and varies as a function of experience and training. However, because human papilloma viruses (HPV) are causative agents and alter the cell cycle in cervical neoplasms, host genes interacting directly or indirectly with HPV oncoproteins have been identified in vitro. Recent research has centered on identifying the host genes upregulated in association with HPV infection, determining their suitability as "surrogate markers" for HPV infection, and using these markers to identify HPV-associated epithelial lesions in tissue or cytologic specimens. This review surveys recent advances in this field, summarizing the advantages and limitations of several candidate biomarkers, including PCNA, Ki-67, cyclin E, p16ink4, MN antigen, carcinoembryonic antigen (CEA), and telomerase in the recognition of preinvasive cervical neoplasia, and discusses their future potential in cervical cancer screening. Based on current studies, the strongest candidates for diagnosis and screening are p16 and cyclin E (squamous) and MN (glandular) biomarkers. As new genes are identified and tested, the concept of biomarkers as tools in primary screening and lesion recognition will continue to mature.

Cadherin expression in glandular tumors of the cervix

BACKGROUND

The cadherins are homotypic adhesion proteins that are important in cell sorting during organogenesis. Classic cadherins include several different types that show tissue specific expression. Specific tissue expression of cadherins often is preserved in neoplastic transformation, and cadherin phenotype can be used to differentiate morphologically similar but histogenetically distinct tumors.

METHODS

The authors examined by using immunohistochemistry in paraffin sections the expression of E- (epithelial) and P- (placental) cadherin in 39 patients with glandular tumors of the cervix, including invasive adenocarcinoma, villoglandular adenocarcinoma, adenocarcinoma in situ (AIS), and adenoma malignum.

RESULTS

In all cases, E-cadherin was expressed in both normal and malignant glands without appreciable differences. P-cadherin, normally confined to basal epithelial cells and not observed in benign glands, was aberrantly expressed in neoplastic glands in 27 cases, including 96%(23 of 24 cases) of invasive cancers, 40% (2 of 5) of villoglandular carcinomas, 25% (2 of 8) of AIS, and 0% (0 of 2) of adenoma malignum.

CONCLUSIONS

The authors' results show that E-cadherin is uniformly expressed in glandular tumors of the cervix with no evidence of decreased expression in these tumors. In addition, P-cadherin is aberrantly expressed in most adenocarcinomas and appears to be preferentially expressed in invasive rather than in situ lesions. Thus, aberrant expression of P-cadherin may be a useful marker of invasive or aggressive clinical behavior in glandular lesions of the cervix.

Endocervical cancer is associated with an increase in the ligands and receptors for transforming growth factor-beta and a contrasting decrease in p27(Kip1)

OBJECTIVE

The aim of this study was to investigate the relationship between the expression of the TGF-beta ligands and TGF-beta receptors to the expression of p27(Kip1), a TGF-beta-regulated gene, in endocervical cancer.

METHODS

To examine the expression of TGF-beta and p27(Kip1) in malignant transformation of the uterine endocervix, a panel of 23 formalin-fixed and paraffin-embedded human cervical specimens, including 8 with benign endocervical glands, 8 with cervical adenocarcinoma in situ, and 7 with cervical adenocarcinomas, was used. Tissues were immunostained with polyclonal antibodies that react specifically with TGF-beta 1, TGF-beta 2, TGF-beta 3, TGF-beta RI, TGF-beta RII, and p27(Kip1).

RESULTS

Immunostaining for TGF-beta 1, TGF-beta 2, TGF-beta 3, TGF-beta RI, TGF-beta RII, and p27(Kip1) was detected in normal endocervix, with the TGF-betas showing weak cytoplasmic staining, while p27(Kip1) showed strong nuclear staining. Expression of TGF-beta increased significantly upon neoplastic transformation with the TGF-beta ligands and receptors showing strong cytoplasmic staining in adenocarcinoma in situ compared to normal endocervix. Interestingly, expression of TGF-beta was lower in adenocarcinoma than in adenocarcinoma in situ, but still significantly higher than in normal endocervix. TGF-beta 2 and TGF-beta 3 showed higher levels of immunostaining than TGF-beta 1 in adenocarcinomas. In contrast, p27(Kip1) protein expression decreased with progressive malignancy, with lower p27(Kip1) protein levels detected in adenocarcinoma than in adenocarcinoma in situ, while normal endocervix showed the highest level of p27(Kip1) protein expression.

CONCLUSION

Elevated expression of the TGF-beta ligands and receptors is found in both cervical adenocarcinoma in situ and adenocarcinoma compared to normal endocervix. In contrast, a progressive decrease in p27(Kip1) occurs upon neoplastic transformation of the normal endocervix to cervical adenocarcinoma. These results suggest that neoplastic transformation of the endocervix may be related to dysregulation of TGF-beta and p27(Kip1) seen as an elevation of TGF-beta and a reduction of p27(Kip1) expression that may lead to loss of cell cycle control.

Replicative adenoviruses for cancer therapy

Rapid advances are being made in the engineering of replication-competent viruses to treat cancer. Adenovirus is a mildly pathogenic human virus that propagates prolifically in epithelial cells, the origin of most human cancers. While virologists have revealed many details about its molecular interactions with the cell, applied scientists have developed powerful technologies to genetically modify or regulate every viral protein. In tandem, the limited success of nonreplicative adenoviral vectors in cancer gene therapy has brought the old concept of adenovirus oncolysis back into the spotlight. Major efforts have been directed toward achieving selective replication by the deletion of viral functions dispensable in tumor cells or by the regulation of viral genes with tumor-specific promoters. However, the predicted replication selectivity has not been realized because of incomplete knowledge of the complex virus-cell interactions and the leakiness of cellular promoters in the viral genome. Capsid modifications are being developed to achieve tumor targeting and enhance infectivity. Cellular and viral functions that confer greater oncolytic potency are also being elucidated. Ultimately, the interplay of the virus with the immune system will likely dictate the success of this approach as a cancer therapy.