Expression of a novel beta 1 integrin in the dysplastic progression of the cervical epithelium

The science behind the effectiveness of in vivo screening

Meta-analyses of studies examining the sensitivity of the Papanicolaou (Pap) smear have revealed that up to 50% evade detection by a single Pap test. Liquid-based preparation techniques have improved the false-negative rate; however, an apparent irreducible 20% false-negative rate still exists. Emerging data now show that aberrant expression of adhesion molecules is seen in a subset of dysplastic lesions of the cervix that fail to be detected by the Pap test, whereas normal patterns were observed in lesions that were Pap positive. These data have led to the hypothesis that there is a subset of lesions where dysplastic cells fail to exfoliate. In this model, the Pap test is extremely unlikely to detect such "nonshedding" lesions as the cells resist being harvested by the collection devices. However, despite their nonshedding behavior, these lesions remain readily identifiable by visual inspection of the cervix after application of acetic acid.

Aberrant expression of E-cadherin in cervical intraepithelial neoplasia correlates with a false-negative Papanicolaou smear

OBJECTIVES

E-cadherin is responsible for cell adhesion in normal cervical epithelium. It is normally absent in the superficial epithelial layers, allowing for exfoliation. We investigated the correlation between E-cadherin distribution and Papanicolaou smear in subjects with cervical dysplasia.

STUDY DESIGN

Tissue samples from 25 women with cervical dysplasia were tested for E-cadherin, beta-catenin, and alpha-catenin expression by immunohistochemistry. The expression pattern of these proteins, whether full thickness or restricted to the basal layers, was correlated with the Papanicolaou smear result.

RESULTS

Of 12 women with normal Papanicolaou smears, 10 of 11 informative cases demonstrated E-cadherin expression throughout all epithelial layers. Eight of 10 informative cases with an abnormal Papanicolaou smear showed E-cadherin only at the basal layers. Alpha-catenin was distributed throughout the entire epithelium in samples of all 25 women.

CONCLUSIONS

Expression of E-cadherin throughout all epithelial layers was correlated with a false-negative Papanicolaou smear. It is likely that aberrant persistence of E-cadherin in these lesions interferes with the exfoliation of abnormal cells.

Surrogate endpoint biomarkers and their modulation in cervical chemoprevention trials

BACKGROUND

Surrogate endpoint biomarkers (SEBs) are used as intermediate indicators of a reduction in cancer incidence in chemoprevention studies. SEBs should be expressed differentially in normal and high risk tissue; appear at a well defined stage of carcinogenesis; be studied with reasonable sensitivity, specificity, and accuracy; and be modulated in chemoprevention trials. The concept of SEBs may be useful in the trials of many new therapies.

METHODS

The current review includes a comprehensive review of the literature. Many SEBs have been the subject of intense study and include quantitative histopathology and cytology, proliferation markers, regulation markers, differentiation markers, general genomic instability markers, and tissue maintenance markers. Because of the critical biologic and epidemiologic role of the human papillomavirus (HPV) in cervical carcinogenesis, the relation between these markers and HPV should be considered. In addition, biomarkers of HPV infection and its regression should be sought.

RESULTS

Several chemoprevention trials have been published that have included the use of SEBs. The biomarkers that appear most promising in these clinical trials can be measured quantitatively and reproducibly: quantitative histology and cytology, proliferating cell nuclear antigen (PCNA), MIB-1, MPM-2, HPV viral load, epidermal growth factor receptor, polyamines, and ploidy. The markers that have been demonstrated to be modulated in chemoprevention trials in the literature are quantitative histology and cytology, PCNA, MPM-2, HPV viral load, and polyamines.

CONCLUSIONS

The surrogate endpoint biomarkers of most interest in future research should correlate well with HPV infection, be modulated by several therapeutic agents, and have limited variability and ease in measurement.

Immunohistochemical study of skin lesions in acute and chronic graft versus host disease following bone marrow transplantation

Allogeneic bone marrow transplantation (BMT) is the therapy of choice for a variety of malignant and nonmalignant disorders; however, a major constraint to successful BMT is graft versus host disease (GVHD). Skin lesions are the earliest presentation of GVHD. Donor-derived cytotoxic T lymphocytes are the effector cells responsible for lesions in the skin and other tissues. Here we show that most skin-infiltrating lymphocytes, in all forms of GVHD, are memory T cells with a predominance of CD4+ cells in the dermis and CD8+ cells in the epidermis. Relatively little attention has been focused on the adhesive phenotype of keratinocytes in GVHD. In this study, immunohistochemical analyses of skin biopsies from BMT patients with acute or chronic GVHD were conducted, with particular emphasis on antigen-presenting cells (APCs) and on keratinocytes. The distribution of APCs in the epidermis (Langerhans' cells) was investigated. Keratinocytes were analyzed for the expression of human leukocyte antigen DR locus (HLA-DR) and of a novel integrin, alpha10.1.2 beta1, which is detected in the basal layer of normal epidermis. Langerhans' cells were decreased in all grades of acute GVHD, but the epidermal APC network was reconstituted in chronic GVHD. HLA-DR was expressed by keratinocytes in grade 2 and 3 acute GVHD lesions, but not in two of three chronic GVHD cases, and in the regression phase of acute GVHD. Integrin chains alpha10.1.2 and beta1 were detected in the epidermal basal cell layer of most GVHD cases but they were also expressed in suprabasal keratinocytes of both acute and chronic GVHD. This latter finding indicates that a proliferative response uncoupled from differentiation occurs in keratinocytes in the course of GVHD.