Acid and neutral cysteine proteinase inhibitor in normal uterine portio and in squamo-epithelial metaplasia, dysplasias and infiltrative carcinoma of the uterine portio

Functional expression of recombinant human stefin A in mammalian and bacterial cells

Recombinant human cysteine protease inhibitor, stefin A, was expressed in both Escherichia coli and BS-C-1 monkey kidney cells utilizing pET and recombinant vaccinia virus systems, respectively. The expressed protein was purified and analyzed by SDS-PAGE and Western blot analysis utilizing a polyclonal antibody against rat cystatin alpha. In both cases the purified protein appeared as a single band corresponding to the molecular weight of stefin A ( approximately 10kDa). Viability of the expressed stefin A was determined by the inhibition of the plant cysteine protease, papain. Recombinant human stefin A expressed in both E. coli and BS-C-1 cells, was shown to almost completely inhibit papain. The expression of a fully functional recombinant human stefin A in the bacterial system provides a highly efficient tool for the production of large quantities of the protein. This can be an important tool in kinetic studies as well as in production of antibodies for other analytical studies (immunoblot, immunohistochemical studies, etc.). Expression in the mammalian cells, on the other hand, can provide a significant research tool to study the functional roles of stefin A in mammalian systems such as regulation of cysteine proteases.

Biological and prognostic role of acid cysteine proteinase inhibitor (ACPI, cystatin A) in non-small-cell lung cancer

BACKGROUND

Acid cysteine protease inhibitor (ACPI) is an intracellular protein, often linked to neoplastic changes in epithelium and thought to have an inhibitory role in malignant transformation.

AIM

To analyse the expression and prognostic role of ACPI in non-small-cell lung cancer (NSCLC).

METHOD

Histological samples from 199 patients with resected NSCLC were stained immunohistochemically for the expression of ACPI in normal and preneoplastic bronchial epithelium, and in various types of lung carcinomas.

RESULTS

A normal bronchial epithelium showed positive staining for ACPI in the basal cells, whereas the upper two-thirds of the dysplastic epithelium was ACPI positive. High staining for ACPI was found in 74% (91/123) of squamous-cell carcinomas, whereas 16% (8/49) of adenocarcinomas and 30% of (8/27) large-cell carcinomas showed the high expression of ACPI (p<0.001). Among squamous-cell carcinomas, low expression of ACPI was correlated with poor tumour differentiation (p=0.032). In the whole tissue, reduced expression of ACPI was associated with tumour recurrence (p=0.024). In overall survival (OS) and disease-free survival (DFS) analyses, the histological type of the tumour (both p<0.001) and stage of the tumour (p=0.001, p=0.013, respectively) were related to patient outcome. Low expression of ACPI in tumour cells was associated with poor OS and DFS (p<0.041, p=0.004, respectively). In multivariate analysis, ACPI did not retain its prognostic value, whereas the traditional factors were the most important prognostic factors.

CONCLUSIONS

ACPI expression is linked with the malignant transformation of the bronchial epithelium and predicts a risk of tumour recurrence as well as poor rate of survival for the patients. However, ACPI does not have any independent prognostic value in NSCLC.

Expression of cystatins, high molecular weight cytokeratin, and proliferation markers in prostatic adenocarcinoma and hyperplasia

BACKGROUND

Prostatic adenocarcinoma is the most common malignancy among men in the western world but the diagnostic and prognostic criteria for it are still not clearly defined. Additional means for its diagnosis and prognosis are clearly needed. Previously it has been shown that cystatin A is expressed in the basal cells of normal prostate and the expression disappears in prostatic carcinoma.

METHODS

We have now studied the expression of both cystatins A and B in benign prostatic hyperplasias (BPH), prostatic intraepithelial neoplasias (PIN) and carcinomas of the prostatic epithelium and compared it with the expression of high molecular weight (HMW) cytokeratin as well as the proliferation markers cyclin A and Ki-67. The expression of the proteins was immunohistochemically assessed using 33 total prostatectomy specimens.

RESULTS

Cystatin A was expressed in the basal cells in all cases of BPH, low-grade PIN, and high-grade PIN whereas carcinomas showed no staining of cystatin A. The 34 beta E12 cytokeratin expression was similar to basal cystatin A staining and was not seen in carcinoma foci. Cystatin B showed both nuclear and cytoplasmic expression in the columnar epithelial cells. The decrease in median cytoplasmic staining of cystatin B in carcinomas compared to other lesions was significant, but there was a significant increase in expression with dedifferentiation of carcinoma. Also cyclin A and Ki-67 staining were significantly different in non-carcinomatous foci compared to carcinoma foci and had a remarkably similar negative correlations with basal cystatin A and 34 beta E12 staining.

CONCLUSIONS

The results show that cystatin expression can be used as an aid in the diagnosis of prostatic adenocarcinoma and especially cystatin A in the distinction between high grade PIN and grade I carcinoma.

The role of vascular permeability factor and basic fibroblast growth factor in tumor angiogenesis

In the last decade a considerable amount of research has been dedicated to studying the process of angiogenesis. In the field of tumor biology angiogenesis is a relevant subject of investigation as well, since newly formed blood vessels are required for the growth of tumors and provide an exit route for metastasizing tumor cells. In this review we discuss some aspects of tumor angiogenesis with emphasis on the role that growth factors bFGF and VPF play in this process. A number of biochemical characteristics and biological properties of the two factors and their receptors are reviewed, and the expression of bFGF and VPF in both normal tissues and in tumors is discussed. Finally, we speculate on the use of bFGF and VPF expression as a diagnostic parameter and on possible clinical applications.

Immunolocalization of cystatin A in neoplastic, virus and inflammatory lesions of the uterine cervix

Cystatin A was immunohistochemically demonstrated in the normal squamous epithelium of the uterine cervix, particularly in the parabasal and superficial cell layers whereas it was absent or scanty in the basal cells and in areas with parakeratosis. Cystatin A was also found in neoplastic lesions (dysplasia, carcinoma in situ and squamous cell carcinoma), but less abundant than in normal squamous epithelium. The immunoreaction in intraepithelial neoplasia was closely related to the degree of morphological maturation of the squamous cells with more abundant cystatin A in low grade dysplasia and less in high grade dysplasia and carcinoma in situ. In squamous cell carcinoma, cystatin A was often abundant in highly differentiated areas and almost absent in poorly differentiated ones. Cystatin A was found in the squamous epithelium in herpes and in condylomatous lesions. It was also found in the cytoplasm of neutrophils, but not in lymphocytes and plasma cells. In unspecific cervicitis, cystatin A was found extracytoplasmatically as small vesicles in the epithelial-stromal junction. The implications of cystatin A in neoplastic, virus, and inflammatory processes are discussed.

Cathepsin B and its endogenous inhibitors: the role in tumor malignancy

Several lysosomal proteinases including the cysteine proteinase cathepsin B have been implicated in malignant progression of tumors. Many investigators have demonstrated correlations between increased activity of cathepsin B and increased metastatic capability of animal tumors or malignancy of human tumors. Such increases in cathepsin B activity in malignant tumors may reflect alterations in synthesis, in activation and processing, and/or in intracellular trafficking and delivery as well as in the endogenous inhibitors of cathepsin B. Increases in mRNA transcripts for cathepsin B have been observed in both murine and human tumors and multiple transcripts for cathepsin B have been identified, but an association of multiple transcripts with malignancy has not been confirmed. Cathepsin B precursors found in human malignant ascites fluid do not possess mannose-rich carbohydrates suggesting that a defect in the post translational processing of carbohydrate moieties on tumor cathepsin B may be responsible for the release of cathepsin B observed in many tumor systems. However, the intracellular trafficking of cathepsin B responsible for its association with plasma membrane/endosomal systems and for its release will require further study as both latent, precursor forms of cathepsin B and native forms of cathepsin B are involved. We speculate that malignant tumor cells adherent to basement membrane are capable of forming a digestive microenvironment in which lysosomal proteinases such as cathepsin B function optimally, a microenvironment similar to that formed between adherent osteoclasts and bone. One of the endogenous cysteine proteinase inhibitors, stefin A, also is affected by malignancy. Reduced expression (mRNA and protein) of stefin A is found as well as a reduction in its inhibitory capacity against cysteine proteinases. The data to date at both the molecular and protein levels supporting a functional role(s) for cathepsin B and its endogenous inhibitors in cancer progression are only correlative. Experimental approaches utilizing well-defined model systems in conjunction with genetic manipulation of cathepsin B and its endogenous inhibitors are needed to provide convincing evidence that cathepsin B has an important role in cancer.

Localization of cathepsin H and its inhibitor in the skin and other stratified epithelia

The rat-skin-derived cysteine proteinase, so-called BANA-hydrolase, which is capable of hydrolysing benzoylarginine naphthylamide and leucine naphthylamide was shown to be immunologically identical to cathepsin H purified from rat liver. The enzyme was immunocytochemically localized in the basal cell layer of rat epidermis. A natural inhibitor of cathepsin H with a molecular weight of about 13,000 was mainly localized in the keratinizing cell layers and showed only a weak reaction in the basal cells. Thus, cathepsin H appears to be a characteristic feature of the proliferating cell layer, whereas the cysteine-proteinase inhibitor is a characteristic feature of keratinizing cells.