Association of nm23 protein levels in human prostates with proliferating cell nuclear antigen expression at autopsy

Global Trends of Latent Prostate Cancer in Autopsy Studies

Simple Summary

The incidence of prostate cancer (PC) is statistically biased due to the increase in prostate-specific antigen (PSA) screening and the accuracy of national cancer registration systems. However, studies on latent PC provide less biased information. This comprehensive review included studies evaluating latent PC in several countries. The prevalence of latent PC has been stable since 1950 in Western countries, but it has increased over time in Asian countries. Latent PC in Asian men has increased in prevalence and is higher in grade. This increase occurred not only due to the increase in PSA screening, but also due to increasing adoption of a Westernized lifestyle. Racial differences between Caucasian and Asian men may also explain the tumor location of latent PC. The autopsy findings in patients with latent PC included a significant proportion of high grade and stage cancers, suggesting a need to reconsider the definition of clinically insignificant PC.

Abstract

The incidence of prostate cancer (PC) has been increasing in Asian countries, where it was previously low. Although the adoption of a Westernized lifestyle is a possible explanation, the incidence is statistically biased due to the increase in prostate-specific antigen (PSA) screening and the accuracy of national cancer registration systems. Studies on latent PC provide less biased information. This review included studies evaluating latent PC in several countries after excluding studies using random or single-section evaluations and those that did not mention section thickness. The findings showed that latent PC prevalence has been stable since 1950 in Western countries, but has increased over time in Asian countries. Latent PC in Asian men has increased in both prevalence and number of high-grade cases. Racial differences between Caucasian and Asian men may explain the tumor location of latent PC. In conclusion, the recent increase in latent PC in Asian men is consistent with an increase in clinical PC. Evidence suggests that this increase is caused not only by the increase in PSA screening, but also by the adoption of a more Westernized lifestyle. Autopsy findings suggest the need to reconsider the definition of clinically insignificant PC.

Role of nm23H1 in predicting metastases in prostatic carcinoma

Background

Non-metastatic nm23H1 gene is thought to play a critical role in cell proliferation. Studies of nm23H1 have been done in many other malignancies. But none of these studies took up nm23H1 gene as predictor in the metastases of prostatic carcinoma.

Aims and Objectives

To study the expression of nm23H1 in prostatic lesion and to correlate nm23H1 expression with presence of metastases, tumour stage, tumour grade and with PSA level serum.

Setting and Design

Tertiary hospital based retrospective and prospective study done in a period of one year from thirty patients having prostatic lesion confirmed by biopsy.

Material and Methods

Immunohistochemistry for nm23H1 was performed on unstained coated sections of prostatic lesions to study the relation with prostatic lesion and their correlation with age, PSA level, tumour stage, grading. Clinical data was collected from medical records.

Statistical Analysis

SPSS Version 15 analysis software was used. The value were presented in number(%) and Mean ± SD.

Results

Majority of patients belong to age group 61 to 70yrs.Gleason score >7 were seen in 55% of patients of adenocarcinoma with and without metastasis. The difference in PSA levels between BPH and adenocarcinoma was significant (P < 0.001). IHC expression for nm23H1 gene showed positive findings in all the cases (P = 1). PSA values >20ng/ml showed maximum % mean expression (98.64%) as compared to PSA levels <10 ng/ml (96.91%).

Conclusion

IHC expression of nm23H1 is not an effective tool to distinguish among the cases of BPH, adenocarcinoma of prostate with and without metastasis. Hence nm23H1 gene does not behave like an antimetastatic gene in prostatic lesions.

Characteristics of a thyroid carcinoma cell line derived from spinal metastasis

We established and characterized a new thyroid cancer cell line came from patients who presented spine metastasis; these cell lines could thus be new in vivo models for studying the biology including metastasis of thyroid cancer.

A thyroid carcinoma cell line named THY28 was established through primary culture of the surgical specimens, which were derived from a Chinese patient with spinal metastasis. The cell morphology, growth kinetics, cell cycle, chromosome number, cell capability of migration, tumorigenicity and cytogenetic features of the cell line were investigated. THY28 cells were subcultured in vitro for more than 50 passages with a human karyotype. The modal number of its chromosomes was mainly from 67 to 85. The doubling time of THY28 cells was 56 hours. The histopathological features of xenograft induced by THY28 cells were consistent with the characteristics of thyroid cancer. The biological and molecular properties of THY28 cells were not entirely consistent with those of other thyroid carcinoma cells such as SW579 and TT cells, indicating biological differences between primary and metastatic thyroid carcinoma cell lines. We have established a novel thyroid carcinoma cell line derived from spinal metastasis, which will provide a useful model for biological or therapeutic studies of thyroid carcinoma metastasis.

Molecular biology of prostate cancer

Development of any cancer reflects a progressive accumulation of alterations in various genes. Oncogenes, tumour suppressor genes, DNA repair genes and metastasis suppressor genes have been investigated in prostate cancer. Here, we review current understanding of the molecular biology of prostate cancer. Detailed understanding of the molecular basis of prostate cancer will provide insights into the aetiology and prognosis of the disease, and suggest avenues for therapeutic intervention in the future.

Human prostate cancer risk factors

Prostate cancer has the highest prevalence of any nonskin cancer in the human body, with similar likelihood of neoplastic foci found within the prostates of men around the world regardless of diet, occupation, lifestyle, or other factors. Essentially all men with circulating androgens will develop microscopic prostate cancer if they live long enough. This review is a contemporary and comprehensive, literature-based analysis of the putative risk factors for human prostate cancer, and the results were presented at a multidisciplinary consensus conference held in Crystal City, Virginia, in the fall of 2002. The objectives were to evaluate known environmental factors and mechanisms of prostatic carcinogenesis and to identify existing data gaps and future research needs. The review is divided into four sections, including 1) epidemiology (endogenous factors [family history, hormones, race, aging and oxidative stress] and exogenous factors [diet, environmental agents, occupation and other factors, including lifestyle factors]); 2) animal and cell culture models for prediction of human risk (rodent models, transgenic models, mouse reconstitution models, severe combined immunodeficiency syndrome mouse models, canine models, xenograft models, and cell culture models); 3) biomarkers in prostate cancer, most of which have been tested only as predictive factors for patient outcome after treatment rather than as risk factors; and 4) genotoxic and nongenotoxic mechanisms of carcinogenesis. The authors conclude that most of the data regarding risk relies, of necessity, on epidemiologic studies, but animal and cell culture models offer promise in confirming some important findings. The current understanding of biomarkers of disease and risk factors is limited. An understanding of the risk factors for prostate cancer has practical importance for public health research and policy, genetic and nutritional education and chemoprevention, and prevention strategies.

Immunopathological prognostic and predictive factors in prostate cancer

Prostate cancer is the leading male malignancy in the Western world. Patients with prostate cancer have an unpredictable clinical course, as three biologically different types of tumor exist. This review summarises some of the recent progress made in understanding the biology of prostate cancer with special reference to the prognostic and predictive role of immunohistochemical markers. The prognostic value of established prognostic variables is also discussed.

Distant metastasis of gastric cancer is associated with elevated expression of the antimetastatic nm23 gene

To understand the clinical significance of nm23 gene expression in gastric cancer patients, the Nm23-H1 protein level of fresh resected specimens from a total of 37 gastric cancer patients was measured by Western blot analysis. The elevated nm23 expression group (Nm23-H1 protein level in tumor tissue greater than the 75th percentile value of patients) was significantly associated with the histologically differentiated type (P = 0.036). This group had a higher incidence of distant (hematogeneous) metastasis (P = 0.0023) and a lower 2-year disease-free survival rate (P = 0.033) than the non-elevated group. The result was not consistent with the previous assumption that nm23 is an antimetastatic gene for gastric cancer.