Tumor vascular signals in renal masses: detection with Doppler US

The vascularity of 49 renal masses (26 malignant and 23 benign lesions) was investigated with duplex Doppler ultrasound. Doppler signals obtained at the margins of renal masses were defined as "tumor signals" when the Doppler-shifted frequency of the lesion exceeded the frequency shift in the ipsilateral main renal artery. These exceeded 2.5 kHz with a 3-MHz insonating frequency. Among the 26 renal masses that subsequently proved to be malignant, tumor signals were obtained in 15 of 18 (83%) untreated renal cell carcinomas, in three of four Wilms tumors, and in two patients with metastases to the kidney, but not in the one patient with lymphoma. None of the 23 benign renal masses demonstrated tumor signals. Tumor vascularity in malignant lesions gives rise to abnormal, high-velocity, Doppler-shifted signals that can help in the differential diagnosis of renal masses.     

Detection of reactive oxygen species (ROS) and apoptosis in human fragmented embryos

In human in-vitro fertilization (IVF)-embryo transfer, the in-vitro culture environment differs from in-vivo conditions in that the oxygen concentration is higher, and in such conditions the mouse embryos show a higher concentration of reactive oxygen species (ROS) in simple culture media. ROS are believed to cause damage to cell membranes and DNA fragmentation in somatic cells. This study was conducted to ascertain the level of H2O2 concentration within embryos and the morphological features of cell damage induced by H2O2. A total of 62 human oocytes and embryos (31 fragmented, 15 non-fragmented embryos, 16 unfertilized oocytes) was obtained from the IVF-embryo transfer programme. The relative intensity of H2O2 concentrations within embryos was measured using 2',7'-dichlorodihydrofluorescein diacetate by Quanti cell 500 fluorescence imaging and DNA fragmentation was observed with transmission electron microscopy and an in-situ apoptosis detection kit. The H2O2 concentrations were significantly higher in fragmented embryos (72.21 +/- 9.62, mean +/- SEM) compared to non-fragmented embryos (31.30 +/- 3.50, P < 0.05) and unfertilized oocytes (30.75 +/- 2.67, P < 0.05). Apoptosis was observed only in fragmented embryos, and was absent in non-fragmented embryos. Electron microscopic findings confirmed apoptotic bodies and cytoplasmic condensation in the fragmented blastomeres. We conclude that there is a direct relationship between increased H2O2 concentration and apoptosis, and that further studies should be undertaken to confirm these findings.      

Genetic characterization of immortalized human prostate epithelial cell cultures. Evidence for structural rearrangements of chromosome 8 and i(8q) chromosome formation in primary tumor-derived cells

We have utilized a combination of conventional and spectral karyotyping (SKY) techniques and allelotype analysis to assess numerical and structural chromosome alterations in two cell lines derived from normal human prostatic epithelium, and three cell lines derived from human prostate primary tumor epithelium, immortalized with the E6 and E7 transforming genes of human papilloma virus (HPV) 16 or the large T-antigen gene of simian virus 40 (SV40). These studies revealed trisomy for chromosome 20 and rearrangements involving chromosomes 3, 4, 8, 9, 10, 16, 17, 18, 19, 21, or 22. In addition, the four HPV-immortalized cell lines exhibited extensive duplications or translocations involving the 11q chromosomal region. Interestingly, allelotyping data disclosed loss of 8p sequences in two of the three primary tumor-derived cell lines, and SKY data revealed that the loss of 8p sequences was directly due to i(8q) chromosome formation and/or other structural alterations of chromosome 8. This provides intriguing evidence that 8p loss in primary human prostate tumors may, in some cases, result from complex structural rearrangements involving chromosome 8. Moreover, the data reported here provide direct evidence that such complex structural rearrangements sometimes include i(8q) chromosome formation.     

E-cadherin expression in prostate cancer: a broad survey using high-density tissue microarray technology

E-cadherin is a calcium 2+-dependent cell-adhesion molecule that determines epithelial development in the embryo and maintains adult differentiated epithelium and homeostasis. Aberrant or decreased expression has been reported to be associated with prostate carcinoma progression. The degree of E-cadherin expression in prostate cancer remains controversial. Some studies have reported decreased expression of E-cadherin as tumors advance and metastasize. Other studies have not demonstrated this relationship. To address these variations, we undertook a study to systematically evaluate E-cadherin expression in a broad range of prostate tissue. Benign prostate, clinically localized prostate cancer, and hormone-refractory metastatic prostate cancer were analyzed under uniform conditions using high-density tissue microarrays (TMA). Formalin-fixed, paraffin-embedded prostate carcinoma from men with clinically localized prostate carcinoma and autopsy material from men who died of widely metastatic, hormone-refractory prostate carcinoma were arrayed into 6 high-density TMA blocks. Benign and atrophic prostate tissue and high-grade prostatic intraepithelial neoplasia (PIN) were also included from the clinically localized cases. Immunohistochemistry was performed using the immunoglobulin G1 mouse monoclonal antibody (HECD-1; Zymed, San Francisco, CA). Membranous staining was recorded as low (aberrant) or high (normal). E-cadherin expression was considered aberrant if less than 70% of the cells had strong membranous staining. A total of 1,220 prostate TMA samples were analyzed. High (normal) E-cadherin expression was seen in 87% of 757 benign, 80% of 41 high-grade PIN, 82% of 325 prostate carcinoma and 90% of 97 hormone-refractory prostate carcinoma TMA samples. Mean E-cadherin expression was determined for each of the 128 clinically localized prostate cancer cases. Aberrant E-cadherin expression showed a statistical trend toward an association with positive surgical margins (P =.012), higher Gleason score (P =.18), and prostate-specific antigen (PSA) failure (Kaplan-Meier analysis, log-rank P =.09). There was a statistically significant association between aberrant E-cadherin expression and larger tumor size (P =.01). No significant associations were seen with extraprostatic extension and seminal vesicle invasion. The current study shows a broad-spectrum approach to evaluating E-cadherin protein expression in prostate carcinoma. Clinically localized prostate tumors, treated with surgery alone, show a high level of E-cadherin expression. Aberrant expression was identified in tumors with positive surgical margins, higher Gleason score, and a higher rate of PSA failure. However, these trends were not statistically significant. A statically significant association between aberrant E-cadherin expression and larger tumor size was identified. In the metastatic hormone-refractory prostate tumors, E-cadherin expression was vastly expressed, and only rare cases had aberrant expression. Therefore, the findings of this study are most consistent with a transient down-regulation of E-cadherin in localized prostate cancer. Metastatic prostate cancer shows strong E-cadherin expression as determined by anti-E-cadherin antibody HECD-1.     

The relationship of microvessel counts to tumor size, estrogen-receptor status, lymph-node metastasis, and disease-free survival in patients with stage-I and stage-ii breast-cancer

Angiogenesis in early stage breast cancer has been suggested to be an independent prognostic factor for metastasis and overall survival. We retrospectively studied 316 cases of early breast cancer with a mean follow-up period of 94 months to determine the role of angiogenesis as a prognostic factor in breast cancer utilizing a Factor VIII immuno-histochemical assay. In a univariate analysis, patients with microvessel counts in the lower 25th percentile had significantly better overall disease-free survival than patients in the upper quartiles (p<0.017). In a multivariate analysis of disease-free survival, microvessel counts did not add to prognostic information when controlling for estrogen receptor status and lymph node status, but did add prognostic information when controlling for tumor size.     

Nuclear morphometry for predicting cervical metastatic potential in laryngeal squamous-cell carcinoma

Quantitative nuclear morphometry (QNM) provides a reliable, reproducible method for measuring the degree of nuclear pleomorphism, a qualitative parameter widely incorporated into histopathological grading schemes. Nuclear shape has successfully been shown to predict primary prostate adenocarcinoma metastatic potential. This investigation utilized QNM to measure the nuclear pleomorphism of 50 patients with primary laryngeal squamous cell carcinoma to determine whether this computer-assisted method could discriminate between those patients with and without cervical metastases. Nuclear cross-sectional area and nuclear roundness as determined by QNM could not discriminate between patients with and without cervical metastases, though significant alterations in nuclear morphology exist between normal laryngeal squamous epithelium and laryngeal squamous cell carcinoma.     

Early castration reduces prostatic carcinogenesis in transgenic mice

Objectives. To test the hypothesis that transgenic mouse models of prostate cancer could be useful for testing chemoprevention strategies by evaluating the effects of early castration on prostate carcinogenesis in TRAMP mice. Human prostate cancer, unlike other cancers, requires androgens for oncogenesis yet acquires partial androgen independence in the castrated milieu. This paradigm is the basis for an ongoing clinical trial using selective androgen deprivation for prostate cancer chemoprevention. However, preclinical correlates for hormonal prevention or other chemoprevention strategies of prostate cancer have not previously been demonstrated in autochthonous models of prostate carcinogenesis.Methods. Magnetic resonance imaging was used to longitudinally measure prostate growth in castrated and noncastrated TRAMP mice, and mice were prospectively examined for the onset of advanced, palpable prostate cancer. Modulation of androgen-responsive oncogene expression, as well as oncogene expression in refractory cancers, was evaluated by Western blot.Results. Early castration significantly reduced prostate tumor growth as measured by magnetic resonance imaging and improved cancer-free survival. Prevention of prostate cancer development in these mice was associated with durable suppression of androgen-responsive oncogene expression (T-antigen expression not detectable by Western blot); prostate cancers refractory to the hormonal prevention strategy demonstrated androgen-independent oncogene expression.Conclusions. These findings suggest that carcinogenesis related to androgen-responsive oncogene expression can be prevented in some cases by hormonal manipulation and that transgenic TRAMP mice are useful for the preclinical evaluation of hormonal and possibly other strategies of prostate cancer chemoprevention.