Increased expression of FGF-8 isoforms and FGF receptors in human premalignant prostatic intraepithelial neoplasia lesions and prostate cancer.

SUMMARY: Fibroblast growth factor 8 (FGF-8) is implicated in growth of prostate cancer. Alternative splicing of the human FGF-8 gene potentially allows coding for four protein isoforms (a, b, e, and f). These isoforms differ in their binding to FGF receptors (FGFR) and in their mitogenic and transforming capacity in transfection assays. Here, we used RT-PCR and immunohistochemistry to study the expression of FGF-8 and FGFR isoforms in human prostate cancer (n = 31). Nonmalignant prostate specimens from cystoprostatectomies (n = 24) were examined as controls. Most prostate cancer samples and some control prostates also contained prostatic intraepithelial neoplasia (PIN) lesions. FGF-8a and e were expressed at significantly higher frequencies in prostate cancer (FGF-8a, 55%; FGF-8e, 45%) than in control samples (FGF-8a, 17%, p = 0.0052; FGF-8e, 8%, p = 0.0031). On the contrary, FGF-8b was found at an equal frequency in prostate cancer (55%) and in control prostates (50%). Furthermore, a combination of two or three FGF-8 isoforms (a, b, and/or e) was also expressed at a higher frequency in prostate cancer than in control samples (45% and 8%, respectively, p = 0.0031). Immunohistochemistry with an antibody recognizing all FGF-8 isoforms was more strongly immunoreactive in prostate cancer cells and PIN lesions than in normal-type epithelium. The receptor splicing variants FGFR1IIIc and FGFR2IIIc, which are activated by FGF-8, were found both in prostate cancer and control samples. Interestingly, immunoreactivity for FGFR1 and FGFR2 was much stronger in prostate cancer cells and PIN than in normal epithelium. These results demonstrate, for the first time, that FGF-8 isoforms and their receptors FGFR1IIIc and FGFR2IIIc are expressed at an increased level not only in prostate cancer but also in premalignant PIN lesions. These data suggest that FGF-8 may have an important autocrine role in the development of human prostate cancer. In addition to FGF-8b, the FGF-8 isoforms a and e may be involved in this process.     

高级别前列腺上皮内瘤变及其他癌前病变的病理特点

研究表明,高级别前列腺上皮内瘤变(HGPIN)是无可置疑的前列腺癌前病变.HGPIN的形态特点是前列腺导管和腺泡的分泌细胞增生,细胞核和核仁肿大与前列腺癌细胞相似,不同的是HGPIN保留有部分基底细胞层.HGPIN与前列腺癌之间有非常密切的关系,因此对HGPIN的诊断和鉴别诊断有重要的临床意义.除了HGPIN以外,目前还提出了一些与前列腺癌的发生可能有关的癌前病变,如:低级别前列腺上皮内瘤变(LGPIN)、增生性炎症性萎缩(PIA)、不典型性腺瘤样增生(AAH).我们旨在对HGPIN及可能为前列腺癌前病变的一些病变的病理形态学、分子学和流行病学研究新进展作一介绍.     

Expression of androgen receptor and growth factors in premalignant lesions of the prostate

Analysis of growth factors and receptors in putative premalignant lesions of prostatic adenocarcinoma should aid our understanding of their growth pathways. Sixty prostatic TURP (transurethral resection of the prostate) specimens exhibiting atypical adenomatous hyperplasia (AAH) and/or prostatic intraepithelial neoplasia (PIN) lesions were assayed by immunohistochemistry for androgen receptor (AR), epidermal growth factor receptor (EGFR), c-erbB-2, transforming growth factor-alpha (TGF-α), vascular endothelial growth factor (VEGF), fibroblast growth factor-2 (FGF-2), MIB-1, E-cadherin, and high molecular weight keratin. Expression of these factors in the lesions was compared with that in the co-existing benign prostatic hyperplasia (BPH) or prostatic adenocarcinoma. Strong AR nuclear staining was observed in the luminal cells, but not the basal cells, of BPH and PIN lesions and in all the carcinomas examined. A similar growth factor and receptor profile was demonstrated in the secretory epithelium of high-grade PIN and carcinoma with a tendency to higher expression of membranous EGFR and c-erbB-2 and cytoplasmic TGF-α, and lower levels of FGF-2 than in low-grade PIN or BPH glands. Also, increased rates of proliferation, as estimated by MIB-1 stained cells, were observed in high-grade PIN in comparison with low-grade PIN and BPH and were not confined to the basal layer. AAH lesions resembled neither BPH nor carcinoma. Proliferation was virtually absent (MIB-1 expression); both AR and E-cadherin expression was significantly reduced; and, with the exception of FGF-2, all the other growth factors and receptors studied were absent. The results presented would support a premalignant role for high-grade PIN, whilst AAH would appear to represent a quiescent phenotype unlikely to progress to neoplasia. Copyright © 1998 John Wiley & Sons, Ltd.     

Estrogen receptor beta expression in invasive breast cancer

The aim of this work was to determine the extent of estrogen receptor beta (ER-beta) expression in invasive breast cancer (BrCA) and whether ER-beta expression is correlated with response to adjuvant hormonal therapy with tamoxifen (AHTT). Immunohistochemical staining (IHC) for estrogen receptor alpha (ER-alpha) and ER-beta was performed on sections of formalin-fixed and paraffin-embedded tissue from 47 unselected invasive breast carcinomas (BrCA). IHC for ER-beta was also performed on sections of BrCA from 118 women who were treated with mastectomy and AHTT. Survival analysis was performed using the Kaplan-Meier method and the log-rank test. Of the 47 unselected BrCA, 17 (36%) were negative for ER-alpha and of these, 8 (47% of ER-alpha negative cases and 17% of all 47 patients) were ER-beta positive. Five of the 8 ER-alpha negative and ER-beta positive cases were positive for ER biochemically. There was no correlation between ER-beta positivity and overall survival in the unselected group. By contrast, in the group of women treated with AHTT, expression of ER-beta in more than 10% of cancer cells was associated with better survival (P = .0077), even in women with node-negative BrCA (P = .0069). In conclusion, our results show that a significant number of women with BrCA are positive for ER-beta only, and may be determined to be ER-negative when currently available IHC is used. ER-beta status is a significant predictor of response to AHTT in women with BrCA. Larger studies with multivariate analysis are needed to confirm these findings.     

Ki-67 expression in early prostate cancer and associated pathological lesions.

AIM: To assess cell proliferation in early prostate cancer and associated pathological lesions. METHODS: Using the Ki-67 antibody, the cell proliferation index was measured in early stage prostatic carcinoma in 37 incidental tumours diagnosed at transurethral prostatectomy (TURP) and in 20 low volume cancers treated by radical prostatectomy. Proliferation indexes have also been measured in areas of normal peripheral zone, transition zone hyperplasia, atrophic appearing lobules, and high grade prostatic intraepithelial neoplasia in the radical prostatectomy cases. RESULTS: In the TURP series the proliferation index correlated with grade and stage. Logistic regression analysis, however, showed that Gleason grade was the most reliable predictor of biopsy proven residual disease and clinical progression. In the radical series transition zone carcinoma the proliferation index was half that of peripheral zone carcinoma. The atrophic lobules also showed a high proliferation index of the same order as seen in the peripheral zone carcinoma. Normal peripheral zone showed the lowest proliferation index and in hyperplastic transition zone it was also less than the other areas. CONCLUSIONS: There is only limited support for the correlation of proliferation index with grade in early stage prostatic carcinoma. The findings do not suggest that proliferation index adds to the prognostic information given by grade and stage in pT1 disease. The significant difference in proliferation index in transition zone and peripheral zone carcinomas supports the morphological distinction of these tumour types and is consistent with differences in biological behaviour. The high proliferation index in lobules considered morphologically atrophic is reminiscent of previous observations in which carcinoma was spatially associated with atrophy.     

Up-regulation of HLA-G expression in cervical premalignant and malignant lesions

The human leukocyte antigen G (HLA-G) molecule, a non-classical major histocompatibility complex class I antigen, exhibits highly limited tissue distribution and gene variation. Recent studies indicate strong immunoinhibitory properties in tumor cells that may favor their escape from anti-tumor immune responses. However, the role of HLA-G in cervical premalignant and malignant lesions has not been defined clearly. In our study, HLA-G expression was studied in cervical tissue from 119 patients with lesions and 22 normal cervical tissue specimens by immunohistochemistry. HLA-G was expressed in 45% (54/119) of cervical lesion-containing tissues while it was rarely detectable (0/22) in the control specimens (P = 0.000). ROC curve analysis showed that HLA-G has an area under the curve (AUC) of 0.694. Furthermore, we investigated soluble HLA-G expression in the plasma of 172 patients with cervical lesions and 20 healthy controls. Significant increases were also observed in soluble HLA-G levels (median, 191.4 vs 45.18 U/ml, P < 0.001). The relative operating characteristic (ROC) curves for soluble HLA-G (sHLA-G), squamous cell carcinoma (SCC), and carbohydrate antigen 125 (CA125) show an AUC of 0.710, 0.634, and 0.588, respectively. At the cut-off values of 108.20 U/ml for sHLA-G, 1.5 ng/ml for SCC, and 35 U/ml for CA125, the sensitivity was 73.30%, 47.83%, and 44.83%, respectively. The detection of soluble HLA-G in plasma may have significance in the early detection of cervical malignant lesions.     

Different perforin expression in peripheral blood and prostate tissue in patients with benign prostatic hyperplasia and prostate cancer

Perforin (P) is a prototypical cytotoxic molecule involved in cell-mediated immunity against various pathogens, alloantigens and particularly different tumours. The purpose of this study was to determine P expression in different lymphocyte subpopulations isolated from peripheral blood and prostate tissue of patients with benign prostatic hyperplasia (BPH) and prostate cancer (PCa) and compare it with the P expression found in the control group. Twenty subjects were recruited in each of the groups. Prostate mononuclear cells of the BPH and PCa tissues were isolated by enzymatic digestion and gradient density centrifugation, whereas peripheral blood mononuclear cells were isolated by gradient density centrifugation alone. Cells and tissue samples were labelled using monoclonal antibodies against P and different surface antigens (CD3, CD4, CD8 and CD56) and analysed by immunofluorescence and flow cytometry. Total P expression in peripheral blood lymphocytes did not differ significantly between BPH/PCa patients and control group, although the BPH and PCa tissue showed lower P expression level. A negative correlation between prostate-specific antigen levels and the overall percentage of P(+), CD3(+) CD56(-) P(+) , and CD3(-) CD56(+) P(+) cells in the prostate tissue was observed only in patients with PCa. Our findings indicate that the low frequency of P(+) lymphocytes, including T, NKT and NK cells, in the prostate tissue of patients with BPH and, particularly, PCa could be the consequence of local tissue microenvironment and one of the mechanisms involved in the pathogenesis of prostate hyperplasia following malignant alteration.     

Cyclooxygenase-2 expression in Helicobacter pylori-associated premalignant and malignant gastric lesions

Expression of cyclooxygenase-2 (COX-2) in various stages of the Helicobacter pylori-associated gastric carcinogenesis pathway has not been elucidated. We investigated the distribution and intensity of COX-2 expression in premalignant and malignant gastric lesions, and monitored the changes after H. pylori eradication. Gastric biopsies from H. pylori-infected patients with chronic active gastritis, gastric atrophy, intestinal metaplasia (IM), gastric adenocarcinoma, and noninfected controls were studied. Expression of COX-2 was evaluated by immunohistochemistry and in situ hybridization. Endoscopic biopsies were repeated 1 year after successful eradication of H. pylori in a group of IM patients for comparing COX-2 expression and progression of IM. In all H. pylori-infected patients, COX-2 expression was predominantly found in the foveolar and glandular epithelium and, to a lesser extent, in the lamina propria. In the noninfected group, only 35% of cases demonstrated weak COX-2 expression. Intensity of COX-2 was not significantly different between the chronic active gastritis, gastric atrophy, IM, and gastric adenocarcinoma groups. In 17 patients with IM, COX-2 expressions in the epithelial cells and stromal cells were reduced 1 year after H. pylori eradication. However, the changes in COX-2 expression did not correlate with progression/regression of IM. Both premalignant and malignant gastric lesions demonstrate strong COX-2 expression. Successful eradication of H. pylori leads to down-regulation of COX-2 expression but failed to reverse IM at 1 year.     

p16INK4A expression in cervical premalignant and malignant lesions

p16^INK4a is a cyclin-dependent kinase (CDK) inhibitor which decelerates cell cycle by inactivating CDKs that phosphorylate pRb. Human Papillomavirus persistent infection plays an important role on cervical carcinogenesis, mainly by the action of two viral oncoproteins, E6 and E7, which interact with p53 and pRb, respectively. Increasing expression of E6 and E7 in dysplastic cervical cells might thus be reflected by increased expression of p16^INK4a. Recent studies revealed that p16^INK4a expression could be a marker for dysplastic and neoplastic cervical cells. The aim of this study was to analyze p16^INK4a expression in cervical preneoplastic and neoplastic lesions and correlate with lesion grade. Expression of p16^INK4a was analyzed by immunohistochemistry. A total of 6 low-grade squamous intraepithelial lesion (LSIL), 21 high-grade squamous intraepithelial lesions (HSIL) and 27 cancer samples were studied. In HPV-positive cervical samples (n = 48), p16^INK4a expression was observed in 1 of 3 LSIL, in 18 of 19 HSIL and in all 26 cancer cases. These results are in accordance with the hypothesis that functional inactivation of pRb by HPV-E7 protein induces p16^INK4a expression in cervical lesions. In our study, a statistically significant association was observed between cervical lesion grade and p16^INK4a expression (P < 0.001).     

FAP-alpha and uPA show different expression patterns in premalignant and malignant esophageal lesions

Fibroblast activation protein-alpha (FAP-alpha) and urokinase-type plasminogen activator (uPA) are serine proteases involved in cancer invasion and metastasis. The authors examined FAP-alpha and uPA expression in premalignant and malignant stages of esophageal adenocarcinoma by immunohistochemistry. Additionally, Western blotting was performed on fresh-frozen tissue samples. FAP-alpha and uPA were detected in metaplastic, dysplastic, and carcinoma cells, as well as in adjacent stroma. Stromal FAP-alpha expression was associated with depth of tumor invasion, while stromal uPA expression correlated with lymph node metastases in adenocarcinomas. Stromal uPA expression in cells with premalignant changes correlated with histological grading. Immunoblotting showed higher protease expression in carcinoma tissues than in normal esophageal epithelium. These results suggest that FAP-alpha and uPA expression in metaplastic, dysplastic, and esophageal cancer tissue is associated with neoplastic progression of esophageal lesions.     

Immunohistochemical expression of prostate tumor overexpressed 1 in cystoprostatectomies with incidental and insignificant prostate cancer. Further evidence for field effect in prostatic carcinogenesis

Prostate tumor overexpressed 1 was recently identified as a novel gene and protein during a differential display screening for genes overexpressed in prostate cancer. It has been suggested that overexpression of prostate tumor overexpressed 1 can contribute to the proliferative status of prostate tumor cells and, thus, to their biologic behavior. Prostate tumor overexpressed 1 and Ki-67 were immunohistochemically evaluated in prostate cancer, high-grade prostatic intraepithelial neoplasia, and normal-looking epithelium in 20 cystoprostatectomies and 20 radical prostatectomies with pT2a Gleason score 6 prostate cancer. The aim was to see whether there were differences in marker expression between cystoprostatectomies and radical prostatectomies. The proportions of prostate tumor overexpressed 1– and Ki-67–positive cells in the cystoprostatectomies and radical prostatectomies increased from normal-looking epithelium through high-grade prostatic intraepithelial neoplasia, away from and adjacent to prostate cancer, to prostate cancer. Prostate tumor overexpressed 1 expression in prostate cancer in cystoprostatectomies was lower than in radical prostatectomies, the differences being significant; there were significant differences in Ki-67 indices. In conclusion, our findings related to prostate tumor overexpressed 1 expression in high-grade prostatic intraepithelial neoplasia, evaluated adjacent and away from prostate cancer, and in incidental and clinical cancers give further support to the concept of field effect in prostatic carcinogenesis as well as to differences in the process of prostatic carcinogenesis between cystoprostatectomies and radical prostatectomies.     

Enhanced expression of parathyroid hormone-related protein in prostate cancer as compared with benign prostatic hyperplasia

Parathyroid hormone-related protein (PTHrP) has been shown to be the primary factor responsible for humoral hypercalcemia of malignancy. Recently PTHrP has been shown to be an early-response gene that may be involved in cellular proliferation or differentiation. In addition, PTHrP has been implicated in the pathogenesis of bone metastases. Bone metastases are a significant complication in patients with prostate cancer. We compared the expression of PTHrP by immunohistochemical staining using a monoclonal antibody directed against epitope between amino acids [53–64] in benign prostatic hyperplasia (BPH) with that in various stages of prostate cancer. Tissue sections were obtained on formalin-fixed paraffin-embedded blocks from BPH, well-differentiated prostate cancer, poorly differentiated prostate cancer, lymph node metastases (n = 15 each), and normal prostate (n = 2). In the normal prostate tissue there was no staining observed. In BPH, 13 of 15 tissue samples were positive for PTHrP immunoreactivity. An average of 33% of the cells stained positive with 1+ intensity. All samples from prostate cancer stained positive for PTHrP. In the samples from well-differentiated prostate cancer, an average of 87% of cells stained positive for PTHrP, whereas 100% of cells were positive in poorly differentiated and metastatic tumors. The intensity of staining was 3+ in well-differentiated tumors and 4+ in poorly differentiated tumors. Therefore, the expression of PTHrP is enhanced in prostate cancer as compared with BPH and is greater in poorly differentiated carcinoma as compared with the well-differentiated tumors. The role of PTHrP in the pathogenesis of prostate cancer deserves further study.