Summary Vascular endothelial growth factor (VEGF) is known to be produced by various solid tumours and is thought to be involved in microvascular permeability and/or angiogenesis. To examine the relationship between VEGF expression in ovarian neoplasms and clinicopathological factors or patient survival, expression of VEGF was analysed immunohistochemically in 110 epithelial ovarian tumours. In addition, VEGF levels in the tumour fluid (17 patients), ascites (12 patients) and sera (38 patients) were determined using enzyme immunoassay. Positive immunostaining for VEGF was observed in 97% (68 out of 70) of ovarian carcinomas, which was significantly higher than that of tumours of low malignant potential (LMP) (13 out of 25; 52%) and benign cystadenomas (5 out of 15; 33%) (P < 0.01). In ovarian carcinomas, strong VEGF immunostaining was also observed more frequently in tumours of clear cell type (P < 0.05) in the advanced stage of disease (P < 0.05) and with positive peritoneal cytology (P < 0.01). Patients with strong VEGF staining had poorer survival rates than those with weak or no immunostaining for VEGF (P < 0.01). These findings suggest that strong VEGF expression plays an important role in the tumour progression of ovarian carcinoma. The enzyme immunoassay revealed higher serum VEGF levels in carcinoma patients than those in patients with LMP or benign tumours (P < 0.01). Serum VEGF levels decreased after the successful removal of tumours in ovarian cancer patients and, in one patient, the serum VEGF level was re-elevated during relapse. Therefore, serum VEGF could be used as a marker for monitoring the clinical course of ovarian cancer patients.

Vascular endothelial growth factor (VEGF) has been suggested to be involved in angiogenesis and microvascular hyperpermeability. We examined immunohistochemically the expression of VEGF in the granulosa and theca cells, along with that of proliferating cell nuclear antigen (PCNA), in the vascular endothelium during the course of follicular development and corpora lutea formation in human ovaries. The immunolocalization of VEGF in these cells was compared with that of another putative angiogenic factor, basic fibroblast growth factor (bFGF). The granulosa cells in the primordial and primary follicles were VEGF negative, but at the preantral stage, the granulosa cells showed weakly positive immunostaining for VEGF. However, the VEGF immunostaining in the granulosa cells was weak throughout the folliculogenesis. In contrast, the theca interna cells of developing follicles showed strong staining for VEGF, which was well correlated with the PCNA positivity in the vascular endothelial cells in the thecal layer. In the atretic follicles, the granulosa and theca cells were VEGF negative. In the corpora lutea, VEGF was strongly expressed in both granulosa and theca lutein cells in the early luteal phase when the PCNA positivity in the endothelium increased, but the VEGF staining in these cells became weak in the mid- and late luteal phases. Accordingly, the PCNA positivity in the vascular endothelium was well correlated with the expression of VEGF in the theca cells during follicular development and atresia, and that in the granulosa and theca lutein cells in corpora lutea formation and regression. In addition, the immunolocalization of VEGF was different from that of bFGF.

A cDNA clone for an auxin-regulated gene was isolated from a tobacco mesophyll protoplast cDNA library by differential screening. Nucleotide sequence analysis showed that the deduced product of the gene, which we have designated par, is hydrophilic and is composed of 220 amino acids. No significant homology to other known proteins was detected. The mRNA of the par gene is -900 bases long and its accumulation was detected in cultured mesophyll protoplasts as early as 30 min after the addition of 2,4-dichlorophenoxyacetic acid to the culture medium. The par mRNA was not detected in leaves or freshly prepared protoplasts or in protoplasts in the absence of 2,4-dichlorophenoxyacetic acid. Expression of the par gene was detected at a low level in actively dividing BY-2 tobacco suspension culture cells. The conspicuous accumulation of par mRNA before the initiation of DNA synthesis in tobacco mesophyll protoplasts suggests that the par gene product could play a role in the initiation of meristematic activity in differentiated mesophyll cells.It has been generally accepted that one of the most conspicuous characteristics of plant cells is totipotency, in which differentiated and nondividing somatic cells of plant tissues regain the ability to divide and ultimately regenerate whole plants. In contrast, no such phenomenon exists in animal systems. A central feature of totipotency, often referred to as "dedifferentiation," is the reinitiation of cell division in differentiated and nondividing cells. This phenomenon, in which differentiated cells pass through the restriction point from the Go phase to the S phase of the cell cycle, remains unexplained in molecular terms.Tobacco mesophyll protoplasts-which are highly homogeneous, typically differentiated, and nondividing-are able to initiate DNA synthesis, divide, and form colonies (1), a process that is dependent on the presence of both auxin and cytokinin. The regeneration of whole plants from these colonies has also been established (2, 3). Thus, tobacco mesophyll protoplasts appear to be suitable material for the analysis of the reinitiation of cell division activity in differentiated plant cells.In this study, to elucidate the mechanism of initiation of meristematic activity in differentiated and nondividing tobacco mesophyll cells, we tried to identify genes that could be activated by plant hormones in the early stages of protoplast culture. Since two-dimensional gel electrophoresis has shown that auxin is more effective than cytokinin in inducing the appearance of proteins that are not found in freshly prepared mesophyll cells (4), we chose to examine genes regulated by auxin during the early stages of culture of tobacco mesophyll protoplasts. In doing so, we isolatkd the cDNA for a gene that could play a role in the initiation of cell division. § MATERIALS AND METHODSPreparation of Protoplasts. Protoplasts were prepared from mesophyll tissues of tobacco (Nicotiana tabacum L. cv. Xanthi nc) according to the two-step procedure described by Okada et al. (5) exc...

Heat shock proteins HSP70 and HSP90 are sex steroid receptor-associated proteins, and HSP90 expression has reportedly been correlated with sex steroid receptor status in endometrial carcinomas. HSP70 is also known to associate with several oncogene products such as p53 protein, and expression of HSP70 has been reported to be a prognostic factor in several malignant neoplasms. In endometrial carcinomas, however, little is known about the prognostic significance of these proteins. Therefore, we analyzed the survival of 44 endometrial carcinoma patients treated in our hospital with reference to the immunohistochemical expressions of HSP70 and HSP90, as well as the clinicopathological factors such as age, menstrual status, FIGO stage, histologic grade, p53 protein overexpression, and sex steroid receptor status. The expression of HSP70 was observed in 50% (22 cases), and strong HSP90 expression in 30% (13 cases) of the 44 carcinomas. The patients with HSP70-positive tumors showed significantly poorer survival than the patients with HSP70-negative tumors (p = 0.045), although multivariate analysis did not reveal HSP70 expression to be an independent prognostic factor. In contrast, the strong expression of HSP90 in the tumor was significantly correlated with a favorable prognosis of the patient (p = 0.026). Other prognostic indicators were FIGO stage (p = 0.0086) and the expression of progesterone receptor (p = 0.042). Accordingly, expressions of HSP70 and HSP90 each have different prognostic significance in endometrial carcinoma and may be useful for prediction of patient survival.

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