Atia A. Hamid

Expression of vascular endothelial growth factor (VEGF) during folliculogenesis and corpus luteum formation in the human ovary

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.

Human chorionic gonadotropin (hCG) inhibits cisplatin‐induced apoptosis in ovarian cancer cells: Possible role of up‐regulation of insulin‐like growth factor‐1 by hCG

Gonadotropins have been suggested to play a role in the development or progression of ovarian cancer, and we have previously reported the expression of luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor in 40% of epithelial ovarian carcinomas. To examine the biological effect of LH/hCG on ovarian cancer cells, apoptosis induced by cisplatin with or without hCG treatment was investigated in 2 ovarian cancer cell lines, OVCAR‐3 and SK‐OV‐3. Stimulation of cell proliferation by hCG was also studied. In addition, to analyze further the mechanism of hCG signaling involved in apoptosis‐inhibition, we examined the expression of LH/hCG receptors and the regulation by hCG for apoptosis‐inhibitory pathways, such as the bcl‐2/bax system and the insulin‐like growth factor‐1 (IGF‐1)/IGF‐1 receptor (IGFR) system. hCG did not increase cell proliferation in either cell line. However, hCG treatment suppressed cisplatin‐induced apoptosis by 58% in the OVCAR‐3 cells, as shown by immunofluorescent staining and quantitation of DNA fragmentation. LH/hCG receptor mRNA was expressed only in OVCAR‐3, and no apoptosis‐inhibitory effect of hCG was observed in the SK‐OV‐3 cells that did not express the receptor. In the OVCAR‐3 cells, hCG significantly increased mRNA expression of IGF‐1, but did not change mRNA levels of bcl‐2/bax. Our findings suggest that LH/hCG influences the chemosensitivity of ovarian cancer cells through an apoptosis‐inhibitory signal possibly via up‐regulation of IGF‐1 expression. Int. J. Cancer 76:571–578, 1998.© 1998 Wiley‐Liss, Inc.

Combination effect of adenovirus-mediated pro-apoptotic bax gene transfer with cisplatin or paclitaxel treatment in ovarian cancer cell lines.

To develop a novel therapeutic strategy for ovarian cancer, we constructed a recombinant adenovirus which highly expresses pro-apoptotic Bax protein and examined its therapeutic effect on a series of ovarian cancer cell lines: A2780, A2780/cDDP, OVCAR-3 and SK-OV-3. A recombinant adenovirus carrying the Bax-alpha gene (AxCALNKYbax) induced high expression of the Bax-alpha protein in all the cell lines. The cytotoxic effect of Bax was observed in three ovarian cancer cell lines: the per cent reduction in the number of cells was 40.0% for cisplatin-sensitive A2780, 50.0% for cisplatin-resistant A2780/cDDP, and 64.8% for marginally cisplatin-resistant OVCAR-3. In contrast, it was only 12.3% for cisplatin-resistant SK-OV-3. Cisplatin-resistant A2780/cDDP had a p53 mutation and exhibited attenuated Bax induction after cisplatin treatment, which may explain why supplementation of Bax was effective in this chemoresistant ovarian cancer. Combination with cisplatin or paclitaxel enhanced the cytotoxic effect of Bax induction in all but one cell line including cisplatin-resistant A2780/cDDP. It appears that adenovirus-mediated Bax induction, with or without combination with conventional chemotherapy, useful strategy for the treatment of ovarian cancer.

C-erbB-2 or mutant Ha-ras induced malignant transformation of immortalized human ovarian surface epithelial cells in vitro

Ovarian cancer is believed to develop from the ovarian surface epithelium through the accumulation of aberrations of oncogenes and/or tumor suppressor genes. However, it is unclear how the gene abnormalities are involved in ovarian carcinogenesis. To elucidate the process, we transfected genes reported to show their abnormalities in human ovarian cancers into human ovarian surface epithelial cells. Immortalization of the cells was achieved by the transfection of SV40 large T antigen (LT) and human telomerase reverse transcriptase (hTERT); however, the resultant cells showed no tumorigenesis. Additional transfection of either c-erbB-2 or mutant Ha-ras into the immortalized cells showed the anchorage-independent growth and tumorigenesis in mice with the incidence of 50% and 40%, respectively. Histologically, all the tumours were undifferentiated. In association with the tumorigenesis, the cells expressing c-erbB-2 or mutant Ha-ras demonstrated increased vascular endothelial growth factor secretion under hypoxia and enhanced resistance to apoptosis compared with the immortalized cells. Collectively, the introduction of either c-erbB-2 or mutant Ha-ras in the cells, which were efficiently immortalized by the transfection of LT and hTERT, showed tumorigenicity, suggesting that c-erbB-2 or mutant Ha-ras genes might be involved in ovarian carcinogenesis.

Expression of cold-inducible RNA-binding protein in the normal endometrium, endometrial hyperplasia, and endometrial carcinoma.

&NA; Cold‐inducible RNA‐binding protein (CIRP), an 18‐kD protein in the mouse and human, is induced by lowering the temperature of cultured cells. CIRP is possibly a cell cycle regulator because its overexpression results in prolongation of G1 phase in vitro. We investigated the immunohistochemical expression of CIRP in 39 endometrial carcinomas, 12 endometrial hyperplasias, and 27 normal endometria using polyclonal antibody against CIRP and confirmed by Western blot analysis. CIRP was localized in the nuclei of glandular, stromal, and endothelial cells. The intensity of CIRP expression in glandular cells during the menstrual cycle was inversely proportional to its proliferative (Ki‐67) activity, whereas it remained unchanged in stromal and vascular endothelial cells. The intensity of CIRP expression in hyperplastic glands was variable, whereas CIRP expression was absent or markedly reduced in most of the endometrial carcinomas. These results suggest that CIRP may participate in the cell cycle regulation of normal endometrium and the loss of its expression may be involved in endometrial carcinogenesis.

Cyclical change of hMSH2 protein expression in normal endometrium during the menstrual cycle and its overexpression in endometrial hyperplasia and sporadic endometrial carcinoma

The role of hMSH2 protein, one of the major DNA repair proteins, until now, had not been elucidated in terms of normal endometrial function during the menstrual cycle. The current study was designed to address this issue and to determine whether the expression of hMSH2 is altered in the course of endometrial carcinogenesis.

Expression of Abnormal Transcripts of the FHIT (Fragile Histidine Triad) Gene in Ovarian Carcinoma

To elucidate the role of the FHIT (fragile histidine triad) gene in ovarian carcinogenesis, the expression of the gene was analysed by reverse transcription-polymerase chain reaction (RT-PCR) in 51 cases of ovarian carcinoma, 6 cases of borderline tumour and 4 cases of benign ovarian tumour. The concomitant expressions of normal and abnormal FHIT transcripts were detected in 39% of carcinomas and in 83% of borderline tumours, while benign tumours and normal ovarian tissues expressed only normal transcript. In addition, there were 4 (8%) cases of carcinoma lacking expression of normal FHIT transcript, all of which were in advanced stages (stage III-IV) and poorly differentiated. These results suggest that the expression of abnormal transcripts of the FHIT gene is a feature of ovarian malignant/borderline tumours and that the complete loss of normal FHIT expression is related to the progression of ovarian carcinoma in a subset of the cases. However, abnormal FHIT transcripts themselves were not associated with any clinicopathological parameters, such as clinical stage, histological subtype of tumour, grade of differentiation or outcome of the patient. Additionally, abnormal FHIT expression was not associated with the presence of loss of heterozygosity (LOH) at this locus, suggesting that abnormal FHIT transcripts are not derived from genetic alteration or that genetic alteration at this locus is complicated.

Early Invasive Adenocarcinoma of the Fallopian Tube: A Case Report and Review of the Literature

We present an early invasive adenocarcinoma of the fallopian tube, which was incidentally found in a 45‐year‐old woman undergoing a laparotomy for uterine myoma. Histological examination of the hydropic tubes revealed widespread endosalpingeal hyperplasia without atypia in both tubes. In addition, the left tube contained 3 scattered lesions of carcinoma in situ, one of which was accompanied by a microfocus of definite stromal invasion confined within the endosalpingeal mucosa. Such a case seems extremely rare, and it might represent the histological appearance of an early invasive feature of tubal carcinoma. We reviewed previously reported cases of in situ and/or early invasive carcinomas of the fallopian tube with respect to the pathological diagnosis and histogenesis of primary tubal adenocarcinomas.