Hideki Sakaguchi

Biologic implications of the expression of vascular endothelial growth factor subtypes in ovarian carcinoma

Vascular endothelial growth factor (VEGF) has been identified as an important factor for tumor angiogenesis, which is essential for the growth, invasion, and metastasis of solid tumors. This study examines the clinical significance of VEGF subtypes in ovarian carcinoma.

Expression of vascular endothelial growth factor (VEGF) and its mRNA in uterine cervical cancers

SummaryTo know the potential of growth, invasion and metastasis of uterine cervical cancer associated with neovascularization, localization of vascular endothelial growth factor (VEGF) and microvessel density in tumours were determined by immunohistochemical staining, the levels of VEGF subtypes were determined by Western blot analysis and by a sandwich enzyme immunoassay, and the levels of VEGF subtype mRNAs were determined by reverse transcription polymerase chain reaction (RT-PCR) – Southern blot analysis in uterine cervical cancers. The relation between VEGF subtype expressions and microvessel density, histological types and clinical stages of uterine cervical cancers was analysed. The expression of VEGF was seen dominantly in the cancer cells, and correlated with microvessel density in uterine cervical cancers. Among the four subtypes of VEGF, the populations of VEGF165 and VEGF121 were dominant in normal uterine cervices and uterine cervical cancers. The levels of VEGF and VEGF165 and VEGF121 mRNAs were remarkably higher in some stage II and III/IV adenocarcinomas of the cervix than in other cases, including normal cervices. Therefore, the elevation of VEGF165 and VEGF121 might contribute to the relatively late advancing via angiogenic activity in some adenocarcinomas of the cervix.

Expressions of vascular endothelial growth factor (VEGF) and its mRNA in uterine endometrial cancers

To know the potential of growth, invasion and metastasis of uterine endometrial cancer associated with neovascularization, the expressions of VEGF and its mRNA, especially their subtypes, in uterine endometrial cancers and normal uterine endometria as controls were determined by Western blot analyses with a sandwich enzyme immunoassay and RT-PCR-Southern blot analysis, respectively, and the relation between their expressions and histological grades, grades of myometrial invasion and clinical stages of uterine endometrial cancers was analyzed. The levels of VEGF (VEGF165 and VEGF121) protein and mRNA were in a wide range and higher in normal uterine endometria than in the malignant counterparts. The levels of VEGF protein were higher in order of histopathological differentiation (normal uterine endometrium > well-differentiated (G1) > moderately differentiated (G2) and poorly differentiated (G3)) and those of VEGF protein and VEGF121 mRNA were lower in order of the advance of clinical stages (normal uterine endometrium > stage I > stage II > stages III and IV). There was, however, no significant difference in their levels among uterine endometrial cancers classified according to grades of myometrial invasion. This suggests that VEGF is downregulated during uterine endometrial cancer progression with dedifferentiation. Namely, VEGF in some endometrial cancers might contribute to the early process of advancing of malignancy via angiogenic activity.

Clinical implication of expression of progesterone receptor form A and B mRNAs in secondary spreading of gynecologic cancers

This study was designed to determine the clinical implication of expression of progesterone receptor form A (PR-A) and B (PR-B) mRNAs in secondary spreading of gynecologic cancers. Approximately equal expression of PR-A and PR-B mRNAs was designated as type AB and dominant expression of PR-B mRNA as type B. Alteration from type AB to type B in the metastatic cancers occurred in 3/8 cases of uterine endometrial cancers, 2/8 cases of uterine cervical cancers, and 2/8 cases of ovarian cancers. Other cancers revealed type B regardless of primary or metastatic status. Thus, all metastatic cancers studied revealed type B. These results suggest that transcription of PR-A mRNA may be damaged, which might lead to uncontrolled overexpression of PR-B mRNA in metastatic lesion, and that the type B status could reveal a highly malignant phenotype in these three gynecologic cancers.

Expression of IP-10 related to angiogenesis in uterine cervical cancers.

Angiogenesis is essential for development, growth and advancement of solid tumours. Interferon-γ-inducible protein 10 (IP-10) regulates lymphocyte chemotaxis, mediates vascular pericyte proliferation and acts as an angiostatic agent, thus inhibiting tumour growth. This prompted us to study the clinical implications of IP-10 expression related to angiogenesis in uterine cervical cancers. The levels of IP-10 decreased with advancement, and the prognosis of the 30 patients with low IP-10 expression in uterine cervical cancers was poor (66%), whereas the 24-month survival rate of the other patients with high IP-10 expression was 90%. Furthermore, IP-10 levels significantly reverse-correlated with vascular endothelial growth factor (VEGF) levels in uterine cervical cancers. Interferon-γ-inducible protein 10 might work on suppression of angiogenesis associated with VEGF in advancement, and can be recognised as a prognostic indicator. Furthermore, IP-10 activation might be effective on the suppression of regrowth or recurrence after intensive treatment for advanced cervical cancers.

Expression of platelet-derived endothelial cell growth factor (PD-ECGF) and its mRNA in uterine cervical cancers.

SummaryAngiogenesis contributes to the growth and secondary spreading of solid tumours. Platelet-derived endothelial cell growth factor (PD-ECGF) is identified as such an angiogenic factor. In the present study, the prognosis of the patients with high PD-ECGF uterine cervical cancers was worse than those with low PD-ECGF cancers, and PD-ECGF expression correlated with cellular proliferation and with vascular density and venous invasion in uterine cervical cancers. Therefore, PD-ECGF might contribute to the growth of uterine cervical cancers via angiogenesis related to vascular spreading. Furthermore, PD-ECGF and its mRNA had a wide range and were highly expressed in uterine cervical cancers, especially squamous cell carcinoma, regardless of clinical stage. Therefore, PD-ECGF in uterine cervical cancers might play a role of basic angiogenesis in all processes of advancing of uterine cervical cancers. This indicates that 5′-deoxy-5-fluorouridine might be highly effective in squamous cell carcinoma of the cervix, which possesses a high activity of thymidine phosphorylase to convert 5′-deoxy-5-fluorouridine to 5-fluorouracil, and that some angiogenic inhibitors of new capillary formation might be effective in the inhibition of tumour growth and spreading associated with angiogenesis.

Clinical Implications of the Expression of Estrogen Receptor-α and -β in Primary and Metastatic Lesions of Uterine Endometrial Cancers

Novel human estrogen receptor (ER)-β was identified in cDNA libraries from human testes. ER-β specifically expresses in the testis, ovary, thymus, spleen, osteoblasts, fetus and uterine endometrium. ER-β might not conserve the same physiological functions as does ER-α. Therefore, expressions of ER-α and ER-β mRNAs in primary and metastatic lesions of uterine endometrial cancers were investigated. The levels of ER-β mRNA were significantly lower than those of ER-α mRNA in uterine endometrial cancers and in normal uterine endometria. The ratio of ER-β to ER-α mRNA in most primary uterine endometrial cancers was similar to that in normal uterine endometria (<0.4% of ER-β mRNA to ER-α mRNA). On the other hand, in 14 of the 20 lymph node metastasis-positive cases of uterine endometrial cancers, the ratio in the metastatic lesion was significantly higher than that in the primary lesion of the corresponding case, and patient prognosis in these cases was extremely poor. Therefore, it is suggested that the intact synchronized expression of ER-β interacting with ER-α might be disrupted, especially in most metastases of uterine endometrial cancers, leading to poor patient prognosis related to estrogen refractoriness.

Clinical implication of expression of vascular endothelial growth factor-C in metastatic lymph nodes of uterine cervical cancers

Vascular endothelial cell growth factor (VEGF)-C levels were significantly (P<0.05) increased in 24 out of 40 metastatic lymph node lesions of uterine cervical cancers. The prognosis of the 24 patients with increased VEGF-C level in metastatic lymph node lesions was poor and the 24-month survival rate was 38%, while the rate of the 16 patients with no change in VEGF-C level in metastatic lymph node lesions was 81%. There was a significant (P<0.01) difference in the 24-month survival rates between the two groups. This is novel, direct evidence that VEGF-C might contribute to the aggressive lymphangitic metastasis in uterine cervical cancers, and that the increase in VEGF-C level from primary tumour to metastatic lymph node might be a prognostic indicator.

Expression of basic fibroblast growth factor and its mRNA in advanced uterine cervical cancers

To know the potential of growth, invasion and metastasis of uterine cervical cancer cells associated with neovascularization, the expression of basic fibroblast growth factor (FGF) and its mRNA in uterine cervical cancers and normal uterine cervices as controls were determined by enzyme-linked immunosorbent assay (ELISA) and reverse transcription-polymerase chain reaction-Southern blot (RT-PCR-SB), respectively. Then, the relations between the expression and the histological grading and clinical staging in cervical cancers were analyzed. The levels of basic FGF and its mRNA were significantly higher in advanced primary uterine cervical cancers, regardless of histological type. Therefore, this status might contribute to the acceleration of growth, invasion, and metastasis with neovascularization in advanced uterine cervical cancers.

Clinical implications of steroid receptor coactivator (SRC)-3 in uterine endometrial cancers ☆

Estrogen is recognized as a significant modifier in the development, growth and invasion of uterine endometrial cancer. Steroid receptor coactivator-3 (SRC-3; AIB1, ACTR, RAC3, TRAM-1, and pCIP) is a member of the p160 family of coactivator for nuclear hormone receptors including estrogen receptor (ER). It is reported that SRC-3 is overexpressed in various cancers. However, SRC-3 expression manner in uterine endometrial cancer is not fully understood. In this study, we showed SRC-3 mRNA expression correlates with clinical stage, depth of myometrial invasion and dedifferentiation. The prognosis of the 25 patients with higher expression of SRC-3 mRNA in uterine endometrial cancers was extremely poor (36%), whereas the 24-month survival rate of the 15 patients with lower expression of SRC-3 mRNA was 96%. These data indicate that SRC-3 might be an important indicator of uterine endometrial cancer advancement and survival.