PubMed Health⌕ Search

Biomedical subjects

Kenji Takakura

Publications and source records attributed to Kenji Takakura.

13 recordsLinked to original sources
PubMed2007

Immortalized ovarian surface epithelial cells acquire tumorigenicity by Acrogranin gene overexpression.

Malignant transformation is caused by multi-step genetic mutations, and growth factors are believed to play important roles in developing and maintaining malignant phenotype. However, there is no direct evidence that a specific growth factor contributes to malignant transformation of phenotypically normal cells. In order to assess the function of Acrogranin (also known as granulin epithelial precursor; GEP) in ovarian carcinogenesis, ovarian surface epithelial (OSE) cells, which are supposed to be the origin of primary ovarian epithelial cancer, were transfected with combined genes of hTERT, SV40 LT, and Acrogranin. Introduction of hTERT and SV40 LT was sufficient for immortalizing OSE cells but not enough for tumor formation in nude mice. In contrast, transfection and overexpression of Acrogranin in immortalized OSE cells showed augmented clonogenicity in soft agar and obvious tumorigenicity in nude mice. This is the first study showing evidence that a specific growth factor plays a direct role in malignant transformation in ovarian cancer development.

Animals↗
PubMed2006

Precise anatomy of the vesico-uterine ligament for radical hysterectomy.

OBJECTIVES: To clarify the anatomy of the vesico-uterine ligament (VUL), we meticulously separated the VUL under magnification (x2.5) during Okabayashi's radical hysterectomy. METHODS: Fifty-nine patients (TNM nomenclature: pTIb: 39, pT2a: 5, pT2b: 7, after trans-arterial anticancer-drug infusion treatment for the cervical cancer: 8) underwent this meticulous operation. Blood loss was recorded at two separate time points: during the separation of the VUL and after removal of the uterus. RESULTS: After complete separation of the uterine artery and superficial uterine vein from the ureter, we could identify the genuine connective tissue of the anterior leaf of the VUL in which we isolate and divide a distinct bundle of blood vessels: the cervicovesical vessels that cross over the ureter from the bladder to the cervix. The remaining tissues in the anterior leaf is only avascular connective tissue. The posterior leaf of the VUL is the tissue residing under the ureter connecting the posterior wall of the bladder and the lateral cervix/upper lateral vagina. In the connective tissues, we identified the middle and inferior vesical veins connecting with the deep uterine vein. The division of these veins could separate the urinary bladder with ureters completely from the lateral cervix and upper vagina. The mean blood loss during the separation of the VUL was 20+/-10 g (N=59) and after radical hysterectomy was 189+/-91.6 g (N=59). CONCLUSION: A precise network of blood vessels in the VUL is identified. The knowledge of this anatomy is important to perform radical hysterectomy.

Arteries↗
PubMed2006

Oncogenic property of acrogranin in human uterine leiomyosarcoma: direct evidence of genetic contribution in in vivo tumorigenesis.

To identify potential oncogenes that contribute to the development of uterine leiomyosarcoma, we conducted a cDNA microarray analysis between normal uterine smooth muscle and uterine leiomyosarcoma. We found that acrogranin (also named PCDGF or progranulin) is overexpressed in uterine leiomyosarcoma. With immunohistochemical staining of 12 leiomyosarcoma cases, we verified acrogranin expression in tumor cells. Furthermore, the intensity of acrogranin expression correlated with high histologic grade and poor prognosis. To directly analyze the oncogenic properties of acrogranin, we established an immortalized uterine smooth muscle cell line by transfection of human telomerase reverse transcriptase into primary culture. This cell line retained the original characteristics of uterine smooth muscle cells, including spindle-shaped extension as well as expression of vimentin, estrogen receptor alpha, progesterone receptor, and alpha smooth muscle actin. Transfection of acrogranin into the immortalized uterine smooth muscle cells resulted in colony formation in soft agar, but the diameter of the colonies did not exceed 100 mum. Transfection of both acrogranin and SV40 early region (SV40ER) into the immortalized uterine smooth muscle cells resulted in an increased number of colonies and increased colony size in soft agar versus transfection of SV40ER alone. We show that only immortalized uterine smooth muscle cells expressing both acrogranin and SV40ER are capable of tumor formation in nude mice. Thus, acrogranin is overexpressed in uterine leiomyosarcoma cells, particularly in high-grade cases, and forced expression of acrogranin in immortalized uterine smooth muscle cells contributes to malignant transformation, which suggest that acrogranin plays an important role in the pathogenesis of uterine leiomyosarcoma.

Adult↗
PubMed2006

Role of salvage cytoreductive surgery in the treatment of patients with recurrent ovarian cancer after platinum-based chemotherapy.

OBJECTIVES: The role of cytoreductive surgery, which is well established in the primary treatment for epithelial ovarian cancer, is controversial in recurrent disease. The aim of this study was to assess the clinical benefit of salvage surgical cytoreduction in patients with recurrent ovarian cancer after platinum-based chemotherapy. METHODS: We conducted a retrospective analysis of 46 patients with recurrent epithelial ovarian cancer treated at our department between 1988 and 2003. Twenty-three patients underwent salvage cytoreductive surgery (cytoreductive group), and the other 23 patients were treated without surgery (control group). RESULTS: Patients in cytoreductive group had a median survival of 41.7 months after recurrence, which was significantly longer than control group (18.8 months; P < 0.01). The duration of stay at home and the period oral intake was preserved were significantly longer in the cytoreductive group. In the cytoreductive group, survival was influenced by the residual disease after surgery (residual tumor diameter, <2 cm vs >2 cm; median survival, 50 months vs 35.2 months; P < 0.05). However, the number of recurrent sites (solitary vs multiple) and the lengths of treatment-free intervals after primary treatment (<6 months vs >6 months) showed no significant influence on survival. CONCLUSIONS: The application of cytoreductive surgery might improve the prognosis of patients with recurrent ovarian cancer if the tumor was resectable. Preserved prognoses of platinum-resistant disease with short treatment-free interval demonstrated in this study suggest that the concept of maximum cytoreduction might be introduced in the treatment of recurrent disease in the future.

Aged↗
PubMed2004

In vivo anti-tumor effect of dual release of cisplatin and adriamycin from biodegradable gelatin hydrogel.

The objective of this paper is to investigate the in vivo anti-tumor effect by dual release of cisplatin (CDDP) and adriamycin (ADM) from a biodegradable hydrogel. Hydrogels with different water contents were prepared through the chemical crosslinking of gelatin by various concentrations of glutaraldehyde. Aqueous solution of CDDP, ADM or their mixture (CDDP+ADM) was impregnated into the freeze-dried hydrogel, followed by air-drying to obtain the dried hydrogel incorporating the corresponding drug. Irrespective of the hydrogel water content, 8-20% of CDDP incorporated and 60-80% of ADM was released from the hydrogel in the phosphate-buffered saline solution (PBS) at 37 degrees C within the initial 6 h and thereafter little release was observed. When intratumorally applied into mice carrying a mass of Meth-AR-1 tumor cells, the hydrogel incorporating CDDP+ADM showed significant higher anti-tumor effect on the tumor growth suppression and on survival period than other drug applications. Combination effect assay revealed that the hydrogel incorporating CDDP+ADM showed a synergistic effect between the CDDP and ADM, while the solution form showed antagonistic. The concentration of CDDP and ADM in the tumor tissue maintained at higher levels over 14 days after application. The time course of in vivo CDDP retention was in a good accordance with that of hydrogel remaining, whereas ADM was released faster, followed by the sustained release for 14 days. No practically problematic change in the mouse body and blood biochemical parameters was observed by application of the hydrogel incorporating CDDP+ADM. We conclude that dual sustained release of CDDP and ADM attached to the tumor synergistically enhanced their in vivo anti-tumor effect through the trans-tissue delivery.

Animals↗
PubMed2004

Increased expression of calcium-binding protein S100 in human uterine smooth muscle tumours.

S100 proteins belong to the EF-hand Ca(2+ )-binding protein family and regulate a variety of cellular processes via interaction with different target proteins. Several diseases, including cancer and melanoma, are related to the abnormal expression of S100 proteins, which are expressed in cell- and tissue-specific manners. We investigated the expression of S100 family members in human uterine smooth muscle tumours. Expression of six members of the S100 protein family: S100A1, A4, A6, A7, A10 and A11, was found in human uterine leiomyoma and myometrium tissue, but expression of other members was not detected by RT-PCR. Real-time PCR showed that S100A11 expression was significantly increased in leiomyoma compared with myometrium. Suppression of S100A11 by small interfering RNA (siRNA) led to apoptosis, and the overexpression of S100A11 inhibited apoptosis in human uterine smooth muscle tumour cells. These findings suggest that S100A11 has an anti-apoptotic function and is related to the process of growth of human uterine leiomyoma.

Cell Line, Tumor↗
PubMed2003

In vivo anti-tumor effect through the controlled release of cisplatin from biodegradable gelatin hydrogel.

This paper is an investigation to achieve the in vivo controlled release of cisplatin (CDDP) from a biodegradable hydrogel. Hydrogels with different water contents were prepared through the chemical crosslinking of gelatin by various concentrations of glutaraldehyde. The gelatin hydrogel incorporating CDDP (CDDP-hydrogel) was prepared by allowing CDDP aqueous solution to sorb into the freeze-dried hydrogel. Irrespective of the hydrogel water content, approximately 10-30% of incorporated CDDP was released from the hydrogel in phosphate-buffered saline solution (PBS) at 37 degrees C within the initial 6 h, while little release was observed thereafter. The amount of CDDP released initially decreased with an increase in the time period of CDDP sorption. When intratumorally applied into Meth-AR-1 tumor-bearing mice, CDDP-hydrogel suppressed in vivo tumor growth to a significantly higher extent than free CDDP at the same dose. The survival rate was significantly higher by the application of CDDP-hydrogel of 40 microg CDDP. The CDDP concentration in the tumor tissue was maintained at a higher level for a longer time period than that of free CDDP. However, no problematic change in the mouse body and blood biochemical parameters was observed on the application of the CDDP-hydrogel. The time course of in vivo CDDP retention was in a good accordance with that of hydrogel remaining. Larger CDDP release was observed from the front surface of hydrogel onto which free CDDP was sorbed, than the back surface of hydrogel. These findings demonstrate that the controlled release of CDDP was based on biodegradation of the hydrogel carrier, but not simple diffusion of CDDP. It is possible that the CDDP molecules immobilized in the gelatin hydrogel were released from the hydrogel only when the hydrogel was degraded to generate some water-soluble gelatin fragments.

Animals↗
PubMed2003

PEP-19 overexpression in human uterine leiomyoma.

Although uterine leiomyomas represent one of the most common neoplasms in adult women, their pathogenesis remains poorly understood. A cDNA microarray analysis was performed to search for candidate genes expressed to a greater degree in leiomyoma compared with matched myometrium. A total of 15 candidate genes was obtained; neuron-specific protein PEP-19 (Purkinje cell protein 4; PCP 4) exhibited a striking difference in expression between leiomyoma and myometrium. Although PEP-19 expression has been reported exclusively in the central nervous system, the present study demonstrated that PEP-19 is also expressed in other human organs, including prostate, kidney and uterus. To clarify the role of PEP-19 in the pathogenesis of leiomyomas, PEP-19 expression was investigated for a series of human leiomyoma, as well as normal myometrium and leiomyosarcoma. PEP-19 mRNA and protein expression were much stronger in leiomyomas compared with normal myometrium, suggesting that PEP-19 might be involved in leiomyoma pathogenesis.

Adult↗
PubMed2003

Use of DNA array to screen blastocyst genes potentially involved in the process of murine implantation.

Conceptus implantation to the mother's uterus is a complex series of events involving coordinated expression of numerous genes at both the embryonic and the uterine sides. Since there are no suitable in vivo or in vitro experimental models, sequential changes occurring during the peri-implantation periods have not been well characterized. Using GeneChip technology and a recently introduced murine in vitro model of implantation, the expression of embryonic genes was examined before and after attachment to the uterine stromal cells. Instead of RNA or mRNA, amplified cRNA was subjected to the GeneChip analysis because amounts of mRNA in each blastocyst were minimal. Among 6,500 gene transcripts examined, changes in mRNA levels for 802 genes were identified. Of these detections, transcripts previously unsuspected were changes in a group of tumor suppressor and stress-induced genes, whose transcripts increased as embryos attached to the membrane. Validity of the data was evaluated using reverse transcription-polymerase chain reaction and in situ hybridization analyses, both of which confirmed developmental changes in selected gene expressions during pre- and post-attachment periods. The present data suggest that GeneChip technology would be very useful for finding genes previously unsuspected, and this method should be used as an initial step, particularly as a screening tool, toward the dissection of complex mechanisms such as the processes of implantation.

Animals↗
PubMed2002

Tranilast inhibits the proliferation of uterine leiomyoma cells in vitro through G1 arrest associated with the induction of p21(waf1) and p53.

Uterine leiomyoma is a mesenchymal tumor composed of smooth muscle cells with fibrous tissues and many mast cells. Tranilast is known to suppress fibrosis or to work as a mast cell stabilizer and is reported to inhibit proliferation of vascular smooth muscle cells. In this study, we examined the effects of tranilast on cultured human leiomyoma cells in vitro to evaluate whether this agent has the potential to inhibit the growth of uterine leiomyomas. Tranilast inhibited the proliferation of cultured leiomyoma cells in a dose-dependent manner without any cytotoxic effect or induction of apoptosis. In association with the inhibitory effect, tranilast induced the cyclin-dependent kinase (CDK) inhibitor p21(waf1) and tumor suppressor gene p53 and decreased CDK2 activity. These results suggest that tranilast arrests the proliferation of uterine leiomyoma cells at the G0/G1 phase, through the suppression of CDK2 activity via an induction of p21(waf1) and p53. Tranilast was concluded to be a potent agent to inhibit proliferative activity of uterine leiomyoma cells.

Blotting, Western↗