Biomedical subjects

Isao Hara

Publications and source records attributed to Isao Hara.

137 records · Page 8Linked to original sources

PubMed2002

Introducing the clusterin gene into human renal cell carcinoma cells enhances their metastatic potential.

PURPOSE: We recently reported a protective role of clusterin expression against apoptosis induced by a wide variety of stimuli in several human cancer models. In the current study we tested the hypothesis that clusterin over expression confers a benefit for the metastasis of renal cell carcinoma through the inhibition of apoptosis induced by the various obstacles the cancer cells may confront after detachment from their primary origin. MATERIALS AND METHODS: We introduced clusterin complementary DNA into human renal cell carcinoma ACHN cells, which do not express detectable level of clusterin expression, and generated the clusterin over expressing cell line ACHN/CL and the control vector only transfected cell line ACHN/C. In vitro anti-cell death activity under anchorage independent conditions among ACHN sublines was examined by limiting dilution assay and cell survival assay in suspension. To investigate the in vivo effects of clusterin over expression on metastatic potentials each cell line was injected into the tail vein or renal subcapsule of nonobese diabetic, severe combined immunodeficient mice and the metastatic features in all abdominal and thoracic organs were evaluated. RESULTS: ACHN/CL showed significantly enhanced growth in limiting dilution cultures compared with ACHN/C. The analysis of cell survival in the floating assay also revealed that ACHN/CL had a powerful survival advantage in suspension compared with ACHN/C. Furthermore, ACHN/CL formed more than 5-fold as many metastatic nodules in the lung after intravenous injection than ACHN/C. Similarly more marked lung metastasis was observed after implanting ACHN/CL cells into the renal subcapsule than after implanting ACHN/C cells. In contrast, there were no significant differences among ACHN sublines in the growth rates in vitro and in vivo, cell motility or invasive ability. CONCLUSIONS: These findings suggest that, if clusterin is over expressed, it prolongs cell survival under unfavorable conditions in the metastatic process, resulting in the enhanced metastatic potential of renal cell carcinoma.

Animals↗

PubMed2002

[Gene therapy for prostate cancer].

The substantial advances made in recent years in the molecular biology of malignant urological tumors and the associated progressive analysis of these conditions at a molecular level have spurred research aimed at gene-based treatment. In the field of prostate cancer, while there have been many ground-breaking studies particularly in the United States, none has yet led to a revolutionary treatment for recurrent prostate cancer. Gene-based treatment is being applied seriously in clinical settings, especially in the United States, but so far without significant effect. Many researchers worldwide are devoting energy to the development of effective vectors. By adjusting the promoter, which has the function of directing the vector, we have developed organ-specific vectors for the treatment of prostate cancer. In the present study, which targeted prostate cancer with bone metastasis, we developed a suicide-gene therapy using an adenovirus vector with an organ-specific osteocalcin promoter. Clinical trials of this vector have already been conducted at the University of Virginia in the United States and have so far confirmed the safety of the therapy. In the present paper we present the results of this gene-therapy research from the basic to the clinical phase alongside an outline of related research at our institution. Gene therapy for cancer is now being targeted not only against the primary tumor but systemic cancers including distant metastases; systemic administration of adenovirus vectors with organ-specific promoters may become one of the most promising systemic anti-tumor therapies of the next-generation.

Genetic Therapy↗

PubMedDate not supplied

Clinical symptoms in localized renal cell carcinoma reflect its invasive potential: comparative study between incidentally detected and symptomatic diseases.

The objectives of this study were to analyze the association of clinical symptoms with several parameters in patients with organ-confined renal cell carcinoma (RCC), and investigate the difference in biologic characteristics between incidentally detected and symptomatic RCCs. This study included 132 patients who were pathologically diagnosed with organ-confined RCC after radical surgery, and their clinicopathologic features were compared to those in patients with incidentally detected and symptomatic diseases. In this series, 91 patients were incidentally diagnosed with RCC, while the remaining 41 had some clinical symptoms. The cause-specific survival in patients with incidental RCC was significantly higher than that in patients with symptomatic RCC, and the presence of clinical symptoms could be an independent predictor of cause-specific survival in these patients. Immunohistochemical staining of resected specimens from these patients were then performed with Ki-67, Bcl-2, matrix metalloproteinase (MMP)-2, MMP-9, and vascular endothelial growth factor antibodies. Despite the lack of differences in Ki-67, Bcl-2, and vascular endothelial growth factor expression between these 2 groups, significantly increased expressions of MMP-2 and MMP-9 in symptomatic RCCs were observed compared with those in incidental RCCs. Moreover, the presence of clinical symptoms in organ-confined RCC was significantly correlated with immunoreactivities of MMP-2 and MMP-9. These findings suggest that clinical symptoms have a significant impact on the prognosis of patients with organ-confined RCC and that the appearance of clinical symptoms may reflect the increased invasive potentials characterized by overexpression of MMPs.

Adenocarcinoma, Clear Cell↗

PubMedDate not supplied

Serum cathepsin D and its density in men with prostate cancer as new predictors of disease progression.

We examined whether serum levels of cathepsin D (CatD) and its density (CatD-D), which was determined by dividing the serum levels of CatD by the prostate volume, could be used as predictors of the progression and prognosis in patients with prostate cancer. Serum levels of CatD in 40 healthy controls, 70 patients with benign prostatic hypertrophy (BPH) and 80 patients with prostate cancer were measured by a sandwich enzyme immunoassay, and prostate volume was measured using transrectal ultrasonography. The mean levels of CatD and CatD-D in patients with prostate cancer were significantly higher than those in healthy controls and patients with BPH. Furthermore, the CatD and CatD-D levels in prostate cancer patients with metastasis were significantly elevated compared with those in patients without metastasis. Among patients who underwent radical prostatectomy, the levels of CatD and CatD-D in patients with pathologically organ-confined disease were significantly lower than in those with extraprostatic disease. However, the elevated levels of CatD and CatD-D were not significantly associated with the cause-specific survival in prostate cancer patients. These findings suggest that the elevation of CatD or CatD-D could be used as new predictors of disease progression, but not prognosis, in patients with prostate cancer.

Aged↗

PubMedDate not supplied

Resistance to cytotoxic chemotherapy-induced apoptosis in human prostate cancer cells is associated with intracellular clusterin expression.

We recently reported the powerful antiapoptotic activity of clusterin against various apoptotic stimuli in prostate cancer model systems; however, the precise mode of clusterin action in target cells remains largely unknown. In the present study, we therefore investigated whether intracellular or extracellular action of clusterin plays a crucial role in cytotoxic chemotherapy-induced apoptosis in androgen-independent human prostate cancer PC3 cells, which express a high level of clusterin. The sensitivity of PC3 cells to paclitaxel was increased by pretreatment with monoclonal antibody (mAb) to clusterin or antisense (AS) oligodeoxynucleotide (ODN) targeting the clusterin gene in a dose-dependent manner at up to 50 microg/ml or 1 microM, respectively. However, clusterin mAb failed to further enhance the sensitivity to paclitaxel of PC3 cells simultaneously treated with 1 microM AS clusterin ODN, whereas AS clusterin ODN further induced the apoptosis of cells treated with 50 microg/ml clusterin mAb. Moreover, the effects of clusterin mAb and AS clusterin ODN on PC3 cells were not reversed by additional treatment with exogenous recombinant clusterin protein. These findings suggest that the sensitivity of PC3 cells to paclitaxel-induced cytotoxicity may be regulated by the intracellular rather than extracellular level of clusterin.

Antibodies, Monoclonal↗

PubMedDate not supplied

Predicting factors for collection of peripheral blood stem cells in patients with advanced germ cell tumors after cisplatin-based combination chemotherapy.

The objectives of this study were to identify the predictive factors for the mobilization of CD34 positive peripheral blood stem cells (PBSC) and to determine the optimal timing of PBSC harvest in patients with advanced germ cell tumors after cisplatin-based combination chemotherapy. Thirty-eight patients with advanced germ cell tumors were enrolled in this study. We undertook a retrospective analysis of 124 aphereses performed between March, 1994 and December, 1999. The predictive value for the optimal timing of PBSC harvest was determined by the analysis of the correlation factors between the number of harvested CD34 positive cells and several clinicopathological factors. The mean number of CD34 positive cells obtained at a single apheresis was 5.38 x 10(6)/kg, and the mean cumulative number of CD34 positive cells in each patient was 24.07 x 10(6)/kg. The number of CD34 positive cells were significantly correlated to the number of previously performed chemotherapies before PBSC harvest, leukocyte count and the percentage of immature leukocytes (myelocytes plus metamyelocytes) (p=0.0098, p=0.011, and p<0.0001, respectively). Multivariate analysis revealed that the number of chemotherapies and the percentage of immature leukocytes were independent predictors for the number of harvested CD34 positive cells (p=0.012 and p=0.016, respectively). The present findings suggest that PBSC harvest should be performed during first-line chemotherapy, and that the monitoring of the percentage of immature leukocytes could be a useful predictor for determining the optimal timing of PBSC harvest.

Adolescent↗

PubMedDate not supplied

Long-term cryopreservation of peripheral blood stem cells in patients with advanced germ cell tumors using the dump-freezing method at -80 degrees C.

The objectives of this study were to evaluate the hematopoietic activity of peripheral blood stem cells (PBSCs) harvested from patients with advanced germ cell tumors after long-term cryopreservation in a mechanical freezer at -80 degrees C. Forty-one patients with advanced tumors were enrolled in this study. Flow cytometric analysis was performed to determine the total cell viability and the viability of CD34 positive cells of PBSCs stored between January 1995 and December 2001. The 41 patients were divided into two groups according to the duration of cryopreservation. In the 21 patients in whom the duration of storage was greater than 5 years, the total cell number did not change significantly before and after long-term cryopreservation (p=0.75). The percentage of viable cells and the total number of viable cells was significantly decreased after long-term cryopreservation (p<0.001 and p<0.05, respectively). However, the percentage of CD34 positive cells was significantly increased to 2.34% from 1.85% (p<0.05), resulting in non-statistically significant change in the total viable CD34 positive cells (p=0.98). A similar relation was found in the 20 patients whose storage duration was less than 2 years, although a significant change was found only in the percentage of viable cells. Moreover, pre-PBSCH factors, including age, cumulative dosage of cisplatin and the International Germ Cell Cancer Collaborative Group classification at the diagnosis did not affect the viable CD34 positive cell count after long-term cryopreservation. In conclusion, the present results suggest that CD34 positive cells could be successfully cryopreserved in a mechanical freezer at -80 degrees C for more than 5 years with no relation to pre-PBSCH factors and efficacy of PBSCH itself.

Adolescent↗

PubMedDate not supplied

Serum level of cathepsin B and its density in men with prostate cancer as novel markers of disease progression.

BACKGROUND: Cathepsin B has been shown to play an important role in invasion and metastasis of prostate cancer. The objective of this study was to determine whether serum levels of cathepsin B and its density (cathepsin B-D) could be used as predictors of disease extension as well as prognosis in patients with prostate cancer. MATERIALS AND METHODS: Serum levels of cathepsin B in 60 healthy controls, 80 patients with benign prostatic hypertrophy (BPH) and 120 patients with prostate cancer were measured by a sandwich enzyme immunoassay. Cathepsin B-D was calculated by dividing the serum levels of cathepsin B by the prostate volume, which was measured using transrectal ultrasonography. We subsequently analyzed the association between these two factors and several clinicopathological factors. RESULTS: The mean values of cathepsin B and cathepsin B-D in patients with prostate cancer were significantly higher than those in healthy controls and BPH patients. Moreover, the cathepsin B and cathepsin B-D levels in patients with metastasis were significantly elevated compared with those in patients without metastasis. Among patients undergoing radical prostatectomy, the levels of cathepsin B and cathepsin B-D in those with pathologically confirmed extraprostatic disease were significantly higher than in patients with organ-confined disease. However, there was no significant association between the elevation of cathepsin B and cathepsin B-D levels and cause-specific survival in prostate cancer patients. CONCLUSION: These findings indicate that the elevation of serum cathepsin B and cathepsin B-D could be used as novel predictors of disease extension, but not survival, in patients with prostate cancer.

Aged↗

PubMedDate not supplied

Urinary levels of vascular endothelial growth factor in patients with prostate cancer as a predictor of disease progression.

BACKGROUND: The objectives of this study were to investigate the association between urinary levels of vascular endothelial growth factor (VEGF) and the progression of prostate cancer, and to evaluate changes in urinary VEGF levels before and after initial treatment. MATERIALS AND METHODS: A total of 97 patients with prostate cancer were included in this study. Of these 97, 52 underwent radical prostatectomy and the remaining 45 received hormonal therapy as initial treatment. Urinary VEGF levels were measured using a sandwich enzyme immunoassay, and the results were analyzed with respect to several clinicopathological factors. RESULTS: The mean urinary level of VEGF in patients with prostate cancer was significantly higher than that in healthy controls. The urinary level of VEGF in prostate cancer patients with metastasis was significantly elevated compared with that in those without metastasis. Among 52 patients who underwent radical prostatectomy, the urinary levels of VEGF in patients with pathologically organ-confined disease were significantly lower than that in those with extraprostatic disease. Furthermore, the urinary VEGF level in 52 patients after radical prostatectomy was significantly lower than that before radical prostatectomy, while there was no significant difference in urinary VEGF level in 45 patients before and after hormonal therapy. CONCLUSION: These findings suggest that the elevation of urinary VEGF could be a useful predictor of disease progression in prostate cancer, and that the urinary levels of VEGF reflect the therapeutic effect of radical prostatectomy, but not that of hormonal therapy.

Antineoplastic Agents, Hormonal↗

PubMedDate not supplied

Enhanced expression of heat shock protein 27 following neoadjuvant hormonal therapy is associated with poor clinical outcome in patients undergoing radical prostatectomy for prostate cancer.

BACKGROUND: The objectives of this study were to characterize changes in the expression of heat shock protein 27 (HSP27) in prostate cancer before and after androgen withdrawal therapy and to assess the prognostic significance of HSP27 expression in patients undergoing radical prostatectomy (RP) following neoadjuvant hormonal therapy (NHT). MATERIALS AND METHODS: This study included 97 patients with clinically localized prostate cancer who received NHT followed by RP. Paired needle biopsy and corresponding RP specimens obtained from these patients were analyzed for expression of the HSP27 protein by immunohistochemical staining. These findings were evaluated with respect to several clinicopathological factors. RESULTS: HSP27 expression in the RP specimens following NHT was significantly up-regulated compared with that in the corresponding needle biopsy specimens. The expression level of HSP27 in the biopsy specimens was significantly associated with the biopsy Gleason score, but not with other factors available before RP. HSP27 expression in the RP specimens was significantly correlated with the pre-operative value of serum prostate-specific antigen and pathological stage, but not with other pathological factors. Biochemical recurrence-free survival in patients with strong HSP27 expression in the RP specimens was significantly lower than that in those with weak HSP27 expression; however, the expression level of HSP27 was not an independent predictor of biochemical recurrence. CONCLUSION: Despite the lack of independent significance, the expression level of HSP27 in prostate cancer tissue after NHT, which may inversely reflect the therapeutic effect of NHT, could be a useful parameter predicting biochemical recurrence in patients undergoing RP.

Aged↗

PubMedDate not supplied

Stable hematopoietic recovery after peripheral blood stem cell transplantation in patients receiving high-dose chemotherapy for advanced germ cell tumors.

AIM: The objective of this study was to evaluate the utility of CD34-positive peripheral blood stem cell transplantation (PBSCT) in the hematopoietic recovery, in patients receiving high-dose chemotherapy (HDCT), for advanced germ cell tumor (GCT). MATERIALS AND METHODS: This study included 41 patients with advanced GCT, who were treated with HTCT combined with PBSCT. PBSCs were harvested after conditioning chemotherapy followed by the administration of granulocyte colony-stimulating factor. A retrospective analysis of a total of 86 PBSCTs was carried out focusing on the effects of several factors, including age (<35 years versus > or = 35 years), CD34-positive cell dose (<5.0 x10(6)/kg versus > or =5.0 x10(6)/kg), indication of HDCT (first-line versus salvage) and previous history of HDCT before PBSCT (with versus without), on hematopoietic recovery after PBSCT. RESULTS: The median number of CD34-positive PBSCs collected during a single apheresis and the median cumulative number of CD34-positive PBSCs from each patient were 8.3x10(6)/kg and 23.2x10(6)/kg, respectively. The median number of PBSCT performed in each patient was two and the median number of CD34-positive cells transplanted during a single course was 5.7x10(6)/kg. The median recovery times to white blood cells (WBC) greater than 500/microl, 1000/microl and 2000/microl were 8, 9 and 10 days, respectively, following PBSCT, while that to neutrophils greater than 500/microl and that to platelets greater than 50000/microl were 9 and 13 days, respectively, following PBSCT Only the recovery time to platelet count greater than 50000/microl was significantly affected by age; however, there were no significant differences in the recovery of WBC, neutrophils and platelets in relation to several parameters examined. CONCLUSION: These findings suggest that CD34-positive PBSCT may facilitate stable hematopoietic recovery after HDCT in patients with advanced GCT, and that HDCT, if combined with PBSCT, could be performed with comparative safety in such patients, irrespective of their individual characteristics.

Adolescent↗