Biomedical subjects

Masayuki Kamada

Publications and source records attributed to Masayuki Kamada.

10 recordsLinked to original sources

PubMed2007

Hsp27 knockdown using nucleotide-based therapies inhibit tumor growth and enhance chemotherapy in human bladder cancer cells.

Heat shock protein 27 (Hsp27) is a cytoprotective chaperone that is phosphoactivated during cell stress that prevents aggregation and/or regulate activity and degradation of certain client proteins. Recent evidence suggests that Hsp27 may be involved in tumor progression and the development of treatment resistance in various tumors, including bladder cancer. The purpose of this study was to examine, both in vitro and in vivo, the effects of overexpression of Hsp27 and, correspondingly, the down-regulation of Hsp27 using small interfering (si) RNA and OGX-427, a second-generation antisense oligonucleotide targeting Hsp27. Hsp27 overexpression increased UMUC-3 cell growth and resistance to paclitaxel. Both OGX-427 and Hsp27 siRNA decreased Hsp27 protein and mRNA levels by >90% in a dose- and sequence-specific manner in human bladder cancer UMUC-3 cells. OGX-427 or Hsp27 siRNA treatment induced apoptosis and enhanced sensitivity to paclitaxel in UMUC-3 cells. In vivo, OGX-427 significantly inhibited tumor growth in mice, enhanced sensitivity to paclitaxel, and induced significantly higher levels of apoptosis compared with xenografts treated with control oligonucleotides. Collectively, these findings suggest that Hsp27 knockdown with OGX-427 and combined therapy with paclitaxel could be a novel strategy to inhibit the progression of bladder cancer.

Animals↗

PubMed2006

[Clinical experience with intravesical instillations of 5-aminolevulinic acid (5-ALA) for the photodynamic diagnosis using fluorescence cystoscopy for bladder cancer].

PURPOSE: To report our clinical experience with intravesical instillations of 5-aminolevulinic acid (5-ALA) for the photodynamic diagnosis of bladder cancer and to assess any side-effects of the diagnostic method. MATERIALS AND METHODS: Photodynamic diagnosis was performed in 18 patients of which 14 were men and 4 women with a median age of 71 years (range 44-84), 7 were primary cases and 11 were recurrent cases with bladder cancer. Two to two and half hours prior to endoscopy 1.5 g 5-ALA dissolved in 50 ml of 8.4% sodium hydrogen carbonate (NaHCO3) solution was instilled intravesically. For fluorescence excitation a blue light source (D-LIGHT System, Karl Storz Endoscopy Japan K. K.) was used. Under white and fluorescence light guidance, tumor locations were recorded, cold cup biopsies were taken and tumors were resected. The levels in images of the 5-aminolevulinic acid-induced fluorescence were compared with the pathological results. The area under the receiver operative characteristic (ROC) curve (AUC) in blue light endoscopy was also compared with that in white light endoscopy. RESULTS: Among the 129 specimens obtained by transurethral biopsy 45 were obtained from polypoid lesion and 84 from non-polypoid lesion, and among the 76 malignant diseases 36 were obtained from polypoid lesion and 40 from non-polypoid lesion (including 19 carcinoma in situ), and 21 patients with dysplasia were detected pathologically, with a sensitivity of 89.5% and specificity of 58.5% with a predictive accuracy of 77.0%. The AUC in blue light endoscopy was more than that in white light endoscopy in not only all cases (p = 0.010) but also in cases with non-polypoid lesion (p = 0.007) and recurrent cases (p = 0.002). Duration of 5-ALA instillation with a median time of 80 (range 30-150) min. did not seem to affect the accuracy of photodynamic diagnosis. Procedures were well tolerated by all patients with mild bladder irritability but no systemic side effect. CONCLUSION: Photodynamic diagnosis with intravesically applied 5-ALA is more effective than observation by conventional cystoscopy in detecting bladder cancer without additional risk or complication, and is expected to become a golden standard in the detection program.

Administration, Intravesical↗

PubMed2006

[Conservative therapy by percutaneous radiofrequency ablation of renal cell carcinomas--therapeutic experiments of four patients with seven renal tumors--].

We report 7 renal cell carcinomas in 4 patients treated by percutaneous image-guided radiofrequency ablation (RFA). The mean age of the patients was 59 years (male: 2, female: 2). All 4 were imperative cases. Two patients (5 tumor) had hereditary multiple renal cell carcinomas with von Hippel-Lindau (VHL) disease. The other two patients had sporadic renal cell carcinomas. RFA was performed guided by computed tomography under conscious sedation with local anesthetics. The mean size of the treated tumors was 4.5 (1.8-8.1) cm. Impedance-regulated RF energy from a generator at 94 (45-130) watts was applied at 11 (8-14) min intervals. The average procedure time was 91 (45-165) minutes. The maximum tissue temperature reached 82 (56-91) degrees C immediately after ablation. Three of the 7 lesions (42.9 %) were locally well controlled during the mean follow-up period of 6.3 (4-9) months. The two patients with VHL disease developed visceral metastasis after There were no major complications. Minor complications encountered included flank pain, nausea, perinephritic hematoma and fever. Although percutaneous image-guided RFA showed limited success in large or central renal tumors, the therapy against small exophytic renal tumors would be well tolerable and successful.

Aged↗

PubMed2005

Levels of angiogenesis and expression of angiogenesis-related genes are prognostic for organ-specific metastasis of renal cell carcinoma.

BACKGROUND: To identify organ-specific, metastasis-related factors that can be used to predict the development and location of metastasis of clear cell renal cell carcinoma (CRCC), the authors assessed the angiogenesis and the expression of angiogenesis-related genes in primary and metastatic tumors. METHODS: They evaluated intratumoral microvessel density (MVD) by immunohistochemical staining, assessed the expression of angiogenesis-related genes by mRNA in situ hybridization, and determined the clinicopathologic characteristics of 92 archival specimens of primary and metastatic CRCCs from 54 patients. All 38 metastatic tumor specimens were resected from 24 patients. RESULTS: The pathologic stage (P=0.026) of the primary tumor specimen was an important predictor for metastasis, as were MVD (P=0.000025) and the ratio of matrix metalloproteinases (MMPs) to E-cadherin (M/E ratio; P=0.000041). In addition, primary tumor specimens resected from patients with metastatic CRCCs had high MVD, high levels of MMP-2 expression, and a high M/E ratio (P <0.05). Relative to the primary tumors, the metastatic tumors also had high MVD, overexpression of basic fibroblast growth factor, vascular endothelial growth factor, interleukin-8, MMPs, and a high M/E ratio (P <0.05). Multivariate analysis revealed that MVD and the M/E ratio in the primary tumor were independent prognostic factors for metastasis (P=0.049 and P=0.001, respectively). Furthermore, the M/E ratio in metastatic tumor specimens resected from the lung and lymph node was an independent prognostic factor for metastasis (P=0.01823 and P=0.03950, respectively). CONCLUSIONS: The current study indicated that angiogenesis and M/E ratio were specific predictors for metastases of RCC, especially to the lung or lymph node. Therefore, MMPs and E-cadherin could be relevant targets for novel therapeutic strategies to control or prevent the metastasis of RCC.

Aged↗

PubMed2005

Genetic changes in localized prostate cancer of Japanese patients shown by comparative genomic hybridization.

To search for additional amplification and deletion sites that may serve as a starting point for the discovery of new oncogenes or tumor suppressor genes, 30 Japanese localized prostate cancers were analyzed by comparative genomic hybridization (CGH) in this study. CGH was used to search for changes in DNA sequence copy-number in a series of 30 primary prostate adenocarcinomas, consisting of 22 cases of pT2N0 (organ confined; without capsular invasion) and 8 cases of pT3N0 (with capsular invasion), removed by radical prostatectomy. CGH revealed that the shortest regions of overlap (SRO) of gains in pT2N0 were at 8q22.2 approximately q24.2, 11q13.1 approximately q14.1, and 12q23 approximately q24.2, whereas the SRO of losses were seen at 8p23.3 approximately p22, 13q21.2 approximately p22, and 18q21 approximately q22. The SRO of gains in pT3N0 were noted at 5q32 approximately q34, 8q22.3 approximately q24.1, 11q14.1 approximately q22.3, and 12q22 approximately q24.2, whereas the SRO of losses were seen at 18q21.2 approximately q23. These results suggest that gains or losses of DNA in these regions are important for prostate cancer progression. The detection of the SRO may serve as a starting point to discover novel oncogenes and tumor suppressor genes involved in prostate cancer progression.

Adenocarcinoma↗

PubMed2004

Recent advances in ideas on the molecular pathology and clinical aspects of Von Hippel-Lindau disease.

Von Hippel-Lindau (VHL) disease is an autosomal dominant disorder that is associated with various tumors and cysts in the central nervous system (CNS) and visceral organs. Inactivation of the VHL tumor-suppressor protein and subsequent loss of function in the VHL, and Elongin BC (VBC) complex result in dysfunction in the ubiquitination of hypoxia-inducible factor (HIF), which is an important step in the development of angiogenic tumors. The most frequent disorders in VHL disease are hemangioblastoma in the CNS and retina, pheochromocytoma in the adrenal gland, renal cell carcinoma, and pancreatic neuroendocrine tumor. Here, we review recent ideas on the pathogenesis and clinical diagnosis and treatment of VHL disease. Progress in molecular diagnosis and molecular targeting therapy is expected for improvement in the diagnosis and treatment of this disease. The family's support for patients with VHL disease is important, being mutually helpful to overcome various social and psychological problems in the patients.

Angiogenesis Inhibitors↗

PubMed2004

[Partial nephrectomy using microwave tissue coagulator--application for laparoscopic operation].

We report our clinical findings on 12 tumors (11 patients) successfully resected by partial nephrectomy with a microwave tissue coagulator (MTC) without renal pedicle clamping, including laparoscopic operation in 4 patients. All patients presented with a renal tumor detected incidentally by ultrasonography or computed tomography. The mean size of renal tumor was 1.9 (range 0.8-3.4) cm. Pathological diagnosis was renal cell carcinoma in 9 tumors and hemorrhagic cyst in 3 tumors. Mean operative time was 249 minutes. Mean blood loss was 183 ml in cases with a laparoscopic operation, that was statistically less than 486 ml in cases with an open operation (p<0.05), and 376 ml in all cases. There was no significant change in the creatinine clearance of cases with laparoscopic operation, compared with that of cases with an open operation. There were no other serious complications postoperatively. These findings suggested that partial nephrectomy with the MTC can be safely and successfully carried out while sparing renal function. Moreover, partial nephrectomy with the MTC for a laparoscopic operation may provide these patients with more benefits.

Adult↗

PubMed2003

Analysis of gene-expression profiles in testicular seminomas using a genome-wide cDNA microarray.

To identify new diagnostic markers for testicular germ cell tumors (TGCTs), including seminomas, as well as potential targets of new drugs for treating the disease, we compared gene-expression profiles of cancer cells from 13 seminomas with normal human testis using laser-capture microdissection and a cDNA microarray representing 23,040 genes. We identified 347 genes that were commonly up-regulated in seminoma cells. The functions of 227 were known to some extent; the remaining 120 included 55 ESTs. On the list were cyclin D2 (CCND2), prostate cancer over-expressed gene 1 (POV1), and junction plakoglobin (JUP), all of which were already known to be over-expressed in seminomas. On the other hand, our protocol selected 593 genes as being commonly down-regulated in seminoma cells. That list included 340 functionally characterized genes; the other 253 included 131 ESTs. To confirm the expression data, we performed semi-quantitative RT-PCR experiments with nine highly up-regulated genes, and the results supported those of our microarray analysis. The information provided here should prove useful for identifying genes whose products might serve as molecular targets for treatment of TGCTs.

Adult↗

PubMed2002

Detection of genetic alterations in advanced prostate cancer by comparative genomic hybridization.

In this study, we examined nine cases of advanced Japanese prostate cancer by comparative genomic hybridization (CGH) to detect chromosomal imbalances across the entire genome and to identify several new regions likely to contain genes important to the development and progression of this disease. These cases had been previously examined for numerical chromosomal aberrations by fluorescence in situ hybridization (FISH). By CGH, the following regions were found to be over-represented (gains), with fluorescence ratio values higher than the threshold: 4p, 6p, 8q, 11q, 12q, 15q, 16p, 17q, 20, and 21 (>4 cases); underrepresentation (losses) involved: 1q, 4q, 5q, 6q, 13q, 14q, and 22 (>4 cases). The shortest regions of overlap (SRO) of gains were noted at 8q24.1 through q24.3, 12q23, and 17q23 through q24 (>5 cases). The SRO of losses were seen at 5q14 through q21, 6q16.1 through q21, 13q21.3 through q22, and 14q21 (>5 cases). Notably, the gain of chromosomes 8 and 12 by CGH was in agreement with the FISH data, suggesting that the gain of chromosomes 8 and 12 may play an important role in prostate carcinogenesis. The genes on the SRO regions were also discussed in relation to oncogenes and bone metastases.

Aged↗

PubMed2002

The prognostic value of angiogenesis and metastasis-related genes for progression of transitional cell carcinoma of the renal pelvis and ureter.

PURPOSE: We reported previously that angiogenesis evaluated by intratumor microvessel density (MVD), expression of such angiogenic factors as vascular endothelial cell growth factor (VEGF) and basic fibroblast growth factor (bFGF), and the matrix metalloproteinase-9:E-cadherin ratio (M:E ratio) could identify patients with advanced transitional cell carcinoma (TCC) of the bladder for whom chemotherapy and cystectomy will be unsuccessful. In the present study, we evaluated the significance of the M:E ratio as a predictor for prognosis for patients with TCC in the upper urinary tract (TCC-UUT). EXPERIMENTAL DESIGN: We evaluated MVD by immunohistochemistry and the expression of angiogenic and metastasis-related factors by in situ hybridization in 55 nephroureterectomy specimens from patients who received no neoadjuvant therapy. The expression of angiogenesis, angiogenic and metastasis-related factors, and clinicopathological characteristics were evaluated for their correlation with metastasis, recurrence, and disease prognosis. RESULTS: We found that tumor grade and pathological stage were important predictors for metastasis and survival in these patients. The expression level of matrix metalloproteinase type 9 (MMP-9) and type 2 (MMP-2) and the M:E ratio correlated with MVD. Increased MVD, elevated expression levels of MMP-9 and MMP-2, and a higher M:E ratio were associated with poor prognosis. Moreover, lower expression levels of E-cadherin were associated with fewer recurrences in the urinary bladder. Multivariate analysis indicated that the M:E ratio and E-cadherin expression were independent prognostic factors for disease progression and intravesical recurrence, respectively. CONCLUSION: We suggest that the M:E ratio and E-cadherin expression may be targets for novel therapeutic strategies.

Adult↗