Characterization of a novel murine preadipocyte line, AP-18, isolated from subcutaneous tissue: analysis of adipocyte-related gene expressions.

Adipocyte lines are a useful tool for adipocyte research. Recently, a new preadipocyte line designated AP-18 was established from subcutaneous tissue of the C3H/He mouse. In this study, we further characterized AP-18 cells. Adipocyte differentiation was assessed by accumulation of fat droplets stained by Oil Red O. The expression of the preadipocyte- or adipocyte-specific genes and adipocytokine genes was analysed qualitatively by RT-PCR and quantitatively by real-time PCR in comparison with the LM cell, a murine fibroblast line, and the 3T3-L1 cell, respectively. AP-18 cells were fibroblastoid in maintenance culture. After the confluence, fat droplets were accumulated in 50-60% of the cells cultured in the medium alone and in 70-90% of the cells cultured with insulin within 2 to 3 weeks. The fat accumulation was not promoted by the addition of dexamethazone, IBMX (3-isobutyl-1-methylxanthine) or troglitazone in combination with insulin, which were obligatory for differentiation of the 3T3-L1 cell, a murine preadipocyte line. Throughout the differentiation, AP-18 cells expressed Pref-1, LPL, C/EBP beta, C/EBP delta, RXR alpha, C/EBP alpha, PPAR gamma, RXR gamma, aP2, GLUT4, SCD1, UCP2, UCP3, TNFalpha, resistin, leptin, adiponectin and PAI-1 genes, but not the UCP1 gene, indicating that the cell is derived from WAT (white adipose tissue). The time course of these gene expressions was similar to that of 3T3-L1 cells, although the expressions were slower and lower in AP-18 cells. These data indicate that AP-18 cells are preadipocytes originated from WAT and differentiate into adipocytes under more physiological conditions than 3T3-L1 cells. AP-18 may be useful in adipocyte research.

Clinicopathological significance of circadian rhythm-related gene expression levels in patients with epithelial ovarian cancer.

OBJECTIVE: Recent studies implicate circadian genes in the regulation of cell cycle, apoptosis, and cell proliferation at a molecular level. These genesey affect cancer incidence, prognosis, and chemosensitivity. In this study, we measured the expression levels of clock genes and correlated their expression levels with clinicopathological parameters in epithelial ovarian cancer. METHODS: The expression levels of core clock genes, per1, per2, per3, cry1, cry2, Bmal1, clock, and CKIepsilon were quantified by real-time quantitative Reverse transcription-polymerase chain reaction in 83 ovarian cancer tissues and 11 normal ovarian tissues. RESULTS: The expression levels of per1, per2, cry2, clock, CKIepsilon in ovarian cancers were significantly lower than those in normal ovaries. In contrast, cry1 expression was highest among the eight examined clock genes, followed by per3 and Bmal1. Cry1 expression was much higher in cancer than that in normal ovaries. Localized circadian gene expression was determined in cancer cells by in situ hybridization analysis. Cry1 expression was significantly reduced in mucinous and grade 3 tumors. Bmal1 expression was also significantly reduced in mucinous adenocarcinomas as compared to other histologies. In a multivariate analysis, the combination of low cry1 expression and low Bmal1 expression was an independent prognostic factor, as well as stage and histological subtype. CONCLUSIONS: The antiphase expression of cry1 and Bmal1 may be preserved in ovarian cancers. The combination of cry1 and Bmal1 expression might become a possible prognostic marker in epithelial ovarian cancer.

Expression of phospholipase D2 in human colorectal carcinoma.

Phospholipase D (PLD) catalyzes the hydrolysis of phosphatidylcholine (PC) to generate phosphatidic acid (PA) and choline. PA acts as a second messenger in cell proliferation; therefore PLD is believed to play an important role in carcinogenesis. PLD activity has been reported to be elevated in human breast, gastric, renal cell and colorectal carcinomas, compared with adjacent non-neoplastic tissues. The activity of PLD was also correlated with nuclear grade in breast cancer, tumor size in gastric carcinoma, and nodal involvement and deeper invasion in colorectal carcinoma. However, the number of cases in each study was small. The aim of this study was to investigate the expression level of PLD2 and its association with clinicopathological features in human colorectal carcinoma. Ninety-seven colorectal carcinomas were obtained from surgery. Expression level of PLD2 was assessed by real-time PCR. The prognostic relevance of PLD2 expression level in patients with colorectal carcinoma was also analyzed by the survival analysis of mortality follow-up data covering the period 2000-2004. PLD expression level was varied from tumor to tumor. Expression level of PLD was significantly correlated with tumor size (P<0.05); it was independent of lymph node metastasis, extent of invasion, pathological classification, distant metastasis and Dukes' stage. PLD expression level was also significantly correlated with survival of patients with colorectal carcinoma (P<0.05). These findings suggested that PLD2 plays an important role in progression of colorectal carcinoma and that PLD2 could be a target for therapy in colorectal carcinoma.

Expression of circadian clock genes in human colorectal adenoma and carcinoma.

Circadian rhythms are fundamental biological systems in most organisms. Epidemiological and animal studies have demonstrated that disruption of circadian rhythms is linked to tumor progression and mammalian tumorigenesis. However, the clinical significance of in situ clock gene expression in precancerous and cancerous colorectal lesions remains unknown. The present study aimed to investigate mRNA transcript levels of circadian clock genes within human colorectal cancer and adenoma tissue sections. Using in situ hybridization, the expression of key clock genes, including period circadian protein homolog (Per) 1 and 2, cryptochrome 1 (Cry1), circadian locomoter output cycles protein kaput (Clock), brain and muscle ARNT-like protein 1 (Bmal1) and casein kinase 1ε (CK1ε) were retrospectively examined in 51 cases of colorectal carcinoma and 10 cases of adenoma. The expression of clock genes was almost undetectable in the majority of adenomas, whereas positive expression of clock genes was observed in 27-47% of carcinomas. Notably, positive Per1, Per2 and Clock staining in colorectal carcinomas were each significantly associated with a larger tumor size (P=0.012, P=0.011 and P=0.009, respectively). Tumors with positive Per2 and Clock expression tended to exhibit deeper depth of invasion and were generally more advanced than tumors that did not express these genes (P=0.052 and P=0.064, respectively). However, no statistically significant association was observed between clock gene expression and clinicopathological variables, including histopathological differentiation, lymph node metastasis, depth of invasion or disease stage, although Per2-positive tumors tended to be associated with poorer overall survival (P=0.060). The results of the current study suggest that dysregulated expression of clock genes may be important in human colorectal tumorigenesis.

[A case of malignant peritoneal mesothelioma successfully treated with carboplatin and paclitaxel].

A 71-year-old woman was seen at our hospital because of abdominal fullness and dyspnea. Examinations revealed a tumor in the pelvis with fluid collection and dissemination was seen in the abdomen and chest. Moreover, hyaluronate in ascites rose to 20,000 mg/dl. Finally, by cytology of ascites using immunohistochemistry, the patient was diagnosed as malignant peritoneal mesothelioma with disseminations in the abdomen and chest. After intraperitoneal administration of 25 mg of cisplatin (CDDP), we started carboplatin (CBDCA) plus paclitaxel (PTX) combination chemotherapy (each treatment course consisted of 100 mg of PTX and 400 mg of CBDCA on day 1 and PTX 100 mg on day 8 and day 15 by intravenous administration followed by 2 drug-free weeks). After the sixth course, a complete remission was observed. Malignant mesothelioma is known to have a poor prognosis. However, we successfully treated malignant peritoneal mesothelioma with CBDCA and PTX combined chemotherapy. Our case suggests that we could improve the prognosis of malignant mesothelioma by aggressive chemotherapy.

BRAF mutations in papillary carcinomas of the thyroid.

BRAF is a serine/threonine kinase that receives a mitogenic signal from RAS and transmits it to the MAP kinase pathway. Recent studies have reported that mutations of the BRAF gene were detected with varying frequencies in several cancers, notably more than 60% in melanoma. We analysed mutations of BRAF and RAS genes in 100 cases of thyroid carcinoma to investigate genetic aberrations in the RAS/RAF/MEK/MAP kinase pathway. BRAF mutations were detected exclusively in papillary carcinomas (40 in 76 cases: 53%), and were exclusively V599E, a mutation frequently observed in other carcinomas. NRAS mutation was observed in six cases (6%), all in histological types other than papillary carcinoma, and was exclusively Q61R. No mutations were found in KRAS or HRAS. Our results suggest that BRAF mutations may play a critical role in the carcinogenesis of papillary carcinoma of the thyroid.

Prognostic value of the Cu-transporting ATPase in ovarian carcinoma patients receiving cisplatin-based chemotherapy.

PURPOSE: A major obstacle in the treatment of ovarian carcinoma is the intrinsic/acquired resistance to cisplatin-based chemotherapy. Cu-transporting ATPase (ATP7B) has been reported to be associated with cisplatin resistance in vitro. However, the clinical significance of this transporter has not previously been addressed. Our goal was to investigate ATP7B expression in ovarian carcinoma and whether its expression correlates with prognosis and reduced responsiveness to cisplatin treatment. EXPERIMENTAL DESIGN: We retrospectively examined the expression of ATP7B and p53 in primary ovarian carcinoma and its association with chemotherapeutic effect. Tissues were surgically removed from 104 ovarian carcinomas patients who received cisplatin-based chemotherapy. We performed immunohistochemical analysis of ATP7B and p53 using a monoclonal antibody against ATP7B and DO7 antibody against p53 protein in 104 ovarian carcinomas and adjacent nonneoplastic tissues. The significance of ATP7B and p53 in the prognosis of patients with ovarian carcinomas was also examined in the survival analysis of mortality follow-up data covering the period between 1988 and 2001. Furthermore, mutation analysis at the six Cu-binding domain and ATP-binding domain, which may be important for cisplatin transport, were performed using single-strand conformational polymorphism after reverse transcriptase-PCR. RESULTS: A variable degree of cytoplasmic staining of ATP7B in tumor cells was observed in 34.6% (36 of 104 cases) of the analyzed carcinomas. ATP7B expression was not observed in adjacent nonneoplastic tissues. ATP7B positivity in poorly/moderately differentiated carcinoma was significantly higher than that in low malignant potential tumor/well-differentiated carcinoma (P = 0.0276). Patients with ATP7B-positive tumors had a significantly inferior response to chemotherapy compared with the patients with ATP7B-negative tumors (P = 0.025). The multivariate Cox regression analysis revealed that ATP7B expression (hazard ratio, 1.8; 95% confidence interval, 1.0-3.2, P = 0.048), as well as International Federation of Gynecologists and Obstetricians stage (hazard ratio, 2.0; 95% confidence interval, 1.1-3.6, P = 0.018), was prognostic for poor disease outcome after adjustment for p53 expression, grade, and residual tumor. p53 expression was detected in 31.5% (26/104 cases). No mutation was observed on the six Cu-binding domain or ATP-binding domain in human ovarian carcinomas expressing ATP7B gene. CONCLUSIONS: This study demonstrates that overexpression of ATP7B in ovarian carcinoma is correlated with unfavorable clinical outcome in patients treated with cisplatin-based chemotherapy. Therefore, ATP7B expression may be considered as a predictive marker of chemoresistance for cisplatin-based chemotherapy in patients with ovarian carcinoma. We further predict that drugs targeting ATP7B might be useful in combination with cisplatin-based regimen for the improvement of patients with ovarian carcinoma.

Translational research in breast cancer.

Translational research (TR) involves both the development of novel diagnostics and novel therapeutics. These two major developmental areas are often associated with each other and these associations often bring new paradigms in the management of cancer patients. For example, the development of trastuzumab-based treatments has been conducted in harmony with the development of new methodologies to assess the expression of the Her-2 gene or protein, and from this, a therapeutic modality was established for breast cancer patients as a novel and individualized treatment system. TR covers a broad spectrum, from diagnosis to treatment, and it seems to act as a catalyst for developing novel paradigms. Therefore, it is crucial to conduct TR in clinical trials, in particular, prospective clinical trials. In this regard, TR can accelerate the development of new methodologies and increase trial efficiency. In this review, we describe the importance of TR, particularly that related to novel therapeutics.

Overcoming multidrug drug resistance in P-glycoprotein/MDR1-overexpressing cell lines by ecteinascidin 743.

Ecteinascidin 743 (Et-743) is a novel anticancer agent forming covalent guanine adducts at specific sites in the DNA minor groove. Et-743 has a unique mechanism of action because it kills cancer cells by poisoning transcription-coupled nucleotide excision repair. Recent studies suggested a complex relationship between P-glycoprotein (P-gp)/MDR1 and Et-743. On one hand, Et-743 was reported to down-regulate the MDR1 promoter in vitro. On the other hand, P-gp overexpression was hypothesized to contribute to Et-743 resistance in an ovarian cell line. The present study was performed to further investigate the relationship between P-gp/MDR1 and the activity of Et-743. First, we found no P-gp/MDR1 overexpression (mRNA and protein levels) in two independently generated Et-743-resistant human colon carcinoma cell lines (HCT116/ER5 and SW480/ER0.5). Secondly, we found no cross-resistance to Et-743 in two well-characterized P-gp/MDR1-overexpressing cell lines (KB-8-5 and KB-C-2). Third, Et-743 pretreatment enhanced the cytotoxicity and the cellular accumulation of doxorubicin and vincristine in P-gp/MDR1-overexpressing KB-8-5/KB-C-2 cell lines. Fourth, we observed P-gp/MDR1 down-regulation by Et-743 in KB-C-2 cells. These results indicate that Et-743 does not select for the emergence of a P-gp phenotype in all cell lines made resistant to Et-743 and that P-gp overexpression is not sufficient to confer resistance to Et-743. Furthermore, Et-743 is an effective agent in P-gp-overexpressing cells. Et-743 can potentiate the activity of other chemotherapeutic agents by down-regulating P-gp/MDR1, suggesting that the combination of Et-743 and chemotherapeutic agents that are substrates for P-gp/MDR1 may be valuable in the clinic.

Hypoxia-inducible factor 1 alpha (HIF-1 alpha) gene expression in human ovarian carcinoma.

Hypoxia-inducible factor 1 alpha (HIF-1 alpha) that regulates genes involved in response to hypoxia and promotes neo-angiogenesis, is a transcriptional factor for vascular endothelial cell growth factor (VEGF). The aim of this study was to examine the expression of HIF-1 alpha and VEGF gene expressions and their relation to angiogenesis, clinicopathologic variables and survival in the patient with human ovarian carcinoma. We retrospectively analyzed HIF-1 alpha and VEGF gene expression levels using reverse transcriptase polymerase chain reaction (RT-PCR) in 60 ovarian carcinomas. Intratumoral microvessel density (IMD) was assessed by immunostaining endothelial cells, using anti-CD 31 antibody in frozen sections. The relationships between the expression level of these genes, IMD and clinicopathologic variables were evaluated by Student's t-test and chi-square tests. Survival analysis was performed by Kaplan-Meier curves. HIF-1 alpha or VEGF gene expression level was independent of age, clinical stage and histological subtype besides grade of tumor. There was no relationship between HIF-1 alpha or VEGF gene expression level and IMD in all carcinomas (R=0.118 and 0.224, respectively). In addition, a weak association between HIF-1 alpha and VEGF gene expression level was observed (R=0.300, P=0.020). The association between VEGF gene expression and IMD was observed (R=0.501, P=0.016). However, no association between IMD and HIF-1 alpha gene expression was observed. Further, both HIF-1 alpha and VEGF gene expression levels had no effect on survival in the patient with ovarian carcinoma. These results suggest that VEGF upregulated by HIF-1 alpha gene may be involved in angiogenesis of some type of ovarian carcinoma, but the expression levels of both genes have no effect on survival in the patients with ovarian carcinoma.

Prognostic value of overexpression of p53 in human ovarian carcinoma patients receiving cisplatin.

A major obstacle to the treatment of ovarian carcinoma is intrinsic/acquired resistance to cisplatin-based chemotherapy. The clinical significance of p53 overexpression in patients with ovarian carcinoma is still controversial. The aim of this study was to investigate the independent prognostic significance of p53 overexpression in patients with ovarian carcinoma who are treated with cisplatin. We retrospectively examined the overexpression of p53 in primary ovarian carcinoma, and its association with chemotherapeutic efficacy. One hundred and thirty four ovarian carcinomas were surgically removed from patients who received adjuvant cisplatin-based chemotherapy. Immunohistochemical analysis of p53 was performed using a DO7 antibody against the p53 protein in 134 ovarian carcinomas. The significance of p53 in the prognosis of patients with ovarian carcinomas was also examined by a survival analysis of mortality follow-up data covering the period from 1988 to 2001. Thirty-three tumors (25%) exhibited p53 overexpression. Overexpression of p53 in grade 2/grade 3 tumors was significantly higher than that seen in grade 1 tumors (P=0.0088, 0.0229). Patients with tumors who also showed overexpression of p53 had a significantly inferior response to chemotherapy compared with the patients with p53-negative tumors (P=0.04). Cox regression analysis revealed that p53 overexpression was prognostic for poor disease outcome after adjustment for FIGO stage, grade and residual tumor. These findings suggest that overexpression of p53 in ovarian carcinoma is associated with unfavorable clinical outcome in patients treated with cisplatin-based chemotherapy. Therefore, detection of p53 overexpression using the DO7 antibody may be considered as a predictive marker of chemoresistance for cisplatin in patients with ovarian carcinoma.

Expression of thymidylate synthase and thymidine phosphorylase in human breast carcinoma: implication for method to detect expression of these molecules in clinic.

Thymidine phosphorylase (dThdPase) is identical to platelet-derived endothelial cell growth factor, and has an angiogenic activity in experimental models and human solid tumors. A critical step in the de novo pathway of DNA synthesis is the production of the pyrimidine nucleotide dTMP from dump and this reaction is catalyzed by thymidylate synthase (TS). Both dThdPase and TS levels seemed to be related to response to 5-fluorouracil (5-FU) therapy in different types of human solid tumors. The present study evaluated dThdPase and TS expression levels by immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR), using a same set of 39 breast carcinoma tissues for both methods. An inverted-relationship in the expression levels of TS and dThdPase was observed. Further, immunohistochemical analysis may be a better tool than analysis by RT-PCR in detection of dThdPase and TS, because of both dThdPase and TS expression in cells besides carcinoma cells. These imply that immunohistochemical analysis of dThdPase and TS is available for selection of patients who will be received 5-FU based chemotherapy.

Copper-transporting P-type adenosine triphosphatase (ATP7B) is expressed in human gastric carcinoma.

This study describes the first report that a copper-transporting P-type adenosine triphosphatase, ATP7B, is expressed in human gastric carcinomas. Herein, we investigated the hypothesis that ATP7B, which was shown to be associated with cisplatin resistance in vitro, is expressed in certain gastric carcinomas. To test this hypothesis, ATP7B expression level was examined in 51 gastric carcinomas by immunohistochemistry. ATP7B protein could be detected in 41.2% (21/51) of gastric carcinoma by immunohistochemical analysis. In ATP7B-positive tumors, adjacent non-neoplastic tissue was similarly analyzed, revealing that ATP7B is upregulated in gastric carcinoma. ATP7B expression in poorly differentiated/undifferentiated carcinoma was significantly higher than that in well/moderately-differentiated carcinoma (P=0.0278). These findings suggested that ATP7B expression might be a chemoresistance marker against cisplatin in some patients with poorly differentiated/undifferentiated gastric carcinoma.

Microdistribution of alpha particles in pathological sections of tissues from thorotrast patients detected by imaging plate autoradiography.

Thorotrast is a colloidal suspension of radioactive (232)ThO(2) that naturally emits alpha particles (90%), beta particles and gamma rays (10%). Thorotrast was used as a radiographic contrast agent in the 1930s-1950s; it caused liver cancer several decades after injection because of its life-long deposition and exposure. Determination of the amount and the distribution of radioactive thorium are essential for assessment of radiation risks. We visualized alpha particles on ordinary archival tissue sections using an imaging plate and a BAS5000 image analyzer. Furthermore, we confirmed that the imaging system is sensitive enough to detect alpha particles and accurate in measuring the total amount of thorium deposited in the organ from a single tissue section. This method revealed that the amount of thorium deposited in tumor tissue is correlated to that in non-tumor tissue. Thorotrast deposition was not associated with DNA damage determined by histochemistry. In combination with histological findings, it is suggested that radioactive thorium always migrates within the deposited organs by macrophages, and that the organs are evenly exposed to alpha particles.

Enhanced nucleotide excision repair in cisplatin resistant human KB carcinoma cells.

We previously reported that enhanced active efflux of cisplatin and increased GSH level were observed in KCP-4 cells. In the present study, KCP-4 cells were found to be cross-resistant to ultraviolet (UV) compared with parental KB-3-1 cells. Enhanced nucleotide excision repair (NER) was verified by time-dependent repair of UV-induced DNA damage. In addition, the amount of platinum bound to DNA after exposure to cisplatin decreased in a time-dependent manner in KCP-4 cells and this was reversed by aphidicolin, a DNA polymerase inhibitor. In stationary phase cultures, aphidicolin increased the sensitivity of KCP-4 cells to cisplatin. The expression of xeroderma pigmentosum complementation group F (XPF), an endonuclease involved in NER, was upregulated in KCP-4 cells. In KCP-4 cells the expression of hMSH6, one of the mismatch repair (MMR) factors, was decreased compared to parental KB-3-1 and revertant KCP-4R cells. However, KCP-4 cells were cross-resistant to oxaliplatin, and microsatellite instability was not observed in them. These findings suggest that the enhanced NER activity for DNA damage caused by cisplatin may be involved in cisplatin resistance in KCP-4 cells.

Expression of copper-transporting P-type adenosine triphosphatase (ATP7B) as a chemoresistance marker in human oral squamous cell carcinoma treated with cisplatin.

An important clinical problem in the treatment of oral squamous cell carcinoma is the intrinsic/acquired resistance to cisplatin-based chemotherapy. Copper-transporting P-type adenosine triphosphate (ATP7B) has been reported to be associated with cisplatin resistance in vitro (Komatsu et al., Cancer Res 60, 1312-1316,2000). However, the clinical significance of this transporter has not previously been addressed. Our aim of this study was to investigate if ATP7B is expressed in oral squamous cell carcinoma and whether its expression correlates with prognosis and reduced responsiveness to cisplatin treatment. Biopsy tissues were obtained from the tumors of 70 patients with oral SCC, and 51 patients received cisplatin-based preoperative chemotherapy. We performed immunohistochemical analysis of ATP7B using monoclonal antibody against ATP7B in 51 oral SCC and adjacent neoplastic tissues. The significance of ATP7B in the prognosis of patients with oral SCC was also examined in the survival analysis of mortality follow-up data covering the period 1991 through 2000. We retrospectively examined the expression of ATP7B in primary oral SCC carcinoma and its association with chemotherapeutic effect. A variable degree of cytoplasmic staining of tumor cells was observed in 54.9% (28/51 cases) of the analyzed carcinomas. Patients with ATP7B-positive tumors had a significantly inferior response to chemotherapy compared with the patients with ATP7B-negative tumors (P = 0.03). The patients who received cisplatin-based chemotherapy with ATP7B-positive carcinomas had a significantly poorer overall survival than those with ATP7B-negative tumors (P = 0.015). These findings suggest that high levels of ATP7B expression in oral SCC are associated with unfavorable clinical outcome in patients with oral SCCs treated with cisplatin-based chemotherapy. ATP7B expression may be a preoperative indicator for a choice of cisplatin in some patients.

Allelotypes as potential prognostic markers in ovarian carcinoma treated with cisplatin-based chemotherapy.

We analyzed a series of ovarian carcinomas from patients treated with cisplatin-based chemotherapy for loss of heterozygosity (LOH) to determine the relationship between microsatellite alteration and prognosis. Patients with tumors that had lost alleles at loci 3p14-21, 12qter, or 17p13.3 showed significantly reduced survival compared to patients with tumors that retained both alleles at those loci. The 5-year mortality rates for patients exhibiting allele loss and patients with allele retention were 50 and 41%, respectively, for the 3p14-21 locus (P=0.0023); 57 and 24%, respectively, for 12qter (P=0.0256); and 55 and 40%, respectively, for 17p13.3 (P=0.0489). A statistically significant difference was also observed with respect to fractional allelic loss (FAL), which was a significant indicator for disease recurrence (P=0.0227). The prognosis of patients with high FAL values were significantly worse compared to those with low FAL values (P=0.0306). Our results suggested that LOH at loci 3p14-21, 12qter, or 17p13.3 was a significant predictor of poor survival in ovarian carcinomas treated with cisplatin-based chemotherapy. Furthermore, the association of FAL value with therapy response indicated that ovarian carcinomas with high levels of chromosomal alteration may be more resistant to this type of chemotherapy.

Expression of copper-transporting P-type adenosine triphosphatase in human esophageal carcinoma.

A major obstacle in the treatment of esophageal carcinoma is the intrinsic/acquired resistance to cisplatin-based chemotherapy. Copper-transporting P-type adenosine triphosphatase (ATP7B) has been reported to be associated with cisplatin resistance in vitro. However, the clinical significance of this transporter has not previously been addressed. Our goal was to investigate if ATP7B is expressed in esophageal carcinoma and whether its expression correlates with reduced responsiveness to cisplatin treatment. We retrospectively examined the expression of ATP7B in primary esophageal carcinoma and its association with chemotherapeutic effect. Tissues were surgically removed from 17 esophageal carcinoma patients. Twelve of them received cisplatin-based chemotherapy before surgery. We performed immunohistochemical analysis of ATP7B using a monoclonal antibody against ATP7B in 17 esophageal carcinomas. A variable degree of cytoplasmic staining of tumor cells was observed in 76.5% (13/17 cases) of the analyzed carcinomas. ATP7B expression was not observed in adjacent non-neoplastic tissues. ATP7B positivity was not significant in gender, age, histopathological grading or TNM categories. Patients with ATP7B-positive tumors tended to have an inferior response to chemotherapy compared with the patients with ATP7B-negative tumors. These findings suggest that overexpression of ATP7B in esophageal carcinoma could be associated with unfavorable clinical outcome in patients treated with cisplatin-based chemotherapy. Therefore, ATP7B gene expression might be considered as a chemoresistance marker for cisplatin in the patients of esophageal carcinoma and provider of important information on the strategy against esophageal carcinoma.

The proliferative activity of ovarian tumors of low malignant potential differs from that of ovarian carcinoma.

Ovarian tumors of low malignant potential (LMPs) are intermediate between adenomas and ovarian carcinomas (OCs); however, whether an LMP is a precursor of OC or is a unique type of tumor that will not progress to OC is still controversial. To gain better insight into the relationship between LMP and OC, we compared proliferative and apoptotic activity and tumor size in 50 cases of LMP and 27 cases of OC. We employed immunohistochemical staining with Ki-67 and apoptotic labeling was based on the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling. The average tumor size observed in mucinous LMP was significantly larger than that in mucinous OC (p = 0.014). In contrast, there was no difference in tumor size between serous OC and serous LMP. The average Ki-67 labeling index (LI) in mucinous OC was significantly higher than that in mucinous LMP (p = 0.028). There was no difference between serous OC and serous LMP in the Ki-67 LI. There was also no difference in apoptotic indeed (AI) between OC and LMP, irrespective of histological subtype. A significant positive relationship between the Ki-67 LI and tumor size was observed in mucinous LMP (R = 0.516, p = 0.0003). Interestingly, the Ki-67 LI was inversely correlated with tumor size in mucinous OC (R = 0.570, p = 0.0317). Significant positive correlations between Ki-67 LI and tumor size were observed in both serous LMP and serous OC (R = 0.707, p = 0.0488, R = 0.789, p = 0.0168, respectively). No association was seen between AI and tumor size in LMP and OC, irrespective of histological subtype. The different associations between proliferative activity and tumor size in the mucinous subtype of LMP and OC suggest that mucinous LMPs may not be precursors of mucinous OCs. In contrast, the similar associations of proliferative activity with tumor size in the serous subtype of LMP and OC suggest that serous LMPs may be precursors of serous OCs.

Thymidine phosphorylase expression in gastric carcinoma as a marker for metastasis.

BACKGROUND: Thymidine phosphorylase (dThdPase) is identical to platelet-derived endothelial cell growth factor (PD-ECCF) and has a function of angiogenesis in vitro and in several types of human carcinoma tissues. We have reported that expression of dThdPase was an independent prognostic factor in 116 gastric carcinomas by immunohistochemical analysis. MATERIALS AND METHODS: In the present study, we updated the analysis of recurrence in 116 patients with gastric carcinomas to find how dThdPase plays an important role in progression of gastric carcinoma. RESULTS: Expression of dThdPase was significantly involved in the progression and metastasis of gastric carcinoma. Further, the proportion of recurrence of the patients with dThdPase-positive gastric carcinoma (23 out of 50, 46.0%) was significantly higher than that with -negative gastric carcinoma (5 out of 66, 7.6%) (p < 0.05). Interestingly, the proportion of hematogenous metastasis (liver, lung) of the patients with dThdPase-positive gastric carcinoma (8 out of 8, 100%) was significantly higher than that with -negative gastric carcinoma (0 out of 8, 0%)) (p < 0.05). The proportion of peritoneal metastasis of the patients with dThdPase-positive gastric carcinoma (10/13, 76.9%) was also significantly higher than that with -negative gastric carcinoma (3 out of 13, 23.1%)) (p < 0.05). CONCLUSION: These findings suggested that dThdPase promotes hematogenous and peritoneal metastases in gastric carcinoma. Inhibition of dThdPase may suppress hematogenous and peritoneal metastases in gastric carcinoma and improve prognosis of patients with gastric carcinoma.