HER2 Overexpression and Amplification in Uterine Carcinosarcomas With Serous Morphology.

Uterine carcinosarcoma (UCS) is an aggressive malignancy with few treatment options. A recent clinical trial has shown an increase in progression-free survival in patients with human epidermal growth factor receptor 2 (HER2)-positive serous endometrial carcinomas treated with anti-HER2-targeted therapies. Few studies have evaluated HER2 expression/amplification in UCS. Similar to serous endometrial carcinoma, the majority of UCS have TP53 mutations and a serous epithelial component, suggesting that UCS may show similar rates of HER2 positivity and therapeutic response. Therefore, we evaluated HER2 expression/amplification in a cohort of UCS over a 5-year period. HER2 immunohistochemistry (IHC) and chromogenic in situ hybridization were performed on tissue microarray and whole tissue sections and scored according to the most recent clinical trial recommendations. Three of 48 UCS (6%) had strong (3+) HER2 IHC expression, and 3 cases (6%) were equivocal (2+). Seven cases (15%) had HER2 amplification by chromogenic in situ hybridization, including all 3 with overexpression and 2 that were equivocal by IHC. Mismatch repair (MMR) protein, p53, and programmed cell death-ligand 1 (PD-L1) expression status was obtained from prior whole section analyses. All HER2-positive cases had a serous morphology and aberrant p53 expression. Only minimal PD-L1 expression was seen in the HER2-positive cases, and none had MMR loss. A subset of UCS with serous morphology have overexpression and/or amplification of HER2, which may predict response to HER2-targeted therapies. HER2-positive UCS may be less susceptible to immune checkpoint inhibition as they uncommonly show MMR deficiency and/or strong PD-L1 expression. Thus, HER2-targeted therapies could be of clinical utility in a subset of UCS without other adjuvant treatment options.

Expression of aurora kinases: Predictor of tumor dissemination in uterine carcinosarcoma.

Uterine carcinosarcoma is a rare, aggressive, and biphasic tumor. It comprises carcinomatous and sarcomatous components, and mitosis-associated factors are thought to discriminate these two lesions. Aurora kinases are mitotic enzymes that are highly expressed in uterine malignancies. To identify the clinical significance of aurora kinase expression, we performed immunohistochemistry on tissue microarrays using cores selected from areas with typical carcinomatous and sarcomatous characteristics. A total of 24 samples were included, from patients at Seoul National University Hospital diagnosed with uterine carcinosarcoma, and who undergone a staging operation between 1997 and 2012. Patients' clinical and pathological data were analyzed, and expression patterns of aurora kinases were investigated. Aurora kinases A and B were dominantly expressed in the cytoplasm, and phospho-aurora kinases A and B were expressed in the nuclei. Phospho-aurora kinase A and aurora kinase B showed significantly higher expression in the carcinomatous component (P=0.012 and 0.008). High expression of phospho-aurora kinase A was associated with lymphatic metastasis such as positive pelvic lymph node and omental involvement (P=0.012 and 0.037). Overexpression of aurora kinase B was related to vascular invasion (P=0.011). High expression of both phospho-aurora kinase A and aurora kinase B was a prognostic factor for progression-free survival in uterine carcinosarcoma (P=0.049). In conclusion, expression of aurora kinases is associated with bidirectional tumor dissemination into the lymphatic and hematogenous pathways. In addition, high expression of phospho-aurora kinase A and aurora kinase B is a predictor of progression-free survival. Therefore, inhibitors of aurora kinases might be a prospective therapeutic options for uterine carcinosarcoma.

Molecular characterization of pulmonary sarcomatoid carcinoma: analysis of 33 cases.

Several targetable genetic alterations have been found in lung cancer, predominantly in adenocarcinomas, which have led to important therapeutic advancements with the advent of targeted therapy. In contrast, the molecular features and presence of targetable genetic abnormalities in pulmonary sarcomatoid carcinomas are largely unknown. Thirty-three cases of pulmonary sarcomatoid carcinoma were tested for approximately 2800 mutations in 50 oncogenes and tumor-suppressor genes, including EGFR, KRAS, NRAS, TP53, BRAF, ERBB2, JAK3, AKT1, ATM, MET, KIT, and PIK3CA. ALK immunostaining was performed, and ALK FISH was performed on cases with any degree of staining. Twenty-four of the 33 cases (72%) had at least one genetic abnormality: 19 cases (58%) had TP53 mutations; 10 cases (30%) had KRAS mutations; AKT1, JAK3, BRAF, NRAS, and PIK3CA mutations were observed in 1 case each (3%). Six of the 19 cases (32%) with a mutation in TP53 had simultaneous mutations in KRAS (18%). The cases with alterations in JAK3, BRAF, and NRAS also had mutations in TP53. The case showing a mutation in PIK3CA had a mutation in KRAS. No EGFR mutations were observed. One case had ALK gene rearrangement. ALK rearrangement was observed in a single case of sarcomatoid carcinoma (3%), which has currently available targeted therapy. Four tumors had mutations in genes with experimental molecular-based therapy, including BRAF, NRAS, PIK3CA, and AKT1. Testing for targetable mutations should be considered for patients with pulmonary sarcomatoid carcinoma, as a subset may benefit from currently approved drugs or clinical trials of novel therapeutic options available for other types of lung cancer.

Neratinib shows efficacy in the treatment of HER2 amplified carcinosarcoma in vitro and in vivo.

OBJECTIVE: Carcinosarcoma is a deadly gynecologic malignancy with few effective treatment options. The study of new therapies is difficult because of its rarity. The objective of this study was to determine the efficacy of neratinib in the treatment of HER2 amplified carcinosarcoma. METHODS: The efficacy of neratinib in the treatment of HER2 amplified carcinosarcoma was determined in vitro using seven primary carcinosarcoma cell lines with differential expression of HER2/neu. Data regarding IC50, cell cycle distribution, and cell signaling changes were assessed by flow cytometry. The efficacy of neratinib was determined in treating mice harboring HER2 amplified carcinosarcoma xenografts. RESULTS: Two of seven (28.5%) carcinosarcoma cell lines were HER2/neu amplified. HER2/neu amplified cell lines SARARK6 and SARARK9 were significantly more sensitive to neratinib than the five non-HER2/neu amplified carcinosarcoma cell lines (mean±SEM IC50:0.014µM±0.004vs.0.164µM±0.019 p=0.0003). Neratinib treatment caused a significant build up in G0/G1 phase of the cell cycle, arrest auto phosphorylation of HER2/neu and activation of S6. Neratinib inhibited tumor growth (p=0.012) and prolonged survival in mice harboring HER2 amplified carcinosarcoma xenografts (p=0.0039). CONCLUSIONS: Neratinib inhibits HER2 amplified carcinosarcoma proliferation, signaling, cell cycle progression and tumor growth in vitro. Neratinib inhibits HER2/neu amplified xenograft growth and improves overall survival. Clinical trials are warranted.

The Effect of Cyclooxygenase-2 Expression in Uterine Carcinosarcoma on Survival: A Reassessment Based on Mature Data.

OBJECTIVE: To reassess the effect cyclooxygenase-2 (COX-2) expression in carcinosarcoma on survival based on mature 5-year survival data. METHOD: A comparison of 5-year survival of 27 patients with carcinosarcoma according to the presence of COX-2 immunohistochemical staining and staining score was performed. RESULTS: The 5-year survival of those with positive and negative COX-2 staining was statistically not different. However, there was a clear trend for more favorable 5-year survival in patients with a high staining score than in those with a low score, and the difference was of borderline significance (38.5% vs 7.1%; P = 0.06). CONCLUSION: In view of the role of COX-2 in carcinogenesis, our finding that COX-2 expression may confer a better survival in patients with carcinosarcoma is intriguing. Larger studies are indicated to elucidate the effect of COX-2 expression on survival in patients with carcinosarcoma because this may have therapeutic implications.

Mammary gland-specific ablation of focal adhesion kinase reduces the incidence of p53-mediated mammary tumour formation.

BACKGROUND: Elevated expression of focal adhesion kinase (FAK) occurs in numerous human cancers including colon-, cervix- and breast cancer. Although several studies have implicated FAK in mammary tumour formation induced by ectopic oncogene expression, evidence supporting a role for FAK in spontaneous mammary tumour development caused by loss of tumour suppressor genes such as p53 is lacking. Alterations in the tumour suppressor gene p53 have been implicated in over 50% of human breast cancers. Given that elevated FAK expression highly correlates with p53 mutation status in human breast cancer, we set out to investigate the importance of FAK in p53-mediated spontaneous mammary tumour development. METHODS: To directly assess the role of FAK, we generated mice with conditional inactivation of FAK and p53. We generated female p53(lox/lox)/FAK(+/+)/WapCre, p53(lox/lox)/FAK(flox/+)/WapCre and p53(lox/lox)/FAK(flox/-)/WapCre mice, and mice with WapCre-mediated conditional expression of p53(R270H), the mouse equivalent of human p53(R273H) hot spot mutation, together with conditional deletion of FAK, P53(R270H/+)/FAK(lox/+)/WapCre and p53(R270H/+)/FAK(flox/-)/WapCre mice. All mice were subjected to one pregnancy to induce WapCre-mediated deletion of p53 or expression of p53 R270H, and Fak genes flanked by two loxP sites, and subsequently followed the development of mammary tumours. RESULTS: Using this approach, we show that FAK is important for p53-induced mammary tumour development. In addition, mice with the mammary gland-specific conditional expression of p53 point mutation R270H, the mouse equivalent to human R273H, in combination with conditional deletion of Fak showed reduced incidence of p53(R270H)-induced mammary tumours. In both models these effects of FAK were related to reduced proliferation in preneoplastic lesions in the mammary gland ductal structures. CONCLUSIONS: Mammary gland-specific ablation of FAK hampers p53-regulated spontaneous mammary tumour formation. Focal adhesion kinase deletion reduced proliferative capacity of p53 null and p53(R270H) mammary epithelial cells but did not lead to increased apoptosis in vivo. Our data identify FAK as an important regulator in mammary epithelial cell proliferation in p53-mediated and p53(R270H)-induced mammary tumour development.

Differential expression of ubiquitin carboxy-terminal hydrolase L1 in breast carcinoma and its biological significance.

Ubiquitin carboxy-terminal hydrolase L1 (UCHL1) is a deubiquitinating enzyme that hydrolyzes ubiquitin. Previous reports have shown both tumorigenic and antitumorigenic roles for UCHL1. However, the expression patterns of UCHL1 protein, an area that is critical for validating its clinicopathologic roles among subtypes of breast cancer, is still lacking. Here we examined the expression of UCHL1 by immunohistochemistry in 243 breast carcinomas of various subtypes. We found expression of UCHL1 in 8.3% of invasive ductal carcinomas but not in other carcinoma subtypes, except for metaplastic carcinomas of the breast, which showed UCHL1 staining in 61.9% of cases, with the sarcomatous components being more intensely stained. UCHL1 expression in invasive ductal carcinomas significantly correlated with a high histologic grade (P = .001), the triple-negative phenotype (P = .02), and the basal-like phenotype (P <.001); furthermore, it was associated with poorer overall survival by univariate and multivariate analyses. Knockdown of UCHL1 in an invasive Snail variant-transfected MCF7 cells with high endogenous UCHL1 protein level significantly reduced invasion and anchorage-independent growth. Conclusively, our results demonstrate a role for UCHL1 in aggressive phenotypes in breast carcinoma. The high expression of UCHL1 in metaplastic carcinomas of the breast, which is pathogenically related to epithelial-mesenchymal transition, may implicate an association between UCHL1 expression and the epithelial-mesenchymal transition in breast cancer.

Expression of receptor tyrosine kinases in esophageal carcinosarcoma.

Esophageal carcinosarcoma (ECS) is a rare malignant neoplasm associated with a poor patient prognosis. It is characterized by the presence of both malignant epithelial and mesenchymal components. Molecular-targeted therapy of several receptor tyrosine kinases (RTKs) has been reported to be effective in the treatment of various malignant tumors, including carcinosarcoma of several organs. This study aimed to assess the therapeutic potential of targeting RTKs in ECS. Overexpression of RTKs was assessed in 21 ECS cases by immunohistochemistry (IHC). Positively stained cases were further examined for RTK gene mutations and amplifications by direct sequencing analysis and fluorescence in situ hybridization. In epithelial components, KIT, platelet-derived growth factor receptor (PDGFR)A, PDGFRB, MET, epidermal growth factor receptor (EGFR) and HER-2 were overexpressed in 1 (4.8%), 1 (4.8%), 0 (0%), 11 (52.4%), 13 (61.9%) and 2 (9.5%) cases, respectively. In the mesenchymal components the corresponding numbers of cases were 2 (9.5%), 2 (9.5%), 0 (0%), 12 (57.1%), 11 (52.4%) and 0 (0%). No mutations in the c-kit, PDGFRA and c-met genes were found. Among 19 EGFR-positive tumors, 2 had EGFR missense mutations (T790A, exon 20) only in the mesenchymal component. Gene amplification or high polysomy of c-kit, PDGFRA, c-met and EGFR was observed in 1 (33.3%), 0 (0%), 3 (18.8%) and 10 (52.6%) cases, respectively. In conclusion, various RTKs, particularly MET and EGFR were overexpressed in ECSs suggesting that molecular-targeted therapies directed to MET, EGFR or other RTKs may be effective in inhibiting the growth or progression of the epithelial and/or mesenchymal component of ECS.

Role of thymidylate synthase and dihydropyrimidine dehydrogenase mRNA expressions in gallbladder carcinoma.

PURPOSE: Thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) are important enzymes in the metabolism of 5-fluorouracil, which have been examined as possible predictive markers. We conducted this study to clarify the role of TS and DPD expressions in gallbladder carcinoma (GBC). METHODS: The subjects were 28 patients who underwent surgical resection of GBC. We examined intratumoral TS and DPD mRNA expressions, using the Danenberg tumor profile method. The expression levels were classified into two groups, based on median values. Clinicopathological variables, including prognosis, were then compared between the high and low expression groups. RESULTS: There was a significant difference in the incidence of lymph node metastasis between the high and low TS expression groups. The incidence of advanced clinical stage was higher in the low TS expression group than in the high TS expression group. However, no clear correlation was observed between the DPD mRNA expression and any clinicopathological variable. There was no significant difference in the postoperative survival rates between the groups, in accordance with the expression of TS or DPD genes. CONCLUSION: Low TS mRNA was correlated with a high incidence of lymph node metastasis and advanced clinical stage. Therefore, TS gene expression may help identify patients at increased risk of the progression of GBC.

Death-associated protein kinase is essential for the survival of various types of uterine cancer cells.

We recently showed that targeted knockdown of death-associated protein kinase (DAPK) expression induces apoptosis in the human endometrial adenocarcinoma cell line HHUA. To investigate the possibility that DAPK may represent a molecular target for anticancer therapies for advanced uterine cancers, we examined the effects of DAPK siRNA transfections on the viability of five different human uterine cancer cell lines. The five uterine cell lines comprised three differentiated endometrial adenocarcinomas, one leiomyosarcoma and one carcinosarcoma. Cell death assays showed that the DAPK siRNA transfection significantly increased the cell death in all five uterine cancer cells examined. Ribonuclease protection assays did not show any remarkable changes in the bcl-2 family gene expressions after the DAPK siRNA transfection in HHUA cells. Since DAPK-mutant mice were reported to be fertile and do not show lethality, DAPK may play a central role in the immortalization and carcinogenesis of uterine cancer cells, possibly without bcl-2 family-related apoptotic regulation. These results indicate that DAPK can be a convincing candidate for molecularly targeted anticancer therapies for patients with various types of advanced uterine cancers, including carcinosarcoma and leiomyosarcoma.

The role of Cox-2 expression in the prognosis of dogs with malignant mammary tumours.

Immunohistochemical detection of Cyclooxygenase (Cox)-1 and -2 enzymes in canine mammary tumours (CMT) has recently been described. However, the prognostic value of their expression needs to be established. The aim of this study was to investigate Cox (-1 and -2) prognostic value in malignant CMT by evaluating its correlation with clinicopathological parameters (tumour size, histological type, necrosis, lymph node metastasis) and with Disease Free Survival (DFS) and Overall Survival (OS). Twenty seven female dogs with malignant tumours were included. Cox-2 expression was associated with lymph node metastasis at surgery time, development of distant metastasis during follow-up (p=0.038), DFS (p=0.03) and OS (p=0.04). Multivariate survival analysis showed that Cox-2 did not retain its significance as an independent prognostic factor. For Cox-1 expression, no statistically significant association was observed. Present study suggests the usefulness of testing Cox-2 specific inhibitors as part of an adjuvant therapy in female dogs with malignant mammary neoplasias.

Expression of Cox-1 and Cox-2 in canine mammary tumours.

The aim of this study was to investigate immunohistochemically the expression of cyclooxygenase-1 (Cox-1) and cyclooxygenase-2 (Cox-2) in canine mammary tumours of different histological types. Cox-1 and Cox-2 enzyme expression was evaluated in 70 mammary samples (four normal, six hyperplastic, 60 neoplastic [21 benign and 39 malignant]). Cox-1 expression was identified in all the samples, and Cox-2 in all the mammary lesions except ductal hyperplasia. Two of the four normal mammary gland samples showed focal immunoreactivity for Cox-2. Cox-1 immunoexpression did not differ significantly between benign and malignant lesions (P=0.272). Cox-2 immunoexpression was higher in malignant tumours than in benign counterparts (P<0.001). Of the malignant tumours, carcinosarcomas and tubulopapillary and squamous cell carcinomas had the highest Cox-2 scores. The study showed that malignant tumours had the highest values of Cox-2 expression, and Cox-2 immunolabelling was particularly intense in histological types classically associated with high malignancy. This suggests that nonsteroidal anti-inflammatory drugs (NSAIDs), particularly Cox-2 inhibitors, may have a useful role to play in the treatment of canine malignant mammary tumours.

Increased expression of calpain 6 in uterine sarcomas and carcinosarcomas: an immunohistochemical analysis.

Calpain 6 (Capn6) is one of the calcium-dependent intracellular nonlysosomal proteases. Recently, Capn6 was found to be overexpressed in leiomyosarcomas (LMSs) compared with normal myometrium. This investigation was performed to determine the expression of Capn6 in uterine sarcomas and carcinosarcomas and to determine whether there is a relationship between the clinical findings and the expression of Capn6. Seventeen cases, treated from 1994 to 2004, were evaluated. These included five LMS, seven endometrial stromal sarcomas, and five uterine carcinosarcomas (malignant mullerian mixed tumor [MMMT]). Formalin-fixed, paraffin-embedded tissue sections were immunostained with anti-Capn6 domain-II (anti-DII) and anti-Capn6 domain-T (anti-DT) antibodies. A semiquantitative assessment was performed. All 17 tumors expressed the Capn6 protein; this finding was in contrast to the absence of expression of the Capn6 protein in all of the normal control tissues. The distribution of staining was diffuse. The cytoplasm and nucleus were stained evenly. The mean age of the patients whose samples were stained strongly by anti-DII was higher (P= 0.031). There were no significant associations between tumor stage and staining intensity by anti-DII (P= 1.000) or anti-DT (P= 0.576). However, there was a marginally significant association between tumor subtype and staining intensity (P= 0.054 and P= 0.053, respectively). The expression of Capn6 had no association with disease-free survival (P= 0.367 and P= 0.166, respectively). All of the uterine sarcomas and MMMTs expressed Capn6 protein. This study showed that there were marginally significant associations between tumor subtypes and staining intensity, but no association was found with tumor stage and survival.

Uterine carcinosarcoma: immunohistochemical studies on tissue microarrays with focus on potential therapeutic targets.

OBJECTIVE: Carcinosarcoma of the uterus is a highly aggressive tumor containing both malignant epithelial and spindle (mesenchymal) components. Because of their rarity and poor clinical outcome, investigations into the expression of potential therapeutic targets are limited. The aim of this study was to determine the expression of therapeutic targets in both the epithelial and spindle (mesenchymal) components in 30 carcinosarcomas using tissue microarrays, for potential treatment strategy. METHODS: We collected formalin-fixed, paraffin-embedded tissue blocks of carcinosarcoma of the uterine corpus resected from 30 patients who had undergone total abdominal hysterectomies at our institution between 1985 and 2005 (ages 38-83 years, mean 65.9 years). All hematoxylin-eosin stained sections from each tumor were reviewed to confirm the pathologic diagnosis. Two tissue cores from the paraffin-embedded tissue blocks were constructed into a tissue microarray. Sections were stained with monoclonal antibodies against HER-2, VEGF, c-KIT, COX-2, and EGFR. Unequivocal staining of at least 5% tumor cells was considered positive. HER-2 amplification was also examined by fluorescence in situ hybridization (FISH) in 2 cases. RESULTS: In the epithelial component, expression of HER-2, VEGF, c-KIT, COX-2, and EGFR were detected in 2 (6%), 30 (100%), 0 (0%), 21 (70%), and 9 (30%) cases, respectively, whereas these expressions in the spindle (mesenchymal) component were detected in 0 (0%), 28 (93%), 0 (0%), 5 (16%), and 20 (67%) cases, respectively. By FISH, one of the two cases with HER-2 expression showed gene amplification (2.62). CONCLUSIONS: VEGF is strongly expressed in both the epithelial and spindle (mesenchymal) components of uterine carcinosarcoma. This result warrants further study to evaluate the possible role of anti-angiogenic agents in cancer therapy for patients with uterine carcinosarcomas. The expression patterns of COX-2 and EGFR differed between the epithelial and spindle (mesenchymal) components. HER-2 and c-KIT are poor therapeutic targets for uterine carcinosarcomas.

NAD dependent 11beta-hydroxysteroid dehydrogenase activity in human endometrium and endometrial tumors.

BACKGROUND: The isoforms of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) types 1 and 2, regulated by ovarian steroids, catalyze the interconversion of glucocorticoids and their 11-keto metabolites. The role of these enzymes in malignancies of human endometrium is unknown. We compare NAD dependent 11beta-HSD (type 2) activity levels among normal human endometrium and endometrial carcinomas of differing grades and histologies. METHODS: NAD dependent 11beta-HSD activity was determined in endometrial tissue obtained from patients undergoing hysterectomy for benign or malignant disease (endometroid, serous and carcinosarcomas). Student's t test was utilized with p < 0.05 considered significant. Data are presented as mean +/- SD. RESULTS: NAD dependent 11beta-HSD activity was present in all endometrial samples. The activities were 0.61+/- 0.27 in normal (n = 9), 0.43 +/- 0.29 in endometrioid endometrial carcinoma (n = 14), 0.50 +/- 0.26 in uterine serous carcinoma (n = 6) and 0.25 +/- 0.37 in carcinosarcomas (n = 9). NAD dependent 11beta-HSD activity was lower in the carcinosarcoma group as compared to normal endometrial tissue (p = 0.03). CONCLUSIONS: NAD dependent type 2 11beta-HSD activity was demonstrated in all normal and endometrial tumors. Enzyme activity in endometroid and uterine serious carcinoma tumors was similar to enzyme activity in normal endometrium. In contrast, carcinosarcomas show significantly lower enzyme activity compared to normal tissue.

Effusion cytodiagnosis of carcinosarcoma derived from the female genital tract: immunohistochemical features of MMP-7 and Ki-67 and immunofluorescence double staining analyses of eight cases.

OBJECTIVE: Expression of Matrix metalloproteinase 7 (MMP-7) and Ki-67 by carcinoma components (CCs) and sarcoma components (SCs) in carcinosarcoma of the female reproductive organs has been investigated by conventional methods, but analysis with immunohistochemical staining of multiple antigens has not been reported. We report the profiles of expression of MMP-7 and Ki-67 in carcinosarcoma determined with immunohistochemical staining techniques. METHODS: We used antibodies against epithelial antigen (EA), epithelial membrane antigen (EMA), and vimentin for immunofluorescence double staining of ascitic fluid in eight cases of carcinosarcoma of female reproductive organs. We also used immunohistochemical triple staining to compare MMP-7 and Ki-67 expression between CCs and SCs in the primary site of carcinosarcoma. RESULTS: Immunofluorescence analysis revealed that all neoplastic cells in the ascitic fluid were positive for EA or EMA, indicating that these cells were CCs. Immunohistochemical analyses of the primary organ of carcinosarcoma revealed that MMP-7 was expressed on CCs in four of eight cases of carcinosarcoma, whereas MMP-7 was not expressed on SCs. The average Ki-67 labeling index (LI) in CCs and SCs was 51.8% and 28.6%, respectively. The difference in Ki-67 LI between CCs and SCs was statistically significant (t test for paired samples, P = 0.0173). CONCLUSIONS: This is the first study to examine carcinosarcoma of the female reproductive organ by immunohistochemical staining for multiple antigens, which allows analysis of mixed tumor elements. In addition, we found that expression of MMP-7 and the average Ki-67 LI differ between CCs and SCs in carcinosarcoma. The predominance of CCs as the malignant cells in the ascitic fluid may be due to cytological differences between CCs and SCs of carcinosarcoma.

Expression of c-kit in uterine carcinosarcoma.

OBJECTIVES: The use of tyrosine kinase inhibitors (TKIs) has resulted in successful treatment of KIT-positive neoplasms. Carcinosarcoma is a very aggressive neoplasm. Consequently, c-kit expression may have significant clinical implications for this tumor. The purpose of the present study was to assess c-kit expression in the carcinomatous and sarcomatous element of carcinosarcoma to identify if KIT represents a therapeutic target for treatment of this neoplasm. METHODS: Immunohistochemical staining for c-KIT was performed on paraffin-embedded tissue blocks of 20 consecutive uterine specimens with carcinosarcoma, 40 with endometrial carcinoma, and 12 with atrophic endometrium. Two pathologists assessed the scoring index of staining. RESULTS: In the stromal element of carcinosarcoma, no immunohistochemically c-KIT stained cells were observed and in the epithelial element, a low scoring index of staining was present. In endometrial endometrioid carcinoma, the scoring index was high in only 15% of the specimens. In the atrophic endometrium, a low scoring index was seen in all specimens. CONCLUSIONS: Our results seem to suggest that c-kit probably plays no major role in the pathogenesis of the majority of these tumors while it may be involved in the pathogenesis of some endometrial carcinomas. In view of the multiple molecular targets that are activated by imatinib mesylate, no definitive conclusions can be drawn with regard its effectiveness in carcinosarcomas based on the present study. Further studies of c-kit expression in larger series of carcinosarcomas in order to settle the controversial issues with regard to frequency of expression, prognostic, and clinical value are warranted.

Effects of tin-protoporphyrin IX on blood flow in a rat tumor model.

Carbon monoxide (CO), one of the products of heme oxygenase (HO) catalyzed heme degradation, is a vasodilator. The aim of the present study was to clarify the role of HO in blood flow maintenance in tumors. Male BD9 rats bearing subcutaneous transplants of the P22 carcinosarcoma tumor were treated intraperitoneally (i.p.) with either tin-protoporphyrin IX (SnPP; 45 micromol/kg), a selective inhibitor of HO or copper-protoporphyrin IX (CuPP; 45 micromol/kg), used as a negative control. The extent of HO activity inhibition was measured using a spectrophotometric assay of bilirubin production and blood flow rates to the tumor and a range of normal tissues were assessed using the uptake of the radiolabelled tracer, iodo-antipyrine ((125)I-IAP). The animals were cannulated under fentanyl citrate/fluanisone (Hypnorm)/midazolam anesthesia. In the P22 tumor, SnPP, but not CuPP, caused a complete inhibition of HO activity 15 min post-treatment. Administration of SnPP 15 min before blood flow measurements reduced tumor blood flow by 17%, with no effects in any of the normal tissues studied. However, CuPP induced a greater reduction in tumor blood flow than SnPP (45% decrease). Furthermore, CuPP caused a reduction in blood flow to the skin and small intestine but a significant increase to skeletal muscle. The current findings conclusively establish only a minor role played by the HO/CO system in the maintenance of blood flow in this tumor system, despite relatively high levels of HO-1 protein and HO activity. The results also highlight the potential usefulness of CuPP as a tumor blood flow modifier.

Evidence for the involvement of polyunsaturated fatty acids in the regulation of long-chain acyl CoA thioesterases and peroxisome proliferation in rat carcinosarcoma.

The feeding of high-fat diets rich in polyunsaturated fatty acids (PUFAs) caused a marked increase in the acyl CoA thioesterase activity of the Walker 256 tumour. Diets containing lower levels of PUFAs did not alter the activity of acyl CoA thioesterase and the exposure of LLC-WRC256 tumour cells, in culture, to PUFAs (150 microM) also was ineffective in altering activity. The tumours from n-3 PUFA-rich and control diets were analysed by transmission electron microscopy in order to compare peroxisomal content. The presence of PUFAs led to an almost 10-fold increase in the number of peroxisomes present in the tumour tissue. A common feature of the PUFA-treated tumour was the presence of many cells containing highly condensed heterochromatin at the periphery of the nucleus, indicative of apoptosis. The sparsity of endoplasmic reticulum and the lack of detection of mitochondrial acyl CoA thioesterase, MTE-I, led to the conclusion that the increase in tumour acyl CoA thioesterase activity may be due to an increase in the activity of the peroxisomal enzyme.