Gene expression analysis identifies two groups of ovarian high-grade serous carcinomas with different prognosis.

Gene expression profiling is an important tool to evaluate genetic heterogeneity in carcinomas and is useful to develop expression-based classifications for many types of cancer, as well as markers of disease outcome. In this study, we have investigated the expression profile of 22 genes involved in the PI3K-AKT pathway in 26 high-grade ovarian carcinomas (19 serous and 7 clear cell carcinomas). Unsupervised hierarchical clustering divided high-grade ovarian carcinomas into three groups. Although all clear cell carcinomas clustered in one group, high-grade serous carcinomas were segregated into two separate groups with different prognosis (P=0.05). High expression of CASP3, XIAP (X-linked inhibitor of apoptosis) , NFKB1, FAS, and GSK3B mRNAs identified high-grade serous carcinomas with better prognosis. In multivariate analysis, these cluster groups were of prognostic significance independent of age, tumor size, and tumor stage (P=0.008). To validate the mRNA expression data, we studied the immunohistochemical expression of caspase-3 and XIAP on a tissue microarray. Immunoreaction for caspase-3 was concordant with the results obtained by mRNA expression analysis (Spearman r=0.762, P=0.000). Caspase-3 was exclusively expressed by the macrophages. Furthermore, co-expression of caspase-3 and XIAP identified high-grade serous carcinomas with different prognosis (P=0.03). Our results suggest that there are different biological subtypes of high-grade serous carcinomas.

Antisense therapeutics for neurofibromatosis type 1 caused by deep intronic mutations.

Neurofibromatosis type 1 (NF1) is an autosomal dominant disorder affecting 1:3,500 individuals. Disease expression is highly variable and complications are diverse. However, currently there is no specific treatment for the disease. NF1 is caused by mutations in the NF1 gene, approximately 2.1% of constitutional mutations identified in our population are deep intronic mutations producing the insertion of a cryptic exon into the mature mRNA. We used antisense morpholino oligomers (AMOs) to restore normal splicing in primary fibroblast and lymphocyte cell lines derived from six NF1 patients bearing three deep intronic mutations in the NF1 gene (c.288+2025T>G, c.5749+332A>G, and c.7908-321C>G). AMOs were designed to target the newly created 5' splice sites to prevent the incorporation of cryptic exons. Our results demonstrate that AMO treatment effectively restored normal NF1 splicing at the mRNA level for the three mutations studied in the different cell lines analyzed. We also found that AMOs had a rapid effect that lasted for several days, acting in a sequence-specific manner and interfering with the splicing mechanism. Finally, to test whether the correction of aberrant NF1 splicing also restored neurofibromin function to wild-type levels, we measured the amount of Ras-GTP after AMO treatment in primary fibroblasts. The results clearly show an AMO-dependent decrease in Ras-GTP levels, which is consistent with the restoration of neurofibromin function. To our knowledge this is the first time that an antisense technique has been used successfully to correct NF1 mutations opening the possibility of a therapeutic strategy for this type of mutation not only for NF1 but for other genetic disorders.

CDC42-positive macrophages may prevent malignant transformation of ovarian endometriosis.

It is currently thought that most clear cell and endometrioid carcinomas arise from ovarian endometriosis. We recently suggested that, besides their origin in the ovary, reduction of CDC42 messenger RNA (a member of the RHO GTPase family) may contribute to explain why clear cell carcinomas are not uncommonly found limited to the ovary (stage I). On the other hand, little is known about the expression of CDC42 in ovarian endometriosis with and without carcinoma. Twenty-two endometriotic cysts not associated with carcinoma, 19 endometriotic cysts associated with carcinoma (contiguous endometriosis), as well as the 19 corresponding tumors (11 clear cell, 4 endometrioid, and 4 mixed-clear cell and endometrioid-carcinomas) were investigated. We analyzed CDC42 expression both by real-time polymerase chain reaction and immunohistochemistry. Endometriotic cysts not associated with carcinoma showed higher expression of CDC42 messenger RNA than cysts associated with carcinoma (P = .002). Immunohistochemically, CDC42 was exclusively expressed by macrophages. CDC42-positive macrophages were present in most of the endometriotic cysts not associated with carcinoma (11/19, or 58%). In contrast, only 5 endometriotic cysts containing carcinoma (contiguous endometriosis) (5/18, or 28%) and 1 ovarian carcinoma arising from endometriosis (1/18, or 5%) had CDC42-positive macrophages (58% versus 28%, P = .065; 28% versus 5%, P = .046). Our results raise the possibility that CDC42-positive macrophages may prevent the development of endometrioid and clear cell carcinomas.

Role of tumor-associated macrophages and angiogenesis in desmoid-type fibromatosis.

Desmoid-type fibromatosis (DTF) is a rare soft tissue tumor with fibroblastic features affecting two to four individuals per million population per year. Despite its bland microscopic appearance, the tumor behaves aggressively. Although unable to metastasize, DTF tends to recur and local recurrences in anatomically critical sites can be fatal. Tumor-associated macrophages (TAM) play an important role in tumor development through the activation of angiogenesis, particularly in cases of epithelial malignancies. The aim of this study is to investigate the prognostic significance of TAMs and the number of microvessels in DTF. Tumor macrophages (CD163), microvessel density (CD31), and beta-catenin were investigated on 69 primary DTF cases with follow-up information. CTNNB1 mutations were also studied. High density of tumor macrophages and high number of microvessels were associated with a significantly worse recurrence-free survival (P = 0.03 and P = 0.007, respectively). There was a significant correlation between microvessel density and CD163 macrophages (P = 0.02). Furthermore, combination of high number of tumor macrophages and high microvessel density greatly improved the statistical significance (P = 0.000005). Macrophages and microvessels may play an important role in the biologic behavior of DTF. This finding could help in the clinical management of patients with DTF.

Ovarian clear cell carcinomas: RHO GTPases may contribute to explain their singular biologic behavior.

Ovarian clear cell carcinoma is found more often confined to the ovary (stage I) than high-grade serous carcinoma. The RHO GTPase family of proteins is involved in tumor invasion and metastasis through regulation of the cytoskeleton. The expression of several RHO family genes, including RHOA, RHOC, CDC42, and 3 ARHGDIs (Rho GDP dissociation inhibitors), was studied by real-time polymerase chain reaction in 22 clear cell carcinomas and 31 high-grade serous carcinomas. Immunoreaction for p21-activated kinase 1 (a downstream effector of CDC42) was also investigated on 6 tissue microarrays containing 76 carcinomas (13 clear cell carcinomas and 63 high-grade serous carcinomas). Eight clear cell carcinomas (8/21; 38%) were at stage I, whereas only 3 high-grade serous carcinomas (3/31; 10%) were at stage I. Postoperatively, all patients were treated with taxane and cisplatinum or carboplatinum. ARHGDIA messenger RNA expression was higher in clear cell carcinomas than high-grade serous carcinomas (P = .07). In contrast, CDC42 messenger RNA levels were lower in clear cell carcinomas than high-grade serous carcinomas (P = .02). Immunoreaction for p21-activated kinase 1 was concordant with the results obtained by real-time polymerase chain reaction for CDC42. In clear cell carcinomas, RHOA and RHOC messenger RNA expression was lower in stage I than in advanced-stage tumors (P = .03 and P = .005, respectively). Furthermore, in high-grade serous carcinomas, RHOA expression was higher in patients who did not respond to chemotherapy (P = .04). ARHGDIA, CDC42, RHOA, and RHOC expression may contribute to explain the different stage at diagnosis of clear cell and high-grade serous carcinomas. RHOA may cause resistance of high-grade serous carcinoma to chemotherapy.

Myometrial invasion and lymph node metastasis in endometrioid carcinomas: tumor-associated macrophages, microvessel density, and HIF1A have a crucial role.

Myometrial invasion is an independent prognostic parameter of the endometrioid carcinomas which correlates with the risk of metastasis to pelvic and/or paraaortic lymph nodes. Recognition of myometrial invasion is sometimes difficult. In fact, myoinvasion is overdiagnosed in routine practice in as many as 25% of the cases. Recently, it has been observed that tumor-associated macrophages stimulate angiogenesis and promote cancer dissemination. Tumor macrophages (CD163), microvessel density (CD31), and hypoxia inducible factor 1 α subunit (HIF1A) were investigated in 64 primary endometrioid carcinomas with (50 cases) and without (14 cases) myometrial invasion as well as in the corresponding regional lymph nodes metastases of 20 of the myoinvasive tumors. Endometrioid carcinomas with myometrial invasion showed higher number of CD163-tumor macrophages and greater microvessel density than endometrioid carcinomas without myometrial invasion (P=0.000 and P=0.000, respectively). In carcinomas confined to the corpus uteri (stage I), expression of HIF1A was associated with deep myoinvasion (stage IC) (P=0.006). There was a significant relationship between microvessel density and CD163-macrophages both in the myoinvasive and nonmyoinvasive tumors. On the other hand, high-grade endometrioid carcinomas had more macrophage infiltrates and microvessels than low-grade tumors (P=0.03 and P=0.07). Also, there was a positive correlation between CD163-macrophages and microvessel density in the primary tumors and their corresponding regional lymph node metastases. These findings link increased microvessel proliferation to stromal macrophage infiltrate and suggest that enhanced tumor angiogenesis, triggered by stromal macrophages, regulates the progression of endometrioid carcinomas. The identical stroma microenvironment found in the primary and the corresponding metastatic tumor suggests that tumor stroma response is determined by the intrinsic biology of the tumor.