Ovarian steroid cell tumor with biallelic adenomatous polyposis coli inactivation in a patient with familial adenomatous polyposis

Familial adenomatous polyposis (FAP) is an autosomal dominant cancer predisposition syndrome that accounts for approximately 0.5–1% of all colorectal cancer cases. It is caused by germline mutations in the gene encoding the adenomatous polyposis coli ( APC ) tumor suppressor. Somatic APC inactivation due to mutation or loss of heterozygosity (LOH) promotes the development of adenomatous polyps by stabilizing the transcriptional coactivator β‐catenin. Although colorectal cancer is by far the most common malignancy seen in FAP patients, the widespread use of prophylactic colectomy in these patients has increased the clinical importance of extracolonic tumors that are part of the neoplastic spectrum in FAP. Many of these tumors exhibit LOH or somatic APC mutation, strongly supporting a causative role of APC inactivation in their pathogenesis. Here we describe a 47‐year‐old female FAP patient with clinical manifestations of virilization who was found to have an ovarian steroid cell tumor, a rare neoplasm not known to be associated with FAP. Immunohistochemical analysis of the ovarian tumor demonstrated strong nuclear β‐catenin staining consistent with somatic APC inactivation, and molecular analysis confirmed biallelic APC inactivation in the tumor. Our findings provide the first evidence that ovarian steroid cell tumors may be an extracolonic manifestation of FAP and implicate β‐catenin activation as an oncogenic mechanism in ovarian steroid cell tumorigenesis. © 2011 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90384/1/20953_ftp.pd

Rationale and design of decision: a double-blind, randomized, placebo-controlled phase III trial evaluating the efficacy and safety of sorafenib in patients with locally advanced or metastatic radioactive iodine (RAI)-refractory, differentiated thyroid cancer

<p>Abstract</p> <p>Background</p> <p>The incidence of thyroid cancer and the number of patients who die from this disease are increasing globally. Differentiated thyroid cancer (DTC) is the histologic subtype present in most patients and is primarily responsible for the increased overall incidence of thyroid cancer. Sorafenib is a multikinase inhibitor that targets several molecular signals believed to be involved in the pathogenesis of thyroid cancer, including those implicated in DTC. In phase II studies of patients with DTC, sorafenib treatment has yielded a median progression-free survival (PFS) of 58 to 84 weeks and disease control rates of 59% to 100%. The DECISION trial was designed to assess the ability of sorafenib to improve PFS in patients with locally advanced or metastatic, radioactive iodine (RAI)-refractory DTC.</p> <p>Methods/design</p> <p>DECISION is a multicenter, double-blind, randomized, placebo-controlled phase III study in patients with locally advanced/metastatic RAI<b>-</b>refractory DTC. Study treatment will continue until radiographically documented disease progression, unacceptable toxicity, noncompliance, or withdrawal of consent. Efficacy will be evaluated every 56 days (2 cycles), whereas safety will be evaluated every 28 days (1 cycle) for the first 8 months and every 56 days thereafter. Following disease progression, patients may continue or start sorafenib, depending on whether they were randomized to receive sorafenib or placebo, at investigator discretion. Patients originally randomized to receive sorafenib will be followed up every 3 months for overall survival (OS); patients originally randomized to receive placebo will be followed up every month for 8 months after cross-over to sorafenib. The duration of the trial is expected to be 30 months from the time the first patient is randomized until the planned number of PFS events is attained. The primary endpoint is PFS; secondary endpoints include OS, time to disease progression, disease control rate, response rate, duration of response, safety, and pharmacokinetic analysis.</p> <p>Discussion</p> <p>The DECISION study has been designed to test whether sorafenib improves PFS in patients with locally advanced or metastatic RAI-refractory DTC.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00984282">NCT00984282</a>; EudraCT: 2009-012007-25.</p

FNA diagnosis of poorly differentiated thyroid carcinoma. A review of the recent literature.

Poorly differentiated thyroid carcinoma (PDTC) is a follicular cell-derived tumour that was recognised as a distinct entity by the World Health Organisation in 2004. The natural history and pathological features of PDTC are reported to be intermediate between those of well-differentiated and undifferentiated (anaplastic) thyroid carcinomas. Preoperative identification of PDTC could facilitate better initial patient management in many cases, namely more extensive surgery, without any delay. However, according to some experts, a diagnosis of PDTC can only be rendered on histologic specimens based on criteria recommended in the Turin proposal. Although high-grade features (namely necrosis and mitoses) can be recognised in FNA material, other cytomorphological features have limited value for the preoperative diagnosis of PDTC and specific features for a definitive diagnosis of PDTC have not yet been clearly defined. Here, we review the current status and future prospects for cytological recognition of PDTC; we emphasise the features that should raise suspicion of this rare condition in FNA cytology and provide an update on molecular features and management of PDTC. Despite proposed histological criteria for the diagnosis of PDTC, its recognition on routine thyroid cytology presents a notable challenge. Current and future advances in molecular testing could contribute to the cytological diagnosis of PDTC

Highly frequent PIK3CA amplification is associated with poor prognosis in gastric cancer

<p>Abstract</p> <p>Background</p> <p>The phosphoinositide 3-kinase (PI3K)/Akt pathway plays a fundamental role in cell proliferation and survival in human tumorigenesis, including gastric cancer. <it>PIK3CA </it>mutations and amplification are two major causes of overactivation of this pathway in human cancers. However, until this work, there was no sound investigation on the association of <it>PIK3CA </it>mutations and amplification with clinical outcome in gastric cancer, particularly the latter.</p> <p>Methods</p> <p>Using direct sequencing and real-time quantitative PCR, we examined <it>PIK3CA </it>mutations and amplification, and their association with clinicopathological characteristics and clinical outcome of gastric cancer patients.</p> <p>Results</p> <p><it>PIK3CA </it>mutations and amplification were found in 8/113 (7.1%) and 88/131 (67%) gastric cancer patients, respectively. <it>PIK3CA </it>amplification was closely associated with increased phosphorylated Akt (p-Akt) level. No relationship was found between <it>PIK3CA </it>mutations and clinicopathological characteristics and clinical outcome in gastric cancer. <it>PIK3CA </it>amplification was significantly positively associated with cancer-related death. Importantly, Kaplan-Meier survival curves revealed that the patients with <it>PIK3CA </it>amplification had significantly shorter survival times than the patients without <it>PIK3CA </it>amplification.</p> <p>Conclusions</p> <p>Our data showed that <it>PIK3CA </it>mutations were not common, but its amplification was very common in gastric cancer and may be a major mechanism in activating the PI3K/Akt pathway in gastric cancer. Importantly, Kaplan-Meier survival curves revealed that <it>PIK3CA </it>amplification was significantly positively associated with poor survival of gastric cancer patients. Collectively, the PI3K/Akt signaling pathway may be an effective therapeutic target in gastric cancer.</p

Poorly differentiated and anaplastic thyroid carcinomas: chromosomal and oligo-array profile of five new cell lines

Information on gene alterations associated to poorly differentiated (PDTC) and anaplastic thyroid carcinomas (ATC) is scarce. Using human cancer cell lines as a tool for gene discovery, we performed a cytogenetic and oligo-array analysis in five new cell lines derived from two PDTC and three ATC. In PDTC we evidenced, as important, the involvement of the MAPK/ERK kinase pathway, and downregulation of a group of suppressor genes that include E-cadherin. In ATC, downregulation of a specific group of oncosuppressor genes was also observed. Our ATC cell lines presented chromosomal markers of gene amplification, and we were able to identify for the first time the nature of the involved amplicon target genes. We found that the main molecular differences between the two cell line types were related to signal transduction pathways, cell adhesion and motility process. TaqMan experiments performed for five amplicon target genes and for two genes, which allowed a clear distinction between ATC and PDTC: CDH13 and PLAU corroborated array results, not only in the cell lines, but also in an additional set of primary 14 PDTC and three ATC. We suggest that our findings may represent new tools for the development of more effective therapies to the hitherto untreatable ATC

Mutations in PIK3CA are infrequent in neuroblastoma

BACKGROUND: Neuroblastoma is a frequently lethal pediatric cancer in which MYCN genomic amplification is highly correlated with aggressive disease. Deregulated MYC genes require co-operative lesions to foster tumourigenesis and both direct and indirect evidence support activated Ras signaling for this purpose in many cancers. Yet Ras genes and Braf, while often activated in cancer cells, are infrequent targets for activation in neuroblastoma. Recently, the Ras effector PIK3CA was shown to be activated in diverse human cancers. We therefore assessed PIK3CA for mutation in human neuroblastomas, as well as in neuroblastomas arising in transgenic mice with MYCN overexpressed in neural-crest tissues. In this murine model we additionally surveyed for Ras family and Braf mutations as these have not been previously reported. METHODS: Sixty-nine human neuroblastomas (42 primary tumors and 27 cell lines) were sequenced for PIK3CA activating mutations within the C2, helical and kinase domain "hot spots" where 80% of mutations cluster. Constitutional DNA was sequenced in cases with confirmed alterations to assess for germline or somatic acquisition. Additionally, Ras family members (Hras1, Kras2 and Nras) and the downstream effectors Pik3ca and Braf, were sequenced from twenty-five neuroblastomas arising in neuroblastoma-prone transgenic mice. RESULTS: We identified mutations in the PIK3CA gene in 2 of 69 human neuroblastomas (2.9%). Neither mutation (R524M and E982D) has been studied to date for effects on lipid kinase activity. Though both occurred in tumors with MYCN amplification the overall rate of PIK3CA mutations in MYCN amplified and single-copy tumors did not differ appreciably (2 of 31 versus 0 of 38, respectively). Further, no activating mutations were identified in a survey of Ras signal transduction genes (including Hras1, Kras2, Nras, Pik3ca, or Braf genes) in twenty-five neuroblastic tumors arising in the MYCN-initiated transgenic mouse model. CONCLUSION: These data suggest that activating mutations in the Ras/Raf-MAPK/PI3K signaling cascades occur infrequently in neuroblastoma. Further, despite compelling evidence for MYC and RAS cooperation in vitro and in vivo to promote tumourigenesis, activation of RAS signal transduction does not constitute a preferred secondary pathway in neuroblastomas with MYCN deregulation in either human tumors or murine models

Activation of the PI3K/AKT Pathway in Merkel Cell Carcinoma

Merkel cell carcinoma (MCC) is a highly aggressive skin cancer with an increasing incidence. The understanding of the molecular carcinogenesis of MCC is limited. Here, we scrutinized the PI3K/AKT pathway, one of the major pathways activated in human cancer, in MCC. Immunohistochemical analysis of 41 tumor tissues and 9 MCC cell lines revealed high levels of AKT phosphorylation at threonine 308 in 88% of samples. Notably, the AKT phosphorylation was not correlated with the presence or absence of the Merkel cell polyoma virus (MCV). Accordingly, knock-down of the large and small T antigen by shRNA in MCV positive MCC cells did not affect phosphorylation of AKT. We also analyzed 46 MCC samples for activating PIK3CA and AKT1 mutations. Oncogenic PIK3CA mutations were found in 2/46 (4%) MCCs whereas mutations in exon 4 of AKT1 were absent. MCC cell lines demonstrated a high sensitivity towards the PI3K inhibitor LY-294002. This finding together with our observation that the PI3K/AKT pathway is activated in the majority of human MCCs identifies PI3K/AKT as a potential new therapeutic target for MCC patients

Decreased expression of haemoglobin beta (HBB) gene in anaplastic thyroid cancer and recovory of its expression inhibits cell growth

Anaplastic thyroid cancer (ATC) is one of the most fulminant and foetal diseases in human malignancies. However, the genetic alterations and carcinogenic mechanisms of ATC are still unclear. Recently, we investigated the gene expression profile of 11 anaplastic thyroid cancer cell lines (ACL) and significant decreased expression of haemoglobin beta (HBB) gene in ACL. Haemoglobin beta is located at 11p15.5, where loss of heterozygosity (LOH) was reported in various kinds of cancers, including ATC, and it has been suggested that novel tumour suppressor genes might exist in this region. In order to clarify the meaning of decreased expression of HBB in ATC, the expression status of HBB was investigated with ACL, ATC, papillary thyroid cancer (PTC) and normal human tissues. Haemoglobin beta showed significant decreased expression in ACLs and ATCs; however, in PTC, HBB expressed equal to the normal thyroid gland. In addition, HBB expressed in normal human tissues ubiquitously. To validate the tumour-suppressor function of HBB, cell growth assay was performed. Forced expression of HBB in KTA2 cell, which is a kind of ACL, significantly suppressed KTA2 growth. The mechanism of downregulation of HBB in ATC is still unclear; however, our results suggested the possibility of HBB as a novel tumour-suppressor gene

Gene expression profiling associated with the progression to poorly differentiated thyroid carcinomas

Poorly differentiated thyroid carcinomas (PDTC) represent a heterogeneous, aggressive entity, presenting features that suggest a progression from well-differentiated carcinomas. To elucidate the mechanisms underlying such progression and identify novel therapeutic targets, we assessed the genome-wide expression in normal and tumour thyroid tissues.info:eu-repo/semantics/publishe