Oncofetal H19 RNA promotes tumor metastasis.

The oncofetal H19 gene transcribes a long non-coding RNA(lncRNA) that is essential for tumor growth. Here we found that numerous established inducers of epithelial to mesenchymal transition(EMT) also induced H19/miR-675 expression. Both TGF-ß and hypoxia concomitantly induced H19 and miR-675 with the induction of EMT markers. We identified the PI3K/AKT pathway mediating the inductions of Slug, H19 RNA and miR-675 in response to TGF-ß treatment, while Slug induction depended on H19 RNA. In the EMT induced multidrug resistance model, H19 level was also induced. In a mouse breast cancer model, H19 expression was tightly correlated with metastatic potential. In patients, we detected high H19 expression in all common metastatic sites tested, regardless of tumor primary origin. H19 RNA suppressed the expression of E-cadherin protein. H19 up-regulated Slug expression concomitant with the suppression of E-cadherin protein through a mechanism that involved miR-675. Slug also up-regulated H19 expression and activated its promoter. Altogether, these results may support the existence of a positive feedback loop between Slug and H19/miR-675, that regulates E-cadherin expression. H19 RNA enhanced the invasive potential of cancer cells in vitro and enhanced tumor metastasis in vivo. Additionally, H19 knockdown attenuated the scattering and tumorigenic effects of HGF/SF. Our results present novel mechanistic insights into a critical role for H19 RNA in tumor progression and indicate a previously unknown link between H19/miR-675, Slug and E-cadherin in the regulation of cancer cell EMT programs.

The increasing complexity of the oncofetal h19 gene locus: functional dissection and therapeutic intervention.

The field of the long non-coding RNA (lncRNA) is advancing rapidly. Currently, it is one of the most popular fields in the biological and medical sciences. It is becoming increasingly obvious that the majority of the human transcriptome has little or no-protein coding capacity. Historically, H19 was the first imprinted non-coding RNA (ncRNA) transcript identified, and the H19/IGF2 locus has served as a paradigm for the study of genomic imprinting since its discovery. In recent years, we have extensively investigated the expression of the H19 gene in a number of human cancers and explored the role of H19 RNA in tumor development. Here, we discuss recently published data from our group and others that provide further support for a central role of H19 RNA in the process of tumorigenesis. Furthermore, we focus on major transcriptional modulators of the H19 gene and discuss them in the context of the tumor-promoting activity of the H19 RNA. Based on the pivotal role of the H19 gene in human cancers, we have developed a DNA-based therapeutic approach for the treatment of cancers that have upregulated levels of H19 expression. This approach uses a diphtheria toxin A (DTA) protein expressed under the regulation of the H19 promoter to treat tumors with significant expression of H19 RNA. In this review, we discuss the treatment of four cancer indications in human subjects using this approach, which is currently under development. This represents perhaps one of the very few examples of an existing DNA-based therapy centered on an lncRNA system. Apart from cancer, H19 expression has been reported also in other conditions, syndromes and diseases, where deregulated imprinting at the H19 locus was obvious in some cases and will be summarized below. Moreover, the H19 locus proved to be much more complicated than initially thought. It houses a genomic sequence that can transcribe, yielding various transcriptional outputs, both in sense and antisense directions. The major transcriptional outputs of the H19 locus are presented here.

Development of targeted therapy for ovarian cancer mediated by a plasmid expressing diphtheria toxin under the control of H19 regulatory sequences.

BACKGROUND: Ovarian cancer ascites fluid (OCAF), contains malignant cells, is usually present in women with an advanced stage disease and currently has no effective therapy. Hence, we developed a new therapy strategy to target the expression of diphtheria toxin gene under the control of H19 regulatory sequences in ovarian tumor cells. H19 RNA is present at high levels in human cancer tissues (including ovarian cancer), while existing at a nearly undetectable level in the surrounding normal tissue. METHODS: H19 gene expression was tested in cells from OCAF by the in-situ hybridization technique (ISH) using an H19 RNA probe. The therapeutic potential of the toxin vector DTA-H19 was tested in ovarian carcinoma cell lines and in a heterotopic animal model for ovarian cancer. RESULTS: H19 RNA was detected in 90% of patients with OCAF as determined by ISH. Intratumoral injection of DTA-H19 into ectopically developed tumors caused 40% inhibition of tumor growth. CONCLUSION: These observations may be the first step towards a major breakthrough in the treatment of human OCAF, while the effect in solid tumors required further investigation. It should enable us to identify likely non-responders in advance, and to treat patients who are resistant to all known therapies, thereby avoiding treatment failure.

Expression of kinase genes in primary hyperparathyroidism: adenoma versus hyperplastic parathyroid tissue.

BACKGROUND: Differentiation between parathyroid hyperplasia and adenoma is difficult and based on the surgeon's skill. Microarrays and other sophisticated research tools generate information about differential gene expression in various tissues. Exploration of genes that express differentially in 1 tissue will enable identification and perhaps development of new methods of preoperative or intraoperative diagnosis. METHODS: RNA was extracted from parathyroid hyperplasia and adenoma tissue and hybridized to a microarray containing 359 human complementary DNAs of known kinase genes. Signals of exposure were scanned and quantified with software for digital image analysis (Atlas-image, v. 2; Clontech Labs Inc, Palo Alto, Calif). The program generates a color schematic comparison view and numeric data in a tabular format for further analysis. RESULTS: The ratio values that are considered significant (< 0.5 or > 1.5) suggest that genes up-regulated in parathyroid adenoma are those responsible for angiogenesis and production of blood vessels. Genes down-regulated in parathyroid adenoma and expressed in hyperplasia are related to a decrease in apoptosis. Moreover, an interesting gene expressed only in the hyperplasia sample is increased in relation to in vivo proliferation activities. CONCLUSIONS: Parathyroid hyperplasia and adenoma are different physiologic conditions. Further analysis of kinase genes involved in angiogenesis and apoptosis will enable design of a chip that concentrates in the different key genes responsible for the transition between hyperplasia and adenoma. Identifying such genes will enable to target both diagnostic and therapeutic approaches.

Early, postinjection MIBI-SPECT as the only preoperative localizing study for minimally invasive parathyroidectomy.

HYPOTHESIS: Early, postinjection technetium Tc 99m sestamibi scintigraphy-single-photon emission computed tomography (MIBI-SPECT) can be used as the only localizing study for focused parathyroidectomy in patients with primary hyperparathyroidism. DESIGN: During a 26-month period, 82 consecutive patients with primary hyperparathyroidism underwent a standard planar scan using a double-tracer subtraction technique for localization. On the morning of surgery, each patient received radiolabeled technetium Tc 99m sestamibi for intraoperative detection and validation. We performed an early, postinjection SPECT study for comparison with the planar study. RESULTS: The SPECT study revealed a sensitivity of 96% vs 78% for the planar study. The SPECT study was helpful in locating adenomas in 10 patients with multinodular goiter disease, of whom 3 patients had ectopic adenomas and 2 patients had 2 adenomas each. A significant correlation was noted between uptake ratio and preoperative parathyroid hormone levels (r = 0.41; P =.04). No recurrent or persistent hyperparathyroidism was reported during a follow-up period of at least 6 months. CONCLUSIONS: Our results encourage the use of preoperative SPECT as the only localizing study on the morning of the operation, both to select patients for minimally invasive radioguided surgery and to provide accurate 3-dimensional information on deeply seated or ectopic adenomas. This approach lowers the costs of preoperative localization and intraoperative validation to a single study. The intraoperative gamma probe technique enables the surgeon to focus the search, provides instant feedback regarding the progress of the operation, reduces surgical trauma and complications, and yields better cosmetic results.

The role of laparoscopy and laparoscopic ultrasound in the diagnosis of cystic lesions of the pancreas.

With the widespread use of advanced imaging techniques, cystic lesions of the pancreas are now diagnosed relatively frequently. The nature of these lesions vary from benign cysts (serous cvstadenoma) or an inflammatory process (pseudocyst), to premalignant (mucinous cystadenoma) or frankly malignant lesions (cystadenocarcinoma). Differentiation of various types of pancreatic cysts presents a diagnostic and therapeutic challenge, as clinical presentation may be vague. Laparoscopic ultrasonography (LAPUS), the biopsy of the cystic wall, and analysis of the cystic aspirate, although expensive and rather invasive procedures, significantly contribute to the differential diagnosis of pancreatic cystic lesions.

[Laparoscopic cryoablation of liver tumors].

BACKGROUND: Hepatic resection remains the gold standard form of treatment for patients with liver metastases. However, only a small percentage of patients are suitable for resection. Local ablation techniques such as cryotherapy have been used with some success in patients with hepatic tumors. We reviewed our experience with cryotherapy via the laparoscopic approach. METHODS: Eighteen patients suffering from unresectable liver tumor were treated at our department. Ten patients suffered from colorectal liver metastases, eight patients suffered from hepatocellular carcinoma. Laparoscopic treatment was performed under general anesthesia commencing with laparoscopy and laparoscopic ultrasound (LAPUS) for accurate disease staging. Patients having extrahepatic liver spread were excluded. Patients with unresectable liver tumor with no evidence of extrahepatic disease were then treated with laparoscopic cryoablation. The laparoscopic cryoablation system consisted of two integrated parts: The cryoablation system (Cryo-hit, Galil Medical, Israel; employing Argon/Helium gases using 5 mm needles) combined with Laparoscopic ultrasound system using a 10 mm US probe (Sharplan U-sight system, Israel). Cryoablation treatment (two cycles of 10 minutes each) starts with the insertion of the cryo-needle under US guidance. Two or more needles are inserted according to tumor configuration. Treatment is continuously monitored by LAPUS. RESULTS: Morbidity consisted mostly of fever (4/18, 22%) due to atelectasis. Two patients bled and were treated conservatively. One patient died following the development of myocardial infarction 3 days after treatment. FOLLOW-UP: After 13-40 months, mean period of 16 months. Eight patients are alive (17, 18, and 29 months, hepatocellular carcinoma; 13-32 months, metastatic disease). It is important to note that 2 patients have had repeat LC and one patient had 3 LC treatments for recurrent metastatic disease. CONCLUSIONS: LC of irresectable liver tumors is feasible, well tolerated and carries relatively low morbidity with no procedure-related mortality. Repeat treatment is possible. Long term survival may be achieved.

Imaging tumours of the ampulla of Vater.

Although comparatively rare, ampullary tumours tend to be more readily curable than periampullary lesions and pancreatic carcinomas, consequent upon an earlier presentation, a lower likelihood of involved lymph nodes or vascular infiltration and a less aggressive histology. Recently, selected early cases have been able to resected endoscopically making accurate preoperative tumour (T) staging critical in such decision making. The most commonly available imaging methods are endoscopic ultrasound (EUS) and CT scanning where in the former case there is variable accuracy for larger (T2/T3) ampullary tumours particularly where the patient has undergone preoperative common bile duct stenting. CT scanning has consistent shown inferior T staging of ampullary tumours when compared with EUS, although it provides information concerning visceral and nodal metastatic disease. Transpapillary intraductal ultrasound (where available) has shown high accuracy for early T1 tumours potentially suitable for endoscopic or local ampullary excision with the added advantage that it may be conducted without preliminary sphincterotomy. Recently, our group has been using intraoperative transduodenal ultrasound which assists surgical decision making concerning local excision or radical pancreaticoduodenal resection. Very recent images using 3-dimensional endoduodenal ultrasound has provided exquisite images of the ampulla and remain to be validated in ampullary neoplasms.

H19-promoter-targeted therapy combined with gemcitabine in the treatment of pancreatic cancer.

Pancreatic cancer is the eighth cancer leading cause of cancer-related death in the world and has a 5-year survival rate of 1-4% only. Gemcitabine is a first line agent for advanced pancreatic therapy; however, its efficacy is limited by its poor intracellular metabolism and chemoresistance. Studies have been conducted in an effort to improve gemcitabine treatment results by adding other chemotherapeutic agents, but none of them showed any significant advantage over gemcitabine monotherapy. We found that 85% of human pancreatic tumors analyzed by in situ hybridization analyses showed moderated to strong expression of the H19 gene. We designed a preclinical study combining gemcitabine treatment and a DNA-based therapy for pancreatic cancer using a non viral vector BC-819 (also known as DTA-H19), expressing the diphtheria toxin A chain under the control of the H19 gene regulatory sequences. The experiments conducted either in an orthotopic and heterotopic pancreatic carcinoma animal model showed better antitumor activity following the sequential administration of the vector BC-819 and gemcitabine as compared to the effect of each of them alone. The results presented in the current study indicate that treatment with BC-819 in combination with gemcitabine might be a viable new therapeutic option for patients with advanced pancreatic cancer.

Regional therapy with DTA-H19 vector suppresses growth of colon adenocarcinoma metastases in the rat liver.

Curative surgery is possible in barely 10% of patients with colorectal liver metastases and combined treatment modalities scarcely improve survival in this group of patients. Hence, investigations of new therapeutic modalities are crucial. Overexpression of the H19 gene in liver metastases points to H19 as a target for cancer gene therapy. Here we have evaluated the possibility of regional intra-arterial treatment of liver meta-stases with the DTA-H19 plasmid. Intra-arterial treatment of a total dose of 2.5 mg (repeated injections of 500 µg DTA-H19 plasmid each dose after the first injection of 1000 µg) caused a significant delay in the tumor growth compared to control group. All of the tumors treated with the control vector increased in size, whereas 35.7% of the tumors in the groups treated with a total amount of 2.5 mg DTA-H19 plasmid shrank in size. The present study showed that the DTA-H19 plasmid administered intra-arterially significantly delayed the tumor growth and even resulted in tumor regression in high percentage of the treated animals with liver metastases of colon cancer. Since human liver metastases demonstrated overexpression of the H19 gene, regional administration of the plasmid seems to be a promising therapeutic approach.

Treatment of ovarian cancer ascites by intra-peritoneal injection of diphtheria toxin A chain-H19 vector: a case report.

INTRODUCTION: Ovarian cancer ascitic fluid, which contains malignant cells, is usually present in women with an advanced stage disease. There are currently no effective therapies for the treatment of ovarian cancer ascitic fluid. We developed a new therapeutic strategy to target expression of the diphtheria toxin fragment A gene in ovarian tumor cells under the control of H19 regulatory sequences. CASE PRESENTATION: A 64-year-old Caucasian woman was diagnosed with a stage IIIc epithelial ovarian cancer. She suffered from progressive disease, accumulation of malignant ascites that needed to be drained weekly, abdominal pain, vomiting, anorexia and severe weakness. Infusion of the diphtheria toxin A chain-H19 plasmid into the peritoneum of our patient resulted in complete resolution of the ascites with minimum adverse events. CONCLUSION: On the basis of this preliminary experience, we are currently conducting an extensive Phase I study on a larger number of patients in order to assess the safety and preliminary efficacy of this novel patient-oriented treatment approach.

Differential expression of kinase genes in primary hyperparathyroidism: adenoma versus normal and hyperplastic parathyroid tissue.

CONTEXT: Differentiation between adenoma and hyperplasia or even normal parathyroid tissue is difficult and based mainly on the surgeon's skill. Exploration of genes that express differentially in these various tissues using microarrays and other sophisticated research tools will enable identification and perhaps development of new methods of perioperative diagnosis. OBJECTIVE: To assemble a panel of kinase genes to differentiate parathyroid adenoma from normal and hyperplastic parathyroid tissue. DESIGN: RNA was extracted from adenoma, hyperplasia, and normal parathyroid tissue and hybridized to a microarray containing 359 human cDNAs of known kinase genes. Signals of exposure were scanned and quantified with software for digital image analysis. Semiquantitative reverse transcriptase polymerase chain reaction analysis of sample genes was performed, up-regulated or down-regulated, to validate the microarray results. RESULTS: The ratio values considered significant (<0.5 or >1.5) suggest that genes up-regulated in parathyroid adenoma are those responsible for blood vessel angiogenesis and genes belonging to the cyclin-dependent kinase inhibitor groups. Genes down-regulated in parathyroid adenoma are related to cellular growth and apoptosis--genes from the mitogen-activated protein kinase group and DNA-dependent protein kinase group. An interesting gene down-regulated in the parathyroid adenoma samples is related to the serine/threonine protein kinases that exert a key function in calcium handling. A panel of 5 genes was defined: p19, p21 and the gene for vascular endothelial growth factor from the up-regulated group, and the gene for protein kinase C and SGK from the down-regulated group. Reverse transcriptase polymerase chain reaction confirmed the microarray results for these genes. CONCLUSIONS: The kinase genes panel presented can be used to differentiate parathyroid adenoma from normal and hyperplastic parathyroid tissue in particular when histopathology fails to provide a decisive diagnosis.

The risk of breast cancer in relation to health habits and occupational exposures.

BACKGROUND: The age-adjusted incidence rate of breast cancer has increased for Israeli women. Our aim was to explore the hypothesis that occupational exposures are important risk factors, taking into consideration main known risk factors. METHODS: The study population included 326 breast cancer cases from one hospital in the center of the country and 413 women without known diagnosis of cancer. Every participant was interviewed using a structured questionnaire. RESULTS: We found that working in textile and clothing and in various industries, OR (95% confidence interval), 1.8 (1.1-3.0), 4.3 (2.0-9.3) respectively, and exposure to ionizing radiation OR 5.3 (2.4-14.1) as well as age and having a family history of breast cancer significantly increased the risk of developing breast cancer. Administrative work, adherence to high fiber diet and low salt diet significantly lowered the risk of breast cancer. CONCLUSIONS: Our study supported the assumption that occupational exposure may contribute to the etiology of breast cancer.

Scanning electron microscopy of thyroid cells under fully hydrated conditions--a novel technique for a seasoned procedure: a brief observation.

Technical information for handling fine-needle aspiration samples from thyroid lesions for WETSEM electron microscopy is presented. The use of wet SEM technology maintains cytological features of the thyroid cells, in the atmospheric electronic microscope chamber without the need for solidification. Images are presented from normal and pathological thyroid specimens showing subcellular elements unavailable to the cytopathologist by light microscopy. Of 24 samples, 18 were adequate for clinical evaluation. In 16 of these 18 specimens, we could find features compatible with the final histological or cytological diagnosis (post-hoc). In two cases, the cell features were too unique to be interpretable. Because this procedure is relatively simple, there is potential for the use of this technology as an adjunct to light microscopy in clinical and research settings.

Combined systemic chronotherapy and hepatic artery infusion for the treatment of metastatic colorectal cancer confined to the liver.

BACKGROUND: The optimal treatment of patients with metastatic colorectal cancer is still a clinical challenge. We describe the use of combined hepatic arterial infusion (HAI) of irinotecan (CPT-11) in conjunction with systemic chronotherapy infusion of 5-fluorouracil (5FU), folinic acid and carboplatin in patients with colorectal liver metastases. METHODS: Twenty-three patients with colorectal cancer and isolated liver metastases were enrolled in this trial. Intraoperative insertion of an intra-arterial catheter into the hepatic artery was accomplished during the colon operation (in cases of synchronous tumor) or as a separate procedure in colorectal cancer patients with newly diagnosed liver metastases. A systemic double-lumen double-chamber port was inserted via the subclavian vein as a separate procedure. The treatment plan included irinotecan given by intra-arterial infusion at 150 mg/m2 for 1 h. After 2 weeks of rest chronomodulated 5FU (700 mg/m(2); peak delivery rate at 04:00 h), leucovorin (175 mg/m2; peak delivery rate at 04:00 h) and carboplatin (40 mg/m2; peak delivery rate at 16:00 h) for 4 days was followed by 10 days' rest and then given again. After 10 days' rest another HAI was introduced using the same method. Each cycle of therapy included 2 HAI courses and 2 chronotherapy courses in between. After 2 complete cycles, patients were evaluated for their response with weekly accessed toxicity recording. RESULTS: Seven women, 8 men, median age 61 years (range 46-72). Eight patients had synchronous colon and hepatic disease and 7 patients had metachronous disease. Ten patients had previously been treated with 5FU and leucovorin while 5 patients were chemonaive. The mean number of cycles were 11.6 per patient (range 8-19). Partial response was achieved in 6 patients (40%) and was followed by laparoscopic radiofrequency ablation in 5 patients (33%). Disease stabilization was observed in 2 patients (13%) and disease progression in 7 patients (47%) mainly after previous chemotherapy failure. Side effects were infrequent and mild including grade 2 GIT complaints (5 patients), RUQ pain during HAI (9 patients) and grade 2 hematological complaints in 2 patients. CONCLUSION: A combined chemotherapy protocol (HAI and chronotherapy) with irinotecan (CPT-11) together with chronomodulated infusion of 5FU, folinic acid and carboplatin can be used in metastatic colorectal patients with a high efficacy rate and minor side effects especially in pretreated patients.

Regulatory sequences of H19 and IGF2 genes in DNA-based therapy of colorectal rat liver metastases.

BACKGROUND: Malignant tumors of the liver are among the most common causes of cancer-related death throughout the world. Current therapeutic approaches fail to control the disease in most cases. This study seeks to explore the potential utility of transcriptional regulatory sequences of the H19 and insulin growth factor 2 (IGF2) genes for directing tumor-selective expression of a toxin gene (A fragment of diphtheria toxin), delivered by non-viral vectors. METHODS: The therapeutic potential of the toxin vectors driven by the H19 and the IGF2-P3 regulatory sequences was tested in a metastatic model of rat CC531 colon carcinoma in liver. RESULTS: Intratumoral injection of these vectors into colon tumors implanted in the liver of rats induced an 88% and a 50% decrease respectively in the median tumor volume as compared with the control groups. This therapeutic action was accompanied by increased necrosis of the tumor. Importantly, no signs of toxicity were detected in healthy animals after their treatment by the toxin expression vectors. CONCLUSIONS: DT-A was preferentially expressed in liver metastases after being transfected with H19 or IGF2-P3 promoter-driven DT-A expression plasmids, causing a very significant inhibition of tumor growth as a result of its cytotoxic effect. Our findings strongly support the feasibility of our proposed therapeutic strategy, which may contribute to open new gene therapeutic options for human liver metastases.

The hepatitis C virus (HCV)-Trimera mouse: a model for evaluation of agents against HCV.

The lack of small-animal models that are suitable for evaluation of agents used to treat infection with hepatitis C virus (HCV) severely hinders the assessment of potential new therapies for the disease. This study created such a model, termed the "HCV-Trimera" model. The HCV-Trimera model was developed by using lethally irradiated mice, reconstituted with SCID mouse bone marrow cells, in which human liver fragments infected ex vivo with HCV had been transplanted. Viremia (positive-strand HCV RNA levels) in HCV-Trimera mice peaked at approximately day 18 after liver transplantation, and an infection rate of 85% was reached. Viral replication in liver grafts was evidenced by the presence of specific negative-strand HCV RNA. The usefulness of this model for evaluation of anti-HCV agents was demonstrated by the ability of a small molecule (an HCV internal ribosomal entry site inhibitor) and an anti-HCV human monoclonal antibody (HCV AB(XTL)68) to reduce virus loads in HCV-Trimera mice in a dose-dependent manner.