鸡贫血病毒的分子生物学研究进展

Chicken anemia virus (CAV) is the main pathogen of chicken infectious anemia (CIA). It is widespread all over the world and becomes one of the main pathogens affecting poultry industry seriously. CAV genome contains three partially overlapped genes, vp1, vp2 and vp3, which encode three kinds of proteins, VP1, VP2 and VP3, respectively. VP1 related to its antigenicity is the only capsid protein of CAV; VP2 might act as a scaffold protein to help VP1 form correct conformation; and VP3, also named apoptin, is related to the pathogenicity of CAV, and is proved by some experimental data to have low acute toxicity and is effective as an anti-tumor agent. According to the molecular biological progression of CAV research, three questions reviewed in this paper are (1) the classification status of CAV, (2) CAV genomic structure, and (3) the encoded proteins (VP1, VP2 and VP3) of CAV genome. Ref

Histopathological study of hepatocellular carcinoma after transcatheter hepatic arterial embolization

AIMS To study the histopathological changes in hepatocellular carcinoma (HCC) after transcatheter arterial embolization (TAE). METHODS Histopathological analysis was made in 39 cases of liver neoplasms after TAE and 11 cases of liver neoplasms after digital selective angiography (DSA), including pathological type, histological grade, necrotic degree, capsule, times of treatment, injured vessel and lymphocyte infiltration. RESULTS Six cases with 100% necrosis, 14 cases with 30% 95% necrosis, 19 cases with 0% 5% necrosis after TAE and 11 cases without necrosis after DSA were found histologically. The necrosis was related to the pathological type, capsule, injured vessels, but not to the histological grade, time of treatment and lymphocyte infiltration of the liver neoplasms. CONCLUSIONS TAE is an effective therapy for the late stage HCC. The encapsulated HCC is a preferable indicator for TAE.

Clinical Analysis of 81 Cases of Benign Retroperitoneal Schwannoma

Objective： To analyze the clinical manifestations of retroperitoneal schwannoma in order to improve the diagnosis and treatment of this rare disease. Methods： Between January 1951 and September 2004, 81 patients with retroperitoneal schwannoma were retrospectively analyzed. Results： All cases received operative therapy. Sixty cases （74.1%） received a total resection; 12 cases （14.9%） subtotal resection, and 9 cases （11.1%） exploration. During the surgical operation, a single tumor was found in 77 cases （95.1%）, and multiple tumors in 4 cases （4.9%）. Most of the retroperitoneal schwannomas located beside the spine. The tumor was a fusiform, round or oval mass that was sharply circumscribed and encapsulated. Pathologic results showed all 81 cases were benign schwannoma. In the 4 cases of multiple tumors, 2 （2.5%） were diagnosed as double-primary tumors associated with ascending colon adenocarcinoma and lung squamous-cell cancer. One case recurred postoperatively. Conclusion： Retroperitoneal schwannoma was rare and preoperative diagnosis was difficult. Most of retroperitoneal schwannoma were benign and the surgical treatment was the first choice.

Replication-selective Oncolytic Adenovirus CNHK300 in the Treatment of Breast Cancer Cell Lines in vitro

Objective： To evaluate the tumor selectivity and therapeutic efficiency of replication-competent adenovirus CNHK300 on human breast cancer cells. Methods： RT-PCR was used to detect the hTERT mRNA activity in various breast cancer and normal fibroblast cell lines. Virus proliferation assay, cell viability assay and Western blot were applied to evaluate the proliferation and cytolysis selectivity of CNHK300. Results： The telomerase activity of MCF-7, BT-549 and SK-BR-3 was positive, while telomerase in MRC-5 and BJ was negative. The progeny virus titers in MCF-7, BT-549 and SK-BR-3 after 48 h of CNHK300 exposure was 40 625, 1 265 and 20 000 fold higher than those of 0 h, even slightly higher than those of wtAd5 （except in SK-BR-3）. ONYX-015 virus proliferation ability was weaker than that of CNHK300 in cancer cells. However, CNHK300 exhibited attenuated replicative ability as compared with wtAd5 in MRC-5 and BJ. The CNHK300 replicatative multiple was 63 and 192 fold at 48 h respectively, while the wtAd5 still multiplied 3 160-4 846 fold. CNHK300 could cause about half of breast cancer cells to die within 7 days at MOI 10 pfu/cell and below, whereas the IC50 in BJ and MRC-5 was as high as MOI 100 pfu/cell. CNHK300 E1A protein could be detected in breast cancer cells and 293 cells but not in normal fibroblast cells. Conclusion： hTERT promoter can successfully modulate the CNHK300 to be selectively replicated in breast cancer cells positive for telomerase, which may be a potential treatment strategy in breast cancer.

Targeting Gene-Virotherapy of Cancer and its prosperity

Gene and viral therapies for cancer have shown some therapeutic effects, but there has been a lack of real breakthrough. To achieve the goal of complete elimination of tumor xenograft in animal models, we have developed a new strategy called Targeting Gene-Virotherapy of Cancer, which aims to combine the advantages of both gene therapy and virotherapy. This new strategy has produced stronger anti-tumor effects than either gene or viral therapy alone. A tumorspecific replicative adenovirus vector, designated as ZD55, was constructed by deletion of the 55kDa E1B region of adenovirus. The resulting viral construct not only retains a similar function to ONYX-015 by specifically targeting p53 negative tumors, but also allows for the insertion of various therapeutic genes to form appropriate ZD55 derivatives due to the newly introduced cloning site, a task not feasible with the original ONYX-015 virus. We showed that the anti-tumor effect of one such derivative, ZD55-IL-24, is at least 100 times more potent than that of either ZD55 virotherapy or Ad-IL-24 gene therapy. Nevertheless, complete elimination of tumor mass by the use of ZD55-1L-24 was only observed in some but not all mice, indicating that one therapeutic gene was not sufficient to ＂cure＂ these mice. When genes with complementary or synergetic effects were separately cloned into the ZD55 vector and used in combination （designated as the Dual Gene Therapy strategy）, much better results were obtained; and it was possible to achieve complete elimination of all the xenograft tumor masses in all mice if two suitable genes were chosen. More comprehensive studies based on this new strategy will likely lead to a protocol for clinical trial. Finally, the concept of Double Controlled Targeting Virus-Dual Gene Therapy for cancer treatment, and the implication of the recent progress in cancer stem cells are also discussed.

Targeting gene-virotherapy of cancer

Our purpose is to completely elimination of xenograft tumor in animal tumor model in order to work out a protocal for the cure of patient. Gene therapy and viral therapy for cancer have got some therapeutic effects, but both have no great breakthrough. Therefore, we worked out a new strategy called Targeting Gene-Virotherapy of Cancer which is a combination of the advantage of gene therapy and virotherapy. This new strategy has stronger antitumor effect than either of them alone. A tumor specific replicative adenovirus vector ZD55 （E1B 55KD deleted Adv.） which is similar to ONYX-015 in targeting fuction but significant different in construction was produced and various single therapeutic gene was inserted into ZD55. Now such a conception as Targeting Gene-Virotherapy of Cancer was raised and systemically studied before, although there are some works on ONYX-015-tk, -cd or cd/-tk etc. separately. The antitumor effect of ZD55-Gene （for example IL-24 gene） is much better than ZD55 （virotherapy） alone and hundred fold high than that ofAd-IL-24 （gene therapy） alone. ZD55-IL-24 was in preclinal studying in the ZD55-IL-24 therapy, completely elimination of tumor mass was occurred in some mice but not in all mice, that means one gene was not effictive enough to eliminate all the tumor mass in all mice. Therefore two genes with compensative or synergetic effect were inserted into ZD55 sepearately and used in combinction. This strategy was called Targeting Dual Gene-Virotherapy of Cancer （with PCT patent）. Then much better results were obtained and all the xenograft tumor masses were completely eliminated in all mice, if two suitable genes were chosen. On the basis of the initiation of two gene results, it was thought about that using two tumors promoter to control the virus vector will be better for the targeting effect and the safty of the drugs. Then double tumor controlled virus vector harboring two genes for cancer therapy was worked out. Better results have been obtained and another patent has been applied. This antitumor strategy could be used to kill all the tumor cells completely in all mice with minimum damage to normal cells.

Development and characterization of multidrug resistant human hepatocarcinoma cell line in nude mice

AIM： To establish a multidrug resistant （MDR） cell subline from the human hepatocardnoma cell line （HepG2） in nude mice. METHODS： HepG2 cell cultures were incubated with increasing concentrations of adriamycin （ADM） to develop an ADM-resistant cell subline （HepG2/ADM） with crossresistance to other chemotherapeutic agents. Twenty male athymic BALB/c-nu/nu mice were randomized into HepG2/nude and HepG2/ADM/nude groups （10 in each group）. A cell suspension （either HepG2 or HepG2/ADM） was injected subcutaneously into mice in each group. Tumor growth was recorded, and animals were sacrificed 4-5 wk after cell implantation. Tumors were prepared for histology, and viable tumor was dispersed into a single-cell suspension. The IC50 values for a number of chemotherapeutic agents were determined by 2, 3-bis （2-methoxy-4-nitro-5-sulfophenyl）-2H-tetrazolium-5-carboxanilide inner salt （MTT） assay. Rhodamine-123 retention/efflux and the level of resistance-associated proteins were determined by flow cytometry. The mRNA expression of mdr1, mrp and Irp genes was detected using reverse transcriptase polymerase chain reaction （RT-PCR） in HepG2/nude and HepG2/ADM/nude groups. RESULTS： The appearances of HepG2/nude cells were slightly different from those of HepG2/ADM/nude cells. Similar tumor growth curves were determined in both groups. A cross-resistance to ADM, vincristine, cisplatin and 5-fluorouracil was seen in HepG2/ADM/nude group. The levels of P-glycoprotein and multidrug resistanceassociated proteins were significantly increased. The mRNA expression levels of mdrl, mrp and/rp were higher in HepG2/ADM/nude cells. CONCLUSION： ADM-resistant HepG2 subline in nude mice has a cross resistance to chemotherapeutic drugs. It may be used as an in vivo model to investigate the mechanisms of MDR, and explore the targeted approaches to overcoming MDR.

Carcinoid tumor of the appendix: A consecutive series from 1237 appendectomies

AIM： To report the experience of the CHU Sart Tilman, University of Liege, Belgium, in the management of appendiceal carinoid tumor. METHODS： A retrospective review of 1237 appendectomies performed in one single centre from January 2000 to May 2004, was undertaken. Analysis of demographic data, clinical presentation, histopathology, operative reports and outcome was presented. RESULTS： Among the 1237 appendectomies, 5 appendiceal carcinoid tumors were identified （0.4%） in 4 male and 1 female patients, with a mean age of 29.2 years （range： 6-82 years）. Acute appendicitis was the clinical presentation for all patients. Four patients underwent open appendectomy and one a laparoscopic procedure. One patient was reoperated to complete the excision of mesoappendix. All tumors were located at the tip of the appendix with a mean diameter of 0.6 cm （range： 0.3-1.0 cm）. No adjuvant therapy was performed. All patients were alive and disease-free during a mean follow-up of 33 mo. CONCLUSION： Appendiceal carcinoid tumor most of-ten presents as appendicitis. In most cases, it is found incidentally during appendectomies and its diagnosis is rarely suspected before histological examination. Appendiceal carcinoid tumor can be managed by simple appendectomy and resection of the mesoappendix, if its size is ≤ 1cm.

Solid-pseudopapillary tumor of the pancreas: Clinical experience and literature review

AIM: To evaluate the clinical presentations of solidpseudopapillary tumor of the pancreas (SPT) and examine the diagnosis, treatment, low grade malignant potential of this rare disease.METHODS: We retrospectively reviewed a series of seven patients with SPT managed in our hospital between July 1990 and October 2003. Six females and one male with mean age of 31 years (range 13 to 50 years) were diagnosed with SPT at our institution.RESULTS: Clinical presentation included a palpable abdominal mass in two patients and vague abdominal discomfort in another two. Two patients were asymptomatic;their tumors were found incidentally on abdominal sonographic examination for other reasons. The final patient was admitted with hemoperitoneum secondary to tumor rupture. The mean diameter of the tumors in the seven patients was 10.5 cm (range 5 to 20 cm). The lesions were located in the body and tail in five cases and in the head of the pancreas in two. Surgical procedures included distal pancreatectomy (3), distal pancreatectomy with splenectomy (2), pancreaticoduodenectomy (1) and a pylorus-preserving Whipple procedure (1). There were gross adhesions or histological evidence of infiltration to the adjacent pancreas and/or splenic capsule in four cases. None of the patients received adjuvant therapy.The mean follow up was 7 years (range 0.5 to 14 years).One patient developed multiple liver metastases after 14 years of follow up.CONCLUSION: SPT is a rare tumor that behaves less aggressively than other pancreatic tumor. However, in cases with local invasion, long-term follow up is advisable.

Low intensity ultrasound-induced apoptosis in human gastric carcinoma cells

AIM： To investigate the low intensity ultrasound （US）- induced apoptosis in human gastric carcinoma cells and its potential mechanism and to suggest a new therapeutic approach to gastric carcinoma. METHODS： Human SGC-7901 gastric carcinoma cells were cultured in vitro and irradiated by low intensity US for 10 min at different intensities with different incubation times after irradiation. Morphologic changes were examined under microscope with trypan blue staining and then the percentage of early apoptotic cells was detected by flow cytometry （FCM） with double staining of fiuorescein isothiocyanate （FITC）- Annexin V/propidium iodide （PI）. Two-dimensional electrophoresis （2DE） was used to get the protein profile and some proteins differently expressed after US irradiation were identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry （MALDI-TOF-MS）. Functional analysis was performed to investigate the mechanism of US-induced cell apoptosis. RESULTS： The percentage of apoptotic cells increased about 10% after US irradiation （12.0 W/cm^2, 12 h culture）, The percentage of early apoptosis and secondary necrosis in the US-irradiated cells increased with the increased US intensity. Moreover, apoptotic cells increased with the increased culture time after US irradiation and reached its maximum at about 12 h.Several new proteins appeared after US irradiation and were up or down regulated more than 2 times. Some heat shock proteins （HSPs） were found to be associated with the signal process simulating the apoptosis of cells. CONCLUSION： Low intensity US could induce apoptosis in human gastric carcinoma cells. US-induced apoptosis is related to US intensity/culture time. US-induced apoptosis may be caspases-dependent and endoplasmic reticulum （ER） stress-triggered apoptosis may also contribute to it. Proteomic experimental system is useful in finding the protein alteration in carcinoma cells after US irradiation, helping to develop a new cancer therapy.

Primary liposarcoma of esophagus:A case report

Liposarcoma is the most common soft tissue sarcoma in adult life while esophageal liposarcoma is an extremely rare tumor. In the world literature, only 14 cases of esophageal liposarcomas have been described. We report a 72-year old male patient who was urgently admitted to our hospital for acute epigastric pain with a burning retrosternal sensation, persistent nausea, vomiting and dysphagia. Barium swallow, upper gastrointestinal （GI） endoscopy, esophageal manometry and CT scan, failed to accurately diagnose the lesion. After surgical resection of an esophageal polypoid tumor, the histological examination revealed a well-differentiated grade Ⅰ liposarcoma. Diagnostic and therapeutic tools were discussed and the results of literature were reviewed.

Evaluation of contrast-enhanced helical hydro-CT in staging gastric cancer

AIM： TO discuss the helical computed tomography （CT） characteristics of gastric cancer and evaluate the diagnostic value of contrast-enhanced helical hydro-CT （HHCT） in staging gastric cancer. METHODS： A total of 50 patients with gastric cancer were included in this study. The CT findings in them were retrospectively analyzed and correlated with pathologic findings at surgery. All patients were preoperatively imaged by plain and contrast-enhanced helical CT afer orally ingesting 1 000-1 500 mL water. Peristalsis was minimized by intravenous administration of spasmolytics. RESULTS： The foci of gastric cancer became more prominent in all the 50 patients and showed strong enhancement in contrast-enhanced HHCT. The tumor was located at the gastric cardia in 14 cases, at the gastric fundus in 3 cases, at the gastric body in 8 cases, at the gastric antrum in 4 cases, at the gastric fundus and the body in 8 cases, at the gastric body and antrum in 11 cases, and at three segments of the stomach in 2 cases. The CT features of gastric cancer were focal or diffuse mural thickening, soft tissue mass, cancerous ulcer, stenosis of stomach, infiltration to adjacent tissues, lymph node and distant metastases. Strong contrast enhancement of the gastric wall was closely related to gastric cancer. The accuracy rate of contrast-enhanced HHCT in staging gastric cancer was 86% （43/50）. The detection rate of lymph node metastases by CT was 60% （12/20）. CONCLUSION： Contrast-enhanced HHCT is a reliable method to diagnose and stage gastric cancer.

MYC and gastric adenocarcinoma carcinogenesis

MYC is an oncogene involved in cell cycle regulation, cell growth arrest, cell adhesion, metabolism, ribosome biogenesis, protein synthesis, and mitochondrial function. It has been described as a key element of several carcinogenesis processes in humans. Many studies have shown an association between MYC deregulation and gastric cancer. MYC deregulation is also seen in gastric preneoplastic lesions and thus it may have a role in early gastric carcinogenesis. Several studies have suggested that amplification is the main mechanism of MYC deregulation in gastric cancer. In the present review, we focus on the deregulation of the MYC oncogene in gastric adenocarcinoma carcinogenesis, including its association with Helicobacterpylori （Hpylon] and clinical applications.

Huge primitive neuroectodermal tumor of the pancreas:Report of a case and review of the literature

Primitive neuroectodermal tumor (PNET) of the pancreas is an extremely rare tumor that usually occurs in children or young adults. We report a case of a 33-year-old male patient with an 18 cm × 18 cm × 16 cm mass arising from the pancreatic body and tail with a one- day history of abdominal pain. Initial CT scan showed no signs of metastatic tumor spread. The tumor caused intrabdominal bleeding and the patient underwent primary tumor resection including partial gastrectomy, left pancreatic resection and splenectomy. Diagnosis of PNET was confi rmed by histology, immunohistochemistry and FISH analysis. All neoplastic cells were stained positive for MIC2-protein (CD99). Approximately one month after surgery, several liver metastases were observed and the patient underwent chemotherapy according to the Euro- Ewing protocol. Subsequent relaparotomy excluded any residual hepatic or extrahepatic abdominal metastases. Although PNET in the pancreas is an extremely rare entity, it should be considered in the diffential diagnosis of pancreatic masses, especially in young patients. This alarming case particularly illustrates that PNET in the pancreas although in an advanced stage can present with only a short history of mild symptoms.

Hepatic progenitor cells in human liver tumor development

In recent years, the results of several studies suggest that human liver tumors can be derived from hepatic progenitor cells rather than from mature cell types. The available data indeed strongly suggest that most combined hepatocellular-cholangiocarcinomas arise from hepatic progenitor cells that retained their potential to differentiate into the hepatocytic and biliary lineages. Hepatic progenitor cells could also be the basis for some hepatocellular carcinomas and hepatocellular adenomas, although it is very difficult to determine the origin of an individual hepatocellular carcinoma. There is currently not enough data to make statements regarding a hepatic progenitor cell origin of cholangiocarcinoma. The presence of hepatic progenitor cell markers and the presence and extent of the cholangiocellular component are factors that are related to the prognosis of hepatocellular carcinomas and combined hepatocellular- cholangiocarcinomas, respectively.

Locoregional IL-2 low dose applications for gastrointestinal tumors

AIM： To explore the feasibility of local interleukin 2 （IL-2） in patients with different forms of abdominal cancer. This required experimentation with the time interval between IL-2 applications and the methods of application. METHODS： Sixteen patients with stages Ⅲ and Ⅳ of gastrointestinal malignancies （primary or metastatic） who were admitted to our Department of Gastroenterology were treated with Iocoregionally applied IL-2 in low doses. RESULTS： No major problems applying Iocoregional IL-2 were encountered. In 6 out of 16 patients, a modest but clinically worthwhile improvement was obtained. Adverse effects were minimal. The therapeutic scheme was well tolerated, even in patients in a poor condition. CONCLUSION： This study demonstrates the feasibility of low dose Iocoregional IL-2 application in advanced abdominal cancer. Local IL-2 therapy gives only negligible adverse effects. The results suggest that it is important to apply intratumorally. Local IL-2 may be given adjunct to standard therapeutic regimes and does not imply complex surgical interventions. These initial results are encouraging.

Synchronous occurrence of gastrointestinal stromal tumors and other primary gastrointestinal neoplasms

AIM： To review clinical and pathologic features of Gastrointestinal strornal tumors （GISTs） occurring synchronously with other primary gastrointestinal neoplasms. METHODS： 28 patients with primary GIST were treated at our institution between 1989 and 2005. Clinical and pathologic records were reviewed. RESULTS： The gastrointestinal stromal tumor occurred simultaneously with other primary GI malignancies in 14% of all patients with GIST. The synchronous stromal tumors were located in the stomach and were incidentally found during the operation. The coexistent neoplasms were colon adenocarcinoma, gastric cancer （2 cases） and gastric lymphoma. CONCLUSION： The synchronous occurrence of GISTs and other gastrointestinal malignancies is more common than it has been considered. The development of gastrointestinal stromal tumors and other neoplasms may involve the same carcinogenic agents.

Pyogenic liver abscess associated with large colonic tubulovillous adenoma

Pyogenic liver abscesses usually occur in association with a variety of diseases. Rarely, liver abscess has been reported as the presenting manifestation of colonic tubulovillous adenoma. We report two cases of pyogenic liver abscess without hepatobiliary disease or other obvious etiologies except that one had a history of diabetes mellitus （DM）. The pathogen in the patient with DM was Klebsiella pneumonia （KP）. In both of the patients, Ueus developed about two to three weeks after the diagnosis of liver abscess. Colonoscopy revealed large polypoid tumors with pathological findings of tubulovillous adenoma in both cases. Two lessons were learned from these two cases： （1） an underlying cause should be aggressively investigated in patients with cryptogenic liver abscess; （2） DM could be one of the etiologies but not necessarily the only cause of KP liver abscess.

Gastric carcinoid tumor in a patient with a past history of gastrointestinal stromal tumor of the stomach

Gastrointestinal stromal tumor is the most common mesenchymal tumor in the gastrointestinal tract. It may coexist with other type of cancers,and if so,the tumors usually involve the stomach. The most common associated cancers are gastrointestinal carcinomas. We report a 65-year-old woman with a history of gastric gastrointestinal stromal tumor who had undergone subtotal segmental gastrectomy. New polypoid lesions were detected on a follow-up gastroscopy one year later. The lesions were biopsied and found to be carcinoid tumors. There was serum hypergastrinemia,and type 1 gastric carcinoid tumor was diagnosed. A total gastrectomy was performed. Pathologic examination revealed both carcinoid tumors and a recurrent gastrointestinal stromal tumor.

Preliminary study on proteomics of gastric carcinoma and its clinical significance

AIM： To explore the preliminary identification of serum protein pattern models that may be novel potential biomarkers in the detection of gastric cancer. METHODS： A total of 130 serum samples, including 70 from patients with gastric cancer and 60 from healthy adults, were detected by surface-enhanced laser desorption and ionization time-of-flight mass spectrometry （SELDI-TOF-MS）. The data of spectra were analyzed by Biomarker Patterns Software （BPS）. Thirty serum samples of gastric cancer patients and 30 serum samples of healthy adults were grouped into the training group to build models, and the other 70 samples were used to test and evaluate the models. The samples of the test group were judged only with their peaks＇ height and were separated into cancer group or healthy control group by BPS automatically and the judgments were checked with the histopathologic diagnosis of the samples. RESULTS： Sixteen mass peaks were found to be potential biomarkers with a significant level of P〈0.01. Among them, nine mass peaks showed increased expression in patients with gastric cancer. Analyzed by BPS, two peaks were chosen to build the model for gastric cancer detection. The sensitivity, specificity, and accuracy of the model were 90%, 36/40, 86.7%, 26/30, and 88.6%, 62/70, respectively, which were greatly higher than those of clinically used serum biomarkers CEA （carcinoembryonic antigen）, CAlg-g and CA72-4. Stage Ⅰ/Ⅱ gastric cancer samples of the test group were all judged correctly.CONCLUSION： The novel biomarkers in serum and the established model could be potentially used in the detection of gastric cancer. However, large-scale studies should be carried on to further explore the clinical impact on the model.