Optimal strategy of systemic treatment for unresectable pancreatic neuroendocrine tumors based upon opinion of Japanese experts.

BACKGROUND/OBJECTIVES: A number of therapeutic agents have been reported to be clinically useful for the management of the patients with unresectable pancreatic neuroendocrine tumors (PanNETs) including somatostatin analogues, molecular-targeted agents and cytotoxic agents. However, the optimal strategy for selection among those treatment modalities above in these patients has remained unexplored. METHODS: Japanese experts for PanNET discussed and determined the optimal treatment strategies according to the results of previously reported studies. RESULTS: The tumor volume of liver metastases and the Ki-67 labeling index were unanimously accepted as indicators of the tumor burden and tumor aggressiveness, respectively, which are two most clinically pivotal factors for determining the strategy of systemic treatment for unresectable PanNETs. In addition, for those with a relatively small tumor burden and slow disease progression, somatostatin analogues were selected as the first-line treatment agents. For those with a relatively large tumor burden and rapid tumor progression, cytotoxic agents were selected, possibly aiming at tumor shrinkage. For those of intermediate tumor volume and/or growth rate, molecular-targeted agents were selected as the first choice. Based on this strategy discussed among the experts, we tentatively prepared a MAP for proposing optimal treatment strategy and examined its validity in some patients with unresectable PanNETs. Results validated the usefulness of this MAP proposed for patients harbouring unresectable PanNETs. CONCLUSION: We herein propose a tentative MAP for optimal treatment selection for the patients harbouring unresectable PanNETs. Further large scale studies are, however, warranted to validate the usefulness of this MAP proposed in this study.

PHLDA3 is a novel tumor suppressor of pancreatic neuroendocrine tumors.

The molecular mechanisms underlying the development of pancreatic neuroendocrine tumors (PanNETs) have not been well defined. We report here that the genomic region of the PHLDA3 gene undergoes loss of heterozygosity (LOH) at a remarkably high frequency in human PanNETs, and this genetic change is correlated with disease progression and poor prognosis. We also show that the PHLDA3 locus undergoes methylation in addition to LOH, suggesting that a two-hit inactivation of the PHLDA3 gene is required for PanNET development. We demonstrate that PHLDA3 represses Akt activity and Akt-regulated biological processes in pancreatic endocrine tissues, and that PHLDA3-deficient mice develop islet hyperplasia. In addition, we show that the tumor-suppressing pathway mediated by MEN1, a well-known tumor suppressor of PanNETs, is dependent on the pathway mediated by PHLDA3, and inactivation of PHLDA3 and MEN1 cooperatively contribute to PanNET development. Collectively, these results indicate the existence of a novel PHLDA3-mediated pathway of tumor suppression that is important in the development of PanNETs.

Concurrent gemcitabine+S-1 neoadjuvant chemotherapy contributes to the improved survival of patients with small borderline-resectable pancreatic cancer tumors.

PURPOSES: In the surgical treatment of pancreatic cancer, margin-negative status is one of the most important determinants of survival. We conducted this study to explore surgical margin status as well as other factors affecting the survival of borderline-resectable pancreatic cancer (BRPC) patients who received neoadjuvant chemotherapy with gemcitabine and S-1. METHODS: Eighteen BRPC patients were prospectively treated with concurrent gemcitabine and S-1 neoadjuvant chemotherapy (NAC+) and 15 of these patients underwent resection. We evaluated the safety and efficacy of this treatment regimen by comparing the outcomes of these patients with those of 19 BRPC patients who did not receive neoadjuvant chemotherapy (NAC-) during the same period. RESULTS: Fifteen (83 %) of the NAC+ patients underwent pancreatectomy. The remaining three patients (17 %) had regional tumor progression or liver metastasis. Of the 15 NAC+ patients who underwent resection, 3 (20 %) had margin-positive status, whereas 9 of the 19 (43 %) NAC- patients had margin-positive status (p = 0.002). However, disease-free survival and overall survival were similar in the two groups (MST 21.7 vs. 21.1 months). NAC+ patients with tumors smaller than 30 mm had favorable overall survival (MST 43.9 vs. 23.1 months, p = 0.0321). Most recurrences developed at distant sites rather than locally in both groups. CONCLUSIONS: In the neoadjuvant setting, gemcitabine and S-1 improved the negative surgical margin rate in BRPC patients, but it did not improve survival. Thus, neoadjuvant chemotherapy should be given to BRPC patients at an earlier stage.

(68)Ga-DOTATOC-PET/CT for effective diagnosis and treatment of pancreatic tail gastrinoma with multiple liver metastases: a case report.

A 40-year-old man admitted to our hospital with diarrhea underwent abdominal computed tomography (CT) which showed multiple masses in the liver and pancreatic tail. Although there were no abnormal accumulations with fluorodeoxyglucose ((18)F) positron emission tomography (FDG-PET), (68)Ga-DOTATOC-PET/CT detected obvious abnormal accumulations for the both lobes of liver and pancreatic tail tumors. The serum gastrin was markedly high, and liver tumor biopsy demonstrated the presence of malignant cells with round nuclei that were positive for gastrin and somatostatin receptor. The patient was diagnosed with pancreatic tail gastrinoma with multiple liver metastases and treated with octreotide, everolimus, and a proton pump inhibitor which functionally controlled tumor growth. This case demonstrates (68)Ga-DOTATOC-PET/CT as a useful modality for the localization, qualitative diagnosis, and treatment of gastrinoma.

[Resection of cholangiolocellular carcinoma successfully responding to neoadjuvant hepatic arterial infusion chemotherapy - report of a case].

A 78-year-old man who had hepatitis C was examined by computed tomography(CT)because of prostate cancer, and was found to have a liver tumor 8. 0 cm in size at S4/S8. The view of the liver tumor was enhanced by CTHA image and washed out by CTAP image. It was suspected to have invaded the RHV and MHV. The pathological examination of the liver biopsy sample revealed cholangiocellular carcinoma or cholangiolocellular carcinoma. Hepatic arterial infusion chemotherapy with gemcitabine and cisplatin was performed. The size of the tumor reduced to 6. 0 cm and the invasion to the RHV was no longer evident. Hepatic resection for the middle two segments was performed after 3 months of chemotherapy. After a histological examination of the resected specimen, the patient was given the final diagnosis of cholangiolocellular carcinoma. Over 50% of the tumor was estimated as necrosis by chemotherapy, indicating that the gemcitabine and cisplatin regimen was remarkably effective. The patient is alive with no evidence of recurrence.

Diagnostic accuracy of [¹8F]-fluoro-L-dihydroxyphenylalanine positron emission tomography scan for persistent congenital hyperinsulinism in Japan.

OBJECTIVE: We aimed to elucidate the accuracy and limitations of [(18)F]-fluoro-L-dihydroxyphenylalanine ([(18) F]DOPA) positron emission tomography (PET) for Japanese patients with congenital hyperinsulinism. Although [(18)F]DOPA PET is reported to be useful for precisely localizing the focal form of congenital hyperinsulinism, previous reports are mostly from European and North American centres. PATIENTS: Seventeen Japanese infants with congenital hyperinsulinism. MEASUREMENTS: [(18)F]DOPA PET studies were carried out, and the results were assessed by simple inspection or by a quantitative measurement termed the 'Pancreas Percentage', which expresses the uptake of the head, body or tail of the pancreas as a percentage of the total maximum standardized uptake value of the whole pancreas. The results were compared with those of other studies, including genetic analysis and histology. RESULTS: By simple inspection, when a single focal uptake was obtained, the localization and histology were correct in all cases that underwent pancreatectomy. However, the overall results were consistent with the molecular diagnosis and histology in only 7/17 and 6/12 patients, respectively. The inaccuracy of PET studies by inspection was because of elevated background uptake that mimicked a diffuse or multifocal appearance. The accuracy improved substantially using the Pancreas Percentage; it was consistent with the molecular diagnosis and histology in 10/17 and 9/12 patients, respectively. CONCLUSIONS: In contrast to the results of previous reports, [(18)F]DOPA PET appears to be less efficient for diagnosing Japanese patients with congenital hyperinsulinism. However, the diagnostic accuracy is substantially improved when this technique is combined with the Pancreas Percentage.

Successful neoadjuvant treatment with radiochemotherapy and systemic chemotherapy for the locally advanced pancreatic head cancer: report of a case.

A 49-year-old man was admitted to the hospital for the upper abdominal pain and was diagnosed as unresectable pancreatic head cancer because of the invasion around the superior mesenteric artery. He was treated with radiochemotherapy, followed by systemic gemcitabine alone for 3 courses. He was further treated with systemic gemcitabine plus S­1 combination therapy for 5 courses. CT examination after these treatments showed a dramatic reduction of the tumor at the head of the pancreas and a pancreatoduodenectomy was performed. Pathologically, there was no residual malignant tumor. He has had no recurrent tumor up until now. Several studies of gemcitabine plus S-1 combination therapy show higher response rates for unresectable tumors. The current case indicates the effectiveness of the radiochemotherapy and gemcitabine plus S­1 combination therapy for locally advanced pancreatic head cancer as a neoadjuvant setting. We consider that multidisciplinary treatment including gemcitabine plus S­1 therapy may prolong the survival time by curative operation.

Noninvasive intraductal papillary mucinous neoplasm with para-aortic lymph node metastasis: report of a case.

Intraductal papillary mucinous neoplasms (IPMNs) with an invasive carcinoma component are categorized as minimally invasive or invasive. The prognosis after resection of minimally invasive IPMNs has been reported to be similar to that after resection of noninvasive IPMNs. We report a case of noninvasive branchduct IPMN with multiple lymph node metastases, including para-aortic node involvement, treated successfully by distal pancreatectomy with lymph node dissection. The patient, a 72-year-old man, had two multilocular cysts in the pancreatic body, 22 mm and 14 mm in diameter, respectively, communicating with the main pancreatic duct. The primary tumor and nodal metastases had similar patterns of mucin expression. The primary tumor contained a region of carcinoma in situ (CIS) without histological evidence of stromal invasion; thus, it was diagnosed as minimally invasive carcinoma. We report this case to emphasize two important points: first, even small branch-duct IPMNs without any indications for resection can have a component of CIS or more advanced disease; and second, even branch-duct IPMNs without any apparent invasive component can be aggressive and spread to the lymph nodes. Therefore, nodal status should be assessed carefully in every patient, even if the primary IPMN is not advanced.

JNETS clinical practice guidelines for gastroenteropancreatic neuroendocrine neoplasms: diagnosis, treatment, and follow-up: a synopsis.

Neuroendocrine neoplasms (NENs) are rare neoplasms that occur in various organs and present with diverse clinical manifestations. Pathological classification is important in the diagnosis of NENs. Treatment strategies must be selected according to the status of differentiation and malignancy by accurately determining whether the neoplasm is functioning or nonfunctioning, degree of disease progression, and presence of metastasis. The newly revised Clinical Practice Guidelines for Gastroenteropancreatic Neuroendocrine Neoplasms (GEP-NENs) comprises 5 chapters-diagnosis, pathology, surgical treatment, medical and multidisciplinary treatment, and multiple endocrine neoplasia type 1 (MEN1)/von Hippel-Lindau (VHL) disease-and includes 51 clinical questions and 19 columns. These guidelines aim to provide direction and practical clinical content for the management of GEP-NEN preferentially based on clinically useful reports. These revised guidelines also refer to the new concept of "neuroendocrine tumor" (NET) grade 3, which is based on the 2017 and 2019 WHO criteria; this includes health insurance coverage of somatostatin receptor scintigraphy for NEN, everolimus for lung and gastrointestinal NET, and lanreotide for GEP-NET. The guidelines also newly refer to the diagnosis, treatment, and surveillance of NEN associated with VHL disease and MEN1. The accuracy of these guidelines has been improved by examining and adopting new evidence obtained after the first edition was published.

Preoperative assessment of para-aortic lymph node metastasis in patients with pancreatic cancer.

BACKGROUND: Para-aortic lymph node (PALN) metastasis is an important prognostic factor in patients with pancreatic cancer, but accurate preoperative diagnosis is difficult. The objective of this study was to assess the accuracy of diagnosis of PALN by computed tomography (CT), magnetic resonance imaging (MRI), and (18)F-fluorodeoxyglucose positron-emission tomography (FDG-PET). METHODS: From August 2005 to July 2008, 119 patients with invasive ductal adenocarcinoma of the pancreas were included in this study. PALNs with a longer diameter >10 mm on CT or MRI were suspected of being involved by metastasis, whereas FDG uptake exceeding that of the adjacent normal tissue was considered to be positive for metastasis on FDG-PET studies. The imaging findings were compared with the pathological diagnosis of PALN metastasis. RESULTS: PALN dissection was performed in 71 patients (60.0%). Although histopathological examination revealed metastasis in 6 patients (8.5%), none of these patients was positive in any of the preoperative imaging studies. The longer diameter, the shorter diameter, the ratio of the two diameters, and the calculated lymph node volume showed no significant differences between patients with and without PALN metastasis. CONCLUSIONS: Preoperative detection of PALN metastasis in patients with pancreatic cancer is very difficult. Intraoperative histopathological examination of frozen sections is necessary if radical resection is contemplated.

Successful left hemihepatectomy and perioperative management of a patient with biliary cystadenocarcinoma, complicated with MELAS syndrome: report of a case.

Mitochondrial Myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like syndrome (MELAS) is a rare, fetal disease caused by a mutation in mitochondrial DNA that leads to impaired oxidative metabolism in skeletal muscle, the central nervous system, and liver function. This report presents the case of a 50-year-old woman with biliary cystadenocarcinoma complicated by MELAS who underwent a successful left hemihepatectomy. In this case, the diagnostic key for the malignant tumor was an (18)F-fluorodeoxyglucose positron emission tomography study, which was useful even in a patient with MELAS, which causes abnormal glucose metabolism. The perioperative management of such patients includes special precautions to prevent lactic acidosis and deterioration of the reserved liver function after a hepatectomy, since the mitochondrial function in MELAS patients is abnormal. The patient in this report has remained free of liver dysfunctions and cancer recurrence for 2 years following the hepatectomy. This is the first report of a successful major hepatectomy for a patient with MELAS.

Xanthogranulomatous cholecystitis complicated with primary sclerosing cholangitis: report of a case.

Patients with primary sclerosing cholangitis (PSC) are at an increased risk for biliary tract carcinoma. The preoperative diagnosis of a biliary tract tumor as a malignancy is difficult, even using new modalities such as multidetector computed tomography (MD-CT), magnetic resonance cholangiopancreatography (MRCP), endoscopic retrograde cholangiography (ERC), and (18)F-fluorodeoxyglucose positron emission tomography (FDG-PET). Surgery is considered to be first line of treatment when these examinations suggest the presence of malignancy in the biliary tract, depending on both the curability of the cancer and the impaired liver function due to PSC. The management of gallbladder masses in patients with PSC remains problematic due to difficulties with the precise diagnosis and adequate surgery. Xanthogranulomatous cholecystitis (XGC) is a type of chronic cholecystitis, and sometimes coexists with gallbladder cancer. It is very difficult to make a preoperative diagnosis differentiating these two diseases. This report presents the case of a patient with XGC, who had been suspected of having gallbladder cancer before surgery, because the tumorous lesion emerged within a year and showed a focally increased uptake by FDG-PET during the follow up for PSC for years. This is the first case of XGC discovered during treatment for PSC.

Adjuvant chemotherapy with fluorouracil plus folinic acid vs gemcitabine following pancreatic cancer resection: a randomized controlled trial.

CONTEXT: Adjuvant fluorouracil has been shown to be of benefit for patients with resected pancreatic cancer. Gemcitabine is known to be the most effective agent in advanced disease as well as an effective agent in patients with resected pancreatic cancer. OBJECTIVE: To determine whether fluorouracil or gemcitabine is superior in terms of overall survival as adjuvant treatment following resection of pancreatic cancer. DESIGN, SETTING, AND PATIENTS: The European Study Group for Pancreatic Cancer (ESPAC)-3 trial, an open-label, phase 3, randomized controlled trial conducted in 159 pancreatic cancer centers in Europe, Australasia, Japan, and Canada. Included in ESPAC-3 version 2 were 1088 patients with pancreatic ductal adenocarcinoma who had undergone cancer resection; patients were randomized between July 2000 and January 2007 and underwent at least 2 years of follow-up. INTERVENTIONS: Patients received either fluorouracil plus folinic acid (folinic acid, 20 mg/m(2), intravenous bolus injection, followed by fluorouracil, 425 mg/m(2) intravenous bolus injection given 1-5 days every 28 days) (n = 551) or gemcitabine (1000 mg/m(2) intravenous infusion once a week for 3 of every 4 weeks) (n = 537) for 6 months. MAIN OUTCOME MEASURES: Primary outcome measure was overall survival; secondary measures were toxicity, progression-free survival, and quality of life. RESULTS: Final analysis was carried out on an intention-to-treat basis after a median of 34.2 (interquartile range, 27.1-43.4) months' follow-up after 753 deaths (69%). Median survival was 23.0 (95% confidence interval [CI], 21.1-25.0) months for patients treated with fluorouracil plus folinic acid and 23.6 (95% CI, 21.4-26.4) months for those treated with gemcitabine (chi(1)(2) = 0.7; P = .39; hazard ratio, 0.94 [95% CI, 0.81-1.08]). Seventy-seven patients (14%) receiving fluorouracil plus folinic acid had 97 treatment-related serious adverse events, compared with 40 patients (7.5%) receiving gemcitabine, who had 52 events (P < .001). There were no significant differences in either progression-free survival or global quality-of-life scores between the treatment groups. CONCLUSION: Compared with the use of fluorouracil plus folinic acid, gemcitabine did not result in improved overall survival in patients with completely resected pancreatic cancer. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00058201.

Ectopic pancreas formation in Hes1 -knockout mice reveals plasticity of endodermal progenitors of the gut, bile duct, and pancreas.

Ectopic pancreas is a developmental anomaly occasionally found in humans. Hes1, a main effector of Notch signaling, regulates the fate and differentiation of many cell types during development. To gain insights into the role of the Notch pathway in pancreatic fate determination, we combined the use of Hes1-knockout mice and lineage tracing employing the Cre/loxP system to specifically mark pancreatic precursor cells and their progeny in Ptf1a-cre and Rosa26 reporter mice. We show that inactivation of Hes1 induces misexpression of Ptf1a in discrete regions of the primitive stomach and duodenum and throughout the common bile duct. All ectopic Ptf1a-expressing cells were reprogrammed, or transcommitted, to multipotent pancreatic progenitor status and subsequently differentiated into mature pancreatic exocrine, endocrine, and duct cells. This process recapitulated normal pancreatogenesis in terms of morphological and genetic features. Furthermore, analysis of Hes1/Ptf1a double mutants revealed that ectopic Ptf1a-cre lineage-labeled cells adopted the fate of region-appropriate gut epithelium or endocrine cells similarly to Ptf1a-inactivated cells in the native pancreatic buds. Our data demonstrate that the Hes1-mediated Notch pathway is required for region-appropriate specification of pancreas in the developing foregut endoderm through regulation of Ptf1a expression, providing novel insight into the pathogenesis of ectopic pancreas development in a mouse model.

Clinical significance of plasma metastin level in pancreatic cancer patients.

Metastin, which is a 54-residue peptide coded by KiSS-1 gene, is an endogenous ligand to a G-protein-coupled receptor GPR54. Metastin suppresses a malignant tumor to metastasize and regulates secretion of gonadotropine releasing hormone. Physiological action of metastin has been focused on in oncology. It is reported that less KiSS-1 gene and more hOT7T175 gene which codes GPR54 are expressed in pancreatic cancers than in normal pancreatic tissues; however, there is no study that investigates the relationship between clinicopathological characteristics and plasma metastin concentration in pancreatic cancer patients. The purpose of this study was to investigate the relationship between plasma metastin-like immunoreactive substance (LI) levels and clinical characteristics in pancreatic cancer patients. Thirty-three patients with pathologically confirmed pancreatic cancer before or just after treatments and 24 healthy volunteers were included in the study. Patients were grouped according to the International Union Against Cancer TNM classification. Plasma metastin-LI was measured by enzyme immunoassay. The plasma metastin-LI levels of cancer patients were significantly higher when compared with healthy volunteers. Significant relationship was not found between the plasma metastin-LI levels and the clinicopathological factors such as tumor size, invasion, lymph node metastasis and distant metastasis. The plasma metastin levels may be a significant biomarker to predict the presence of pancreatic cancer and could be used in pancreatic cancer screening.

Single-institution validation of the international consensus guidelines for treatment of branch duct intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND: The international consensus guidelines (the guidelines) for management of intraductal papillary mucinous neoplasms (IPMNs) of the pancreas recommend surgical resection of branch duct IPMNs with any of the following features: cyst size >30 mm, mural nodules, main pancreatic duct diameter >6 mm, positive cytology, and symptoms. The aim of this study was to evaluate the usefulness of these guidelines for resection of branch duct IPMNs. METHODS: We reviewed 84 consecutive patients with branch duct IPMNs who underwent surgical resection at our hospital between January 1984 and December 2007. RESULTS: Sixty-nine patients had indications for resection according to the guidelines. Malignant IPMNs had significantly larger cysts than benign tumors (P = 0.026). Patients with malignant IPMNs had significantly more indications for resection than those with benign IPMNs (2.6 +/- 1.0 vs. 1.7 +/- 0.9, P < 0.001), and 36 of the 37 patients with malignant IPMNs had indications. The sensitivity of the guidelines for predicting malignancy was 97.3%. One of 15 patients without indications had malignancy, and the specificity was low (29.8%). CONCLUSIONS: The guidelines show a high sensitivity for predicting malignancy of branch duct IPMNs, but the specificity is low. The cyst size and the total number of indications in each patient should be taken into account when predicting the risk of malignancy for branch duct IPMNs.

Hepatocellular carcinoma with duodenal invasion resected subsequent to multimodal therapies: A case report.

INTRODUCTION: Gastrointestinal (GI) involvement in hepatocellular carcinoma (HCC) is uncommon. In particular, HCC with duodenal invasion is known to be a rare condition. In such cases, surgical indication has been generally negative except in few reported cases. To our knowledge, this report describes the first case of HCC with duodenal invasion, resected by hepatectomy accompanied by pancreas-preserving partial duodenectomy (HPPD) following multimodal therapies including systemic sorafenib administration. CASE PRESENTATION: A 65-year-old man had been repeatedly treated for multiple HCCs by transarterial chemoembolization (TACE) and sorafenib. However, the main tumor formerly ruptured began to involve his duodenum, causing GI bleeding. The collateral vessels from the pancreatic and omental branches entered the tumor and nullified the transarterial hemostatic embolization. Hence, HPPD was performed to preserve the major Vater papilla. Histopathological examination revealed poorly-to -moderately differentiated HCC cells invading the duodenum. DISCUSSION AND CONCLUSION: HPPD treatment successfully removed HCC with duodenal invasion achieving viable tumor clearance status (R0). We underline the importance of achieving viable tumor clearance status at any time during the treatment course of patients with advanced HCC as this approach may be the only approach to enable HCC patients with duodenal invasion to resume a healthy life.

Adenovirus vectors with chimeric type 5 and 35 fiber proteins exhibit enhanced transfection of human pancreatic cancer cells.

Adenovirus (Ad) vectors are widely used for gene transfer. Efficient gene transfer into malignant cells is an important requirement for anticancer gene therapy, but transgene expression after transfer with adenoviral vectors varies among different cancer cell lines. Recently, Ad vectors containing chimeric type 5 and 35 fiber proteins have been developed. We evaluated the expression of coxsackie and adenovirus receptor (CAR), as well as integrins alphaV, beta3 and beta5, in seven human pancreatic cancer cell lines and assessed the relationship between expression of these molecules and Ad transfection efficiency. We compared the transfection efficiency of a conventional type 5 Ad vector (Ad5GFP) with that of an Ad vector containing chimeric type 5 and 35 fiber proteins (Ad5/35GFP), which expressed green fluorescent protein (GFP) driven by the cytomegalovirus promoter. There was strong CAR expression by AsPC-1, CFPAC-1 and PANC-1 cells, whereas the other cell lines showed weak expression. There was strong integrin beta3 expression by MIAPaCa-2, PANC-1 and Suit-2 cells, but expression by AsPC-1, BxPC-3, CFPAC-1 and HPAC cells was weak. Transfection efficiency of the vectors for human pancreatic cancer cell lines was not directly related to the CAR or integrin expression. However, transfection by Ad5/35GFP was significantly greater than by Ad5GFP at MOIs of 10 and 25 in all five human pancreatic cell lines. In conclusion, the Ad5/35GFP vector mediates more efficient gene transfer to human pancreatic cancer cells. These results may have implications for improving the efficiency of Ad-mediated gene transfer and developing adenoviral vectors.