Development of miniature base editors using engineered IscB nickase.

As a miniature RNA-guided endonuclease, IscB is presumed to be the ancestor of Cas9 and to share similar functions. IscB is less than half the size of Cas9 and thus more suitable for in vivo delivery. However, the poor editing efficiency of IscB in eukaryotic cells limits its in vivo applications. Here we describe the engineering of OgeuIscB and its corresponding ωRNA to develop an IscB system that is highly efficient in mammalian systems, named enIscB. By fusing enIscB with T5 exonuclease (T5E), we found enIscB-T5E exhibited comparable targeting efficiency to SpG Cas9 while showing reduced chromosome translocation effects in human cells. Furthermore, by fusing cytosine or adenosine deaminase with enIscB nickase, we generated miniature IscB-derived base editors (miBEs), exhibiting robust editing efficiency (up to 92%) to induce DNA base conversions. Overall, our work establishes enIscB-T5E and miBEs as versatile tools for genome editing.

Targeting leucine-rich repeat serine/threonine-protein kinase 2 sensitizes pancreatic ductal adenocarcinoma to anti-PD-L1 immunotherapy.

Pancreatic ductal adenocarcinoma (PDAC) is not sensitive to immune checkpoint blockade therapy, and negative feedback of tumor immune evasion might be partly responsible. We isolated CD8+ T cells and cultured them in vitro. Proteomics analysis was performed to compare changes in Panc02 cell lines cultured with conditioned medium, and leucine-rich repeat kinase 2 (LRRK2) was identified as a differential gene. LRRK2 expression was related to CD8+ T cell spatial distribution in PDAC clinical samples and upregulated by CD8+ T cells via interferon gamma (IFN-γ) simulation in vitro. Knockdown or pharmacological inhibition of LRRK2 activated an anti-pancreatic cancer immune response in mice, which meant that LRRK2 acted as an immunosuppressive gene. Mechanistically, LRRK2 phosphorylated PD-L1 at T210 to inhibit its ubiquitination-mediated proteasomal degradation. LRRK2 inhibition attenuated PD-1/PD-L1 blockade-mediated, T cell-induced upregulation of LRRK2/PD-L1, thus sensitizing the mice to anti-PD-L1 therapy. In addition, adenosylcobalamin, the activated form of vitamin B12, which was found to be a broad-spectrum inhibitor of LRRK2, could inhibit LRRK2 in vivo and sensitize PDAC to immunotherapy as well, which potentially endows LRRK2 inhibition with clinical translational value. Therefore, PD-L1 blockade combined with LRRK2 inhibition could be a novel therapy strategy for PDAC.

Large primary hepatocellular carcinoma: transarterial chemoembolization monotherapy versus combined transarterial chemoembolization-percutaneous microwave coagulation therapy.

BACKGROUND AND AIM: To evaluate the clinical benefits of transarterial chemoembolization (TACE) monotherapy or TACE combined with percutaneous microwave coagulation therapy (PMCT) and the long-term survival rate of patients with large primary hepatocellular carcinoma (HCC) treated with these techniques. METHODS: This is a retrospective study involving 136 patients with unresectable large HCC (189 tumor nodules, ≥ 5.0 cm in diameter) admitted to Sun Yat-Sen University Memorial Hospital (Guangzhou, China) between January 2004 and December 2011. The median follow-up time was 41 months (range, 6-96 months). Of these patients, 80 patients received TACE monotherapy and 56 patients received TACE combined with PMCT. The median interval between treatments and overall survival (OS) were hierarchically analyzed using log-rank tests. RESULTS: All patients successfully underwent TACE alone or TACE with PMCT with no serious complications. The median survival time was 13 months (range, 3-84 months) for the TACE group and 25 months (range, 7-96 months) for the TACE-PMCT group. The 1-year, 3-year, and 5-year OS rates were 62.5%, 17.5%, and 5.0% in the TACE group, respectively. In contrast, in the TACE-PMCT group, the 1-year, 3-year, and 5-year OS rates were 87.5%, 50.0%, and 10.0%, respectively. This difference was statistically significant between the groups (P < 0.001). CONCLUSIONS: TACE combined with PMCT had advantages in prolonging OS with satisfying time to progression and improving liver function in patients with large unresectable HCC. The results suggest that further prospective studies are required to confirm the findings of this study.

Programmable deaminase-free base editors for G-to-Y conversion by engineered glycosylase.

Current DNA base editors contain nuclease and DNA deaminase that enables deamination of cytosine (C) or adenine (A), but no method for guanine (G) or thymine (T) editing is available at present. Here we developed a deaminase-free glycosylase-based guanine base editor (gGBE) with G editing ability, by fusing Cas9 nickase with engineered N-methylpurine DNA glycosylase protein (MPG). By several rounds of MPG mutagenesis via unbiased and rational screening using an intron-split EGFP reporter, we demonstrated that gGBE with engineered MPG could increase G editing efficiency by more than 1500 fold. Furthermore, this gGBE exhibited high base editing efficiency (up to 81.2%) and high G-to-T or G-to-C (i.e. G-to-Y) conversion ratio (up to 0.95) in both cultured human cells and mouse embryos. Thus, we have provided a proof-of-concept of a new base editing approach by endowing the engineered DNA glycosylase the capability to selectively excise a new type of substrate.

Engineered CRISPR-OsCas12f1 and RhCas12f1 with robust activities and expanded target range for genome editing.

The type V-F CRISPR-Cas12f system is a strong candidate for therapeutic applications due to the compact size of the Cas12f proteins. In this work, we identify six uncharacterized Cas12f1 proteins with nuclease activity in mammalian cells from assembled bacterial genomes. Among them, OsCas12f1 (433 aa) from Oscillibacter sp. and RhCas12f1 (415 aa) from Ruminiclostridium herbifermentans, which respectively target 5' T-rich Protospacer Adjacent Motifs (PAMs) and 5' C-rich PAMs, show the highest editing activity. Through protein and sgRNA engineering, we generate enhanced OsCas12f1 (enOsCas12f1) and enRhCas12f1 variants, with 5'-TTN and 5'-CCD (D = not C) PAMs respectively, exhibiting much higher editing efficiency and broader PAMs, compared with the engineered variant Un1Cas12f1 (Un1Cas12f1_ge4.1). Furthermore, by fusing the destabilized domain with enOsCas12f1, we generate inducible-enOsCas12f1 and demonstate its activity in vivo by single adeno-associated virus delivery. Finally, dead enOsCas12f1-based epigenetic editing and gene activation can also be achieved in mammalian cells. This study thus provides compact gene editing tools for basic research with remarkable promise for therapeutic applications.

FIVES: A Fundus Image Dataset for Artificial Intelligence based Vessel Segmentation.

Retinal vasculature provides an opportunity for direct observation of vessel morphology, which is linked to multiple clinical conditions. However, objective and quantitative interpretation of the retinal vasculature relies on precise vessel segmentation, which is time consuming and labor intensive. Artificial intelligence (AI) has demonstrated great promise in retinal vessel segmentation. The development and evaluation of AI-based models require large numbers of annotated retinal images. However, the public datasets that are usable for this task are scarce. In this paper, we collected a color fundus image vessel segmentation (FIVES) dataset. The FIVES dataset consists of 800 high-resolution multi-disease color fundus photographs with pixelwise manual annotation. The annotation process was standardized through crowdsourcing among medical experts. The quality of each image was also evaluated. To the best of our knowledge, this is the largest retinal vessel segmentation dataset for which we believe this work will be beneficial to the further development of retinal vessel segmentation.

Ratio of Conjugated Chenodeoxycholic to Muricholic Acids is Associated with Severity of Nonalcoholic Steatohepatitis.

OBJECTIVE: Bile acids (BAs) are important molecules in the progression of nonalcoholic fatty liver disease. This study aimed to investigate BA profile alterations in Chinese nonalcoholic steatohepatitis (NASH) patients. METHODS: BA profiles in serum and liver tissues were determined by ultraperformance liquid chromatography coupled to tandem mass spectrometry in patients from two different clinical centers. RESULTS: A total of 134 participants were enrolled in this study to serve as the training (n = 87) and validation (n = 47) cohorts. The ratio of circulating conjugated chenodeoxycholic acids to muricholic acids (P = 0.001) was elevated from healthy controls to non-NASH individuals to NASH individuals in a stepwise manner in the training cohort and was positively associated with the histological severity of NASH: steatosis (R2 = 0.12), lobular inflammation (R2 = 0.12), ballooning (R2 = 0.11), and fibrosis stage (R2 = 0.18). The ratio was elevated in the validation cohort of NASH patients (P < 0.001), and it was able to predict NASH (area under the receiver operating characteristic curve: 75%) and significant fibrosis (area under the receiver operating characteristic curve: 71%) in these two cohorts. Moreover, this elevated ratio and impaired farnesoid X receptor signaling were found in the NASH liver. CONCLUSIONS: Altered BA profile in NASH is closely associated with the severity of liver lesions, and it has the potential for predicting NASH development.

[Comparison of MR cholangiopancreatography and surgical diagnosis of extrahepatic bile duct carcinoma].

OBJECTIVE: This work was done to compare the validity of various imaging methods, e.g. ultrasonography (US), computed tomography (CT), endoscopic retrograde cholangiopancreatography (ERCP), percutaneous transhepatic cholangiography (PTC), and, especially, magnetic resonance cholangiopancreatography (MRCP) for extrahepatic bile duct carcinoma. METHODS: Sixty-five such patients who were operated and confirmed by pathology were used. Sixty patients had been examined by US; 52 by CT; 20 by ERCP; 9 by PTC and 20 by MRCP. The results of these imaging methods were compared with those of operative and pathological findings. RESULTS: The diagnostic accuracy rates of site location were US 81.7%, CT 84.6%, ERCP 75.0%, PTC 88.9% and MRCP 100%, respectively. The quality diagnostic accuracy rates were US 73.3%, CT 82.7%, ERCP 75.0%, PTC 88.9% and MRCP 95.0%, respectively. CONCLUSION: MRCP is superior to US, CT, ERCP and PTC not only in demonstrating the position but also the nature of extrahepatic bile duct carcinoma.

[MR cholangiopancreatography and MR imaging in the diagnosis of extrahepatic cholangiocarcinoma].

OBJECTIVE: To evaluate the imaging features of MR Imaging (MRI) and MR cholangiopancreatography (MRCP) and their clinical value in the diagnosis of extrahepatic cholangiocarcinoma. METHODS: MRI was performed in 54 patients with extrahepatic cholangiocarcinoma proved surgically and pathologically, MRCP in 44 patients, Gadolinium-enhanced in 29 patients. MRI, MRCP and pathological findings were analyzed retrospectively. RESULTS: By MRI, the mass was shown (n = 39) and all bile duct thickened (n = 13) in extrahepatic cholangiocarcinoma. Gadolinium-enhanced ones revealed calcified focus (n = 22). By MRCP, interrupted, abruptly cut-off or cone-like changes of the bile duct (n = 16), beak-like or mouse tail changes (n = 26) or tumbler mouth appearance (n = 2) were shown. The bile duct distal to the obstruction was observed in 29 patients. Of the 54 patients examined by MRI in combination with MRCP, correct tumor localization was made in 52 (96.3%) and correct judgement of tumor nature in 50 (92.6%). CONCLUSION: Conventional MRI is an effective supplement to MRCP in the diagnosis of extrahepatic cholangiocarcinoma. MRCP combined with MRI is able to significantly improve the diagnostic accuracy of MR examination.

Interventional digital subtraction angiography for small bowel gastrointestinal stromal tumors with bleeding.

AIM: To retrospectively evaluate the diagnostic efficacy of interventional digital subtraction angiography (DSA) for bleeding small bowel gastrointestinal stromal tumors (GISTs). METHODS: Between January 2006 and December 2013, small bowel tumors in 25 consecutive patients undergoing emergency interventional DSA were histopathologically confirmed as GIST after surgical resection. The medical records of these patients and the effects of interventional DSA and the presentation and management of the condition were retrospectively reviewed. RESULTS: Of the 25 patients with an age range from 34- to 70-year-old (mean: 54 ± 12 years), 8 were male and 17 were female. Obscure gastrointestinal bleeding, including tarry or bloody stool and intermittent melena, was observed in all cases, and one case also involved hematemesis. Nineteen patients required acute blood transfusion. There were a total of 28 small bowel tumors detected by DSA. Among these, 20 were located in the jejunum and 8 were located in the ileum. The DSA characteristics of the GISTs included a hypervascular mass of well-defined, homogeneous enhancement and early developed draining veins. One case involved a complication of intussusception of the small intestine that was discovered during surgery. No pseudoaneurysms, arteriovenous malformations or fistulae, or arterial rupture were observed. The completely excised size was approximately 1.20 to 5.50 cm (mean: 3.05 ± 1.25 cm) in maximum diameter based on measurements after the resection. There were ulcerations (n = 8), erosions (n = 10), hyperemia and edema (n = 10) on the intra-luminal side of the tumors. Eight tumors in patients with a large amount of blood loss were treated with transcatheter arterial embolization with gelfoam particles during interventional DSA. CONCLUSION: Emergency interventional DSA is a useful imaging option for locating and diagnosing small bowel GISTs in patients with bleeding, and is an effective treatment modality.

Percutaneous ablation therapy versus surgical resection in the treatment for early-stage hepatocellular carcinoma: a meta-analysis of 21,494 patients.

PURPOSE: To compare comprehensively the benefits of radiofrequency ablation (RFA) and percutaneous ethanol injection (PEI) with those of surgical resection (SR) in early-stage hepatocellular carcinoma (HCC). METHODS: The potentially relevant studies comparing the efficacy and safety of RFA and/or PEI with those of SR were searched using the databases such as PubMed, MEDLINE, Embase and Chinese databases (CNKI and Wanfang data). Overall survival rate, recurrence-free survival rate and complications were compared and analyzed. Pooled odds ratios with 95 % confidence intervals (95 % CIs) were calculated using either the fixed-effects model or random-effects model. All statistic analyses were conducted using the Review Manager (version 5.1.) from the Cochrane Collaboration. RESULTS: Our analysis showed that the overall survival rate in patients treated with SR was significantly higher than that of percutaneous ablation therapy (PAT) [SR vs. PAT: 95 % confidence interval (95 % CI)2-year 0.46-0.89, P = 0.009; 95 % CI3-year 0.57-0.83, P < 0.0001; 95 % CI5-year 0.45-0.46, P < 0.0001]. SR was associated with significantly higher recurrence-free survival rate compared with PAT (SR vs. PAT: 95 % CI1-year 0.51-0.90, P = 0.008; 95 % CI2-year 0.41-0.78, P = 0.0004; 95 % CI3-year 0.38-0.77, P = 0.0006; 95 % CI5-year 0.33-0.61, P < 0.0001). SR resulted in longer survival than PAT in HCCs no larger than 3 cm. PAT was associated with less complications compared with SR (PAT vs. SR: 95 % CI 0.14-0.76, P = 0.01). CONCLUSIONS: Although SR was associated with more complications, SR was superior to RFA and PEI for treatment of patients with early-stage HCC.

Effect of PEG-PDLLA polymeric nanovesicles loaded with doxorubicin and hematoporphyrin monomethyl ether on human hepatocellular carcinoma HepG2 cells in vitro.

OBJECTIVE: To evaluate the cytotoxicity of poly(ethylene glycol)-block-poly(D,L-lactic acid) (PEG-PDLLA) nanovesicles loaded with doxorubicin (DOX) and the photosensitizer hematoporphyrin monomethyl ether (HMME) on human hepatocellular carcinoma HepG2 cells and to investigate potential apoptotic mechanisms. METHODS: PEG-PDLLA nanovesicles were simultaneously loaded with DOX and HMME (PEG-PDLLA-DOX-HMME), and PEG-PDLLA nanovesicles were loaded with DOX (PEG-PDLLA-DOX), HMME (PEG-PDLLA-HMME), or the PEG-PDLLA nanovesicle alone as controls. The cytotoxicity of PEG-PDLLA-DOX-HMME, PEG-PDLLA-DOX, PEG-PDLLA-HMME, and PEG-PDLLA against HepG2 cells was measured, and the cellular reactive oxygen species, percentage of cells with mitochondrial membrane potential depolarization, and apoptotic rate following treatment were determined. RESULTS: Four nanovesicles (PEG-PDLLA-DOX-HMME, PEG-PDLLA-DOX, PEG-PDLLA-HMME, and PEG-PDLLA) were synthesized, and mean particle sizes were 175±18 nm, 154±3 nm, 196±2 nm, and 147±15 nm, respectively. PEG-PDLLA-DOX-HMME was more cytotoxic than PEG-PDLLA-DOX, PEG-PDLLA-HMME, and PEG-PDLLA. PEG-PDLLA-HMME-treated cells had the highest mean fluorescence intensity, followed by PEG-PDLLA-DOX-HMME-treated cells, whereas PEG-PDLLA-DOX- and PEG-PDLLA-treated cells had a similar fluorescence intensity. Mitochondrial membrane potential depolarization was observed in 54.2%, 59.4%, 13.8%, and 14.8% of the cells treated with PEG-PDLLA-DOX-HMME, PEG-PDLLA-HMME, PEG-PDLLA-DOX, and PEG-PDLLA, respectively. The apoptotic rate was significantly higher in PEG-PDLLA-DOX-HMME-treated cells compared with PEG-PDLLA-DOX- and PEG-PDLLA-HMME-treated cells. CONCLUSION: The PEG-PDLLA nanovesicle, a drug delivery carrier, can be simultaneously loaded with two anticancer drugs (hydrophilic DOX and hydrophobic HMME). PEG-PDLLA-DOX-HMME cytotoxicity to HepG2 cells is significantly higher than the PEG-PDLLA nanovesicle loaded with DOX or HMME alone, and DOX and HMME have a synergistic effect against human hepatocellular carcinoma HepG2 cells.

Folate-targeted polymeric micelles loaded with ultrasmall superparamagnetic iron oxide: combined small size and high MRI sensitivity.

Targeted delivery of contrast agents is a highly desirable strategy for enhancing diagnostic efficiency and reducing side effects and toxicity. Water-soluble and tumor-targeting superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized by loading hydrophobic SPIONs into micelles assembled from an amphiphilic block copolymer poly(ethylene glycol)- poly(ε-caprolactone) (PEG-PCL) bearing folate in the distal ends of PEG chains. Compared to the water-soluble SPIONs obtained by small molecular surfactant coating, ultrasmall SPION encapsulation with PEG-PCL micelles (PEG-PCL-SPIONs) simultaneously increases transverse (r(2)) and decreases longitudinal (r(1)) magnetic resonance (MR) relaxivities of water proton in micelle solution, leading to a notably high r(2)/r(1) ratio up to 78, which makes the PEG-PCL-SPIONs a highly sensitive MR imaging (MRI) T(2) contrast agent. The mean size of folate-attached SPION micelles (Fa-PEG-PCL-SPIONs) is 44 ± 3 nm on average, ideal for in vivo MRI applications in which long circulation is greatly determined by small particle size and is highly desirable. Prussian blue staining of BEL-7402 cells over-expressing folate receptors, after incubation with micelle-containing medium, demonstrated that folate functionalization of the magnetic particles significantly enhanced their cell uptake. The potential of Fa-PEG-PCL-SPIONs as a potent MRI probe for in vivo tumor detection was assessed. At 3 hours after intravenous injection of the Fa-PEG-PCL-SPION solution into mice bearing subcutaneous xenografts of human BEL-7402 hepatoma, a 41.2% signal intensity decrease was detected in the T(2)-weighted MR images of the tumor, indicating the efficient accumulation of Fa-PEG-PCL-SPIONs in the tumor tissue.

Continuous transarterial infusion chemotherapy with gemcitabine and 5-Fluorouracil for advanced pancreatic carcinoma.

PURPOSE: Pancreatic carcinoma is one of the most malignant tumors of the alimentary system, with relatively high incidence rates. The purpose of this study was to assess the efficacy and safety of two regimens for advanced pancreatic carcinoma: continuous transarterial infusion versus systemic venous chemotherapy with gemcitabine and 5-fluorouracil. METHODS: Of the 48 patients with advanced pancreatic carcinoma receiving chemotherapy with gemcitabine and 5-fluorouracil, 24 received the selective transarterial infusion, and 24 the systemic chemotherapy. For the continuous transarterial infusion group (experimental group), all patients received gemcitabine 1000 mg/m2,given by 30-minute transarterial infusion, on day 1 of a 4-week cycle for 2 cycles, and a dose of 600 mg/ m2 5-fluorouracil was infused on days 1~5 of a 4-week cycle for 2 cycles. For the systemic venous group (control group), gemcitabine and 5-fluorouracil were infused through a peripheral vein, a dose of 1000 mg/m2 gemcitabine being administrated over 30 min on days 1 and 8 of a 4-week cycle for 2 cycles, and a dose of 600 mg/m2 5-fluorouracil was infused on days 1~5 of a 4-week cycle for 2 cycles. The effectiveness and safety were evaluated after 2 cycles according to WHO criteria. RESULTS: The objective effective rate in transarterial group was 33.3% versus 25% in the systemic group, the difference not being significant (P=0.626). Clinical benefit rates(CBR) in the transarterial and systemic groups were 83.3% and 58.3%, respectively (P=0.014). The means and medians for survival time in transarterial group were higher than those of the systemic group (P<0.005). at the same time, the adverse effects did not significantly differ between the two groups (P>0.05). CONCLUSION: Continuous transarterial infusion chemotherapy with gemcitabine and 5-fluorouracil could improve clinical benefit rate and survival time of patients with advanced pancreatic carcinoma, compared with systemic venous chemotherapy. Since adverse effects were limited in the transarterial group, the regimen of continuous transarterial infusion chemotherapy can be used more extensively in clinical practice. A CT and MRI conventional sequence can be used for efficacy evaluation after chemotherapy in pancreatic carcinoma.

Folate-functionalized polymeric micelles based on biodegradable PEG-PDLLA as a hepatic carcinoma-targeting delivery system.

Targeted delivery of anti-cancer drugs is a highly desirable strategy to improve therapeutic outcome because of the combination of enhanced efficacy and reduced toxicity. In this study, the anti-cancer drug doxorubicin (DOX) was accommodated in the cores of polymeric micelles self-assembled from amphiphilic block copolymers of poly(ethylene glycol)(PEGs) and poly(D,L-lactide) (PDLLA) with a targeting ligand (folate) attached to the distal ends of the PEG (Folate-PEG-PDLLA). In vitro tumor cell targeting efficacy was evaluated upon observing cellular uptake of these micelles by human hepatic carcinoma cells (Bel 7402 cells) overexpressing surface receptors for folate. In control release tests, DOX behavior of controlled release in folate receptor-mediated micellar folate-PEG-PDLLA-DOX-micelles was obvious, with pH sensitivity. Bel 7402 cells showed micelles to have low toxicity and suggested potential therapeustic application as a multifunctional platform for tumor management.

[Dynamic contrast-enhanced MR imaging and digital subtraction angiography manifestation of hepatic focal nodular hyperplasia].

BACKGROUND & OBJECTIVE: Focal nodular hyperplasia (FNH) is a rare benign hepatic tumor and its imaging diagnosis remains difficult. This study was to analyze dynamic contrast-enhanced MR imaging and digital subtraction angiography (DSA) manifestation of FNH, and to improve the diagnostic accuracy of FNH. METHODS: The MRI and DSA imaging data of 30 patients with FNH proved by pathology were reviewed. Conventional contrast-enhanced MRI was completed in 11 patients; dynamic contrast-enhanced MRI was completed in 15 patients. DSA was completed in 10 patients. RESULTS: On dynamic contrast-enhanced MRI scan, 18 lesions in 15 patients showed obvious enhancement at arterial phase and prolonged enhancement at delayed phase. Central scars were found in 11 lesions, and showed enhancement since portal vein phase till delayed phase. The time-signal intensity curves of the 18 lesions were ascended rapidly at arterial phase, and descended slowly at portal vein phase and delayed phase. On DSA examination, 13 lesions in the ten patients showed dilated feeding arteries, and radiate feeding arterial branches were seen in eight lesions. CONCLUSIONS: Dynamic contrast-enhanced MRI can fully show abnormal signal of the central scar of FNH. The time-signal intensity curve of FNH ascends rapidly and descends slowly. On DSA imaging, the feeding arteries of FNH spread radially. Dynamic contrast-enhanced MRI and DSA could improve the diagnostic accuracy of FNH.

[Efficacy of selective continuous transarterial infusion chemotherapy on advanced pancreatic cancer].

BACKGROUND & OBJECTIVE: Advanced pancreatic cancer is mainly treated by chemotherapy with poor prognosis. This study was designed to evaluate clinical efficacy and application of selective continuous transarterial infusion chemotherapy in treating patients with advanced pancreatic cancer. METHODS: Twenty patients with advanced pancreatic cancer were treated by selective continuous transarterial infusion chemotherapy. The interventional treatment was performed with Seldinger technique,12 patients received percutaneous femoral artery cannulization and catheter retention, 8 received percutaneous left subclavian artery port-catheter system implantation. Chemotheraputic drugs were continuously infused when the catheter was selectively placed in turner feeding artery. Nine patients were treated with pirarubicin (THP)/adriamycin (ADM) plus hydroxycamptothecin (HCPT),and 5-fluorouracil (5-FU)/calcium folinate (CF) regimen,and 11 were treated with gemcitabine (GEM) plus carboplatin (CBP),and 5-FU/CF regimen. Treatment regimens were repeated every 4-6 weeks with each cycle of 4 days. Tumor response rate,clinical benefit response (CBR),and survival time were observed. RESULTS: Objective response rate was 10% with 1 case of complete remission (CR), and 1 case of partial remission (PR), CBR was 70% (14/20), 6-,and 9-month survival rates were 58.8%,and 39.2%. Median survival time for all patients was 8.8 months. No complication related to cannulization was found. CONCLUSION: Selective continuous transarterial infusion chemotherapy is safe,and has good efficacy in treating patients with advanced pancreatic cancer, it may prolong survival time of patients.