Ming Shen

Synergistic antitumor activity of withaferin A combined with oxaliplatin triggers reactive oxygen species-mediated inactivation of the PI3K/AKT pathway in human pancreatic cancer cells

Application of oxaliplatin for the treatment of pancreatic cancer (PC) is restricted owing to its toxic side effects and drug resistance. We investigated how withaferin A (WA), a bioactive component isolated from the medicinal plant Withania somnifera, acts synergistically with oxaliplatin on human PC in vitro and in vivo. We found that WA enhanced oxaliplatin-induced growth suppression and apoptosis in PC cells dramatically through a mechanism involving mitochondrial dysfunction and inactivation of the PI3K/AKT pathway. Combination treatment resulted in significant accumulation of intracellular reactive oxygen species (ROS). Pretreatment of cells with the ROS scavenger N-acetylcysteine completely blocked the apoptosis induced by combination treatment, and recovered expression of AKT inactivation, which revealed the important role of ROS in apoptosis and AKT regulation. In vivo, combination therapy showed the strongest anti-tumor effects compared with single agents, without obvious additional toxicity. These results support the notion that combination treatment with oxaliplatin and WA could facilitate development of an effective strategy for PC treatment.

CD133 + gallbladder carcinoma cells exhibit self-renewal ability and tumorigenicity

AIM To identify cancer stem cells (CSCs) in human gallbladder carcinomas (GBCs). METHODS Primary GBC cells were cultured under serum-free conditions to produce floating spheres. The stem-cell properties of the sphere-forming cells, including self-renewal, differentiation potential, chemoresistance and tumorigenicity, were determined in vitro or in vivo. Cell surface expression of CD133 was investigated in primary tumors and in spheroid cells using flow cytometry. The sphere-colony-formation ability and tumorigenicity of CD133(+) cells were assayed. RESULTS In vitro culture experiments revealed that floating spheroids were generated from primary GBC cells, and these sphere-forming cells could generate new progeny spheroids in serum-free media. Spheroid cells were differentiated under serum-containing conditions with downregulation of the stem cell markers Oct-4, Nanog, and nestin (P < 0.05). The differentiated cells showed lower spheroid-colony-formation ability than the original spheroid cells (P < 0.05). Spheroid cells were more resistant to chemotherapeutic reagents than the congenetic adherent cells (P < 0.05). Flow cytometry showed enriched CD133(+) population in sphere-forming cells (P < 0.05). CD133(+) cells possessed high colony-formation ability than the CD133(-) population (P < 0.01). CD133(+) cells injected into nude mice revealed higher tumorigenicity than their antigen-negative counterparts (P < 0.05). CONCLUSION CD133 may be a cell surface marker for CSCs in GBC.

Simultaneous inhibition of the ubiquitin-proteasome system and autophagy enhances apoptosis induced by ER stress aggravators in human pancreatic cancer cells

ABSTRACT In contrast to normal tissue, cancer cells display profound alterations in protein synthesis and degradation. Therefore, proteins that regulate endoplasmic reticulum (ER) homeostasis are being increasingly recognized as potential therapeutic targets. The ubiquitin-proteasome system and autophagy are crucially important for proteostasis in cells. However, interactions between autophagy, the proteasome, and ER stress pathways in cancer remain largely undefined. This study demonstrated that withaferin-A (WA), the biologically active withanolide extracted from Withania somnifera, significantly increased autophagosomes, but blocked the degradation of autophagic cargo by inhibiting SNARE-mediated fusion of autophagosomes and lysosomes in human pancreatic cancer (PC) cells. WA specifically induced proteasome inhibition and promoted the accumulation of ubiquitinated proteins, which resulted in ER stress-mediated apoptosis. Meanwhile, the impaired autophagy at early stage induced by WA was likely activated in response to ER stress. Importantly, combining WA with a series of ER stress aggravators enhanced apoptosis synergistically. WA was well tolerated in mice, and displayed synergism with ER stress aggravators to inhibit tumor growth in PC xenografts. Taken together, these findings indicate that simultaneous suppression of 2 key intracellular protein degradation systems rendered PC cells vulnerable to ER stress, which may represent an avenue for new therapeutic combinations for this disease.

LncRNA AFAP1-AS1 promotes growth and metastasis of cholangiocarcinoma cells

We investigated the role of actin filament associated protein 1 antisense RNA1 (AFAP1-AS1) lncRNA in promoting cholangiocarcinoma (CCA). qRT-PCR analysis of patient samples showed that AFAP1-AS1 expression was higher in CCA tumors than matched adjacent non-tumor tissue. AFAP1-AS1 levels were also higher in CCA cell lines (HuCCT1 and TFK-1) than a normal biliary epithelium cell line (HIBEpic). AFAP1-AS1 knockdown in CCA cell lines using shAFAP1-AS1 reduced cell proliferation and colony formation in CCK-8 and colony formation assays, respectively. Cell cycle analysis demonstrated that AFAP1-AS1 knockdown resulted in G0/G1 cell cycle arrest and inhibition of S-G2/M transition compared to the controls. CCA cells transfected with shAFAP1-AS1 also exhibited reduced metastasis and invasiveness in Transwell and wound healing assays. This was further confirmed in xenograft experiments with nude mice using CCA cells transfected with shAFAP1-AS1 or control shRNA. AFAP1-AS1 knockdown cells produced smaller tumors, demonstrating that AFAP1-AS1 promotes tumor growth in vivo. AFAP1-AS1 knockdown also increased expression of actin filament associated protein 1 (AFAP1) and reduced cell stress filament integrity, as determined from western blot and immunofluorescence assays, respectively. These findings indicate that AFAP1-AS1 exerts oncogenic effects in CCA. We postulate that AFAP1-AS1 is a potentially useful diagnostic and prognostic biomarker and therapeutic target for CCA.We investigated the role of actin filament associated protein 1 antisense RNA1 (AFAP1-AS1) lncRNA in promoting cholangiocarcinoma (CCA). qRT-PCR analysis of patient samples showed that AFAP1-AS1 expression was higher in CCA tumors than matched adjacent non-tumor tissue. AFAP1-AS1 levels were also higher in CCA cell lines (HuCCT1 and TFK-1) than a normal biliary epithelium cell line (HIBEpic). AFAP1-AS1 knockdown in CCA cell lines using shAFAP1-AS1 reduced cell proliferation and colony formation in CCK-8 and colony formation assays, respectively. Cell cycle analysis demonstrated that AFAP1-AS1 knockdown resulted in G0/G1 cell cycle arrest and inhibition of S-G2/M transition compared to the controls. CCA cells transfected with shAFAP1-AS1 also exhibited reduced metastasis and invasiveness in Transwell and wound healing assays. This was further confirmed in xenograft experiments with nude mice using CCA cells transfected with shAFAP1-AS1 or control shRNA. AFAP1-AS1 knockdown cells produced smaller tumors, demonstrating that AFAP1-AS1 promotes tumor growth in vivo. AFAP1-AS1 knockdown also increased expression of actin filament associated protein 1 (AFAP1) and reduced cell stress filament integrity, as determined from western blot and immunofluorescence assays, respectively. These findings indicate that AFAP1-AS1 exerts oncogenic effects in CCA. We postulate that AFAP1-AS1 is a potentially useful diagnostic and prognostic biomarker and therapeutic target for CCA.

Par3 regulates invasion of pancreatic cancer cells via interaction with Tiam1

The conserved polarity complex, which comprises partitioning-defective proteins Par3, Par6, and the atypical protein kinase C, affects various cell-polarization events, including assembly of tight junctions. Control of tight junction assembly is closely related to invasion and migration potential. However, as the importance of conserved polarity complexes in regulating pancreatic cancer invasion and metastasis is unclear, we investigated their role and mechanism in pancreatic cancers. We first detect that the key protein of the conserved polarity complex finds that only Par3 is down-regulated in pancreatic cancer tissues while Par6 and aPKC show no difference. What is more, Par3 tissues level was significantly and positively associated with patient overall survival. Knocking-down Par3 promotes pancreatic cancer cells invasion and migration. And Par3 requires interaction with Tiam1 to affect tight junction assembly, and then affect invasion and migration of pancreatic cancer cells. Then, we find that tight junction marker protein ZO-1 and claudin-1 are down-regulated in pancreatic cancer tissues. And the relationship of the expression of Par3 and ZO-1 in pancreatic cancer tissue is linear correlation. We establish liver metastasis model of human pancreatic cancer cells in Balb/c nude mice and find that knocking down Par3 promotes invasion and metastasis and disturbs tight junction assembly in vivo. Taken together, these results suggest that the Par3 regulates invasion and metastasis in pancreatic cancers by controlling tight junction assembly.

Blocking NF-κB is essential for the immunotherapeutic effect of recombinant IL-18 in pancreatic cancer

Purpose: We sought to find new immune-based treatments for pancreatic cancer. Experimental Design: We detected IL18 expression in plasma and specimens from patients with pancreatic cancer. We then investigated whether IL18 had a therapeutic effect for pancreatic cancer in vitro and in vivo and any underlying mechanisms. Results: Higher plasma IL18 was associated with longer overall survival (OS), but higher IL18 in pancreatic cancer tissues was associated with shorter OS and increased invasion and metastasis. Recombinant IL18 alone had no antitumor effect in the syngeneic mice with orthotopically transplanted tumors and promoted tumors in immunocompromised mice; it also facilitated immune responses in vitro and in vivo by augmenting the activity of cytotoxic T cells and NK cells in peripheral blood and lymph nodes. However, IL18 promoted the proliferation and invasion of pancreatic cancer cells, in vitro and in vivo, through the NF-κB pathway. Nevertheless, by coadministrating IL18 with BAY11-7082, an NF-κB inhibitor, we were able to prevent the procancerous effects of IL18 and prolong the survival time of the mice. Conclusions: IL18 has both cancer-promoting and cancer-suppressing functions. Although its single-agent treatment has no therapeutic effect on pancreatic cancer, when combined with the NF-κB pathway inhibitor, IL18 improved survival in a murine pancreatic cancer model. Our study implies the possibility of a combinational immunotherapy that uses IL18 and targets NF-κB pathway. Clin Cancer Res; 22(23); 5939–50. ©2016 AACR.

A new approach for Roux-en-Y reconstruction after pancreaticoduodenectomy

BACKGROUND Postoperative pancreatic fistula remains the most common complication of pancreaticoduodenectomy (PD) and is potentially lethal. It contributes significantly to prolonged hospitalization and mortality. In this study, we introduced a new technical approach, a modified Roux-en-Y reconstruction and evaluated its safety and feasibility. METHODS We retrospectively reviewed the patients who had undergone PD with the modified Roux-en-Y reconstructive technique for periampullary malignancies from January 2011 to June 2012. The data on complications, hospital stay and outcomes after the modified Roux-en-Y reconstruction were analyzed. RESULTS The reconstruction was performed in 171 patients, of whom 92 received pancreaticogastrostomy and 79 received pancreaticojejunostomy. The median duration of surgery was 4.0 hours (range 3.1-6.9) in all patients, and the median blood loss was 530 mL (range 200-2000). Sixty-nine patients were subjected to transfusions, with a median transfusion volume of 430 mL (range 200-1400). The median hospital stay of the patients was 14 days (range 11-38). Their operative mortality was zero and overall morbidity was 18.1% (31 patients). Only four patients (2.3%) developed pancreatic fistulas (grade A fistulas in two patients and grade B in two patients); no patients developed grade C fistula. None of the patients developed bile reflux gastritis. CONCLUSIONS The modified Roux-en-Y reconstruction, which isolates biliary anastomosis from pancreatic, gastric or jejunal anastomosis, is a safe, reliable, and favorable technique. But it needs further investigation in randomized controlled trials.

A Modified Technique of End-to-End Pancreaticojejunostomy With Transpancreatic Interlocking Mattress Sutures†

Postoperative pancreatic fistula (POPF) represents the most important cause of morbidity after pancreaticoduodenectomy (PD) and contributes to prolonged hospitalization and increased mortality rates. This study presents a new technique, which involves end‐to‐end pancreaticojejunostomy with transpancreatic interlocking mattress sutures, and evaluates its safety and reliability.

Total arterial devascularization first technique for resection of pancreatic head cancer during pancreaticoduodenectomy.

Integrated resection of the pancreatic head is the most difficult step in radical pancreaticoduodenectomy (RPD) in patients with the portal vein (PV) and superior mesenteric vein (SMV) invasion or oppression by the tumor. This study introduced a new idea and skill named the “total arterial devascularization first” (TADF) technique and its applications in RPD. Three arterial blood supplies of pancreatic head were obstructed before dissection of veins. The critical steps included exposure of the anterior surface of the abdominal aorta (AA) by completely transecting neural and connective tissue between superior mesenteric artery (SMA) and pancreatic mesounsinate, and transection of the mesounsinate from the origin of SMA to the root of the celiac trunk. From January 2012 through May 2013, a total of 58 patients with PV/SMV invasion or oppression underwent RPD using this technique. The median operative time was 5.1 h (ranging 4.5–8.1 h). The median intraoperative blood loss was 450 mL (ranging 200–900 mL). No intraoperative and postoperative bleeding of pancreatic head region occurred. Among the 58 patients, 21 were subjected to vessel lateral wall angiectomy or angiorrhaphy, and 10 to angiectomy and end-to-end anastomosis. The incidence of postoperative bleeding, postoperative pancreatic fistula and biliary fistula was 5.2%, 6.8%, and 1.7%, respectively. No patients died 3 months after operation. The TADF technique is a new method for intricate RPD and could improve the security of surgery and reduce intraoperative bleeding, which is expected to become standardized surgical approach for RPD.SummaryIntegrated resection of the pancreatic head is the most difficult step in radical pancreaticoduodenectomy (RPD) in patients with the portal vein (PV) and superior mesenteric vein (SMV) invasion or oppression by the tumor. This study introduced a new idea and skill named the “total arterial devascularization first” (TADF) technique and its applications in RPD. Three arterial blood supplies of pancreatic head were obstructed before dissection of veins. The critical steps included exposure of the anterior surface of the abdominal aorta (AA) by completely transecting neural and connective tissue between superior mesenteric artery (SMA) and pancreatic mesounsinate, and transection of the mesounsinate from the origin of SMA to the root of the celiac trunk. From January 2012 through May 2013, a total of 58 patients with PV/SMV invasion or oppression underwent RPD using this technique. The median operative time was 5.1 h (ranging 4.5–8.1 h). The median intraoperative blood loss was 450 mL (ranging 200–900 mL). No intraoperative and postoperative bleeding of pancreatic head region occurred. Among the 58 patients, 21 were subjected to vessel lateral wall angiectomy or angiorrhaphy, and 10 to angiectomy and end-to-end anastomosis. The incidence of postoperative bleeding, postoperative pancreatic fistula and biliary fistula was 5.2%, 6.8%, and 1.7%, respectively. No patients died 3 months after operation. The TADF technique is a new method for intricate RPD and could improve the security of surgery and reduce intraoperative bleeding, which is expected to become standardized surgical approach for RPD.

Regulatory B cells induced by pancreatic cancer cell-derived interleukin-18 promote immune tolerance via the PD-1/PD-L1 pathway

Dysregulation of regulatory B cells (Bregs), a type of immunosuppressive lymphocyte, are associated with development of autoimmune diseases and cancers. Bregs produce immune tolerance-inducing cell surface molecules and tolerogenic cytokines (interleukin [IL]-10 and transforming growth factor-beta). We previously showed that levels of the inflammatory cytokine IL-18 were increased in patients with pancreatic cancer. In the present study study, we found that pancreatic cancer cell-derived IL-18 increases Breg-induced immunosuppression. IL-18 also promoted B-cell proliferation and IL-10 expression in vivo and in vitro. In addition, IL-18 upregulated membrane PD-1 in B cells and inhibited the antibody-dependent cellular cytotoxicity of Tc cells and natural killer cells. Finally, the combination of a natural IL-18 inhibitor (IL-18BP) and a PD-1/PD-L1 inhibitor suppressed tumor growth and metastasis in a murine pancreatic cancer model. Our results show that IL-18 and PD-1/PD-L1 could be therapeutic targets in pancreatic cancer.