Vitamin B6 Competition in the Tumor Microenvironment Hampers Antitumor Functions of NK Cells.

Nutritional factors play crucial roles in immune responses. The tumor-caused nutritional deficiencies are known to affect antitumor immunity. Here, we demonstrate that pancreatic ductal adenocarcinoma (PDAC) cells can suppress NK-cell cytotoxicity by restricting the accessibility of vitamin B6 (VB6). PDAC cells actively consume VB6 to support one-carbon metabolism, and thus tumor cell growth, causing VB6 deprivation in the tumor microenvironment. In comparison, NK cells require VB6 for intracellular glycogen breakdown, which serves as a critical energy source for NK-cell activation. VB6 supplementation in combination with one-carbon metabolism blockage effectively diminishes tumor burden in vivo. Our results expand the understanding of the critical role of micronutrients in regulating cancer progression and antitumor immunity, and open new avenues for developing novel therapeutic strategies against PDAC. SIGNIFICANCE: The nutrient competition among the different tumor microenvironment components drives tumor growth, immune tolerance, and therapeutic resistance. PDAC cells demand a high amount of VB6, thus competitively causing NK-cell dysfunction. Supplying VB6 with blocking VB6-dependent one-carbon metabolism amplifies the NK-cell antitumor immunity and inhibits tumor growth in PDAC models. This article is featured in Selected Articles from This Issue, p. 5.

MUC1 promotes glycolysis through inhibiting BRCA1 expression in pancreatic cancer.

Enhanced glucose metabolism is one of the hallmarks of pancreatic cancer. MUC1, a transmembrane protein, is a global regulator of glucose metabolism and essential for progression of pancreatic cancer. To clarify the role of MUC1 in glucose metabolism, we knocked out MUC1 in Capan-1 and CFPAC-1 cells. MUC1 knockout (KO) cells uptook less glucose and secreted less lactate with a much lower proliferating rate. The mRNA level of key enzymes in glycolysis also decreased significantly in MUC1 KO cells. We also observed increased expression of breast cancer type 1 susceptibility protein (BRCA1) in MUC1 KO cells. Since BRCA1 has a strong inhibitory effect on glycolysis, we want to know whether the decreased glucose metabolism in MUC1 KO cells is due to increased BRCA1 expression. We treated wild type (WT) and MUC1 KO cells with BRCA1 inhibitor. BRCA1 inhibition significantly enhanced glucose uptake and lactate secretion in both WT and MUC1 KO cells. Expression of key enzymes in glycolysis also elevated after BRCA1 inhibition. Elevated glucose metabolism is known to facilitate cancer cells to gain chemoresistance. We treated MUC1 KO cells with gemcitabine and FOLFIRINOX in vitro and in vivo. The results showed that MUC1 KO sensitized pancreatic cancer cells to chemotherapy both in vitro and in vivo. In conclusion, we demonstrated that MUC1 promotes glycolysis through inhibiting BRCA1 expression. MUC1 may be a therapeutic target in pancreatic cancer treatment.

The efficacy of combination of induction chemotherapy and irreversible electroporation ablation for patients with locally advanced pancreatic adenocarcinoma.

BACKGROUND AND OBJECTIVES: Irreversible electroporation (IRE) is a non-thermal focal therapy that utilizes high voltage electric pulses to permanently rupture the cellular membrane and induce cell death. In this multi-center study, we evaluated the safety and efficacy of IRE in patients with locally advanced pancreatic cancer (LAPC). METHODS: From 2012 to 2015, we performed laparotomic and laparoscopic IRE in a total of 70 patients with stage III LAPC. Either gemcitabine-based or TS-1 (Tegafur, Gimeracil, and Oteracil) chemotherapy was applied for at least 3 months before the IRE. RESULTS: No IRE-related deaths occurred. A median follow-up of 28.1 months showed that six patients (8.6%) experienced local recurrence and 24 (34%) experienced distant progression. The overall median survival from the time of treatment was 22.6 months, and the progression-free survival (PFS) was 15.4 months. The overall survival in the patients who used gemcitabine-based reagents was 19.1 months and that of those who used TS-1 was 28.7 months. The PFS for these two groups were 13.2 months and 26.4 months; the difference is significant. CONCLUSIONS: Our study suggests that IRE is safe and effective for the control of LAPC. We surmise that the addition of IRE to a chemotherapy regimen may provide a survival advantage.

Perioperative oral supplementation with fish oil promotes liver regeneration following partial hepatectomy in mice via AMPK activation.

The present study aimed to observe the effects of perioperative oral supplementation with fish oil (FO) on liver regeneration in mice and examine the potential mechanism. A total of 120 male ICR mice were randomly divided into 5 groups: Sham, Control, fish oil (FO), Compound C [the AMP­activated protein kinase (AMPK) inhibitor dorsomorphin], and Compound C + FO. Changes in liver function, alterations in hepatocyte proliferation and in the expression of polarization markers, and activation of AMPK signaling were examined following partial hepatectomy (PH). The results demonstrated that restoration of serum alanine aminotransferase (ALT) and total bilirubin (TBIL) levels were significantly faster in FO­treated mice compared with Control mice, and this effect was suppressed by treatment with Compound C. FO­treated mice exhibited increased numbers of Ki­67 positive hepatocytes and their postoperative liver­to­body weight ratio was significantly increased compared with the Control mice, which was also suppressed by co­treatment with the AMPK inhibitor. Furthermore, protein expression of Occludin, Claudin­3, tight junction protein 1 and bile salt export pump was gradually increased in FO­treated mice compared with Control, whereas Compound C treatment reversed this effect. Therefore, the present study revealed that perioperative oral supplementation with FO may promote liver regeneration and improved liver function in mice following PH through AMPK activation.

Effect of parenteral fish oil lipid emulsion in parenteral nutrition supplementation combined with enteral nutrition support in patients undergoing pancreaticoduodenectomy.

BACKGROUND: The effect of parenteral fish oil lipid emulsion in parenteral nutrition (PN) supplementation combined with enteral nutrition (EN) support on pancreaticoduodenectomy (PD) was investigated with a randomized controlled clinical trial at the Affiliated Drum Tower Hospital. MATERIALS AND METHODS: Seventy-six patients who underwent PD in the Department of Hepatobiliary Surgery were randomly divided into 2 groups: the polyunsaturated fatty acid (PUFA) group (n = 38) and control group (n = 38). Patients in the PUFA group received parenteral fish oil lipid emulsion supplementation combined with early EN support for 5 days after PD. Venous blood samples were obtained for assay on the day before surgery and on day 6 after surgery. RESULTS: Compared with the results of the control group, a significant difference was seen in the extent of the decrease in total protein and prealbumin in the PUFA group (P < .05). Alanine aminotransferase (ALT), aspartate aminotransferase (AST), and lactate dehydrogenase (LDH) were significantly decreased on day 6 in the PUFA group (P < .01), and a significant difference was seen in the extent of decrease in ALT, AST, and LDH in the PUFA group (P < .05). The ratio of infectious complications in the PUFA group was significantly decreased, as well as the postoperative hospital stay (P < .05), and there was no hospital mortality in this study. CONCLUSION: Parenteral fish oil lipid emulsion in PN supplementation combined with EN support can greatly improve the nutrition state and liver function of patients, decrease the incidence of infectious morbidities, and shorten the postoperative hospital stay.

Effects of ω-3 fish oil lipid emulsion combined with parenteral nutrition on patients undergoing liver transplantation.

BACKGROUND: The effect of parenteral nutrition (PN) support supplemented with ω-3 fatty acids was investigated in a randomized, controlled clinical trial at the Affiliated Drum Tower Hospital, Medical School of Nanjing University. MATERIALS AND METHODS: Ninety-eight patients with the diagnosis of end-stage liver disease or hepatic cellular carcinoma were admitted for orthotopic liver transplantation at the Affiliated Drum Tower Hospital. The patients were randomly divided into 3 groups: diet group (n = 32), PN group (n = 33), and polyunsaturated fatty acid (PUFA) group (n = 33). Patients in the PN and PUFA groups received isocaloric and isonitrogenous PN for 7 days after surgery. Venous heparin blood samples were obtained for assay on days 2 and 9 after surgery. A pathological test was performed after reperfusion of the donor liver and on day 9. RESULTS: Alanine aminotransferase levels were improved significantly by PUFA treatment compared with traditional PN support (P < .05). Compared with the results on day 9 in the PN group, a significant difference was seen in the extent of increase of the prognostic nutrition index and prealbumin in the PUFA group. The pathological results also showed that ω-3 fatty acid supplementation reduced hepatic cell injury. PUFA therapy also decreased the incidence of infectious morbidities and shortened the posttransplant hospital stay significantly. CONCLUSION: Posttransplant PN support can greatly improve metabolism of protein and nutrition states of patients. ω-3 fatty acid-supplemented PN significantly reduces injury of the transplanted liver, decreases the incidence of infectious morbidities, and shortens posttransplant hospital stay.

Liver-protecting effects of omega-3 fish oil lipid emulsion in liver transplantation.

AIM: To investigate the liver-protecting effect of parenteral nutrition (PN) support with omega-3 fatty acids in a randomized controlled clinical trial. METHODS: Sixty-six patients with the diagnosis of end-stage liver disease or hepatic cellular carcinoma were admitted to the Affiliated Drum Tower Hospital, Nanjing University, China for orthotopic liver transplantation. The patients were randomly divided into two groups: PN group (n = 33) and polyunsaturated fatty acid (PUFA) group (n = 33). All patients received isocaloric and isonitrogenous PN for seven days after surgery, and in PUFA group omega-3 fish oil lipid emulsion replaced part of the standard lipid emulsion. Liver function was tested on days 2 and 9 after surgery. Pathological examination was performed after reperfusion of the donor liver and on day 9. Clinical outcome was assessed based on the post-transplant investigations, including: (1) post-transplant mechanical ventilation; (2) total hospital stay; (3) infectious morbidities; (4) acute and chronic rejection; and (5) mortality (intensive care unit mortality, hospital mortality, 28-d mortality, and survival at a one-year post-transplant surveillance period). RESULTS: On days 2 and 9 after operation, a significant decrease of alanine aminotransferase (299.16 U/L ± 189.17 U/L vs 246.16 U/L ± 175.21 U/L, P = 0.024) and prothrombin time (5.64 s ± 2.06 s vs 2.54 s ± 1.15 s, P = 0.035) was seen in PUFA group compared with PN group. The pathological results showed that omega-3 fatty acid supplement improved the injury of hepatic cells. Compared with PN group, there was a significant decrease of post-transplant hospital stay in PUFA group (18.7 d ± 4.0 d vs 20.6 d ± 4.6 d, P = 0.041). Complications of infection occurred in 6 cases of PN group (2 cases of pneumonia, 3 cases of intra-abdominal abscess and 1 case of urinary tract infection), and in 3 cases of PUFA group (2 cases of pneumonia and 1 case of intra-abdominal abscess). No acute or chronic rejection and hospital mortality were found in both groups. The one-year mortality in PN group was 9.1% (3/33), one died of pulmonary infection, one died of severe intra-hepatic cholangitis and hepatic dysfunction and the other died of hepatic cell carcinoma recurrence. Only one patient in PUFA group (1/33, 3.1%) died of biliary complication and hepatic dysfunction during follow-up. CONCLUSION: Post-transplant parenteral nutritional support combined with omega-3 fatty acids can significantly improve the liver injury, reduce the infectious morbidities, and shorten the post-transplant hospital stay.

Omega-3 polyunsaturated fatty acids promote liver regeneration after 90% hepatectomy in rats.

AIM: To evaluate the effectiveness of omega-3 polyunsaturated fatty acid (ω-3 PUFA) administration on liver regeneration after 90% partial hepatectomy (PH) in rats. METHODS: ω-3 PUFAs were intravenously injected in the ω-3 PUFA group before PH surgery. PH, sparing only the caudate lobe, was performed in both the control and the ω-3 PUFA group. Survival rates, liver weight/body weight ratios, liver weights, HE staining, transmission electron microscope imaging, nuclear-associated antigen Ki-67, enzyme-linked immunosorbent assay and signal transduction were evaluated to analyze liver regeneration. RESULTS: All rats in the control group died within 30 h after hepatectomy. Survival rates in the ω-3 PUFA group were 20/20 at 30 h and 4/20 1 wk after PH. Liver weight/body weight ratios and liver weights increased significantly in the ω-3 PUFA group. The structure of sinusoidal endothelial cells and space of Disse was greatly restored in the ω-3 PUFA group compared to the control group after PH. In the ω-3 PUFA group, interleukin (IL)-4 and IL-10 levels were significantly increased whereas IL-6 and tumor necrosis factor-α levels were dramatically decreased. In addition, activation of protein kinase B (Akt) and of signal transducer and activator of transcription 3 signaling pathway were identified at an earlier time after PH in the ω-3 PUFA group. CONCLUSION: Omega-3 polyunsaturated fatty acids may prevent acute liver failure and promote liver regeneration after 90% hepatectomy in rats.

A monoclonal-antibody-based ELISA for the detection of human FADD (Fas-associated death domain).

FADD (Fas-associated death domain) has been widely expressed in various tissues and its expression has been recently demonstrated to correlate with tumour progression and prognosis. Currently, measurement of FADD expression mainly depends on Western-blot or immunohistochemical approaches. To develop a conventional sandwich ELISA avenue for the detection of FADD protein to supplement Western blotting or immunohistochemistry, a series of mAbs (monoclonal antibodies) specific for FADD protein, designated 3A3, 3F9, 3G4, 4B9, 4G1, 7A8, 7B8 and 7F4, were produced by fusing mouse s/p20 myeloma cells with the spleen cells of a mouse immunized with the Escherichia coli-expressed recombinant His(6)-FADD protein. On the basis of the characterization of these mAbs, purified 3F9 was selected as the capture antibody and the biotin-conjugated 3A3 was selected as the detection antibody in sandwich ELISA. The limit of detection for the ELISA was 0.3 ng of purified His(6)-FADD (FADD tagged with hexahistidine), and it could detect both recombinant and native human FADD protein. Furthermore, the positive reaction of the ELISA could be blocked by rabbit anti-FADD sera. All of these results indicated that the ELISA developed in the present paper could be a promising tool for detection of FADD protein.

Matrine protects sinusoidal endothelial cells from cold ischemia and reperfusion injury in rat orthotopic liver transplantation.

The effect of matrine on cold ischemia and reperfusion injury of sinusoidal endothelial cells (SEC) was investigated in rats using an orthotopic liver transplantation (OLT) model. Syngeneic Sprague-Dawley (SD) rats were randomly assigned to 4 groups of 32 rats: untreated group (controls), low-dose treated group, high-dose treated group, and sham operation group (normals). After 5 hr of preservation in Ringer's solution, orthotopic implantation of the donor liver was performed. At 1, 2, 4, and 24 hr after reperfusion, 6 rats from each group were killed to collect blood and to excise the median hepatic lobe; the other 8 rats were observed to assess the 1-wk survival rate post-transplantation. All transplant recipients in the untreated group (controls) died within 48 hr, mostly between 10 to 20 hr. Matrine treatment increased the 1-wk survival rate to 75% in both treated groups. Plasma levels of hyaluronic acid (HA) at 1, 2, and 4 hr post-implantation were decreased significantly by matrine treatment. The immunohistochemical expression of intercellular adhesion molecule-1 (ICAM-1) in rat liver decreased significantly in both treated groups, and the pathological changes of SEC were ameliorated. Matrine markedly inhibited the activation of Kupffer cells and their release of tumor necrosis factor (TNF). Hepatic malondialdehyde (MDA) levels and superoxide dismutase (SOD) activities were improved by matrine administration. In conclusion, matrine can protect SEC from cold ischemia and reperfusion injury after rat orthotopic liver transplantation.