Variations in the cystic duct: frequency and the relationship among insertion sides and heights on the bile duct.

BACKGROUND: Evaluation of the cystic duct anatomy prior to bile duct or gallbladder surgery is important, to decrease the risk of bile duct injury. This study aimed to clarify the frequency of cystic duct variations and the relationship between them. METHODS: Data of 205 patients who underwent cholecystectomy after imaging at Sada Hospital, Japan, were analyzed. The Chi-square test was used to analyze the relationships among variations. RESULTS: The lateral and posterior sides of the bile duct were the two most common insertion points (92 patients, 44.9%), and the middle height was the most common insertion height (135 patients, 65.9%). Clinically important variations (spiral courses, parallel courses, low insertions, and right hepatic duct draining) relating to the risk of bile duct injury were observed in 24 patients (11.7%). Regarding the relationship between the insertion sides and heights, we noticed that the posterior insertion frequently existed in low insertions (75.0%, P < 0.001) and did not exist in high insertions. In contrast, the anterior insertion coexisted with high and never low insertions. Spiral courses have two courses: anterior and posterior, and anterior ones were only found in high insertion cases. CONCLUSIONS: The insertion point of the cystic duct and the spiral courses tended to be anterior or lateral superiorly and posterior inferiorly. Clinically significant variations in cystic duct insertions are common and surgeons should be cautious about these variations to avoid complications.

Effect of gallbladder polyp size on the prediction and detection of gallbladder cancer.

BACKGROUND: Gallbladder polyps are relatively common. Although most gallbladder polyps are benign, some are malignant. Current guidelines state that malignancy should be suspected for polyps ≥ 10 mm in diameter. We clarified the cancer detection rates in accordance with the size distribution of gallbladder polyps, and evaluated the effectiveness of the reported risk factors in predicting malignancy. METHODS: In this retrospective case-control study, our institutional database was searched to identify patients who underwent laparoscopic cholecystectomy for benign or malignant gallbladder polyps at Sada Hospital, Japan. The chi-squared test was used to analyze the risk factors for malignancy. RESULTS: There were 227 protruding gallbladder lesions. The 206 benign polyps had a diameter of 2-21 mm, while the 21 malignant polyps were 7-60 mm. The cancer detection rates were 16.4% for lesions ≥ 10 mm, 55.9% for lesions ≥ 15 mm, and 94.1% for lesions ≥ 20 mm. Of the benign lesions, cholesterol polyps were the most frequent (50-100%) in all size ranges, even in large lesions (≥ 15 mm). The sessile lesion morphology was significantly more frequent in malignant (60%) than benign lesions (3.4%, p < 0.00001). Multiple polyps were frequently diagnosed not only as cholesterol polyps (81.1%), but also as adenomas (60%); adenomas were found as a single adenoma within other types of polyps. There were two cases of malignant small gallbladder polyps (< 10 mm); these lesions met the surgical indications of a size increase during observation or a sessile morphology. CONCLUSIONS: The cancer detection rate increased significantly with an increase in the lesion size. Risk factors such as a sessile polyp morphology or an increase in lesion size were effective in predicting malignancy for small gallbladder polyps. It might be difficult to accurately predict the pathologic diagnoses of gallbladder polyps preoperatively, as cholesterol polyps were most frequent, even in the large size range.

Axon Guidance Molecules Promote Perineural Invasion and Metastasis of Orthotopic Pancreatic Tumors in Mice.

BACKGROUND & AIMS: Little is known about mechanisms of perineural invasion (PNI) by pancreatic ductal adenocarcinomas (PDAs) or other tumors. Annexin A2 (ANXA2) regulates secretion of SEMA3D, an axon guidance molecule, which binds and activates the receptor PLXND1 to promote PDA invasion and metastasis. We investigated whether axon guidance molecules promote PNI and metastasis by PDA cells in mice. METHODS: We performed studies in a dorsal root ganglion (DRG) invasion system, wild-type C57BL/6 mice (controls), mice with peripheral sensory neuron-specific disruption of PlxnD1 (PLAC mice), LSL-KRASG12D/+;LSL-TP53R172H/+;PDX-1-CRE+/+ (KPC) mice, and KPC mice crossed with ANXA2-knockout mice (KPCA mice). PDA cells were isolated from KPC mice and DRG cells were isolated from control mice. Levels of SEMA3D or ANXA2 were knocked down in PDA cells with small hairpin and interfering RNAs and cells were analyzed by immunoblots in migration assays, with DRGs and with or without antibodies against PLXND1. PDA cells were injected into the pancreas of control and PLAC mice, growth of tumors was assessed, and tumor samples were analyzed by histology. DRG cells were incubated with SEMA3D and analyzed by live imaging. We measured levels of SEMA3D and PLXND1 in PDA specimens from patients with PNI and calculated distances between tumor cells and nerves. RESULTS: DRG cells increase the migration of PDC cells in invasion assays; knockdown of SEMA3D in PDA cells or antibody blockade of PLXND1 on DRG cells reduced this invasive activity. In mice, orthotopic tumors grown from PDA cells with knockdown of SEMA3D, and in PLAC mice, orthotopic tumors grown from PDA cells, had reduced innervation and formed fewer metastases than orthotopic tumors grown from PDA cells in control mice. Increased levels of SEMA3D and PLXND1 in human PDA specimens associated with PNI. CONCLUSIONS: DRG cells increase the migratory and invasive activities of pancreatic cancer cells, via secretion of SEMA3D by pancreatic cells and activation of PLXND1 on DRGs. Knockdown of SEMA3D and loss of neural PLXND1 reduces innervation of orthotopic PDAs and metastasis in mice. Increased levels of SEMA3D and PLXND1 in human PDA specimens associated with PNI. Strategies to disrupt the axon guidance pathway mediated by SEMA3D and PLXND1 might be developed to slow progression of PDA.

Extradomain-B Fibronectin-Targeted Dextran-Based Chemical Exchange Saturation Transfer Magnetic Resonance Imaging Probe for Detecting Pancreatic Cancer.

A dextran-peptide conjugate was developed for magnetic resonance (MR) molecular imaging of pancreatic ductal adenocarcinoma (PDAC) through its overexpressed microenvironment biomarker, extradomain-B fibronectin (EDB-FN). This new agent consists of diamagnetic and biocompatible dextran and a targeting peptide. Dextrans can be directly detected by chemical exchange saturation transfer magnetic resonance imaging (CEST MRI) without the need for radionuclide or metallic labeling. In addition, large molecular weight dextran, dextran 10 (MW ∼ 10 kDa), provides an approximately 50 times higher sensitivity per molecule than a single glucose unit. The potential of this highly biocompatible diamagnetic probe is demonstrated in a murine syngeneic allograft PDAC tumor model. The biocompatibility and sensitivity of this new agent clearly show potential for a path to clinical translation.

Functional and Structural Divergence in Human TRPV1 Channel Subunits by Oxidative Cysteine Modification.

Transient receptor potential vanilloid 1 (TRPV1) channel is a tetrameric protein that acts as a sensor for noxious stimuli such as heat and for diverse inflammatory mediators such as oxidative stress to mediate nociception in a subset of sensory neurons. In TRPV1 oxidation sensing, cysteine (Cys) oxidation has been considered as the principle mechanism; however, its biochemical basis remains elusive. Here, we characterize the oxidative status of Cys residues in differential redox environments and propose a model of TRPV1 activation by oxidation. Through employing a combination of non-reducing SDS-PAGE, electrophysiology, and mass spectrometry we have identified the formation of subunit dimers carrying a stable intersubunit disulfide bond between Cys-258 and Cys-742 of human TRPV1 (hTRPV1). C258S and C742S hTRPV1 mutants have a decreased protein half-life, reflecting the role of the intersubunit disulfide bond in supporting channel stability. Interestingly, the C258S hTRPV1 mutant shows an abolished response to oxidants. Mass spectrometric analysis of Cys residues of hTRPV1 treated with hydrogen peroxide shows that Cys-258 is highly sensitive to oxidation. Our results suggest that Cys-258 residues are heterogeneously modified in the hTRPV1 tetrameric complex and comprise Cys-258 with free thiol for oxidation sensing and Cys-258, which is involved in the disulfide bond for assisting subunit dimerization. Thus, the hTRPV1 channel has a heterogeneous subunit composition in terms of both redox status and function.

Maintenance of algal endosymbionts in Paramecium bursaria: a simple model based on population dynamics.

Algal endosymbiosis is widely distributed in eukaryotes including many protists and metazoans, and plays important roles in aquatic ecosystems, combining phagotrophy and phototrophy. To maintain a stable symbiotic relationship, endosymbiont population size in the host must be properly regulated and maintained at a constant level; however, the mechanisms underlying the maintenance of algal endosymbionts are still largely unknown. Here we investigate the population dynamics of the unicellular ciliate Paramecium bursaria and its Chlorella-like algal endosymbiont under various experimental conditions in a simple culture system. Our results suggest that endosymbiont population size in P. bursaria was not regulated by active processes such as cell division coupling between the two organisms, or partitioning of the endosymbionts at host cell division. Regardless, endosymbiont population size was eventually adjusted to a nearly constant level once cells were grown with light and nutrients. To explain this apparent regulation of population size, we propose a simple mechanism based on the different growth properties (specifically the nutrient requirements) of the two organisms, and based from this develop a mathematical model to describe the population dynamics of host and endosymbiont. The proposed mechanism and model may provide a basis for understanding the maintenance of algal endosymbionts.

Podoplanin expression in cancer-associated fibroblasts enhances tumor progression of invasive ductal carcinoma of the pancreas.

BACKGROUND: Interactions between cancer cells and surrounding cancer-associated fibroblasts (CAFs) play an important role in cancer progression. Invasive ductal carcinoma (IDC) of the pancreas is characterized by abundant fibrous connective tissue called desmoplasia. Podoplanin (PDPN) is a lymphatic vessel marker (D2-40), and expression of PDPN by stromal CAFs has been reported to be a prognostic indicator in various types of cancer. METHODS: Expression of PDPN in pancreatic IDCs was assessed by immunohistochemical examination in 105 patients who underwent pancreatic resection. Primary CAFs were established from pancreatic cancer tissue obtained by surgery. Quantitative reverse transcription-polymerase chain reaction and flow cytometric analysis were performed to investigate PDPN expression in CAFs. We sorted CAFs according to PDPN expression, and analyzed the functional differences between PDPN+ CAFs and PDPN- CAFs using indirect co-culture with pancreatic cancer cell lines. We also investigated the culture conditions to regulate PDPN expression in CAFs. RESULTS: PDPN expression in stromal fibroblasts was associated with lymphatic vessel invasion (P = 0.0461), vascular invasion (P = 0.0101), tumor size ≥ 3 cm (P = 0.0038), histological grade (P = 0.0344), Union for International Cancer Control classification T stage (P = 0.029), and shorter survival time (P < 0.0001). Primary CAFs showed heterogeneous PDPN expression in vitro. Moreover, migration and invasion of pancreatic cancer cell lines (PANC-1 and SUIT-2) were associated with PDPN expression in CAFs (P < 0.01) and expression of CD10, matrix metalloproteinase (MMP) 2, and MMP3. In cultured CAFs, PDPN positivity changed over time under several conditions including co-culture with cancer cells, different culture media, and addition of growth factor. CONCLUSIONS: PDPN-expressing CAFs enhance the progression of pancreatic IDC, and a high ratio of PDPN-expressing CAFs is an independent predictor of poor outcome. Understanding the regulation of the tumor microenvironment is an important step towards developing new therapeutic strategies.

Intraductal papillary mucinous neoplasms of the pancreas with distinct pancreatic ductal adenocarcinomas are frequently of gastric subtype.

OBJECTIVE: To identify a high-risk group of patients with pancreatic ductal adenocarcinoma (PDAC), independently arising in the pancreas with intraductal papillary mucinous neoplasm (IPMN), using histopathologic subtypes. BACKGROUND: Pathologic features of IPMN with distinct PDAC, including histopathologic subtypes of IPMN and PDAC phenotypes, have not been well characterized. Mucin expression patterns and the mutational status of GNAS and KRAS are useful to explore the relationship between these 2 lesion types. METHODS: Clinicopathologic data of 179 resected IPMNs and 180 resected PDACs without IPMNs as a control group were reviewed. IPMNs were classified into 4 grades (low-grade, intermediate-grade, high-grade dysplasia, and an associated invasive carcinoma) and 4 subtypes (gastric, intestinal, pancreatobiliary, and oncocytic). The expression of MUC1, MUC2, MUC5AC, MUC6, and CDX2 was investigated by immunohistochemistry in IPMNs and PDACs with and without IPMNs. The mutational status of GNAS and KRAS was evaluated by cycle sequencing in PDACs and pre-/coexisting IPMNs. RESULTS: Twenty-six synchronous or metachronous PDACs were identified in 20 patients (11.2%) with IPMNs. Occurrence of concomitant PDACs was more frequently observed in gastric-type IPMNs (18/110, 16.4%) compared with intestinal (1/49, 2.0%), pancreatobiliary (1/17, 5.9%), or oncocytic-type (0/3, 0%) (P = 0.047). Both PDACs with and without IPMNs were frequently positive for MUC1, MUC5AC, and MUC6 expression, as assessed by immunohistochemistry, but were negative for MUC2 and CDX2. The mucin-staining patterns were similar to those of invasive tubular adenocarcinoma arising from gastric-type IPMNs. Mutation of GNAS within codon 201 was not detected in PDACs and gastric-type IPMNs, whereas most of these exhibited KRAS mutations. However, the R201H GNAS mutation was detected in 1 intestinal-type IPMN with distinct PDAC. CONCLUSIONS: Mucin expression patterns demonstrate that PDAC without GNAS mutations of an aggressive phenotype frequently arise in the pancreas with benign gastric-type IPMN in the absence of GNAS mutations.

Hypoxia enhances the interaction between pancreatic stellate cells and cancer cells via increased secretion of connective tissue growth factor.

BACKGROUND: Pancreatic cancer (PC), a hypovascular tumor, thrives under hypoxic conditions. Pancreatic stellate cells (PSCs) promote PC progression by secreting soluble factors, but their functions in hypoxia are poorly understood. This study aimed to clarify the effects of hypoxic conditions on the interaction between PC cells and PSCs. METHODS: We isolated human PSCs from fresh pancreatic ductal adenocarcinomas and analyzed functional differences in PSCs between normoxia (21% O2) and hypoxia (1% O2), including expression of various factors related to tumor-stromal interactions. We particularly analyzed effects on PC invasiveness of an overexpressed molecule-connective tissue growth factor (CTGF)-in PSCs under hypoxic conditions, using RNA interference techniques. RESULTS: Conditioned media from hypoxic PSCs enhanced PC cell invasiveness more intensely than that from normoxic PSCs (P < 0.01). When co-cultured with PSCs, PC cell invasion was more enhanced under hypoxia than under normoxia (P < 0.05). Among various soluble factors, which were related to invasiveness, CTGF was one of the overexpressed molecules in hypoxic PSCs. A higher level of CTGF expression was also found in supernatant of hypoxic PSCs than in supernatant of normoxic PSCs. PC cell invasiveness was reduced by CTGF knockdown in hypoxic PSCs co-cultured with PC cells (P < 0.05). CONCLUSION: Hypoxia induces PSCs' secretion of CTGF, leading to enhancement of PC invasiveness. CTGF derived from hypoxia-stimulated PSCs may be a new therapeutic target for pancreatic cancer.

Combination therapy of portal vein resection and adjuvant gemcitabine improved prognosis of advanced pancreatic cancer.

BACKGROUND/AIMS: Although adjuvant chemotherapy (AC) using gemcitabine improves the prognosis of patients with resectable pancreatic cancer, the effect of gemcitabine AC on the prognosis of patients with borderline resectable pancreatic cancer is not clear. METHODOLOGY: We analyzed the prognosis of patients with pancreatic cancer who underwent curative pancreatoduodenectomy or total pancreatectomy in combination with portal/superior mesenteric vein resection (PVR) [PVR (+) group] or without PVR [PVR(-) group]. RESULTS: MST of the PVR (+) group was significantly shorter than that of the PVR(-) group (p=0.017). In contrast, when we focused on the patients with gemcitabine AC, there was no significant difference in MST between the PVR (+) and the PVR (-) groups (p=0.247). Furthermore, we compared MST of two subgroups in the PVR (+) group depending on gemcitabine AC status. In the PVR (+) group, MST of the patients with gemcitabine AC was significantly longer than that without gemcitabine AC (p=0.003). This was also true for the patients with pancreatic cancer which had histologically proven invasion to portal/superior mesenteric vein (PV/SMV) (p=0.001). CONCLUSIONS: The prognosis of patients with pancreatic cancer invading PV/SMV can be improved by combination therapy with PVR and gemcitabine adjuvant chemotherapy.

Direct identification of T cell epitopes in cancer tissues.

Prediction of tumor-specific T cell epitopes is an important part of cancer immunotherapies. In the past, tumor-specific T cell epitopes were identified by mapping the epitopes on the known cancer-testis antigens and tumor-associated antigens or antigens that react to the T cells induced by the cancer vaccine therapy. More recently, in silico prediction of mutation-associated neoepitopes from the whole-exome sequencing (WES) results has become another approach. However, although this approach often identifies many predicted peptides, only few have been shown to be immunogenic. Mass spectrometry (MS) has also been used to directly identify the T cell epitopes presented on tumor cell by eluting the peptides from human leukocyte antigens (HLA) class I and class II molecules. This approach of identifying neoepitopes was demonstrated to be feasible in high tumor mutation burden (TMB) tumors such as melanoma. However, identifying low-TMB-tumor-specific T cell epitopes has been challenging. Recently, Fujiwara et al. reported their successful result in identifying T cell epitopes in a low TMB tumor, namely pancreatic ductal adenocarcinoma (PDAC). Using the MS approach, they identified T cell epitopes shared by multiple pancreatic cancer patients with different HLA types. Moreover, they demonstrated that the identified epitopes bound non-matched HLA molecules and induced T cell response in peripheral T cells from non-HLA-type matched patients. Their study has opened a new venue for identifying T cell epitopes in a non-immunogenic tumor such as PDAC for the design and development of vaccine and T cell therapy.

Engineered TCR T-cell therapy targeting mass spectrometry-identified natural epitope in PDAC.

Tumor antigens are crucial targets for T-cell-based therapy to induce tumor-specific rejection. However, identifying pancreatic ductal adenocarcinoma (PDAC)-specific T-cell epitopes has been challenging. Using advanced mass spectrometry (MS) analysis, we previously identified cancer-associated, class I MHC-bound epitopes shared by multiple PDAC patients with different HLA-A types. Here, we investigated one of these epitopes, LAMC2203-211, a naturally occurring nonmutated epitope on the LAMC2 protein. Following stimulation with the LAMC2203-211 peptide, we cloned T-cell receptors (TCRs) and transduced them into the Jurkat human T-cell line using a lentiviral vector. We found that Jurkat cells expressing LAMC2203-211-specific TCRs resulted in potent, LAMC2 specific, in vitro cytotoxic effects on PDAC cells. Furthermore, in mice that harbored either subcutaneously or orthotopically implanted tumors originating from both HLA-A allele-matched and unmatched PDAC patients, tumor growth was suppressed in a LAMC2-dependent manner following the infusion of LAMC2-targeting T cells. We have therefore developed a LAMC2-specific TCR-based T-cell therapy strategy likely suitable for many PDAC patients. This is the first study to adopt MS analysis to identify natural CD8+ T-cell epitopes in PDAC that could potentially serve as targets for PDAC immunotherapy.

Tumor- and Nerve-Derived Axon Guidance Molecule Promotes Pancreatic Ductal Adenocarcinoma Progression and Metastasis through Macrophage Reprogramming.

Axon guidance molecules were found to be the gene family most frequently altered in pancreatic ductal adenocarcinoma (PDA) through mutations and copy number changes. However, the exact molecular mechanism regarding PDA development remained unclear. Using genetically engineered mouse models to examine one of the axon guidance molecules, semaphorin 3D (SEMA3D), we found a dual role for tumor-derived SEMA3D in malignant transformation of pancreatic epithelial cells and a role for nerve-derived SEMA3D in PDA development. This was demonstrated by the pancreatic-specific knockout of the SEMA3D gene from the KRAS G12D and TP53 R 172 H mutation knock-in, PDX1-Cre (KPC) mouse model which demonstrated a delayed tumor initiation and growth comparing to the original KPC mouse model. Our results showed that SEMA3D knockout skews the macrophages in the pancreas away from M2 polarization, providing a potential mechanistic role of tumor-derived SEMA3D in PDA development. The KPC mice with the SEMA3D knockout remained metastasis-free, however, died from primary tumor growth. We then tested the hypothesis that a potential compensation mechanism could result from SEMA3D which is naturally expressed by the intratumoral nerves. Our study further revealed that nerve-derived SEMA3D does not reprogram macrophages directly, but reprograms macrophages indirectly through ARF6 signaling and lactate production in PDA tumor cells. SEMA3D increases tumor-secreted lactate which is sensed by GPCR132 on macrophages and subsequently stimulates pro-tumorigenic M2 polarization in vivo. Tumor intrinsic- and extrinsic-SEMA3D induced ARF6 signaling through its receptor Plexin D1 in a mutant KRAS-dependent manner. Consistently, RNA sequencing database analysis revealed an association of higher KRAS MUT expression with an increase in SEMA3D and ARF6 expression in human PDAs. Moreover, multiplex immunohistochemistry analysis showed an increased number of M2-polarized macrophages proximal to nerves in human PDA tissue expressing SEMA3D. Thus, this study suggests altered expression of SEMA3D in tumor cells lead to acquisition of cancer-promoting functions and the axon guidance signaling originating from nerves is "hijacked" by tumor cells to support their growth. Other axon guidance and neuronal development molecules may play a similar dual role which is worth further investigation. One sentence summary: Tumor- and nerve-derived SEMA3D promotes tumor progression and metastasis through macrophage reprogramming in the tumor microenvironment. STATEMENT OF SIGNIFICANCE: This study established the dual role of axon guidance molecule, SEMA3D, in the malignant transformation of pancreatic epithelial cells and of nerve-derived SEMA3D in PDA progression and metastasis. It revealed macrophage reprogramming as the mechanism underlying bothroles. Together, this research elucidated how inflammatory responses promote invasive PDA progression and metastasis through an oncogenic process.

Steroid-free living donor liver transplantation for HCV--a multicenter prospective cohort study in Japan.

This prospective, non-randomized, multicenter cohort study analyzed the safety and efficacy of a steroid-free immunosuppressive (IS) protocol for hepatitis C virus (HCV)-positive living donor liver transplant (LDLT) recipients in Japan. Of 68 patients enrolled from 13 transplant centers, 56 fulfilled the inclusion/exclusion criteria; 27 were assigned the steroid-free IS protocol (Fr group) and 29 the traditional steroid-containing IS protocol (St group). Serum HCV RNA levels increased over time and were higher in the St group until postoperative day 90 (POD 14, p=0.013). Preemptive anti-HCV therapy was started in a higher percentage of recipients (59.3%) in the Fr group than in the St group (31.0%, p=0.031), mainly due to early HCV recurrence. The incidence of HCV recurrence at one yr was lower in the Fr group (22.2%) than in the St group (41.4%; p=0.066). The incidence of acute cellular rejection was similar between groups. New onset diabetes after transplant, cytomegalovirus infection, and renal dysfunction were significantly less frequent in the Fr group than in the St group (p=0.022, p<0.0001, p=0.012, respectively). The steroid-free IS protocol safely reduced postoperative morbidity and effectively suppressed both the HCV viral load in the early post-transplant period and HCV recurrence in HCV-positive LDLT recipients.

Single-incision laparoscopic cholecystectomy with needle graspers.

BACKGROUND/AIMS: Single-incision laparoscopic cholecystectomy (SILC) is a promising alternative to standard multi-incision laparoscopic cholecystectomy (LC). However, generalization of SILC is still hampered by technical difficulties mainly associated with the lack of trocars used for retraction of the gallbladder. We therefore developed a modified method of SILC with the use of needle graspers (SILC-N) for optimal retraction and exposure. METHODOLOGY: In addition to two trocars inserted through a single transumbilical incision, two needle ports were placed on the right subcostal and lateral abdominal wall, through which needle graspers were used for retraction of the gallbladder. Since December, 2009, 12 patients with symptomatic cholelithiasis were treated by SILC-N. RESULTS: SILC-N was successfully performed in all but one patient requiring a conversion to the 4-port LC with a mean operative time of 71.5 (48-107) minutes. None of the patients experienced intraoperative or postoperative complications. The transumbilical incision and pinholes for needle graspers were almost invisible on discharge. CONCLUSIONS: Our preliminary results suggest that SILC-N is a simple, safe and feasible technique of cholecystectomy offering similar postoperative recovery and better cosmetic outcome as compared to conventional LC.

Direct identification of HLA class I and class II-restricted T cell epitopes in pancreatic cancer tissues by mass spectrometry.

BACKGROUND: Identifying T cell epitopes on pancreatic ductal adenocarcinoma (PDAC) associated antigens or neoantigens has been a challenge. In this study, we attempted to identify PDAC T cell epitopes by mass spectrometry (MS). METHODS: We isolated HLA class I (HLA-I) and HLA class II (HLA-II)-restricted peptides, respectively, from tissues of human PDAC by using the pan-HLA-I or pan-HLA-II affinity purification column and identified T cell epitopes by peptidome analysis with MS. RESULTS: Through peptidome analysis, we identified T cell epitopes shared by multiple patients with different HLA types and those containing sequences of both anti-HLA-I and HLA-II antibodies-affinity purified peptides. The identified epitopes bound non-matched HLA molecules and induced T cell response in peripheral T cells from both HLA-type matched and non-matched patients. Peptides containing both HLA class I and class II epitopes were able to induce polyfunctional cytokine responses in peripheral T cells. CONCLUSIONS: T cell epitopes in PDAC can be discovered by the MS approach and can be designed into vaccine and TCR-T cell therapies for both HLA-type matched and non-matched patients.

Immune cell atlas of cholangiocarcinomas reveals distinct tumor microenvironments and associated prognoses.

BACKGROUND: Immunotherapy has demonstrated a limited clinical efficacy in approximately 5% of cholangiocarcinoma. The main challenges for an effective immunotherapy response in cholangiocarcinoma arise from the tumor microenvironment, which is poorly understood. METHODS: For a comprehensive analysis of the tumor microenvironment in cholangiocarcinoma, we performed multiplex immunohistochemistry with two 15-marker immune panels and Nanostring assays for a comprehensive analysis of 104 surgically resected cholangiocarcinomas including intrahepatic, hilar, and distal cholangiocarcinoma. We also validated some key findings with a batch integration analysis of published single cell RNA sequencing data. RESULTS: This study found that natural killer cells occupy the largest immune cell compartment in cholangiocarcinoma. Granzyme-B+CD8+ effector T cells are significantly associated with better overall survival in both intrahepatic and distal cholangiocarcinoma. Above 85% of intrahepatic cholangiocarcinomas with higher density of PD-1-EOMES-CD8+ effector T cells are associated with long-term survival. However, only the density of PD-1-EOMES-CD8+ T cells in the tumor areas, but not in the peripheries of the tumors, is prognostic. In all three cholangiocarcinoma subtypes, T regulator cells are significantly associated with a poor prognosis; however, M1 and M2 tumor-associated macrophages or PD-L1+ tumor-associated macrophage demonstrate different prognostic values. Combining PD-L1+ M1 or M2, PD-L1- M1 or M2 tumor-associated macrophages, and T regulator cells to subgroup intrahepatic and distal cholangiocarcinoma, the prognosis is significantly better distinguished. Moreover, PD-L1- M2 tumor-associated macrophages is associated with a good prognosis in intrahepatic and distal cholangiocarcinoma, suggesting this subtype of M2 tumor-associated macrophages may be antitumoral. Interestingly, lower densities of various types of immunosuppressive cells are associated with decreased infiltration of effector T cells in distal and hilar cholangiocarcinoma, but not in intrahepatic cholangiocarcinoma. In intrahepatic cholangiocarcinoma, PD-L1+ tumor-associated macrophages exert their immunosuppressive function likely through promoting T cell exhaustion. CONCLUSIONS: This study suggests that the densities of Granzyme-B+CD8+ effector T cells and non-exhausted PD-1-EOMES-CD8+ T cells and the PD-L1 status in the tumor-associated macrophages are prognostic makers in cholangiocarcinomas. The study also supports targeting PD-L1+ tumor-associated macrophages as the immunotherapy for cholangiocarcinoma.

CCR2/CCR5 inhibitor permits the radiation-induced effector T cell infiltration in pancreatic adenocarcinoma.

The resistance of pancreatic ductal adenocarcinoma (PDAC) to immune checkpoint inhibitors (ICIs) is attributed to the immune-quiescent and -suppressive tumor microenvironment (TME). We recently found that CCR2 and CCR5 were induced in PDAC following treatment with anti-PD-1 antibody (αPD-1); thus, we examined PDAC vaccine or radiation therapy (RT) as T cell priming mechanisms together with BMS-687681, a dual antagonist of CCR2 and CCR5 (CCR2/5i), in combination with αPD-1 as new treatment strategies. Using PDAC mouse models, we demonstrated that RT followed by αPD-1 and prolonged treatment with CCR2/5i conferred better antitumor efficacy than other combination treatments tested. The combination of RT + αPD-1 + CCR2/5i enhanced intratumoral effector and memory T cell infiltration but suppressed regulatory T cell, M2-like tumor-associated macrophage, and myeloid-derived suppressive cell infiltration. RNA sequencing showed that CCR2/5i partially inhibited RT-induced TLR2/4 and RAGE signaling, leading to decreased expression of immunosuppressive cytokines including CCL2/CCL5, but increased expression of effector T cell chemokines such as CCL17/CCL22. This study thus supports the clinical development of CCR2/5i in combination with RT and ICIs for PDAC treatment.

Changes in Attitudes of Japanese Doctors toward Complementary and Alternative Medicine-Comparison of Surveys in 1999 and 2005 in Kyoto.

We surveyed the attitudes of Japanese medical doctors toward complementary and alternative medicine (CAM) in 1999. It is supposed that the situation concerning CAM has been changing recently. The aim of the present study is to survey the attitude of doctors toward CAM again, and to examine changes in attitude over the last 6 years. The attitudes of medical doctors belonging to the Kyoto Medical Association toward CAM were surveyed by a structured, self-administered questionnaire in 1999 and 2005. The results showed that the doctors familiar with the term "CAM", practicing CAM therapies, and attending meetings or training courses related with CAM, increased significantly from 1999 to 2005. The doctors who possessed knowledge of CAM also increased significantly from 1999 to 2005. Almost all doctors believed in the effectiveness of Kampo (Japanese traditional herbal medicine) and acupuncture. The number of doctors who believed in the effectiveness of aromatherapy and ayurveda increased significantly in 2005, compared with 1999. In the near future, 58% of doctors desired to practice CAM therapies. In conclusion, the numbers of doctors who practice CAM therapies, possess CAM knowledge and desire to practice such therapies have increased over the last 6 years in Japan.

[A case of undifferentiated colon cancer responding to FOLFIRI therapy].

We report a case of undifferentiated colon cancer treated with FOLFIRI therapy. A 69-year-old male had suffered from descending colon cancer. He underwent a left hemicolectomy with D3 dissection. Histopathologically, the tumor was undifferentiated carcinoma, and the cytology of ascites was positive. Peritoneal disseminations occurred soon after surgery, and these tumors did not respond to FOLFOX4 therapy. FOLFIRI therapy was employed, and it reduced the size of these tumors once. However, the therapy failed to control the tumor progression 2 months later. Although we started bevacizumab and S-1, the patient died 11 months after the operation. The present case demonstrates the efficacy of FOLFIRI therapy for undifferentiated colon cancer.