Regulatory network analysis of Dclk1 gene expression reveals a tuft cell-ILC2 axis that inhibits pancreatic tumor progression.

Dclk1 expression defines a rare population of cells in the normal pancreas whose frequency is increased at early stages of pancreatic tumorigenesis. The identity and the precise roles of Dclk1 expressing cells in pancreas have been matter of debate, although evidence suggests their involvement in a number of key functions, including regeneration and neoplasia. We employed a recently developed Dclk1 reporter mouse model and single cell RNAseq analysis to define Dclk1 expressing cells in normal pancreas and pancreatic neoplasia. In normal pancreas, Dclk1 epithelial expression identifies subsets of ductal, islet and acinar cells. In pancreatic neoplasia, Dclk1 expression identifies five epithelial cell populations, among which acinar-to-ductal metaplasia (ADM)-like cells and tuft-like cells are predominant. These two cell populations play opposing roles in pancreatic neoplasia, with Dclk1 + ADM-like cells sustaining tumor growth while Dclk1 + tuft-like cells restraining tumor progression. The differentiation of Kras mutant acinar cells into Dclk1 + tuft-like cells requires the activation of the transcription factor SPIB and is further supported by a cellular paracrine loop involving cancer group 2 innate lymphoid cells (ILC2) and cancer activated fibroblasts (CAFs) that provide IL13 and IL33, respectively. In turn, Dclk1 + tuft-like cells release angiotensinogen that plays protective roles against pancreatic neoplasia. Overall, our study provides novel insights on the biology of Dclk1 + cells in normal pancreas and unveils a protective axis against pancreatic neoplasia, involving CAFs, ILC2 and Dclk1 + tuft-like cells, which ultimately results in angiotensinogen release.

Loss of Trefoil Factor 1 Accelerates the Immune Response to Colorectal Cancer.

BACKGROUND/AIM: Recent studies suggest that PD-L1 expression in immune cells, rather than tumor cells, plays a key role in tumor immunity. Trefoil factor family 1 (TFF1) is a secreted protein expressed mainly by the gastrointestinal epithelium and is related to the development of malignant disease. This study investigated the effects of TFF1 on tumor immunity in a xenograft mouse model of colorectal cancer (CRC). MATERIALS AND METHODS: MC38 cells were implanted in wild-type (WT) and TFF1KO mice, and the tumor micro-environment was investigated using immunohistochemistry. The circulating immune cells were analyzed using flow cytometry. RESULTS: Tumor growth was suppressed in TFF1KO mice. In the tumor microenvironment, CD8- and CD4-positive T cells and CD11c-positive dendritic cells (DCs) were frequently found in TFF1KO mice. When an immune checkpoint inhibitor was administered to these mice, almost half of the tumors in TFF1KO mice showed a complete response. The number of circulating PD-L1/DCs was markedly associated with tumor volume, with TFF1 deletion accelerating this effect and its injection decreasing it. These findings indicate that loss of TFF1 activates tumor immunity via frequent T-cell priming by DCs, and eventually suppresses tumor growth in CRC. In addition, the number of circulating PD-L1/DCs was identified as a predictive marker of checkpoint-inhibiting therapy efficacy. CONCLUSION: Loss of TFF1 resulted in accelerated immune response to colorectal cancer. Further studies are needed to investigate the precise mechanisms of TFF1 in immunotolerance and develop a novel TFF1-inhibiting immunotherapeutic strategy for CRC.

Trefoil factor 1 suppresses stemness and enhances chemosensitivity of pancreatic cancer.

BACKGROUND AND AIMS: Pancreatic cancer is one of the most lethal malignancies, partly due to resistance to conventional chemotherapy. The chemoresistance of malignant tumors is associated with epithelial-mesenchymal transition (EMT) and the stemness of cancer cells. The aim of this study is to investigate the availability and functional mechanisms of trefoil factor family 1 (TFF1), a tumor-suppressive protein in pancreatic carcinogenesis, to treat pancreatic cancer. METHODS: To investigate the role of endogenous TFF1 in human and mice, specimens of human pancreatic cancer and genetically engineered mouse model of pancreatic cancer (KPC/TFF1KO; Pdx1-Cre/LSL-KRASG12D/LSL-p53R172H/TFF1-/-) were analyzed by immunohistochemistry (IHC). To explore the efficacy of extracellular administration of TFF1, recombinant and chemically synthesized TFF1 were administered to pancreatic cancer cell lines, a xenograft mouse model and a transgenic mouse model. RESULTS: The deficiency of TFF1 was associated with increased EMT of cancer cells in mouse models of pancreatic cancer, KPC. The expression of TFF1 in cancer cells was associated with better survival rate of the patients who underwent chemotherapy, and loss of TFF1 deteriorated the benefit of gemcitabine in KPC mice. Extracellular administration of TFF1 inhibited gemcitabine-induced EMT, Wnt pathway activation and cancer stemness, eventually increased apoptosis of pancreatic cancer cells in vitro. In vivo, combined treatment of gemcitabine and subcutaneous administration of TFF1 arrested tumor growth in xenograft mouse model and resulted in the better survival of KPC mice by inhibiting EMT and cancer stemness. CONCLUSION: These results indicate that TFF1 can contribute to establishing a novel strategy to treat pancreatic cancer patients by enhancing chemosensitivity.

TLK1 Inhibition Enhances the Anticancer Effect of Deep UV Irradiation Through CHK1 Activation.

BACKGROUND/AIM: A deep ultraviolet (DUV) light-emitting diode (LED) is a device that can irradiate electromagnetic waves from 250 nm to 350 nm. Tousled-like kinase 1 (TLK1) encodes a nuclear serine/threonine kinase, which is thought to influence the effects of DUV irradiation in cancer. The aim of this study was to clarify the interaction of TLK1 with DUV irradiation-induced DNA damage in cancer cells. MATERIALS AND METHODS: Pancreatic cancer cell lines were treated with or without DUV. TLK1 expression and phosphorylation in the two groups were examined. Then, these cancer cell lines were treated with thioridazine (THD), DUV or both. Thereafter, cytomorphology and apoptosis were assessed. Several proteins related to DNA damage, were analyzed in cancer cells treated with DUV and THD. Tumors in a subcutaneous xenograft model were treated with THD, DUV, or both for six weeks. RESULTS: DUV irradiation induced the phosphorylation of TLK1 in pancreatic cancer cell lines. Cytomorphology was significantly changed in pancreatic cancer cells treated with DUV and THD. TLK1 inhibition enhanced DUV irradiation-induced apoptosis in cancer cells. Interestingly, CHK1 and pCHK1 expression was suppressed after TLK1 inhibition. In addition, inhibition of MRE11 led to a decrease in the expression of CHK1 and pCHK1, accompanied by a notable increase in apoptosis. In the subcutaneous xenograft models, the tumor volume in the DUV and THD groups was lower than that in the other groups. CONCLUSION: TLK1 phosphorylation is an important event in DUV irradiation. DUV irradiation combined with TLK1 inhibition has therapeutic potential in pancreatic cancer cells.

A clinical assessment of three-dimensional-printed liver model navigation for thrice or more repeated hepatectomy based on a conversation analysis.

PURPOSES: We performed a conversation analysis of the speech conducted among the surgical team during three-dimensional (3D)-printed liver model navigation for thrice or more repeated hepatectomy (TMRH). METHODS: Seventeen patients underwent 3D-printed liver navigation surgery for TMRH. After transcription of the utterances recorded during surgery, the transcribed utterances were coded by the utterer, utterance object, utterance content, sensor, and surgical process during conversation. We then analyzed the utterances and clarified the association between the surgical process and conversation through the intraoperative reference of the 3D-printed liver. RESULTS: In total, 130 conversations including 1648 segments were recorded. Utterance coding showed that the operator/assistant, 3D-printed liver/real liver, fact check (F)/plan check (Pc), visual check/tactile check, and confirmation of planned resection or preservation target (T)/confirmation of planned or ongoing resection line (L) accounted for 791/857, 885/763, 1148/500, 1208/440, and 1304/344 segments, respectively. The utterance's proportions of assistants, F, F of T on 3D-printed liver, F of T on real liver, and Pc of L on 3D-printed liver were significantly higher during non-expert surgeries than during expert surgeries. Confirming the surgical process with both 3D-printed liver and real liver and performing planning using a 3D-printed liver facilitates the safe implementation of TMRH, regardless of the surgeon's experience. CONCLUSIONS: The present study, using a unique conversation analysis, provided the first evidence for the clinical value of 3D-printed liver for TMRH for anatomical guidance of non-expert surgeons.

Financial burden of surgical treatment for retroperitoneal sarcoma.

PURPOSES: The purpose of this study was to compare the financial burden of surgery for retroperitoneal sarcoma (RPS) and gastric cancer (GC). METHODS: All patients who underwent surgery for GC or RPS between 2020 and 2021 at Nagoya University Hospital were included. The clinical characteristics, surgical fees per surgeon, and surgical fees per hour were compared between the two groups. RESULTS: The GC and RPS groups included 35 and 63 patients, respectively. In the latter group, 37 patients (59%) underwent tumor resection combined with organ resection; the most common organ was the intestine (n = 23, 37%), followed by the kidney (n = 16, 25%). The mean operative time (248 vs. 417 min, p < 0.001) and intraoperative blood loss (423 vs. 1123 ml, p < 0.001) were significantly greater in the RPS group than in the GC group. The mean surgical fee per surgeon was USD 1667 in the GC group and USD 1022 in the RPS group (p < 0.001) and USD 1388 and USD 777 per hour, respectively (p < 0.001). CONCLUSIONS: The financial burden of surgical treatment for RPS is unexpectedly higher than that for GC.

Spot scanning proton therapy for unresectable bulky retroperitoneal dedifferentiated liposarcoma: a case report.

The development of effective treatment strategies for unresectable retroperitoneal sarcoma is desirable. Herein, we suggest that definitive proton therapy (PT) could be a promising treatment option, regardless of the large size of the tumor. A 52-year-old man presented with a discomfort of the lower abdomen. Computed tomography revealed a retroperitoneal tumor, measuring over 20 cm in the largest dimensions, which was surrounded by the gastrointestinal (GI) tract. Biopsy revealed dedifferentiated liposarcoma. Neoadjuvant chemotherapy was ineffective, and the tumor was ultimately deemed unresectable. The patient opted to receive PT instead of continuation of chemotherapy. Spot scanning PT (SSPT) at a total dose of 60.8 Gy (relative biological effectiveness) in 16 fractions was employed. SSPT administered a dose to the tumor while successfully sparing the surrounding GI tract. He did not receive any maintenance systemic therapy after PT. The tumor gradually shrunk over more than 7 years, with no evidence of recurrence outside the irradiation field. The initial measurable tumor volume of 2925 cc decreased to 214 cc at the final follow-up, seven and a half years after PT. The patient is alive without any severe complications.

Utility of modified pancreaticoduodenectomy (Hi-cut PD) for middle-third cholangiocarcinoma: an alternative to hepatopancreaticoduodenectomy.

BACKGROUND: The standard procedure for middle-third cholangiocarcinoma (MCC) is pancreaticoduodenectomy (PD); hepatopancreaticoduodenectomy (HPD) is often performed despite its high risk. There is no clear selection guidance for these procedures. METHODS: Patients with MCC who underwent HPD or PD were retrospectively evaluated. The conventional PD was modified (mPD) to transect the bile duct beyond or close to the cranial level of the portal bifurcation. RESULTS: The mPD group (n = 55) was characterized by older age, shorter operation time, less blood loss, and less frequent complications than were observed in the HPD group (n = 34). The median grossly tumor-free margin of the proximal bile duct (GM) was 13 mm vs 20 mm (P = 0.006). Overall survival did not differ significantly between groups (48% vs 53% at 5 years, P = 0.399). Multivariate analysis identified positive surgical margin as a sole independent prognostic factor (hazard ratio, 1.89; P = 0.043), which was statistically associated with GM length. Five-year survival for mPD patients with GM ≥15 mm was significantly better than that for those who had GM <15 mm (69% vs 33%, P = 0.011) and comparable to that of HPD patients (53%, P = 0.450). CONCLUSION: The mPD may be recommended in patients with MCC, provided that GM ≥15 mm is expected from the preoperative radiological imaging. Otherwise, HPD should be considered.

Liver remnant volume to body weight ratio of 0.65% as a lower limit in right hepatic trisectionectomy with bile duct resection.

BACKGROUND: Previous studies have suggested the utility of an indocyanine green plasma clearance rate of the future liver remnant (FLR) (ICGK-F) ≥0.05 in hepatobiliary resection to reduce the surgical risk. The present study aimed to verify whether future liver remnant size rather than ICGK-F matters in extended hepatobiliary resection. METHODS: Between 2004 and 2021, patients who underwent right hepatic trisectionectomy with bile duct resection were included. The effect of the FLR volume-to-body weight ratio (FLR/BW) and ICGK-F on posthepatectomy liver failure was evaluated along with other parameters. RESULTS: Among 91 study patients, the median ICGK-F, FLR, and FLR/BW were 0.057 (range, 0.027-0.099), 392 mL (145-705), and 0.78% (0.40-1.37), respectively. Posthepatectomy liver failure occurred in 23 patients. The incidence was 10 (40%) in 25 patients with an ICGK-F <0.05 and 12 (18%) in 65 patients with an ICGK-F ≥0.05 (P = .053); 13 (52%) in 25 patients with a FLR/BW <0.65% and 10 (15%) in 66 patients with a FLR/BW ≥0.65% (P = .001). Multivariate analysis showed that a FLR/BW <0.65% (odds ratio, 11.7; P = .005), age ≥65 years (odds ratio, 31.7; P < .001), and blood loss ≥25 mL/kg (odds ratio, 22.1; P = .004) were independent predictors of posthepatectomy liver failure, but ICGK-F <0.05 was not (P = .499). According to the meeting number of 3 factors, posthepatectomy liver failure incidence was 0 of 22 (0%) in patients with 0 factors, 6 of 43 (14%) in patients with 1, and 17 of 26 (65%) in patients with 2 or 3 (P < .001). CONCLUSION: A FLR/BW ≥0.65% may serve as a volumetric basis to reduce posthepatectomy liver failure after extended hepatobiliary resection.

Tff2 defines transit-amplifying pancreatic acinar progenitors that lack regenerative potential and are protective against Kras-driven carcinogenesis.

While adult pancreatic stem cells are thought not to exist, it is now appreciated that the acinar compartment harbors progenitors, including tissue-repairing facultative progenitors (FPs). Here, we study a pancreatic acinar population marked by trefoil factor 2 (Tff2) expression. Long-term lineage tracing and single-cell RNA sequencing (scRNA-seq) analysis of Tff2-DTR-CreERT2-targeted cells defines a transit-amplifying progenitor (TAP) population that contributes to normal homeostasis. Following acute and chronic injury, Tff2+ cells, distinct from FPs, undergo depopulation but are eventually replenished. At baseline, oncogenic KrasG12D-targeted Tff2+ cells are resistant to PDAC initiation. However, KrasG12D activation in Tff2+ cells leads to survival and clonal expansion following pancreatitis and a cancer stem/progenitor cell-like state. Selective ablation of Tff2+ cells prior to KrasG12D activation in Mist1+ acinar or Dclk1+ FP cells results in enhanced tumorigenesis, which can be partially rescued by adenoviral Tff2 treatment. Together, Tff2 defines a pancreatic TAP population that protects against Kras-driven carcinogenesis.

The Goal of Intraoperative Blood Loss in Major Hepatobiliary Resection for Perihilar Cholangiocarcinoma: Saving Patients From a Heavy Complication Burden.

OBJECTIVE: To determine the goal of intraoperative blood loss in hepatectomy for perihilar cholangiocarcinoma. BACKGROUND: Although massive bleeding can negatively affect the postoperative course, the target value of intraoperative bleeding to reduce its adverse impact is unknown. METHODS: Patients who underwent major hepatectomy for perihilar cholangiocarcinoma between 2010 and 2019 were included. Intraoperative blood loss was adjusted for body weight [adjusted blood loss (aBL)], and the overall postoperative complications were evaluated by the comprehensive complication index (CCI). The impact of aBL on CCI was assessed by the restricted cubic spline regression. RESULTS: A total of 425 patients were included. The median aBL was 17.8 (interquartile range, 11.8-26.3) mL/kg, and the CCI was 40.6 (33.7-49.5). Sixty-three (14.8%) patients had an aBL<10 mL/kg, nearly half (45.4%) of the patients were in the range of 10 ≤aBL<20 mL/kg, and 37 (8.7%) patients had an aBL >40 mL/kg. The spline regression analysis showed a nonlinear incremental association between aBL and CCI; CCI remained flat with an aBL under 10 mL/kg; increased significantly with an aBL ranging from 10 to 20 mL/kg; grew gradually with an aBL over 20 mL/kg. These inflection points of ~10 and 20 mL/kg were almost consistent with the cutoff values identified by the recursive partitioning technique. After adjusting for other risk factors for the postoperative course, the spline regression identified a similar model. CONCLUSIONS: aBL had a nonlinear aggravating effect on CCI after hepatectomy for perihilar cholangiocarcinoma. The primary goal of aBL should be <10 mL/kg to minimize CCI.

Two-step arterial reconstruction technique for en bloc resection of a large retroperitoneal liposarcoma involving the common iliac artery.

Retroperitoneal liposarcoma (RPLS) is a rare but challenging neoplasm, which is frequently associated with iliac vessel invasion. We describe how we used a two-step arterial reconstruction technique to perform en bloc resection of a large RPLS involving the iliac arteries in three patients. A temporal long in situ graft bypass was established using a prosthetic vascular graft during dissection of the tumor. This bypass provided an unobscured surgical field, while maintaining blood flow in the lower limb during the operation. After removal of the tumor and washing out the abdominal cavity, the new prosthetic vascular graft of a suitable length was placed. No graft-related complications, including vascular graft infection or graft occlusion, occurred during the follow-up period. This novel technique appears to provide a safe and effective way to remove large RPLSs involving the retroperitoneal major vessels.

Cyclodextrin Conjugated α-Bisabolol Suppresses FAK Phosphorylation and Induces Apoptosis in Pancreatic Cancer.

BACKGROUND/AIM: α-Bisabolol is an essential oil component extracted from plants, such as chamomile. We have previously reported that α-bisabolol suppressed proliferation, invasion, and motility of pancreas cancer. Cyclodextrin improved the solubility of α-bisabolol, therefore it enabled to administer intravenously. The aim of this study was to clarify the effect of cyclodextrin conjugated α-bisabolol (CD-BSB) and the signals pathways associated with α-bisabolol for pancreatic cancer. MATERIALS AND METHODS: Human pancreatic cancer cell lines were treated with or without CD-BSB. Cytomorphology and apoptosis were assessed in these treated groups. In addition, several phosphorylated proteins were analyzed to clarify the signal pathway concerning CD-BSB. In subcutaneous xenograft model, tumor volume and Ki-67 expression were evaluated among Control (untreated), CD-BSB, or Gemcitabine (GEM). RESULTS: CD-BSB significantly changed cytomorphology and induced apoptosis in pancreatic cancer cells. CD-BSB suppressed phosphorylation of focal adhesion kinase (FAK). In addition, pFAK 397 was inhibited by CD-BSB in a concentration-dependent manner in cancer cells. In the subcutaneous xenograft models, the tumor volume in the CD-BSB groups was lower than Control groups. Ki67-positive cells in CD-BSB treated group were lower than the GEM-treated groups. CONCLUSION: We clarified the efficiency of CD-BSB in xenograft tumor using intravenous administration. α-Bisabolol suppresses phosphorylation of FAK 397 and impairs cytoskeletal polymerization in a pancreatic cancer cell line. Further investigations are required to reveal the precise mechanisms of the antitumor effects of solubilized α-bisabolol to facilitate its clinical application. Our data indicate that solubilized α-bisabolol has therapeutic potential and could improve the prognosis of cancer patients.

Antitumor Effects of Deep Ultraviolet Irradiation for Pancreatic Cancer.

BACKGROUND/AIM: Deep ultraviolet (DUV) light spans within the 250 nm to 350 nm invisible wavelength range. Although it strongly damages various cells, the efficacy of DUV irradiation on pancreatic cancer cells has never been clarified. The purpose of this study was to reveal the antitumor effects of DUV irradiation on pancreatic cancer cells. MATERIALS AND METHODS: Human pancreatic cancer cell lines were eradicated with DUV or ultraviolet A (UVA) for 5 s. Several angiogenesis-related proteins were studied in cancer cells after DUV irradiation using a protein antibody array. A subcutaneous xenograft model was established by inoculation of pancreatic cancer cells into mice. Tumors in this model were irradiated with DUV or UVA once or twice for two weeks. Tumor volumes in these groups (DUV×1: one irradiation, DUV×2: two irradiations, and untreated) were analyzed one week after the second irradiation. RESULTS: DUV irradiation significantly changed the cytomorphology of pancreatic cancer cells. In addition, DUV irradiation induced apoptosis on pancreatic cancer cells more strongly than UVA irradiation and no irradiation. Interestingly, lower expression of thrombospondin 1 (TSP1) and tissue inhibitor of metalloproteinase 1 (TIMP1) was identified after DUV treatment. The tumor volume in the DUV-treated groups (DUV×1 and DUV×2) was smaller than that in the untreated group. CONCLUSION: Further investigations are required to reveal the precise mechanisms of the antitumor effects of DUV irradiation and to facilitate its clinical application as a new therapy for pancreatic cancer. Overall, DUV irradiation can be potentially used as a therapeutic option of pancreatic malignancy.

Is a specific T classification needed for extrahepatic intraductal papillary neoplasm of the bile duct (IPNB) type 2 associated with invasive carcinoma?

BACKGROUND: The necessity of a specific T classification for extrahepatic intraductal papillary neoplasm of the bile duct (IPNB) type 2, one of the precursors of cholangiocarcinoma (CC), remains unclear. METHODS: Patients who underwent resection for extrahepatic biliary tumors were reviewed. Relapse-free survival (RFS) was compared between IPNB type 2 and CC, stratified by T classification. RESULTS: The cohort involved 443 patients with IPNB type 2 (n = 57) and CC (n = 386). In 342 patients with perihilar tumors, 5-year RFS of IPNB type 2 and CC group was 49.8% versus 34.5% (p = .012), respectively. The RFS was 54.6% versus 47.2% (p = .110) for pT1-2 tumors and 28.6% versus 22.7% (p = .436) for pT3-4 tumors, respectively. In 92 patients with distal tumors, 5-year RFS was 47.4% versus 42.1% (p = .678). The RFS was 68.2% versus 49.6% (p = .422) for pT1 tumors and 18.8% versus 38.3% (p = .626) for pT2-3 tumors, respectively. Multivariate analysis identified that poor histologic grade (HR, 2.105; p < .001), microscopic venous invasion (HR, 1.568; p = .002), and nodal metastasis (HR, 1.547; p < .001) were independent prognostic deteriorators, while tumor type (IPNB type 2 vs. CC) was not. CONCLUSIONS: Prognostic impact of IPNB type 2 was limited, suggesting unnecessity of a specific T classification for IPNB type 2 with invasive carcinoma.

Which modality is better to diagnose high-grade transformation in retroperitoneal liposarcoma? Comparison of computed tomography, positron emission tomography, and magnetic resonance imaging.

BACKGROUND: Survival in patients with retroperitoneal liposarcoma (RPLS) depends on the surgical management of the dedifferentiated foci. The present study investigated the diagnostic yield of contrast-enhanced CT, 18F-fluorodeoxyglucose positron emission tomography (PET), and diffusion-weighted MRI in terms of dedifferentiated foci within the RPLS. METHODS: Patients treated with primary or recurrent RPLS who underwent the above imaging between January 2010 and December 2021 were retrospectively reviewed. The diagnostic accuracy of the three modalities for histologic subtype of dedifferentiated liposarcoma (DDLS) and French Federation of Cancer Center (FNCLCC) grade 2/3 were compared using receiver operating characteristic curves and areas under the curves (AUCs). RESULTS: The cohort involved 32 patients with 53 tumors; 30 of which exhibited DDLS and 31 of which did FNCLCC grades 2/3. The optimal thresholds for predicting DDLS were mean CT value of 31 Hounsfield Unit (HU) (AUC = 0.880, 95% CI 0.775-0.984; p < 0.001), maximum standardized uptake value (SUVmax) of 2.9 (AUC = 0.865 95% CI 0.792-0.980; p < 0.001), while MRI failed to differentiate DDLS. The cutoff values for distinguishing FNCLCC grades 1 and 2/3 were a mean CT value of 24 HU (AUC = 0.858, 95% CI 0.731-0.985; p < 0.001) and SUVmax of 2.9 (AUC = 0.885, 95% CI 0.792-0.978; p < 0.001). MRI had no sufficient power to separate these grades. CONCLUSIONS: Contrast-enhanced CT and PET were useful for predicting DDLS and FNCLCC grade 2/3, while MRI was inferior to these two modalities.

A proposal of drain removal criteria in hepatobiliary resection.

BACKGROUND: Standardized criteria for drain removal in hepatobiliary resection are lacking. Here, we evaluated the outcomes of delayed removal policy in this extended surgery. METHODS: Patients undergoing hepatectomy with biliary reconstruction between 2012 and 2018 were retrospectively reviewed. The drains were removed on postoperative day (POD) 7 when the drainage fluid was grossly serous, biochemically normal, and negative for bacterial contamination as assessed by Gram staining; additionally, no abnormal fluid collection was confirmed by computed tomography. Clinically relevant abdominal complications (CRACs), including biliary leakage, pancreatic fistula or intra-abdominal abscess, served as the primary outcome measure. RESULTS: Among 374 study patients, surgical drains were removed in 166 (44.3%) patients who met the criteria. Of these patients, 16 (9.6%) patients subsequently required additional drainage due to CRAC. Drains were retained and exchanged in 208 (55.6%) patients who did not meet the criteria. Of these, exchanged drains were soon removed in 34 patients due to no signs of CRAC. The diagnostic ability of the criteria revealed 0.916 sensitivity, 0.815 specificity, and 0.866 accuracy. CONCLUSION: The four findings on POD 7 worked well as criteria for drain removal, and these criteria may be helpful in drain management after hepatobiliary resection.

Anti-Malignant Effect of Tensile Loading to Adherens Junctions in Cutaneous Squamous Cell Carcinoma Cells.

Actomyosin contractility regulates various cellular processes including proliferation and differentiation while dysregulation of actomyosin activity contributes to cancer development and progression. Previously, we have reported that actomyosin-generated tension at adherens junctions is required for cell density-dependent inhibition of proliferation of normal skin keratinocytes. However, it remains unclear how actomyosin contractility affects the hyperproliferation ability of cutaneous squamous cell carcinoma (cSCC) cells. In this study, we find that actomyosin activity is impaired in cSCC cells both in vitro and in vivo. External application of tensile loads to adherens junctions by sustained mechanical stretch attenuates the proliferation of cSCC cells, which depends on intact adherens junctions. Forced activation of actomyosin of cSCC cells also inhibits their proliferation in a cell-cell contact-dependent manner. Furthermore, the cell cycle arrest induced by tensile loading to adherens junctions is accompanied by epidermal differentiation in cSCC cells. Our results show that the degree of malignant properties of cSCC cells can be reduced by applying tensile loads to adherens junctions, which implies that the mechanical status of adherens junctions may serve as a novel therapeutic target for cSCC.

Interleukin-1ß-induced pancreatitis promotes pancreatic ductal adenocarcinoma via B lymphocyte-mediated immune suppression.

OBJECTIVE: Long-standing chronic pancreatitis is an established risk factor for pancreatic ductal adenocarcinoma (PDAC). Interleukin-1ß (IL-1ß) has been associated in PDAC with shorter survival. We employed murine models to investigate the mechanisms by which IL-1ß and chronic pancreatitis might contribute to PDAC progression. DESIGN: We crossed LSL-Kras+/G12D;Pdx1-Cre (KC) mice with transgenic mice overexpressing IL-1ß to generate KC-IL1ß mice, and followed them longitudinally. We used pancreatic 3D in vitro culture to assess acinar-to-ductal metaplasia formation. Immune cells were analysed by flow cytometry and immunohistochemical staining. B lymphocytes were adoptively transferred or depleted in Kras-mutant mice. B-cell infiltration was analysed in human PDAC samples. RESULTS: KC-IL1ß mice developed PDAC with liver metastases. IL-1ß treatment increased Kras+/G12D pancreatic spheroid formation. CXCL13 expression and B lymphocyte infiltration were increased in KC-IL1ß pancreata. Adoptive transfer of B lymphocytes from KC-IL1ß mice promoted tumour formation, while depletion of B cells prevented tumour progression in KC-IL1ß mice. B cells isolated from KC-IL1ß mice had much higher expression of PD-L1, more regulatory B cells, impaired CD8+ T cell activity and promoted tumorigenesis. IL-35 was increased in the KC-IL1ß pancreata, and depletion of IL-35 decreased the number of PD-L1+ B cells. Finally, in human PDAC samples, patients with PDAC with higher B-cell infiltration within tumours showed significantly shorter survival. CONCLUSION: We show here that IL-1ß promotes tumorigenesis in part by inducing an expansion of immune-suppressive B cells. These findings point to the growing significance of B suppressor cells in pancreatic tumorigenesis.

Is constant negative pressure for external drainage of the main pancreatic duct useful in preventing pancreatic fistula following pancreatoduodenectomy?

BACKGROUND: This study sought to investigate the utility of constant negative pressure for external drainage of the main pancreatic duct in preventing postoperative pancreatic fistula (POPF) after pancreatoduodenectomy. METHODS: Only patients with soft pancreas were included. In the former period (July 2013 to May 2015), gravity dependent drainage was applied (gravity dependent drainage group), and in the latter period (June 2015 to November 2016), constant negative pressure drainage (negative pressure drainage group) was applied to the main pancreatic duct stent. RESULTS: There were 37 patients in the gravity dependent drainage group and 39 patients in the negative pressure drainage group. Clinically relevant POPF occurred in 21 patients (56.8%) in the gravity dependent drainage group and 13 patients (33.3%) in the negative pressure drainage group (p = 0.040). The incidence rate of major complications (Clavien-Dindo grade > III) was significantly lower in the negative pressure drainage group (13.2%) compared to the gravity dependent drainage group (48.7%) (p = 0.001). In-hospital stay was also significantly shorter in the negative pressure drainage group compared to the gravity dependent drainage group (median 25 vs. 33 days, p = 0.024). Multivariate analysis demonstrated that the gravity dependent drainage was one of the independent risk factors for the incidence of POPF (odds ratio, 3.33; p = 0.032). CONCLUSIONS: In patients with soft pancreas, the incidence rate of clinically relevant POPF may be reduced by applying constant negative pressure to the pancreatic duct stent. It also has a potential to reduce overall incidence of major complications and shorten in-hospital stay after pancreatoduodenectomy.