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.

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.

Patient survey on cancer genomic medicine in Japan under the national health insurance system.

In Japan, comprehensive genomic profiling (CGP) tests have been reimbursed under the national health care system for solid cancer patients who have finished standard treatment. More than 50,000 patients have taken the test since June 2019. We performed a nation-wide questionnaire survey between March 2021 and July 2022. Questionnaires were sent to 80 designated Cancer Genomic Medicine Hospitals. Of the 933 responses received, 370 (39.7%) were web based and 563 (60.3%) were paper based. Most patients (784, 84%) first learned about CGP tests from healthcare professionals, and 775 (83.1%) gave informed consent to their treating physician. At the time of informed consent, they were most worried about test results not leading to novel treatment (536, 57.4%). On a scale of 0-10, 702 respondents (75.2%) felt that the explanations of the test result were easy to understand (7 or higher). Ninety-one patients (9.8%) started their recommended treatment. Many patients could not receive recommended treatment because no approved drugs or clinical trials were available (102/177, 57.6%). Ninety-eight patients (10.5%) did not wish their findings to be disclosed. Overall satisfaction with the CGP test process was high, with 602 respondents (64.5%) giving a score of 7-10. The major reason for choosing 0-6 was that the CGP test result did not lead to new treatment (217/277, 78.3%). In conclusion, satisfaction with the CGP test process was high. Patients and family members need better access to information. More patients need to be treated with genomically matched therapy.

Human resources for administrative work to carry out a comprehensive genomic profiling test in Japan.

Comprehensive genomic profiling (CGP) tests have been nationally reimbursed in Japan since June 2019 under strict restrictions, and over 46,000 patients have taken the test. Core Hospitals and Designated Hospitals host molecular tumor boards, which is more time-consuming than simply participating in them. We sent a questionnaire to government-designated Cancer Genomic Medicine Hospitals, including all 12 Core Hospitals, all 33 Designated Hospitals, and 117 of 188 Cooperative Hospitals. The questionnaire asked how much time physicians and nonphysicians spent on administrative work for cancer genomic medicine. For every CGP test, 7.6 h of administrative work was needed. Physicians spent 2.7 h/patient, while nonphysicians spent 4.9 h/patient. Time spent preparing for molecular tumor boards, called Expert Panels, was the longest, followed by time spent participating in Expert Panels. Assuming an hourly wage of ¥24,000/h for physicians and ¥2800/h for nonphysicians, mean labor cost was ¥78,071/patient. On a monthly basis, more time was spent on administrative work at Core Hospitals compared with Designated Hospitals and Cooperative Hospitals (385 vs. 166 vs. 51 h/month, respectively, p < 0.001). Consequently, labor cost per month was higher at Core Hospitals than at Designated Hospitals and Cooperative Hospitals (¥3,951,854 vs. ¥1,687,167 vs. ¥487,279/month, respectively, p < 0.001). Completing a CGP test for a cancer patient in Japan is associated with significant labor at each hospital, especially at Core Hospitals. Streamlining the exchange of information and simplifying Expert Panels will likely alleviate this burden.

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.

Impact of combined resection of the internal iliac artery on loss of volume of the gluteus muscles after pelvic exenteration.

PURPOSE: To clarify the influence of additional internal iliac artery (IIA) resection on the loss of the gluteus muscle volume after pelvic exenteration (PE). METHODS: The subjects of this retrospective analysis were 78 patients who underwent PE with or without IIA resection (n = 44 and n = 34, respectively) between 2006 and 2018. The areas of gluteal muscles (GMs) and psoas muscles (PSMs) were calculated using CT images before and 6 months after PE, and the difference was compared. RESULTS: The volumes of the GMs and PSMs were significantly reduced after PE (P < 0.001 and P = 0.005, respectively). In the IIA resection group, the GMs were significantly reduced after surgery, but the PSMs were not. The maximum GM (Gmax) was the most atrophied among the GMs. Multivariable analysis revealed that complete IIA resection was an independent promotor of the loss of volume of the Gmax (P = 0.044). In 18 patients with unilateral IIA resection, the downsizing rate of the Gmax was significantly greater on the resected side than on the non-resected side (P = 0.008). CONCLUSIONS: The GMs and PSMs were significantly smaller after PE. Complete IIA resection reduced the Gmax area remarkably. Preservation of the superior gluteus artery is likely to help maintain Gmax size, suggesting a potential preventative measure against secondary sarcopenia.

Minimum radial margin in pelvic exenteration for locally advanced or recurrent rectal cancer.

PURPOSE: The aim of this study was to clarify the suitable radial margin (RM) for favourable outcomes after pelvic exenteration (PE), focusing on the discrepancy between the concepts of circumferential resection margin (CRM) and traditional R status. METHODS: Seventy-three patients with locally advanced (LARC, n = 24) or locally recurrent rectal cancer (LRRC, n = 49) who underwent PE between 2006 and 2018 were retrospectively analysed. Patients were histologically classified into the following 3 groups; wide RM (≥1 mm, n = 45), narrow RM (0-1 mm, n = 10), and exposed RM (n = 18). The analysis was performed not only in the entire cohort but also in each disease group separately. RESULTS: The rates of traditional R0 (RM > 0 mm) and wide RM were 75.3% and 61.6%, respectively, resulting in the discrepancy rate of 13.7% between the two concepts. Preoperative radiotherapy was given in 12.3%. In the entire cohort, the local recurrence and overall survival (OS) rates for narrow RMs were significantly worse than those for wide RMs (p < 0.001 and p = 0.002), but were similar to those for exposed RMs. In both LARC and LRRC, RM < 1 mm resulted in significantly worse local recurrence and OS rates compared to the wide RMs. Multivariate analysis showed that RM < 1 mm was an independent risk factor for local recurrence in both LARC (HR 15.850, p = 0.015) and LRRC (HR 4.874, p = 0.005). CONCLUSIONS: Narrow and exposed RMs had an almost equal impact on local recurrence and poor OS after PE. Preoperative radiotherapy might have a key role to ensure a wide RM.

Trefoil factor 1 inhibits the development of esophageal adenocarcinoma from Barrett's epithelium.

Trefoil factor family 1 (TFF1) is one of three members of the trefoil factor family that are abundantly expressed in the gastrointestinal mucosal epithelium. Recent studies have shown that TFF1 acts as a tumor suppressor in gastric, pancreatic and hepatocellular carcinogenesis; however, little is known about its function in esophageal carcinogenesis, especially in esophageal adenocarcinoma (EAC). Barrett's epithelium is the metaplastic columnar epithelium of the esophagus and a known premalignant lesion of EAC. To investigate the role of TFF1 in EAC development, a mouse model of Barrett's epithelium was employed, and human specimens of EAC were assessed by immunohistochemistry (IHC) and methylation-specific PCR. Wild-type (WT) mice underwent gastrojejunostomy on the forestomach, resulting in the development of Barrett's epithelium-like (BE-like) epithelium adjacent to the anastomotic site. BE-like epithelium in these mice expressed TFF1, indicating the association of TFF1 with esophageal adenocarcinoma. TFF1-knockout (TFF1KO) mice underwent the same procedure as well, revealing that a deficiency in TFF1 resulted in the development of adenocarcinoma in the anastomotic site, presumably from BE-like epithelium. IHC of human samples revealed strong TFF1 expression in Barrett's epithelium, which was lost in some EACs, confirming the association between TFF1 and EAC development. Aberrant DNA hypermethylation in TFF1 promoter lesions was detected in TFF1-negative human EAC samples, further confirming not only the role of TFF1 in EAC but also the underlying mechanisms of TFF1 regulation. In addition, IHC revealed the nuclear translocation of ß-catenin in human and mouse EAC, suggesting that activation of the Wnt/ß-catenin pathway was induced by the loss of TFF1. In conclusion, these results indicate that TFF1 functions as a tumor suppressor to inhibit the development of esophageal carcinogenesis from Barrett's epithelium.

Trefoil factor family 2 inhibits cholangiocarcinogenesis by regulating the PTEN pathway in mice.

Trefoil factor family 2 (TFF2) is one of three trefoil factor family proteins and is expressed abundantly in the gastrointestinal epithelium. Recent studies have shown that TFF2 acts as a tumor suppressor in gastric and pancreatic carcinogenesis; however, little is known about its function in cholangiocarcinogenesis. To investigate the function of TFF2 in cholangiocellular carcinoma (CCC), immunohistochemistry of surgically resected human CCC samples was performed. TFF2 expression was upregulated in the early stage and lost in the late stage of cholangiocarcinogenesis, suggesting the association of TFF2 and CCC. A TFF2 expression vector was then transfected into a CCC cell line (HuCCT1) in vitro, revealing that TFF2 functions as a tumor suppressor not only by inhibiting proliferation and invasion but also by promoting the apoptosis of cancer cells. In addition, PTEN signaling activity was downregulated by TFF2, suggesting an association between TFF2 and PTEN. Next, hepatic carcinogenesis model mice (KC; albumin-Cre/Lox-Stop-Lox KRASG12D) were bred with TFF2-knockout mice to generate a TFF2-deficient mouse model (KC/TFF2-/-). Although the incidence of hepatocellular carcinoma was not different between KC/TFF2-/- mice and control mice, biliary intraepithelial neoplasm (BilIN), the precursor of CCC, was frequently found in the biliary epithelium of KC/TFF2-/- mice. Immunohistochemistry revealed that BilIN samples from these mice did not express PTEN. In addition, two KC/TFF2-/- mice developed CCC adjacent to BilIN, suggesting that TFF2 functions to inhibit the development of CCC in vivo. These results indicate that TFF2 acts as a tumor suppressor to inhibit the development of CCC by regulating PTEN activity.

Premalignant pancreatic cells seed stealth metastasis in distant organs in mice.

Recent findings suggest that the dissemination of tumor cells occurs at the early stage of breast and pancreatic carcinogenesis, which is known as early dissemination. The evidence of early dissemination has been demonstrated predominantly in the bloodstream and bone marrow; however, limited evidence has revealed the existence and behavior of disseminated cells in distant organs. Here, we show that premalignant pancreatic cells seed distant stealth metastasis that eventually develops into manifest metastasis. By analyzing lineage-labeled pancreatic cancer mouse models (KPCT/TFF1KO; Pdx1-Cre/LSL-KRASG12D/LSL-p53R172H/LSL-tdTomato/TFF1KO), we found that premalignant pancreatic cells, rather than mature malignant cells, were prone to enter the bloodstream and reside in the bone marrow, liver, and lung. While these metastatic cells exhibited the characteristics of the cells of host organs and did not behave as malignant cells, they underwent malignant transformation and formed distinct tumors. Surprisingly, the manifestation of distant metastasis occurred even before tumor development in the primary site. Our data revealed that disseminated premalignant cells reside stealthily in distant organs and evolve in parallel with the progression of the primary tumor. These observations suggest that we must rebuild a therapeutic strategy for metastatic pancreatic cancer.

A presurgical prognostic stratification based on nutritional assessment and carbohydrate antigen 19-9 in pancreatic carcinoma: An approach with nonanatomic biomarkers.

BACKGROUND: Nutritional status and tumor markers are important prognostic indicators for surgical decisions in pancreatic carcinoma. This study aimed to stratify the probability of surviving pancreatic carcinoma based on systematically chosen nonanatomic biomarkers. METHODS: We included 187 consecutive patients that underwent surgical resections for pancreatic carcinoma. We performed multivariable analyses to evaluate prognostic indicators, including 4 blood-test indexes: the neutrophil-to-lymphocyte ratio, platelet-to-lymphocyte ratio, prognostic nutritional index, and the modified Glasgow prognostic score; and 4 body-composition indexes: the normalized total psoas muscle area, the normalized total elector spine muscle area, the psoas muscle computed tomography value, and the elector spine muscle computed tomography value. RESULTS: Poor survival was associated with 2 independent risk factors: neutrophil-to-lymphocyte ratio ≥3.0 (hazard ratio, 1.54) and prognostic nutritional index <36 (hazard ratio, 1.60), and with high carbohydrate antigen 19-9 levels (≥37 IU/mL). The 2 indexes were not significantly associated with clinicopathological factors, including carbohydrate antigen 19-9. Patients with no risk factors had significantly better survival than those with 1 (P = .007) or 2 risk factors (P = .001), and survival was similar in the latter 2 groups (P = .253). A presurgical nonanatomic scoring system (range, 0-2) was constructed: 0 points for no risk factors, 1 point for 1 or 2 nutritional risk factors, and 1 point for carbohydrate antigen 19-9 ≥37 IU/mL. Survival rate at 3 years decreased with increasing scores (76% for score 0, 42% for score 1, and 21% for score 2; all P < .05). CONCLUSION: Neutrophil-to-lymphocyte ratio and prognostic nutritional index were independent prognostic risk factors in pancreatic carcinoma and integrating these indexes with carbohydrate antigen 19-9 levels could successfully stratify survival.

Trefoil Factor Family 1 Inhibits the Development of Hepatocellular Carcinoma by Regulating ß-Catenin Activation.

BACKGROUND AND AIMS: Recent studies have suggested that trefoil factor family 1 (TFF1) functions as a tumor suppressor in gastric and pancreatic carcinogenesis. APPROACH AND RESULTS: To investigate the role of TFF1 in hepatocarcinogenesis, we performed immunohistochemical staining of surgically resected human liver samples, transfected a TFF1 expression vector into hepatocellular carcinoma (HCC) cell lines, and employed a mouse model of spontaneous HCC development (albumin-cyclization recombination/Lox-Stop-Lox sequence-Kirsten rat sarcoma viral oncogene homologG12D [KC]); the model mouse strain was bred with a TFF1-knockout mouse strain to generate a TFF1-deficient HCC mouse model (KC/TFF1-/- ). TFF1 expression was found in some human samples with HCC. Interestingly, TFF1-positive cancer cells showed a staining pattern contradictory to that of proliferating cell nuclear antigen, and aberrant DNA hypermethylation in TFF1 promoter lesions was detected in HCC samples, indicating the tumor-suppressive role of TFF1. In vitro, induction of TFF1 expression resulted in impaired proliferative activity and enhanced apoptosis in HCC cell lines (HuH7, HepG2, and HLE). These anticancer effects of TFF1 were accompanied by the loss of nuclear ß-catenin expression, indicating inactivation of the ß-catenin signaling pathway by TFF1. In vivo, TFF1 deficiency in KC mice accelerated the early development and growth of HCC, resulting in poor survival rates. In addition, immunohistochemistry revealed that the amount of nuclear-localized ß-catenin was significantly higher in KC/TFF1-/- mice than in KC mice and that human HCC tissue showed contradictory expression patterns for ß-catenin and TFF1, confirming the in vitro observations. CONCLUSIONS: TFF1 might function as a tumor suppressor that inhibits the development of HCC by regulating ß-catenin activity.

NEK2 Is an Effective Target for Cancer Therapy With Potential to Induce Regression of Multiple Human Malignancies.

Cancer is characterized by uncontrolled cell proliferation due to the aberrant activity of various proteins. Cell cycle-related proteins are thought to be important in several functions, such as proliferation, invasion and drug resistance in human malignancies. Never in mitosis gene A-related kinase 2 (NEK2) is a cell cycle-related protein. NEK2 is highly expressed in various tumor types and cancer cell lines. NEK2 expression is correlated with rapid relapse and poor outcome in multiple cancer types. Several researchers have demonstrated that NEK2 inhibition results in anticancer effects against many types of cancers, both in vitro and in vivo. Recent research strongly indicates the advantages of NEK2-targeted therapy for cancer. This review focuses on the current understanding of NEK2 in cancer and the rationale of a xenograft cancer model for cancer treatment. A possible therapeutic strategy, such as inhibitor and nucleic acid medicine targeting of NEK2, is also discussed.

Loss of trefoil factor 1 inhibits biliary regeneration but accelerates the hepatic differentiation of progenitor cells in mice.

Although the regeneration of the adult liver depends on hepatic progenitor cells (HPCs), many uncertainties regarding hepatic regeneration in the injured liver remain. Trefoil factor family 1 (TFF1), a secretory protein predominantly expressed in the gastrointestinal tract, is responsible for mucosal restitution. Here, we investigated the role of TFF1 in liver regeneration using a mouse model of hepatic injury (choline-deficient ethionine-supplemented diet and carbon tetrachloride administration) and genetically engineered mice (TFF1 knockout (TFF1-/-)). Immunohistochemistry analysis of human liver samples revealed TFF1 expression in the hepatocytes close to ductular reaction and the regenerating biliary epithelium in injured liver. The number of cytokeratin 19 (CK19)-positive bile ducts was significantly decreased in the TFF1-/- mice after liver injury. Notch pathway in the TFF1-/- mice was also downregulated. HPCs in the control mice differentiated into biliary cells (CK19+/SRY HMG box 9 (SOX9)+) more frequently. In contrast, HPCs in the TFF1-/- mice more frequently differentiated into a hepatic lineage (alpha fetoprotein+/SOX9+) after acute liver damage. Hepatocyte proliferation was upregulated, and the liver weight was increased in TFF1-/- mice in response to chronic liver damage. Thus, TFF1 is responsible for liver regeneration after liver injury by promoting HPC differentiation into a biliary lineage and inhibiting HPC differentiation into a hepatic lineage.

Trefoil factor 1 inhibits epithelial-mesenchymal transition of pancreatic intraepithelial neoplasm.

The tumor-suppressive role of trefoil factor family (TFF) members in gastric carcinogenesis has been suggested, but their significance and mechanisms in other digestive diseases remain elusive. To clarify the role of TFF1 in pancreatic carcinogenesis, we performed IHC on human samples, transfected siRNA against TFF1 into pancreatic cancer cell lines, and employed mouse models in which PanIN development and loss of TFF1 occur simultaneously. In human samples, the expression of TFF1 was specifically observed in pancreatic intraepithelial neoplasm (PanIN), but was frequently lost in the invasive component of pancreatic ductal adenocarcinoma (PDAC). When the expression of TFF1 was suppressed in vitro, pancreatic cancer cell lines showed enhanced invasive ability and features of epithelial-mesenchymal transition (EMT), including upregulated Snail expression. TFF1 expression was also observed in PanIN lesions of Pdx-1 Cre; LSL-KRASG12D (KC) mice, a model of pancreatic cancer, and loss of TFF1 in these mice resulted in the expansion of PanIN lesions, an EMT phenotype in PanIN cells, and an accumulation of cancer-associated fibroblasts (CAFs), eventually resulting in the development of invasive adenocarcinoma. This study indicates that the acquisition of TFF1 expression is an early event in pancreatic carcinogenesis and that TFF1 might act as a tumor suppressor to prevent EMT and the invasive transformation of PanIN.

Pre-exposure to Fluorouracil Increased Trifluridine Incorporation and Enhanced its Anti-tumor Effect for Colorectal Cancer.

BACKGROUND/AIM: Trifluridine/tipiracil (FTD/TPI) is used for metastatic colorectal cancer, that is refractory to 5-fluorouracil (5-FU)-based therapies. However, the impact of pre-exposure to 5-FU on the anti-cancer effect of FTD, which is a key component of FTD/TPI, is unclear. MATERIALS AND METHODS: The incorporation into DNA and anti-cancer activity of FTD were analyzed in several cancer cell lines under response to FTD treatment with or without 5-FU pre-exposure. The volumes of tumors in xenografted nude mice were examined among groups that were either untreated or treated with S-1, FTD/TPI or FTD/TPI with pre-exposure to S-1. RESULTS: Pre-exposure to 5-FU significantly increased FTD incorporation into DNA and enhanced its anti-cancer effect for viability and proliferation of cancer cells. In the xenograft nude mouse model, the tumor volumes in the FTD/TPI-treated and S-1-pre-exposed group were lower than those in the FTD/TPI-only-treated group. Although both FTD dose and exposure time in the FTD/TPI-treated and S-1-pre-exposed mice were smaller than those in the FTD/TPI-only-treated mice, the incorporated FTD in the tumors in the former group was 86.5% of that in the latter group. CONCLUSION: Pre-exposure to 5-FU enhanced the incorporation into DNA and the anti-cancer effect of FTD in the context of colorectal cancer. Our data indicate the potential for a new sequential therapy using S-1 and FTD/TPI to improve prognosis of colorectal cancer.

Inhibition of Toll-like receptor 4 ameliorates experimental postischemic injury in the cholestatic liver through inhibition of high-mobility group box protein b1 (HMGB1) signaling.

BACKGROUND: The objective of this study was to elucidate whether the inhibition of Toll-like receptor 4 attenuates liver injury ischemia/reperfusion in the cholestatic liver. METHOD: Rats were assigned into sham, bile duct ligation, sham ischemia/reperfusion (ischemia/reperfusion after laparotomy), and bile duct ligation ischemia/reperfusion (ischemia/reperfusion after bile duct ligation) groups. In some rats, TAK-242, an inhibitor of Toll-like receptor 4, was administered 15 minutes before ischemia/reperfusion. We measured intrahepatic Toll-like receptor 4 expression, serum hepatic marker expression, liver necrosis, gene expression of inflammation-associated factors, and serum high-mobility group box protein b1 levels. RESULTS: Intrahepatic Toll-like receptor 4 expression was significantly greater in the bile duct ligation group than in the sham group. Toll-like receptor 4 expression was further increased after ischemia/reperfusion in bile duct ligation ischemia/reperfusion groups. The levels of serum hepatic markers were significantly greater in both the sham ischemia/reperfusion and bile duct ligation ischemia/reperfusion groups than in the groups without ischemia/reperfusion. Liver necrosis was greater in the bile duct ligation group than in the sham group and was further increased in the bile duct ligation ischemia/reperfusion group. Genomic expression of inflammation-associated factors was also significantly greater in the bile duct ligation ischemia/reperfusion group than in the sham group. Serum high-mobility groups box protein b1 levels were greater in the bile duct ligation ischemia/reperfusion group than in the sham group (28.1 ng/ml versus 9.2 ng/ml, P = .011) and the bile duct ligation group (28.1 ng/ml versus 10.6 ng/ml, P = .017). These changes in the bile duct ligation ischemia/reperfusion group were significantly attenuated by preconditioning with TAK242. CONCLUSIONS: Toll-like receptor 4 inhibition has a potential to minimize severe injury after ischemia/reperfusion in the cholestatic liver through inhibition of high-mobility groups box protein b1.

Cells of origin of pancreatic neoplasms.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignant disease associated with poor prognosis, despite recent medical advances. It is of great importance to understand the initial events and cells of origin of pancreatic cancer to prevent the development and progression of PDAC. There are three distinct precursor lesions that develop into PDAC: pancreatic intraepithelial neoplasms (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and mucinous cystic neoplasms (MCNs). Studies on genetically engineered mouse models have revealed that the initiation and development of these lesions largely depend on genetic alterations. These lesions originate from different populations in the pancreas. PanIN development seems to be the result of the transdifferentiation of acinar cells, whereas IPMNs most likely arise from the progenitor niche of the pancreatic ductal epithelium. Pancreatic carcinogenesis is dependent on various events, including gene alterations, environmental insults, and cell types. However, further studies are needed to fully understand the initial processes of pancreatic cancer.

Trefoil factor family 1 expression in the invasion front is a poor prognostic factor associated with lymph node metastasis in pancreatic cancer.

OBJECTIVES: Trefoil Factor Family protein 1 (TFF1) is secreted from mucus-producing cells. The relationship between TFF1 expression and clinical outcome in pancreatic ductal adenocarcinoma (PDAC) remains unknown. We aimed to evaluate the prognostic significance of TFF1 expression in PDAC. METHODS: TFF1 expression was examined on paraffin-embedded sections from 91 patients with resected PDAC using immunohistochemistry. The relationships between TFF1 expression and clinicopathological features were analyzed. RESULTS: Among 91 PDAC patients, 71 patients (79.7%) showed TFF1 expression in cancer cells. In a subgroup of 71 patients, TFF1 expression was predominantly observed in the central part of the tumor, whereas TFF1 expression in the invasion front was reduced in 33 patients (46.4%). A significant correlation between preserved TFF1 expression in the invasion front and lymph node metastasis was observed. Univariate survival analysis revealed that preserved TFF1 expression in the invasion front, positive lymphatic invasion, lymph node metastasis and R1 resection was a significant poor prognostic factor in TFF1-positive PDAC patients. CONCLUSIONS: TFF1 expression is frequently lost or decreased in the invasion front of human PDAC, and preserved TFF1 expression in the invasion front might predict poor survival in patients with PDAC.