Appendectomy and Long-term Colorectal Cancer Incidence, Overall and by Tumor Fusobacterium nucleatum Status.

OBJECTIVE: To test hypotheses that appendectomy history might lower long-term colorectal cancer risk and that the risk reduction might be strong for tumors enriched with Fusobacterium nucleatum, bacterial species implicated in colorectal carcinogenesis. BACKGROUND: The absence of the appendix, an immune system organ and a possible reservoir of certain pathogenic microbes, may affect the intestinal microbiome, thereby altering long-term colorectal cancer risk. METHODS: Utilizing databases of prospective cohort studies, namely the Nurses' Health Study and the Health Professionals Follow-up Study, we examined the association of appendectomy history with colorectal cancer incidence overall and subclassified by the amount of tumor tissue Fusobacterium nucleatum​​ (Fusobacterium animalis). We used an inverse probability weighted multivariable-adjusted duplication-method Cox proportional hazards regression model. RESULTS: During the follow-up of 139,406 participants (2,894,060 person-years), we documented 2811 incident colorectal cancer cases, of which 1065 cases provided tissue F. nucleatum analysis data. The multivariable-adjusted hazard ratio of appendectomy for overall colorectal cancer incidence was 0.92 (95% CI, 0.84-1.01). Appendectomy was associated with lower F. nucleatum-positive cancer incidence (multivariable-adjusted hazard ratio, 0.53; 95% CI, 0.33-0.85; P=0.0079), but not F. nucleatum-negative cancer incidence (multivariable-adjusted hazard ratio, 0.98; 95% CI, 0.83-1.14), suggesting a differential association by F. nucleatum status (Pheterogeneity=0.015). This differential association appeared to persist in various participant/patient strata including tumor location and microsatellite instability status. CONCLUSIONS: Appendectomy likely lowers the future long-term incidence of F. nucleatum-positive (but not F. nucleatum-negative) colorectal cancer. Our findings do not support the existing hypothesis that appendectomy may increase colorectal cancer risk.

Western-Style Diet, pks Island-Carrying Escherichia coli, and Colorectal Cancer: Analyses From Two Large Prospective Cohort Studies.

BACKGROUND & AIMS: Evidence supports a carcinogenic role of Escherichia coli carrying the pks island that encodes enzymes for colibactin biosynthesis. We hypothesized that the association of the Western-style diet (rich in red and processed meat) with colorectal cancer incidence might be stronger for tumors containing higher amounts of pks+E coli. METHODS: Western diet score was calculated using food frequency questionnaire data obtained every 4 years during follow-up of 134,775 participants in 2 United States-wide prospective cohort studies. Using quantitative polymerase chain reaction, we measured pks+E coli DNA in 1175 tumors among 3200 incident colorectal cancer cases that had occurred during the follow-up. We used the 3200 cases and inverse probability weighting (to adjust for selection bias due to tissue availability), integrated in multivariable-adjusted duplication-method Cox proportional hazards regression analyses. RESULTS: The association of the Western diet score with colorectal cancer incidence was stronger for tumors containing higher levels of pks+E coli (Pheterogeneity = .014). Multivariable-adjusted hazard ratios (with 95% confidence interval) for the highest (vs lowest) tertile of the Western diet score were 3.45 (1.53-7.78) (Ptrend = 0.001) for pks+E coli-high tumors, 1.22 (0.57-2.63) for pks+E coli-low tumors, and 1.10 (0.85-1.42) for pks+E coli-negative tumors. The pks+E coli level was associated with lower disease stage but not with tumor location, microsatellite instability, or BRAF, KRAS, or PIK3CA mutations. CONCLUSIONS: The Western-style diet is associated with a higher incidence of colorectal cancer containing abundant pks+E coli, supporting a potential link between diet, the intestinal microbiota, and colorectal carcinogenesis.

Tumor microenvironmental 15-PGDH depletion promotes fibrotic tumor formation and angiogenesis in pancreatic cancer.

The arachidonic acid cascade is a major inflammatory pathway that produces prostaglandin E2 (PGE2). Although inhibition of 15-hydroxyprostaglandin dehydrogenase (15-PGDH) is reported to lead to PGE2 accumulation, the role of 15-PGDH expression in the tumor microenvironment remains unclear. We utilized Panc02 murine pancreatic cancer cells for orthotopic transplantation into wild-type and 15-pgdh+/- mice and found that 15-pgdh depletion in the tumor microenvironment leads to enhanced tumorigenesis accompanied by an increase in cancer-associated fibroblasts (CAFs) and the promotion of fibrosis. The fibrotic tumor microenvironment is widely considered to be hypovascular; however, we found that the angiogenesis level is maintained in 15-pgdh+/- mice, and these changes were also observed in a genetically engineered PDAC mouse model. Further confirmation revealed that fibroblast growth factor 1 (FGF1) is secreted by pancreatic cancer cells after PGE2 stimulation, consequently promoting CAF proliferation and vascular endothelial growth factor A (VEGFA) expression in the tumor microenvironment. Finally, in 15-pgdh+/- Acta2-TK mice, depletion of fibroblasts inhibited angiogenesis and cancer cell viability in orthotopically transplanted tumors. These findings highlighted the role of 15-pgdh downregulation in enhancing PGE2 accumulation in the pancreatic tumor microenvironment and in subsequently maintaining the angiogenesis level in fibrotic tumors along with CAF expansion.

Immune cell profiles in the tumor microenvironment of early-onset, intermediate-onset, and later-onset colorectal cancer.

BACKGROUND: Despite heightened interest in early-onset colorectal cancer (CRC) diagnosed before age 50, little is known on immune cell profiles of early-onset CRC. It also remains to be studied whether CRCs diagnosed at or shortly after age 50 are similar to early-onset CRC. We therefore hypothesized that immune cell infiltrates in CRC tissue might show differential heterogeneity patterns between three age groups (< 50 "early onset," 50-54 "intermediate onset," ≥ 55 "later onset"). METHODS: We examined 1,518 incident CRC cases with available tissue data, including 35 early-onset and 73 intermediate-onset cases. To identify immune cells in tumor intraepithelial and stromal areas, we developed three multiplexed immunofluorescence assays combined with digital image analyses and machine learning algorithms, with the following markers: (1) CD3, CD4, CD8, CD45RO (PTPRC), and FOXP3 for T cells; (2) CD68, CD86, IRF5, MAF, and MRC1 (CD206) for macrophages; and (3) ARG1, CD14, CD15, CD33, and HLA-DR for myeloid cells. RESULTS: Although no comparisons between age groups showed statistically significant differences at the stringent two-sided α level of 0.005, compared to later-onset CRC, early-onset CRC tended to show lower levels of tumor-infiltrating lymphocytes (P = 0.013), intratumoral periglandular reaction (P = 0.025), and peritumoral lymphocytic reaction (P = 0.044). Compared to later-onset CRC, intermediate-onset CRC tended to show lower densities of overall macrophages (P = 0.050), M1-like macrophages (P = 0.062), CD14+HLA-DR+ cells (P = 0.015), and CD3+CD4+FOXP3+ cells (P = 0.039). CONCLUSIONS: This hypothesis-generating study suggests possible differences in histopathologic lymphocytic reaction patterns, macrophages, and regulatory T cells in the tumor microenvironment by age at diagnosis.

Association of autophagy status with amount of Fusobacterium nucleatum in colorectal cancer.

Fusobacterium nucleatum (F. nucleatum), which has been associated with colorectal carcinogenesis, can impair anti-tumour immunity, and actively invade colon epithelial cells. Considering the critical role of autophagy in host defence against microorganisms, we hypothesised that autophagic activity of tumour cells might influence the amount of F. nucleatum in colorectal cancer tissue. Using 724 rectal and colon cancer cases within the Nurses' Health Study and the Health Professionals Follow-up Study, we evaluated autophagic activity of tumour cells by immunohistochemical analyses of BECN1 (beclin 1), MAP1LC3 (LC3), and SQSTM1 (p62) expression. We measured the amount of F. nucleatum DNA in tumour tissue by quantitative polymerase chain reaction (PCR). We conducted multivariable ordinal logistic regression analyses to examine the association of tumour BECN1, MAP1LC3, and SQSTM1 expression with the amount of F. nucleatum, adjusting for potential confounders, including microsatellite instability status; CpG island methylator phenotype; long-interspersed nucleotide element-1 methylation; and KRAS, BRAF, and PIK3CA mutations. Compared with BECN1-low cases, BECN1-intermediate and BECN1-high cases were associated with lower amounts of F. nucleatum with odds ratios (for a unit increase in three ordinal categories of the amount of F. nucleatum) of 0.54 (95% confidence interval, 0.29-0.99) and 0.31 (95% confidence interval, 0.16-0.60), respectively (Ptrend < 0.001 across ordinal BECN1 categories). Tumour MAP1LC3 and SQSTM1 levels were not significantly associated with the amount of F. nucleatum (Ptrend > 0.06). Tumour BECN1, MAP1LC3, and SQSTM1 levels were not significantly associated with patient survival (Ptrend > 0.10). In conclusion, tumour BECN1 expression is inversely associated with the amount of F. nucleatum in colorectal cancer tissue, suggesting a possible role of autophagy in the elimination of invasive microorganisms. © 2019 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

An integrated analysis of lymphocytic reaction, tumour molecular characteristics and patient survival in colorectal cancer.

BACKGROUND: Histological lymphocytic reaction is regarded as an independent prognostic marker in colorectal cancer. Considering the lack of adequate statistical power, adjustment for selection bias and comprehensive tumour molecular data in most previous studies, we investigated the strengths of the prognostic associations of lymphocytic reaction in colorectal carcinoma by utilising an integrative database of two prospective cohort studies. METHODS: We examined Crohn's-like reaction, intratumoural periglandular reaction, peritumoural reaction and tumour-infiltrating lymphocytes in 1465 colorectal carcinoma cases. Using covariate data of 4420 colorectal cancer cases in total, inverse probability-weighted Cox proportional hazard regression model was used to control for selection bias (due to tissue availability) and potential confounders, including stage, MSI status, LINE-1 methylation, PTGS2 and CTNNB1 expression, KRAS, BRAF and PIK3CA mutations, and tumour neoantigen load. RESULTS: Higher levels of each lymphocytic reaction component were associated with better colorectal cancer-specific survival (Ptrend < 0.002). Compared with cases with negative/low intratumoural periglandular reaction, multivariable-adjusted HRs were 0.55 (95% CI, 0.42-0.71) in cases with intermediate reaction and 0.20 (95% CI, 0.12-0.35) in cases with high reaction. These relationships were consistent in strata of MSI status or neoantigen loads (Pinteraction > 0.2). CONCLUSIONS: The four lymphocytic reaction components are prognostic biomarkers in colorectal carcinoma.

Postoperative nonalcoholic fatty liver disease is correlated with malnutrition leading to an unpreferable clinical course for pancreatic cancer patients undergoing pancreaticoduodenectomy.

PURPOSES: This study aimed to clarify the impact of postoperative nonalcoholic fatty liver disease (NAFLD) on the clinical course of patients with pancreatic ductal adenocarcinoma (PDAC). METHODS: One hundred and eight patients with pancreatic cancer undergoing pancreaticoduodenectomy (PD) with curative intent in between 2005 and 2016 were enrolled in this study. Post-PD NAFLD was assessed by computed tomography (CT), which was routinely performed at 3 months, 6 months, and 1 year after surgery. The clinical impact of post-PD NAFLD was examined from an oncological perspective. RESULTS: There were 50 (46.2%) post-PD NAFLD patients. The NAFLD group showed significantly lower CT values at 3 months, 6 months, and 1 year after surgery than those without NAFLD. Patients with NAFLD showed significant body weight loss and a decrease in serum albumin level after surgery compared with those without NAFLD. Consequently, the 70% completion rate of adjuvant chemotherapy with gemcitabine, but not S1, was significantly lower in the NAFLD group than in the non-NAFLD group. The 5-year overall survival and disease-free survival rates were comparable between the two groups. CONCLUSION: Post-PD NAFLD was associated with malnutrition in patients with PDAC, reducing their tolerance to gemcitabine-based adjuvant chemotherapy. Post-PD NAFLD needs to be emphasized and requires special nutritional intervention in patients with PDAC.

Clinical role of serum programmed death ligand 1 in patients with hepatocellular carcinoma: Where does it come from?

PURPOSES: Programmed death ligand 1 (PD-L1) is a key target for the treatment of several malignancies. The present study was conducted to clarify the role of serum PD-L1 in hepatocellular carcinoma (HCC). METHODS: Serum PD-L1 (sPD-L1) was examined by an enzyme-linked immunosorbent assay in 153 patients with HCC who underwent curative hepatectomy at Kumamoto University in 2011-2016. The expression of PD-L1 in tissue (tPD-L1) was investigated by immunohistochemistry. The clinical roles of the PD-L1 expression in both serum and tissue were examined. RESULTS: The sPD-L1 was significantly elevated in HCC patients compared to patients without any malignant or inflammatory disease (234 vs. 93 pg/mL, p < 0.0001). The percentage of the tPD-L1-positive area (%tPD-L1) in the background liver was significantly higher than in the tumor (1.52% vs. 0.48%, p < 0.0001). The %tPD-L1 in the background liver but not in the tumor was significantly correlated with the sPD-L1 level (p = 0.0079). The sPD-L1, %tPD-L1 in the tumor, and %tPD-L1 in the background liver were not correlated with the overall survival after surgery. CONCLUSION: PD-L1-expressing cells in the background liver, but not in the tumor tissue, appeared to contribute to the sPD-L1 level. The sPD-L1 level may thus not indicate the tumor burden in patients with HCC.

Lysyl oxidase induces epithelial-mesenchymal transition and predicts intrahepatic metastasis of hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) has high recurrence rates even after curative hepatectomy. Drug therapy for recurrence of HCC is still limited; therefore, identifying new therapeutic targets is urgently needed. We searched for genes that would predict HCC recurrence from intrahepatic metastasis in an exhaustive DNA microarray database by searching genes associated with high early recurrence rate and having higher expression in the tumor area compared to background liver. We detected lysyl oxidase (LOX) and validated the clinical significance of LOX in 358 patients who underwent hepatectomy. Expression of LOX was evaluated by qRT- PCR, and immunohistochemical (IHC) staining. High LOX expression group had a significantly higher recurrence rate than the low LOX expression group (2-year recurrence rate was 64.0% vs 24.2%, P < .0001 for IHC) and poorer survival rate (5-year rate was 60.1% vs 86.2%, P < .0001 for IHC). Multivariate analysis showed that high LOX expression was an independent risk factor for early recurrence (IHC: HR, 2.52; P < .0001). Bioinformatic analysis showed that LOX expression was associated with hypoxia-inducible factor-1α (HIF-1α) and the hypoxia cascade, suggesting that HIF-1α or hypoxia regulates LOX expression and induces epithelial-mesenchymal transition (EMT). In vitro, LOX and HIF-1α were involved in migration and invasion capability. High LOX expression is associated with EMT markers and predicts early recurrence and poor survival in patients with HCC. These findings indicate that lysyl oxidase could be a potential therapeutic target for early recurrence of HCC.

PD-L1 expression enhancement by infiltrating macrophage-derived tumor necrosis factor-α leads to poor pancreatic cancer prognosis.

Immunotherapy using anti-PD-1/PD-L1 antibodies for several types of cancer has received considerable attention in recent decades. However, the molecular mechanism underlying PD-L1 expression in pancreatic ductal adenocarcinoma (PDAC) cells has not been clearly elucidated. We investigated the clinical significance and regulatory mechanism of PD-L1 expression in PDAC cells. Among the various cytokines tested, tumor necrosis factor (TNF)-α upregulated PD-L1 expression in PDAC cells through NF-κB signaling. The induction of PD-L1 expression was also caused by co-culture with activated macrophages, and the upregulation was inhibited by neutralization with anti-TNF-α antibody after co-culture with activated macrophages. PD-L1 expression in PDAC cells was positively correlated with macrophage infiltration in tumor stroma of human PDAC tissues. In addition, survival analysis revealed that high PD-L1 expression was significantly associated with poor prognosis in 235 PDAC patients and especially in patients harboring high CD8-positive T-cell infiltration. These findings indicate that tumor-infiltrating macrophage-derived TNF-α could be a potential therapeutic target for PDAC.

Impact of loss-of-function mutations at the RNF43 locus on colorectal cancer development and progression.

RNF43 mutations are frequently detected in colorectal cancer cells and lead to a loss of function of the ubiquitin E3 ligase. Here, we investigated the clinical significance of RNF43 mutations in a large Japanese cohort and the role of RNF43 at various stages of colorectal cancer development and progression. Mutation analysis of the RNF43 gene locus with pyrosequencing technology detected RNF43 hotspot mutations in one (0.88%) of 113 colorectal polyp cases and in 30 (6.45%) of 465 colorectal cancer cases. Moreover, patients with colorectal cancer harbouring mutated RNF43 experienced a higher recurrence rate than those harbouring non-mutated RNF43. In addition, the growth of RNF43 wild-type colorectal cancer cell lines was significantly increased by RNF43 silencing. We generated Rnf43 knockout mice in a C57BL/6 N background by using the CRISPR-Cas9 system. Although intestinal organoids from Rnf43 knockout mice did not show continuous growth in the absence of R-spondin, an azoxymethane/dextran sodium sulphate mouse model demonstrated that tumours were markedly larger in Rnf43 knockout mice than in wild-type mice. These findings provide evidence that Wnt signalling activation by RNF43 mutations during the tumourigenic stage enhances tumour growth and promotes a high recurrence rate in colorectal cancer patients. Copyright © 2018 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Clinical role of fludeoxyglucose (18F) positron emission tomography/computed tomography (18F-FDG PET/CT) in patients with pancreatic neuroendocrine tumors.

PURPOSES: Clinical predictive markers for the malignant potential of pancreatic neuroendocrine tumors (PNETs) are limited without histological investigation. We reported previously that a loss of the regular enhancement pattern in preoperative computed tomography (CT) was correlated with the malignant tumor phenotype. This study aimed to establish whether the metabolic aspect of the tumor evaluated by fludeoxyglucose (18F) positron emission tomography/computed tomography 18F-FDG PET/CT is associated with the tumor imaging characteristics and postoperative oncological outcome. METHODS: Among 77 patients who underwent surgery with curative intent for a PNET at our institution between 2001 and 2017, 24 who received 18F-FDG PET/CT before surgery were enrolled in this study. The clinical importance of the standardized uptake value (SUVmax) was investigated with regard to tumor progression and prognosis after curative surgery. RESULTS: There were four (16%) patients with insulinoma. The mean tumor size was 17 mm and when the median value of the SUVmax (= 2.0) was measured as the cut-off value, the SUVmax ≥ 2.0 group (n = 12) was associated with large tumor size (p = 0.021), high tumor grade (p = 0.015), and irregular pattern on CT (p = 0.0055). The SUVmax was not correlated with age, gender, whether the tumor was functioning or non-functioning, or lymph node metastasis. The SUVmax ≥ 2.0 group had significantly poorer disease-free survival (median, 3.5 vs 16.2 months; p = 0.023) and poorer overall survival (median, 8.8 vs 16.2 months; p = 0.042). CONCLUSION: An SUVmax ≥ 2.0 on 18F-FDG PET/CT might be associated with higher malignant potential of PNETs.

Downregulation of 15-hydroxyprostaglandin dehydrogenase by interleukin-1ß from activated macrophages leads to poor prognosis in pancreatic cancer.

Chronic inflammation has a crucial role in cancer development and the progression of various tumors, including pancreatic ductal adenocarcinoma (PDAC). The arachidonate cascade is a major inflammatory pathway that produces several metabolites, such as prostaglandin E2. The enzyme 15-hydroxyprostaglandin dehydrogenase (15-PGDH) degrades prostaglandin and is frequently decreased in several types of cancer; however, the molecular mechanisms of 15-PGDH suppression are unclear. The current study was carried out to elucidate the molecular mechanisms and clinical significance of 15-PGDH suppression in PDAC. Here, we showed that interleukin-1ß (IL-1ß), a pro-inflammatory cytokine, downregulates 15-PGDH expression in PDAC cells, and that IL-1ß expression was inversely correlated with 15-PGDH levels in frozen PDAC tissues. We also found that activated macrophages produced IL-1ß and reduced 15-PGDH expression in PDAC cells. Furthermore, the number of CD163-positive tumor-associated macrophages was shown to be inversely correlated with 15-PGDH levels in PDAC cells by immunohistochemical staining of 107 PDAC samples. Finally, we found that low 15-PGDH expression was significantly associated with advanced tumors, presence of lymph node metastasis and nerve invasion, and poor prognosis in PDAC patients. Our results indicate that IL-1ß derived from TAMs suppresses 15-PGDH expression in PDAC cells, resulting in poor prognosis of PDAC patients.

Tumour-infiltrating inflammatory and immune cells in patients with extrahepatic cholangiocarcinoma.

BACKGROUND: Inflammation and immune characteristics of the tumour microenvironment have therapeutic significance. The aim of this study was to investigate the clinical impact on disease progression in human extrahepatic cholangiocarcinoma (ECC). METHODS: A total of 114 consecutive ECC patients with curative resection between 2000 and 2014 were enrolled. Tumour infiltrating CD66b+ neutrophils (TANs; tumour associated neutrophils), CD163+ M2 macrophages (TAMs; tumour associated macrophages), CD8+ T cells, and FOXP3+ regulatory T cells (Tregs) were assayed by immunohistochemistry, and their relationships with patient clinicopathological characteristics and prognosis were evaluated. RESULTS: Tumour associated neutrophils were inversely correlated with CD8+ T cells (P=0.0001) and positively correlated with Tregs (P=0.001). High TANs (P=0.01), low CD8+ T cells (P=0.02), and high Tregs (P=0.04) were significantly associated with poor overall survival (OS). A high-risk signature, derived from integration of intratumoural inflammatory and immune cells, was significantly associated with poor recurrence-free survival (P=0.01) and OS (P=0.0008). A high-risk signature was correlated with postoperative distant metastases. Furthermore, a high-risk signature was related to the resistance to gemcitabine-based chemotherapy used after recurrence. CONCLUSIONS: Our data showed that tumour infiltrating inflammatory and immune cells may play a pivotal role in ECC progression and a high-risk signature predicted poor prognosis in ECC patients.

Activation of Transforming Growth Factor Beta 1 Signaling in Gastric Cancer-associated Fibroblasts Increases Their Motility, via Expression of Rhomboid 5 Homolog 2, and Ability to Induce Invasiveness of Gastric Cancer Cells.

BACKGROUND & AIMS: Fibroblasts that interact with cancer cells are called cancer-associated fibroblasts (CAFs), which promote progression of different tumor types. We investigated the characteristics and functions of CAFs in diffuse-type gastric cancers (DGCs) by analyzing features of their genome and gene expression patterns. METHODS: We isolated CAFs and adjacent non-cancer fibroblasts (NFs) from 110 gastric cancer (GC) tissues from patients who underwent gastrectomy in Japan from 2008 through 2016. Cells were identified using specific markers of various cell types by immunoblot and flow cytometry. We selected pairs of CAFs and NFs for whole-exome and RNA sequencing analyses, and compared expression of specific genes using quantitative reverse transcription PCR. Protein levels and phosphorylation were compared by immunoblot and immunofluorescence analyses. Rhomboid 5 homolog 2 (RHBDF2) was overexpressed from a transgene in fibroblasts or knocked down using small interfering RNAs. Motility and invasiveness of isolated fibroblasts and GC cell lines (AGS, KATOIII, MKN45, NUGC3, NUGC4, OCUM-2MD3 and OCUM-12 cell lines) were quantified by real-time imaging analyses. We analyzed 7 independent sets of DNA microarray data from patients with GC and associated expression levels of specific genes with patient survival times. Nude mice were given injections of OCUM-2MD3 in the stomach wall; tumors and metastases were collected and analyzed by immunohistochemistry. RESULTS: Many of the genes with increased expression in CAFs compared with NFs were associated with transforming growth factor beta 1 (TGFB1) activity. When CAFs were cultured in extracellular matrix, they became more motile than NFs; DGC cells incubated with CAFs were also more motile and invasive in vitro than DGC cells not incubated with CAFs. When injected into nude mice, CAF-incubated DGC cells invaded a greater number of lymphatic vessels than NF-incubated DGC cells. We identified RHBDF2 as a gene overexpressed in CAFs compared with NFs. Knockdown of RHBDF2 in CAFs reduced their elongation and motility in response to TGFB1, whereas overexpression of RHBDF2 in NFs increased their motility in extracellular matrix. RHBDF2 appeared to regulate oncogenic and non-canonical TGFB1 signaling. Knockdown of RHBDF2 in CAFs reduced cleavage of the TGFB receptor 1 (TGFBR1) by ADAM metallopeptidase domain 17 (ADAM17 or TACE) and reduced expression of genes that regulate motility. Incubation of NFs with in interleukin 1 alpha (IL1A), IL1B or tumor necrosis factor, secreted by DGCs, increased fibroblast expression of RHBDF2. Simultaneous high expression of these cytokines in GC samples was associated with shorter survival times of patients. CONCLUSIONS: In CAFs isolated from human DGCs, we observed increased expression of RHBDF2, which regulates TGFB1 signaling. Expression of RHBDF2 in fibroblasts is induced by inflammatory cytokines (such as IL1A, IL1B, and tumor necrosis factor) secreted by DGCs. RHBDF2 promotes cleavage of TGFBR1 by activating TACE and motility of CAFs in response to TGFB1. These highly motile CAFs induce DGCs to invade extracellular matrix and lymphatic vessels in nude mice.

Colorectal Cancer Stem Cells Acquire Chemoresistance Through the Upregulation of F-Box/WD Repeat-Containing Protein 7 and the Consequent Degradation of c-Myc.

The cancer stem cell (CSC) paradigm suggests that tumors are organized hierarchically. Chugai previously established an LGR5+ human colorectal cancer (CRC) stem-cell-enriched cell line (colorectal CSCs) that expresses well-accepted colorectal CSC markers and that can dynamically switch between proliferative and drug-resistant noncycling states. We performed this study to elucidate the molecular mechanisms responsible for evading cell death in colorectal CSCs mediated by anticancer agents. During the cell cycle arrest caused by anticancer agents, we found that c-Myc expression was substantially decreased in colorectal CSCs. The c-Myc expression alterations were mediated by upregulation of F-box/WD repeat-containing protein 7 (FBXW7), as evidenced through FBXW7-small interfering RNA knockdown experiments that resulted in enhanced cell sensitivity to anticancer agents. Upregulation of FBXW7 following drug treatment was not evident in commercially available cancer cell lines. Colorectal CSCs were induced to differentiation by Matrigel and fetal bovine serum. Differentiated CSCs treated with anticancer agents did not show upregulation of FBXW7 and were more sensitive to irinotecan (CPT-11), highlighting the potential CSC-specific nature of our data. The FBXW7 over-expression was further validated in resected liver metastatic sites in CRC patients after chemotherapy. In conclusion, our study revealed that a CSC-specific FBXW7-regulatory mechanism is strongly associated with resistance to chemotherapeutic agents. Inhibition of FBXW7-upregulation in CSCs following chemotherapy may enhance the response to anticancer agents and represents an attractive strategy for the elimination of colorectal CSCs. Stem Cells 2017;35:2027-2036.

A new strategy based on fluorodeoxyglucose-positron emission tomography for managing liver metastasis from colorectal cancer.

BACKGROUND: Prognostic models are needed to manage liver metastasis from colorectal cancer (CRLM). Thus, we developed an algorithm to guide treatment based on the standardized uptake value (SUV) from fluorodeoxyglucose-positron emission tomography (FDG-PET). METHODS: We retrospectively evaluated 148 patients who underwent surgery for CRLM, including 107 cases of primary surgery and 41 cases with preoperative chemotherapy before conversion surgery. We evaluated the prognostic value of perioperative SUV among primary surgery cases, as well as the prognostic value of the SUV change ratio after conversion surgery (postchemotherapy/prechemotherapy SUV). RESULTS: In the primary surgery group, recurrence-free survival (RFS) was independently predicted by an SUV of ≥6.04 (P = 0.042) and ≥4 liver metastases ( P = 0.003). The combination of an SUV of ≥6.04 and ≥4 liver metastases was strongly associated with poor RFS ( P < 0.001). In the conversion surgery group, the SUV change ratio was associated with tumor size change and pathological response. An SUV change ratio of ≥0.293 was associated with shorter RFS ( P = 0.006) and independently predicted RFS ( P = 0.026). We established a therapeutic algorithm for managing CRLM based on these results. CONCLUSION: FDG-PET may be useful for predicting recurrence and prognosis in cases of CRLM, and our algorithm may be useful for managing multiple CRLMs.

Clinical significance of half-lives of tumor markers α-fetoprotein and des-γ-carboxy prothrombin after hepatectomy for hepatocellular carcinoma.

AIM: The prognostic significance of the half-lives (HLs) of α-fetoprotein (AFP) and des-γ-carboxy prothrombin (DCP) in patients undergoing hepatectomy for hepatocellular carcinoma (HCC) is unclear. We evaluated the HLs of AFP and DCP in a cohort of such patients. METHODS: This study included data on 202 patients with HCC who underwent curative hepatectomy and had preoperative AFP concentrations ≥100 ng/mL or DCP ≥200 mAU/mL. We calculated the HLs of AFP and DCP from their values just before and 1 month after hepatectomy. We identified three groups: a normalization group, tumor marker concentrations within normal range 1 month post-hepatectomy; a long group, HL of AFP ≥7 days or DCP ≥4 days; and a short group, remaining patients. We evaluated associations between HL and prognosis. RESULTS: Three-year recurrence-free survival (RFS) in the normalization (n = 70), short (n = 71), and long groups (n = 61) was 41.3%, 46.0%, and 16.8%, respectively (P = 0.002). Five-year overall survival (OS) of normalization, short, and long groups was 72.6, 70.6 and 43.8%, respectively (P = 0.002). Multivariate analysis revealed that long HL is an independent risk factor for poor RFS (hazard ratio [HR] 2.21, P = 0.0006) and poor OS (HR 2.70, P = 0.004). The extrahepatic recurrence rate was 21.3% (13/61) in the long group, which is higher than in the normalization group (8.6%, 6/70) (P = 0.04) and short group (9.9%, 7/71) (P = 0.07). CONCLUSION: Post-hepatectomy HLs of AFP and DCP are predictors of long-term outcome in patients with HCC.

Impact of surgical treatment after sorafenib therapy for advanced hepatocellular carcinoma.

BACKGROUND: For advanced hepatocellular carcinoma (HCC), surgical treatment after sorafenib induction has rarely been reported. We examined the survival benefit of additional surgical treatment in sorafenib-treated patients. METHODS: Thirty-two advanced HCC patients were given sorafenib from July 2009 to July 2012, and we statistically analyzed the relevant predictive factors of the long-term survival. The institutional review board of Kumamoto University Hospital approved this study (Approval number 1038). RESULTS: The median duration of sorafenib administration was 56.5 days (range 5-945). The cumulative overall survival rate was 44.6, 33.4, 26.0 and 17.8% at 1, 2, 3 and 5 years, respectively. The median survival time was 11.2 months. A survival of more than 3 years after the initiation of sorafenib induction was observed in seven patients, five of whom were subjected to additional surgical intervention. Additional surgery was the most significant factor predicting a survival exceeding 3 years (P < 0.0001) and represents an independent prognostic factor [hazard ratio (HR) 0.07; P = 0.01], followed by the total dose of sorafenib. The surgical interventions comprised two hepatic resections ± radiofrequency ablation, two radiofrequency ablations and one lung resection. CONCLUSIONS: A long-term survival might be obtained for select HCC patients given adequate additional surgical treatment, even after sorafenib induction.

Enhancer of zeste homolog 2 (EZH2) regulates tumor angiogenesis and predicts recurrence and prognosis of intrahepatic cholangiocarcinoma.

BACKGROUND: Enhancer of zeste homolog 2 (EZH2) is the catalytic subunit of the polycomb repressive complex 2 (PRC2) and regulates tumor malignancy by gene silencing via histone methylation. In this study we investigate the role of EZH2 in angiogenesis of intrahepatic cholangiocarcinoma (ICC). METHODS: The influence of EZH2 on tumor angiogenesis was examined by bioinformatics analysis of a public database. We also assessed the correlation between EZH2 and vasohibin 1 (VASH1) expression in 47 patients with ICC by immunohistochemical (IHC) staining and in vitro gene silencing assays. The prognostic significance of EZH2 and VASH1 expression by IHC was also examined in the ICC cohort. RESULTS: Bioinformatics analysis showed that EZH2 was associated with several angiogenesis gene sets in the public database. EZH2 suppressed VASH1 expression in in vitro assays and IHC studies. EZH2-high/VASH1-low status was independently associated with poor disease-free survival (P = 0.019) and poor overall survival (P = 0.0055). CONCLUSION: The current study demonstrated that high EZH2 expression was associated with activation of tumor angiogenesis, and activation of the EZH2-mediated angiogenesis pathway predicted the prognosis of patients with ICC.