Host antibacterial defense of 6-10 Gy γ-irradiated mice subjected to lentiviral vector-based Gas5 gene therapy.

Gut bacteria-associated sepsis is a serious concern in patients with gastrointestinal acute radiation syndrome (GIARS). In our previous studies, all mice exposed to 8 Gy of whole body γ-irradiation (8 Gy GIARS-mice) died by sepsis stemming from bacterial translocation. M1Mϕ located in the bacterial translocation site (i.e., the mesenteric lymph nodes, MLNs) have been characterized as major antibacterial effector cells. However, M2bMϕ, inhibitor cells for M1Mϕ polarization, predominated in the MLNs of these mice. The reduced expression of long noncoding RNA Gas5 was associated with M2bMϕ polarization. In this study, we tried to reduce the mortality rate of 8 Gy GIARS-mice through Gas5 gene transduction using lentivirus (Gas5 lentivirus). After Gas5 lentivirus injection, Gas5 RNA was overexpressed in MLN-F4/80+ cells of 8 Gy GIARS-mice, and these cells were identified as non-M2bMϕ. All of the 8 Gy GIARS-mice injected with Gas5 lentivirus survived 30 days or more after irradiation, and bacterial translocation and subsequent sepsis were shown to be minimal in these mice. These results indicate that the antibacterial resistance of 8 Gy GIASR-mice can be restored through the modulation of M2bMϕ located in the bacterial translocation site by Gas5 transduction.

Glycyrrhizin Protects γ-Irradiated Mice from Gut Bacteria-Associated Infectious Complications by Improving miR-222-Associated Gas5 RNA Reduction in Macrophages of the Bacterial Translocation Site.

Gut bacteria-associated sepsis is a serious concern in patients with gastrointestinal acute radiation syndrome (GIARS). In our previous studies, gut bacteria-associated sepsis caused high mortality rates in mice exposed to 6-9 Gy of γ-rays. IL-12+CD38+ iNOS+ Mϕ (M1Mϕ) located in the bacterial translocation site (mesenteric lymph nodes [MLNs]) of unirradiated mice were characterized as host defense antibacterial effector cells. However, cells isolated from the MLNs of GIARS mice were mostly CCL1+IL-10+LIGHT+miR-27a+ Mϕ (M2bMϕ, inhibitor cells for the M1Mϕ polarization). Reduced long noncoding RNA Gas5 and increased miR-222 expression in MLN-Mϕ influenced by the irradiation were shown to be associated with M2bMϕ polarization. In this study, the mortality of mice exposed to 7 Gy of γ-rays (7 Gy GIARS mice) was completely controlled after the administration of glycyrrhizin (GL), a major active ingredient in licorice root (Glycyrrhiza glabra). Bacterial translocation and subsequent sepsis were minimal in 7 Gy GIARS mice treated with GL. Increased Gas5 RNA level and decreased miR-222 expression were shown in MLN-Mϕ isolated from 7 Gy GIARS mice treated with GL, and these macrophages did not display any properties of M2bMϕ. These results indicate that gut bacteria-associated sepsis in 7 Gy GIARS mice was controlled by the GL through the inhibition of M2bMϕ polarization at the bacteria translocation site. Expression of Ccl1, a gene required for M2bMϕ survival, is silenced in the MLNs of 7 Gy GIARS mice because of Gas5 RNA, which is increased in these cells after the suppression of miR-222 (a Gas5 RNA expression inhibitor) by the GL.

Survival of Mice with Gastrointestinal Acute Radiation Syndrome through Control of Bacterial Translocation.

Macrophages (Mϕ) with the M2b phenotype (Pheno2b-Mϕ) in bacterial translocation sites have been described as cells responsible for the increased susceptibility of mice with gastrointestinal acute radiation syndrome to sepsis caused by gut bacteria. In this study, we tried to reduce the mortality of mice exposed to 7-10 Gy of gamma rays by controlling Pheno2b-Mϕ polarization in bacterial translocation sites. MicroRNA-222 was induced in association with gamma irradiation. Pheno2b-Mϕ polarization was promoted and maintained in gamma-irradiated mice through the reduction of a long noncoding RNA growth arrest-specific transcript 5 (a CCL1 gene silencer) influenced by this microRNA. Therefore, the host resistance of 7-9-Gy gamma-irradiated mice to sepsis caused by bacterial translocation was improved after treatment with CCL1 antisense oligodeoxynucleotide. However, the mortality of 10-Gy gamma-irradiated mice was not alleviated by this treatment. The crypts and villi in the ileum of 10-Gy gamma-irradiated mice were severely damaged, but these were markedly improved after transplantation of intestinal lineage cells differentiated from murine embryonic stem cells. All 10-Gy gamma-irradiated mice given both of the oligodeoxynucleotide and intestinal lineage cells survived, whereas all of the same mice given either of them died. These results indicate that high mortality rates of mice irradiated with 7-10 Gy of gamma rays are reducible by depleting CCL1 in combination with the intestinal lineage cell transplantation. These findings support the novel therapeutic possibility of victims who have gastrointestinal acute radiation syndrome for the reduction of their high mortality rates.

Short-Term Alcohol Abstinence Improves Antibacterial Defenses of Chronic Alcohol-Consuming Mice against Gut Bacteria-Associated Sepsis Caused by Enterococcus faecalis Oral Infection.

The effects of short-term alcohol abstinence on host antibacterial resistance against Enterococcus faecalis oral infection was investigated in chronic alcohol-consuming mice [mice with 0.1 g/day of 20% ethanol consumption for 12 or 16 weeks (CAC-mice)]. These mice were highly susceptible to the infection; however, after 7 days of alcohol abstinence (aaCAC-mice), their antibacterial resistances were completely restored to the normal mouse level. Normal mice inoculated with CAC-mouse hepatic macrophages were shown to be susceptible to the infection, whereas the same macrophage preparation from aaCAC-mice did not impair the antibacterial resistance of normal mice. aaCAC-mouse liver macrophages protected nonobese diabetic-severe combined immunodeficiency IL-2Rγnull mice exposed to E. faecalis, whereas those from CAC-mice did not. Monocyte-derived (MD) M2b macrophages were predominantly isolated from CAC-mouse livers, but these cells were not significantly isolated from aaCAC-mouse livers. Hepatic MD macrophages from aaCAC-mice switched to M1 macrophages in response to bacterial antigen, whereas the same macrophage preparation from CAC-mice did not. M1 Kupffer cells, M2a Kupffer cells, and MD M2b macrophages were shown to be not bactericidal, whereas E. faecalis was killed effectively by M1 macrophages derived from aaCAC-mouse hepatic MD macrophages. These results indicate that MD M2b macrophages predominantly distributed in the liver are responsible for the impaired resistance of CAC-mice to E. faecalis oral infection, and aaCAC-mice without MD M2b macrophages in the livers are resistant to the infection.

M2b macrophage polarization accompanied with reduction of long noncoding RNA GAS5.

Macrophages (Mϕ) are highly plastic and change their functional phenotypes depending on microenvironmental signals. Recent studies have shown that microRNAs are involved in the polarization of Mϕ. In this study, we demonstrated that the phenotype of M2bMϕ [CCL1(+) IL-10(+) LIGHT(+)] switches to other phenotypes with interchangeability attained through the increased expression of growth arrest-specific 5 RNA (GAS5 RNA), a long noncoding RNA. GAS5 RNA has been described as a silencer of the CCL1 gene. Various phenotypes of Mϕ were prepared from bone marrow-derived Mϕ (BMDMϕ) after stimulation with IFNγ [M(IFNγ)/M1Mϕ], IL-4 [M(IL-4)/M2aMϕ], LPS and immobilized IgG [M(LPS + IC)/M2bMϕ], and IL-10 [M(IL-10)/M2cMϕ]. BMDMϕ cultured with medium [M(no)/quiescent Mϕ] were used as a control. As compared to Μ(no), M(IFNγ), M(IL-4) and M(IL-10), the reduced level of GAS5 RNA was shown in M(LPS + IC). CCL1 and LIGHT mRNAs (typical biomarkers of M2bMϕ) were not expressed by M(LPS + IC) transduced with a GAS5 gene using lentiviral vector. The reduction of GAS5 RNA in M(LPS + IC) was mediated by the activation of nonsense-mediated RNA decay (NMD) pathway. BMDMϕ overexpressed with GAS5 RNA after GAS5 gene transduction did not polarize to M2bMϕ even though they were stimulated with LPS and IC in combination. These results indicate that the reduction of GAS5 RNA influenced by the NMD pathway activation leads to the Mϕ polarization stimulated with LPS and IC in combination.

Macrophage polarization and MRSA infection in burned mice.

Mortality associated with Staphylococcus aureus infection remains high during the sub-acute phase of burn injury. In this study, we aimed to improve antibacterial resistance of sub-acutely burned mice through macrophage polarization. Sepsis did not develop in mice at the sub-acute phase of 5% total body surface area (TBSA) burn after being infected with methicillin-resistant S. aureus (MRSA), and M1 macrophages (interleukin (IL)-10-IL-12+ inducible nitric oxide synthase+ Mφ) were isolated from these mice. In contrast, predominantly M2b macrophages (C-C motif chemokine ligand 1 (CCL1)+IL-10+IL-12- Mφ) were isolated from mice with >15% TBSA burn, and all of these mice died after the same MRSA infection. Comparing NOD scid gamma mice inoculated with Mφ with 25% TBSA burns, all mice treated with CCL1 antisense oligodeoxynucleotide (ODN) survived after MRSA infection, whereas all untreated mice given the same infection died within 4 days. CCL1 antisense ODN has been characterized as a specific polarizer of M2bMφ. M1Mφ were isolated from MRSA-infected mice with 25% TBSA burn after treatment with CCL1 antisense ODN, and these mice were shown to be resistant against a lethal dose of MRSA infection. M1Mφ were also isolated from 25% TBSA-burned mice infected with MRSA when the ODN was administered therapeutically, and subsequent sepsis was effectively controlled in these mice. These results indicate that the M2bMφ polarizer is beneficial for controlling MRSA infection in mice at the sub-acute phase of severe burn injury.

M2b Monocytes Provoke Bacterial Pneumonia and Gut Bacteria-Associated Sepsis in Alcoholics.

Chronic alcohol consumption markedly impairs host antibacterial defense against opportunistic infections. γ-irradiated NOD-SCID IL-2Rγ(null) mice inoculated with nonalcoholic PBMCs (control PBMC chimeras) resisted Klebsiella pneumonia and gut bacteria-associated sepsis, whereas the chimeras created with alcoholic PBMCs (alcoholic PBMC chimeras) were very susceptible to these infections. M1 monocytes (IL-12(+)IL-10(-)CD163(-)CD14(+) cells), major effector cells in antibacterial innate immunity, were not induced by a bacterial Ag in alcoholic PBMC cultures, and M2b monocytes (CCL1(+)CD163(+)CD14(+) cells), which predominated in alcoholic PBMCs, were shown to be inhibitor cells on the Ag-stimulated monocyte conversion from quiescent monocytes to M1 monocytes. CCL1, which functions to maintain M2b macrophage properties, was produced by M2b monocytes isolated from alcoholic PBMCs. These M2b monocytes reverted to quiescent monocytes (IL-12(-)IL-10(-)CCL1(-)CD163(-)CD14(+) cells) in cultures supplemented with CCL1 antisense oligodeoxynucleotide, and the subsequent quiescent monocytes easily converted to M1 monocytes under bacterial Ag stimulation. Alcoholic PBMC chimeras treated with CCL1 antisense oligodeoxynucleotide were resistant against pulmonary infection by K. pneumoniae and sepsis stemming from enterococcal translocation. These results indicate that a majority of monocytes polarize to an M2b phenotype in association with alcohol abuse, and this polarization contributes to the increased susceptibility of alcoholics to gut and lung infections. Bacterial pneumonia and gut bacteria-associated sepsis, frequently seen in alcoholics, can be controlled through the polarization of macrophage phenotypes.

M2b macrophage elimination and improved resistance of mice with chronic alcohol consumption to opportunistic infections.

Alcohol abuse was found to predispose persons to opportunistic infections. In this study, we tried to improve the host antibacterial resistance of chronic alcohol-consuming (CAC) mice to opportunistic infections. Bactericidal macrophages with functions to produce IL-12 and to express mRNAs for CXCL9 and inducible nitric oxide synthase (M1 macrophages) were characterized as the main effector cells in host antibacterial innate immunities against infections with opportunistic pathogens. However, CAC mice were found to be carriers of M2b macrophages [macrophages with functions to produce IL-10 and to express mRNAs for CD163, chemokine ligand (CCL)1, and LIGHT (homologous to lymphotoxin, exhibits inducible expression, competes with herpes simplex virus glycoprotein D for high-voltage electron microscopy on T cells)], which were inhibitory on macrophage conversion from resident macrophages to M1 macrophages. Under treatment with CCL1 antisense oligodeoxynucleotides, a specific inhibitor of M2b macrophages, CAC mouse macrophages reverted to resident macrophages, and M1 macrophages were induced by a bacterial antigen from macrophages of CAC mice that were previously treated with the oligodeoxynucleotides. Opportunistic infections (enterococcal translocation and Klebsiella pneumonia) in CAC mice were completely controlled by CCL1 antisense oligodeoxynucleotides. These results indicate that certain opportunistic infections in alcoholics are controllable through the modulation of M2b macrophages.

The nucleolar protein Myb-binding protein 1A (MYBBP1A) enhances p53 tetramerization and acetylation in response to nucleolar disruption.

Tetramerization of p53 is crucial to exert its biological activity, and nucleolar disruption is sufficient to activate p53. We previously demonstrated that nucleolar stress induces translocation of the nucleolar protein MYBBP1A from the nucleolus to the nucleoplasm and enhances p53 activity. However, whether and how MYBBP1A regulates p53 tetramerization in response to nucleolar stress remain unclear. In this study, we demonstrated that MYBBP1A enhances p53 tetramerization, followed by acetylation under nucleolar stress. We found that MYBBP1A has two regions that directly bind to lysine residues of the p53 C-terminal regulatory domain. MYBBP1A formed a self-assembled complex that provided a molecular platform for p53 tetramerization and enhanced p300-mediated acetylation of the p53 tetramer. Moreover, our results show that MYBBP1A functions to enhance p53 tetramerization that is necessary for p53 activation, followed by cell death with actinomycin D treatment. Thus, we suggest that MYBBP1A plays a pivotal role in the cellular stress response.

Orosomucoid 1 drives opportunistic infections through the polarization of monocytes to the M2b phenotype.

Orosomucoid (ORM, composed of two isoforms, ORM1 and ORM2) has been described as an inducer of M2 macrophages, which are cells that decrease host antibacterial innate immunities. However, it is unknown which phenotypes of M2 macrophages are induced by ORM. In this study, healthy donor monocytes stimulated with ORM (ORM-monocytes) were characterized phenotypically and biologically. CCL1 (a biomarker of M2b macrophages) and IL-10 were detected in monocyte cultures supplemented with ORM1; however, CCL17 (a biomarker of M2a macrophages) and CXCL13 (a biomarker of M2c macrophages) were not produced in these cultures. All of these soluble factors were not detected in the culture fluids of monocytes stimulated with ORM2. Monocytes stimulated with ORM1 were characterized as CD64(-)CD209(-)CD163(+)CCL1(+) cells. MRSA and Enterococcus faecalis infections were accelerated in chimeras (NOD/scid IL-2Rγ(null) mice reconstituted with white blood cells) after inoculation with monocytes stimulated with ORM1 or treatment with ORM1; however, the infections were greatly mitigated in both chimeras inoculated with ORM1-stimulated monocytes and treated with ORM1, after an additional treatment with an inhibitor of M2b macrophages (CCL1 antisense ODN). These results indicate that ORM1 stimulates quiescent monocytes to polarize to M2b monocytes. The regulation of M2b macrophages may be beneficial in controlling opportunistic infections in patients with a large amount of plasma ORM1.

Peritoneal Microenvironment Promotes Appendiceal Adenocarcinoma Growth: A Multi-omics Approach Using Patient-Derived Xenografts.

Appendiceal adenocarcinoma (AA) is unique from other gastrointestinal malignancies in that it almost exclusively metastasizes to the peritoneal cavity. However, few studies have investigated the molecular interaction of the peritoneal microenvironment and AA. Here, we use a multi-omics approach with orthotopic and flank-implanted patient-derived xenografts (PDX) to study the effect of the peritoneal microenvironment on AA. AA tumors implanted in the peritoneal microenvironment tended to grow faster and displayed greater nuclear expression of Ki-67 relative to the same tumors implanted in the flank. Comparing the tumor-specific transcriptome (excluding stromal transcription), the peritoneal microenvironment relatively upregulated genes related to proliferation, including MKI67 and EXO1. Peritoneal tumors were also enriched for proliferative gene sets, including E2F and Myc Targets. Proteomic studies found a 2.5-fold increased ratio of active-to-inactive phosphoforms of the YAP oncoprotein in peritoneal tumors, indicating downregulation of Hippo signaling. IMPLICATIONS: The peritoneal microenvironment promotes growth of appendiceal tumors and expression of proliferative pathways in PDXs.

Serum Tumor Markers and Outcomes in Patients With Appendiceal Adenocarcinoma.

Importance: Serum tumor markers carcinoembryonic antigen (CEA), carbohydrate antigen 19-9 (CA19-9), and cancer antigen 125 (CA125) have been useful in the management of gastrointestinal and gynecological cancers; however, there is limited information regarding their utility in patients with appendiceal adenocarcinoma. Objective: To assess the association of serum tumor markers (CEA, CA19-9, and CA125) with clinical outcomes and pathologic and molecular features in patients with appendiceal adenocarcinoma. Design, Setting, and Participants: This is a retrospective cohort study at a single tertiary care comprehensive cancer center. The median (IQR) follow-up time was 52 (21-101) months. Software was used to query the MD Anderson internal patient database to identify patients with a diagnosis of appendiceal adenocarcinoma and at least 1 tumor marker measured at MD Anderson between March 2016 and May 2023. Data were analyzed from January to December 2023. Main Outcomes and Measures: Association of serum tumor markers with survival in patients with appendiceal adenocarcinoma. Cox proportional hazards regression analyses were also performed to assess associations between clinical factors (serum tumor marker levels, demographics, and patient and disease characteristics) and patient outcomes (overall survival). Results: A total of 1338 patients with appendiceal adenocarcinoma were included, with a median (range) age at diagnosis of 56.5 (22.3-89.6) years. The majority of the patients had metastatic disease (1080 patients [80.7%]). CEA was elevated in 742 of the patients tested (56%), while CA19-9 and CA125 were elevated in 381 patients (34%) and 312 patients (27%), respectively. Individually, elevation of CEA, CA19-9, or CA125 were associated with worse 5-year survival; elevated vs normal was 81% vs 95% for CEA (hazard ratio [HR], 4.0; 95% CI, 2.9-5.6), 84% vs 92% for CA19-9 (HR, 2.2; 95% CI, 1.4-3.4), and 69% vs 93% for CA125 (HR, 4.6; 95% CI, 2.7-7.8) (P < .001 for all). Quantitative evaluation of tumor markers was associated with outcomes. Patients with highly elevated (top 10th percentile) CEA, CA19-9, or CA125 had markedly worse survival, with 5-year survival rates of 59% for CEA (HR, 9.8; 95% CI, 5.3-18.0), 64% for CA19-9 (HR, 6.0; 95% CI, 3.0-11.7), and 57% for CA125 (HR, 7.6; 95% CI, 3.5-16.5) (P < .001 for all). Although metastatic tumors had higher levels of all tumor markers, when restricting survival analysis to 1080 patients with metastatic disease, elevated CEA, CA19-9, or CA125 were all still associated worse survival (HR for CEA, 3.4; 95% CI, 2.5-4.8; P < .001; HR for CA19-9, 1.8; 95% CI, 1.2-2.7; P = .002; and HR for CA125, 3.9; 95% CI, 2.4-6.4; P < .001). Interestingly, tumor grade was not associated with CEA or CA19-9 level, while CA-125 was slightly higher in high-grade tumors relative to low-grade tumors (mean value, 18.3 vs 15.0; difference, 3.3; 95% CI, 0.9-3.7; P < .001). Multivariable analysis identified an incremental increase in the risk of death with an increase in the number of elevated tumor markers, with an 11-fold increased risk of death in patients with all 3 tumor markers elevated relative to those with none elevated. Somatic mutations in KRAS and GNAS were associated with significantly higher levels of CEA and CA19-9. Conclusions and Relevance: In this retrospective study of serum tumor markers in patients with appendiceal adenocarcinoma, CEA, CA19-9, and CA125 were associated with overall survival in appendiceal adenocarcinoma. Given their value, all 3 biomarkers should be included in the initial workup of patients with a diagnosis of appendiceal adenocarcinoma.

Intraperitoneal Paclitaxel Is a Safe and Effective Therapeutic Strategy for Treating Mucinous Appendiceal Adenocarcinoma.

Appendiceal adenocarcinomas (AA) are a rare and heterogeneous mix of tumors for which few preclinical models exist. The rarity of AA has made performing prospective clinical trials difficult, which has partly contributed to AA remaining an orphan disease with no chemotherapeutic agents approved by the FDA for its treatment. AA has a unique biology in which it frequently forms diffuse peritoneal metastases but almost never spreads via a hematogenous route and rarely spreads to lymphatics. Given the localization of AA to the peritoneal space, intraperitoneal delivery of chemotherapy could be an effective treatment strategy. Here, we tested the efficacy of paclitaxel given by intraperitoneal administration using three orthotopic patient-derived xenograft (PDX) models of AA established in immunodeficient NSG mice. Weekly intraperitoneal paclitaxel treatment dramatically reduced AA tumor growth in all three PDX models. Comparing the safety and efficacy of intravenous with intraperitoneal administration, intraperitoneal delivery of paclitaxel was more effective, with reduced systemic side effects in mice. Given the established safety record of intraperitoneal paclitaxel in gastric and ovarian cancers, and lack of effective chemotherapeutics for AA, these data showing the activity of intraperitoneal paclitaxel in orthotopic PDX models of mucinous AA support the evaluation of intraperitoneal paclitaxel in a prospective clinical trial. SIGNIFICANCE: The activity and safety of intraperitoneal paclitaxel in orthotopic PDX models of mucinous appendiceal adenocarcinoma supports the evaluation of intraperitoneal paclitaxel in a prospective clinical trial of this rare tumor type.

Antitumor activity of intraperitoneal paclitaxel in orthotopic patient-derived xenograft models of mucinous appendiceal adenocarcinoma.

Appendiceal adenocarcinomas (AAs) are a rare and heterogeneous mix of tumors for which few preclinical models exist. The rarity of AA has made performing prospective clinical trials difficult, and in part because of this AA remains an orphan disease with no chemotherapeutic agents approved by the FDA for its treatment. AA has a unique biology in which it frequently forms diffuse peritoneal metastases, but almost never spreads via a hematogenous route and rarely spreads to lymphatics. Given its localization to the peritoneal space we hypothesized that intraperitoneal (IP) delivery of chemotherapy could be an effective treatment strategy. Here we tested the efficacy paclitaxel given by IP administration using three orthotopic PDX models of AA established in NSG mice. Weekly treatment of 25.0 mg/kg of IP paclitaxel dramatically reduced AA tumor growth in TM00351 (81.9% reduction vs. control), PMP-2 (98.3% reduction vs. control), and PMCA-3 (71.4% reduction vs. control) PDX models. Comparing the safety and efficacy of intravenous (IV) to IP administration in PMCA-3, neither 6.25 nor 12.5 mg/kg of IV paclitaxel significantly reduced tumor growth. These results suggest that IP administration of paclitaxel is favorable to IV administration. Given the established safety record of IP paclitaxel in gastric and ovarian cancers, and lack of effective chemotherapeutics for AA, these data showing the activity of IP paclitaxel in orthotopic PDX models of mucinous AA support the evaluation of IP paclitaxel in a prospective clinical trial.

The Clinical Significance of CEA, CA19-9, and CA125 in Management of Appendiceal Adenocarcinoma.

Importance: Serum tumor markers CEA, CA19-9, & CA125 have been useful in the management of gastrointestinal and gynecological cancers, however there is limited information regarding their utility in patients with appendiceal adenocarcinoma. Objective: Assessing the association of serum tumor markers (CEA, CA19-9, and CA125) with clinical outcomes, pathologic, and molecular features in patients with appendiceal adenocarcinoma. Design: This is a retrospective study with results reported in 2023. The median follow-up time was 43 months. Setting: Single tertiary care comprehensive cancer center. Participants: Under an approved Institutional Review Board protocol, the Palantir Foundry software system was used to query the MD Anderson internal patient database to identify patients with a diagnosis of appendiceal adenocarcinoma and at least one tumor marker measured at MD Anderson between 2016 and 2023. Results: A total of 1,338 patients with appendiceal adenocarcinoma were included, with a median age of 56.5 years. The majority of the patients had metastatic disease (80.7%). CEA was elevated in more than half of the patients tested (56%), while CA19-9 and CA125 were elevated in 34% and 27%, respectively. Individually, elevation of CEA, CA19-9, or CA125 were associated with worse 5-year survival; 82% vs 95%, 84% vs 92%, and 69% vs 93% elevated vs normal for CEA, CA19-9, and CA125 respectively (all p<0.0001). Quantitative evaluation of tumor markers increased prognostic ability. Patients with highly elevated (top 10th percentile) CEA, CA19-9 or CA125 had markedly worse survival with 5-year survival rates of 59%, 64%, and 57%, respectively (HR vs. normal : 9.8, 6.0, 7.6, all p<0.0001). Although metastatic tumors had higher levels of all tumor markers, when restricting survival analysis to 1080 patients with metastatic disease elevated CEA, CA19-9 or CA125 were all still associated worse survival (HR vs. normal : 3.4, 1.8, 3.9, p<0.0001 for CEA and CA125, p=0.0019 for CA19-9). Interestingly tumor grade was not associated with CEA or CA19-9 level, while CA-125 was slightly higher in high relative to low-grade tumors (18.3 vs. 15.0, p=0.0009). Multivariable analysis identified an incremental increase in the risk of death with an increase in the number of elevated tumor markers, with a 11-fold increased risk of death in patients with all three tumor markers elevated relative to those with none elevated. Mutation in KRAS and GNAS were associated with significantly higher levels of CEA and CA19-9. Conclusions: These findings demonstrate the utility of measuring CEA, CA19-9, and CA125 in the management of appendiceal adenocarcinoma. Given their prognostic value, all three biomarkers should be included in the initial workup of patients diagnosed with appendiceal adenocarcinoma.

Oncogene addiction to GNAS in GNASR201 mutant tumors.

The GNASR201 gain-of-function mutation is the single most frequent cancer-causing mutation across all heterotrimeric G proteins, driving oncogenesis in various low-grade/benign gastrointestinal and pancreatic tumors. In this study, we investigated the role of GNAS and its product Gαs in tumor progression using peritoneal models of colorectal cancer (CRC). GNAS was knocked out in multiple CRC cell lines harboring GNASR201C/H mutations (KM12, SNU175, SKCO1), leading to decreased cell-growth in 2D and 3D organoid models. Nude mice were peritoneally injected with GNAS-knockout KM12 cells, leading to a decrease in tumor growth and drastically improved survival at 7 weeks. Supporting these findings, GNAS overexpression in LS174T cells led to increased cell-growth in 2D and 3D organoid models, and increased tumor growth in PDX mouse models. GNAS knockout decreased levels of cyclic AMP in KM12 cells, and molecular profiling identified phosphorylation of ß-catenin and activation of its targets as critical downstream effects of mutant GNAS signaling. Supporting these findings, chemical inhibition of both PKA and ß-catenin reduced growth of GNAS mutant organoids. Our findings demonstrate oncogene addiction to GNAS in peritoneal models of GNASR201C/H tumors, which signal through the cAMP/PKA and Wnt/ß-catenin pathways. Thus, GNAS and its downstream mediators are promising therapeutic targets for GNAS mutant tumors.

Pathologic Inflammation in Malnutrition Is Driven by Proinflammatory Intestinal Microbiota, Large Intestine Barrier Dysfunction, and Translocation of Bacterial Lipopolysaccharide.

Acute malnutrition, or wasting, is implicated in over half of all deaths in children under five and increases risk of infectious disease. Studies in humans and preclinical models have demonstrated that malnutrition is linked to an immature intestinal microbiota characterized by increased prevalence of Enterobacteriaceae. Observational studies in children with moderate acute malnutrition (MAM) have also observed heightened systemic inflammation and increased circulating bacterial lipopolysaccharides (LPS; endotoxin). However, the mechanisms that underpin the systemic inflammatory state and endotoxemia, and their pathophysiological consequences, remain uncertain. Understanding these pathophysiological mechanisms is necessary to design targeted treatments that will improve the unacceptable rate of failure or relapse that plague current approaches. Here we use a mouse model of MAM to investigate the mechanisms that promote inflammation in the malnourished host. We found that mice with MAM exhibited increased systemic inflammation at baseline, increased translocation of bacteria and bacterial LPS, and an exaggerated response to inflammatory stimuli. An exaggerated response to bacterial LPS was associated with increased acute weight loss. Remarkably, intestinal inflammation and barrier dysfunction was found in the cecum and colon. The cecum showed a dysbiotic microbiota with expansion of Gammaproteobacteria and some Firmicutes, and contraction of Bacteroidetes. These changes were paralleled by an increase in fecal LPS bioactivity. The inflammatory phenotype and weight loss was modulated by oral administration of non-absorbable antibiotics that altered the proportion of cecal Gammaproteobacteria. We propose that the heightened inflammation of acute malnutrition is the result of changes in the intestinal microbiota, intestinal barrier dysfunction in the cecum and colon, and increased systemic exposure to LPS.

Estrogen inhibits transforming growth factor beta signaling by promoting Smad2/3 degradation.

Estrogen is a growth factor that stimulates cell proliferation. The effects of estrogen are mediated through the estrogen receptors, ERalpha and ERbeta, which function as ligand-induced transcription factors and belong to the nuclear receptor superfamily. On the other hand, TGF-beta acts as a cell growth inhibitor, and its signaling is transduced by Smads. Although a number of studies have been made on the cross-talk between estrogen/ERalpha and TGF-beta/Smad signaling, whose molecular mechanisms remain to be determined. Here, we show that ERalpha inhibits TGF-beta signaling by decreasing Smad protein levels. ERalpha-mediated reductions in Smad levels did not require the DNA binding ability of ERalpha, implying that ERalpha opposes the effects of TGF-beta via a novel non-genomic mechanism. Our analysis revealed that ERalpha formed a protein complex with Smad and the ubiquitin ligase Smurf, and enhanced Smad ubiquitination and subsequent degradation in an estrogen-dependent manner. Our observations provide new insight into the molecular mechanisms governing the non-genomic functions of ERalpha.

Estrogen and antiestrogens alter breast cancer invasiveness by modulating the transforming growth factor-ß signaling pathway.

In the later stages of breast cancer, estrogen receptor (ER)α-negative cancers typically have higher histological grades than ERα-positive cancers, and transforming growth factor (TGF)-ß promotes invasion and metastasis. Our previous study indicated that ERα inhibited TGF-ß signaling by inducing the degradation of Smad in an estrogen-dependent manner. In the present study, we report that the suppressive effects of ERα and estrogen on tumor progression are mediated by inhibiting TGF-ß signaling. Furthermore, we investigated the effects of antiestrogens such as ICI182,780 (ICI) or tamoxifen (TAM) on TGF-ß signaling and breast cancer invasiveness. The levels of total Smad and pSmad were reduced by estrogen, whereas ICI slightly increased them, and TAM had no effect. To investigate the effect of antiestrogens on breast cancer invasiveness, we generated highly migratory and invasive MCF-7-M5 cells. The migration and invasion of these cells were suppressed by the inhibitor of TGF-ß receptor kinase, SB-505124, and estrogen. However, antiestrogens did not suppress the migration and invasion of these cells. In addition, we screened TGF-ß target genes whose expression was reduced by estrogen treatment and identified four genes associated with breast cancer invasiveness and poor prognosis. The expression of these genes was not decreased by antiestrogens. These observations provide a new insight into estrogen function and the mechanisms underlying estrogen-mediated suppression of tumor progression.

PPARgamma ligands suppress the feedback loop between E2F2 and cyclin-E1.

PPARgamma is a nuclear hormone receptor that plays a key role in the induction of peroxisome proliferation. A number of studies showed that PPARgamma ligands suppress cell cycle progression; however, the mechanism remains to be determined. Here, we showed that PPARgamma ligand troglitazone inhibited G1/S transition in colon cancer cells, LS174T. Troglitazone did not affect on either expression of CDK inhibitor (p18) or Wnt signaling pathway, indicating that these pathways were not involved in the troglitazone-dependent cell cycle arrest. GeneChip and RT-PCR analyses revealed that troglitazone decreased mRNA levels of cell cycle regulatory factors E2F2 and cyclin-E1 whose expression is activated by E2F2. Down-regulation of E2F2 by troglitazone results in decrease of cyclin-E1 transcription, which could inhibit phosphorylation of Rb protein, and consequently evoke the suppression of E2F2 transcriptional activity. Thus, we propose that troglitazone suppresses the feedback loop containing E2F2, cyclin-E1, and Rb protein.