Efficacy and safety of Piwei Peiyuan Prescription in the treatment of chronic atrophic gastritis: A multicenter, double-blind, double-simulated, randomized, controlled clinical trial

The incidence of chronic atrophic gastritis (CAG) is on the rise due to the growing pressure in modern social life, increasing bad living habits and emotional disorders (such as anxiety and depression), and the aging of the population. Of note, digestive system diseases are the dominant diseases in the field of traditional Chinese medicine (TCM). Therefore, this study evaluated the efficacy and safety of Piwei Peiyuan Prescription, a TCM prescription, in the treatment of CAG through a multicenter, double-blind, randomized, controlled design. This research was organized by the Second Affiliated Hospital of Anhui University of TCM and simultaneously performed in 6 centers. A total of 120 CAG patients were included and randomized into 2 groups: group A (treatment with Piwei Peiyuan granules plus Weifuchun Simulant) and Group B (treatment with Weifuchun Tablets plus Piwei Peiyuan Simulant). These 2 groups were compared in terms of gastroscopy scores, TCM syndrome scores, and serological indicators at baseline and within 12 weeks after treatment. According to endoscopic biopsy for pathological observation, atrophy (2.56 ± 1.08 vs 3.00 ± 1.00, P = .028) and intestinal epithelial hyperplasia (1.00 ± 1.43 vs 1.69 ± 1.80, P = .043) scores were lower in group A than in group B. For the more, group A had higher effective rates for inflammation, atrophy, and intestinal metaplasia (IM) in various regions of the stomach, especially for atrophy/IM of the gastric angle (64%, P = .034) and atrophy/IM of the lesser curvature of gastric antrum (63%, P = .042) than group B. According to TCM syndrome scores, Piwei Peiyuan Prescription improved the scores of gastric distension (2.30 ± 1.13 vs 2.80 ± 0.99, P = .022), preference for warmth and pressure (1.44 ± 1.06 vs 1.36 ± 1.10, P = .041), and poor appetite and indigestion (0.78 ± 0.66 vs 1.32 ± 0.72, P = .018). GAS, MTL, and PGE2 expression was significantly elevated after treatment with Piwei Peiyuan Prescription (P < .001). Piwei Peiyuan Prescription is effective for CAG treatment with high safety.

Discovery of Novel, Selective Prostaglandin EP4 Receptor Antagonists with Efficacy in Cancer Models

Prostaglandin E2 (PGE₂) receptor 4 (EP4) is one of four EP receptors commonly upregulated in the tumor microenvironment and plays vital roles in stimulating cell proliferation, invasion, and metastasis. Biochemical blockade of the PGE₂-EP4 signaling pathway is a promising strategy for controlling inflammatory and immune related disorders. Recently combination therapies of EP4 antagonists with anti-PD-1 or chemotherapy agents have emerged in clinical studies for lung, breast, colon, and pancreatic cancers. Herein, a novel series of indole-2-carboxamide derivatives were identified as selective EP4 antagonists, and SAR studies led to the discovery of the potent compound 36. Due to favorable pharmacokinetics properties and good oral bioavailability (F = 76%), compound 36 was chosen for in vivo efficacy studies. Compound 36 inhibited tumor growth in a CT-26 colon cancer xenograft better than E7046 and a combination of 36 with capecitabine significantly suppressed tumor growth (TGI up to 94.26%) in mouse models.

Discovery and Optimization of 7-Alkylidenyltetrahydroindazole-Based Acylsulfonamide EP3 Antagonists

A novel series of 7-alkylidenyltetrahydroindazole-based acylsulfonamides were discovered as potent EP3 antagonists. The initial lead compound 7 exhibited potent in vitro EP3 inhibitory activity and good selectivity against other EP receptors. In addition, compound 7 demonstrated in vivo activity in a rat ivGTT model, reversing the suppressive effect of the EP3-specific agonist sulprostone on glucose-stimulated insulin secretion. Further optimization to improve the pharmacokinetic profile led to the discovery of compounds 26 and 28 with potent in vitro activity and significantly lower in vivo clearance and higher oral exposure than compound 7.

Anti-Inflammatory Drugs Remodel the Tumor Immune Environment to Enhance Immune Checkpoint Blockade Efficacy

Identifying strategies to improve the efficacy of immune checkpoint blockade (ICB) remains a major clinical need. Here, we show that therapeutically targeting the COX2/PGE2/EP2-4 pathway with widely used nonsteroidal and steroidal anti-inflammatory drugs synergized with ICB in mouse cancer models. We exploited a bilateral surgery model to distinguish responders from nonresponders shortly after treatment and identified acute IFNγ-driven transcriptional remodeling in responder mice, which was also associated with patient benefit to ICB. Monotherapy with COX2 inhibitors or EP2-4 PGE2 receptor antagonists rapidly induced this response program and, in combination with ICB, increased the intratumoral accumulation of effector T cells. Treatment of patient-derived tumor fragments from multiple cancer types revealed a similar shift in the tumor inflammatory environment to favor T-cell activation. Our findings establish the COX2/PGE2/EP2-4 axis as an independent immune checkpoint and a readily translatable strategy to rapidly switch the tumor inflammatory profile from cold to hot. SIGNIFICANCE: Through performing in-depth profiling of mice and human tumors, this study identifies mechanisms by which anti-inflammatory drugs rapidly alter the tumor immune landscape to enhance tumor immunogenicity and responses to immune checkpoint inhibitors.See related commentary by Melero et al., p. 2372.This article is highlighted in the In This Issue feature, p. 2355.

Combination of EP4 antagonist MF-766 and anti-PD-1 promotes anti-tumor efficacy by modulating both lymphocytes and myeloid cells

Prostaglandin E₂ (PGE₂), an arachidonic acid pathway metabolite produced by cyclooxygenase (COX)-1/2, has been shown to impair anti-tumor immunity through engagement with one or more E-type prostanoid receptors (EP_1-4). Specific targeting of EP receptors, as opposed to COX-1/2 inhibition, has been proposed to achieve preferential antagonism of PGE₂–mediated immune suppression. Here we describe the anti-tumor activity of MF-766, a potent and highly selective small-molecule inhibitor of the EP₄ receptor. EP₄ inhibition by MF-766 synergistically improved the efficacy of anti-programmed cell death protein 1 (PD-1) therapy in CT26 and EMT6 syngeneic tumor mouse models. Multiparameter flow cytometry analysis revealed that treatment with MF-766 promoted the infiltration of CD8⁺ T cells, natural killer (NK) cells and conventional dendritic cells (cDCs), induced M1-like macrophage reprogramming, and reduced granulocytic myeloid-derived suppressor cells (MDSC) in the tumor microenvironment (TME). In vitro experiments demonstrated that MF-766 restored PGE₂-mediated inhibition of lipopolysaccharide (LPS)-induced tumor necrosis factor (TNF)-α production in THP-1 cells and human blood, and PGE₂-mediated inhibition of interleukin (IL)-2-induced interferon (IFN)-γ production in human NK cells. MF-766 reversed the inhibition of IFN-γ in CD8⁺ T-cells by PGE₂ and impaired suppression of CD8⁺ T-cells induced by myeloid-derived suppressor cells (MDSC)/PGE_2. In translational studies using primary human tumors, MF-766 enhanced anti-CD3-stimulated IFN-γ, IL-2, and TNF-α production in primary histoculture and synergized with pembrolizumab in a PGE₂ high TME. Our studies demonstrate that the combination of EP₄ blockade with anti-PD-1 therapy enhances antitumor activity by differentially modulating myeloid cell, NK cell, cDC and T-cell infiltration profiles.

Wnt signaling enhances macrophage responses to IL-4 and promotes resolution of atherosclerosis

Atherosclerosis is a disease of chronic inflammation. We investigated the roles of the cytokines IL-4 and IL-13, the classical activators of STAT6, in the resolution of atherosclerosis inflammation. Using Il4-/-Il13-/- mice, resolution was impaired, and in control mice, in both progressing and resolving plaques, levels of IL-4 were stably low and IL-13 was undetectable. This suggested that IL-4 is required for atherosclerosis resolution, but collaborates with other factors. We had observed increased Wnt signaling in macrophages in resolving plaques, and human genetic data from others showed that a loss-of-function Wnt mutation was associated with premature atherosclerosis. We now find an inverse association between activation of Wnt signaling and disease severity in mice and humans. Wnt enhanced the expression of inflammation resolving factors after treatment with plaque-relevant low concentrations of IL-4. Mechanistically, activation of the Wnt pathway following lipid lowering potentiates IL-4 responsiveness in macrophages via a PGE2/STAT3 axis.

Pacemaking Activity in the Peripheral Nervous System: Physiology and Roles of Hyperpolarization Activated and Cyclic Nucleotide-Gated Channels in Neuropathic Pain

The most famous pacemaking activity found in the human body is in the cardiac system. However, pacemaking is also widely present in the nervous system. The ion channels responsible for the pacemaking activity are called hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels. HCN channels are activated during hyperpolarization and create an inward current named I_h containing mixed sodium and potassium ions. The molecular mechanism of these unique features remains mysterious. In the peripheral nervous system (PNS), pacemaking is unique because it is only present in pathologic states when nerve damage occurs and leads to neuropathic pain. For this reason, pacemaking in neuropathic pain is also known as ectopic discharge. In our literature review, the HCN channel physiology is one of the research interests. We will present studies exploring the molecular mechanisms involved in HCN gating and ion permeability. The second research question is, what makes the pacemaking activity unique in the PNS? Thus, our paper will include studies that discuss the role of HCN channels in neuropathic pain. Given the fundamental role of HCN channels in regulating neuronal cells' discharge activity, the modulation of their function for therapeutic purposes could be useful in various pathological conditions. Here we review the present knowledge of the efficacy of HCN blocker treating neuropathic pain in humans.

Induction of DNMT3B by PGE2 and IL6 at Distant Metastatic Sites Promotes Epigenetic Modification and Breast Cancer Colonization

Current cancer treatments are largely based on the genetic characterization of primary tumors and are ineffective for metastatic disease. Here we report that DNA methyltransferase 3B (DNMT3B) is induced at distant metastatic sites and mediates epigenetic reprogramming of metastatic tumor cells. Multiomics analysis and spontaneous metastatic mouse models revealed that DNMT3B alters multiple pathways including STAT3, NFκB, PI3K/Akt, β-catenin, and Notch signaling, which are critical for cancer cell survival, apoptosis, proliferation, invasion, and colonization. PGE2 and IL6 were identified as critical inflammatory mediators in DNMT3B induction. DNMT3B expression levels positively correlated with human metastatic progression. Targeting IL6 or COX-2 reduced DNMT3B induction and improved chemo or PD1 therapy. We propose a novel mechanism linking the metastatic microenvironment with epigenetic alterations that occur at distant sites. These results caution against the "Achilles heel" in cancer therapies based on primary tumor characterization and suggests targeting DNMT3B induction as new option for treating metastatic disease. SIGNIFICANCE: These findings reveal that DNMT3B epigenetically regulates multiple pro-oncogenic signaling pathways via the inflammatory microenvironment at distant sites, cautioning the clinical approach basing current therapies on genetic characterization of primary tumors.

The TLR-2/TLR-6 agonist macrophage-activating lipopeptide-2 augments human NK cell cytotoxicity when PGE2 production by monocytes is inhibited by a COX-2 blocker

Macrophage-activating lipopeptide-2 (MALP-2) is a potent inducer of proinflammatory cytokine secretion by macrophages, monocytes, and dendritic cells. MALP-2 was reported to be involved in natural killer (NK) cell activation and ensuing tumor rejection. However, the mechanism of MALP-2-mediated NK cell activation remained unclear. Therefore, we studied the effects of MALP-2 on cultured human NK cells. We found that MALP-2 had no direct effect on NK cells. Instead, MALP-2 acted on monocytes and triggered the release of different molecules such as interleukin (IL)-1β, IL-6, IL-10, IL-12, IL-15, interferon gamma-induced protein (IP-10), and prostaglandin (PG)-E2. Our data show that monocyte-derived IP-10 could significantly induce NK cell cytotoxicity as long as the immunosuppression by PGE2 is specifically inhibited by cyclooxygenase (COX)-2 blockade. In summary, our results show that MALP-2-mediated stimulation of monocytes results in the production of several mediators which, depending on the prevailing conditions, affect the activity of NK cells in various ways. Hence, MALP-2 administration with concurrent blocking of COX-2 can be considered as a promising approach in MALP-2-based adjuvant tumor therapies.

Human T-cell leukemia virus type-I Tax induces the expression of CD83 on T cells

BACKGROUND

CD83, a cell surface glycoprotein that is stably expressed on mature dendritic cells, can be transiently induced on other hematopoietic cell lineages upon cell activation. In contrast to the membrane form of CD83, soluble CD83 appears to be immunosuppressive. In an analysis of the phenotype of leukemic CD4(+) T cells from patients with adult T-cell leukemia (ATL), we found that a number of primary CD4(+) T cells became positive for cell surface CD83 after short-term culture, and that most of these CD83(+) CD4(+) T cells were positive for human T-cell leukemia virus type-I (HTLV-I) Tax (Tax1). We hypothesized that Tax1 is involved in the induction of CD83.

RESULT

We found that CD83 was expressed selectively on Tax1-expressing human CD4(+) T cells in short-term cultured peripheral blood mononuclear cells (PBMCs) isolated from HTLV-I(+) donors, including ATL patients and HTLV-I carriers. HTLV-I-infected T cell lines expressing Tax1 also expressed cell surface CD83 and released soluble CD83. CD83 can be expressed in the JPX-9 cell line by cadmium-mediated Tax1 induction and in Jurkat cells or PBMCs by Tax1 introduction via infection with a recombinant adenovirus carrying the Tax1 gene. The CD83 promoter was activated by Tax1 in an NF-κB-dependent manner. Based on a previous report showing soluble CD83-mediated prostaglandin E2 (PGE2) production from human monocytes in vitro, we tested if PGE2 affected HTLV-I propagation, and found that PGE2 strongly stimulated expression of Tax1 and viral structural molecules.

CONCLUSIONS

Our results suggest that HTLV-I induces CD83 expression on T cells via Tax1 -mediated NF-κB activation, which may promote HTLV-I infection in vivo.

Concurrent targeting of eicosanoid receptor 1/eicosanoid receptor 4 receptors and COX-2 induces synergistic apoptosis in Kaposi's sarcoma-associated herpesvirus and Epstein-Barr virus associated non-Hodgkin lymphoma cell lines

The effective antitumorigenic potential of nonsteroidal anti-inflammatory drugs (NSAIDs) and eicosonoid (EP; EP1-4) receptor antagonists prompted us to test their efficacy in Kaposi's sarcoma-associated herpesvirus (KSHV) and Epstein-Barr virus (EBV) related lymphomas. Our study demonstrated that (1) EP1-4 receptor protein levels vary among the various non-Hodgkin's lymphoma (NHL) cell lines tested (BCBL-1:KSHV+/EBV-;BC-3: KSHV+/EBV-; Akata/EBV+: KSHV-/EBV+; and JSC-1 cells: KSHV+/EBV + cells); (2) 5.0 μM of EP1 antagonist (SC-51322) had a significant antiproliferative effect on BCBL-1, BC-3, Akata/EBV+, and JSC-1 cells; (3) 50.0 μM of EP2 antagonist (AH6809) was required to induce a significant antiproliferative effect on BCBL-1, Akata/EBV+, and JSC-1 cells; (4) 5.0 μM of EP4 antagonist (GW 627368X) had a significant antiproliferative effect on BC-3, Akata/EBV+, and JSC-1 cells; (5) COX-2 selective inhibitor celecoxib (5.0 μM) had significant antiproliferative effects on BCBL-1, BC-3, Akata/EBV+, and JSC-1 cells; and (6) a combination of 1.0 μM each of celecoxib, SC-51322 and GW 627368X could potentiate the proapoptotic properties of celecoxib or vice-versa. Overall, our studies identified the synergistic antiproliferative effect of NSAIDs and EP receptor blockers on KSHV and EBV related B cell malignancies.

Prostaglandin E2 induces transcription of skeletal muscle mass regulators interleukin-6 and muscle RING finger-1 in humans

Cyclooxygenase (COX) inhibiting drugs augment muscle mass and strength improvements during resistance exercise based treatment of sarcopenia in older individuals. Initial evidence suggests a potential mechanism of COX inhibitor blunted prostaglandin (PG) E2 stimulation of interleukin (IL)-6 and the ubiquitin ligase MuRF-1, reducing their inhibition on muscle growth. The purpose of this investigation was to determine if PGE2 stimulates IL-6 and MuRF-1 transcription in skeletal muscle. Muscle biopsies were obtained from 10 young individuals and incubated ex vivo with PGE2 or control and analyzed for IL-6 and MuRF-1 mRNA levels. PGE2 upregulated (P<0.05) expression of both IL-6 (195%) and MuRF-1 (51%). A significant relationship was found between IL-6 and MuRF-1 expression after incubation with PGE2 (r=0.77, P<0.05), suggesting regulation through a common pathway. PGE2 induces IL-6 and MuRF-1 transcription in human skeletal muscle, providing a mechanistic link between COX inhibiting drugs, PGE2, and the regulation of muscle mass.

Gene therapy for acute lung injury

The remarkable transition of biological science into the age of molecular biology held great promise for development of new therapies for treatment of human disease. The fact that the technology exists for analyzing genetic material in exquisite detail and constructing DNA in virtually any desired form was the basis for promising rapid translation into clinical medicine and the final cure for genetically determined diseases; cystic fibrosis is the prime example of such a lung disease. The promise was not kept, at least not in a time frame which was expected. That result is neither because the rationale was faulty nor because the tools of molecular biology were wanting. The devil was and is in the details. How do you deliver DNA to the desired cell targets in amounts sufficient to accomplish the desired effect? Viral vectors have received the most attention, but viral vectors have proven to have both theoretical and practical problems. In the lungs, these vectors have not fulfilled their original promise. Non-viral based strategies work in a general sense, but efficiency of gene delivery in vivo has been a limitation. In addition, the experimental end points in both clinical and preclinical investigation have been most often designed to demonstrate phenomenology rather than potential efficacy. And, why limit the potential of gene therapy to inherited disease? In fact, treatment of acquired diseases by increasing or decreasing expression of a given gene in the lungs that would hasten recovery from an acquired disease might be easier than treating inherited disease because the requirements for duration of transgene expression would be less stringent. Over the past two decades, we have learned enough about the pathogenesis of acute lung injury to predict that increased (or decreased) production of certain biologically active mediators should be beneficial. Genes encoding some of these mediators have been cloned and constructs made which express the genes. It is now possible using either viral or non-viral strategies to deliver expression constructs to the lungs and, since acute lung injury has a dismal prognosis and no effective drugs have been identified, this seems a good clinical target for gene therapy. In preclinical studies, we have shown that increased expression of the gene encoding the constitutive form of the cyclooxygenase gene (COX-1) results in increased production of prostacyclin and PGE2 by the lungs and inhibits endotoxin induced pulmonary hypertension and edema. Additional studies demonstrate that increased expression of the alpha-1 antitrypsin gene in human respiratory epithelium in culture and in vivo has anti-viral and anti-inflammatory effects that are not predicted by extracellular concentrations of the transgene product. Thus, acute lung injury is a reasonable target for gene therapy, and evidence to date indicates that current technology is sufficiently robust to pursue this novel area for treatment of this devastating disease.

Indomethacin modulation of adriamycin-induced effects on multiple cytolytic effector functions

The anticancer agent, Adriamycin (ADM), in addition to being a potent cytotoxic drug has been shown to be an effective immunomodulator. This study was undertaken to determine whether ADM-induced changes in the production of prostaglandins (particularly PGE2) are involved in ADM-associated modifications of selected host defenses. Spleen cells from normal or ADM-treated (5 mg/kg; day -5) C57BL/6 mice were assessed for the following activities: fresh (day 0) and cultured natural killer (NK), cytotoxic T lymphocyte, lymphokine-activated killer (LAK), Fc-dependent phagocytosis and tumoricidal macrophage. All activities were assessed with and without the addition of indomethacin, an inhibitor of the first step of the cyclo-oxygenase pathway of prostaglandin synthesis. Depending on culture conditions, the cytotoxic T lymphocyte and splenic tumoricidal macrophage activities were either unaffected or were augmented by ADM treatment of the spleen donor mice or by addition of indomethacin to the culture, and these effects were apparently independent of one another. In contrast, ADM treatment generally resulted in reduced NK and LAK activities relative to control and elevated Fc-dependent phagocytosis. The addition of indomethacin to the culture effectively reversed these effects. Furthermore, spleen cells from ADM-treated mice were found to produce twice the amount of PGE2 in culture compared to cells from untreated mice. Finally, the direct addition of PGE2 to NK cultures resulted in a dose-dependent inhibition of NK activity and the dose required was comparable to the amount of PGE2 produced by cultured spleen cells from ADM-treated mice. Taken together, these results indicate that at least some of the immunomodulatory effects of ADM are an indirect result of ADM-induced changes in PGE2 production.

Regression mechanisms of mouse fibrosarcoma cells after in vitro exposure to quercetin: diminution of tumorigenicity with a corresponding decrease in the production of prostaglandin E2

We have previously reported that both regressor (QR) and progressor (metastatic, QP) clones were obtained after the in vitro exposure of a mouse fibrosarcoma BMT-11 cl-9 to quercetin. In this study, we investigated possible mechanisms of spontaneous regression of QR clones as compared with tumorigenic QP and BMT-11 cl-9 tumor clones. We observed that BMT-11 cl-9 cells produced relatively high amounts of prostaglandin E2 (PGE2) during in vitro culture. The average production by 11 subclones of BMT-11 cl-9 cells was 9236 +/- 2829 pg/ml whereas that by 9 QR clones was 3411 +/- 2213 pg/ml (P less than 0.02). Indomethacin not only inhibited in vitro PGE2 synthesis by QP clones (high-PGE2 producers) but also the s.c. growth of QP clones in mice. Chronological changes in host immune responses to tumor-associated antigen were measured by cytotoxic T lymphocyte (CTL) activity examined after mixed lymphocyte/tumor cell culture of spleen cells obtained from tumor-bearing mice. The CTL activity disappeared abruptly in the spleen of QP-clone-bearing mice 21 days after the inoculation of tumors, whereas the spleen cells of QR-clone-inoculated mice retained their CTL activity. We determined that the mechanism responsible for the regression of these regressor clones is not due to any qualitative or quantitative increase in pre-existing membrane antigens, nor the emergence of new antigen(s) on the cell surface of the QR clones: nor was it due to enhanced susceptibility of QR clones to natural killer cells, lymphokine-activated killer cells and macrophages. These finding suggest that the regression mechanism of QR clones may be the diminished inhibition of host response to tumor-associated antigen caused by the reduced production of PGE2 by QR clones.

Increased plasma levels of leukotriene B4 and prostaglandin E2 in cats experimentally inoculated with feline infectious peritonitis virus

Specific-pathogen-free kittens experimentally infected with feline infectious peritonitis virus (FIPV) subsequently demonstrated increased plasma levels of the arachidonic acid metabolites, leukotriene (LT) B4 and prostaglandin (PG) E2. Significant increases (P less than 0.025) in LTB4 plasma levels occurred in all (5/5) FIPV-inoculated kittens on postchallenge-exposure days (PCD) 7 and 14 vs PCD 0. Significant increases (P less than 0.05) in PGE2 plasma levels occurred in 80% (4/5) of FIPV-infected kittens on PCD 7 and 14. Maximal mean plasma levels of LTB4 and PGE2 occurred on PCD 7 (502.5 +/- 45.6 pg/ml and 1108.0 +/- 247.9 pg/ml, respectively). A positive correlation was found between LTB4 plasma levels and body temperature (r = 0.609, P less than 0.01). Mean survival time in FIPV-inoculated kittens was 19.4 +/- 3.2 days. Gross lesions, including peritoneal or pleural effusions (or both) and connective tissue edema, indicated an increased vascular permeability in the FIPV-infected kittens. Histologically, lesions were characterized by vasculitis or perivasculitis, vasodilatation, perivascular edema, and fibrinonecrotizing and pyogranulomatous inflammation. Immunofluorescent studies of tissues from FIPV-infected kittens demonstrated foci of polymorphonuclear leukocytes and FIPV-positive macrophages oriented around dilated blood vessels. Seemingly, arachidonic acid metabolites, including LTB4 or PGE2 released from macrophages, neutrophils or other cells, may be involved in the pathogenesis of FIP vascular and inflammatory lesions and in some of the clinical disease manifestations.

Increased production of tumor necrosis factor and prostaglandin E2 by monocytes in cancer patients and its unique modulation by their plasma

We investigated the role of monocytes in the production of tumor necrosis factor (TNF) and prostaglandin E2 (PGE2) in 77 cancer patients with malignancies of the digestive tract, using 30 normal individuals and 18 noncancer patients as controls. Monocytes were incubated with lipopolysaccharide for 20 h, and TNF production and PGE2 production were analyzed by bioassays. Elevated levels of TNF (greater than 512 U/ml) and PGE2 (greater than 8 ng/ml) production were demonstrated in many cancer patients when these factors were induced in the medium with 10% fetal bovine serum. The elevated level of TNF was seen to be restricted for the most part to patients with malignancies. Thus, 51 out of 59 cancer patients (86%), consisting of 44 primary cancer patients and 15 recurrent cancer patients, showed an increased level of TNF. In contrast, almost all of 18 postoperative cancer patients showed TNF levels comparable to those of normal individuals. Furthermore, 16 primary cancer patients were also demonstrated to have reduced levels of TNF production by monocytes after curative operation. When 10% cancer-patient plasma was added to the induction culture, TNF production by monocytes was drastically suppressed in the cancer patients. Interestingly, the same addition of plasma induced a prominent enhancement of PGE2 production in the cancer patients. The plasma of noncancer patients did not modulate production of these factors. No TNF activity was found in the plasma of cancer patients, but such plasma did contain an increased level of PGE2 (100-300 pg/ml). Although PGE2 (greater than 2 ng/ml) was able to suppress TNF production by monocytes, the addition of 10% plasma PGE2 was not enough to induce suppression. An unknown factor(s) in the plasma of cancer patients may uniquely modulate the elevated TNF and PGE2 production in these patients.

T cell recruitment from the thymus to the spleen in tumor-bearing mice. I. Analysis of recruited cells by surface markers

After inoculation of tumor cells (methylcholanthrene-induced sarcoma), the number of Thy 1+ cells and PNA (peanut agglutinin) binding cells, which were shown to be different subpopulations were increased in the spleen of thymus-intact mice, in contrast this increase was not observed in adult thymectomized mice. In experiments performed concurrently with splenic cell analysis, we found that the plasma PGE2 levels declined in parallel with the tumor growth. Prevention of such a decline of plasma PGE2 level by replenishment with exogenous PGE2 inhibited the splenic cell increase in tumor bearers. In the tumor-bearing mice, cell traffic systems from the thymus to the periphery was ascertained by injecting fluorescein diacetate (FDA) into the thymus and observing fluorescein positive cells in the periphery. We suggest that increased recruitment of thymic cells to the periphery may be mediated by PGE2 in the presence of a tumor.