The anti-B7-H4 checkpoint synergizes trastuzumab treatment to promote phagocytosis and eradicate breast cancer

Trastuzumab is a humanized mAb used to treat HER2-overexpressing breast cancer; however its mechanisms remain to be fully elucidated. Previous studies suggest a role for immunity in mediating trastuzumab-specific antitumor effects. This study evaluated the role(s) of trastuzumab and other antibodies on macrophage activation and Ab-dependent cell-mediated phagocytosis (ADCP) of HER2⁺ breast cancer cells in vitro and in vivo. We employed orthotopic implantation of HER2⁺ murine breast cancer (BC) cells in immunocompetent mouse models, a human HER2⁺ BC xenograft in an immune humanized mouse model, and human PDXs involving adoptive transfer of autologous macrophages to simulate an endogenous mammary tumor-immune microenvironment. Our study demonstrated that trastuzumab greatly and consistently increased macrophage frequency and tumor-cell phagocytosis, and that concurrent knockdown of B7-H4 by a neutralizing antibody increased immune cell infiltration and promoted an antitumor phenotype. Furthermore, neoadjuvant trastuzumab therapy significantly upregulated B7-H4 in the cancer-infiltrating macrophages of HER2⁺ BC patients, which predicted poor trastuzumab response. We suggest that strategies to specifically enhance ADCP activity might be critical to overcoming resistance to HER2 mAb therapies by inhibiting tumor growth and potentially enhance antigen presentation. Furthermore, these results advance the understanding of macrophage plasticity by uncovering a dual role for ADCP in macrophages involving elimination of tumors by engulfing cancer cells while causing a concomitant undesired effect by upregulating immunosuppressive checkpoints.

The long-term effectiveness of metabolic control on cardiovascular disease in patients with diabetes in a real-world health care setting - A prospective diabetes management study

AIMS

To determine the incidence rates of cardiovascular disease (CVD) and assess the effect of metabolic risk factor management on the development of CVD in patients with diabetes.

METHODS

We studied 733 patients with diabetes without prior CVD in the Shanghai Taopu community health service center. Success in managing CVD risk factors was evaluated as follows: (1) glucose control (haemoglobin A1c [HbA1c] <7.0% in patients aged <65years and <8.0% in patients aged ≥65years), (2) blood pressure control (<140/90mmHg), and (3) lipid control (high-density lipoprotein cholesterol ≥1.0mmol/L in men and ≥1.3mmol/L in women, and triglycerides <1.7mmol/L).

RESULTS

During a median 8.0-year follow-up, 206 CVD incident cases were identified. Each 1% increment in HbA1c, 10mmHg increment in systolic blood pressure (SBP), and 1mmol/L increment in triglycerides during follow-up significantly increased the risk of CVD by 17%, 37%, and 14%, respectively. Compared to those who did not, patients who met the blood pressure and glucose control goals during follow-up had a 64% and a 29% decreased risk of CVD, respectively. The multivariable-adjusted hazard ratios of CVD were 1.00, 1.78 (95% confidence interval [CI] 1.10-2.87), and 2.51 (95% CI 1.54-4.07) among patients who attained three, two, and one/none of the CVD factor control goals (HbA1c, blood pressure, and lipid) during follow-up, respectively.

CONCLUSIONS

Average levels of HbA1c, SBP, and triglycerides during follow-up were positively associated with the risk of CVD, and treatment targeting multiple factors can significantly reduce CVD risk.

Abstract ES10-2: Understanding breast cancer using a developmental perspective

Parallels among embryonic development, stem cells, and cancer have long been recognized. We identified, isolated, and characterized stem cells that first become committed to a mammary fate during embryogenesis; we refer to these cells as fetal mammary stem cells (fMaSCs). Lineage tracing, in vitro sphere formation, and in vivo transplantation studies by our group and many others all confirm that cells in the embryo are the bipotent progenitors of the mammary gland. There is debate, however, on whether such bipotent cells persist into the adult, or whether the luminal and basal lineages are maintained by unipotent progenitors. To gain insight into the relationships between fMaSCs and breast cancer, and to investigate their potential persistence in the adult, we have applied bulk and single cell RNA-sequencing (sc-RNA-seq) and single nucleus ATAC-sequencing (snATAC-seq) throughout mammary development. The results to be discussed demonstrate that fMaSC transcriptomes are heterogeneous, but all share co-expression of genes associated with luminal and basal cell fates. This fits a model in which the bipotent state is created by a balance of lineage specifiers. We also find that the fMaSC transcriptome is highly enriched in basal-like human breast cancers and identify potential embryonic pathways that correlate with poor prognosis. We used a variety of computational tools to infer the gene expression programs that ensue when fMaSCs commit to luminal and basal states. The data from scRNA-seq and snATAC-seq demonstrate that the transitions are gradual, not precipitous, and that luminal and basal cells exhibit significant transcriptomic and epigenetic heterogeneity. This challenges the notion that the mammary gland consists of discrete cell types defined by rigid transcriptomic parameters, and reveals a potential for intrinsic phenotypic plasticity of normal mammary cells. Using the combined databases, we identified Sox10 as a significantly differentially expressed cell state regulator. We show that tumors are heterogeneous with regard to Sox10 expression, and that locally invasive cells tend to express high Sox10 levels. Elevated Sox10 correlates with acquisition of a neural-crest like, EMT-related state. Implications for interception of metastasis by targeting neural crest-like cells will be discussed. Finally, we have generated a web resource that is available to the scientific community to enable the transcription and epigenetic characteristics of any gene of interest to be tracked through mammary development (https://wahl-labsalk.shinyapps.io/Mammary_snATAC/).

Citation Format: GM Wahl, Z Ma, C Chung, C Dravis, BT Spike, RR Giraddi, O Balcioglu, C Fan, B Hagos, R Heinz, Herrera-Valdez J, X Hou, J Hwang, R Lasken, G Luna, NE Lytle, EM Mehrabad, M Novotny, CM Perou, O Poirion, S Preissl, B Ren, T Reya, CL Trejo, KT Varley. Understanding breast cancer using a developmental perspective [abstract]. In: Proceedings of the 2019 San Antonio Breast Cancer Symposium; 2019 Dec 10-14; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2020;80(4 Suppl):Abstract nr ES10-2.

Decrease of FGF19 contributes to the increase of fasting glucose in human in an insulin-independent manner

PURPOSE

The ileum-derived fibroblast growth factor 19 (FGF19) plays key roles in hepatic glucose homeostasis in animals in an insulin-independent manner. Here, we analyzed the association of FGF19 with glucose effectiveness (GE, the insulin-independent glucose regulation), as well as hepatic glucose production (HGP) in Chinese subjects.

METHODS

GE was measured by frequently sampled intravenous glucose tolerance test (FSIVGTT) in normal glucose tolerance (NGT), isolated-impaired glucose tolerance (I-IGT), and isolated-impaired fasting glucose (I-IFG) subjects. The oral glucose tolerance test-derived surrogate of GE (oGE) was determined in NGT, I-IFG, combined glucose intolerance (CGI), and type 2 diabetes (T2DM) subjects. HGP was assessed by labeled ([3-³H]-glucose) hyperinsulinemic-euglycemic clamp in NGT subjects. Insulin secretion and sensitivity were calculated by the hyperglycemic and hyperinsulinemic-euglycemic clamps in a subgroup of NGT, I-IGT, and I-IFG subjects. Serum FGF19 levels were determined by ELISA.

RESULTS

FGF19 positively correlated with GE (r = 0.29, P = 0.004) as determined by FSIVGTT. The result was further confirmed by oGE (r = 0.261, P < 0.001). FGF19 was negatively associated with FPG (r = - 0.228, P = 0.025), but the association no longer existed after adjusting for GE (r = - 0.177, P = 0.086). FGF19 was negatively associated with basal HGP (r = - 0.697, P = 0.006). However, the correlation between FGF19 and insulin secretion and sensitivity were not found.

CONCLUSIONS

FGF19 levels are associated positively with GE and negatively with HGP. The increase of FPG in human is at least partially due to the decrease of FGF19 in an insulin-independent manner.

Blockade of Immune-Checkpoint B7-H4 and Lysine Demethylase 5B in Esophageal Squamous Cell Carcinoma Confers Protective Immunity against P. gingivalis Infection

Pathogens are capable of hijacking immune defense mechanisms, thereby creating a tolerogenic environment for hypermutated malignant cells that arise within the site of infection. Immune checkpoint-oriented immunotherapies have shown considerable promise. Equally important, the epigenetic reprogramming of an immune-evasive phenotype that activates the immune system in a synergistic manner can improve immunotherapy outcomes. These advances have led to combinations of epigenetic- and immune-based therapeutics. We previously demonstrated that Porphyromonas gingivalis isolated from esophageal squamous cell carcinoma (ESCC) lesions represents a major pathogen associated with this deadly disease. In this study, we examined the mechanisms associated with host immunity during P. gingivalis infection and demonstrated that experimentally infected ESCC responds by increasing the expression of B7-H4 and lysine demethylase 5B, which allowed subsequent in vivo analysis of the immunotherapeutic effects of anti-B7-H4 and histone demethylase inhibitors in models of chronic infection and immunity against xenografted human tumors. Using three different preclinical mouse models receiving combined therapy, we showed that mice mounted strong resistance against P. gingivalis infection and tumor challenge. This may have occurred via generation of a T cell-mediated response in the microenvironment and formation of immune memory. In ESCC subjects, coexpression of B7-H4 and KDM5B correlated more significantly with bacterial load than with the expression of either molecule alone. These results highlight the unique ability of P. gingivalis to evade immunity and define potential targets that can be exploited therapeutically to improve the control of P. gingivalis infection and the development of associated neoplasia.

Discovery of potential biomarkers for osteoporosis using LC-MS/MS metabolomic methods

Our study focused on the associations of metabolites with BMD and osteoporosis, finding that several metabolites are associated with BMD, and metabolites combined with bone turnover markers tend to be more sensitive in distinguishing osteoporosis in both males and postmenopausal females, which might be meaningful for the early diagnosis of osteoporosis.

INTRODUCTION

Our study aimed to evaluate the association of metabolites with bone, trying to find new metabolic markers that are distinguishing for low bone mineral density (BMD).

METHODS

Our study recruited 320 participants, including 138 males and 182 postmenopausal females from the Shanghai area. Bone turnover markers (BTMs), including osteocalcin, PINP and β-CTX, and other biochemical traits were tested. BMD values of the lumber spine (L1-4), femoral neck and total hip were determined using dual-energy X-ray absorptiometry and the serum metabolome profiles including 221 metabolites from five groups (acylcarnitines, amino acids, biogenic amines, glycerophospholipids, sphingolipids and hexose) were assessed by mass spectrometry.

RESULTS

No visual separation in the metabolic profiles between different BMD groups was observed in principal component analysis (PCA) or partial least squares discriminant analysis (PLS-DA) models. We compared metabolites in three groups with different BMD levels in males and postmenopausal females separately and further filtering these metabolites via random forest-based feature selection, a commonly applied machine learning algorithm which could select the features with the greatest impact on osteoporosis, then metabolites with the highest importance (≥ 5%) (5 in males and 9 in postmenopausal females) were selected to construct better models for osteoporosis classification. After adding these selected metabolites to the model, the area under the curve (AUC) of receiver operating characteristic (ROC) curves increased significantly (BTMs: AUC 0.729, 95% CI 0.647-0.802, p < 0.0001, model 1: AUC = 0.828, 95% CI 0.754-0.888, p < 0.0001; model 1 versus model of BTMs: p = 0.0158) compared to the AUC of the BTM-only model in males. Similar results were also observed in postmenopausal females (BTMs: AUC = 0.638, 95% CI 0.562-0.708, p = 0.0025; model 2: AUC = 0.741, 95% CI 0.669-0.803, p < 0.0001; model 1 versus model of BTMs: p = 0.0182).

CONCLUSION

Metabolites combined with traditional BTMs tend to better markers for distinguishing osteoporosis in both males and postmenopausal females than BTMs alone.

miR-25 Mediates Retinal Degeneration Via Inhibiting ITGAV and PEDF in Rat

BACKGROUND

Age-related macular degeneration (AMD) is the main cause of irreversible blindness in the elderly. Oxidative stress in retinal pigment epithelium (RPE) is deemed to play a pivotal role in the pathogenesis of AMD. miR-25 functions as an essential modulator in response to oxidative-stress in several cell types, but its function in RPE cells is poorly understood.

OBJECTIVE

To explore the roles of miR-25 in RPE cells and in the development of AMD.

METHODS

A rat model of retinal degeneration was induced by sodium iodate (SI). Subretinal injection of antagomiR-25 was performed for the intervention while the scramble as control. Visual responses were recorded with Electroretinogram (ERG). TUNEL assay was performed to detect apoptosis. Phagosome quantification in vivo was performed to evaluate RPE cell function. Oxygen-glucose deprivation treatment was performed to mimic in vitro oxidative stress. Gene expression at mRNA level and protein level were performed by quantitative polymerase chain reaction (qPCR) and Western Blot, respectively. The pigment epithelium derived factor (PEDF) level in the cultured medium was measured by Enzyme-linked immunosorbent assay (ELISA). The interaction between miR-25 and integrin αV (IGTAV) / PEDF 3'UTR was examined by dual luciferase assay. Chromatin immunoprecipitation (ChIP) assay was performed to examine its transcriptional regulation of miR-25.

RESULTS

Oxidative stress up-regulated miR-25 in RPE cells in very early stage, accompanied by decreased phagocytosis and reduced growth factor secretion in those cells. Such changes preceded RPE cell apoptosis and visual impairment in the SItreated rats. Furthermore, antagomiR-25 intervention effectively rescued RPE cells from degeneration in such model. The increased miR-25 was confirmed to mediate RPE degeneration through direct targeting IGTAV and PEDF. On the other hand, upstream, miR-25 was found to be up-regulated by STAT3 signaling under oxidative stress in both in vivo and in vitro models.

CONCLUSION

Our findings demonstrate that, in SI-treated rats, oxidative stress activates STAT3 signaling which up-regulates miR-25 expression, in a very early stage. The increased miR-25 then inhibits ITGAV and PEDF expressions, resulting in RPE phagocytosis dysfunction and then RPE apoptosis and visual impairment as observed in patients with AMD. These findings lead us to a better understanding of AMD pathogenesis, and suggest that miR-25 could be a potential therapeutic target for oxidative stress related RPE diseases, like AMD.

The recruitment of extra-intestinal cells to the injured mucosa promotes healing in radiation enteritis and chemical colitis in a mouse parabiosis model

Mucosal healing occurs through migration and proliferation of cells within injured epithelium, yet these processes may be inadequate for mucosal healing after significant injury where the mucosa is denuded. We hypothesize that extra-intestinal cells can contribute to mucosal healing after injury to the small and large intestine. We generated parabiotic pairs between wild-type and tdTomato mice, which were then subjected to radiation-induced enteritis and 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced colitis. We now show that as compared with singleton mice, mice with a parabiotic partner were protected against intestinal damage as revealed by significantly reduced weight loss, reduced expression of pro-inflammatory cytokines, reduced enterocyte apoptosis, and improved crypt proliferation. Donor cells expressed CD45-, Sca-1+, c-kit+, and CXCR4+ and accumulated around the injured crypts but did not transdifferentiate into epithelia, suggesting that extra-intestinal cells play a paracrine role in the healing response, while parabiotic pairings with Rag1-/- mice showed improved healing, indicating that adaptive immune cells were dispensable for mucosal healing. Strikingly, ablation of the bone marrow of the donor parabionts removed the protective effects. These findings reveal that the recruitment of extra-intestinal, bone marrow-derived cells into the injured intestinal mucosa can promote mucosal healing, suggesting novel therapeutic approaches for severe intestinal disease.

Analysis of radioactive waste generated during the cyclotron production of 99mTc

Past and prospective shortages of medical radioisotopes have driven recent developments in the direct production of ^99mTc via the ¹⁰⁰Mo(p,2n)^99mTc reaction. The cyclotron-based production method has been shown to successfully produce ^99mTc, however trace impurities present in the enriched molybdenum target can also lead to the unintended creation of other radioisotopes which constitute waste. The isotopic composition of the waste has to be investigated in order to determine how it can be handled, transported and safely stored. In this article, we report which waste radioisotopes are created alongside ^99mTc during target irradiation. Results are based on the gamma spectroscopy of waste produced. Significant complexities in the emission spectra made automated identification of radioisotopes inaccurate; complexities were resolved using a manual radioisotope identification procedure. The impact of target composition, integrated beam current and duration of target irradiation on the waste produced was studied. Results indicate that an average of 0.059  ±  0.003 GBq of waste is generated per 1 GBq of ^99mTc produced. Two-thirds of the total waste activity produced was attributed to ⁹⁹Mo (T _1/2  =  66 h) alone, while a total of fifty radioisotopes were found in the waste. Long-lived isotopes (T _1/2  >  2 months) constituted only 1% of the total waste activity at end of beam (EOB). In conclusion, it was determined that the waste generated during cyclotron-based ^99mTc production was acceptably low for routine clinical production.