[Identification of key genes in Wilms tumor based on high-throughput RNA sequencing and their impacts on prognosis and immune responses]

OBJECTIVE

To identify the key genes differentially expressed in Wilms tumor and analyze their potential impacts on prognosis and immune responses of the patients.

METHODS

High-throughput RNA sequencing was used to identify the differentially expressed mRNAs in clinical samples of Wilms tumor and paired normal tissues, and their biological functions were analyzed using GO, KEGG and GSEA enrichment analyses. The hub genes were identified using STRING database, based on which a prognostic model was constructed using LASSO regression. The mutations of the key hub genes were analyzed and their impacts on immunotherapy efficacy was predicted using the cBioPortal platform. RT-qPCR was used to verify the differential expressions of the key hub genes in Wilms tumor.

RESULTS

Of the 1612 differentially expressed genes identified in Wilms tumor, 1030 were up-regulated and 582 were down-regulated, involving mainly cell cycle processes and immune responses. Ten hub genes were identified, among which 4 genes (TP53, MED1, CCNB1 and EGF) were closely related to the survival of children with Wilms tumor. A 3-gene prognostic signature was constructed through LASSO regression analysis, and the patients stratified into with high- and low-risk groups based on this signature had significantly different survival outcomes (HR=1.814, log-rank P=0.002). The AUCs of the 3-, 5- and 7-year survival ROC curves of this model were all greater than 0.7. The overall mutations in the key hub genes or the individual mutations in TP53/CCNB1 were strongly correlated with a lower survival rates, and a high TP53 expression was correlated with a poor immunotherapy efficacy. RT-qPCR confirmed that the key hub genes had significant differential expressions in Wilms tumor tissues and cells.

CONCLUSION

TP53 gene plays an important role in the Wilms tumor and may potentially serve as a new immunotherapeutic biomarker as well as a therapeutic target.

Probiotic Limosilactobacillus reuteri DSM 17938 Changes Foxp3 Deficiency-Induced Dyslipidemia and Chronic Hepatitis in Mice

The probiotic Limosilactobacillus reuteri DSM 17938 produces anti-inflammatory effects in scurfy (SF) mice, a model characterized by immune dysregulation, polyendocrinopathy, enteropathy, and X-linked inheritance (called IPEX syndrome in humans), caused by regulatory T cell (Treg) deficiency and is due to a Foxp3 gene mutation. Considering the pivotal role of lipids in autoimmune inflammatory processes, we investigated alterations in the relative abundance of lipid profiles in SF mice (± treatment with DSM 17938) compared to normal WT mice. We also examined the correlation between plasma lipids and gut microbiota and circulating inflammatory markers. We noted a significant upregulation of plasma lipids associated with autoimmune disease in SF mice, many of which were downregulated by DSM 17938. The upregulated lipids in SF mice demonstrated a significant correlation with gut bacteria known to be implicated in the pathogenesis of various autoimmune diseases. Chronic hepatitis in SF livers responded to DSM 17938 treatment with a reduction in hepatic inflammation. Altered gene expression associated with lipid metabolism and the positive correlation between lipids and inflammatory cytokines together suggest that autoimmunity leads to dyslipidemia with impaired fatty acid oxidation in SF mice. Probiotics are presumed to contribute to the reduction of lipids by reducing inflammatory pathways.

[A sampling survey of intraoperative facial nerve monitoring in China]

Objective: This study aims to investigate the current application and the level of knowledge of intraoperative facial nerve monitoring among medical staff in China. Methods: A comprehensive online questionnaire was conducted among medical professionals across different regions in China from October 2022 to February 2023. The survey exclusively targeted departments specializing in otolaryngology, head and neck surgery, neurosurgery, and oral and maxillofacial surgery. The questionnaire covered various aspects including general information, intraoperative facial nerve monitoring practices, training history, indications for monitoring, parameters used during monitoring procedures, as well as factors influencing its implementation. Results: A total of 417 participants from 31 provincial, municipal, and autonomous regions were included. Intraoperative facial nerve monitoring was found to be implemented in 227 (54.4%,227/417) repondents of 53 institutions (24.9%, 53/213). The top three indications for implementing this technique were acoustic neuroma, parotid gland surgery, and modified middle ear surgery (mastoidectomy). Herein 81.1%(184/227) medical staff involved in intraoperative facial nerve monitoring had received relevant training, 57.3%(130/227)-92.1%(209/227) reported a lack of clear description regarding recording thresholds, stimulation currents/frequencies/wave widths. Conclusion: The majority of the institutions surveyed have not yet adopted intraoperative facial nerve monitoring. Furthermore, significant gaps concerning the procedure exist. It is imperative to establish standards or guidelines to promote its better development and application.

[Bioinformatics analysis of the RNA binding protein DDX39 of Toxoplasma gondii]

OBJECTIVE

To analyze the RNA binding protein of Toxoplasma gondii (TgDDX39) using bioinformatics technology, and to evaluate the immunogenicity of TgDDX39, so as to provide insights into development of toxoplasmosis vaccines.

METHODS

The amino acid sequences of TgDDX39 were retrieved from the ToxoDB database, and the physicochemical properties, transmembrane structure domain, signal peptide sites, post-translational modification sites, coils, secondary and tertiary structures, hydrophobicity, and antigenic epitopes of the TgDDX39 protein were predicted using online bioinformatics tools, incluiding ProtParam, TMHMM 2.0, SignalP 5.0, NetPhos 3.1, COILS, SOPMA, Phyre2, ProtScale, ABCpred, SYFPEITHI and DNA-STAR.

RESULTS

TgDDX39 protein was predicted to be an unstable hydrophilic protein with the molecular formula of C2173H3458N598O661S18, which contained 434 amino acids and had an estimated molecular weight of 49.1 kDa and a theoretical isoelectric point of 5.55. The protein was predicted to have an extremely low possibility of signal peptides, without transmembrane regions, and contain 27 phosphorylation sites. The β turn and random coils accounted for 39.63% of the secondary structure of the TgDDX39 protein, and a coiled helix tended to produce in one site. In addition, the TgDDX39 protein contained multiple B and T cell antigenic epitopes.

CONCLUSIONS

Bioinformatics analyses predict that TgDDX39 protein has high immunogenicity and contains multiple antigenic epitopes. TgDDX39 protein is a potential candidate antigen for vaccine development.

Efficacy and Safety of Local Radiotherapy Combined with Chemotherapy ± Bevacizumab in the Treatment of Patients with Advanced and Recurrent Metastatic Cervical Cancer

PURPOSE/OBJECTIVE(S)

To observe the efficacy and safety of local radiotherapy combined with chemotherapy ± bevacizumab in the treatment of patients with advanced or recurrent metastatic cervical cancer.

MATERIALS/METHODS

A total of 53 patients with advanced and recurrent metastatic cervical cancer who had received local radiotherapy combined with chemotherapy ± bevacizumab in Affiliated Cancer Hospital of Guizhou Medical University from July 2018 to October 2021 were collected. The recurrence types included 21 patients of pelvic recurrence, 7 patients of distant metastasis, 14 patients of complex pelvic recurrence and distant metastasis, and 11 patients of advanced stage (initial diagnosis stage IVB). The primary endpoints were objective response rate (ORR) and disease control rate (DCR). The secondary endpoints were progression-free survival (PFS), overall survival (OS) and incidence of adverse reactions.

RESULTS

(1) Complete response (CR) was achieved in 4 patients (7.5%), partial response (PR) in 34 patients (64.2%), stable disease (SD) in 12 patients (22.6%), and disease progression (PD) in 3 patients (5.7%), ORR was 71.7%, DCR was 94.3%. (2) The follow-up time was 5.3 to 45.7 months, the median OS was 29.3 months, the median PFS was 15.7 months, the one-year and two-year OS were 83.0% and 59.2%, and the 1-year and two-year PFS were 62.2% and 34.4%. (3) Recurrence type, tumor size at the time of recurrence, and efficacy after radiotherapy were significant factors for PFS and OS rates in multivariate analysis. (4) The main adverse reactions were myelosuppression, gastrointestinal reaction and urinary reaction. Grade IV leukopenia occurred at 13.2%, grade IV neutropenia at 11.3%, grade IV thrombocytopenia at 15.1%, and grade IV anemia at 5.7%, all of which were tolerable. The gastrointestinal and urinary reactions were mainly grade I-II, and the incidence of vesical or rectovaginal fistulas was about 7.5% (2 patients had rectovaginal fistulas and 2 patients had vesto-vaginal fistulas).

CONCLUSION

Local radiotherapy combined with chemotherapy ± bevacizumab can improve the efficacy and survival of patients with advanced and recurrent metastatic cervical cancer. Adverse reactions are tolerable and may provide survival benefits in these patients.

Effect of Concurrent Chemoradiotherapy on Regulatory T Cells,CD8/Treg Ratio,PD1 and CTLA-4 in Patients with Cervical Cancer

PURPOSE/OBJECTIVE(S)

To investigate the significance of chemoradiotherapy on regulatory T (Treg) cells, CD8 / Treg ratio, squamous cell carcinoma antigen (SCC), PD1, and CTLA-4 in the peripheral blood of cervical cancer (CC)patients.

MATERIALS/METHODS

A retrospective study was performed 56 cervical cancer patients treated with concurrent chemoradiotherapy from September 06, 2019 to April 19, 2021 were selected, in patients who underwent surgery. Flow cytometry was used to determine the levels of regulatory T cells, CD8 / Treg ratio, squamous cell carcinoma antigen, PD1, and CTLA-4 in the peripheral blood of patients before and after concurrent therapy, Differences in relative level values before and after treatment were calculated using statistical protocols such as the paired samples t-test.

RESULTS

The proportion of CD4+CD25+CD127low Treg in CD4+T cells was (15.96±4.29) % in cervical cancer patients and (9.76±4.21) % in healthy controls, and the difference between the two groups was statistically significant (P < 0.05). In different age groups, Treg, CD8 levels, CD4/CD8 ratio and CD8/Treg ratio before and after radiotherapy and chemotherapy had no significant relationship with age and pathological types (P > 0.05), but CD8/Treg ratio was higher in patients with adenocarcinoma than in patients with squamous cell carcinoma after radiotherapy and chemotherapy, and the difference was statistically significant (Z = -2.076 P = 0.038). For postoperative patients, CD8 levels were lower before and after chemoradiotherapy than after chemoradiotherapy (T = -2.320 P = 0.020). In terms of PD1, regardless of age, pathological type, the level of PD1 after radiotherapy and chemotherapy was higher than that before chemotherapy, and the difference was statistically significant. The level of adenocarcinoma (53.50±10.16) % was significantly higher than that of squamous carcinoma (43.72±11.89) % (T = -2.609 P = 0.011). The PD1 level of patients with cervical cancer radical resection (41.64±13.29) % was lower than that of patients without cervical cancer radical resection (46.84±10.61) %, the difference was statistically significant (T = 2.187 P = 0.031). The PD1 level of patients without pelvic lymph node metastasis (48.84±10.04) was significantly higher than that of patients with pelvic lymph node metastasis (42.96±10.85), and the difference was statistically significant (T = -2.019 P = 0.049), There were no significant differences in vascular positivity, invasion depth, stump positivity, pelvic lymph node positivity and Treg level, CD8 level, CTLA4 level, SCC, CD4/CD8 ratio, CD8/Treg ratio (ALL P > 0.05).

CONCLUSION

The level of Treg cells in patients with cervical cancer is significantly higher than that in healthy people, and it does not decrease immediately after radiotherapy and chemotherapy. Peripheral blood Treg, PD1, CD8 and CD8/Treg can reflect the immune function of the body, which may provide a certain reference for immunotherapy.

Long-Term Outcome of Rectal Cancer Patients Treated by High-Dose Radiotherapy and Concurrent Chemotherapy

PURPOSE/OBJECTIVE(S)

To explore the therapeutic efficacy and adverse effects of high-dose radiotherapy concurrently with chemotherapy in treating patients with non-metastatic rectal cancer.

MATERIALS/METHODS

Patients were enrolled if they were diagnosed with stage I-III rectal adenocarcinoma, refused surgery and received high-dose pelvic radiotherapy and concurrent chemotherapy instead. Their clinical data were retrospectively analyzed for calculating local control and survival rates. Treatment related toxicities was evaluated according to the Common Terminology Criteria for Adverse Events (version 5.0).

RESULTS

Between April 2006 and February 2021, a total of 93 patients in our medical center were eligible for this study, with a median age of 61 (range, 21-84) years. Of those, 86 (92.5%) patients had tumors located within 5 cm of the anal verge. There were 8 (8.6%), 30 (32.3%) and 55 (59.1%) patients diagnosed with stage I, II and III, respectively. All patients received fluorouracil-based chemotherapy (single-agent fluorouracil or FOLFOX regimen). The irradiation techniques included three-dimensional conformal and intensity-modulated radiation therapy. The median total radiation dose for gross tumor volume (GTV) was 80 (range, 60-90) Gy. The 15 (16.1%) patients refusing surgery before treatment received one course of radiation (60-70 Gy/30-35 Fr). And a 2-course radiation (Course 1, 45-50 Gy/25 Fr; Course 2: 24-40 Gy/12-20 Fr) were given to the 78 (83.9%) patients who failed to achieve clinical complete remission (cCR) after neoadjuvant chemoradiotherapy but still refused surgery, with a median interval of 79 (range, 35-195) days. The median follow-up duration was 66 (range, 10-161) months. The 3- and 5-year overall survival (OS) rates for all patients were 90.5% and 72.7%, respectively. The clinical complete remission rate at the end of chemoradiotherapy was 69.9%. Colostomy was performed in the 14 patients whose rectal tumor did not attain cCR or progressed. There was no grade 4/5 severe acute toxicity. No patient suffered from intestinal perforation. Only one patient developed anal stenosis. Because of rectal bleeding, blood transfusion was performed in 7 patients, and one patient underwent an enterostomy.

CONCLUSION

High-dose radiotherapy concurrent with chemotherapy brought encouraging survival outcomes, satisfactory organ preservation and acceptable short- and long-term side effects. It might be a safe and non-invasive alternative to abdominoperineal resection in rectal cancer patients refusing or unsuitable for surgery, especially for those with a low-position tumor.

Silva Classification System for HPV-Related EAC of Stage I ∼ IIIc1p Cervical Adenocarcinoma and Its Effect on Prognosis and Survival

PURPOSE/OBJECTIVE(S)

The proportion of adenocarcinoma in cervical cancer gradually increased and presented a younger trend. The previous pathological classification of cervical adenocarcinoma is difficult to provide reference for clinical treatment. In recent years, Silva classification, a new pathologic system for cervical adenocarcinoma, has been confirmed to be suitable for HPV-associated adenocarcinoma (HPVA), and has shown certain clinical application value in subsequent studies. Therefore, this study will retrospectively analyze the distribution of Silva typing system in patients with HPVA under standard treatment mode and its relationship with prognosis and survival.

MATERIALS/METHODS

From January 2010 to September 2021, 124 cervical adenocarcinoma patients with HPVA were retrospectively included, who underwent radical resection of cervical cancer. The HE staining sections of the patients were divided into SilvaA, SilvaB, and SilvaC types according to the Silva typing system. Kaplan-Meier calculation was used for single-factor analysis, and COX stepwise regression model was used for multi-factor analysis.

RESULTS

Of the 124 patients with HPVA who could be graded according to the Silva system, 16 (12.9%, 16/124) were SilvaA, 27 (21.7%, 27/124) SilvaB, and 81 (65.4%, 81/124) SilvaC. In Silva classification, FIGO staging of Silva A and B was stage I. And FIGO staging of Silva C was more significantly later than the staging of Silva A and B. All lymph node metastases and paruterine infiltrates were found only in Silva C. In addition, the patients with Silva C large mass accounted for a higher proportion (41.7%). SilvaA type cervical adenocarcinoma patients were in a survival state by the end of follow-up. Among Silva B, 3 patients died due to tumor, and the 5-year OS rate were 91.3%. Among SilvaC, 15 patients died due to tumor, and the 5-year OS rate were 76.5%. FIGO stage and lymph node invasion were the influencing factors for survival and prognosis of Silva classification (P <0.05). FIGO stage, tumor size, lymph node invasion, and paralegal invasion were the influencing factors for survival and prognosis of SilvaC patients (P <0.05).

CONCLUSION

Silva model classification system combined with clinicopathological features has certain clinical value for the prognostic guidance of HPVA patients. Among Silva classification, SilvaC had the worst prognosis. Late FIGO stage, lymph node metastasis, and paralegal infiltration are the influencing factors for survival and prognosis of SilvaC type.

Optimal design of surface CO2 observation network to constrain China's land carbon sink

Accurate estimate of the size of land carbon sink is essential for guiding climate mitigation actions to fulfill China's net-zero ambitions before 2060. The atmospheric inversion is an effective approach to provide spatially explicit estimate of surface CO2 fluxes that are optimally consistent with atmospheric CO2 measurements. But atmospheric inversion of China's land carbon sink has enormous uncertainties, with one major source arising from the poor coverage of CO2 observation stations. Here we use a regional atmospheric inversion framework to design an observation network that could minimize uncertainties in inverted estimate of China's land carbon sink. Compared with the large spread of inverted sink (∼1PgCa-1) from state-of-the-art inversions using existing CO2 observations, the uncertainty is constrained within 0.3PgCa-1 when a total of 30 stations were deployed, and is further reduced to approximately 0.2PgCa-1 when 60 stations were deployed. The proposed stations are mostly distributed over areas with high biosphere productivity during the growing season, such as Southeast China, Northeast China, North China, and the Tibetan Plateau. Moreover, the proposed stations can cover areas where existing satellites have limited coverage due to cloud shadowing in the monsoon season or over complex topography. Such ground-based observation network will be a critical component in the future integrated observing system for monitoring China's land carbon fluxes.

[An improved 4-vessel intermittent occlusion method for establishing rat models of global cerebral ischemia-reperfusion injury]

OBJECTIVE

To improve the classical 4-vessel occlusion (4VO) model established by Pulsinelli and Brierley.

METHODS

Thirty-two male SD rats were randomized into sham operation group, I4VO-Con10 group, I4VO-Int10 group and I4VO-Int15 group. The sham surgery group underwent exposure of the bilateral vertebral arteries and carotid arteries without occlusion to block blood flow. The I4VO-Con10 group experienced continuous ischemia by occluding the bilateral vertebral arteries and carotid arteries for 10 minutes followed by reperfusion for 24 hours. The I4VO-Int10 and I4VO-Int15 groups were subjected to intermittent ischemia. The I4VO- Int10 group underwent 5 minutes of ischemia, followed by 5 minutes of reperfusion and another 5 minutes of ischemia, and then reperfusion for 24 hours. The I4VO-Int15 group experienced 5 minutes of ischemia followed by two cycles of 5 minutes of reperfusion and 5 minutes of ischemia, and then reperfusion for 24 hours. The regional cerebral blood flow (rCBF) was monitored with laser Doppler scanning, and survival of the rats was observed. HE staining was used to observe hippocampal pathologies to determine the optimal method for modeling. Another 48 rats were randomized into 6 groups, including a sham operation group and 5 model groups established using the optimal method. The 5 I4VO model groups were further divided based on the reperfusion time points (1, 3, 7, 14, and 28 days) into I4VO-D1, I4VO-D3, I4VO-D7, I4VO- D14, and I4VO- D28 groups. Body weight changes and survival of the rats were recorded. HE staining was used to observe morphological changes in the hippocampal, retinal and optic tract tissues. The Y-maze test and light/dark box test were used to evaluate cognitive and visual functions of the rats in I4VO-D28 group.

RESULTS

Occlusion for 5 min for 3 times at the interval of 5 min was the optimal method for 4VO modeling. In the latter 48 rats, the body weight was significantly lower than that of the sham-operated rats at 1, 3, 7, 14 and 28 days after modeling without significant difference in survival rate among the groups. The rats with intermittent vessel occlusion exhibited progressive deterioration of hippocampal neuronal injury and neuronal loss. Cognitive impairment was observed in the rats in I4VO-D28 group, but no obvious ischemic injury of the retina or the optic tract was detected.

CONCLUSION

The improved 4VO model can successfully mimic the main pathological processes of global cerebral ischemia-reperfusion injury without causing visual impairment in rats.

[Identification and verification of α-11 giardin-interacting protein]

OBJECTIVE

To identify and verify the interacting protein of α-11 giardin, so as provide the experimental evidence for studies on the α-11 giardin function.

METHODS

The yeast two-hybrid cDNA library of the Giardia lambia C2 strain and the bait plasmid of α-11 giardin were constructed. All proteins interacting with α-11 giardin were screened using the yeast two-hybrid system. α-11 giardin and all screened potential interacting protein genes were constructed into pBiFc-Vc-155 and pBiFc-Vn-173 plasmids, and co-transfected into the breast cancer cell line MDA-MB-231. The interactions between α-11 giardin and interacting proteins were verified using bimolecular fluorescence complementation (BiFC).

RESULTS

The yeast two-hybrid G. lambia cDNA library which was quantified at 2.715 × 10⁷ colony-forming units (CFU) and the bait plasmid containing α-11 giardin gene without an autoactivation activity were constructed. Following two-round positive screening with the yeast two-hybrid system, two potential proteins interacting with α-11 giardin were screened, including eukaryotic translation initiation factor 5A (EIF5A), calmodulin-dependent protein kinase (CAMKL) and nicotinamide adenine dinucleotide phosphate-specific glutamate dehydrogenase (NADP-GDH), hypothetical protein 1 (GL50803_95880), hypothetical protein 2 (GL50803_87261) and a protein from Giardia canis virus. The α-11 giardin and EIF5A genes were transfected into the pBiFc-Vc-155 and pBiFc-Vn-173 plasmids using BiFC, and the recombinant plasmids pBiFc-Vc-155-α-11 and pBiFc-Vn-173-EIF5A were co-tranfected into MDA-MB-231 cells, which displayed green fluorescence under a microscope, indicating the interaction between α-11 giardin and EIF5A protein in cells.

CONCLUSIONS

The yeast two-hybrid cDNA library of the G. lambia C2 strain has been successfully constructed, and six potential protein interacting with α-11 giardin have been identified, including EIF5A that interacts with α-11 giardin in cells.

Abstract 1202: Targeting cell adhesion molecule 1 (CADM1) with an antibody drug conjugate for the treatment of osteosarcoma

Introduction: Survival outcomes for patients with osteosarcoma have been stagnant for decades. There is an urgent need to identify new surface targets in osteosarcoma and develop novel therapies to increase cure rates. Antibody-drug conjugates, due to their targeted delivery of cytotoxic payloads to specific targets, are an attractive class of agents for potential use in osteosarcoma.

Methods: We used an integrated proteomic and transcriptomic surfaceome profiling approach to identify cell-surface proteins that are highly expressed in osteosarcoma but minimally expressed on normal tissues. Cell-surface expression of the identified target antigen was validated by IHC and flow cytometry in osteosarcoma cell lines, patient-derived xenograft (PDX) models, and a patient tumor tissue microarray. As a proof of concept, humanized CADM1 antibody (clone PTA021-A1) was conjugated with tesirine (SG3249), a pyrrolobenzodiazepine (PBD) dimer payload. The antitumor activity of this antibody-drug conjugate was tested in vitro and in vivo in osteosarcoma cell lines and PDX models.

Results: Cell Adhesion Molecule 1 (CADM1) was found to be enriched in osteosarcoma at both protein and mRNA levels, while minimally expressed in normal tissues. Flow cytometry validated the cell-surface localization and expression levels of CADM1 in 7 osteosarcoma cell lines. We performed immunohistochemistry (IHC) staining using an osteosarcoma tissue microarray from 37 patients and 19 PDX models. CADM1 was expressed in 100% of the patient samples and PDXs. The newly developed ADC induced cytotoxic effects in 100% (5/5) of osteosarcoma cell lines, with IC 50 at 120h ranging from 0.009 to 0.1 ug/ml. In vivo testing is ongoing. Preliminary data shows objective response and prolonged survival in selected osteosarcoma PDX models. The mice tolerated the ADC well with minimal toxicity.

Conclusions: CADM1 is highly expressed in most osteosarcoma samples and minimally expressed in normal human tissue, which makes it an attractive target for respective antigen-targeting ADC therapies. The CADM1 targeting ADC showed antitumor activities in osteosarcoma preclinical models which may warrant further investigation of CADM1 targeted therapies for osteosarcoma.

Acknowledgments: This work was funded by Swim Across America, the Foster Foundation, the Osteosarcoma Institute Translational and Preclinical Grant, and the Barbara Epstein Foundation.

Citation Format: Yifei Wang, Zhongting Zhang, Wendong Zhang, Xiangjun Tian, Rossana Lazcano, Michael Roth, Jonathan Gill, Douglas Harrison, Zhaohui Xu, Yizheng Tu, Sylvester Jusu, Giuseppe Longo, Xin Zhou, Jing Wang, Richard Gorlick. Targeting cell adhesion molecule 1 (CADM1) with an antibody drug conjugate for the treatment of osteosarcoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1202.

FGL2-targeting T cells exhibit antitumor effects on glioblastoma and recruit tumor-specific brain-resident memory T cells

Although tissue-resident memory T (TRM) cells specific for previously encountered pathogens have been characterized, the induction and recruitment of brain TRM cells following immune therapy has not been observed in the context of glioblastoma. Here, we show that T cells expressing fibrinogen-like 2 (FGL2)-specific single-chain variable fragments (T-αFGL2) can induce tumor-specific CD8+ TRM cells that prevent glioblastoma recurrence. These CD8+ TRM cells display a highly expanded T cell receptor repertoire distinct from that found in peripheral tissue. When adoptively transferred to the brains of either immunocompetent or T cell-deficient naïve mice, these CD8+ TRM cells reject glioma cells. Mechanistically, T-αFGL2 cell treatment increased the number of CD69+CD8+ brain-resident memory T cells in tumor-bearing mice via a CXCL9/10 and CXCR3 chemokine axis. These findings suggest that tumor-specific brain-resident CD8+ TRM cells may have promising implications for the prevention of brain tumor recurrence.

A quasi-two-dimensional fluid experimental apparatus based on tank-in-tank configuration

The fluid tank is an essential facility for experimental research on fluid mechanics. However, owing to the hydrostatic fluid pressure, a fine uniformity of the narrow channel is difficult to be maintained in a tall narrow-channel tank. To address this issue, we proposed a quasi-two-dimensional fluid experimental apparatus based on a "tank-in-tank" configuration and built with an outer tank and an inner tank. The outer tank was cuboid-shaped and used to load the fluid medium, while the inner tank, consisting of two parallel glass plates, was embedded into the outer tank and served as the experimental channel. The hydrostatic pressure acting on the channel was balanced so that a high level of uniformity was maintained over the whole channel. The available height and width of the channel were 2800 and 1500 mm, respectively, while its gap distance could be adaptive from 0 to 120 mm. Experimental research on motion characteristics of circular disks falling in the quasi-2D channel was implemented to investigate the effects of the falling environment and disk geometry. Four distinct falling types were observed, and the wake flow fields of the falling disks were visualized. The Reynolds numbers of falling disks ranged from 400 to 63 000 presently. Chaotic motion and regular motion were demarcated at Re ≈ 30 000. An analytical model was established to predict the final average falling velocity and Reynolds number. Finally, potential directions for future research and improvements to the apparatus were suggested.

Genetic polymorphisms in MIR1208 and MIR5708 are associated with susceptibility to COPD in the Chinese population

BACKGROUND

Chronic obstructive pulmonary disease (COPD) is a complex disease characterized by limited airflow and is influenced by genetic and environmental factors. The purpose of this study was to investigate the effects of gene polymorphisms in MIR5708 and MIR1208 on COPD risk.

METHODS

Four single nucleotide polymorphisms (SNPs) in MIR5708 (rs6473227 and rs16907751) and MIR1208 (rs2608029 and rs13280095) were selected and genotyped among 315 COPD patients and 314 healthy controls using the Agena MassARRAY platform. SPSS 18.0 was used for statistical analysis and data processing. Odds ratios (ORs) and 95% confidence intervals (CIs) were calculated to assess the association between genetic variants of MIR1208 and MIR5708 and COPD risk.

RESULTS

The results suggested that rs16907751 variants in MIR5708 contributed to an increased susceptibility to COPD in the allelic (P = 0.001), co-dominant (homozygous) (P = 0.001), dominant (P = 0.017), recessive (P = 0.002), and additive (P = 0.002) models. The effects of MIR5708 and MIR1208 gene polymorphisms on the risk of COPD were age-, sex-, smoking status-, and BMI-related. Furthermore, the C-A and G-A haplotypes of rs2608029 and rs13280095 in MIR1208 were identified as risk factors for COPD in the population over 70 years (P = 0.029) and in women (P = 0.049), respectively. Finally, significant associations between rs16907751genotypes with pulse rate and forced expiratory volume in 1 s were found among COPD patients.

CONCLUSION

Genetic polymorphisms in MIR5708 and MIR1208 are associated with increased risk of COPD in China.

Constraining China's land carbon sink from emerging satellite CO2 observations: Progress and challenges

Land carbon sink is a vital component for the achievement of China's ambitious carbon neutrality goal, but its magnitude is poorly known. Atmospheric observations and inverse models are valuable tools to constrain the China's land carbon sink. Space-based CO₂ measurements from satellites form an emerging data stream for application of such atmospheric inversions. Here, we reviewed the satellite missions that is dedicated to the monitoring of CO₂ , and the recent progresses on the inversion of China's land carbon sink using satellite CO₂ measurements. We summarized the limitations and challenges in current space platforms, retrieval algorithms, and the inverse modeling. It is shown that there are large uncertainties of contemporary satellite-based estimates of China's land carbon sink. We discussed future opportunities of continuous improvements in three aspects to better constrain China's land carbon sink with space-based CO₂ measurements.

Mutant p53 drives an immune cold tumor immune microenvironment in oral squamous cell carcinoma

The critical role of the tumor immune microenvironment (TIME) in determining response to immune checkpoint inhibitor (ICI) therapy underscores the importance of understanding cancer cell-intrinsic mechanisms driving immune-excluded ("cold") TIMEs. One such cold tumor is oral cavity squamous cell carcinoma (OSCC), a tobacco-associated cancer with mutations in the TP53 gene which responds poorly to ICI therapy. Because altered TP53 function promotes tumor progression and plays a potential role in TIME modulation, here we developed a syngeneic OSCC models with defined Trp53 (p53) mutations and characterized their TIMEs and degree of ICI responsiveness. We observed that a carcinogen-induced p53 mutation promoted a cold TIME enriched with immunosuppressive M2 macrophages highly resistant to ICI therapy. p53-mutated cold tumors failed to respond to combination ICI treatment; however, the combination of a programmed cell death protein 1 (PD-1) inhibitor and stimulator of interferon genes (STING) agonist restored responsiveness. These syngeneic OSCC models can be used to gain insights into tumor cell-intrinsic drivers of immune resistance and to develop effective immunotherapeutic approaches for OSCC and other ICI-resistant solid tumors.

Body mass index increases the recurrence risk of breast cancer: a dose-response meta-analysis from 21 prospective cohort studies

OBJECTIVE

The purpose of this study was to investigate the effect of body mass index (BMI) on the recurrence risk of breast cancer.

STUDY DESIGN

Dose-response meta-analysis.

METHODS

Cohort studies that included BMI and the recurrence of breast cancer were selected through various databases including PubMed, Web of Science, the China National Knowledge Infrastructure (CNKI), Chinese Scientific Journals (VIP), and Wanfang Data Knowledge Service Platform (WanFang) until November 30, 2021. The Newcastle-Ottawa Scale (NOS) was used to evaluate the quality of literature. A two-stage random-effects meta-analysis was performed to assess the dose-response relationship between BMI and breast cancer recurrence risk. Heterogeneity between studies is assessed using I².

RESULTS

The relative risk (RR) of BMI <25 kg/m² vs BMI ≥25 kg/m², BMI <30 kg/m² vs BMI ≥30 kg/m² were 1.09 (95% CI: 1.00-1.19) and 1.15 (95% CI: 1.04-1.27), suggesting that BMI had a significant effect on the recurrence risk of breast cancer, and there might be a dose-response relationship between them. A total of 21 studies were included in dose-response meta-analysis, which showed that there was a positive linear correlation between BMI and the risk of recurrence (RR = 1.02, 95% CI: 1.01-1.03). For every 1 kg/m² increment of BMI, the risk of recurrence increased by approximately 2%. In subgroup analyses, positive linear dose-response relationships between BMI and recurrence risk were observed among Asian and study period >10 years groups. For every 1 kg/m² increment of BMI, the risk of recurrence increased by 3.41% and 1.87%, respectively.

CONCLUSIONS

The recurrence risk of breast cancer increases with BMI, which is most obvious among Asian women.

[Management of the internal carotid artery during lateral skull base surgery: a series of 41 cases]

Objective: To introduce our experience on dealing with the internal carotid artery (ICA) during the resection of lateral skull base tumors, and to explore the reference values for using radiological findings to make a rational surgical plan. Methods: A retrospective study of patients who underwent resection of lateral skull base tumors involving ICA at Peking Union Medical College Hospital from May 2015 to May 2021 was conducted. The demographic information, preoperative examinations, diagnosis, surgical details and follow-ups were collected. A total of 41 patients were enrolled [24 (58.5%] females, 17 (41.5%) males], with an average age of 47.9 years. According to the preoperative imaging findings, the relationships between the tumors and ICA were divided into four types: adjacency, compression, invasion and ICA aneurysm. Results: The ICA was preserved in 32 (78.0%, 32/41) cases and was reconstructed in nine (22.0%, 9/41) cases. All the 27 (65.9%, 27/41) tumors adjacent to ICA were successfully separated from the artery. Among the 11 tumors compressing the ICA, six were resected with the involved ICA segment and vascular reconstruction was conducted. One (2.4%, 1/41) tumor invading ICA and two (4.9%, 2/41) ICA aneurysms required revascularization. The mean follow-up time was (26.1±2.9) months. There was no recurrence, except one case of adenoid cystic carcinoma which had brain metastases one year after surgery. Conclusions: According to the preoperative imaging, lateral skull base tumors adjacent to ICA can be detached from the vascular surface. Separation should be attempted first for tumors compressing ICA, and revascularization should be followed if separation failed. Vascular reconstruction is usually needed in the removal of tumors invading ICA and ICA aneurysms. Preoperative radiology can provide good references for planning a surgery for lateral skull base tumors.

[Berberine inhibits erastin-induced ferroptosis of mouse hippocampal neuronal cells possibly by activating the Nrf2-HO-1/GPX4 pathway]

OBJECTIVE

To explore the mechanism by which berberine inhibits ferroptosis of mouse hippocampal neuronal cells (HT22).

METHODS

Cultured HT22 cells were pretreated with 30 or 60 μmol/L berberine for 2 h before exposure to 0.5 μmol/L erastin for 8 h, and the cell proliferation, intracellular ferric iron level, changes in intracellular reactive oxygen species (ROS) and cell apoptosis were detected using CCK-8, Fe²⁺ fluorescent probe, fluorescent dye (DAPI) and fluorescent probe (H2DCFH-DA). RT-qPCR and Western blotting were used to detect the mRNA and protein expressions of Nrf2, HO-1 and GPX4 in the cells. We further tested the effects of treatments with 2 μmol/L ML385 (a Nrf2 inhibitor), 60 μmol/L berberine and erastin in the cells to explore the protective mechanism of berberine against erastin-induced ferroptosis in the neuronal cells.

RESULTS

Treatment with 0.5 μmol/L erastin significantly lowered the viability of HT22 cells (P < 0.05) and increased the production of ROS, cell apoptosis rate and ferric iron level (P < 0.05). Pretreatment with 30 and 60 μmol/L berberine both significantly increased the vitality of erastin-exposed cells (P < 0.05) and lowered the levels of intracellular ROS and ferric iron content (P < 0.05). RT-qPCR and Western blotting showed that berberine obviously promoted the expressions of Nrf2, HO-1 and GPX4 in the cells (P < 0.05), and treatment with ML385 significantly inhibited the Nrf2-HO-1/GPX4 pathway, increased intracellular ROS and ferric iron contents and mitigated the protective effect of berberine against erastin-induced ferroptosis (P < 0.05).

CONCLUSION

Berberine can inhibit erastin-induced ferroptosis in HT22 cells possibly by activating the Nrf2-HO-1/ GPX4 pathway.

The Safety and Efficacy of Flow Diversion versus Conventional Endovascular Treatment for Intracranial Aneurysms: A Meta-analysis of Real-world Cohort Studies from the Past 10 Years

BACKGROUND

Although the flow diverter has advantages in the treatment of intracranial aneurysms, pooled studies that directly compare it with conventional endovascular treatments are rare.

PURPOSE

Our aim was to compare the safety and efficacy of flow-diverter and conventional endovascular treatments in intracranial aneurysms.

DATA SOURCES

We performed a comprehensive search of the literature using PubMed, EMBASE, and the Cochrane Database.

STUDY SELECTION

We included only studies that directly compared the angiographic and clinical outcomes of flow-diverter and conventional endovascular treatments.

DATA ANALYSIS

Random effects or fixed effects meta-analysis was used to pool the cumulative rate of short- and long-term angiographic and clinical outcomes.

DATA SYNTHESIS

Eighteen studies with 1001 patients with flow diverters and 1133 patients with conventional endovascular treatments were included; 1015 and 1201 aneurysm procedures were performed, respectively. The flow-diverter group had aneurysms of a larger size (standard mean difference, 0.22; 95% CI, 0.03-0.41; P = .026). There was a higher risk of complications in the flow-diverter group compared with the conventional endovascular group (OR, 1.4; 95% CI, 1.01-1.96; P = .045) during procedures. The follow-up angiographic results of flow-diverter treatment indicated a higher rate of complete occlusion (OR, 2.55; 95% CI, 1.70-3.83; P < .001) and lower rates of recurrence (OR, 0.24; 95% CI, 0.12-0.46; P < .001) and retreatment (OR, 0.31; 95% CI, 0.21-0.47; P < .001).

LIMITATIONS

Limitations include a retrospective, observational design in some studies, high heterogeneity, and selection bias.

CONCLUSIONS

Compared with the conventional endovascular treatments, the placement of a flow diverter may lead to more procedure-related complications, but there is no difference in safety, and it is more effective in the long term.

Abstract 2016: Preclinical evaluation of uPARAP (MRC2) antibody-drug conjugates (ADCE-003,010,011) in osteosarcoma pdx models

Introduction: Antibody-drug Conjugates (ADCs) targeting differentially expressed tumor cell-surface antigens show robust clinical activity in several solid tumor cancers, but none is yet available for osteosarcoma. Due to the high unmet medical need in this indication, there is an urgent requirement to identify respective osteosarcoma cell-surface antigens and evaluate the antitumor activity of an ADC that can deliver tailored cytotoxic payloads to osteosarcoma tumors expressing these targets.

Methods: We used an integrated proteomic and transcriptomic surfaceome profiling approach to identify cell-surface proteins that are highly expressed in osteosarcoma but minimally expressed on normal tissues. uPARAP (MRC2) was found to be enriched in osteosarcoma at both protein and mRNA levels. The cell-surface expression of uPARAP (MRC2) was further validated by IHC and flow cytometry with osteosarcoma cell lines, PDX models, and patient tumor tissue microarray. As a proof of concept, three MRC2 targeted ADCs with different Microtubulin- and alkylating agent types of payloads were tested in 8 osteosarcoma PDX models. uPARAP (MRC2) ADC, control ADC, or vehicle control was administered IV to mice harboring flank tumors at a dose of 3mg/kg, weekly X 3 (ADCE-003), 2mg/kg on Day 1 (ADCE-010), and 10mg/kg weekly X 2 (ADCE-011). EFS for treatment (T) and control (C) groups, minimum relative tumor volume (minRTV), and objective response measures were analyzed.

Results: Western blotting confirmed the expression of uPARAP (MRC2) in 8 osteosarcoma cell lines and 8 PDX models. Flow cytometry further validated cell-surface localization and expression levels of uPARAP (MRC2) in 7 osteosarcoma cell lines. We then performed immunohistochemistry (IHC) staining using an osteosarcoma tissue microarray from 37 patients and 19 PDX models. uPARAP (MRC2) was expressed in 97% of the patient samples and 95% of the PDXs. 51% of the patient samples and 39% of the PDXs had an overall H-score of 100 or higher. Mice tolerated ADCs well with minimal toxicity. All 3 ADCs significantly prolonged EFS in 6/8 osteosarcoma models. Complete response (CR) or maintained CR were observed in 2 models in ADCE-010 and ADCE-011 groups, respectively.

Conclusions: uPARAP (MRC2) is highly expressed in most osteosarcoma samples, which makes it a viable target for respective antigen targeting ADC therapies. Three uPARAP (MRC2) targeting ADCs showed antitumor activities in osteosarcoma preclinical models which warrant further investigation of uPARAP targeting ADC therapies for osteosarcoma.

Citation Format: Yifei Wang, Wendong Zhang, Zhongting Zhang, Xiangjun Tian, Rossana Lazcano, Pooja Hingorani, Michael Roth, Jonathan Gill, Douglas Harrison, Zhaohui Xu, Jing Wang, Niels Behrendt, Christoffer F. Nielsen, Lars H. Engelholm, Richard Gorlick. Preclinical evaluation of uPARAP (MRC2) antibody-drug conjugates (ADCE-003,010,011) in osteosarcoma pdx models [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 2016.

Impact of probiotic Limosilactobacillus reuteri DSM 17938 on amino acid metabolism in the healthy newborn mouse

We studied the effect of feeding a single probiotic Limosilactobacillus reuteri DSM 17938 (LR 17938) on the luminal and plasma levels of amino acids and their derivatives in the suckling newborn mouse, using gas chromatography and high-performance liquid chromatography. We found that LR 17938 increased the relative abundance of many amino acids and their derivatives in stool, while it simultaneously significantly reduced the plasma levels of three amino acids (serine, citrulline, and taurine). Many peptides and dipeptides were increased in stool and plasma, notably gamma-glutamyl derivatives of amino acids, following ingestion of the LR 17938. Gamma-glutamyl transformation of amino acids facilitates their absorption. LR 17938 significantly upregulated N-acetylated amino acids, the levels of which could be useful biomarkers in plasma and warrant further investigation. Specific fecal microbiota were associated with higher levels of fecal amino acids and their derivatives. Changes in luminal and circulating levels of amino acid derivatives, polyamines, and tryptophan metabolites may be mechanistically related to probiotic efficacy.

Comprehensive surfaceome profiling to identify and validate novel cell-surface targets in osteosarcoma

Immunoconjugates targeting cell-surface antigens have demonstrated clinical activity to enable regulatory approval in several solid and hematologic malignancies. We hypothesize that a rigorous and comprehensive surfaceome profiling approach to identify osteosarcoma-specific cell-surface antigens can similarly enable development of effective therapeutics in this disease. Herein, we describe an integrated proteomic and transcriptomic surfaceome profiling approach to identify cell-surface proteins that are highly expressed in osteosarcoma but minimally expressed on normal tissues. Using this approach, we identified targets that are highly expressed in osteosarcoma. Three targets, MT1-MMP, CD276, and MRC2, were validated as overexpressed in osteosarcoma. Further, we tested BT1769, an MT1-MMP-targeted Bicycle toxin conjugate, in osteosarcoma PDX models. The results showed BT1769 had encouraging anti-tumor activity, high affinity for its target and a favorable pharmacokinetic profile. This confirms the hypothesis that our approach identifies novel targets with significant therapeutic potential in osteosarcoma.

[Etiology, diagnosis and treatment of infraoccluded primary second molars]

Infraocclusion is a phenomenon that the relative occlusal growth of a tooth stops after the period of active eruption and then the tooth becomes depressed below the occlusal plane. Infraocclusion occurred more commonly in children and the mostly affected teeth were the primary mandibular second molars. The occlusal problem caused by infraocclusion may progressively worsen with age. This review summarizes the etiology, diagnosis and treatment of infraoccluded second primary molars, so as to provide reference for the dental clinicians.

[Effects of eye exercises on axial eye elongation in junior students]

Objective: To evaluate the association between the eye exercises and one-year axial eye elongation in grade 7 students in Beijing. Methods: Sampling was performed using a multistage random cluster approach, and 1 443 students of grade 7 were selected from 9 middle schools in 6 districts for the baseline survey. Data were collected by questionnaires and axial length measurement. Multiple linear regression analysis was used to evaluate the association between eye exercises and excessive axial eye elongation. Results: Among 1 197 (82.95%) students with complete information, the median (Q_R) age was 12.00 (1.00) years old, girls accounted for 44.28%, and the median (Q_R) axial eye elongation was 0.22 (0.18) mm. In the multiple linear regression analysis, the frequency of eye exercises was significantly correlated with excessive axial eye elongation in boys (β=-0.135, 95%CI:-0.253--0.018) but not in girls (β=-0.075, 95%CI:-0.207- 0.058) after adjusting for sex, age, body height, the number of myopic parents, time spent outdoors and time spent on reading and writing outside class; while the seriousness of eye exercises was not significantly associated with axial eye elongation in boys (β=-0.028, 95%CI: -0.114-0.058) and girls (β=-0.035, 95%CI: -0.134-0.064). Conclusion: The increased frequency of eye exercises is beneficial to control the axial eye elongation in boys in Beijing.

[Clinicopathological features of malignant mixed mesodermal tumor: analysis of 50 cases]

Objective: To investigate the clinicpathological, immunohistochemical and molecular genetic features of malignant mixed mesodermal tumor (MMMT) in the female reproductive system. Methods: To analyze its histopathological characteristics, we performed a retrospective review of the MMMT cases diagnosed at PLA General Hospital, Beijing, China during 2005-2019 using its surgical and pathological databases. EnVision immunohistochemical staining was used to detect the expression of ER, PR, p16, p53 and MMR proteins. Results: Fifty cases were conformed to the diagnosis, including 29 cases originated in the uterus, 16 cases in ovary, 4 cases of synchronous occurrence in uterus and ovary, 1 case in cervix. The tumor was histologically composed of two components, namely carcinoma and sarcoma ones, with clear borderline or blend mutually. The proportion of cancer component in the whole tumor ranged from 5%-90%. The proportion of carcinoma was more than 50% in 76% of the cases, and less than 50% in 24% of cases, including 2 cases with<10% of carcinoma. In the cases of primary uterine MMMT, the main carcinoma type was high grade endometrioid carcinoma (55%, 16/29). In ovarian MMMT, the main carcinoma type was serous carcinoma (12/16), while that of cervical MMMT was squamous cell carcinoma. The others were clear cell carcinoma or the undifferentiated carcinoma. There was one carcinoma type in most cases, only 7 cases had two carcinoma types. Homologous sarcomas, including stromal sarcoma, leiomyosarcoma and high-grade spindle cell sarcomas, were more commonly found in uterine MMMT (72.4%, 21/29). While heterogenic sarcomas, including chondrosarcoma, osteosarcoma and rhabdomyosarcoma, were more commonly noted in ovarian MMMT (12/16) than MMMT of other sites. There were 10 cases that consisted of two types of sarcomas. The synchronous MMMT of uterus and ovary had similar morphology and the types of carcinoma and sarcoma. The tumor cells that spread or metastasized to lymph node, omentum, intestinal wall or skin were all carcinoma cells, and were morphologically consistent with the original tumors. Immunohistochemically, ER and PR were both negative (23/25 in uterine, 8/10 in ovarian tumors). p16 was strongly positive (11/11 in uterine tumors, and 6/6 in ovarian tumors), with similar expression patterns in the carcinoma and sarcoma components. p53 showed mutant-type staining (64%, 21/33) and expressed synchronously in carcinoma and sarcoma components. p53 mutation was found in 35% cases of endometrial carcinoma and 46.7% cases of non-endometrial carcinoma. p53 mutation was also found in only 31.8% cases of heterogenic sarcomas, but in 50% of non-heterogenic sarcomas. Twenty-eight cases (28/33, 85%) presented intact mismatch repair proteins, while 5 cases (5/33, 15%) presented deficient mismatch repair proteins. Conclusions: MMMT in female reproductive system is a rare high-grade biphasic tumor with complex and diverse morphology. The immunohistochemical features are characterized by negative ER/PR and strongly positive p16, mostly mutant p53 and proficient mismatch repair proteins. The patients with a high FIGO stage have worse prognosis.

P–420 uncomplicated oocyte donation pregnancies display elevated CD163 positive type 2 macrophage load in the decidua, which is associated with fetal-maternal HLA class II mismatches

Study question

Do quantity and composition of decidual macrophages differ between uncomplicated oocyte donation (OD) pregnancies and non-OD in vitro fertilization (IVF) pregnancies?

Summary answer

OD placentas show higher decidual CD163 positive fraction within the total macrophage population compared to non-OD IVF placentas.

What is known already

The embryo of an OD pregnancy is completely allogeneic to the mother, which may lead to a bigger challenge for the maternal immune system to tolerize the fetus compared to autologous pregnancies. Placental macrophages may be essential in maintaining a healthy pregnancy. Macrophages can be classified into different categories based on phenotype and characteristics, in which type 2 macrophages are thought to exhibit immune suppressive activity.

Study design, size, duration

This retrospective case-control study included patients who delivered in the Leiden University Medical Center between January 1st 2006 and July 1st 2016. A total of 42 pregnancies were enrolled in this study, conceived by uncomplicated singleton OD pregnancies (n = 25) or non-OD IVF pregnancies (n = 17). Medical records were reviewed and clinical data were collected. Placental tissue samples were collected for immunohistochemical staining and blood samples were collected for HLA typing.

Participants/materials, setting, methods

Placentas were collected and immunohistochemically stained for CD14 (pan-macrophage marker) and CD163 (type 2 macrophage marker). The extent of staining was quantitated by digital image analysis software. To assess mismatching, maternal and fetal DNA was typed for HLA-A, -B, C, -DRB1, and -DQB1.

Main results and the role of chance

A significantly lower percentage of CD14 positive staining was observed in the decidua basalis of OD pregnancies compared to non-OD IVF pregnancies (p = 0.030). Consequently, the CD163/CD14 ratio in OD group was higher than in non-OD IVF group (p = 0.243). In the parietalis, OD pregnancies demonstrated a significantly higher percentage of CD163+ staining (p = 0.040) and a significantly higher CD163/CD14 ratio (p = 0.032) compared to non-OD IVF group. The reproducibility of this quantitative analysis was found to be high. OD group was separated into a syngeneic group (number of mismatches lower than half of the antigens per HLA locus) and an allogeneic group (number of mismatches higher than half of the antigens per HLA locus). Significant differences of CD163+ and CD163/CD14 ratio were found in the decidua parietalis when comparing the HLA-classII-allogeneic OD group with the non-OD IVF group (p = 0.047). This difference was not found for the HLA-class-II-syngeneic OD group.

Limitations, reasons for caution

Our study only focused on decidua basalis and parietalis, no other locations in the placentas. Larger sample size might be needed to verify the association between macrophages and HLA mismatches.

Wider implications of the findings: To our knowledge, this study is the first to quantify a higher CD163 positive M2 macrophages load within the total decidual macrophages of uncomplicated OD pregnancy compared to non-OD IVF pregnancies.

Trial registration number

Not applicable

P-420 Pre-selected for an award: Uncomplicated oocyte donation pregnancies display elevated CD163 positive type 2 macrophage load in the decidua, which is associated with fetal-maternal HLA class II mismatches

Study question

Do quantity and composition of decidual macrophages differ between uncomplicated oocyte donation (OD) pregnancies and non-OD in vitro fertilization (IVF) pregnancies?

Summary answer

OD placentas show higher decidual CD163 positive fraction within the total macrophage population compared to non-OD IVF placentas.

What is known already

The embryo of an OD pregnancy is completely allogeneic to the mother, which may lead to a bigger challenge for the maternal immune system to tolerize the fetus compared to autologous pregnancies. Placental macrophages may be essential in maintaining a healthy pregnancy. Macrophages can be classified into different categories based on phenotype and characteristics, in which type 2 macrophages are thought to exhibit immune suppressive activity.

Study design, size, duration

This retrospective case-control study included patients who delivered in the Leiden University Medical Center between January 1st 2006 and July 1st 2016. A total of 42 pregnancies were enrolled in this study, conceived by uncomplicated singleton OD pregnancies (n = 25) or non-OD IVF pregnancies (n = 17). Medical records were reviewed and clinical data were collected. Placental tissue samples were collected for immunohistochemical staining and blood samples were collected for HLA typing.

Participants/materials, setting, methods

Placentas were collected and immunohistochemically stained for CD14 (pan-macrophage marker) and CD163 (type 2 macrophage marker). The extent of staining was quantitated by digital image analysis software. To assess mismatching, maternal and fetal DNA was typed for HLA-A, -B, C, -DRB1, and -DQB1.

Main results and the role of chance

A significantly lower percentage of CD14 positive staining was observed in the decidua basalis of OD pregnancies compared to non-OD IVF pregnancies (p = 0.030). Consequently, the CD163/CD14 ratio in OD group was higher than in non-OD IVF group (p = 0.243). In the parietalis, OD pregnancies demonstrated a significantly higher percentage of CD163+ staining (p = 0.040) and a significantly higher CD163/CD14 ratio (p = 0.032) compared to non-OD IVF group. The reproducibility of this quantitative analysis was found to be high. OD group was separated into a syngeneic group (number of mismatches lower than half of the antigens per HLA locus) and an allogeneic group (number of mismatches higher than half of the antigens per HLA locus). Significant differences of CD163+ and CD163/CD14 ratio were found in the decidua parietalis when comparing the HLA-classII-allogeneic OD group with the non-OD IVF group (p = 0.047). This difference was not found for the HLA-class-II-syngeneic OD group.

Limitations, reasons for caution

Our study only focused on decidua basalis and parietalis, no other locations in the placentas. Larger sample size might be needed to verify the association between macrophages and HLA mismatches.

Wider implications of the findings

To our knowledge, this study is the first to quantify a higher CD163 positive M2 macrophages load within the total decidual macrophages of uncomplicated OD pregnancy compared to non-OD IVF pregnancies.

Trial registration number

not applicable