Prenatal diagnosis of a fetus with mosaic trisomy 2 and uniparental disomy of chromosome 2 / 中华围产医学杂志

This paper presented the prenatal genetic analysis of a case of mosaic trisomy 2 combined with uniparental disomy 2. The pregnant women underwent non-invasive prenatal testing in Zhuhai Center for Maternal and Child Health Care on February 2019, which indicated an increased number of chromosome 2. Subsequently, amniocentesis was performed at 21 +2 weeks for prenatal diagnosis. No abnormalities were detected through the karyotype analysis of amniotic fluid cells. Chromosome microarray analysis of uncultured amniotic fluid cells revealed a duplication of 2.3 copies in chromosome 2 and 64.3 Mb regions of homozygosity in the 2q21.2q33.1 region. The comparison of single nucleotide information on fetus-parent chromosome 2 showed that the regions of homozygosity of the fetal 2q21.2q33.1 was paternal uniparental isodisomy (2), with the rest of chromosome 2 being paternal uniparental heterodisomy (2).Ultrasound results at 27 +6, 31 +6, and 34 +5 weeks of gestation showed continued exacerbation of fetal growth retardation with placental abnormalities and fetal blood flow spectrum abnormalities. Due to threatened preterm delivery at 35 +3 weeks, The pregnant woman chose to give up the fetus and delivered a stillbirth.

Ethical Issues and Resolutions in Human-animal Chimera Research / 中国医学伦理学

Human-animal chimera technology is increasingly applied to large animals. It is highly possible to cultivate human organs in pigs for transplantation in the future. Chimeric animals contain more and more human materials and are present in their brains and reproductive systems, which may humanize them and give them a higher moral status and even dignity. It raises an important ethical question: should such chimeric animals be created? If so, how they should be treated. It is not convincing to refute the research of human-animal chimera with the arguments of destroying natural order, unnatural and moral chaos. But the non-identity view holds that scientific research makes the lives of chimeric animals more valuable and that they are not actually harmed because their only other options do not exist. The answers to these ethical questions can resolve the ethical risks arising from the research of human-animal chimera.

Research on technological innovation of PROTAC in China from the perspective of patent / 中国药房

OBJECTIVE To provide information service support for research on proteolysis targeting chimera （PROTAC） in China and provide reference for technical development and patent layout of relevant drug research and development institutions. METHODS The patent analysis method was used to search the patent applications related to PROTAC technology that had been applied to China National Intellectual Property Administration and had been issued before Feb. 2022， using the HimmPat patent database as the search platform. The patent application trend， technology life cycle， main applicants， technology source countries， technology themes， improvement routes and other patent data were analyzed. RESULTS & CONCLUSIONS A total of 133 patents were included in this study. The patent application for PROTAC technology started relatively late in China， with the number of applicants increasing from 2 in 2015 to 30 in 2020， and the number of applications increasing from 2 in 2015 to 38 in 2020. Both the annual patent application volume and the number of applicants were in a period of rapid growth， but the average annual application volume of a single applicant was still less than 2， indicating that research in this field was still in the early stage of technology development； the number of applications from Arvinas， Hisco， and Hinova Pharmaceutical Inc. ranked among the top. Although the number of domestic applications led that of foreign applications in China， the average number of simple peer applications and the average number of simple peer countries in domestic patent applications was only 1.5， which was far lower than that of foreign applications in China， reflecting that there was still room for improvement in the “quality” level of domestic applications. The initial improvements in PROTAC technology mainly focused on the selection of E3 ligands， targets and ligands， and then new improvements such as new PROTAC development， linker design and matching methods emerged， indicating that the patent applicant had started a multi-track layout in the early stages of the development of PROTAC technology. It is suggested that the research and development of PROTAC drugs in China should focus on improving the oral bioavailability and biosafety of PROTAC drugs， overcoming potential drug resistance， and exploring rational design and evaluation methods.

Research progress of PROTACs in the treatment of prostate cancer / 中华泌尿外科杂志

The major challenges in drug therapy for prostate cancer are the ineffectiveness and resistance to androgen deprivation therapy, the low response to immunotherapy and the poor efficacy of small molecule targeted drugs. As a brand-new drug design concept, proteolysis targeting chimera (PROTAC) reveals its strength in the field of cancer treatment by connecting the target protein to the ubiquitin-proteasome system and triggering the degradation of the target protein. In recent years, basic medical research on targeting androgen receptors, cell proliferation, and transcriptional regulation proteins for the treatment of prostate cancer has achieved significant progress. Meanwhile, clinical trials related to PROTAC for the treatment of prostate cancer are gradually being carried out. In an era of big data and precision medicine, PROTAC is a breakthrough in the field of prostate cancer drug therapy. This article summarizes the fundamental principles of PROTACs and the basic and clinical research advances in the field of prostate cancer treatment.

Application of PROTACs in Hematological Malignancies--Review / 中国实验血液学杂志

Proteolysis-targeting chimeras (PROTACs) are heterobifunctional small molecules by utilizing the ubiquitin proteasome system (UPS) to degrade proteins of interest. PROTACs have exhibited unprecedented efficacy and specificity in degrading various oncogenic proteins because of their unique mechanism of action, ability to target "undruggable" and mutant proteins. A series of PROTACs have been developed to degrade multiple key protein targets for the treatment of hematologic malignancy. Notably, PROTACs that target BCL-XL, IRAK4, STAT3 and BTK have entered clinical trials. The known PROTACs that have the potential to be used to treat various hematological malignancies are systematically summarized in this review.

Advances in the preclinical and clinical research of proteolysis targeting chimera / 生物工程学报

Proteolysis targeting chimera (PROTAC) refers to heterobifunctional small molecules that can simultaneously bind an E3 ubiquitin ligase and a target protein, enabling specific degradation of the target protein with the aid of the ubiquitin proteasome system. At present, most PROTAC drugs are in the clinical trial stage, and the ligands are mainly non-covalent compounds. PROTAC drugs have the advantage of overcoming drug resistance and degrading "undruggable" target proteins, but non-covalent ligands could lead to the hook effect that undermines drug efficacy. With its own advantages, covalent ligands can avoid the occurrence of this phenomenon, which is of great help to the development of PROTAC. This review summarizes the progress in preclinical and clinical research and application of PROTAC molecules targeting three different classes of protein targets, including intranuclear, transmembrane, and cytosolic proteins. We also offer perspective discussions to provide research ideas and references for the future development of PROTAC.

Desenvolvimento e avaliação de uma proteína quimérica recombinante para o diagnóstico e prognóstico das leishmanioses tegumentar e visceral / Development and evaluation of a recombinant chimeric protein for the diagnosis and prognosis of tegumentary and visceral leishmaniasis

As leishmanioses são doenças tropicais negligenciadas com alta endemicidade e que afetam milhares de pessoas no mundo. Sua infecção é causada por parasitos protozoários do gênero Leishmania. A diversidade biológica entre as espécies é quem permite determinar as manifestações clínicas, sendo elas na forma de leishmaniose visceral (LV) ou leishmaniose tegumentar (LT). Dentre estas manifestações, a LV é considerada a mais grave, devido sua alta letalidade e grande emergência em indivíduos com a infecção provocada pelo vírus da imunodeficiência humana (HIV). Atualmente, as medidas de controle e prevenção adotadas pela Organização Mundial da Saúde (OMS), baseiam-se em uma combinação de estratégias de intervenção contra a infecção, uma vez que o diagnóstico eficaz e precoce é indispensável para que se possa intervir com o tratamento adequado, diminuindo índices de mortalidade e a evolução de complicações clínicas. Entretanto, os testes sorológicos utilizados apresentam sensibilidade e especificidade prejudicadas em pacientes com leishmanioses e/ou coinfectados LV/HIV, devido a baixos ní-veis de anticorpos antileishmanial ou pela presença de doenças que causem reação cruzada, levando a resultados falso-positivos. A sensibilidade torna-se também variável em pacientes tratados, uma vez que a sorologia pode manter-se positiva por meses ou anos após o fim do tratamento e cura da doença. Buscando resolver tal problemática, a identificação de novos antígenos, por meio de análises de bioinformática associadas à imunoproteômica, tem permitido a detecção de novas proteínas com potencial aplicação diagnóstica. Em estudos anteriores, as proteínas hipotéticas LiHyT, LiHyD, LiHyV e LiHyP foram encontradas em espécies de Leishmania spp, e avaliadas em suas versões recombinantes por meio de ensaios de ELISA, obtendo resultados satisfatórios para a detecção da LV humana e canina. Com base nessas informações, o presente trabalho teve como objetivo desenvolver uma proteína quimera recombinante base-ada na predição de epítopos lineares específicos de células B das quatro proteínas antigênicas de L. infantum citadas e avaliar o potencial diagnóstico, assim como dos peptídeos individuais que a constituíram, frente à leishmaniose humana, bem como com a coinfecção com HIV, além de testar os antígenos como marcadores prognóstico após o tratamento da LV e LT. As sequências de aminoácidos das proteínas foram avaliadas e oito epítopos de células B foram preditos e utilizados na construção de uma nova proteína quimérica. A proteína foi expressa, purificada e avaliada como antígeno recombinante em ELISA para o diagnóstico de LV, LT, coinfecção LV/HIV e prognóstico em amostras de pacientes tratados de LV e LT. Os epítopos de células B usados na construção da quimera foram sintetizados e também testados em ELISA frente às mesmas amostras, assim como um extrato antigênico solúvel de Leishmania braziliensis (SLA). Os resultados mostraram que a proteína quimera apresentou sensibilidade e especificidade de 100% para diagnosticar a LV, LT e LV/HIV, enquanto os peptídeos sintéticos apresentaram sensibilidade variando entre eles de 9,1% a 90,9% para amostras de LT e 76,8% a 99,2% para amostras de LV e LV/HIV, já os valores de especificidade atingiram 98,3% a 99,1% para LT e 67,1% a 95,7% para LV e LV/HIV. O SLA apresentou sensibilidade e especificidade de 18,2% e 98,3% para LT, e 56,8% a 69,5% para amostras de LV e LV/HIV, respectivamente. Uma avaliação prognóstica preliminar mostrou ainda que os anticorpos anti-quimera diminuíram em níveis significativos, quando comparada a reatividade sorológica antes e seis meses após o tratamento, sugerindo um possível papel prognóstico da quimera para as leishmanioses. O presente estudo, mostrou-se eficaz na construção e avaliação de novos candidatos, que demonstram ter um bom desempenho na detecção diagnóstica e prognóstica para as leishmanioses e dos casos de coinfecção LV/HIV.

Leishmaniasis are neglected tropical diseases with high endemicity that affect thousands of people in the world. Infection is caused by protozoan parasites of the genus Leishmania. The biological diversity between species is what allows determining the clinical manifestations, either in the form of visceral leishmaniasis (VL) or tegumentary leishmaniasis (TL). Among these clinical manifestations, VL is considered the most serious, due to its high lethality and great emergence in individuals with infection caused by the human immunodeficiency virus (HIV). Currently, the control and prevention measures adopted by the World Health Organiza-tion (WHO) are based on a combination of intervention strategies against the infection, since an effective and early diagnosis is essential to intervene with the appropriate treatment, decrea-sing mortality rates and evolution of clinical complications. However, the serological tests used show impaired sensitivity and specificity in patients with leishmaniasis and/or coinfected with VL/HIV, due to low levels of anti-leishmanial antibodies or the presence of diseases that cause cross-reaction, leading to false-positive results. The sensitivity also becomes variable in treated patients, since the serology can remain positive for months or years after the end of the trea-tment and cure of the disease. Seeking to solve this problem, the identification of new antigens, through bioinformatic analysis associated with immunoproteomic, has allowed the detection of new proteins with potential diagnostic application. In previous studies, the hypothetical proteins LiHyT, LiHyD, LiHyV and LiHyP were found in species of Leishmania spp, and evaluated in their recombinant versions through ELISA assays, and satisfactory results were obtained for the detection of human and canine VL. Based on this information, the present work aimed to develop a recombinant chimera protein through on the prediction of specific linear epitopes of B cells derived from these four antigenic proteins of L. infantum and to evaluate its diagnostic potential, as well as the individual peptides that constitute it, against human leishmaniasis, as well as co-infection with HIV, in addition to testing them as possible prognostic markers of patients after VL and TL treatment. The amino acid sequences of the proteins were evaluated and eight B cell epitopes were predicted and used in the construction of a new chimeric protein. The protein was expressed, purified and evaluated as a recombinant antigen in ELISA for the diagnosis of VL, TL, VL/HIV co-infection and prognosis in samples from patients treated for VL and TL. The B cell epitopes used in the construction of the chimera were synthesized and also tested in ELISA against the same samples, as well as a soluble Leishmania braziliensis antigenic extract (SLA). The results showed that the chimera protein apresented sensitivity and specificity of 100% for diagnosing VL, TL and VL/HIV, while the synthetic peptides showed sensitivity ranging from 9.1% to 90.9% for TL samples and 76.8 % to 99.2% for VL and VL/HIV samples, while the specificity values reached from 98.3% to 99.1% for TL and 67.1% to 95.7% for VL and VL/HIV. The SLA showed sensitivity and specificity of 18.2% and 98.3% for TL, and 56.8% to 69.5% for VL and VL/HIV samples, respectively. A preliminary prog-nostic evaluation also showed that anti-chimera antibodies significantly decreased when com-pared to serological reactivity before and six months after treatment, suggesting a possible prognostic role of the antigen for leishmaniasis. The present study proved to be effective in the construction and evaluation of new candidates, who demonstrate good performance in diagnos-tic and prognostic detection for leishmaniasis and VL/HIV co-infection.

Three Different Strategies for Repair of Symptomatic or Aneurysmatic Aberrant Right Subclavian Arteries

ABSTRACT Introduction: In this study, we aimed to present three different methods for symptomatic aberrant right subclavian artery (ARSA) surgery. Methods: We identified 11 consecutive adult patients undergoing symptomatic and/or aneurysmal ARSA repair between January 2016 and December 2020. Symptoms were dysphagia (n=8) and dyspnea + dysphagia (n=3). Six patients had aneurysm formation of the ARSA (mean diameter of 4.2 cm [range 2.8 - 6.3]). All data were analyzed retrospectively. Results: Median age of the patients (7 females/4 males) was 55 years (range 49 - 62). The first four patients (36.4%) underwent hybrid repair using thoracic endovascular aortic repair (TEVAR) and bilateral carotid-subclavian artery bypass (CScBp). Three patients (27.2%) were treated by open ARSA resection/ligation with left mini posterolateral thoracotomy (LMPLT) and right CScBp. And the last four patients (36.4%) underwent ARSA resection/ligation with LMPLT and ascending aorta-right subclavian artery bypass with upper mini sternotomy (UMS). Two of the four patients who underwent TEVAR + bilateral CScBp had continuing dysphagia cause of persistent esophageal compression. Brachial plexus injury developed in one of three patients who underwent LMPLT + right CScBp. Pleural effusion treated with thoracentesis alone was observed in one of four patients who underwent UMS + LMPLT. Conclusion: Among the symptomatic and/or aneurysmal ARSA treatment approaches, surgical and hybrid methods are used. There is still no consensus on how to manage these patients. In our study, we recommend the UMS + LMPLT method, since the risk of complications with anatomical bypass is less, and we have more successful surgical results.

Genetic analysis of 387 cases of fetal sex chromosome abnormalities detected from amniotic fluid samples / 中华围产医学杂志

Objective:To analyze fetal sex chromosome abnormalities in prenatal diagnosis based on amniotic fluid cell culture.Methods:Clinical data of 12 164 pregnant women who underwent amniocentesis in Maternal and Child Health Hospital of Hunan Province from January 2017 to December 2020 were retrospectively analyzed. For those diagnosed with fetal sex chromosome abnormalities, the results of karyotyping and chromosome microarray analysis (CMA) were analyzed and described.Results:(1) Among the 12 164 cases, fetal sex chromosome abnormalities were detected in 387 cases (3.2%), including 351 cases with abnormal sex chromosome karyotype and 36 with sex chromosome microdeletion/microduplication. (2) High-risk patients indicated by non-invasive prenatal test (NIPT) had the highest proportion of sex chromosomes abnormalities (74.2%, 287/387), followed by those with other ultrasound abnormalities (8.5%, 33/387), high risk of Down syndrome screening (7.0%, 27/387), advanced maternal age (4.7%, 18/387), history of adverse pregnant or delivery (3.3%, 13/387), and nuchal translucency thickening or cervical lymphatic hygroma (2.3%, 9/387). (3) Detected chromosome karyotype abnormalities included numerical abnormalities [73.2%(257/351)], mosaicism [18.8(66/351)], and structural abnormalities [8.0%(28/351)], among which, 47,XXY [46.7%(120/257)], 45,X/46,XX[48.5%(32/66)], and X chromosome deletion [39.3%(11/28)] were the most common, respectively. Among 36 sex chromosome microdeletions/microduplications cases, 15(41.7%) were with pathogenic copy number variation (CNV), including 14 cases of X chromosome microdeletion/microduplication; 7(19.4%) with benign CNV, and 14(38.9%) with CNV of unknown clinical significance. The fragment size [ M (min-max)] of the 15 pathogenic CNV was 1.68 Mb(0.37-9.20 Mb). Of the nine cases with microdeletions, seven were found with deletion in the Xp22.31 region. Conclusions:Numerical abnormalities are the most common fetal sex chromosome abnormalities detected from amniotic fluid samples. Others included mosaicism and chromosome structure abnormalities.

Recent progress of targeted small molecular CDK9 degraders based on PROTAC technology / 药学学报

CDKs proteins are a kind of cell cycle protein-dependent kinases, which serve as important roles in controlling cell division and transcriptional stages. Among them, CDK9, as a key regulator responsible for the transcriptional elongation of cells, drives the development of various malignant cells and is considered as an important target in the field of anti-tumor drug development. However, the CDK family proteins feature high conservativeness and similarity in structure, leading to the poor selectivity and severe side effects for traditional small-molecular CDK9 inhibitors, which has limited their clinical applications. In view of this, there is an urgent need to investigate CDK9 targets through a novel strategy. The PROTAC is an emerging drug discovery strategy that the degrader could specifically recognize the target protein through indirect linkage with ubiquitin ligases and ultimately eliminate the target protein through the ubiquitination degradation system. This paper provides a brief overview of the structure and function of CDK9 protein, its relationship with the poor prognosis of clinical diseases, as well as the currently reported small molecular inhibitors. The latest research progress on the targeted degradation of CDK9 protein based on PROTAC technology is highlighted. Finally, the development prospects of this target protein in this novel technology field are summarized and prospected, aiming to provide a reference for the development of antitumor drugs in this direction.

Research advances in new technologies in targeted protein degradation / 药学学报

In recent years, the targeted protein degradation technology has developed quickly, with proteolysis-targeting chimera (PROTAC) as the best-known strategy through exploring the ubiquitin-proteasome system. A number of new targeted protein degradation strategies have been emerging to expand the scope of protein degradation technology, including lysosome-targeting chimeras (LYTACs), autophagy-targeting chimeras (AUTACs), autophagosome-tethering compounds (ATTECs) and chimeras based on chaperone-mediated autophagy (CMA). The emerging methodologies have explored another important protein degradation system in eukaryotes-lysosomal systems, such as the endosome-lysosome pathway and the autophagy-lysosome pathway. This review summaries the mechanisms and features of different strategies for targeted protein degradation, with a special emphasis on the new targeted protein degradation technologies, such as their current status, advantages and limitations.

Ethical Issues and Resolutions in Human-animal Chimera Research / 中国医学伦理学

Human-animal chimera technology is increasingly applied to large animals. It is highly possible to cultivate human organs in pigs for transplantation in the future. Chimeric animals contain more and more human materials and are present in their brains and reproductive systems, which may humanize them and give them a higher moral status and even dignity. It raises an important ethical question: should such chimeric animals be created? If so, how they should be treated. It is not convincing to refute the research of human-animal chimera with the arguments of destroying natural order, unnatural and moral chaos. But the non-identity view holds that scientific research makes the lives of chimeric animals more valuable and that they are not actually harmed because their only other options do not exist. The answers to these ethical questions can resolve the ethical risks arising from the research of human-animal chimera.

Recent progress in targeting degradation of FAK based on PROTAC / 药学学报

Local focal adhesion kinase (FAK) is a non-receptor intracellular tyrosine kinase that plays an important role in tumor initiation, development, metastasis and invasion, and is considered to be an important target for the development of antineoplastic drugs. It has both kinase-dependent and non-kinase-dependent scaffolding functions. However, traditional small molecular inhibitors can only inhibit its kinase-dependent activity, so it is difficult to target the kinase-independent scaffolding function. Therefore, there is an urgent need for novel strategies to enhance FAK targeting to lay the foundation for determining the druggability and discovery of FAK inhibitors. Proteolysis targeting chimera (PROTAC) is a new drug development strategy that can recruit E3 ligase to specifically ubiquitinylate target proteins for degradation through the proteasome system. The unique mechanism of action of the PROTAC system could be used to target and degrade the FAK protein, thus eliminating the scaffolding function of FAK. In this review, FAK protein, the signaling pathway, and small molecule inhibitors are briefly described, and the latest research progress in targeting the degradation of FAK using PROTAC technology is summarized.

Progress of drugs targeting E3 ubiquitin ligase / 中国药理学通报

The ubiquitin-proteasome pathway is one of the most important pathways of cell protein degradation in eukaryotes, and plays an important role in the regulation of cell proliferation, differentiation, apoptosis, DNA repair and other physiological activities. E3 ubiquitin ligase is the major component of ubiquitinproteasome system, which is responsible for substrate recognition. The abnormal regulation of E3 ubiquitin ligase may cause many diseases such as cancer, Alzheimer's disease and Parkinson's disease. Here, we summarizes the progress of drugs targeting E3 ubiquitin ligase in cancer, Alzheimer's disease, Parkinson's disease, diabetic complications, atherosclerosis, and inflammatory bowel diseases. At present, only a few of small molecule antagonists or agonists targeting E3 ubiquitin ligase are under development. The study of natural products in China is leading the way in the world, and numerous natural products have been identified for pharmacological effects on E3 ubiquitin ligase, which may open up a new avenue for multiple complex diseases.

Examples of biology-driven drug design / 药学学报

Pharmacological activity and drug likeness depend in principle upon the microscopic structure and macroscopic properties of drugs, which reside in their molecular structures. By means of medicinal chemistry the evolution of an active compound to a novel drug (NME) essentially makes the two pillars coexistence in one chemical structure, which either could merge as an intrinsic structure or connect from external fragments to each other with covalent bonds. Since the new millennium the advance in biology provides several knowledge and technologies, for example humanized monoclonal antibody, proteasome-ubiquitin system, allosteric modulation, natural macromolecules, structural biology, etc., for innovation of novel medicines. Taking several examples on marketed drugs or drug candidates in clinical trials, this article tries to concisely illustrate R & D conception of biology-driven drug design.

Establishment and validation of OX40/FcγR-humanized mice for the study of agonistic anti-OX40 antibody / 上海交通大学学报（医学版）

Objective • To establish a rapid method to evaluate the activity of agonistic antibody using OX40 (tumor necrosis factor receptor superfamily member 4)/FcγR (Fcγ receptor)-humanized mice. Methods • Bone marrow cells from OX40-humanized mice and FcγR-humanized mice were collected and mixed with equal ratio. Then the mixed bone marrow cells were administrated into irradiated wild-type mice through the tail veins. The reconstruction efficiency of the immune system was confirmed by detecting the expression of hOX40 and hFcγR in the immune cells of chimera mice. After the chimera mice were generated successfully, they were used to evaluate the immunostimulatory activity of anti-hOX40 antibodies to CD4+ or CD8+ T cells. The results of flow cytometry were statistically analyzed. The unpaired t-test was used to compare the means between the two groups, and oneway ANOVA was used to compare the means between multiple groups. Results • Flow cytometry analysis showed that wild-type recipient mice were efficiently reconstituted with hFcγR expressing cells and hOX40 expressing cells to generate OX40/FcγR-humanized bone marrow chimera mice. In these mice, B cells and myeloid cells expressed hFcγRs (P<0.05), and T cells expressed hOX40 upon in vitro stimulation (P<0.05). When these mice were used to evaluate the immunostimulatory activity of anti-hOX40 antibody, significant expressions of IFN-γ and hOX40 were observed (P<0.05). Conclusion • OX40/FcγR-humanized bone marrow chimera mice are generated based on hFcγR expressing cells and hOX40 expressing cells, suggesting a rapid method to build a mouse model with both hFcγR and hOX40 expression. These mice are suitable for evaluating the immunostimulatory activity of agonistic human anti-hOX40 antibodies.

Lymphatic vessels, miRNAs, and CAR T cells in tumor immunology / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

This special feature contains three review articles that summarize recent advances pertaining to tumor immunobiology. Normalization of antitumor immunity through checkpoint inhibitors has achieved significant clinical success and benefited many cancer patients. However, not all cancer patients respond to these treatments, and among the responders, some may develop resistance and others may suffer autoimmunity that requires intervention. Tumor immunotherapy holds promise for further improving the survival of cancer patients, but deeper understanding of immunological networks that regulate anti- and pro-tumor immunity is needed. The review papers collected in this issue cover a few topics that may stimulate future interest in the relevant research field.

Prenatal diagnosis of mosaic trisomy 2: a case report / 中华围产医学杂志

We reported a case of mosaic trisomy 2.The patient was a 29-year-old gravida who underwent amniocentesis at 20 weeks of gestation because of high risk of trisomy-21 in the first trimester screening.The test result revealed a karyotype of 47,XN,+2[10]/46,XX[40].At 26 gestational weeks,the fetus was found severe fetal growth restriction and oligohydramnios which was considered to be at risk of mosaic trisomy 2.The pregnancy was terminated at 27+ gestational weeks.The fetus had obviously abnormal appearances,including dolichocephaly,low-set ears,and micromandible.Autopsy was not performed due to the parents' refusal.

Identification and analysis of chimeric rates in Down syndrome chimeric mice by quantitative real time PCR / 上海交通大学学报（医学版）

Objective • To establish a method for identifying the chimeric rates in Down syndrome chimeric mice, and study the chimeric rules in different organs. Methods • The proportion of trisomic cells (Tc1 cells) in different organs was calculated by detecting the relative quantity of human chromosome 21 (Hsa21) and mouse chromosome 15 (Mmu15) in samples. The relative quantity of Hsa21 and Mmu15 was evaluated with specific primers for genes SIM2 on Hsa21 and Derl1 on Mmu15, respectively, by quantitative real time PCR (qPCR) technology. Results • Three mice were chimeras and the chimeric levels of Tc1 cells were different in various tissues. The chimeric rates in hearts of these 3 mice were 8.98%, 21.71% and 57.70%; in cerebellums, the chimeric rates were 5.62%, 20.17% and 40.43%; in brains, the rates were 8.48%, 15.35% and 20.45%; in livers, the rates were 2.66%, 6.50% and 16.84%; and in spleens, the rates were 1.73%, 3.80% and 11.80%. Conclusion • The chimeric rate of trisomic cells in Down syndrome chimeric mice can be detected by qPCR technology by using primers for genes on specific chromosomes. The chimerism occurs in the hearts, cerebellums, brains, livers and spleens of the chimeric mice and the chimeric rate of Tc1 cells tends to be the highest in the hearts.

Sex chromosome aneuploidy screened by non-invasive prenatal testing from 35827 singletons: prenatal diagnosis and pregnancy determinations / 中华围产医学杂志

Objective To assess the positive predictive value (PPV) of fetal sex chromosome aneuploidy (SCA) identified by non-invasive prenatal testing (NIPT) and investigate families' acceptance of SCA fetus. Methods All suspected SCA cases screened by NIPT from singletons were reviewed in Prenatal Diagnosis Center of Shanghai First Maternity and Infant Hospital from April 1, 2015 to October 31, 2017. Maternal age, NIPT indications, prenatal diagnosis protocols, testing results and their pregnancy determinations were analyzed. Results NIPT was provided to 35827 singletons and 86 suspected SCA cases were identified out of 35823 successful ones, giving a positive detection rate of 0.24％. The average maternal age was (31.5±5.0) years. After genetic counseling, 20 patients declined prenatal diagnosis,the rest 66 cases proceeded with aminiocentesis and fetal chromosomal testing, of which 32 were cytogenetically diagnosed as SCA with the PPV of 48.5％ . The SCA fetus consisted of 25 sex chromosome trisomies (seven cases of 47,XXX, three cases of 47,XYY and 15 cases of 47,XXY), one monosomy X (45,X), three mosacisms (47,XXY/48,XXYY, 47,XXX/45,X, 45,X/46,XX, one for each) and three microdeletions/microduplications. Besides, two false positive NIPT cases were proved to be low level of maternal mosacism (45,X/46,XX, 5％ and 10％ for each). After genetic counseling, 17 out of 20 who declined prenatal diagnosis and 9 out of 32 who diagnosed fetal SCAs continued their pregnancies, with a combined proportion of continued pregnancy of 50％. Thirty-four pregnancies were also continued after exclusion of SCA. Interestingly, the proportion of continued pregnancy among those sex chromosomal trisomy fetuses was only 32％(8/25). Conclusions As a safe and rapid prenatal testing for common autosomal aneuploidies, NIPT could also identify some types of SCA, but with relatively low PPV. More long-term researches are required to determine its sensitivity and specificity. For some types of SCA with mild phenotypes, some family would continue the pregnancy. Therefore, limitations of NIPT should be appropriately explained during both pre- and post-testing counseling.