1.Identification of GSK3 family and regulatory effects of brassinolide on growth and development of Nardostachys jatamansi.
Yu-Yan LEI ; Zheng MA ; Jing WEI ; Wen-Bing LI ; Ying LI ; Zheng-Ming YANG ; Shao-Shan ZHANG ; Jing-Qiu FENG ; Hua-Chun SHENG ; Yuan LIU
China Journal of Chinese Materia Medica 2025;50(2):395-403
This study identified 8 members including NjBIN2 of the GSK3 family in Nardostachys jatamansi by bioinformatics analysis. Moreover, the phylogenetic tree revealed that the GKS3 family members of N. jatamansi had a close relationship with those of Arabidopsis. RT-qPCR results showed that NjBIN2 presented a tissue-specific expression pattern with the highest expression in roots, suggesting that NjBIN2 played a role in root growth and development. In addition, the application of epibrassinolide or the brassinosteroid(BR) synthesis inhibitor(brassinazole) altered the expression pattern of NjBIN2 and influenced the photomorphogenesis(cotyledon opening) and root development of N. jatamansi, which provided direct evidence about the functions of NjBIN2. In conclusion, this study highlights the roles of BIN2 in regulating the growth and development of N. jatamansi by analyzing the expression pattern and biological function of NjBIN2. It not only enriches the understanding about the regulatory mechanism of the growth and development of N. jatamansi but also provides a theoretical basis and potential gene targets for molecular breeding of N. jatamansi with improved quality in the future.
Brassinosteroids/metabolism*
;
Steroids, Heterocyclic/metabolism*
;
Gene Expression Regulation, Plant/drug effects*
;
Plant Proteins/metabolism*
;
Phylogeny
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Nardostachys/metabolism*
;
Plant Growth Regulators/pharmacology*
;
Plant Roots/drug effects*
2.Genetic profiling and intervention strategies for phenylketonuria in Gansu, China: an analysis of 1 159 cases.
Chuan ZHANG ; Pei ZHANG ; Bing-Bo ZHOU ; Xing WANG ; Lei ZHENG ; Xiu-Jing LI ; Jin-Xian GUO ; Pi-Liang CHEN ; Ling HUI ; Zhen-Qiang DA ; You-Sheng YAN
Chinese Journal of Contemporary Pediatrics 2025;27(7):808-814
OBJECTIVES:
To investigate the molecular epidemiology of children with phenylketonuria (PKU) in Gansu, China, providing foundational data for intervention strategies.
METHODS:
A retrospective analysis was conducted on 1 159 PKU families who attended Gansu Provincial Maternity and Child Care Hospital from January 2012 to December 2024. Sanger sequencing, multiplex ligation-dependent probe amplification, whole exome sequencing, and deep intronic variant analysis were used to analyze the PAH gene.
RESULTS:
For the 1 159 children with PKU, 2 295 variants were identified in 2 318 alleles, resulting in a detection rate of 99.01%. The detection rates were 100% (914/914) in 457 classic PKU families, 99.45% (907/912) in 456 mild PKU families, and 96.34% (474/492) in 246 mild hyperphenylalaninemia families. The 2 295 variants detected comprised 208 distinct mutation types, among which c.728G>A (14.95%, 343/2 295) had the highest frequency, followed by c.611A>G (4.88%, 112/2 295) and c.721C>T (4.79%, 110/2 295). The cumulative frequency of the top 23 hotspot variants reached 70.28% (1 613/2 295), and most variant alleles were detected in exon 7 (29.19%, 670/2 295).
CONCLUSIONS
Deep intronic variant analysis of the PAH gene can improve the genetic diagnostic rate of PKU. The development of targeted detection kits for PAH hotspot variants may enable precision screening programs and enhance preventive strategies for PKU.
Humans
;
Phenylketonurias/epidemiology*
;
Female
;
Male
;
Retrospective Studies
;
Phenylalanine Hydroxylase/genetics*
;
Mutation
;
Child, Preschool
;
China/epidemiology*
;
Child
;
Infant
3.Celastrol directly targets LRP1 to inhibit fibroblast-macrophage crosstalk and ameliorates psoriasis progression.
Yuyu ZHU ; Lixin ZHAO ; Wei YAN ; Hongyue MA ; Wanjun ZHAO ; Jiao QU ; Wei ZHENG ; Chenyang ZHANG ; Haojie DU ; Meng YU ; Ning WAN ; Hui YE ; Yicheng XIE ; Bowen KE ; Qiang XU ; Haiyan SUN ; Yang SUN ; Zijun OUYANG
Acta Pharmaceutica Sinica B 2025;15(2):876-891
Psoriasis is an incurable chronic inflammatory disease that requires new interventions. Here, we found that fibroblasts exacerbate psoriasis progression by promoting macrophage recruitment via CCL2 secretion by single-cell multi-omics analysis. The natural small molecule celastrol was screened to interfere with the secretion of CCL2 by fibroblasts and improve the psoriasis-like symptoms in both murine and cynomolgus monkey models. Mechanistically, celastrol directly bound to the low-density lipoprotein receptor-related protein 1 (LRP1) β-chain and abolished its binding to the transcription factor c-Jun in the nucleus, which in turn inhibited CCL2 production by skin fibroblasts, blocked fibroblast-macrophage crosstalk, and ameliorated psoriasis progression. Notably, fibroblast-specific LRP1 knockout mice exhibited a significant reduction in psoriasis like inflammation. Taken together, from clinical samples and combined with various mouse models, we revealed the pathogenesis of psoriasis from the perspective of fibroblast-macrophage crosstalk, and provided a foundation for LRP1 as a novel potential target for psoriasis treatment.
4.Expert consensus on the diagnosis and treatment of cemental tear.
Ye LIANG ; Hongrui LIU ; Chengjia XIE ; Yang YU ; Jinlong SHAO ; Chunxu LV ; Wenyan KANG ; Fuhua YAN ; Yaping PAN ; Faming CHEN ; Yan XU ; Zuomin WANG ; Yao SUN ; Ang LI ; Lili CHEN ; Qingxian LUAN ; Chuanjiang ZHAO ; Zhengguo CAO ; Yi LIU ; Jiang SUN ; Zhongchen SONG ; Lei ZHAO ; Li LIN ; Peihui DING ; Weilian SUN ; Jun WANG ; Jiang LIN ; Guangxun ZHU ; Qi ZHANG ; Lijun LUO ; Jiayin DENG ; Yihuai PAN ; Jin ZHAO ; Aimei SONG ; Hongmei GUO ; Jin ZHANG ; Pingping CUI ; Song GE ; Rui ZHANG ; Xiuyun REN ; Shengbin HUANG ; Xi WEI ; Lihong QIU ; Jing DENG ; Keqing PAN ; Dandan MA ; Hongyu ZHAO ; Dong CHEN ; Liangjun ZHONG ; Gang DING ; Wu CHEN ; Quanchen XU ; Xiaoyu SUN ; Lingqian DU ; Ling LI ; Yijia WANG ; Xiaoyuan LI ; Qiang CHEN ; Hui WANG ; Zheng ZHANG ; Mengmeng LIU ; Chengfei ZHANG ; Xuedong ZHOU ; Shaohua GE
International Journal of Oral Science 2025;17(1):61-61
Cemental tear is a rare and indetectable condition unless obvious clinical signs present with the involvement of surrounding periodontal and periapical tissues. Due to its clinical manifestations similar to common dental issues, such as vertical root fracture, primary endodontic diseases, and periodontal diseases, as well as the low awareness of cemental tear for clinicians, misdiagnosis often occurs. The critical principle for cemental tear treatment is to remove torn fragments, and overlooking fragments leads to futile therapy, which could deteriorate the conditions of the affected teeth. Therefore, accurate diagnosis and subsequent appropriate interventions are vital for managing cemental tear. Novel diagnostic tools, including cone-beam computed tomography (CBCT), microscopes, and enamel matrix derivatives, have improved early detection and management, enhancing tooth retention. The implementation of standardized diagnostic criteria and treatment protocols, combined with improved clinical awareness among dental professionals, serves to mitigate risks of diagnostic errors and suboptimal therapeutic interventions. This expert consensus reviewed the epidemiology, pathogenesis, potential predisposing factors, clinical manifestations, diagnosis, differential diagnosis, treatment, and prognosis of cemental tear, aiming to provide a clinical guideline and facilitate clinicians to have a better understanding of cemental tear.
Humans
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Dental Cementum/injuries*
;
Consensus
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Diagnosis, Differential
;
Cone-Beam Computed Tomography
;
Tooth Fractures/therapy*
5.Clinical pathological characteristics and immune microenvironment significance of EGFR T790M mutation in non-small cell lung cancer patients and its prognostic implications
Yicong LIN ; Yue WANG ; Qianqian XUE ; Qiang ZHENG ; Yan JIN ; Ziling HUANG ; Yuan LI
China Oncology 2024;34(4):368-379
Background and purpose:Epidermal growth factor receptor exon 20 T790M(EGFR T790M)mutation is one of the acquired resistance mechanisms in non-small cell lung cancer(NSCLC)against first-/second-generation EGFR tyrosine kinase inhibitors(EGFR TKIs).Additionally,EGFR T790M mutation can also be observed in NSCLC patients who have not undergone EGFR TKIs treatment.This study aimed to compare the clinical pathological characteristics and prognostic differences between NSCLC patients with de novo and acquired EGFR T790M mutation,and further explore the immune microenvironment features of acquired T790M mutation in NSCLC.Methods:This study retrospectively included 3 762 cases of NSCLC diagnosed at Fudan University Shanghai Cancer Center from April 2020 to September 2022.Among them,2 070 cases(55.02%)exhibited EGFR mutations,and 556 cases(14.77%)received EGFR TKIs treatment.Specifically,there were 119 cases(3.16%)of NSCLC with EGFR T790M mutation,including 51 cases(1.35%)of de novo T790M mutation and 68 cases(1.81%)of acquired EGFR T790M mutation.Clinical data of the patients were collected for comparative analysis between NSCLC patients with de novo and acquired T790M mutation.Multiple immunofluorescence histochemistry(mIHC)was employed to explore the immune microenvironment characteristics of NSCLC patients with acquired T790M mutation.Results:The proportion of de novo and acquired T790M mutations was higher in female patients compared to males.Patients with de novo T790M mutation tended to be younger.Both de novo and acquired T790M mutations were more commonly found in poorly differentiated carcinomas.Among NSCLC patients with de novo T790M mutation,there was a higher rate of programmed death ligand-1(PD-L1)expression(60.00%).In contrast,among NSCLC patients with acquired T790M mutation,the rate of PD-L1 expression was lower(22.39%).Acquired T790M mutation in NSCLC was often accompanied by TP53 alterations(39.7%).Cox regression analysis results indicated that mesenchymal to epithelial transition(MET)factor alteration was a risk factor for the occurrence of acquired T790M mutation(P=0.000 5).The average overall survival(OS)showed no significant difference between de novo and acquired T790M mutations(35.4 and 37.3 months respectively).However,patients with acquired T790M mutation exhibited a higher proportion of recurrence and metastasis.In acquired T790M mutation,there was a higher presence of immune cell infiltration within the stromal compartment,such as CD20+B cells,CD23+B cells,CD8+T cells,CD8+PD-1-/+cells,CD20+PD-1-/+cells and CD23+PD-1-/+cells.Additionally,the study found that when EGFR was accompanied by tumor suppressor gene(TSG)alterations,the average distance between tumor cells and CD8+T cells,CD20+B cells,CD8+PD-1+cells,CD20+PD-1+cells and CD23+PD-1+cells was closer compared to cases with only EGFR mutations.Conclusion:In comparison to patients with de novo T790M mutation,patients with acquired T790M mutation exhibit a lower rate of PD-L1 positivity.Acquired T790M mutation often accompanies TP53 alterations,and MET alteration is identified as a risk factor triggering acquired T790M mutation.Although patients with acquired T790M mutation face higher risk of recurrence and metastasis,their average OS does not significantly differ from those with de novo T790M mutation.In cases of acquired T790M mutation,the presence of TSG mutations can alter the spatial distribution of immune cells,potentially leading to benefits from immunotherapy.
6.The correlation between colorectal cancer tissues JAK2 gene mutations and TCF3 protein expression with clinical pathological features and prognosis
Ke-Jin YAN ; Hong-Liang ZHU ; Xian-Qiang XIE ; Dong-Sheng LI ; Zeng-Lu ZHENG ; Ji-Yang LI
Modern Interventional Diagnosis and Treatment in Gastroenterology 2024;29(6):675-680,690
Objective To explore the correlation between colorectal cancer tissue Janus kinase 2(JAK2)gene mutations and T cytokine 3(TCF3)protein expression with clinical pathological characteristics and prognosis,and to provide laboratory reference indicators for early evaluation of the illness severity and prognosis of colorectal cancer.Methods A retrospective analysis was conducted on the data of 50 colorectal cancer patients who were admitted from January 2016 to April 2021 and retained colon cancer and adjacent tissue wax blocks.Basic information,clinical and pathological features such as TNM staging,lymph node metastasis,and 3-year survival prognosis of the patients were collected.The wax blocks of colon cancer and adjacent tissues of patients were detected,in which Taqman fluorescence probe method was applied to detect the distribution of JAK2 gene at the rs2230724 locus AA,AG,and GG genotypes in colon cancer tissues,and immunohistochemistry method was applied to detect the positive expression rate of TCF3 protein in colon cancer and adjacent tissues.The basic information,JAK2 rs2230724 gene mutation,and TCF3 protein expression of patients with different clinical and pathological characteristics were compared,and the influencing factors of clinical and pathological characteristics of colon cancer was analyzed by logistic regression model.Kaplan Meier survival curve was applied to compare the survival prognosis of patients with JAK2 gene mutations and TCF3 protein expression in colorectal cancer tissue,and Cox regression model was applied to analyze the risk factors affecting the prognosis of colorectal cancer patients.Results The positive expression rate of TCF3 protein in colon cancer tissues was higher than that in adjacent tissues(P<0.05).The age,BMI,proportion of GG genotype at rs2230724 locus of JAK2 gene and positive expression rate of TCF3 protein in TNM stage Ⅲ colon cancer patients were higher than those in TNM stage Ⅰ-Ⅱ patients(P<0.05);The age,BMI,smoking rate,proportion of GG type at the rs2230724 locus of JAK2 gene in colon cancer tissue,and positive expression rate of TCF3 protein in patients with lymph node metastasis were higher than those without lymph node metastasis(P<0.05);The results of the logistic regression model analysis showed that the influencing factors of clinical pathological features such as TNM staging and lymph node metastasis in colon cancer were age,mutation of JAK2 gene rs2230724 site in colon cancer tissue,and positive expression rate of TCF3 protein(P<0.05).The Kaplan Meier survival curve analysis showed that patients with JAK2 gene rs2230724 GG genotype and TCF3 protein positivity in colon cancer tissue had higher cumulative all-cause mortality rates(P<0.05).The results of univariate and multivariate Cox regression model analysis showed that independent risk factors affecting the prognosis of colorectal cancer patients include JAK2 gene rs2230724 site GG type,TCF3 protein positive expression,TNM stage Ⅲ,lymph node metastasis,and age.Conclusion The proportion of JAK2 gene rs2230724 GG type and TCF3 protein expression in colorectal cancer tissues are related to their clinical pathological characteristics and prognosis,and can be used as reference indicators for evaluating clinical pathological characteristics and predicting prognosis of colorectal cancer.
7.Epidemiological investigation of iron deficiency among preschool children in 10 provinces, autonomous regions, or municipalities in China
Lei WANG ; Jie SHAO ; Wenhong DONG ; Shuangshuang ZHENG ; Bingquan ZHU ; Qiang SHU ; Wei CHEN ; Lichun FAN ; Jin SUN ; Yue GAO ; Youfang HU ; Nianrong WANG ; Zhaohui WANG ; Tingting NIU ; Yan LUO ; Ju GAO ; Meiling TONG ; Yan HU ; Wei XIANG ; Zhengyan ZHAO ; Meng MAO ; Fan JIANG
Chinese Journal of Pediatrics 2024;62(5):416-422
Objective:To understand the current status of anemia, iron deficiency, and iron-deficiency anemia among preschool children in China.Methods:A cross-sectional study was conducted with a multi-stage stratified sampling method to select 150 streets or townships from 10 Chinese provinces, autonomous regions, or municipalities (East: Jiangsu, Zhejiang, Shandong, and Hainan; Central: Henan; West: Chongqing, Shaanxi, Guizhou, and Xinjiang; Northeast: Liaoning). From May 2022 to April 2023, a total of 21 470 children, including community-based children aged 0.5 to<3.0 years receiving child health care and kindergarten-based children aged 3.0 to<7.0 years, were surveyed. They were divided into 3 age groups: infants (0.5 to<1.0 year), toddlers (1.0 to<3.0 years), and preschoolers (3.0 to<7.0 years). Basic information such as sex and date of birth of the children was collected, and peripheral blood samples were obtained for routine blood tests and serum ferritin measurement. The prevalence rates of anemia, iron deficiency, and iron-deficiency anemia were analyzed, and the prevalence rate differences were compared among different ages, sex, urban and rural areas, and regions using the chi-square test.Results:A total of 21 460 valid responses were collected, including 10 780 boys (50.2%). The number of infants, toddlers, and preschoolers were 2 645 (12.3%), 6 244 (29.1%), and 12 571 (58.6%), respectively. The hemoglobin level was (126.7±14.8) g/L, and the serum ferritin level was 32.3 (18.5, 50.1) μg/L. The overall rates of anemia, iron deficiency, and iron-deficiency anemia were 10.4% (2 230/21 460), 28.3% (6 070/21 460), and 3.9% (845/21 460), respectively. The prevalence rate of anemia was higher for boys than for girls (10.9% (1 173/10 780) vs. 9.9% (1 057/10 680), χ2=5.58, P=0.018), with statistically significant differences in the rates for infants, toddlers and preschoolers (18.0% (475/2 645), 10.6% (662/6 244), and 8.7% (1 093/12 571), respectively, χ2=201.81, P<0.01), and the rate was significantly higher for children in rural than that in urban area (11.8% (1 516/12 883) vs. 8.3% (714/8 577), χ2=65.54, P<0.01), with statistically significant differences in the rates by region ( χ2=126.60, P<0.01), with the highest rate of 15.8% (343/2 173) for children in Central region, and the lowest rate of 5.3% (108/2 053) in Northeastern region. The prevalence rates of iron deficiency were 33.8% (895/2 645), 32.2% (2 011/6 244), and 25.2% (3 164/12 571) in infants, toddlers, and preschoolers, respectively, and 30.0% (3 229/10 780) in boys vs. 26.6% (2 841/10 680) in girls, 21.7% (1 913/8 821), 40.0% (870/2 173), 27.1% (2 283/8 413), 48.9% (1 004/2 053) in Eastern, Central, Western, and Northeastern regions, respectively, and each between-group showed a significant statistical difference ( χ2=147.71, 29.73, 773.02, all P<0.01). The prevalence rate of iron-deficiency anemia showed a significant statistical difference between urban and rural areas, 2.9% (251/8 577) vs. 4.6% (594/12 883) ( χ2=38.62, P<0.01), while the difference in iron deficiency prevalence was not significant ( χ2=0.51, P=0.476). Conclusions:There has been a notable improvement in iron deficiency and iron-deficiency anemia among preschool children in China, but the situation remains concerning. Particular attention should be paid to the prevention and control of iron deficiency and iron-deficiency anemia, especially among infants and children in the Central, Western, and Northeastern regions of China.
8.Tenecteplase versus alteplase in treatment of acute ST-segment elevation myocardial infarction: A randomized non-inferiority trial
Xingshan ZHAO ; Yidan ZHU ; Zheng ZHANG ; Guizhou TAO ; Haiyan XU ; Guanchang CHENG ; Wen GAO ; Liping MA ; Liping QI ; Xiaoyan YAN ; Haibo WANG ; Qingde XIA ; Yuwang YANG ; Wanke LI ; Juwen RONG ; Limei WANG ; Yutian DING ; Qiang GUO ; Wanjun DANG ; Chen YAO ; Qin YANG ; Runlin GAO ; Yangfeng WU ; Shubin QIAO
Chinese Medical Journal 2024;137(3):312-319
Background::A phase II trial on recombinant human tenecteplase tissue-type plasminogen activator (rhTNK-tPA) has previously shown its preliminary efficacy in ST elevation myocardial infarction (STEMI) patients. This study was designed as a pivotal postmarketing trial to compare its efficacy and safety with rrecombinant human tissue-type plasminogen activator alteplase (rt-PA) in Chinese patients with STEMI.Methods::In this multicenter, randomized, open-label, non-inferiority trial, patients with acute STEMI were randomly assigned (1:1) to receive an intravenous bolus of 16 mg rhTNK-tPA or an intravenous bolus of 8 mg rt-PA followed by an infusion of 42 mg in 90 min. The primary endpoint was recanalization defined by thrombolysis in myocardial infarction (TIMI) flow grade 2 or 3. The secondary endpoint was clinically justified recanalization. Other endpoints included 30-day major adverse cardiovascular and cerebrovascular events (MACCEs) and safety endpoints.Results::From July 2016 to September 2019, 767 eligible patients were randomly assigned to receive rhTNK-tPA ( n = 384) or rt-PA ( n = 383). Among them, 369 patients had coronary angiography data on TIMI flow, and 711 patients had data on clinically justified recanalization. Both used a –15% difference as the non-inferiority efficacy margin. In comparison to rt-PA, both the proportion of patients with TIMI grade 2 or 3 flow (78.3% [148/189] vs. 81.7% [147/180]; differences: –3.4%; 95% confidence interval [CI]: –11.5%, 4.8%) and clinically justified recanalization (85.4% [305/357] vs. 85.9% [304/354]; difference: –0.5%; 95% CI: –5.6%, 4.7%) in the rhTNK-tPA group were non-inferior. The occurrence of 30-day MACCEs (10.2% [39/384] vs. 11.0% [42/383]; hazard ratio: 0.96; 95% CI: 0.61, 1.50) did not differ significantly between groups. No safety outcomes significantly differed between groups. Conclusion::rhTNK-tPA was non-inferior to rt-PA in the effect of improving recanalization of the infarct-related artery, a validated surrogate of clinical outcomes, among Chinese patients with acute STEMI.Trial registration::www.ClinicalTrials.gov (No. NCT02835534).
9.Functional near infrared imaging of college students on speech fluency tasks in traumatized
ZHENG Minxiao, ZHU Dongmei, WEI Qiang, XIANG Nian, QIU Min, XIAO Qiang, LI Xiaonan, ZHANG Yan
Chinese Journal of School Health 2024;45(3):375-378
Objective:
The study aims to explore the neural mechanism of cognitive differences in college students with posttraumatic stress disorder under verbal fluency task based on functional near infrared spectroscopy (fNIRS), so as to provide neuroimaging support for the evaluation, diagnosis and treatment of posttraumatic stress disorder(PTSD).
Methods:
Posttaumatic Stress Disorder Checklist Combat(PCL-C) was used to screen the subjects, including 21 students in PTSD group (PCL-C≥38) and 30 students in control group from September to Novenber in 2020. A 53 channel near infrared spectroscopy device was used to collect cerebral blood oxygen signals under the verbal fluency task, and correlation analysis, Mann Whitney U test and independent sample t test were performed on the results.
Results:
The difference in the total average score of PCL-C Scale between PTSD group and the control group(46.38±6.96,25.57±6.09) was statistically significant ( t=11.33, P <0.05). Correlation analysis showed that Avg-HbO in left dorsolateral prefrontal lobe was negatively correlated with PCL-C Score ( r=-0.37, P <0.05). Mann Whitney U test showed that in the left dorsolateral prefrontal lobe (Ch6), the Avg-HbO change in PTSD group [0.19(-0.09, 0.86)mmol/(L〖KG*7〗·mm)] was significantly lower than the control group [0.79( 0.37 , 1.47)mmol/(L ·mm)] ( Z=2.16, P <0.05), which was statistically significant.
Conclusions
The degree of PTSD was negatively correlated with the index of oxygenated hemoglobin in the left dorsolateral prefrontal lobe, and the oxygenated hemoglobin content in the PTSD group was lower than that in the normal group. In the future, fNIRS may be used to collect blood oxygen signals from the left dorsolateral prefrontal lobe in cognitive tasks to provide imaging evidence for the identification of PTSD.
10.DNA Polymerase θ: a Multifunctional and Error-prone DNA End Repair Enzyme
Yao WANG ; Guo-Jiang CHEN ; Jian-Nan FENG ; Yan-Chun SHI ; Jing WANG ; Yuan-Qiang ZHENG
Progress in Biochemistry and Biophysics 2024;51(3):493-503
DNA polymerase theta (Polθ), also known as DNA polymerase θ, is the member of the DNA polymerase A family and plays a crucial role in the repair of DNA double-strand breaks (DSB). Polθ has 3 distinct structural domains: the N-terminal helicase-like domain with a conserved sequence, the C-terminal polymerase domain, and the central domain, which is a disordered sequence connecting these two regions. Notably, Polθ is the only known polymerase in eukaryotes that possesses helicase activity. However, it is also an error-prone polymerase. When DNA DSBs occur, a specialized network consisting of at least 4 pathways, including classical-non homologous end joining (C-NHEJ), homologous recombination (HR), single-strand annealing (SSA), and alternative-end joining (Alt-EJ), is responsible for repairing DNA damage caused by DSBs. In the absence of major DNA repair pathways like HR, cells rely on Alt-EJ pathway mediated by Polθ to repair damaged DNA and maintain genomic stability. Nevertheless, due to the low fidelity of Polθ, Alt-EJ repair often leads to errors. Depletion of Polθ has shown to increases DSB formation and compromise genomic stability. Conversely, overexpression of Polθ has been associated with increases DNA damage markers and impairs cell cycle progression. As a result, the impact of Polθ on genome stability remains controversial. Furthermore, overexpression of Polθ is frequently observed in cancer and is associated with a characteristic mutational signature and poor prognosis. Depleting Polθ in an HR-deficient background has been shown to impair cell viability, suggesting a synthetic lethal (SL) relationship between Polθ and HR factors. In recent years, targeted chemotherapy drugs that inhibit tumor growth have gained significant attention. However, off-target effects and drug resistance pose challenges for clinical application, particularly with poly-ADP-ribose polymerase inhibitor (PARPi). Blocking Polθ activity in HR-deficient tumor cells has been found to reverse PARPi resistance, making Polθ a very promising therapeutic target in cancer treatment. The availability of crystal structures for both helicase and polymerase domain has facilitated the design of potent inhibitors of Polθ. Currently, several highly specific and effective small molecule inhibitors targeting Polθ, such as Novobiocin, RP-6685, and ART558, have been reported to effectively block various cancers with HR deficiency. The initial success of these inhibitors points to new directions for treating BRCA1/2-mutated tumors. Additionally, reducing the Alt-EJ repair pathway mediated by Polθ can improve HR repair efficiency and increase the chance of exogenous gene target integration (TI), suggesting potential new applications for Polθ inhibitors. This article reviews the recent research progress on the molecular function of Polθ and its involvement in the Alt-EJ pathway modification mechanism, providing insights for a deeper understanding of this field.


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