Clinical and molecular significance of homologous recombination deficiency positive non-small cell lung cancer in Chinese population:An integrated genomic and transcriptional analysis

Objective:The clinical significance of homologous recombination deficiency(HRD)in breast cancer,ovarian cancer,and prostate cancer has been established,but the value of HRD in non-small cell lung cancer(NSCLC)has not been fully investigated.This study aimed to systematically analyze the HRD status of untreated NSCLC and its relationship with patient prognosis to further guide clinical care.Methods:A total of 355 treatment-naïve NSCLC patients were retrospectively enrolled.HRD status was assessed using the AmoyDx Genomic Scar Score(GSS),with a score of≥50 considered HRD-positive.Genomic,transcriptomic,tumor microenvironmental characteristics and prognosis between HRD-positive and HRDnegative patients were analyzed.Results:Of the patients,25.1%(89/355)were HRD-positive.Compared to HRD-negative patients,HRDpositive patients had more somatic pathogenic homologous recombination repair(HRR)mutations,higher tumor mutation burden(TMB)(P<0.001),and fewer driver gene mutations(P<0.001).Furthermore,HRD-positive NSCLC had more amplifications in PI3K pathway and cell cycle genes,MET and MYC in epidermal growth factor receptor(EGFR)/anaplastic lymphoma kinase(ALK)mutant NSCLC,and more PIK3CA and AURKA in EGFR/ALK wild-type NSCLC.HRD-positive NSCLC displayed higher tumor proliferation and immunosuppression activity.HRD-negative NSCLC showed activated signatures of major histocompatibility complex(MHC)-II,interferon(IFN)-γand effector memory CD8+T cells.HRD-positive patients had a worse prognosis and shorter progressionfree survival(PFS)to targeted therapy(first-and third-generation EGFR-TKIs)(P=0.042).Additionally,HRDpositive,EGFR/ALK wild-type patients showed a numerically lower response to platinum-free immunotherapy regimens.Conclusions:Unique genomic and transcriptional characteristics were found in HRD-positive NSCLC.Poor prognosis and poor response to EGFR-TKIs and immunotherapy were observed in HRD-positive NSCLC.This study highlights potential actionable alterations in HRD-positive NSCLC,suggesting possible combinational therapeutic strategies for these patients.

Histological Assessment of Bone Regeneration in the Maxilla with Homologous Bone Graft:A Feasible Option for Maxillary Bone Reconstruction

Bone biomaterials have been increasingly used to reconstruct maxillary atrophic ridges.Thus,the aim of this study was to evaluate bone reconstruction in the maxilla using a homologous cortico-cancellous FFB(lyophilized)graft and verify its reliability.Eight individuals were included from 2014 to 2018.The first surgery was performed to install homologous bone blocks in the maxilla.The period of the second intervention varied between 5 months and 15 days to 11 months(≈7.93 months).The biopsies were taken from the central region of the matured graft during the surgery for implant placement.All patients presented clinical and radiographic conditions for the installation of dental implants.There was a 100%of survival rate.The histological assessment showed that the homologous block bone graft was an osteoconductive biomaterial,with connective tissue present,and newly formed bone juxtaposed on its surface.There were bone trabeculae with osteocytes and active osteoblasts with connective tissue in the mineralization process;the remodeling process can be found through the reverse lines.A limited focus of necrosis with fibrosis was detected,with small resorption and areas of inflammatory infiltrate,but without clinical significance.The homologous block bone graft can be considered a feasible option to substitute the autogenous bone graft(gold standard),with predictable clinical and favorable histological results.The patients had a shorter surgical period,low morbidity,and an unlimited amount of biomaterial available at an accessible cost.

Association between homologous recombination deficiency and outcomes with platinum and platinum-free chemotherapy in patients with triple-negative breast cancer

Objective:The choice of chemotherapeutic regimen for triple-negative breast cancer(TNBC)remains controversial.Homologous recombination deficiency(HRD)has attracted increasing attention in informing chemotherapy treatment.This study was aimed at investigating the feasibility of HRD as a clinically actionable biomarker for platinum-containing and platinum-free therapy.Methods:Chinese patients with TNBC who received chemotherapy between May 1,2008 and March 31,2020 were retrospectively analyzed with a customized 3D-HRD panel.HRD positivity was defined by an HRD score≥30 or deleterious BRCA1/2 mutation.A total of 386 chemotherapy-treated patients with TNBC were screened from a surgical cohort(NCT01150513)and a metastatic cohort,and 189 patients with available clinical and tumor sequencing data were included.Results:In the entire cohort,49.2%(93/189)of patients were identified as HRD positive(40 with deleterious BRCA1/2 mutations and 53 with BRCA1/2 intact with an HRD score of≥30).In the first-line metastatic setting,platinum therapy was associated with longer median progression-free survival(mPFS)than platinum-free therapy[9.1 vs.3.0 months;hazard ratio(HR),0.43;95%confidence interval 0.22–0.84;P=0.01].Among HRD-positive patients,the mPFS was significantly longer in those treated with platinum rather than platinum-free therapy(13.6 vs.2.0 months;HR,0.11;P=0.001).Among patients administered a platinum-free regimen,HRD-negative patients showed a PFS significantly superior to that of HRD-positive patients(P=0.02;treatment-biomarker P-interaction=0.001).Similar results were observed in the BRCA1/2-intact subset.In the adjuvant setting,HRD-positive patients tended to benefit more from platinum chemotherapy than from platinum-free chemotherapy(P=0.05,P-interaction=0.02).Conclusions:HRD characterization may guide decision-making regarding the use of platinum treatment in patients with TNBC in both adjuvant and metastatic settings.

Distributed Secure State Estimation of Multi-Agent Systems Under Homologous Sensor Attacks

This paper addresses the problem of distributed secure state estimation for multi-agent systems under homologous sensor attacks.Two types of secure Luenberger-like distributed observers are proposed to estimate the system state and attack signal simultaneously.Specifically,the proposed two observers are applicable to deal with the cases in the presence and absence of time delays during network communication.It is also shown that the proposed observers can ensure the attack estimations from different agents asymptotically converge to the same value.Sufficient conditions for guaranteeing the asymptotic convergence of the estimation errors are derived.Simulation examples are finally provided to demonstrate the effectiveness of the proposed results.

基于广义逆的桁架结构非线性homologous设计方法

运用M-P广义逆理论,研究了桁架结构的非线性homologous设计问题。将homologous变形约束条件引入结构基本方程,运用M-P广义逆矩阵的性质,将基本方程解的存在条件表示为含可变节点坐标变量的非线性方程组,通过求解该非线性方程组找到了满足homologous变形约束要求的解,并为此推导了AA+(A为任意矩阵,A+为A的M-P广义逆矩阵)求偏导数的显式表达。最后的算例验证了本方法的正确性和有效性。

Analysis of Growth Characteristics and Differentially Expressed Homologous Genes in Rhodobacter sphaeroides under Normal and Simulated Microgravity Conditions

The term “microgravity” is used to describe the “weightlessness” or “zero-g” circumstances that can only be found in space beyond earth’s atmosphere. Rhodobacter sphaeroides is a gram-negative purple phototroph, used as a model organism for this study due to its genomic complexity and metabolic versatility. Its genome has been completely sequenced, and profiles of the differential gene expression under aerobic, semi-aerobic, and photosynthetic conditions were examined. In this study, we hypothesized that R. sphaeroides will show altered growth characteristics, morphological properties, and gene expression patterns when grown under simulated microgravity. To test that, we measured the optical density and colony-forming units of cell cultures grown under both microgravity and normal gravity conditions. Differences in the cell morphology were observed using scanning electron microscopy (SEM) images by measuring the length and the surface area of the cells under both conditions. Furthermore, we also identified homologous genes of R. spheroides using the differential gene expression study of Acidovorax under microgravity in our laboratory. Growth kinetics results showed that R. sphaeroides cells grown under microgravity experience a shorter log phase and early stationary phase compared to the cells growing under normal gravity conditions. The length and surface area of the cells under microgravity were significantly higher confirming that bacterial cells experience altered morphological features when grown under microgravity conditions. Differentially expressed homologous gene analysis indicated that genes coding for several COG and GO functions, such as metabolism, signal-transduction, transcription, translation, chemotaxis, and cell motility are differentially expressed to adapt and survive microgravity.

Inhibition of KU70 and KU80 by CRISPR interference,not NgAgo interference,increases the efficiency of homologous recombination in pig fetal fibroblasts

Non-homologous end-joining(NHEJ) is a predominant pathway for the repair of DNA double-strand breaks(DSB). It inhibits the efficiency of homologous recombination(HR) by competing for DSB targets. To improve the efficiency of HR, multiple CRISPR interference(CRISPRi) and Natronobacterium gregoryi Argonaute(NgAgo) interference(NgAgoi) systems have been designed for the knockdown of NHEJ key molecules, KU70, KU80, polynucleotide kinase/phosphatase(PNKP), DNA ligase IV(LIG4), and NHEJ1. Suppression of KU70 and KU80 by CRISPRi dramatically promoted(P<0.05) the efficiency of HR to 1.85-and 1.58-fold, respectively, whereas knockdown of PNKP, LIG4, and NHEJ1 repair factors did not significantly increase(P>0.05) HR efficiency. Interestingly, although the NgAgoi system significantly suppressed(P<0.05) KU70, KU80, PNKP, LIG4, and NHEJ1 expression, it did not improve(P>0.05) HR efficiency in primary fetal fibroblasts. Our result showed that both NgAgo and catalytically inactive Cas9(dCas9) could interfere with the expression of target genes, but the downstream factors appear to be more active following CRISPR-mediated interference than that of NgAgo.

具有非线性homologous变形约束的桁架结构形态分析

研究了具有非线性homologous变形约束条件的桁架结构形态分析问题。在已有的线性homologous变形约束桁架形态分析的基础上,将结构的节点分成三类:homologous变形约束节点,形状可变节点和边界点。运用Moore-Penrose广义逆矩阵性质,将基础方程组解的存在条件表示为包含形状可变节点未知坐标的非线性方程组,为采用Newton-Raphson方法求解非线性方程组,对AA+(A为任意矩阵,A+为A的Moore-Penrose广义逆矩阵)求偏导数,找到了满足保型要求的形态,给出的桁架算例说明了本文方法的有效性。

Double versus single homologous intrauterine insemination for male factor infertility： a systematic review and meta-analysis

Male factor infertility affects 30%-50% of infertile couples worldwide, and there is an increasing interest in the optimal management of these patients. In studies comparing double and single intrauterine insemination （IUI）, a trend towards higher pregnancy rates in couples with male factor infertility was observed. Therefore, we set out to perform a meta-analysis to examine the superiority of double versus single IUI with the male partner＇s sperm in couples with male factor infertility. An odds ratio （OR） of 95% confidence intervals （CIs） was calculated for the pregnancy rate. Outcomes were analysed by using the ManteI-Haesel or DerSimonian-Laird model accordingto the heterogeneity of the results. Overall, five trials involving 1125 IUI cycles were included in the meta-analysis. There was a two-fold increase in pregnancies after a cycle with a double IUI compared with a cycle with a single IUI （OR. 2.0; 95% CI. 1.07-3.75; P〈O.03）. Nevertheless, this result was mainly attributed to the presence of a large trial that weighted as almost 50% in the overall analysis. Sensitivity analysis, excluding this large trial, revealed only a trend towards higher pregnancy rates among double IUI cycles （OR. 1.58; 95% CI. 0.59-4.21）, but without statistical significance （P=0.20）. Our systematic review highlights that the available evidence regarding the use of double IUI in couples with male factor infertility is fragmentary and weak. Although there may be a trend towards higher pregnancy rates when the number of IUIs per cycle is increased, further large and well-designed randomized trials are needed to provide solid evidence toide current clinical practice.

C/EBP homologous protein deficiency aggravates acute pancreatitis and associated lung injury

AIM:To investigate the pathophysiological role of C/EBP homologous protein(CHOP)in severe acute pancreatitis and associated lung injury.METHODS:A severe acute pancreatitis model was induced with 6 injections of cerulein(Cn,50μg/kg)at 1-h intervals,then intraperitoneal injection of lipopolysaccharide(LPS,7.5 mg/kg)in CHOP-deficient(Chop-/-)mice and wild-type(WT)mice.Animals were sacrificed under anesthesia,3 h or 18 h after LPS injection.Serum amylase,lipase,and cytokines[interleukin(IL)-6 and tumor necrosis factor(TNF)-α],pathological changes,acute lung injury,and apoptosis in the pancreas were evaluated.Serum amylase and lipase activities were detected using a medical automatic chemical analyzer.Enzyme-linked immunosorbent assay kits were used to evaluate TNF-αand IL-6 levels in mouse serum and lung tissue homogenates.Apoptotic cells in sections of pancreatic tissues were determined by terminal deoxynucleotidyl transferase-mediated dUTPbiotin nick-end labeling(TUNEL)analysis.The mouse carotid arteries were cannulated and arterial blood samples were collected for PaO2analysis.The oxygenation index was expressed as PaO2/FiO2.RESULTS:Administration of Cn and LPS for 9 and 24 h induced severe acute pancreatitis in Chop-/-and WT mice.When comparing Chop-/-mice and WT mice,we observed that CHOP-deficient mice had greater increases in serum TNF-α(214.40±19.52 pg/mL vs 150.40±16.70 pg/mL;P=0.037),amylase(4236.40±646.32U/L vs 2535.30±81.83 U/L;P=0.041),lipase(1678.20±170.57 U/L vs 1046.21±35.37 U/L;P=0.008),and IL-6(2054.44±293.81 pg/mL vs 1316.10±108.74pg/mL;P=0.046)than WT mice.The histopathological changes in the pancreases and lungs,decreased PaO2/FiO2ratio,and increased TNF-αand IL-6 levels in the lungs were greater in Chop-/-mice than in WT mice(pancreas:Chop-/-vs WT mice,hemorrhage,P=0.005;edema,P=0.005;inflammatory cells infiltration,P=0.005;total scores,P=0.006;lung:hemorrhage,P=0.017;edema,P=0.017;congestion,P=0.017;neutrophil infiltration,P=0.005,total scores,P=0.001;PaO2/FiO2ratio:393±17.65 vs 453.8,P=0.041;TNF-α:P=0.043;IL-6,P=0.040).Results from TUNEL analysis indicated increased acinar cell apoptosis in mice following the induction of acute pancreatitis.However,Chop-/-mice displayed significantly reduced pancreatic apoptosis compared with the WT mice(201.50±31.43vs 367.00±47.88,P=0.016).CONCLUSION:These results suggest that CHOP can exert protective effects against acute pancreatitis and limit the spread of inflammatory damage to the lungs.

The mutational pattern of homologous recombination(HR)-associated genes and its relevance to the immunotherapeutic response in gastric cancer

Objective:Currently,there is an urgent need to identify immunotherapeutic biomarkers to increase the benefit of immune checkpoint inhibitors(ICIs)for patients with gastric cancer(GC).Homologous recombination deficiency(HRD)can modify the tumor immune microenvironment by increasing the presence of tumor-infiltrating lymphocytes and therefore might serve as a biomarker of immunotherapeutic response.We aimed to analyze the mutational pattern of HR-associated genes in Chinese patients with GC and its relevance to the tumor immune profile and clinical immunotherapeutic response.Methods:A panel of 543 cancer-associated genes was used to analyze genomic profiles in a cohort comprising 484 Chinese patients with GC.Correlations between HR gene mutations and tumor immunity or clinical outcomes were identified via bioinformatic analysis using 2 GC genomic datasets(TCGA and MSK-IMPACT).Results:Fifty-one of the 484(10.54%)patients carried at least one somatic mutation in an HR gene;ATM(16/484,3.31%)was among the most frequently mutated HR genes in the Chinese cohort.Mutations in HR genes were associated with elevated tumor mutational burden,enhanced immune activity,and microsatellite instability status.In the MSK-IMPACT cohort comprising 49 patients with stomach adenocarcinoma or gastroesophageal junction adenocarcinoma treated with ICIs,patients with HR-mut GC(n=12)had significantly better overall survival than those with HR-wt GC(n=37)(log-rank test,P<0.05).Conclusions:Our data suggest that detection of somatic mutations in HR genes might aid in identifying patients who might benefit from immune checkpoint blockade therapy.

miR-506: a regulator of chemo-sensitivity through suppression of the RAD51-homologous recombination axis

Ovarian carcinoma is the most lethal gynecologic malignancy. Resistance to platinum is considered the major problem afecting prognosis. Our recent study established that micro RNA-506(mi R-506) expression was closely associated with progression-free survival and overall survival in two independent patient cohorts totaling 598 epithelial ovarian cancer cases. Further functional study demonstrated that mi R-506 could augment the response to cisplatin and olaparib through targeting RAD51 and suppressing homologous recombination in a panel of ovarian cancer cell lines. Systemic delivery of mi R-506 in an orthotopic ovarian cancer mouse model signiicantly augmented the cisplatin response, thus recapitulating the clinical observation. Therefore, mi R-506 plays a functionally important role in homologous recombination and has important therapeutic value for sensitizing cancer cells to chemotherapy, especially in chemo-resistant patients with attenuated expression of mi R-506.

Effects of serum containing natural cerebrolysin on glucose-regulated protein 78 and CCAAT enhancer-binding protein homologous protein expression in neuronal PC12 cells following tunicamycin-induced endoplasmic reticulum stress

BACKGROUND： Glucose-regulated protein 78 （GRP78）, a marker of endoplasmic reticulum stress, can prolong cell survival. Alternatively, CCAAT enhancer-binding protein homologous protein （CHOP）, a transcription factor specific for endoplasmic reticulum stress, can cause cell cycle arrest and cell apoptosis. OBJECTIVE： To study the protective effects of serum containing natural cerebrolysin on endoplasmic reticulum stress in tunicamycin-induced neuronal PC12 cells, and analyze the influence on GRP78 and CHOP expressions. DESIGN, TIME AND SETTING： A parallel controlled study was performed at the Institute of Integrated Western and Traditional Chinese Medicine, Shenzhen Hospital, Southern Medical University, between March 2006 and August 2008. MATERIALS： Adult Sprague-Dawley rats were perfused with natural Cerebrolysin aqueous extract （0.185 g/kg/d） to produce serum containing natural Cerebrolysin. Physiological saline was used to produce blank serum. PC12 cell line was provided by Shanghai Institute of Cell Biology, Chinese Academy of Science. Tunicamycin was provided by Sigma （St. Louis, USA）, and natural Cerebrolysin, containing ginseng, rhizoma gastrodiae, and gingko leaf （1：2：2）, by Shengzhen Institute of Integrated Western and Traditional Chinese Medicine. METHODS： PC12 cells were treated with DMEM culture media containing 10% blank serum （normal control group）, tunicamycin （1 μg/mL; model group）, and 5%, 10%, and 15% serum containing natural cerebrolysin and tunicamycin （1 μ g/mL; low-, moderate-, and high-dose serum containing natural cerebrotysin groups）, for 2 hours. MAIN OUTCOME MEASURES： PC12 cells were treated with tunicamycin for 48 hours after which apoptosis was measured using the TUNEL method to calculate apoptotic index. GRP78 expression was detected using immunocytochemistry. After 24 hours of treatment with tunicamycin, GRP78 and CHOP mRNA expressions were measured using RT-PCR. RESULTS： The apoptotic index and CHOP mRNA expression were in the model group and three cerebrolysin groups were significantly increased when compared to the normal control group （P 〈 0.05）. In contrast, GRP78 mRNA and protein expressions were significantly decreased （P 〈 0.05）. CONCLUSION： Serum containing natural cerebrolysin significantly reduced apoptosis in neuronal PC12 cells following tunicamycin-induced endoplasmic reticulum stress. These results may be related to an up-regulation of GRP78 expression and down-regulation of CHOP expression, both of which displayed dose-dependent effects.

Homologous fault monitoring technology of redundant INS in airborne avionics systems

Redundant technology plays an important role in improving the reliability and fault-tolerance of the airborne avionics systems. A Markov state transition model is introduced to the reliability analysis of the redundant inertial navigation system （RINS） in airborne navigation systems. An information processing mechanism based on difference filtering is put forward to strengthen the consistency between the outputs of the equal-precision inertial navigation system （INS）. On this basis, the homologous fault monitoring algorithm is designed to realize the homologous fault monitoring of RINS. The simulation is carried out based on the above algorithms, and the results verify the effectiveness of the proposed fault monitoring algorithm based on difference filtering. Research results have good reference value for the configuration and design of RINS in airborne integrated avionics systems.

Gene Sequence, Soluble Expression and Homologous Comparison of a D-Hydantoinase fromPseudomonas putida YZ-26

A 1440bp open-reading frame encoding D-hydantoinase from Pseudomonas putida YZ-26 was cloned and sequenced（ GenBank AY387829）. The DNA fragment was inserted into Nde and BamHI sites of vector pET-3a, yielding a recombinant plasmid, pET-HDT. After being transferred into the host strain, the artificial strain, pET-HDT/ E. coli BL21 can express the D-hydantoinase as the soluble form in the Lura-Bertani medium without addition of any inducers. The activity of the enzyme toward substrate DL-hydantoin can reach 3000-4000 IU per cells from one-liter bacterial culture incubated at 30 ℃ for 10-12 h. By the comparison of amino acid sequence homology, hydrophobic residues analysis and secondary structure prediction, it was found that D-hydantoinase reported herein is quite similar to that from Pseudomonas putdia CCRC12857, and alike to that from Pseudomonas putdia DSM84 or other bacteria. A rapid and efficient purification procedure of the enzyme was performed by a three-step procedure： ammonium sulfate fractionation, phenyl Sepharose hydrophobic interaction chromatography and Sephacryl S-200 gel filtration. The molecular mass of the monomeric enzyme is 52042 Da as determined by MALDI-TOF mass spectrometry.

Blockage of ETS homologous factor inhibits the proliferation and invasion of gastric cancer cells through the c-Met pathway

BACKGROUND Gastric cancer(GC)is one of the most common and deadliest types of cancer worldwide due to its delayed diagnosis and high metastatic frequency,but its exact pathogenesis has not been fully elucidated.ETS homologous factor(EHF)is an important member of the ETS family and contributes to the pathogenesis of multiple malignant tumors.To date,whether EHF participates in the development of GC via the c-Met signaling pathway remains unclear.AIM To investigate the role and mechanism of EHF in the occurrence and development of GC.METHODS The expression of EHF mRNA in GC tissues and cell lines was measured by quantitative PCR.Western blotting was performed to determine the protein expression of EHF,c-Met,and its downstream signal molecules.The EHF expression in GC tissues was further detected by immunohistochemical staining.To investigate the role of EHF in GC oncogenesis,small interfering RNA(siRNA)against EHF was transfected into GC cells.The cell proliferation of GC cells was determined by Cell Counting Kit-8 and colony formation assays.Flow cytometry was performed following Annexin V/propidium iodide(PI)to identify apoptotic cells and PI staining to analyze the cell cycle.Cell migration and invasion were assessed by transwell assays.RESULTS The data showed that EHF was upregulated in GC tissues and cell lines in which increased expression of c-Met was also observed.Silencing of EHF by siRNA reduced the proliferation of GC cells.Inhibition of EHF induced significant apoptosis and cell cycle arrest in GC cells.Cell migration and invasion were significantly inhibited.EHF silencing led to c-Met downregulation and further blocked the Ras/c-Raf/extracellular signal-related kinase 1/2(Erk1/2)pathway.Additionally,phosphatase and tensin homolog was upregulated and glycogen synthase kinase 3 beta was deactivated.Moreover,inactivation of signal transducer and activator of transcription 3 was detected following EHF inhibition,leading to inhibition of the epithelial-to-mesenchymal transition(EMT).CONCLUSION These results suggest that EHF plays a key role in cell proliferation,invasion,apoptosis,the cell cycle and EMT via the c-Met pathway.Therefore,EHF may serve as an antineoplastic target for the diagnosis and treatment of GC.

Efficiency of olaparib in colorectal cancer patients with an alteration of the homologous repair protein

Precision medicine is defined by the administration of drugs based on the tumor's particular genetic characteristics. It is developing quickly in the field of cancer therapy. For example, KRAS, NRAS and BRAF genetic testing demonstrates its efficiency for precision medicine in colorectal cancer(CRC). Besides for these well-known mutations, the purpose of performing larger genetic testing in this pathology is unknown. Recent reports have shown that using the poly ADP ribose polymerase(PARP) inhibitor olaparib in patients with homologous repair enzyme deficiency gave positive clinical results in breast, ovarian and prostate cancers. We have reported here the cases of 2 patients with multi-treated metastatic CRC who underwent somatic and constitutional exome analyses. The analyses revealed a loss of function mutation in a homologous repair enzyme resulting in the loss of heterozygosity for both patients(Check2 for the first patient and RAD51 C for the second one). Both patients were treated with off-label usage of olaparib. While the first patient showed clinical benefit, reduction of carcinoembryonic antigen tumor marker and radiologic response, the second patient quickly presented a progression of the tumor. Additional genetic analyses revealed a frameshift truncating mutation of the TP53BP1 gene in the patient who progressed. Interestingly, deficiency in TP53BP1 was previously described to confer resistance to olaparib in mice breast cancer models. Our findings suggest that exome analysis may be a helpful tool to highlight targetable mutations in CRC and that olaparib may be efficient in patients with a homologous repair deficiency.

BLM helicase inhibition synergizes with PARP inhibition to improve the radiosensitivity of olaparib resistant non-small cell lung cancer cells by inhibiting homologous recombination repair

Objective:We aimed to investigate the radiosensitizing efficacy of the poly-ADP-ribose polymerase(PARP)inhibitor,olaparib,and the Bloom syndrome protein(BLM)helicase inhibitor,ML216,in non-small cell lung cancer(NSCLC)cells.Methods:Radiosensitization of NSCLC cells was assessed by colony formation and tumor growth assays.Mechanistically,the effects of ML216,olaparib,and radiation on cell and tumor proliferation,DNA damage,cell cycle,apoptosis,homologous recombination(HR)repair,and non-homologous end joining(NHEJ)repair activity were determined.Results:Both olaparib and ML216 enhanced the radiosensitivities of olaparib-sensitive H460 and H1299 cells,which was seen as decreased surviving fractions and Rad51 foci,increased total DNA damage,andγH2AX and 53BP1 foci(P<0.05).The expressions of HR repair proteins were remarkably decreased in olaparib-treated H460 and H1299 cells after irradiation(P<0.05),while olaparib combined with ML216 exerted a synergistic radiosensitization effect on olaparib-resistant A549 cells.In addition to increases of double strand break(DSB)damage and decreases of Rad51 foci,olaparib combined with ML216 also increased pDNA-PKcs(S2056)foci,abrogated G2 cell cycle arrest,and induced apoptosis in A549 lung cancer after irradiation in vitro and in vivo(P<0.05).Moreover,Western blot showed that olaparib combined with ML216 and irradiation inhibited HR repair,promoted NHEJ repair,and inactivated cell cycle checkpoint signals both in vitro and in vivo(P<0.05).Conclusions:Taken together,these results showed the efficacy of PARP and BLM helicase inhibitors for radiosensitizing NSCLC cells,and supported the model that BLM inhibition sensitizes cells to PARP inhibitor-mediated radiosensitization,as well as providing the basis for the potential clinical development of this combination for tumors intrinsically resistant to PARP inhibitors and radiotherapy.

Discussion on application of food-medicine homologous traditional Chinese medicine in prevention prescriptions for Coronavirus Disease 2019 (COVID-19)

From sorting out and statistical analysis of 172 prevention prescriptions for Coronavirus Disease 2019 (COVID-19) put forward by government departments, medical institutions and TCM clinical experts in various provinces, municipalities and autonomous regions, the results showed that food-medicine homologous traditional Chinese medicine (abbreviated as"food-medicine materials") such as honeysuckle, licorice, agastache, tangerine peel, fresh reed rhizome, perilla and platycodon are used most frequently. Combined with TCM theory and modern pharmacology analysis, not only deeper understandin/g of the application value of food-medicine materials, but also reference value of their daily use and development of related products reference in the future is expected to be acquired.

Ontogenes and the Paradox of Homologous Pairing

The mutations in ontogenes have been shown to drastically increase the nondisjunction of X chromosomes in the D. melanogaster meiosis. This means that ontogenes are involved in the process that brings the homologs together although both the genes and ontogenes are finally paired. The phenomenon named the paradox of homologous pairing is described. Chromosomal rearrangements (inversions and translocations) lead to formation of specific topological figures (loops and crosses) during pairing. The mutual arrangement of the nucleotide sequences of homologous ontogenes before and after formation of such figures is different. Their arrangement coincides after a figure is formed and the pairing looks homologous. However, before the figure is formed, their arrangement does not match and the pairing is actually nonhomologous. The available data on ontogenes allows this paradox to be resolved. It is assumed that the sequence of each ontogene possesses a factor that 1) is a product of this nucleotide sequence;2) is co-located with this sequence;and 3) generates approaching independently of nucleotide sequence position in space. The sole candidate to the role of this factor is the DNA conformation of ontogene. The conformation in the form of a solenoid of DNA is able to generate an electromagnetic field independent of the orientation of the DNA itself. The proposed resolution of the paradox is considered in terms of the problem of genetic homology.