Tau Aggregation-Dependent Lipid Peroxide Accumulation Driven by the hsa_circ_0001546/14-3-3/CAMK2D/Tau Complex Inhibits Epithelial Ovarian Cancer Peritoneal Metastasis

Intraperitoneal dissemination is the main method of epithelial ovarian cancer (EOC) metastasis, which is related to poor prognosis and a high recurrence rate. Circular RNAs (circRNAs) are a novel class of endogenous RNAs with covalently closed loop structures that are implicated in the regulation of tumor development. In this study, hsa_circ_0001546 is downregulated in EOC primary and metastatic tissues vs. control tissues and this phenotype has a favorable effect on EOC OS and DFS. hsa_circ_0001546 can directly bind with 14-3-3 proteins to act as a chaperone molecule and has a limited positive effect on 14-3-3 protein stability. This complex recruits CAMK2D to induce the Ser324 phosphorylation of Tau proteins, changing the phosphorylation status of Tau bound to 14-3-3 and ultimately forming the hsa_circ_0001546/14-3-3/CAMK2D/Tau complex. The existence of this complex stimulates the production of Tau aggregation, which then induces the accumulation of lipid peroxides (LPOs) and causes LPO-dependent ferroptosis. In vivo, treatment with ferrostatin-1 and TRx0237 rescued the inhibitory effect of hsa_circ_0001546 on EOC cell spreading. Therefore, based on this results, ferroptosis caused by Tau aggregation occurs in EOC cells, which is not only in Alzheimer's disease- or Parkinson's disease-related cells and this kind of ferroptosis driven by the hsa_circ_0001546/14-3-3/CAMK2D/Tau complex is LPO-dependent rather than GPX4-dependent is hypothesized.

[Risk factors of massive introperative blood loss in posterior spinal fusion for adolescent idiopathic scoliosis]

Objective: To investigate the risk factors and prognostic impact of massive introperative blood loss in posterior spinal fusion (PSF) surgery for adolescent idiopathic scoliosis (AIS). Methods: Clinical data were collected of 1 896 AIS patients who underwent PSF surgery under general anesthesia in Drum Tower Hospital Affiliated to Nanjing University Medical School from November 2010 to October 2019 and retrospectively analyzed. According to the volume of intraoperative blood loss, the patients were divided into the massive introperative blood loss group [estimated blood loss (EBL)/estimated blood volume (EBV)≥30%] and the non-massive introperative blood loss group (EBL/EBV<30%). The perioperative parameters between the two groups were compared, single factor analysis and multivariate logistic regression analysis was performed to identify independent risk factors related to massive introperative blood loss in PSF surgery. Results: A total of 1 896 AIS patients who underwent PSF surgery were included in the study. There were 298 males and 1 598 females, with an age of (14.5±1.7) years. Among them, 633 (33%) experienced massive intraoperative blood loss. The factors significantly related to the massive blood loss during PSF surgery in this study are: sex, body mass index(BMI), preoperative blood platelet count (PLT), prothrombin time, international normalized ratio(INR), preoperative Cobb angle, duration of operation, the number of fused levels, the number of screws, thoracoplasty, intraoperative use of tranexamic acid and dexmedetomidine; The independent factors included duration of operation longer than 4 hours(OR=4.311,P<0.001), the number of fused levels to be more than 10(OR=4.044,P<0.001), thoracoplasty (OR=2.174,P=0.019), BMI lower than 18.1 kg/m²(OR=2.094,P<0.001), preoperative PLT less than 186.5×10⁹/L(OR=1.480,P=0.009), preoperative INR larger than 1 (OR=1.531,P=0.003) and preoperative Cobb angle larger than 53°(OR=1.306,P=0.036) ;Intraoperative use of tranexamic acid (OR=0.770, P=0.047) and dexmedetomidine (OR=0.653, P=0.008) are protective factors for massive intraoperative blood loss. In addition, in the massive intraoperative blood loss group, length of postoperative hospital stay (P<0.001), volume of postoperative incision drainage (P<0.001), postoperative allogeneic blood transfusion rate (22.7% vs 14.3%, P<0.001), incidence of postoperative hypoalbuminemia (90.3% vs 80.7%, P<0.001) and the number of rescue opioid analgesic requirements after surgery (P=0.006) were significantly higher than those in the non-massive introperative blood loss group. Conclusions: Longer operation duration, higher number of fusion levels, lower BMI, lower preoperative PLT, higher INR, larger preoperative Cobb angle and intraoperative thoraplasty are independent risk factors for massive intraoperative blood loss in AIS patients undergoing PSF surgery. Intraoperative use of tranexamic acid and dexmedetomidine can reduce the risk of massive blood loss in PSF surgery. Massive intraoperative blood loss significantly affects the patient's prognosis.

[Risk factors for postoperative intestinal obstruction in patients undergoing robot-assisted laparoscopic radical prostatectomy]

Objective: To analyze the risk factors of postoperative intestinal obstruction (POI) in patients undergoing robot-assisted laparoscopic radical prostatectomy (RARP). Methods: The clinical data of 573 patients receiving RARP from January to December 2019 in Nanjing Drum Tower Hospital were analyzed retrospectively. According to the occurrence of POI, the cases were divided into the occurrence group and the non-occurrence group. The clinical data of the two groups were compared and the risk factors of POI were investigated by multivariate logistic regression. Results: Forty-five of 573 patients (7.9%) had POI. Between the two groups, preoperative underlying diseases (cardiopathy, COPD, hypoalbuminemia), preoperative chemotherapy, preoperative WBC, operation time, blood loss, blood transfusion rate, postoperative early fever, length of stay were statistically significant (P<0.05). Multivariable logistic regression analysis showed that heart disease (OR=2.331, P=0.036), COPD (OR=4.285, P=0.001), hypoalbuminemia(OR=2.142, P=0.026), blood loss (≥4.26 ml/kg) (OR=2.388, P=0.010), operative time (≥225 min) (OR=4.200, P<0.001), and postoperative early fever (OR=2.773, P=0.004) were independent risk factors for POI after RARP. Conclusions: The incidence of POI following RARP is related to multiple perioperative factors. Improving the preoperative heart and lung function, correcting hypoalbuminemia, reducing intraoperative bleeding, shortening the operation time, and preventing early postoperative infection may be important measures to reduce the risk of POI in RARP patients.

[Microbial Community Succession in Industrial Composting with Livestock Manure and Peach Branches and Relations with Environmental Factors]

This study sets out to understand the evolution of the microbial community structure in industrial composting with livestock manure and peach branches. Pig manure, peach branches, and decomposed organic fertilizer were used as materials for composting. Changes in physical and chemical indicators and the evolution in the structure of the compost microbial community, determined by high-throughput sequencing, were analyzed. The results of physical and chemical parameters show that the pile reached the high-temperature stage on day 2, and the thermophilic period lasted for 30 days. The changes in total carbon were volatile, and there was an overall decline in the amount of TOC in the whole process of composting; The final content of TN was 20.58 g·kg^-1, which was 5.90% lower compared to the initial compost. Alpha analysis indicated that a different microbial community diversity existed at different times during aerobic composting periods. At the bacterial phyla level, Firmicutes and Actinobacteria were the dominant phyla, and the proportion of relative abundance were 79.31%-95.09% and 2.98%-19.70%, respectively, in the entire compost. The relative abundance of Firmicutes and Actinobacteria were 87.36% and 9.66%, respectively, and their respective relative abundances were 79.38% and 19.70% at the end of composting. At the bacterial genus level, the dominant group changed from Clostridium_sensu_stricto_1, Terrisporobacter, and Bacillus to norank_f_Bacillaceae, Bacillus, Oceanbacillus, and Pseudogracilibacillus; Regarding the fungus phyla, the Ascomycota was the dominant phylum. For the fungus genus, the relative abundance of norank_c_Sordariomycetes gradually increased during composting, and finally was predominant group. The redundancy analysis (RDA) showed that the correlation rank between environmental factors and microbial community structure was:pH > NH₄⁺-N > T > TOC > TN, where pH had the greatest impact on the microbial community composition. norank_c_Sordariomycetes, norank_o_Sordariales, and norank_c_Agaricomycetes may be related to the volatilization of ammonium nitrogen.

MicroRNA-296-5p promotes healing of diabetic wound by targeting sodium-glucose transporter 2 (SGLT2)

BACKGROUND

Diabetic wounds are refractory and very difficult to heal. We aimed to use miRNA to identify novel and specific molecular markers for diabetes mellitus (DM) diagnosis and treatment.

METHODS

The expression level of miR-296-5p was determined in tissue samples of 12 DM patients. The effect of miR-296-5p on proliferation of β-cells was examined using Cell Counting Kit-8 (CCK-8) and colony formation assay. The effect of miR-296-5p on cell cycle progression was analysed using flow cytometry. The target gene was verified using luciferase reporter assay. A rat diabetes model was used to assess the effect of miR-296-5p in vivo.

RESULTS

Overexpression of miR-296-5p suppressed cell proliferation, arrested cell cycle progression, and increased the healing rate of diabetic wounds both in vivo and in vitro. TargetScan analysis results showed that miR-296-5p is a direct regulator of SGLT2.

CONCLUSIONS

miR-296-5p can increase the healing rate of diabetic wounds and may be an effective molecular tool in DM diagnosis and therapy.

Effect of RRS1 gene knockdown on BT549 cell line proliferation and apoptosis in breast cancer

The RRS1 regulator of ribosome synthesis has recently been reported a new target gene linked to cancer development. This study therefore investigates RRS1effectsb on BT549 cell proliferation and apoptosis in breast cancer. Western blot (WB) and real - time quantitative PCR (qPCR) were used to detect the relative expression of RRS1 in breast cancer cells BT-549 and the normal HMEC mammary gland epithelial cells. BT-549 cells were cultured and infected with retroviruses and RRS1 expression was detected by qPCR and WB. The MTT assay, Caspase-3/7 and flow cytometry (FCM) then detected growth and apoptosis in the BT549 breast cancer BT cell. WB detected the expression of Bcl-2 and Bax genes related to apoptosis at the protein level, and MTT assay confirmed that RRS1 knockdown significantly decreased cell viability (p<0.05) and induced apoptosis which was rescued by shRNA-RRS1 expression. The amount of caspase-3 increased significantly and apoptosis was obvious. The apoptotic cells amount analyzed by FCM was significantly increased and RRS1 knockdown also decreased the expression of apoptosis related protein bcl-2 and simultaneously increased the expression of Bax (p<0.05). Finally, the RRS1 gene was highly expressed in breast cancer cell line BT549 and its knockdown significantly reduced proliferation and apoptosis in BT549 cell. These results suggest that RRS1 is a novel gene related to breast cancer and has an important role in breast cancer proliferation and apoptosis.

MiR-146a-5p inhibits cell proliferation and cell cycle progression in NSCLC cell lines by targeting CCND1 and CCND2

Previous studies have indicated that miR-146a-5p acts as an oncogene in several types of cancer, yet a tumor suppressor gene in others. In non-small cell lung cancer (NSCLC), one report showed that it was downregulated and played the role of tumor suppressor. However, another study showed that miR-146a-5p was overexpressed in the serum of NSCLC patients compared to healthy controls. Therefore, it is obvious that further study of the function of miR-146a-5p in NSCLC is necessary to fully understand its importance. Herein, we have verified that miR- 146a- 5p acts as a tumor suppressor in NSCLC. Our data revealed that the expression level of miR-146a-5p was significantly decreased in several human NSCLC cell lines, and also less abundant in human NSCLC tissues, when compared with controls. Moreover, we observed that miR-146a-5p could suppress cell proliferation, both in vitro and in vivo. Our results also showed that miR-146a-5p directly targeted the 3′-UTR of CCND1 and CCND2 mRNAs as well as decreased their expression at both mRNA and protein levels, causing cell cycle arrest at the G0/G1 phase. Furthermore, siRNA-mediated downregulation of CCND1 or CCND2 yielded the same effects on proliferation and cell cycle arrest as miR-146a-5p upregulation did in the NSCLC cell lines. We confirmed that the expression of miR-146a-5p had negative relationship with CCND1 or CCND2. Besides, we also found that miR-146a-5p could inhibit tumor growth in xengroft mouse models, and CCND1 and CCND2 were downregulated in miR-146a-5p overexpressed xengroft tumor tissues. In summary, our results demonstrated that miR-146a-5p could suppress the proliferation and cell cycle progression in NSCLC cells by inhibiting the expression of CCND1 and CCND2.

mTOR signaling-related MicroRNAs and Cancer involvement

MicroRNAs (miRNAs) are a class of single-stranded RNAs, 18-23 nucleotides in length that regulate gene expression at the post-transcriptional level. Dysregulation of miRNAs has been closely associated with the development of cancer. In the process of tumorigenesis, mammalian target of rapamycin (mTOR) plays important roles, and the mTOR signaling pathway is aberrant in various types of human cancers, including non-small cell lung cancer (NSCLC), breast cancer, prostate cancer, as well as others. However, the relationship between miRNAs and the mTOR signaling pathway is indistinct. Herein, we not only summarize the progress of miRNAs and the mTOR signaling pathway in cancers, but also highlight their role in the diagnosis and treatment in the clinic.

Direct repression of the oncogene CDK4 by the tumor suppressor miR-486-5p in non-small cell lung cancer

MicroRNAs are a class of non-coding single-stranded RNA, 20-23 nucleotide in length, which can be involved in the regulation of gene expression. Through binding with 3′-untranslated regions (3′-UTR), microRNAs can cause degradation of target mRNAs or inhibition of translation, and thus regulating the expression of genes at the post-transcriptional level. In this study, we found that miR-486-5p was significantly downregulated in non-small cell lung cancer (NSCLC) tissues and cell lines, suggesting that miR-486-5p might function as a tumor suppressor in lung cancer. Additionally, we showed that CDK4, an oncogene that plays an important role in cell cycle G1/S phase progression, was directly targeted by miR-486-5p. Furthermore, our data reveals that knockdown of CDK4 by siRNA can inhibit cell proliferation, promote apoptosis, and impede cell-cycle progression. In epigenetics, the upstream promoter of miR-486-5p was strongly regulated by methylation in NSCLC. Collectively, our results suggest that miR-486-5p could not only inhibit NSCLC by downregulating the expression of CDK4, but also be as a promising and potent therapy in the near future.

[Risk factors associated with massive drainage after posterior spinal orthopaedic surgery for adolescent scoliosis]

Objective: To identify risk factors that influence the massive drainage after posterior spinal orthopaedic surgery for adolescent scoliosis. Methods: A total of 1 461 patients from 11 to 18 years old diagnosed with adolescent scoliosis who underwent first posterior spinal orthopaedic surgery in affiliated Drum Tower Hospital, Medical School of Nanjing University between November 2010 and October 2015 were retrospectively reviewed. Patients were categorized on the basis of massive or normal drainage, with the boundary 30(th) percentile of drainage/estimated blood volume. Preoperative factors including age, gender, body mass index(BMI), ASA physical status, diagnostic type of scoliosis, main Cobb angle, laboratory tests, intraoperative factors including the number of fusion level and screws, tranexamic acid used or not, use of osteotomy and thoracoplasty, use of cell salvage technology, duration of operation, the volume of urine output, blood loss, fluid therapy and transfusion, postoperative factors including the length of hospital stay, number of transfusion, the volume of drainage, time of drain were collected. Univariate and multivariate analyses were used to determine risk factors which were independently associated with massive drainage. Results: The average drainage was (856.3±333.4)ml. 479(32.8%) patients had massive drainage(drainage≥30% of drainage/estimated blood volume). Multivariate analysis identified risk factors of massive drainage: BMI<17.63 kg/m(2), odds ratio(OR)=2.90, preoperative platelet count<190×10(9)/L (OR=1.67), preoperative main Cobb angle≥55 degrees(OR=1.66), number of fusion levels≥11(OR=2.33), number of screws≥15(OR=1.73), use of osteotomy(OR=1.54), intraoperative volume of crystalloids≥35.63 ml/kg(OR=1.40), intraoperative volume of colloids≥28.92 ml/kg(OR=1.82), intraoperative volume of transfusion≥19.55 ml/kg(OR=1.72), while the use of tranexamic acid(OR=0.26) was the only protective factor. Conclusion: BMI<17.63 kg/m(2,) preoperative platelet count<190×10(9)/L, preoperative main Cobb angle≥55 degrees, number of fusion levels≥11, number of screws≥15, use of osteotomy, intraoperative volume of crystalloids≥35.63 ml/kg, intraoperative volume of colloids≥28.92 ml/kg, intraoperative volume of transfusion≥19.55 ml/kg were risk factors associated with massive drainage after posterior spinal orthopaedic surgery for adolescent scoliosis, while the use of tranexamic acid could decrease the possibility of massive drainage.

[Study of epidemic area on Tsutsugamushi disease in Taizhou from 2013 to 2014]

Objective: To study the epidemiological characteristics of tsutsugamushi disease, and to confirm the existence of the disease's epidemic foci in Taizhou. Methods: From 2013 to 2014, Dongxing town hospital and Xingqiao town hospital were selected as specimen collection sites in Jingjiang city. Blood samples (5 ml) were collected from 40 patients with acute tsutsugamushi disease. A total of 59 rodents were captured with cage night method in the survey sites at 5, 7, 9, 10, and 11 months in 2013, from which, the spleen, liver, and kidney specimens were selected. Chigger mites were captured by small blackboard method and from the ears of the captured rodents. A total of 226 small blackboards were laid, 27 mites were captured, and the samples were grounded into suspension. Nested-polymerase chain reaction and cell and tissue culture techniques were used to test the specimen from the probable patients, host animals and chigger mites. Results: Among the 40 acute tsutsugamushi disease blood samples, 29 were found to meet the test requirements, 17 were positive for orientia tsutsugamushi nucleic acid with 59% of the positive rate, and 1 stran orientia tsutsugamushi was isolated. 59 rats were captured and the density of mice was 5.5%. Among them, there were 26 Mus musculus (2.4%), 18 Rattus flavipectus (1.7%) and 15 Smelly shrew (density 1.4%). 1 Smelly shrew was tested positive for orientia tsutsugamushi nucleic acid, and the negative results were found in the other rodent specimens. 27 Chigge mites were collected by small blackboard method and the density of mites was 0.12 for each blackboard, among which 3 larvae and 24 nymphs were found. 33 Chigger mites were collected from the ears of 3 Smelly shrew, and the density of the mite was 11 per mouse. All the captured Chigger mites were identified as Leptotrombidium scutellare and 1 group of specimens of Chigger mites from the external environment were positive for orientia tsutsugamushi nucleic acid. Conclusion: There was a high density of mice in the epidemic area from May to November and the species of the chigger mites were Chigger mites in Taizhou. The nucleic acid of the oriental tsutsugamushi was detected in the patients with acute scrub typhus, rodents and vectors. According to the above-mentioned results, it was considered that the scrub typhus epidemic area of Taizhou city has the natural foci of scrub typhus.

Tanshinones suppress AURKA through up-regulation of miR-32 expression in non-small cell lung cancer

Tanshinone is the liposoluble constituent of Salia miltiorrhiza, a root used in traditional herbal medicine which is known to possess certain health benefits. Although it is known that tanshinones, including tanshinone I (T1), tanshinone IIA (T2A), and cryptotanshinone (CT), can inhibit the growth of lung cancer cells in vitro, the mechanism under which they act is still unclear. AURKA, an oncogene, encodes a serine-threonine kinase which regulates mitotic processes in mammalian cells. Here, we reported that tanshinones mediate AURKA suppression partly through up-regulating the expression of miR-32. We found that tanshinones could inhibit cell proliferation, promote apoptosis, and impede cell-cycle progression, thus performing an antineoplastic function in non-small cell lung cancer (NSCLC). Additionally, we demonstrated that tanshinones attained these effects in part by down-regulating AURKA, corroborating previous reports. Our results showed that in NSCLC, similar effects were obtained with knock-down of the AURKA gene by siRNA. We also verified that AURKA was the direct target of miR-32. Collectively, our results demonstrated that tanshinones could inhibit NSCLC by suppressing AURKA via up-regulating the expressions of miR-32 and other related miRNAs.

Transcriptome sequencing and analysis of the coconut leaf beetle, Brontispa longissima

The coconut leaf beetle, Brontispa longissima, is a destructive pest of palm plants. Although its ecological and biological characteristics are well understood, its genetic information remains largely unknown. To advance our understanding of its molecular ba-sis of biology and ecology, we sequenced and analyzed its whole transcriptome by using high-throughput Illumina paired-end sequencing technology. Approximately 8.08 Gb of clean reads were generated in a single run, which were assembled by using Trinity into 41,652 unigenes with an average length of 932 bp. By sequence similarity searches for known proteins, 23,077 (55.4%) unigenes were annotated by BLASTx searches against the NCBI non-redundant protein database. Of the unigenes assembled, 18,153 and 13,733 were assigned to Gene Ontology and Clusters of Orthologous Groups of proteins, respectively. In addition, 10,415 unigenes were mapped onto 247 pathways using the Kyoto Encyclopedia of Genes and Genomes Pathway database. These transcriptomic resources will facilitate gene identification and elucidate the molecular mechanisms of biological and ecological aspects under-lying this palm pest, in order to design a new control strategy.

Immunization with mutant HPV16 E7 protein inhibits the growth of TC-1 cells in tumor-bearing mice

Two human papillomavirus (HPV) 16 oncogenic proteins, E6 and E7, are co-expressed in the majority of HPV16-induced cervical cancer cells. Thus, the E6 and E7 proteins are good targets for developing therapeutic vaccines for cervical cancer. In the present study, immunization with the mutant non-transforming HPV16 E7 (mE7) protein was demonstrated to inhibit the growth of TC-1 cells in the TC-1 mouse model. The HPV16 mE7 gene was amplified by splicing overlap extension polymerase chain reaction using pET-28a(+)-E7 as a template, and the gene was cloned into pET-28a(+) to form pET-28a(+)-mE7. Compared with the E7 protein, mE7 lacks amino acid residues 94–98, and at residue 24, there is a Cys to Gly substitution. pET-28a(+)-mE7 was then introduced into Escherichia coli Rosetta. The expression of mE7 was induced by isopropyl β-D-1-thiogalactopyranoside. The mE7 protein was purified using Ni-NTA agarose and detected by SDS-PAGE and western blot analysis. In the tumor prevention model, no tumor was detected in the mice vaccinated with the mE7 protein. After 40 days, the tumor-free mice and control mice were challenged with 2×10⁵ TC-1 cells. All control mice developed tumors six days later, but mE7 immunized mice were tumor free until 90 days. In the tumor therapy model, the TC-1 cells were initially injected subcutaneously, and the mice were subsequently vaccinated. Vaccination against the mE7 protein may significantly inhibit TC-1 cell growth compared to the control. These results demonstrated that immunization with the HPV16 mE7 protein elicited a long-term protective immunity against TC-1 tumor growth and generated a significant inhibition of TC-1 growth in a TC-1 mouse model.

MicroRNA-34a inhibits the proliferation and promotes the apoptosis of non-small cell lung cancer H1299 cell line by targeting TGFβR2

MicroRNAs (MiRNAs) are small non-coding RNA molecules which act as important regulators of post-transcriptional gene expression by binding 3'-untranslated region (3'-UTR) of target messenger RNA (mRNA). In this study, we analyzed miRNA-34a (miR-34a) as a tumor suppressor in non-small cell lung cancer (NSCLC) H1299 cell line. The expression level of miR-34a in four different NSCLC cell lines, H1299, A549, SPCA-1, and HCC827, was significantly lower than that in the non-tumorigenic bronchial epithelium cell line BEAS-2B. In human NSCLC tissues, miR-34a expression level was also significantly decreased in pT2-4 compared with the pT1 group. Moreover, miR-34a mimic could inhibit the proliferation and triggered apoptosis in H1299 cells. Luciferase assays revealed that miR-34a inhibited TGFβR2 expression by targeting one binding site in the 3'-UTR of TGFβR2 mRNA. Quantitative real-time PCR (qRT-PCR) and Western blot assays verified that miR-34a reduced TGFβR2 expression at both mRNA and protein levels. Furthermore, downregulation of TGFβR2 by siRNA showed the same effects on the proliferation and apoptosis as miR-34a mimic in H1299 cells. Our results demonstrated that miR-34a could inhibit the proliferation and promote the apoptosis of H1299 cells partially through the downregulation of its target gene TGFβR2.

Collisional 3He and 129Xe frequency shifts in Rb-noble-gas mixtures

The Fermi-contact interaction that characterizes collisional spin exchange of a noble gas with an alkali-metal vapor also gives rise to NMR and EPR frequency shifts of the noble-gas nucleus and the alkali-metal atom, respectively. We have measured the enhancement factor κ0 that characterizes these shifts for Rb-129Xe to be 493±31, making use of the previously measured value of κ0 for Rb-3He. This result allows accurate 129Xe polarimetry with no need to reference a thermal-equilibrium NMR signal.

Mutation analysis of BRIP1/BACH1 in BRCA1/BRCA2 negative Chinese women with early onset breast cancer or affected relatives

The proper interaction between BRIP1/BACH1 and BRCA1 protein has been found to be crucial for BRCA1-mediated DNA double-strand break repair and BRIP1/BACH1 mutations were estimated to confer a relative risk for breast cancer of 2.0 in western populations. In Chinese population, BRCA1 mutations could explain a relatively large proportion of inherited breast cancer cases in comparison with BRCA2 mutations, which probably deduced a hypothesis that those genes involved in BRCA1-mediated DNA repair pathway might play a more significant role in the etiology of Chinese breast cancer. To investigate the contribution of BRIP1/BACH1 mutations to the predisposition of Chinese non-BRCA1/BRCA2 hereditary breast cancer, we screened all the coding exons and adjacent intronic splice junction regions of BRIP1/BACH1 in 357 Chinese women with early-onset breast cancer or affected relatives from five different breast disease clinical centers in China, using PCR-DHPLC and DNA sequencing analysis. Some genetic variants identified in the cases were then studied in 864 normal controls with no personal or family history of breast cancer. We found no protein-truncated mutations in our population, while a novel recurrent non-synonymous variant, Q944E, was detected in two independent families in contrast with none in the controls, interestingly, this alteration occurs in the BRCA1 binding domain of the BACH1 protein. Then a further study performed on the two mutation positive families revealed the partial co-segregation of this mutation allele with cancer. The novel alteration Q944E identified in our study possibly represents a rare disease-related allele, nevertheless functional analysis is still warranted to resolve the ability of this altered BACH1 protein to bind BRCA1. Altogether, the results of our study indicated that germline mutations in BRIP1/BACH were extremely rare in Chinese population and there was no evidence for the recommendation of BRIP1/BACH1 for genetic testing in Chinese.

[Progress of miRNA and its functions in eukaryotes]

Two major kinds of non-coding RNAs play important roles in eukaryotes. One is microRNA (miRNA), the other is small interference RNA (siRNA). miRNA, 19-25 nt in length, functions in regulation of gene expression and development. Many kinds of miRNAs and some proteins assemble in a complex, miRNP, where miRNA gives its function, siRNA directs the target mRNA in RNA interference (RNAi). Some distinct differences are existed between miRNA and siRNA. The regulation mechanism of miRNA may be conserved in eukaryotes.

[A study on the organization and management of pulmonary tuberculosis case-finding at district general hospitals]

As the prevalence of tuberculosis has been improved after the implementation of tuberculosis control programme especially chemotherapy for a certain period of time, a study of promotion of case-finding activities in general hospitals of the district level was carried out in 1986-1988 in an urban district of Beijing. After special training and motivation to the physicians and health workers involved, their basic knowledge and new concepts of tuberculosis control were promoted. There were seven targets for both quantity and quality control and evaluation of case-findings. After implementation of plan about 75% of active pulmonary tuberculosis and all sputum smear positive cases were detected among suspects with respiratory symptoms. Doctor's delay were much improved from 54.7% in 1986 to only 5.9% in 1988.