Brain metastasis was a common metastasis site and leading cause of death in non-small cell lung cancer (NSCLC). Tyrosine kinase inhibitors had improved survival of NSCLC patients with positive drive gene. It also brings good news to NSCLC patients with positive drive gene and brain metastases. However, there is still no effective treatment for NSCLC patients with drive gene-negative and brain metastases. In recent years, immunotherapy has made breakthrough progress and become important first and second line treatment options of NSCLC especially in patients with drive gene-negative. The role of immunotherapy in specific populations of NSCLC-brain metastasis patients, especially drive gene-negative patients has become the focus of attention. In this report, we review the research progress of immunotherapy in NSCLC with brain metastases, especially in driver-negative patients, analyze the limitations of existing research and future challenge.
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Brain Neoplasms ; immunology ; secondary ; therapy ; Carcinoma, Non-Small-Cell Lung ; genetics ; pathology ; Humans ; Immunotherapy ; methods ; Lung Neoplasms ; genetics ; pathology ; Patient Selection

OBJECTIVETo assess the impact of natural selection and genetic background on the polymorphisms of HLA-G 3-untranslated regions (UTR) among five ethnic Chinese populations.

METHODSPCR and DNA sequencing were used to determine the polymorphisms among 432 individuals from the five ethnic populations. Their genetic background was determined by genotyping of 10 short tandem repeats (STRs).

RESULTSEight variations were identified among Gelao, Mongolian and Kirgiz populations, while only 7 were found in Shui and Dai people. For all 3 southern populations (Gelao, Shui, and Dai), the observed heterozygosites (Ho) was higher than expected heterozygosities (He). But this was reversed for the 2 northern populations (Mongolian and Kirgiz). The Ho and He of the 10 neutral STRs were in random distribution. Ewens-Watterson testing based on haplotypes of the HLA-G 3'UTR has suggested that a natural selection had occurred in the region where Dai and Shui had inhabited, but not in the northern region where Mongolian and Kirgiz population inhabited. Polygenetic trees based on the HLA and STRs were also different.

CONCLUSIONThe HLA-G 3'UTR of Dai and Shui people who lived in southern China may have subjected to a selection pressure. Based on current knowledge, this pressure may have been driven by a pathogenic selection.

3' Untranslated Regions ; genetics ; China ; ethnology ; Female ; HLA-G Antigens ; genetics ; Humans ; Male ; Microsatellite Repeats ; Polymorphism, Genetic ; Selection, Genetic

We investigated the genetic diversity and evolution of the M gene of human influenza A viruses in Hangzhou (Zhejiang province, China) from 2009 to 2013, including subtypes of A(H1N1) pdm09 strains and seasonal A(H3N2) strains. Subtypes of analyzed viruses were identified by cell culture and real-time reverse transcription-polymerase chain reaction, followed by cloning, sequencing and phylogenetic analyses of the M gene. Assessment of 5675 throat swabs revealed a positive rate for the influenza virus of 20.46%, and 827 cases were diagnosed as. infections due to influenza A viruses. Seventy-six influenza-A strains were selected randomly from nine stages during six phases of a virus epidemic. Sequences of the M gene showed high homology among six epidemics with identities of amino-acid sequences of 98.98-100%. All strains contained the adamantine-resistant mutation S31N in its M2 protein. Two of the A(H1N1)pdm09 strains had double mutants of V27A/S31N or V271/S31N. One of the seasonal A(H3N2) viruses had another form of double-mutant R45H/S31N. Evolutionary rate of the M gene was much lower than that of the HA gene and NA gene. Compared with A(H3N2) strains, higher positive pressure on the M1 and M2 proteins of A(H1N1) pdm09 viruses was observed. Separate analyses of M1 and M2 proteins revealed very different selection pressures. Knowledge of the genetic diversity and evolution of the M gene of human influenza-A viruses will be valuable for the control and prevention of diseases.
Amino Acid Substitution ; China ; epidemiology ; Evolution, Molecular ; Genetic Variation ; Humans ; Influenza A Virus, H1N1 Subtype ; classification ; genetics ; isolation & purification ; Influenza A Virus, H3N2 Subtype ; classification ; genetics ; isolation & purification ; Influenza, Human ; epidemiology ; virology ; Phylogeny ; Selection, Genetic ; Viral Matrix Proteins ; genetics ; Viral Proteins ; chemistry ; genetics

One of the main topics in population genetics is identification of adaptive selection among populations. For this purpose, population history should be correctly inferred to evaluate the effect of random drift and exclude it in selection identification. With the rapid progress in genomics in the past decade, vast genome-scale variations are available for population genetic analysis, which however requires more sophisticated models to infer species' demographic history and robust methods to detect local adaptation. Here we aim to review what have been achieved in the fields of demographic modeling and selection detection. We summarize their rationales, implementations, and some classical applications. We also propose that some widely-used methods can be improved in both theoretical and practical aspects in near future.
Adaptation, Physiological ; genetics ; Demography ; Evolution, Molecular ; Genetics, Population ; Genome ; Models, Genetic ; Polymorphism, Genetic ; Selection, Genetic ; genetics

Pdm09 virus outbreak occurred in Mainland China in May 2009, a few months later, the prevalence of seasonal H1N1(sH1N1) influenza virus that already circulated in human for tens of years began to decline and disappeared afterwards. To identify the reason for the rapid decline of sH1N1 in mainland China, we sequenced the HA1 of sH1N1 during 2006-2011, and then analyzed the selective pressure in different phases. Our results showed before Pdm09 outbreak, the omega value was 0. 36 while after Pdm09 outbreak the omega value was 0. 28 and significant difference (t test, P<0. 05) was identified. We concluded that sH1N1 obtained stronger purifying selection after Pdm09 outbreak in China. This might one of the major reasons causing the disappearance of sH1N1 in human.
China ; Humans ; Influenza A Virus, H1N1 Subtype ; classification ; genetics ; isolation & purification ; Influenza, Human ; virology ; Phylogeny ; Seasons ; Selection, Genetic

Epidermal growth factor receptor (EGFR) is an attractive target for tumor therapy because it is overexpressed in the majority of solid tumors and the increase in receptor expression levels has been linked with a poor clinical prognosis. Also it is well established that blocking the interaction of EGFR and the growth factors could lead to the arrest of tumor growth and possibly result in tumor cell death. A13 is a murine monoclonal antibody (mAb) that specifically binds to various sets of EGFR-expressing tumor cells and inhibits EGF-induced EGFR phosphorylation. We isolated human immunoglobulin genes by guided selection based on the mAb A13. Four different human single chain Fvs (scFvs) were isolated from from hybrid scFv libraries containing a human VH repertoire with the VL of mAb A13 and a human VL repertoire with the VH of mAb A13. All the 4 scFvs bound to EGFR-expressing A431 cells. One scFv (SC414) with the highest affinity was converted to IgG1 (ER414). The ER414 exhibited ~17 fold lower affinity compared to the A13 mAb. In addition the ER414 inhibited an EGF-induced tyrosine phosphorylation of EGFR with much lower efficacy compared to the A13 mAb and Cetuximab (Merck KgaA, Germany). We identified that the epitope of A13 mAb is retained in ER414. This approach will provide an efficient way of converting a murine mAb to a human mAb.
Animals ; Antibodies, Monoclonal, Humanized/*genetics/immunology/therapeutic use ; Antibody Affinity ; Cell Line, Tumor ; Directed Molecular Evolution/*methods ; Epitope Mapping ; Epitopes/genetics/immunology/therapeutic use ; Humans ; *Immunotherapy ; Mice ; Neoplasms/*therapy ; Phosphorylation/drug effects ; Protein Binding ; Receptor, Epidermal Growth Factor/*antagonists & inhibitors/immunology ; Selection, Genetic ; Single-Chain Antibodies/*genetics/immunology/therapeutic use

OBJECTIVETo analyze the human leukocyte antigens(HLA)-A, -B, -Cw, -DRB1 and DQB1 nucleotide sequences between patients waiting for allogenic hematopoietic stem-cell transplantation (HSCT) and donors in Chinese population, and to establish strategy for maximizing optimal donor selection.

METHODSHLA high-resolution typing in a total of 537 recipient-donor pairs was determined by sequence based typing (SBT) method. The nucleotide BLAST tool was used to compare the nucleotide sequences among recipient-donor pairs.

RESULTSOnly 16.20% (88/537) of recipient-donor pairs were found to fully match for nucleotide sequences of all HLA-A,-B,-Cw, -DRB1 and -DQB1 loci. Mismatch rate in single locus were 8.38% in HLA-A, 0.74% in HLA-B, 12.29% in HLA-C, 2.42% in HLA-DRB1, and 2.79% in HLA-DQB1, respectively. Mismatch rate in two or multiple HLA loci was 42.65%. Nonpermissive allele mismatch combinations (A 02:01-A 02:06, A 02:06-A 02:07, Cw 03:04-Cw 15:02, Cw 03:03-Cw 04:01, Cw 03:04-Cw 14:02, Cw 03:03-Cw 08:01, DRB1 04:03:01-DRB1 04:05) were detected in single mismatch HLA locus of recipient-donor pairs, mismatches of B 07:05:01-B 07:06, Cw 07:01:01-Cw 07:06 combinations outside of epitope positions were detected in two recipient-donor pairs.

CONCLUSIONOur data suggested that attention should be paid in comparing nucleotide sequences between recipient and donor, and in distinguishing nucleotide sequence mismatches within and outside of the epitope positions. These results could serve as guidelines for donor selection.

Base Sequence ; Donor Selection ; methods ; Epitopes ; genetics ; HLA Antigens ; genetics ; Hematopoietic Stem Cell Transplantation ; methods ; Humans ; Tissue Donors

BACKGROUNDThe mechanisms of action of volatile anesthetics are still unknown. Recently, the use of genetics as a means to investigate anesthetic action has increased in scale. However, only limited forward genetic approach studies were performed in mammals, especially with volatile anesthetics as the selection agent. In the present study, a selective breeding process was designed to produce strains of mice with different sensitivity to isoflurane.

METHODSOne hundred and sixty male and female virgin outbred ICR/CD-1 mice at 65 - 70 days of age were selected as original generation, and the median effective dose (ED(50)) of inhaled isoflurane were measured by probit analysis with the loss of righting reflex as the endpoint of anesthesia. The most sensitive males and females were selected and mated one another randomly, as with the most resistant males and females. Thus two branches of mice (sensitive and resistant to isoflurane) were created and allowed to produce the next generation. At 65 - 70 days of age, screening experiment was performed in offspring, by selecting the most sensitive mice in sensitive branch and the most resistant mice in resistant branch. Selected males and females within each branch were mated one another randomly to produce the following generation. The same procedure was performed in the offspring. The process of screening and breeding was repeated for 8 generations, and then strains were conserved by mating the offspring one another randomly within each branch for 3 generations. Each pair of mice was allowed to produce the second litters as a backup, and isoflurane ED(50) was measured in mice from the second litters.

RESULTSIsoflurane righting reflex ED(50)s (95% confidence limit (CL)) in original mice were 0.65% (0.58% - 0.72%) in females and 0.63% (0.56% - 0.69%) in males. After the 4th generation, isoflurane ED(50)s in resistant branch were significantly higher than those in sensitive branch (P < 0.05), for both in females and males. In the 11th generation, isoflurane ED(50) in the two branches differed by 32% in females and 36% in males.

CONCLUSIONSAfter 8 generations of selective breeding and 3 generations of strain conservation, two strains of mice with high and low sensitivity to isoflurane were developed. The separation of inhaled anesthetic requirement in parents could be transferred to the offspring in mice.

Anesthetics, Inhalation ; therapeutic use ; Animals ; Breeding ; methods ; Female ; Isoflurane ; therapeutic use ; Male ; Mice ; Mice, Inbred ICR ; Reflex ; drug effects ; Selection, Genetic ; genetics

Plant Dicer-like (DCL) and Argonaute (AGO) are the key enzymes involved in anti-virus post-transcriptional gene silencing (AV-PTGS). Here we show that AV-PTGS exhibited nucleotide preference by calculating a relative AV-PTGS efficiency on processing viral RNA substrates. In comparison with genome sequences of dicot-infecting Turnip mosaic virus (TuMV) and monocot-infecting Cocksfoot streak virus (CSV), viral-derived small interfering RNAs (vsiRNAs) displayed positive correlations between AV-PTGS efficiency and G+C content (GC%). Further investigations on nucleotide contents revealed that the vsiRNA populations had G-biases. This finding was further supported by our analyses of previously reported vsiRNA populations in diverse plant-virus associations, and AGO associated Arabidopsis endogenous siRNA populations, indicating that plant AGOs operated with G-preference. We further propose a hypothesis that AV-PTGS imposes selection pressure(s) on the evolution of plant viruses. This hypothesis was supported when potyvirus genomes were analysed for evidence of GC elimination, suggesting that plant virus evolution to have low GC% genomes would have a unique function, which is to reduce the host AV-PTGS attack during infections.
Arabidopsis ; enzymology ; genetics ; virology ; Base Composition ; Dactylis ; enzymology ; genetics ; virology ; Genes, Plant ; Genes, Viral ; Models, Genetic ; Mustard Plant ; enzymology ; genetics ; virology ; Plant Diseases ; genetics ; virology ; Plant Proteins ; metabolism ; Plant Viruses ; genetics ; pathogenicity ; Plants ; enzymology ; genetics ; virology ; Potyvirus ; genetics ; pathogenicity ; RNA Interference ; RNA, Plant ; genetics ; RNA, Small Interfering ; chemistry ; genetics ; metabolism ; RNA, Viral ; chemistry ; genetics ; metabolism ; RNA-Induced Silencing Complex ; metabolism ; Ribonuclease III ; metabolism ; Selection, Genetic ; Substrate Specificity

DNA barcoding is a powerful approach for characterizing species of organisms, especially those with almost identical morphological features, thereby helping to to establish phylogenetic relationships and reveal evolutionary histories. In this study, we chose a 648-bp segment of the mitochondrial gene, cytochrome c oxidase subunit 1 (COI), as a standard barcode region to establish phylogenetic relationships among brine shrimp (Artemia) species from major habitats around the world and further focused on the biodiversity of Artemia species in China, especially in the Tibetan Plateau. Samples from five major salt lakes of the Tibetan Plateau located at altitudes over 4,000 m showed clear differences from other Artemia populations in China. We also observed two consistent amino acid changes, 153A/V and 183L/F, in the COI gene between the high and low altitude species in China. Moreover, indels in the COI sequence were identified in cyst and adult samples unique to the Co Qen population from the Tibetan Plateau, demonstrating the need for additional investigations of the mitochondrial genome among Tibetan Artemia populations.
Animals ; Artemia ; classification ; genetics ; Base Sequence ; China ; DNA, Mitochondrial ; chemistry ; genetics ; Electron Transport Complex IV ; genetics ; Genetic Variation ; Molecular Sequence Data ; Phylogeny ; Selection, Genetic ; Sequence Analysis, DNA ; Sequence Homology, Nucleic Acid ; Tibet