Immunotherapy: A new target for cancer cure (Review).

Cancer is the leading cause of death globally and there is a worldwide cancer epidemic. Immunotherapy has emerged as a promising anticancer therapy. In particular, oncolytic viruses destroy cancer cells without destroying normal tissue via viral self­replication and anti­tumor immune responses, showing potential for cancer therapy. The present review discusses the role of the immune system in the treatment of tumor. The strategies for treating tumors are briefly introduced from aspects of active immunization and passive immunotherapy and the dendritic cell vaccines and oncolytic viruses are highlighted, as well as use of blood group A antigen in the treatment of solid tumors.

Comparison of genetic diversity between ancient and common populations of Docynia delavayi (Franch.) Schneid.

Docynia delavayi (Franch.) Schneid. (D. delavayi), is a wild fruit tree which combines edible, medicinal, ecological and ornamental uses. In this study, ancient and common populations of D. delavayi were examined for genetic diversity and structure using SSR markers. As a result, a total of 136 alleles were detected at 18 SSR loci, with the mean of 7.56 alleles. The value of Na, Ne, I, He and Nm of the ancient populations were lower than those of the common populations except for Ho and Fst. It indicates that the genetic diversity of the common populations is higher than that in ancient populations. The genetic differences between ancient populations were slightly greater than those between common populations, which demonstrated less gene flow between ancient populations. According to the analysis of molecular variance (AMOVA), the genetic variation within the common population was greater than that in the ancient population, indicating that there was a higher genetic diversity within the common population. Also, the clustering heatmap results are partially consistent with the principal coordinate analysis (PCoA) results. Moreover, the mantel test showed an extremely significant correlation between genetic and geography distance (r = 0.214, p < 0.0001). Based on this work, we proposed strategies for protecting, which offers a theoretical basis for their effective utilization and conservation of D. delavayi ancient tree resources.

[Chloroplast genome phylogeny and codon preference of Docynia longiunguis].

Docynia longiunguis is a plant uniquely present in China and is of high edible and medicinal value. The analysis of its chloroplast genome will help clarify the phylogenetic relationship among Docynia and facilitate the development and utilization of D. longiunguis resources. Based on the alignment of chloroplast genome sequences of related species, the phylogeny and codon preference were analyzed. The total length of D. longiunguis chloroplast genome sequence was 158 914 bp (GenBank accession number is MW367027), with an average GC content of 36.7%. The length of the large single-copy (LSC), the small single-copy (SSC), and inverted repeats (IRs) are 87 020 bp, 19 156 bp, and 26 369 bp, respectively. A total of 102 functional genes were annotated, including 72 protein-coding genes, 26 tRNA genes, and 4 rRNA genes. The best model for constructing phylogenetic tree was TVM+F+R2. D. longiunguis and Docynia indica were clustered into a single group, while Docynia and Malus were clustered into a single group. Comparison of the chloroplast genome sequences of D. longiunguis and its five related species revealed that trnY (GUA)-psbD, ndhC-trnV (UAC), accD-psaI, psbZ-trnfM (CAU), ndhF-trnL gene regions varied greatly. The nucleic acid diversity analysis showed that there were 11 high variation areas with nucleotide variability > 0.01, all were located in the LSC and SSC regions. Except for D. longiunguis, the trnH genes in other sequences were located at the IRs/LSC junction and did not cross the boundary. Codon preference analysis showed that D. longiunguis chloroplast genome has the largest number of isoleucine (Ile) codons, up to 1 205. D. longiunguis has the closest genetic relationship with Malus baccata, Malus sieboldii, Malus hupehensis and Chaenomeles sinensis. Its chloroplast genome codon prefers to end with A/T. The chloroplast genome of D. longiunguis and other Rosaceae chloroplast genomes showed great differences in gene distribution in four boundary regions, while relatively small differences from the chloroplast genomes of Docynia delavayi and D. indica of the same genus were observed. The genome annotation, phylogenetic analysis and sequence alignment of chloroplast genome of D. longiunguis may facilitate the identification, development and utilization of this species.

Application of Circulating Tumor DNA as a Biomarker for Non-Small Cell Lung Cancer.

BACKGROUND: Non-small cell lung cancer (NSCLC) is one of the most prevalent causes of cancer-related death worldwide. Recently, there are many important medical advancements on NSCLC, such as therapies based on tyrosine kinase inhibitors and immune checkpoint inhibitors. Most of these therapies require tumor molecular testing for selecting patients who would benefit most from them. As invasive biopsy is highly risky, NSCLC molecular testing based on liquid biopsy has received more and more attention recently. OBJECTIVE: We aimed to introduce liquid biopsy and its potential clinical applications in NSCLC patients, including cancer diagnosis, treatment plan prioritization, minimal residual disease detection, and dynamic monitoring on the response to cancer treatment. METHOD: We reviewed recent studies on circulating tumor DNA (ctDNA) testing, which is a minimally invasive approach to identify the presence of tumor-related mutations. In addition, we evaluated potential clinical applications of ctDNA as blood biomarkers for advanced NSCLC patients. RESULTS: Most studies have indicated that ctDNA testing is critical in diagnosing NSCLC, predicting clinical outcomes, monitoring response to targeted therapies and immunotherapies, and detecting cancer recurrence. Moreover, the changes of ctDNA levels are associated with tumor mutation burden and cancer progression. CONCLUSION: The ctDNA testing is promising in guiding the therapies on NSCLC patients.

Predicting Cancer Tissue-of-Origin by a Machine Learning Method Using DNA Somatic Mutation Data.

Patients with carcinoma of unknown primary (CUP) account for 3-5% of all cancer cases. A large number of metastatic cancers require further diagnosis to determine their tissue of origin. However, diagnosis of CUP and identification of its primary site are challenging. Previous studies have suggested that molecular profiling of tissue-specific genes could be useful in inferring the primary tissue of a tumor. The purpose of this study was to evaluate the performance somatic mutations detected in a tumor to identify the cancer tissue of origin. We downloaded the somatic mutation datasets from the International Cancer Genome Consortium project. The random forest algorithm was used to extract features, and a classifier was established based on the logistic regression. Specifically, the somatic mutations of 300 genes were extracted, which are significantly enriched in functions, such as cell-to-cell adhesion. In addition, the prediction accuracy on tissue-of-origin inference for 3,374 cancer samples across 13 cancer types reached 81% in a 10-fold cross-validation. Our method could be useful in the identification of cancer tissue of origin, as well as the diagnosis and treatment of cancers.