Tracing back of relapse clones by Ig/TCR gene rearrangements reveals complex patterns of recurrence in pediatric acute lymphoblastic leukemia

INTRODUCTION

Relapse remained the major obstacle to improving the prognosis of children with acute lymphoblastic leukemia (ALL). This study aimed to investigate the changing patterns of Ig/TCR gene rearrangements between diagnosis and relapse and the clinical relevance and to explore the mechanism of leukemic relapse.

METHODS

Clonal Ig/TCR gene rearrangements were screened by multiplex PCR amplification in 85 paired diagnostic and relapse bone marrow (BM) samples from children with ALL. The new rearrangements presented at relapse were quantitatively assessed by the RQ-PCR approach targeting the patient-specific junctional region sequence in 19 diagnostic samples. The relapse clones were further back-traced to diagnostic and follow-up BM samples from 12 patients.

RESULTS

Comparison of Ig/TCR gene rearrangements between diagnosis and relapse showed that 40 (57.1%) B-ALL and 5 (33.3%) T-ALL patients exhibited a change from diagnosis to relapse, and 25 (35.7%) B-ALL patients acquired new rearrangements at relapse. The new relapse rearrangements were present in 15 of the 19 (78.9%) diagnostic samples as shown by RQ-PCR, with a median level of 5.26 × 10-2 . The levels of minor rearrangements correlated with B immunophenotype, WBC counts, age at diagnosis, and recurrence time. Furthermore, back-tracing rearrangements in 12 patients identified three patterns of relapse clone dynamics, which suggested the recurrence mechanisms not only through clonal selection of pre-existing subclones but also through an ongoing clonal evolution during remission and relapse.

CONCLUSION

Backtracking Ig/TCR gene rearrangements in relapse clones of pediatric ALL revealed complex patterns of clonal selection and evolution for leukemic relapse.

Identification and characterization of cotton PHYTOCHROME-INTERACTING FACTORs in temperature-dependent flowering

PHYTOCHROME INTERACTING FACTORs (PIFs) assimilate with light and temperature signs to control plant growth and development. However, little is known about PIFs in crop plants such as cotton. Here, we identified 68 PIF proteins and their coding genes from an allotetraploid and three diploid ancestors. Cotton PIFs contain typical APA and APB motifs by means of which they bind to phytochrome phyA and phyB, respectively, and have a bHLH domain and a nuclear localization sequence necessary for bHLH-type transcription factors. Bioinformatics analysis showed that the promoter of each PIF gene contains multiple cis-acting elements and that the evolution of cotton genomes likely underwent loss, recombination, and tandem replication. Further observations indicated that the sensitivity of cotton PIF expression to low or high temperature was significantly different, of which allotetraploid Gossypium hirsutum PIF4a (GhPIF4a) was induced by high temperature. GhPIF4a promotes flowering in cotton and Arabidopsis and binds to the promoter of GhFT (FLOWERING LOCUS T) increasing with temperature rise. In conclusion, our work identifies the evolutionary and structural characteristics and functions of PIF family members in cotton.

Interaction between CASP8AP2 and ZEB2-CtBP2 Regulates the Expression of LEF1

Low expression of CTBP2 and CASP8AP2 correlated with poor outcome and predicted risk of relapse in pediatric B-cell acute lymphoblastic leukemia (B-ALL). This study aimed to investigate the molecular mechanism by which CASP8AP2 regulates LEF1 expression by interacting with CtBP2 and ZEB2 in Acute lymphoblastic lymphoma (ALL). There was an interaction between CASP8AP2, ZEB2, and CtBP2, and then the interaction between CtBP2 and ZEB2 was observed after downregulating the expression of CASP8AP2. The wild type (containing the ZEB2 binding site) or mutant (containing a mutant binding site) LEF1 gene promoter sequence was inserted into the pGL3-basic plasmid, and a dual-luciferase reporter gene detection system was used to observe how CASP8AP2, ZEB2, and CtBP2 regulate the transcription of the LEF1 gene. We conclude that CASP8AP2, CtBP2, and ZEB2 can all bind to the LEF1 gene promoter region and reduce the luciferase activity of the LEF1 promoter. Meanwhile, the interaction of ZEB2 and the LEF1 promoter was significantly weakened after downregulation of CASP8AP2. Knockdown of CASP8AP2 in the 697 cell lines resulted in the significant upregulation of the mRNA expression levels of the stemness-related genes CD44, JAG1, and SALL4. In conclusion, CASP8AP2 is vital for the interaction between CtBP2 and ZEB2, inhibiting LEF1 and stemness-related genes expression ALL.Supplemental data for this article is available online at https://doi.org/10.1080/08880018.2022.2033369 .

Effect of 1-aminocyclopropane-1-carboxylic acid accumulation on Verticillium dahliae infection of upland cotton

BACKGROUND

Verticillium wilt of cotton is a serious disease caused by the infection of soil borne fungus Verticillium dahliae Kleb, and the infection mechanisms may involve the regulation of phytohormone ethylene. The precursor of ethylene biosynthesis is 1-aminocyclopropane-1-carboxylic acid (ACC), whose biosynthesis in vivo depends on activation of ACC synthase (ACS). Here, we investigated how ACS activation and ACC accumulation affected the infection of V. dahliae strain Vd991 on cotton (Gossypium hirsutum L.) cultivar YZ1.

RESULTS

Preliminary observations indicated that ACC applications reduced the disease incidence, disease index and stem vascular browning by impeding fungal biomass accumulation. Transcriptome and qRT-PCR data disclosed that Vd991 induced GhACS2 and GhACS6 expression. GhACS2- or GhACS6-overexpressing transgenic YZ1 lines were generated, respectively. In a Verticillium disease nursery with about 50 microsclerotia per gram of soil, these ACC-accumulated plants showed decreased disease indexes, stem fungal biomasses and vascular browning. More importantly, these transgenic plants decreased the green fluorescent protein-marked Vd991 colonization and diffusion in root tissues. Further, either ACC treatment or ACC-accumulating cotton plants activated salicylic acid (SA)-dependent resistance responses.

CONCLUSIONS

The GhACS2- and GhACS6-dependent ACC accumulations enhanced the resistance of cotton to V. dahliae in a SA-dependent manner, and this lays a foundation for cotton resistance breeding.

[Functional polymorphism sites in non-coding regions of folate metabolism-related genes in the reproductive-aged population of Hubei Province]

Objective

To investigate the distribution of the functional polymorphisms in the non-coding regions of folate metabolism-related genes in the reproductive-aged population of Hubei Province.

METHODS

Using Sanger sequencing, we examined the polymorphisms of the genes MTR (rs28372871 and rs1131450), MTRR (rs326119) and CBS (rs2850144) in 790 subjects before and during pregnancy from April 2020 to March 2021. We compared the distributions of the four loci between different populations.

RESULTS

The distributions of the four genotypes of rs28372871, rs1131450, rs326119 and rs2850144 all conformed to the Hardy-Weinberg equilibrium (HWE). Statistically significant differences were observed in the polymorphism distribution of rs28372871 between Hubei and Jiangsu (P < 0.05), in that of rs1131450 between Hubei and Shanghai (P < 0.05), and in that of rs2850144 between Hubei and Yazd, Iran (P < 0.01).

CONCLUSIONS

This was the first investigation on the distribution of MTR, MTRR and CBS gene polymorphisms in the reproductive-aged population of Hubei Province. The effects of the functional loci in both encoding and non-coding regions of folate metabolism-related genes have to be comprehensively considered so as to formulate an appropriate folate-supplementary protocol.

Correlation of trauma and cause of death to accident reconstruction: a case of a flight accident report

This paper reports on the disaster that occurred after a flight was hijacked at Baiyuen International Airport in Guangzhou, China, on Tuesday, 2 Oct. 1990. The authors show the results of analyses for the causes of death and trauma and compare the disaster with several previous flight accidents that have occurred in China. The authors show, with the analysis on this accident, the possibility and reliability of reconstructing a disaster by medicolegal investigation.