Deletion of the transcriptional regulator TFAP4 accelerates c-MYC-driven lymphomagenesis

Advancing the genetic engineering toolbox by combining AsCas12a knock-in mice with ultra-compact screening

Cas12a is a next-generation gene editing tool that enables multiplexed gene targeting. Here, we present a mouse model that constitutively expresses enhanced Acidaminococcus sp. Cas12a (enAsCas12a) linked to an mCherry fluorescent reporter. We demonstrate efficient single and multiplexed gene editing in vitro, using primary and transformed cells from enAsCas12a mice. We further demonstrate successful in vivo gene editing, using normal and cancer-prone enAsCas12a stem cells to reconstitute the haematopoietic system of wild-type mice. We also present compact, genome-wide Cas12a knockout libraries, with four crRNAs per gene encoded across one (Scherzo) or two (Menuetto) vectors, and demonstrate the utility of these libraries across methodologies: in vitro enrichment and drop-out screening in lymphoma cells and immortalised fibroblasts, respectively, and in vivo screens to identify lymphoma-driving events. Finally, we demonstrate CRISPR multiplexing via simultaneous gene knockout (via Cas12a) and activation (via dCas9-SAM) using primary T cells and fibroblasts. Our enAsCas12a mouse and accompanying crRNA libraries enhance genome engineering capabilities and complement current CRISPR technologies.

In silico analysis of lncRNA-miRNA-mRNA signatures related to Sorafenib effectiveness in liver cancer cells

BACKGROUND

Hepatocellular carcinoma (HCC) is the most common subtype of primary liver cancer with varied incidence and epidemiology worldwide. Sorafenib is still a recommended treatment for a large proportion of patients with advanced HCC. Different patterns of treatment responsiveness have been identified in differentiated hepatoblastoma HepG2 cells and metastatic HCC SNU449 cells.

AIM

To define the long non-codingRNA-microRNA-mRNA (lncRNA-miRNA-mRNA) predicted signatures related to selected hallmarks of cancer (apoptosis, autophagy, cell stress, cell dedifferentiation and invasiveness) in RNAseq studies using Sorafenib-treated HepG2 and SNU449 cells. Various available software analyses allowed us to establish the lncRNA-miRNA-mRNA regulatory axes following treatment in HepG2 and SNU449 cells.

METHODS

HepG2 and SNU449 cells were treated with Sorafenib (10 μmol/L) for 24 hours. Total RNA, including small and long RNA, was extracted with a commercial miRNeasy kit. RNAseq was carried out for the identification of changes in lncRNA-miRNA-mRNA regulatory axes.

RESULTS

MALAT, THAP9-AS1 and SNGH17 appeared to coordinately regulate miR-374b-3p and miR-769-5p that led to upregulation of SMAD7, TIRARP, TFAP4 and FAXDC2 in HepG2 cells. SNHG12, EPB41 L4A-AS1, LINC01578, SNHG12 and GAS5 interacted with let-7b-3p, miR-195-5p and VEGFA in SNU449 cells. The axes MALAT1/hsa-mir-374b-3p/SMAD7 and MALAT1/hsa-mir-769-5p/TFAP4 were of high relevance for Sorafenib response in HepG2 cells, whereas PVT1/hsa-miR-195-5p/VEGFA was responsible for the differential response of SNU449 cells to Sorafenib treatment.

CONCLUSION

Critical lncRNAs acting as sponges of miRNA were identified that regulated mRNA expression, whose proteins mainly increased the antitumor effectiveness of the treatment (SMAD7, TIRARP, TFAP4, FAXDC2 and ADRB2). However, the broad regulatory axis leading to increased VEGFA expression may be related to the side effect of Sorafenib in SNU449 cells.

Genetic association of GJA8 with long-segment Hirschsprung's disease in southern Chinese children

Background

Hirschsprung's disease (HSCR) is a complex congenital neurodevelopmental disorder affecting colons caused by both genetic and environmental factors. Although several genes have been identified as contributing factors in HSCR, the pathogenesis is still largely unclear, especially for the low prevalent long-segment HSCR (L-HSCR). Gap junction protein alpha 8 (GJA8) is involved in several physiological processes and has been implicated in several diseases. However, the relationship between GJA8 single nucleotide polymorphism (SNP) rs17160783 and HSCR in the southern Chinese population remains unknown. The study aimed to explore the association of genetic variants in GJA8 and HSCR susceptibility in southern Chinese.

Methods

SNP rs17160783 A>G in GJA8 was genotyped by TaqMan SNP Genotyping Assay in all samples, which included 1,329 HSCR children (cases) and 1,473 healthy children (controls). Odds ratio (OR) and 95% confidence interval (CI) were used to evaluate the association of GJA8 polymorphisms with HSCR susceptibility. The GTEx database and transcription factor binding site (TFBS) prediction were used to analyze the potential regulatory function of rs17160783.

Results

Genetic association analysis illustrated that rs17160783 could increase the risk of L-HSCR (Padj=0.04, ORadj =1.48, 95% CI: 1.02-2.14). We also found that GJA8 expression was increased in HSCR and neurodevelopmentally impaired animal models. External epigenetic data revealed that GJA8 rs17160783 may have the potential to regulate the expression of the GJA8, possibly by altering the binding of transcription factors for GJA8, and consequently impacting the PI3K-Akt signaling pathway during the enteric nervous system (ENS) development.

Conclusions

Our results suggested that rs17160783 might play a regulatory role in GJA8 expression and increase the susceptibility of L-HSCR in children from southern China.

Ultrasound-responsive spherical nucleic acid against c-Myc/PD-L1 to enhance anti-tumoral macrophages in triple-negative breast cancer progression

Triple-negative breast cancer (TNBC) is the most challenging breast cancer subtype because of its aggressive behavior and limited therapeutic targets. c-Myc is hyperactivated in the majority of TNBC tissues, however, it has been considered an "undruggable" target due to its disordered structure. Herein, we developed an ultrasound-responsive spherical nucleic acid (SNA) against c-Myc and PD-L1 in TNBC. It is a self-assembled and carrier-free system composed of a hydrophilic small-interfering RNA (siRNA) shell and a hydrophobic core made of a peptide nucleic acid (PNA)-based antisense oligonucleotide (ASO) and a sonosensitizer. We accomplished significant enrichment in the tumor by enhanced permeability and retention (EPR) effect, the controllable release of effective elements by ultrasound activation, and the combination of targeted therapy, immunotherapy and physiotherapy. Our study demonstrated significant anti-tumoral effects in vitro and in vivo. Mass cytometry showed an invigorated tumor microenvironment (TME) characterized by a significant alteration in the composition of tumor-associated macrophages (TAM) and decreased proportion of PD-1-positive (PD-1+) T effector cells after appropriate treatment of the ultrasound-responsive SNA (USNA). Further experiments verified that tumor-conditioned macrophages residing in the TME were transformed into the anti-tumoral population. Our finding offers a novel therapeutic strategy against the "undruggable" c-Myc, develops a new targeted therapy for c-Myc/PD-L1 and provides a treatment option for the TNBC.