THAP7 promotes cell proliferation by regulating the G1/S phase transition via epigenetically silencing p21 in lung adenocarcinoma

Mutation of the Thap4 gene causes dwarfism and testicular anomalies in rats and mice

The petit (pet) locus is associated with dwarfism, testicular anomalies, severe thymic hypoplasia, and high postnatal lethality, which are inherited in autosomal recessive mode of inheritance in rats with a Wistar strain genetic background. Linkage analysis localized the pet locus between 98.7 Mb and 101.2 Mb on rat chromosome 9. Nucleotide sequence analysis identified 2 bp deletion in exon 2 of the Thap4 gene as the causative mutation for pet. This deletion causes a frameshift and premature termination codon, resulting in a truncated THAP4 protein lacking approximately two-thirds of the C-terminal side. Thap4 is expressed in various organs, including the testis and thymus in rats. To elucidate the biological function of THAP4 in other species, we generated Thap4 knockout mice lacking exon 2 of the Thap4 gene through genome editing. Thap4 knockout mice also exhibited dwarfism and small testis but did not show high postnatal lethality. Thymus weights of adult Thap4 knockout male mice were significantly higher compared to wild-type male mice. Although Thap4 knockout male mice were fertile, their testis contained seminiferous tubules with spermatogenesis and degenerative seminiferous tubules lacking germ cells. Additionally, we observed vacuoles in seminiferous tubules, and clusters of cells in the lumen in seminiferous tubules in Thap4 knockout male mice. These results demonstrate that spontaneous mutation of Thap4 gene in rats and knockout of Thap4 gene in mice both cause dwarfism and testicular anomalies. Thap4 gene in rats and mice is essential for normal testicular development, maintaining spermatogenesis throughout the entire region of seminiferous tubules.

CircNRD1 elevates THAP domain containing 11 through sequestering microRNA-421 to inhibit gastric cancer growth and tumorigenesis

We explored the role and mechanism of circular RNAcircNRD1 in gastric cancer (GC) progression, aiming to identify new bio-markers for the treatment and prognosis of GC patients. The RNA expression was examined by reverse transcription-quantitative polymerase chain reaction. Cell proliferation, migration and invasion were analyzed by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, 5-ethynyl-2'-deoxyuridine (EdU) incorporation assay, scratch assay and transwell assay. Western blot assay was conducted for protein expression measurement. Dual-luciferase reporter, RNA immunoprecipitation, and RNA pull-down assays were conducted to verify the interaction between microRNA-421 (miR-421) and circNRD1 or THAP domain containing 11 (THAP11). Xenograft tumor model was established to perform in vivo experiments. CircNRD1 was notably downregulated in GC tissues and cell lines. Additionally, decreased circNRD1 level was closely associated with advanced tumor stage and dismal prognosis in GC patients. CircNRD1 overexpression suppressed the proliferation and metastasis of GC cells. CircNRD1 acted as a molecular sponge for miR-421 in GC cells, and the antitumor impacts of circNRD1 overexpression in GC cells could be alleviated by miR-421 overexpression. miR-421 directly targeted THAP11, and circNRD1 could up-regulate THAP11 expression in GC cells through sponging miR-421. THAP11 knockdown reversed circNRD1 overexpression-induced tumor suppressing effects in GC cells. CircNRD1 overexpression significantly blocked tumor growth in vivo. CircNRD1 suppressed the proliferation and metastasis of GC cells in vitro and blocked tumor growth in vivo via modulating miR-421/THAP11 axis.

Epigenetic regulator RNF20 underlies temporal hierarchy of gene expression to regulate postnatal cardiomyocyte polarization

Differentiated cardiomyocytes (CMs) must undergo diverse morphological and functional changes during postnatal development. However, the mechanisms underlying initiation and coordination of these changes remain unclear. Here, we delineate an integrated, time-ordered transcriptional network that begins with expression of genes for cell-cell connections and leads to a sequence of structural, cell-cycle, functional, and metabolic transitions in mouse postnatal hearts. Depletion of histone H2B ubiquitin ligase RNF20 disrupts this gene network and impairs CM polarization. Subsequently, assay for transposase-accessible chromatin using sequencing (ATAC-seq) analysis confirmed that RNF20 contributes to chromatin accessibility in this context. As such, RNF20 is likely to facilitate binding of transcription factors at the promoters of genes involved in cell-cell connections and actin organization, which are crucial for CM polarization and functional integration. These results suggest that CM polarization is one of the earliest events during postnatal heart development and provide insights into how RNF20 regulates CM polarity and the postnatal gene program.

Construction and experimental validation of an acetylation-related gene signature to evaluate the recurrence and immunotherapeutic response in early-stage lung adenocarcinoma

BACKGROUND

Acetylation is a reversible epigenetic process, playing an important role in the initiation and progression of malignant tumors. However, the prognosis value of acetylation-related genes in the early-stage lung adenocarcinoma (LUAD) remains obscure.

MATERIALS AND METHODS

The acetylation-related genes were collected and clustered based on transcriptome sequencing of the patients with early-stage LUAD from the Cancer Genome Atlas. The genomic divergence analysis, protein-protein interaction network construction, Lasso regression, and univariate Cox regression were used to identify the significant biomarkers for the recurrence of the early-stage LUAD. The multivariate Cox regression was used to establish the predictive model. Gene Expression Omnibus was systemically retrieved and four independent datasets were used for external validation. 23 early-stage LUAD samples were collected from the local hospital to detect the expression difference of the genes in the model. Transfection assays were performed to verify the regulatory ability of the screened gene to the proliferation of LUAD cell lines. The single-cell RNA sequencing of the early-stage LUAD patients and two lung cancer cohorts receiving immunotherapy were utilized to explore the predictive ability of the established model to immunotherapeutic sensitivity.

RESULTS

The clustering based on acetylation-related genes was significantly associated with the recurrence (P < 0.01) and immune infiltration statuses. Through a series of bioinformatical and machine learning methods, RBBP7 and YEATS2 were ultimately identified. Accordingly, a novel gene signature containing RBBP7 and YEATS2 was developed to evaluate the recurrence-free survival of early-stage LUAD, which was then validated in five independent cohorts (pooled hazard ratio = 1.88, 95% confidence interval = 1.49-2.37) and 23 local clinical samples (P < 0.01). The knock-down of YEATS2 obviously suppressed proliferation of H1975 and HCC-827 cells. Single-cell RNA sequencing analyses indicated that RBBP7 and YEATS2 were both associated with the tumor immune response, and the prognosis signature could predict the immunotherapeutic response in two cohorts receiving immunotherapy (P < 0.05; P < 0.01).

CONCLUSIONS

Totally, an acetylation-related gene signature is constructed, helping to evaluate the recurrence and immunotherapeutic effectiveness of early-stage LUAD patients.

Silencing LMNB1 Contributes to the Suppression of Lung Adenocarcinoma Development

Purpose

Lung cancer has been recognized as the most fatal malignant tumor with the highest morbidity and mortality in recent years.

Materials and Methods

In this study, we found that LMNB1, which is an important component protein of the nuclear skeleton, was significantly upregulated in lung adenocarcinoma (LUAD) and correlated with the pathological stage as well as lymphatic metastasis.

Results

In vitro loss-of-function study utilizing LMNB1 knockdown LUAD cell lines demonstrated that depletion of LMNB1 inhibited development of LUAD through regulating cell proliferation, cell apoptosis, cell cycle and cell motility. Decreased tumorigenesis of LMNB1 knockdown LUAD cells was proved in mice xenograft models. Moreover, the mechanism by which LMNB1 promotes LUAD was explored through the expression evaluation of apoptosis-related proteins and cancer-related signaling pathways.

Conclusion

In conclusion, our study identified LMNB1 as a tumor promotor and a potential therapeutic target in LUAD.