CSNK2A1-mediated phosphorylation of HMGA2 modulates cisplatin resistance in cervical cancer

Chromatin modifier Hmga2 promotes adult hematopoietic stem cell function and blood regeneration in stress conditions

The molecular mechanisms governing the response of hematopoietic stem cells (HSCs) to stress insults remain poorly defined. Here, we investigated effects of conditional knock-out or overexpression of Hmga2 (High mobility group AT-hook 2), a transcriptional activator of stem cell genes in fetal HSCs. While Hmga2 overexpression did not affect adult hematopoiesis under homeostasis, it accelerated HSC expansion in response to injection with 5-fluorouracil (5-FU) or in vitro treatment with TNF-α. In contrast, HSC and megakaryocyte progenitor cell numbers were decreased in Hmga2 KO animals. Transcription of inflammatory genes was repressed in Hmga2-overexpressing mice injected with 5-FU, and Hmga2 bound to distinct regions and chromatin accessibility was decreased in HSCs upon stress. Mechanistically, we found that casein kinase 2 (CK2) phosphorylates the Hmga2 acidic domain, promoting its access and binding to chromatin, transcription of anti-inflammatory target genes, and the expansion of HSCs under stress conditions. Notably, the identified stress-regulated Hmga2 gene signature is activated in hematopoietic stem progenitor cells of human myelodysplastic syndrome patients. In sum, these results reveal a TNF-α/CK2/phospho-Hmga2 axis controlling adult stress hematopoiesis.

Characterization of HMGA2 variants expands the spectrum of Silver-Russell syndrome

Silver-Russell syndrome (SRS) is a heterogeneous disorder characterized by intrauterine and postnatal growth retardation. HMGA2 variants are a rare cause of SRS and its functional role in human linear growth is unclear. Patients with suspected SRS negative for 11p15LOM/mUPD7 underwent whole-exome and/or targeted-genome sequencing. Mutant HMGA2 protein expression and nuclear localization were assessed. Two Hmga2-knockin mouse models were generated. Five clinical SRS patients harbored HMGA2 variants with differing functional impacts: 2 stop-gain nonsense variants (c.49G>T, c.52C>T), c.166A>G missense variant, and 2 frameshift variants (c.144delC, c.145delA) leading to an identical, extended-length protein. Phenotypic features were highly variable. Nuclear localization was reduced/absent for all variants except c.166A>G. Homozygous knockin mice recapitulating the c.166A>G variant (Hmga2K56E) exhibited a growth-restricted phenotype. An Hmga2Ter76-knockin mouse model lacked detectable full-length Hmga2 protein, similarly to patient 3 and 5 variants. These mice were infertile, with a pygmy phenotype. We report a heterogeneous group of individuals with SRS harboring variants in HMGA2 and describe the first Hmga2 missense knockin mouse model (Hmga2K56E) to our knowledge causing a growth-restricted phenotype. In patients with clinical features of SRS but negative genetic screening, HMGA2 should be included in next-generation sequencing testing approaches.

Current insights into the oncogenic roles of lncRNA LINC00355

Long noncoding RNAs (lncRNAs) are a class of nonprotein-coding transcripts that are longer than 200 nucleotides. LINC00355 is a lncRNA located on chromosome 13q21.31 and is consistently upregulated in various cancers. It regulates the expression of downstream genes at both transcriptional and posttranscriptional levels, including eight microRNAs (miR-15a-5p, miR-34b-5p, miR-424-5p, miR-1225, miR-217-5p, miR-6777-3p, miR-195, and miR-466) and three protein-coding genes (ITGA2, RAD18, and UBE3C). LINC00355 plays a role in regulating various biological processes such as cell cycle progression, proliferation, apoptosis, epithelial-mesenchymal transition, invasion, and metastasis of cancer cells. It is involved in the regulation of the Wnt/β-catenin signaling pathway and p53 signaling pathway. Upregulation of LINC00355 has been identified as a high-risk factor in cancer patients and its increased expression is associated with poorer overall survival, recurrence-free survival, and disease-free survival. LINC00355 upregulation has been linked to several unfavorable clinical characteristics, including advanced tumor node metastasis and World Health Organization stages, reduced Karnofsky Performance Scale scores, increased tumor size, greater depth of invasion, and more extensive lymph node metastasis. LINC00355 induces chemotherapy resistance in cancer cells by regulating five downstream genes, namely HMGA2, ABCB1, ITGA2, WNT10B, and CCNE1 genes. In summary, LINC00355 is a potential oncogene with great potential as a diagnostic marker and therapeutic target for cancer.

Signatures of Co-Deregulated Genes and Their Transcriptional Regulators in Kidney Cancers

There are several studies on the deregulated gene expression profiles in kidney cancer, with varying results depending on the tumor histology and other parameters. None of these, however, have identified the networks that the co-deregulated genes (co-DEGs), across different studies, create. Here, we reanalyzed 10 Gene Expression Omnibus (GEO) studies to detect and annotate co-deregulated signatures across different subtypes of kidney cancer or in single-gene perturbation experiments in kidney cancer cells and/or tissue. Using a systems biology approach, we aimed to decipher the networks they form along with their upstream regulators. Differential expression and upstream regulators, including transcription factors [MYC proto-oncogene (MYC), CCAAT enhancer binding protein delta (CEBPD), RELA proto-oncogene, NF-kB subunit (RELA), zinc finger MIZ-type containing 1 (ZMIZ1), negative elongation factor complex member E (NELFE) and Kruppel-like factor 4 (KLF4)] and protein kinases [Casein kinase 2 alpha 1 (CSNK2A1), mitogen-activated protein kinases 1 (MAPK1) and 14 (MAPK14), Sirtuin 1 (SIRT1), Cyclin dependent kinases 1 (CDK1) and 4 (CDK4), Homeodomain interacting protein kinase 2 (HIPK2) and Extracellular signal-regulated kinases 1 and 2 (ERK1/2)], were computed using the Characteristic Direction, as well as GEO2Enrichr and X2K, respectively, and further subjected to GO and KEGG pathways enrichment analyses. Furthermore, using CMap, DrugMatrix and the LINCS L1000 chemical perturbation databases, we highlight putative repurposing drugs, including Etoposide, Haloperidol, BW-B70C, Triamterene, Chlorphenesin, BRD-K79459005 and β-Estradiol 3-benzoate, among others, that may reverse the expression of the identified co-DEGs in kidney cancers. Of these, the cytotoxic effects of Etoposide, Catecholamine, Cyclosporin A, BW-B70C and Lasalocid sodium were validated in vitro. Overall, we identified critical co-DEGs across different subtypes in kidney cancer, and our results provide an innovative framework for their potential use in the future.

CircNDST1 promotes papillary thyroid cancer progression via its interaction with CSNK2A1 to activate the PI3K-Akt pathway and epithelial-mesenchymal transition

BACKGROUND

Multiple studies have established a strong relationship between circRNA and cancer progression. Cervical lymph node metastasis is a key factor influencing the surgical approach and distant metastasis of papillary thyroid cancer (PTC). However, the role of circNDST1 in PTC has not been investigated. Our research focused on revealing the function and mechanism of action of circNDST1 in PTC.

METHODS

High-throughput sequencing and qPCR were used to assess the expression of circRNA in PTC tissues with extensive cervical lymph node metastasis and circNDST1 in cell lines, respectively. The proliferative effects of circNDST1 in vitro and in vivo were analyzed using CCK8, clone formation assay, EdU, and nude mouse tumorigenesis assay. The transwell scratch assay was employed in the scrutiny of the effect of circNDST1 on the migration and invasion abilities of thyroid cancer cells, while circNDST1's influence on the PI3K-Akt pathway and the Epithelial-Mesenchymal Transition (EMT) key protein expression was evaluated utilizing RNA sequencing and western blot. RNA pull-down and RIP were used to examine the binding of circNDST1 to CSNK2A1.

RESULTS

CircNDST1 was highly expressed in PTC cell lines, but knocking it down inhibited the proliferation, migration, and invasive abilities of TPC1 and KTC1 cell lines. CircNDST1 bonded with CSNK2A1 and promoted the interaction between CSNK2A1 and Akt, leading to the activation of the PI3K-Akt pathway and EMT.

CONCLUSION

CircNDST1's high expression boosted thyroid cancer progression through the activation of the PI3K-Akt pathway and EMT in a CSNK2A1-dependent manner.

Long noncoding RNA LINC01426 promotes the progression of lung adenocarcinoma via regulating miRNA-125a-5p/ casein kinase 2 alpha 1 axis

Although long noncoding RNAs (lncRNAs) in lung adenocarcinoma (LUAD) have been increasingly studied, LINC01426 has not been fully investigated in LUAD. The GEPIA database revealed that LINC01426 was upregulated in LUAD tissues. In our study, we further verified the significantly high expression of LINC01426 in LUAD tissues and cell lines. We also analyzed the LINC01426 expression level and LUAD clinical features and found that high LINC01426 expression was associated with tumor diameter; tumor, node, and metastases (TNM) staging; lymph node metastasis (LNM); and overall survival (OS) rate of LUAD patients. In vitro experiments revealed that suppression of LINC01426 could repress the proliferation, migration and invasion of LUAD cells. Then, the bioinformatic analysis revealed that there were binding domains between miR-125a-5p and the 3′-UTR of LINC01426. As revealed by dual-luciferase reporter gene experiment and RNA Binding Protein Immunoprecipitation (RIP) assay, miR-125a-5p could bind to LINC01426. Additionally, the results of qRT-PCR and Pearson’s analysis respectively revealed that miR-125a-5p was slightly expressed in LUAD and its expression was negatively correlated with LINC01426. Moreover, casein kinase 2 alpha 1 (CSNK2A1) was predicted to bind to miR-125a-5p. CSNK2A1 expression was remarkably high in LUAD tissues, negatively associated with miR-125a-5p, and positively correlated with LINC01426. Subsequently, our results showed that CSNK2A1 enhanced the malignant progression of LUAD cells. Overall, our study revealed that LINC01426 might regulate the malignant phenotype of LUAD via the miR-125a-5p/CSNK2A1 axis.