CRISPR-Cas9 Screen Identifies DYRK1A as a Target for Radiotherapy Sensitization in Pancreatic Cancer

MicroRNA-298 determines the radio-resistance of colorectal cancer cells by directly targeting human dual-specificity tyrosine(Y)-regulated kinase 1A

BACKGROUND

Radiotherapy stands as a promising therapeutic modality for colorectal cancer (CRC); yet, the formidable challenge posed by radio-resistance significantly undermines its efficacy in achieving CRC remission.

AIM

To elucidate the role played by microRNA-298 (miR-298) in CRC radio-resistance.

METHODS

To establish a radio-resistant CRC cell line, HT-29 cells underwent exposure to 5 gray ionizing radiation that was followed by a 7-d recovery period. The quantification of miR-298 levels within CRC cells was conducted through quantitative RT-PCR, and protein expression determination was realized through Western blotting. Cell viability was assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and proliferation by clonogenic assay. Radio-induced apoptosis was discerned through flow cytometry analysis.

RESULTS

We observed a marked upregulation of miR-298 in radio-resistant CRC cells. MiR-298 emerged as a key determinant of cell survival following radiation exposure, as its overexpression led to a notable reduction in radiation-induced apoptosis. Intriguingly, miR-298 expression exhibited a strong correlation with CRC cell viability. Further investigation unveiled human dual-specificity tyrosine(Y)-regulated kinase 1A (DYRK1A) as miR-298's direct target.

CONCLUSION

Taken together, our findings underline the role played by miR-298 in bolstering radio-resistance in CRC cells by means of DYRK1A downregulation, thereby positioning miR-298 as a promising candidate for mitigating radio-resistance in CRC.

Research progress on the antitumor effects of harmine

Harmine is a naturally occurring β-carboline alkaloid originally isolated from Peganum harmala. As a major active component, harmine exhibits a broad spectrum of pharmacological properties, particularly remarkable antitumor effects. Recent mechanistic studies have shown that harmine can inhibit cancer cell proliferation and metastasis through epithelial-to-mesenchymal transition, cell cycle regulation, angiogenesis, and the induction of tumor cell apoptosis. Furthermore, harmine reduces drug resistance when used in combination with chemotherapeutic drugs. Despite its remarkable antitumor activity, the application of harmine is limited by its poor solubility and toxic side effects, particularly neurotoxicity. Novel harmine derivatives have demonstrated strong clinical application prospects, but further validation based on drug activity, acute toxicity, and other aspects is necessary. Here, we present a review of recent research on the action mechanism of harmine in cancer treatment and the development of its derivatives, providing new insights into its potential clinical applications and strategies for mitigating its toxicity while enhancing its efficacy.

Applications of CRISPR screening to lung cancer treatment

Lung cancer is an extremely aggressive and highly prevalent disease worldwide, and it is one of the leading causes of cancer death. Deciphering intrinsic genetic mechanism, finding new targets, and overcoming drug resistance are the key to lung cancer treatment. High-throughput CRISPR screening has been extensively used to obtain the genes related to cancers including lung cancer. This review describes CRISPR/Cas9 or CRISPR/dCas9-based technologies for high-throughput screening. We summarize the applications of CRISPR screening technology in exploring the mechanism of lung cancer development in vivo or in vitro, overcoming drug resistance, improving the effect of immunotherapy, and discovering new therapeutic targets. This review highlights the potential of CRISPR screening in combination with tumor barcoding and high-throughput sequencing (Tuba-seq) to precisely quantify the impact of alterations in many tumor suppressor genes on lung cancer.

Copper-mediated novel cell death pathway in tumor cells and implications for innovative cancer therapies

Previous investigations have unraveled an array of cellular demise modalities, encompassing apoptosis, necrosis, pyroptosis, iron death, and several others. These diverse pathways of cell death have been harnessed as therapeutic strategies for eradicating tumor cells. Recent scientific inquiries have unveiled a novel mode of cell death, namely copper death, which is contingent upon intracellular copper levels. Diverging from conventional cell death mechanisms, copper death exhibits a heightened reliance on mitochondrial respiration, specifically the tricarboxylic acid (TCA) cycle. Tumor cells exhibit distinctive metabolic profiles and an elevated copper content compared to their normal counterparts. The emergence of copper death presents a tantalizing prospect for targeted therapies in the realm of cancer treatment. Thus, the primary objective of this review is to introduce the proteins and intricate mechanisms underlying copper death, while comprehensively summarizing the extensive body of knowledge concerning its ramifications across diverse tumor types. The insights garnered from this comprehensive synthesis will serve as an invaluable reference for driving the development of tailor-made therapeutic interventions for tumors.

Comparative Efficacy and Selectivity of Pharmacological Inhibitors of DYRK and CLK Protein Kinases

Dual-specificity, tyrosine phosphorylation-regulated kinases (DYRKs) and cdc2-like kinases (CLKs) play a large variety of cellular functions and are involved in several diseases (cognitive disorders, diabetes, cancers, etc.). There is, thus, growing interest in pharmacological inhibitors as chemical probes and potential drug candidates. This study presents an unbiased evaluation of the kinase inhibitory activity of a library of 56 reported DYRK/CLK inhibitors on the basis of comparative, side-by-side, catalytic activity assays on a panel of 12 recombinant human kinases, enzyme kinetics (residence time and K_d), in-cell inhibition of Thr-212-Tau phosphorylation, and cytotoxicity. The 26 most active inhibitors were modeled in the crystal structure of DYRK1A. The results show a rather large diversity of potencies and selectivities among the reported inhibitors and emphasize the difficulties to avoid "off-targets" in this area of the kinome. The use of a panel of DYRKs/CLKs inhibitors is suggested to analyze the functions of these kinases in cellular processes.

The Omnipresence of DYRK1A in Human Diseases

The increasing population will challenge healthcare, particularly because the worldwide population has never been older. Therapeutic solutions to age-related disease will be increasingly critical. Kinases are key regulators of human health and represent promising therapeutic targets for novel drug candidates. The dual-specificity tyrosine-regulated kinase (DYRKs) family is of particular interest and, among them, DYRK1A has been implicated ubiquitously in varied human diseases. Herein, we focus on the characteristics of DYRK1A, its regulation and functional role in different human diseases, which leads us to an overview of future research on this protein of promising therapeutic potential.

Identification of Novel Regulators of Radiosensitivity Using High-Throughput Genetic Screening

The biological impact of ionizing radiation (IR) on humans depends not only on the physical properties and absorbed dose of radiation but also on the unique susceptibility of the exposed individual. A critical target of IR is DNA, and the DNA damage response is a safeguard mechanism for maintaining genomic integrity in response to the induced cellular stress. Unrepaired DNA lesions lead to various mutations, contributing to adverse health effects. Cellular sensitivity to IR is highly correlated with the ability of cells to repair DNA lesions, in particular coding sequences of genes that affect that process and of others that contribute to preserving genomic integrity. However, accurate profiling of the molecular events underlying individual sensitivity requires techniques with sensitive readouts. Here we summarize recent studies that have used whole-genome analysis and identified genes that impact individual radiosensitivity. Whereas microarray and RNA-seq provide a snapshot of the transcriptome, RNA interference (RNAi) and CRISPR-Cas9 techniques are powerful tools that enable modulation of gene expression and characterizing the function of specific genes involved in radiosensitivity or radioresistance. Notably, CRISPR-Cas9 has altered the landscape of genome-editing technology with its increased readiness, precision, and sensitivity. Identifying critical regulators of cellular radiosensitivity would help tailor regimens that enhance the efficacy of therapeutic treatments and fast-track prediction of clinical outcomes. It would also contribute to occupational protection based on average individual sensitivity, as well as the formulation of countermeasures to the harmful effects of radiation.