Cyclin K interacts with β-catenin to induce Cyclin D1 expression and facilitates tumorigenesis and radioresistance in lung cancer

Inhibition of the Cyclin K-CDK12 complex induces DNA damage and increases the effect of androgen deprivation therapy in prostate cancer

Androgen deprivation therapy (ADT) is the mainstay of the current first-line treatment concepts for patients with advanced prostate carcinoma (PCa). However, due to treatment failure and recurrence investigation of new targeted therapeutics is urgently needed. In this study, we investigated the suitability of the Cyclin K-CDK12 complex as a novel therapeutic approach in PCa using the new covalent CDK12/13 inhibitor THZ531. Here we show that THZ531 impairs cellular proliferation, induces apoptosis, and decreases the expression of selected DNA repair genes in PCa cell lines, which is associated with an increasing extent of DNA damage. Furthermore, combination of THZ531 and ADT leads to an increase in these anti-tumoral effects in androgen-sensitive PCa cells. The anti-proliferative and pro-apoptotic activity of THZ531 in combination with ADT was validated in an ex vivo PCa tissue culture model. In a retrospective immunohistochemical analysis of 300 clinical tissue samples we show that Cyclin K (CycK) but not CDK12 expression correlates with a more aggressive type of PCa. In conclusion, this study demonstrates the clinical relevance of the CycK-CDK12 complex as a promising target for combinational therapy with ADT in PCa and its importance as a prognostic biomarker for patients with PCa.

CCNK Gene Deficiency Influences Neural Progenitor Cells Via Wnt5a Signaling in CCNK-Related Syndrome

OBJECTIVE

Rare variants of CCNK (cyclin K) give rise to a syndrome with intellectual disability. The purpose of this study was to describe the genotype-phenotype spectrum of CCNK-related syndrome and the underlying molecular mechanisms of pathogenesis.

METHODS

We identified a number of de novo CCNK variants in unrelated patients. We generated patient-induced pluripotent stem cells (iPSCs) and neural progenitor cells (NPCs) as disease models. In addition, we constructed NPC-specific Ccnk knockout (KO) mice and performed molecular and morphological analyses.

RESULTS

We identified 2 new patients harboring CCNK missense variants and followed-up 3 previous reported patients, which constitute the largest patient population analysis of the disease. We demonstrate that both the patient-derived NPC models and the Ccnk KO mouse displayed deficient NPC proliferation and enhanced apoptotic cell death. RNA sequencing analyses of these NPC models uncovered transcriptomic signatures unique to CCNK-related syndrome, revealing significant changes in genes, including WNT5A, critical for progenitor proliferation and cell death. Further, to confirm WNT5A's role, we conducted rescue experiments using NPC and mouse models. We found that a Wnt5a inhibitor significantly increased proliferation and reduced apoptosis in NPCs derived from patients with CCNK-related syndrome and NPCs in the developing cortex of Ccnk KO mice.

INTERPRETATION

We discussed the genotype-phenotype relationship of CCNK-related syndrome. Importantly, we demonstrated that CCNK plays critical roles in NPC proliferation and NPC apoptosis in vivo and in vitro. Together, our study highlights that Wnt5a may serve as a promising therapeutic target for the disease intervention. ANN NEUROL 2023;94:1136-1154.

Recent advances in targeting the "undruggable" proteins: from drug discovery to clinical trials

Undruggable proteins are a class of proteins that are often characterized by large, complex structures or functions that are difficult to interfere with using conventional drug design strategies. Targeting such undruggable targets has been considered also a great opportunity for treatment of human diseases and has attracted substantial efforts in the field of medicine. Therefore, in this review, we focus on the recent development of drug discovery targeting "undruggable" proteins and their application in clinic. To make this review well organized, we discuss the design strategies targeting the undruggable proteins, including covalent regulation, allosteric inhibition, protein-protein/DNA interaction inhibition, targeted proteins regulation, nucleic acid-based approach, immunotherapy and others.

Coming of Age: Targeting Cyclin K in Cancers

Cyclins and cyclin-dependent kinases (CDKs) play versatile roles in promoting the hallmarks of cancer. Therefore, cyclins and CDKs have been widely studied and targeted in cancer treatment, with four CDK4/6 inhibitors being approved by the FDA and many other inhibitors being examined in clinical trials. The specific purpose of this review is to delineate the role and therapeutic potential of Cyclin K in cancers. Studies have shown that Cyclin K regulates many essential biological processes, including the DNA damage response, mitosis, and pre-replicative complex assembly, and is critical in both cancer cell growth and therapeutic resistance. Importantly, the druggability of Cyclin K has been demonstrated in an increasing number of studies that identify novel opportunities for its use in cancer treatment. This review first introduces the basic features and translational value of human cyclins and CDKs. Next, the discovery, phosphorylation targets, and related functional significance of Cyclin K-CDK12/13 complexes in cancer are detailed. This review then provides a summary of current Cyclin K-associated cancer studies, with an emphasis on the available Cyclin K-targeting drugs. Finally, the current knowledge gaps regarding the potential of Cyclin K in cancers are discussed, along with interesting directions for future investigation.

Carbon ions trigger DNA damage response to overcome radioresistance by regulating β-catenin signaling in quiescent HeLa cells

Quiescent cancer cells are major impediments to effective radiotherapy (RT) and exhibit limited sensitivity to traditional photon therapy. Herein, the functional role and underlying mechanism of carbon ions in overcoming the radioresistance of quiescent cervical cancer HeLa cells were determined. Briefly, serum withdrawal was used to induce synchronized quiescence in HeLa cells. Quiescent HeLa cells displayed strong radioresistance and DNA repair potential. After irradiation with carbon ions, the DNA damage repair pathway may markedly rely on error-prone nonhomologous end-joining in proliferating cells, whereas the high-precision homologous recombination pathway is more relevant in quiescent cells. This phenomenon could be explained by the ionizing radiation (IR)-induced cell cycle re-entry of quiescent cancer cells. There are three strategies for eradicating quiescent cancer cells using high-linear energy transfer (LET) carbon ions: direct cell death through complex DNA damage; apoptosis via an enhanced mitochondria-mediated intrinsic pathway; forced re-entry of quiescent cancer cells into the cell cycle, thereby improving their susceptibility to IR. Silencing β-catenin signaling is essential for maintaining the dormant state in quiescent cells. Herein, carbon ions activated the β-catenin pathway in quiescent cells, and inhibition of this pathway improved the resistance of quiescent HeLa cells to carbon ions by alleviating DNA damage, improving DNA damage repair, maintaining quiescent depth, and inhibiting apoptosis. Collectively, carbon ions conquer the radioresistance of quiescent HeLa cells by activating β-catenin signaling, which provides a theoretical basis for improved therapeutic effects in patients with middle-advanced-stage cervical cancer with radioresistance.

A novel approach for the analysis of single-cell RNA sequencing identifies TMEM14B as a novel poor prognostic marker in hepatocellular carcinoma

A fundamental goal in cancer-associated genome sequencing is to identify the key genes. Protein-protein interactions (PPIs) play a crucially important role in this goal. Here, human reference interactome (HuRI) map was generated and 64,006 PPIs involving 9094 proteins were identified. Here, we developed a physical link and co-expression combinatory network construction (PLACE) method for genes of interest, which provides a rapid way to analyze genome sequencing datasets. Next, Kaplan‒Meier survival analysis, CCK8 assays, scratch wound assays and Transwell assays were applied to confirm the results. In this study, we selected single-cell sequencing data from patients with hepatocellular carcinoma (HCC) in GSE149614. The PLACE method constructs a protein connection network for genes of interest, and a large fraction (80%) of the genes (screened by the PLACE method) were associated with survival. Then, PLACE discovered that transmembrane protein 14B (TMEM14B) was the most significant prognostic key gene, and target genes of TMEM14B were predicted. The TMEM14B-target gene regulatory network was constructed by PLACE. We also detected that TMEM14B-knockdown inhibited proliferation and migration. The results demonstrate that we proposed a new effective method for identifying key genes. The PLACE method can be used widely and make outstanding contributions to the tumor research field.

Targeting cyclin D1 as a therapeutic approach for papillary thyroid carcinoma

Cyclin D1 functions as a mitogenic sensor that specifically binds to CDK4/6, thereby integrating external mitogenic inputs and cell cycle progression. Cyclin D1 interacts with transcription factors and regulates various important cellular processes, including differentiation, proliferation, apoptosis, and DNA repair. Therefore, its dysregulation contributes to carcinogenesis. Cyclin D1 is highly expressed in papillary thyroid carcinoma (PTC). However, the particular cellular mechanisms through which abnormal cyclin D1 expression causes PTC are poorly understood. Unveiling the regulatory mechanisms of cyclin D1 and its function in PTC may help determine clinically effective strategies, and open up better opportunities for further research, leading to the development of novel PTC regimens that are clinically effective. This review explores the mechanisms underlying cyclin D1 overexpression in PTC. Furthermore, we discuss the role of cyclin D1 in PTC tumorigenesis via its interactions with other regulatory elements. Finally, recent progress in the development of therapeutic options targeting cyclin D1 in PTC is examined and summarized.

Aberrant Cyclin D1 splicing in cancer: from molecular mechanism to therapeutic modulation

Cyclin D1 (CCND1), a crucial mediator of cell cycle progression, possesses many mutation types with different mutation frequencies in human cancers. The G870A mutation is the most common mutation in CCND1, which produces two isoforms: full-length CCND1a and divergent C-terminal CCND1b. The dysregulation of the CCND1 isoforms is associated with multiple human cancers. Exploring the molecular mechanism of CCND1 isoforms has offer new insight for cancer treatment. On this basis, the alterations of CCND1 gene are described, including amplification, overexpression, and mutation, especially the G870A mutation. Subsequently, we review the characteristics of CCND1 isoforms caused by G870A mutation. Additionally, we summarize cis-regulatory elements, trans-acting factors, and the splice mutation involved in splicing regulation of CCND1. Furthermore, we highlight the function of CCND1 isoforms in cell cycle, invasion, and metastasis in cancers. Importantly, the clinical role of CCND1 isoforms is also discussed, particularly concerning prognosis, chemotherapy, and radiotherapy. Last, emphasis is given to the corrective strategies that modulate the cancerous CCND1 isoforms. Thus, it is highlighting significance of aberrant isoforms of CCND1 as targets for cancer therapy.

Deciphering the Biological Effects of Radiotherapy in Cancer Cells

Radiotherapy remains an effective conventional method of treatment for patients with cancer. However, the clinical efficacy of radiotherapy is compromised by the development of radioresistance of the tumor cells during the treatment. Consequently, there is need for a comprehensive understanding of the regulatory mechanisms of tumor cells in response to radiation to improve radiotherapy efficacy. The current study aims to highlight new developments that illustrate various forms of cancer cell death after exposure to radiation. A summary of the cellular pathways and important target proteins that are responsible for tumor radioresistance and metastasis is also provided. Further, the study outlines several mechanistic descriptions of the interaction between ionizing radiation and the host immune system. Therefore, the current review provides a reference for future research studies on the biological effects of new radiotherapy technologies, such as ultra-high-dose-rate (FLASH) radiotherapy, proton therapy, and heavy-ion therapy.

NEIL3 Mediates Lung Cancer Progression and Modulates PI3K/AKT/mTOR Signaling: A Potential Therapeutic Target

Background. Nei endonuclease VIII-like 3 (NEIL3) is widely involved in pathophysiological processes of the body; however, its role in lung cancer has not been conclusively determined. Objective. This study is aimed at exploring the role of NEIL3 in lung cancer. Methods. The public data used in this study were downloaded from The Cancer Genome Atlas (TCGA) database. “Limma” in R was used for the analysis of differentially expressed genes. Clinical correlations and prognostic analyses were performed using the survival package in R. The proliferative abilities of lung cancer cells were evaluated by the CCK8 and colony formation assays while their invasive and migration abilities were assessed by the transwell and wound healing assays. Quantitative real-time PCR (qRT-PCR) and western blot analyses were utilized to detect RNA and protein levels. Biological differences between groups were determined by gene set enrichment analysis (GSEA). Tumor Immune Dysfunction and Exclusion (TIDE) as well as Genomics of Drug Sensitivity in Cancer (GDSC) was used for immunotherapeutic and chemotherapeutic sensitivity analyses. Results. NEIL3 was upregulated in NSCLC tissues and cell lines, implying that it is involved in lung cancer initiation and progression. Clinical correlation and prognostic analyses showed that NEIL3 was associated with worse clinical features (stage and T and N classifications) and poor prognostic outcomes. In vitro, NEIL3 significantly enhanced NSCLC proliferation, invasion, and migration. GSEA indicated that NEIL3 might be involved in PI3K/AKT/mTOR, G2/M checkpoints, and E2F target pathways. Inhibition of NEIL3 suppressed cyclinD1 and p-AKT protein levels; however, it had no effects on AKT levels, indicating that NEIL3 can partially activate the PI3K/AKT/mTOR signaling pathway. The predicted result of TIDE indicated that immunotherapeutic nonresponders had elevated NEIL3 levels. Moreover, there was a positive correlation between NEIL3 levels and chemosensitivity to cisplatin and paclitaxel. Conclusion. In general, NEIL3 mediates NSCLC progression and affects sensitivity to immunotherapy and chemotherapy; therefore, it is a potential molecular target for treatment.

Pre-mRNA processing factor 19 functions in DNA damage repair and radioresistance by modulating cyclin D1 in hepatocellular carcinoma

Pre-mRNA processing factor 19 (PRP19) is elevated in hepatocellular carcinoma (HCC); however, little is known about its function in DNA damage repair in HCC. In this study, analysis of The Cancer Genome Atlas data and our tumor models after ionizing radiation (IR) treatment indicated that increased expression of PRP19 was positively correlated with DNA damage repair. Gain of PRP19 expression induced by plasmids resulted in decreases in apoptosis and double-strand breaks (DSBs), and an increase in cell survival after IR. Loss of PRP19 expression induced by small interfering RNAs resulted in the accumulation of apoptosis and DSBs, and a decrease in cell survival. Mechanistically, the effect of PRP19 on DNA damage repair was mediated by the modulation of cyclin D1 expression in HCC. PRP19 controlled the translation of cyclin D1 by modulating eukaryotic initiation factor 4E. PRP19 affected the DNA damage repair ability of cyclin D1 by interacting with the WD40 domain. The combination of PRP19 and cyclin D1 was more valuable than each single marker for predicting the prognosis of patients. Taken together, the present results demonstrate that PRP19 promotes DNA damage repair by modulating cyclin D1 expression and function, thereby contributing to the radioresistance in HCC.

Cyy260, a novel small molecule inhibitor, suppresses non-small cell lung cancer cell growth via JAK2/STAT3 pathway

Non-small cell lung cancer (NSCLC) is a malignant tumor that accounts for the most new cancer cases and cancer-related deaths worldwide, and the proliferation and metastasis of NSCLC are the main reasons for treatment failure and patient death. Traditional chemotherapeutic drugs have low selectivity, which can kill cancer cells and cause damage to normal cells at the same time. Therefore, it is particularly important to study therapies that target cancer cells and to find low-toxicity, high-efficiency anticancer drugs. Cyy260 is a novel small molecule inhibitor that we synthesized for the first time. Here, we investigated the in vitro and in vivo antitumor activities of Cyy260 and explored the underlying mechanisms in NSCLC. Cyy260 had a concentration- and time-dependent inhibitory effect on NSCLC cells, but it was less toxic to normal cells. Cyy260 regulated apoptosis through intracellular and extracellular apoptotic pathways. In addition, Cyy260 could also induce cell cycle arrest, thereby inhibiting cell proliferation. Further analysis of molecular mechanisms showed that the JAK2/STAT3 signaling pathway was involved in the antitumor effect mediated by Cyy260. Analysis of subcutaneously transplanted tumors in mice showed that Cyy260 suppressed tumor growth in vivo. Our results proved that Cyy260 is a novel inhibitor of the JAK2/STAT3 pathway thus may have potential in therapy of NSCLC and other cancers.

Targeted Therapies in Lung Cancers: Current Landscape and Future Prospects

BACKGROUND

Lung cancer is the most common and malignant cancer worldwide. Targeted therapies have emerged as a promising treatment strategy for lung cancers.

OBJECTIVE

The objective of this study is to evaluate the current landscape of targets and finding promising targets for future new drug discovery for lung cancers by identifying the science-technology-clinical development pattern and mapping the interaction network of targets.

METHODS

Targets for cancers were classified into 3 groups based on a paper published in Nature. We search for scientific literature, patent documents and clinical trials of targets in Group 1 and Group 2 for lung cancers. Then, a target-target interaction network of Group 1 was constructed, and the science-technology-clinical(S-T-C) development patterns of targets in Group 1 were identified. Finally, based on the cluster distribution and the development pattern of targets in Group 1, interactions between the targets were employed to predict potential targets in Group 2 on drug development.

RESULTS

The target-target interaction(TTI)network of group 1 resulted in 3 clusters with different developmental stages. The potential targets in Group 2 are divided into 3 ranks. Level-1 is the first priority and level-3 is the last. Level-1 includes 16 targets, such as STAT3, CRKL, and PTPN11, that are mostly involved in signaling transduction pathways. Level-2 and level-3 contain 8 and 6 targets related to various biological functions.

CONCLUSION

This study will provide references for drug development in lung cancers, emphasizing that priorities should be given to targets in Level-1, whose mechanisms are worth further exploration.