Targeting CDK2 in cancer: challenges and opportunities for therapy

Rupatadine inhibits colorectal cancer cell proliferation through the PIP5K1A/Akt/CDK2 pathway

BACKGROUND

Phosphatidylinositol-4-phosphate 5-kinase type 1 alpha (PIP5K1A) acts upstream of the Akt regulatory pathway and is abnormally expressed in many types of malignancies. However, the role and mechanism of PIP5K1A in colorectal cancer (CRC) have not yet been reported. In this study, we aimed to determine the association between PIP5K1A and progression of CRC and assess the efficacy and mechanism by which rupatadine targets PIP5K1A.

METHODS

Firstly, expression and function of PIP5K1A in CRC were investigated by human colon cancer tissue chip analysis and cell proliferation assay. Next, rupatadine was screened by computational screening and cytotoxicity assay and interactions between PIP5K1A and rupatadine assessed by kinase activity detection assay and bio-layer interferometry analysis. Next, rupatadine's anti-tumor effect was evaluated by in vivo and in vitro pharmacodynamic assays. Finally, rupatadine's anti-tumor mechanism was explored by quantitative real-time reverse-transcription polymerase chain reaction, western blot, and immunofluorescence.

RESULTS

We found that PIP5K1A exerts tumor-promoting effects as a proto-oncogene in CRC and aberrant PIP5K1A expression correlates with CRC malignancy. We also found that rupatadine down-regulates cyclin-dependent kinase 2 and cyclin D1 protein expression by inhibiting the PIP5K1A/Akt/GSK-3β pathway, induces cell cycle arrest, and inhibits CRC cell proliferation in vitro and in vivo.

CONCLUSIONS

PIP5K1A is a potential drug target for treating CRC. Rupatadine, which targets PIP5K1A, could serve as a new option for treating CRC, its therapeutic mechanism being related to regulation of the Akt/GSK-3β signaling pathway.

Phytochemical analysis, in-vitro and in-silico study of antiproliferative activity of ethyl acetate fraction of Launaea cornuta (Hochst. ex Oliv. & Hiern) C. Jeffrey against human cervical cancer cell line

Introduction: Cervical cancer is one of the leading causes of death among women globally due to the limitation of current treatment methods and their associated adverse side effects. Launaea cornuta is used as traditional medicine for the treatment of a variety of diseases including cancer. However, there is no scientific validation on the antiproliferative activity of L. cornuta against cervical cancer. Objective: This study aimed to evaluate the selective antiproliferative, cytotoxic and antimigratory effects of L. cornuta and to explore its therapeutical mechanisms in human cervical cancer cell lines (HeLa-229) through a network analysis approach. Materials and methods: The cytotoxic effect of L. cornuta ethyl acetate fraction on the proliferation of cervical cancer cells was evaluated by 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) bioassay and the antimigratory effect was assessed by wound healing assays. Compounds were analysed using the qualitative colour method and gas chromatography-mass spectroscopy (GC-MS). Subsequently, bioinformatic analyses, including the protein-protein interaction (PPI) network analysis, Gene Ontology (GO), and Kyoto Encyclopaedia of Genes and Genomes (KEGG) analysis, were performed to screen for potential anticervical cancer therapeutic target genes of L. cornuta. Molecular docking (MD) was performed to predict and understand the molecular interactions of the ligands against cervical cancer. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was performed to validate the network analysis results. Results: L. cornuta ethyl acetate fraction exhibited a remarkable cytotoxic effect on HeLa-229 proliferation (IC50 of 20.56 ± 2.83 μg/mL) with a selectivity index (SI) of 2.36 with minimal cytotoxicity on non-cancerous cells (Vero-CCL 81 (IC50 of 48.83 ± 23.02). The preliminary screening revealed the presence of glycosides, phenols, saponins, terpenoids, quinones, and tannins. Thirteen compounds were also identified by GC-MS analysis. 124 potential target genes associated with the effect of L. cornuta ethyl acetate fraction on human cervical cancer were obtained, including AKT1, MDM2, CDK2, MCL1 and MTOR were identified among the top hub genes and PI3K/Akt1, Ras/MAPK, FoxO and EGFR signalling pathways were identified as the significantly enriched pathways. Molecular docking results showed that stigmasteryl methyl ether had a good binding affinity against CDK2, ATK1, BCL2, MDM2, and Casp9, with binding energy ranging from -7.0 to -12.6 kcal/mol. Tremulone showed a good binding affinity against TP53 and P21 with -7.0 and -8.0 kcal/mol, respectively. This suggests a stable molecular interaction of the ethyl acetate fraction of L. cornuta compounds with the selected target genes for cervical cancer. Furthermore, RT-qPCR analysis revealed that CDK2, MDM2 and BCL2 were downregulated, and Casp9 and P21 were upregulated in HeLa-229 cells treated with L. cornuta compared to the negative control (DMSO 0.2%). Conclusion: The findings indicate that L. cornuta ethyl acetate fraction phytochemicals modulates various molecular targets and pathways to exhibit selective antiproliferative and cytotoxic effects against HeLa-229 cells. This study lays a foundation for further research to develop innovative clinical anticervical cancer agents.

Multiplexed Profiling of CDK Kinase Activities in Tumor Biopsies with Fluorescent Peptide Biosensors

Detection of disease biomarkers constitutes a major challenge for the development of personalized and predictive diagnostics as well as companion assays. Protein kinases (PKs) involved in the coordination of cell cycle progression and proliferation that are hyperactivated in human cancers constitute attractive pharmacological targets and relevant biomarkers. Although it is relatively straightforward to assess the relative abundance of PKs in a biological sample, there is not always a direct correlation with enzymatic activity, which is regulated by several posttranslational mechanisms. Studies of relative abundance therefore convey limited information, and the lack of selective, sensitive, and standardized tools together with the inherent complexity of biological samples makes it difficult to quantify PK activities in physio-pathological tissues. To address this challenge, we have developed a toolbox of fluorescent biosensors that report on CDK activities in a sensitive, selective, dose-dependent, and quantitative fashion, which we have implemented to profile CDK activity signatures in cancer cell lines and biopsies from human tumors. In this study, we report on a standardized and calibrated biosensing approach to quantify CDK1,2,4, and 6 activities simultaneously through a combination of four different biosensors in a panel of 40 lung adenocarcinoma and 40 follicular lymphoma samples. CDK activity profiling highlighted two major patterns which were further correlated with age, sex of patients, tumor size, grade, and genetic and immunohistochemical features of the biopsies. Multiplex CDKACT biosensing technology provides new and complementary information relative to current genetic and immunohistochemical characterization of tumor biopsies, which will be useful for diagnostic purposes, potentially guiding therapeutic decision. These fluorescent peptide biosensors offer promise for personalized diagnostics based on kinase activity profiling.

Molecular docking and MD simulation studies of 4-thiazol-N-(pyridin-2-yl)pyrimidin-2-amine derivatives as novel inhibitors targeted to CDK2/4/6

PURPOSE

Nowadays, cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have been approved for treating metastatic breast cancer and have achieved inspiring curative effects. But some discoveries have indicated that CDK 4/6 are not the requisite factors in some cell types because CDK2 partly compensates for the inhibition of CDK4/6. Thus, it is urgent to design CDK2/4/6 inhibitors for significantly enhancing their potency. This study aims to explore the mechanism of the binding of CDK2/4/6 kinases and their inhibitors to design novel CDK2/4/6 inhibitors for significantly enhancing their potency in different kinds of cancers.

MATERIALS AND METHODS

A series of 72 disparately functionalized 4-substituted N-phenylpyrimidin-2-amine derivatives exhibiting potent inhibitor activities against CDK2, CDK4 and CDK6 were collected to apply to this research. The total set of these derivatives was divided into a training set (54 compounds) and a test set (18 compounds). The derivatives were constructed through the sketch molecule module in SYBYL 6.9 software. A Powell gradient algorithm and Tripos force field were used to calculate the minimal structural energy and the minimized structure was used as the initial conformation for molecular docking. By the means of 3D-QSAR models, partial least squares (PLS) analysis, molecular dynamics (MD) simulations and binding free energy calculations, we can find the relationship between structure and biological activity.

RESULTS

In this study, we used molecular docking, 3D-QSAR and molecular dynamics simulation methods to comprehensively analyze the interaction and structure-activity relationships of 72 new CDK2/4/6 inhibitors. We used detailed statistical data to reasonably verify the constructed 3D-QSAR models for three receptors (q2 of CDK2 = 0.714, R2pred = 0.764, q2 = 0.815; R2pred of CDK4 = 0.681, q2 = 0.757; R2pred of CDK6 = 0.674). MD simulations and decomposition energy analysis validated the reasonability of the docking results and identified polar interactions as crucial factors that influence the different bioactivities of the studied inhibitors of CDK2/4/6 receptors, especially the electrostatic interactions of Lys33/35/43 and Asp145/158/163. The nonpolar interaction with Ile10/12/19 was also critical for the differing potencies of the CDK2/4/6 inhibitors. We concluded that the following probably enhanced the bioactivity against CDK2/4/6 kinases: (1) electronegative groups at the N1-position and electropositive and moderate-sized groups at ring E; (2) electrogroups featured at R2; (3) carbon atoms at the X-position or ring C replaced by a benzene ring; and (4) an electrogroup as R4.

CONCLUSION

Previous studies, to our knowledge, only utilized a single approach of 3D-QSAR and did not integrate this method with other sophisticated techniques such as molecular dynamics simulations to discover new potential inhibitors of CDK2, CDK4, or CDK6. So we applied the intergenerational technology, such as 3D-QSAR technology, molecular docking simulation techniques, molecular dynamics simulations and MMPBSA19/MMGBSA20-binding free energy calculations to statistically explore the correlations between the structure with biological activities. The constructed 3D-QSAR models of the three receptors were reasonable and confirmed by the excellent statistical data. We hope the results obtained from this work will provide some useful references for the development of novel CDK2/4/6 inhibitors.

Molecular docking approach for the design and synthesis of new pyrazolopyrimidine analogs of roscovitine as potential CDK2 inhibitors endowed with pronounced anticancer activity

Cyclin-dependent kinase 2 (CDK2) is a vital protein for controlling cell cycle progression that is critically associated with various malignancies and its inhibition could offer a convenient therapeutic approach in designing anticancer remedies. Consequently, this study aimed to design and synthesize new CDK2 inhibitors featuring roscovitine as a template model. The purine ring of roscovitine was bioisosterically replaced with the pyrazolo[3,4-d]pyrimidine scaffold, in addition to some modifications in the side chains. A preliminary molecular docking study for the target chemotypes in the CDK2 binding domain revealed their ability to accomplish similar binding patterns and interactions to that of the lead compound roscovitine. Afterwards, synthesis of the new derivatives was accomplished. Then, the initial anticancer screening at a single dose by the NCI revealed that compounds 7a, 9c, 11c, 17a and 17b achieved the highest GI% values reaching up to 150 % indicating their remarkable activity. These derivatives were subsequently selected to undertake five-dose testing, where compounds 7a, 9c, 11c and 17a unveiled the most pronounced activity against almost the full panel with GI50 ranges; 1.41-28.2, 0.116-2.39, 0.578-60.6 and 1.75-42.4 µM, respectively and full panel GI50 (MG-MID); 8.24, 0.6, 2.46 and 6.84 µM, respectively. CDK2 inhibition assay presented compounds 7a and 9c as the most potent inhibitors with IC50 values of 0.262 and 0.281 µM, respectively which are nearly 2.4 folds higher than the reference ligand roscovitine (IC50 = 0.641 µM). Besides, flow cytometric analysis on the most susceptible and safe cell lines depicted that 7a caused cell cycle arrest at G1/S phase in renal cancer cell line (RXF393) while 9c led to cell growth arrest at S phase in breast cancer cell line (T-47D) along with pronounced apoptotic induction in the mentioned cell lines. These findings afforded new anticancer pyrazolo[3,4-d]pyrimidine, roscovitine analogs, acting via CDK2 inhibition.

TRIM47 silencing inhibits the malignant biological behaviors of prostate cancer cells by regulating MDM2/p53 signaling

Prostate cancer (PCa) is a prevalent male malignancy globally. Tripartite motif 47 (TRIM47) has been reported to be associated with PCa. However, how TRIM47 acts on PCa is still incompletely understood. Here, we explored the biological roles of TRIM47 in PCa cells and investigated its potential regulatory mechanism. TRIM47 expression in PCa cells was detected by qRT-PCR and western blot. After TRIM47 silencing, the viability of PCa cells was measured using CCK-8 method. Flow cytometry was employed to estimate cell cycle. Cell apoptotic level was subjected to appraisement with TUNEL assay. Additionally, wound healing- and transwell assays were adopted for evaluation of migration and invasion of PCa cells. Moreover, the Biogrid database and HDOCK SERVER predicated that TRIM47 could interact with mouse double minute 2 (MDM2), which was detected using the Co-immunoprecipitation (co-IP) assay and glutathione S-transferase (GST) pull-down assay. The expression of proteins in MDM2/p53 signaling was detected by western blot analysis. Results indicated that TRIM47 expression was highly expressed in PCa cells. TRIM47 knockdown inhibited PCa proliferation and cell cycle whereas promoted cell apoptosis. Besides, TRIM47 knockdown significantly inhibited the migration and invasion of PCa cells. In addition, TRIM47 was proved to bind to MDM2 and regulated MDM2/p53 expression. Importantly, MDM2 overexpression counteracted the impacts of TRIM47 knockdown on cell viability, cell cycle, apoptosis, migration and invasion by regulating the MDM2/p53 pathway. Collectively, our results suggested that TRIM47 silencing inhibits the malignant biological behaviors of prostate cancer cells by regulating MDM2/p53 signaling, which may provide a novel therapeutic target for PCa treatment.

miR-92b-3p protects retinal tissues against DNA damage and apoptosis by targeting BTG2 in experimental myopia

BACKGROUND

Myopia is one of the eye diseases that can damage the vision of young people. This study aimed to explore the protective role of miR-92b-3p against DNA damage and apoptosis in retinal tissues of negative lens-induced myopic (LIM) guinea pigs by targeting BTG2.

METHODS

Biometric measurements of ocular parameters, flash electroretinogram (FERG), and retinal thickness (RT) were performed after miR-92b-3p intravitreal injection in LIM guinea pigs. The apoptotic rate was detected by Annexin V-FITC/PI double staining, and the change in mitochondrial membrane potential was measured by JC-1 staining. Retinal apoptosis and expression of p53, BTG2, and CDK2 were explored by TdT-mediated dUTP-biotin nick labeling (TUNEL) and immunofluorescence staining assays, respectively. BTG2 and its upstream and downstream molecules at gene and protein levels in retinal tissues were measured by real-time quantitative PCR (qPCR) and Western blotting.

RESULTS

Compared with normal controls (NC), the ocular axial length of LIM guinea pig significantly increased, whereas refraction decreased. Meanwhile, dMax-a and -b wave amplitudes of ERG declined, retinal thickness was decreased, the number of apoptotic cells and apoptotic rate in LIM eyes was exaggerated, and the mitochondrial membrane potential significantly decreased. In addition, results of qPCR and Western blot assays showed that the expression levels of p53, BTG2, CDK2, and BAX in LIM guinea pigs were higher than the levels of the NC group, whereas the BCL-2 expression level was decreased. By contrast, the miR-92b-3p intravitreal injection in LIM guinea pigs could significantly inhibit axial elongation, alleviate DNA damage and apoptosis, and thus protect guinea pigs against myopia.

CONCLUSION

In conclusion, p53 and BTG2 were activated in the retinal tissue of myopic guinea pigs, and the activated BTG2 could elevate the expression of CDK2 and BAX, and attenuate the expression of BCL-2, which in turn promote apoptosis and eventually lead to retinal thinning and impaired visual function in myopic guinea pigs. The miR-92b-3p intravitreal injection can attenuate the elongation of ocular length and retinal thickness, and inhibit the CDK2, BAX, and p53 expression by targeting BTG2, thereby ameliorating DNA damage and apoptosis in LIM guinea pigs and protecting ocular tissues.

Bruceantinol works as a CDK2/4/6 inhibitor to inhibit the growth of breast cancer cells

Bruceantinol (BOL), isolated from the dried fruit of the Brucea javanica (L.) Merr., exhibits cytotoxic effects on breast cancer cells. However, the underlying mechanism remains to be fully addressed. In this paper, the MCF-7 and MDA-MB-231 human breast cancer cell lines were used as experimental models to uncover how BOL inhibits breast cancer cell growth. The effects of BOL on cell growth, proliferation, the cell cycle, and apoptosis were investigated using the MTT assays, EdU incorporation assays, and flow cytometry, respectively. Bioinformatics techniques were applied to predict the key targets of BOL in breast cancer. Subsequent validation of these targets and the anti-breast cancer mechanism of BOL was conducted through Western blotting, RT-PCR, siRNA transfection, and molecular docking analysis. The results demonstrated that BOL dose- and time-dependently reduced the growth of both cell lines, impeded cell proliferation, disrupted the cell cycle, and induced necrosis in MCF-7 cells and apoptosis in MDA-MB-231 cells. Furthermore, CDK2/4/6 were identified as BOL targets, and their knockdown reduced cell sensitivity to BOL. BOL was found to potentially bind with CDK2/4/6 to facilitate protein degradation through the proteasome pathway. Additionally, BOL activated ERK in MDA-MB-231 cells, and this activation was required for BOL's functions in these cells. Collectively, BOL may act as an inhibitor of CDK2/4/6 to exert anti-breast cancer effects. Its effects on cell growth and CDK2/4/6 expression may also depend on ERK activation in HRs-HER2- breast cancer cells. These results suggest the potential of using BOL for treating breast cancer.

DNMT1-targeting remodeling global DNA hypomethylation for enhanced tumor suppression and circumvented toxicity in oral squamous cell carcinoma

BACKGROUND

The faithful maintenance of DNA methylation homeostasis indispensably requires DNA methyltransferase 1 (DNMT1) in cancer progression. We previously identified DNMT1 as a potential candidate target for oral squamous cell carcinoma (OSCC). However, how the DNMT1- associated global DNA methylation is exploited to regulate OSCC remains unclear.

METHODS

The shRNA-specific DNMT1 knockdown was employed to target DNMT1 on oral cancer cells in vitro, as was the use of DNMT1 inhibitors. A xenografted OSCC mouse model was established to determine the effect on tumor suppression. High-throughput microarrays of DNA methylation, bulk and single-cell RNA sequencing analysis, multiplex immunohistochemistry, functional sphere formation and protein immunoblotting were utilized to explore the molecular mechanism involved. Analysis of human samples revealed associations between DNMT1 expression, global DNA methylation and collaborative molecular signaling with oral malignant transformation.

RESULTS

We investigated DNMT1 expression boosted steadily during oral malignant transformation in human samples, and its inhibition considerably minimized the tumorigenicity in vitro and in a xenografted OSCC model. DNMT1 overexpression was accompanied by the accumulation of cancer-specific DNA hypomethylation during oral carcinogenesis; conversely, DNMT1 knockdown caused atypically extensive genome-wide DNA hypomethylation in cancer cells and xenografted tumors. This novel DNMT1-remodeled DNA hypomethylation pattern hampered the dual activation of PI3K-AKT and CDK2-Rb and inactivated GSK3β collaboratively. When treating OSCC mice, targeting DNMT1 achieved greater anticancer efficacy than the PI3K inhibitor, and reduced the toxicity of blood glucose changes caused by the PI3K inhibitor or combination of PI3K and CDK inhibitors as well as adverse insulin feedback.

CONCLUSIONS

Targeting DNMT1 remodels a novel global DNA hypomethylation pattern to facilitate anticancer efficacy and minimize potential toxic effects via balanced signaling synergia. Our study suggests DNMT1 is a crucial gatekeeper regarding OSCC destiny and treatment outcome.

5-Oxo-dihydropyranopyran derivatives as anti-proliferative agents; synthesis, biological evaluation, molecular docking, MD simulation, DFT, and in-silico pharmacokinetic studies

A series of ethyl 2-amino-7-methyl-5-oxo-4-phenyl-4,5-dihydropyrano[4,3-b]pyran-3-carboxylate derivatives (4a-j) bearing different substitutions on the C4-phenyl ring was synthesized. The anti-proliferative activity of all the synthesized compounds was assessed against two human cancer-cell lines, including SW-480 and MCF-7, by using MTT method. Derivatives 4g, 4i, and 4j, possessing 4-NO2, 4-Cl, and 3,4,5-(OCH3)3 substitutions, were found to be the most potent compounds against both cell lines. The obtained IC50 values for 4g, 4i, and 4j were 34.6, 35.9, and 38.6 μM against SW-480 cells and 42.6, 34.2, and 26.6 μM against MCF-7 cells, respectively. Evaluation of the free radical scavenging potential of the compounds against DPPH radicals showed the highest result for compound 4j with an EC50 value of 580 μM. Molecular docking studies revealed the compounds were well accommodated within the binding site of cyclin-dependent kinase-2 (CDK2) with binding energies comparable to those of DTQ (the co-crystallized inhibitor) and BMS-265246 (a well-known CDK2 inhibitor). Molecular dynamics simulation studies confirmed the interactions and stability of the 4g-CDK2 complex. All derivatives, except 4g, were predicted to comply with the drug-likeness rules. Compound 4j may be proposed as an anti-cancer lead candidate for further studies due to the promising findings from in-silico pharmacokinetic studies, such as high GI absorption, not being a P-gp substrate, and being a P-gp inhibitor. Density functional theory (DFT) analysis was performed at the B3LYP/6-311++G (d,p) level of theory to examine the reactivity or stability descriptors of 4d, 4g, 4i, and 4j derivatives. The highest value of energy gap between HOMO and LUMO and thermochemical parameters were obtained for 4i and 4j.

Triggering Breast Cancer Apoptosis via Cyclin-Dependent Kinase Inhibition and DNA Damage by Novel Pyrimidinone and 1,2,4-Triazolo[4,3-a]pyrimidinone Derivatives

Combinations of apoptotic inducers are common clinical practice in breast cancer. However, their efficacy is limited by the heterogeneous pharmacokinetic profiles. An advantageous alternative is merging their molecular entities in hybrid multitargeted scaffolds exhibiting synergistic activities and uniform distribution. Herein, we report apoptotic inducers simultaneously targeting DNA and CDK-2 (cyclin-dependent kinase-2) inspired by studies revealing that CDK-2 inhibition sensitizes breast cancer to DNA-damaging agents. Accordingly, rationally substituted pyrimidines and triazolopyrimidines were synthesized and assayed by MTT against MCF-7, MDA-MB231, and Wi-38 cells compared to doxorubicin. The N-(4-amino-2-((2-hydrazinyl-2-oxoethyl)thio)-6-oxo-1,6-dihydropyrimidin-5-yl)acetamide 5 and its p-nitrophenylhydrazone 8 were the study hits against MCF-7 (IC50 = 0.050 and 0.146 μM) and MDA-MB231 (IC50 = 0.826 and 0.583 μM), induced DNA damage at 10.64 and 30.03 nM, and inhibited CDK-2 (IC50 = 0.172 and 0.189 μM). 5 induced MCF-7 apoptosis by 46.75% and disrupted cell cycle during S phase. Docking and MD simulations postulated their stable key interactions.

CDCA3 is a potential biomarker for glioma malignancy and targeted therapy

CDCA3, a cell cycle regulator gene that plays a catalytic role in many tumors, was initially identified as a regulator of cell cycle progression, specifically facilitating the transition from the G2 phase to mitosis. However, its role in glioma remains unknown. In this study, bioinformatics analyses (TCGA, CGGA, Rembrandt) shed light on the upregulation and prognostic value of CDCA3 in gliomas. It can also be included in a column chart as a parameter predicting 3- and 5-year survival risk (C index = 0.86). According to Gene Set Enrichment Analysis and gene ontology analysis, the biological processes of CDCA3 are mainly concentrated in the biological activities related to cell cycle such as DNA replication and nuclear division. CDCA3 is closely associated with many classic glioma biomarkers (CDK4, CDK6), and inhibitors of CDK4 and CDK6 have been shown to be effective in tumor therapy. We have demonstrated that high expression of CDCA3 indicates a higher malignancy and poorer prognosis in gliomas.

Clinicopathological Significance of Cyclin-Dependent Kinase 2 (CDK2) in Ductal Carcinoma In Situ and Early-Stage Invasive Breast Cancers

Cyclin-dependent kinase 2 (CDK2) is a key cell cycle regulator, with essential roles during G1/S transition. The clinicopathological significance of CDK2 in ductal carcinomas in situ (DCIS) and early-stage invasive breast cancers (BCs) remains largely unknown. Here, we evaluated CDK2's protein expression in 479 BC samples and 216 DCIS specimens. Analysis of CDK2 transcripts was completed in the METABRIC cohort (n = 1980) and TCGA cohort (n = 1090), respectively. A high nuclear CDK2 protein expression was significantly associated with aggressive phenotypes, including a high tumour grade, lymph vascular invasion, a poor Nottingham prognostic index (all p-values < 0.0001), and shorter survival (p = 0.006), especially in luminal BC (p = 0.009). In p53-mutant BC, high nuclear CDK2 remained linked with worse survival (p = 0.01). In DCIS, high nuclear/low cytoplasmic co-expression showed significant association with a high tumour grade (p = 0.043), triple-negative and HER2-enriched molecular subtypes (p = 0.01), Comedo necrosis (p = 0.024), negative ER status (p = 0.004), negative PR status (p < 0.0001), and a high proliferation index (p < 0.0001). Tumours with high CDK2 transcripts were more likely to have higher expressions of genes involved in the cell cycle, homologous recombination, and p53 signaling. We provide compelling evidence that high CDK2 is a feature of aggressive breast cancers. The clinical evaluation of CDK2 inhibitors in early-stage BC patients will have a clinical impact.

DDX18 Facilitates the Tumorigenesis of Lung Adenocarcinoma by Promoting Cell Cycle Progression through the Upregulation of CDK4

Lung adenocarcinoma (LUAD) is the most prevalent and aggressive subtype of lung cancer, exhibiting a dismal prognosis with a five-year survival rate below 5%. DEAD-box RNA helicase 18 (DDX18, gene symbol DDX18), a crucial regulator of RNA metabolism, has been implicated in various cellular processes, including cell cycle control and tumorigenesis. However, its role in LUAD pathogenesis remains elusive. This study demonstrates the significant upregulation of DDX18 in LUAD tissues and its association with poor patient survival (from public databases). Functional in vivo and in vitro assays revealed that DDX18 knockdown potently suppresses LUAD progression. RNA sequencing and chromatin immunoprecipitation experiments identified cyclin-dependent kinase 4 (CDK4), a cell cycle regulator, as a direct transcriptional target of DDX18. Notably, DDX18 depletion induced G1 cell cycle arrest, while its overexpression promoted cell cycle progression even in normal lung cells. Interestingly, while the oncogenic protein c-Myc bound to the DDX18 promoter, it did not influence its expression. Collectively, these findings establish DDX18 as a potential oncogene in LUAD, functioning through the CDK4-mediated cell cycle pathway. DDX18 may represent a promising therapeutic target for LUAD intervention.

Discovery of novel macrocyclic derivatives as potent and selective cyclin-dependent kinase 2 inhibitors

Cyclin-dependent kinase 2 (CDK2) is a member of CDK family of kinases (CDKs) that regulate the cell cycle. Its inopportune or over-activation leads to uncontrolled cell cycle progression and drives numerous types of cancers, especially ovarian, uterine, gastric cancer, as well as those associated with amplified CCNE1 gene. However, developing selective lead compound as CDK2 inhibitors remains challenging owing to similarities in the ATP pockets among different CDKs. Herein, we described the optimization of compound 1, a novel macrocyclic inhibitor targeting CDK2/5/7/9, aiming to discover more selective and metabolically stable lead compound as CDK2 inhibitor. Molecular dynamic (MD) simulations were performed for compound 1 and 9 to gain insights into the improved selectivity against CDK5. Further optimization efforts led to compound 22, exhibiting excellent CDK2 inhibitory activity, good selectivity over other CDKs and potent cellular effects. Based on these characterizations, we propose that compound 22 holds great promise as a potential lead candidate for drug development.

Network pharmacology and molecular docking reveal the mechanisms of curcumin activity against esophageal squamous cell carcinoma

Background: Curcumin (CUR), an effective traditional Chinese medicinal extract, displays good anti-cancer activity against various cancers. Nevertheless, the impacts and fundamental mechanisms of CUR to treat esophageal squamous cell carcinoma (ESCC) yet to be comprehensively clarified. This study examined the suppressive impacts of CUR on ESCC. Methods: For a comprehensive understanding of the effect of CUR in ESCC. The CUR targets and ESCC-related genes were identified respectively, and the intersection targets between CUR and ESCC were acquired. Then, we examined the intersection targets and discovered genes that were expressed differently in ESCC. Using DAVID, enrichment analyses were conducted on the targets of CUR-ESCC. The STRING database and Cytoscape v.3.9.1 were utilized to build networks for protein-protein interaction (PPI) and drug-target-pathway. Furthermore, the interactions between CUR and its core targets were confirmed by molecular docking studies. To confirm the effects of CUR on ESCC cells, in vitro experiments were finally conducted. Results: Overall, 47 potential CUR targets for ESCC treatment were identified. The KEGG pathway enrichment analysis identified 61 signaling pathways, primarily associated with the FoxO signaling, the cell cycle, cellular senescence, the IL-17 signaling pathway which play important roles in ESCC progression. In the PPI network and the docking results identified CHEK1 and CDK6 as the core targets that positively associated with ESCC survival. CUR arrested ESCC cells at the G2/M and S phases, as shown by flow cytometry. Colony formation and CCK8 assays showed that CUR can inhibit the proliferative ability of ESCC cells. The Transwell invasion results validated that CUR can significantly inhibit the invasion rates of ESCC cells. Conclusion: Collectively, these findings indicate that CUR exhibits pharmacological effects on multiple targets and pathways in ESCC.

CCNA2 and KIF23 are molecular targets for the prognosis of adenoid cystic carcinoma

OBJECTIVE

Adenoid cystic carcinoma (ACC) is a tumor type derived from glands. However, relationship between CCNA2 and KIF23, and adenoid cystic carcinoma remains unclear.

METHODS

GSE36820 and GSE88804 profiles for ACC were obtained from the Gene Expression Omnibus (GEO). Differentially expressed genes (DEGs) were identified, and Weighted Gene Co-expression Network Analysis (WGCNA) was conducted. Subsequently, the construction and analysis of protein-protein interaction (PPI) network, functional enrichment analysis, and Gene Set Enrichment Analysis (GSEA) were performed. A gene expression heat map was generated to visually depict the expression difference of core genes between adenoid cystic carcinoma and normal samples. TargetScan was employed to identify miRNAs that regulated central DEGs. Western blotting (WB) was conducted for cell verification.

RESULTS

A total of 885 DEGs were identified. GO and KEGG analyses revealed their main enrichment in responses to chemical stimuli, cell proliferation, tissue development, and regulation of cell proliferation. The GO and KEGG results indicated significant enrichment in aldosterone-regulated sodium reabsorption, the cell cycle, and the PPAR signaling pathway. Notably, core genes (CCNA2 and KIF23) were found to be highly expressed in Adenoid Cystic Carcinoma samples and expressed at low levels in normal samples. WB validated the overexpression of CCNA2 and KIF23 in the Adenoid Cystic Carcinoma group, confirming the protein-level changes associated with cell cycle, metastasis, apoptosis, and inflammatory factors in Adenoid Cystic Carcinoma groups with gene overexpression and knockout.

CONCLUSIONS

CCNA2 and KIF23 exhibit high expression levels in ACC, suggesting their potential role as molecular targets for this malignancy.

Cyclin-dependent kinase 2 (CDK2) inhibitors and others novel CDK inhibitors (CDKi) in breast cancer: clinical trials, current impact, and future directions

Aberrant cyclin-dependent kinase 2 (CDK2) activation has been identified as a main resistance mechanism to CDK4/6 inhibition in hormone-receptor positive (HR+) breast cancer. Additionally, consistent preclinical evidence states its crucial role in MYC and CCNE1 overexpressed cancer survival, such as triple-negative breast cancers (TNBC), thus representing an appealing and relatively unexplored target treatment opportunity. Despite emerging initial results of novel CDK2 inhibitors (CDK2i) activity, a comprehensive outcomes collection is currently absent from the scientific literature. We aim to provide an overview of ongoing clinical trials involving CDK2i in the context of metastatic breast cancer (mBC), either as monotherapy or in combination with other agents. The review extends beyond CDK2i to encompass novel emerging CDK4 inhibitors, combined CDK2/4/6 inhibitors, and the well-known pan-CDK inhibitors including those specifically directed at CDK2. Delving into the results, we critically appraise the observed clinical efficacy and offer valuable insights into their potential impact and future applications.

Exploring new quinazolin-4(3H)-one derivatives as CDK2 inhibitors: Design, synthesis, and anticancer evaluation

In the present work, five series of new 2,3-disubstituted quinazolin-4(3H)-ones 4a-c, 5a-d, 6a-g, 7a,b, and 9a-c were designed, synthesized, and screened in vitro for their cytotoxic activity against 60 cancer cell lines by the National Cancer Institute, USA. Five candidates 4c, 6a, 6b, 6d, and 6g revealed promising cytotoxicity with significant percentage growth inhibition in the range of 81.98%-96.45% against the central nervous system (CNS) (SNB-19), melanoma (MDA-MB-435), and non-small cell lung cancer (HOP-62) cell lines. The in vitro cytotoxic half maximal inhibitory concentration (IC50 ) values for the most active compounds 4c, 6a, 6b, 6d, and 6g against the most sensitive cell lines were evaluated. Additionally, screening their cyclin-dependent kinase 2 (CDK2) inhibitory activity was performed. Ortho-chloro-benzylideneamino derivative 6b emerged as the most potent compound with IC50  = 0.67 µM compared to Roscovitine (IC50  = 0.64 µM). The most active candidates arrested the cell cycle at G1, S phases, or both, leading to cell death and inducing apoptosis against CNS (SNB-19), melanoma (MDA-MB-435), and non-small cell lung cancer (HOP-62) cell lines. The molecular docking study verified the resulting outcomes for the most active candidates in the CDK2-binding pocket. Finally, physicochemical, and pharmacokinetic properties deduced that compounds 4c, 6a, 6b, 6d, and 6g displayed significant drug-likeness properties. According to the obtained results, the newly targeted compounds are regarded as promising scaffolds for the continued development of novel CDK2 inhibitors.

Safety, tolerability, pharmacokinetics, and antitumor activity of adavosertib in Japanese patients with advanced solid tumors: A phase I, open-label study

INTRODUCTION

We aimed to assess the safety, pharmacokinetic profile, and antitumor activity of adavosertib monotherapy in Japanese patients with advanced solid tumors.

MATERIALS AND METHODS

This was a single-center, open-label, phase I study with two consecutive cohorts (250 mg and 200 mg cohorts). Patients received adavosertib at 250 mg or 200 mg, orally once daily for 5 days on and 2 days off for Weeks 1 and 2 of a 21-day cycle.

RESULTS

Dose-limiting toxicities (Grade 3 febrile neutropenia) occurred in 2/6 patients in the 250 mg cohort. None of the three patients in the 200 mg cohort developed dose-limiting toxicities. The most frequent treatment-emergent adverse event was nausea (250 mg: 83.3 %; 200 mg: 100.0 %). Median time to peak drug concentration was 4.03 and 2.08 h after the first dose and 2.82 and 1.90 h after multiple dosing in the 250 and 200 mg cohorts, respectively; respective mean terminal elimination half-lives were 7.36 and 7.30 h (first dose) and 10.55 and 8.88 h (multiple dosing). Systemic exposure increased in a slightly more than dose-proportional manner. No RECIST v1.1 response was observed. Disease control rate was 0 % and 33.3 % in the 250 and 200 mg cohorts, respectively. One patient (33.3 %) in the 200 mg cohort showed a best overall response of stable disease at ≥ 8 weeks; the rest showed progressive disease.

CONCLUSIONS

Adavosertib 200 mg once daily was well tolerated in this patient population and no safety concerns were raised. Exposure increased in a slightly more than dose-proportional manner and limited antitumor activity was shown.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT04462952.

Curcumin in Cancer and Inflammation: An In-Depth Exploration of Molecular Interactions, Therapeutic Potentials, and the Role in Disease Management

This paper delves into the diverse and significant roles of curcumin, a polyphenolic compound from the Curcuma longa plant, in the context of cancer and inflammatory diseases. Distinguished by its unique molecular structure, curcumin exhibits potent biological activities including anti-inflammatory, antioxidant, and potential anticancer effects. The research comprehensively investigates curcumin's molecular interactions with key proteins involved in cancer progression and the inflammatory response, primarily through molecular docking studies. In cancer, curcumin's effectiveness is determined by examining its interaction with pivotal proteins like CDK2, CK2α, GSK3β, DYRK2, and EGFR, among others. These interactions suggest curcumin's potential role in impeding cancer cell proliferation and survival. Additionally, the paper highlights curcumin's impact on inflammation by examining its influence on proteins such as COX-2, CRP, PDE4, and MD-2, which are central to the inflammatory pathway. In vitro and clinical studies are extensively reviewed, shedding light on curcumin's binding mechanisms, pharmacological impacts, and therapeutic application in various cancers and inflammatory conditions. These studies are pivotal in understanding curcumin's functionality and its potential as a therapeutic agent. Conclusively, this review emphasizes the therapeutic promise of curcumin in treating a wide range of health issues, attributed to its complex chemistry and broad pharmacological properties. The research points towards curcumin's growing importance as a multi-faceted natural compound in the medical and scientific community.

INX-315, a Selective CDK2 Inhibitor, Induces Cell Cycle Arrest and Senescence in Solid Tumors

Cyclin-dependent kinase 2 (CDK2) is thought to play an important role in driving proliferation of certain cancers, including those harboring CCNE1 amplification and breast cancers that have acquired resistance to CDK4/6 inhibitors (CDK4/6i). The precise impact of pharmacologic inhibition of CDK2 is not known due to the lack of selective CDK2 inhibitors. Here we describe INX-315, a novel and potent CDK2 inhibitor with high selectivity over other CDK family members. Using cell-based assays, patient-derived xenografts (PDX), and transgenic mouse models, we show that INX-315 (i) promotes retinoblastoma protein hypophosphorylation and therapy-induced senescence (TIS) in CCNE1-amplified tumors, leading to durable control of tumor growth; (ii) overcomes breast cancer resistance to CDK4/6i, restoring cell cycle control while reinstating the chromatin architecture of CDK4/6i-induced TIS; and (iii) delays the onset of CDK4/6i resistance in breast cancer by driving deeper suppression of E2F targets. Our results support the clinical development of selective CDK2 inhibitors.

SIGNIFICANCE

INX-315 is a novel, selective inhibitor of CDK2. Our preclinical studies demonstrate activity for INX-315 in both CCNE1-amplified cancers and CDK4/6i-resistant breast cancer. In each case, CDK2 inhibition induces cell cycle arrest and a phenotype resembling cellular senescence. Our data support the development of selective CDK2 inhibitors in clinical trials. See related commentary by Watts and Spencer, p. 386. This article is featured in Selected Articles from This Issue, p. 384.

Discovery of (4-Pyrazolyl)-2-aminopyrimidines as Potent and Selective Inhibitors of Cyclin-Dependent Kinase 2

CDK2 is a critical regulator of the cell cycle. For a variety of human cancers, the dysregulation of CDK2/cyclin E1 can lead to tumor growth and proliferation. Historically, early efforts to develop CDK2 inhibitors with clinical applications proved unsuccessful due to challenges in achieving selectivity over off-target CDK isoforms with associated toxicity. In this report, we describe the discovery of (4-pyrazolyl)-2-aminopyrimidines as a potent class of CDK2 inhibitors that display selectivity over CDKs 1, 4, 6, 7, and 9. SAR studies led to the identification of compound 17, a kinase selective and highly potent CDK2 inhibitor (IC50 = 0.29 nM). The evaluation of 17 in CCNE1-amplified mouse models shows the pharmacodynamic inhibition of CDK2, measured by reduced Rb phosphorylation, and antitumor activity.

Synthesis of 6,8-diaminopurines via acid-induced cascade cyclization of 5-aminoimidazole precursors and preliminary anticancer evaluation

Inspired by the pharmacological interest generated by 6-substituted purine roscovitine for cancer treatment, 5-aminoimidazole-4-carboxamidine precursors containing a cyanamide unit were prepared by condensation of 5-amino-N-cyanoimidazole-4-carbimidoyl cyanides with a wide range of primary amines. When these amidine precursors were combined with acids, a fast cascade cyclization occurred at room temperature, affording new 6,8-diaminopurines with the N-3 and N-6 substituents changed relatively to the original positions they occupied in the amidine and imidazole moieties of precursors. The efficacy and wide scope of this method was well demonstrated by an easy and affordable synthesis of 22 6,8-diaminopurines decorated with a wide diversity of substituents at the N-3 and N-6 positions of the purine ring. Preliminary in silico and in vitro assessments of these 22 compounds were carried out and the results showed that 13 of these tested compounds not only exhibited IC50 values between 1.4 and 7.5 μM against the colorectal cancer cell line HCT116 but also showed better binding energies than known inhibitors in docking studies with different cancer-related target proteins. In addition, good harmonization observed between in silico and in vitro results strengthens and validates this preliminary evaluation, suggesting that these novel entities are good candidates for further studies as new anticancer agents.

Multiplex single-cell chemical genomics reveals the kinase dependence of the response to targeted therapy

Chemical genetic screens are a powerful tool for exploring how cancer cells' response to drugs is shaped by their mutations, yet they lack a molecular view of the contribution of individual genes to the response to exposure. Here, we present sci-Plex-Gene-by-Environment (sci-Plex-GxE), a platform for combined single-cell genetic and chemical screening at scale. We highlight the advantages of large-scale, unbiased screening by defining the contribution of each of 522 human kinases to the response of glioblastoma to different drugs designed to abrogate signaling from the receptor tyrosine kinase pathway. In total, we probed 14,121 gene-by-environment combinations across 1,052,205 single-cell transcriptomes. We identify an expression signature characteristic of compensatory adaptive signaling regulated in a MEK/MAPK-dependent manner. Further analyses aimed at preventing adaptation revealed promising combination therapies, including dual MEK and CDC7/CDK9 or nuclear factor κB (NF-κB) inhibitors, as potent means of preventing transcriptional adaptation of glioblastoma to targeted therapy.

Cell cycle plasticity underlies fractional resistance to palbociclib in ER+/HER2- breast tumor cells

The CDK4/6 inhibitor palbociclib blocks cell cycle progression in Estrogen receptor-positive, human epidermal growth factor 2 receptor-negative (ER+/HER2-) breast tumor cells. Despite the drug's success in improving patient outcomes, a small percentage of tumor cells continues to divide in the presence of palbociclib-a phenomenon we refer to as fractional resistance. It is critical to understand the cellular mechanisms underlying fractional resistance because the precise percentage of resistant cells in patient tissue is a strong predictor of clinical outcomes. Here, we hypothesize that fractional resistance arises from cell-to-cell differences in core cell cycle regulators that allow a subset of cells to escape CDK4/6 inhibitor therapy. We used multiplex, single-cell imaging to identify fractionally resistant cells in both cultured and primary breast tumor samples resected from patients. Resistant cells showed premature accumulation of multiple G1 regulators including E2F1, retinoblastoma protein, and CDK2, as well as enhanced sensitivity to pharmacological inhibition of CDK2 activity. Using trajectory inference approaches, we show how plasticity among cell cycle regulators gives rise to alternate cell cycle "paths" that allow individual tumor cells to escape palbociclib treatment. Understanding drivers of cell cycle plasticity, and how to eliminate resistant cell cycle paths, could lead to improved cancer therapies targeting fractionally resistant cells to improve patient outcomes.

Molecules inducing specific cyclin-dependent kinase degradation and their possible use in cancer therapy

Cyclin-dependent kinases (CDKs) play an important role in the regulation of cell proliferation, and many CDK inhibitors were developed. However, pan-CDK inhibitors failed to be approved due to intolerant toxicity or low efficacy and the use of selective CDK4/6 inhibitors is limited by resistance. Protein degraders have the potential to increase selectivity, efficacy and overcome resistance, which provides a novel strategy for regulating CDKs. In this review, we summarized the function of CDKs in regulating the cell cycle and transcription, and introduced the representative CDK inhibitors. Then we made a detailed introduction about four types of CDKs degraders, including their action mechanisms, research status and application prospects, which could help the development of novel CDKs degraders.

P129, a pyrazole ring-containing isolongifolanone-derivate: synthesis and investigation of anti-glioma action mechanism

BACKGROUND

Cyclin-dependent kinase-2 (CDK-2) is an important regulatory factor in the G1/S phase transition. CDK-2 targeting has been shown to suppress the viability of multiple cancers. However, the exploration and application of a CDK-2 inhibitor in the treatment of glioblastoma are sparse.

METHODS

We synthesized P129 based on isolongifolanone, a natural product with anti-tumor activity. Network pharmacology analysis was conducted to predict the structural stability, affinity, and pharmacological and toxicological properties of P129. Binding analysis and CETSA verified the ability of P129 to target CDK-2. The effect of P129 on the biological behavior of glioma cells was analyzed by the cell counting kit-8, colony formation, flow cytometry, and other experiments. Western blotting was used to detect the expression changes of proteins involved in the cell cycle, cell apoptosis, and epithelial-mesenchymal transition.

RESULTS

Bioinformatics analysis and CETSA showed that P129 exhibited good intestinal absorption and blood-brain barrier penetrability together with high stability and affinity with CDK-2, with no developmental toxicity. The viability, proliferation, and migration of human glioma cells were significantly inhibited by P129 in a dose- and time-dependent manner. Flow cytometry and western blotting analyses showed G0/G1 arrest and lower CDK-2 expression in cells treated with P129 than in the controls. The apoptotic ratio of glioma cells increased significantly with increasing concentrations of P129 combined with karyopyknosis and karyorrhexis. Apoptosis occurred via the mitochondrial pathway.

CONCLUSION

The pyrazole ring-containing isolongifolanone derivate P129 exhibited promising anti-glioma activity by targeting CDK-2 and promoting apoptosis, indicating its potential importance as a new chemotherapeutic option for glioma.

Triazolopyrimidine Derivatives: An Updated Review on Recent Advances in Synthesis, Biological Activities and Drug Delivery Aspects

Molecules containing triazolopyrimidine core showed diverse biological activities, including anti-Alzheimer's, anti-diabetes, anti-cancer, anti-microbial, anti-tuberculosis, anti-viral, anti-malarial, anti-inflammatory, anti-parkinsonism, and anti-glaucoma activities. Triazolopyrimidines have 8 isomeric structures, including the most stable 1,2,4-triazolo[1,5- a] pyrimidine ones. Triazolopyrimidines were obtained by using various chemical reactions, including a) 1,2,4-triazole nucleus annulation to pyrimidine, b) pyrimidines annulation to 1,2,4-triazole structure, c) 1,2,4-triazolo[l,5-a] pyrimidines rearrangement, and d) pyrimidotetrazine rearrangement. This review discusses synthetic methods, recent pharmacological actions and drug delivery perspectives of triazolopyrimidines.

Synergistic anticancer effect by targeting CDK2 and EGFR-ERK signaling

The EGFR-RAS-ERK pathway is one of the most important signaling cascades in cell survival, growth, and proliferation. Aberrant activation of this pathway is a common mechanism in various cancers. Here, we report that CDK2 is a novel regulator of the ERK pathway via USP37 deubiquitinase (DUB). Mechanistically, CDK2 phosphorylates USP37, which is required for USP37 DUB activity. Further, USP37 deubiquitinates and stabilizes ERK1/2, thereby enhancing cancer cell proliferation. Thus, CDK2 is able to promote cell proliferation by activating USP37 and, in turn, stabilizing ERK1/2. Importantly, combined CDK1/2 and EGFR inhibitors have a synergetic anticancer effect through the downregulation of ERK1/2 stability and activity. Indeed, our patient-derived xenograft (PDX) results suggest that targeting both ERK1/2 stability and activity kills cancer cells more efficiently even at lower doses of these two inhibitors, which may reduce their associated side effects and indicate a potential new combination strategy for cancer therapy.

circRACGAP1 Promotes Proliferation of Non-Small Cell Lung Cancer Cells through the miR-1296/CDK2 Pathway

Circular RNAs (circRNAs) have played an essential role in cancer development. This study aimed to illustrate the impact and potential mechanism of circRACGAP1 action in NSCLC development. The expression patterns of circRACGAP1, miR-1296, and CDK2 in NSCLC tissues and cell lines were analysed by RT-qPCR. The function of circRACGAP1 in NSCLC cell proliferation and apoptosis was investigated using the CCK-8 assay, flow cytometry, TUNEL staining, and Western blot. The interaction among circRACGAP1, miR-1296, and CDK2 was clarified by dual-luciferase reporter assay while the correlation was confirmed by the Pearson correlation coefficient. The expression of circRACGAP1 and CDK2 was up-regulated in NSCLC tissues, while the expression of miR-1296 was down-regulated. Cell function studies further revealed that circRACGAP1 could promote NSCLC cell proliferation, accelerate the cell cycle process, up-regulate B-cell lymphoma 2 (Bcl2) expression, and down-regulate Bcl2-associated X (Bax) expression. miR-1296 was identified as a downstream target to reverse circRACGAP1-mediated cell proliferation. miR-1296 directly targeted the 3'-UTR of CDK2 to regulate proliferation and apoptosis of NSCLC cells. Additionally, the dual-luciferase reporter assay and Pearson correlation coefficient analysis proved that circRACGAP1 acted in NSCLC cells by negatively regulating miR-1296 expression and positively regulating CDK2 expression. In summary, our study revealed that circRACGAP1 promoted NSCLC cell proliferation by regulating the miR-1296/CDK2 pathway, providing potential diagnostic and therapeutic targets for NSCLC.

Epidermal growth factor receptor dual-target inhibitors as a novel therapy for cancer: A review

Overexpression of the epidermal growth factor receptor (EGFR) has been linked to several human cancers, including esophageal cancer, pancreatic cancer, anal cancer, breast cancer, and lung cancer, particularly non-small cell lung cancer (NSCLC). Therefore, EGFR has emerged as a critical target for treating solid tumors. Many 1st-, 2nd-, 3rd-, and 4th-generation EGFR single-target inhibitors with clinical efficacy have been designed and synthesized in recent years. Drug resistance caused by EGFR mutations has posed a significant challenge to the large-scale clinical application of EGFR single-target inhibitors and the discovery of novel EGFR inhibitors. Therapeutic methods for overcoming multipoint EGFR mutations are still needed in medicine. EGFR dual-target inhibitors are more promising than single-target inhibitors as they have a lower risk of drug resistance, higher efficacy, lower dosage, and fewer adverse events. EGFR dual-target inhibitors have been developed sequentially to date, providing new options for remission in patients with previously untreatable malignancies and laying the groundwork for a future generation of compounds. This paper introduces the EGFR family proteins and their synergistic effects with other anticancer targets, and provides a comprehensive review of the development of EGFR dual-target inhibitors in cancer, as well as the opportunities and challenges associated with those fields.

A newly identified lncRNA lnc000100 regulates proliferation and differentiation of cattle skeletal muscle cells

Cattle skeletal muscle development is a complex and highly coordinated biological process mediated by a series of myogenic regulators, which plays a critical role in beef yield and quality. Long non-coding RNAs (lncRNAs) have been shown to regulate skeletal muscle development. However, the molecular mechanism by which lncRNAs regulate skeletal muscle development is largely unknown. We performed transcriptome analysis of muscle tissues of adult and embryo Angus cattle to investigate the mechanism by which lncRNA regulates skeletal muscle development between adult and embryo cattle. A total of 37,115 candidate lncRNAs were detected, and a total of 1,998 lncRNAs were differentially expressed between the muscle tissue libraries of adult and embryo cattle, including 1,229 up-regulated lncRNAs and 769 down-regulated lncRNAs (adult cattle were the control group). We verified the expression of 7 differentially expressed lncRNAs by quantitative real-time PCR (RT-qPCR), and analysed the tissue expression profile of lnc000100, which is down-regulated in the longest dorsal muscle during foetal life and which is highly specifically expressed in muscle tissue. We found that the interference of lnc000100 significantly inhibited cell proliferation and promoted cell differentiation. Lnc000100 was located in the nucleus by RNA-FISH. Our research provides certain resources for the analysis of lncRNA regulating cattle skeletal muscle development, and may also provide new insights for improving beef production and breed selection.

Design, Synthesis, In Vitro, and In Silico Studies of New N5-Substituted-pyrazolo[3,4-d]pyrimidinone Derivatives as Anticancer CDK2 Inhibitors

CDK2 is a key player in cell cycle processes. It has a crucial role in the progression of various cancers. Hepatocellular carcinoma (HCC) and colorectal cancer (CRC) are two common cancers that affect humans worldwide. The available therapeutic options suffer from many drawbacks including high toxicity and decreased specificity. Therefore, there is a need for more effective and safer therapeutic agents. A series of new pyrazolo[3,4-d]pyrimidine analogs was designed, synthesized, and evaluated as anticancer agents against the CRC and HCC cells, HCT116, and HepG2, respectively. Pyrazolo[3,4-d]pyrimidinone derivatives bearing N5-2-(4-halophenyl) acetamide substituents were identified as the most potent amongst evaluated compounds. Further evaluation of CDK2 kinase inhibition of two potential cytotoxic compounds 4a and 4b confirmed their CDK2 inhibitory activity. Compound 4a was more potent than the reference roscovitine regarding the CDK2 inhibitory activity (IC50 values: 0.21 and 0.25 µM, respectively). In silico molecular docking provided insights into the molecular interactions of compounds 4a and 4b with important amino acids within the ATP-binding site of CDK2 (Ile10, Leu83, and Leu134). Overall, compounds 4a and 4b were identified as interesting CDK2 inhibitors eliciting antiproliferative activity against the CRC and HCC cells, HCT116 and HepG2, respectively, for future further investigations and development.

Molecular overlay-guided design of new CDK2 inhibitor thiazepinopurines: Synthesis, anticancer, and mechanistic investigations

Adopting the molecular overlay approach, three novel sets of thiazepinopurines with expected cytotoxicity and CDK2 inhibition potential were designed and synthesized. This was accomplished through the heteroannelation of purines, for the first time, with thiazepine. The obtained thiazepinopurines derivatives were assessed for their cytotoxicity toward tumor cells of three different types, HepG2, MCF-7, and PC-3 as well as one normal cell (WI38). Among the studied compounds, 3b and 3c exhibited significant antiproliferative activity against tumor cells presenting IC50 range of 5.52-17.09 µM in comparison with Roscovitine (9.32-13.82 µM). Additionally, both compounds displayed superior selectivity indices (SI = 3.00-7.15) toward tested cancer cells. The 4-chlorophenyl analog 3b has shown the best selectivity index, and hence it has been subjected to additional investigations to determine its proper mechanistic effect. Accordingly, the CDK2 inhibition potential, apoptosis induction, and cell cycle analysis of MCF-7 were evaluated. Results revealed that this analog displayed a potent CDK2 inhibition potential with an IC50 value of 0.219 µM. Findings also showed that 3b was thought to arrest MCF-7 cell cycle at S phase together with apoptosis induction by the increased expression of Bax, Caspase-8, and -9 markers with a concomitant decrease in Bcl-2 expression. Besides, the probable interaction of 3b with CDK2 binding pocket was investigated by molecular docking.

KIF11 serves as a cell cycle mediator in childhood acute lymphoblastic leukemia

OBJECTIVE

To identify key gene in childhood acute lymphoblastic leukemia (ALL) through weighted gene co-expression network analysis (WGCNA), and their enriched biological functions and signaling pathways.

METHODS

Array data of the GSE73578 dataset, involving 46 childhood ALL samples, were acquired from the Gene Expression Omnibus (GEO) database. Hub modules associated with childhood ALL were screened out by WGCNA. Enriched biological functions and signaling pathways were then identified by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG). Hub genes were selected by overlapping those between down-regulated genes in GSE73578, GSE4698 and the hub module. Guilt by association (GBA) was adopted to verify the function of the identified KIF11 gene and to predict its target genes. Regulatory effects of KIF11 on the proliferation and cell cycle progression of ALL in vitro were determined by cytological experiments.

RESULTS

WGCNA showed that the yellow module was the most relevant to childhood ALL treatment, containing 698 genes that were enriched in cell division, mitotic nuclear division, DNA replication and DNA repair, cell cycle, DNA replication and the P53 signaling pathway. The KIF11 gene was screened out and predicted as a cell cycle mediator in childhood ALL. Knockdown of KIF11 in ALL cells inhibited cell proliferation and arrested cell cycle progression in G2/M phase.

CONCLUSIONS

The KIF11 gene is critical in the treatment process of childhood ALL, which is a promising therapeutic target for childhood ALL.

CT2-3 induces cell cycle arrest and apoptosis in rheumatoid arthritis fibroblast-like synoviocytes through regulating PI3K/AKT pathway

Rheumatoid arthritis (RA) is a kind of chronic autoimmune disease. The existing therapies encountered several challenges. Therefore, continued novel anti-RA drug discovery remains necessary for RA therapy. Recently, our group reported a novel compound named CT2-3, which could be realized as a hybrid of the natural product magnolol and phthalimide and exhibited anti-lung cancer activity. However, the effect of CT2-3 on RA is unclear. Here, we aim to explore the effect and potential mechanism of CT2-3 on the abnormal functions of RA-fibroblast-like synoviocytes (RA-FLSs). In this study, we identified the important role of the dysregulated cell cycle and apoptosis of RA-FLSs in RA progression. Interestingly, we found that CT2-3 inhibited the proliferation and DNA replication of primary RA-FLSs and immortalized RA-FLSs namely MH7A. In addition, CT2-3 downregulated the mRNA and protein expression of cyclin-dependent kinase 2 (CDK2), cyclin A2, and cyclin B1, resulting in cell cycle arrest of primary RA-FLSs and MH7A cells. Also, CT2-3 downregulated the level of B-cell lymphoma-2 (Bcl-2), and increased the level of Bcl-2 associated X (Bax), contributing to apoptosis of primary RA-FLSs and MH7A cells. Furthermore, differential analyses of RNA-sequencing, Western blot, and network pharmacological analysis confirmed that CT2-3 inhibited phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT) pathway of primary RA-FLSs and MH7A cells. In conclusion, CT2-3 induces cell cycle arrest and apoptosis in RA-FLSs through modulating PI3K/AKT pathway, which may serve as a potential lead compound for further novel small molecule anti-RA drug development.

Identification of natural marine compounds as potential inhibitors of CDK2 using molecular docking and molecular dynamics simulation approach

The multifunctional enzyme cyclin-dependent kinase 2 (CDK2) protein is essential for cell proliferation, transcription and modulation of the cell cycle. There is a dysfunction that is connected to various diseases, such as cancer, making it an important treatment target in oncology and beyond. The goal of this study is to identify novel CDK2 ATP binding site inhibitors using in silico drug designing. To find competitive inhibitors for the ATP site, molecular docking, molecular dynamics (MD) simulation and free-binding energy calculations were used. Natural compounds retrieved from marine sources (fungi and algae) were docked against protein, and the best-binding compounds were further evaluated using MD simulations. LIG1, LIG2 and LIG3 (ΔGPB = -19.98, -15.82 and -12.98 kcal/mol, respectively) were placed in the top positions based on their overall binding energy calculated using MMPBSA approach. Stability of the complexes was confirmed by carefully analyzing the rmsd and rmsf patterns retrieved from the MD trajectories. Several residues and areas (Leu124, Val123, Phe80, Leu83, Glu81, Arg 126, Asn132, Leu134, Gln131, Lys88 and Glu195) appear to be critical for inhibitor retention across the active pocket, according to RMSD and RMSF. The dynamics of the ligands inside the active pocket were mapped using principle component analysis. It has been observed that LIG1-3 appear to be the best possible inhibitors due to their high binding energies, interaction pattern and retention inside the active pocket.Communicated by Ramaswamy H. Sarma.

LINC00955 suppresses colorectal cancer growth by acting as a molecular scaffold of TRIM25 and Sp1 to Inhibit DNMT3B-mediated methylation of the PHIP promoter

BACKGROUND

Long non-coding RNAs play an important role in the development of colorectal cancer (CRC), while many CRC-related lncRNAs have not yet been identified.

METHODS

The relationship between the expression of LINC00955 (Long Intergenic Non-protein Coding RNA 955) and the prognosis of colorectal cancer patients was analyzed using the sequencing results of the TCGA database. LINC00955 expression levels were measured using qRT-PCR. The anti-proliferative activity of LINC00955 was evaluated using CRC cell lines in vitro and xenograft models in nude mice in vivo. The interaction of TRIM25-Sp1-DNMT3B-PHIP-CDK2 was analyzed by western blotting, protein degradation experiment, luciferase, RNA-IP, RNA pull-down assays and immunohistochemically analysis. The biological roles of LINC00955, tripartite motif containing 25 (TRIM25), Sp1 transcription factor (Sp1), DNA methyltransferase 3 beta (DNMT3B), pleckstrin homology domain interacting protein (PHIP), cyclin dependent kinase 2 (CDK2) in colorectal cancer cells were analyzed using ATP assays, Soft agar experiments and EdU assays.

RESULTS

The present study showed that LINC00955 is downregulated in CRC tissues, and such downregulation is associated with poor prognosis of CRC patients. We found that LINC00955 can inhibit CRC cell growth both in vitro and in vivo. Evaluation of its mechanism of action showed that LINC00955 acts as a scaffold molecule that directly promotes the binding of TRIM25 to Sp1, and promotes ubiquitination and degradation of Sp1, thereby attenuating transcription and expression of DNMT3B. DNMT3B inhibition results in hypomethylation of the PHIP promoter, in turn increasing PHIP transcription and promoting ubiquitination and degradation of CDK2, ultimately leading to G0/G1 growth arrest and inhibition of CRC cell growth.

CONCLUSIONS

These findings indicate that downregulation of LINC00955 in CRC cells promotes tumor growth through the TRIM25/Sp1/DNMT3B/PHIP/CDK2 regulatory axis, suggesting that LINC00955 may be a potential target for the therapy of CRC.

Design, Synthesis, Antitumour Evaluation, and In Silico Studies of Pyrazolo-[1,5-c]quinazolinone Derivatives Targeting Potential Cyclin-Dependent Kinases

An efficient, straightforward, and metal-free methodology to rapidly access functionalised pyrazolo-[1,5-c]quinazolinones via a [3 + 2] dipolar cycloaddition and regioselective ring expansion process was developed. The synthesised compounds were characterised by methods such as NMR, HRMS, and HPLC. The in vitro antiproliferative activity against A549 cells (non-small cell lung cancer) was significant for compounds 4i, 4m, and 4n with IC50 values of 17.0, 14.2, and 18.1 μM, respectively. In particular, compounds 4t and 4n showed inhibitory activity against CDK9/2. Predicted biological target and molecular modelling studies suggest that the compound 4t may target CDKs for antitumour effects. The synthesised derivatives were considered to have moderate drug-likeness and sufficient safety in silico. In summary, a series of pyrazolo-[1,5-c]quinazolinone derivatives with antitumour activity is reported for the first time. We provide not only a simple and efficient synthetic method but also helpful lead compounds for the further development of novel cyclin-dependent kinase (CDK) inhibitors.

Diagnostics and treatment of ovarian cancer in the era of precision medicine - opportunities and challenges

Due to predictions of increasing incidences and deaths from ovarian cancer, this neoplasm is a challenge for modern health care. The advent of NGS technology has made it possible to understand the molecular characteristics of many cancers, including ovarian cancer. The data obtained in research became the basis for the development of molecularly targeted therapies thus leading to the entry of NGS analysis into the diagnostic process of oncological patients. This review presents targeted therapies currently in preclinical or clinical trials, whose promising results offer hope for their use in clinical practice in the future. As more therapeutic options emerge, it will be necessary to modify molecular diagnostic regimens to select the best treatment for a given patient. New biomarkers are needed to predict the success of planned therapy. An important aspect of public health is molecular testing in women with a familial predisposition to ovarian cancer enabling patients to be included in prevention programs. NGS technology, despite its high throughput, poses many challenges, from the quality of the diagnostic material used for testing to the interpretation of results and classification of sequence variants. The article highlights the role of molecular testing in ongoing research and also its role in the diagnostic and therapeutic process in the era of personalized medicine. The spread of genetic testing in high-risk groups, the introduction of more targeted therapies and also the possibility of agnostic therapies could significantly improve the health situation for many women worldwide.

Synthesis of tricyclic and tetracyclic benzo[6,7]cycloheptane derivatives linked morpholine moiety as CDK2 inhibitors

With the aim of developing cyclin-dependent kinase 2 (CDK2) inhibitors with strong antibreast cancer efficacy, new tricyclic and tetracyclic benzo[6,7]cycloheptane derivatives were synthesized. The newly synthesized tri- and tetracyclic derivatives were achieved from the reaction of 4-(4-morpholin-4-yl-phenyl)-1,3,4,5,6,7-hexahydro-benzo[6,7]cyclohepta[1,2-d]pyrimidine-2-thione (5) with α-haloketone derivatives as hydrazonyl chlorides, phenacyl bromide derivatives, chloroacetone, and ethyl substituted acetate derivatives. The MCF-7 and MDA-MB-231 breast cancer cell lines were utilized to examine the anticancer properties. Compounds 5 and 8 were shown to be the most effective, with half-maximal inhibitory concentration (IC50 ) values between 5.73 and 9.11 µM, which are on the level with doxorubicin. Mechanistic studies showed that 5 and 8 caused tumor cell death by inducing apoptosis and they also produced cancer arrest in the S phase of the cell cycle. In addition, compounds 5 and 8 showed strong anti-CDK2 action (IC50  = 0.112 and 0.18 µM, respectively) comparable to roscovitine (IC50  = 0.127 µM). Moreover, the docking result demonstrated that derivatives 5 and 8 fit into the CDK2 active site in the proper orientation.

Machine Learning-Based Virtual Screening and Molecular Simulation Approaches Identified Novel Potential Inhibitors for Cancer Therapy

Cyclin-dependent kinase 2 (CDK2) is a promising target for cancer treatment, developing new effective CDK2 inhibitors is of great significance in anticancer therapy. The involvement of CDK2 in tumorigenesis has been debated, but recent evidence suggests that specifically inhibiting CDK2 could be beneficial in treating certain tumors. This approach remains attractive in the development of anticancer drugs. Several small-molecule inhibitors targeting CDK2 have reached clinical trials, but a selective inhibitor for CDK2 is yet to be discovered. In this study, we conducted machine learning-based drug designing to search for a drug candidate for CDK2. Machine learning models, including k-NN, SVM, RF, and GNB, were created to detect active and inactive inhibitors for a CDK2 drug target. The models were assessed using 10-fold cross-validation to ensure their accuracy and reliability. These methods are highly suitable for classifying compounds as either active or inactive through the virtual screening of extensive compound libraries. Subsequently, machine learning techniques were employed to analyze the test dataset obtained from the zinc database. A total of 25 compounds with 98% accuracy were predicted as active against CDK2. These compounds were docked into CDK2's active site. Finally, three compounds were selected based on good docking score, and, along with a reference compound, underwent MD simulation. The Gaussian naïve Bayes model yielded superior results compared to other models. The top three hits exhibited enhanced stability and compactness compared to the reference compound. In conclusion, our study provides valuable insights for identifying and refining lead compounds as CDK2 inhibitors.

Synthesis and SARs study of novel spiro-oxindoles as potent antiproliferative agents with CDK-2 inhibitory activities

A series of 16 novel spirooxindole analogs 8a-p were designed and constructed via cost-effective single-step multicomponent [3+2] cycloaddition reaction of azomethine ylide (AY) generated in situ from substituted isatin (6a-d) with suitable amino acids (7a-c) and ethylene-engrafted pyrazole derivatives (5a,b). The potency of all compounds was assayed against a human breast cancer cell line (MCF-7) and a human liver cell line (HepG2). Spiro compound 8c was the most active member among the synthesized candidates, with exceptional cytotoxicity against the MCF-7 and HepG2 cell lines, with IC50 values of 0.189 ± 0.01 and 1.04 ± 0.21 µM, respectively. The candidate 8c exhibited more potent activity (10.10- and 2.27-fold) than the standard drug roscovitine (IC50  = 1.91 ± 0.17 µM (MCF-7) and 2.36 ± 0.21 µM (HepG2)). Compound 8c was investigated for epidermal growth factor receptor (EGFR) inhibition; it exhibited promising IC50 values of 96.6 nM compared with 67.3 nM for erlotinib. The IC50 value of 8c (34.98 nM) exhibited cyclin-dependent kinase 2 (CDK-2) inhibition, being more active than roscovitine the (IC50  = 140 nM) in targeting the CDK-2 kinase enzyme. Additionally, for apoptosis induction of compound 8c in MCF-7, it upregulated the expression levels of proapoptotic genes for P53, Bax, caspases-3, 8, and 9 at up to 6.18, 4.8, 9.8, 4.6, 11.3 fold-change, respectively, and downregualted the level of the antiapoptotic gene for Bcl-2 by 0.14-fold. Finally, a molecular docking study of the most active compound 8c highlighted a good binding affinity with Lys89 as the key amino acid for CDK-2 inhibition.

Synthesis and Antitumor Activity of Panaxadiol Pyrazole and Isooxazole Derivatives

In this study, we designed and synthesized 19 nitrogen-containing heterocyclic derivatives of panaxadiol (PD). We first reported the antiproliferative activity of these compounds against four different tumor cells. The results of the MTT assay showed that the PD pyrazole derivative (compound 12b) had the best antitumor activity and could significantly inhibit the proliferation of four tested tumor cells. For A549 cells, the IC50 value was as low as 13.44±1.23 μM. Western blot analysis showed that the PD pyrazole derivative was a bifunctional regulator. On the one hand, it can down-regulate the expression of HIF-1α by acting on PI3 K/AKT signaling pathway in A549 cells. On the other hand, it can induce the decrease of CDKs protein family and E2F1 protein expression levels, thus playing a crucial role in cell cycle arrest. According to the results of molecular docking, we found that multiple hydrogen bonds were formed between the PD pyrazole derivative and two related proteins, and the docking score of the derivative was also significantly higher than that of the crude drug. In summary, the study of the PD pyrazole derivative laid a foundation for the development of ginsenoside as an antitumor agent.

Multiplex single-cell chemical genomics reveals the kinase dependence of the response to targeted therapy

Chemical genetic screens are a powerful tool for exploring how cancer cells' response to drugs is shaped by their mutations, yet they lack a molecular view of the contribution of individual genes to the response to exposure. Here, we present sci-Plex-Gene-by-Environment (sci-Plex-GxE), a platform for combined single-cell genetic and chemical screening at scale. We highlight the advantages of large-scale, unbiased screening by defining the contribution of each of 522 human kinases to the response of glioblastoma to different drugs designed to abrogate signaling from the receptor tyrosine kinase pathway. In total, we probed 14,121 gene-by-environment combinations across 1,052,205 single-cell transcriptomes. We identify an expression signature characteristic of compensatory adaptive signaling regulated in a MEK/MAPK-dependent manner. Further analyses aimed at preventing adaptation revealed promising combination therapies, including dual MEK and CDC7/CDK9 or NF-kB inhibitors, as potent means of preventing transcriptional adaptation of glioblastoma to targeted therapy.

Significance of RB Loss in Unlocking Phenotypic Plasticity in Advanced Cancers

Cancer cells can undergo plasticity in response to environmental stimuli or under selective therapeutic pressures that result in changes in phenotype. This complex phenomenon of phenotypic plasticity is now recognized as a hallmark of cancer. Lineage plasticity is often associated with loss of dependence on the original oncogenic driver and is facilitated, in part, by underlying genomic and epigenetic alterations. Understanding the molecular drivers of cancer plasticity is critical for the development of novel therapeutic strategies. The retinoblastoma gene RB1 (encoding RB) is the first tumor suppressor gene to be discovered and has a well-described role in cell-cycle regulation. RB is also involved in diverse cellular functions beyond cell cycle including differentiation. Here, we describe the emerging role of RB loss in unlocking cancer phenotypic plasticity and driving therapy resistance across cancer types. We highlight parallels in cancer with the noncanonical role of RB that is critical for normal development and lineage specification, and the downstream consequences of RB loss including epigenetic reprogramming and chromatin reorganization that can lead to changes in lineage program. Finally, we discuss potential therapeutic approaches geared toward RB loss cancers undergoing lineage reprogramming.

MiR-17- 5p/RRM2 regulated gemcitabine resistance in lung cancer A549 cells

The main objective of this study is to investigate the regulatory roles of the miR-17-5p/RRM2 axis in A549/G+ cells' gemcitabine resistance. The cell viability was determined using CCK8 and clonogenic assays. Gene expression level analysis by RT-qPCR and Western blotting. Cell cycle analysis by flow cytometry. The dual luciferase activity assay was used to verify the target gene of miR-17-5p. In gemcitabine-resistant cell line A549G+, the drug resistance decreased after up-regulation of MiR-17-5p expression. The proportion of cell cycle G1 phase increased, and the S phase decreased. The expression level of cell cycle-related proteins CCNE1, CCNA2, and P21 decreased. The opposite results emerged after the down-regulation of MiR-17-5p expression in gemcitabine-sensitive cell line A549G-. The expression levels of PTEN and PIK3 in A549G+ cells were higher than in A549G-cells, but p-PTEN was lower than that in A549G-. After up-regulating the expression of MiR-17-5p in A549G+, the expression levels of p-PTEN increased, and the expression level of p-AKT decreased. After down-regulating miR-17-5p expression, the opposite results emerged. The dual-luciferase reporter assay and restorative experiments proved that RRM2 is one of the target genes for MiR-17-5p. Our results suggested that the miR-17-5p/RRM2 axis could adjust gemcitabine resistance in A549 cells, and the p-PTEN/PI3K/AKT signal pathway might be involved in this regulatory mechanism.

Signal Pathways and microRNAs in Osteosarcoma Growth and the Dual Role of Mesenchymal Stem Cells in Oncogenesis

The major challenges in Osteosarcoma (OS) therapy are its heterogeneity and drug resistance. The development of new therapeutic approaches to overcome the major growth mechanisms of OS is urgently needed. The search for specific molecular targets and promising innovative approaches in OS therapy, including drug delivery methods, is an urgent problem. Modern regenerative medicine focuses on harnessing the potential of mesenchymal stem cells (MSCs) because they have low immunogenicity. MSCs are important cells that have received considerable attention in cancer research. Currently, new cell-based methods for using MSCs in medicine are being actively investigated and tested, especially as carriers for chemotherapeutics, nanoparticles, and photosensitizers. However, despite the inexhaustible regenerative potential and known anticancer properties of MSCs, they may trigger the development and progression of bone tumors. A better understanding of the complex cellular and molecular mechanisms of OS pathogenesis is essential to identify novel molecular effectors involved in oncogenesis. The current review focuses on signaling pathways and miRNAs involved in the development of OS and describes the role of MSCs in oncogenesis and their potential for antitumor cell-based therapy.

A targeted genetic modifier screen in Drosophila uncovers vulnerabilities in a genetically complex model of colon cancer

Received on 16 January 2023; accepted on 21 February 2023Kinases are key regulators of cellular signal transduction pathways. Many diseases, including cancer, are associated with global alterations in protein phosphorylation networks. As a result, kinases are frequent targets of drug discovery efforts. However, target identification and assessment, a critical step in targeted drug discovery that involves identifying essential genetic mediators of disease phenotypes, can be challenging in complex, heterogeneous diseases like cancer, where multiple concurrent genomic alterations are common. Drosophila is a particularly useful genetic model system to identify novel regulators of biological processes through unbiased genetic screens. Here, we report 2 classic genetic modifier screens focusing on the Drosophila kinome to identify kinase regulators in 2 different backgrounds: KRAS TP53 PTEN APC, a multigenic cancer model that targets 4 genes recurrently mutated in human colon tumors and KRAS alone, a simpler model that targets one of the most frequently altered pathways in cancer. These screens identified hits unique to each model and one shared by both, emphasizing the importance of capturing the genetic complexity of human tumor genome landscapes in experimental models. Our follow-up analysis of 2 hits from the KRAS-only screen suggests that classical genetic modifier screens in heterozygous mutant backgrounds that result in a modest, nonlethal reduction in candidate gene activity in the context of a whole animal-a key goal of systemic drug treatment-may be a particularly useful approach to identify the most rate-limiting genetic vulnerabilities in disease models as ideal candidate drug targets.