Ovarian cancer is the most lethal malignancy affecting the female reproductive system. Pharmacological inhibitors targeting CDK4/6 have demonstrated promising efficacy across various cancer types. However, their clinical benefits in ovarian cancer patients fall short of expectations, with only a subset of patients experiencing these advantageous effects. This study aims to provide further clinical and biological evidence for antineoplastic effects of a CDK4/6 inhibitor (TQB4616) in ovarian cancer and explore underlying mechanisms involved. Patient-derived ovarian cancer organoid models were established to evaluate the effectiveness of TQB3616. Potential key genes related to TQB3616 sensitivity were identified through RNA-seq analysis, and TRIM4 was selected as a candidate gene for further investigation. Subsequently, co-immunoprecipitation and GST pull-down assays confirmed that TRIM4 binds to hnRNPDL and promotes its ubiquitination through RING and B-box domains. RIP assay demonstrated that hnRNPDL binded to CDKN2C isoform 2 and suppressed its expression by alternative splicing. Finally, in vivo studies confirmed that the addition of siTRIM4 significantly improved the effectiveness of TQB3616. Overall, our findings suggest that TRIM4 modulates ubiquitin-mediated degradation of hnRNPDL and weakens sensitivity to CDK4/6 inhibitors in ovarian cancer treatment. TRIM4 may serve as a valuable biomarker for predicting sensitivity to CDK4/6 inhibitors in ovarian cancer.
Humans ; Female ; Ovarian Neoplasms/pathology* ; Animals ; Tripartite Motif Proteins/genetics* ; Mice ; Cyclin-Dependent Kinase 4/antagonists & inhibitors* ; Cell Line, Tumor ; Cyclin-Dependent Kinase 6/antagonists & inhibitors* ; Protein Kinase Inhibitors/pharmacology* ; Ubiquitin/metabolism* ; Xenograft Model Antitumor Assays ; Ubiquitination ; Antineoplastic Agents/pharmacology*

The inhibition of cyclin-dependent kinases (CDKs) is considered a promising strategy for cancer treatment due to their role in cell cycle regulation. However, CDK inhibitors with no selectivity among CDK families have not been approved. A CDK inhibitor with high selectivity for CDK4/6 exhibited significant treatment effects on breast cancer and has become a heavy bomb on the market. Subsequently, resistance gradually decreased the efficacy of selective CDK4/6 inhibitors in breast cancer treatment. In this review, we first introduce the development of selective CDK4/6 inhibitors and then explain the role of CDK2 activation in inducing resistance to CDK4/6 inhibitors. Moreover, we focused on the development of CDK2/4/6 inhibitors and selective CDK2 inhibitors, which will aid in the discovery of novel CDK inhibitors targeting the cell cycle in the future.
Humans ; Cell Cycle/drug effects* ; Protein Kinase Inhibitors/chemistry* ; Cyclin-Dependent Kinases/metabolism* ; Neoplasms/genetics* ; Antineoplastic Agents/pharmacology* ; Animals ; Breast Neoplasms/enzymology* ; Cyclin-Dependent Kinase 4/metabolism*

Gastric cancer (GC) is characterized by high morbidity and mortality rates. Chinese agarwood comprises the resin-containing wood of Aquilaria sinensis (Lour.) Gilg., traditionally utilized for treating asthma, cardiac ischemia, and tumors. However, comprehensive research regarding its anti-GC effects and underlying mechanisms remains limited. In this study, Chinese agarwood petroleum ether extract (CAPEE) demonstrated potent cytotoxicity against human GC cells, with half maximal inhibitory concentration (IC₅₀) values for AGS, HGC27, and MGC803 cells of 2.89, 2.46, and 2.37 μg·mL^-1, respectively, at 48 h. CAPEE significantly induced apoptosis in these GC cells, with B-cell lymphoma-2 (BCL-2) associated X protein (BAX)/BCL-2 antagonist killer 1 (BAK) likely mediating CAPEE-induced apoptosis. Furthermore, CAPEE induced G₀/G₁ phase cell cycle arrest in human GC cells via activation of the deoxyribonucleic acid (DNA) damage-p21-cyclin D1/cyclin-dependent kinase 4 (CDK4) signaling axis, and increased Fe²⁺, lipid peroxides and reactive oxygen species (ROS) levels, thereby inducing ferroptosis. Ribonucleic acid (RNA) sequencing, real-time quantitative polymerase chain reaction (RT-qPCR), and Western blotting analyses revealed CAPEE-mediated upregulation of heme oxygenase-1 (HO-1) in human GC cells. RNA interference studies demonstrated that HO-1 knockdown reduced CAPEE sensitivity and inhibited CAPEE-induced ferroptosis in human GC cells. Additionally, CAPEE administration exhibited robust in vivo anti-GC activity without significant toxicity in nude mice while inhibiting tumor cell growth and promoting apoptosis in tumor tissues. These findings indicate that CAPEE suppresses human GC cell growth through upregulation of the DNA damage-p21-cyclin D1/CDK4 signaling axis and HO-1-mediated ferroptosis, suggesting its potential as a candidate drug for GC treatment.
Animals ; Humans ; Mice ; Antineoplastic Agents, Phytogenic ; Apoptosis/drug effects* ; Cell Line, Tumor ; Cyclin D1/genetics* ; Cyclin-Dependent Kinase 4/genetics* ; DNA Damage/drug effects* ; Drugs, Chinese Herbal/pharmacology* ; Ferroptosis/drug effects* ; G1 Phase Cell Cycle Checkpoints/drug effects* ; Heme Oxygenase-1/genetics* ; Mice, Inbred BALB C ; Mice, Nude ; Plant Extracts/pharmacology* ; Stomach Neoplasms/physiopathology* ; Thymelaeaceae/chemistry* ; Up-Regulation/drug effects*

OBJECTIVE: To explore the correlation between chromosome 8 open reading frame 76 (C8orf76) and cyclin-dependent kinase 4 (CDK4) and the potential predictive effect of C8orf76 and CDK4 on the prognosis of colorectal cancer (CRC). METHODS: We constructed a protein-protein interaction network of C8orf76-related genes and analyzed the prognostic signatures of C8orf76 and CDK4. Clinicopathological features of C8orf76 and CDK4 were visualized using a nomogram. RESULTS: C8orf76 and CDK4 levels were positively correlated in two independent human CRC cohorts ( n = 83 and n = 597). A consistent positive correlation was observed between C8orf76 and CDK4 expression in the CRC cell lines. The nomogram included prognostic genes (C8orf76 and CDK4) and pathological N and M stages. The concordance index (C-index) in our cohort was 0.776, which suggests that the ability of the indicators to predict the overall survival of patients with CRC in our cohort was strong. CONCLUSION We found that C8orf76 was positively correlated with CDK4 in both the cohorts as well as in CRC cell lines. Therefore, C8orf76 and CDK4 can be used as potential biomarkers to predict the prognosis of CRC.
Humans ; Colorectal Neoplasms/diagnosis* ; Cyclin-Dependent Kinase 4/metabolism* ; Prognosis ; Male ; Female ; Middle Aged ; Biomarkers, Tumor/genetics* ; Aged ; Cell Line, Tumor ; Gene Expression Regulation, Neoplastic

Humans ; Cyclin D1 ; Melanoma ; Skin Neoplasms ; Cyclin-Dependent Kinase 4

OBJECTIVE: To investigate the value of using MDM2 amplification probe and DDIT3 dual-color, break-apart rearrangement probe fluorescence in situ hybridization (FISH) technique in the diagnosis of liposarcoma. METHODS: In the study, 62 cases of liposarcoma diagnosed in Peking University First Hospital from January 2015 to December 2019 were analysed for clinicopathological information. Of these 62 cases of liposarcoma, all were analysed for MDM2 amplification and 48 cases were analysed for DDIT3 rearrangement using a FISH technique. Our study aimed to evaluate the status of MDM2 and DDIT3 by FISH in liposarcoma and correlate it with diagnosis of different subtypes of liposarcoma. The subtypes of liposarcoma were classified according to the FISH results, combined with the relevant clinicopathological features. RESULTS: The patients aged 31-89 years (mean: 59 years) with a 1.75:1 male to female ratio. Histologically, there were 20 cases of atypical lipomatous tumour/well-differentiated liposarcoma (ALT/WDLPS), 26 cases of dedifferentiated liposarcoma (DDLPS), 13 myxoid liposarcoma (MLPS) and 3 pleomorphic liposarcoma (PLPS). Tumors with DDLPS (23/26) and WDLPS (8/20) were localized retroperitoneally, while both tumours of MLPS and PLPS were localized extra-retroperitoneally, and the difference of sites among the four subtypes of liposarcoma was statistically significant (P < 0.05). Histologically, varied mucoid matrix could be observed in the four subtypes of liposarcoma, and the difference was statistically significant (P < 0.05). MDM2 gene amplification was demonstrated in all cases of ALT/WDLPS and DDLPS (100%, 20/20 and 26/26 respectively); DDIT3 gene rearrangement was noted only in MLPS (100%, 13/13); most cases of DDLPS (96.2%, 25/26) and ALT/WDLPS (83.3%, 5/6, 6 cases selected for detection) demonstrated the picture of amplification of the DDIT3 telomeric tag. According to the instructions of DDIT3 break-apart rearrangement probe, the 5' telomere probe and 3' centromere probe spanned but did not cover the DDIT3 gene itself, on the contrary, the 5' telomere probe covered the CDK4 gene, while the DDIT3 and CDK4 gene were located adjacent to each other on chromosome, therefore, when the amplification signal appeared on the telomeric tag of the DDIT3 rearrangement probe, it indeed indicated the CDK4 gene amplification rather than the DDIT3 gene rearrangement. Then the 10 cases with DDIT3 telomeric tag amplification were selected for CDK4 and DDIT3 gene amplification probe FISH tests, and all the cases showed CDK4 gene amplification (100%, 10/10) and two of the 10 cases demonstrated co-amplification of CDK4 and DDIT3 (20%, 2/10); DDIT3 polysomy detected by DDIT3 gene rearrangement probe was found in 1 case of DDLPS and 2 cases of PLPS (66.7%, 2/3) with morphology of high-grade malignant tumour and poor prognosis. CONCLUSION Our results indicate that a diagnosis of different subtype liposarcoma could be confirmed based on the application of MDM2 and DDIT3 FISH, combined with clinicopathological findings. It is also noteworthy that atypical signals should be correctly interpreted to guide correct treatment of liposarcomas.
Male ; Female ; Humans ; In Situ Hybridization, Fluorescence/methods* ; Cyclin-Dependent Kinase 4/metabolism* ; Liposarcoma/pathology* ; Lipoma/pathology* ; Gene Amplification ; Transcription Factor CHOP/genetics* ; Proto-Oncogene Proteins c-mdm2/metabolism*

Cyclin-dependent kinase 4/6 (CDK4/6) inhibitors have led transformative breakthrough of clinical therapy for hormone receptor (HR)-positive, human epidermal growth factor receptor 2 (HER-2)-negative breast cancer patients. CDK4/6 inhibitors that have been marketed in China include Ribociclib, Palbociclib, Abemaciclib and Dalpiciclib. For HR-positive HER-2-negative locally advanced and metastatic breast cancer, CDK4/6 inhibitors combined with endocrine therapy have become standard regimen, which can prolong the survival of patients. In the adjuvant treatment stage of early breast cancer, CDK4/6 inhibitors have also achieved positive results and been approved for indications. At present, CDK4/6 inhibitors have been widely used in clinical practice in China. In order to further improve the standardized application of CDK4/6 inhibitors in China, the Breast Cancer Expert Committee of the National Center for Cancer Quality Control and the Professional Committee of Clinical Research of Cancer Drugs of the Chinese Anti-Cancer Association organized the related expert to update the consensus based on the "CDK4/6 inhibitor consensus on clinical application of in the treatment of hormone receptor positive human epidermal growth factor receptor 2 negative advanced breast cancer (2021 edition)" . The updated consensus systematically introduces the pharmacological characteristics, drug monitoring and adverse event management, etc., of CDK4/6 inhibitors to promote the accuracy of clinical decision-making with the ultimate goal to prolong the overall survival of patients and improve the quality of life.
Humans ; Female ; Breast Neoplasms/pathology* ; Quality of Life ; Consensus ; Triple Negative Breast Neoplasms/drug therapy* ; Receptor, ErbB-2/metabolism* ; Protein Kinase Inhibitors ; Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Cyclin-Dependent Kinase 4/metabolism*

Cyclin-dependent kinases 4/6 (CDK4/6) inhibitors are anti-tumor agents for the treatment of hormone receptor-positive breast cancer. Palbociclib, abemaciclib and dalpiciclib have been approved for the treatment of breast cancer in China. Common adverse effects of CDK4/6 inhibitors include bone marrow suppression, gastrointestinal toxicities, liver dysfunction, and skin or subcutaneous tissue adverse reactions (AEs). The Breast Cancer Expert Group of Chinese Society of Clinical Oncology (CSCO) summarized the incidence, clinical manifestations, and grading of the AEs. This expert consensus reports measures of AE management on the basis of experience of clinical practice and the latest advances worldwide, aiming to guide clinical practice by the way of managing AE and help to choose the best treatment regimen.
Female ; Humans ; Aminopyridines/adverse effects* ; Antineoplastic Agents/adverse effects* ; Breast Neoplasms/drug therapy* ; Consensus ; Cyclin-Dependent Kinase 4/antagonists & inhibitors* ; Protein Kinase Inhibitors/adverse effects* ; Cyclin-Dependent Kinase 6/antagonists & inhibitors*

The development and progression of most cancers have been well recognized as the result of highly activated cell cycle. Cyclin dependent kinase 4/6 plays important roles not only in mitosis, but also in multiple biological processes that contribute to cancer development, such as aging, apoptosis and histone modification. Three FDA approved CDK4/6 inhibitors, Palbociclib, Ribociclib and Abemaciclib, have been used as targeted cancer therapeutic agents to benefit patients with endocrine therapy-resistant breast cancer and other types of cancer, prolonging their survival. However, the clinical application of these inhibitors also leads to acquired drug resistance and other problems. This paper reviews the regulatory roles of CDK4/6, the application of CDK4/6 inhibitors in cancer and the challenge of drug resistance.
Breast Neoplasms ; Cyclin-Dependent Kinase 4/therapeutic use* ; Cyclin-Dependent Kinase 6/therapeutic use* ; Female ; Humans ; Molecular Targeted Therapy ; Protein Kinase Inhibitors/therapeutic use* ; Signal Transduction

The introduction of cyclin-dependent kinase (CDK) 4/6 inhibitors has revolutionized the clinical management paradigm of hormone receptor (HR) positive/human epidermal growth factor receptor (HER) 2 negative breast cancer. As of today, CDK 4/6 inhibitors including Palbociclib, Ribociclib, and Abemaciclib have been widely approved by regulatory agencies. Randomized clinical trials demonstrated that CDK 4/6 inhibitors in combination with an aromatase inhibitor (AI) or fulvestrant in the first-, second- or later-line setting for HR positive/HER2 negative locally advanced or metastatic breast cancer led to substantial reduction in the risk of disease progression or death. Adverse effects of treatment were manageable and as or better than expected in terms of patient satisfaction. Considering CDK4/6 inhibitors in combination with endocrine therapy being a novel approach in China clinical practice, the panel developed the consensus comprehensively describing the pharmacology properties, monitoring strategy during treatment and adverse events management, to facilitate greater understanding in Chinese oncologists of a whole new therapeutic class of drug, promote accuracy of clinical decision and help reach the ultimate goal of improving survival and quality of life of the target patient population.
Antineoplastic Combined Chemotherapy Protocols/therapeutic use* ; Breast Neoplasms/drug therapy* ; China ; Consensus ; Cyclin-Dependent Kinase 4 ; Cyclin-Dependent Kinase 6 ; Humans ; Protein Kinase Inhibitors/therapeutic use* ; Quality of Life ; Receptor, ErbB-2