CDK4, CDK6/cyclin-D1 Complex Inhibition and Radiotherapy for Cancer Control: A Role for Autophagy

In silico discovery of potential PPI inhibitors for anti-lung cancer activity by targeting the CCND1-CDK4 complex via the P21 inhibition mechanism

Non-Small Cell Lung Cancer (NSCLC) is a prevalent and deadly form of lung cancer worldwide with a low 5-year survival rate. Current treatments have limitations, particularly for advanced-stage patients. P21, a protein that inhibits the CCND1-CDK4 complex, plays a crucial role in cell proliferation. Computer-Aided Drug Design (CADD) based on pharmacophores can screen and design PPI inhibitors targeting the CCND1-CDK4 complex. By analyzing known inhibitors, key pharmacophores are identified, and computational methods are used to screen potential PPI inhibitors. Molecular docking, pharmacophore matching, and structure-activity relationship studies optimize the inhibitors. This approach accelerates the discovery of CCND1-CDK4 PPI inhibitors for NSCLC treatment. Molecular dynamics simulations of CCND1-CDK4-P21 and CCND1-CDK4 complexes showed stable behavior, comprehensive sampling, and P21's impact on complex stability and hydrogen bond formation. A pharmacophore model facilitated virtual screening, identifying compounds with favorable binding affinities. Further simulations confirmed the stability and interactions of selected compounds, including 513457. This study demonstrates the potential of CADD in optimizing PPI inhibitors targeting the CCND1-CDK4 complex for NSCLC treatment. Extended simulations and experimental validations are necessary to assess their efficacy and safety.

miR-329b-5p Affects Sheep Intestinal Epithelial Cells against Escherichia coli F17 Infection

Diarrhea is the most common issue in sheep farms, typically due to pathogenic Escherichia coli (E. coli) infections, such as E. coli F17. microRNA, a primary type of non-coding RNA, has been shown to be involved in diarrhea caused by pathogenic E. coli. To elucidate the profound mechanisms of miRNA in E. coli F17 infections, methods such as E. coli F17 adhesion assay, colony counting assay, relative quantification of bacterial E. coli fimbriae gene expression, indirect immune fluorescence (IF), Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU), Western blotting (WB), and scratch assay were conducted to investigate the effect of miR-329b-5p overexpression/knock-down on E. coli F17 susceptibility of sheep intestinal epithelial cells (IECs). The findings indicated that miR-329b-5p enhances the E. coli F17 resistance of sheep IECs to E.coli F17 by promoting adhesion between E. coli F17 and IEC, as well as IEC proliferation and migration. In summary, miR-329b-5p plays a crucial role in the defense of sheep IECs against E. coli F17 infection, providing valuable insights into its mechanism of action.

Long non-coding RNA PWRN1 affects ovarian follicular development by regulating the function of granulosa cells

RESEARCH QUESTION

What is the role of Prader-Willi region non-protein coding RNA 1 (PWRN1) in ovarian follicular development and its molecular mechanism?

DESIGN

The expression and localization of PWRN1 were detected in granulosa cells from patients with different ovarian functions, and the effect of interfering with PWRN1 expression on cell function was detected by culturing granulosa cells in vitro. Furthermore, the effects of interfering with PWRN1 expression on ovarian function of female mice were explored through in-vitro and in-vivo experiments.

RESULTS

The expression of PWRN1 was significantly lower in granulosa cells derived from patients with diminished ovarian reserve (DOR) compared with patients with normal ovarian function. By in-vitro culturing of primary granulosa cells or the KGN cell line, the results showed that the downregulation of PWRN1 promoted granulosa cell apoptosis, caused cell cycle arrested in S-phase, generated high levels of autophagy and led to significant decrease in steroidogenic capacity, including inhibition of oestradiol and progesterone production. In addition, SIRT1 overexpression could partially reverse the inhibitory effect of PWRN1 downregulation on cell proliferation. The results of in-vitro culturing of newborn mouse ovary showed that the downregulation of PWRN1 could slow down the early follicular development. Further, by injecting AAV-sh-PWRN1 in mouse ovarian bursa, the oestrous cycle of mouse was affected, and the number of oocytes retrieved after ovulation induction and embryos implanted after mating was significantly reduced.

CONCLUSION

This study systematically elucidated the novel mechanism by which lncRNA PWRN1 participates in the regulation of granulosa cell function and follicular development.

Novel phloretin-based combinations targeting glucose metabolism in hepatocellular carcinoma through GLUT2/PEPCK axis of action: in silico molecular modelling and in vivo studies

Hepatocellular carcinoma (HCC) is commonly associated with disturbances in glucose metabolism and enhanced glycolysis. However, a controversial role for gluconeogenesis was reported to be tumor-promoting and tumor-suppressive. We investigated novel anti-HCC treatments through either the simultaneous inhibition of glycolysis and gluconeogenesis by "phloretin" and "sodium meta-arsenite", respectively (Combination 1); or the concurrent inhibition of glycolysis and induction of gluconeogenesis by phloretin and dexamethasone, respectively, (combination 2). A total of 110 Swiss albino mice were divided into eleven groups, HCC was induced by N, N-dimethyl-4-aminoazobenzene. We have measured the expression of the glucose transporter 2 (GLUT2), Phosphoenolpyruvate carboxykinases (PEPCK), Caspase-3, Beclin 1, Cyclin D1, and cytokeratin 18 genes; blood glucose and ATP levels; alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities. Furthermore, in silico molecular docking was performed to investigate the potential drug-receptor interactions. Histologically, the phloretin-based combinations resulted in a significant regression of malignant tissue compared to various treatments. GLUT2 and PEPCK mRNA analysis indicated successful off/on modulation of glycolysis and gluconeogenesis. Docking confirmed the potent binding between phloretin, sodium meta-arsenite, and dexamethasone with GLUT2, PEPCK, and Retinoid X Receptor Alpha, respectively. Molecularly, Combination 2 resulted in the highest reduction in cyclin D1, cytokeratin 18, and Beclin 1 expression contemporaneously with the upregulation in Caspase-3 levels. Biochemically, both combinations caused a significant reduction in ATP levels, ALT, and AST activity compared to the other groups. In conclusion, we propose two novel phloretin-based combinations that can be used in treating HCC through the regulation of glucose metabolism and ATP production.

Novel roles of PIWI proteins and PIWI-interacting RNAs in human health and diseases

Non-coding RNA has aroused great research interest recently, they play a wide range of biological functions, such as regulating cell cycle, cell proliferation, and intracellular substance metabolism. Piwi-interacting RNAs (piRNAs) are emerging small non-coding RNAs that are 24-31 nucleotides in length. Previous studies on piRNAs were mainly limited to evaluating the binding to the PIWI protein family to play the biological role. However, recent studies have shed more lights on piRNA functions; aberrant piRNAs play unique roles in many human diseases, including diverse lethal cancers. Therefore, understanding the mechanism of piRNAs expression and the specific functional roles of piRNAs in human diseases is crucial for developing its clinical applications. Presently, research on piRNAs mainly focuses on their cancer-specific functions but lacks investigation of their expressions and epigenetic modifications. This review discusses piRNA's biogenesis and functional roles and the recent progress of functions of piRNA/PIWI protein complexes in human diseases. Video Abstract.

CDK6 is a novel predictive and prognosis biomarker correlated with immune infiltrates in multiple human neoplasms, including small cell lung carcinoma

The roles of cyclin-dependent kinase 6 (CDK6) in various cancers, including small cell lung carcinoma (SCLC), remain unclear. Here, 111,54 multi-center samples were investigated to determine the expression, clinical significance, and underlying mechanisms of CDK6 in 34 cancers. The area under the curve (AUC), Cox regression analysis, and the Kaplan-Meier curves were used to explore the clinical value of CDK6 in cancers. Gene set enrichment analysis and correlation analysis were performed to detect potential CDK6 mechanisms. CDK6 expression was essential in 24 cancer cell types. Abnormal CDK6 expression was observed in 14 cancer types (e.g., downregulated in breast invasive carcinoma; p < 0.05). CDK6 allowed six cancers to be distinguished from their controls (AUC > 0.750). CDK6 expression was a prognosis marker for 13 cancers (e.g., adrenocortical carcinoma; p < 0.05). CDK6 was correlated with several immune-related signaling pathways and the infiltration levels of certain immune cells (e.g., CD8+ T cells; p < 0.05). Downregulated CDK6 mRNA and protein levels were observed in SCLC (p < 0.05, SMD = - 0.90). CDK6 allowed the identification of SCLC status (AUC = 0.91) and predicted a favorable prognosis for SCLC patients (p < 0.05). CDK6 may be a novel biomarker for the prediction and prognosis of several cancers, including SCLC.

Circular RNA EIF3I promotes papillary thyroid cancer progression by interacting with AUF1 to increase Cyclin D1 production

Circular RNAs (circRNAs) play an important role in regulating the development of human cancers through diverse biological functions. However, the exact molecular mechanisms underlying the role of circRNAs in papillary thyroid cancer (PTC) remain largely unknown. Here, we found that hsa_circ_0011385, designated as circular eukaryotic translation initiation factor 3 subunit I (circEIF3I), preferentially localized in the cytoplasm of PTC cells and was more stable than its linear counterpart, EIF3I. Gain- and loss-of-function studies indicated that circEIF3I promoted PTC progression by facilitating cell proliferation, cell cycle, cell migration, and invasion in vitro, as well as PTC cell proliferation in vivo. Mechanistically, circEIF3I interacted with AU-rich element (ARE) RNA-binding factor 1 (AUF1) in the cytoplasm of PTC cells, thus reducing the degradation of Cyclin D1 mRNA and increasing Cyclin D1 protein production, ultimately resulting in PTC progression. Collectively, our results demonstrate the vital role of circEIF3I in PTC progression, supporting its significance as a potential therapeutic target.

CCND1-Induced Autophagy Contributes to Lymph Node Metastasis in Endometrial Cancer

Endometrial cancer with lymph node metastasis shows poor prognosis, while the biomarker to predict the metastasis is lacking. The relative mRNA or protein expression of cyclin D1 (CCND1) and autophagy-related molecules were detected in real-time PCR and Western blot. Correlation analysis was applied to identify any significant patterns, and receiver operating characteristics (ROC) was performed to assess the prediction value. CCND1 vector was transfected in Ishikawa (ISK) cells, and the relative expression of autophagy-related molecules was detected with Western blot. CCND1 was overexpressed in endometrial cancer and correlated with lymph node metastasis. ROC analysis found that CCND1 had a predictive value to discriminate tumors from normal tissues (cut off=1.455; sensitivity, 71%; specificity, 84%; area under curve (AUC) 0.82; p<0.001) and had a predictive value to indicate metastasis (cut off=1.871; sensitivity, 54.17%; specificity, 75%; AUC 0.674; p=0.003). Increased BECLIN1 (r=0.39, p<0.001) and ATG5 (r=0.41, p<0.001) expression were positively correlated to CCND1. On the other hand, the relative protein expression of CCND1, BECLIN1, ATG5, ATG7, and LC3 I/II were also increased in tumor tissues. CCND1 overexpressed ISK cells showed upregulated BECLIN1, ATG5, ATG7, and LC3 I/II expression. CCND1 promoted autophagy may contribute to lymph node metastasis in endometrial cancer.

Autophagy and Breast Cancer: Connected in Growth, Progression, and Therapy

Despite an increase in the incidence of breast cancer worldwide, overall prognosis has been consistently improving owing to the development of multiple targeted therapies and novel combination regimens including endocrine therapies, aromatase inhibitors, Her2-targeted therapies, and cdk4/6 inhibitors. Immunotherapy is also being actively examined for some breast cancer subtypes. This overall positive outlook is marred by the development of resistance or reduced efficacy of the drug combinations, but the underlying mechanisms are somewhat unclear. It is interesting to note that cancer cells quickly adapt and evade most therapies by activating autophagy, a catabolic process designed to recycle damaged cellular components and provide energy. In this review, we discuss the role of autophagy and autophagy-associated proteins in breast cancer growth, drug sensitivity, tumor dormancy, stemness, and recurrence. We further explore how autophagy intersects and reduces the efficacy of endocrine therapies, targeted therapies, radiotherapy, chemotherapies as well as immunotherapy via modulating various intermediate proteins, miRs, and lncRNAs. Lastly, the potential application of autophagy inhibitors and bioactive molecules to improve the anticancer effects of drugs by circumventing the cytoprotective autophagy is discussed.

PIMREG is a prognostic biomarker involved in immune microenvironment of clear cell renal cell carcinoma and associated with the transition from G1 phase to S phase

Background

Clear cell renal cell carcinoma (ccRCC) is one of the most common tumors in the world and affects human health seriously. PIMREG is a mitotic regulator which is essential to the metaphase-to-anaphase transition in cell cycle. Although PIMREG plays a crucial role in the malignant progression of tumors, there are few reports on its role in ccRCC.

Methods

The transcriptional expression profile and clinical data of PIMREG were downloaded from TCGA database and verified by qRT-PCR. Kaplan-Meier plotter was used to analyze the effect of PIMREG on overall survival (OS), disease specific survival (DSS) and progression-free interval (PFI) of patients with ccRCC. Univariable and multivariable Cox regression analysis were used to determine the independent prognostic factors of ccRCC. The effects of PIMREG on cell migration and invasion were detected by wound healing assay and transwell invasion assay, and CCK-8 assay, colony formation assay and cell cycle assay were used to detect the effect of PIMREG on cell proliferation. In addition, the changes in cell cycle related proteins were detected by western blot.

Results

PIMREG was highly expressed in human ccRCC and was positively correlated with pathologic stage, TNM stage and histologic grade. In addition, patients with high expression of PIMREG had a poor prognosis. Univariable and multivariable Cox regression analysis identified that PIMREG was an independent prognostic factor of ccRCC. Additionally, PIMREG was also closely related to immune cell infiltration. Experiments in vitro identified that the knockdown of PIMREG could significantly inhibit the proliferation, migration and invasion abilities of ccRCC. The expression of cyclin D1, CDK4 and CDK6 was also significantly reduced after PIMREG knockdown.

Conclusions

PIMREG plays a vital role in the development of ccRCC and may become a potential therapeutic target in the future.

Deciphering the Immunomodulatory Role of Cyclin-Dependent Kinase 4/6 Inhibitors in the Tumor Microenvironment

Cancer is characterized by persistent cell proliferation driven by aberrant cell cycle regulation and stimulation of cyclin-dependent kinases (CDKs). A very intriguing and potential approach for the development of antitumor medicines is the suppression of CDKs that lead to induction of apoptosis and cell cycle arrest. The shift of the cell cycle from the G0/G1 phase to the S phase, which is characterized by active transcription and synthesis, depends on the development of the cyclin D-CDK4/6 complex. A precise balance between anticancer activity and general toxicity is demonstrated by CDK inhibitors, which can specifically block CDK4/6 and control the cell cycle by reducing the G1 to S phase transition. CDK4/6 inhibitors have recently been reported to exhibit significant cell growth inhibition via modulating the tumour microenvironment in cancerous cells. One significant new understanding is that these inhibitors serve important functions in the interaction among tumour cells and the host immune system in addition to being cytostatic. Herein, we discuss the biological significance of CDK4/6 inhibitors in cancer therapeutics, as well as their biological impact on T cells and other important immune cells. Furthermore, we explore the integration of preclinical findings of these pharmaceuticals' ability to enhance antitumor immunity.

FBXO43 increases CCND1 stability to promote hepatocellular carcinoma cell proliferation and migration

Background and Aims

Abnormal expression of E3 ubiquitin ligase plays an important role in the development and progression of hepatocellular carcinoma (HCC), although the mechanism has remained elusive. This study aimed to investigate the biological function and potential mechanism of FBXO43 in HCC.

Methods

FBXO43 expression in tissues and cells were detected by quantitative real-time PCR (qRT-PCR), Western blot, and immunohistochemistry (IHC). The Kaplan-Meier method and Cox regression analysis were used to explore the correlation between the expression level of FBXO43 and the clinical survival. MTT assay, EdU incorporation, colony formation, Transwell, and wound healing assays were performed to evaluate the function of FBXO43 in cell proliferation and migration in vitro. The interaction between FBXO43 and cyclin D1 (CCND1) was assessed by co-immunoprecipitation (Co-IP) assay and in vivo ubiquitination assay.

Results

We found that FBXO43 was upregulated in HCC patient tissues and positively associated with poor clinicopathological features. Meanwhile, HCC patients with high expression of FBXO43 had shorter overall survival (OS) and disease-free survival (DFS). Furthermore, knockdown of FBXO43 inhibited HCC cell proliferation, migration and epithelial-mesenchymal transition (EMT) in HCC cells. Mechanistically, FBXO43 interacted with CCND1 and promoted its stability by polyubiquitination, leading to HCC cell proliferation, migration and EMT. Functional rescue experiments demonstrated that knockdown of CCND1 blocks FBXO43-mediated cell proliferation and metastasis.

Conclusions

FBXO43, as an independent prognostic biomarker, promotes HCC cell proliferation, metastasis and EMT by stability of CCND1, which provides a new potential strategy for HCC treatment by targeting FBXO43-CCND1 axis.

Targeting PI3K/AKT/mTOR Signaling Pathway as a Radiosensitization in Head and Neck Squamous Cell Carcinomas

Globally, there are over half a million new patients with head and neck squamous cell carcinomas (HNSCC) every year. The current therapeutic approaches to HNSCC are surgery and adjuvant radiotherapy. These approaches carry a high incidence of metastasis or recurrence from HNSCC cells' radioresistance. Recent studies have revealed that a combination with radiosensitizers can be used to improve the radioresistance in HNSCC; however, few agents are approved as radiosensitizers. The constitutive activation of phosphatidylinositol-3-kinase (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR) pathway is a vitally oncogenic type of signaling that promotes tumorigenesis, metastasis, and radiotherapy resistance in HNSCC. Pharmacological targeting of PI3K/AKT/mTOR signaling pathway is considered a promising strategy of radiosensitization in HNSCC. In this review, we summarize the oncogenic significance of PI3K/AKT/mTOR signaling in HNSCC with radiotherapy resistance and highlight the therapeutic potential of small molecule inhibitors against PI3K/AKT/mTOR signaling for the radiosensitization in HNSCC treatment. It provides a mechanistic framework for the development of new drugs for radiosensitization in HNSCC radiotherapy via targeting PI3K/AKT/mTOR signaling pathway.

Studies on Chemical Composition of Pueraria lobata and Its Anti-Tumor Mechanism

Fourteen compounds were isolated from Pueraria lobata (Willd.) Ohwi by column chromatography and preparative thin-layer chromatography; the structures were identified by spectroscopic analysis and compared with data reported in the literature. Seven compounds were isolated and identified from Pueraria lobata for the first time: Linoleic acid, Sandwicensin, Isovanillin, Ethyl ferulate, Haginin A, Isopterofuran, 3′.7-Dihydroxyisoflavan. The other 10 compounds were structurally identified as follows: Lupenone, Lupeol, β-sitosterol, Genistein, Medicarpin, Coniferyl Aldehyde, Syringaldehyde. All compounds were evaluated for their ability to inhibit SW480 and SW620 cells using the CCK-8 method; compound 5 (Sandwicensin) had the best activity, and compounds 6, 9, 11 and 12 exhibited moderate inhibitory activity. In addition, the targets and signaling pathways of Sandwicensin treatment for CRC were mined using network pharmacology, and MAPK3, MTOR, CCND1 and CDK4 were found to be closely associated with Sandwicensin treatment for CRC; the GO and KEGG analysis showed that Sandwicensin may directly regulate the cycle, proliferation and apoptosis of CRC cells through cancer-related pathways.

Identification of Enhancer RNA CDK6-AS1 as a Potential Novel Prognostic Biomarker in Gastric Cancer

Background: This study aimed to confirm the role of enhancer RNAs (eRNAs) in gastric cancer and their clinical utility.

Methods: We used Cox survival and relevance analysis to identify the candidate eRNAs in gastric cancer and performed Gene Ontology and Reactome pathway enrichment to determine the potential functions of eRNAs. Correlation between eRNA, tumor-infiltrating immune cells, and drug sensitivity was then analyzed.

Results:CDK6-AS1, a long non-coding RNA cyclin-dependent kinase 6, may serve as a poor potential prognostic biomarker candidate in gastric cancer with a positive correlation with its target gene CDK6. The low CDK6-AS1 expression group showed more frequent mutated driver genes than the high expression group. Moreover, CDK6-AS1 is involved in a key oncogenic pathway of the cell cycle and RNA transcription. CDK6-AS1 also shows dysregulations and associations with prognosis at the pan-cancer level. This eRNA may also be associated with immune cell infiltration and drug sensitivity.

Conclusion:CDK6-AS1 may be a potential prognostic biomarker and chemotherapeutic drug sensitivity predictor in gastric cancer.

Cyclin-Dependent Kinase 6 Identified as the Target Protein in the Antitumor Activity of Tetrastigma hemsleyanum

Background

Tetrastigma hemsleyanum (T. hemsleyanum) is widely used as an adjuvant drug for tumor therapy but its antitumor therapeutic targets and molecular mechanisms have remained unclear. The prediction and analysis of natural products has previously used only network pharmacology methods to identify potential target proteins from public databases. In this study, we use comprehensive bioinformatics analysis and experimental verification to determine the antitumor mechanism of T. hemsleyanum.

Methods

Network pharmacology analysis was used to predict the potential in vivo target proteins of T. hemsleyanum. The expression matrix and clinical data to perform an analysis of hub genes were collected from the TCGA and GTEx databases, specifically the analysis of expression, prognosis, tumor immune cell infiltration analysis, immune checkpoint genes, microsatellite instability, tumor mutational burden, tumor neoantigen, and immune microenvironment, which identify the roles and biological functions of the hub genes in pan-cancer. Finally, gene set enrichment analysis was used to verify the biological processes and signaling pathways involved in the pan-cancer expression profile.

Results

We found 124 potential in vivo target proteins of T. hemsleyanum through network pharmacological analysis, and five hub genes (AKR1C1, MET, PTK2, PIK3R1, and CDK6) were then screened by protein–protein interaction (PPI) network analysis and molecular complex detection analysis (MCODE). Experimental intervention with an aqueous extract of T. hemsleyanum verified that these hub genes are the target proteins involved in the regulation of T. hemsleyanum in cells. A pan-cancer analysis then confirmed that CDK6 and MET are potential targets upon which T. hemsleyanum may exert antitumor action, especially in ACC, CESC, LGG, and PAAD. The CDK6 protein targeted by T. hemsleyanum is also involved in the immune and mutation process of pan-cancer, especially in the regulation of immune cell infiltration, immune checkpoint gene expression, microsatellite instability, tumor mutation burdens, and tumor neoantigens. Together, these analyses show that T. hemsleyanum affects tumor immune regulation and genomic stability. Finally, a gene set enrichment analysis confirmed that T. hemsleyanum regulates the cell cycle checkpoint.

Conclusions

We found that T. hemsleyanum can behave as an antitumor agent by acting as a potential cell cycle checkpoint inhibitor in CDK6-driven tumors, such as ACC, CESC, LGG, and PAAD, and that it acts as a tyrosine kinase receptor inhibitor that inhibits the expression of the proto-oncogene MET. Combined with an analysis of immune and mutation correlations in pan-cancer, we determined that T. hemsleyanum may function biologically as an immune regulator and interfere with the stability of the tumor genome, which is worthy of further study.