Cyclin D1 Protein Research Articles

Effect of tRF-28-ZJ47D112Z4DZ on the pathogenesis of gastric cancer through targeting cyclin D1/CDK4 and its early diagnostic value.

475 Background: Gastric cancer exhibits high incidence and mortality rates worldwide. Current research on gastric cancer aims to discover stable and effective early diagnostic markers, as well as uncover the disease's pathogenesis. tRNA-derived fragment (tRF) is a newly discovered regulatory non-coding RNA, which plays an important role in tumor diagnosis and treatment. Methods: This study, through transcriptome sequencing and MINTBase v2.0 database, screened out a new molecule tRF-28-ZJ47D112Z4DZ (tRF-28) related to gastric cancer. An absolute quantitative method was established to quantify the level of tRF-28 in plasma. ROC curve, survival curve, Cox regression model were constructed, and clinicopathological factors were collected to analyze the diagnostic value of tRF-28. "Overexpression" and "knockdown" tRF-28 gastric cancer cell models and xenograft tumor models were established to study the effects of tRF-28 on cell proliferation. Using bioinformatics, qRT-PCR, Western blot, dual luciferase reporter gene, fluorescence in situ hybridization, RNA binding protein immunoprecipitation assay, rescue experiment and immunohistochemistry to study the regulatory role of tRF-28 by binding to the 3'UTR of CCND1. Results: This study clarified the tRF-28 levels in the plasma of healthy individuals, and gastric benign and malignant lesions, providing a new candidate biomarker for the early diagnosis of gastric cancer. Through upregulating and downregulating the level of tRF-28 in gastric cancer cells, it was revealed that tRF-28 inhibits the proliferation of gastric cancer cells in vivo and in vitro by regulating key proteins such as Cyclin D1, CDK4, Rb, and p-Rb. In studying specific molecular mechanisms, tRF-28 and CCND1 were co-located in the cytoplasm. tRF-28 combines with Ago2 protein to form a complex and plays a role in silencing the target gene CCND1 in the cytoplasm. The rescue experiments revealed that silencing the target gene CCND1 can reverse the carcinogenesis effect of tRF-28 inhibitors, clarifying the biological functions of tRF-28 by regulating CCND1. Conclusions: Based on a series of research findings, we elucidated that tRF-28 form a complex with Ago2 protein, binding to the 3' UTR of CCND1 to downregulate Cyclin D1, CDK4, and other critical proteins, thereby inhibiting the proliferation of gastric cancer cells. Our study aims to offer new insights into identifying potential early diagnostic markers and therapeutic targets for gastric cancer.

Exploring the antiproliferative effect of PI3K/Akt/mTOR pathway and CDK4/6 inhibitors in human papillomavirus‑positive and ‑negative head and neck squamous cell carcinoma cell lines.

Human papillomavirus (HPV)‑positive and -negative head and neck squamous cell carcinoma (HNSCC) are often associated with activation of the phosphatidylinositol 3‑kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) pathway due to mutations or amplifications in PI3KCA, loss of PTEN or activation of receptor tyrosine kinases. In HPV‑negative tumors, CDKN2A (encoding p16 protein) inactivation or CCND1 (encoding Cyclin D1 protein) amplification frequently results in sustained cyclin‑dependent kinase (CDK) 4/6 activation. The present study aimed to investigate the efficacy of the CDK4/6 inhibitors (CDKi) palbociclib and ribociclib, and the PI3K/Akt/mTOR pathway inhibitors (PI3Ki) gedatolisib, buparlisib and alpelisib, in suppressing cell viability of HPV‑positive and ‑negative HNSCC cell lines. Inhibitor efficacy was assessed in vitro using MTT assay and western blotting analysis. Cell cycle analysis was performed using flow cytometry and apoptosis was assessed using annexin V staining. Metabolic changes in terms of glycolysis and oxidative metabolism were measured by Seahorse XF96 extracellular Flux analysis. The results of the present study showed that both HPV‑positive and ‑negative HNSCC cell lines were sensitive to PI3Ki. In general, PI3Ki decreased PI3K/Akt/mTOR pathway activity, resulting in apoptosis, and decreased oxidative and glycolytic metabolism. The CDKi were particularly effective in blocking HPV‑negative cell line viability, showing decreased retinoblastoma expression and G1‑phase cell cycle arrest, whereas apoptosis was not induced. Thus, PI3Ki and CDKi efficiently inhibited their respective pathways and HNSCC cell viability in vitro, with the latter occurring only in HPV‑negative cell lines. Whereas PI3Ki induced apoptosis and attenuated cellular metabolism, CDKi led to cell cycle arrest. Further research should be performed to elucidate whether (a combination of) these inhibitors may be effective therapeutic agents for patients with HNSCC.

LncRNA-ANRIL regulates CDKN2A to promote malignant proliferation of Kasumi-1 cells

ObjectiveThis study aimed to investigate the regulatory effects of long non-coding RNA-ANRIL on CDKN2A in the cell cycle of Kasumi-1 cells and elucidate the underlying molecular mechanisms.MethodsANRIL and CDKN2A expression levels were quantified using RT-qPCR in peripheral blood samples from acute myeloid leukemia (AML) patients. CDKN2A knockdown efficiency was validated via RT-qPCR, and cell cycle distribution was analyzed using flow cytometry. Cell proliferation assays were conducted with CCK-8 following palbociclib treatment and CDKN2A downregulation. RNA immunoprecipitation (RIP) identified potential ANRIL-associated targets, while western blotting assessed the expression levels of GSK3β/β-catenin/cyclin D1 signaling components and related proteins.ResultsANRIL and CDKN2A were markedly overexpressed in AML patient samples. Knockdown of ANRIL and CDKN2A led to G1 phase arrest accompanied by reduced CDK2/4/6 and cyclin D1 protein levels, while ANRIL upregulation induced the opposite effect. Palbociclib treatment for 24 h and 48 h elevated the G1 phase cell population and suppressed CDK2/4/6 and cyclin D1 protein expression, demonstrating its ability to counteract ANRIL-driven cell cycle progression. Downregulation of ANRIL and CDKN2A also suppressed the GSK3β/β-catenin signaling pathway, reducing cyclin D1 expression, whereas ANRIL upregulation reactivated this axis. Co-transfection experiments showed that simultaneous cyclin D1 suppression and ANRIL overexpression attenuated ANRIL’s stimulatory effects on cell cycle progression. RIP analysis confirmed a physical interaction between ANRIL and CDKN2A. Furthermore, CDKN2A downregulation inhibited cell proliferation and reversed GSK3β/β-catenin/cyclin D1 pathway activation mediated by ANRIL upregulation.ConclusionANRIL facilitates Kasumi-1 cell survival by modulating CDKN2A to activate the GSK3β/β-catenin/cyclin D1 signaling pathway.

Identification of KRT16 and ANXA10 as cell cycle regulation genes for lung adenocarcinoma based on self-transcriptome sequencing of surgical samples and TCGA public data mining

AimThis study aimed to identify the genes associated with the development of lung adenocarcinoma (LUAD) and potential therapeutic targets.MethodsDifferentially expressed genes (DEGs) were identified by self-transcriptome sequencing of tumor tissues and paracancerous tissues resected during surgery and combined with The Cancer Genome Atlas (TCGA) data to screen for the genes associated with LUAD prognosis. The expression was validated at mRNA and protein levels, and the gene knockdown was used to examine the impact and underlying mechanisms on lung cancer cells.ResultsA total of 227 DEGs were identified by transcriptome sequencing, and the 20 DEGs with the most significant differences were used for co-analysis with TCGA data. The findings suggested that KRT16 and ANXA10 might have an important role in the development of LUAD after validating the mRNA and protein expression levels at the cellular level. The knockdown of KRT16 and ANXA10 inhibited the proliferation of lung cancer cells, and the cell cycle was blocked in the G1 phase. The expression of the G1/S–phase cell cycle checkpoint–related proteins cyclin D1 and cyclin E was inhibited by KRT16 and ANXA10 knockdown, respectively. The tumor formation ability decreased after KRT16 or ANXA10 knockdown in vivo.ConclusionsKRT16 and ANXA10 are potential genes regulating the development of LUAD. Also, they may be potential targets for the targeted therapy of LUAD by inhibiting the proliferation of lung cancer cells and blocking the cell cycle by affecting key protein expression levels at cell cycle checkpoints.

Design, synthesis and biological evaluation of bisnoralcohol derivatives as novel IRF4 inhibitors for the treatment of multiple myeloma.

Interferon regulatory factor 4 (IRF4) is specifically overexpressed in multiple myeloma (MM) and mediates MM progression and survival, making it an emerging target for MM treatment. However, no chemical entity with a defined structure capable of directly binding to and inhibiting IRF4 has been reported. We screened our small library of steroid analogs and identified bisnoralcohol (BA) derivative 18 as a novel hit compound capable of inhibiting IRF4, with an IC50 of 13.46μM. Based on 18, a series of BA derivatives was synthesized and evaluated for their inhibitory effects on IRF4 and antiproliferative activities against MM cell lines. Among these compounds, 41 (SH514) exhibited the highest potency, with an IC50 value of 2.63μM for inhibiting IRF4, and IC50 values of 0.08μM and 0.11μM for inhibiting the proliferation of IRF4-high-expressing NCI-H929 and MM.1R MM cells, respectively. SH514 can bind to the IRF4-DBD domain with a KD of 1.28μM. SH514 selectively and potently inhibits IRF4-high-expressing MM cells over IRF4-low-expressing MM cells. Mechanistic studies demonstrated that SH514 suppresses the downstream genes of IRF4, including CCNC, CANX, E2F5, CMYC, HK2, and Blimp1, and inhibited the expression of cell cycle-related proteins CDC2, Cyclin B1, Cyclin D1, Cyclin E1, and CMYC in MM cells. In vivo, SH514 effectively inhibited the proliferation of MM tumors, showing much better antitumor efficacy than the clinical drug lenalidomide, and exhibited no significant toxicity. Thus, these IRF4 inhibitors could serve as promising leads for the development of novel anti-multiple myeloma agents.

Mechanism of electroacupuncture on hippocampal neuron regeneration in depression rats based on Wnt/β-catenin and Notch signaling pathway

To observe the effect of electroacupuncture (EA) on the proliferation of hippocampal neurons and Wnt/β-catenin and Notch signaling pathways in depression like behavior rats, so as to explore its mechanism underlying improvement of depression. SD rats were randomly divided into blank, model, medication and EA groups, with 12 rats in each group. The depression model was established by chronic unpredictable mild stimulation combined with solitary raising for 35 consecutive days. After 14 days modeling, EA was applied to "Baihui"(GV20) and "Taichong"(LR3) for 15 min once daily for 3 weeks. For rats of the medication group, clomipramine (2.5 mg/kg) was given (i.p.) once a day for 3 weeks. The depression-like behavior was evaluated by open field test and forced swimming test. The ultrastructure of hippocampal neurons was observed by transmission electron microscope (TEM). The positive expression of 5-bromo-2'-deoxyuridine/neuron-specific nucleoprotein (BrdU/NeuN) in hippocampal dentate gyrus of rats was detected by immunofluorescence double labeling method. Western blot was used to detect the relative expression of Wnt/β-catenin and Notch pathway key proteins β-catenin, G1/S-specific cyclin-D1 (Cyclin D1), NICD and Hes1 in hippocampus of rats. Compared with the blank group, the total distance and average speed of open field movement were decreased (P<0.01), and the immobility time of forced swimming was increased (P<0.01). The positive expression of BrdU/NeuN in hippocampal dentate gyrus was decreased (P<0.01). The relative expression of β-catenin and Cyclin D1 protein in hippocampus were decreased (P<0.01), while the relative expression of NICD and Hes1 protein increased (P<0.01) in the model group. Following the treatment and compared with the model group, the total distance and average speed of movement in the open field were increased (P<0.05), and the immobility time of forced swimming was decreased (P<0.05) in both medication and EA groups. The positive expression of BrdU/NeuN in hippocampal dentate gyrus was increased (P<0.01). The relative expression of β-catenin and Cyclin D1 protein in hippocampus were increased (P<0.01), while the relative expression of NICD and Hes1 protein were decreased (P<0.01, P<0.05) in both medication and EA groups. TEM microscope observation showed irregularity of hippocampal neurons, rupture of nuclear membranes, disruption of mitochondrial structure, and dilation of endoplasmic reticulum in the model group, which was relatively milder in both medication and EA groups. EA can improve the depressive state of depression model rats, which may be associated with its functions in regulating Wnt and Notch signaling pathways, thereby promoting the regeneration of hippocampal neurons.

Rosmanol Effectively Prevents Diethylnitrosamine-induced Hepatocellular Carcinoma in Rats by Regulating the PI3K/Akt Signaling Pathway

Background Hepatocellular carcinoma (HCC) is the third principal reason for tumor-linked fatalities globally. There is no effective cure for HCC due to rapid progression and poor prognosis. Rosmanol (RM) is a phenolic diterpene antioxidant that exhibits anti-inflammatory and anticancer properties. Purpose This research aims to examine the chemopreventive efficacy of RM on the PI3K/Akt pathway as a potential mechanism for its protective effect against N-diethylnitrosamine (DEN)-induced HCC. Materials and Methods Wistar albino male rats were separated into four sets: normal control (NC); DEN-induced HCC model; DEN+RM (40 mg/kg bw); and RM (40 mg/kg bw) alone. To evaluate the chemopreventive mechanism, we assessed the change in body weight, liver weight, hepatotoxicity markers, antioxidant enzymes, lipid peroxidation, proliferation proteins, cytokines, histopathology, and western blot. Results and Conclusion Our data revealed that RM could reduce the loss of body weight, liver weight, toxicity enzymes, oxidative stress, inflammation, and restructuring of the hepatocellular architecture against DEN-stimulated HCC rats. RM-alone treated rats exhibited comparable activity with NC. Furthermore, RM attenuates PCNA and cyclin-D1 protein expression by the regulation of the PI3K/Akt pathway. The possible chemopreventive activities of RM may be owing to its antioxidative, anti-inflammatory, and antiproliferative effects. Thus, RM may aid as an innovative remedial agent for HCC treatment.

YKL-06-061 exerts antitumor effect through G1/S phase arrest by downregulating c-Myc and inhibition of metastasis via SIK1 upregulation in pancreatic cancer.

Pancreatic cancer ranks fourth among cancer-related deaths with a low 5-year overall survival rate of less than 13%. At present, treatment of pancreatic cancer is still based on chemotherapy, but the efficacy is limited. Thus, a novel therapeutic agent for pancreatic cancer therapy is urgently needed. A library of compounds was screened, and YKL-06-061, a selective inhibitor of salt-inducible kinases (SIKs), was discovered for its ability of inhibiting the proliferation and metastasis of pancreatic cancer cells in vitro and reducing the growth of xenografts in nude mice in vivo. The results from transcriptome analysis showed that YKL-06-061 influenced the mRNA levels of many genes related to c-Myc and SIK1 signals. Based on this, it was found that YKL-06-061 induced cell cycle arrest at the G1 phase and decreased the levels of c-Myc, CDK4, and cyclin D1 protein. At the same time, YKL-06-061 inhibited invasion and metastasis of cancer cells, increased the levels of SIK1 and E-cadherin protein, and lowered vimentin and ZEB-1. Moreover, YKL-06-061 effectively enhanced the antiproliferation of gemcitabine or doxorubicin in pancreatic cancer cells in a synergistic manner. Collectively, these findings implicate YKL-06-061 as a promising therapeutic agent for patients with pancreatic cancer.

E2F8 facilitates malignant phenotypes of muscle-invasive bladder cancer via increasing MCM7 expression.

E2F transcription factor 8 (E2F8) is an important regulator of the cell cycle. In this study, we first assessed the expression of E2F8 in bladder cancer and examined its effects in the malignant phenotypes of bladder cancer cell lines. We found that E2F8 was upregulated in bladder cancer tissues, and the increased expression was positively associated with higher clinical stage. E2F8 knockdown suppressed bladder cancer cell proliferation, accompanied by the performance of G1 phase arrest and the upregulated Cyclin D1 protein expression. The migrative and invasive capability was reduced in E2F8-depleted bladder cancer cells. Cisplatin resistance is an important cause of bladder cancer relapse. E2F8 downregulation facilitated cisplatin-induced apoptosis of bladder cancer cells. MCM7 is regulated by E2F and has been shown to participate in bladder cancer. There was a positive correlation between E2F8 and MCM7 expression in bladder cancer. We confirmed that E2F8 bound to the promoter region of MCM7 and activated MCM7 transcription. MCM7 overexpression abrogated the suppressive effects of E2F8 knockdown on malignant phenotypes of bladder cancer cells. We also demonstrated that E2F8 knockdown suppressed bladder cancer progression in vivo. In conclusion, we verify that E2F8 functioned in bladder cancer, and might exert its function via MCM7.

Zuogui pills ameliorate chemotherapy-induced ovarian aging by improving stemness, regulating cell cycle and reducing apoptosis of oogonial stem cells via the Notch1/Nrf2 pathway

Ethnopharmacological relevanceZuogui Pills (ZGP) is a classic traditional Chinese herbal formula originating from the Ming Dynasty. It has been widely used in the treatment of kidney deficiency-related diseases, including ovarian aging. Aim of the studyTo investigate the effects and potential mechanisms of ZGP on ovarian aging induced by the chemotherapeutic agent cyclophosphamide (CTX), as well as its impact on the therapeutic target, oogonial stem cells (OSCs), involving the Notch1/nuclear factor erythroid 2-related factor 2 (Nrf2) pathway. Materials and methodsThis study utilized High-Performance Liquid Chromatography (HPLC) to analyze the active components of Zuogui Pills (ZGP). In vivo experiments involved the establishment of an ovarian aging model in female rats through intraperitoneal injection of CTX, followed by an 8-week treatment with ZGP and dehydroepiandrosterone (DHEA). The Notch pathway inhibitor DAPT was administered via intraperitoneal injection, followed by ZGP intervention to validate its therapeutic effects. Transcriptomic sequencing was used to analyze the differential genes before and after ZGP treatment of CTX-induced ovarian aging, and KEGG and GO analyses were applied to assess the changes in relevant signaling pathways and biological processes. In vitro experiments included the extraction, separation, and purification of ovarian germ stem cells, followed by transfection with a Notch1 overexpression plasmid. The CTX active component 4-Hydroxycyclophosphamide (4HC) was used for model intervention, and ZGP, DHEA-containing serum, and DAPT were applied to intervene with the oogonial stem cells. The effects of CTX modeling, the therapeutic efficacy of ZGP, and the general condition of the rats were observed. H&E staining was employed to assess ovarian morphology and follicle counting at various stages. Serum hormone levels were measured using ELISA, while qPCR, Western blot, flow cytometry, immunofluorescence, and IHC were utilized to analyze the expression of the Notch1/Nrf2 pathway, cell cycle proteins, and stemness-related indicators. Flow cytometry, TUNEL fluorescence, and CCK8 assays were conducted to evaluate changes in cell cycle composition, apoptosis, and proliferation. Finally, ChIP-qPCR was employed to validate the transcriptional regulation of the target gene NFE2L2 by Notch1. ResultsZGP improved serum sex hormones in ovarian aging rats, enhanced ovarian index, and optimized ovarian and uterine morphology, as well as follicle quantity composition. After transcriptome sequencing, KEGG analysis enriched the Notch signaling pathway and cell cycle, while GO analysis highlighted enrichment in the Notch pathway and stem cell population maintenance. Various experiments validated that ZGP significantly improved the expression of cell cycle-related proteins Cyclin D1 (CCND1), Cyclin E1 (CCNE1), cyclin-dependent kinase inhibitor 1a (CDKN1A), stemness markers Mouse Vasa Homolog (MVH), Octamer-binding Transcription Factor 4 (Oct4), Fragilis, 5-Bromo-2′-deoxyuridine (BrdU), as well as Notch1 and Nrf2 in aging ovarian tissues and OSCs. Additionally, ZGP promoted the proliferation of 4HC-damaged OSCs, optimized OSCs cell cycle composition, reduced G0/G1 phase arrest, and decreased early and late apoptosis. ZGP could reverse the detrimental effects on stemness and cell cycle of OSCs caused by blocking the Notch pathway. Furthermore, ZGP may activate the regulation of its target gene NFE2L2 by upregulating Notch1 expression in OSCs, thereby exerting therapeutic effects. ConclusionZGP protects ovarian function in CTX-induced ovarian aging rats by regulating the Notch1/Nrf2 pathway. It restores serum sex hormone levels, maintains normal follicle development, promotes the proliferation of aged OSCs, optimizes the cell cycle, reduces apoptosis, and preserves stemness, thereby alleviating ovarian aging.

Clinical significance of Cyclin D1 by complete quantification detection in mantle cell lymphoma: positive indicator in prognosis

ObjectivesThe positive expression of Cyclin D1 in immunohistochemical (IHC) staining serves as the cornerstone for diagnosing mantle cell lymphoma (MCL). However, existing literature does not conclusively establish whether the expression ratio and staining intensity significantly influence diagnostic outcomes or patient prognosis. In this retrospective study, the correlation between comprehensive Cyclin D1 quantification and the prognosis of MCL patients was studied.MethodsThe Cyclin D1 protein level was assessed in 120 formalin-fixed paraffin-embedded samples from MCL patients using the quantitative dot blot (QDB) analysis technique. R language software was employed for statistical analysis to determine the optimal threshold with statistical significance. Additionally, Kaplan-Meier method was utilized to evaluate the relationship between the absolute level of Cyclin D1 protein and overall survival (OS) of patients. Furthermore, the Chi-square test was applied to analyze the causes of single and multiple fractures, with a significance level of p < 0.05. Finally, the Log-rank test was used to compare two survival curves, where a significance level of p < 0.05 was considered statistically significant.ResultsAt the optimized cutoff of 0.46 nmol/g, univariate analysis revealed a positive correlation between Cyclin D1 protein level and patient survival (OS). Specifically, in the subgroup with complete quantification of Cyclin D1 higher than the cutoff, the 5-year OS was 18%, whereas in the subgroup with complete quantification of Cyclin D1 lower than the cutoff, the 5-year OS was 4.8% (Log-rank test, P = 0.017). This indicates that patients with Cyclin D1 levels above the cutoff had significantly better overall survival compared to those below the cutoff. Additionally, in the Pearson distribution test, Ki-67 emerged as an independent prognostic factor for the complete quantification of Cyclin D1. Notably, Cyclin D1 complete quantification results remained unaffected by factors such as gender, age, LDH (Lactate Dehydrogenase) level, Ann Arbor stage(AAS), Ki-67, IPI(International prognostic index), MIPI(Mantle International prognostic index), and MIPI-c (MIPI Combined with Ki-67 Proliferation Index Chi-square test, p > 0.05).ConclusionsComprehensive Cyclin D1 quantification, especially above a threshold, significantly correlates with better overall survival in MCL. This highlights its prognostic importance in MCL management. Full quantification of CyclinD1 aids MCL prognosis, while QDB technology for biomarker quantification supports precise clinical prognostic stratification.

Down-regulation of ESRP2 inhibits breast cancer cell proliferation via inhibiting cyclinD1

Epithelial splicing regulatory protein 2 (ESRP2),an important alternative splicing protein of mRNA, is reported to have a dual role in tumors, which can promote or inhibit the occurrence and development of tumors. However, the function and mechanism of ESRP2 in breast cancer (BC) remain unclear. The distribution of ESRP2 expression in breast cancer and the correlation between ESRP2 expression and the overall survival rate were detected by The Cancer Genome Atlas (TCGA) database. Gene Ontology(GO)analysis, containing biological process, cellular components, and molecular function, was utilized to evaluate the potential mechanism of ESRP2 in breast cancer. The ESRP2 expression in breast cancer cell lines was detected by real-time quantitative PCR analysis (RT-qPCR) and western blotting. Cell clone was performed to examine the proliferation of ESRP2 knockdown in MCF-7 cells. The cell cycle was measured by flow cytometry assays. The role of ESRP2 knockdown in synergistic effect with chemotherapeutic agents was also determined by MTT assay. Bioinformatics analysis demonstrated that the ESRP2 gene was elevated in breast cancer cells and its overexpression was strongly correlated with shorter overall survival. GO analysis revealed that ESRP2 expression was related to cell proliferation. ESRP2 mRNA and protein expression were elevated in breast cancer cell lines, compared to the normal human breast cell line MCF-10 A. Dwon-regulation of ESRP2 inhibited cell proliferation and promoted the sensitivity of chemotherapy drug, Cisplatin(DDP) and Paclitaxel (TAXOL), in MCF-7 cells.Additionally, ESRP2 knockdown obstructed the cell cycle at the G1 phase and caused a decrease in cyclinD1 protein expression. These findings reveal that ESRP2 is highly expressed in breast cancer and is correlated with poor prognosis in breast cancer patients. ESRP2 knockdown can inhibit MCF-7 cell proliferation by arresting the cell cycle at the G1 phase and promoting the sensitivity of chemotherapy drugs (DDP and TAXOL)in MCF-7 cells. ESRP2 may be required for the regulation of breast cancer progression, as well as a critical target for the clinical treatment of breast cancer.

Repurposing of sericin combined with dactolisib or vitamin D to combat non-small lung cancer cells through computational and biological investigations

This study aims to repurpose sericin in combating non-small lung cancer cells (A549 and H460) by combining it with dactolisib or vitamin D to reduce the dose of dactolisib and boost the anticancer effectiveness of dactolisib and vitamin D. Therefore, the binding affinities of individual and combined drugs were examined using in silico and protein-protein interaction studies, targeting NF-κB, Cyclin D1, p-AKT, and VEGF1 proteins. The findings manifested remarkable affinities for combinatorial drugs compared to individual compounds. To substantiate these findings, the combined IC50 for each combination (sericin + dactolisib and sericin + vitamin D) were determined, reporting 31.9 and 41.8 µg/ml, respectively, against A549 cells and 47.9 and 55.3 µg/ml, respectively, against H460 cells. Furthermore, combination indices were assessed to lower the doses of each drug. Interestingly, in vitro results exhibited marked diminutions in NF-κB, Cyclin D1, p-AKT, and VEGF1 after treatment with sericin + dactolisib and sericin + vitamin D compared to control lung cancer cells and those treated with a single drug. Moreover, A549 and H460 cells treated with both combinations demonstrated augmented caspase-3 levels, implying substantial apoptotic activity. Altogether, these results accentuated the prospective implementation of sericin in combination with dactolisib and vitamin D at low doses to preclude lung cancer cell proliferation.

Impaired cyclin D3 protein degradation contributes to trastuzumab resistance in HER2 positive breast cancer

As the first anti-HER2 targeted agent approved by FDA in 1998, Trastuzumab has significantly improved the outcome of patients with HER2 positive metastatic breast cancer. Unfortunately, resistance to trastuzumab is a severe obstacle to its therapeutic efficacy in clinical application, and its mechanism has not yet been fully elucidated. In our study, we found that stabilization of cyclin D3 could be one reason for trastuzumab resistance. Trastuzumab could induce G1/G0 phase arrest by downregulating cyclin D3 protein expression. However, the protein expression of cyclin D3 was not affected in trastuzumab-resistant cells, which might be related to aberrant activation of ERK signaling pathway. Furthermore, degradation of cyclin D3 protein by trastuzumab was mainly resulted from ubiquitin-dependent proteasome mechanism instead of transcriptional regulation. In trastuzumab-resistant breast cancer cells, trastuzumab-induced degradation of cyclin D3 protein was abrogated. When the ubiquitin pathway was inhibited, cells would show a predisposition to resistance to trastuzumab. Further, CDK4/6 inhibitor can inhibit the proliferation of trastuzumab-resistant HER-2 positive breast cancer cells. Therefore, combination of CDK4/6 inhibitors and anti-HER2 targeted therapy may be an alternative and promising strategy to overcome trastuzumab resistance in the future.

Downregulation of lncRNA-MALAT1, Altered Immunohistochemical Expression of Cyclin D1 Protein and E-Cadherin Protein in Correlation to Meningioma Grades.

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is known to be upregulated in the tumors with ability to metastasize. In contrast, long non-coding Ribonuclei acid (lncRNA) MALAT1 was reported by some studies to be downregulated in meningioma cells. E-cadherin and Cyclin D1 are prognostic indicators and possible attractive targets for the treatment of recurring and aggressive meningioma. This study aimed to evaluate the expression level of lncRNA MALAT1, as well as Cyclin D1 and E-cadherin immunohistochemical expression in meningiomas (Grade 1 and 2) and their association with the clinicopathological parameters of the studied cases. Quantitative determination of relative expression levels of lncRNA-MALAT1 in 64 cases of meningioma to 5 controls of normal dura mater was performed, in addition to evaluation of E-cadherin and Cyclin D1 immunohistochemical expression. The results were tested for association with the clinicopathological parameters. lncRNA-MALAT1 expression were downregulated in 49/64 of the cases of meningioma (76%) in comparison to control. There were significant association of expression of lncRNA-MALAT1 with grade, brain invasion and increased mitosis (p=0.007, 0.04, 0.006 respectively). There were also significant associations of strong E-cadherin and negative Cyclin D1 proteins expression with grade 1 (p = 0.02, 0.004), low mitosis (p=0.03, and 0.04) and brain invasion (p=0.04, 0.03) respectively. Additionally, a significant weak negative correlation between E-cadherin and Cyclin D1 expression was fond, yet no significant correlation between lncRNA MALAT1 expression and either of E-cadherin or Cyclin D1 expression could be achieved. lncRNA MALAT1 is downregulated in meningiomas and associated with increased aggressiveness. Overexpressed cyclin D1 and decreased E-cadherin expression are also associated with high grade meningioma.

Evaluation of Cyclin D1 protein and its association with the clinicopathological characteristics and prognosis of lung cancer: A retrospective study from Southern Kerala, India.

Cyclin D1 is a protein that can enhance the proliferation of cancer cells and has been detected in various malignancies, including lung cancer. However, routine examinations for Cyclin D1 in lung cancer cases have not been conducted in Kerala. This study sought to evaluate the links between cyclin D1 expression, clinicopathological characteristics, and 2-year survival rates in lung cancer. This retrospective cohort study used medical records and paraffin blocks of lung cancer patients at the Regional Cancer Centre in Kerala, India, between 2015 and 2018. The data were collected from 61 subjects, comprising of lung adenocarcinoma (18%), lung squamous cell carcinoma (27.9%), non-small-cell lung carcinoma (18%), poorly differentiated carcinoma (19.7%), and negative for malignant cells (16.4%). Data analysis was conducted using SPSS. The study revealed that 31.10% of the lung cancer patients exhibited overexpression of cyclin D1. A significant correlation was observed between cyclin D1 expression and histopathological results (P = 0.002), indicating that the level of cyclin D1 might be linked to specific histopathological subtypes of lung cancer. Despite this significant finding, cyclin D1 expression did not show any association with the clinical stage of the cancer or other clinical characteristics of the patients. Furthermore, when examining the 2-year survival rates of the patients, the study found no significant difference between those who had overexpression of cyclin D1 and those who did not (P = 0.145). Cyclin D1 expression was associated with histology type of lung cancer with no significant association to prognosis.

Association of Genetic Variants at the CDKN1B and CCND2 Loci Encoding p27Kip1 and Cyclin D2 Cell Cycle Regulators with Susceptibility and Clinical Course of Chronic Lymphocytic Leukemia.

Beyond the essential role of p27Kip1 and cyclin D2 in cell cycle progression, they are also shown to confer an anti-apoptotic function in peripheral blood (PB) lymphocytes. Although the aberrant longevity and expression of p27Kip1 and cyclin D2 in leukemic cells is well documented, the exact mechanisms responsible for this phenomenon have yet to be elucidated. This study was undertaken to determine the associations between polymorphisms in the CDKN1B and CCND2 genes (encoding p27Kip1 and cyclin D2, respectively) and susceptibility to chronic lymphocytic leukemia (CLL), as well as their influence on the expression of both cell cycle regulators in PB leukemic B cells and non-malignant T cells from untreated CLL patients divided according to the genetic determinants studied. Three CDKN1B single-nucleotide polymorphisms (SNPs), rs36228499, rs34330, and rs2066827, and three CCND2 SNPs, rs3217933, rs3217901, and rs3217810, were genotyped using a real-time PCR system. The expression of p27Kip1 and cyclin D2 proteins in both leukemic B cells and non-malignant T cells was determined using flow cytometry. We found that the rs36228499A and rs34330T alleles in CDKN1B and the rs3217810T allele in the CCND2 gene were more frequent in patients and were associated with increased CLL risk. Moreover, we observed that patients possessing the CCND2rs3217901G allele had lower susceptibility to CLL (most pronounced in the AG genotype). We also noticed that the presence of the CDKN1Brs36228499CC, CDKN1Brs34330CC, CDKN1Brs2066827TT, and CCND2rs3217901AG genotypes shortened the time to CLL progression. Statistically significant functional relationships were limited to T cells and assigned to CDKN1B polymorphic variants; carriers of the polymorphisms rs34330CC and rs36228499CC (determining the aggressive course of CLL) expressed a decrease in p27Kip1 and cyclin D2 levels, respectively. We indicate for the first time that genetic variants at the CDKN1B and CCND2 loci may be considered as a potentially low-penetrating risk factor for CLL and determining the clinical outcome.

Oncogenic accumulation of cysteine promotes cancer cell proliferation by regulating the translation of D-type cyclins

Malignant cells exhibit a high demand for amino acids to sustain their abnormal proliferation. Particularly, the intracellular accumulation of cysteine is often observed in cancer cells. Previous studies have shown that deprivation of intracellular cysteine in cancer cells results in the accumulation of lipid peroxides in the plasma membrane and induction of ferroptotic cell death, indicating that cysteine plays a critical role in the suppression of ferroptosis. Herein, we found that the oncogenic accumulation of cysteine also contributes to cancer cell proliferation by promoting the cell cycle progression, which is independent of its suppressive effect on ferroptosis. The growth ability of four types of cancer cells, including murine hepatocarcinoma cells, but not of primary hepatocytes, were dependent on the exogenous supply of cysteine. Deprivation of intracellular cysteine in cancer cells induced cell cycle arrest at the G0/G1 phase, accompanied by a decrease in the expression of cyclin D1 and D2 proteins. The cysteine deprivation-induced decrease in D-type cyclin expression was associated with the upregulation of eukaryotic translation initiation factor 4E binding protein 1, which represses the translation of cyclin D1 and D2 proteins by binding to eukaryotic translation initiation factor 4E. Similar results were observed in hepatocarcinoma cells treated with erastin, an inhibitor of cystine/glutamate antiporter, xCT. These findings reveal an unappreciated role of cysteine in regulating the growth of malignant cancer cells and deepen our understanding of the cytotoxic effect of xCT inhibitor to prevent cancer cell proliferation.

Effects of Down-Regulation of PAK1 on Differentiation and Apoptosis of MPN Cells with MPLW515L Gene Mutation and Survival of 6133/MPL Mice

To investigate the effects of down-regulation of p21 activated kinase 1 (PAK1) on the proliferation, differentiation, and apoptosis of myeloproliferative neoplasm (MPN) cells (6133/MPL) with thrombopoietin receptor MPL mutation at codon 515 (MPLW515L) and survival of 6133/MPL mice. Interference with the protein level of PAK1 in 6133/MPL cells was assessed using lentivirus-mediated shRNA transfection technology. CCK-8 assay was used to detect the effect of down-regulation of PAK1 on the proliferation viability of 6133/MPL cells, and colony-forming ability was measured by cell counting. Flow cytometry was used to detect the PAK1 kinase activity on the ability of polyploid DNA formation and cell apoptosis in 6133/MPL cells. The expression of cyclin D1, cyclin D3 and apoptosis-related protein Bax was detected by Western blot. The infiltration of tumor cells in spleen and bone marrow of 6133/MPL mice were detected by HE staining. Down-regulation of PAK1 inhibited the proliferation and reduced the ability of cell colony formation of 6133/MPL cells. After knocking down PAK1, the content of polyploid DNA in 6133/MPL cells increased from 31.8 to 57.5% and 48.0%, and the proportion of apoptosis increased approximately to 10.8%. Down-regulation of PAK1 led to a reduction of infiltration of tumor cells in liver and bone marrow of 6133/MPL mice, thereby prolonging survival time. Down-regulation of PAK1 can significantly inhibit the growth of 6133/MPL cells, promote the formation of polyploid DNA, induce 6133/MPL cell apoptosis, and prolong the survival time of 6133/MPL mice.

Hsa_circ_0007765 Promotes Platelet-Derived Growth Factor-BB-Induced Proliferation and Migration of Human Aortic Vascular Smooth Muscle Cells in Atherosclerosis.

Humanaorticvascularsmoothmusclecells (HA-VSMCs) play vital roles in the pathogenesis ofvasculardiseases, including Atherosclerosis (AS). Circular RNAs (circRNAs) have been reported to regulate the biological functions of HA-VSMCs.Therefore, this study aimed to explore the role and mechanism of hsa_circRNA_102353 (circ_0007765) in platelet-derived growth factor-BB (PDGF-BB)-induced HA-VSMCs. Circ_0007765, microRNA-654-3p (miR-654-3p), and Fibroblast Growth Factor Receptor Substrate 2 (FRS2) expression were measured using real-time quantitative polymerase chain reaction (RT-qPCR). Cell proliferative ability, invasion, and migration were detected by 3-(4, 5-dimethyl-2-thiazolyl)-2, 5-diphenyl-2-H-tetrazolium bromide (MTT), 5-ethynyl-2'-deoxyuridine (EdU), Transwell, and wound healing assays. CyclinD1, MMP2, and FRS2 protein levels were assessed using a Western blot assay. Binding between miR-654-3p and circ_0007765 or FRS2 was predicted by Circinteractome or TargetScan, and verified using dual-luciferase reporter and RNA pull-down assays. PDGF-BB induced HA-VSMC proliferation, invasion, and migration. Circ_0007765 and FRS2 expression levels were increased in PDGF-BB-treated HA-VSMCs, and the miR-654-3p level was reduced. Moreover, circ_0007765 absence hindered PDGF-BB-induced HA-VSMC proliferation, invasion, and migration in vitro. At the molecular level, circ_0007765 increased FRS2 expression by acting as a sponge for miR-654-3p. Our findings revealed that circ_0007765 boosted PDGF-BB-induced HA-VSMC proliferation and migration through elevating FRS2 expression via adsorbing miR-654-3p, providing a feasible therapeutic strategy for AS.