Expression Of Cyclin Research Articles

Synergistic inhibition of proliferation and induction of apoptosis in oral tongue squamous cell carcinoma by mebendazole and paclitaxel via PI3K/AKT pathway mitigation.

Serve as one of common cancer in the mouth, oral tongue squamous cell carcinoma (OTSCC) is a serious problem affecting human oral health. The aim of this study was to evaluate the effects of mebendazole (MBZ) alone and combined with paclitaxel on the proliferation and occurrence of OTSCC and its molecular mechanism. Cell viability, apoptosis, cell cycle distribution, and the expression of PI3K, p-PI3K, AKT, and p-AKT were evaluated by Cell Counting Kit-8 (CCK-8), flow cytometry, and Western blot, respectively. Immunofluorescence was used to assess changes in microtubule morphology of CAL-27 and UM-SCC-1 cells with α-tubulin antibody labeling. The CCK-8 assay revealed a dose-dependent inhibitory effect of both MBZ and paclitaxel on CAL-27 and UM-SCC-1 cells. The apoptosis assay showed significantly elevated levels of apoptosis-specific markers, cleaved caspase-3, and cleaved PARP, in the combined treatment group compared to the control and single-agent groups. The combination of MBZ and paclitaxel showed enhanced inhibition of key PI3K/AKT pathway proteins' phosphorylation and reduced expression of Cyclin B and PCNA compared to the control. The α-tubulin staining area was notably reduced in the combined treatment group relative to the other groups. Both MBZ and paclitaxel treatments inhibited of cell proliferation and microtubule formation by reducing the PI3K/AKT pathway in CAL-27 and UM-SCC-1 cells, with the combination demonstrating synergistic effects. Our study suggests MBZ and paclitaxel as potential agents for the treatment of OTSCC.

Hepatitis B Virus-Induced Resistance to Sorafenib and Lenvatinib in Hepatocellular Carcinoma Cells: Implications for Cell Viability and Signaling Pathways.

Background/Objectives: Sorafenib and lenvatinib are tyrosine kinase inhibitors used in hepatocellular carcinoma (HCC) treatment. This study investigates how hepatitis B virus (HBV) infection affects their efficacy in HepG2 hepatoma cells. Methods: HepG2 and HBV-infected HepG2/2215 cells were treated with varying concentrations of both drugs. The cell viability, cell cycle gene expression, cycle progression, and phosphorylation levels of ERK and AKT were analyzed. Results: The HBV-infected cells showed significant alterations in their cell cycle gene expressions, with an 80-fold increase in CCND2 expression and a higher proportion of cells in the G2/M phase, indicating enhanced proliferation. While both drugs decreased HepG2 cell viability in a concentration-dependent manner, HBV infection conferred resistance, as evidenced by the increased viable cells in the HepG2/2215 cultures. Sorafenib and lenvatinib decreased key cyclin and cyclin-dependent kinase expressions in uninfected cells, with less effect on the HBV-infected cells. Both drugs lowered the pERK and pAKT levels in the HepG2 cells. In the HBV-infected cells, sorafenib reduced the pERK and pAKT levels to a lesser extent. However, treatment with lenvatinib elevated the levels of pERK and pAKT. Conclusions: In conclusion, HBV infection increases resistance to both sorafenib and lenvatinib in hepatoma cells by influencing the cell cycle regulatory genes and critical signaling pathways. However, the resistance mechanisms likely differ between the two medications.

Hepatocyte-Specific HuR Protects Against Acetaminophen-Induced Liver Injury in Mice.

Acetaminophen (APAP) overdose is a major cause of drug-induced liver injury (DILI) in many countries. Hepatocyte proliferation, autophagy and antioxidant capacity are crucial to the prognosis of APAP-induced liver injury, but the underlying mechanisms are not fully understood. Here, we found that human antigen R (HuR) protein expression was markedly increased in the model of APAP-induced liver injury, and conditional hepatocyte-specific HuR knockout aggravated APAP-induced liver injury in mice. Further investigation of the underlying mechanisms of HuR's protective effects showed that conditional hepatocyte-specific HuR knockout reduced the protein expression of cyclin A1, cyclin B1, cyclin D1, CDK2, ATG3, ATG5, ATG7 and NRF2 in mice, reducing hepatocyte proliferation, autophagy and antioxidant capacity. Mechanistically, HuR could physically associate with the 3'-untranslated regions (UTRs) of cyclin A1, cyclin B1, cyclin D1, Cdk2, Atg3, Atg5, Atg7 and Nrf2 mRNAs, thereby regulating their translation. These findings suggest that HuR attenuates APAP-induced liver injury by regulating hepatocyte proliferation, autophagy and antioxidant capacity.

TRAF4 promotes lung cancer development by activating tyrosine kinase of EGFR

Objective: To explore the role of tumor necrosis factor receptor-associated factor 4 (TRAF4) in promoting the abnormal activation of epidermal growth factor receptor (EGFR) and its effect on lung cancer cell proliferation, migration and invasion. Methods: Tumor tissues from patients who underwent lung adenocarcinoma resection at The First Affiliated Hospital of Second Military Medical University, from January 2015 to May 2017 were collected, and the expressions of TRAF4 and Ki-67 in lung cancer tissues were detected by immunohistochemistry, the mRNA levels of Cyclin D and Vimentin were detected by real-time fluorescence quantitative PCR (qRT-PCR). The effect of TRAF4 on the tumor growth ability of lung cancer A549 cells was investigated by the xenograft model, the effect of TRAF4 or EGFR on the tumor proliferation ability was detected by using cell counting kit 8 (CCK8) and BrdU assay, and the migration and invasion abilities of tumor cells were detected by Transwell assay. Different structural domain deletion expression vectors of TRAF4 and EGFR were constructed to transfect cells, and the interaction mode of TRAF4 and EGFR was investigated by immunoprecipitation assay. Results: The expression of TRAF4 in non-small cell lung cancer (NSCLC) tissues was positively correlated with the expressions of Ki-67, cyclin D, and vimentin (r2: 0.438, 0.695, and 0.736, respectively, all P＜0.01). Immunohistochemical assay of tumor tissues from NSCLC patients showed that tissues with high expression of TRAF4 were also high in Ki-67. Patients with high TRAF4 expression (TRAF4 positivity >30%) had a shorter progression-free survival (PFS) time than that of patients with low TRAF4 expression (TRAF4 positivity ≤30%) (median PFS of 12 and 19 months, respectively; P=0.034). Traf4-/- cells had a weakened proliferative capacity than traf4+/+ cells and formed tumors with smaller size (P＜0.05). The expression level of Ki-67 in the tumor tissues formed by traf4-/- cells [(45.6±8.7)%] was lower than that in the tumor tissues formed by traf4+/+ cells [(62.3±10.3)%, P=0.015], the mRNA levels of cyclin D (1.01±0.15) and vimentin (1.01±0.12) in the traf4-/- cells were lower than those of the traf4+/+ cells (3.41±0.32 and 3.12±0.18, respectively, both P＜0.05).The western blot results showed that, with the elevated intracellular expression level of TRAF4, phosphorylation level of EGFR was significantly increased in both wild-type EGFR and activation mutant EGFR-expression cells. The capacities of proliferation, migration and invasion of A549 cells was weakened after EGFR knockdown (all P＜0.01). Immunoprecipitation experiments showed that TRAF4 binds to the peptide segment of the near-membrane region of EGFR through the TRAF structural domain, and the mutual binding between EGFR molecules was enhanced under TRAF4 overexpression conditions. Increasing TRAF4 expression promoted EGFR molecular phosphorylation and activation of downstream signaling. Conclusions: TRAF4 expression is elevated in NSCLC tissues and tumor cells, which promotes tumor proliferation, migration and invasion. TRAF4 directly binds to EGFR molecules, enhances its own phosphorylation and activates the downstream signaling pathway by promoting the interaction between EGFR molecules.

RETINOBLASTOMA-RELATED Has Both Canonical and Noncanonical Regulatory Functions During Thermo-Morphogenic Responses in Arabidopsis Seedlings.

Warm temperatures accelerate plant growth, but the underlying molecular mechanism is not fully understood. Here, we show that increasing the temperature from 22°C to 28°C rapidly activates proliferation in the apical shoot and root meristems of wild-type Arabidopsis seedlings. We found that one of the central regulators of cell proliferation, the cell cycle inhibitor RETINOBLASTOMA-RELATED (RBR), is suppressed by warm temperatures. RBR became hyper-phosphorylated at a conserved CYCLIN-DEPENDENT KINASE (CDK) site in young seedlings growing at 28°C, in parallel with the stimulation of the expressions of the regulatory CYCLIN D/A subunits of CDK(s). Interestingly, while under warm temperatures ectopic RBR slowed down the acceleration of cell proliferation, it triggered elongation growth of post-mitotic cells in the hypocotyl. In agreement, the central regulatory genes of thermomorphogenic response, including PIF4 and PIF7, as well as their downstream auxin biosynthetic YUCCA genes (YUC1-2 and YUC8-9) were all up-regulated in the ectopic RBR expressing line but down-regulated in a mutant line with reduced RBR level. We suggest that RBR has both canonical and non-canonical functions under warm temperatures to control proliferative and elongation growth, respectively.

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 (4E-BP1), which represses the translation of cyclin D1 and D2 proteins by binding to eukaryotic translation initiation factor 4E (eIF4E). Similar results were observed in hepatocarcinoma cells treated with erastin, an xCT inhibitor. 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.

Mitochondrion-targeted selenium nanoparticles stabilized by Sargassum fusiforme polysaccharides increase reactive oxygen species-mediated antitumour activity

Authors prepared a nanoselenium particle stabilized with Sargassum fusiforme polysaccharide (SFPS-Tw-SeNPs) and confirmed that it could effectively inhibit the proliferation of A549 lung cancer cells in vitro. The aim of this study was to investigate its anti-lung cancer effect in vitro and in vivo and its possible mechanism. In cell experiments, AO/EB staining revealed that SFPS-Tw-SeNPs could induce the apoptosis of A549 cells and produce red fluorescence by inserting into DNA through damaged cell membranes, increasing the production of reactive oxygen species (ROS). SFPS-Tw-SeNPs that is loaded with coumarin-6 entered the cells in a concentration-dependent and time-dependent manner, acting on the mitochondria, reducing the mitochondrial membrane potential, increasing the Bax/Bcl-2 ratio, and increasing the expression of Cleaved-Caspase 3, Cleaved-Caspase 9, Cleaved-PARP and Cytochrome C-induced apoptosis in cells. In addition, the SFPS-Tw-SeNPs blocked the PI3K/AKT signalling pathway, downregulated the expression of Cyclin-A and CDK2, upregulated the expression of P21, and arrested the cell in the G1 phase. In animal experiments, SFPS-Tw-SeNPs treatment significantly inhibited the growth of A549 tumour xenografts but did not significantly negatively affect the body of the animals. Overall, SFPS-Tw-SeNPs have the potential to be developed as a pharmaceutical drug to prevent and treat non-small cell lung cancer.

The Impact of Amphimedon chloros Ethyl Acetate Extract on MDA-MB-231 Cell Lines' Expression of Bax, Cyclin D, Caspase 3, P21, C-myc, and Bcl2: Mechanism of inhibition of the Growth of Cancer Cells

The Impact of Amphimedon chloros Ethyl Acetate Extract on MDA-MB-231 Cell Lines' Expression of Bax, Cyclin D, Caspase 3, P21, C-myc, and Bcl2: Mechanism of inhibition of the Growth of Cancer Cells

Elevated origin recognition complex subunit 6 expression promotes non-small cell lung cancer cell growth

Exploring novel targets for non-small cell lung cancer (NSCLC) remains of utmost importance. This study focused on ORC6 (origin recognition complex subunit 6), investigating its expression and functional significance within NSCLC. Analysis of the TCGA-lung adenocarcinoma database revealed a notable increase in ORC6 expression in lung adenocarcinoma tissues, correlating with reduced overall survival, advanced disease stages, and other key clinical parameters. Additionally, in patients undergoing surgical resection of NSCLC at a local hospital, ORC6 mRNA and protein levels were elevated in NSCLC tissues while remaining low in adjacent normal tissues. Comprehensive bioinformatics analyses across various cancers suggested that ORC6 might play a significant role in crucial cellular processes, such as mitosis, DNA synthesis and repair, and cell cycle progression. Knocking down ORC6 using virus-delivered shRNA in different NSCLC cells, both primary and immortalized, resulted in a significant hindrance to cell proliferation, cell cycle progression, migration and invasion, accompanied by caspase-apoptosis activation. Similarly, employing CRISPR-sgRNA for ORC6 knockout (KO) exhibited significant anti-NSCLC cell activity. Conversely, increasing ORC6 levels using a viral construct augmented cell proliferation and migration. Silencing or knockout of ORC6 in primary NSCLC cells led to reduced expression of several key cyclins, including Cyclin A2, Cyclin B1, and Cyclin D1, whereas their levels increased in NSCLC cells overexpressing ORC6. In vivo experiments demonstrated that intratumoral injection of ORC6 shRNA adeno-associated virus markedly suppressed the growth of primary NSCLC cell xenografts. Reduced ORC6 levels, downregulated cyclins, and increased apoptosis were evident in ORC6-silenced NSCLC xenograft tissues. In summary, elevated ORC6 expression promotes NSCLC cell growth.

Novel hydrazide-hydrazone containing 1,2,4-triazole as potent inhibitors of antiapoptotic protein Bcl-xL: Synthesis, biological evaluation, and docking studies.

This study describes the synthesis and characterization of a series of novel hydrazide-hydrazone derivatives containing a 1,2,4-triazole ring. The compounds were characterized using various spectroscopic techniques, such as FT-IR, 1H-NMR, 13C-NMR, HRMS, and elemental analysis. The antiproliferative activity of the synthesized compounds was evaluated against a panel of human cancer cell lines (HCT-116, HepG-2, KLN205, LTPA, U138, and SW620) and healthy cell lines (HSkMC and iPSCs). Among the compounds tested, compounds 4, 5p, 5r, and 5s showed the highest effectiveness in inhibiting the growth of cancer cells with Bcl-xL inhibitory concentration (IC50) values. These compounds further demonstrated selective cytotoxicity against the Bcl-xL-dependent lymphoma cell line (DBs). Molecular docking studies were also performed to investigate the potential binding interactions of compounds 4, 5p, 5r, and 5s with the active site of Bcl-xL (PDB ID: 7LH7, 1.4 Å). Mechanistic studies revealed that compounds 4, 5r, and 5s induced apoptosis predominantly through the intrinsic mitochondrial pathway, while compound 5p exhibited a distinct cell cycle arrest profile, impacting both the S and G2/M phases. Western blot analysis suggested that these compounds may downregulate cyclin expression, thereby blocking its association with Bcl-xL. Overall, these results demonstrate the potential of these novel hydrazide-hydrazone derivatives as anticancer agents with activity comparable or superior to doxorubicin and 5-fluorouracil.

CD8 + T-cells restrict the development of peritoneal metastasis and support the efficacy of hyperthermic intraperitoneal chemotherapy (HIPEC)

Multimodal therapy for peritoneal metastasis (PM) including cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC) provides long-term survival in highly selected colorectal cancer patients. Mechanisms behind HIPEC are unknown and may include induction of adaptive immunity. We therefore analyzed human PM samples and explored the impact of HIPEC in experimental models. Human samples from colorectal primary tumors (n = 19) and PM lesions (n = 37) were examined for the presence of CD8 + T-cells and their association with disease free (DFS) and overall survival (OS). CD8 + T cell response after HIPEC was assessed using an in-vivo PM mouse model, tumor cell lines and patient-derived tumor organoids. Patients with high intraepithelial CD8 + T cell counts showed longer DFS and OS. In the mouse model, HIPEC controlled growth of PM and increased numbers of functional granzyme positive CD8 + T cells within tumors. Cell lines and human organoids that were treated with heated chemotherapies showed immunogenic changes, reflected by significantly higher levels of MHC-class I molecules and expression of Cancer Testis Antigens Cyclin A1 and SSX-4. Using in-vitro co-culture assays, we noticed that cancer cells treated with heated chemotherapy primed dendritic cells, which subsequently enhanced effector functions of CD8 + T cells. The presence of CD8 + T-cells within PM lesions is associated with prolonged survival of patients with PM. Data from PM mouse model and in-vitro assay show that heated chemotherapies induce immunogenic changes on cancer cells leading to induction of CD8 + T-cells mediated immunity, which seems to control growth of PM lesions in mice after HIPEC.

Exploring the therapeutic potential of rabdoternin E in lung cancer treatment: Targeting the ROS/p38 MAPK/JNK signaling pathway.

Lung cancer has the highest incidence and mortality rates of all cancer types in China and therefore represents a serious threat to human health. In the present study, the mechanism of rabdoternin E against the proliferation of the lung cancer cell line A549 was explored. It was found that rabdoternin E caused the accumulation of large amounts of reactive oxygen species (ROS), promoted cell S phase arrest by reducing the expression of CDK2 and cyclin A2, induced apoptosis by increasing the Bax/Bcl‑2 ratio and promoted the phosphorylation of proteins in the ROS/p38 MAPK/JNK signaling pathway, which is associated with apoptosis and ferroptosis. In addition, it was also found that Z‑VAD‑FMK (an apoptosis inhibitor), ferrostatin‑1 (ferroptosis inhibitor) and N‑acetylcysteine (a ROS inhibitor) could partially or greatly reverse the cytotoxicity of rabdoternin E to A549 cells. Similarly, NAC (N‑acetylcysteine) treatment notably inhibited the rabdoternin E‑stimulated p38 MAPK and JNK activation. Furthermore, in vivo experiments in mice revealed that Rabdoternin E markedly reduced tumor volume and weight and regulated the expression levels of apoptosis and ferroptosis‑related proteins (including Ki67, Bcl‑2, Bax, glutathione peroxidase 4, solute carrier family 7 member 11 and transferrin) in the tumor tissues of mice. Histopathological observation confirmed that the number of tumor cells decreased markedly after administration of rabdoternin E. Taken together, rabdoternin E induced apoptosis and ferroptosis of A549 cells by activating the ROS/p38 MAPK/JNK signaling pathway. Therefore, the results of the present study showed that rabdoternin E is not toxic to MCF‑7 cells (normal lung cells), had no significant effect on body weight and was effective and therefore may be a novel therapeutic treatment for lung cancer.

Knockdown of PAIP1 Inhibits Breast Cancer Cell Proliferation by Regulating Cyclin E2 mRNA Stability.

Polyadenylate-binding protein-interacting protein 1 (PAIP1) is a protein that modulates translation initiation in eukaryotic cells. Studies have shown that PAIP1 was overexpressed in various type of cancers, and drives cancer progression by promoting cancer cell proliferation, invasion, and migration. In our previous study, we identified that PAIP1 was overexpressed in breast cancer, and the expression was correlated with poor prognosis. However, the biological function of PAIP1 in breast cancer has not been clearly understood. In this study, we constructed PAIP1 specifically silenced breast cancer cells. Then, cell proliferation, cell cycle distribution, and apoptosis were detected in PAIP1 knockdown cells. RNA-seq analysis was performed to predict the downstream target of PAIP1, and the molecular mechanism was explored. As a results, we found that knockdown of PAIP1 repressed cell proliferation, induced cell cycle arrest, and triggers apoptosis. Xenograft mouse model showed that knockdown of PAIP1 inhibits cell growth in vivo. RNA-seq predicted that CCNE2 mRNA was one of the downstream targets of PAIP1. In addition, we identified that knockdown of PAIP1-inhibited cell proliferation through modulating cyclin E2 expression. Mechanically, knockdown of PAIP1 reduces the expression of cyclin E2 by regulating the mRNA stability of cyclin E2. Moreover, in breast cancer tissues, we found that the expression of PAIP1 was positively correlated with cyclin E2. Taken together, our findings establish the role and mechanism of PAIP1 in breast cancer progression, indicating that PAIP1 would be a new therapeutic target for breast cancer treatment.

Role of sodium-dependent vitamin C transporter 2 in human periodontal ligament fibroblasts.

Ascorbic acid (AA) is a water-soluble vitamin that has antioxidant properties and regulates homeostasis of connective tissue through controlling various enzymatic activities. Two cell surface glycoproteins, sodium-dependent vitamin C transporter (SVCT) 1 and SVCT2, are known as ascorbate transporters. The purpose of this study was to investigate the expression pattern and functions of SVCTs in periodontal ligament (PDL) and PDL fibroblast (PDLF). Gene expression was examined using real-time polymerase chain reaction (PCR) and reverse transcription PCR. SVCT2 expression was determined by immunofluorescence staining, western blot and flow cytometry. ALP activity and collagen production were examined using ALP staining and collagen staining. Short interfering RNA was used to knock down the gene level of SVCT2. Change of comprehensive gene expression under SVCT2 knockdown condition was examined by RNA-sequencing analysis. Real-time PCR, fluorescent immunostaining, western blot and flowy cytometry showed that SVCT2 was expressed in PDLF and PDL. ALP activity, collagen production, and SVCT2 expression were enhanced upon AA stimulation in PDLF. The enhancement of ALP activity, collagen production, and SVCT2 expression by AA was abolished under SVCT2 knockdown condition. RNA-sequencing revealed that gene expression of CLDN4, Cyclin E2, CAMK4, MSH5, DMC1, and Nidgen2 were changed by SVCT2 knockdown. Among them, the expression of MSH5 and DMC1, which are related to DNA damage sensor activity, was enhanced by AA, suggesting the new molecular target of AA in PDLF. Our study reveals the SVCT2 expression in PDL and the pivotal role of SVCT2 in mediating AA-induced enhancements of ALP activity and collagen production in PDLF. Additionally, we identify alterations in gene expression profiles, highlighting potential molecular targets influenced by AA through SVCT2. These findings deepen our understanding of periodontal tissue homeostasis mechanisms and suggest promising intervention targeting AA metabolism.

Fucoidan from Sargassum hemiphyllum (Turner) C. Agardh inhibits human hepatoma cell (HepG2) through cell cycle arrest and apoptotic induction

Cancer has become one of the most serious diseases threatening human health, while traditional chemotherapeutic drugs have serious side effects. Drugs of marine origin have attracted many scholars due to their remarkable effectiveness, low drug resistance and low adverse reactions. In this study, the fucoidan DF1 and DF2 extracted from Sargassum hemiphyllum (Turner) C. Agardh were used to explore their effects on induced HepG2 hepatoma cell apoptosis and their relevant molecular mechanisms of apoptosis in HepG2 cells were analyzed by flow cytometry and western blotting assay. DF1 and DF2 could induce excess intracellular reactive oxygen species (ROS) production in HepG2 cells and lead to stimulation of the mitochondrial apoptotic pathway, up-regulate the protein expressions of Bax, Cytochrome C and Cleaved-Caspase-3/8, and down-regulate the protein expressions of Bcl-2 and Caspase-3/8/9. Meanwhile, DF1 and DF2 could induce HepG2 cell cycle arrest in the S-phase and up-regulate the protein expression of p21, and down-regulate the expression of Cyclin A and CDK2. This study provides a scientific basis for the development of VC/H2O2-treated fucoidans as anticancer drugs or adjuvant drugs.

Targeting proliferating cell nuclear antigen enhances ionizing radiation-induced cytotoxicity in prostate cancer cells.

Proliferating cell nuclear antigen (PCNA) is essential for DNA replication and repair, cell growth, and survival. PCNA also enhances androgen receptor (AR) signaling in prostate cancer (PC) cells. We identified a PCNA interaction protein (PIP) box at the N-terminal domain of AR and developed a small peptide PCNA inhibitor R9-AR-PIP containing AR PIP-box. We also identified a series of small molecule PCNA inhibitors (PCNA-Is) that bind directly to PCNA and interrupt PCNA functions. The present study investigated the effects of the PCNA inhibitors on the sensitivity of PC cells to X-ray radiation. The effects of targeting PCNA on radio sensitivity of PC cells were investigated in four lines of castration-resistant PC (CRPC) cells with different AR expression statuses. The cells were treated with the PCNA inhibitors and X-ray radiation alone or in combination. The effects of the treatment on expression of AR target genes, DNA damage response, DNA damage, homologous recombination repair (HRR), and cytotoxicity were evaluated. We found that the androgen response element (ARE) occupancy of the DNA damage response gene PARP1 by AR is significantly attenuated by PCNA-I1S or R9-AR-PIP combined with X-ray radiation, while X-ray radiation alone does not enhance the ARE occupancy. PCNA-I1S or R9-AR-PIP alone significantly inhibits occupancy of the AR-occupied regions (AROR) in PRKDC and XRCC2 genes. R9-AR-PIP and PCNA-I1S inhibit expression of AR-Vs target gene cyclin A2 and show the additive effects with radiation in AR-positive CRPC cells. Targeting PCNA by PCNA-I1S and R9-AR-PIP downregulates expression of DNA damage response genes EXO1, Rad54L, Rad51, and/or PARP1 and shows the additive effects with radiation as compared with their respective controls in AR-positive CRPC LNCaP-AI, 22Rv1, and R1-D567 cells, but not in AR-negative PC-3 cells. R9-AR-PIP and PCNA-I1S elevate the levels of phospho-DNA-PKcs(S2056) and γH2AX, indicating DNA damage in response to radiation in AR-positive cells. The HRR is significantly attenuated by PCNA inhibitors PCNA-I1S, R9-AR-PIP, and T2AA in all four CRPC cells examined, and inhibited by Enzalutamide (Enz) only in 22RV1 cells. The cytotoxicity induced by X-ray radiation in androgen-dependent LNCaP cells is enhanced by Enz and a lower concentration of R9-AR-PIP in the colony formation assay. R9-AR-PIP at higher concentration reduces the colony formation and has an additive effect with X-ray radiation in all AR expressing cells, regardless of AR-FL and AR-Vs, but does not significantly alter the colony formation in AR-negative PC-3 cells. PCNA-I1S attenuates colony formation and has an additive effect with ionizing radiation in all four CRPC cells, regardless of AR expression status. These data provide a strong rationale for the therapy studies using PCNA-I1S or R9-AR-PIP in combination with X-ray radiation against CRPC tumors in preclinical models.

Expression and localization of Cyclin D1/Nanog and NF-κB/Bax protein in dysplastic testicles of mice

Testicular dysplasia significantly impairs male reproductive capacity. This study investigated the expression of Cyclin D1/Nanog and NF-κB/Bax in dysplastic testes of mice using histological staining, Western blotting, and immunohistochemistry. The results showed that Nanog and Bax expression were significantly higher in dysplastic testicular tissue than in normal tissue (P < 0.01). Cyclin D1 protein expression was higher in normal testis tissue than in dysplastic testis (P < 0.01). NF-κB was highly expressed in cryptorchid and normal testis with no significant difference (P > 0.05). Immunolocalization revealed that Nanog, NF-κB, and Bax were expressed in the cytoplasm of Leydig and spermatogenic cells. Cyclin D1 primarily expressed in the nucleus of Sertoli cells. These findings suggest that altered expression of Nanog, Cyclin D1, and Bax may contribute to testicular dysplasia. This study provides a scientific foundation for detecting testicular dysplasia and selecting appropriate animal models, ultimately informing strategies to improve male reproductive health.

Investigating the Anticancer Effects of Pleurotus ostreatus Polysaccharide on G0/G1 Cell Cycle Arrest and Apoptosis in Ehrlich Ascites Carcinoma Cells.

Cancer is one of the leading causes of mortality worldwide. Despite the advancement of cancer treatment by various means including surgery, chemotherapy etc, cancer is still a challenging disease to manage. This study was undertaken to investigate extraction, purification, structural elucidation, and the potential anti-cancer effects of Pleurotus ostreatus polysaccharide (POP). The anti-cancer activities were performed on the Ehrlich Ascites Carcinoma Cell Line. The results demonstrated that the MW of POP was154649.8 Da with homopolysaccharide composed of D-glucose units, featuring (1→6)-α-D-Glcp backbone with O-6 branches and T-α-D-Glcp terminations. and the yield was 6.27 %. The antitumor activity assessment demonstrated significant cytotoxicity of POP against Ehrlich Ascites Carcinoma (EAC) cells, with an IC50 of 121.801 μg mL, supported by LDH release analysis. POP inhibited cell migration, invasion, and colony formation, indicating its potential as an anti-cancer agent. POP elicited the apoptotic activity with the upregulation of Caspase-9 and Bax, and downregulation of Bcl-2. The DNA fragmentation assay further confirmed apoptosis-mediated DNA degradations. Additionally, POP-induced cell cycle arrest at the G0/G1 phase, by altering the expression of p53, Cyclin D, and Cdk4 proteins. So, Pleurotus ostreatus polysaccharide (POP) showed significant cytotoxicity on Ehrlich Ascites Carcinoma cells, indicating potential as an anti-cancer agent.

ORANGE interplays with TCP7 to regulate endoreduplication and leaf size.

Leaf size is a crucial agronomic trait directly affecting crop yield, which is mainly determined by coordinated cell proliferation, growth, and differentiation. Although endoreduplication is known to be correlated with the onset of cell differentiation and leaf size, the underlying molecular mechanisms are largely unclear. The DnaJ-like zinc finger domain-containing protein ORANGE (OR) was initially demonstrated to confer the massive accumulation of carotenoids in cauliflower curds. However, the cauliflower or mutant also possesses other phenotypes such as smaller curds, smaller leaves with elongated petioles, and delayed flowering. Here, we demonstrated that OR physically interacts with the transcription factor TCP7, which promotes endoreduplication by inducing the expression of the cell cycle gene CYCLIN D 1;1 (CYCD1;1). Overexpression of OR resulted in smaller rosette leaves, whereas the OR-silencing plants had larger rosette leaves than wild-type plants. Our microscopic observations and flow cytometry analysis revealed that the variation in leaf size was a result of different endoreduplication levels. Genetic analyses showed that OR functions antagonistically with TCP7 in regulating the endoreduplication levels in leaf cells. While the expression of OR is induced by TCP7, OR represses the transactivation activity of TCP7 by affecting its binding capability to the TCP-binding motif in the promoter region of CYCD1;1. Through this interaction, OR negatively regulates the expression of CYCD1;1 and reduces the nuclear ploidy level in rosette leaf cells. Our findings provide new insights into the regulatory network of leaf size and also reveal a regulatory circuit controlling endoreduplication in leaf cells.

Sodium Butyrate (NaB) and Sodium Propionate (NaP) Reduce Cyclin A2 Expression, Inducing Cell Cycle Arrest and Proliferation Inhibition of Different Breast Cancer Subtypes, Leading to Apoptosis.

Sodium butyrate (NaB) and sodium propionate (NaP) have recently garnered attention for their role in regulating inflammation and controlling signaling pathways of cell growth and apoptosis, potentially preventing cancer development. However, their therapeutic effect and the underlying mechanisms involved remain elusive in breast cancer. This study aims at investigating the anticancer role of NaB and NaP in different types of breast cancer by assessing their antiproliferative effect on MCF-7 and MDA-MB-231 cells (through an MTT assay), as well as their ability to alter the cell cycle and cyclin expression (using flow cytometry and RT-qPCR, respectively), and to promote apoptosis (using Annexin V-FITC conjugated and sub-G1 phase techniques). MDA-MB-231 cell proliferation was inhibited by NaB and NaP in a dose- and time-dependent manner with respective IC50 values of 2.56 mM and 6.49 mM. Treatment induced cell arrest in the G1 phase which was further supported by the significant reduction in cyclin A2 and cyclin B1 expressions. Finally, NaB, and less significantly NaP, induced apoptosis in a dose-dependent manner with higher concentrations required for MDA-MB-231 than MCF-7. Our findings elucidate the cyclin-dependent inhibitory effect of NaB and NaP on the progression of different breast cancer subtypes, thus highlighting their therapeutic potential in breast cancer.