CDK2-AP1 inhibits growth of breast cancer cells by regulating cell cycle and increasing docetaxel sensitivity in vivo and in vitro

Design, Synthesis, Biological Evaluation and Molecular Docking Studies of a New Series of Maleimide Derivatives

A series of novel maleimide derivatives were synthesized, with various heterocyclic compounds serving as side chains in the synthesis process. The structural characteristics of these compounds were elucidated through the application of 1H-NMR spectroscopy, 13C-NMR (APT) spectroscopy, and high-resolution mass spectrometry (HRMS). The anti-cancer potential of these compounds was subsequently assessed in vitro, utilizing two distinct breast cancer cell lines, namely MDA-MB-231 and MCF-7, via MTT assay. Among the 12 newly synthesized compounds, 4 a, 4 b, 4 c, 4 d, 5 a, 5 b, 5 c and 5 d were determined to show the most promising anti-cancer activity against both breast cancer cell lines. Moreover, the morphological changes induced in the cells following a 24-hour incubation period with these compounds were observed using light microscopy. Additionally, molecular dynamics simulations were conducted to assess the stability of the bound conformations of the compounds to the target protein GSK-3β as obtained through molecular docking calculations.

Design, synthesis, and in silico insights of novel N'-(2-oxoindolin-3-ylidene)piperidine-4-carbohydrazide derivatives as VEGFR-2 inhibitors

Vascular endothelial growth factor (VEGF) is a crucial key factor in breast tumorigenesis. VEGF plays an important role in angiogenesis, tumor proliferation, and metastasis. Herein, we report the design and synthesis of twenty-one novel piperidine/oxindole derivatives as potential VEGFR-2 inhibitors. The designed compound library aimed to occupy the binding site of VEGFR-2 in a similar binding pattern to that of the reference VEGFR-2 inhibitor Sorafenib. The synthesized compounds were biologically evaluated for their cytotoxic effects against two breast cancer cell lines (MCF-7 and MDA-MB-468). Compounds 12e and 6n were the most potent cytotoxic derivatives against the former and the latter cell lines, showing IC50 values of 8.00 and 0.60 µM, respectively. Furthermore, all the synthesized compounds were evaluated for their inhibitory activities towards VEGFR-2, with compound 12e showing the most potent activity with an IC50 value of 45.9 nM, surpassing the reference standard Sorafenib (IC50 = 48.6 nM). Additionally, compound 6n emerged as the top performer when tested with the other most promising compounds for their cytotoxic effects on HUVEC (IC50 = 28.77 nM). The designed library of compounds was subjected to molecular docking and molecular dynamic simulations, which revealed key binding interactions within the VEGFR-2 active site, including hydrogen bonding with Cys919, Glu885, and Asp1046 residues. Moreover, in silico predictions of physicochemical and pharmacokinetic properties for the target compounds indicated favorable drug-like characteristics.

Design, synthesis, antineoplastic activity of new pyrazolo[3,4-d]pyrimidine derivatives as dual CDK2/GSK3β kinase inhibitors; molecular docking study, and ADME prediction

In the current study, novel pyrazolo[3,4-d]pyrimidine derivatives 5a-h were designed and synthesized as targeted anti-cancer agents through dual CDK2/GSK-3β inhibition. The designed compounds demonstrated moderate to potent activity on the evaluated cancer cell lines (MCF-7 and T-47D). Compounds 5c and 5 g showed the most promising cytotoxic activity against the tested cell lines surpassing that of the used reference standard; staurosporine. On the other hand, both compounds showed good safety and tolerability on normal fibroblast cell line (MCR5). The final compounds 5c and 5 g showed a promising dual CDK2/GSK-3β inhibitory activity with IC50 of 0.244 and 0.128 μM, respectively, against CDK2, and IC50 of 0.317 and 0.160 μM, respectively, against GSK-3β. Investigating the effect of compounds 5c and 5 g on CDK2 and GSK-3β downstream cascades showed that they reduced the relative cellular content of phosphorylated RB1 and β-catenin compared to that in the untreated MCF-7 cells. Moreover, compounds 5c and 5 g showed a reasonable selective inhibition against the target kinases CDK2/GSK-3β in comparison to a set of seven off-target kinases. Furthermore, the most potent compound 5 g caused cell cycle arrest at the S phase in MCF-7 cells preventing the cells' progression to G2/M phase inducing cell apoptosis. Molecular docking studies showed that the final pyrazolo[3,4-d]pyrimidine derivatives have analogous binding modes in the target kinases interacting with the hinge region key amino acids. Molecular dynamics simulations confirmed the predicted binding mode by molecular docking. Moreover, in silico predictions indicated their favorable physicochemical and pharmacokinetic properties in addition to their promising cytotoxic activity.

Transcriptome Profiling of Cardiac Glycoside Treatment Reveals EGR1 and Downstream Proteins of MAPK/ERK Signaling Pathway in Human Breast Cancer Cells

Cardiac glycosides (CGs) constitute a group of steroid-like compounds renowned for their effectiveness in treating cardiovascular ailments. In recent times, there has been growing recognition of their potential use as drug leads in cancer treatment. In our prior research, we identified three highly promising CG compounds, namely lanatoside C (LC), peruvoside (PS), and strophanthidin (STR), which exhibited significant antitumor effects in lung, liver, and breast cancer cell lines. In this study, we investigated the therapeutic response of these CGs, with a particular focus on the MCF-7 breast cancer cell line. We conducted transcriptomic profiling and further validated the gene and protein expression changes induced by treatment through qRT-PCR, immunoblotting, and immunocytochemical analysis. Additionally, we demonstrated the interactions between the ligands and target proteins using the molecular docking approach. The transcriptome analysis revealed a cluster of genes with potential therapeutic targets involved in cytotoxicity, immunomodulation, and tumor-suppressor pathways. Subsequently, we focused on cross-validating the ten most significantly expressed genes, EGR1, MAPK1, p53, CCNK, CASP9, BCL2L1, CDK7, CDK2, CDK2AP1, and CDKN1A, through qRT-PCR, and their by confirming the consistent expression pattern with RNA-Seq data. Notably, among the most variable genes, we identified EGR1, the downstream effector of the MAPK signaling pathway, which performs the regulatory function in cell proliferation, tumor invasion, and immune regulation. Furthermore, we substantiated the influence of CG compounds on translational processes, resulting in an alteration in protein expression upon treatment. An additional analysis of ligand-protein interactions provided further evidence of the robust binding affinity between LC, PS, and STR and their respective protein targets. These findings underscore the intense anticancer activity of the investigated CGs, shedding light on potential target genes and elucidating the probable mechanism of action of CGs in breast cancer.

CircNCOR1 regulates breast cancer radiotherapy efficacy by regulating CDK2 via hsa-miR-638 binding

BACKGROUND

Despite aggressive local and regional therapy, triple-negative breast cancer (TNBC) is characterized by an increased risk of locoregional recurrence. RNA-sequencing data has identified a large number of circRNAs in primary breast cancers, but the role of specific circRNAs in regulating the radiosensitivity of TNBC is not fully understood. This research aimed to investigate the function of circNCOR1 in the radiosensitivity of TNBC.

METHODS

CircRNA high-throughput sequencing was conducted on two breast cancer MDA-MB-231 and BT549 cell lines after 6 Gy radiation. The relationship between circNCOR1, hsa-miR-638, and CDK2 was determined by RNA immunoprecipitation (RIP), FISH and luciferase assays. The proliferation and apoptosis of breast cancer cells were measured by CCK8, flow cytometry, colony formation assays, and western blot.

RESULTS

Differential expression of circRNAs was closely related to the proliferation of breast cancer cells after irradiation. Overexpression of circNCOR1 facilitated the proliferation of MDA-MB-231 and BT549 cells and impaired the radiosensitivity of breast cancer cells. Additionally, circNCOR1 acted as a sponge for hsa-miR-638 to regulate the downstream target protein CDK2. Overexpression of hsa-miR-638 promoted apoptosis of breast cancer cells, while overexpression of CDK2 alleviated apoptosis and increased proliferation and clonogenicity. In vivo, overexpression of circNCOR1 partially reversed radiation-induced loosening of tumor structures and enhanced tumor cell proliferation.

CONCLUSION

Our results demonstrated that circNCOR1 bounds to hsa-miR-638 and targets CDK2, thereby regulating the radiosensitivity of TNBC.

Invention of 3Mint for feature grouping and scoring in multi-omics

Advanced genomic and molecular profiling technologies accelerated the enlightenment of the regulatory mechanisms behind cancer development and progression, and the targeted therapies in patients. Along this line, intense studies with immense amounts of biological information have boosted the discovery of molecular biomarkers. Cancer is one of the leading causes of death around the world in recent years. Elucidation of genomic and epigenetic factors in Breast Cancer (BRCA) can provide a roadmap to uncover the disease mechanisms. Accordingly, unraveling the possible systematic connections between-omics data types and their contribution to BRCA tumor progression is crucial. In this study, we have developed a novel machine learning (ML) based integrative approach for multi-omics data analysis. This integrative approach combines information from gene expression (mRNA), microRNA (miRNA) and methylation data. Due to the complexity of cancer, this integrated data is expected to improve the prediction, diagnosis and treatment of disease through patterns only available from the 3-way interactions between these 3-omics datasets. In addition, the proposed method bridges the interpretation gap between the disease mechanisms that drive onset and progression. Our fundamental contribution is the 3 Multi-omics integrative tool (3Mint). This tool aims to perform grouping and scoring of groups using biological knowledge. Another major goal is improved gene selection via detection of novel groups of cross-omics biomarkers. Performance of 3Mint is assessed using different metrics. Our computational performance evaluations showed that the 3Mint classifies the BRCA molecular subtypes with lower number of genes when compared to the miRcorrNet tool which uses miRNA and mRNA gene expression profiles in terms of similar performance metrics (95% Accuracy). The incorporation of methylation data in 3Mint yields a much more focused analysis. The 3Mint tool and all other supplementary files are available at https://github.com/malikyousef/3Mint/.

Identification of 3-(piperazinylmethyl)benzofuran derivatives as novel type II CDK2 inhibitors: design, synthesis, biological evaluation, and in silico insights

In the current work, a hybridisation strategy was adopted between the privileged building blocks, benzofuran and piperazine, with the aim of designing novel CDK2 type II inhibitors. The hybrid structures were linked to different aromatic semicarbazide, thiosemicarbazide, or acylhydrazone tails to anchor the designed inhibitors onto the CDK2 kinase domain. The designed compounds showed promising CDK2 inhibitory activity. Compounds 9h, 11d, 11e and 13c showed potent inhibitory activity (IC₅₀ of 40.91, 41.70, 46.88, and 52.63 nM, respectively) compared to staurosporine (IC₅₀ of 56.76 nM). Moreover, benzofurans 9e, 9h, 11d, and 13b showed promising antiproliferative activities towards different cancer cell lines, and non-significant cytotoxicity on normal lung fibroblasts MRC-5 cell line. Furthermore, a cell cycle analysis as well as Annexin V-FITC apoptosis assay on Panc-1 cell line were performed. Molecular docking simulations were performed to explore the ability of target benzofurans to adopt the common binding pattern of CDK2 type II inhibitors.

CRIF1-CDK2 Interface Inhibitors Enhance Taxol Inhibition of the Lethal Triple-Negative Breast Cancer

Simple Summary

This study reported our most recent results for targeting triple-negative breast cancer (TNBC) with a low survival rate, using CR6-interacting factor 1–cyclin-dependent kinase 2 (CRIF1–CDK2) interface inhibitors, by inhibiting the resistance to taxol treatment. Presently, over 50% of TNBC patients become resistant to chemotherapy and, to date, no solution is available. The combined treatment, using CRIF1–CDK2 interface inhibitors with chemotherapy, provides an unprecedented strategy against the deadly TNBC.

Abstract

Paclitaxel (taxol), a chemotherapeutic agent, remains the standard of care for the lethal triple-negative breast cancer (TNBC). However, over 50% of TNBC patients become resistant to chemotherapy and, to date, no solution is available. CR6-interacting factor 1 (CRIF1) is reported to act as a negative regulator of the cell cycle by interacting with cyclin-dependent kinase 2 (CDK2). In our study, two selective CRIF1–CDK2 interface inhibitors were used to investigate whether they could exert anti-proliferative activity on the TNBC cell lines. When combined with taxol treatment, these two inhibitors can advance the cells from G0/G1 to S and G2/M phases, producing irreparable damage to the cells, which then undergo apoptosis. Moreover, they enhanced the reduction in cell proliferation induced by taxol in TNBC cells, thereby improving sensitivity to taxol in these cell lines. Importantly, the inhibitors did not regulate the cell cycle in normal cells, indicating their high selectivity towards TNBC cells. Overall, the resistance to the anti-proliferative effects induced by taxol can be significantly reduced by the combined treatment with selective CRIF1–CDK2 interface inhibitors, making a conceptual advance in the CDK-related cancer treatment.

Novel oxindole/benzofuran hybrids as potential dual CDK2/GSK-3β inhibitors targeting breast cancer: design, synthesis, biological evaluation, and in silico studies

The serine/threonine protein kinases CDK2 and GSK-3β are key oncotargets in breast cancer cell lines, therefore, in the present study three series of oxindole-benzofuran hybrids were designed and synthesised as dual CDK2/GSK-3β inhibitors targeting breast cancer (5a-g, 7a-h, and 13a-b). The N1 -unsubstituted oxindole derivatives, series 5, showed moderate to potent activity on both MCF-7 and T-47D breast cancer cell lines. Compounds 5d-f showed the most potent cytotoxic activity with IC50 of 3.41, 3.45 and 2.27 μM, respectively, on MCF-7 and of 3.82, 4.53 and 7.80 μM, respectively, on T-47D cell lines, in comparison to the used reference standard (staurosporine) IC50 of 4.81 and 4.34 μM, respectively. On the other hand, the N1 -substituted oxindole derivatives, series 7 and 13, showed moderate to weak cytotoxic activity on both breast cancer cell lines. CDK2 and GSK-3β enzyme inhibition assay of series 5 revealed that compounds 5d and 5f are showing potent dual CDK2/GSK-3β inhibitory activity with IC50 of 37.77 and 52.75 nM, respectively, on CDK2 and 32.09 and 40.13 nM, respectively, on GSK-3β. The most potent compounds 5d-f caused cell cycle arrest in the G2/M phase in MCF-7 cells inducing cell apoptosis because of the CDK2/GSK-3β inhibition. Molecular docking studies showed that the newly synthesised N1 -unsubstituted oxindole hybrids have comparable binding patterns in both CDK2 and GSK-3β. The oxindole ring is accommodated in the hinge region interacting through hydrogen bonding with the backbone CO and NH of the key amino acids Glu81 and Leu83, respectively, in CDK2 and Asp133 and Val135, respectively, in GSK-3β. Whereas, in series 7 and 13, the N1 -substitutions on the oxindole nucleus hinder the compounds from achieving these key interactions with hinge region amino acids what rationalises their moderate to low anti-proliferative activity.

Design, synthesis, in vitro antiproliferative evaluation and GSK-3β kinase inhibition of a new series of pyrimidin-4-one based amide conjugates

A new series of novel amide conjugates of pyrimidin-4-one and aromatic/heteroaromatic /secondary cyclic amines has been synthesized and their in vitro antiproliferative activities against a panel of 60 human cancer cell lines of nine different cancer types were tested at NCI. Among the synthesized compounds, compound (4i) showed significant anti-proliferative activity. Compound (4i) displayed most potent activity against the breast tumor cell line T-47D and CNS tumor cell line SNB-75 exhibiting a growth of 1.93 % and 14.63 %, respectively. ADMET studies of the synthesized compounds were also performed and they were found to exhibit good drug like properties. Compound (4i) was found to exhibit potential inhibitory effect over GSK-3β with IC₅₀ value of 71 nM. The molecular docking studies revealed that (4i) showed good binding affinity to GSK-3β and revealed multiple H-bonding and p-cation interactions with important amino acid residues on the receptor site. Compound (4i) may thus serve as a potential candidate for further development of novel anticancer therapeutics.

Transcriptomics and Metabolomics Integration Reveals Redox-Dependent Metabolic Rewiring in Breast Cancer Cells

Rewiring glucose metabolism toward aerobic glycolysis provides cancer cells with a rapid generation of pyruvate, ATP, and NADH, while pyruvate oxidation to lactate guarantees refueling of oxidized NAD⁺ to sustain glycolysis. CtPB2, an NADH-dependent transcriptional co-regulator, has been proposed to work as an NADH sensor, linking metabolism to epigenetic transcriptional reprogramming. By integrating metabolomics and transcriptomics in a triple-negative human breast cancer cell line, we show that genetic and pharmacological down-regulation of CtBP2 strongly reduces cell proliferation by modulating the redox balance, nucleotide synthesis, ROS generation, and scavenging. Our data highlight the critical role of NADH in controlling the oncogene-dependent crosstalk between metabolism and the epigenetically mediated transcriptional program that sustains energetic and anabolic demands in cancer cells.

Computational study to evaluate the potency of phytochemicals in Boerhavia diffusa and the impact of point mutation on cyclin-dependent kinase 2-associated protein 1

A protein's function is closely related to its structural properties. Mutations can affect the functionality of a protein. Different cancer tissues have found disordered expression of the cyclin-dependent kinase 2-associated Protein 1 (CDK2AP1) gene. A protein molecule's conformational flexibility affects its interaction with phytochemicals and their biological partners at various levels. Boerhavia diffusa has been investigated most extensively for its medicinal activities like anticancer properties. It contains many bioactive compounds like Boeravinone A, Boeravinone B, Boeravinone C, Boeravinone D, Boeravinone E, Boeravinone F, Boeravinone G, Boeravinone H, Boeravinone I and Boeravinone J. We have studied to analyse the binding efficacy properties as well as essential dynamic behaviour, free energy landscape of both the native and mutant protein CDK2AP1 with bioactive compounds from Boerhavia diffusa plant extracts through computational approaches by homology modelling, docking and molecular dynamics simulation. From the molecular docking study, we found that. Boeravinone J have best binding affinity (-7.9 kcal/mol) towards the native protein of CDKAP1 compared to others phytochemicals. However, we found the binding energy for H23R and C105R (mutation point) -7.8 and -7.6 kcal/mol, respectively. A single minima energy point (from 100 ns molecular dynamics simulation study) was found in the H23R mutant with Boeravinone J complex suggested that minimum structural changes with less conformational mobility compared C105A mutant model.Communicated by Ramaswamy H. Sarma.

Cancer as an infectious disease: A different treatment alternative using a combination of tigecycline and pyrvinium pamoate - An example of breast cancer

BACKGROUND

Tigecycline is an antibiotic that well tolerated for treating complicated infections. It has received attention as an anti-cancer agent and expected to solve two major obstacles, sides effects that accompany chemotherapy and drug resistance, in the breast cancer treatment. However, previous studies reported that the levels in the blood are typically low of tigecycline, so higher doses are needed to treat cancer, that may increase the risk of side effects. To achieve better anti-cancer effects for tigecycline, we need to find a novel adjunct agent.

METHODS

In this study, we used different concentration of pyrvinium pamoate combined with tigecycline to treat cell. And assess the effect of two drugs in inhibit cell proliferation, induce cell autophagy, or increase cell apoptosis to evaluate the consequent of combined therapy.

RESULTS

We observed that after the combined therapy, the cell cycle arrest at G1/s phase, the level of p21 increased, but decreased the levels of CDK2. Others, two drugs via different mechanisms to inhibit cancer cell proliferation and with selective cytotoxic to different cell lines. That could enhance the effect of breast cancer treatment.

CONCLUSION

Combining low dose of tigecycline use with pyrvinium pamoate is a novel approach for breast cancer treatment. Appropriate combined therapy in breast cancer is recommended to improve outcomes. Other problems like drug resistance occur in patients or the microbes surrounding breast tissues would confer susceptibility to cancers then influence the effectiveness of treatment, which could be improved through combined therapy.

Elacestrant (RAD1901) exhibits anti-tumor activity in multiple ER+ breast cancer models resistant to CDK4/6 inhibitors

Background

Addition of CDK4/6 inhibitors (CDK4/6i) to endocrine therapy significantly increased progression-free survival, leading to their approval and incorporation into the metastatic breast cancer treatment paradigm. With these inhibitors being routinely used for patients with advanced estrogen receptor-positive (ER+) breast cancer, resistance to these agents and its impact on subsequent therapy needs to be understood. Considering the central role of ER in driving the growth of ER+ breast cancers, and thus endocrine agents being a mainstay in the treatment paradigm, the effects of prior CDK4/6i exposure on ER signaling and the relevance of ER-targeted therapy are important to investigate. The objective of this study was to evaluate the anti-tumor activity of elacestrant, a novel oral selective estrogen receptor degrader (SERD), in preclinical models of CDK4/6i resistance.

Methods

Elacestrant was evaluated as a single agent, and in combination with alpelisib or everolimus, in multiple in vitro models and patient-derived xenografts that represent acquired and “de novo” CDK4/6i resistance.

Results

Elacestrant demonstrated growth inhibition in cells resistant to all three approved CDK4/6i (palbociclib, abemaciclib, ribociclib) in both ESR1 wild-type and mutant backgrounds. Furthermore, we demonstrated that elacestrant, as a single agent and in combination, inhibited growth of patient-derived xenografts that have been derived from a patient previously treated with a CDK4/6i or exhibit de novo resistance to CDK4/6i. While the resistant lines demonstrate distinct alterations in cell cycle modulators, this did not affect elacestrant’s anti-tumor activity. In fact, we observe that elacestrant downregulates several key cell cycle players and halts cell cycle progression in vitro and in vivo.

Conclusions

We demonstrate that breast cancer tumor cells continue to rely on ER signaling to drive tumor growth despite exposure to CDK4/6i inhibitors. Importantly, elacestrant can inhibit this ER-dependent growth despite previously reported mechanisms of CDK4/6i resistance observed such as Rb loss, CDK6 overexpression, upregulated cyclinE1 and E2F1, among others. These data provide a scientific rationale for the evaluation of elacestrant in a post-CDK4/6i patient population. Additionally, elacestrant may also serve as an endocrine backbone for rational combinations to combat resistance.

Cathepsin L interacts with CDK2-AP1 as a potential predictor of prognosis in patients with breast cancer

Cathepsin L (CTSL) is a lysosomal acid cysteine protease that has been implicated in tumorigenesis and malignant progression. In the present study, the role of CTSL in tumorigenesis and prognosis of breast cancer was evaluated. The prognostic value of CTSL was analyzed using immunohistochemistry in patients with breast cancer, as well as online microarray datasets. CTSL expression was knocked down in the breast cancer cell line T-47D using RNA interference. MTT and colony formation assays were performed to assess the role of CTSL in the proliferation of breast cancer cells. Cell cycle progression and apoptosis were measured using flow cytometry. A physical interaction of CTSL and cyclin dependent kinase 2 associated protein 1 (CDK2-AP1) was determined using a glutathione S-transferase pull-down assay. Endogenous CTSL expression was high in breast cancer cells and exhibited an inverse association with CDK2-AP1 expression; aberrant expression of CTSL in breast cancer tissues predicted an improved clinical outcome and prognosis. In addition, CTSL knockdown decelerated the progression of breast cancer cells by arresting cell cycle progression and increasing apoptosis. Thus, CTSL may be a potential therapeutic target for treating patients with breast cancer.

To control or to be controlled? Dual roles of CDK2 in DNA damage and DNA damage response

CDK2 (cyclin-dependent kinase 2), a member of the CDK family, has been shown to play a role in many cellular activities including cell cycle progression, apoptosis and senescence. Recently, accumulating evidence indicates that CDK2 is involved in DNA damage and DNA repair response (DDR). When DNA is damaged by internal or external genotoxic stresses, CDK2 activity is required for proper DNA repair in vivo and in vitro, whereas inactivation of CDK2 by siRNA techniques or by inhibitors could result in DNA damage and stimulate DDR. Hence, CDK2 seems to play dual roles in DNA damage and DDR. On one aspect, it is activated and stimulates DDR to repair DNA damage when DNA damage occurs; on the other hand, its inactivation directly leads to DNA damage and evokes DDR. Here, we describe the roles of CDK2 in DNA damage and DDR, and discuss the potential application of CDK2 inhibitors as anti-cancer agents.

Clinicopathological Features of Triple-Negative Breast Cancer Epigenetic Subtypes

BACKGROUND/OBJECTIVE

Triple-negative breast cancer (TNBC) is a heterogeneous collection of breast tumors with numerous differences including morphological characteristics, genetic makeup, immune-cell infiltration, and response to systemic therapy. DNA methylation profiling is a robust tool to accurately identify disease-specific subtypes. We aimed to generate an epigenetic subclassification of TNBC tumors (epitypes) with utility for clinical decision-making.

METHODS

Genome-wide DNA methylation profiles from TNBC patients generated in the Cancer Genome Atlas project were used to build machine learning-based epigenetic classifiers. Clinical and demographic variables, as well as gene expression and gene mutation data from the same cohort, were integrated to further refine the TNBC epitypes.

RESULTS

This analysis indicated the existence of four TNBC epitypes, named as Epi-CL-A, Epi-CL-B, Epi-CL-C, and Epi-CL-D. Patients with Epi-CL-B tumors showed significantly shorter disease-free survival and overall survival [log rank; P = 0.01; hazard ratio (HR) 3.89, 95% confidence interval (CI) 1.3-11.63 and P = 0.003; HR 5.29, 95% CI 1.55-18.18, respectively]. Significant gene expression and mutation differences among the TNBC epitypes suggested alternative pathway activation that could be used as ancillary therapeutic targets. These epigenetic subtypes showed complementarity with the recently described TNBC transcriptomic subtypes.

CONCLUSIONS

TNBC epigenetic subtypes exhibit significant clinical and molecular differences. The links between genetic make-up, gene expression programs, and epigenetic subtypes open new avenues in the development of laboratory tests to more efficiently stratify TNBC patients, helping optimize tailored treatment approaches.

Essential role of JunD in cell proliferation is mediated via MYC signaling in prostate cancer cells

JunD, a member of the AP-1 family, is essential for cell proliferation in prostate cancer (PCa) cells. We recently demonstrated that JunD knock-down (KD) in PCa cells results in cell cycle arrest in G1-phase concomitant with a decrease in cyclin D1, Ki67, and c-MYC, but an increase in p21 levels. Furthermore, the over-expression of JunD significantly increased proliferation suggesting JunD regulation of genes required for cell cycle progression. Here, employing gene expression profiling, quantitative proteomics, and validation approaches, we demonstrate that JunD KD is associated with distinct gene and protein expression patterns. Comparative integrative analysis by Ingenuity Pathway Analysis (IPA) identified 1) cell cycle control/regulation as the top canonical pathway whose members exhibited a significant decrease in their expression following JunD KD including PRDX3, PEA15, KIF2C, and CDK2, and 2) JunD dependent genes are associated with cell proliferation, with MYC as the critical downstream regulator. Conversely, JunD over-expression induced the expression of the above genes including c-MYC. We conclude that JunD is a crucial regulator of cell cycle progression and inhibiting its target genes may be an effective approach to block prostate carcinogenesis.

Effects of combined inhibition of STAT3 and VEGFR2 pathways on the radiosensitivity of non-small-cell lung cancer cells

Purpose

The goals of this study were to determine the effects of combined inhibition of STAT3 and vascular endothelial growth factor receptor 2 (VEGFR2) pathways on the radiosensitivity of non-small-cell lung cancer (NSCLC) cells, and to assess the underlying mechanisms.

Methods

The expressions of VEGFR2, STAT3, related signaling molecules, hypoxia-inducible factor 1-alpha (HIF-1α), and cyclin D1 were determined by Western blotting. Radiosensitivity was assessed using the colony-forming assay, and cell cycle and cell death were analyzed by flow cytometry. A nude mouse xenograft tumor model of Calu-1 cells was established. The hepatorenal toxicity of the above-mentioned treatment on tumor-bearing mice was observed by H&E staining. The expression of STAT3, VEGFR2, HIF-1α, and cyclin D1 of the transplanted tumor tissues was detected by immunohistochemistry. Apoptosis of tumor tissues was evaluated by TUNEL staining.

Results

In vitro, we selected two cell lines with high expression levels of STAT3, including Calu-1 cells that exhibit high VEGFR2 expression and A549 cells that exhibit low VEGFR2 expression. When apatinib treatment was combined with S3I-201, the expression of VEGFR2, STAT3, and their downstream signaling molecules was significantly decreased (P<0.01). There was an increase in cell death and G2/M phase arrest after treatments, with the most significant changes occurring upon dual inhibition of STAT3 and VEGFR2 (P<0.01). In vivo, combined treatment of radiotherapy and dual inhibition of VEGFR2 and STAT3 was well tolerated and did not deliver additional toxicity. Compared with the control group and the radiation treatment (RT) + apatinib or RT + S3I-201 duplex group, the expression level of STAT3, p-STAT3, VEGFR2, HIF-1α, and cyclin D1 in the triple group (RT + apatinib + S3I-201) was the lowest, and the proportion of apoptotic cells was the highest (P<0.05).

Conclusion

The combined inhibition of VEGFR2 and STAT3 is effective in enhancing radiosensitizing effects in NSCLC cells.

mRNA Expression of CDK2AP1 in Human Breast Cancer: Correlation with Clinical and Pathological Parameters

BACKGROUND

Cyclin-dependent kinase 2-associated protein 1 (CDK2AP1) interacts with CDK2AP2, modulates the actions of transforming growth factor-B1, cyclin-dependent kinase 2 and retinoblastoma protein, and closely interacts with micro-RNA21 and micro-RNA25. Our objective was to determine if CDK2AP1 mRNA expression levels were consistent with tumour-suppressive functions in breast cancer.

MATERIALS AND METHODS

A total of 134 samples were analysed. CDK2AP1 mRNA levels were measured using quantitative polymerase chain reaction (RT-PCR) and normalised against glyceraldehyde 3-phosphate dehydrogenase mRNA. Levels in breast cancer and adjacent non-cancerous breast tissue were analysed against pathological and clinical parameters (TNM staging, survival over a 10-year follow-up period).

RESULTS

Normalised CDK2AP1 expression was 38-fold higher in adjacent non-cancerous breast tissue than in breast cancer. CDK2AP1 expression in disease-free patients at 10 years was more than threefold that of patients who died of breast cancer. However, neither of these differences in expression levels reached statistical significance. CDK2AP1 mRNA levels were higher in TNM1 compared to TNM3 (p=0.016) and with TNM4 (p=0.016). There were no significant associations between CDK2AP1 expression and estrogen receptor status, tumour grade and tumour type. There was no significant difference in overall survival between patients with high and those with low CDK2AP1 mRNA levels after a median follow-up of 10 years (Kaplan-Meier analysis, p=0.872).

CONCLUSION

To our knowledge, this is the first study in the literature to examine the mRNA expression of CDK2AP1 in human breast cancer over a long-term follow-up period. A compelling relationship exists between high CDK2AP1 mRNA expression and lower TNM classification of breast cancer, which is consistent with CDK2AP1 having a tumour-suppressive function.

MCR-click synthesis, molecular docking and cytotoxicity evaluation of a new series of indole–triazole–coumarin hybrid peptidomimetics

The design and synthesis of a new series of indole–triazole-coumarin hybrids as potential CDK2 inhibitors is described.

The soy-derived peptide Vglycin inhibits the growth of colon cancer cells in vitro and in vivo

Vglycin, a novel natural polypeptide isolated from pea seeds, possesses antidiabetic properties. Our previous studies have shown that Vglycin can induce the differentiation of human colon adenocarcinoma cells. We aimed to determine the anticancer activity of Vglycin against colon cancer cells and to elucidate related apoptosis-inducing mechanisms. Treatment with purified Vglycin significantly reduced growth, viability, and colony formation of CT-26, SW480, and NCL-H716 colon cancer cells in a dose-dependent manner while down-regulating the expression of proliferating cell nuclear antigen. Mouse xenograft studies showed a 38% inhibition of colon cancer growth in mice treated with Vglycin (20 mg/kg/day) at day 21. Furthermore, the potential mechanisms involved in Vglycin-induced cell apoptosis were examined using cell cycle studies, ultrastructural examination, as well as apoptosis-associated pathway analysis. The results showed that Vglycin significantly promoted apoptosis and G1/S phase cell cycle arrest. As revealed by Western blot, the expression of CDK2 and Cyclin D1 was down-regulated in all three Vglycin-treated colon cancer cells, indicating that the CDK2/Cyclin D1 cell cycle pathway involved in the initiation and progression of colon cancer. Moreover, the inhibition of Vglycin-induced cell proliferation in colon cancer cells was accompanied by alteration of the expression levels of the apoptosis-related proteins Bax, Bcl-2 and Mcl-1, and an increase of caspase-3 activity. Together, our results suggest that Vglycin may be another plant-derived peptide that suppresses colon cancer, supporting the continued investigation of Vglycin as therapeutic agent for colon cancer. Impact statement The antidiabetic properties and the capability of inducing differentiation of human colon adenocarcinoma cells of Vglycin have been reported in our previous studies. However, the anticancer potential of Vglycin on colon cancer cells and its possible related mechanisms were still unknown. In this study, we found that Vglycin could reduce growth, viability, and colony formation or colony size of CT-26, SW480, and NCL-H716 colon cancer cells. Moreover, Vglycin decreased tumor volume by 38% in xenograft mice transplanted with CT-26 cells. The mechanisms of these phenomena may be due to the down-regulated CDK2 and Cyclin D1, G1/S phase cell cycle arrest, and the dysregulated expression of Bax, Bcl-2, and Mcl-1. The findings highlight the anticancer potential of Vglycin against colon cancer cells, and suggest Vglycin may be another colon cancer potential suppressive component of plant-derived peptides.

Bufalin inhibits proliferation of human gastric cancer MGC803 cells via TGFβ1/smad signaling pathways

AIM: To investigate whether TGFβ1/smad signaling pathways are involved in the effect of Bufalin on the proliferation of human gastric cancer MGC803 cells.

METHODS: Human gastric cancer MGC803 cells were treated with Bufalin. Cell proliferation was tested by MTT assay and Trypan blue assay. The content of TGFβ1 protein in culture medium treated with Bufalin was detected by ELISA. The expressions of cyclinD1, phosphorylated smad3 and smad4 was detected by Western blot.

RESULTS: Bufalin significantly reduced the viability of MGC803 cells in a dose-dependent manner, and there was a significant difference among different concentrations (F = 13.216, P = 0.002). The results of Trypan blue assay showed a similar trend (χ² = 9.667, P = 0.022). Compared with the control group, the expression of TGFβ1 protein in culture medium was decreased after the cells were treated with Bufalin (F = 36.455, P < 0.001), and the expression of P-smad3 and cyclinD1 protein in MGC803 cells was also decreased after the cells were treated with Bufalin (P < 0.05). However, the content of smad4 protein in MGC803 cells was increased after the application of Bufalin (P < 0.001).

CONCLUSION: Bufalin inhibits the proliferation of MGC803 cells via mechanisms possibly associated with inhibiting TGFβ1/smad signaling transduction pathways.