Decoding the links between mitosis, cancer, and chemotherapy: The mitotic checkpoint, adaptation, and cell death

Chromosome Missegregation Triggers Tumor Cell Pyroptosis and Enhances Anti-Tumor Immunotherapy in Colorectal Cancer

Immune checkpoint inhibitor (ICI) therapy is a promising anti-tumor therapeutic strategy; however, its efficacy in solid tumors is limited. Chromosome missegregation is common in various solid tumors; however, its role in tumor progression remains poorly understood, and its correlation with ICI is yet to be explored. Here, it is found that increased chromosome missegregation promotes tumor immune microenvironment, and eventually immunotherapeutic efficacy, by triggering pyroptosis. yin yang 2 (YY2) is identified as a mitotic checkpoint regulator, which promotes chromosome missegregation by upregulating BUB1B transcription. Increased chromosome missegregation promoted the formation of micronuclei and release of double-stranded DNA (dsDNA) into the cytosol, triggering an AIM2-mediated cytosolic dsDNA response. The subsequent pyroptosis strengthened the tumor immune microenvironment, thereby enhancing immunoinfiltration and cytotoxicity of CD8+ T cells, while preventing their exhaustion. Finally, through in vitro and in vivo experiments, it is demonstrated that combining YY2 overexpression-induced chromosome missegregation/cytosolic dsDNA response and PD-1 inhibitor significantly enhanced the efficacy of ICI immunotherapy in microsatellite instable and microsatellite stable colorectal cancer cells. Together, these findings provide new insights on the role of chromosome missegregation in triggering cytosolic dsDNA response-mediated pyroptosis and modulating the tumor immune microenvironment, suggesting a novel strategy for improving ICI therapeutic efficacy in colorectal cancer.

Exploring Neuroprotection against Radiation-Induced Brain Injury: A Review of Key Compounds

Brain radiation is a crucial tool in neuro-oncology for enhancing local tumor control, but it can lead to mild-to-profound and progressive impairments in cognitive function. Radiation-induced brain injury is a significant adverse effect of radiotherapy for cranioencephalic tumors, primarily caused by indirect cellular damage through the formation of free radicals. This results in late neurotoxicity manifesting as cognitive impairment due to free radical production. The aim of this review is to highlight the role of different substances, such as drugs used in the clinical setting and antioxidants such as ascorbate, in reducing the neurotoxicity associated with radiation-induced brain injury. Currently, there is mainly preclinical and clinical evidence supporting the benefit of these interventions, representing a cost-effective and straightforward neuroprotective strategy.

Exploring the promising role of chitosan delivery systems in breast cancer treatment: A comprehensive review

Breast cancer presents a significant global health challenge, driving the development of novel treatment strategies for therapeutic interventions. Nanotechnology has emerged as a promising avenue for addressing this challenge, with Chitosan (CS) nanoparticles receiving prominence due to their unique characteristics and multitude of potential applications. This review provides a comprehensive overview of the role of Chitosan nanoparticles in breast cancer therapy. The review begins by emphasizing the prevalence and importance of breast cancer as a major health issue, underscoring the necessity for effective treatments. It then delves into the application of Chitosan nanoparticles in breast cancer therapy. One key aspect discussed is their role as carriers for anticancer drugs, enabling targeted delivery and improved cellular uptake. Furthermore, the review explores modified Chitosan nanoparticles and strategies for enhancing their efficacy and specificity in breast cancer treatment. It also examines Chitosan conjugates and hybrids, which offer innovative approaches for combination therapy. Additionally, metal and magnetic Chitosan nanoparticles are discussed spanning their capacity to assist in imaging, hyperthermia, as well as targeted drug delivery. In conclusion, the review summarizes the current research landscape regarding Chitosan nanoparticles for breast cancer therapy and offers insights into future directions. Overall, the review highlights the versatility, potential benefits, and future prospects of Chitosan nanoparticles in combating breast cancer.

Development and validation of a mitotic catastrophe-related genes prognostic model for breast cancer

Background

Breast cancer has become the most common malignant tumor in women worldwide. Mitotic catastrophe (MC) is a way of cell death that plays an important role in the development of tumors. However, the exact relationship between MC-related genes (MCRGs) and the development of breast cancer is still unclear, and further research is needed to elucidate this complexity.

Methods

Transcriptome data and clinical data of breast cancer were downloaded from the Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) database. We identified differential expression of MCRGs by comparing tumor tissue with normal tissue. Subsequently, we used COX regression analysis and LASSO regression analysis to construct the prognosis risk model of MCRGs. Kaplan-Meier survival curve and receiver operating characteristic (ROC) curve were used to evaluate the predictive ability of prognostic model. Moreover, the clinical relevance, gene set enrichment analysis (GSEA), immune landscape, tumor mutation burden (TMB), and immunotherapy and drug sensitivity analysis between high-risk and low-risk groups were systematically investigated. Finally, we validated the expression levels of genes involved in constructing the prognostic model through real-time quantitative polymerase chain reaction (RT-qPCR) at the cellular and tissue levels.

Results

We identified 12 prognostic associated MCRGs, four of which were selected to construct prognostic model. The Kaplan-Meier analysis suggested that patients in the high-risk group had a shorter overall survival (OS). The Cox regression analysis and ROC analysis indicated that risk model had independent and excellent ability in predicting prognosis of breast cancer patients. Mechanistically, a remarkable difference was observed in clinical relevance, GSEA, immune landscape, TMB, immunotherapy response, and drug sensitivity analysis. RT-qPCR results showed that genes involved in constructing the prognostic model showed significant abnormal expressions and the expression change trends were consistent with the bioinformatics results.

Conclusions

We established a prognosis risk model based on four MCRGs that had the ability to predict clinical prognosis and immune landscape, proposing potential therapeutic targets for breast cancer.

Biological and metabolomics-guided isolation of tetrahydrofurofuran lignan from Croton spp. with antiproliferative activity against human melanoma cell line

The Croton genus (Euphorbiaceae) is recognized as a promising source for identifying bioactive compounds with antiproliferative activity. However, knowledge on the chemical composition and activity of Croton floribundus, Croton echinocarpus, and Croton zehntneri is limited. Thus, this study aimed to investigate the antiproliferative activity of these species on cells derived from tumoral breast, lung, and melanoma cells, and primary fibroblasts derived from human skin. Metabolomic strategies were applied via ultra-performance liquid chromatography coupled with high-resolution mass spectrometry and multivariate statistical analysis to target the main active compound. The C. floribundus leaf extract exhibited the highest activity, with an IC50 value lower than that of the reference drug - temozolomide - in the most responsive cell line - SK-MEL-147 - and in all the evaluated melanoma cell lines (SK-MEL-147, CHL-1 and WM-1366). Four tetrahydrofurofuran lignans were isolated for the first time from the most promising fraction of the C. floribundus extract. According to the metabolomic and multivariate statistical analyses, the isolated lignan epi-yangambin constituted the main antiproliferative compound against SK-MEL-147; furthermore, it exhibited selective antiproliferative activity for this cell line (IC50 = 13.09 μg/mL and selectivity index = 3.82; temozolomide, IC50 = 121.50 μg/mL) due to, at least in part, its ability to inhibit cell cycle progression at G2/M. This is especially relevant considering the high resistance of melanoma cells to available drugs. Thus, epi-yangambin can serve as a prototype for further antiproliferative investigations.

Emerging mechanisms and promising approaches in pancreatic cancer metabolism

Pancreatic cancer is an aggressive cancer with a poor prognosis. Metabolic abnormalities are one of the hallmarks of pancreatic cancer, and pancreatic cancer cells can adapt to biosynthesis, energy intake, and redox needs through metabolic reprogramming to tolerate nutrient deficiency and hypoxic microenvironments. Pancreatic cancer cells can use glucose, amino acids, and lipids as energy to maintain malignant growth. Moreover, they also metabolically interact with cells in the tumour microenvironment to change cell fate, promote tumour progression, and even affect immune responses. Importantly, metabolic changes at the body level deserve more attention. Basic research and clinical trials based on targeted metabolic therapy or in combination with other treatments are in full swing. A more comprehensive and in-depth understanding of the metabolic regulation of pancreatic cancer cells will not only enrich the understanding of the mechanisms of disease progression but also provide inspiration for new diagnostic and therapeutic approaches.

A Novel 2-Methoxyestradiol Derivative: Disrupting Mitosis Inhibiting Cell Motility and Inducing Apoptosis in HeLa Cells In Vitro

The clinical application of 2-methoxyestradiol (2ME) in cancer therapy has been limited by its low solubility and rapid metabolism. Derivatives of 2ME have been synthesised to enhance bioavailability and decrease hepatic metabolism. Compound 4a, an analog of 2ME, has demonstrated exceptional pharmacological activity, in addition to promising pharmacokinetic profile. Our study, therefore, aimed at exploring the anticancer effects of 4a on the cervical cancer cell line, HeLa. Compound 4a exhibited a significant and dose-dependent antimetastatic and antiinvasive impact on HeLa cells, as determined by wound-healing and Boyden chamber assays, respectively. Hoechst/Propidium iodide (HOPI) double staining showcased a substantial induction of apoptosis via 4a, with minimal necrotic effect. Flow cytometry revealed a significant G2/M phase arrest, accompanied by a noteworthy rise in the sub-G1 cell population, indicating apoptosis, 18 h post-treatment. Moreover, a cell-independent tubulin polymerisation assay illustrated compound 4a's ability to stabilise microtubules by promoting tubulin polymerisation. Molecular modelling experiments depicted that 4a interacts with the colchicine-binding site, nestled between the α and β tubulin dimers. Furthermore, 4a displayed an affinity for binding to and activating ER-α, as demonstrated by the luciferase reporter assay. These findings underscore the potential of 4a in inhibiting HPV18+ cervical cancer proliferation and cellular motility.

Calreticulin and JAK2V617F driver mutations induce distinct mitotic defects in myeloproliferative neoplasms

Myeloproliferative neoplasms (MPNs) encompass a diverse group of hematologic disorders driven by mutations in JAK2, CALR, or MPL. The prevailing working model explaining how these driver mutations induce different disease phenotypes is based on the decisive influence of the cellular microenvironment and the acquisition of additional mutations. Here, we report increased levels of chromatin segregation errors in hematopoietic cells stably expressing CALRdel52 or JAK2V617F mutations. Our investigations employing murine 32DMPL and human erythroleukemic TF-1MPL cells demonstrate a link between CALRdel52 or JAK2V617F expression and a compromised spindle assembly checkpoint (SAC), a phenomenon contributing to error-prone mitosis. This defective SAC is associated with imbalances in the recruitment of SAC factors to mitotic kinetochores upon CALRdel52 or JAK2V617F expression. We show that JAK2 mutant CD34 + MPN patient-derived cells exhibit reduced expression of the master mitotic regulators PLK1, aurora kinase B, and PP2A catalytic subunit. Furthermore, the expression profile of mitotic regulators in CD34 + patient-derived cells allows to faithfully distinguish patients from healthy controls, as well as to differentiate primary and secondary myelofibrosis from essential thrombocythemia and polycythemia vera. Altogether, our data suggest alterations in mitotic regulation as a potential driver in the pathogenesis in MPN.

The Application of Kinesin Inhibitors in Medical Issues

Kinesins are a group of motor proteins in charge of several crucial functions in the cell. These proteins often bind to microtubules and perform their functions using the energy produced by ATP hydrolysis. One function of mitotic kinesin, a subclass of kinesin that is expressed during cell division at the mitotic phase, is to create the mitotic spindle. Uncontrolled cell growth is one trait of cancerous cells. Traditional anticancer medications still used in clinics include taxanes (paclitaxel) and vinca alkaloids (vincristine, vinblastine), which interfere with microtubule dynamics. However, because non-dividing cells like post-mitotic neurons contain microtubules, unwanted side effects like peripheral neuropathy are frequently found in patients taking these medications. More than ten members of the mitotic kinesin family play distinct or complementary roles during mitosis. The mitotic kinesin family's KSP, or Eg5, is regarded as its most dramatic target protein. The current work systematically reviews the use of kinesin inhibitors in the medical field. The challenges of KSP and the practical solutions are also examined, and the outcomes of the previous works are reported. The significant gaps and shortcomings of the related works are also highlighted, which can be an onset topic for future works.

Metabolic Interplay in the Tumor Microenvironment: Implications for Immune Function and Anticancer Response

Malignant tumors exhibit rapid growth and high metabolic rates, similar to embryonic stem cells, and depend on aerobic glycolysis, known as the "Warburg effect". This understanding has enabled the use of radiolabeled glucose analogs in tumor staging and therapeutic response assessment via PET scans. Traditional treatments like chemotherapy and radiotherapy target rapidly dividing cells, causing significant toxicity. Despite immunotherapy's impact on solid tumor treatment, gaps remain, leading to research on cancer cell evasion of immune response and immune tolerance induction via interactions with the tumor microenvironment (TME). The TME, consisting of immune cells, fibroblasts, vessels, and the extracellular matrix, regulates tumor progression and therapy responses. TME-targeted therapies aim to transform this environment from supporting tumor growth to impeding it and fostering an effective immune response. This review examines the metabolic disparities between immune cells and cancer cells, their impact on immune function and therapeutic targeting, the TME components, and the complex interplay between cancer cells and nontumoral cells. The success of TME-targeted therapies highlights their potential to achieve better cancer control or even a cure.

Therapeutic role of 2-stearoxyphenethyl phosphocholine targeting microtubule dynamics and Wnt/β-catenin/EMT signaling in human colorectal cancer cells

The inhibition of cell death, perturbation of microtubule dynamics, and acceleration of Wnt/β-catenin/epithelial-mesenchymal transition (EMT) signaling are fundamental processes in the progression and metastasis of colorectal cancer (CRC). To explore the role of 2-stearoxyphenethyl phosphocholine (stPEPC), an alkylphospholipid-based compound, in CRC, we conducted an MTT assay, cell cycle analysis, western blot analysis, immunoprecipitation, immunofluorescence staining, Annexin V/propidium iodide double staining, small interfering RNA gene silencing, a wound-healing assay, an invasion assay, and terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay in the human CRC cell lines HT29 and HCT116. stPEPC showed anti-proliferative properties and mitotic cell accumulation via upregulated phosphorylation of BUBR1 and an association between mitotic arrest deficiency 2 (MAD2) and cell division cycle protein 20 homolog (CDC20). These results suggest that activation of the mitotic checkpoint complex and tubulin polymerization occurred, resulting in mitotic catastrophe in HT29 and HCT116 cells. In addition, stPEPC attenuated cell migration and invasion by regulating proteins mediated by EMT, such as E-cadherin and occludin. stPEPC altered the protein expression of Wnt3a and phosphorylation of low-density lipoprotein receptor-related protein 6 (LRP6), glycogen synthase kinase 3β (GSK3β), and β-catenin as well as their target genes, including cMyc and cyclin D1, in CRC cells. Thus, stPEPC may be useful for developing new drugs to treat human CRC.

Biallelic MAD2L1BP (p31comet) mutation is associated with mosaic aneuploidy and juvenile granulosa cell tumors

MAD2L1BP-encoded p31comet mediates Trip13-dependent disassembly of Mad2- and Rev7-containing complexes and, through this antagonism, promotes timely spindle assembly checkpoint (SAC) silencing, faithful chromosome segregation, insulin signaling, and homology-directed repair (HDR) of DNA double-strand breaks. We identified a homozygous MAD2L1BP nonsense variant, R253*, in 2 siblings with microcephaly, epileptic encephalopathy, and juvenile granulosa cell tumors of ovary and testis. Patient-derived cells exhibited high-grade mosaic variegated aneuploidy, slowed-down proliferation, and instability of truncated p31comet mRNA and protein. Corresponding recombinant p31comet was defective in Trip13, Mad2, and Rev7 binding and unable to support SAC silencing or HDR. Furthermore, C-terminal truncation abrogated an identified interaction of p31comet with tp53. Another homozygous truncation, R227*, detected in an early-deceased patient with low-level aneuploidy, severe epileptic encephalopathy, and frequent blood glucose elevations, likely corresponds to complete loss of function, as in Mad2l1bp-/- mice. Thus, human mutations of p31comet are linked to aneuploidy and tumor predisposition.

Dual impacts of mesenchymal stem cell-derived exosomes on cancer cells: unravelling complex interactions

Mesenchymal stem cells (MSCs) are multipotent, self-renewing stromal cells found in a variety of adult tissues. MSCs possess a remarkable ability to migrate towards tumor sites, known as homing. This homing process is mediated by various factors, including chemokines, growth factors, and extracellular matrix components present in the tumor microenvironment. MSCs release extracellular vesicles known as exosomes (MSC-Exos), which have been suggested to serve a key role in mediating a wide variety of MSC activities. Through cell-cell communication, MSC-Exos have been shown to alter recipient cell phenotype or function and play as a novel cell-free alternative for MSC-based cell therapy. However, MSC recruitment to tumors allows for their interaction with cancer cells and subsequent regulation of tumor behavior. MSC-Exos act as tumor niche modulators via transferring exosomal contents, such as specific proteins or genetic materials, to the nearby cancer cells, leading to either promotion or suppression of tumorigenesis, angiogenesis, and metastasis, depending on the specific microenvironmental cues and recipient cell characteristics. Consequently, there is still a debate about the precise relationship between tumor cells and MSC-Exos, and it is unclear how MSC-Exos impacts tumor cells. Although the dysregulation of miRNAs is caused by the progression of cancer, they also play a direct role in either promoting or inhibiting tumor growth as they act as either oncogenes or tumor suppressors. The utilization of MSC-Exos may prove to be an effective method for restoring miRNA as a means of treating cancer. This review aimed to present the existing understanding of the impact that MSC-Exos could have on cancer. To begin with, we presented a brief explanation of exosomes, MSCs, and MSC-Exos. Following this, we delved into the impact of MSC-Exos on cancer growth, EMT, metastasis, angiogenesis, resistance to chemotherapy and radiotherapy, and modulation of the immune system. Opposing effects of mesenchymal stem cells-derived exosomes on cancer cells.

Cortical tension drug screen links mitotic spindle integrity to Rho pathway

Mechanical force generation plays an essential role in many cellular functions, including mitosis. Actomyosin contractile forces mediate changes in cell shape in mitosis and are implicated in mitotic spindle integrity via cortical tension. An unbiased screen of 150 small molecules that impact actin organization and 32 anti-mitotic drugs identified two molecular targets, Rho kinase (ROCK) and tropomyosin 3.1/2 (Tpm3.1/2), whose inhibition has the greatest impact on mitotic cortical tension. The converse was found for compounds that depolymerize microtubules. Tpm3.1/2 forms a co-polymer with mitotic cortical actin filaments, and its inhibition prevents rescue of multipolar spindles induced by anti-microtubule chemotherapeutics. We examined the role of mitotic cortical tension in this rescue mechanism. Inhibition of ROCK and Tpm3.1/2 and knockdown (KD) of cortical nonmuscle myosin 2A (NM2A), all of which reduce cortical tension, inhibited rescue of multipolar mitotic spindles, further implicating cortical tension in the rescue mechanism. GEF-H1 released from microtubules by depolymerization increased cortical tension through the RhoA pathway, and its KD also inhibited rescue of multipolar mitotic spindles. We conclude that microtubule depolymerization by anti-cancer drugs induces cortical-tension-based rescue to ensure integrity of the mitotic bipolar spindle mediated via the RhoA pathway. Central to this mechanism is the dependence of NM2A on Tpm3.1/2 to produce the functional engagement of actin filaments responsible for cortical tension.

Meta-analysis of genome-wide association studies of gestational duration and spontaneous preterm birth identifies new maternal risk loci

BACKGROUND

Preterm birth (<37 weeks of gestation) is a major cause of neonatal death and morbidity. Up to 40% of the variation in timing of birth results from genetic factors, mostly due to the maternal genome.

METHODS

We conducted a genome-wide meta-analysis of gestational duration and spontaneous preterm birth in 68,732 and 98,370 European mothers, respectively.

RESULTS

The meta-analysis detected 15 loci associated with gestational duration, and four loci associated with preterm birth. Seven of the associated loci were novel. The loci mapped to several biologically plausible genes, for example HAND2 whose expression was previously shown to decrease during gestation, associated with gestational duration, and GC (Vitamin D-binding protein), associated with preterm birth. Downstream in silico-analysis suggested regulatory roles as underlying mechanisms for the associated loci. LD score regression found birth weight measures as the most strongly correlated traits, highlighting the unique nature of spontaneous preterm birth phenotype. Tissue expression and colocalization analysis revealed reproductive tissues and immune cell types as the most relevant sites of action.

CONCLUSION

We report novel genetic risk loci that associate with preterm birth or gestational duration, and reproduce findings from previous genome-wide association studies. Altogether, our findings provide new insight into the genetic background of preterm birth. Better characterization of the causal genetic mechanisms will be important to public health as it could suggest new strategies to treat and prevent preterm birth.

Biallelic variants in CRIPT cause a Rothmund-Thomson-like syndrome with increased cellular senescence

PURPOSE

Rothmund-Thomson syndrome (RTS) is characterized by poikiloderma, sparse hair, small stature, skeletal defects, cancer, and cataracts, resembling features of premature aging. RECQL4 and ANAPC1 are the 2 known disease genes associated with RTS in >70% of cases. We describe RTS-like features in 5 individuals with biallelic variants in CRIPT (OMIM 615789).

METHODS

Two newly identified and 4 published individuals with CRIPT variants were systematically compared with those with RTS using clinical data, computational analysis of photographs, histologic analysis of skin, and cellular studies on fibroblasts.

RESULTS

All CRIPT individuals fulfilled the diagnostic criteria for RTS and additionally had neurodevelopmental delay and seizures. Using computational gestalt analysis, CRIPT individuals showed greatest facial similarity with individuals with RTS. Skin biopsies revealed a high expression of senescence markers (p53/p16/p21) and the senescence-associated ß-galactosidase activity was elevated in CRIPT-deficient fibroblasts. RECQL4- and CRIPT-deficient fibroblasts showed an unremarkable mitotic progression and unremarkable number of mitotic errors and no or only mild sensitivity to genotoxic stress by ionizing radiation, mitomycin C, hydroxyurea, etoposide, and potassium bromate.

CONCLUSION

CRIPT causes an RTS-like syndrome associated with neurodevelopmental delay and epilepsy. At the cellular level, RECQL4- and CRIPT-deficient cells display increased senescence, suggesting shared molecular mechanisms leading to the clinical phenotypes.

A prognostic model based on the Augmin family genes for LGG patients

Gliomas are the most prevalent primary tumors in the central nervous system. Despite some breakthroughs in the treatment of glioma in recent years, survival rates remain low. Although genes of the Augmin family play a key role in microtubule nucleation, the role they play in gliomas is unclear. Transcriptome data were extracted from UCSC XENA and GTEx for low-grade glioma (LGG) and normal tissues, respectively. The protein interaction network associated with Augmin family genes was established using STRING and GeneMANIA databases. Enrichment analysis of gene-related functions and pathways was used to explore potential biological pathways and TIMER to assess immune cell infiltration. Regression analysis and Kaplan-Meier analysis were used to look at the clinical characteristics of the Augmin family genes and the association with the prognosis of patients with glioma. The results showed that the mRNA expression of Augmin family genes was significantly elevated in LGG tissues, except for HAUS7. Immunoregulation, cell cycle, apoptosis and other signaling pathways may be involved in the development and progression of LGG. Except for HAUS4 and HAUS7, the expression of all genes was positively correlated with immune cell infiltration. High expression of HAUS1, HAUS3, HAUS5, HAUS7, HAUS8 and low expression of HAUS4, HAUS6 in LGG was associated with poor prognosis. The risk models constructed based on the pivotal genes HAUS2, HAUS4 and HAUS8 were validated by nomogram and confirmed to be clinically useful for predicting the prognosis of LGG.

Involvement of Bcl-2 Family Proteins in Tetraploidization-Related Senescence

The B-cell lymphoma 2 (Bcl-2) family of proteins is the main regulator of apoptosis. However, multiple emerging evidence has revealed that Bcl-2 family proteins are also involved in cellular senescence. On the one hand, the different expression of these proteins determines the entry into senescence. On the other hand, entry into senescence modulates the expression of these proteins, generally conferring resistance to apoptosis. With some exceptions, senescent cells are characterized by the upregulation of antiapoptotic proteins and downregulation of proapoptotic proteins. Under physiological conditions, freshly formed tetraploid cells die by apoptosis due to the tetraploidy checkpoint. However, suppression of Bcl-2 associated x protein (Bax), as well as overexpression of Bcl-2, favors the appearance and survival of tetraploid cells. Furthermore, it is noteworthy that our laboratory has shown that the joint absence of Bax and Bcl-2 antagonist/killer (Bak) favors the entry into senescence of tetraploid cells. Certain microtubule inhibitory chemotherapies, such as taxanes and vinca alkaloids, induce the generation of tetraploid cells. Moreover, the combined use of inhibitors of antiapoptotic proteins of the Bcl-2 family with microtubule inhibitors increases their efficacy. In this review, we aim to shed light on the involvement of the Bcl-2 family of proteins in the senescence program activated after tetraploidization and the possibility of using this knowledge to create a new therapeutic strategy targeting cancer cells.

Metabolism-related signatures is correlated with poor prognosis and immune infiltration in hepatocellular carcinoma via multi-omics analysis and basic experiments

Background

Metabolism is an ordered series of biological processes that occur in an organism. Altered cellular metabolism is often closely associated with the development of cancer. The aim of this research was to construct a model by multiple metabolism-related molecules to diagnose and assess the prognosis of patients.

Method

WGCNA analysis was used to screen out differential genes. GO, KEGG are used to explore potential pathways and mechanisms. The lasso regression model was used to filter out the best indicators to construct the model. Single-sample GSEA (ssGSEA) assess immune cells abundance, immune terms in different Metabolism Index (MBI) groups. Human tissues and cells were used to verify the expression of key genes.

Result

WGCNA clustering grouped genes into 5 modules, of which 90 genes from the MEbrown module were selected for subsequent analysis. GO analysis was found that BP mainly has mitotic nuclear division, while KEGG pathway is enriched to Cell cycle, Cellular senescence. Mutation analysis revealed that the frequency of TP53 mutations was much higher in samples from the high MBI group than in the low MBI group. Immunoassay revealed that patients with higher MBI have higher macrophage and Regulatory T cells (Treg) abundance, while NK cells were lowly expressed in the high MBI group. RT-qPCR and immunohistochemistry (IHC) revealed that the hub genes expression is higher in cancer tissues. The expression in hepatocellular carcinoma cells was also much higher than that in normal hepatocytes.

Conclusion

In conclusion, a metabolism-related model was constructed that can be used to estimate the prognosis of hepatocellular carcinoma, and the clinical treatment of different hepatocellular carcinoma patients with medications was guided.

Apoptosis as a Barrier against CIN and Aneuploidy

Aneuploidy is the gain or loss of entire chromosomes, chromosome arms or fragments. Over 100 years ago, aneuploidy was described to be a feature of cancer and is now known to be present in 68-90% of malignancies. Aneuploidy promotes cancer growth, reduces therapy response and frequently worsens prognosis. Chromosomal instability (CIN) is recognized as the main cause of aneuploidy. CIN itself is a dynamic but stochastic process consisting of different DNA content-altering events. These can include impaired replication fidelity and insufficient clearance of DNA damage as well as chromosomal mis-segregation, micronuclei formation, chromothripsis or cytokinesis failure. All these events can disembogue in segmental, structural and numerical chromosome alterations. While low levels of CIN can foster malignant disease, high levels frequently trigger cell death, which supports the "aneuploidy paradox" that refers to the intrinsically negative impact of a highly aberrant karyotype on cellular fitness. Here, we review how the cellular response to CIN and aneuploidy can drive the clearance of karyotypically unstable cells through the induction of apoptosis. Furthermore, we discuss the different modes of p53 activation triggered in response to mitotic perturbations that can potentially trigger CIN and/or aneuploidy.

Machine learning identifies exosome features related to hepatocellular carcinoma

Background: Hepatocellular carcinoma (HCC) is one of the most malignant tumors with a poor prognosis. There is still a lack of effective biomarkers to predict its prognosis. Exosomes participate in intercellular communication and play an important role in the development and progression of cancers.

Methods: In this study, two machine learning methods (univariate feature selection and random forest (RF) algorithm) were used to select 13 exosome-related genes (ERGs) and construct an ERG signature. Based on the ERG signature score and ERG signature-related pathway score, a novel RF signature was generated. The expression of BSG and SFN, members of 13 ERGs, was examined using real-time quantitative polymerase chain reaction and immunohistochemistry. Finally, the effects of the inhibition of BSG and SFN on cell proliferation were examined using the cell counting kit-8 (CCK-8) assays.

Results: The ERG signature had a good predictive performance, and the ERG score was determined as an independent predictor of HCC overall survival. Our RF signature showed an excellent prognostic ability with the area under the curve (AUC) of 0.845 at 1 year, 0.811 at 2 years, and 0.801 at 3 years in TCGA, which was better than the ERG signature. Notably, the RF signature had a good performance in the prediction of HCC prognosis in patients with the high exosome score and high NK score. Enhanced BSG and SFN levels were found in HCC tissues compared with adjacent normal tissues. The inhibition of BSG and SFN suppressed cell proliferation in Huh7 cells.

Conclusion: The RF signature can accurately predict prognosis of HCC patients and has potential clinical value.

Mesenchymal stem cell-derived exosomes in cancer therapy resistance: recent advances and therapeutic potential

Mesenchymal stem cells (MSCs) are multipotent stromal cells that can be obtained from various human tissues and organs. They can differentiate into a wide range of cell types, including osteoblasts, adipocytes and chondrocytes, thus exhibiting great potential in regenerative medicine. Numerous studies have indicated that MSCs play critical roles in cancer biology. The crosstalk between tumour cells and MSCs has been found to regulate many tumour behaviours, such as proliferation, metastasis and epithelial-mesenchymal transition (EMT). Multiple lines of evidence have demonstrated that MSCs can secrete exosomes that can modulate the tumour microenvironment and play important roles in tumour development. Notably, very recent works have shown that mesenchymal stem cell-derived exosomes (MSC-derived exosomes) are critically involved in cancer resistance to chemotherapy agents, targeted-therapy drugs, radiotherapy and immunotherapy. In this review, we systematically summarized the emerging roles and detailed molecular mechanisms of MSC-derived exosomes in mediating cancer therapy resistance, thus providing novel insights into the clinical applications of MSC-derived exosomes in cancer management.

CDC20-Mediated hnRNPU Ubiquitination Regulates Chromatin Condensation and Anti-Cancer Drug Response

Cell division cycle 20 (CDC20) functions as a critical cell cycle regulator. It plays an important role in cancer development and drug resistance. However, the molecular mechanisms by which CDC20 regulates cellular drug response remain poorly understood. Chromatin-associated CDC20 interactome in breast cancer cells was analyzed by using affinity purification coupled with mass spectrometry. hnRNPU as a CDC20 binding partner was validated by co-immunoprecipitation and immunostaining. The molecular domain, comprising amino acid residues 461-653, on hnRNPU required for its interaction with CDC20 was identified by mapping of interactions. Co-immunoprecipitation showed that CDC20-mediated hnRNPU ubiquitination promotes its interaction with the CTCF and cohesin complex. The effects of CDC20-hnRNPU on nuclear size and chromatin condensation were investigated by analyzing DAPI and H2B-mCherry staining, respectively. The role of CDC20-hnRNPU in tumor progression and drug resistance was examined by CCK-8 cell survival and clonogenic assays. Our study indicates that CDC20-mediated ubiquitination of hnRNPU modulates chromatin condensation by regulating the interaction between hnRNPU and the CTCF-cohesin complex. Dysregulation of the CDC20-hnRNPU axis contributes to tumor progression and drug resistance.

Long non-coding RNA PVT1: A promising chemotherapy and radiotherapy sensitizer

The long non-coding RNA (lncRNA) PVT1 was first found to activate variant translocations in the plasmacytoma of mice. Human lncPVT1 is located on chromosome 8q24.21, at the same locus as the well-known MYC oncogene. LncPVT1 has been found to promote the progression of various malignancies. Chemoresistance and radioresistance seriously affect tumor treatment efficacy and are associated with the dysregulation of physiological processes in cancer cells, including apoptosis, autophagy, stemness (for cancer stem cells, CSC), hypoxia, epithelial–mesenchymal transition (EMT), and DNA damage repair. Previous studies have also implicated lncPVT1 in the regulation of these physiological mechanisms. In recent years, lncPVT1 was found to modulate chemoresistance and radioresistance in some cancers. In this review, we discuss the mechanisms of lncPVT1-mediated regulation of cellular chemoresistance and radioresistance. Due to its high expression in malignant tumors and sensitization effect in chemotherapy and radiotherapy, lncPVT1 is expected to become an effective antitumor target and chemotherapy and radiotherapy sensitizer, which requires further study.

Insight and Recent Advances into the Role of Topography on the Cell Differentiation and Proliferation on Biopolymeric Surfaces

It is well known that surface topography plays an important role in cell behavior, including adhesion, migration, orientation, elongation, proliferation and differentiation. Studying these cell functions is essential in order to better understand and control specific characteristics of the cells and thus to enhance their potential in various biomedical applications. This review proposes to investigate the extent to which various surface relief patterns, imprinted in biopolymer films or in polymeric films coated with biopolymers, by utilizing specific lithographic techniques, influence cell behavior and development. We aim to understand how characteristics such as shape, dimension or chemical functionality of surface relief patterns alter the orientation and elongation of cells, and thus, finally make their mark on the cell proliferation and differentiation. We infer that such an insight is a prerequisite for pushing forward the comprehension of the methodologies and technologies used in tissue engineering applications and products, including skin or bone implants and wound or fracture healing.

Reconstitution of kinetochore motility and microtubule dynamics reveals a role for a kinesin-8 in establishing end-on attachments

During mitosis, individual microtubules make attachments to chromosomes via a specialized protein complex called the kinetochore to faithfully segregate the chromosomes to daughter cells. Translocation of kinetochores on the lateral surface of the microtubule has been proposed to contribute to high fidelity chromosome capture and alignment at the mitotic midzone, but has been difficult to observe in vivo because of spatial and temporal constraints. To overcome these barriers, we used total internal reflection fluorescence (TIRF) microscopy to track the interactions between microtubules, kinetochore proteins, and other microtubule-associated proteins in lysates from metaphase-arrested Saccharomyces cerevisiae. TIRF microscopy and cryo-correlative light microscopy and electron tomography indicated that we successfully reconstituted interactions between intact kinetochores and microtubules. These kinetochores translocate on the lateral microtubule surface toward the microtubule plus end and transition to end-on attachment, whereupon microtubule depolymerization commences. The directional kinetochore movement is dependent on the highly processive kinesin-8, Kip3. We propose that Kip3 facilitates stable kinetochore attachment to microtubule plus ends through its abilities to move the kinetochore laterally on the surface of the microtubule and to regulate microtubule plus end dynamics.

Minnelide synergizes with conventional chemotherapy by targeting both cancer and associated stroma components in pancreatic cancer

Addition of nab-paclitaxel to gemcitabine offers a survival benefit of only 6 weeks over gemcitabine alone at a cost of increased toxicity in PDAC. The goal of the present study is to evaluate the efficacy of Minnelide, a water-soluble prodrug of triptolide, in combination with the standard of care regimen for chemotherapy with the added advantage of reducing the doses of these drugs to minimize toxicity. Pancreatic cancer cell lines were implanted subcutaneously or orthotopically in athymic nude or C57BL/6J mice. Subsequently, animals were randomized and received saline or minnelide or full dose chemotherapy or low dose chemotherapy or minnelide in combination with low dose chemotherapy. Our results show that a combination of low doses of Minnelide with Gemcitabine + nab-paclitaxel significantly inhibited tumor progression and increased the survival of tumor-bearing mice in comparison with conventional chemotherapy alone. Moreover, combination therapy significantly reduced cancer-related morbidity by decreasing ascites and metastasis and effectively targeted both cancer and the associated stroma. In vitro studies with a combination of low doses of triptolide and paclitaxel significantly decreased the cell viability, increased apoptosis and led to significantly increased M-phase cell cycle arrest in various pancreatic cancer cell lines as compared to either drug alone. Our results show that Minnelide synergizes with conventional chemotherapy leading to a significant reduction in the doses of these toxic drugs, all the while achieving better efficacy in the treatment of PDAC. This combination effectively targeted both the cancer and the associated stromal components of pancreatic cancer.

Primary acute lymphoblastic leukemia cells are susceptible to microtubule depolymerization in G1 and M phases through distinct cell death pathways

Microtubule targeting agents (MTAs) are widely used cancer chemotherapeutics which conventionally exert their effects during mitosis, leading to mitotic or postmitotic death. However, accumulating evidence suggests that MTAs can also generate death signals during interphase, which may represent a key mechanism in the clinical setting. We reported previously that vincristine and other microtubule destabilizers induce death not only in M phase but also in G1 phase in primary acute lymphoblastic leukemia cells. Here, we sought to investigate and compare the pathways responsible for phase-specific cell death. Primary acute lymphoblastic leukemia cells were subjected to centrifugal elutriation, and cell populations enriched in G1 phase (97%) or G2/M phases (80%) were obtained and treated with vincristine. We found death of M phase cells was associated with established features of mitochondrial-mediated apoptosis, including Bax activation, loss of mitochondrial transmembrane potential, caspase-3 activation, and nucleosomal DNA fragmentation. In contrast, death of G1 phase cells was not associated with pronounced Bax or caspase-3 activation but was associated with loss of mitochondrial transmembrane potential, parylation, nuclear translocation of apoptosis-inducing factor and endonuclease G, and supra-nucleosomal DNA fragmentation, which was enhanced by inhibition of autophagy. The results indicate that microtubule depolymerization induces distinct cell death pathways depending on during which phase of the cell cycle microtubule perturbation occurs. The observation that a specific type of drug can enter a single cell type and induce two different modes of death is novel and intriguing. These findings provide a basis for advancing knowledge of clinical mechanisms of MTAs.

Emerging roles of mitotic autophagy

Lysosomes exert pleiotropic functions to maintain cellular homeostasis and degrade autophagy cargo. Despite the great advances that have boosted our understanding of autophagy and lysosomes in both physiology and pathology, their function in mitosis is still controversial. During mitosis, most organelles are reshaped or repurposed to allow the correct distribution of chromosomes. Mitotic entry is accompanied by a reduction in sites of autophagy initiation, supporting the idea of an inhibition of autophagy to protect the genetic material against harmful degradation. However, there is accumulating evidence revealing the requirement of selective autophagy and functional lysosomes for a faithful chromosome segregation. Degradation is the most-studied lysosomal activity, but recently described alternative functions that operate in mitosis highlight the lysosomes as guardians of mitotic progression. Because the involvement of autophagy in mitosis remains controversial, it is important to consider the specific contribution of signalling cascades, the functions of autophagic proteins and the multiple roles of lysosomes, as three entangled, but independent, factors controlling genomic stability. In this Review, we discuss the latest advances in this area and highlight the therapeutic potential of targeting autophagy for drug development.

Gastric cancer biomarker analysis in patients treated with different adjuvant chemotherapy regimens within SAMIT, a phase III randomized controlled trial

Biomarkers for selecting gastric cancer (GC) patients likely to benefit from sequential paclitaxel treatment followed by fluorinated-pyrimidine-based adjuvant chemotherapy (sequential paclitaxel) were investigated using tissue samples of patients recruited into SAMIT, a phase III randomized controlled trial. Total RNA was extracted from 556 GC resection samples. The expression of 105 genes was quantified using real-time PCR. Genes predicting the benefit of sequential paclitaxel on overall survival, disease-free survival, and cumulative incidence of relapse were identified based on the ranking of p-values associated with the interaction between the biomarker and sequential paclitaxel or monotherapy groups. Low VSNL1 and CD44 expression predicted the benefit of sequential paclitaxel treatment for all three endpoints. Patients with combined low expression of both genes benefitted most from sequential paclitaxel therapy (hazard ratio = 0.48 [95% confidence interval, 0.30-0.78]; p < 0.01; interaction p-value < 0.01). This is the first study to identify VSNL1 and CD44 RNA expression levels as biomarkers for selecting GC patients that are likely to benefit from sequential paclitaxel treatment followed by fluorinated-pyrimidine-based adjuvant chemotherapy. Our findings may facilitate clinical trials on biomarker-oriented postoperative adjuvant chemotherapy for patients with locally advanced GC.

Targeting nucleotide metabolism: a promising approach to enhance cancer immunotherapy

Targeting nucleotide metabolism can not only inhibit tumor initiation and progression but also exert serious side effects. With in-depth studies of nucleotide metabolism, our understanding of nucleotide metabolism in tumors has revealed their non-proliferative effects on immune escape, indicating the potential effectiveness of nucleotide antimetabolites for enhancing immunotherapy. A growing body of evidence now supports the concept that targeting nucleotide metabolism can increase the antitumor immune response by (1) activating host immune systems via maintaining the concentrations of several important metabolites, such as adenosine and ATP, (2) promoting immunogenicity caused by increased mutability and genomic instability by disrupting the purine and pyrimidine pool, and (3) releasing nucleoside analogs via microbes to regulate immunity. Therapeutic approaches targeting nucleotide metabolism combined with immunotherapy have achieved exciting success in preclinical animal models. Here, we review how dysregulated nucleotide metabolism can promote tumor growth and interact with the host immune system, and we provide future insights into targeting nucleotide metabolism for immunotherapeutic treatment of various malignancies.

Research progress on antineoplastic, antibacterial, and anti-inflammatory activities of seven-membered heterocyclic derivatives

Abstract:

Seven-membered heterocyclic compounds are important drug scaffolds, because of their unique chemical structures. They widely exist in natural products and show a variety of biological activities. They have commonly been used in central nervous system drugs in the past 30 years. In the past decade, there are many studies on the activities of antitumor, antibacterial, etc. Herein, we summarize the research advances in different kinds of seven-membered heterocyclic compounds containing nitrogen, oxygen, and sulfur heteroatoms with antitumor, antisepsis, and anti-inflammation activities in the past ten years, which is expected to be beneficial to the development and design of novel drugs for the corresponding indications.

Paclitaxel resistance is mediated by NF-κB on mesenchymal primary breast cancer cells

Paclitaxel has been used widely to treat breast cancer and other types of cancer. However, resistance is a major cause of failure for treatment and results in cancer progression. The present study investigated the association between paclitaxel resistance and the mesenchymal phenotype, using a model of primary breast cancer cells and employing four different cultures, two with an epithelial phenotype (MBCDF and MBCD17) and two with a mesenchymal phenotype (MBCDF-D5 and MBCD3). Epithelial-mesenchymal markers were evaluated by western blotting; MBCDF and MBCD17 cells expressed E-cadherin, SNAIL, Slug, and Twist, low levels of N-cadherin, but not vimentin. MBCDF-D5 and MBCD3 cells expressed N-cadherin, vimentin, and higher levels of SNAIL, and low levels of E-cadherin, Slug, and Twist. Cell viability was evaluated using a crystal violet assay after paclitaxel treatment; primary breast cancer cells with mesenchymal phenotype were resistant to paclitaxel compared with the epithelial primary breast cancer cells. Furthermore, using western blotting, it was revealed that mesenchymal cells had elevated levels of nuclear factor-κΒ (NF-κB) p65 and IκB kinase (IKK). Additionally, it was demonstrated that paclitaxel-induced degradation of the inhibitor of NF-κB, activation of NF-κB in a dose-dependent manner, and Bcl-2 and Bcl-xL upregulation. Finally, employing western blotting and crystal violet assays, the effects of the proteasome inhibitor ALLN were assessed. ALLN inhibited paclitaxel-induced NF-κB activation and restored the sensitivity to paclitaxel. Together, these data suggest that targeting the NF-κB/IKK axis might be a promising strategy to overcome paclitaxel resistance.

Polo-Like Kinase 1 Regulates Chromosomal Instability and Paclitaxel Resistance in Breast Cancer Cells

Purpose

Chromosomal instability (CIN) contributes to intercellular genetic heterogeneity and has been implicated in paclitaxel (PTX) resistance in breast cancer. In this study, we explored polo-like kinase 1 (PLK1) as an important regulator of mitotic integrity and as a useful predictive biomarker for PTX resistance in breast cancer.

Methods

We performed PTX resistance screening using the human kinome CRISPR/Cas9 library in breast cancer cells. In vitro cell proliferation and apoptosis assays and in vivo xenograft experiments were performed to determine the effects of PLK1 on breast cancer cells. Immunofluorescence microscopy was used to measure the degree of multipolar cell division.

Results

Kinome-wide CRISPR/Cas9 screening identified various kinases involved in PTX resistance in breast cancer cells; among these, PLK1 was chosen for further experiments. PLK1 knockdown inhibited the proliferation of MDA-MB-231 and MDA-MB-468 cells in vitro and in vivo. Moreover, PLK1 silencing sensitized breast cancer cells and mouse xenograft tumor models to PTX cytotoxicity. Silencing of PLK1 induced the formation of multipolar spindles and increased the percentage of multipolar cells. In addition, PLK1 silencing resulted in the downregulation of BubR1 and Mad2 in breast cancer cells. Furthermore, PLK1 upregulation in primary breast cancer was associated with decreased overall patient survival based on the analysis of The Cancer Genome Atlas and Molecular Taxonomy of Breast Cancer International Consortium databases.

Conclusion

PLK1 plays an important role in PTX resistance by regulating CIN in breast cancer cells. Targeting PLK1 may be an effective treatment strategy for PTX-resistant breast cancers.

Indolin-2-one derivatives as selective Aurora B kinase inhibitors targeting breast cancer

Aurora B is a pivotal cell cycle regulator where errors in its function results in polyploidy, genetic instability, and tumorigenesis. It is overexpressed in many cancers, consequently, targeting Aurora B with small molecule inhibitors constitutes a promising approach for anticancer therapy. Guided by structure-based design and molecular hybridization approach we developed a series of fifteen indolin-2-one derivatives based on a previously reported indolin-2-one-based multikinase inhibitor (1). Seven derivatives, 5g, 6a, 6c-e, 7, and 8a showed preferential antiproliferative activity in NCI-60 cell line screening and out of these, carbamate 6e and cyclopropylurea 8a derivatives showed optimum activity against Aurora B (IC₅₀ = 16.2 and 10.5 nM respectively) and MDA-MB-468 cells (IC₅₀ = 32.6 ± 9.9 and 29.1 ± 7.3 nM respectively). Furthermore, 6e and 8a impaired the clonogenic potential of MDA-MB-468 cells. Mechanistic investigations indicated that 6e and 8a induced G2/M cell cycle arrest, apoptosis, and necrosis of MDA-MB-468 cells and western blot analysis of 8a effect on MDA-MB-468 cells revealed 8a's ability to reduce Aurora B and its downstream target, Histone H3 phosphorylation. 6e and 8a displayed better safety profiles than multikinase inhibitors such as sunitinib, showing no cytotoxic effects on normal rat cardiomyoblasts and murine hepatocytes. Finally, 8a demonstrated a more selective profile than 1 when screened against ten related kinases. Based on these findings, 8a represents a promising candidate for further development to target breast cancer via Aurora B selective inhibition.

Phosphoproteomics Provides Novel Insights into the Response of Primary Acute Lymphoblastic Leukemia Cells to Microtubule Depolymerization in G1 Phase of the Cell Cycle

Microtubule targeting agents (MTAs) have been used for the treatment of cancer for many decades and are among the most successful chemotherapeutic agents. However, their application and effectiveness are limited because of toxicity and resistance as well as a lack of knowledge of molecular mechanisms downstream of microtubule inhibition. Insights into key pathways that link microtubule disruption to cell death is critical for optimal use of these drugs, for defining biomarkers useful in patient stratification, and for informed design of drug combinations. Although MTAs characteristically induce death in mitosis, microtubule destabilizing agents such as vincristine also induce death directly in G1 phase in primary acute lymphoblastic leukemia (ALL) cells. Because many signaling pathways regulating cell survival and death involve changes in protein expression and phosphorylation, we undertook a comprehensive quantitative proteomic study of G1 phase ALL cells treated with vincristine. The results revealed distinct alterations associated with c-Jun N-terminal kinase signaling, anti-proliferative signaling, the DNA damage response, and cytoskeletal remodeling. Signals specifically associated with cell death were identified by pre-treatment with the CDK4/6 inhibitor palbociclib, which caused G1 arrest and precluded death induction. These results provide insights into signaling mechanisms regulating cellular responses to microtubule inhibition and provide a foundation for a better understanding of the clinical mechanisms of MTAs and for the design of novel drug combinations. The mass spectrometry proteomics data have been deposited to the PRIDE Archive (http://www.ebi.ac.uk/pride/archive/) via the PRIDE partner repository with the data set identifier PXD027190 and 10.6019/PXD027190.

Curcumin Reduces Colorectal Cancer Cell Proliferation and Migration and Slows In Vivo Growth of Liver Metastases in Rats

Background: New therapeutic approaches are an essential need for patients suffering from colorectal cancer liver metastases. Curcumin, a well-known plant-derived polyphenol, has been shown to play a role in the modulation of multiple signaling pathways involved in the development and progression of certain cancer cells in vitro. This study aims to assess the anti-tumor effect of curcumin on CC531 colorectal cancer cells, both in vitro and in vivo. Methods: On CC531 cultures, the cell viability and cell migration capacity were analyzed (wound healing test) 24, 48, and 72 h after treatment with curcumin (15, 20, 25, or 30 µM). Additionally, in WAG/RijHsd tumor-bearing rats, the total and individual liver lobe tumor volume was quantified in untreated and curcumin-treated animals (200 mg/kg/day, oral). Furthermore, serum enzyme measurements (GOT, GPT, glucose, bilirubin, etc.) were carried out to assess the possible effects on the liver function. Results: In vitro studies showed curcumin’s greatest effects 48h after application, when all of the tested doses reduced cell proliferation by more than 30%. At 72 h, the highest doses of curcumin (25 and 30 µM) reduced cell viability to less than 50%. The wound healing test also showed that curcumin inhibits migration capacity. In vivo, curcumin slowed down the tumor volume of liver implants by 5.6-fold (7.98 ± 1.45 vs. 1.41 ± 1.33; p > 0.0001). Conclusions: Curcumin has shown an anti-tumor effect against liver implants from colorectal cancer, both in vitro and in vivo, in this experimental model.

M2 Muscarinic Receptor Activation Impairs Mitotic Progression and Bipolar Mitotic Spindle Formation in Human Glioblastoma Cell Lines

Background: Glioblastoma multiforme (GBM) is characterized by several genetic abnormalities, leading to cell cycle deregulation and abnormal mitosis caused by a defective checkpoint. We previously demonstrated that arecaidine propargyl ester (APE), an orthosteric agonist of M2 muscarinic acetylcholine receptors (mAChRs), arrests the cell cycle of glioblastoma (GB) cells, reducing their survival. The aim of this work was to better characterize the molecular mechanisms responsible for this cell cycle arrest. Methods: The arrest of cell proliferation was evaluated by flow cytometry analysis. Using immunocytochemistry and time-lapse analysis, the percentage of abnormal mitosis and aberrant mitotic spindles were assessed in both cell lines. Western blot analysis was used to evaluate the modulation of Sirtuin2 and acetylated tubulin—factors involved in the control of cell cycle progression. Results: APE treatment caused arrest in the M phase, as indicated by the increase in p-HH3 (ser10)-positive cells. By immunocytochemistry, we found a significant increase in abnormal mitoses and multipolar mitotic spindle formation after APE treatment. Time-lapse analysis confirmed that the APE-treated GB cells were unable to correctly complete the mitosis. The modulated expression of SIRT2 and acetylated tubulin in APE-treated cells provides new insights into the mechanisms of altered mitotic progression in both GB cell lines. Conclusions: Our data show that the M2 agonist increases aberrant mitosis in GB cell lines. These results strengthen the idea of considering M2 acetylcholine receptors a novel promising therapeutic target for the glioblastoma treatment.

Survival prediction based on the gene expression associated with cancer morphology and microenvironment in primary central nervous system lymphoma

Dysregulation of cell morphology and cell-cell interaction results in cancer cell growth, migration, invasion, and metastasis. Besides, a balance between the extracellular matrix (ECM) and matrix metalloprotease (MMP) is required for cancer cell morphology and angiogenesis. Here, we determined gene signatures associated with the morphology and microenvironment of primary central nervous system lymphoma (PCNSL) to enable prognosis prediction. Next-generation sequencing (NGS) on 31 PCNSL samples revealed gene signatures as follows: ACTA2, ACTR10, CAPG, CORO1C, KRT17, and PALLD in cytoskeleton, CDH5, CLSTN1, ITGA10, ITGAX, ITGB7, ITGA8, FAT4, ITGAE, CDH10, ITGAM, ITGB6, and CDH18 in adhesion, COL8A2, FBN1, LAMB3, and LAMA2 in ECM, ADAM22, ADAM28, MMP11, and MMP24 in MMP. Prognosis prediction formulas with the gene expression values and the Cox regression model clearly divided survival curves of the subgroups in each status. Furthermore, collagen genes contributed to gene network formation in glasso, suggesting that the ECM balance controls the PCNSL microenvironment. Finally, the comprehensive balance of morphology and microenvironment enabled prognosis prediction by a combinatorial expression of 8 representative genes, including KRT17, CDH10, CDH18, COL8A2, ADAM22, ADAM28, MMP11, and MMP24. Besides, these genes could also diagnose PCNSL cell types with MTX resistances in vitro. These results would not only facilitate the understanding of biology of PCNSL but also consider targeting pathways for anti-cancer treatment in personalized precision medicine in PCNSL.

FOXM1 repression increases mitotic death upon antimitotic chemotherapy through BMF upregulation

Inhibition of spindle microtubule (MT) dynamics has been effectively used in cancer treatment. Although the mechanisms by which MT poisons elicit mitotic arrest are fairly understood, efforts are still needed towards elucidating how cancer cells respond to antimitotic drugs owing to cytotoxicity and resistance side effects. Here, we identified the critical G2/M transcription factor Forkhead box M1 (FOXM1) as a molecular determinant of cell response to antimitotics. We found FOXM1 repression to increase death in mitosis (DiM) due to upregulation of the BCL-2 modifying factor (BMF) gene involved in anoikis, an apoptotic process induced upon cell detachment from the extracellular matrix. FOXM1 binds to a BMF intronic cis-regulatory element that interacts with both the BMF and the neighbor gene BUB1B promoter regions, to oppositely regulate their expression. This mechanism ensures that cells treated with antimitotics repress BMF and avoid DiM when FOXM1 levels are high. In addition, we show that this mechanism is partly disrupted in anoikis/antimitotics-resistant tumor cells, with resistance correlating with lower BMF expression but in a FOXM1-independent manner. These findings provide a stratification biomarker for antimitotic chemotherapy response.

Morphologic Analysis of Urinary Podocytes in Focal Segmental Glomerulosclerosis

BACKGROUND

The development of glomerulosclerosis in FSGS is associated with a reduction in podocyte number in the glomerular capillary tufts. Although it has been reported that the number of urinary podocytes in FSGS exceeds that of minimal-change nephrotic syndrome, the nature of events that promote podocyte detachment in FSGS remains elusive.

METHODS

In this study, we provide detailed, morphologic analysis of the urinary podocytes found in FSGS by examining the size of the urinary podocytes from patients with FSGS, minimal-change nephrotic syndrome, and GN. In addition, in urinary podocytes from patients with FSGS and minimal-change nephrotic syndrome, we analyzed podocyte hypertrophy and mitotic catastrophe using immunostaining of p21 and phospho-ribosomal protein S6.

RESULTS

The size of the urinary podocytes was strikingly larger in samples obtained from patients with FSGS compared with those with minimal-change nephrotic syndrome and GN (P=0.008). Urinary podocytes from patients with FSGS had a higher frequency of positive immunostaining for p21 (P<0.001) and phospho-ribosomal protein S6 (P=0.02) than those from patients with minimal-change nephrotic syndrome. Characteristic features of mitotic catastrophe were more commonly observed in FSGS than in minimal-change nephrotic syndrome urinary samples (P=0.001).

CONCLUSIONS

We posit that the significant increase in the size of urinary podocytes in FSGS, compared with those in minimal-change nephrotic syndrome, may be explained by hypertrophy and mitotic catastrophe.

Heterogeneous Nuclear Ribonucleoproteins: Implications in Neurological Diseases

Heterogenous nuclear ribonucleoproteins (hnRNPs) are a complex and functionally diverse family of RNA binding proteins with multifarious roles. They are involved, directly or indirectly, in alternative splicing, transcriptional and translational regulation, stress granule formation, cell cycle regulation, and axonal transport. It is unsurprising, given their heavy involvement in maintaining functional integrity of the cell, that their dysfunction has neurological implications. However, compared to their more established roles in cancer, the evidence of hnRNP implication in neurological diseases is still in its infancy. This review aims to consolidate the evidences for hnRNP involvement in neurological diseases, with a focus on spinal muscular atrophy (SMA), Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD), multiple sclerosis (MS), congenital myasthenic syndrome (CMS), and fragile X-associated tremor/ataxia syndrome (FXTAS). Understanding more about hnRNP involvement in neurological diseases can further elucidate the pathomechanisms involved in these diseases and perhaps guide future therapeutic advances.

The Mad2-Binding Protein p31comet as a Potential Target for Human Cancer Therapy

The spindle assembly checkpoint (SAC) is a surveillance mechanism that prevents mitotic exit at the metaphase-to-anaphase transition until all chromosomes have established correct bipolar attachment to spindle microtubules. Activation of SAC relies on the assembly of the mitotic checkpoint complex (MCC), which requires conformational change from inactive open Mad2 (OMad2) to the active closed Mad2 (C-Mad2) at unattached kinetochores. The Mad2-binding protein p31^comet plays a key role in controlling timely mitotic exit by promoting SAC silencing, through preventing Mad2 activation and promoting MCC disassembly. Besides, increasing evidences highlight the p31^comet potential as target for cancer therapy. Here, we provide an updated overview of the functional significance of p31^comet in mitotic progression, and discuss the potential of deregulated expression of p31^comet in cancer and in therapeutic strategies.

Depletion of Survivin suppresses docetaxel-induced apoptosis in HeLa cells by facilitating mitotic slippage

The anticancer effects of taxanes are attributed to the induction of mitotic arrest through activation of the spindle assembly checkpoint. Cell death following extended mitotic arrest is mediated by the intrinsic apoptosis pathway. Accordingly, factors that influence the robustness of mitotic arrest or disrupt the apoptotic machinery confer drug resistance. Survivin is an inhibitor of apoptosis protein. Its overexpression is associated with chemoresistance, and its targeting leads to drug sensitization. However, Survivin also acts specifically in the spindle assembly checkpoint response to taxanes. Hence, the failure of Survivin-depleted cells to arrest in mitosis may lead to taxane resistance. Here we show that Survivin depletion protects HeLa cells against docetaxel-induced apoptosis by facilitating mitotic slippage. However, Survivin depletion does not promote clonogenic survival of tumor cells but increases the level of cellular senescence induced by docetaxel. Moreover, lentiviral overexpression of Survivin does not provide protection against docetaxel or cisplatin treatment, in contrast to the anti-apoptotic Bcl-xL or Bcl-2. Our findings suggest that targeting Survivin may influence the cell response to docetaxel by driving the cells through aberrant mitotic progression, rather than directly sensitizing cells to apoptosis.

CentTracker: a trainable, machine-learning-based tool for large-scale analyses of Caenorhabditis elegans germline stem cell mitosis

Investigating the complex interactions between stem cells and their native environment requires an efficient means to image them in situ. Caenorhabditis elegans germline stem cells (GSCs) are distinctly accessible for intravital imaging; however, long-term image acquisition and analysis of dividing GSCs can be technically challenging. Here we present a systematic investigation into the technical factors impacting GSC physiology during live imaging and provide an optimized method for monitoring GSC mitosis under minimally disruptive conditions. We describe CentTracker, an automated and generalizable image analysis tool that uses machine learning to pair mitotic centrosomes and that can extract a variety of mitotic parameters rapidly from large-scale data sets. We employ CentTracker to assess a range of mitotic features in a large GSC data set. We observe spatial clustering of mitoses within the germline tissue but no evidence that subpopulations with distinct mitotic profiles exist within the stem cell pool. We further find biases in GSC spindle orientation relative to the germline’s distal–proximal axis and thus the niche. The technical and analytical tools provided herein pave the way for large-scale screening studies of multiple mitotic processes in GSCs dividing in situ, in an intact tissue, in a living animal, under seemingly physiological conditions.

Gene Expression Changes and Associated Pathways Involved in the Progression of Prostate Cancer Advanced Stages

Prostate cancer (PC) is one of the most common cancers among men worldwide, and advanced PCs, such as locally advanced PC (LAPC) and castration-resistant PC (CRPC), present the greatest challenges in clinical management. Current indicators have limited capacity to predict the disease course; therefore, better prognostic markers are greatly needed. In this study, we performed a bioinformatic analysis of The Cancer Genome Atlas (TCGA) datasets, including RNA-Seq data from the prostate adenocarcinoma (PRAD; n = 55) and West Coast Dream Team – metastatic CRPC (WCDT-MCRPC; n = 84) projects, to evaluate the transcriptome changes associated with progression-free survival (PFS) for LAPC and CRPC, respectively. We identified the genes whose expression was positively/negatively correlated with PFS. In LAPC, the genes with the most significant negative correlations were ZC2HC1A, SQLE, and KIF11, and the genes with the most significant positive correlations were SOD3, LRRC26, MIR22HG, MEG3, and MIR29B2CHG. In CRPC, the most significant positive correlations were found for BET1, CTAGE5, IFNGR1, and GIMAP6, and the most significant negative correlations were found for CLPB, PRPF19, ZNF610, MPST, and LINC02001. In addition, we performed a gene network interaction analysis using STRINGdb, which revealed a significant relationship between genes predominantly involved in the cell cycle and characterized by upregulated expression in early recurrence. Based on the results, we propose several genes that can be used as potential prognostic markers.

10-(4-Phenylpiperazine-1-carbonyl)acridin-9(10H)-ones and related compounds: Synthesis, antiproliferative activity and inhibition of tubulin polymerization

As part of our continuing search for potent inhibitors of tubulin polymerization, two novel series of 42 10-(4-phenylpiperazine-1-carbonyl)acridin-9(10H)-ones and N-benzoylated acridones were synthesized on the basis of a retrosynthetic approach. All newly synthesized compounds were tested for antiproliferative activity and interaction with tubulin. Several analogs potently inhibited tumor cell growth. Among the compounds tested, 10-(4-(3-methoxyphenyl)piperazine-1-carbonyl)acridin-9(10H)-one (17c) exhibited excellent growth inhibitory effects on 93 tumor cell lines, with an average GI₅₀ value of 5.4 nM. We were able to show that the strong cytotoxic effects are caused by disruption of tubulin polymerization, as supported by the EBI (N,N'-Ethylenebis(iodoacetamide)) assay and the fact that the most potent inhibitors of cancer cell growth turned out to be the most efficacious tubulin polymerization inhibitors. Potencies were nearly comparable or superior to those of the antimitotic reference compounds. Closely related to this, the most active analogs inhibited cell cycling at the G2/M phase at concentrations down to 30 nM and induced apoptosis in K562 leukemia cells. We believe that our work not only proves the excellent suitability of the acridone scaffold for the design of potent tubulin polymerization inhibitors but also enables synthetic access to further potentially interesting N-acylated acridones.

Identification of Potential Diagnostic and Prognostic Biomarkers for Colorectal Cancer Based on GEO and TCGA Databases

Colorectal cancer (CRC) is one of the most common neoplastic diseases worldwide. With a high recurrence rate among all cancers, treatment of CRC only improved a little over the last two decades. The mortality and morbidity rates can be significantly lessened by earlier diagnosis and prompt treatment. Available biomarkers are not sensitive enough for the diagnosis of CRC, whereas the standard diagnostic method, endoscopy, is an invasive test and expensive. Hence, seeking the diagnostic and prognostic biomarkers of CRC is urgent and challenging. With that order, we screened the overlapped differentially expressed genes (DEGs) of GEO (GSE110223, GSE110224, GSE113513) and TCGA datasets. Subsequent protein-protein interaction network analysis recognized the hub genes among these DEGs. Further functional analyses including Gene Ontology and KEGG pathway analysis and gene set enrichment analysis were processed to investigate the role of these genes and potential underlying mechanisms in CRC. Kaplan-Meier analysis and Cox hazard ratio analysis were carried out to clarify the diagnostic and prognostic role of these genes. In conclusion, our present study demonstrated that CCNA2, MAD2L1, DLGAP5, AURKA, and RRM2 are all potential diagnostic biomarkers for CRC and may also be potential treatment targets for clinical implication in the future.

Taxanes in cancer treatment: Activity, chemoresistance and its overcoming

Since 1984, when paclitaxel was approved by the FDA for the treatment of advanced ovarian carcinoma, taxanes have been widely used as microtubule-targeting antitumor agents. However, their historic classification as antimitotics does not describe all their functions. Indeed, taxanes act in a complex manner, altering multiple cellular oncogenic processes including mitosis, angiogenesis, apoptosis, inflammatory response, and ROS production. On the one hand, identification of the diverse effects of taxanes on oncogenic signaling pathways provides opportunities to apply these cytotoxic drugs in a more rational manner. On the other hand, this may facilitate the development of novel treatment modalities to surmount anticancer drug resistance. In the latter respect, chemoresistance remains a major impediment which limits the efficacy of antitumor chemotherapy. Taxanes have shown impact on key molecular mechanisms including disruption of mitotic spindle, mitosis slippage and inhibition of angiogenesis. Furthermore, there is an emerging contribution of cellular processes including autophagy, oxidative stress, epigenetic alterations and microRNAs deregulation to the acquisition of taxane resistance. Hence, these two lines of findings are currently promoting a more rational and efficacious taxane application as well as development of novel molecular strategies to enhance the efficacy of taxane-based cancer treatment while overcoming drug resistance. This review provides a general and comprehensive picture on the use of taxanes in cancer treatment. In particular, we describe the history of application of taxanes in anticancer therapeutics, the synthesis of the different drugs belonging to this class of cytotoxic compounds, their features and the differences between them. We further dissect the molecular mechanisms of action of taxanes and the molecular basis underlying the onset of taxane resistance. We further delineate the possible modalities to overcome chemoresistance to taxanes, such as increasing drug solubility, delivery and pharmacokinetics, overcoming microtubule alterations or mitotic slippage, inhibiting drug efflux pumps or drug metabolism, targeting redox metabolism, immune response, and other cellular functions.

Limitations of an ex vivo breast cancer model for studying the mechanism of action of the anticancer drug paclitaxel

Paclitaxel is widely used in the treatment of breast, ovarian, lung, and other cancers. Its primary mechanism is to prevent microtubule depolymerization causing loss of dynamic instability crucial for normal microtubule function leading to mitotic arrest. Prolonged mitotic arrest results in cell death as a secondary response. The effects of paclitaxel are typically studied in cell lines which precludes assessment of the possible influence of tumor-associated cells. We therefore examined paclitaxel action ex vivo in fresh explant cultures of human breast tumors. Surprisingly, we found that paclitaxel failed to induce tumor cell death in explant culture, in contrast to several other cytotoxic agents including salinomycin and vincristine. The lack of effect was not due to defective drug uptake, and furthermore, analysis of H&E stained tumor slices indicated that paclitaxel treatment caused defective (granular) mitosis and chromosomal condensation in 5-10% of tumor cells after 72 h. These results suggest that while paclitaxel was able to penetrate into the tumor slice and disrupt mitosis in cycling tumor cells, any ensuing cell death likely occurred beyond the useful lifetime of the tumor slices. We conclude that explant culture systems may be inappropriate for the study of cytotoxic drugs where a delay exists between the drug's primary and secondary modes of action.