Cyclin A1 expression and paclitaxel resistance in human ovarian cancer cells

Competing endogenous RNA networks in ovarian cancer: from bench to bedside

Epithelial ovarian cancer is responsible for the majority of ovarian malignancies, and its highly invasive nature and chemoresistant development have been major obstacles to treating patients with mainstream treatments. In recent decades, the significance of microRNAs (miRNAs), circular RNAs (circRNAs), long non-coding RNAs (lncRNAs), and competing endogenous RNAs (ceRNAs) has been highlighted in ovarian cancer development. This hidden language between these RNAs has led to the discovery of enormous regulatory networks in ovarian cancer cells that substantially affect gene expression. Aside from providing ample opportunities for targeted therapies, circRNA- and lncRNA-mediated ceRNA network components provide invaluable biomarkers. The current study provides a comprehensive and up-to-date review of the recent findings on the significance of these ceRNA networks in the hallmarks of ovarian cancer oncogenesis, treatment, diagnosis, and prognosis. Also, it provides the authorship with future perspectives in the era of single-cell RNA sequencing and personalized medicine.

Screening of potential hub genes involved in Kidney Wilms tumor via bioinformatics analysis and experimental validation

BACKGROUND

Wilms tumor (WT) is the most common pediatric embryonal tumor. Improving patient outcomes requires advances in understanding and targeting the multiple genes and cellular control pathways, but its pathogenesis is currently not well-researched. We aimed to identify the potential molecular biological mechanism of WT and develop new prognostic markers and molecular targets by comparing gene expression profiles of Wilms tumors and fetal normal kidneys.

METHODS

Differential gene expression analysis was performed on Wilms tumor transcriptomic data from the GEO and TARGET databases. For biological functional analysis, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were utilized. Out of 24 hub genes identified, nine were found to be prognostic-related through univariate Cox regression analysis. These nine genes underwent LASSO regression analysis to enhance the predictive capability of the model. The key hub genes were validated in the GSE73209 datasets, and cell function experiments were conducted to identify the genes' functions in WiT-49 cells.

RESULTS

The enrichment analysis revealed that DEGs were significantly involved in the regulation of angiogenesis and regulation of cell differentiation. 24 DEGs were identified through PPI networks and the MCODE algorithm, and 9 of 24 genes were related to WT patients' prognosis. EMCN and CCNA1 were identified as key hub genes, and related to the progression of WT. Functionally, over-expression of EMCN and CCNA1 knockdown inhibited cell viability, proliferation, migration, and invasion of Wilms tumor cells.

CONCLUSIONS

EMCN and CCNA1 were identified as key prognostic markers in Wilms tumor, suggesting their potential as therapeutic targets. Differential gene expression and enrichment analyses indicate significant roles in angiogenesis and cell differentiation.

N6-Methyladenosine-Modified KREMEN2 Promotes Tumorigenesis and Malignant Progression of High-Grade Serous Ovarian Cancer

High-grade serous ovarian cancer (HGSOC) remains the most lethal female cancer by far. Herein, clinical HGSOC samples had higher N6-methyladenosine (m6A) modification than normal ovarian tissue, and its dysregulation had been reported to drive aberrant transcription and translation programs. However, Kringle-containing transmembrane protein 2 (KREMEN2) and its m6A modification have not been fully elucidated in HGSOC. In this study, the data from the high-throughput messenger RNA (mRNA) sequencing of clinical samples were processed using the weighted correlation network analysis and functional enrichment analysis. Results revealed that KREMEN2 was a driver gene in the tumorigenesis of HGSOC and a potential target of m6A demethylase fat-mass and obesity-associated protein (FTO). KREMEN2 and FTO levels were upregulated and downregulated, respectively, and correlation analysis showed a significant negative correlation in HGSOC samples. Importantly, upregulated KREMEN2 was remarkably associated with lymph node metastasis, distant metastasis, peritoneal metastasis, and high International Federation of Gynecology and Obstetrics stage (Ⅲ/Ⅳ), independent of the age of patients. KREMEN2 promoted the growth of HGSOC in vitro and in vivo, which was dependent on FTO. The methylated RNA immunoprecipitation qPCR and RNA immunoprecipitation assays were performed to verify the m6A level and sites of KREMEN2. FTO overexpression significantly decreased m6A modification in the 3' and 5' untranslated regions of KREMEN2 mRNA and downregulated its expression. In addition, we found that FTO-mediated m6A modification of KREMEN2 mRNA was recognized and stabilized by the m6A reader IGF2BP1 rather than by IGF2BP2 or IGF2BP3. This study highlights the m6A modification of KREMEN2 and extends the importance of RNA epigenetics in HGSOC.

Deciphering the Molecular Mechanisms behind Drug Resistance in Ovarian Cancer to Unlock Efficient Treatment Options

Ovarian cancer is a highly lethal form of gynecological cancer. This disease often goes undetected until advanced stages, resulting in high morbidity and mortality rates. Unfortunately, many patients experience relapse and succumb to the disease due to the emergence of drug resistance that significantly limits the effectiveness of currently available oncological treatments. Here, we discuss the molecular mechanisms responsible for resistance to carboplatin, paclitaxel, polyadenosine diphosphate ribose polymerase inhibitors, and bevacizumab in ovarian cancer. We present a detailed analysis of the most extensively investigated resistance mechanisms, including drug inactivation, drug target alterations, enhanced drug efflux pumps, increased DNA damage repair capacity, and reduced drug absorption/accumulation. The in-depth understanding of the molecular mechanisms associated with drug resistance is crucial to unveil new biomarkers capable of predicting and monitoring the kinetics during disease progression and discovering new therapeutic targets.

Transcriptome analysis of polyploid giant cancer cells and their progeny reveals a functional role for p21 in polyploidization and depolyploidization

Polyploid giant cancer cells (PGCC) are frequently detected in tumors and are increasingly recognized for their roles in chromosomal instability and associated genome evolution that leads to cancer recurrence. We previously reported that therapy stress promotes polyploidy, and that acid ceramidase plays a role in depolyploidization. In this study, we used an RNA-seq approach to gain a better understanding of the underlying transcriptomic changes that occur as cancer cells progress through polyploidization and depolyploidization. Our results revealed gene signatures that are associated with disease-free and/or overall survival in several cancers and identified the cell cycle inhibitor CDKN1A/p21 as the major hub in PGCC and early progeny. Increased expression of p21 in PGCC was limited to the cytoplasm. We previously demonstrated that the sphingolipid enzyme acid ceramidase is dispensable for polyploidization upon therapy stress but plays a crucial role in depolyploidization. The current study demonstrates that treatment of cells with ceramide is not sufficient for p53-independent induction of p21 and that knockdown of acid ceramidase, which hydrolyzes ceramide, does not interfere with upregulation of p21. In contrast, blocking the expression of p21 with UC2288 prevented the induction of acid ceramidase and inhibited both the formation of PGCC from parental cells as well as the generation of progeny from PGCC. Taken together, our data suggest that p21 functions upstream of acid ceramidase and plays an important role in polyploidization and depolyploidization.

The Role of Transglutaminase 2 in Cancer: An Update

Transglutaminase type 2 (TG2) is the most ubiquitously expressed and well characterized member of the transglutaminase family. It is a ubiquitous multifunctional enzyme implicated in the regulation of several cellular pathways that support the survival, death, and general homeostasis of eukaryotic cells. Due to its multiple localizations both inside and outside the cell, TG2 participates in the regulation of many crucial intracellular signaling cascades in a tissue- and cell-specific manner, making this enzyme an important player in disease development and progression. Moreover, TG2 is capable of modulating the tumor microenvironment, a process of dynamic tissue remodeling and biomechanical events, resulting in changes which influence tumor initiation, growth, and metastasis. Even if generally related to the Ca2+-dependent post-translational modification of proteins, a number of different biological functions have been ascribed to TG2, like those of a peptide isomerase, protein kinase, guanine nucleotide binder, and cytosolic-nuclear translocator. With respect to cancer, TG2's role is controversial and highly debated; it has been described both as an anti- and pro-apoptotic factor and is linked to all the processes of tumorigenesis. However, numerous pieces of evidence support a tissue-specific role of TG2 so that it can assume both oncogenic and tumor-suppressive roles.

Target Selection for T-Cell Therapy in Epithelial Ovarian Cancer: Systematic Prioritization of Self-Antigens

Adoptive T cell-receptor therapy (ACT) could represent a promising approach in the targeted treatment of epithelial ovarian cancer (EOC). However, the identification of suitable tumor-associated antigens (TAAs) as targets is challenging. We identified and prioritized TAAs for ACT and other immunotherapeutic interventions in EOC. A comprehensive list of pre-described TAAs was created and candidates were prioritized, using predefined weighted criteria. Highly ranked TAAs were immunohistochemically stained in a tissue microarray of 58 EOC samples to identify associations of TAA expression with grade, stage, response to platinum, and prognosis. Preselection based on expression data resulted in 38 TAAs, which were prioritized. Along with already published Cyclin A1, the TAAs KIF20A, CT45, and LY6K emerged as most promising targets, with high expression in EOC samples and several identified peptides in ligandome analysis. Expression of these TAAs showed prognostic relevance independent of molecular subtypes. By using a systematic vetting algorithm, we identified KIF20A, CT45, and LY6K to be promising candidates for immunotherapy in EOC. Results are supported by IHC and HLA-ligandome data. The described method might be helpful for the prioritization of TAAs in other tumor entities.

Concomitant Use of Sulforaphane Enhances Antitumor Efficacy of Sunitinib in Renal Cell Carcinoma In Vitro

Simple Summary

Despite recent advances in treating metastatic renal cell carcinoma (RCC), many patients develop resistance to therapy, resulting in treatment failure. Sunitinib is one drug used to treat metastasized RCC and resistance eventually develops in most patients. In the present in vitro investigation, sulforaphane, a natural compound known to possess antitumor properties without inducing severe side effects, enhanced the efficacy of sunitinib by preventing tumor growth and proliferation in sunitinib-resistant RCC. Sulforaphane, therefore, could prove beneficial as an integrative component in treating metastasized RCC with sunitinib. Further investigation is required to verify these in vitro findings and to evaluate sulforaphane’s clinical value.

Abstract

Chronic treatment of renal cell carcinoma (RCC) with the tyrosine kinase inhibitor sunitinib (ST) inevitably induces resistance and tumor re-activation. This study investigated whether adding the natural compound sulforaphane (SFN) with its anti-cancer properties could improve ST efficacy in vitro. The RCC cell lines A498, Caki1, KTCTL26, and 786O were exposed to ST, SFN, or both (dual therapy, DT) before (short-term exposure) and during ST-resistance buildup (long-term 8-week exposure). Tumor growth, proliferation, and clone formation were evaluated, as was cell cycle progression and cell cycle regulating proteins. In nonresistant cells (short-term), DT induced a higher reduction in cell viability in three cell lines as compared to monotherapy with either ST or SFN. Long-term SFN or DT significantly reduced tumor growth and proliferation, whereas ST alone had no effect or even elevated proliferation in three cell lines. SFN or DT (but not ST alone) also blocked clonogenic growth. Both long-term SFN and DT enhanced the number of cells in the S- and/or G2/M-phase. Protein analysis in 786O cells revealed a down-regulation of cyclin dependent kinase (CDK) 1 and 2. CDK2 or Cyclin A knockdown caused reduced 786O growth activity. SFN therefore inhibits or delays resistance to chronic ST treatment.

PPARγ regulates the expression of genes involved in the DNA damage response in an inflamed endometrium

Inflammation is a biological response of the immune system, which can be triggered by many factors, including pathogens. These factors may induce acute or chronic inflammation in various organs, including the reproductive system, leading to tissue damage or disease. In this study, the RNA-Seq technique was used to determine the in vitro effects of peroxisome proliferator-activated receptor gamma (PPARγ) ligands on the expression of genes and long non-coding RNA, and alternative splicing events (ASEs) in LPS-induced inflammation of the porcine endometrium during the follicular phase of the estrous cycle. Endometrial slices were incubated in the presence of LPS and PPARγ agonists (PGJ2 or pioglitazone) and a PPARγ antagonist (T0070907). We identified 169, 200, 599 and 557 differentially expressed genes after LPS, PGJ2, pioglitazone or T0070907 treatment, respectively. Moreover, changes in differentially expressed long non-coding RNA and differential alternative splicing events were described after the treatments. The study revealed that PPARγ ligands influence the LPS-triggered expression of genes controlling the DNA damage response (GADD45β, CDK1, CCNA1, CCNG1, ATM). Pioglitazone treatment exerted a considerable effect on the expression of genes regulating the DNA damage response.

Generation of Two Paclitaxel-Resistant High-Grade Serous Carcinoma Cell Lines With Increased Expression of P-Glycoprotein

Debulking surgery followed by chemotherapy are the standard of care for high-grade serous carcinoma. After an initial good response to treatment, the majority of patients relapse with a chemoresistant profile, leading to a poor overall survival. Chemotherapy regimens used in high-grade serous carcinomas are based in a combination of classical chemotherapeutic drugs, namely, Carboplatin and Paclitaxel. The mechanisms underlying drug resistance and new drug discovery are crucial to improve patients’ survival. To uncover the molecular mechanisms of chemoresistance and test drugs capable of overcoming this resistant profile, it is fundamental to use good cellular models capable of mimicking the chemoresistant disease. Herein, we established two high-grade serous carcinoma cell lines with intrinsic resistance to Carboplatin and induced Paclitaxel resistance (OVCAR8 PTX R C and OVCAR8 PTX R P) derived from the OVCAR8 cell line. These two chemoresistant cell line variants acquired an enhanced resistance to Paclitaxel-induced cell death by increasing the drug efflux capacity, and this resistance was stable in long-term culture and following freeze/thaw cycles. The mechanism underlying Paclitaxel resistance resides in a significant increase in P-glycoprotein expression and, when this drug efflux pump was blocked with Verapamil, cells re-acquired Paclitaxel sensitivity. We generated two high-grade serous carcinoma cell lines, with a double-chemoresistant (Carboplatin and Paclitaxel) phenotype that mimics the majority of tumor recurrences in ovarian cancer context. This robust tool is suitable for preliminary drug testing towards the development of therapeutic strategies to overcome chemoresistance.

Acute cadmium exposure induces GSDME-mediated pyroptosis in triple-negative breast cancer cells through ROS generation and NLRP3 inflammasome pathway activation

Cadmium (Cd) exposure can exert an impact on carcinogenicity of breast cancer, however, the mechanism is not fully understood in triple-negative breast cancer (TNBC). We performed a TNBC MDA-MB-231 cell model and assessed the toxic effect of Cd exposure (0, 10, 20, 50, 60, 80 μM). Cd reduced cell viability in a time- and dose-dependent manner, followed by cell cycle arrest in S phase with alterations of cyclin 1A1, cyclin 1D1 and CDK2. Lactate dehydrogenase (LDH) release, apoptosis and pyroptosis were increased, which were relieved by z-VAD. Elevated ROS and NLRP3, caspase-1, IL-1β and IL-18 were detected, which was attenuated by N-acetylcysteine. Increased bax and decreased caspase-8, caspase-9 and caspase-3 were found. gasdermin E (GSDME) was activated with cleavage of GSDME-NT, which was retarded by z-VAD. Additionally, p38 MAPK signaling pathway was activated. Our data demonstrate GSDME-activated pyroptosis in Cd toxicity, implying a potential impact on TNBC.

Applications of Multi-omics Approaches for Exploring the Molecular Mechanism of Ovarian Carcinogenesis

Ovarian cancer ranks as the fifth most common cause of cancer-related death in females. The molecular mechanisms of ovarian carcinogenesis need to be explored in order to identify effective clinical therapies for ovarian cancer. Recently, multi-omics approaches have been applied to determine the mechanisms of ovarian oncogenesis at genomics (DNA), transcriptomics (RNA), proteomics (proteins), and metabolomics (metabolites) levels. Multi-omics approaches can identify some diagnostic and prognostic biomarkers and therapeutic targets for ovarian cancer, and these molecular signatures are beneficial for clarifying the development and progression of ovarian cancer. Moreover, the discovery of molecular signatures and targeted therapy strategies could noticeably improve the prognosis of ovarian cancer patients.

Histone methyltransferase EZH2 epigenetically affects CCNA1 expression in acute myeloid leukemia

Cyclin A1 (CCNA1) is an alternative A-type cyclin that is expressed in acute myeloid leukemia (AML). However, its functions in AML cell chemoresistance, an important cause for mortality, are incompletely understood. The purpose of this study was to expound the role and potential mechanism of CCNA1 in AML cell chemoresistance. Upregulation of CCNA1 promoted resistance of AML cells to PKC412, AC220, and AraC. Mechanistically, it was confirmed that CCNA1 transcription was negatively regulated by forkhead box A2 (FOXA2), and the downregulation of FOXA2 promoted chemoresistance in AML cells. Moreover, the promoter sequence of CCNA1 has a significant H3K27me3 modification. Enhancer of zeste homolog 2 (EZH2) enhanced H3K27me3 modification of CCNA1 promoter to inhibit CCNA1 expression, thus promoting sensitivity of AML cells to drugs. Taken together, these findings lead to deeper insights into the mechanism of AML cell chemo-sensitivity by inhibiting CCNA1 at the transcriptional level.

WDNE: an integrative graphical model for inferring differential networks from multi-platform gene expression data with missing values

The mechanisms controlling biological process, such as the development of disease or cell differentiation, can be investigated by examining changes in the networks of gene dependencies between states in the process. High-throughput experimental methods, like microarray and RNA sequencing, have been widely used to gather gene expression data, which paves the way to infer gene dependencies based on computational methods. However, most differential network analysis methods are designed to deal with fully observed data, but missing values, such as the dropout events in single-cell RNA-sequencing data, are frequent. New methods are needed to take account of these missing values. Moreover, since the changes of gene dependencies may be driven by certain perturbed genes, considering the changes in gene expression levels may promote the identification of gene network rewiring. In this study, a novel weighted differential network estimation (WDNE) model is proposed to handle multi-platform gene expression data with missing values and take account of changes in gene expression levels. Simulation studies demonstrate that WDNE outperforms state-of-the-art differential network estimation methods. When applied WDNE to infer differential gene networks associated with drug resistance in ovarian tumors, cell differentiation and breast tumor heterogeneity, the hub genes in the estimated differential gene networks can provide important insights into the underlying mechanisms. Furthermore, a Matlab toolbox, differential network analysis toolbox, was developed to implement the WDNE model and visualize the estimated differential networks.

LINC00184 Promotes Ovarian Cancer Cells Proliferation and Cisplatin Resistance by Elevating CNTN1 Expression via Sponging miR-1305

Objective

Cisplatin resistance is one of the main reasons for treatment failure in ovarian cancer (OC). Here, the effects of LINC00184 on cisplatin-resistant OC were studied.

Patients and Methods

LINC00184, miR-1305 and CNTN1 expression in tissues from 70 OC patients was determined by qRT-PCR, in situ hybridization and Western blot. OC cell lines and OC cisplatin-resistant cell lines were cultured. Cells were transfected using Lipofectamine 2000 and treated with 100 nM cisplatin. Cell proliferation and apoptosis were researched by the CCK-8 assay and flow cytometry. A dual-luciferase reporter gene assay and RNA pull-down were performed to explore the relationship between two genes. LINC00184, miR-1305 and CNTN1 expression in cells was detected by qRT-PCR and Western blot. An in vivo experiment was conducted using nude mice. Ki67 and CNTN1 expression and apoptosis of xenograft tumors were investigated using immunohistochemistry and a TUNEL assay.

Results

LINC00184 was up-regulated in OC clinical tissues and OC cells, especially in cisplatin-resistant OC patients and cells (p<0.01 or p<0.0001). LINC00184 overexpression significantly enhanced OC cell proliferation and cisplatin resistance, and inhibited OC cell apoptosis (p<0.05 or p<0.01). LINC00184 elevated CNTN1 expression via sponging miR-1305. LINC00184 overexpression markedly exacerbated the malignant phenotype of OC cells and cisplatin-resistant OC cells via the miR-1305/CNTN1 axis (p<0.01). Silencing of LINC00184 significantly suppressed OC cell growth and cisplatin resistance in vivo (p<0.01). LINC00184 silencing inhibited Ki67 and CNTN1 expression and promoted apoptosis of xenograft tumors. CNTN1 overexpression promoted proliferation and cisplatin resistance, and reduced apoptosis of OC cells (p<0.05 or p<0.01).

Conclusion

LINC00184 promoted OC cell proliferation and cisplatin resistance by elevating CNTN1 expression via sponging miR-1305.

Therapeutic strategies to overcome taxane resistance in cancer

One of the primary causes of attenuated or loss of efficacy of cancer chemotherapy is the emergence of multidrug resistance (MDR). Numerous studies have been published regarding potential approaches to reverse resistance to taxanes, including paclitaxel (PTX) and docetaxel, which represent one of the most important classes of anticancer drugs. Since 1984, following the FDA approval of paclitaxel for the treatment of advanced ovarian carcinoma, taxanes have been extensively used as drugs that target tumor microtubules. Taxanes, have been shown to affect an array of oncogenic signaling pathways and have potent cytotoxic efficacy. However, the clinical success of these drugs has been restricted by the emergence of cancer cell resistance, primarily caused by the overexpression of MDR efflux transporters or by microtubule alterations. In vitro and in vivo studies indicate that the mechanisms underlying the resistance to PTX and docetaxel are primarily due to alterations in α-tubulin and β-tubulin. Moreover, resistance to PTX and docetaxel results from: 1) alterations in microtubule-protein interactions, including microtubule-associated protein 4, stathmin, centriole, cilia, spindle-associated protein, and kinesins; 2) alterations in the expression and activity of multidrug efflux transporters of the ABC superfamily including P-glycoprotein (P-gp/ABCB1); 3) overexpression of anti-apoptotic proteins or inhibition of apoptotic proteins and tumor-suppressor proteins, as well as 4) modulation of signal transduction pathways associated with the activity of several cytokines, chemokines and transcription factors. In this review, we discuss the abovementioned molecular mechanisms and their role in mediating cancer chemoresistance to PTX and docetaxel. We provide a detailed analysis of both in vitro and in vivo experimental data and describe the application of these findings to therapeutic practice. The current review also discusses the efficacy of different pharmacological modulations to achieve reversal of PTX resistance. The therapeutic roles of several novel compounds, as well as herbal formulations, are also discussed. Among them, many structural derivatives had efficacy against the MDR phenotype by either suppressing MDR or increasing the cytotoxic efficacy compared to the parental drugs, or both. Natural products functioning as MDR chemosensitizers offer novel treatment strategies in patients with chemoresistant cancers by attenuating MDR and increasing chemotherapy efficacy. We broadly discuss the roles of inhibitors of P-gp and other efflux pumps, in the reversal of PTX and docetaxel resistance in cancer cells and the significance of using a nanomedicine delivery system in this context. Thus, a better understanding of the molecular mechanisms mediating the reversal of drug resistance, combined with drug efficacy and the application of target-based inhibition or specific drug delivery, could signal a new era in modern medicine that would limit the pathological consequences of MDR in cancer patients.

Where does cellular senescence belong in the pathophysiology of ovarian cancer?

Although ovarian cancer is the leading cause of death from gynecological malignancies, there are still some issues that hamper accurate interpretation of the complexity of cellular and molecular events underlying the pathophysiology of this disease. One of these is cellular senescence, which is the process whereby cells irreversibly lose their ability to divide and develop a phenotype that fuels a variety of age-related diseases, including cancer. In this review, various aspects of cellular senescence associated with intraperitoneal ovarian cancer metastasis are presented and discussed, including mechanisms of senescence in normal peritoneal mesothelial cells; the role of senescent mesothelium in ovarian cancer progression; the effect of drugs commonly used as first-line therapy in ovarian cancer patients on senescence of normal cells; mechanisms of spontaneous senescence in ovarian cancer cells; and, last but not least, other pharmacologic strategies to induce senescence in ovarian malignancies. Collectively, this study shows that cellular senescence is involved in several aspects of ovarian cancer pathobiology. Proper understanding of this phenomenon, particularly its clinical relevance, seems to be critical for oncology patients from both therapeutic and prognostic perspectives.

CCNA1 gene as a potential diagnostic marker in papillary thyroid cancer

The malignancy that most affects the endocrine system is thyroid neoplasm, with an increasing incidence over the years. The most prevalent histological type of the carcinomas that affect the thyroid gland is papillary carcinoma with a prevalence of 80 % worldwide. The current diagnostic methodology may present inconclusive results, emphasizing the need for new effective and sensitive techniques to aid the diagnosis. For this, it is necessary to understand molecular and protein mechanisms in the identification of diagnostic and predictive markers in the lesions. The Cyclin A1 protein, encoded by the CCNA1 gene, is an important cell cycle regulator, belonging to the MAPK/ERK signaling pathway directly involved with thyroid cancer. The aim of this study was to evaluate the CCNA1 gene and Cyclin A1 protein expression in papillary thyroid carcinoma, follicular thyroid carcinoma, and benign thyroid lesions, by real time quantitative PCR and immunohistochemistry analysis, respectively, to verify their roles as potential diagnostic and predictive markers to future applications in the clinical routine. Overexpression of CCNA1 gene was observed in the papillary carcinoma group compared to the normal group (P = 0.0023), benign lesions (P = 0.0011), colloid goiter (P = 0.0124), and follicular carcinoma (P = 0.0063). No differential expression was observed in the papillary primary tumor group from negative lymph nodes compared with the one from positive lymph nodes (P = 0.3818). Although an increased expression of Cyclin A1 was observed in the PTC group compared to the other one in the IHC analysis, no significant difference was observed (Fisher's exact Test). A Cyclin A1 overexpression was detected with weak to mid-moderate immunoreactivity in the benign group (k = 0.56), (score 1.5); mid-moderate to moderate in the goiter group (k = 0.58); weak in the FTC group (k = 0.33); and mid-moderate to moderate in the PTC group (k = 0.48). Due to the small sample size in the IHC analysis and to the fact that not all RNA is translated into protein, the diagnostic potential of Cyclin A1 could not be assessed. However, these findings highlight the potential of the CCNA1 gene as a diagnostic marker for papillary thyroid carcinoma.

Mechanisms of Taxane Resistance

The taxane family of chemotherapy drugs has been used to treat a variety of mostly epithelial-derived tumors and remain the first-line treatment for some cancers. Despite the improved survival time and reduction of tumor size observed in some patients, many have no response to the drugs or develop resistance over time. Taxane resistance is multi-faceted and involves multiple pathways in proliferation, apoptosis, metabolism, and the transport of foreign substances. In this review, we dive deeper into hypothesized resistance mechanisms from research during the last decade, with a focus on the cancer types that use taxanes as first-line treatment but frequently develop resistance to them. Furthermore, we will discuss current clinical inhibitors and those yet to be approved that target key pathways or proteins and aim to reverse resistance in combination with taxanes or individually. Lastly, we will highlight taxane response biomarkers, specific genes with monitored expression and correlated with response to taxanes, mentioning those currently being used and those that should be adopted. The future directions of taxanes involve more personalized approaches to treatment by tailoring drug-inhibitor combinations or alternatives depending on levels of resistance biomarkers. We hope that this review will identify gaps in knowledge surrounding taxane resistance that future research or clinical trials can overcome.

Inducible aging in Hydra oligactis implicates sexual reproduction, loss of stem cells, and genome maintenance as major pathways

Freshwater polyps of the genus Hydra do not age. However, temperature stress induces aging and a shift from reproduction by asexual budding to sexual gamete production in a cold-sensitive (CS) strain of H. oligactis. We sequenced the transcriptome of a male CS strain before and after this life history shift and compared changes in gene expression relative to those seen in a cold-resistant (CR) strain that does not undergo a life history shift in response to altered temperature. We found that the switch from non-aging asexual reproduction to aging and sexual reproduction involves upregulation of genes not only involved in gametogenesis but also genes involved in cellular senescence, apoptosis, and DNA repair accompanied by a downregulation of genes involved in stem cell maintenance. These results suggest that aging is a byproduct of sexual reproduction-associated cellular reprogramming and underscore the power of these H. oligactis strains to identify intrinsic mechanisms of aging.

PTPN11 Knockdown Prevents Changes in the Expression of Genes Controlling Cell Cycle, Chemotherapy Resistance, and Oncogene-Induced Senescence in Human Thyroid Cells Overexpressing BRAF V600E Oncogenic Protein

The MAPK (RAS/BRAF/MEK/ERK) signaling pathway is a kinase cascade involved in the regulation of cell proliferation, differentiation, and survival in response to external stimuli. The V600E mutation in the BRAF gene has been detected in various tumors, resulting in a 500-fold increase in BRAF kinase activity. However, monotherapy with selective BRAF V600E inhibitors often leads to reactivation of MAPK signaling cascade and emergence of drug resistance. Therefore, new targets are being developed for the inhibition of components of the aberrantly activated cascade. It was recently discovered that resistance to BRAF V600E inhibitors may be associated with the activity of the tyrosine phosphatase SHP-2 encoded by the PTPN11 gene. In this paper, we analyzed transcriptional effects of PTPN11 gene knockdown and selective suppression of BRAF V600E in a model of thyroid follicular epithelium. We found that the siRNA-mediated knockdown of PTPN11 after vemurafenib treatment prevented an increase in the expression CCNA1 and NOTCH4 genes involved in the formation of drug resistance of tumors. On the other hand, downregulation of PTPN11 expression blocked the transcriptional activation of genes (p21, p15, p16, RB1, and IGFBP7) involved in cell cycle regulation and oncogene-induced senescence in response to BRAF V600E expression. Therefore, it can be assumed that SHP-2 participates not only in emergence of drug resistance in cancer cells, but also in oncogene-induced cell senescence.

Overexpression of cyclin A1 promotes meiotic resumption but induces premature chromosome separation in mouse oocyte

Mammalian cyclin A1 is prominently expressed in testis and essential for meiosis in the male mouse, however, it shows weak expression in ovary, especially during oocyte maturation. To understand why cyclin A1 behaves in this way in the oocyte, we investigated the effect of cyclin A1 overexpression on mouse oocyte meiotic maturation. Our results revealed that cyclin A1 overexpression triggered meiotic resumption even in the presence of germinal vesicle breakdown inhibitor, milrinone. Nevertheless, the cyclin A1-overexpressed oocytes failed to extrude the first polar body but were completely arrested at metaphase I. Consequently, cyclin A1 overexpression destroyed the spindle morphology and chromosome alignment by inducing premature separation of chromosomes and sister chromatids. Therefore, cyclin A1 overexpression will prevent oocyte maturation although it can promote meiotic resumption. All these results show that decreased expression of cyclin A1 in oocytes may have an evolutional significance to keep long-lasting prophase arrest and orderly chromosome separation during oocyte meiotic maturation.

Berberine induces dose-dependent quiescence and apoptosis in A549 cancer cells by modulating cell cyclins and inflammation independent of mTOR pathway

AIM

Emerging studies have shown that application of low concentration of bioactive phytomolecules can confer anti-proliferative effects on tumour cells by inducing senescence pathways. The alkaloid berberine is recognized for its anti-cancer attributes but its potential to induce senescence in tumour cells is least understood.

MATERIALS AND METHODS

The present work assessed the mechanisms pertaining to dose-dependent anti-proliferative effects of berberine in the perspective of senescence and inflammation using human non-small cell lung cancer cell line (A549).

KEY FINDINGS

Amongst the different tested bioactive phytomolecules, berberine treatment suppressed the proliferation of A549 cells regardless of the concentration applied. Application of low doses of berberine induced a weak SA-β-gal activity and p21^WAF1 expression but did not show evidence of SASP activation due to absence of NF-κB activation and expression of proinflammatory genes. However, treatment with higher dose of berberine showed no evidence of SA-β-gal activity or p21^WAF1 expression, but instead induced apoptosis and suppressed the expression of cell cyclins. The proliferative capacity of berberine treated cells was at par with control cells and no SA-β-gal activity could be observed in first generation of berberine treated cells. mTOR pathway showed no distinct activation on account of berberine treatment thereby further emphasizing that low dose of berberine induced quiescence and not senescence in A549 cells.

SIGNIFICANCE

Taken together, our observations indicate that despite its strong anti-proliferative effects, low dose berberine treatment may only induce transient changes akin to quiescence that needs to be considered before implying pro-senescence attributes of berberine in cancer therapeutics.

The Human Papillomavirus (HPV) E1 protein regulates the expression of cellular genes involved in immune response

The Human Papillomavirus (HPV) E1 protein is the only viral protein with enzymatic activity. The main known function of this protein is the regulation of the viral DNA replication. Nevertheless, it has been demonstrated that the ablation of HPV18 E1 mRNA in HeLa cells promotes a deregulation of several genes, particularly those involved in host defense mechanisms against viral infections; however, the specific contribution of E1 protein in HPV-independent context has not been studied. The aim of this work was to determine the effect of the HPV E1 protein in the regulation of cellular gene expression profiles evaluated through RNA-seq. We found that E1 proteins from HPV16 and 18 induced an overexpression of different set of genes associated with proliferation and differentiation processes, as well as downregulation of immune response genes, including IFNβ1 and IFNλ1 and Interferon-stimulated gene (ISG), which are important components involved in the antiviral immune response. Together, our results indicate that HR-(High-Risk) and LR-(Low-Risk) HPV E1 proteins play an important role in inhibiting the anti-viral immune response.

Inhibition of Phosphatidylinositol 3-kinase (PI3K) Signaling Synergistically Potentiates Antitumor Efficacy of Paclitaxel and Overcomes Paclitaxel-Mediated Resistance in Cervical Cancer

Acquired paclitaxel (PTX) resistance limits its effectiveness and results in advanced cancer progression. This review investigated whether the inhibition of phosphatidylinositol 3-kinase (PI3K) signaling overcomes paclitaxel resistance in cervical cancer. It was established paclitaxel-resistant cell lines (PTX-R ME180/PTX-R HeLa) and determined the combination index for paclitaxel and PI3K inhibitors (BYL-719/ LY294002) by tetrazolium dye assay. Flow cytometry was used to detect the cell cycle and apoptosis. Migration and invasion were explored by wound healing and transwell assays. Genes related to multiple pathways were assessed by a western blot. It was found that the PI3K pathway was significantly activated in paclitaxel-resistant HeLa and ME180 cells compared to parental cells. PTX + PI3K inhibitor combined therapy showed a synergistic effect by strengthening paclitaxel-induced S and G2M arrest in PTX-R cell sublines by the inactivation of cyclin A1, cyclin B1, cyclin E, and Cdc2 expression. Moreover, combination therapy significantly enhanced drug sensitivity and apoptosis through the activation of Bax, and cleavage of poly-(ADP-ribose) polymerase compared with paclitaxel alone. In addition, PI3K inhibition also suppressed tumor migration and invasion by targeting β-catenin and matrix metalloproteinase-2/9. The authors suggest that the combination of a PI3K inhibitor with paclitaxel may enhance antitumor activity through a cascade of PI3K signaling events.

Biomarkers of drug resistance in ovarian cancer - an update

Introduction: Ovarian cancer, consisting predominantly of ovarian carcinoma, is the most lethal gynecologic malignancy. Diagnosis at the advanced stage, particularly in high-grade serous carcinoma which is the most common and clinically aggressive histotype, is a major factor negatively affecting survival, while tumor heterogeneity and chemoresistance often preclude complete elimination of tumor cells even following radical surgery and combination chemotherapy. Recently, inhibition of angiogenesis and inhibition of poly (ADP-ribose) polymerase (PARP) have shown benefit in the treatment of this cancer. Areas covered: Extensive research has identified molecules associated with resistance to chemotherapy and implicated several biomarkers affecting response to antiangiogenic therapy and PARP inhibition. This review discusses recent data in this field. The presented data, gathered in a PubMed search focusing on the years 2016-2018, focus on regulators of the cell cycle and mitosis, cancer stem cell-related molecules, the immune response, receptor tyrosine kinases and related signaling pathways, BRCA and other DNA repair molecules, microRNAs, and other cancer-associated molecules. Expert opinion: Future research is likely to focus on histotype-specific analyses of clinical specimens and patient-generated cultures applying cutting-edge molecular technology, in the aim of identifying major regulators of chemotherapy response.

Cyclin A1 is associated with poor prognosis in oesophageal squamous cell carcinoma

Dysregulation of cyclin A1 (CCNA1) is implicated in the carcinogenesis, progression and metastasis of many types of solid tumours. In the present study, an mRNA single-channel expression profile chip experiment revealed that the CCNA1 mRNA levels in oesophageal squamous cell carcinoma (ESCC) were increased >10-fold compared with those in the adjacent non-cancer tissues. Reverse transcription-quantitative polymerase chain reaction and immunohistochemistry analyses were performed to additionally investigate the role of CCNA1 in the development and progression of ESCC in patients treated by radical resection of the oesophagus. The association between CCNA1 mRNA expression and the clinicopathological parameters of patients with ESCC was statistically analysed. The results indicated that upregulation of CCNA1 occurred in ~70% of patients with ESCC, and increased CCNA1 mRNA expression was significantly associated with advanced clinical stage, lymph node metastasis, invasiveness and poor clinical outcome, including disease-free survival and overall survival rates. Taken together, the data suggested that CCNA1 had an important function in ESCC development and progression, and may serve as a prognostic biomarker and therapeutic target in ESCC.

Immunohistochemical analysis of cyclin A expression in Wilms tumor

Background

Cyclin A overexpression is found in a variety of human tumors and correlates with unfavorable outcome. We analyzed immunohistochemical expression of cyclin A in Wilms tumor (WT) in relation to clinicopathological characteristics, preoperative chemotherapy (PrOpChTh), and overall survival (OS).

Methods

This retrospective study involved 43 patients who underwent nephrectomy from January 1996 to October 2010. Tumor stage and histological subtype were determined by revised Societé International d’Oncologie Pediatrique protocol, based on histological components/alterations caused by PrOpChTh, within the prognostic group of low, intermediate and high risk, and with criteria for anaplasia. The regressive/necrotic changes in total tumor mass of primary tumor and the proportion of epithelial, blastemal, and stromal components in the remaining viable tumor tissue were also determined. Cyclin A expression was evaluated by immunohistochemistry using a polyclonal rabbit, antihuman antibody (H-432).

Results

Cyclin A overexpression was found in 34.3% of WTs, with higher frequency in tumors with epithelial (31.3%) and blastemal (37.1%) components than those with stromal component (17.7%). Regarding histological type, cyclin A overexpression was found most often in focal anaplasia (100%), stromal (60%), and diffuse anaplastic (66.7) WTs. The overexpression was also more frequent in stages 3 and 4 (77.8% and 66.7%, respectively) compared to tumors in stages 1 and 2 (13.3% and 12.5%, respectively; p = 0.004) in all components, as well as in blastemal component in stages 3 and 4 (77.8% and 66.7%, respectively) vs. stages 1 and 2 (13.3% and 25%, respectively, p = 0.009). Cyclin A overexpression in all components was 66.7% in WTs with metastasis and 31.3% in WTs without metastasis (p = 0.265, Fisher test). Log-rank testing revealed differences of OS regarding stage (p = 0.000), prognostic groups (p = 0.001), and cyclin A expression in blastemal component (p = 0.025). After univariate analysis, tumor stage (p = 0.001), prognostic group (p = 0.004), and cyclin A expression in blastemal component (p = 0.042) were significant prognostic factors for OS; however, after multivariate analysis, none of these factors were confirmed as independent predictors of survival.

Discussion

This study showed that cyclin A overexpression might be associated with the development and progression of WT with anaplasia. Also, cyclin A overexpression was more often observed in advanced stages (3 and 4) of WT, in the group of high-risk WTs, and in focal and diffuse anaplasia WTs. There was no relation of cyclin A overexpression and metastatic ability of WT. Although this study has not confirmed the prognostic value of cyclin A overexpression, its association with unfavorable prognosis should be further evaluated.

The expressions of DNA methyltransferase 1 (DNMT1) and cyclin A1 (CCNA1) in cervical carcinogenesis

OBJECTIVES

The purpose of the present study was to investigate the expressions of DNA methyltransferase 1 (DNMT1) and cyclin A1 (CCNA1) protein and mRNA in the process of cervical carcinogenesis.

METHODS

The specimens were separated into the following groups: control (n=30), low-grade squamous intraepithelial lesions (LSIL, n=30), high-grade squamous intraepithelial lesions (HSIL) and squamous cell cervical cancers (SCC, n=30). Immunohistochemical examination, Western blot and real-time quantitative PCR were used to investigate the protein and mRNA expressions of DNMT1 and CCNA1 in cervical tissues.

RESULTS

We found that the positive expression rate and intensity of DNMT1 mRNA and protein gradually increased in the process of cervical carcinogenesis. However, the increase of the positive expression rate of DNMT1 mRNA and protein form the LSIL group to HSIL group was not significant (P>0.05). After cervical intraepithelial neoplasia (CIN), the positive expression rate and intensity of CCNA1 mRNA and protein significantly decreased with the aggravation of cervical lesions (P<0.05), and there was no significant difference between the LSIL and control groups (P>0.05).

CONCLUSIONS

With the severity of cervical lesions, the expression of DNMT1 protein and mRNA increased gradually. The expression of CCNA1 protein and mRNA decreased gradually. The DNMT1 and CCNA1 expressions are associated with cervical lesions.

Antiviral effect of baicalin phospholipid complex against duck hepatitis A virus type 1

Duck hepatitis A virus type 1 (DHAV-1) is one of the main pathogens of ducklings and causes a high mortality rate. Baicalin (BA) has potent antiviral effect, but the solubility is very poor. In order to increase the absorption, solubility, and pharmacological activity, the phospholipid complex was used to modify BA in present study. Therefore, BA phospholipid complex (BAPC) was prepared. The anti-DHAV-1 abilities of BA and BAPC in vitro was evaluated by cell counting kit-8 and reverse transcription quantitative PCR. The curative effects of BA and BAPC on ducklings which were infected by DHAV-1 in addition to the ALT and AST levels were also detected. The results indicated the anti-DHAV-1 ability of BAPC was stronger than that of BA both in vitro and in vivo. To explore the anti-DHAV-1 mechanism, the influence of BAPC on DHAV-1 adsorption, replication, and release was studied. Furthermore, the anti-oxidative and immuno-enhancing abilities of BAPC in the treatment of infected ducklings were also determined. The results showed BAPC inhibited DHAV-1 adsorption, replication and release. Furthermore, it played anti-oxidative and immno-enhancing roles in the treatment, and the immno-enhancing role was crucial to the treatment.

A panel of three oxidative stress-related genes predicts overall survival in ovarian cancer patients received platinum-based chemotherapy

Ovarian cancer yields the highest mortality rate of all lethal gynecologic cancers, and the prognosis is unsatisfactory with the major obstacle in resistance to chemotherapy. The generation of reactive oxygen species (ROS) in tumor tissues was associated with chemotherapeutic effectiveness by mediating cellular longevity. In this study, we screened the prognostic values of oxidative stress-related genes in ovarian cancer patients received platinum-based chemotherapy, and conducted a prognostic gene signature composing of three genes, TXNRD1, GLA and GSTZ1. This three-gene signature was significantly associated with overall survival (OS), but not progression-free survival (PFS), in both training (n=276) and validation cohorts (n=230). Interestingly, we found that the prognostic value of three-gene signature was reinforced in platinum-sensitive patients. Subgroup analysis further suggested that patients with elder age, higher pathological grades and advanced tumor stages in low-risk score group could benefit from platinum-based chemotherapy. Functional analysis showed that the inactivation of several signaling pathways, including cell cycle, insulin-like growth factor 1 (IGF1) /mTOR and Fas pathways, was affected by three genes. Collectively, our results provided evidence that a panel of three oxidative stress-related gene signature had prognostic values for ovarian cancer patients received platinum-based chemotherapy.

Identification of long non-coding RNA signature for paclitaxel-resistant patients with advanced ovarian cancer

Ovarian cancer is the most lethal gynecologic malignancy, characterized by late diagnosis, frequent relapse, and easy development of chemoresistance. Recent studies suggest that lncRNAs are involved in ovarian cancer onset and progression, as well as the resistance in paclitaxel-containing chemotherapy. However, the genome-wide expression pattern and associated functional implications of lncRNAs in paclitaxel-resistant ovarian cancer cells remain undetermined. In the present study, we identified a panel of lncRNAs aberrantly expressed in both paclitaxel resistant ovarian cancer tissues and cell lines, including XR_948297, XR_947831, XR_938728, XR_938392, NR_103801, NR_073113, and NR_036503. Moreover, the seven-lncRNA signature showed a relatively high predictive accuracy of chemoresistance with an area under the ROC curve (AUC) of 0.93, and was associated with progression-free survival inovarian cancer patients (HR=2.05, p=0.015). Our function prediction demonstrated that the seven-lncRNA signature was positively correlated with a cluster containing 129 genes enriched in insulin secretion-related pathway. Our findings suggest that the seven-lncRNA signature may be utilized as potent biomarkers for predicting chemoresistance for ovarian cancer patients with paclitaxel-containing chemotherapy.