RRM1, TUBB3, TOP2A, CYP19A1, CYP2D6: Difference between mRNA and protein expression in predicting prognosis of breast cancer patients

Lidocaine Inhibits Rat Prostate Cancer Cell Invasiveness and Voltage-Gated Sodium Channel Expression in Plasma Membrane

There is increasing evidence, mostly from breast cancer, that use of local anaesthetics during surgery can inhibit disease recurrence by suppressing the motility of the cancer cells dependent on inherent voltage-gated sodium channels (VGSCs). Here, the possibility that lidocaine could affect cellular behaviours associated with metastasis was tested using the Dunning cell model of rat prostate cancer. Mostly, the strongly metastatic (VGSC-expressing) Mat-LyLu cells were used under both normoxic and hypoxic conditions. The weakly metastatic AT-2 cells served for comparison in some experiments. Lidocaine (1-500 μM) had no effect on cell viability or growth but suppressed Matrigel invasion dose dependently in both normoxia and hypoxia. Used as a control, tetrodotoxin produced similar effects. Exposure to hypoxia increased Nav1.7 mRNA expression but VGSCα protein level in plasma membrane was reduced. Lidocaine under both normoxia and hypoxia had no effect on Nav1.7 mRNA expression. VGSCα protein expression was suppressed by lidocaine under normoxia but no effect was seen in hypoxia. It is concluded that lidocaine can suppress prostate cancer invasiveness without effecting cellular growth or viability. Extended to the clinic, the results would suggest that use of lidocaine, and possibly other local anaesthetics, during surgery can suppress any tendency for post-operative progression of prostate cancer.

The mechanisms of multidrug resistance of breast cancer and research progress on related reversal agents

Chemotherapy is the mainstay in the treatment of breast cancer. However, many drugs that are commonly used in clinical practice have a high incidence of side effects and multidrug resistance (MDR), which is mainly caused by overexpression of drug transporters and related enzymes in breast cancer cells. In recent years, researchers have been working hard to find newer and safer drugs to overcome MDR in breast cancer. In this review, we provide the molecule mechanism of MDR in breast cancer, categorize potential lead compounds that inhibit single or multiple drug transporter proteins, as well as related enzymes. Additionally, we have summarized the structure-activity relationship (SAR) based on potential breast cancer MDR modulators with lower side effects. The development of novel approaches to suppress MDR is also addressed. These lead compounds hold great promise for exploring effective chemotherapy agents to overcome MDR, providing opportunities for curing breast cancer in the future.

Impact of organic anion transporting polypeptide, P-glycoprotein, and breast cancer resistance protein transporters on observed tamoxifen and endoxifen concentration and adverse effects

OBJECTIVE

Drug transporters are important determinants of drug disposition and response. Tamoxifen is an antiestrogen for breast cancer therapy known for adverse drug reactions (ADRs). In this study, the involvement of OATP transporters in tamoxifen and endoxifen transport was studied in vitro while the impact of single nucleotide variation (SNV) in OATP and efflux transporters P-glycoprotein ( ABCB1 ) and Breast Cancer Resistance Protein ( ABCG2 ) on ADRs during tamoxifen therapy were assessed.

METHODS

Patients receiving tamoxifen for breast cancer, who were CYP2D6 normal metabolizers were enrolled ( n  = 296). Patients completed a survey that captured ADRs and a blood sample was collected. Tamoxifen and endoxifen plasma concentration were measured, while DNA was genotyped for SNVs in ABCB1, ABCG2, SLCO1A2, SLCO1B1 , and SLCO2B1 . HEK293T cells were used to determine the extent of OATP-mediated transport of tamoxifen and endoxifen.

RESULTS

Common SNVs of ABCB1, ABCG2, SLCO1A2 , and SLCO1B1 were not associated with tamoxifen or endoxifen concentration. However, tamoxifen concentration was significantly higher in carriers of SLCO2B1 c.935G>A (129.8 ng/mL) compared to wildtype (114.9 ng/mL; P  = 0.036). Interestingly, subjects who carried SLCO1A2 c.38A>G reported significantly less dizziness ( P  = 0.016). In-vitro analysis demonstrated increased cellular accumulation of tamoxifen in cells overexpressing OATP1A2 and 1B1, but endoxifen uptake was not effected in OATP overexpressing cells.

CONCLUSIONS

We showed that OATP1A2 , a transporter known to be expressed at the blood-brain barrier, is capable of tamoxifen transport. Additionally, OATP1A2 c.38A>G was associated with reduced ADRs. Taken together, our findings suggest genetic variation in OATP transporters may be an important predictor of tamoxifen ADRs.

Oncogenic role and potential regulatory mechanism of topoisomerase IIα in a pan-cancer analysis

Topoisomerase IIα (TOP2A) plays an oncogenic role in multiple tumor types. However, no pan-cancer analysis about the function and the upstream molecular mechanism of TOP2A is available. For the first time, we analyzed potential oncogenic roles of TOP2A in 33 cancer types via The Cancer Genome Atlas (TCGA) database. Overexpression of TOP2A was existed in almost all cancer types, and related to poor prognosis and advanced pathological stages in most cases. Besides, the high frequency of TOP2A genetic alterations was observed in several cancer types, and related to prognosis in some cases. Moreover, we conduct upstream miRNAs and lncRNAs of TOP2A to establish ceRNA networks in kidney renal clear cell carcinoma (SNHG3-miR-139-5p), kidney renal papillary cell carcinoma (TMEM147-AS1/N4BP2L2-IT2/THUMPD3-AS1/ERICD/TTN-AS1/SH3BP5-AS1/THRB-IT1/SNHG3/NEAT1-miR-139-5p), liver hepatocellular carcinoma (SNHG3/THUMPD3-AS1/NUTM2B-AS1/NUTM2A-AS1-miR-139-5p and SNHG6/GSEC/SNHG1/SNHG14/LINC00265/MIR3142HG-miR-101-3p) and lung adenocarcinoma (TYMSOS/HELLPAR/SNHG1/GSEC/SNHG6-miR-101-3p). TOP2A expression was generally positively correlated with cancer associated fibroblasts, M0 and M1 macrophages in most cancer types. Furthermore, TOP2A was positively associated with expression of immune checkpoints (CD274, CTLA4, HAVCR2, LAG3, PDCD1 and TIGIT) in most cancer types. Our first TOP2A pan-cancer study contributes to understanding the prognostic roles, immunological roles and potential upstream molecular mechanism of TOP2A in different cancers.

The CYP19A1 rs700519 Polymorphism and Breast Cancer Susceptibility in China: A Case-Control Study and Updated Meta-Analysis

Objective: Breast cancer (BC), the most prevalent cancer in women, has been associated with several genetic factors, including the CYP19A1 rs700519 polymorphism; however, the conclusions have not been consistent. This case-control study and meta-analysis aimed to further assess the relationship between the CYP19A1 rs700519 polymorphism and BC susceptibility. Materials and Methods: We conducted a case-control study to assess the relationship of the CYP19A1 rs700519 polymorphism with the risk and prognosis of BC. Subsequently, we performed a meta-analysis of the case-control studies. Results: In the case-control study, we found a significant negative relationship between the rs700519 AA genotype and risk (χ² = 7.503, p < 0.01) and disease-free survival rates (hazard rate = 0.400, 95% confidence interval [CI] = 0.181-0.883, p < 0.01) of patients with BC, especially in postmenopausal hormone receptor-positive (HR⁺) patients. Nine case-control studies were included in the meta-analysis. The CYP19A1 rs700519 polymorphism was significantly associated with BC susceptibility in the dominant (odds ratio [OR] = 0.95, 95% CI = 0.90-1.00, p = 0.05) and allelic models (OR = 0.84, 95% CI = 0.75-0.93, p < 0.01), but not in the recessive model. Sensitivity analysis revealed that the study results were stable, whereas the funnel plot revealed some publication bias. Conclusions: The CYP19A1 rs700519 polymorphism is related to breast tumorigenesis.

Tumor Microenvironment Subtypes and Immune-Related Signatures for the Prognosis of Breast Cancer

Objective

To better understand the immune-related heterogeneity of tumor microenvironment (TME) and establish a prognostic model for breast cancer in clinical practice.

Methods

For the 2620 breast cancer cases obtained from The Cancer Genome Atlas and the Molecular Taxonomy of Breast Cancer International Consortium, the CIBERSORT algorithm was performed to identify the immunological pattern, which underwent consensus clustering to curate TME subtypes, and biological profiles were explored by enrichment analysis. Random forest analysis, least absolute shrinkage, and selection operator analysis, in addition to uni- and multivariate COX regression analyses, were successively employed to precisely select the significant genes with prediction values for the introduction of the prognostic model.

Results

Three TME subtypes with distinct molecular and clinical features were identified by an unsupervised clustering approach, of which the molecular heterogeneity could be the result of cell cycle dysfunction and the variation of cytotoxic T lymphocyte activity. A total of 15 significant genes were proposed to construct the prognostic immune-related score system, and a predictive model was established in combination with clinicopathological characteristics for the survival of breast cancer patients. For immunological signatures, proactivity of CD8 T lymphocytes and hyperangiogenesis could be attributed to heterogeneous survival profiles.

Conclusions

We developed and validated a prognostic model based on immune-related signatures for breast cancer. This promising model is justified for validation and optimized in future clinical practice.

Regulation of breast cancer metastasis signaling by miRNAs

Despite the decline in death rate from breast cancer and recent advances in targeted therapies and combinations for the treatment of metastatic disease, metastatic breast cancer remains the second leading cause of cancer-associated death in U.S. women. The invasion-metastasis cascade involves a number of steps and multitudes of proteins and signaling molecules. The pathways include invasion, intravasation, circulation, extravasation, infiltration into a distant site to form a metastatic niche, and micrometastasis formation in a new environment. Each of these processes is regulated by changes in gene expression. Noncoding RNAs including microRNAs (miRNAs) are involved in breast cancer tumorigenesis, progression, and metastasis by post-transcriptional regulation of target gene expression. miRNAs can stimulate oncogenesis (oncomiRs), inhibit tumor growth (tumor suppressors or miRsupps), and regulate gene targets in metastasis (metastamiRs). The goal of this review is to summarize some of the key miRNAs that regulate genes and pathways involved in metastatic breast cancer with an emphasis on estrogen receptor α (ERα+) breast cancer. We reviewed the identity, regulation, human breast tumor expression, and reported prognostic significance of miRNAs that have been documented to directly target key genes in pathways, including epithelial-to-mesenchymal transition (EMT) contributing to the metastatic cascade. We critically evaluated the evidence for metastamiRs and their targets and miRNA regulation of metastasis suppressor genes in breast cancer progression and metastasis. It is clear that our understanding of miRNA regulation of targets in metastasis is incomplete.

Influence of CYP19A1 gene expression levels in women with breast cancer: a systematic review of the literature

Breast cancer is the most frequently diagnosed malignant neoplasm in women and is considered a multifactorial disease of unknown etiology. One of the major risk factors is genetic alteration. Changes in CYP19A1 gene expression levels have been associated with increased risk and increased aggressiveness of breast cancer. Increased CYP19A1 gene expression and/or aromatase activity are among the major regulatory events for intratumoral production of estrogens in breast malignant tissues. This systematic review aimed to investigate the influence of CYP19A1 gene expression levels in women with breast cancer. The research was carried out using the PubMed, Scopus, and Web of Science databases. Searches were conducted between February 2 and May 15, 2019. Inclusion criteria were studies published between 2009 and 2019, English language publications, and human studies addressing the gene expression of CYP19A1 in breast cancer. A total of 6.068 studies were identified through PubMed (n=773), Scopus (n=2,927), and the Web of Science (n=2,368). After selecting and applying the inclusion and exclusion criteria, six articles were included in this systematic review. This systematic review provides evidence that increased or decreased levels of CYP19A1 gene expression may be related to pathological clinical factors of disease, MFS, OS, DFS, WATi, markers of metabolic function, concentrations of E1, FSH, and in the use of multiple exons 1 of the CYP19A1 gene in breast cancer.

Identification of core miRNAs and regulatory pathways in breast cancer by integrated bioinformatics analysis

Breast cancer (BC) ranks first among malignancies in the female population due to its complicated pathological progression and poor prognosis. Hence, the aim of the present study was to identify potential molecular prognostic biomarkers able to predict the prognosis of BC patients. We integrated two microRNA (miRNA) expression microarrays and three gene microarrays related to BC from the NCBI Gene Expression Comprehensive (GEO) database to screen for differentially expressed miRNAs and identify their regulatory networks. The Kaplan-Meier plotter online analysis tool was used to assess the overall survival value of miRNAs expression in BC patients. The LinkedOmics online tool was used to analyze genes correlated with miRNAs expression. To clarify the upstream regulation mechanism of genes, we used ChIP-Atlas to identify and screen for transcription factors and visually verify them using the Integrative Genomics Viewer. To further analyze the downstream regulatory mechanism of miRNA in BC, we verified differentially expressed genes (DEGs) correlated to miRNAs in three GEO gene microarrays and the gene set predicted by miRWalk. The open access Metascape program allowed analysis of Gene Ontology (GO) processes, KEGG pathways and GO enrichment was performed on the DEGs. To further identify hub genes, Cytoscape software and its plug-in were applied to construct protein-protein interaction networks. In the present study, several possible molecules and related pathways related to miR-483 were identified by bioinformatics analysis. These molecules and pathways might represent key mechanisms involved in BC progression and development. This work provides a novel view and insight in the pathogenesis, treatment and prognosis for BC.

Assessment of ERBB2 and TOP2α gene status and expression profile in feline mammary tumors: findings and guidelines

In humans, the ERBB2 gene amplification and overexpression are biomarkers for invasive breast cancer and a therapeutic target. Also, TOP2α gene aberrations predict the response to anthracycline-based adjuvant chemotherapy. Although feline mammary tumors (FMTs) are good models in comparative oncology, scarce data is available regarding the ERBB2 and TOP2α status. In this study, and for the first time, the ERBB2 DNA status and RNA levels of intracellular (ICD) and extracellular (ECD) coding regions were compared with TOP2α gene status and expression profile, in samples of FMTs and disease-free tissues from the same animal. Results showed that ERBB2 and TOP2α gene status are highly correlated (r=0.87, p<0.0001, n=25), with few tumor samples presenting amplification. Also, the majority of the FMTs showed ERBB2 overexpression coupled with TOP2α overexpression (r=0.87, p<0.0001, n=27), being the ERBB2-ICD and ECD transcripts highly correlated (r=0.97, p<0.0001, n=27). Significant associations were found between TOP2α gene status or ERBB2 and TOP2α RNA levels with several clinicopathological parameters. This work highlights the need of experimental designs for a precise evaluation of ERBB2 and TOP2α gene status and its expression in FMTs, to improve their clinical management and to further validate them as a suitable model for comparative oncology studies.

Identification of Potential Crucial Genes and Key Pathways in Breast Cancer Using Bioinformatic Analysis

Background: The molecular mechanism of tumorigenesis remains to be fully understood in breast cancer. It is urgently required to identify genes that are associated with breast cancer development and prognosis and to elucidate the underlying molecular mechanisms. In the present study, we aimed to identify potential pathogenic and prognostic differentially expressed genes (DEGs) in breast adenocarcinoma through bioinformatic analysis of public datasets.

Methods: Four datasets (GSE21422, GSE29431, GSE42568, and GSE61304) from Gene Expression Omnibus (GEO) and the Cancer Genome Atlas (TCGA) dataset were used for the bioinformatic analysis. DEGs were identified using LIMMA Package of R. The GO (Gene Ontology) and KEGG (Kyoto Encyclopedia of Genes and Genomes) analyses were conducted through FunRich. The protein-protein interaction (PPI) network of the DEGs was established through STRING (Search Tool for the Retrieval of Interacting Genes database) website, visualized by Cytoscape and further analyzed by Molecular Complex Detection (MCODE). UALCAN and Kaplan–Meier (KM) plotter were employed to analyze the expression levels and prognostic values of hub genes. The expression levels of the hub genes were also validated in clinical samples from breast cancer patients. In addition, the gene-drug interaction network was constructed using Comparative Toxicogenomics Database (CTD).

Results: In total, 203 up-regulated and 118 down-regulated DEGs were identified. Mitotic cell cycle and epithelial-to-mesenchymal transition pathway were the major enriched pathways for the up-regulated and down-regulated genes, respectively. The PPI network was constructed with 314 nodes and 1,810 interactions, and two significant modules are selected. The most significant enriched pathway in module 1 was the mitotic cell cycle. Moreover, six hub genes were selected and validated in clinical sample for further analysis owing to the high degree of connectivity, including CDK1, CCNA2, TOP2A, CCNB1, KIF11, and MELK, and they were all correlated to worse overall survival (OS) in breast cancer.

Conclusion: These results revealed that mitotic cell cycle and epithelial-to-mesenchymal transition pathway could be potential pathways accounting for the progression in breast cancer, and CDK1, CCNA2, TOP2A, CCNB1, KIF11, and MELK may be potential crucial genes. Further, it could be utilized as new biomarkers for prognosis and potential new targets for drug synthesis of breast cancer.

The downregulation of lncRNA EMX2OS might independently predict shorter recurrence-free survival of classical papillary thyroid cancer

Homeobox protein Emx2 is a transcription factor that is encoded by the EMX2 gene. In this study, using data from the Cancer Genome Atlas-Thyroid Cancer (TCGA-THCA), we aimed to examine the expression profile of EMX2 and its antisense transcript EMX2OS in papillary thyroid cancer (PTC), their prognostic value and potential regulatory networks. Results showed that in the three variants of PTC, EMX2 was significantly downregulated in classical PTC, while EMX2OS were significantly downregulated in follicular and classical PTC, compared with adjacent normal tissues. Kaplan-Meier survival curves showed that EMX2 and EMX2OS expression was not related to RFS in follicular PTC. In comparison, the high EMX2 or EMX2OS group were associated with better RFS compared with their respective low expression group in classical PTC (p = 0.007 and 0.004 respectively). Correlation analysis showed that EMX2 and EMX2OS were highly co-expressed in PTC tissues (Spearman’s r = 0.83). By performing stepwise regression, we found that EMX2OS was better than EMX2 in predicting RFS in classical PTC. Multivariate analysis confirmed that high EMX2OS expression was an independent indicator of favorable RFS in classical PTC (HR: 0.239, 95%CI: 0.100 = 0.569, p = 0.001), after adjustment of pathological stages and residual tumors. By performing in silico analysis, we found that the genes co-expressed with EMX2 or EMX2OS were highly overlapped. KEGG pathway analysis showed that these genes were enriched in the ECM-receptor interaction, focal adhesion, and PI3K-Akt signaling, protein digestion and absorption and proteoglycans in cancer pathways, which are closely related to cancer initiation and progression. Based on the findings, we infer that decreased EMX2OS expression might be a valuable prognostic biomarker of unfavorable RFS in classical PTC.

Identification of Five Genes as a Potential Biomarker for Predicting Progress and Prognosis in Adrenocortical Carcinoma

Background: Adrenocortical carcinoma (ACC) is a limited endocrine fatality with a minor diagnosis and rare remedial options. The progressive and predictive meaning of message RNA (mRNA) expression oddity in ACC has been studied extensively in recent years. However, differences in measurement platforms and lab protocols as well as small sample sizes can render gene expression levels incomparable.

Methods: An extensive study of GEO datasets was conducted to define potential mRNA biomarkers for ACC. The study compared the mRNA expression profiles of ACC tissues and neighboring noncancerous adrenal tissues in the pair. The study covered a sum of 165 tumors and 36 benign control samples. Hub genes were identified through a protein-protein interaction (PPI) network and Robust Rank Aggregation method. Then the Cancer Genome Atlas (TCGA) and Oncomine database were used to perform the validation of hub genes. 4 ACC tissues and 4 normal tissues were collected and then Polymerase Chain Reaction (PCR), Western-blot and immunofluorescence were conducted to validate the expression of five hub genes.

Results: We identified five statistically significant genes (TOP2A, NDC80, CEP55, CDKN3, CDK1) corrected with clinical features. The expression of five hub genes in TCGA and Oncomine database were significantly overexpressed in ACC compared with normal ones. Among all the TCGA ACC cases, the strong expression of TOP2A (logrank p=1.4e-04, HR=4.7), NDC80 (logrank p=8.8e-05, HR=4.9), CEP55 (logrank p=5.2e-07, HR=8.6), CDKN3 (log rank p=2.3e-06, HR=7.6) and CDK1 (logrank p=7e-08, HR=11) were correlated with low comprehensive survival, disease free survival (logrank p < 0.001), pathology stage and pathology T stage (FDR < 0.001). PCR results showed that the transcriptional levels of these five genes were significantly higher in ACC tissues than in normal tissues. The western blotting results also showed that the translational level of TOP2A was significantly higher in tumor tissues than in normal tissues. The results of immunofluorescence showed that TOP2A was abundantly observed in the adrenal cortical cell membrane and nucleus and its expression in ACC tissues was significantly higher than that in normal tissues.

Conclusions: The distinguished five genes may be utilized to form a board of progressive and predictive biomarkers for ACC for clinical purpose.

Identification of endothelial selectin as a potential prognostic marker in breast cancer

Endothelial selectin (ELAM1 or CD62E) has been previously reported as being associated with the prognosis of multiple types of cancer. However, its prognostic value in breast cancer (BC) remains unclear. The aim of the present study was to investigate the prognostic value of ELAM1 mRNA expression in BC tissue. The prognostic value of ELAM1 mRNA was assessed in patients with BC using the Kaplan-Meier plotter (KM-plot) database. The KM-plot generated updated ELAM1 mRNA expression data and survival analysis from a total of 3,951 patients with BC, gathered from 35 datasets. Low expression of ELAM1 mRNA was correlated with a poorer overall survival in 1,402 patients with BC followed for 20 years [hazard ratio (HR), 0.71; 95% confidence interval (CI), 0.57–0.88; log-rank P=0.0016]. Low expression of ELAM1 was also correlated with poorer relapse-free survival (HR, 0.69; 95% CI, 0.62–0.77; log-rank P=2.2e-11) in 3,951 patients and poorer distant metastasis-free survival (HR, 0.79; 95% CI, 0.65–0.96; log-rank P=0.02) in 1,746 patients with BC followed for 20 years. Results from the Metabolic gEne RApid visualizer database indicated that ELAM1 mRNA expression was elevated in normal tissue. The results of the present study suggest that ELAM1 mRNA is a potential prognostic and metastatic marker in patients with BC.

OTUD7B upregulation predicts a poor response to paclitaxel in patients with triple-negative breast cancer

Paclitaxel is a first-line chemotherapeutic for patients with breast cancer, particularly triple-negative breast cancer (TNBC). Molecular markers for predicting pathologic responses to paclitaxel treatment is thus urgently needed since paclitaxel resistance is still a clinical issue in treating TNBCs. We investigated the transcriptional profiling of consensus genes in HCC38 (paclitaxel-sensitive) and MDA-MB436 (paclitaxel-resistant) TNBC cells post-treatment with paclitaxel. We found that OTUD7B was downregulated in HCC38 but upregulated in MDA-MB436 cells after paclitaxel treatment at cytotoxic concentrations. Moreover, our data showed that OTUD7B expression causally correlated with IC₅₀ of paclitaxel in a panel of TNBC cell lines. Moreover, we found that OTUD7B upregulation was significantly detected in primary breast cancer tissues compared to normal breast tissues but inversely correlated with tumor growth in TNBC cells. Besides, the increased levels of OTUD7B transcript appeared to causally associate with invasive potentials in TNBC cells. In assessments of recurrence/metastasis-free survival probability, high-levels of OTUD7B transcripts strongly predicted a poor prognosis and unfavorable response to paclitaxel-based chemotherapy in patients with TNBCs. In silico analysis suggested that OTUD7B regulation, probably owing to miR-1180 downregulation, may negatively regulate the NF-κB-Lin28 axis which in turn triggers Let-7 microRNA-mediated caspase-3 downregulation, thereby conferring paclitaxel resistance in TNBCs. These findings suggest that OTUD7B may be a useful biomarker for predicting the anti-cancer effectiveness of paclitaxel and could serve as a new drug target for enhancing the canceridal efficiency of paclitaxel against TNBCs.

Co-expression network analysis identified six hub genes in association with progression and prognosis in human clear cell renal cell carcinoma (ccRCC)

Human clear cell renal cell carcinoma (ccRCC) is one of the most common types of malignant adult kidney tumors. We constructed a weighted gene co-expression network to identify gene modules associated with clinical features of ccRCC (n = 97). Six hub genes (CCNB2, CDC20, CEP55, KIF20A, TOP2A and UBE2C) were identified in both co-expression and protein-protein interaction (PPI) networks, which were highly correlated with pathologic stage. The significance of expression of the hub genes in ccRCC was ranked top 4 among all cancers and correlated with poor prognosis. Functional analysis revealed that the hub genes were significantly enriched in cell cycle regulation and cell division. Gene set enrichment analysis suggested that the samples with highly expressed hub gene were correlated with cell cycle and p53 signaling pathway. Taken together, six hub genes were identified to be associated with progression and prognosis of ccRCC, and they might lead to poor prognosis by regulating p53 signaling pathway.

Prevalence of βIII-tubulin (TUBB3) expression in human normal tissues and cancers

Microtubules are multifunctional cytoskeletal proteins that are involved in crucial cellular roles including maintenance of cell shape, intracellular transport, meiosis, and mitosis. Class III beta-tubulin (βIII-tubulin, also known as TUBB3) is a microtubule protein, normally expressed in cells of neuronal origin. Its expression was also reported in various other tumor types, such as several types of lung cancer, ovarian cancer, and esophageal cancer. TUBB3 is of clinical relevance as overexpression has been linked to poor response to microtubule-targeting anti-cancer drugs such as taxanes. To systematically investigate the epidemiology of TUBB3 expression in normal and neoplastic tissues, we used tissue microarrays for analyzing the immunohistochemically detectable expression of TUBB3 in 3911 tissue samples from 100 different tumor categories and 76 different normal tissue types. At least 1 tumor with weak expression could be found in 93 of 100 (93%) different tumor types, and all these 93 entities also had at least 1 tumor with strong positivity. In normal tissues, a particularly strong expression was found in neurons of the brain, endothelium of blood vessels, fibroblasts, spermatogenic cells, stroma cells, endocrine cells, and acidophilic cells of the pituitary gland. In tumors, strong TUBB3 expression was most frequently found in various brain tumors (85%-100%), lung cancer (35%-80%), pancreatic adenocarcinoma (50%), renal cell carcinoma (15%-80%), and malignant melanoma (77%). In summary, these results identify a broad spectrum of cancers that can at least sporadically express TUBB3. Testing of TUBB3 in cancer types eligible for taxane-based therapies could be helpful to identify patients who might best benefit from this treatment.

Suppression of PTEN/AKT signaling decreases the expression of TUBB3 and TOP2A with subsequent inhibition of cell growth and induction of apoptosis in human breast cancer MCF-7 cells via ATP and caspase-3 signaling pathways

The aim of the present study was to evaluate the effects of PTEN/AKT signaling on TUBB3 and TOP2A expression and on the subsequent cell growth of human breast cancer MCF-7 cells. We found that the disease-free survival (DFS) and overall survival (OS) of breast cancer patients with TUBB3‑positive tumors were lower than these rates in the patients with TUBB3-negative tumors. Meanwhile, DFS and OS of breast cancer patients with TOP2A-positive tumors were also lower than these rates in patients with TOP2A-negative tumors. Suppression of PTEN reduced the protein expression of TUBB3 and TOP2A in MCF-7 cells. Suppression of PTEN also reduced cell proliferation and induced apoptosis and caspase-3 activity in MCF-7 cells. Moreover, an increase in ATP also reduced TUBB3 and TOP2A protein expression, reduced cell proliferation and induced apoptosis and caspase-3 activity in the MCF-7 cells following suppression of PTEN. Suppression of phosphorylation-AKT (p-AKT) reduced the protein expression of TUBB3 and TOP2A in the MCF-7 cells. Suppression of p-AKT also reduced cell proliferation and induced apoptosis and caspase-3 activity in the MCF-7 cells. Then, ATP also reduced TUBB3 and TOP2A protein expression, reduced cell proliferation and induced apoptosis and caspase-3 activity in MCF-7 cells following suppression of p-AKT. These results suggest that PTEN/AKT signaling affects the expression of TUBB3 and TOP2A reducing cell growth and inducing apoptosis of human breast cancer MCF-7 cells through ATP and caspase-3 signaling pathways. TUBB3 and TOP2A may be promising prognostic markers for the efficacy of adjuvant cisplatin-based chemotherapy.