Gene expression profiling of KBH-A42, a novel histone deacetylase inhibitor, in human leukemia and bladder cancer cell lines

Systematic Review: Characteristics and Preclinical Uses of Bladder Cancer Cell Lines

BACKGROUND

Bladder cancer (BC) cell lines are indispensable in basic and preclinical research. Currently, an up-to-date and comprehensive overview of available BC cell lines is not available.

OBJECTIVE

To provide an overview and resources on the origin, pathological and molecular characteristics of commonly used human, murine and canine BC cell lines.

METHODS

A PubMed search was performed for relevant articles published between 1980 and 2017 according to the following MeSH terms: cell line; cell line, tumor; urinary bladder neoplasms; carcinoma, transitional cell. The Cellosaurus database was searched, using the term "bladder" and/or "urothelial carcinoma". We followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.

RESULTS

We provide information on 157 human, murine and canine BC cell lines. 103 human BC cell lines have molecular data available, of which 69 have been profiled by at least one "omic" technology. We outline how these cell lines are currently being used for in vitro and in vivo experimental models. These results allow direct comparison of BC cell lines to patient samples, providing information needed to make informed decisions on the most genomically appropriate cell line to answer research questions. Furthermore, we show that cross-contamination remains an issue and describe guidelines for prevention.

CONCLUSIONS

In the BC field, multiple human, murine and canine BC cell lines have been developed and many have become indispensable for in vitro and in vivo research. High-throughput -omic technologies have dramatically increased the amount of molecular data on these cell lines. We synthesized a comprehensive overview of these data as a resource for the BC scientific community.

HDAC inhibitor PAC-320 induces G2/M cell cycle arrest and apoptosis in human prostate cancer

HDAC inhibitors (HDACis) have been demonstrated with profound antiproliferative activities in various tumor types. Previously, we screened several polyoxometalate HDACis based on our p21 luciferase promoter system and demonstrated that such HDACis have antitumor activity. Here, we further investigate the antitumor mechanism of PAC-320, a compound among the polyoxometalates, in human prostate cancer. We demonstrate that PAC-320 is a broad-spectrum HDACi and could inhibit growth of prostate cancer cells in vitro and in vivo. Furthermore, we find that PAC-320 induces cell cycle arrest at G2/M phase and apoptosis. Mechanically, PAC-320 induced cell cycle arrest is associated with an increase of p21 and decrease of cyclin A and cyclin B1, while PAC-320 induced apoptosis is mediated through mitochondria apoptotic pathway and is closely associated with increase of BH3-only proteins Noxa and Hrk. Meanwhile, we demonstrate that p38 MAPK pathway is involved in PAC-320 induced antiproliferative activities in prostate cancer. Taken together, our data indicates that PAC-320 has potent prostate cancer inhibitory activity in vitro and in vivo, which is mediated by G2/M cell cycle arrest and apoptosis.

Breast cancer cells evade paclitaxel-induced cell death by developing resistance to dasatinib

Triple negative breast cancer (TNBC), which does not express the progesterone, estrogen, or HER2/neu receptor, is aggressive and difficult to treat. Paclitaxel, a tubulin stabilizing agent, is one of the most frequently prescribed anticancer agents for breast cancers, including TNBC. Residual disease that occurs due to resistance or partial resistance of cancer cells in a tumor against anticancer agents is the most important issue in oncology. In the present study, when MDA-MB-231 cells, a TNBC cell line, were treated with 30 µM paclitaxel, a slightly higher concentration than its GI₅₀ value, for 6 days, a small number of cells with different morphologies survived. Among the surviving cells, small round cells were isolated, cloned, and named MDA-MB-231-JYJ cells. MDA-MB-231-JYJ cells were observed to be highly proliferative and tumorigenic. In addition, signal transduction molecules involved in proliferation, survival, malignancy, or stemness of cancer cells, such as c-Src, c-Met, Notch 1, c-Myc, Sox2, Oct3/4, Nanog, and E-cadherin were highly expressed or activated. While further study is required, MDA-MB-231-JYJ cells appear to have some of the characteristics of cancer precursor cells. Although MDA-MB-231-JYJ cells were isolated from the cells that survived in the continuous presence of paclitaxel, they were not resistant to paclitaxel but developed resistance to dasatinib, a Bcr-Abl and Src kinase family inhibitor. The activated state of Src and Notch 1, and the expression levels of c-Myc and cyclins in MDA-MB-231-JYJ cells were less affected than MDA-MB-231 cells by the treatment of dasatinib, which may explain the resistance of MDA-MB-231-JYJ cells to dasatinib. These results suggest that cancer cells that become resistant to dasatinib during the process of paclitaxel therapy in patients may appear, and caution is required in the design of clinical trials using these two agents.

Inhibitors of enzymes catalyzing modifications to histone lysine residues: structure, function and activity

Gene expression is partly controlled by epigenetic mechanisms including histone-modifying enzymes. Some diseases are caused by changes in gene expression that can be mitigated by inhibiting histone-modifying enzymes. This review covers the enzyme inhibitors targeting histone lysine modifications. We summarize the enzymatic mechanisms of histone lysine acetylation, deacetylation, methylation and demethylation and discuss the biochemical roles of these modifications in gene expression and in disease. We discuss inhibitors of lysine acetylation, deacetylation, methylation and demethylation defining their structure-activity relationships and their potential mechanisms. We show that there are potentially indiscriminant off-target effects on gene expression even with the use of selective epigenetic enzyme inhibitors.

Identification of Mitoxantrone as a TRAIL-sensitizing agent for Glioblastoma Multiforme

Tumor necrosis factor related apoptosis-inducing ligand (TRAIL) has tremendous promise in treating various forms of cancers. However, many cancer cells exhibit or develop resistance to TRAIL. Interestingly, many studies have identified several secondary agents that can overcome TRAIL resistance. To expand on these studies, we conducted an extensive drug-re-profiling screen to identify FDA-approved compounds that can be used clinically as TRAIL-sensitizing agents in a very malignant type of brain cancer, Glioblastoma Multiforme (GBM). Using selected isogenic GBM cell pairs with differential levels of TRAIL sensitivity, we revealed 26 TRAIL-sensitizing compounds, 13 of which were effective as single agents. Cardiac glycosides constituted a large group of TRAIL-sensitizing compounds, and they were also effective on GBM cells as single agents. We then explored a second class of TRAIL-sensitizing drugs, which were enhancers of TRAIL response without any effect on their own. One such drug, Mitoxantrone, a DNA-damaging agent, did not cause toxicity to non-malignant cells at the doses that synergized with TRAIL on tumor cells. We investigated the downstream changes in apoptosis pathway components upon Mitoxantrone treatment, and observed that Death Receptors (DR4 and DR5) expression was upregulated, and pro-apoptotic and anti-apoptotic gene expression patterns were altered in favor of apoptosis. Together, our results suggest that combination of Mitoxantrone and TRAIL can be a promising therapeutic approach for GBM patients.

Molecular genetic study of novel biomarkers for early diagnosis of oral squamous cell carcinoma

Objectives: Early detection and treatment of an oral squamous cell carcinoma (OSCC) is critical because of its rapid growth, frequent lymph-node metastasis, and poor prognosis. However, no clinically-valuable methods of early diagnosis exist, and genetic analysis of OSCCs has yielded no biomarkers. Study Design: We investigated the expression of genes associated with inflammation in OSCCs via a quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis of microarray data. Tumor and normal tissues from five patients with an OSCC were used for microarray analysis. Differentially-expressed genes, identified using permutation, local pooled error (LPE), t-tests, and significance analysis of microarrays (SAM), were selected as candidate genetic markers. Results: Two groups corresponding to tissue identity were evident, implying that their differentially-expressed genes represented biological differences between tissues. Fifteen genes were identified using the Student’s paired t-test (p<0.05) and the SAM, with a false discovery rate of less than 0.02. Based on gene expression, these 15 genes can be used to classify an OSCC. A genetic analysis of functional networks and ontologies, validated by using a qRT-PCR analysis of the tissue samples, identified four genes, ADAM15, CDC7, IL12RB2 and TNFRSF8, that demonstrated excellent concordance with the microarray data. Conclusions: Our study demonstrated that four genes (ADAM15, CDC7, IL12RB2 and TNFRSF8) had potential as novel biomarkers for the diagnosis and the treatment of an OSCC.

Key words:Biomarker, microarray, quantitative reverse transcription polymerase chain reaction, oral squamous cell carcinoma, gene expression profiling.

Expression of histone deacetylases 1, 2 and 3 in urothelial bladder cancer

BACKGROUND

Histone deacetylases (HDACs) are known to be associated with an overexpression in different types of cancer such as colon and prostate cancer. In this study we aimed to evaluate the protein expression of class I HDACs in urothelial carcinoma of the bladder.

METHODS

A tissue microarray containing 348 tissuesamples from 174 patients with a primary urothelial carcinoma of the bladder was immunohistochemically stained for HDAC 1, 2 and 3. Intensity of staining was evaluated and the association with clinico-pathological features and prognosis was assessed.

RESULTS

High HDAC expression levels were found in 40 to 60% of all investigated urothelial carcinomas (HDAC-1: 40%, HDAC-2: 42%, HDAC-3: 59%).HDAC-1 and HDAC-2 were significantly associated with higher tumour grades.Although all three markers could not predict progression in univariate analyses, high HDAC-1 expression was associated with a trend toward poorer prognosis. Patients with high-grade tumours and high expression levels of HDAC-1 were more likely to progress compared to all other patients (p < 0.05).

CONCLUSIONS

High-grade noninvasive papillary bladder tumours are associated with high expression levels of HDAC-1 and HDAC-2. High grade tumours in combination with high expression of HDAC-1 showed a worse prognosis than the other tumours. The high expression levels of HDACs observed particularly in high grade urothelial bladder cancer clearly warrant subsequent studies on the potential use of HDAC inhibitors as a novel therapeutic approach.

Elevated serine protease HtrA1 inhibits cell proliferation, reduces invasion, and induces apoptosis in esophageal squamous cell carcinoma by blocking the nuclear factor-κB signaling pathway

Emerging evidence has demonstrated that high-temperature requirement protein A1 (HtrA1) appears to be involved in several important biological processes in mammals such as growth, apoptosis, embryogenesis, invasion, metastasis, and cancer and has been verified to be reduced in a variety of human tumors. However, its precise functions and molecular mechanisms in esophageal squamous cell carcinoma (ESCC) remain unclear. Here, we detected HtrA1 level in ESCC tissues and cells and investigated the biological roles of HtrA1 in ESCC. We found that expressions of HtrA1 mRNA and protein in ESCC tissues and cells were significantly lower than those in normal esophageal epithelial tissues and cells (P < 0.05). Expressions of HtrA1 mRNA and protein were closely associated with TNM staging and lymph node metastasis (P < 0.05). Additionally, the survival rate of patients with low HtrA1 level was lower than those patients with high HtrA1 level (P < 0.05). Elevated HtrA1 level markedly inhibited cell proliferation in vitro and in vivo, reduced cell invasion in vitro, and induced cell apoptosis. Notably, HtrA1 overexpression inhibited phosphorylation levels of IκBα and p65 subunit of the NF-κB signaling pathway, but increased total IκBα level, coupled with decreases of Ki-67, Bcl-2, Bcl-xL, cyclin D1, and MMP-9 proteins and increase of caspase-3 activity. Overall, these data suggest that HtrA1 may play critical roles in the tumorgenesis and progression of ESCC, and HtrA1 overexpression exerts its anti-tumor effect by blocking the NF-κB signaling pathway; thus, manipulation of HtrA1 may be an effective molecular target for ESCC treatment.