Inhibitory Effects of 5-Aza-2'-Deoxycytidine and Trichostatin A in Combination with p53-Expressing Adenovirus on Human Laryngocarcinoma Cells

Pharmacological Properties of Trichostatin A, Focusing on the Anticancer Potential: A Comprehensive Review

Trichostatin A (TSA), a natural derivative of dienohydroxamic acid derived from a fungal metabolite, exhibits various biological activities. It exerts antidiabetic activity and reverses high glucose levels caused by the downregulation of brain-derived neurotrophic factor (BDNF) expression in Schwann cells, anti-inflammatory activity by suppressing the expression of various cytokines, and significant antioxidant activity by suppressing oxidative stress through multiple mechanisms. Most importantly, TSA exhibits potent inhibitory activity against different types of cancer through different pathways. The anticancer activity of TSA appeared in many in vitro and in vivo investigations that involved various cell lines and animal models. Indeed, TSA exhibits anticancer properties alone or in combination with other drugs used in chemotherapy. It induces sensitivity of some human cancers toward chemotherapeutical drugs. TSA also exhibits its action on epigenetic modulators involved in cell transformation, and therefore it is considered an epidrug candidate for cancer therapy. Accordingly, this work presents a comprehensive review of the most recent developments in utilizing this natural compound for the prevention, management, and treatment of various diseases, including cancer, along with the multiple mechanisms of action. In addition, this review summarizes the most recent and relevant literature that deals with the use of TSA as a therapeutic agent against various diseases, emphasizing its anticancer potential and the anticancer molecular mechanisms. Moreover, TSA has not been involved in toxicological effects on normal cells. Furthermore, this work highlights the potential utilization of TSA as a complementary or alternative medicine for preventing and treating cancer, alone or in combination with other anticancer drugs.

Long noncoding RNA NEAT1 inhibits the acetylation of PTEN through the miR-524-5p /HDAC1 axis to promote the proliferation and invasion of laryngeal cancer cells

Long noncoding RNA nuclear paraspeckle assembly transcript 1 (lncRNA NEAT1) is abnormally expressed in numerous tumors and functions as an oncogene, but the role of NEAT1 in laryngocarcinoma is largely unknown. Our study validated that NEAT1 expression was markedly upregulated in laryngocarcinoma tissues and cells. Downregulation of NEAT1 dramatically suppressed cell proliferation and invasion through inhibiting miR-524-5p expression. Additionally, NEAT1 overexpression promoted cell growth and metastasis, while overexpression of miR-524-5p could reverse the effect. NEAT1 increased the expression of histone deacetylase 1 gene (HDAC1) via sponging miR-524-5p. Mechanistically, overexpression of HDAC1 recovered the cancer-inhibiting effects of miR-524-5p mimic or NEAT1 silence by deacetylation of tensin homolog deleted on chromosome ten (PTEN) and inhibiting AKT signal pathway. Moreover, in vivo experiments indicated that silence of NEAT1 signally suppressed tumor growth. Taken together, knockdown of NEAT1 suppressed laryngocarcinoma cell growth and metastasis by miR-524-5p/HDAC1/PTEN/AKT signal pathway, which provided a potential therapeutic target for laryngocarcinoma.

Down-regulation of PCK2 inhibits the invasion and metastasis of laryngeal carcinoma cells

Laryngeal carcinoma is one of the common malignancies of head and neck. However, the pathogenesis of laryngeal cancer has been not completely clear. To identify the effects of hypoxia on the invasion, metastasis, and metabolism of laryngeal carcinoma, iTRAQ-labeling-with-LC-MS/MS analysis was performed to identify differentially expressed proteins of the SCC10A cells under hypoxia and normoxia, while metabolites were examined by metabolic profiling. 155 proteins and 180 metabolites were identified and the PCK2 protein was selected for validation by Western Blotting. Immunohistochemistry (IHC) was performed to analyze the expression of PCK2 in formalin-fixed paraffin-embedded (FFPE) tissue sections, including laryngeal squamous cell carcinoma tissues from various stages. Collectively, we report that down-regulation of PCK2 inhibits the invasion, migration, and proliferation of laryngeal cancer under hypoxia and down-regulation of PCK2 may be used as a new strategy for laryngeal cancer therapy.

Cytotoxicity and degradation product identification of thermally treated ceftiofur

Ceftiofur (CEF) is a cephalosporin antibiotic and is a commonly used drug in animal food production. As a heat-labile compound, the residual CEF toxicity after thermal treatment has rarely been reported. This study was to investigate the potential toxicity of thermally treated CEF and determine the toxic components. By cytotoxicity tests and liquid chromatography-mass spectrometry (LC-MS) assays, the cytotoxicity of the thermally treated CEF (TTC) and the components of TTC was identified, respectively. Our results showed that TTC exhibited significantly increased toxicity compared with CEF towards LO2 cells by inducing apoptosis. Through LC-MS assays, we identified that the toxic compound of TTC was CEF-aldehyde (CEF-1). The IC₅₀ value of CEF-1 on LO2 cells treated for 24 h was 573.1 μg mL⁻¹, approximately 5.3 times lower than CEF (3052.0 μg mL⁻¹) and 3.4 times lower than TTC (1967.0 μg mL⁻¹). Moreover, we found that CEF-1 was also present in thermally treated desfuroylceftiofur (DFC), the primary metabolite of CEF, indicating that residual CEF or DFC could produce CEF-1 during the heating process. These findings suggest that CEF-1 is a newly identified toxic compound, and CEF-1 may pose a potential threat to food safety or public health.

Ceftiofur (CEF) is a cephalosporin antibiotic and is a commonly used drug in animal food production. This study investigated the cytotoxicity of thermally treated CEF.

CircPLEKHM3 acts as a tumor suppressor through regulation of the miR-9/BRCA1/DNAJB6/KLF4/AKT1 axis in ovarian cancer

BACKGROUND

Emerging evidence has shown that circular RNAs (circRNAs) play essential roles in cancer biology and are potential biomarkers and targets for cancer therapy. However, the expression and function of circRNAs in ovarian carcinogenesis and its progression remain elusive.

METHODS

RNA sequencing was performed to reveal circRNA expression profiles in ovarian cancerous and normal tissues. Single-molecule RNA in-situ hybridization was used to quantify circPLEKHM3 expression in tumor tissues. Cell-based in-vitro and in-vivo assays were subsequently conducted to support the clinical findings.

RESULTS

CircPLEKHM3 was identified as one of the most significantly down-regulated circRNAs in ovarian cancer tissues compared with normal tissues. Its expression was further decreased in peritoneal metastatic ovarian carcinomas compared to primary ovarian carcinomas. Patients with lower circPLEKHM3 tend to have a worse prognosis. Functionally, circPLEKHM3 overexpression inhibited cell growth, migration and epithelial-mesenchymal transition, whereas its knockdown exerted an opposite role. Further analyses showed that circPLEKHM3 sponged miR-9 to regulate the endogenous expression of BRCA1, DNAJB6 and KLF4, and consequently inactivate AKT1 signaling. In addition, AKT inhibitor MK-2206 could block the tumor-promoting effect of circPLEKHM3 depletion, and potentiate Taxol-induced growth inhibition of ovarian cancer cells.

CONCLUSIONS

Our findings demonstrated that circPLEKHM3 functions as a tumor suppressor in ovarian cancer cells by targeting the miR-9/BRCA1/DNAJB6/KLF4/AKT1 axis and may be used as a prognostic indicator and therapeutic target in ovarian cancer patients. The new strategy for treating ovarian cancer by a combination therapy of Taxol with MK-2206 is worth further investigation, especially in ovarian cancer patients with loss of circPLEKHM3 expression.

Ophiopogonin D inhibits cell proliferation and induces apoptosis of human laryngocarcinoma through downregulation of cyclin B1 and MMP-9 and upregulation of p38-MAPK signaling

The pharmacological actions of Ophiopogonin D include resistance to cardiovascular and cerebrovascular diseases, anti-aging effects, improvement in learning deficit and dysmnesia, anti-tumor, anti-radiation and anti-inflammatory effects, immunoregulation, and the relief of cough and hepatopulmonary pathological lesions. However, the efficacy of Ophiopogonin D on human laryngocarcinoma remains to be elucidated. The present study therefore investigated whether the anti-cancer effect of Ophiopogonin D inhibits cell proliferation and induces apoptosis of human laryngocarcinoma. In the present study, it was found that Ophiopogonin D inhibited cell proliferation, promoted cytotoxicity, induced apoptosis and increased caspase-3/9 activity in human laryngocarcinoma cells. Ophiopogonin D significantly suppressed cyclin B1 and matrix metalloproteinase-9 (MMP-9) protein expression, and upregulated p-p38 MAPK protein expression in human laryngocarcinoma cells. Together, these results suggest Ophiopogonin D inhibits cell proliferation and induced apoptosis in human laryngocarcinoma cells through downregulation of cyclin B1 and MMP-9 and upregulation of the p38 MAPK signaling pathway. Therefore, Ophiopogonin D may be a potential therapy for the treatment of human laryngocarcinoma.

Bcl-2 overexpression contributes to laryngeal carcinoma cell survival by forming a complex with Hsp90β

Laryngeal carcinoma (LC) is one of the most common malignant tumors of all head and neck squamous cell carcinomas (HNSCCs). However, the molecular mechanism and genetic basis of the development of LC have not been fully elucidated. To explore the possible mechanism, targeted proteomic analysis was performed on Bcl-2-associated proteins from LC cells. According to our results, 35 proteins associated with Bcl-2 were identified and Hsp90β was confirmed by co-immunoprecipitation and western blot analysis. Protein‑protein interaction (PPI) analysis indicated that Bcl-2‑Hsp90β interactions may be involved in the anti-apoptotic progression of LC. Further results revealed that disruption of the Bcl-2-Hsp90β interaction inhibited the anti-apoptotic ability of Bcl-2 and decreased the caspase activation in LC, which has broad implications for the better understanding of tumor formation, tumor cell survival and development of metastasis due to Bcl-2. Collectively, we report the mechanism by which Bcl-2 functions in LC as an anti-apoptotic factor in relation to its association with proteins and potentially identify a Bcl-2/Hsp90β axis as a novel target for LC therapy.

MiR-210 links hypoxia with cell proliferation regulation in human Laryngocarcinoma cancer

The microRNA hsa-miR-210 (miR-210) is associated with hypoxia; however its function has not fully identified. In the present study, we aim to detect its role concerning proliferation in Laryngocarcinoma. We found that miR-210 was highly expressed in hypoxia, which inhibited proliferation by inducing cell cycle arrest in G1/G0 as well as apoptosis. We further identified that miR-210 targeted fibroblast growth factor receptor-like 1 (FGFRL1). Down regulation of FGFRL1 decreased cell proliferation by promoting proportion of cells in G1/G0 phase and decreasing in S and G2/M phases. Moreover, overexpression of FGFRL1 effectively released the miR-210-induced suppression of SCC10A cell proliferation. Expression of miR-210 repressed tumor xenograft growth in vivo as well. Together, our findings reveal a new mechanism of adaptation to hypoxia that miR-210 inhibits the proliferation via inducing cell cycle arrest and apoptosis by the targeting of FGFRL1. J. Cell. Biochem. 116: 1039-1049, 2015. © 2015 Wiley Periodicals, Inc.

Liriodenine induces the apoptosis of human laryngocarcinoma cells via the upregulation of p53 expression

Laryngocarcinoma is one of the most aggressive cancers that affects the head and neck region. The survival rate of patients with laryngocarcinoma is low due to late metastases and the resistance of the disease to chemotherapy and radiotherapy. Liriodenine, an alkaloid extracted from a number of plant species, has demonstrated antitumor effects on multiple types of cancer. However, the effects of liriodenine upon laryngocarcinoma, and the underlying mechanisms, are yet to be elucidated. The present study therefore investigated the potential antitumor effects of liriodenine on HEp-2 human laryngocarcinoma cells in vitro and HEp-2-implanted nude mice in vivo. Liriodenine induced significant apoptosis and inhibition of cell migration in the HEp-2 cells. Furthermore, the rate of tumor growth in the HEp-2-implanted nude mice was inhibited by the administration of liriodenine. The potential mechanism underlying the antitumor effects of liriodenine may result from an upregulative effect upon p53 expression, which ultimately induces cellular apoptosis. By contrast, the downregulation of p53 significantly reduced the antitumor effects of liriodenine. Together, these results suggest that liriodenine exhibits potent antitumor activities in laryngocarcinoma HEp-2 cells, in vitro and in vivo, via the upregulation of p53 expression. Liriodenine may therefore be a potential therapy for the treatment of laryngocarcinoma.

The synergistic effects of low dose fluorouracil and TRAIL on TRAIL-resistant human gastric adenocarcinoma AGS cells

The TNF-related apoptosis-inducing ligand (TRAIL) is a TNF family member which has been under intense focus because of its remarkable ability to induce apoptosis in malignant human cells while leaving normal cells unscathed. However, many cancer cells remain resistant to TRAIL. In this study, we had investigated the synergistic effects of low dose fluorouracil (5-Fu) and TRAIL on TRAIL-resistant human gastric adenocarcinoma AGS cells and explored the potential mechanisms. Cell viability was analyzed by sulforhodamine B (SRB) assay and the synergistic effects were evaluated by Jin's formula and confirmed by both morphological changes under inverted microscope and flow cytometry. The expression of TRAIL-R1 (death receptor 4, DR4), TRAIL-R2 (DR5), TRAIL-R3 (decoy receptor, DcR1), TRAIL-R4 (DcR2), procaspase-3, procaspase-8, and procaspase-9 was detected by western blotting. Our results showed that there were significant synergistic effects of low dose 5-Fu and TRAIL on TRAIL-resistant AGS cells, and this effect was supposed to be mediated by decreasing DcR2 expression and increasing DR5 expression. The extrinsic and intrinsic apoptosis pathways were both activated. The data suggest that combined treatment of low dose 5-Fu and TRAIL can be an effective therapeutic approach for gastric adenocarcinoma.