Epithelial-mesenchymal transition (EMT) has been reported to play pivotal roles in tumor invasion and metastasis. Inhibition of EMT may exert beneficial effects in regulating metastasis. Oridonin (ORI), an active diterpenoid compound isolated from Rabdosia rubescens, was found to be a potent anti-metastatic agent. However, the possible involvement of ORI in the EMT in malignant melanoma is unclear. The present study found that ORI inhibited cell migration, invasion, and adhesion in A375 and B16-F10 melanoma cells. The transforming growth factor-beta 1 (TGF-beta 1)-induced EMT was also inhibited in ORI-treated cells, as reflected in the upregulation of E-cadherin, and downregulation of vimentin and Snail. Similar results were observed in A375 and B16-F10 melanoma cells treated with ORI. Furthermore, pre-treatment with ORI blocked the TGF-beta 1-induced phosphoinositide 3-kinase (PI3K)/AKT serine/threonine kinase (Akt)/glycogen synthase kinase (GSK)-beta 3 signaling pathway activation. These effects mimicked PI3 kinase inhibitor LY294002 treatment. ORI interfered with the PI3K/Akt/GSK-3 beta pathway, and reversed TGF-beta 1-induced EMT, which suppressed the invasion and metastasis of melanoma cells. Taken together, the present study demonstrated that ORI inhibits melanoma cells migration, invasion, and adhesion and TGF-beta 1-induced EMT through the PI3K/Akt/GSK-3 beta signaling pathway. These findings suggest that ORI is a promising anti-metastasis agent for melanoma.
Tribbles homolog 3 (TRB3), a type of pseudokinase that contains a consensus serine/threonine kinase catalytic core structure, is upregulated in hepatocellular carcinoma. However, the effect of TRB3 expression in hepatocellular carcinoma and the molecular mechanisms underlying TRB3-mediated effects on tumorigenesis in hepatocellular carcinoma have not been fully elucidated. The present study focused on the effect of TRB3 expression in MHCC97H hepatocellular carcinoma cells and investigated the underlying molecular mechanisms in MHCC97H cells. In the present study, it was revealed that TRB3 was significantly overexpressed in the MHCC97H hepatocellular carcinoma cell compared with L-02 normal hepatic cells. Under endoplasmic reticulum (ER) stress induced by thapsigargin and tunicamycin, the levels of TRB3, CCAAT/enhancer binding protein homologous protein (CHOP), protein kinase B (AKT) and phosphorylated (p)AKT expression were upregulated. Furthermore, when the expression of TRB3 was silenced by short hairpin (sh)RNA, the survival of MHCC97H hepatocellular carcinoma cells was increased. Notably, following transduction with lentiviral containing TRB3-shRNA, cell survival also increased after treatment with chemotherapy drug cisplatin. The present study demonstrated that knockdown of CHOP by shRNA was able to reduce TRB3 expression, and the knockdown of TRB3 markedly increased the level of pAKT. TRB3 was overexpressed in MHCC97H hepatocellular carcinoma cells, particularly under endoplasmic reticulum stress. Knockdown of TRB3 was able to increase cell survival. Therefore, TRB3 expression may induce apoptosis and reverse resistance to chemotherapy in MHCC97H hepatic carcinoma cells. The present study suggests that TRB3 is a key molecule that mediates the crosstalk between ER stress and AKT signal pathways. Furthermore, the present study may provide further insight into the cancer biology of hepatocellular carcinoma and the development of anticancer drugs targeting the ER stress and AKT signaling pathways.
Tumor hypoxia is common in a number of solid tumor types including gastric cancer, and is associated with treatment resistance and poor prognosis. The present study aimed to investigate the function of hypoxia-associated genetic polymorphisms in predicting treatment response and survival in patients with metastatic gastric cancer (MGC) treated with EOF (oxaliplatin and 5-fluorouracil combined with epirubicin) as first-line chemotherapy. The present retrospective study enrolled 108 Chinese patients with MGC receiving EOF as first-line chemotherapy, and genotyped six single nucleotide polymorphisms (SNPs) in four hypoxia-associated genes [myoglobin (MB) rs7292 and rs7293, ATP Binding Cassette Subfamily G Member 2 rs2231142, MutL homolog 1 (MLH1) rs1800734 and rs9852810, and Poly(ADP-Ribose) Polymerase 1 rs11364101. The results of the present study indicated that the CT/TT genotype of MB rs7292, as well as the GG genotype of MLH1 rs9852810, were independent favorable predictive factors of progression-free survival [PFS; MB rs7292: hazard ratio (HR)=0.135, 95% confidence interval (CI)=0.057-0.321, P<0.001; MLH1 rs9852810: HR=0.494, 95% CI=0.267-0.913, P=0.024). Using a prognostic index based on the favorable SNPs for PFS (MB rs7292 CT/TT genotype, and MLH1 rs9852810 GG genotype), patients were classified into a low-risk group (involving one or two of the two SNPs) and a high-risk group (involving neither of the two SNPs), with a PFS of 180.0 and 117.0 days, respectively (P=0.002). The results of the present study demonstrated that the CT/TT genotype of MB rs7292 and the GG genotype of MLH1 rs9852810 were independent favorable predictive factors of PFS in patients with MGC treated with EOF. Identification of those SNPs in blood samples may allow for the prediction of the short-term efficacy of first-line EOF treatment in patients with MGC.
Legg-Calve-Perthes disease (LCPD) commonly onsets in adolescents, and threatens their health. However, the potential mechanism underlying LCPD remains unclear. MicroRNA (miR)-206 and SRY-box 9 (SOX9) serve an important role in chondrocytes; however, their role in LCPD remains ambiguous. In the present study, whether miR-206 and SOX9 mediated cell apoptosis in dexamethasone (DEX)-induced LCPD was investigated. The chondrocytes of the LCPD and normal control group were isolated from clinical tissues. Reverse transcription-quantitative polymerase chain reaction was used to evaluate the expression of miR-206 and SOX9 mRNA. Western blotting was used to measure the protein level of SOX9. A combination of Annexin V-fluorescein isothiocyanate flow cytometry was used to assess cell apoptosis. The association between miR-206 and SOX9 was detected using a luciferase reporter assay. miR-206 was overexpressed while SOX9 was downregulated in chondrocytes treated with DEX obtained from patients with LCPD. miR-206 targeted SOX9 to regulate its expression. Overexpression of miR-206 promoted cell apoptosis in TC28, while it was reversed by SOX9 over expression. TC28 cells pretreated with DEX significantly promoted cell apoptosis, while cells transfected with miR-206 inhibitor significantly reversed the effect; however, downregulated SOX9 abolished the effects of miR-206 inhibitor. SOX9 mediated by miR-206 possibly contributed to the pathogenesis of LCPD. The results of the present study suggest that miR-206 and SOX9 function as important therapeutic targets for the future of clinical therapy.
The angiopoietin 1 (Ang1)/angiopoietin receptor (Tie2) signaling pathway may have a notable role in the pathogenesis of inflammatory diseases. The abnormal expression of angiopoietin 1 and Tie2 has also been reported in various malignant tumors, including papillary thyroid carcinoma (PTC). However, the role and mechanism of the Angl/Tie2 pathway in the progression of PTC remains unclear. Therefore, the aims of the present study were to clarify this. Significantly high expression levels of Angl and Tie2 were observed in PTC tissues and cell lines. Furthermore, MTT and wound-healing assays revealed that the Angl-mediated stimulation of human PTC cells resulted in increased proliferation and migration. Conversely, the downregulation of Tie2 levels using short hairpin RNA targeted at Tie2 abrogated the Angl-mediated effect on cell proliferation and migration. In studying the expression of phosphoinositide-3 kinase (PI3K)/RAC serine/threonine-protein kinase (Akt) pathway, the upregulation of Angl /Tie2 was found to be associated with the activation of the PI3K/Akt pathway in PTC. In conclusion, the data from the present study indicated that the Angl /Tie2 induces PTC oncogenesis via the PI3K/Akt pathway, providing novel insights into human PTC therapy.
Malignant glioma is an aggressive type of cancer. Increasing evidence has suggested that microRNAs (miRs) regulate gene expression post-transcriptionally to affect cancer development and progression. Aberrant expression of miR-509-3p has been reported in cancer studies. However, the expression and mechanism of its function in glioma remains unclear. The present study demonstrated that miR-509-3p was downregulated in glioma tissue samples relative to non-tumor tissues, and that low miR-509-3p expression was associated with a reduced overall survival time. Functional studies revealed that the overexpression of miR-509-3p inhibited cell proliferation, induced apoptosis and suppressed cell migration and invasion via negatively regulating the expression of X-linked inhibitor of apoptosis. The data therefore suggested that miR-509-3p serves an important role in the development and progression of glioma, implicating its possible application in clinical practice as a biomarker and a potential novel therapeutic target.
Multiple myeloma (MM) is a malignant disorder characterized by the neoplastic growth of plasma cells in the bone marrow. MicroRNAs (miRNAs/miRs) modulate key regulatory cell pathways via their influence on target genes, and may serve a crucial function in tumorigenesis. Previous studies have indicated that the downregulation of miR-15a and miR-16 contributes to MM pathogenesis. However, the functional mechanisms of miR-15a and miR-16 in MM remain unclear. In the present study, potential target sites for miR-15a and miR-16 were identified on the calcineurin-binding protein 1 (CABINI) mRNA sequence from analyses of previously published crosslinking, ligation and sequencing of hybrids data. Again-of-function study was also performed, which determined that miR-15a/16 directly targeted CABINI mRNA and negatively regulated the expression of CABINI at the mRNA and protein level in MM cells. A cell proliferation assay demonstrated that the upregulation of miR-15a and miR-16 inhibited the proliferation of MM cells via targeting CABINI. miR-15a and miR-16 were significantly decreased in MM specimens, compared with in normal specimens, whereas CABIN1 mRNA levels were significantly higher in MM samples compared with in normal samples. CABINI mRNA levels were negatively correlated with miR-15a and miR-16 expression levels in MM tissues, as determined using Pearson's correlation coefficient analysis. The results of the present study indicate that the downregulation of miR-15a and miR-16 promotes tumor proliferation in MM by increasing CABIN1 expression. The present study may aid elucidation of the functions of miR-15a and miR-16 and their function in MM carcinogenesis.
The identification of microRNAs (miRNAs/miRs) has enabled the improved understanding of the carcinogenesis and progression of hepatocellular carcinoma (HCC). miRNAs are small non-coding RNAs comprised of 19-24 nucleotides that regulate the expression of target genes. In the present study, miR-138 was demonstrated to be downregulated in human HCC tissues and cell lines. Restoration of miR-138 expression repressed the proliferation, migration and invasion of HCC cells. Furthermore, specificity protein 1 (SP1) was identified as a target gene of miR-138 in HCC using bioinformatics analysis, luciferase reporter assay, reverse transcription-quantitative polymerase chain reaction and western blot analysis. Knockdown of SP1 produced similar suppressive effects to those induced by miR-138 overexpression in HCC cells. These results indicate that miR-138 targeted SP1 to repress the growth, migration and invasion of HCC cells, and may therefore represent a therapeutic target in human HCC.
Melittin is a 26 amino acid residue antimicrobial peptide with known antitumor activity. In the present study, a novel peptide TT-1, derived from melittin and contained only 11 amino acids, was designed, and its antitumor effect was investigated. The present study is aimed to elucidate the effects and relative mechanisms of TT-1 on a human thyroid cancer cell line (TT) in vitro and in vivo. Cell viability assays, Annexin V/propidium iodide assays, western blotting and quantitative reverse transcription polymerase chain reaction were performed. Furthermore, a tumor-xenograft model was established to investigate the apoptotic mechanisms of TT-1 on TT cells. The results obtained indicated that TT-1 was able to suppress the proliferation of TT cells and exhibited low cytotoxicity to normal thyroid cells in vitro. The apoptotic rates of TT cells were also increased following TT-1 treatment. Additionally, TT-1 stimulated caspase-3, caspase-9 and Bax, and inhibited B-cell lymphoma 2 mRNA and protein expression. Finally, it was also demonstrated that TT-1 is able to markedly suppress tumor growth in a TT-bearing nude mouse model. In summary, TT-1 may inhibit the proliferation of TT cells by inducing apoptosis in vitro and in vivo, indicating that TT-1 may be a potential candidate for the treatment of thyroid cancer.
Esophageal cancer is one of the most common types of cancer with poor prognosis. The molecular mechanisms of esophageal cancer progression remain unknown. In the present study, the aim was to investigate the clinical significance and biological function of protease asparaginyl endopeptidase (AEP) in esophageal cancer. The expression of AEP in esophageal cancer was examined, and its association with clinicopathological factors and patient prognosis was analyzed. A series of functional and mechanistic assays were performed to further investigate the underlying molecular mechanisms, and functions in esophageal cancer. The expression of AEP was elevated in esophageal cancer tissues, and patients with high AEP expression displayed a significantly shorter survival time compared with those with low AEP expression. In addition, loss of function experiments demonstrated that knockdown of AEP significantly reduced the migration and invasion ability of esophageal cancer cells. Furthermore, the pro-oncogenic effects of AEP in esophageal cancer were mediated by the upregulation of matrix-metalloproteinase 2 and 3. Taken together, the data from the present study indicates that high AEP expression is associated with esophageal cancer progression and AEP is an indicator of poor prognosis in patients with esophageal cancer. AEP therefore, may be considered as a novel prognostic biomarker or potential therapeutic target in esophageal cancer.
To screen for marker genes associated with to the metastasis of prostate cancer (PCa), in silico analysis of the Gene Expression Omnibus dataset GSE27616, which included 4 metastatic and 5 localized PCa tissue samples, was performed. Differentially expressed genes (DEGs) were identified. Their potential functions were identified by Gene Ontology and Kyoto Encyclopedia of Gene Genomes pathway enrichment analyses. Furthermore, protein-protein interaction (PPI) networks for DEGs were constructed using Cytoscape. Module analysis of the PPI networks was performed with Cluster ONE. A total of 561 DEGs were screened, including 208 upregulated and 353 downregulated genes. Proliferating cell nuclear antigen (PCNA) and cluster of differentiation 4 (CD4) exhibited the highest degrees of connectivity in the PPI networks for up- and down-regulated DEGs, respectively. The DEGs in module A, including CD58,2,4 and major histocompatibility complex, class II DP-131 were enriched in 'cell adhesion molecules'. Anaphase promoting complex subunit 4, cell division cycle 20 and cell division cycle 16 in module B were primarily enriched in 'cell cycle'. The DEGs, including CD4, PCNA and baculoviral IAP repeat containing 5, may have critical roles in PCa metastasis and could thus be used as novel biomarker candidates for metastatic PCa. However, further studies are required to verify these results.
Increasing evidence suggests that metformin use is associated with a decreased risk of cancer. The traditional therapies for gastric cancer (GC) are gastrectomy and chemoradiotherapy; however, these therapies may cause certain adverse effects, which affect a patient's quality of life, and the overall survival rate is low. At present, little is known about whether the use of metformin decreases the risk of GC in patients with type 2 diabetes. Therefore, in the present study, a systematic review was performed to analyze the effect of metformin on GC. A literature search was conducted in PubMed, EMBASE, and the Cochrane Library databases for articles published up to June 30th, 2016. The studies that evaluated GC patients treated with metformin and compared them with GC patients treated with other antidiabetic drugs were reviewed. Eligible studies were evaluated using the Newcastle-Ottawa Scale. Adjusted hazard ratio and 95% confidence intervals were determined to evaluate the effect of metformin on GC. From the 422 articles evaluated, 5 studies involving a total of 1,804,479 patients met the inclusion criteria and were qualitatively analyzed. The quality of all selected articles was classified as moderate. These studies reported that the long-term use of metformin was associated with a lower risk of GC compared with the lack of use of metformin or the use of other hypoglycemic drugs. In GC patients with diabetes who were subjected to gastrectomy, the cumulative use of metformin reduced the rates of disease recurrence and of all-cause and cancer-specific mortality. Despite the limited number of studies on this subject, currently available evidence indicates that metformin is associated with a decreased risk of GC and improves survival in patients with type 2 diabetes. However, more well-designed trials are required to elucidate this association.
Increasing evidence demonstrates that microRNAs (miRNAs/miRs), a type of non-coding small RNA, can regulate tumor cell migration, invasion and metastasis, and may therefore serve a major function in the occurrence and development of tumors. The present study investigated the effect of miR-383 on the proliferation, migration and invasion of colon cancer HT-29 and LoVo cell lines. The expression of miR-383 in colon cancer and adjacent non-tumor tissues was examined by reverse transcription-quantitative polymerase chain reaction. MiR-383 upregulation was stimulated by transfection with a miR-383 mimic. Cell proliferation was measured with MTT and colony formation assays, and cell migration and invasion potential were examined by Transwell chamber assays. A proliferating-inducing ligand (APRIL), myeloid cell leukemia-1 and cyclooxygenase-2 protein expression was analyzed by western blotting. The expression of miR-383 was decreased in colon cancer tissues compared with adjacent non-tumor tissues (P<0.05). Transfection with a miR-383 mimic suppressed proliferation and inhibited cell migration and invasion in HT-29 and LoVo colon cancer cell lines. Overexpression of miR-383 in HT-29 and LoVo cells resulted in the suppression of APRIL protein expression. In conclusion, miR-383 was downregulated in colon cancer. The upregulation of miR-383 inhibited proliferation, migration and invasion of colon cancer cells, potentially through the regulation of target gene APRIL.
Programmed cell death (PDCD)5 is cloned from human leukemia cell line TF-1. PDCD5 is one of the members of the programmed cell death protein family that is frequently involved in tumor growth and apoptosis. To investigate the molecular and cellular functions of PDCD5, the present study established a PDCD5 stably overexpressing A431 cell line and examined the role of PDCD5 in cell proliferation, cell cycle progression and apoptosis. The data demonstrated that over expression of PDCD5 significantly inhibited cell proliferation, induced cell cycle arrest at G2/M phase and apoptosis in A431 cells. The expression profiles of certain key regulators of these cellular events were further investigated, including P53, B cell lymphoma (BCL)-2, BCL-2 associated X protein (BAX) and caspase (CASP)3. The data demonstrated that at the transcript and protein levels, P53, BAX and CASP3 were all upregulated in the PDCD5 stably overexpressing A431 cells whereas BCL-2 was downregulated, indicating that PDCD5 acts as an important upstream regulator of P53, BCL-2, BAX and CASP3. The data suggest that PDCD5 regulates cell proliferation, cell cycle progression and apoptosis in A431 cells. PDCD5 may be a novel tumor suppressor gene, and may be potentially used for cancer treatment in the future.
Studied as a type of tumor suppressor, microRNA (miR) performs an important role in growth and apoptosis of various human carcinomas. However, the effects of miR-144 on osteosarcoma growth and apoptosis, as well as possible underlying mechanisms, remain unclear. The present study investigated the expression of miR-144 in osteosarcoma MG-63 and U-2 OS cell lines compared with osteoblast cells. In order to elucidate the effects of miR-144 on osteosarcoma, miR-144 was upregulated in MG-63 and U-2 OS cells by transfecting chemically synthesized miR-144 mimics. Bioinformatics analysis of potential miR-144 target genes was performed using TargetScanHuman 7.0 and confirmed by luciferase assay. This analysis identified mammalian target of rapamycin (mTOR) as a target of miR-144. The present results indicated that the overexpression of miR-144 may significantly inhibit proliferation and promote apoptosis of MG-63 and U-2 cells compared with scramble control. Furthermore, the effects of miR-144 on osteosarcoma were associated with the mTOR signaling pathway via directly targeting the 3' untranslated region of mTOR mRNA, resulting in a decrease in the level of mTOR protein. In summary, miR-144 was demonstrated to act as a tumor suppressor, which inhibits proliferation and promotes apoptosis of osteosarcoma cell lines. In addition, this effect was mediated by direct targeting on mTOR following inhibition of the mTOR signaling pathway. The present study suggested that miR-144 may be a candidate for the gene therapy of osteosarcoma.