Comprehensive molecular characterization of hypertension-related genes in cancer.

BACKGROUND: During cancer treatment, patients have a significantly higher risk of developing cardiovascular complications such as hypertension. In this study, we investigated the internal relationships between hypertension and different types of cancer. METHODS: First, we comprehensively characterized the involvement of 10 hypertension-related genes across 33 types of cancer. The somatic copy number alteration (CNA) and single nucleotide variant (SNV) of each gene were identified for each type of cancer. Then, the expression patterns of hypertension-related genes were analyzed across 14 types of cancer. The hypertension-related genes were aberrantly expressed in different types of cancer, and some were associated with the overall survival of patients or the cancer stage. Subsequently, the interactions between hypertension-related genes and clinically actionable genes (CAGs) were identified by analyzing the co-expressions and protein-protein interactions. RESULTS: We found that certain hypertension-related genes were correlated with CAGs. Next, the pathways associated with hypertension-related genes were identified. The positively correlated pathways included epithelial to mesenchymal transition, hormone androgen receptor, and receptor tyrosine kinase, and the negatively correlated pathways included apoptosis, cell cycle, and DNA damage response. Finally, the correlations between hypertension-related genes and drug sensitivity were evaluated for different drugs and different types of cancer. The hypertension-related genes were all positively or negatively correlated with the resistance of cancer to the majority of anti-cancer drugs. These results highlight the importance of hypertension-related genes in cancer. CONCLUSIONS: This study provides an approach to characterize the relationship between hypertension-related genes and cancers in the post-genomic era.

Cannabinoid Receptor Type 2 Agonist Reduces Morphine Tolerance via Mitogen Activated Protein Kinase Phosphatase Induction and Mitogen Activated Protein Kinase Dephosphorylation.

Morphine is an opioid drug often used in treating moderate to severe pain. However, morphine tolerance in patients limits its used in clinical settings. Our previous study showed that a cannabinoid type 2 (CB2) receptor agonist attenuated morphine tolerance. However, the exact mechanism by which CB2 agonists reduce morphine tolerance remains unclear. In this study, we investigated the effect of mitogen activated protein kinase (MAPK) and mitogen activated protein kinase phosphatases 1 and 3 (MKP-1 and MKP-3) on the regulation of morphine tolerance by CB2 receptor agonist. Chronic morphine treatments for 7 days reduced the protein expression of MKP-1 and MKP-3 in the spinal cord and increased the phosphorylation of p38, ERK1/2 and the level of proinflammatory mediator, such as IL-1ß, IL-6 and TNF-α. Coadministration of CB2 receptor agonist AM1241 alleviated the inhibition of MKP-1 and MKP-3 by chronic morphine administration and reduced the expression of phosphorylated MAPK and proinflammatory factors. The effect of the CB2 receptor agonist on morphine-induced downregulation of MKP-1 and MKP-3 was reversed by the MKP-1 and MKP-3 antagonist triptolide. Our findings suggested that CB2 receptor agonist may induce the expression of MKP-1 and MKP-3 to promote MAPK dephosphorylation and reduce the production of downstream cytokine, thereby reducing morphine tolerance. This finding suggested that MKPs may serve as a new target for alleviating morphine tolerance.

Therapeutic Targeting of Tumor Cells Rich in LGR Stem Cell Receptors.

LGR5 and LGR6 mark epithelial stem cells in many niches including the ovarian surface and fallopian tube epithelia from which ovarian cancer arises. Human ovarian cancers express these receptors at high levels and express one of their ligands, RSPO1, at levels uniquely higher than all other tumor types except mesothelioma. Reasoning that these receptors are also important to tumor stem cells, arming the LGR binding domain of RSPO1 with a cytotoxin may permit depletion of the tumor stem cells. The Fu1-Fu2 receptor binding domain of RSPO1 (R1FF), containing a sortase recognition sequence at the C-terminal end, was produced in bacteria and a single molecule of MMAE was attached to each R1FF through a val-cit-PAB linker using the sortase reaction, thus producing a homogeneous population of armed molecules. R1FF-MMAE demonstrated (1) selective LGR-dependent binding, uptake, and cytotoxicity; (2) low nM cytotoxicity to multiple types of human tumor cell lines in vitro; (3) favorable plasma pharmacokinetic properties when administered iv with an elimination half-life of 27.8 h; (4) favorable absorption from the peritoneal cavity; and (5) therapeutic activity in aggressive xenograft models of ovarian cancer in the absence of any weight loss or other adverse events. These results demonstrate that the Fu1-Fu2 domain of RSPO1 can be exploited to deliver a potent cytotoxin to tumor cells that express the LGR4-6 family of stem cell receptors.

The identification of six risk genes for ovarian cancer platinum response based on global network algorithm and verification analysis.

Ovarian cancer is the most lethal gynaecological cancer, and resistance of platinum-based chemotherapy is the main reason for treatment failure. The aim of the present study was to identify candidate genes involved in ovarian cancer platinum response by analysing genes from homologous recombination and Fanconi anaemia pathways. Associations between these two functional genes were explored in the study, and we performed a random walk algorithm based on reconstructed gene-gene network, including protein-protein interaction and co-expression relations. Following the random walk, all genes were ranked and GSEA analysis showed that the biological functions focused primarily on autophagy, histone modification and gluconeogenesis. Based on three types of seed nodes, the top two genes were utilized as examples. We selected a total of six candidate genes (FANCA, FANCG, POLD1, KDM1A, BLM and BRCA1) for subsequent verification. The validation results of the six candidate genes have significance in three independent ovarian cancer data sets with platinum-resistant and platinum-sensitive information. To explore the correlation between biomarkers and clinical prognostic factors, we performed differential analysis and multivariate clinical subgroup analysis for six candidate genes at both mRNA and protein levels. And each of the six candidate genes and their neighbouring genes with a mutation rate greater than 10% were also analysed by network construction and functional enrichment analysis. In the meanwhile, the survival analysis for platinum-treated patients was performed in the current study. Finally, the RT-qPCR assay was used to determine the performance of candidate genes in ovarian cancer platinum response. Taken together, this research demonstrated that comprehensive bioinformatics methods could help to understand the molecular mechanism of platinum response and provide new strategies for overcoming platinum resistance in ovarian cancer treatment.

Comprehensive analysis of mRNA-level and miRNA-level subpathway activities for identifying robust ovarian cancer prognostic signatures.

Ovarian cancer (OvCa) causes the highest mortality among all gynaecologic cancers. A large number of mRNA- or miRNA-based signatures were identified for OvCa patient prognosis. However, the comprehensive analysis of function-level prognostic signatures is currently not considered in OvCa. In the present study, we respectively inferred subpathway activities from mRNA and miRNA levels based on high-throughput expression profiles and reconstructed subpathways. Firstly, the activities of two tumour pathways were calculated and the difference between normal and tumour samples were analysed using multiple tumour types. Then, we calculated subpathway activities for OvCa based on the expression profiles from both mRNA and miRNA levels. Furthermore, based on these subpathway activity matrices, we performed bootstrap analysis to obtain sub-training sets and utilized univariate method to identify robust OvCa prognostic subpathways. A comprehensive comparison of subpathway results between these two levels was performed. As a result, we observed subpathway mutual exclusion trend between the levels of mRNA and miRNA, which indicated the necessary of combining mRNA-miRNA levels. Finally, by using ICGC data as testing sets, we utilized two strategies to verify survival predictive power of the mRNA-miRNA combined subpathway signatures and performed comparisons with results from individual levels. It was confirmed that our framework displayed application to identify robust and efficient prognostic signatures for OvCa, and the combined signatures indeed exhibited advantages over individual ones. In the study, we took a step forward in relevant novel integrated functional signatures for OvCa prognosis.

PRSS1 Upregulation Predicts Platinum Resistance in Ovarian Cancer Patients.

Ovarian cancer is the most frequent cause of death among gynecologic malignancies. A total of 80% of patients who have completed platinum-based chemotherapy suffer from relapse and develop resistance within 2 years. In the present study, we obtained patients' complete platinum (cisplatin and carboplatin) medication information from The Cancer Genome Atlas database and then divided them into two categories: resistance and sensitivity. Difference analysis was performed to screen differentially expressed genes (DEgenes) related to platinum response. Subsequently, we annotated DEgenes into the protein-protein interaction network as seed nodes and analyzed them by random walk. Finally, second-ranking protease serine 1 gene (PRSS1) was selected as a candidate gene for verification analysis. PRSS1's expression pattern was continuously studied in Oncomine and cBio Cancer Genomic Portal databases, revealing the key roles of PRSS1 in ovarian cancer formation. Hereafter, we conducted in-depth explorations on PRSS1's platinum response to ovarian cancer through tissue and cytological experiments. Quantitative real-time polymerase chain reaction and Western blot assay results indicated that PRSS1 expression levels in platinum-resistant samples (tissue/cell) were significantly higher than in samples sensitive to platinum. By cell transfection assay, we observed that knockdown of PRSS1 reduced the resistance of ovarian cancer cells to cisplatin. Meanwhile, overexpression of PRSS1 increased the resistance to cisplatin. In conclusion, we identified a novel risk gene PRSS1 related to ovarian cancer platinum response and confirmed its key roles using multiple levels of low-throughput experiments, revealing a new treatment strategy based on a novel target factor for overcoming cisplatin resistance in ovarian cancer.

Expression and clinicopathological significance of hematopoietic pre-B cell leukemia transcription factor-interacting protein in cervical carcinoma.

Hematopoietic pre-B-cell leukemia transcription factor(PBX)-interacting protein (HPIP) is overexpressed in various malignancies, but its role in cervical cancer (CC) remains unknown. This study investigated the correlations of HPIP expression with clinicopathological factors and prognosis of cervical carcinoma patients. Expression of HPIP was detected in CC from 167 patients along with 45 corresponding normal cervical specimens by immunohistochemistry. HPIP immunoreactivity was overexpressed in CC cases compared with that in normal endometrium (P < 0.05). High HPIP expression was positively correlated with FIGO stage, histological grade, lymph node metastasis and recurrence (P < 0.05). Patients with high HPIP expression exhibited significantly poorer overall survival (OS) and disease-free survival (DFS) than patients with low HPIP expression (both P < 0.001). Cox multivariate analysis showed that high HPIP expression was an independent prognostic factor for both OS [hazard ratio (HR) = 8.791, 95% confidence interval (CI) = 2.098-36.826; P = 0.003 and DFS of patients with CC (HR = 10.485, 95% CI = 2.512-36.826; P = 0.001)]. We identified HPIP protein expression as a novel independent poor prognostic indicator in CC.

Ellagic acid induces HeLa cell apoptosis via regulating signal transducer and activator of transcription 3 signaling.

Ellagic acid has been reported to possess various activities, including anti-inflammatory, anti-oxidative, antiviral and anticancer abilities. However, the effect and underlying molecular mechanism of ellagic acid on cervical carcinoma remain unclear. Therefore, the present study aimed to investigate the effects of ellagic acid on human cervical carcinoma cells and the molecular mechanism involved. The present study assessed the survival of HeLa cells cultured in vitro using an MTT assay. Apoptosis rate and cell cycle of HaLa cells were measured using an Annexin V-Fluorescein isothiocyanate/propidium iodide Apoptosis Detection and Cell Cycle Analysis kits, respectively, following treatment with varying concentrations of ellagic acid. Further effects of ellagic acid on HeLa cells was assessed using flow cytometry and western blotting. Ellagic acid treatment significantly inhibited cell proliferation of the human cervical carcinoma HeLa, SiHa and C33A cells. In HeLa cells, it was observed that ellagic acid arrested the cell cycle at G1 phase, induced cell apoptosis, suppressed the phosphorylation of Janus kinase 2 and signal transducer and activator of transcription 3 (STAT3), as well as modulated the expression of associated proteins. Collectively, the results of the present study provide evidence that ellagic acid inhibits cervical carcinoma cell proliferation, and induces apoptosis and cell cycle arrest at G1 phase possibly via the regulation of STAT3 signaling.

Identification of Subpathway Signatures For Ovarian Cancer Prognosis by Integrated Analyses of High-Throughput miRNA and mRNA Expression.

BACKGROUND/AIMS: Ovarian cancer (OC) causes more death and serious conditions than any other female reproductive cancers, and many expression signatures have been identified for OC prognoses. However, no significant overlap is found among signatures from different studies, indicating the necessity of signature identifications at the functional level. METHODS: We performed an integrated analyses of miRNA and gene expressions to identify OC prognostic subpathways (pathway regions). Using The Cancer Genome Atlas data set, we identified core prognostic subpathways, and calculated subpathway risk scores using both miRNA and gene components. Finally, we performed global risk impact analyses to optimize core subpathways using the random walk algorithm. RESULTS: Subpathway-level analyses displayed more robust results than the gene- and miRNA-level analyses. Moreover, we verified the advantage of core subpathways over the entire pathway-based results and their prognostic performance in two independent validation data sets. Based on the global impact score, 13 subpathway signatures were selected and a combined subpathway-based risk score was further calculated for OC patient prognoses. CONCLUSIONS: Overall, it was possible to systematically perform integrated analyses of the expression levels of miRNAs and genes to identify prognostic subpathways and infer subpathway risk scores for use in OC clinical applications.

Effects of coadministration of low dose cannabinoid type 2 receptor agonist and morphine on vanilloid receptor 1 expression in a rat model of cancer pain.

Morphine is widely used as an analgesic to treat moderate to severe pain, but chronic morphine use is associated with development of tolerance and dependence, which limits its analgesic efficacy. Our previous research has showed that nonanalgetic dose of a cannabinoid type 2 (CB2) receptor agonist reduced morphine tolerance in cancer pain. A previous study showed the colocalization of CB2 and transient receptor potential vanilloid 1 (TRPV1) in human and rat dorsal root ganglia (DRG) sensory neurons. Whether coadministration of a CB2 receptor agonist and morphine could reduce TRPV1 expression in morphine­induced antinociception and tolerance in cancer pain is unclear. Therefore, we investigated the effects of coadministration of a CB2 receptor agonist AM1241 and morphine on TRPV1 expression and tolerance in cancer pain. Coadministration of AM1241 and morphine for 8 days significantly reduced morphine tolerance, as assessed by measuring paw withdrawal latency to a radiant heat stimulation, in Walker 256 tumor­bearing rats. Repeated morphine treatment for a period of 8 days induced upregulation of the TRPV1 protein expression levels in the DRG in the tumor­bearing rats, although no change in mRNA expression. Pretreatment with AM1241 reduced this morphine­induced upregulation of TRPV1 and the effect was reversed by the CB2 receptor antagonist AM630. Our findings suggest that coadministration of a CB2 receptor agonist AM1241 and morphine reduced morphine tolerance possibly through regulation of TRPV1 protein expression in the DRG in cancer pain.

MicroRNA-595 sensitizes ovarian cancer cells to cisplatin by targeting ABCB1.

Ovarian cancer is among the leading cause of cancer-related deaths in females. In this study, we demonstrated that miR-595 expression was downregulated in the ovarian cancer tissues and cell lines. miR-595 expression was lower in the lymph node metastases tissues than in the primary ovarian cancer tissues and normal tissues. Furthermore, miR-595 overexpression suppressed the ovarian cancer cell proliferation, colony formation and invasion and promoted the sensitivity of ovarian cancer cell to cisplatin. We identified ABCB1 as a direct target gene of miR-595 in the ovarian cancer cell. ABCB1 expression was upregulated in the ovarian cancer tissues and cell lines. Morevoer, the expression level of ABCB1 was inversely correlated with miR-595 in the ovarian cancer tissues. In addition, overexpression of ABCB1 decreased the miR-595-overexpressing HO8910PM and SKOV-3 cell sensitivity to cisplatin. Ectopic expression of ABCB1 promoted the miR-595-overexpressing HO8910PM and SKOV-3 cell proliferation, colony formation and invasion. These data suggested that miR-595 acted a tumor suppressor role in ovarian cancer development and increased the sensitivity of ovarian cancer to cisplatin.

Low-Dose Cannabinoid Type 2 Receptor Agonist Attenuates Tolerance to Repeated Morphine Administration via Regulating µ-Opioid Receptor Expression in Walker 256 Tumor-Bearing Rats.

BACKGROUND: Morphine is widely used in patients with moderate and severe cancer pain, whereas the development of drug tolerance remains a major problem associated with opioid use. Previous studies have shown that cannabinoid type 2 (CB2) receptor agonists induce morphine analgesia, attenuate morphine tolerance in normal and neuropathic pain animals, induce transcription of the µ-opioid receptor (MOR) gene in Jurkat T cells, and increase morphine analgesia in cancer pain animals. However, no studies of the effects of CB2 receptor agonists on morphine tolerance in cancer pain have been performed. Therefore, we investigated the effect of repeated intrathecal (IT) injection of the low-dose CB2 receptor agonist AM1241 on the development of morphine tolerance in walker 256 tumor-bearing rats. We also tested the influence of the CB2 receptor agonist AM1241 on MOR protein and messenger ribonucleic acid (mRNA) expression in the rat spinal cord and dorsal root ganglia (DRG). METHODS: Walker 256 cells were implanted into the plantar region of each rat's right hindpaw. Tumor-bearing rats received IT injection of the CB2 receptor agonist AM1241 or antagonist AM630 with or without morphine subcutaneously twice daily for 8 days. Rats receiving drug vehicle only served as the control group. Mechanical paw withdrawal threshold and thermal paw withdrawal latency were assessed by a von Frey test and hot plate test 30 minutes after drug administration every day. MOR protein and mRNA expression in the spinal cord and DRG were detected after the last day (day 8) of drug administration via Western blot and real-time reverse transcription polymerase chain reaction. The data were analyzed via analysis of variance followed by Student t test with Bonferroni correction for multiple comparisons. RESULTS: Repeated morphine treatments reduced the mechanical withdrawal threshold and thermal latency. Coadministration of a nonanalgetic dose of the CB2 receptor agonist AM1241 with morphine significantly inhibited the development of morphine tolerance and increased the MOR protein expression in the spinal cord and DRG and mRNA expression in the spinal cord in tumor-bearing rats. CONCLUSIONS: Our findings indicate that IT injection of a nonanalgetic dose of a CB2 receptor agonist increased the analgesia effect and alleviated tolerance to morphine in tumor-bearing rats, potentially by regulating MOR expression in the spinal cord and DRG. This receptor may be a new target for prevention of the development of opioid tolerance in cancer pain.