Dicer affects cisplatin‑mediated apoptosis in epithelial ovarian cancer cells

Silencing of Dicer enhances dacarbazine resistance in melanoma cells by inhibiting ADSL expression

Dacarbazine (DTIC) is the primary first-line treatment for advanced-stage metastatic melanoma; thus, DTIC resistance is poses a major challenge. Therefore, investigating the mechanism underlying DTIC resistance must be investigated. Dicer, a type III cytoplasmic endoribonuclease, plays a pivotal role in the maturation of miRNAs. Aberrant Dicer expression may contribute to tumor progression, clinical aggressiveness, and poor prognosis in various tumors. Dicer inhibition led to a reduction in DTIC sensitivity and an augmentation in stemness in melanoma cells. Clinical analyses indicated a low Dicer expression level as a predictor of poor prognosis factor. Metabolic alterations in tumor cells may interfere with drug response. Adenylosuccinate lyase (ADSL) is a crucial enzyme in the purine metabolism pathway. An imbalance in ADSL may interfere with the therapeutic efficacy of drugs. We discovered that DTIC treatment enhanced ADSL expression and that Dicer silencing significantly reduced ADSL expression in melanoma cells. Furthermore, ADSL overexpression reversed Dicer silencing induced DTIC resistance and cancer stemness. These findings indicate that Dicer-mediated ADSL regulation influences DTIC sensitivity and stemness in melanoma cells.

KRAS Hijacks the miRNA Regulatory Pathway in Cancer

Extensive studies have focused on the misregulation of individual miRNAs in cancer. More recently, mutations in the miRNA biogenesis and processing machinery have been implicated in several malignancies. Such mutations can lead to global miRNA misregulation, which may promote many of the well-known hallmarks of cancer. Interestingly, recent evidence also suggests that oncogenic Kristen rat sarcoma viral oncogene homolog (KRAS) mutations act in part by modulating the activity of members of the miRNA regulatory pathway. Here, we highlight the vital role mutations in the miRNA core machinery play in promoting malignant transformation. Furthermore, we discuss how mutant KRAS can simultaneously impact multiple steps of miRNA processing and function to promote tumorigenesis. Although the ability of KRAS to hijack the miRNA regulatory pathway adds a layer of complexity to its oncogenic nature, it also provides a potential therapeutic avenue that has yet to be exploited in the clinic. Moreover, concurrent targeting of mutant KRAS and members of the miRNA core machinery represents a potential strategy for treating cancer.

Network Pharmacology, Molecular Docking, and Experimental Validation to Unveil the Molecular Targets and Mechanisms of Compound Fuling Granule to Treat Ovarian Cancer

Background

Compound fuling granule (CFG) is a traditional Chinese medicine formula that is used for more than twenty years to treat ovarian cancer (OC) in China. However, the underlying processes have yet to be completely understood. This research is aimed at uncovering its molecular mechanism and identifying possible therapeutic targets.

Methods

Significant genes were collected from Therapeutic Target Database and Database of Gene-Disease Associations. The components of CFG were analyzed by LC-MS/MS, and the active components of CFG were screened according to their oral bioavailability and drug-likeness index. The validated targets were extracted from PharmMapper and PubChem databases. Venn diagram and STRING website diagrams were used to identify intersection targets, and a protein-protein interaction network was prepared using STRING. The ingredient-target network was established using Cytoscape. Molecular docking was performed to visualize the molecule-protein interactions using PyMOL 2.3. Enrichment and pathway analyses were performed using FunRich software and Reactome pathway, respectively. Experimental validations, including CCK-8 assay, wound-scratch assay, flow cytometry, western blot assay, histopathological examination, and immunohistochemistry, were conducted to verify the effects of CFG on OC cells.

Results

A total of 56 bioactive ingredients of CFG and 185 CFG-OC-related targets were screened by network pharmacology analysis. The potential therapeutic targets included moesin, glutathione S-transferase kappa 1, ribonuclease III (DICER1), mucin1 (MUC1), cyclin-dependent kinase 2 (CDK2), E1A binding protein p300, and transcription activator BRG1. Reactome analysis showed 51 signaling pathways (P < 0.05), and FunRich revealed 44 signaling pathways that might play an important role in CFG against OC. Molecular docking of CDK2 and five active compounds (baicalin, ignavine, lactiflorin, neokadsuranic acid B, and deoxyaconitine) showed that baicalin had the highest affinity to CDK2. Experimental approaches confirmed that CFG could apparently inhibit OC cell proliferation and migration in vitro; increase apoptosis; decrease the protein expression of MUC1, DICER1, and CDK2; and suppress the progression and distant metastasis of OC in vivo. DICER1, a tumor suppressor, is essential for microRNA synthesis. Our findings suggest that CFG may impair the production of miRNAs in OC cells.

Conclusion

Based on network pharmacology, molecular docking, and experimental validation, the potential mechanism underlying the function of CFG in OC was explored, which supplies the theoretical groundwork for additional pharmacological investigation.

Antagonistic Interaction between Histone Deacetylase Inhibitor: Cambinol and Cisplatin-An Isobolographic Analysis in Breast Cancer In Vitro Models

Breast cancer (BC) is the leading cause of death in women all over the world. Currently, combined chemotherapy with two or more agents is considered a promising anti-cancer tool to achieve better therapeutic response and to reduce therapy-related side effects. In our study, we demonstrated an antagonistic effect of cytostatic agent-cisplatin (CDDP) and histone deacetylase inhibitor: cambinol (CAM) for breast cancer cell lines with different phenotypes: estrogen receptor positive (MCF7, T47D) and triple negative (MDA-MB-231, MDA-MB-468). The type of pharmacological interaction was assessed by an isobolographic analysis. Our results showed that both agents used separately induced cell apoptosis; however, applying them in combination ameliorated antiproliferative effect for all BC cell lines indicating antagonistic interaction. Cell cycle analysis showed that CAM abolished cell cycle arrest in S phase, which was induced by CDDP. Additionally, CAM increased cell proliferation compared to CDDP used alone. Our data indicate that CAM and CDDP used in combination produce antagonistic interaction, which could inhibit anti-cancer treatment efficacy, showing importance of preclinical testing.

Translational Theragnosis of Ovarian Cancer: where do we stand?

BACKGROUND

Ovarian cancer is the second most common gynecologic malignancy, accounting for approximately 220,000 deaths annually worldwide. Despite radical surgery and initial high response rates to platinum- and taxane-based chemotherapy, most patients experience a relapse, with a median progression-free survival of only 18 months. Overall survival is approximately 30% at 5 years from the diagnosis. In comparison, patients out from breast cancer are more than 80 % after ten years from the disease discovery. In spite of a large number of published fundamental and applied research, and clinical trials, novel therapies are urgently needed to improve outcomes of the ovarian cancer. The success of new drugs development in ovarian cancer will strongly depend on both fully genomic disease characterization and, then, availability of biomarkers able to identify women likely to benefit from a given new therapy.

METHODS

In this review, the focus is given to describe how complex is the diseases under the simple name of ovarian cancer, in terms of cell tumor types, histotypes, subtypes, and specific gene mutation or differently expressed in the tumor with respect the healthy ovary. The first- and second-line pharmacological treatment clinically used over the last fifty years are also described. Noteworthy achievements in vitro and in vivo tested new drugs are also summarized. Recent literature related to up to date ovarian cancer knowledge, its detection by biomarkers and chemotherapy was searched from several articles on Pubmed, Google Scholar, MEDLINE and various Governmental Agencies till April 2019.

RESULTS

The papers referenced by this review allow a deep analysis of status of the art in the classification of the several types of ovarian cancer, the present knowledge of diagnosis based on biomarkers and imaging techniques, and the therapies developed over the past five decades.

CONCLUSION

This review aims at stimulating more multi-disciplinary efforts to identify a panel of novel and more specific biomarkers to be used to screen patients for a very early diagnosis, to have prognosis and therapy efficacy indications. The desired final goal would be to have available tools allowing to reduce the recurrence rate, increase both the disease progression free interval and of course the overall survival at five years from the diagnosis that today is still very low.

MiRNA-103/107 in Primary High-Grade Serous Ovarian Cancer and Its Clinical Significance

High levels of miRNA-103/107 are associated with poor outcomes in the case of breast cancer patients. MiRNA-103/107-DICER axis may be one of the key regulators of cancer aggressiveness. MiRNA-103/107 expression levels have never been related to patients' clinicopathological data in epithelial ovarian cancer. We aimed to assess miRNA-103/107 expression levels in high grade serous ovarian cancer tissues. Expression levels of both miRNAs were related to the clinicopathological features and survival. We also evaluated expression levels of miRNA-103/107 and DICER in selected ovarian cancer cell lines (A2780, A2780cis, SK-OV-3, OVCAR3). We assessed the relative expression of miRNA-103/107 (quantitative reverse transcription-polymerase chain reaction) in fifty archival formalin-fixed paraffin-embedded tissue samples of primary high grade serous ovarian cancer. Then, miRNA-103/107 and DICER expression levels were evaluated in selected ovarian cancer cell lines. Additionally, DICER, N-/E-cadherin protein levels were assessed with the use of western blot. We identified miRNA-107 up-regulation in ovarian cancer in comparison to healthy tissues (p = 0.0005). In the case of miRNA-103, we did not observe statistically significant differences between cancerous and healthy tissues (p = 0.07). We did not find any correlations between miRNA-103/107 expression levels and clinicopathological features. Kaplan-Meier survival (disease-free and overall survival) analysis revealed that both miRNAs could not be considered as prognostic factors. SK-OV-3 cancer cell lines were characterized by high expression of miRNA-103/107, relatively low expression of DICER (western-blot), and relatively high N-cadherin levels in comparison to other ovarian cancer cell lines. Clinical and prognostic significance of miRNA-103/107 was not confirmed in our study.

MicroRNA-892a regulates laryngocarcinoma cell proliferation via Dicer

IMPACT STATEMENT

This work expanded the knowledge of the molecular mechanisms underlying LC progression by exploring the role of miR-892a in the viability of TU212 and M4E cells. The results showed that miR-892a, which exhibited elevated expression in LC cells and tissue specimens of patients with LC, exerted an inhibitory effect on Dicer expression, whereas silencing of miR-892a in TU212 and M4E cells hindered cell proliferation and growth and promoted apoptosis. Furthermore, miR-892a was demonstrated to directly target Dicer 3'-UTR and inhibit its expression. These findings demonstrated that miR-892a acted as an LC oncogene via its action on Dicer, which further confirmed that miR-892a can serve as a diagnostic indicator or promising agent for LC treatment.