Novel Approaches in Ovarian Cancer Research against Heterogeneity, Late Diagnosis, Drug Resistance, and Transcoelomic Metastases

Inhibition of nicotinamide dinucleotide salvage pathway counters acquired and intrinsic poly(ADP-ribose) polymerase inhibitor resistance in high-grade serous ovarian cancer

Epithelial ovarian cancer is the most lethal gynecological malignancy, owing notably to its high rate of therapy-resistant recurrence in spite of good initial response to chemotherapy. Although poly(ADP-ribose) polymerase inhibitors (PARPi) have shown promise for ovarian cancer treatment, extended therapy usually leads to acquired PARPi resistance. Here we explored a novel therapeutic option to counter this phenomenon, combining PARPi and inhibitors of nicotinamide phosphoribosyltransferase (NAMPT). Cell-based models of acquired PARPi resistance were created through an in vitro selection procedure. Using resistant cells, xenograft tumors were grown in immunodeficient mice, while organoid models were generated from primary patient tumor samples. Intrinsically PARPi-resistant cell lines were also selected for analysis. Our results show that treatment with NAMPT inhibitors effectively sensitized all in vitro models to PARPi. Adding nicotinamide mononucleotide, the resulting NAMPT metabolite, abrogated the therapy-induced cell growth inhibition, demonstrating the specificity of the synergy. Treatment with olaparib (PARPi) and daporinad (NAMPT inhibitor) depleted intracellular NAD+ , induced double-strand DNA breaks, and promoted apoptosis as monitored by caspase-3 cleavage. The two drugs were also synergistic in mouse xenograft models and clinically relevant patient-derived organoids. Therefore, in the context of PARPi resistance, NAMPT inhibition could offer a promising new option for ovarian cancer patients.

Ovarian Cancer Metastasis to the Central Nervous System: A Literature Review

Ovarian cancer is one of the leading causes of cancer-related deaths among women in the United States. Metastasis to the central nervous system has become more frequent in the previous decades, however, treatment options remain limited. In this review, we discuss the pathophysiology of ovarian cancer and how metastasis to the central nervous system typically occurs. We then discuss cases of metastasis presented in the literature to evaluate current treatment regimens and protocols. Finally, we highlight emerging treatment options that are being utilized in clinics to provide personalized treatment therapy for a patient's unique diagnosis. This review aims to further the understanding of pathophysiology, stimulate further innovative treatments, and present accessible resources through tables and figures.

Multifunctional Magnetic Nanoparticles for MRI-guided Co-delivery of Erlotinib and L-Asparaginase to Ovarian Cancer

AIM(S)

The use of magnetic nanoparticles (MNPs) in biomedical applications has been wildly opted due to their unique properties. The objective of this study was to evaluate the effects of aptamer-armed MNPs in ovarian cancer treatment and as T2 weighted MRI contrast agent.

METHODS

Here, we designed MNPs loaded with erlotinib (ERL/SPION-Val-PEG) and conjugated them with anti-mucin16 (MUC16) aptamer to introduce new image-guided nanoparticles (NPs) for targeted drug delivery as well as non-invasive magnetic resonance imaging (MRI) contrast agents. Also, the combination of our nanosystem (NS) along with L-Asparaginase (L-ASPN) led to synergistic effects in terms of reducing cell viability in ovarian cancer cells, which could suggest a novel combination therapy.

RESULTS

The mean size of our NS was about 63.4 ± 3.4 nm evaluated by DLS analysis and its morphology was confirmed using TEM. Moreover, the functional groups, as well as magnetic properties of our NS, were examined by FT-IR and VSM tests, respectively. The loading efficacy of erlotinib on MNPs was about 80% and its release reached 70.85% over 7 days in the pH value of 5.4. The MR images and flow cytometry results revealed that the cellular uptake of ERL/SPION-Val-PEG-MUC16 NPs in cells with MUC16 overexpression was considerably higher than unarmed NPs. In addition, T2-weight MR images of ovarian cancer-bearing mice indicated significant signal intensity changes at the tumor site 4 h after intravenous injection compared to the non-target MNPs.

CONCLUSIONS

Our data suggest ERL/SPION-Val-PEG NPs as an image-guided co-drug delivery system for ovarian cancer.

Nanodrug Delivery Systems for the Treatment of Ovarian Cancer

Despite advances achieved in medicine, chemotherapeutics still has detrimental side effects with ovarian cancer (OC), accounting for numerous deaths among females. The provision of safe, early detection and active treatment of OC remains a challenge, in spite of improvements in new antineoplastic discovery. Nanosystems have shown remarkable progress with impact in diagnosis and chemotherapy of various cancers, due to their ideal size; improved drug encapsulation within its interior core; potential to minimize drug degradation; improve in vivo drug release kinetics; and prolong blood circulation times. However, nanodrug delivery systems have few limitations regarding its accuracy of tumour targeting and the ability to provide sustained drug release. Hence, a cogent and strategic approach has focused on nanosystem functionalization with antibody-based ligands to selectively enhance cellular uptake of antineoplastics. Antibody functionalized nanosystems are (advanced) synthetic candidates, with a broad range of efficiency in specific tumour targeting, whilst leaving normal cells unaffected. This article comprehensively reviews the present status of nanosystems, with particular emphasis on nanomicelles for molecular diagnosis and treatment of OC. In addition, biomarkers of nanosystems provide important prospects as chemotherapeutic strategies to upsurge the survival rate of patients with OC.

Long non-coding RNA LINC01627 is a prognostic risk factor for epithelial ovarian cancer

Ovarian malignancies are commonly diagnosed cancers of the female reproductive system. Recent studies have revealed that long non-coding RNAs (lncRNAs) can regulate a variety of oncological processes. In the present study, ovarian cancer expression datasets were searched in the GEO database using the GPL570 platform. Differential lncRNA expression between normal ovarian tissues and ovarian tumors were analyzed using the R package 'limma', and patient prognosis was accessed using the package 'survival'. Four databases, GSE14001, GSE18520, GSE38666 and GSE40595, were used for the analysis. A total of 64 lncRNAs were highly expressed and 4 were downregulated within these four databases. Prognostic analysis of the 68 lncRNAs in the four databases was performed, and revealed that the expression of long intergenic non-protein coding RNA 1627 (LINC01627) was negatively associated with patient prognosis in GSE19829 and GSE62193; there was no association between LINC01627 expression and patient's prognosis in GSE18520 or GSE63885. To investigate the proposed association between LINC01627 and patient prognosis, meta-analysis revealed that the total hazard ratio was 1.38 and the 95% confidence interval was between 1.04 and 1.83. Subgroup analysis revealed that LINC01627 may predict patient prognosis in high-grade, advanced and serous epithelial ovarian cancer, which was a risk factor for prognosis. Further assessment was performed in clinical samples and ovarian cancer cells, where the knockdown of LINC01627 inhibited the proliferative and migratory capacities of HO8910 and HEY cells. Collectively, the present results suggested that lncRNA LINC01627 may serve an oncogenic role in the development of epithelial ovarian tumors.