Metastatic gynecologic malignancies: advances in treatment and management

A nanocomposite competent to overcome cascade drug resistance in ovarian cancer via mitochondria dysfunction and NO gas synergistic therapy

Ovarian cancer (OC) is one of the most common and recurring malignancies in gynecology. Patients with relapsed OC always develop "cascade drug resistance" (CDR) under repeated chemotherapy, leading to subsequent failure of chemotherapy. To overcome this challenge, amphiphiles (P1) carrying a nitric oxide (NO) donor (Isosorbide 5-mononitrate, ISMN) and high-density disulfide are synthesized for encapsulating mitochondria-targeted tetravalent platinum prodrug (TPt) to construct a nanocomposite (INP@TPt). Mechanism studies indicated that INP@TPt significantly inhibited drug-resistant cells by increasing cellular uptake and mitochondrial accumulation of platinum, depleting glutathione, and preventing apoptosis escape through generating highly toxic peroxynitrite anion (ONOO-). To better replicate the microenvironmental and histological characteristics of the drug resistant primary tumor, an OC patient-derived tumor xenograft (PDXOC) model in BALB/c nude mice was established. INP@TPt showed the best therapeutic effects in the PDXOC model. The corresponding tumor tissues contained high ONOO- levels, which were attributed to the simultaneous release of O2•- and NO in tumor tissues. Taken together, INP@TPt-based systematic strategy showed considerable potential and satisfactory biocompatibility in overcoming platinum CDR, providing practical applications for ovarian therapy.

PSME3 induces radioresistance and enhances aerobic glycolysis in cervical cancer by regulating PARP1

Cervical cancer (CC) ranks the fourth in gynecologic cancers. The incidence and mortality of CC has been decreased due to the cancer screening and early treatments in recent years, but the prognosis of CC patients at advanced stage is still sorrowful. Whether PSME3 exerted a role in the radioresistance of CC cells remains to be investigated. In this study, the expression of PSME3 in mRNA and protein levels was measured by RT-qPCR and western blot analysis, and increased expression of PSME3 in CC tissues and cells was observed. CCK-8 and colony formation assay revealed that the cell viability and proliferation of Hela and CaSki cells treated with different doses of X-ray was reduced due to the depletion of PSME3, indicating that silencing of PSME3 enhanced the radiosensitivity of CC cells. In addition, repair on DNA damage in CC cells was enhanced by PSME3 and the damage was attenuated by PSME3. Besides, the expression of glycolysis-related proteins (GLUT1, PGC-1α, LDHA and HK2) were enhanced by PSME3 but reduced by silencing PSME3 in CC cells. PSME3 restraint attenuated the levels of glucose consumption and lactate production, suggesting PSME3 depletion suppressed abnormal glycolysis of CC cells. Mechanically, PSME3 increased the PARP1 expression via elevating c-myc. Finally, we observed PSME3 attenuation inhibited CC growth in vivo. In conclusion, PSME3 enhanced radioresistance and aerobic glycolysis in CC by regulating PARP1, which might shed a light into the function of PSME3 in CC treatment.

Glutamine metabolism targeting liposomes for synergistic chemosensitization and starvation therapy in ovarian cancer

Platinum-based chemotherapy is a first-line therapeutic regimen against ovarian cancer (OC); however, the therapeutic potential is always reduced by glutamine metabolism. Herein, a valid strategy of inhibiting glutamine metabolism was proposed to cause tumor starvation and chemosensitization. Specifically, reactive oxygen species-responsive liposomes were developed to co-deliver cisplatin (CDDP) and bis-2-(5-phenylacetamido-1,3,4-thiadiazol-2-yl) ethyl sulfide (BPTES) [C@B LPs]. The C@B LPs induced effective tumor cell starvation and significantly sensitized OC cells to CDDP by reducing glutathione generation to prevent CDDP detoxification, suppressing ATP production to avoid CDDP efflux, hindering nucleotide synthesis to aggravate DNA damage induced by CDDP, and blocking mammalian target of rapamycin (mTOR) signaling to promote cell apoptosis. More importantly, C@B LPs remarkably inhibited tumor growth in vivo and reduced the side effects. Taken together, this study provided a successful strategy of synergistic chemosensitization and starvation therapy escalating the rate of therapeutic success in OCs. STATEMENT OF SIGNIFICANCE: This work proposed a valid strategy of inhibiting glutamine metabolism to cause tumor starvation and chemosensitization. Specifically, ROS-responsive liposomes were developed to co-deliver cisplatin CDDP and BPTES [C@B LPs]. The C@B LPs induced effective tumor cell starvation and significantly sensitized OC cells to cisplatin by reducing glutathione generation to prevent cisplatin detoxification, suppressing ATP production to avoid cisplatin efflux, hindering nucleotide synthesis to aggravate DNA damage induced by cisplatin, and blocking mTOR signaling to promote cell apoptosis. More importantly, C@B LPs remarkably inhibited tumor growth in vivo and reduced the side effects. Taken together, this study provided a successful strategy of synergistic chemosensitization and starvation therapy escalating the rate of therapeutic success in OCs.

Micturition symptoms in gynecologic cancer patients receiving paclitaxel and platinum-based chemotherapy regimen: a prospective study

OBJECTIVE

To evaluate the effect of paclitaxel and platinum-based chemotherapy (PT) on micturition symptoms.

METHODS

All gynecologic cancer patients who were assigned to receive the PT regimen and understood the Thai language were invited to participate in this study. The exclusion criteria were as follows: abnormal urinary symptoms, retained urinary catheter or percutaneous nephrostomy, anticholinergic drug use, or scheduled to receive radiation therapy after the completion of chemotherapy. The participants were interviewed using three Thai validated questionnaires, the incontinence impact questionnaire-short form, urogenital distress inventory short form, and Sandvik score, on the day before receiving the first cycle of chemotherapy (pre-treatment), on the day before receiving the 4th cycle (mid-treatment), and 46 weeks after completing 69 cycles (post-treatment). The scores at the three time points were compared. Patients who received less than three cycles were not included in the analysis.

RESULTS

One hundred and ten patients were included in this study. There were significant differences in the median questionnaire scores at the three time points for both carboplatin plus paclitaxel and cisplatin plus paclitaxel. However, when using a pairwise difference between the two treatment protocols, there were no significant changes in the score from pre-treatment to post-treatment.

CONCLUSION

The PT regimen has an impact on micturition symptoms during chemotherapy which recover after treatment completion.

The risk of distant metastases in patients with gynecologic cancers after surgery: a population-based study

The aim of the study was to determine the risk of distant metastases in patients with gynecologic cancers after surgery, including cervical, uterine and ovarian cancers. This is a retrospective study evaluating gynecologic cancer from 2009 to 2014 using population-based administrative datasets from the Health and Welfare Data Science Center (HWDC) and from The National Health Informatics Project (NHIP). A total of 1,464 gynecologic cancer patients, including 321 cervical cancer patients, 724 uterine cancer patients and 419 ovarian cancer patients, were analyzed retrospectively from 2009 to 2014. Among the cervical cancer patients, 173 (53.89%) received surgery only and 148 (46.11%) received surgery with radiotherapy /chemotherapy. Among the uterus cancer patients, 425(58.70%) received surgery only and 299 (41.3%) received surgery with radiotherapy /chemotherapy. Among the ovarian cancer patients, 81 (19.33%) received surgery only and 338 (80.67%) received surgery with radiotherapy/chemotherapy. Among patients with brain, liver or lung metastasis, cervical cancer patients have more cumulative metastasis-free survival than those ovarian cancer (p=0.0041). In analyzing liver metastasis based on primary cancer sites, cervical cancer patients and uterine cancer cases have more cumulative metastasis- free survival than those ovarian cancer (p<0.0001). In conclusion, ovarian cancer patients have higher risk of liver metastasis than cervical or uterine cancer. There were significantly different of pathological stage for cumulative metastasis-free survival among gynecologic cancer patients with brain or liver or lung metastasis. Pathological T stage remains the main predictive for distant metastasis of gynecologic cancer.

The therapeutic potential of exosomal miR-22 for cervical cancer radiotherapy

Cervical cancer is the fourth-most prevalent malignancy in women. For advanced cervical cancer, radiotherapy is a major treatment. Micro RNAs (miRNAs) are small, noncoding RNAs that negatively regulate the target gene expression posttranscriptionally. miR-22 is frequently downregulated in various cancers including cervical cancer, and is associated with a poor prognosis in cervical cancer. Exosomes are small endosomally secreted vesicles that carry components such as proteins, messenger RNA (mRNA), DNA and miRNA. We investigated whether or not exosomes can efficiently deliver miR-22 to recipient cervical cancer cells and affect the gene expression in the cells, as well as assessed the role of exosomal miR-22 in radiosensitivity. Exosomes containing high levels of miR-22 were extracted by ultracentrifugation and then characterized by Western blotting, a nanoparticle tracking analysis and electron microscopy. The high presence of miR-22 in the exosome was confirmed by real-time polymerase chain reaction. After the administration of the collected exosomal miR-22 to SKG-II and C4-I cervical cancer cells, the level of miR-22 in the cells was significantly increased, indicating the absorption of the exosomal miR-22. When miR-22 encapsulated in exosomes was administered to the SKG-II cells, the level of c-Myc binding protein (MYCBP) and human telomerase reverse transcriptase (hTERT) was significantly decreased in correlation with increased radiosensitivity determined by a clonogenic assay. Taken together, these results suggest that the administration of exosomal miR-22 may be a novel drug delivery system for cervical cancer radiotherapy.

Inhibition of the MYC-Regulated Glutaminase Metabolic Axis Is an Effective Synthetic Lethal Approach for Treating Chemoresistant Ovarian Cancers

Amplification and overexpression of the MYC oncogene in tumor cells, including ovarian cancer cells, correlates with poor responses to chemotherapy. As MYC is not directly targetable, we have analyzed molecular pathways downstream of MYC to identify potential therapeutic targets. Here we report that ovarian cancer cells overexpressing glutaminase (GLS), a target of MYC and a key enzyme in glutaminolysis, are intrinsically resistant to platinum-based chemotherapy and are enriched with intracellular antioxidant glutathione. Deprivation of glutamine by glutamine-withdrawal, GLS knockdown, or exposure to the GLS inhibitor CB-839 resulted in robust induction of reactive oxygen species in high GLS-expressing but not in low GLS-expressing ovarian cancer cells. Treatment with CB-839 rendered GLS^high cells vulnerable to the poly(ADP-ribose) polymerase (PARP) inhibitor, olaparib, and prolonged survival in tumor-bearing mice. These findings suggest consideration of applying a combined therapy of GLS inhibitor and PARP inhibitor to treat chemoresistant ovarian cancers, especially those with high GLS expression. SIGNIFICANCE: Targeting glutaminase disturbs redox homeostasis and nucleotide synthesis and causes replication stress in cancer cells, representing an exploitable vulnerability for the development of effective therapeutics. GRAPHICAL ABSTRACT: http://cancerres.aacrjournals.org/content/canres/80/20/4514/F1.large.jpg.

Ovarian, uterine, and cervical cancer patients with distant metastases at diagnosis: most common locations and outcomes

To determine the location patterns of distant metastases at initial staging and outcomes of ovarian, uterine, and cervical cancer patients. Data were obtained from the SEER database from 2010 to 2015. Analyses were performed using Kaplan-Meier and multivariate Cox proportional hazard methods. Of 3035 patients (median age: 63, range: 17-95) with stage IV gynecologic cancer, ovarian, uterine, and cervical cancers were present in 42%, 40%, and 18% of the cohort. The proportion of lung, liver, bone and brain metastases were identified in 38%, 57%, 4%, and 1% of ovarian cancer patients, 62%, 22%, 13%, and 3% of uterine cancer patients, and 59%, 16%, 23%, and 2% of cervical cancer patients, respectively. The 5-year disease-specific survival for all patients was 19%. Those with liver metastases had survival rates of 26% compared to 15% for lung, 13% for bone, and 6% for brain (p < 0.0001). Patients with ovarian, uterine, and cervical cancers had survival rates of 28%, 12%, and 12%, respectively (p < 0.0001). On multivariate analysis, brain metastasis (HR = 1.64, 95% CI 1.21-2.22, p < 0.01), uterine (HR = 1.77, 95 CI 1.56-2.02, p < 0.0001) and cervical (HR = 1.35, 95% CI 1.11-1.63, p < 0.01) cancers, and lack of insurance (HR = 1.41, 95% CI 1.16-1.73, p < 0.001) were independent predictors for poorer survival. Age, year, region, and race did not affect prognosis. Stage IV ovarian cancer most frequently metastasizes to the liver, whereas uterine and cervical cancers spread more to the lung. Overall, these patients have poor prognosis, particularly those with uterine or cervical primary disease or brain metastases.

Dual Actions of Ketorolac in Metastatic Ovarian Cancer

Cytoreductive surgery and chemotherapy are cornerstones of ovarian cancer treatment, yet disease recurrence remains a significant clinical issue. Surgery can release cancer cells into the circulation, suppress anti-tumor immunity, and induce inflammatory responses that support the growth of residual disease. Intervention within the peri-operative window is an under-explored opportunity to mitigate these consequences of surgery and influence the course of metastatic disease to improve patient outcomes. One drug associated with improved survival in cancer patients is ketorolac. Ketorolac is a chiral molecule administered as a 1:1 racemic mixture of the S- and R-enantiomers. The S-enantiomer is considered the active component for its FDA indication in pain management with selective activity against cyclooxygenase (COX) enzymes. The R-enantiomer has a previously unrecognized activity as an inhibitor of Rac1 (Ras-related C3 botulinum toxin substrate) and Cdc42 (cell division control protein 42) GTPases. Therefore, ketorolac differs from other non-steroidal anti-inflammatory drugs (NSAIDs) by functioning as two distinct pharmacologic entities due to the independent actions of each enantiomer. In this review, we summarize evidence supporting the benefits of ketorolac administration for ovarian cancer patients. We also discuss how simultaneous inhibition of these two distinct classes of targets, COX enzymes and Rac1/Cdc42, by S-ketorolac and R-ketorolac respectively, could each contribute to anti-cancer activity.

KISS1/KISS1R in Cancer: Friend or Foe?

The KISS1 gene encodes KISS1, a protein that is rapidly processed in serum into smaller but biologically active peptides called kisspeptins (KPs). KISS1 and the KPs signal via the G-protein coupled receptor KISS1R. While KISS1 and KPs are recognized as potent positive regulators of the reproductive neuroendocrine axis in mammals, the first reported role for KISS1 was that of metastasis suppression in melanoma. Since then, it has become apparent that KISS1, KPs, and KISS1R regulate the development and progression of several cancers but interestingly, while these molecules act as suppressors of tumorigenesis and metastasis in many cancers, in breast and liver cancer they function as promoters. Thus, they join a small but growing number of molecules that exhibit dual roles in cancer highlighting the importance of studying cancer in context. Given their roles, KISS1, KPs and KISS1R represent important molecules in the development of novel therapies and/or as prognostic markers in treating cancer. However, getting to that point requires a detailed understanding of the relationship between these molecules and different cancers. The purpose of this review is therefore to highlight and discuss the clinical studies that have begun describing this relationship in varying cancer types including breast, liver, pancreatic, colorectal, bladder, and ovarian. An emerging theme from the reviewed studies is that the relationship between these molecules and a given cancer is complex and affected by many factors such as the micro-environment and steroid receptor status of the cancer cell. Our review and discussion of these important clinical studies should serve as a valuable resource in the successful development of future clinical studies.