Injectable three-dimensional tumor microenvironments to study mechanobiology in ovarian cancer

Epithelial ovarian cancers are among the most aggressive forms of gynecological malignancies. Despite the advent of poly adenosine diphosphate-ribose polymerase (PARP) and checkpoint inhibitors, improvement to patient survival has been modest. Limited in part by clinical translation, beneficial therapeutic strategies remain elusive in ovarian cancers. Although elevated levels of extracellular proteins, including collagens, proteoglycans, and glycoproteins, have been linked to chemoresistance, they are often missing from the processes of drug- development and screening. Biophysical and biochemical signaling from the extracellular matrix (ECM) determine cellular phenotype and affect both tumor progression and therapeutic response. However, many state-of-the-art tumor models fail to mimic the complexities of the tumor microenvironment (TME) and omit key signaling components. In this article, two interpenetrating network (IPN) hydrogel scaffold platforms, comprising of alginate-collagen or agarose-collagen, have been characterized for use as 3D in vitro models of epithelial ovarian cancer ECM. These highly tunable, injection mold compatible, and inexpensive IPNs replicate the critical governing physical and chemical signaling present within the ovarian TME. Additionally, an effective and cell-friendly live-cell retrieval method has been established to recover cells post-encapsulation. Lastly, functional mechanotransduction in ovarian cancers was demonstrated by increasing scaffold stiffness within the 3D in vitro ECM models. With these features, the agarose-collagen and alginate-collagen hydrogels provide a robust TME for the study of mechanobiology in epithelial cancers. STATEMENT OF SIGNIFICANCE: Ovarian cancer is the most lethal gynecologic cancer afflicting women today. Here we present the development, characterization, and validation of 3D interpenetrating platforms to shift the paradigm in standard in vitro modeling. These models help elucidate the roles of biophysical and biochemical cues in ovarian cancer progression. The agarose-collagen and alginate-collagen interpenetrating network (IPN) hydrogels are simple to fabricate, inexpensive, and can be modified to create custom mechanical stiffnesses and concentrations of bio-adhesive motifs. Given that investigations into the roles of biophysical characteristics in ovarian cancers have provided incongruent results, we believe that the IPN platforms will be critically important to uncovering molecular drivers. We also expect these platforms to be broadly applicable to studies involving mechanobiology in solid tumors.

Exercise Among Women With Ovarian Cancer: A Feasibility and Pre-/Post-Test Exploratory Pilot Study

PURPOSE/OBJECTIVES

To establish the feasibility and acceptability of completing a higher dose of the planned physical activity volume among women with ovarian cancer, including those undergoing active treatment. 
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DESIGN

A pre-/post-test exercise intervention. All participants were asked to complete 225 minutes per week of physical activity for 26 weeks. Multiple supports were provided, including exercise DVDs, self-reported logs, and an objective physical activity tracker (Fitbit®).
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SETTING

Home-based exercise intervention with in-person training and telephone follow-ups.
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SAMPLE

10 women with ovarian cancer who were treated within Penn Medicine in Philadelphia, Pennsylvania.
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METHODS

Home-based, in-person exercise counseling was provided by an exercise trainer weekly for the first six weeks and then monthly for a total of 26 weeks. Weekly follow-up telephone calls were used to assess exercise adherence and barriers to completing exercise, review symptom changes, and provide behavioral support. 
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MAIN RESEARCH VARIABLES

Feasibility and acceptability.
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FINDINGS

Eight participants completed the study and achieved at least 80% of the prescribed exercise dose. Five participants were undergoing chemotherapy simultaneously. Participants experienced no adverse events during the 26-week intervention. Compared to baseline, average steps increased by 1,593 per day and moderate-intensity physical activity increased by 15 minutes per day. 
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CONCLUSIONS

A 225-minutes-per-week exercise program is feasible and acceptable in a population of patients with ovarian cancer. Participants significantly improved their physical activity during the 26-week intervention.
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IMPLICATIONS FOR NURSING

The findings suggest that nursing professionals could recommend that women with ovarian cancer exercise 225 minutes per week regardless of cancer and/or treatment trajectory. For those experiencing aches and pains, behavioral supports and suggestions of a lower exercise dose are needed to maintain physical activity.

Randomized multicenter phase II trial comparing two schedules of etirinotecan pegol (NKTR-102) in women with recurrent platinum-resistant/refractory epithelial ovarian cancer

PURPOSE

Etirinotecan pegol (NKTR-102) is a unique, long-acting topoisomerase-I inhibitor with prolonged systemic exposure to SN38 (7-ethyl-10-hydroxycamptothecin), the active metabolite of irinotecan. This randomized phase II trial investigated two dosing schedules of etirinotecan pegol in patients with platinum-resistant/refractory ovarian carcinoma.

PATIENTS AND METHODS

A total of 71 eligible patients were randomly assigned to receive etirinotecan pegol 145 mg/m(2) every 14 or 21 days until progression or unacceptable adverse events (AEs). The primary end point was objective response rate (ORR) by RECIST (version 1.0). Secondary end points included response by Gynecologic Cancer Intergroup criteria, duration of ORR, progression-free survival (PFS), and overall survival (OS).

RESULTS

The overall confirmed ORR was 20% (95% CI, 10% to 30%): 20% for once every 14 days, and 19% for once every 21 days. Median response duration was 4.1 months for once every 14 days and 4.0 months for once every 21 days. Median PFS for every 14 and every 21 days was 4.1 and 5.3 months, respectively, and median OS was 10.0 and 11.7 months, respectively. Etirinotecan pegol was well tolerated, with the most common grade 3 to 4 AEs being dehydration (24%) and diarrhea (23%). Diarrhea, dehydration, nausea, and neutropenia were less frequent with the schedule of once every 21 days than with that of once every 14 days.

CONCLUSION

Both schedules of etirinotecan pegol showed activity in patients with heavily pretreated ovarian cancer, with encouraging ORR and PFS rates. The schedule of once every 21 days was better tolerated and had slightly longer PFS and OS rates. The treatment schedule of etirinotecan pegol 145 mg/m(2) once every 21 days was selected for the expanded phase II study and is preferred for future phase III studies. These findings provide support to directly compare etirinotecan pegol versus one of the approved drugs (eg, pegylated liposomal doxorubicin or topotecan) in platinum-resistant ovarian cancer.