Abstract 6223: PD3D®models: New age in cancer research and clinical diagnostics

Patient-derived 3D cell culture models (PD3D®) developed as a powerful tool for disease modelling, biomarker and drug discovery. Currently, they are gaining increasing significance in the field of personalized oncology, as they recapitulate the histopathology of the original tumor tissue and preserve its genetic markup. PD3D® can be used to model intratumoral heterogeneity and for medium and high throughput drug screens. Using a reverse clinical engineering approach, PD3D® models allow identification of chemoresistance/sensitivity signatures (i.e., biomarkers) and can be applied in personalized oncology to identify treatment for an individual patient. We successfully established PD3D® models from more than 300 tumor tissue samples, ranging from more prevalent cancers like colorectal, breast and pancreas carcinoma, to rare tumor entities including various sarcoma types and thymoma. PD3D® models from different tumor entities differ in morphology and culture media requirements. When treating PD3D® from the same tumor entity with standard of care drugs, we found that their response differed, as does clinical response of patients. Furthermore, we successfully used PD3D® models to identify a biomarker for predicting chemosensitivity towards a targeted drug. For application of PD3D® in truly personalized oncology, we developed a protocol that allows us to generate a PD3D® culture and perform a drug sensitivity assay for an individual patient within a therapy-relevant timeframe. Using this protocol, we identified a combination therapy for a pretreated, metastasized appendix carcinoma within 29 days, that resulted in stable disease of the patient. In conclusion, PD3D® models can be derived from various cancer entities and used to analyze drug response in cohorts of models for drug development or identification of signatures related to drug resistance or sensitivity. Furthermore, PD3D® models can be used to predict a patient tumor’s drug response in a personalized manner, supporting the oncologist to identify the best treatment option for the patient.

Citation Format: Alina Pflaume, Samantha Exner, Katja Herrera-Glomm, Jürgen Loskutov, Ulrike Pfohl, Manuela Regenbrecht, Sushmitha Sankarasubramanian, Lena Wedeken, Sabine Finkler, Larissa Ruhe, Quirin Graf Adelmann, Christoph Reinhard, Philipp Stroebel, Christian R. Regenbrecht. PD3D®models: New age in cancer research and clinical diagnostics [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6223.

Abstract 6224: The bad, the ugly and the ultra-rare: All cancers are equal in the face of personalized medicine

Cancer represents a huge health problem worldwide and is well-recognized as an extremely heterogeneous disease affecting all the tissues and organs. The incidence of the particular cancer type is directly connected to the availability of specific medication and amount of the research focused on it, resulting in a high unmet medical need for treatment options for rare cancers. Currently, NCI defines “rare cancer” as cancer with an incidence rate below 15 per 10^5 people per year and recently the term “ultra-rare cancer” was defined as cancer with an incidence rate below 1 per 10^6 people per year. These encompass drastically understudied entities, usually with poor prognosis and grim outlook for an improvement in treatment. Low incidence of such cancers makes development of targeted therapies not interesting from a commercial point of view and completely abolishes the possibility of large-scale clinical trials. Therefore, a personalized medicine approach appears to be the most promising strategy for the patients to get adequate care.

Here we report our experience with personalized oncology solutions for rare and ultra-rare cancers. We utilized patient derived 3D (PD3D) cultures to evaluate prospective therapeutic options in these exceptional cases to support the oncologists in providing personalized care to the patients. Fresh surgical specimens underwent several steps of mechanical and chemical dissociation. Subsequently, cell aggregates were seeded into 24 well plates in matrix-like scaffolds and allowed to grow until they started forming colonies. After harvesting, the cells underwent pathology evaluation to confirm origin and diagnosis. Therapies, recommended by the case leading oncologist, were used for drug sensitivity testing after transferring cells semi- automatically to 384-well plates.

Over the last 18 months, we handled 6 cases classified as rare or ultra-rare cancers. The diagnoses included: clear cell sarcoma, extra-skeletal myxoid chondrosarcoma, CIC-rearranged round cell sarcoma, pleomorphic liposarcoma, cardiac angiosarcoma and clear cell endometrial carcinoma. In all cases we were able to successfully establish PD3D cultures and perform a drug screen, identifying a potential treatment for the patient.

Overall, our results indicate that it is feasible to utilize our testing strategy for rare and ultra-rare cancer entities. Further research and rigorous follow up is required to confirm the benefit of the personalized approach vs current strategies. However, a demand for personalized care in such cases is clearly visible.

Citation Format: Juergen Loskutov, Manuela Regenbrecht, Rica Sauer, Sabine Finkler, Maya Niethard, Christoph Reinhard, Christian Regenbrecht. The bad, the ugly and the ultra-rare: All cancers are equal in the face of personalized medicine [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6224.

Precision Oncology Beyond Genomics: The Future Is Here-It Is Just Not Evenly Distributed

Cancer is a multifactorial disease with increasing incidence. There are more than 100 different cancer types, defined by location, cell of origin, and genomic alterations that influence oncogenesis and therapeutic response. This heterogeneity between tumors of different patients and also the heterogeneity within the same patient's tumor pose an enormous challenge to cancer treatment. In this review, we explore tumor heterogeneity on the longitudinal and the latitudinal axis, reviewing current and future approaches to study this heterogeneity and their potential to support oncologists in tailoring a patient's treatment regimen. We highlight how the ideal of precision oncology is reaching far beyond the knowledge of genetic variants to inform clinical practice and discuss the technologies and strategies already available to improve our understanding and management of heterogeneity in cancer treatment. We will focus on integrating multi-omics technologies with suitable in vitro models and their proficiency in mimicking endogenous tumor heterogeneity.

Inhibiting phosphoglycerate dehydrogenase counteracts chemotherapeutic efficacy against MYCN-amplified neuroblastoma

Here we sought metabolic alterations specifically associated with MYCN amplification as nodes to indirectly target the MYCN oncogene. Liquid chromatography-mass spectrometry-based proteomics identified seven proteins consistently correlated with MYCN in proteomes from 49 neuroblastoma biopsies and 13 cell lines. Among these was phosphoglycerate dehydrogenase (PHGDH), the rate-limiting enzyme in de novo serine synthesis. MYCN associated with two regions in the PHGDH promoter, supporting transcriptional PHGDH regulation by MYCN. Pulsed stable isotope-resolved metabolomics utilizing ¹³ C-glucose labeling demonstrated higher de novo serine synthesis in MYCN-amplified cells compared to cells with diploid MYCN. An independence of MYCN-amplified cells from exogenous serine and glycine was demonstrated by serine and glycine starvation, which attenuated nucleotide pools and proliferation only in cells with diploid MYCN but did not diminish these endpoints in MYCN-amplified cells. Proliferation was attenuated in MYCN-amplified cells by CRISPR/Cas9-mediated PHGDH knockout or treatment with PHGDH small molecule inhibitors without affecting cell viability. PHGDH inhibitors administered as single-agent therapy to NOG mice harboring patient-derived MYCN-amplified neuroblastoma xenografts slowed tumor growth. However, combining a PHGDH inhibitor with the standard-of-care chemotherapy drug, cisplatin, revealed antagonism of chemotherapy efficacy in vivo. Emergence of chemotherapy resistance was confirmed in the genetic PHGDH knockout model in vitro. Altogether, PHGDH knockout or inhibition by small molecules consistently slows proliferation, but stops short of killing the cells, which then establish resistance to classical chemotherapy. Although PHGDH inhibition with small molecules has produced encouraging results in other preclinical cancer models, this approach has limited attractiveness for patients with neuroblastoma.

Reflection of neuroblastoma intratumor heterogeneity in the new OHC-NB1 disease model

Accurate modeling of intratumor heterogeneity presents a bottleneck against drug testing. Flexibility in a preclinical platform is also desirable to support assessment of different endpoints. We established the model system, OHC-NB1, from a bone marrow metastasis from a patient diagnosed with MYCN-amplified neuroblastoma and performed whole-exome sequencing on the source metastasis and the different models and passages during model development (monolayer cell line, 3D spheroid culture and subcutaneous xenograft tumors propagated in mice). OHC-NB1 harbors a MYCN amplification in double minutes, 1p deletion, 17q gain and diploid karyotype, which persisted in all models. A total of 80-540 single-nucleotide variants (SNVs) was detected in each sample, and comparisons between the source metastasis and models identified 34 of 80 somatic SNVs to be propagated in the models. Clonal reconstruction using the combined copy number and SNV data revealed marked clonal heterogeneity in the originating metastasis, with four clones being reflected in the model systems. The set of OHC-NB1 models represents 43% of somatic SNVs and 23% of the cellularity in the originating metastasis with varying clonal compositions, indicating that heterogeneity is partially preserved in our model system.

Early discharge and home care after unplanned cesarean birth: nursing care time

OBJECTIVE

This study examined the mean nursing time spent providing discharge planning and home care to women who delivered by unplanned cesarean birth and examined differences in nursing time required by women with and without morbidity.

DESIGN

A secondary analysis of nursing time from a randomized trial of transitional care (discharge planning and home follow-up) provided to women after cesarean delivery.

SETTING

An urban tertiary-care hospital.

PATIENTS

The sample (N = 61) of black and white women who had unplanned cesarean births and their full-term newborn was selected randomly. Forty-four percent of the women had experienced pregnancy complications.

INTERVENTIONS

Advanced practice nurses provided discharge planning and 8-week home follow-up consisting of home visits, telephone outreach, and daily telephone availability.

OUTCOME MEASURE

Nursing time required was dictated by patient need and provider judgment rather than by reimbursement plan.

RESULTS

More than half of the women required more than two home visits; mean home visit time was 1 hour. For women who experienced morbidity mean discharge planning time was 20 minutes more and mean home visit time 40 minutes more.

CONCLUSIONS

Current health care services that provide one or two 1-hour home visits to childbearing women at high risk may not be meeting the education and resource needs of this group.

Solid-state 13C-NMR of [(3-13C)Pro]bacteriorhodopsin and [(4-13C)Pro]bacteriorhodopsin: evidence for a flexible segment of the C-terminal tail

The configuration of an Xaa-Pro bond can be determined by solid-state magic-angle-sample-spinning (MASS)-13C-NMR spectroscopy since the chemical shifts of C beta and Cgamma of the proline ring are sensitive to the isomerization state of the preceding peptide bond. (3-13C)Pro and (4-13C)Pro have been chemically synthesized; the former by means of an asymmetric synthesis. The 13C-labeled Pro residues were biosynthetically incorporated into bacteriorhodopsin with a yield of 80%. The solid-state-MASS-13C-NMR spectra of [(3-13C)Pro]bacteriorhodopsin and [(4-13C)Pro]bacteriorhodopsin revealed isotropic chemical shifts at 29.8 ppm and 25.5 ppm, respectively. From the chemical-shift values we conclude that all Xaa Pro peptide bonds are in the trans configuration confirming previous results from solution-NMR studies on solubilized bacteriorhodopsin in organic solvents [Deber, M.C., Sorrell, B.J. & Xu, G.Y. (1990) Biochem. Biophys. Res. Commun. 172, 862-869]. Inversion-recovery experiments could differentiate between three classes of Pro residues distinguished by their relaxation time t1. Tentatively, these three distinct groups of Pro residues could be assigned to the helical, the loop, and the C-terminal parts of the protein. The resonances of the two C-terminal Pro could be identified by removing the C-terminus by proteolysis. Although they are separated by only one Glu they occupy different chemical environments and possess different flexibilities. These results indicate that the first part of the C-terminal tail is constrained. Pro238 marks the position where the tail becomes freely mobile. It is proposed that the C-terminus is fixed to the membrane via salt bridges between divalent cations and negative charges of the C-terminus as well as interhelical loops.

A randomized trial of early hospital discharge and home follow-up of women having cesarean birth

OBJECTIVE

To determine the safety, efficacy, and cost savings of early hospital discharge of women delivered by unplanned cesarean delivery.

METHODS

Using randomized assignment, 61 postpartum women were discharged from the hospital at the usual time, and 61 were discharged early and had nurse specialist home follow-up care. The latter group received comprehensive discharge planning, instruction, counseling, home visits, and daily on-call availability from the nurse specialists. Both groups were followed from delivery to 8 weeks postpartum.

RESULTS

Women who were discharged early and received transitional home care services by clinical nurse specialists were sent home a mean of 30.3 hours earlier than the control group (P < .001). They had significantly greater satisfaction with care, more of their infants had timely immunizations at the end of follow-up, and they had a 29% reduction in health care charges compared to the control group receiving routine care. Although there were no statistically significant differences in maternal and infant rehospitalizations and acute-care visits, there were more maternal rehospitalizations in the control group than in the nurse specialist-followed group (three versus zero). No statistically significant differences were found between the groups in the outcomes of maternal affect and overall functional status.

CONCLUSION

Early hospital discharge of women after unplanned cesarean birth, using the model of nurse specialist transitional home care, is safe, feasible, and cost-effective.

New York's role as a center for health care: an analysis of nonresident patients served by New York City hospitals

Patients who reside outside of New York City have long been an important segment of the patient population at New York City hospitals. Each year, as far back as systematic data are available, approximately 10 percent of all patients at New York City hospitals have been non residents. Increasing competition and changing reimbursement policies compel hospitals in New York City to assess their role in caring for these patients and its economic implications. This report provides a comprehensive assessment of the characteristics of nonresident patients and their significance to the city's hospitals. Using data from all New York City hospitals, the report analyzes the demographics, insurance coverage, and case-mix characteristics of nonresident and resident patients. And, using more detailed data from New York University Medical Center and Columbia-Presbyterian Medical Center, it addresses the financial and reimbursement policy questions posed by the care of nonresident patients. The key findings of the report are as follows: A total of 115,307 nonresidents were hospitalized in New York City in 1982; this figure represents 10.4 percent of all patients in city hospitals. Over 80 percent of nonresident patients come from 14 counties surrounding New York City. Nonresident patients are a crucial component of the patient population at six hospitals that are the principal affiliates of a medical school and the six specialty hospitals. At academic health centers, nonresidents represent 25 percent of all inpatients; at the specialty hospitals, they represent 36 percent. Manhattan hospitals account for 69 percent of all nonresident discharges in the city. Outside of Manhattan, only Montefiore Medical Center and Long Island Jewish Medical Center have substantial numbers of nonresident patients. Among nonresident patients, 75 percent of admissions are scheduled in advance and 72 percent of hospital stays are for surgical procedures. In contrast, among resident patients, only 50 percent of admissions ares scheduled and 52 percent are for surgical procedures. Almost two-thirds of nonresident patients are covered by private insurance, compared to one-third of residents. Nonresident patients require more hospital resources on average than residents do. The average Diagnosis Related Group (DRG) weight, a measure of expected resource intensity, is 22.5 percent higher for nonresidents than for residents. However, nonresidents also come to New York City hospitals for relatively routine care. For example, the most common diagnoses among nonresidents and residents are uncomplicated deliveries and abortions. At New York University Medical Center and Columbia-Presbyterian Medical Center, nonresidents have higher average charges than residents, but the charge differences are much smaller than the DRG weight differences. Thus, within a given DRG, nonresidents consume fewer resources than residents. Under Medicare's Prospective Payment System bases on DRGs, nonresidents appear to be financially attractive to New York hospitals, based on the experience of New York University Medical Center.