Abstract 162: Individualizing treatment using patient derived organoids, BH3 profiling and microfluidics: A proof of concept in a patient with low-grade serous ovarian carcinoma

Background N of 1 treatment paradigms represent the pinnacle of personalized medicine in which a patient’s tumors are profiled to guide treatment. Low-grade serous ovarian cancer (LGSC) is a distinct subtype of ovarian cancer, comprising ~10% of serous carcinomas and typically characterized by a younger age of onset. Molecularly, these tumors are often characterized by alterations within the Ras signaling pathway, including KRAS mutations. Clinically, LGSC is often resistant to standard cytotoxic chemotherapy, but may have sensitivity to hormonal therapy or MEK inhibitors. Here we report on a platform and proof of concept in one LGSC patient to evaluate personalized tumor-directed therapy regimens using patient-derived organoids (PDOs), BH3 profiling and viability evaluation in 3D microfluidic devices.

Methods A patient with LGSC presented to the Dana Farber Cancer Institute and was treated with carboplatin and paclitaxel before a total abdominal hysterectomy with a bilateral salpingo-oophorectomy. Tissue was obtained under an IRB approved protocol and PDOs were established. Standard of care and non-standard of care treatments including doxorubicin, abemaciclib, letrozole, alpelisib, tamoxifen, trametinib, venetoclax, and navitoclax were evaluated by two orthogonal assays. First, they were tested for delta priming by BH3 profiling (Bhola et.al., Sci Signal. 2020 ) and second for cell viability using 3D microfluidic devices by TMRM/DRAQ7 dual-color fluorescent staining. Standard of care treatments carboplatin and paclitaxel were evaluated as individual treatments and in combination in 3D microfluidic devices.

Results We successfully established a PDO model from the patient’s tumor sample in 14 days. BH3 profiling at 24 hours and viability in 3D microfluidic devices after 6 days in treatment showed that from the eight tested drugs, the model was sensitive to navitoclax and venetoclax. Average percent change in viability was -91.5% and -89.9%, respectively, and the drugs had a dynamic BH3 profiling index of 551.4 AUC (+/- 76.63) and 488.9 AUC (+/- 21.46) with the threshold of response being >175 for BH3 profiling. Trametinib showed a clear response in 3D, with an average percent change of -72.6% compared to the control but no significant response in BH3 profiling. Neither carboplatin and paclitaxel alone, nor in combination, elicited a significant change in viability. This observation was consistent with the patient’s history prior to surgery, where the tumor did not demonstrate significant clinical response to neoadjuvant carboplatin and paclitaxel therapy.

Conclusions We describe a proof of concept of a N of 1 response assessment platform for LGSC using PDOs, BH3 profiling and live/dead fluorescent staining in microfluidic devices and demonstrate that BH3 profiling and 3D viability assessment assays show good congruity.

Citation Format: Brittany Meisenheimer, Ha V. Vo, Kelley E. McQueeney, Aisha L. Saldanha, Carina Feeney, Courtney H. Qi, Swati Narayan, Jennifer D. Curtis, Marisa R. Nucci, Anthony Letai, Cloud P. Paweletz, Joyce F. Liu, Ursula A. Matulonis, Elena Ivanova. Individualizing treatment using patient derived organoids, BH3 profiling and microfluidics: A proof of concept in a patient with low-grade serous ovarian carcinoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 162.

Abstract 3065: Establishment and characterization of a platform of endometrial cancer organoids

Background: Endometrial cancer is the most commonly diagnosed gynecologic cancer in the US; the incidence is rising, and survival rates for this cancer are decreasing. There is a paucity of effective treatment for recurrent endometrial cancer, especially high grade endometrial cancers (HGEC) which include serous, carcinosarcoma, endometrioid, and clear cell histologies. Models that mimic the clinical and molecular characteristics of HGEC are lacking. To support the development of next generation therapeutics for endometrial cancer, we report on the establishment of 3D endometrial patient-derived organoids (PDOs) from HGEC.

Methods: 26 Tumors from 21 different patients with HGEC (Serous, Carcinosarcoma, Clear Cell and High-grade Endometrioid subtypes) who underwent surgical resection (n= 13), biopsy (n = 7), paracentesis (n = 3) or thoracentesis (n = 3) were passaged as 3D organoid cultures in Matrigel in an optimized media. Robust models (defined by average days to passage <14 days) were viably banked. 3 frozen models were also thawed and re-cultured to assess the viability post freezing. PDOs were collected for H&E staining and their histology was compared to the original diagnosis. DNA replication rate and the effect of replication stress on organoid growth were assessed by the DNA Fiber Assay and immunofluorescence (IF). Finally, an established clear cell endometrial cancer organoid model was engrafted in mice to generate a Patient-Derived Xenograft (PDX) model.

Results: Endometrial PDOs were successfully developed from 19 of 26 original samples for an overall success rate of 73.1%. Successful PDOs were developed from multiple histologies, including 8 carcinosarcoma, 6 uterine serous, 2 endometrioid, 2 clear cell and 1 mixed uterine serous and endometrioid. Though biopsy samples had initially fewer viable cells, our overall success rate was similar at 85.7% compared to 84.6% for surgical resections and higher than 66.7% for paracenteses. Samples obtained via thoracentesis did not form PDOs. Endometrial PDOs were histologically validated to match the primary patient tumor. Freeze thawing had no effect on morphology and growth characteristics. DNA fiber assays could be successfully conducted in PDOs, with a reduction in replication rate observed in PDO models treated with ATR or WEE1 inhibitors, with concurrent increase in y-H2AX and decrease in pRPA2 observed by IF. We also successfully generated a validated PDX model from organoids. Studies to determine molecular fidelity between the original patient tumor and established organoids are ongoing.

Conclusions: We describe the successful establishment of 19 endometrial PDO models which retain original tumor morphology and demonstrate sensitivity to drug-induced DNA damage. 3D endometrial organoids can therefore be used for further target discovery and validation as well as biomarker studies to advance targeted therapies for high-grade endometrial cancer.

Citation Format: Aisha L. Saldanha, Ha V. Vo, Kevin Vasquez, Kenneth Ngo, Shrabasti Roychoudhury, Carina Feeney, Courtney H. Qi, Swati Narayan, Jennifer D. Curtis, Prafulla C. Gokhale, Dipanjan Chowdhury, Cloud P. Paweletz, Marisa R. Nucci, Ursula A. Matulonis, Elena Ivanova, Joyce F. Liu. Establishment and characterization of a platform of endometrial cancer organoids [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 3065.

Abstract 1048: Genomic analysis of patients with relapsed ovarian cancer enrolled in a phase II trial of nivolumab and bevacizumab

We analyzed genomic alterations in patients with relapsed ovarian cancer treated with combined nivolumab and bevacizumab in a phase II clinical trial, in order to identify potential biomarkers of response. Thirty-eight patients were treated with nivolumab and bevacizumab and the previously reported overall response rate was 28.9% (Liu et al, JAMA Oncology, 2019). Formalin-fixed paraffin-embedded patient tumor samples (acquired pre-treatment) underwent whole-exome sequencing, followed by quality control filtering and analysis of mutations, insertions/deletions, copy-number alterations, and mutational signatures using established methods. Differences in genomic event rates were assessed between response groups, as defined by presence or absence of objective response or clinical benefit. We describe the genomic alterations in all patients treated with nivolumab and bevacizumab, including several long-term responders with treatment duration >24 months. The observed alterations in the patient cohort reflected known patterns of common mutations (e.g. TP53) and copy-number alterations (e.g. MYC amplification) in ovarian cancer. Within the limits of sample size, no significant differences in frequency of specific mutations were observed between response groups, with the possible exception of mutations in SETD1B, a histone methyltransferase, which were more frequent in the subset of patients lacking clinical benefit. BRCA1/2 mutation rate was similar between groups. Tumor mutational burden was not significantly different between groups. Initial exploratory analysis for copy-number alterations did not reveal genes with differential copy-number alterations between the response groups, and further analyses of copy-number alterations and mutational signatures are in progress. In summary, we describe genomic biomarker analysis from tumors of patients with relapsed ovarian cancer receiving treatment with nivolumab and bevacizumab. Taken together, we did not identify genomic alterations that clearly distinguish responding and non-responding patients in the data evaluated to date. Analysis of targeted RNA-sequencing data is planned as a next step. Further studies are needed to identify genomic or transcriptomic biomarkers of responses to checkpoint blockade and anti-angiogenic therapy in ovarian cancer.

Citation Format: Elizabeth H. Stover, Svitlana Tyekucheva, Yiwen Liu, Jennifer D. Curtis, Richard T. Penson, Joyce F. Liu. Genomic analysis of patients with relapsed ovarian cancer enrolled in a phase II trial of nivolumab and bevacizumab [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1048.

Teaching the clinical interpretation of peripheral blood smears to a second-year medical school class using the PeripheralBlood-Tutor computer program

The interpretation of peripheral blood smears has an important role in the diagnosis of hematologic diseases and is, therefore, part of the education of physicians and technologists. We describe a computer program, PeripheralBlood-Tutor (Lippincott-Raven, Philadelphia, Pa), that teaches the morphologic features of normal and abnormal peripheral blood smears; we also describe the evaluation of the effectiveness of the program in 133 second-year medical students who were required to use the program in their hematology course. The version of the PeripheralBlood-Tutor used in the study had 2 distinct but equivalent 20-question examinations; one examination, the pretest, was taken before the students viewed the contents of the program, and the other examination, the posttest, was taken after completing the program. The mean score on the pretest was 61% (SD, 14%), the mean on the posttest was 91% (SD, 10%), and the improvement was significant. In addition, 4 questions about peripheral blood smears, which were based on printed images, were administered at the end of the hematology course. The students scored an average of 2.75 (SD, 0.86), and a positive correlation was found between these scores and the scores on the Tutor posttest. The results of the study suggest that PeripheralBlood-Tutor is feasible to implement, and it helps students learn to interpret peripheral blood smears. The use of PeripheralBlood-Tutor is now a requirement in the medical school curriculum, the medical technology program, and the pathology residency at the University of Washington, Seattle.

Computer programs that teach the interpretation of image-based laboratory tests

OBJECTIVE

To review the effort of the University of Washington (UW) Department of Laboratory Medicine to develop and use personal computer programs to teach the interpretation of image-based clinical laboratory tests to medical technologists and other health care workers.

DATA SOURCES

Professional journals and books; Software owned by and licensed by the University of Washington.

STUDY SELECTION

Not applicable.

DATA EXTRACTION

Not applicable.

DATA SYNTHESIS

We have been developing interactive personal computer (PC) programs for teaching image-based laboratory tests to medical technologists and other health care workers. The programs, called "Laboratory Tutors," are useful for teaching microscope-based tests and tests based on electrophoresis. Our programs include ANA-Tutor, which teaches the immunofluorescence assay for anti-nuclear antibodies; Gram Stain-Tutor, which teaches the direct Gram stain; Electrophoresis-Tutor, which teaches the interpretation of agarose gel protein electrophoretic patterns; Urinalysis-Tutor, which teaches the microscopic examination of urine sediment; in addition to other programs. The tutorials are all based on high-quality digital images that were acquired and processed using digital imaging systems. They require minimal computer literacy and have a number of advantages over standard approaches to teaching image-based laboratory tests. The computer tutorials are used in UW's medical technology and medical school curriculum, where they are used as supplements to traditional instruction.

CONCLUSION

Laboratory tutors are computer programs that use high resolution digital images to teach the interpretation of image-based laboratory tests. We plan to continue to develop these programs, study their educational effectiveness, and update them periodically.

Developmental anatomy of internal cavities of epidermal origin in leaves of Polygonum (Polygonaceae)

Two types of internal oil cavity that develop from the epidermis occur in leaves of 15 species of Polygonum, sect. Persicaria. In one type, found in 10 species, epidermal cells develop directly into epidermal/epithelial (E/E) cells. In P. hydropiper, a single protoderm cell enlarges, grows into the mesophyll, and divides only anticlinically to form three, to seven (usually four) E/E cells. The enlarging E/E cells separate along the medial pan of their shared walls to form a central cavity. The protoplast of each E/E cell then retracts from the inner cell wall and deposits a new cell wall to form a peripheral lacuna between the original inner wall and the new wall. The original cell walls between central cavity and peripheral lacunae eventually disappear leaving an oil-filled mature internal cavity but with each E/E tell tip still exposed at the surface. The second type, found m five species, involves both subepidermal and epidermal cells. In our examples. P. glabrum and P. densiflorum, the initial protoderm cell divides anticlinally to form 8-20 cells, most of which grow into the mesophyll, divide periclinally, and separate to become epithelial cells surrounding a cavity. The Outermost cells remain epidermal the deeper ones are secondarily subepidermal. Peripheral lacunae and a central cavity form as in the epidermal cavity, but they do not merge into a single mature cavity. Epithelial cells, peripheral lacunae, and central cavity collectively form a subepidermal cavity complex.

Evaluation of neurotoxicity after subarachnoid injection of large volumes of local anesthetic solutions

Recent case reports describing prolonged neurologic deficit after accidental spinal anesthesia with large volumes of 2-chloroprocaine have led to the suggestion that chloroprocaine may be more likely to cause such complications than other local anesthetics. We evaluated the neurologic effects of lumbar puncture alone and of large-volume subarachnoid administration of 2-chloroprocaine (3%), bupivacaine (0.75%), lidocaine (2%), Elliott's solution B (which is similar to CSF), or the carrier solution of 2-chloroprocaine (Nesacaine) in 48 sheep and 8 monkeys. Cerebrospinal fluid of sheep was collected on days 1 and 7 for biochemical and biological analyses, and CSF pressures of monkeys were recorded before and after injection. Animals were observed for neurologic deficits for seven days. Twelve sheep were unable to stand. Monkeys, on the other hand, had no apparent neurologic deficits. Autopsies revealed that 5 of the 12 sheep had lumbar subpial demyelination with macrophage infiltration: two of the five had received lidocaine; two received 2-chloroprocaine; and one had only a lumbar puncture. Two other sheep also had subpial demyelination: one had received lidocaine and one received 2-chloroprocaine. Three of the eight monkeys had lumbar subpial demyelination with macrophage invasion; two had received bupivacaine, and one received 2-chloroprocaine. No solution produced significant abnormalities in sheep CSF composition. We conclude that no local anesthetic or solution was more neurotoxic than another when injected in large volumes into the subarachnoid space of sheep or monkeys.

Epidural morphine for the relief of postoperative pain after cesarean delivery

To determine the safety, efficacy, and dose response of epidurally administered morphine for analgesia after cesarean delivery, 40 healthy women who underwent cesarean delivery with epidural anesthesia were randomly assigned to receive one of four regimens for relief of postoperative pain: intramuscular administration of morphine, 7.5 mg (N = 10); or epidural administration of morphine, 2 mg (N = 10), 5 mg (N = 10), or 7.5 mg (N = 10). Evaluations were made of intensity and relief of pain, time to administration of additional analgesic medications, changes in vital signs and blood-gas tensions, and adverse effects. Intramuscular administration of 7.5 mg of morphine effectively relieved pain for only a short time. When morphine was administered epidurally, 2 mg proved ineffective whereas both 5 mg and 7.5 mg provided substantial pain relief for approximately 24 h. There were no significant changes in vital signs or blood-gas tensions. Side effects included pruritus and nausea, which occurred frequently but were usually mild and easily treated. We concluded that either 5 mg or 7.5 mg of morphine epidurally administered was effective and safe in providing prolonged analgesia after cesarean delivery.

A horseradish peroxidase study of primary afferent projections to the medullary cuneate nucleus in the rat

HRP was used to label first order afferent cells of the dorsal root ganglia which synapse at the cuneate nucleus. The results show that it is a population of predominantly large cells that project monosynaptically to the medullary cuneate nucleus and thus support anatomical and physiological studies showing that directly projecting axons to the dorsal column nuclei are larger, faster and conduct information from a select class of sensitive cutaneous mechanoreceptors. The finding, that approximately 20% of DRG neurons can be labeled from the dorsal column nuclei, is consistent with previous estimates of dorsal root fiber projections in the dorsal column based on Marchi degeneration.

Effects of secretin, pancreozymin, or gastrin on the response of the endocrine pancreas to administration of glucose or arginine in man

Intravenous administration of porcine secretin or pancreozymin or synthetic human gastrin II resulted in raised increments in serum immunoreactive insulin during intravenous infusion of glucose in normal man. Enhancement of serum immunoreactive insulin by each hormone was associated with accelerated disposal of glucose. In response to prolonged intravenous infusion of arginine with pancreozymin there was a maintained rise in immunoreactive insulin and glucagon-like immunoreactivity in the blood. These effects of pancreozymin and arginine were not reproduced with secretin and arginine, and may have been due to the stimulation of glucagon secretion together with insulin by pancreozymin. Enteric infusion of hydrochloric acid, or stimulation of gastric acid secretion by betazole, presumed to cause release of endogenous secretin, led to enhancement of insulin secretion during intravenous infusion of glucose. Enteric infusion of arginine, presumed to cause release of endogenous pancreozymin, led to a rise in serum immunoreactive insulin not attributable to effects of circulating glucose and amino acids. It is concluded that secretin and pancreozymin released in response to physiological stimuli contribute to stimulation of the endocrine pancreas after ingestion of food.

Insulinotropic action of secretin

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