Pharmacogenomics elective focused on advanced lab techniques, game-based learning, and business plan development

BACKGROUND AND PURPOSE

Many medications contain labeling information related to pharmacogenomics. Effective education in this area is critical to ensure that future healthcare professionals are equipped with the skills needed to optimize patient therapy based on genetic testing results. This study focused on a novel elective course designed to educate students in pharmacogenomics.

EDUCATIONAL ACTIVITY AND SETTING

We developed a one credit hour pharmacogenomics elective course divided into three main content areas. The first section incorporated traditional lecture to review and cover new content not otherwise covered in the curriculum. The second section applied foundational content from the first session through an educational review game and simulated business plan. The third section of the course provided students an overview of laboratory techniques and sample collection procedures. To evaluate the effectiveness of these activities, students provided feedback through course evaluations and completed pre- and posttests on basic pharmacogenomics content.

FINDINGS

Overall, the course improved knowledge among students, and students provided positive feedback. Students averaged 9% higher on the posttest compared to the pretest (P = .03). Course evaluations trended positive with ratings close to "strongly agree." The most frequent comments stated an appreciation for the interactive components of the course and recommended increasing the elective to two credit hours.

SUMMARY

Through incorporation of novel lab techniques, game-based learning, and an innovative business plan process, the course increased student knowledge and received positive feedback. These new techniques could serve as a model for other pharmacogenomics training programs.

DDDR-25. CO-INHIBITION OF KINASE SIGNALING PATHWAYS AND EPIGENETIC REGULATORS OVERCOMES COMPENSATORY EFFECTS IN PEDIATRIC HIGH-GRADE GLIOMAS

Pediatric high-grade gliomas (pHGG) confer poor survival outcomes with minimal treatment options due to a high rate of therapeutic resistance and few surgical options. One subgroup of pHGG is diffuse intrinsic pontine glioma (DIPG). Patient-derived cell lines, such as SU-DIPG-XIII, SU-DIPG-VI, and SU-DIPG-IV, recapitulate epigenetic mutations seen in patients. In these lines, lysine-specific demethylase 1 (LSD1) is overexpressed and knockdown/inhibition slows growth, therefore, optimizing LSD1 inhibitor treatment regimens is promising. In other models, MEK kinase activation acts as a mechanism of resistance to LSD1 inhibitors. This is relevant to DIPG due to the frequency of dysregulated and mutated upstream kinase pathways. Thus, we sought to identify the connection between LSD1 and kinase signaling as a therapeutic co-inhibition strategy in DIPG. Pharmacologically relevant catalytic LSD1 inhibitors were assessed using the alamarBlue viability assay and demonstrated wide ranges of IC₅₀ values with ORY-1001(19 μM to > 150 μM), ORY-2001( > 50 μM), GSK-LSD1(134 μM to > 500 μM), and IMG-7289(1.6 μM-179 μM) in the SU-DIPG lines. Resistance mechanisms from kinase modulation were investigated via Western Blot to determine if kinase inhibition could sensitize these cells to LSD1 inhibition. We discovered that LSD1 inhibition caused an unexpected increase in pAKT and pERK, suggesting enhanced activity of protumorigenic kinases. To overcome kinase activation from LSD1 inhibition, MEK or PI3K inhibitors, including selumetinib, trametinib, and BKM120, were tested. A novel dual kinase inhibitor directed against EGFR and PI3K, MTX-241F, was also assessed. Several combinations caused a significant increase in efficacy measured by cell viability. We further observed that the addition of kinase inhibitors with LSD1 inhibition decreased phosphorylated kinases. Overall, the combination enhanced in vitro efficacy in contrast to single-agent inhibition supporting an interplay between LSD1 and kinase signaling in pHGG. Future studies will assess this combination utilizing orthotopic xenograft models of DIPG

Abstract 3329: Efficacy of EGFR/PI3K signaling inhibition is enhanced with LSD1 inhibition in glioblastoma stem cell (GSC) models

Mutated and dysregulated protein kinases, such as EGFR and PI3K, have become major targets in cancer therapy due to the growth advantage they confer and the frequency of alterations. In glioblastoma (GBM), EGFR and PI3K are two of the most mutated genes and result in hyperactivation of these kinases. However, single agent inhibition has offered minimal success, largely due to the development of resistance from compensatory downstream signaling pathways. One strategy to circumvent resistance and improve efficacy in GBM is to use combination therapy, such as concurrent inhibition of EGFR or PI3K with inhibition of relevant epigenetic modulators. In GBM, lysine-specific demethylase 1 (LSD1) is an important epigenetic regulator that has shown to promote kinase signaling in cancer models. Therefore, the present study sought to define the relationship between the EGFR/PI3K signaling pathway and LSD1 and to evaluate the efficacy of co-inhibition of EGFR/PI3K and LSD1 in GBM.Transcriptional changes were examined following knockdown of LSD1 in isogenic human GBM cells using RNA-seq. These data were analyzed by GSEA to evaluate biological processes associated with the LSD1 expression. We identified several kinase signaling processes that were enriched in GBM cells with wild type LSD1 such as gene sets for regulation of PI3K activity, RTK binding, and transmembrane RTK activity. The effect of kinase inhibition on LSD1 expression was assessed using western blot analysis. We also evaluated the effects of LSD1 inhibition on expression of downstream kinase signaling proteins. Three kinase inhibitors directed against either EGFR or PI3K were evaluated in GSCs as single agents and in combination with LSD1 inhibitors. The three kinase inhibitors, osimertinib, erlotinib, and BKM120, all have evidence of some brain penetrance. We also evaluated a novel dual kinase inhibitor, MTX-241, which targets both EGFR and PI3K simultaneously. Five LSD1 inhibitors were assessed for their ability to enhance efficacy of EGFR/PI3K inhibitors.Our results demonstrate that LSD1 protein expression can be modulated by stimulation of EGFR in patient-derived GSCs. We observed an increase in LSD1 protein expression following the addition of EGF in GSC 17 cells. The concurrent inhibition of EGFR/PI3K and LSD1 enhanced the in vitro efficacy compared to single agent, supporting convergence of kinase signaling and LSD1 dependent pathways. In fact, several treatment combinations of EGFR/PI3K inhibitors and LSD1 inhibitors resulted in synergistic effects in multiple GSC lines.In summary, our results highlight the need for effective therapy combinations that can reduce the population of GSCs and avoid the adaptive resistance that is typical of kinase inhibitors. Future studies will focus on evaluating the efficacy and tolerability of the most promising treatment combinations in vivo using orthotopic xenograft models of the GSCs.

Citation Format: Lea Stitzlein, Matthew Luetzen, Caitlin McCabe, Maninder Khosla, Melissa Singh, Xiaoping Su, Yue Lu, Joy Gumin, Frederick Lang, Christopher Whitehead, Judith Sebolt-Leopold, Joya Chandra. Efficacy of EGFR/PI3K signaling inhibition is enhanced with LSD1 inhibition in glioblastoma stem cell (GSC) models [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 3329.

Abstract LB120: A novel peptide-drug conjugate induces DNA damage in SSTR2-expressing cells

Introductory statement: To overcome enzyme-mediated resistance mechanisms associated with the DNA alkylating agent, temozolomide (TMZ), we seek to develop a peptide-drug conjugate (PDC) for selective drug delivery in cells that express the somatostatin receptor subtype-2 (SSTR2). Material and methods: The clinically used somatostatin analog, 68Ga-DOTA-TOC, was used as a model for development of the SSTR2-targeted PDC. Synthesis was performed by (i) replacing DOTA with a multimodality chelator (MMC), (ii) attaching a modified TMZ analog to MMC, and (iii) conjugating the payload moiety to TOC on solid-phase. The resulting product, MMC(TMZ)-TOC, was radiolabeled with 67Ga using cation exchange chromatography methods optimized for 68Ga. Retention of SSTR2 binding was examined in cell lines with different expression level of SSTR2 with and without blocking doses of octreotide. A membrane acid wash was performed to evaluate internalization efficiency. The cytotoxicity of MMC(TMZ)-TOC was tested in IMR-32 cells that endogenously express SSTR2, and potency was compared to free-TMZ. An alkaline comet assay was then performed to assess the DNA-damaging properties of the PDC in the presence and absence of SSTR2 blocking. Unpublished results: MMC(TMZ)-TOC was efficiently produced with chemical purity >90% as shown by high-performance liquid chromatography (HPLC). Radiochemical purity following 67Ga labeling was >95% and indicates the feasibility of using the MMC to directly label the drug conjugates. Cell-based experiments showed that specific binding of the 67Ga-labeled PDC was similar to 67Ga-DOTA-TOC and correlated with SSTR2 expression. In HCT116-SSTR2 cells that overexpress SSTR2, 14.8±4.8% of 67Ga-MMC(TMZ)-TOC and 17.0±4.2% of 67Ga-DOTA-TOC were taken up by cells. Blocking the excess octreotide reduced binding to near background levels, illustrating receptor-mediated uptake of the PDC. Acid-washing demonstrated internalization of 67Ga-MMC(TMZ)-TOC after receptor-binding, indicating retention of the agonist properties of TOC after payload conjugation. Results from the cell cytotoxicity study demonstrated that the PDC inhibited cell growth in a dose-dependent manner that was similar to free-TMZ, with the IC50 values of 81.6 and 75.6 µM for free-TMZ and MMC(TMZ)-TOC, respectively. The comet assay revealed that MMC(TMZ)-TOC was effective in causing DNA damage in cells that express SSTR2, as shown by reduced cytotoxic effects when co-incubated with octreotide. Conclusions: We showed that a clinically used SSTR2-targeted radiopharmaceutical can be converted into a PDC that retains receptor-binding and internalization properties. We also showed that the cytotoxic effects of TMZ are maintained by the PDC. Based on these results, in vivo evaluation of MMC(TMZ)-TOC is warranted to assess its potential as a targeted therapy for NETs.

Citation Format: Solmaz AghaAmiri, Sukhen C. Ghosh, Lea Stitzlein, Servando Hernandez Vargas, Bruno Perlatti, Daniel M. Halperin, Ali Azhdarinia. A novel peptide-drug conjugate induces DNA damage in SSTR2-expressing cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr LB120.

Evaluating the Antiparasitic Activity of Novel BPZ Derivatives Against Toxoplasma gondii

Prevalence studies revealed that one-third of the human population is chronically infected with Toxoplasma gondii. Presently, such infections are without medical treatment that effectively eradicates the parasite once it is in its latent form. Moreover, the therapeutics used to treat acute infections are poorly tolerated by patients and also cause the parasite to convert into long-lasting tissue cysts. Hence, there is a dire need for compounds with antiparasitic activity against all forms of T. gondii. This study examines the antiparasitic capacity of nine novel bisphenol Z (BPZ) derivatives to determine whether they possessed any activity that prevented T. gondii replication. To begin assessing the efficacy of the novel derivatives, parasites were treated with increasing concentrations of the compounds, then doubling assays and MitoTracker staining were performed. Three of the nine compounds demonstrated strong inhibitory activity, i.e., parasite replication significantly decreased with higher concentrations. Additionally, many of the treated parasites exhibited decreases in fluorescent signaling and disruption of mitochondrial morphology. These findings suggest that bisphenol Z compounds disrupt mitochondrial function to inhibit parasite replication and may provide a foundation for the development of new and effective treatment modalities against T. gondii.